Electrode structure

Abstract

To provide a battery structure that suppresses bias in the surface pressure distribution during restraint and can suppress the increase in complexity and size of a device.SOLUTION: An electrode structure includes: a power storage module laminate in which a plurality of power storage modules are stacked via a cooling structure; and a restraint fixture that restrains the power storage module laminate by applying pressure to the inner side of the lamination direction. The power storage modules adjacent to each other via the cooling structure are electrically connected to each other via the cooling structure. The cooling structure has a cooling channel inside which the refrigerant flows. The cooling structure can be elastically deformed in the lamination direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application relates to an electrode structure.

Background Art

[0002] Conventionally, an electrode structure is known in which a stacked body of power storage modules stacked via a cooling plate is constrained using a restraining jig. In such an electrode structure, since the cooling plate is in contact with the power storage module, even if the power storage module generates heat due to charge and discharge, the heat is transferred to the cooling plate and can be dissipated from the cooling plate.

[0003] As documents disclosing such a battery structure, there are Patent Documents 1 and 2. Patent Documents 1 and 2 disclose a battery structure in which a flow path through which a refrigerant flows is provided in the cooling plate in order to enhance the heat dissipation performance of the cooling plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the above-described electrode structure, the stacked body of power storage modules is constrained by applying pressure inward in the stacking direction to the stacked body of power storage modules using a restraining jig. The restraining jig generally includes restraining plates disposed on both end faces in the stacking direction of the stacked body of power storage modules and restraining members (for example, bolts and nuts) provided at the ends of the restraining plates, and by restraining the restraining plates with the restraining members, it is possible to apply pressure toward the inside in the stacking direction to the stacked body of power storage modules.

[0006] Here, when a restraining pressure is applied to the power storage module laminate by the restraining plate, the pressure applied is greater at the portion closer to the restraining member and smaller at the portion farther from the restraining member, which is a problem. Then, there is a problem that a difference occurs in the pressure applied between the portion close to the restraining member and the portion far from it, resulting in a bias in the surface pressure distribution of the power storage module laminate. The bias in the surface pressure distribution becomes more prominent when a large-area power storage module is used.

[0007] In response to such a problem, in Patent Document 2, an insulating elastic member (for example, rubber) was disposed between the restraining plate and the power storage module to make the surface pressure distribution of the power storage module laminate uniform. However, in a battery structure, an increase in the number of members leads to complication and enlargement of the device, which is not preferable. For example, although reducing the thickness of the elastic member can suppress the enlargement of the device to some extent, the effect of suppressing the bias in the surface pressure distribution is also reduced.

[0008] Therefore, the main object of the present disclosure is to provide a battery structure capable of suppressing the bias in the surface pressure distribution during restraint and suppressing the complication and enlargement of the device.

Means for Solving the Problem

[0009] As one aspect for solving the above problems, the present disclosure provides a power storage module laminate in which a plurality of power storage modules are laminated via a cooling structure, and a restraining jig that applies pressure inward in the lamination direction to restrain the power storage module laminate. Adjacent power storage modules sandwiching the cooling structure are electrically connected via the cooling structure. The cooling structure includes a cooling flow path through which a refrigerant flows inside, and the cooling structure is elastically deformable in the lamination direction.

[0010] In the above electrode structure, the cooling structure may include two plate-like members arranged in the lamination direction, a plurality of struts connecting the two plate-like members, a plurality of deformable struts connected to the two plate-like members and deformable in the lamination direction, and a cooling flow path disposed between the two plate-like members. In this case, the restraining jig includes a restraining plate disposed on both end faces of the power storage module laminate in the stacking direction, and a restraining member that restrains the power storage module laminate by sandwiching it in the stacking direction with the restraining plates, and the restraining member may be disposed at both end portions in the width direction of the restraining plate. Further, the support columns are disposed at portions other than both end portions in the width direction of the region sandwiched between the two plate-like members, and the deformable support columns may be disposed at both end portions in the width direction of the region.

[0011] Alternatively, in the above electrode structure, the restraining jig includes a restraining plate disposed on both end faces of the power storage module laminate in the stacking direction, and a restraining member that restrains the power storage module laminate by sandwiching it in the stacking direction with the restraining plates, and the restraining member is disposed at both end portions in the width direction of the restraining plate. The cooling structure includes two plate-like members arranged in the stacking direction, a plurality of support columns connecting the two plate-like members, and a cooling flow path disposed between the two plate-like members. The support columns may be disposed at portions other than both end portions in the width direction of the region sandwiched between the two plate-like members. In this case, the entire cooling flow path may be filled with a mesh-like metal member.

[0012] In the above electrode structure, the difference between the maximum surface pressure and the minimum surface pressure in the surface pressure distribution of the power storage module laminate may be in the range of 40 kPa to 160 kPa.

Advantages of the Invention

[0013] According to the electrode structure of the present disclosure, since a cooling structure that is elastically deformable in the stacking direction is disposed between the power storage modules, it is possible to suppress the unevenness of the surface pressure distribution of the power storage module laminate during restraint while ensuring heat dissipation. Further, in order to suppress the unevenness of the surface pressure distribution, it is not necessary to dispose a new member as in Patent Document 2, so the number of members can be reduced. Therefore, according to the electrode structure of the present disclosure, it is possible to suppress the complication and enlargement of the device.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0015] Hereinafter, the electrode structure of the present disclosure will be described using one embodiment.

[0016] [Electrode Structure 100] A cross-sectional view of the electrode structure 100 is shown in FIG. 1. Hereinafter, the left-right direction in FIG. 1 will be referred to as the width direction, the up-down direction as the stacking direction, and the back-front direction as the length direction for explanation.

[0017] The electrode structure 100 includes a power storage module stack 30 in which a plurality of power storage modules 10 are stacked via a cooling structure 20, and a restraint jig 40 that applies pressure to the inside in the stacking direction to restrain the power storage module stack 30.

[0018] [Power Storage Module 10] As shown in FIG. 1, the electrode structure 100 includes two power storage modules 10. As shown in FIG. 1, among the two power storage modules 10, the power storage module 10 arranged on the upper side in the stacking direction is referred to as the first power storage module 10a, and the power storage module 10 arranged on the lower side in the stacking direction is referred to as the second power storage module 10b.

[0019] The power storage module 10 has a plurality of electrodes and a plurality of electrolyte layers, and the electrodes and the electrolyte layers are alternately laminated. The power storage module 10 may be a non-aqueous secondary battery or an all-solid-state secondary battery. Further, from the viewpoint of output improvement, the power storage module 10 may be a bipolar-type power storage module. The shape of the power storage module 10 is not particularly limited, but may be, for example, a substantially rectangular shape when viewed in the stacking direction. Hereinafter, the case where the power storage module 10 is a bipolar-type power storage module will be exemplified.

[0020] Fig. 2 shows a cross-sectional view of an end portion of the power storage module 10. As shown in Fig. 2, the power storage module 10 includes an electrode laminate 18 and a sealing member 19 provided on the entire side surface of the electrode laminate 18. Further, the power storage module 10 includes a non-aqueous electrolyte inside.

[0021] (Electrode laminate 18) The electrode laminate 18 includes a plurality of bipolar electrodes 14 and a plurality of separators 15, and the bipolar electrodes 14 and the separators 15 are alternately laminated. The number of the bipolar electrodes 14 and the separators 15 is not particularly limited and may be appropriately set according to the target battery performance. Further, the electrode laminate 18 further includes an end positive electrode 16 disposed at the upper end portion in the stacking direction and an end negative electrode 17 disposed at the lower end portion in the stacking direction.

[0022] The bipolar electrode 14 includes a current collector 11, a positive electrode layer 12 disposed on the lower surface of the current collector 11, and a negative electrode layer 13 disposed on the upper surface of the current collector 11. Thus, the bipolar electrode 14 has electrode layers of different polarities on both surfaces of the current collector 11.

[0023] The current collector 11 is a sheet-shaped conductive member. Examples of the current collector 11 include metal foils such as stainless steel, iron, copper, aluminum, titanium, and nickel. The metal foil may be made of an alloy containing two or more of these metals. Further, the metal foil may be subjected to surface treatment such as predetermined plating. The current collector 11 may be composed of a plurality of metal foils. In this case, the metal foils may be joined with an adhesive or the like, or may be joined by pressing or the like. The shape of the current collector 11 is not particularly limited, but may be, for example, a substantially rectangular shape. The thickness of the current collector 11 is not particularly limited, but is, for example, 5 μm or more and 70 μm or less.

[0024] The positive electrode layer 12 contains a positive electrode active material. The positive electrode active material is not particularly limited and may be appropriately selected from known materials according to the intended battery performance. For example, composite oxides, metal lithium, sulfur, and the like can be mentioned. The composition of the composite oxide includes, for example, at least one of iron, manganese, titanium, nickel, cobalt, and aluminum, and lithium. Examples of the composite oxide include olivine-type lithium iron phosphate (LiFePO 4 ) and the like.

[0025] The positive electrode layer 12 may optionally contain a conductive assistant. The conductive assistant is not particularly limited and may be appropriately selected from known materials according to the intended battery performance. For example, carbon materials such as acetylene black, carbon black, and graphite can be mentioned.

[0026] The positive electrode layer 12 may optionally contain a binder. The binder is not particularly limited and may be appropriately selected from known materials according to the intended battery performance. For example, fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber; thermoplastic resins such as polypropylene and polyethylene; imide resins such as polyimide and polyamideimide; acrylic resins such as alkoxysilyl group-containing resins and poly(meth)acrylic acid; styrene-butadiene rubber (SBR); carboxymethyl cellulose; alginates such as sodium alginate and ammonium alginate; water-soluble cellulose ester cross-linked bodies; starch-acrylic acid graft polymers, and the like can be mentioned.

[0027] The shape of the positive electrode layer 12 is not particularly limited and may be a substantially rectangular shape. The thickness of the positive electrode layer 12 is not particularly limited and is, for example, in the range of 1 μm to 1 mm. The area of the positive electrode layer 12 may be made smaller than that of the negative electrode layer 13. The content of each material in the positive electrode layer 12 is not particularly limited and may be appropriately set according to the target battery performance. Note that the positive electrode layer 20 may contain materials other than those described above.

[0028] The negative electrode layer 13 contains a negative electrode active material. The negative electrode active material is not particularly limited and may be appropriately selected from known materials according to the target battery performance. Examples include carbon such as graphite, artificial graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, and soft carbon, metal compounds, elements or compounds alloyable with lithium, and boron-added carbon. Examples of elements alloyable with lithium include silicon and tin.

[0029] The negative electrode layer 13 may optionally contain a conductive assistant. The conductive assistant is not particularly limited and may be appropriately selected from known materials according to the target battery performance. For example, it may be appropriately selected from the conductive assistants applicable to the positive electrode layer 12.

[0030] The negative electrode layer 13 may optionally contain a binder. The binder is not particularly limited and may be appropriately selected from known materials according to the target battery performance. For example, it may be appropriately selected from the binders applicable to the positive electrode layer 12.

[0031] The shape of the negative electrode layer 13 is not particularly limited and may be a substantially rectangular shape. The thickness of the negative electrode layer 13 is not particularly limited and is, for example, in the range of 1 μm to 1 mm. From the viewpoint of improving the output, the area of the negative electrode layer 13 may be made larger than that of the positive electrode layer 12. The content of each material in the negative electrode layer 13 is not particularly limited and may be appropriately set according to the target battery performance. Note that the negative electrode layer 13 may contain materials other than those described above.

[0032] The method for manufacturing the bipolar electrode 14 is not particularly limited, and a known method may be adopted. For example, for example, the materials constituting the electrode layer (positive electrode layer 12 or negative electrode layer 13) are mixed in a mortar or the like and pressed to obtain the electrode layer, and the obtained electrode layer may be disposed on each surface of the current collector 11. Alternatively, after mixing the materials constituting the electrode layer with a solvent to obtain a slurry, the slurry may be applied and dried on each surface of the current collector 11.

[0033] The separator 15 is disposed between adjacent bipolar electrodes 14, between the bipolar electrode 14 and the end positive electrode 17, and between the bipolar electrode 14 and the end negative electrode 18. The separator 15 is a sheet-like member and is a member for preventing short circuit between electrode layers. The material of the separator 15 is not particularly limited, and examples thereof include porous films and non-woven fabrics made of polyolefin resins such as polyethylene (PE) and polypropylene (PP). The shape of the separator 15 is not particularly limited and may be a substantially rectangular shape. The thickness of the separator 15 is not particularly limited and is, for example, in the range of 1 μm to 1 mm.

[0034] The separator 15 is impregnated with a non-aqueous electrolyte and thereby functions as an electrolyte layer. The non-aqueous electrolyte contains a non-aqueous solvent and an electrolyte (supporting salt). The non-aqueous solvent is not particularly limited, and examples thereof include cyclic carbonates, cyclic esters, chain carbonates, chain esters, ethers, and the like. The supporting salt is, for example, a lithium salt. The lithium salt is, for example, LiBF 4 , LiPF 6 , LiN(FSO 2 ) 2 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 and the like. The non-aqueous solvent and the indicator salt may be used singly or in combination of a plurality of types.

[0035] The end positive electrode 16 has a current collector 11 and a positive electrode layer 12 disposed on the lower surface of the current collector 11. The end positive electrode 16 is disposed at the upper end portion of the electrode laminate 18 in the stacking direction. Further, the end positive electrode 16 is stacked on the separator 15 such that the positive electrode layer 12 of the end positive electrode 16 faces the negative electrode layer 13 of the bipolar electrode 14.

[0036] The end negative electrode 17 has a current collector 11 and a negative electrode layer 13 disposed on the upper surface of the current collector 11. The end negative electrode 17 is disposed at the lower end portion of the electrode laminate 18 in the stacking direction. Specifically, the end negative electrode 17 is stacked on the separator 15 such that the negative electrode layer 13 of the end negative electrode 17 faces the positive electrode layer 12 of the bipolar electrode 14.

[0037] The method for manufacturing the end positive electrode 16 and the end negative electrode 17 is not particularly limited, and known methods may be appropriately employed. For example, a method similar to the method for manufacturing the bipolar electrode 14 described above may be employed.

[0038] (Sealing member 19) The sealing member 19 is provided on the entire side surface of the electrode laminate 18, and is a member that holds the plurality of bipolar electrodes 14, the end positive electrode 16, and the end negative electrode 17, and is a resin having insulating properties. Further, the sealing member 19 is also a member for sealing the electrolytic solution in the internal space of the power storage module 10.

[0039] The material of the sealing member 19 includes, for example, a resin member exhibiting heat resistance. Examples of the resin member exhibiting heat resistance include polyimide, polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), and PA66.

[0040] (Manufacturing method of the power storage module 10) A manufacturing method of the power storage module 10 will be described using an example. First, a sheet-shaped sealing member (sealing member sheet) is arranged in advance on each current collector 11. Specifically, the sealing member sheet is arranged so as to surround the outer edge of the current collector 11, and the sealing member sheet is joined to the current collector 11. Next, using the current collector 11 on which the sealing member sheet is arranged, the bipolar electrode 14, the end positive electrode 16, and the end negative electrode 17 are manufactured. These obtained electrodes and the separator 15 are laminated to manufacture the electrode laminate 18. Subsequently, a plurality of sealing member sheets provided on the side surface of the electrode laminate 18 are joined to form the sealing member 19. Then, by injecting a non-aqueous electrolyte into the internal space of the sealed power storage module 10, the power storage module 10 is obtained.

[0041] Alternatively, the sealing member 19 is arranged on each side surface of the electrode laminate 18 by injection molding, and the power storage module 10 is obtained by injecting a non-aqueous electrolyte into the internal space of the sealed power storage module 10.

[0042] <Cooling structure 20> The cooling structure 20 is disposed between the power storage modules 10, and the power storage modules 10 adjacent to each other with the cooling structure 20 therebetween are electrically connected via the cooling structure 20. Thereby, the power storage module laminate 50 is electrically connected as a whole. Further, the cooling structure 20 is provided with a cooling flow path 24 through which a refrigerant flows inside. Thus, the heat generated by charging and discharging of the power storage module 10 can be transferred to the cooling structure 20 and exchange heat with the refrigerant in the cooling flow path 24, so that the cooling structure 20 has high heat dissipation and temperature controllability. Furthermore, the cooling structure 20 has a structure that can be elastically deformed in the stacking direction. Thereby, it is possible to suppress the deviation of the surface pressure distribution of the power storage module laminate 50 during restraint. As described above, when adopting the bipolar type power storage module 10, the power storage module 10 may be enlarged in order to improve the output. As the power storage module 10 becomes larger, the deviation of the surface pressure distribution during restraint becomes more prominent. Therefore, the battery structure 100 is a suitable structure when including a large power storage module 10 (for example, a power storage module having a length in the width direction of 1 m or more and 3 m or less and a length in the length direction of 1 m or more and 3 m or less). The detailed structure of the cooling structure 20 will be described below.

[0043] Fig. 3 shows a cross-sectional view of the cooling structure 20. As shown in Fig. 3, the cooling structure 20 includes two plate-like members 21 arranged in the stacking direction, a plurality of struts 22 connecting the two plate-like members 21, a plurality of deformable struts 23 connected to the two plate-like members 21 and deformable in the stacking direction, and a cooling flow path 24 disposed between the two plate-like members 21.

[0044] (Plate-like member 21) The plate-like member 21 is a plate-like member having a substantially rectangular shape. The plate-like member 21 may be made of a material having conductivity. For example, metal materials such as iron, copper, and stainless steel can be mentioned. As shown in Fig. 3, among the two plate-like members 21, the plate-like member 21 disposed on the upper side in the stacking direction is defined as the first plate-like member 21a, and the plate-like member 21 disposed on the lower side in the stacking direction is defined as the second plate-like member 21b.

[0045] The area of the plate-like member 21 may be smaller or larger than the area of the power storage module 10. However, as will be described later, since the cooling structure 20 is a member for suppressing the non-uniformity of the surface pressure distribution of the power storage module laminate 30 during restraint, the area of the plate-like member 21 is made equal to or larger than the area of the power storage module 10. Specifically, the area of the plate-like member 21 may be 90% or more and 200% or less of the area of the power storage module 10, or may be 100% or more and 150% or less. The thickness of the plate-like member 21 is not particularly limited, but is set to a thickness that can be elastically deformed in the stacking direction by the restraint pressure applied by the restraint jig 40. For example, the thickness of the plate-like member 21 may be 2 mm or more and 20 mm or less.

[0046] (Support pillar 22) The support pillar 22 is a rod-shaped member extending in the stacking direction and is connected to two plate-like members 21. The plurality of support pillars 22 are arranged in a region sandwiched between the two plate-like members 21, at portions other than both end portions in the width direction. That is, the plurality of support pillars 22 are arranged at the central portion in the width direction of the region. Thereby, the plurality of support pillars 22 support the two plate-like members 21. The support pillar 22 may be made of a material having conductivity. For example, a metal material that can be adopted for the plate-like member 21 can be mentioned. The upper end portion of the support pillar 22 is connected to the lower surface of the first plate-like member 21a, and the lower end portion is connected to the upper surface of the second plate-like member 21a. Therefore, the first plate-like member 21a and the second plate-like member 21b are electrically connected via the support pillar 22.

[0047] (Deformable support pillar 23) The deformable support pillar 23 is a rod-shaped member that can be elastically deformed in the stacking direction and is connected to two plate-like members 21. As shown in FIG. 3, the deformable support pillar 23 has an S-shaped leaf spring structure. Specifically, the deformable support pillar 23 has portions 23a and 23b extending in the stacking direction and a portion 23c extending in the width direction. The upper end portion of the portion 23a is connected to the first plate-like member 21a, and the lower end portion is connected to one end of the portion 23c. Also, the lower end portion of the portion 23b is connected to the second plate-like member 21b, and the upper end portion is connected to the other end of the portion 23c. How the deformable support pillar 23 elastically deforms in the stacking direction will be described later.

[0048] The material of the deformable support column 23 is not particularly limited as long as it can be elastically deformed as described later. That is, the deformable support column 23 may or may not have conductivity. This is because the two plate-like members 21 are electrically connected via the support column 22. For example, the material of the deformable support column 23 may be a resin material or a metal material. From the viewpoint of ease of manufacturing, it may be composed of the same metal material as the support column 22.

[0049] The deformable support columns 23 are arranged at both end portions in the width direction in the region sandwiched between the two plate-like members 21. The end portions in the width direction in the region sandwiched between the two plate-like members 21 are in the range of 10% to 30% from the outer edge in the width direction of the region toward the inside in the width direction based on the length in the width direction of the region (the length in the width direction of the plate-like member 21). As will be described later, the range in which the deformable support columns 23 are arranged is appropriately adjusted so as to suppress the deviation of the surface pressure distribution. The degree of elastic deformation of the deformable support columns 23 in the stacking direction may be appropriately set according to the surface pressure distribution at the time of restraint. For example, the degree of elastic deformation of the deformable support columns 23 in the stacking direction can be appropriately adjusted by changing the material and thickness of the deformable support columns 23.

[0050] (Cooling channel 24) The cooling channel 24 is a channel through which a refrigerant can flow, and is formed between the two plate-like members 21. Specifically, the cooling channel 24 is a region sandwiched between the two plate-like members 21 and is a region other than the support columns 22 and the deformable support columns 23. That is, the cooling channel 24 is a channel formed in the gaps between the support columns 22, the gaps between the deformable support columns 23, the gaps between the support columns 22 and the deformable support columns 23, etc. The refrigerant is usually air. In addition, when using a cooling channel 24 having an elastic structure in which portions other than the inlet and outlet are sealed, an insulating liquid such as a fluorine-based insulating liquid may be used.

[0051] <Electrode laminate 30> The electrode laminate 30 is a laminate of the power storage module 10 and the cooling structure 20. Specifically, the first power storage module 10a is disposed above the cooling structure 20 in the stacking direction, and the second power storage module 10b is disposed below the cooling structure 20 in the stacking direction. Thus, the cooling structure 20 is sandwiched between the first power storage module 10a and the second power storage module 10b. More specifically, the current collector 11 of the end negative electrode 17 of the first power storage module 10a is in contact with the upper surface of the first plate-like member 21a of the cooling structure 20, and the current collector 11 of the end positive electrode 16 of the second power storage module 10a is in contact with the lower surface of the second plate-like member 21b of the cooling structure 20. As described above, since the cooling structure 20 has conductivity, the first power storage module 10a and the second power storage module 10b are electrically connected via the cooling structure 20.

[0052] <Constraint jig 40> The constraint jig 40 is a member that applies pressure inward in the stacking direction to constrain the power storage module laminate 30 and ensure contact between the power storage module 10 and the cooling structure 20 and contact between the electrodes in the power storage module 10. As shown in FIG. 1, the constraint jig 40 includes a constraint plate 41 disposed on both end faces of the power storage module laminate 30 in the stacking direction, and a constraint member 42 that constrains the power storage module laminate 30 so as to sandwich it in the stacking direction.

[0053] (Constraint plate 41) The constraint plate 41 has a substantially rectangular shape and serves to sandwich the power storage module laminate 30 from the stacking direction. The constraint plate 41 may be subjected to a predetermined insulation treatment in order to prevent it from being electrically connected to the power storage module laminate 30. Alternatively, an insulating resin member may be disposed between the constraint plate 41 and the power storage module laminate 30. The area of the constraint plate 41 may be larger than the area of the power storage module 10 disposed on the end face of the power storage module laminate 30. Specifically, the area of the constraint plate 41 may be more than 100% and not more than 200% of the area of the power storage module 10, or may be not less than 120% and not more than 150%.

[0054] (Constraint member 42) The restraining member 42 is disposed at both end portions in the width direction of the restraining plate 41, and is a member that restrains the two restraining plates 41 so as to apply a pressure toward the inside in the stacking direction to the power storage module laminate 30. The "end portion in the width direction of the restraining plate 41" means an end portion in the width direction of the restraining plate 41 that exceeds the power storage module laminate 30. In other words, in the stacking direction view, it is an end portion in the width direction of the restraining plate 41 that does not overlap with the power storage module laminate 30.

[0055] The configuration of the restraining member 42 is not particularly limited as long as it can apply a restraining pressure toward the inside in the stacking direction to the power storage module laminate 30 sandwiched between the restraining plates 41. In FIG. 1, a restraining member 42 having a bolt 42a and a nut 42b is illustrated. The restraining pressure applied to the power storage module laminate 30 can be adjusted by adjusting the tightening strength of the nut 42b.

[0056] <Suppression of bias in surface pressure distribution> As described above, the restraining jig 40 has restraining members 42 at both end portions in the width direction of the restraining plate 41, and the restraining members 42 apply a pressure toward the inside in the stacking direction to the power storage module laminate 30. For this reason, the power storage module laminate 30 is applied with a higher surface pressure at a position closer to the restraining member 42 and a lower surface pressure at a position farther away. Therefore, when using a laminate in which only the power storage modules 10 are stacked, a bias occurs in the surface pressure distribution.

[0057] Therefore, in the battery structure 100, a power storage module laminate 30 in which a plurality of power storage modules 10 are stacked is used via the cooling structure 20. As described above, the cooling structure 20 is provided at both end portions in the width direction of the region where the deformable struts 23 are sandwiched between the two plate-like members 21. The deformable strut 23 has a leaf spring structure and is elastically deformable in the stacking direction. Therefore, both end portions in the width direction of the cooling structure 20 are also elastically deformable in the stacking direction.

[0058] Fig. 4 is an enlarged view of the end portion of the cooling structure 20 in the width direction, showing the state in which the deformable support column 23 is elastically deformed in the stacking direction. Fig. 4 shows the state of the cooling structure 20 before and after the restraint pressure is applied by the restraint jig 40. When the restraint pressure is applied by the restraint jig 40, the cooling structure 20 elastically deforms as shown in the lower figure from the upper figure in Fig. 4. Specifically, since a higher restraint pressure is applied to the end portion in the width direction of the plate-like member 21 than to the central portion, it elastically deforms so as to warp inward in the stacking direction. Along with this, the portion 23c of the deformable support column 23 also elastically deforms so as to warp. Since the support column 22 does not elastically deform in the stacking direction, its shape is maintained. Therefore, when looking at the entire cooling structure 20, both end portions in the width direction of the cooling structure 20 elastically deform in the stacking direction.

[0059] By including such a cooling structure 20, the electrode structure 100 can suppress the deviation of the surface pressure distribution due to the elastic deformation of the cooling structure 20 even when a restraint pressure is applied to the power storage module laminate 30 by the restraint jig 40.

[0060] The surface pressure distribution of the power storage module laminate 30 can be measured by using a known surface pressure distribution measuring device. Specifically, a surface pressure distribution sensor is inserted between the restraint plate 41 and the power storage module laminate 30, and the surface pressure distribution of the power storage module laminate 30 can be measured by applying a restraint pressure in that state.

[0061] The suppression of the deviation of the surface pressure distribution, which is the effect of the electrode structure 100, can be confirmed by comparing the case with the cooling structure 20 provided and the case without it. Specifically, the surface pressure distributions of both are compared, and when the difference between the maximum surface pressure and the minimum surface pressure becomes smaller in the surface pressure distribution, it is determined that the deviation of the surface pressure distribution is suppressed. When the difference between the maximum surface pressure and the minimum surface pressure is within the range of 40 kPa to 160 kPa, it can be determined that the deviation of the surface pressure distribution is significantly suppressed.

[0062] <Suppressing the complication and enlargement of the device> As described above, the cooling structure 20 has heat dissipation properties and elastic deformability, and is a member that combines the role of a conventional cooling plate and the role of an elastic member. Therefore, in the electrode structure 100, it is not necessary to use these members separately, so it is possible to suppress the complication and enlargement of the device.

[0063] <Other forms of the cooling structure 20> Other forms of the cooling structure 20 will be described. Cross-sectional views of the cooling structures 120, 220, and 320 are shown in FIGS. 5(A) to 5(C), respectively.

[0064] First, the cooling structure 120 shown in FIG. 5(A) will be described. The cooling structure 120 has the same configuration as the cooling structure 20, except that the deformable support 23 is changed to the deformable support 123. The deformable support 123 has a structure excluding the portion 23c from the deformable support 23 and is deformable in the stacking direction. Further, the deformable support 123 does not prevent the deformation even when the end portion in the width direction of the plate-like member 21 is elastically deformed by the restraint pressure. Therefore, the degree of elastic deformation of the cooling structure 120 depends on the degree of elastic deformation of the plate-like member 21. Comparing the cooling structure 120 with the cooling structure 20, the cooling structure 120 does not include the deformable support 23 having a leaf spring structure, which increases the difficulty of adjusting the degree of its elastic deformation. On the other hand, the cooling structure 120 sufficiently has the effect of suppressing the deviation of the surface pressure distribution of the power storage module laminate.

[0065] Next, the cooling structure 220 shown in FIG. 5(B) will be described. The cooling structure 220 has the same configuration as the cooling structure 20, except that the deformable support 23 is removed from the cooling structure 20. Similar to the cooling structure 120, the cooling structure 220 does not prevent the elastic deformation of the end portion in the width direction of the plate-like member 21 due to the restraint pressure. Therefore, similar to the cooling structure 120, the cooling structure 220 has the effect of suppressing the deviation of the surface pressure distribution of the power storage module laminate. Further, since the cooling structure 220 does not include a deformable support, the manufacturing cost can be reduced.

[0066] Next, the cooling structure 320 shown in FIG. 5(C) will be described. The cooling structure 320 has a structure in which the entire cooling flow path 24 of the cooling structure 220 is filled with a mesh-shaped metal member 325. The material of the mesh-shaped metal member 325 is not particularly limited, and examples thereof include iron, copper, and stainless steel. Since the mesh-shaped metal member 325 has elasticity, it substitutes for the role of the deformable support column 23. Therefore, similar to the cooling structure 120, the cooling structure 320 has the effect of suppressing the deviation of the surface pressure distribution of the power storage module laminate.

[0067] As shown in FIG. 5(C), although the metal member 325 is filled in the entire cooling flow path 24, it may be arranged only at both ends in the width direction in the region sandwiched between the two plate-like members. However, when the metal member 325 is arranged only at both ends in the width direction in the said region, since the refrigerant becomes difficult to flow in the region where the metal member 325 is arranged compared with the region where it is not arranged, there is a possibility that the heat dissipation property of the cooling structure 320 may decrease. From this point of view, it is preferable that the metal member 325 is filled in the entire cooling flow path 24. However, this is not the case when the electrode structure includes a mechanism or device capable of controlling the flow of the refrigerant.

[0068] [Supplementary Explanation] In one embodiment, two power storage modules 10a and 10b were used, but the electrode structure of the present disclosure is not limited to this, and the number of power storage modules may be two or more. The number of power storage modules may be appropriately set according to the intended performance. When the number of power storage modules is three or more, the cooling structure may be arranged in at least one of the stacked power storage modules, or may be arranged in each of the stacked power storage modules.

[0069] In one embodiment, in the region sandwiched between two plate-like members 21, the support column 22 is disposed at the central portion in the width direction, and the deformable support columns are disposed at both ends in the width direction. This is because the restraining members 42 are disposed at both ends in the width direction of the restraining plate 41. However, in the electrode structure of the present disclosure, the position of the restraining member is not limited to both ends in the width direction of the restraining plate, and any position where a restraining pressure can be applied to the power storage module laminate may be used. Therefore, in the electrode structure of the present disclosure, the positions of the support column and the deformable support columns are not limited either, and may be appropriately set according to the deviation of the surface pressure distribution of the power storage module laminate.

[0070] As described above, the electrode structure of the present disclosure has been described using one embodiment. According to the electrode structure of the present disclosure, it is possible to suppress the deviation of the surface pressure distribution of the power storage module laminate during restraint. In addition, in order to suppress the deviation of the surface pressure distribution, it is not necessary to arrange a new member as in Patent Document 2, so the number of members can be reduced. Therefore, according to the electrode structure of the present disclosure, it is possible to suppress the complication and enlargement of the device.

Description of Reference Numerals

[0071] 10 Power storage module 10a First power storage module 10b Second power storage module 11 Current collector 12 Positive electrode layer 13 Negative electrode layer 14 Bipolar electrode 15 Separator 16 End positive electrode 17 End negative electrode 18 Electrode laminate 19 Sealing member 20, 120, 220, 320 Cooling structure 21 Plate-like member 21a First plate-like member 21b Second plate-like member 22 Support column 23, 123 Deformable support column 24 Cooling flow path 30 Power storage module laminate 40 Constraint Fixture 41 Constraint Plate 42 Constraint Member 100 Battery Structure 325 Metal Member

Claims

1. A laminated structure comprising a first plate-like member and a second plate-like member aligned in the stacking direction, and a plurality of deformable struts connecting the two plate-like members; the plurality of deformable struts include a first deformable strut and a second deformable strut arranged adjacent to each other in a width direction; the deformable support includes a portion extending in a first stacking direction and having one end connected to the first plate-like member, a portion extending in a second stacking direction and having one end connected to the second plate-like member, and a portion extending in a width direction connecting the portion extending in the first stacking direction and the portion extending in the second stacking direction, the other end of the portion extending in the first stacking direction and the other end of the portion extending in the second stacking direction are connected to the portion extending in the width direction, forming a step in the deformable support; A cooling structure, wherein the steps of the first deformable strut and the adjacent second deformable strut face in the same direction.

2. The connection point of the first deformable support with the first plate-like member and the connection point of the first deformable support with the second plate-like member are arranged offset in the width direction, a connection point of the second deformable strut with the first plate-like member and a connection point of the second deformable strut with the second plate-like member are disposed so as to be offset in the width direction, a connection point of the first deformable strut with the first plate-like member and a connection point of the second deformable strut with the second plate-like member are disposed so as to be offset in the width direction, a connection point of the first deformable strut with the second plate-like member and a connection point of the second deformable strut with the first plate-like member are arranged to be offset in the width direction; The cooling structure of claim 1 .

3. At least a part of the connection between the portion extending in the first stacking direction and the portion extending in the width direction is closer to the second plate-like member than at least a part of the connection between the portion extending in the second stacking direction and the portion extending in the width direction; 2. The cooling structure of claim 1, wherein at least a portion of a connection between the portion extending in the second stacking direction and the portion extending in the width direction is positioned closer to the first plate-shaped member than at least a portion of a connection between the portion extending in the first stacking direction and the portion extending in the width direction.

4. A cooling structure as described in claim 1, wherein the widthwise distance between the portion extending in the widthwise direction of the first deformable support and the portion extending in the widthwise direction of the second deformable support is shorter than the widthwise distance between the portion extending in the first stacking direction of the first deformable support and the portion extending in the first stacking direction of the second deformable support.

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