ABSTRACT
Abstract
Provided is a battery module that allows suppressing impairment of battery performance, through suitable control of a restraining pressure that is exerted in the stacking direction of a stack, also in a case where unit cells expand/shrink when charged/discharged. The battery module is provided with a stack in which a plurality of unit cells is stacked, and with a pressure regulation member, which is disposed at least at one site from among a gap between the stacked unit cells, and a first end and a second end in the stacking direction, and which regulates a restraining pressure exerted in the stacking direction of the stack. The pressure regulation member is provided with a liquid holding section and a liquid storage section. The liquid holding section is provided with a liquid holding body capable of holding a liquid. The liquid storage section has a space capable of storing the liquid.
Description
CROSS-REFERENCE
The present application claims priority to Japanese Patent Application No. 2018-007552 filed on Jan. 19, 2018, and the entire contents thereof are incorporated into the present specification by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a battery module. More particularly, the present invention relates to a battery module in which a plurality of unit cells is held in a restrained state.
2. Description of the Related Art
Battery modules provided with unit cells such as lithium ion secondary batteries or nickel-hydride batteries have gained in importance as power sources for installation in vehicles that are driven by electricity, and as power sources installed in electric appliances such as personal computers and portable terminals. In particular, battery modules that utilize unit cells in the form of lithium ion secondary batteries that are lightweight and boast high energy density are preferred as high-output power sources for vehicle drive in electric vehicles (EV), plug-in hybrid vehicles (PHV) and hybrid vehicles (HV), and the demand for such batteries is expected to further grow in the future.
In a typical configuration, such battery modules are constructed through stacking of a plurality of unit cells and through restraining of the stack of unit cells in a state in which a predetermined load is applied in the stacking direction. Unit cells are restrained mainly from the viewpoint of vibration resistance and shock resistance of the battery module, and securing battery performance. Examples of prior art documents relating to this art include Japanese Patent Application Publication No. 2008-277042. Japanese Patent Application Publication No. 2008-277042 discloses a battery module provided with an interposed member that can expand in an environment at low temperature (typically +4° C. or lower).
SUMMARY OF THE INVENTION
In battery modules of this kind, the magnitude of the restraining load that is applied to the unit cells at the time of construction of the battery module might vary due to the fact that some of the unit cells expand/shrink during use of the battery (when charged/discharged), and due to deterioration of the battery module over time. Further, the magnitude of the restraining load might vary depending on the usage environment of the battery (for instance air temperature). Accordingly, it has been necessary to regulate the pressure acting on the unit cells in response to changes in the restraining load.
However, control of the restraining pressure in conventional battery modules was insufficient. In particular, it has been necessary to control restraining pressure more satisfactorily in a case where the battery module is constructed using unit cells having a tendency to expand/shrink significantly during battery charging and discharge. For instance sufficient control of restraining pressure is required in a case where expansion of the unit cells progresses as the temperature of the battery module rises. The performance of the battery module may drop unless suitable restraining pressure is applied.
It is an object of the present invention, arrived at in the light of the above considerations, to provide a battery module that allows suppressing impairment of battery performance, through suitable control of the restraining pressure that is exerted in the stacking direction of a stack, also in a case where unit cells expand/shrink when charged/discharged.
The present invention provides a battery module having: a stack in which a plurality of unit cells is stacked; and a pressure regulation member, which is disposed at least at one site from among a gap between the stacked unit cells, and a first end and a second end in the stacking direction, and which regulates a restraining pressure exerted in the stacking direction of the stack.
The unit cell is provided with an exterior body, an electrode body accommodated in the exterior body, and a positive electrode terminal and a negative electrode terminal electrically connected to the electrode body and led out from the exterior body. The pressure regulation member is provided with a liquid holding section and a liquid storage section. The liquid holding section is formed at a position at which the restraining pressure is applied, and includes a liquid and a liquid holding body capable of holding the liquid, wherein the liquid holding body is further capable of reversibly releasing and absorbing the liquid. The liquid storage section is formed at a position at which the restraining pressure is not applied (for instance, a position in the direction along which the positive electrode terminal and the negative electrode terminal are led out from the exterior body). Further, a boundary between the liquid holding section and the liquid storage section is formed so that the liquid can move reversibly therethrough while movement of the liquid holding body towards the liquid storage section is hindered.
If a concern arises that restraining pressure exerted in the stacking direction of the stack may vary on account of expansion of the unit cells during battery charging and discharge, the restraining pressure in the battery module having such a configuration can be regulated, to lie within a suitable range, through movement the liquid from the liquid holding section to the liquid storage section in the pressure regulation member. Conversely, if a concern arises that the restraining pressure exerted in the stacking direction of the stack may vary through shrinkage of the unit cells during use of the battery, the restraining pressure can be regulated to lie in a suitable range through movement of the liquid from the liquid storage section to the liquid holding section in the pressure regulation member. In such a configuration the restraining pressure applied to the stack can be suitably controlled also in a case where the unit cells expand/shrink during use of the battery.
In another preferred implementation of the battery module disclosed herein, the liquid holding body contains a water-absorbing polymer having temperature responsiveness. In such a battery module a liquid is released from the absorbing polymer depending on the temperature, and flows readily towards the liquid storage section, when the unit cells expand as a result of a rise in battery temperature. In a battery module having such a configuration, therefore, the restraining pressure applied to the stack can be suitably controlled in particular in a case where the temperature of the battery module is high (for instance 30° C. or higher).
In another preferred implementation of the battery module disclosed herein, the liquid holding body contains a polymer porous body that deforms elastically on account of the restraining pressure. The liquid holding body can suitably release and absorb a liquid, and accordingly the pressure regulation member provided with the above liquid holding body allows suitably controlling the restraining pressure applied on the stack. The liquid holding body can deform elastically on account of the restraining pressure, and accordingly the restraining pressure can be suitably controlled also by elastic forces arising from elastic deformation.
In another preferred implementation of the battery module disclosed herein, the liquid holding body is held in the liquid holding section in a state in which the liquid holding body is accommodated in a container into and out of which the liquid can reversibly flow. In such a configuration the function of the liquid holding body can be brought out over long periods of time, without collapse of the shape of the liquid holding body.
In another preferred implementation of the battery module disclosed herein, two or more liquid storage sections are formed at positions in mutually different directions with respect to the liquid holding section. In such a configuration, movement of the liquid from the liquid holding section to a plurality of liquid storage sections can be completed within a shorter time. The restraining pressure on the stack by the pressure regulation member can be effectively controlled yet more quickly as a result.
In another preferred implementation of the battery module disclosed herein, the liquid storage section is formed at a region overlapping the positive electrode terminal and/or the negative electrode terminal (hereafter both terminals may be also referred to collectively as âpositive and negative electrode terminalsâ) in the stacking direction (that is, when viewed from the stacking direction). In such a configuration the liquid storage section that must be disposed at a position at which the restraining pressure is not applied is set to overlap, in the stacking direction, the position at which there are disposed the positive and negative electrode terminals of the unit cells that make up the stack. As a result, it is not necessary to further provide separately a space for arranging the liquid storage section, different from the space at which there are disposed the positive and negative electrode terminals led out from the exterior body of the unit cells. A large such space is undesirable, since this may give rise to a drop in battery capacity per unit volume in the battery module. Therefore, the battery module of the present form allows increasing the effective utilization of the volume (volume efficiency) of the battery module as a whole.
In another preferred implementation of the battery module disclosed herein, the positive electrode terminal and the negative electrode terminal are each led out in different directions from two opposing sides of the exterior body, and the pressure regulation member has two liquid storage sections, wherein the two liquid storage sections are respectively formed at regions overlapping the positive electrode terminal and the negative electrode terminal in the stacking direction. In a battery module having such a configuration, control of the restraining pressure on the stack by the pressure regulation member can be accomplished quickly, and it becomes possible to secure satisfactorily the volume efficiency the battery module as a whole, in a battery module configured in the form of a stack of unit cells of a type where positive and negative electrode terminals are led out in respective separate directions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective-view diagram illustrating schematically the structure of a battery module according to an embodiment;
FIG. 2 is a cross-sectional diagram of FIG. 1 as viewed from arrows II-IIâ²;
FIG. 3 is a plan-view diagram illustrating schematically a pressure regulation member according to an embodiment;
FIG. 4 is a perspective-view diagram including a cross-section, along line IV-IVâ², of the pressure regulation member illustrated in FIG. 3 ;
FIG. 5 is a cross-sectional diagram of FIG. 1 as viewed from arrows V-Vâ²;
FIG. 6 is diagram of a battery module according to another embodiment, viewed from line V-Vâ² of FIG. 1 ;
FIG. 7 is a cross-sectional diagram illustrating schematically a battery module according to another embodiment; and
FIG. 8 is a cross-sectional diagram illustrating schematically a battery module according to another embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be explained next with reference to accompanying drawings as appropriate. Any features other than the matter specifically set forth in the present specification and that may be necessary for carrying out the present invention can be regarded as instances of design matter, for a person skilled in the art, based on known techniques in the relevant technical field. The invention can be realized on the basis of the disclosure of the present specification and common technical knowledge in the relevant technical field. In the drawings below, members and portions that elicit identical effects are denoted with identical reference numerals, and a recurrent explanation thereof will be omitted or simplified. The dimensional relationships (length, width, thickness and so forth) in the figures do not necessarily reflect actual dimensional relationships. The figures are merely illustrative in nature, and unless otherwise stated are not meant to limit the present invention any way.
The art disclosed herein can be used for various sealed-type batteries in which the interior of a case is shut off from the external environment by a battery case. Typically, the art is used for various batteries in which a battery case shuts off flow of gases, liquids and solids between the interior and the exterior of the case. In the explanation below, the configuration of a sealed-type battery in which the art of the present invention can be used will be explained first, in a simple manner by way of an example of a lithium ion secondary battery. The sealed-type battery pertaining to the use of the present invention is not meant to be limited to lithium ion secondary batteries.
FIG. 1 is a perspective-view diagram illustrating schematically the structure of a battery module 100 according to an embodiment. FIG. 2 is a schematic diagram illustrating schematically a cross-section of FIG. 1 as viewed from arrows II-IIâ². As illustrated in FIG. 1 and FIG. 2 , the battery module 100 is provided with a stack 20 having a plurality of unit cells 10 , a pair of end plates
30 A, 30 B, a pair of side plates
40 A, 40 B, and a pressure regulation member 60 .
The stack 20 is configured through stacking and arrangement of the plurality of unit cells 10 (preferably chargeable/dischargeable unit cells 10 ) in a predetermined stacking direction (arrow X direction in FIG. 1 ). Although not illustrated in the figures, members other than the unit cells 10 (for instance cooling plates) may be interposed between the unit cells 10 . For instance metal-made plates for uniformly transmitting pressu
CROSS-REFERENCE
The present application claims priority to Japanese Patent Application No. 2018-007552 filed on Jan. 19, 2018, and the entire contents thereof are incorporated into the present specification by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a battery module. More particularly, the present invention relates to a battery module in which a plurality of unit cells is held in a restrained state.
2. Description of the Related Art
Battery modules provided with unit cells such as lithium ion secondary batteries or nickel-hydride batteries have gained in importance as power sources for installation in vehicles that are driven by electricity, and as power sources installed in electric appliances such as personal computers and portable terminals. In particular, battery modules that utilize unit cells in the form of lithium ion secondary batteries that are lightweight and boast high energy density are preferred as high-output power sources for vehicle drive in electric vehicles (EV), plug-in hybrid vehicles (PHV) and hybrid vehicles (HV), and the demand for such batteries is expected to further grow in the future.
In a typical configuration, such battery modules are constructed through stacking of a plurality of unit cells and through restraining of the stack of unit cells in a state in which a predetermined load is applied in the stacking direction. Unit cells are restrained mainly from the viewpoint of vibration resistance and shock resistance of the battery module, and securing battery performance. Examples of prior art documents relating to this art include Japanese Patent Application Publication No. 2008-277042. Japanese Patent Application Publication No. 2008-277042 discloses a battery module provided with an interposed member that can expand in an environment at low temperature (typically +4° C. or lower).
SUMMARY OF THE INVENTION
In battery modules of this kind, the magnitude of the restraining load that is applied to the unit cells at the time of construction of the battery module might vary due to the fact that some of the unit cells expand/shrink during use of the battery (when charged/discharged), and due to deterioration of the battery module over time. Further, the magnitude of the restraining load might vary depending on the usage environment of the battery (for instance air temperature). Accordingly, it has been necessary to regulate the pressure acting on the unit cells in response to changes in the restraining load.
However, control of the restraining pressure in conventional battery modules was insufficient. In particular, it has been necessary to control restraining pressure more satisfactorily in a case where the battery module is constructed using unit cells having a tendency to expand/shrink significantly during battery charging and discharge. For instance sufficient control of restraining pressure is required in a case where expansion of the unit cells progresses as the temperature of the battery module rises. The performance of the battery module may drop unless suitable restraining pressure is applied.
It is an object of the present invention, arrived at in the light of the above considerations, to provide a battery module that allows suppressing impairment of battery performance, through suitable control of the restraining pressure that is exerted in the stacking direction of a stack, also in a case where unit cells expand/shrink when charged/discharged.
The present invention provides a battery module having: a stack in which a plurality of unit cells is stacked; and a pressure regulation member, which is disposed at least at one site from among a gap between the stacked unit cells, and a first end and a second end in the stacking direction, and which regulates a restraining pressure exerted in the stacking direction of the stack.
The unit cell is provided with an exterior body, an electrode body accommodated in the exterior body, and a positive electrode terminal and a negative electrode terminal electrically connected to the electrode body and led out from the exterior body. The pressure regulation member is provided with a liquid holding section and a liquid storage section. The liquid holding section is formed at a position at which the restraining pressure is applied, and includes a liquid and a liquid holding body capable of holding the liquid, wherein the liquid holding body is further capable of reversibly releasing and absorbing the liquid. The liquid storage section is formed at a position at which the restraining pressure is not applied (for instance, a position in the direction along which the positive electrode terminal and the negative electrode terminal are led out from the exterior body). Further, a boundary between the liquid holding section and the liquid storage section is formed so that the liquid can move reversibly therethrough while movement of the liquid holding body towards the liquid storage section is hindered.
If a concern arises that restraining pressure exerted in the stacking direction of the stack may vary on account of expansion of the unit cells during battery charging and discharge, the restraining pressure in the battery module having such a configuration can be regulated, to lie within a suitable range, through movement the liquid from the liquid holding section to the liquid storage section in the pressure regulation member. Conversely, if a concern arises that the restraining pressure exerted in the stacking direction of the stack may vary through shrinkage of the unit cells during use of the battery, the restraining pressure can be regulated to lie in a suitable range through movement of the liquid from the liquid storage section to the liquid holding section in the pressure regulation member. In such a configuration the restraining pressure applied to the stack can be suitably controlled also in a case where the unit cells expand/shrink during use of the battery.
In another preferred implementation of the battery module disclosed herein, the liquid holding body contains a water-absorbing polymer having temperature responsiveness. In such a battery module a liquid is released from the absorbing polymer depending on the temperature, and flows readily towards the liquid storage section, when the unit cells expand as a result of a rise in battery temperature. In a battery module having such a configuration, therefore, the restraining pressure applied to the stack can be suitably controlled in particular in a case where the temperature of the battery module is high (for instance 30° C. or higher).
In another preferred implementation of the battery module disclosed herein, the liquid holding body contains a polymer porous body that deforms elastically on account of the restraining pressure. The liquid holding body can suitably release and absorb a liquid, and accordingly the pressure regulation member provided with the above liquid holding body allows suitably controlling the restraining pressure applied on the stack. The liquid holding body can deform elastically on account of the restraining pressure, and accordingly the restraining pressure can be suitably controlled also by elastic forces arising from elastic deformation.
In another preferred implementation of the battery module disclosed herein, the liquid holding body is held in the liquid holding section in a state in which the liquid holding body is accommodated in a container into and out of which the liquid can reversibly flow. In such a configuration the function of the liquid holding body can be brought out over long periods of time, without collapse of the shape of the liquid holding body.
In another preferred implementation of the battery module disclosed herein, two or more liquid storage sections are formed at positions in mutually different directions with respect to the liquid holding section. In such a configuration, movement of the liquid from the liquid holding section to a plurality of liquid storage sections can be completed within a shorter time. The restraining pressure on the stack by the pressure regulation member can be effectively controlled yet more quickly as a result.
In another preferred implementation of the battery module disclosed herein, the liquid storage section is formed at a region overlapping the positive electrode terminal and/or the negative electrode terminal (hereafter both terminals may be also referred to collectively as âpositive and negative electrode terminalsâ) in the stacking direction (that is, when viewed from the stacking direction). In such a configuration the liquid storage section that must be disposed at a position at which the restraining pressure is not applied is set to overlap, in the stacking direction, the position at which there are disposed the positive and negative electrode terminals of the unit cells that make up the stack. As a result, it is not necessary to further provide separately a space for arranging the liquid storage section, different from the space at which there are disposed the positive and negative electrode terminals led out from the exterior body of the unit cells. A large such space is undesirable, since this may give rise to a drop in battery capacity per unit volume in the battery module. Therefore, the battery module of the present form allows increasing the effective utilization of the volume (volume efficiency) of the battery module as a whole.
In another preferred implementation of the battery module disclosed herein, the positive electrode terminal and the negative electrode terminal are each led out in different directions from two opposing sides of the exterior body, and the pressure regulation member has two liquid storage sections, wherein the two liquid storage sections are respectively formed at regions overlapping the positive electrode terminal and the negative electrode terminal in the stacking direction. In a battery module having such a configuration, control of the restraining pressure on the stack by the pressure regulation member can be accomplished quickly, and it becomes possible to secure satisfactorily the volume efficiency the battery module as a whole, in a battery module configured in the form of a stack of unit cells of a type where positive and negative electrode terminals are led out in respective separate directions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective-view diagram illustrating schematically the structure of a battery module according to an embodiment;
FIG. 2 is a cross-sectional diagram of FIG. 1 as viewed from arrows II-IIâ²;
FIG. 3 is a plan-view diagram illustrating schematically a pressure regulation member according to an embodiment;
FIG. 4 is a perspective-view diagram including a cross-section, along line IV-IVâ², of the pressure regulation member illustrated in FIG. 3 ;
FIG. 5 is a cross-sectional diagram of FIG. 1 as viewed from arrows V-Vâ²;
FIG. 6 is diagram of a battery module according to another embodiment, viewed from line V-Vâ² of FIG. 1 ;
FIG. 7 is a cross-sectional diagram illustrating schematically a battery module according to another embodiment; and
FIG. 8 is a cross-sectional diagram illustrating schematically a battery module according to another embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be explained next with reference to accompanying drawings as appropriate. Any features other than the matter specifically set forth in the present specification and that may be necessary for carrying out the present invention can be regarded as instances of design matter, for a person skilled in the art, based on known techniques in the relevant technical field. The invention can be realized on the basis of the disclosure of the present specification and common technical knowledge in the relevant technical field. In the drawings below, members and portions that elicit identical effects are denoted with identical reference numerals, and a recurrent explanation thereof will be omitted or simplified. The dimensional relationships (length, width, thickness and so forth) in the figures do not necessarily reflect actual dimensional relationships. The figures are merely illustrative in nature, and unless otherwise stated are not meant to limit the present invention any way.
The art disclosed herein can be used for various sealed-type batteries in which the interior of a case is shut off from the external environment by a battery case. Typically, the art is used for various batteries in which a battery case shuts off flow of gases, liquids and solids between the interior and the exterior of the case. In the explanation below, the configuration of a sealed-type battery in which the art of the present invention can be used will be explained first, in a simple manner by way of an example of a lithium ion secondary battery. The sealed-type battery pertaining to the use of the present invention is not meant to be limited to lithium ion secondary batteries.
FIG. 1 is a perspective-view diagram illustrating schematically the structure of a battery module 100 according to an embodiment. FIG. 2 is a schematic diagram illustrating schematically a cross-section of FIG. 1 as viewed from arrows II-IIâ². As illustrated in FIG. 1 and FIG. 2 , the battery module 100 is provided with a stack 20 having a plurality of unit cells 10 , a pair of end plates
30 A, 30 B, a pair of side plates
40 A, 40 B, and a pressure regulation member 60 .
The stack 20 is configured through stacking and arrangement of the plurality of unit cells 10 (preferably chargeable/dischargeable unit cells 10 ) in a predetermined stacking direction (arrow X direction in FIG. 1 ). Although not illustrated in the figures, members other than the unit cells 10 (for instance cooling plates) may be interposed between the unit cells 10 . For instance metal-made plates for uniformly transmitting pressure from the pressure regulation member 60 to mutually opposing surfaces (hereafter âstacking surfacesâ), in the stacking direction X of the unit cells 10 that make up the stack 20 , may be interposed between the unit cells 10 and the below-described pressure regulation member 60 .
Unit Cells
The unit cells 10 are suitably all-solid-state batteries, and more suitably all-solid-state lithium secondary batteries or lithium-sulfur secondary batteries. All-solid-state batteries are typically provided with a positive electrode, a negative electrode and a solid electrolyte. In a case where the unit cells 10 are all-solid-state batteries, the stacking directions of the positive electrode, the negative electrode and the solid electrolyte are the same as the stacking direction X of the stack 20 . The unit cells 10 may be nonaqueous electrolyte secondary batteries. Nonaqueous electrolyte secondary batteries are typically provided with a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte solution. In a case where the unit cells 10 are nonaqueous electrolyte secondary batteries, the stacking directions of the positive electrode, the negative electrode, and the separator are the same as the stacking direction X of the stack 20 . In the battery module 100 of one embodiment disclosed herein a restraining load is applied perpendicularly to electrode surfaces within the unit cells 10 .
In a case where all-solid-state batteries are used as the unit cells 10 , the edges of stacking surfaces, being the surfaces of the unit cells 10 in a direction (i.e. in-plane direction of the YZ plane in FIG. 1 ) perpendicular to the stacking direction X of the stack 20 tend to expand/shrink to a greater extent than the central portion, during charging/discharge of the battery. The art disclosed herein allows suitably regulating the restraining pressure over the entire stacking surface of the unit cells 10 including the edges, and accordingly the present invention can be meaningfully used in unit cells 10 that are all-solid-state batteries.
The unit cells 10 may be fuel cells or secondary batteries such as nickel-hydride batteries. In the present specification, the term âsecondary batteryâ denotes a general electric storage device that can be charged and discharged repeatedly, and encompasses so-called storage batteries and electric storage elements such as electrical double layer capacitors.
The unit cells 10 are each provided with an exterior body 14 that accommodates therein a power generation element in the form of the above-described electrode body having the positive electrode and negative electrode, an electrolyte and so forth, and with a positive electrode terminal 12 A and a negative electrode terminal 12 B that are led out from the exterior body 14 . The positive electrode terminal 12 A and the negative electrode terminal 12 B are electrically connected to the electrode body. In an example illustrated in FIG. 1 , the positive electrode terminal 12 A and the negative electrode terminal 12 B are led out in the same direction, from a same side of the exterior body 14 .
The positive electrode terminal 12 A and the negative electrode terminal 12 B of the unit cells 10 may be led out individually from two mutually opposing sides of the exterior body 14 (see FIG. 6 described below).
The material used in the positive electrode of the unit cells 10 in a case where these are all-solid-state batteries is not particularly limited, and there can be used materials that are utilized in positive electrodes of conventional all-solid-state batteries. For instance a lamellar, olivine-type or spinel-type compound can be used as the positive electrode active material in the positive electrode. Specific examples include for instance lithium cobaltate (LiCoO 2 ); lithium nickelate (LiNiO 2 ); lithium manganate (LiMnO 2 ); lithium nickel manganese cobaltate (LiNi 1âyâz Co y Mn z O 2 , for instance LiNi 1/3 Co 1/3 Mn 1/3 O 2 ); lithium nickel cobaltate (LiNi 1âx Co x O 2 ); lithium nickel manganate (LiNi 1âx Mn x O 2 ); lithium manganate (LiMn 2 O 4 ); lithium manganate compounds (Li 1+x M y Mn 2âxây O 4 ; M=Al, Mg, Fe, Cr, Co, Ni or Zn); lithium metal phosphates (LiMPO 4 , M=Fe, Mn, Co or Ni); lithium metal fluorophosphates (Li 2 MPO 4 F, M=Fe, Mn, Co or Ni); lithium metal phosphates (Li 2 MP 2 O 7 , M=Fe, Mn, Co or Ni); and lithium titanate (Li x TiO y ). Alternatively, the positive electrode active material may contain sulfur (S), or be sulfur.
The art disclosed herein allows regulating suitably the restraining pressure that is applied in stacking direction X of the stack 20 even upon expansion/shrinkage of the unit cells 10 during charging/discharge of the battery. Accordingly, the use of the art pertaining to the present invention is particularly meaningful in unit cells 10 that utilize, as a positive electrode material, sulfur (S) having the tendency to expand/shrink significantly during charging/discharge.
The material used in the negative electrode of the unit cells 10 in a case where these are all-solid-state batteries is not particularly limited, and there can be used materials that are utilized in negative electrodes of conventional all-solid-state batteries. For instance a metal or a carbon material can be used as the negative electrode active material in the negative electrode. Examples of the metal include for instance Li, Sn, Si, Al, In and Sb as well as combinations and alloys of the foregoing. Examples of the carbon materials include for instance carbon materials having a graphite structure (layered structure) at least in part. Specific examples include natural and artificial graphite, soft carbon, hard carbon, low-temperature fired carbon and combinations of the foregoing.
The art disclosed herein allows regulating suitably the restraining pressure that is applied in the stacking direction X of the stack 20 , even upon expansion/shrinkage of the unit cells 10 during charging/discharge of the battery. Accordingly, the use of the art according to the present invention is particularly meaningful in unit cells 10 in which a metal such a Sn or Si or an alloy being a combination of the foregoing, having the tendency to expand/shrink significantly during charging/discharge, is used as the negative electrode material.
In a case where the unit cells 10 are all-solid-state batteries, a material that is utilized in solid electrolytes of conventional all-solid-state batteries can be used also herein, without particular limitations, as the solid electrolyte contained in the unit cells 10 . For instance inorganic solid electrolytes such as sulfides and oxides can be used as the solid electrolyte. Sulfide solid electrolytes can be preferably used among the foregoing. The solid electrolyte may be crystalline, amorphous, or a glass ceramic. Examples of sulfide-based solid electrolytes include for instance amorphous ones such as Li 2 SâSiS 2 -based, Li 2 SâSiS 2 âLiI-based and Li 2 SâSiS 2 âLi 3 PO 4 -based solid electrolytes, crystalline ones such as Li 10 GeP 2 S 12 , and glass ceramics such as Li 7 P 3 S 11 and Li 3.25 P 0.95 S 4 . Examples of oxide-based solid electrolytes include for instance La 0.51 Li 0.34 TiO 2.94 , Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 and Li 7 La 3 Zr 2 O 12 .
The exterior body 14 is preferably made up of a material that is thin, lightweight, highly flexible, melts easily for instance through thermal welding or ultrasonic welding, and is excellent in airtightness and water impermeability. The exterior body 14 may for instance be made up of a laminate film having a three-layer structure in which a metal layer is disposed between two polymer resin layers. The metal layer may for instance be configured out of a metal foil such as aluminum, stainless steel, nickel or copper. The polymer resin layer may for instance be configured out of a thermoplastic resin film, for example a polyolefin such as polyethylene or polypropylene, or ethylene vinyl acetate. Unit cells 10 such as the one illustrated in the figures, in which the exterior body 14 has a flat thin plate-like shape made up of such a laminate film, tend to exhibit significant expansion/shrinkage during charging/discharge, and hence the art of the present invention can be suitably used in those unit cells 10 .
End Plates
The pair of end plates
30 A, 30 B is disposed at both ends of the stack 20 in the stacking direction X. In the present embodiment, the end plate 30 A is disposed at a first end of the stack 20 in the stacking direction X, via the pressure regulation member 60 . The end plate 30 B is disposed at a second end of the stack 20 in the stacking direction X. Material and shapes capable of withstanding the restraining load acting on the stack 20 are used in the end plates
30 A, 30 B. The end plates
30 A, 30 B may be made of a metal or a resin, and may for instance be made of carbon steel. The end plates
30 A, 30 B have a plate-like shape.
Side Plates
The stack 20 is disposed between a pair of side plates
40 A, 40 B. As illustrated in FIG. 2 , the side plates
40 A, 40 B are disposed spaced from the stack 20 . The side plate 40 A and the side plate 40 B oppose each other across the stack 20 . The side plates
40 A, 40 B connect the pair of end plates
30 A, 30 B. Specifically the side plate 40 A connects a first end of the end plate 30 A in the direction of arrow Z in FIG. 1 to a first end of the end plate 30 B in the direction of arrow Z in FIG. 1 . The side plate 40 B connects a second end of the end plate 30 A in the direction of arrow Z in FIG. 1 to a second end of the end plate 30 B in the direction of arrow Z in FIG. 1 . The side plates
40 A, 40 B may be formed of the same material as that of the end plates
30 A, 30 B, or may be formed of a different material.
The side plates
40 A, 40 B and the end plates
30 A, 30 B may be connected by a fastening member such as bolts. Alternatively, the side plates
40 A, 40 B and the end plates
30 A, 30 B may be connected through strong joining, for instance by welding. In a case where the side plates
40 A, 40 B and the end plates
30 A, 30 B are joined by welding, a metal is preferably used as the material of the end plates
30 A, 30 B and of the side plates
40 A, 40 B.
Pressure Regulation Member
In the embodiment illustrated in FIG. 1 and FIG. 2 , the pressure regulation member 60 is disposed between the end plate 30 A and one end of the stack 20 in the stacking direction X. The pressure regulation member 60 can regulate the pressure (restraining pressure) acting in the stacking direction X of the stack 20 . In such a configuration the pressure regulation member 60 is disposed only at one of the ends of the stack 20 in the stacking direction X. The configuration of the battery module 100 is thus simple, and accordingly the battery module 100 can be made readily more compact.
FIG. 3 is a plan-view diagram illustrating schematically the pressure regulation member 60 according to an embodiment. FIG. 4 is a schematic perspective-view diagram of the pressure regulation member 60 including a cross-section of FIG. 3 along line VI-VIâ². The pressure regulation member 60 is provided with an exterior film 58 formed in the shape of a bag, and with a liquid holding section 62 and a liquid storage section 64 that are formed inside the bag-shaped exterior film 58 . A boundary 56 between the liquid holding section 62 and the liquid storage section 64 is formed so as to enable reversible movement of a liquid, while isolating the liquid holding section 62 and the liquid storage section 64 . For instance two exterior films 58 , top and bottom, positioned at the boundary 56 of the bag-shaped exterior films 58 , are heat-welded in the form of a dotted line (i.e. in the form of a broken line having appropriate gaps); as a result, the liquid can reversibly move between the liquid holding section 62 and the liquid storage section 64 , and there can be formed the boundary 56 that hinders movement of a below-described liquid holding body 66 towards the liquid storage section 64 .
The exterior films 58 are preferably made up of a material that is thin, lightweight, highly flexible, melts easily for instance through thermal welding or ultrasonic welding, and is excellent in airtightness and water impermeability. The exterior films 58 may for instance be made up of a laminate film having a three-layer structure in which a metal layer is disposed between two polymer resin layers. The metal layer may for instance be configured out of a metal foil such as aluminum, stainless steel, nickel or copper, and is preferably made up of an aluminum foil. The resin layer may for instance be configured out of a thermoplastic resin film, for example a polyolefin such as polyethylene or polypropylene, or ethylene vinyl acetate, with polyethylene and polypropylene being preferred among the foregoing.
The liquid holding body 66 is disposed in the liquid holding section 62 . The liquid holding body 66 is made up of a material capable of holding a liquid, and reversibly releasing and absorbing the liquid. A space that allows storing moving liquid when released from the liquid holding body 66 is formed in the liquid storage section 64 .
In such a configuration, when external pressure exerted on liquid holding body 66 increases, the liquid is released from the liquid holding body 66 , and moves to the liquid storage section 64 , through the boundary 56 , whereupon there decreases the thickness of the site of the pressure regulation member 60 at which the liquid holding body 66 is disposed. When the external pressure exerted on the liquid holding body 66 decreases, conversely, the liquid is absorbed by the liquid holding body 66 , and as a result the liquid from inside liquid storage section 64 flows through the boundary 56 towards the liquid holding body 66 , whereupon there increases the thickness of the site of the pressure regulation member 60 at which the liquid holding body 66 is disposed. Thus pressure from outside can be buffered through changes in the thickness of the pressure regulation member 60 in response to external pressure.
CLAIMS
Claims ( 7 )
What is claimed is:
1. A battery module, comprising: a stack in which two or more unit cells are stacked; and
a pressure regulation member, which is disposed at least at one site from among a gap between the stacked unit cells, and a first end and a second end in the stacking direction, and which regulates a restraining pressure exerted in the stacking direction of the stack,
wherein the unit cell is provided with an exterior body, an electrode body accommodated in the exterior body, and a positive electrode terminal and a negative electrode terminal electrically connected to the electrode body and led out from the exterior body;
the pressure regulation member is provided with a liquid holding section and a liquid storage section;
the liquid holding section
is formed at a position at which the restraining pressure is applied, and
includes a liquid and a liquid holding body capable of holding the liquid,
wherein the liquid holding body is capable of reversibly releasing and absorbing the liquid;
the liquid holding section
is formed at a position at which the restraining pressure is not applied, and
has a space capable of storing the liquid; and
a boundary between the liquid holding section and the liquid storage section is formed so that the liquid can move reversibly therethrough while movement of the liquid holding body towards the liquid storage section is hindered.
2. The battery module of claim 1 , wherein the liquid holding body contains a water-absorbing polymer having temperature responsiveness.
3. The battery module of claim 1 , wherein the liquid holding body contains a polymer porous body that deforms elastically on account of the restraining pressure.
4. The battery module of claim 1 , wherein the liquid holding body is held in the liquid holding section in a state in which the liquid holding body is accommodated in a container into and out of which the liquid can reversibly flow.
5. The battery module of claim 1 , wherein two or more liquid storage sections are formed at positions in mutually different directions with respect to the liquid holding section.
6. The battery module of claim 1 , wherein the liquid storage section is formed at a region overlapping the positive electrode terminal and/or the negative electrode terminal in the stacking direction.
7. The battery module of claim 1 ,
wherein the positive electrode terminal and the negative electrode terminal are each led out in different directions from two opposing sides of the exterior body;
the pressure regulation member has two liquid storage sections; and
the two liquid storage sections are respectively formed at regions overlapping the positive electrode terminal and the negative electrode terminal in the stacking direction.
US16/250,057
2018-01-19
2019-01-17
Battery module
Active
2039-07-19
US10886558B2
( en )
Applications Claiming Priority (2)
Application Number
Priority Date
Filing Date
Title
JP2018007552A
JP7022311B2
( en )
2018-01-19
2018-01-19
Battery module
JP2018-007552
2018-01-19
Publications (2)
Publication Number
Publication Date
US20190229364A1
US20190229364A1 ( en )
2019-07-25
US10886558B2
true
US10886558B2 ( en )
2021-01-05
Family
ID=67300181
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
US16/250,057
Active
2039-07-19
US10886558B2
( en )
2018-01-19
2019-01-17
Battery module
Country Status (3)
Country
Link
US
( 1 )
US10886558B2
( en )
JP
( 1 )
JP7022311B2
( en )
CN
( 1 )
CN110061160B
( en )
Families Citing this family (15)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
CN113994534B
( en )
*
2019-07-10
2024-04-02
æ¬ç°æç å·¥ä¸æ ªå¼ä¼ç¤¾
Electric storage module and method of manufacturing electric storage module
EP3799179A1
( en )
*
2019-09-26
2021-03-31
Manuel Torres Martinez
Pressurized electrochemical battery and process for manufacturing the same
JP7226229B2
( en )
*
2019-09-27
2023-02-21
ãã¨ã¿èªåè»æ ªå¼ä¼ç¤¾
Battery stack and manufacturing method thereof
WO2021106691A1
( en )
*
2019-11-27
2021-06-03
京ã»ã©æ ªå¼ä¼ç¤¾
Electrochemical cell
CN114788086B
( en )
*
2019-12-11
2024-06-07
æ ªå¼ä¼ç¤¾æç°å¶ä½æ
Solid-state battery
KR102433361B1
( en )
2019-12-17
2022-08-16
주ìíì¬ ìì§ìëì§ì루ì
Battery module and battery pack including the same
JP7198417B2
( en )
*
2020-02-19
2023-01-04
ãã¨ã¿èªåè»æ ªå¼ä¼ç¤¾
BATTERY AND METHOD FOR MANUFACTURING BATTERY
CN113451666B
( en )
*
2020-03-27
2025-01-07
ä¸æSdiæ ªå¼ä¼ç¤¾
Battery system and operating method thereof, and battery pack and vehicle including the same
HUE071136T2
( en )
*
2020-03-27
2025-08-28
Samsung Sdi Co Ltd
Battery pack pressurized with a fluid spring
WO2021215427A1
( en )
*
2020-04-21
2021-10-28
æ ªå¼ä¼ç¤¾ã¹ãªã¼ãã
Battery and method for controlling same
KR102773568B1
( en )
*
2020-07-22
2025-02-27
주ìíì¬ ìì§ìëì§ì루ì
Battery module, battery module system and battery pack including the battery module
JP2022038245A
( en )
*
2020-08-26
2022-03-10
æ ªå¼ä¼ç¤¾ï¼§ï½ã¦ã¢ãµ
Power storage device
JP7651916B2
( en )
*
2021-04-02
2025-03-27
ãã¨ã¿èªåè»æ ªå¼ä¼ç¤¾
Power storage device
DE102022128907A1
( en )
2022-11-02
2024-05-02
Dr. Ing. H.C. F. Porsche Aktiengesellschaft
Compression pad with a selectively or semi-permeable separating layer and manufacturing process for a battery cell stack with these compression pads
CN116598542A
( en )
*
2023-06-30
2023-08-15
å京亿åéç§æè¡ä»½æéå ¬å¸
Stability control system and method for compressive force of stacked structure
Citations (8)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US5786980A
( en )
*
1996-02-02
1998-07-28
Evans Capacitor Company, Incorporated
Electrical component package and packaged electrical component
US6200698B1
( en )
*
1999-08-11
2001-03-13
Plug Power Inc.
End plate assembly having a two-phase fluid-filled bladder and method for compressing a fuel cell stack
US6258475B1
( en )
*
1998-02-17
2001-07-10
Honda Giken Kogyo Kabushiki Kaisha
Fastening structure for fuel cell stack
JP2003045477A
( en )
2001-08-01
2003-02-14
Toshiba Corp
Alkaline secondary batteries, hybrid cars and electric vehicles
JP2008277042A
( en )
2007-04-26
2008-11-13
Toyota Motor Corp
Power storage device
US20170133705A1
( en )
*
2014-03-17
2017-05-11
Nissan Motor Co., Ltd.
Pressurization Device for Battery Cells
US9653710B2
( en )
*
2014-04-09
2017-05-16
Robert Bosch Gmbh
Electrical energy stores, and method for operating an electrical energy store
US20200168959A1
( en )
*
2017-07-21
2020-05-28
Quantumscape Corporation
Active and passive battery pressure management
Family Cites Families (11)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
CN1217089A
( en )
*
1996-03-22
1999-05-19
æ ªå¼ä¼ç¤¾æ¥ç«å¶ä½æ
Lithium rechargeable batteries, chargers and information terminal equipment
JP2007018753A
( en )
*
2005-07-05
2007-01-25
Gs Yuasa Corporation:Kk
battery
JP5636634B2
( en )
*
2009-02-25
2014-12-10
ãã¨ã¿èªåè»æ ªå¼ä¼ç¤¾
Electrode plate pressurizing device
JP2010238554A
( en )
*
2009-03-31
2010-10-21
Toyota Motor Corp
Storage element holder
DE102011015152A1
( en )
*
2011-03-25
2012-09-27
Li-Tec Battery Gmbh
Energy storage device, energy storage cell and Wärmeleitelement with elastic means
JP2012221773A
( en )
*
2011-04-11
2012-11-12
Toyota Motor Corp
Solid-state battery, and solid-state battery system
CN202585639U
( en )
*
2012-03-20
2012-12-05
æå·ä¹è£æééçµç§ææéå ¬å¸
Novel lithium battery module
JP2014170697A
( en )
*
2013-03-05
2014-09-18
Honda Motor Co Ltd
Battery pack
JP6442907B2
( en )
*
2014-08-07
2018-12-26
æ ªå¼ä¼ç¤¾è±ç°èªåç¹æ©
Battery module
JP6350172B2
( en )
*
2014-09-25
2018-07-04
æ ªå¼ä¼ç¤¾è±ç°èªåç¹æ©
Battery module
KR102082384B1
( en )
*
2015-08-11
2020-02-27
주ìíì¬ ìì§íí
Battery Pack Comprising Metallic Pack Case and Thermal Conduction Member
2018
2018-01-19
JP
JP2018007552A
patent/JP7022311B2/en
active
Active
2019
2019-01-15
CN
CN201910038352.9A
patent/CN110061160B/en
active
Active
2019-01-17
US
US16/250,057
patent/US10886558B2/en
active
Active
Patent Citations (9)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US5786980A
( en )
*
1996-02-02
1998-07-28
Evans Capacitor Company, Incorporated
Electrical component package and packaged electrical component
US6258475B1
( en )
*
1998-02-17
2001-07-10
Honda Giken Kogyo Kabushiki Kaisha
Fastening structure for fuel cell stack
US6200698B1
( en )
*
1999-08-11
2001-03-13
Plug Power Inc.
End plate assembly having a two-phase fluid-filled bladder and method for compressing a fuel cell stack
JP2003045477A
( en )
2001-08-01
2003-02-14
Toshiba Corp
Alkaline secondary batteries, hybrid cars and electric vehicles
JP2008277042A
( en )
2007-04-26
2008-11-13
Toyota Motor Corp
Power storage device
US20100136461A1
( en )
2007-04-26
2010-06-03
Akira Tsujiko
Power storage device
US20170133705A1
( en )
*
2014-03-17
2017-05-11
Nissan Motor Co., Ltd.
Pressurization Device for Battery Cells
US9653710B2
( en )
*
2014-04-09
2017-05-16
Robert Bosch Gmbh
Electrical energy stores, and method for operating an electrical energy store
US20200168959A1
( en )
*
2017-07-21
2020-05-28
Quantumscape Corporation
Active and passive battery pressure management
Also Published As
Publication number
Publication date
JP7022311B2
( en )
2022-02-18
JP2019128980A
( en )
2019-08-01
CN110061160A
( en )
2019-07-26
US20190229364A1
( en )
2019-07-25
CN110061160B
( en )
2021-08-31
Similar Documents
Publication
Publication Date
Title
US20190229364A1
( en )
2019-07-25
Battery module
KR100942986B1
( en )
2010-02-17
Battery module with adhesive member attached between battery cells
EP4435949A1
( en )
2024-09-25
Battery cell, battery, and electrical device
KR101983391B1
( en )
2019-05-28
Cooling Device for Battery Module and Battery Module Assembly having the same
JP7022307B2
( en )
2022-02-18
Battery module
KR20140064418A
( en )
2014-05-28
Secondary battery module
JP2017531286A
( en )
2017-10-19
Battery pack case with efficient cooling structure
JP2024529370A
( en )
2024-08-06
Batteries and electrical equipment
KR20160106932A
( en )
2016-09-13
Pouch type secondary battery
JP2008282648A
( en )
2008-11-20
Assembled battery
JP2009048965A
( en )
2009-03-05
Battery pack and manufacturing method thereof
CN115917861B
( en )
2025-02-18
Battery, device using battery, method for preparing battery, and preparation equipment
EP4579878A1
( en )
2025-07-02
Battery and electrical device
EP4675730A1
( en )
2026-01-07
Battery, electric device and energy storage device
EP4579879A1
( en )
2025-07-02
Battery and electrical device
CN108023061A
( en )
2018-05-11
Secondary cell
JP2024512829A
( en )
2024-03-21
Batteries, power consumption equipment, battery manufacturing methods and equipment
JP7022308B2
( en )
2022-02-18
Battery module
US20240222758A1
( en )
2024-07-04
Battery, electric apparatus, and method and apparatus for manufacturing battery
EP4468485A1
( en )
2024-11-27
Battery cell, battery module, battery, and power-consuming apparatus
WO2022104546A1
( en )
2022-05-27
Battery, device using battery, preparation method for battery and preparation device thereof
KR20190082180A
( en )
2019-07-09
Secondary Battery Module
EP4293800A1
( en )
2023-12-20
Battery module, batery pack and vehicle comprising same
CN220341278U
( en )
2024-01-12
Battery and electric equipment
EP4456297A1
( en )
2024-10-30
Battery and electrical device
Legal Events
Date
Code
Title
Description
2019-01-17
AS
Assignment
Owner name : TOYOTA JIDOSHA KABUSHIKI KAISHA, JAPAN
Free format text : ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAKAMOTO, TAKUMA;YAMAMOTO, SATOMI;TANIMOTO, KOICHI;AND OTHERS;SIGNING DATES FROM 20181110 TO 20181219;REEL/FRAME:048048/0426
2019-01-17
FEPP
Fee payment procedure
Free format text : ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY
2020-09-14
STPP
Information on status: patent application and granting procedure in general
Free format text : NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS
2020-12-16
STCF
Information on status: patent grant
Free format text : PATENTED CASE
2024-06-19
MAFP
Maintenance fee payment
Free format text : PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY
Year of fee payment : 4