ABSTRACT
Abstract
Provided is a secondary battery, where a positive electrode includes a first covered part covered with a positive electrode active material layer and a positive electrode active material non-covered part on a positive electrode foil, and a negative electrode includes a second covered part covered with a negative electrode active material layer and a negative electrode active material non-covered part on a negative electrode foil, the positive electrode active material non-covered part is joined to the positive electrode current-collecting plate at one end of an electrode wound body, and the negative electrode active material non-covered part is joined to the negative electrode current-collecting plate at the other end of the electrode wound body.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of PCT patent application no. PCT/JP2020/028295, filed on Jul. 21, 2020, which claims priority to Japanese patent application no. JP2019-139813 filed on Jul. 30, 2019, the entire contents of which are being incorporated herein by reference.
BACKGROUND
The present disclosure generally relates to a secondary battery, a battery pack, an electronic device, an electric tool, an electric aircraft, and an electric vehicle.
Lithium ion batteries have been developed for applications that require high power, such as electric tools and automobiles. Methods for achieving high power include a method of high-rate discharge for the flow of a relatively large current from a battery. The high-rate discharge has a problem with the internal resistance of the battery, because of the flow of the large current.
SUMMARY
The present disclosure generally relates to a secondary battery, a battery pack, an electronic device, an electric tool, an electric aircraft, and an electric vehicle.
The conventional battery technology, for example, has a problem in that, because welding points are denser toward the center in order to collect current from the whole wound foil ends, simply folding and overlapping the foil produces a region with less overlap of the foils on the center side of the electrode assembly, which is perforated at the time of welding. Moreover, another problem is that a sufficient space is required in the central part of the electrode assembly at the time of can bottom welding in the assembly process, and when the foil is folded from the outer periphery toward the central part, the central space formed at the time of the winding is blocked, thereby failing to achieve the assembly.
Accordingly, an object of the present disclosure is to provide a battery for high-rate discharge, which can be reliably welded.
For solving the above-described problems, the present disclosure provides a secondary battery according to an embodiment including: an electrode wound body that has a positive electrode and a negative electrode stacked with a separator interposed therebetween and has a wound structure; and a positive electrode current-collecting plate and a negative electrode current-collecting plate, accommodated in an exterior can,
where the positive electrode includes a first covered part covered with a positive electrode active material layer and a positive electrode active material non-covered part on a positive electrode foil, the negative electrode includes a second covered part covered with a negative electrode active material layer and a negative electrode active material non-covered part on a negative electrode foil, the positive electrode active material non-covered part is joined to the positive electrode current-collecting plate at one end of the electrode wound body, the negative electrode active material non-covered part is joined to the negative electrode current-collecting plate at the other end of the electrode wound body, one or both of the positive electrode active material non-covered part and the negative electrode active material non-covered part have a surface formed by bending toward the central axis of the wound structure and overlapping each other, and at least parts of the active material non-covered parts near the central axis are multiply bent in the case of observing sections of the active material non-covered parts in the plane including the central axis.
Further, the present disclosure provides a battery pack including:
the secondary battery as described herein; a controller configured to control the secondary battery; and an exterior body that encloses the secondary battery.
The present disclosure provides an electronic device including the secondary battery as described herein or the battery pack as described herein.
The present disclosure provides an electric tool according to an embodiment including the battery pack described above, which is configured to use the battery pack as a power supply.
The present disclosure provides an electric aircraft according to an embodiment including:
the battery pack as described herein; a plurality of rotor blades; a motor that rotates each of the rotor blades; a support shaft that supports each of the rotor blades and the motor; a motor controller configured to control rotation of the motor; and a power supply line that supplies power to the motor, where the battery pack is connected to the power supply line.
The present disclosure provides an electric vehicle according to an embodiment including the secondary battery described above, including
a conversion device that receives power supply from the secondary battery to convert the power to a driving force for the electric vehicle, and a controller configured to perform information processing related to vehicle control, based on information on the second battery.
According to at least an embodiment of the present disclosure, the foil and the current-collecting plate can be reliably welded, the internal resistance of the battery can be reduced, or a high-power battery can be achieved.
It is to be noted that the contents of the present disclosure are not to be construed as being limited by the effects illustrated in this specification. It should be understood that the effects described in the present specification are only examples, and additional effects may be further provided.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a sectional view of a battery according to an embodiment of the present disclosure.
FIG. 2 is a diagram illustrating an example of a relationship among a positive electrode, a negative electrode, and a separator disposed in an electrode wound body according to an embodiment of the present disclosure.
FIG. 3 A is a plan view of a positive electrode current-collecting plate according to an embodiment of the present disclosure, and FIG. 3 B is a plan view of a negative electrode current-collecting plate according to an embodiment of the present disclosure.
FIG. 4 A to 4 F are diagrams illustrating a process for assembling a battery according to an embodiment of the present disclosure.
FIG. 5 is a front view and a bottom view of a jig for use in an example according to an embodiment.
FIG. 6 is a front view of another jig for in an example according to an embodiment of the present disclosure.
FIG. 7 A is a view illustrating an end surface according to an embodiment of the present disclosure, and FIG. 7 B is a schematic view of a section taken along a broken line AAâ² in FIG. 7 A .
FIG. 8 A is a view illustrating an end surface according to a comparative example, and FIG. 8 B is a schematic view of a section taken along a broken line BBâ² in FIG. 8 A .
FIG. 9 is a connection diagram for use in description of a battery pack as an application example according to an embodiment of the present disclosure.
FIG. 10 is a connection diagram for use in description of an electric tool as an application example according to an embodiment of the present disclosure.
FIG. 11 is a connection diagram for use in description of an unmanned aircraft as an application example according to an embodiment of the present disclosure.
FIG. 12 is a connection diagram for use in description of an electric vehicle as an application example according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
As described herein, the present disclosure will be described based on examples with reference to the drawings, but the present disclosure is not to be considered limited to the examples, and various numerical values and materials in the examples are considered by way of example.
In the embodiment of the present disclosure, a cylindrical lithium ion battery will be described as an example of the secondary battery. Obviously, any battery other than the lithium ion battery or a battery that has any shape other than the cylindrical shape may be used.
First, the overall configuration of the lithium ion battery will be described. FIG. 1 is a schematic sectional view of a lithium ion battery 1 . The lithium ion battery 1 is, for example, a cylindrical lithium ion battery 1 that has an electrode wound body 20 is housed inside an exterior can 11 as shown in FIG. 1 .
Specifically, the lithium ion battery 1 includes, for example, a pair of insulating plates 12 and 13 and an electrode wound body 20 inside the cylindrical exterior can 11 . The lithium ion battery 1 may further, however, include, for example, any one of, or two or more of a positive temperature coefficient (PTC) element, a reinforcing member, and the like inside the exterior can 11 .
The exterior can 11 is a member that mainly houses the electrode wound body 20 . The exterior can 11 is, for example, a cylindrical container with one end thereof opened and the other end thereof closed. More specifically, the exterior can 11 has an opened end (open end 11 N). The exterior can 11 contains, for example, any one of, or two or more of metal materials such as iron, aluminum, and alloys thereof. The surface of the exterior can 11 may be, however, plated with, for example, any one of, or two or more of metal materials such as nickel.
Each of the insulating plates 12 and 13 is, for example, a dish-shaped plate that has a surface perpendicular to the winding axis of the electrode wound body 20 , that is, a surface perpendicular to the Z axis in FIG. 1 . In addition, the insulating plates 12 and 13 are disposed so as to sandwich the electrode wound body 20 therebetween, for example.
The open end 11 N of the exterior can 11 has, for example, a battery cover 14 and a safety valve mechanism 30 are crimped with a gasket 15 . The battery cover 14 serves as a âcover memberâ according to an embodiment of the present disclosure, and the gasket 15 serves as a âsealing memberâ according to an embodiment of the present disclosure. Thus, with the electrode wound body 20 and the like housed inside the exterior can 11 , the exterior can 11 is sealed. Accordingly, the open end 11 N of the exterior can 11 has a crimped structure (crimped structure 11 R) formed by the battery cover 14 and the safety valve mechanism 30 crimped with the gasket 15 . More specifically, a bent part 11 P is a so-called crimp part, and the crimped structure 11 R is a so-called crimp structure.
The battery cover 14 is a member that closes the open end 11 N of the exterior can 11 mainly with the electrode wound body 20 and the like housed inside the exterior can 11 . The battery cover 14 contains, for example, the same material as the material that forms the exterior can 11 . The central region of the battery cover 14 protrudes in the +Z direction, for example. Thus, the region (peripheral region) of the battery cover 14 other than the central region has contact with, for example, the safety valve mechanism 30 .
The gasket 15 is a member mainly interposed between the exterior can 11 (bent part 11 P) and the battery cover 14 to seal the gap between the bent part 11 P and the battery cover 14 . For example, asphalt or the like may be, however, applied to the surface of the gasket 15 .
The gasket 15 contains, for example, any one of, or two or more of insulating materials. The types of the insulating materials are not particularly limited, and may be, for example, a polymer material such as a polybutylene terephthalate (PBT) and a polypropylene (PP). In particular, the insulating material is preferably a polybutylene terephthalate. This is because the gap between the bent part 11 P and the battery cover 14 is sufficiently sealed while the exterior can 11 and the battery cover 14 are electrically separated from each other.
The safety valve mechanism 30 mainly releases the sealed state of the exterior can 11 to release the pressure (internal pressure) inside the exterior can 11 , if necessary, when the internal pressure is increased. The cause of the increase in the internal pressure of exterior can 11 is, for example, a gas generated due to a decomposition reaction of an electrolytic solution during charging or discharging.
For the cylindrical lithium ion battery, a band-shaped positive electrode 21 and a band-shaped negative electrode 22 are spirally wound with a separator 23 interposed therebetween, impregnated with an electrolytic solution, and housed in the exterior can 11 . The positive electrode 21 is obtained by forming a positive electrode active material layer 21 B on one or both surfaces of a positive electrode foil 21 A, and the material of the positive electrode foil 21 A is, for example, a metal foil made of aluminum or an aluminum alloy. The negative electrode 22 is obtained by forming a negative electrode active material layer 22 B on one or both surfaces of a negative electrode foil 22 A, and the material of the negative electrode foil 22 A is, for example, a metal foil made of nickel, a nickel alloy, copper, or a copper alloy. The separator 23 is a porous and insulating film, which enables transfer of substances such as ions and an electrolytic solution while electrically insulating the positive electrode 21 and the negative electrode 22 .
The positive electrode active material layer 21 B and the negative electrode active material layer 22 B respectively cover most of the positive electrode foil 21 A and the negative electrode foil 22 A, but intentionally, neither of the layers covers one end periphery in the short axis direction of the band. Hereinafter,
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of PCT patent application no. PCT/JP2020/028295, filed on Jul. 21, 2020, which claims priority to Japanese patent application no. JP2019-139813 filed on Jul. 30, 2019, the entire contents of which are being incorporated herein by reference.
BACKGROUND
The present disclosure generally relates to a secondary battery, a battery pack, an electronic device, an electric tool, an electric aircraft, and an electric vehicle.
Lithium ion batteries have been developed for applications that require high power, such as electric tools and automobiles. Methods for achieving high power include a method of high-rate discharge for the flow of a relatively large current from a battery. The high-rate discharge has a problem with the internal resistance of the battery, because of the flow of the large current.
SUMMARY
The present disclosure generally relates to a secondary battery, a battery pack, an electronic device, an electric tool, an electric aircraft, and an electric vehicle.
The conventional battery technology, for example, has a problem in that, because welding points are denser toward the center in order to collect current from the whole wound foil ends, simply folding and overlapping the foil produces a region with less overlap of the foils on the center side of the electrode assembly, which is perforated at the time of welding. Moreover, another problem is that a sufficient space is required in the central part of the electrode assembly at the time of can bottom welding in the assembly process, and when the foil is folded from the outer periphery toward the central part, the central space formed at the time of the winding is blocked, thereby failing to achieve the assembly.
Accordingly, an object of the present disclosure is to provide a battery for high-rate discharge, which can be reliably welded.
For solving the above-described problems, the present disclosure provides a secondary battery according to an embodiment including: an electrode wound body that has a positive electrode and a negative electrode stacked with a separator interposed therebetween and has a wound structure; and a positive electrode current-collecting plate and a negative electrode current-collecting plate, accommodated in an exterior can,
where the positive electrode includes a first covered part covered with a positive electrode active material layer and a positive electrode active material non-covered part on a positive electrode foil, the negative electrode includes a second covered part covered with a negative electrode active material layer and a negative electrode active material non-covered part on a negative electrode foil, the positive electrode active material non-covered part is joined to the positive electrode current-collecting plate at one end of the electrode wound body, the negative electrode active material non-covered part is joined to the negative electrode current-collecting plate at the other end of the electrode wound body, one or both of the positive electrode active material non-covered part and the negative electrode active material non-covered part have a surface formed by bending toward the central axis of the wound structure and overlapping each other, and at least parts of the active material non-covered parts near the central axis are multiply bent in the case of observing sections of the active material non-covered parts in the plane including the central axis.
Further, the present disclosure provides a battery pack including:
the secondary battery as described herein; a controller configured to control the secondary battery; and an exterior body that encloses the secondary battery.
The present disclosure provides an electronic device including the secondary battery as described herein or the battery pack as described herein.
The present disclosure provides an electric tool according to an embodiment including the battery pack described above, which is configured to use the battery pack as a power supply.
The present disclosure provides an electric aircraft according to an embodiment including:
the battery pack as described herein; a plurality of rotor blades; a motor that rotates each of the rotor blades; a support shaft that supports each of the rotor blades and the motor; a motor controller configured to control rotation of the motor; and a power supply line that supplies power to the motor, where the battery pack is connected to the power supply line.
The present disclosure provides an electric vehicle according to an embodiment including the secondary battery described above, including
a conversion device that receives power supply from the secondary battery to convert the power to a driving force for the electric vehicle, and a controller configured to perform information processing related to vehicle control, based on information on the second battery.
According to at least an embodiment of the present disclosure, the foil and the current-collecting plate can be reliably welded, the internal resistance of the battery can be reduced, or a high-power battery can be achieved.
It is to be noted that the contents of the present disclosure are not to be construed as being limited by the effects illustrated in this specification. It should be understood that the effects described in the present specification are only examples, and additional effects may be further provided.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a sectional view of a battery according to an embodiment of the present disclosure.
FIG. 2 is a diagram illustrating an example of a relationship among a positive electrode, a negative electrode, and a separator disposed in an electrode wound body according to an embodiment of the present disclosure.
FIG. 3 A is a plan view of a positive electrode current-collecting plate according to an embodiment of the present disclosure, and FIG. 3 B is a plan view of a negative electrode current-collecting plate according to an embodiment of the present disclosure.
FIG. 4 A to 4 F are diagrams illustrating a process for assembling a battery according to an embodiment of the present disclosure.
FIG. 5 is a front view and a bottom view of a jig for use in an example according to an embodiment.
FIG. 6 is a front view of another jig for in an example according to an embodiment of the present disclosure.
FIG. 7 A is a view illustrating an end surface according to an embodiment of the present disclosure, and FIG. 7 B is a schematic view of a section taken along a broken line AAâ² in FIG. 7 A .
FIG. 8 A is a view illustrating an end surface according to a comparative example, and FIG. 8 B is a schematic view of a section taken along a broken line BBâ² in FIG. 8 A .
FIG. 9 is a connection diagram for use in description of a battery pack as an application example according to an embodiment of the present disclosure.
FIG. 10 is a connection diagram for use in description of an electric tool as an application example according to an embodiment of the present disclosure.
FIG. 11 is a connection diagram for use in description of an unmanned aircraft as an application example according to an embodiment of the present disclosure.
FIG. 12 is a connection diagram for use in description of an electric vehicle as an application example according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
As described herein, the present disclosure will be described based on examples with reference to the drawings, but the present disclosure is not to be considered limited to the examples, and various numerical values and materials in the examples are considered by way of example.
In the embodiment of the present disclosure, a cylindrical lithium ion battery will be described as an example of the secondary battery. Obviously, any battery other than the lithium ion battery or a battery that has any shape other than the cylindrical shape may be used.
First, the overall configuration of the lithium ion battery will be described. FIG. 1 is a schematic sectional view of a lithium ion battery 1 . The lithium ion battery 1 is, for example, a cylindrical lithium ion battery 1 that has an electrode wound body 20 is housed inside an exterior can 11 as shown in FIG. 1 .
Specifically, the lithium ion battery 1 includes, for example, a pair of insulating plates 12 and 13 and an electrode wound body 20 inside the cylindrical exterior can 11 . The lithium ion battery 1 may further, however, include, for example, any one of, or two or more of a positive temperature coefficient (PTC) element, a reinforcing member, and the like inside the exterior can 11 .
The exterior can 11 is a member that mainly houses the electrode wound body 20 . The exterior can 11 is, for example, a cylindrical container with one end thereof opened and the other end thereof closed. More specifically, the exterior can 11 has an opened end (open end 11 N). The exterior can 11 contains, for example, any one of, or two or more of metal materials such as iron, aluminum, and alloys thereof. The surface of the exterior can 11 may be, however, plated with, for example, any one of, or two or more of metal materials such as nickel.
Each of the insulating plates 12 and 13 is, for example, a dish-shaped plate that has a surface perpendicular to the winding axis of the electrode wound body 20 , that is, a surface perpendicular to the Z axis in FIG. 1 . In addition, the insulating plates 12 and 13 are disposed so as to sandwich the electrode wound body 20 therebetween, for example.
The open end 11 N of the exterior can 11 has, for example, a battery cover 14 and a safety valve mechanism 30 are crimped with a gasket 15 . The battery cover 14 serves as a âcover memberâ according to an embodiment of the present disclosure, and the gasket 15 serves as a âsealing memberâ according to an embodiment of the present disclosure. Thus, with the electrode wound body 20 and the like housed inside the exterior can 11 , the exterior can 11 is sealed. Accordingly, the open end 11 N of the exterior can 11 has a crimped structure (crimped structure 11 R) formed by the battery cover 14 and the safety valve mechanism 30 crimped with the gasket 15 . More specifically, a bent part 11 P is a so-called crimp part, and the crimped structure 11 R is a so-called crimp structure.
The battery cover 14 is a member that closes the open end 11 N of the exterior can 11 mainly with the electrode wound body 20 and the like housed inside the exterior can 11 . The battery cover 14 contains, for example, the same material as the material that forms the exterior can 11 . The central region of the battery cover 14 protrudes in the +Z direction, for example. Thus, the region (peripheral region) of the battery cover 14 other than the central region has contact with, for example, the safety valve mechanism 30 .
The gasket 15 is a member mainly interposed between the exterior can 11 (bent part 11 P) and the battery cover 14 to seal the gap between the bent part 11 P and the battery cover 14 . For example, asphalt or the like may be, however, applied to the surface of the gasket 15 .
The gasket 15 contains, for example, any one of, or two or more of insulating materials. The types of the insulating materials are not particularly limited, and may be, for example, a polymer material such as a polybutylene terephthalate (PBT) and a polypropylene (PP). In particular, the insulating material is preferably a polybutylene terephthalate. This is because the gap between the bent part 11 P and the battery cover 14 is sufficiently sealed while the exterior can 11 and the battery cover 14 are electrically separated from each other.
The safety valve mechanism 30 mainly releases the sealed state of the exterior can 11 to release the pressure (internal pressure) inside the exterior can 11 , if necessary, when the internal pressure is increased. The cause of the increase in the internal pressure of exterior can 11 is, for example, a gas generated due to a decomposition reaction of an electrolytic solution during charging or discharging.
For the cylindrical lithium ion battery, a band-shaped positive electrode 21 and a band-shaped negative electrode 22 are spirally wound with a separator 23 interposed therebetween, impregnated with an electrolytic solution, and housed in the exterior can 11 . The positive electrode 21 is obtained by forming a positive electrode active material layer 21 B on one or both surfaces of a positive electrode foil 21 A, and the material of the positive electrode foil 21 A is, for example, a metal foil made of aluminum or an aluminum alloy. The negative electrode 22 is obtained by forming a negative electrode active material layer 22 B on one or both surfaces of a negative electrode foil 22 A, and the material of the negative electrode foil 22 A is, for example, a metal foil made of nickel, a nickel alloy, copper, or a copper alloy. The separator 23 is a porous and insulating film, which enables transfer of substances such as ions and an electrolytic solution while electrically insulating the positive electrode 21 and the negative electrode 22 .
The positive electrode active material layer 21 B and the negative electrode active material layer 22 B respectively cover most of the positive electrode foil 21 A and the negative electrode foil 22 A, but intentionally, neither of the layers covers one end periphery in the short axis direction of the band. Hereinafter, the part covered with no active material layer 21 B or 22 B is appropriately referred to as an active material non-covered part. In the cylindrical battery, the electrode wound body 20 is wound in such a manner that an active material non-covered part 21 C of the positive electrode and an active material non-covered part 22 C of the negative electrode are overlapped with each other with the separator 23 interposed therebetween so as to face in opposite directions.
FIG. 2 shows an example of a structure with the positive electrode 21 , the negative electrode 22 , and the separator 23 stacked before winding. The active material non-covered part 21 C (the upper hatched part in FIG. 2 ) of the positive electrode has a width denoted by A, and the active material non-covered part 22 C (the lower hatched part in FIG. 2 ) of the negative electrode has a width denoted by B. According to one embodiment, A>B is preferred, for example, A=7 (mm) and B=4 (mm). A part of the active material non-covered part 21 C of the positive electrode, protruded from one end of the separator 23 in the width direction, has a length denoted by C, and a part of the active material non-covered part 22 C of the negative electrode, protruded from the other end of the separator 23 in the width direction, has a length denoted by D. According to one embodiment, C>D is preferred, for example, C=4.5 (mm) and D=3 (mm).
The active material non-covered part 21 C of the positive electrode is made of, for example, aluminum, whereas the active material non-covered part 22 C of the negative electrode is made of, for example, copper, and thus, the active material non-covered part 21 C of the positive electrode is typically softer (has a lower Young's modulus) than the active material non-covered part 22 C of the negative electrode. Thus, according to one embodiment, A>B and C>D are more preferred, and in this case, when the active material non-covered part 21 C of the positive electrode and the active material non-covered part 22 C of the negative electrode are bent at the same pressure simultaneously from both electrode sides, the positive electrode 21 and the negative electrode 22 may be similar in the height of the bent part, measured from the tip of the separator 23 . In this case, the active material non-covered parts 21 C and 22 C are bent to appropriately overlap with each other, thus allowing the active material non-covered parts 21 C and 22 C and current-collecting plates 24 and 25 to be easily joined by laser welding. Joining according to one embodiment means joining by laser welding, but the joining method is not limited to laser welding.
For the positive electrode 21 , a section of 3 mm in width, including the boundary between the active material non-covered part 21 C and the active material covered part 21 B, is coated with an insulating layer 101 (gray region part in FIG. 2 ). Further, the whole region of the active material non-covered part 21 C of the positive electrode, opposed the active material covered part 22 B of the negative electrode with the separator interposed therebetween, is covered with the insulating layer 101 . The insulating layer 101 has the effect of reliably preventing any internal short circuit of the battery 1 if any foreign matter enters between the active material covered part 22 B of the negative electrode and the active material non-covered part 21 C of the positive electrode. In addition, the insulating layer 101 has the effect of, when an impact is applied to the battery 1 , absorbing the impact and reliably preventing the active material non-covered part 21 C of the positive electrode from being bent or short-circuited with the negative electrode 22 .
The central axis of the electrode wound body 20 has a through hole 26 formed. The through hole 26 is a hole for insertion of a winding core for assembling the electrode wound body 20 and an electrode rod for welding. The electrode wound body 20 is wound in an overlapping manner such that the active material non-covered part 21 C of the positive electrode and the active material non-covered part 22 C of the negative electrode face in the opposite directions, and thus, the active material non-covered part 21 C of the positive electrode is gathered at one (end 41 ) of the ends of the electrode wound body, whereas the active material non-covered part 22 C of the negative electrode is gathered at the other (end 42 ) of the ends of the electrode wound body 20 . For improving contact with the current-collecting plates 24 and 25 for current extraction, the active material non-covered parts 21 C and 22 C are bent, and the ends 41 and 42 form flat surfaces. The bending directions are directions from the outer edges 27 and 28 of the ends 41 and 42 toward the through hole 26 , and peripheral active material non-covered parts that are adjacent in the wound state are bent in a manner of overlapping with each other. It is to be noted that the surface may be a flat surface or a surface with a raised part. In any case, the surface has only to be a smooth surface to the extent that the joint to the current-collecting plate is not affected if the surface has some unevenness. Hereinafter, a flat surface will be described as an example.
When each of the active material non-covered parts 21 C and 22 C are bent so as to have an overlap, it seems possible for the ends 41 and 42 to have flat surfaces, but if no processing is performed before bending, wrinkles or voids (voids, spaces) are generated at the ends 41 and 42 at the time of bending. In this regard, the âwrinklesâ or âvoidsâ are portions where the bent active material non-covered parts 21 C and 22 C are biased, thereby causing the ends 41 and 42 to have no flat surfaces. For preventing the generation of wrinkles and voids, grooves 43 (see, for example, FIG. 4 B ) are formed in radiation directions from the through hole 26 . The groove 43 extends from the outer edges 27 and 28 of the ends 41 and 42 to the through hole 26 in the central axis. The central axis of the electrode wound body 20 has the through hole 26 , and the through hole 26 is used as a hole into which a welding tool is inserted in the process of assembling the lithium ion battery 1 . The grooves 43 remain in the flat surfaces also after bending the active material non-covered parts 21 C and 22 C, and parts without the grooves 43 are joined (welded or the like) to the positive electrode current-collecting plate 24 or the negative electrode current-collecting plate 25 . It is to be noted that the grooves 43 as well as the flat surfaces may be joined to a part of the current-collecting plates 24 and 25 .
The detailed configuration of the electrode wound body 20 , that is, the respective detailed configuration of the positive electrode 21 , negative electrode 22 , separator 23 , and electrolytic solution will be described later.
In a common lithium ion battery, for example, a lead for current extraction is welded to each one of the positive electrode and negative electrode, but this is not suitable for high-rate discharge because of the high internal resistance of the battery and the temperature increased by heat generation of the lithium ion battery in the case of discharging. Thus, in the lithium ion battery according to one embodiment, the internal resistance of the battery is kept low by disposing the positive electrode current-collecting plate 24 and the negative electrode current-collecting plate 25 at the ends 41 and 42 , and welding at multiple points to the active material non-covered parts 21 C and 22 C of the positive electrode and negative electrode present at the ends 41 and 42 . The ends 41 and 42 are bent to form flat surfaces, which also contributes to the reduction in resistance.
FIG. 3 A and FIG. 3 B show examples of the current collecting plates. FIG. 3 A shows the positive electrode current-collecting plate 24 , and FIG. 3 B shows the negative electrode current-collecting plate 25 . The material of the positive electrode current-collecting plate 24 is, for example, a metal plate made of a simple substance of aluminum or an aluminum alloy or a composite thereof, and the material of the negative electrode current-collecting plate 25 is, for example, a metal plate made of a simple substance of nickel, a nickel alloy, copper, or a copper alloy or a composite thereof. As shown in FIG. 3 A , the positive electrode current-collecting plate 24 has the shape of a flat fan-shaped part 31 with a rectangular band-shaped part 32 attached thereto. The fan-shaped part 31 has, near the center thereof, a hole 35 formed, and the hole 35 is located at a position corresponding to the through hole 26 .
A hatched part in FIG. 3 A is an insulating part 32 A where an insulating tape is attached to the band-shaped part 32 or an insulating material is applied thereto, and the part below the hatched part in the drawing is a connecting part 32 B to a sealing plate that also serves as an external terminal. It is to be noted that in the case of a battery structure without any metallic center pin (not shown) in the through hole 26 , the band-shaped part 32 has a low probability of coming into contact with a site with a negative electrode potential, and thus, there is no need for the insulating part 32 A. In such a case, the widths of the positive electrode 21 and negative electrode 22 can be increased by an amount corresponding to the thickness of the insulating part 32 A to increase the charge/discharge capacity.
The negative electrode current collecting plate 25 has substantially the same shape as the positive electrode current collecting plate 24 , but has a different band-shaped part. The band-shaped part 34 of the negative electrode current-collecting plate in FIG. 3 B is shorter than the band-shaped part 32 of the positive electrode current-collecting plate, without any part corresponding to the insulating part 32 A. The band-shaped part 34 has a round protrusion (projection) 37 indicated by a plurality of circles. During resistance welding, current is concentrated on the protrusion, and the protrusion is melted to weld the band-shaped part 34 to the bottom of the exterior can 11 . Similarly to the positive electrode current-collecting plate 24 , the negative electrode current-collecting plate 25 has a hole 36 near the center of a fan-shaped part 33 , and the hole 36 is located at a position corresponding to the through hole 26 . The fan-shaped part 31 of the positive electrode current-collecting plate 24 and the fan-shaped part 33 of the negative electrode current-collecting plate 25 have a fan shape, and thus cover a part of the ends 41 and 42 . The reason that the whole is not covered to allow an electrolytic solution to smoothly permeate the electrode wound body in the assembly of the battery, or to make it easier for the gas generated when the battery reaches an abnormally high-temperature state or overcharge state to be released to the outside of the battery.
The positive electrode active material layer 21 B includes, as a positive electrode active material, any one of, or two or more of positive electrode materials capable of occluding and releasing lithium. However, the positive electrode active material layer 21 B may further include any one of, or two or more of other materials such as a positive electrode binder and a positive electrode conductive agent. The positive electrode material is preferably a lithium-containing compound, and more specifically, is preferably a lithium-containing composite oxide, a lithium-containing phosphate compound, or the like.
The lithium-containing composite oxide is an oxide containing lithium and one, or two or more other elements (elements other than lithium) as constituent elements, and the oxide has, for example, any of a layered rock salt-type crystal structure, a spinel-type crystal structure, and the like. The lithium-containing phosphate compound is a phosphate compound containing lithium and one, or two or more other elements as constituent elements, and the compound has an olivine-type crystal structure or the like.
The positive electrode binder includes any one of, or two or more of synthetic rubbers and polymer compounds, for example. The synthetic rubbers may be, for example, styrene-butadiene rubbers, fluorine rubbers, ethylene propylene diene, and the like. Examples of the polymer compounds include a polyvinylidene fluoride and a polyimide.
The positive electrode conductive agent includes, for example, any one of, or two or more of carbon materials and the like, for example. The carbon materials may be, for example, graphite, carbon black, acetylene black, Ketjen black, and the like. The positive electrode conductive agent may be, however, a metal material, a conductive polymer, or the like as long as the agent is a conductive material.
The surface of the negative electrode foil 22 A is preferably roughened. This is because the adhesion of the negative electrode active material layer 22 B to the negative electrode foil 22 A is improved due to a so-called anchor effect. In this case, the surface of the negative electrode foil 22 A has only to be roughened at least in a region opposed to the negative electrode active material layer 22 B. The roughening method is, for example, a method such as forming fine particles through the use of electrolytic treatment. The electrolytic treatment provides the surface of the negative electrode foil 22 A with irregularities, because fine particles are formed on the surface of the negative electrode foil 22 A with an electrolytic method in an electrolytic cell. Copper foil prepared by an electrolytic method is generally referred to as electrolytic copper foil.
The negative electrode active material layer 22 B includes, as a negative electrode active material, any one of, or two or more of negative electrode materials capable of occluding and releasing lithium. The negative electrode active material layer 22 B may, however, further include any one of, or two or more of other materials such as a negative binder and a negative electrode conductive agent.
The negative electrode material is, for example, a carbon material. This is because a high energy density can be stably achieved due to the very small change in crystal structure at the time of occlusion and release of lithium. In addition, this is because the carbon materials also function as negative electrode conductive agents, thus improving the conductivity of the negative electrode active material layer 22 B.
The carbon materials may be, for example, graphitizable carbon, non-graphitizable carbon, and graphite. However, the interplanar spacing of the (002) plane in the non-graphitizable carbon is preferably 0.37 nm or more, and the interplanar spacing of the (002) plane in the graphite is preferably 0.34 nm or less. More specifically, the carbon materials may be, for example, pyrolytic carbons, coke, glassy carbon fibers, fired products of organic polymer compounds, activated carbon, and carbon blacks. Examples of the coke include pitch coke, needle coke, and petroleum coke. The fired products of organic polymer compounds are obtained by firing (carbonizing) polymer compounds such as a phenol resin and a furan resin at appropriate temperatures. Besides, the carbon materials may be low-crystallinity carbon subjected to a heat treatment at a temperature of about 1000° C. or lower, or may be amorphous carbon. It is to be noted that the shapes of the carbon materials may be any of fibrous, spherical, granular and scaly.
In the lithium ion battery 1 , when the open-circuit voltage (that is, the battery voltage) in a fully charged case is 4.25 V or higher, the release amount of lithium per unit mass is increased also with the use of the same positive electrode active material as compared with a case where the open-circuit voltage in the fully charged case is 4.20 V, and the amount of the positive electrode active material and the amount of the negative electrode active material are thus adjusted accordingly. Thus, a high energy density is achieved.
The separator 23 is interposed between the positive electrode 21 and the negative electrode 22 to allow passage of lithium ions while preventing a short circuit due to the current caused by the contact between the positive electrode 21 and the negative electrode 22 . The separator 23 is any one of, or two or more of porous membranes such as synthetic resins and ceramics, for example, and may be a laminated film of two or more porous membranes. The synthetic resins may be, for example, polytetrafluoroethylene, polypropylene, polyethylene, and the like.
In particular, the separator 23 may include, for example, the above-mentioned porous film (substrate layer), and a polymer compound layer provided on one or both sides of the substrate layer. This is because the adhesion of the separator 23 to each of the positive electrode 21 and the negative electrode 22 is improved, thus keeping the electrode wound body 20 from warping. Thus, the inhibited decomposition reaction of the electrolytic solution, and also, the suppressed leakage of the electrolytic solution with which the substrate layer impregnated, make the resistance less likely to increase also with repeated charging/discharging, and keep the secondary battery from swelling.
The polymer compound layer contains, for example, a polymer compound such as a polyvinylidene fluoride. This is because the polymer compound is excellent in physical strength and electrochemically stable. The polymer compound may be, however, a compound other than a polyvinylidene fluoride. In the case of forming the polymer compound layer, for example, a solution in which a polymer compound is dissolved in an organic solvent or the like is applied to the substrate layer, and then the substrate layer is dried. It is to be noted that after immersing the substrate layer in the solution, the base material layer may be dried. This polymer compound layer may include any one of, or two or more of insulating particles such as inorganic particles, for example. The type of the inorganic particles is, for example, an aluminum oxide, an aluminum nitride, or the like.
The electrolytic solution includes a solvent and an electrolyte salt. The electrolytic solution may further include, however, any one of, or two or more of other materials such as additives.
The solvent includes any one of, or two or more of nonaqueous solvents such as organic solvents. The electrolytic solution including a nonaqueous solvent is a so-called nonaqueous electrolytic solution.
The nonaqueous solvent is, for example, a cyclic carbonate, a chain carbonate, a lactone, a chain carboxylate, a nitrile (mononitrile), or the like.
The electrolyte salt includes any one of, or two or more of salts such as lithium salts, for example. However, the electrolyte salt may contain a salt other than lithium salts, for example. The salt other than lithium may be, for example, salts of light metals other than lithium.
The lithium salt may be, for example, lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium tetraphenylborate (LiB(C 6 H 5 ) 4 ), lithium methanesulfonate (LiCH 3 SO 3 ), lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), lithium tetrachloroaluminate (LiAlCl 4 ), dilithium hexafluorosilicate (Li 2 SiF 6 ), lithium chloride (LiCl) and Lithium bromide (LiBr), and the like.
Above all, any one of, or two or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, and lithium hexafluoroarsenate is preferred, and lithium hexafluorophosphate is more preferred.
The content of the electrolyte salt is not particularly limited, but preferably 0.3 mol/kg to 3 mol/kg with respect to the solvent.
A method for manufacturing the lithium ion battery 1 according to one embodiment will be described with reference to FIG. 4 A to FIG. 4 F . First, a positive electrode active material was applied to the surface of the band-shaped positive electrode foil 21 A to form a covered part for the positive electrode 21 , and a negative electrode active material was applied to the surface of the band-shaped negative electrode foil 22 A to form a covered part for the negative electrode 22 . In this case, the active material non-covered parts 21 C and 22 C without the positive electrode active material or negative electrode active material applied were prepared at one end of the positive electrode 21 in the widthwise direction and one end of the negative electrode 22 in the widthwise direction. Notches were formed in parts of the active material non-covered parts 21 C and 22 C, corresponding to the winding starts at the time of winding. The positive electrode 21 and the negative electrode 22 were subjected to steps such as drying. Then, the electrodes were stacked with the separator 23 interposed therebetween such that the active material non-covered part 21 C of the positive electrode and the active material non-covered part 22 C of the negative electrode were oriented in opposite directions, and spirally wound so as to form the through hole 26 in the central axis and dispose the formed notches near the central axis, thereby preparing the electrode wound body 20 as shown in FIG. 4 A .
Next, as shown in FIG. 4 B , an end of a thin flat plate (for example, 0.5 mm in thickness) or the like was pressed perpendicularly to the ends 41 and 42 to locally bend the ends 41 and 42 and then prepare the grooves 43 . In accordance with this method, the groove 43 extending toward the central axis was prepared in radiation directions from the through hole 26 . The number of the grooves 43 and the arrangement, shown in FIG. 4 B , is considered by way of example only. Then, as shown in FIG. 4 C , the same pressure was applied simultaneously from both electrode sides in a direction substantially perpendicular to the ends 41 and 42 to bend the active material non-covered part 21 C of the positive electrode and the active material non-covered part 22 C of the negative electrode, and then form the ends 41 and 42 so as to have flat surfaces. In this case, the load was applied with the plate surface of the flat plate or the like such that the active material non-covered parts at the ends 41 and 42 overlapped and then bent toward the through hole 26 . Thereafter, the fan-shaped part 31 of positive electrode current-collecting plate 24 was subjected to laser welding to the end 41 , and the fan-shaped part 33 of the negative electrode current-collecting plate 25 was subjected to laser welding to the end 42 .
Thereafter, as shown in FIG. 4 D , the band-shaped parts 32 and 34 of the current collecting plates 24 , 25 were bent, and the insulating plates 12 and 13 (or insulating tapes) were attached to the positive electrode current collecting plate 24 and the negative electrode current collecting plate 25 , the electrode wound body 20 assembled as mentioned above was inserted into the exterior can 11 shown in FIG. 4 E , and the bottom of the exterior can 11 was subjected to welding. After injecting an electrolytic solution into the exterior can 11 , sealing was performed with the gasket 15 and the battery cover 14 as shown in FIG. 4 F .
EXAMPLES
The present disclosure will be specifically described with reference to an example of comparing the difference in the structure of the active material non-covered part with the use of the lithium ion battery 1 prepared in the manner mentioned above. It is to be noted that the present disclosure is not to be considered limited to the examples described below.
In the example and the comparative example, the battery size was 18650, and the number of grooves 43 was 4, 6, or 8. The thicknesses of the active material non-covered parts 21 C and 22 C were adjusted to 10 μm.
The jig 51 shown in FIG. 5 was used to make the grooves 43 . The jig 51 in FIG. 5 has, at the bottom thereof, a flat surface part 52 , a pin 53 erected in a direction perpendicular to flat surface part 52 at a center position of flat surface part 52 , and flat plates 54 erected in a direction perpendicular to flat surface part 52 radially and equiangularly spaced from the pin 53 . The pin 53 was inserted into the through hole 26 of the electrode wound body 20 , and the flat plates 54 were pressed against the ends 41 and 42 to produce the grooves 43 . Subsequently, the jig 61 illustrated in FIG. 6 was used to bend the ends 41 and 42 . The jig 61 in FIG. 6 has, at the bottom thereof, a flat surface part 62 , and a pin 63 erected at the center of the flat surface part 62 in a direction perpendicular to the flat surface part 62 . The pin 63 was inserted into the through hole 26 of the electrode wound body 20 , and the flat surface part 62 was pressed against the ends 41 and 42 to produce a flat surface.
With jigs including no pin 53 or pin 63 unlike the configurations of FIGS. 5 and 6 , grooves 43 were produced, and the ends 41 and 42 were bent to produce a flat surface.
FIGS. 7 A and 7 B show schematic views of the ends 41 and 42 according to the example, and FIGS. 8 A and 8 B show schematic views of the ends 41 and 42 according to the comparative example. According to the example ( FIG. 7 A ), the protrusion of the active material non-covered parts 21 C and 22 C into the through hole 26 by bending is prevented by the pin 53 and the pin 63 , thus keeping the through hole 26 without being blocked, whereas according to the comparative example ( FIG. 8 A ), the through hole 26 is blocked by the bent active material non-covered parts 21 C and 22 C. According to the example, a welding rod was inserted in the welding step ( FIG. 4 D ) for the bottom of the exterior can, thereby successfully achieving welding, but according to the comparative example, the welding rod was not inserted, thereby failing to achieve welding.
In this regard, when the sections of the active material non-covered parts 21 C and 22 C are observed, according to the example, as shown in FIG. 7 B , the active material non-covered parts 21 C and 22 C are multiply bent and densely packed near the through hole 26 of the ends 41 and 42 , for example, in a region of about 0.7 mm from the surface in the depth direction, and are not protruded into the through hole 26 . Accordingly, as a result of the laser welding after overlapping the current-collecting plates 24 and 25 , the laser welding was successfully achieved also near the through-hole 26 (no welding defect due to a perforation or the like). In contrast, according to the comparative example, as shown in FIG. 8 B , the active material non-covered parts 21 C and 22 C are not multiply bent or not densely packed near the through hole 26 , and thus, as a result of the laser welding, welding defects such as a perforation were generated.
In this regard, whether the active material non-covered parts 21 C and 22 C are âmultiply bent or notâ can be determined by whether at least parts of sections of the individual active material non-covered parts near the central axis appear to be multiply bent or not in the case of observing the sections of the active material non-covered parts in the plane including the central axis of the electrode wound body. In addition, the number of active material non-covered parts multiply bent near the central axis (the number of active material non-covered parts that appear to be multiply bent in a sectional view) is 8 counted from the central axis side in the example ( FIG. 7 B ). As a preferred aspect of the present disclosure, the number of active material non-covered parts multiply bent is 5 or more. In contrast, the upper limit of the number of active material non-covered parts multiply bent is preferably 15 (not shown), and there is substantially no active material non-covered part multiply bent on the side opposite to the central axis side.
In addition, the multiply bent region is preferably present in a region of 0.1 mm or more and 1.5 mm or less in depth from the surface formed by bending the active material non-covered parts 21 C and 22 C toward the central axis of the wound structure in a mutually overlapping manner.
In accordance with the method according to the example, the walls are formed so as not to protrude into the through hole 26 at the time of bending the active material non-covered parts 21 C and 22 C toward the centers, thereby making it possible to form a structure in which the active material non-covered parts 21 C and 22 C protruded externally are densely packed near the through hole 26 and are denser than at the outer periphery. In this case, because the ends 41 and 42 form flat surfaces, laser welding can be not only adequately performed, but also achieved without causing any perforation, also at sites where the density of welded points near the through hole 26 is high at the time of the laser welding, thereby causing a heat-affected zone.
While the embodiment of the present disclosure have been concretely described above, the contents of the present disclosure are not to be considered limited to the embodiment described above, and it is possible to make various modifications based on technical idea of the present disclosure.
In the example and comparative example, the number of grooves 43 was adjusted to 4, 6, or 8, but other numbers may be employed. The battery size was 18650, but may be 21700 or any other size.
The positive electrode current-collecting plate 24 and the negative electrode current-collecting plate 25 respectively include the fan-shaped parts 31 and 33 in the shape a fan, which may have other shapes.
FIG. 9 is a block diagram illustrating a circuit configuration example in the case of applying a battery according to an embodiment of the present disclosure (hereinafter, referred to appropriately as a secondary battery) to a battery pack 330 . The battery pack 300 includes an assembled battery 301 , an exterior, a switch unit 304 including a charge control switch 302 a and a discharge control switch 303 a , a current detection resistor 307 , a temperature detection element 308 , and a control unit (controller) 310 .
In addition, the battery pack 300 includes a positive electrode terminal 321 and a negative electrode terminal 322 , and in the case of charging, the positive electrode terminal 321 and the negative electrode terminal 322 are connected respectively to a positive electrode terminal and a negative electrode terminal of a charger to perform charging. In addition in the case of using an electronic device, the positive electrode terminal 321 and the negative electrode terminal 322 are connected respectively to a positive electrode terminal and a negative electrode terminal of the electronic device to perform discharging.
The assembled battery 301 has a plurality of secondary batteries 301 a connected in series and/or in parallel. The secondary battery 301 a is a secondary battery according to the present disclosure. It is to be noted that FIG. 9 shows therein a case where six secondary batteries 301 a are connected to arrange two batteries in parallel and three batteries in series (2P3S) as an example, but any other connecting method may be employed, such as u in parallel and v in series (u and v are integers).
The switch unit 304 includes the charge control switch 302 a and a diode 302 b as well as the discharge control switch 303 a and a diode 303 b , and the switch unit 304 is controlled by the control unit 310 . The diode 302 b has a polarity in the reverse direction with respect to the charging current flowing in the direction from the positive electrode terminal 321 to the assembled battery 301 and in the forward direction with respect to the discharging current flowing in the direction from the negative electrode terminal 322 to the assembled battery 301 . The diode 303 b has a polarity in the forward direction with respect to the charging current and in the reverse direction with respect to the discharging current. It is to be noted that the switch unit 304 is provided on the positive side in the example, but may be provided on the negative side.
The charge control switch 302 a is turned off if the battery voltage reaches an overcharge detection voltage, and is controlled by a charge/discharge control unit such that no charging current flows through the current path of the assembled battery 301 . After the charge control switch 302 a is turned off, only discharging is possible through the diode 302 b . In addition, the charge control switch 302 a is turned off if a large current flows at the time of charging, and is controlled by the control unit 310 so as to cut off a charging current flowing through the current path of the assembled battery 301 . The control unit (controller) 310 includes at least one of a central processing unit (CPU), a processor or the like.
The discharge control switch 303 a is turned off if the battery voltage reaches an overdischarge detection voltage, and is controlled by the control unit 310 such that no discharging current flows through the current path of the assembled battery 301 . After the discharge control switch 303 a is turned off, only charging is possible through the diode 303 b . In addition, the discharge control switch 303 a is turned off if a large current flows at the time of discharging, and is controlled by the control unit 310 so as to cut off a discharging current flowing through the current path of the assem
CLAIMS
Claims ( 18 )
The invention claimed is:
1 . A secondary battery comprising:
an electrode wound body that has a positive electrode and a negative electrode stacked with a separator interposed therebetween and has a wound structure; and a positive electrode current-collecting plate and a negative electrode current-collecting plate, wherein the electrode wound body, the positive electrode current-collecting plate and the negative electrode current-collecting plate are accommodated in an exterior can, wherein the positive electrode includes a first covered part covered with a positive electrode active material layer and a positive electrode active material non-covered part on a positive electrode foil, the negative electrode includes a second covered part covered with a negative electrode active material layer and a negative electrode active material non-covered part on a negative electrode foil, the positive electrode active material non-covered part is joined to the positive electrode current-collecting plate at one end of the electrode wound body, the negative electrode active material non-covered part is joined to the negative electrode current-collecting plate at the other end of the electrode wound body, one or both of the positive electrode active material non-covered part and the negative electrode active material non-covered part have a surface formed by bending toward a central axis of the wound structure and overlapping each other, and at least parts of the active material non-covered parts near the central axis are multiply bent to include a plurality of multiply bent parts in a case of observing sections of the active material non-covered parts in a plane including the central axis, wherein the multiply bent parts directly overlap each other in a repeating zigzag structure, which is disposed between at least one of:
the first covered part and the positive electrode current-collecting plate, or
the second covered part and the negative electrode current-collecting plate.
2 . The secondary battery according to claim 1 , wherein a number of the active material non-covered parts multiply bent near the central axis is 5 or more and 15 or less counted from the central axis.
3 . The secondary battery according to claim 2 , wherein the active material non-covered parts multiply bent is in a region that has a depth of 0.1 mm or more and 1.5 mm or less from the surface.
4 . The secondary battery according to claim 1 , wherein the active material non-covered parts multiply bent is in a region that has a depth of 0.1 mm or more and 1.5 mm or less from the surface.
5 . The secondary battery according to claim 1 , wherein the surface has a groove.
6 . The secondary battery according to claim 1 , wherein the surface includes a flat surface or a surface with a raised part.
7 . The secondary battery according to claim 1 , wherein
a width of the positive electrode active material non-covered part is larger than a width of the negative electrode active material non-covered part, an end of the positive electrode active material non-covered part and an end of the negative electrode active material non-covered part is protruded outward from the separator, and a length of a part of the positive electrode active material non-covered part protruded from one end of the separator in a width direction is larger than a length of a part of the negative electrode active material non-covered part protruded from the other end of the separator in the width direction.
8 . The secondary battery according to claim 1 , wherein a part of the positive electrode active material non-covered part that faces the negative electrode with the separator interposed therebetween has an insulating layer.
9 . The secondary battery according to claim 1 , wherein a material of the positive electrode foil includes aluminum or an aluminum alloy.
10 . The secondary battery according to claim 1 , wherein a material of the negative electrode foil includes a simple substance of nickel, a nickel alloy, copper, a copper alloy, or a composite thereof.
11 . A battery pack comprising:
the secondary battery according to claim 1 ; a controller configured to control the secondary battery; and an exterior body that encloses the secondary battery.
12 . An electronic device comprising the battery pack according to claim 11 .
13 . An electric tool comprising the battery pack according to claim 11 ,
wherein the electric tool is configured to use the battery pack as a power supply.
14 . An electric aircraft comprising:
the battery pack according to claim 11 ; a plurality of rotor blades; a motor that rotates each of the rotor blades; a support shaft that supports each of the rotor blades and the motor; a motor controller configured to control rotation of the motor; and a power supply line that supplies power to the motor, wherein the battery pack is connected to the power supply line.
15 . The electric aircraft according to claim 14 , comprising:
a plurality of pairs of the rotor blades facing each other; and a plurality of the battery packs, wherein the plurality of pairs of rotor blades and the plurality of battery packs are equal in number.
16 . An electronic device comprising the secondary battery according to claim 1 .
17 . An electric vehicle including the secondary battery according to claim 1 , comprising:
a conversion device that receives power supply from the secondary battery to convert the power to a driving force for the electric vehicle; and a controller configured to perform information processing related to vehicle control, based on information on the second battery.
18 . The secondary battery according to claim 1 , wherein at the end surface in a cross-section including the central axis, the multiply-bent parts are denser near the central axis than near an outer peripheral side.
US17/581,286
2019-07-30
2022-01-21
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
Active
2042-11-01
US12620597B2
( en )
Applications Claiming Priority (3)
Application Number
Priority Date
Filing Date
Title
JP2019139813
2019-07-30
JP2019-139813
2019-07-30
PCT/JP2020/028295
WO2021020237A1
( en )
2019-07-30
2020-07-21
Secondary battery, battery pack, electronic device, electric tool, electric airplane and electric vehicle
Related Parent Applications (1)
Application Number
Title
Priority Date
Filing Date
PCT/JP2020/028295
Continuation
WO2021020237A1
( en )
2019-07-30
2020-07-21
Secondary battery, battery pack, electronic device, electric tool, electric airplane and electric vehicle
Publications (2)
Publication Number
Publication Date
US20220149444A1
US20220149444A1 ( en )
2022-05-12
US12620597B2
true
US12620597B2 ( en )
2026-05-05
Family
ID=74230270
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
US17/581,286
Active
2042-11-01
US12620597B2
( en )
2019-07-30
2022-01-21
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
Country Status (4)
Country
Link
US
( 1 )
US12620597B2
( en )
JP
( 1 )
JP7287467B2
( en )
CN
( 1 )
CN114128023B
( en )
WO
( 1 )
WO2021020237A1
( en )
Families Citing this family (25)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
WO2021149555A1
( en )
*
2020-01-23
2021-07-29
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary battery, electronic device, and electric tool
PL4047703T3
( en )
2021-01-19
2024-04-29
Lg Energy Solution, Ltd.
Electrode terminal, cylindrical battery cell, battery pack and vehicle
US12132227B2
( en )
2021-01-19
2024-10-29
Lg Energy Solution, Ltd.
Battery, and battery pack and vehicle comprising the same
HUE067564T2
( en )
*
2021-02-09
2024-10-28
Contemporary Amperex Technology Hong Kong Ltd
Electrode assembly and related battery, apparatus, manufacturing method, and manufacturing apparatus
US12537229B2
( en )
2021-02-19
2026-01-27
Lg Energy Solution, Ltd.
Riveting structure of electrode terminal, and cylindrical battery cell, battery pack and vehicle including the same
WO2023014018A1
( en )
2021-08-05
2023-02-09
주ìíì¬ ìì§ìëì§ì루ì
Electrode assembly, secondary battery, battery pack and automobile comprising same
EP4398408A4
( en )
*
2021-08-30
2025-07-02
Panasonic Holdings Corp
BATTERY AND CONNECTION PROCEDURE
US20240405292A1
( en )
*
2021-09-09
2024-12-05
Panasonic Holdings Corporation
Method of manufacturing battery and battery
WO2023054579A1
( en )
*
2021-10-01
2023-04-06
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary battery
CN118266118A
( en )
*
2021-11-18
2024-06-28
æ ªå¼ä¼ç¤¾æç°å¶ä½æ
Secondary batteries, battery packs, electronic devices, electric tools, electric aircraft, and electric vehicles
WO2023090368A1
( en )
2021-11-18
2023-05-25
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary battery, battery pack, electronic device, power tool, electric aircraft, and electric vehicle
CN118266117A
( en )
*
2021-11-18
2024-06-28
æ ªå¼ä¼ç¤¾æç°å¶ä½æ
Secondary batteries, battery packs, electronic devices, electric tools, electric aircraft, and electric vehicles
US20250079530A1
( en )
*
2021-11-24
2025-03-06
Lg Energy Solution, Ltd.
Electrode assembly and manufacturing apparatus and method thereof, cylindrical battery including the electrode assembly, and battery pack and vehicle including the same
WO2023162530A1
( en )
2022-02-22
2023-08-31
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary battery, battery pack, electronic device, power tool, electric aircraft, and electric vehicle
JP7694803B2
( en )
2022-03-14
2025-06-18
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary battery, battery pack, electronic device, power tool, electric aircraft, and electric vehicle
WO2023189636A1
( en )
*
2022-03-28
2023-10-05
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, electric vehicle, and method for manufacturing electrode winding body for secondary battery
WO2023189564A1
( en )
*
2022-03-30
2023-10-05
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Battery
DE212022000300U1
( en )
*
2022-10-13
2024-06-19
Eve Power Co., Ltd.
Coil structure and battery
DE102022004514A1
( en )
2022-12-02
2024-06-13
Mercedes-Benz Group AG
Energy storage device for a battery module of an at least partially electrically operated motor vehicle
CN120958622A
( en )
*
2023-03-31
2025-11-14
æ ªå¼ä¼ç¤¾æç°å¶ä½æ
tabless battery
JP2025056435A
( en )
2023-09-27
2025-04-08
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary batteries and battery packs
JP2025056436A
( en )
2023-09-27
2025-04-08
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary batteries and battery packs
JP2025056438A
( en )
2023-09-27
2025-04-08
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary batteries and battery packs
JP2025056439A
( en )
2023-09-27
2025-04-08
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary batteries and battery packs
JP2025056437A
( en )
2023-09-27
2025-04-08
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary batteries and battery packs
Citations (14)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
JP2001028274A
( en )
1999-02-24
2001-01-30
Sanyo Electric Co Ltd
Electrical energy storing element
US20020104524A1
( en )
2001-02-07
2002-08-08
Reible James Patrick
Pneumatic projectile launching apparatus with partition apparatus and opposed-piston regulator
JP2003022842A
( en )
2001-05-02
2003-01-24
Ngk Insulators Ltd
Lithium secondary battery
JP2008166030A
( en )
2006-12-27
2008-07-17
Sanyo Electric Co Ltd
Manufacturing method of spiral electrode body, and manufacturing method of closed battery using this
US20090280406A1
( en )
*
2006-06-02
2009-11-12
Kiyomi Kozuki
Secondary battery
JP2010257851A
( en )
2009-04-27
2010-11-11
Toyota Motor Corp
Battery manufacturing method
WO2011001639A1
( en )
2009-06-30
2011-01-06
ããã½ããã¯æ ªå¼ä¼ç¤¾
Nonaqueous electrolyte secondary battery
US20130252053A1
( en )
*
2012-03-20
2013-09-26
Samsung Sdi Co., Ltd.
Secondary battery
US20160226056A1
( en )
2013-09-25
2016-08-04
Commissariat à l'Energie Atomique et aux Energies Alternatives
Method for producing an electrochemical bundle of a lithium battery
WO2017061066A1
( en )
2015-10-05
2017-04-13
ã½ãã¼æ ªå¼ä¼ç¤¾
Residual quantity measuring device, battery pack, electric power tool, electric-type aircraft, electric vehicle and power supply
US20180254529A1
( en )
*
2017-03-01
2018-09-06
Ford Global Technologies, Llc
Lithium replenishment for containing capacity loss in li ion batteries
US20180366786A1
( en )
2017-06-14
2018-12-20
Automotive Energy Supply Corporation
Lithium ion secondary battery element and lithium ion secondary battery
US20190312252A1
( en )
*
2016-06-24
2019-10-10
Samsung Sdi Co., Ltd.
Rechargeable battery
US20200026269A1
( en )
*
2018-07-19
2020-01-23
Aurora Flight Sciences Corporation
Performance monitoring system for an electric drive system
Family Cites Families (11)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
JP2000268803A
( en )
*
1999-03-19
2000-09-29
Nec Corp
Non-aqueous electrolyte secondary battery
JP3831595B2
( en )
*
2000-09-26
2006-10-11
ä¸æ´é»æ©æ ªå¼ä¼ç¤¾
Cylindrical secondary battery
JP2002198100A
( en )
*
2000-12-26
2002-07-12
Shin Kobe Electric Mach Co Ltd
Battery
JP2006012801A
( en )
*
2004-05-28
2006-01-12
M & G Eco Battery Institute Co Ltd
Secondary battery
JP4222292B2
( en )
*
2004-11-08
2009-02-12
ã½ãã¼æ ªå¼ä¼ç¤¾
Secondary battery
JP2008218203A
( en )
*
2007-03-05
2008-09-18
Sony Corp
Electrodes and batteries
JP2008243672A
( en )
*
2007-03-28
2008-10-09
Toshiba Corp
Secondary electrode for rechargeable battery, lithium ion rechargeable battery and rechargeable battery pack
JP5326645B2
( en )
*
2009-02-20
2013-10-30
æ°ç¥æ¸é»æ©æ ªå¼ä¼ç¤¾
Lithium ion capacitor
JP5428988B2
( en )
*
2010-03-25
2014-02-26
ãã¨ã¿èªåè»æ ªå¼ä¼ç¤¾
Wound electrode body type battery, method for manufacturing the same, vehicle and device, and electrode winding device
EP2573857B1
( en )
*
2010-05-18
2016-03-02
Toyota Jidosha Kabushiki Kaisha
Nonaqueous electrolyte secondary battery, vehicle, and device using battery
WO2018110067A1
( en )
*
2016-12-16
2018-06-21
æ ªå¼ä¼ç¤¾æç°è£½ä½æ
Secondary cell, cell pack, electric vehicle, power storage system, electric tool, and electronic device
2020
2020-07-21
JP
JP2021536974A
patent/JP7287467B2/en
active
Active
2020-07-21
CN
CN202080047979.1A
patent/CN114128023B/en
active
Active
2020-07-21
WO
PCT/JP2020/028295
patent/WO2021020237A1/en
not_active
Ceased
2022
2022-01-21
US
US17/581,286
patent/US12620597B2/en
active
Active
Patent Citations (20)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
JP2001028274A
( en )
1999-02-24
2001-01-30
Sanyo Electric Co Ltd
Electrical energy storing element
US20020104524A1
( en )
2001-02-07
2002-08-08
Reible James Patrick
Pneumatic projectile launching apparatus with partition apparatus and opposed-piston regulator
JP2003022842A
( en )
2001-05-02
2003-01-24
Ngk Insulators Ltd
Lithium secondary battery
US20090280406A1
( en )
*
2006-06-02
2009-11-12
Kiyomi Kozuki
Secondary battery
JP2008166030A
( en )
2006-12-27
2008-07-17
Sanyo Electric Co Ltd
Manufacturing method of spiral electrode body, and manufacturing method of closed battery using this
JP2010257851A
( en )
2009-04-27
2010-11-11
Toyota Motor Corp
Battery manufacturing method
WO2011001639A1
( en )
2009-06-30
2011-01-06
ããã½ããã¯æ ªå¼ä¼ç¤¾
Nonaqueous electrolyte secondary battery
US20120088137A1
( en )
2009-06-30
2012-04-12
Kensuke Nakura
Nonaqueous electrolyte secondary battery
CN102473956A
( en )
2009-06-30
2012-05-23
æ¾ä¸çµå¨äº§ä¸æ ªå¼ä¼ç¤¾
Nonaqueous electrolyte secondary battery
US20130252053A1
( en )
*
2012-03-20
2013-09-26
Samsung Sdi Co., Ltd.
Secondary battery
US20160226056A1
( en )
2013-09-25
2016-08-04
Commissariat à l'Energie Atomique et aux Energies Alternatives
Method for producing an electrochemical bundle of a lithium battery
JP2016532990A
( en )
2013-09-25
2016-10-20
ã³ãããµãªã¢ 㢠ã¬ãã«ã¸ã¼ ã¢ããã¼ã¯ 㨠㪠ã¼ãã«ã¸ ã¶ã«ã¿ããã¤ã´
Method for producing electrochemical bundle of lithium battery
WO2017061066A1
( en )
2015-10-05
2017-04-13
ã½ãã¼æ ªå¼ä¼ç¤¾
Residual quantity measuring device, battery pack, electric power tool, electric-type aircraft, electric vehicle and power supply
US20180203069A1
( en )
2015-10-05
2018-07-19
Murata Manufacturing Co., Ltd.
Residual quantity measuring device, battery pack, electric power tool, electric aircraft, electric vehicle, and power supply device
US20190312252A1
( en )
*
2016-06-24
2019-10-10
Samsung Sdi Co., Ltd.
Rechargeable battery
US20180254529A1
( en )
*
2017-03-01
2018-09-06
Ford Global Technologies, Llc
Lithium replenishment for containing capacity loss in li ion batteries
US20180366786A1
( en )
2017-06-14
2018-12-20
Automotive Energy Supply Corporation
Lithium ion secondary battery element and lithium ion secondary battery
CN109088091A
( en )
2017-06-14
2018-12-25
汽车è½æºä¾åºå ¬å¸
Lithium ion secondary battery element and lithium ion secondary battery
JP2019003789A
( en )
2017-06-14
2019-01-10
ãªã¼ãã¢ã¼ãã£ãã¨ãã¸ã¼ãµãã©ã¤æ ªå¼ä¼ç¤¾
Lithium ion secondary battery element and lithium ion secondary battery
US20200026269A1
( en )
*
2018-07-19
2020-01-23
Aurora Flight Sciences Corporation
Performance monitoring system for an electric drive system
Non-Patent Citations (6)
* Cited by examiner, â Cited by third party
Title
Chinese Office Action issued Aug. 14, 2023 in corresponding Chinese Application No. 202080047979.1.
International Search Report of corresponding PCT application PCT/JP2020/028295, dated Oct. 13, 2020.
Japanese Office Action issued Sep. 20, 2022 in corresponding Japanese Application No. 2021-536973.
Chinese Office Action issued Aug. 14, 2023 in corresponding Chinese Application No. 202080047979.1.
International Search Report of corresponding PCT application PCT/JP2020/028295, dated Oct. 13, 2020.
Japanese Office Action issued Sep. 20, 2022 in corresponding Japanese Application No. 2021-536973.
Also Published As
Publication number
Publication date
US20220149444A1
( en )
2022-05-12
CN114128023A
( en )
2022-03-01
JPWO2021020237A1
( en )
2021-02-04
WO2021020237A1
( en )
2021-02-04
JP7287467B2
( en )
2023-06-06
CN114128023B
( en )
2024-03-29
Similar Documents
Publication
Publication Date
Title
US20220149444A1
( en )
2022-05-12
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
US12255289B2
( en )
2025-03-18
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
US12308395B2
( en )
2025-05-20
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
US12249693B2
( en )
2025-03-11
Secondary battery including non-covered part having bent flat surface with groove passing through central axis and another groove not passing through central axis, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle including the same
US12415262B2
( en )
2025-09-16
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
JP7315005B2
( en )
2023-07-26
Secondary batteries, battery packs, electric tools, electric aircraft and electric vehicles
US20220149443A1
( en )
2022-05-12
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
US12246602B2
( en )
2025-03-11
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
US12211974B2
( en )
2025-01-28
Secondary battery, battery pack, electronic device, electric tool, electric aircraft, and electric vehicle
WO2022163482A1
( en )
2022-08-04
Secondary battery, electronic device, and electric tool
US20240405290A1
( en )
2024-12-05
Secondary battery, battery pack, electronic equipment, electric tool, electric aircraft, and electric vehicle
US20240270395A1
( en )
2024-08-15
Secondary battery, battery pack, electronic equipment, electric tool, electric aircraft, and electric vehicle
Legal Events
Date
Code
Title
Description
2022-01-21
FEPP
Fee payment procedure
Free format text : ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY
2022-01-26
AS
Assignment
Owner name : MURATA MANUFACTURING CO., LTD., JAPAN
Free format text : ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OTANI, AKIRA;REEL/FRAME:058781/0296
Effective date : 20211216
2022-02-17
STPP
Information on status: patent application and granting procedure in general
Free format text : DOCKETED NEW CASE - READY FOR EXAMINATION
2024-09-19
STPP
Information on status: patent application and granting procedure in general
Free format text : NON FINAL ACTION MAILED
2024-12-19
STPP
Information on status: patent application and granting procedure in general
Free format text : RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER
2025-04-15
STPP
Information on status: patent application and granting procedure in general
Free format text : FINAL REJECTION MAILED
2025-07-31
STPP
Information on status: patent application and granting procedure in general
Free format text : DOCKETED NEW CASE - READY FOR EXAMINATION
2025-08-25
STPP
Information on status: patent application and granting procedure in general
Free format text : NON FINAL ACTION COUNTED, NOT YET MAILED
2025-08-26
STPP
Information on status: patent application and granting procedure in general
Free format text : NON FINAL ACTION MAILED
2025-12-14
STPP
Information on status: patent application and granting procedure in general
Free format text : RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER
2026-01-12
STPP
Information on status: patent application and granting procedure in general
Free format text : NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS
Free format text : ALLOWED -- NOTICE OF ALLOWANCE NOT YET MAILED
2026-01-13
STPP
Information on status: patent application and granting procedure in general
Free format text : NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS
2026-03-31
STPP
Information on status: patent application and granting procedure in general
Free format text : PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED
Free format text : PUBLICATIONS -- ISSUE FEE PAYMENT RECEIVED
2026-04-22
STCF
Information on status: patent grant
Free format text : PATENTED CASE