Battery

Abstract

The invention provides a battery. The present invention is provided with: a resin frame body which is provided on the outer periphery of a laminated body so as to be connected to a current collector foil, which is a region where a positive electrode active material layer and a negative electrode active material layer are not formed, of a current collector of the bipolar electrode, said region being a region where the positive electrode active material layer and the negative electrode active material layer are not formed; and a separator comprising an insulating material, the separator being positioned between the current collector foil and the separator so that the distance in the orthogonal direction, which is the direction orthogonal to the stacking direction of the positive electrode active material layer and the negative electrode active material layer, is longer than the distance in the orthogonal direction to the housing.

Description

Technical Field

[0001] The present invention relates to batteries. Background Art

[0002] In the following Japanese Patent Laid-Open No. 2018-049794, a battery is disclosed in which a plurality of electrodes including bipolar electrodes and a plurality of separators located between adjacent electrodes are stacked in a predetermined stacking direction. The bipolar electrode has a current collector, a positive electrode active material layer formed on one side of the current collector and having an outer peripheral end located closer to the inner peripheral side than the outer peripheral end of the current collector, and a negative electrode active material layer formed on the other side of the current collector and having an outer peripheral end located closer to the inner peripheral side than the outer peripheral end of the current collector. Furthermore, the battery comprises: a frame made of resin arranged on the outer periphery of the stack in a manner connected to the collector foil where the positive electrode active material layer and the negative electrode active material layer are not formed on each current collector. Furthermore, the battery has a separator located between adjacent collector foils and connected to the inner peripheral surface of the frame. Summary of the invention

[0003] The separator of the battery of the above-mentioned Japanese Patent Publication No. 2018-049794 is connected to the inner peripheral surface of the frame. That is, the distance from the positive electrode active material layer and the negative electrode active material layer to the separator is long. Therefore, when an external force is applied to the battery, the collector foil of at least one collector is deformed at a short distance to the positive electrode active material layer and the negative electrode active material layer, and there is a possibility of penetrating the separator and contacting the collector foil of other collectors. In such a manner, when two collector foils are short-circuited, the positive electrode active material layer and the negative electrode active material layer are prone to high temperature due to the heat generated by the short circuit.

[0004] The present invention has been made in consideration of the above facts, and an object of the present invention is to provide a battery in which a short circuit between two current collector foils that tends to increase the temperature of the positive electrode active material layer and the negative electrode active material layer is unlikely to occur when an external force is applied.

[0005] A battery according to a first aspect includes a stacked body formed by stacking a plurality of bipolar electrodes and a plurality of separators in a predetermined stacking direction.

[0006] The plurality of bipolar electrodes have:

[0007] Current collector;

[0008] a positive electrode active material layer formed on one surface of the current collector and having an outer peripheral end portion located further inward than an outer peripheral end portion of the current collector; and

[0009] a negative electrode active material layer formed on the other surface of the current collector and having an outer peripheral end located further inward than an outer peripheral end of the current collector,

[0010] The plurality of separators are located between the positive electrode active material layer and the negative electrode active material layer.

[0011] The battery has:

[0012] a resin frame provided on the outer periphery of the stacked body so as to be connected to a portion of each of the current collectors where the positive electrode active material layer and the negative electrode active material layer are not formed, that is, a current collector foil; and

[0013] A separator made of an insulating material is located between the collector foil and the separator such that a distance to the positive electrode active material layer and the negative electrode active material layer in a direction perpendicular to the stacking direction is longer than a distance to the frame in the direction perpendicular to the stacking direction.

[0014] When an external force is applied to the battery of the first embodiment, the collector foil of at least one collector may be deformed, penetrate the separator and contact the other collector foil. At this time, the separator composed of an insulating material located between the collector foil and the separator prevents the portion of the collector foil that is short in the orthogonal direction to the positive electrode active material layer and the negative electrode active material layer from contacting the other collector foil. Therefore, when an external force is applied to the battery of the first embodiment, a short circuit that makes the positive electrode active material layer and the negative electrode active material layer easily heated is unlikely to occur between the two collector foils.

[0015] The battery of the second aspect is characterized in that in the first aspect,

[0016] The outer peripheral end of the negative electrode active material layer is located further outward than the outer peripheral end of the positive electrode active material layer.

[0017] The separator is provided on the current collector so as to face the positive electrode active material layer from the outer peripheral side in the orthogonal direction.

[0018] At least a portion of the separator and the outer peripheral end of the negative electrode active material layer are aligned in the stacking direction.

[0019] In the battery of the second embodiment, the distance between the separator and the positive electrode active material layer in the orthogonal direction is short. Therefore, when external force is applied to the battery of the second embodiment, a short circuit is unlikely to occur between the two current collector foils, which may easily increase the temperature of the positive electrode active material layer.

[0020] A battery according to a third aspect is a battery according to the first aspect or the second aspect,

[0021] The separator and the positive electrode active material layer have the same dimensions in the stacking direction.

[0022] According to the third embodiment, compared with the case where the dimension of the separator in the stacking direction is smaller than the dimension of the positive electrode active material layer in the stacking direction, when external force is applied to the battery, a short circuit that causes the positive electrode active material layer and the negative electrode active material layer to easily heat up is less likely to occur between the two collector foils.

[0023] A battery according to a fourth aspect is a battery according to the first aspect or the second aspect,

[0024] A sealing material independent of the separator is provided between a part of the current collector and the frame to seal the space between the current collector and the frame in a liquid-tight state.

[0025] According to the fourth aspect, a portion of the current collector and the frame are sealed in a liquid-tight state by a sealing material independent of the spacer.

[0026] The battery according to the fifth aspect is, in the first aspect or the second aspect,

[0027] When observing the battery along the stacking direction, the distance in the orthogonal direction between the outer peripheral surface of the separator located between the positive electrode active material layer or the negative electrode active material layer and the frame and the outer peripheral surface of the negative electrode active material layer is more than 10 times the distance in the stacking direction between adjacent collectors.

[0028] According to the fifth embodiment, compared with the case where the distance in the orthogonal direction between the outer surface of the separator located between the positive electrode active material layer or the negative electrode active material layer and the frame and the outer surface of the negative electrode active material layer is less than 10 times the distance in the stacking direction between adjacent collectors, when external force is applied to the battery, it is difficult for a short circuit to occur between the two collector foils, which would cause the positive electrode active material layer and the negative electrode active material layer to easily become hot.

[0029] As described above, the battery according to the present invention has an excellent effect that when an external force is applied to the battery, a short circuit that tends to increase the temperature of the positive electrode active material layer and the negative electrode active material layer is unlikely to occur between the two current collector foils. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0031] Figure 1 It is a schematic perspective view of a bipolar lithium ion secondary battery according to an embodiment.

[0032] Figure 2 It is along Figure 1 Schematic cross-sectional view of the 2-2 line.

[0033] Figure 3 It is a perspective view showing a bipolar electrode and a separator in a separated state.

[0034] Figure 4 This is a schematic cross-sectional view of a portion of a battery according to a first modification.

[0035] Figure 5 It is a schematic cross-sectional view of a portion of a battery according to a second modification.

[0036] Figure 6 It is a schematic cross-sectional view of a portion of a battery according to a third modification. DETAILED DESCRIPTION

[0037] The following describes a bipolar lithium-ion secondary battery (hereinafter referred to as battery 10) according to an embodiment. Battery 10 can be mounted on various devices. Battery 10 according to this embodiment is mounted on a battery electric vehicle (BEV) and can supply power to an electric motor as a driving source. In addition, arrows UP, FR, and LH in the drawings respectively indicate the upper side in the up-down direction, the front side in the front-back direction, and the left side in the left-right direction.

[0038] First, a basic structure of the battery 10 will be described. The battery 10 of the present embodiment includes a laminate 15 and a resin member (frame) 30 .

[0039] The stacked body 15 is in a predetermined stacking direction ( Figure 1 The electrode is composed of a plurality of electrodes, a plurality of separators 25 and a plurality of spacers 27 stacked in the vertical direction. These electrodes include a negative terminal electrode 17, a positive terminal electrode 20 and a plurality of bipolar electrodes 23. Figure 2 In the figure, illustration of a part of the bipolar electrodes 23 is omitted.

[0040] The negative terminal electrode 17 includes a current collector 18 and a surface ( Figure 1 The positive terminal electrode 20 includes a current collector 18 and a surface ( Figure 1 The positive electrode active material layer 21 is provided on the lower surface of the current collector 18. Each bipolar electrode 23 includes a current collector 18 and a positive electrode active material layer 21 provided on one side of the current collector 18 ( Figure 2 The negative electrode active material layer 19 is provided on the upper surface of the current collector 18, and the negative electrode active material layer 19 is provided on the other surface of the current collector 18 ( Figure 2 The positive electrode active material layer 21 has a lower surface.

[0041] A separator 25 is provided between the negative active material layer 19 of the negative terminal electrode 17 and the positive active material layer 21 of the bipolar electrode 23 adjacent to the negative terminal electrode 17. Furthermore, a separator 25 is provided between the positive active material layer 21 of the positive terminal electrode 20 and the negative active material layer 19 of the bipolar electrode 23 adjacent to the positive terminal electrode 20. Furthermore, a separator 25 is provided between the negative active material layer 19 of the adjacent bipolar electrode 23 and the positive terminal electrode 20.

[0042] like Figure 1 as well as Figure 2 As shown in FIG. 1 , both end faces of the stacked body 15 including the negative terminal electrode 17, the positive terminal electrode 20, the bipolar electrode 23 and the separator 25 in the stacking direction are formed by the collector 18. Figure 2 as well as Figure 3 As shown, the outer peripheral portion of each current collector 18 when the stacked body 15 is viewed along the stacking direction is the current collector foil 18 - 1 located on the outer peripheral side of the negative electrode active material layer 19 and the positive electrode active material layer 21 .

[0043] The shape (planar shape) of the stacked body 15 when viewed along the stacking direction of the present embodiment is a rectangle. That is, the shape of the current collector 18, the negative electrode active material layer 19, the positive electrode active material layer 21, and the separator 25 when viewed along the stacking direction of the stacked body 15 is a rectangle. Figure 2 It can be seen that when the stack 15 is observed along the stacking direction, the outer peripheral end of each negative electrode active material layer 19 is located on the outer peripheral side than the outer peripheral end of each positive electrode active material layer 21. Furthermore, the shapes of the negative electrode active material layers 19 when the stack 15 is observed along the stacking direction are the same, and the shapes of the positive electrode active material layers 21 when the stack 15 is observed along the stacking direction are the same. Furthermore, the shapes of the current collectors 18 when the stack 15 is observed along the stacking direction are the same. Furthermore, the shapes of the separators 25 when the stack 15 is observed along the stacking direction are the same.

[0044] Furthermore, if Figure 2 as well as Figure 3 As shown in FIG. 1 , a spacer 27 is fixed to the lower surface of the collector foil 18-1 of each collector 18 of the positive terminal electrode 20 and each bipolar electrode 23. The spacer 27 is formed of a material having insulating properties and heat resistance. For example, the constituent material of the spacer 27 is silicone resin. Figure 2 It can be seen that the rear portion 27B of each separator 27 is aligned with the rear end of each negative electrode active material layer 19 in the vertical direction, and the front portion 27F of each separator 27 is aligned with the front end of each negative electrode active material layer 19 in the vertical direction. Figure 3) is arranged in the vertical direction with the left end of each negative electrode active material layer 19, and the right side portion 27R of each separator 27 (see Figure 3 ) are arranged in the vertical direction with the right end of each negative electrode active material layer 19. Furthermore, the inner peripheral surface of each separator 27 and the outer peripheral surface of each positive electrode active material layer 21 are opposed to each other while forming a small gap. Furthermore, the vertical dimension (thickness) of each separator 27 is the same as the vertical dimension (thickness) of each positive electrode active material layer 21. Therefore, the lower surface of each separator 27 is in contact with the upper surface of the separator 25.

[0045] Here, the direction perpendicular to the stacking direction (vertical direction) is defined as the perpendicular direction. That is, the left-right direction and the front-back direction are included in the perpendicular direction. The distance 27LT in the front-back direction between the front end surface of the front portion 27F of the separator 27 and the front end surface of the negative electrode active material layer 19 (see Figure 2 ) is greater than the distance 18DL between adjacent current collectors 18 in the stacking direction (refer to Figure 2 The distance 27LT in the front-to-back direction between the rear end surface of the rear portion 27B of the separator 27 and the rear end surface of the negative electrode active material layer 19 (see Figure 2 ) is greater than the distance 18DL between adjacent current collectors 18 in the stacking direction (refer to Figure 2 The distance 27LT (not shown) between the left side surface of the left side portion of the separator 27 and the left end surface of the negative electrode active material layer 19 in the left-right direction is greater than the distance 18DL (see FIG. 18 ) between adjacent current collectors 18 in the stacking direction. Figure 2 The distance 27LT (not shown) between the right side surface of the right side portion of the separator 27 and the right end surface of the negative electrode active material layer 19 in the left-right direction is greater than the distance 18DL (see FIG. 18 ) between adjacent current collectors 18 in the stacking direction. Figure 2 ) is significantly longer. The distance 18DL is the distance in the vertical direction between the upper surface of one current collector 18 and the lower surface of the current collector 18 adjacent to the current collector 18 from above. Furthermore, each distance 27LT is preferably 10 times longer than the distance 18DL.

[0046] A resin component 30 as an integrally molded resin product is provided at the periphery of the stack 15. The resin component 30 is integrated at the periphery of the stack 15 in an airtight and liquid-tight state so as to cover the periphery of the stack 15. The shape of the resin component 30 when cut along a cross section perpendicular to the stacking direction is a rectangle with a rectangular opening formed in the center. The resin component 30 is made of an insulating resin material. The constituent material of the resin component 30 is, for example, polypropylene, polyethylene, polystyrene, ABS resin, acid-modified polypropylene, acid-modified polyethylene, or acrylonitrile styrene resin. For example, the resin component 30 may be provided integrally at the periphery of the stack 15 by insert molding performed while the stack 15 is arranged inside a molding die (not shown).

[0047] Although not shown in the figure, an electrolyte is provided inside the stacked body 15 , and the electrolyte is impregnated into the negative terminal electrode 17 , the positive terminal electrode 20 , and the bipolar electrode 23 .

[0048] Furthermore, if Figure 2 As shown, a sealing material 29 made of an insulating material is formed in a liquid-tight state on the entire surface of the end portion of the inner peripheral surface side of the central opening 30S of the collector foil 18-1 of each collector 18 and the inner peripheral surface of the central opening 30S. Figure 2 In the figure, the sealing material 29 is shown only for the collector foil 18 - 1 of the current collector 18 located at the bottom, and the sealing material 29 of the other current collectors 18 (the collector foil 18 - 1 ) is omitted from illustration.

[0049] The battery 10 having the above-described structure is fixed, via fixing means, to the upper surface of a substantially horizontal plate member (not shown) forming a part of the vehicle body component of the battery-electric vehicle.

[0050] like Figure 1 as well as Figure 2As shown, the outer peripheral ends of the negative terminal electrode 17, the positive terminal electrode 20, and the collectors 18 of the bipolar electrode 23 and the outer peripheral ends of the separators 25 are located inside the resin member 30. On the other hand, the outer peripheral ends of the negative active material layers 19 and the positive active material layers 21 are located on the inner peripheral side than the inner peripheral surface of the central opening 30S of the resin member 30. Furthermore, the collector 18 of the negative terminal electrode 17 is exposed through one opening end of the central opening 30S, and the collector 18 of the positive terminal electrode 20 is exposed through the other opening end of the central opening 30S. Therefore, the power generated by the battery 10 can be supplied to various electrical devices and electronic devices (not shown) provided in the above-mentioned battery electric vehicle through the first conductive member (not shown) and the second conductive member (not shown). The first conductive member is connected to the collector 18 of the negative terminal electrode 17 through one opening end of the central opening 30S. The second conductive member is connected to the current collector 18 of the positive terminal electrode 20 via the other opening end of the central opening 30S.

[0051] Function and effect

[0052] Next, the operation and effects of this embodiment will be described.

[0053] Here, it is assumed that a vehicle (not shown) traveling forward in the rear area of ​​the battery-electric vehicle collides with the rear end of the battery-electric vehicle. When such a collision occurs in the battery-electric vehicle, a component (not shown) provided in the vehicle body and located immediately after the battery 10 moves forward relative to the battery 10, and sometimes collides violently with the rear portion 30R of the resin component 30 (see Figure 1 , Figure 2 ).

[0054] In this case, due to external force applied to the battery 10, for example, the collector foil 18-1 of the collector 18U of one collector 18 may be deformed and penetrate the adjacent separator 25 while contacting the collector foil 18-1 of the collector 18D of the other collector 18. Figure 2As shown, the distance in the front-to-back direction from the rear portion 27B to the rear end surfaces of the negative electrode active material layer 19 and the positive electrode active material layer 21 is shorter than the distance in the front-to-back direction from the rear portion 27B of the separator 27 fixed to the lower surface of the collector foil 18-1 of the collector 18U to the rear portion 30R of the resin member 30. That is, the rear portion 27B is fixed to the collector foil 18-1 of the collector 18U in a state close to the rear ends of the negative electrode active material layer 19 and the positive electrode active material layer 21. Therefore, the portion of the collector foil 18-1 of the collector 18U located further rearward than the rear portion 27B penetrates the adjacent separator 25 and contacts the collector foil 18-1 of the collector 18D. That is, the spacer 27 (rear portion 27B) located between the current collector 18U and the separator 25 prevents the portion of the current collector foil 18-1 of the current collector 18U that is short in distance to the negative electrode active material layer 19 and the positive electrode active material layer 21 from contacting the current collector foil 18-1 of the current collector 18D. For example, there is almost no possibility that the portion of the current collector foil 18-1 of the current collector 18U that is located further forward than the rear end of the rear portion 27B contacts the current collector foil 18-1 of the current collector 18D. When it is assumed that a portion of the collector foil 18-1 of the collector 18U of the battery 10 at which the distance to the negative electrode active material layer 19 and the positive electrode active material layer 21 is short contacts the collector foil 18-1 of the collector 18D, the distance between the short-circuit portion of the collectors 18U and 18D and the negative electrode active material layer 19 and the positive electrode active material layer 21 is short, so there is a possibility that the negative electrode active material layer 19 and the positive electrode active material layer 21 will become hot due to the heat generated at the short-circuit portion. On the other hand, when the collector foil 18-1 of the collector 18U, which is located further rearward than the rear portion 27B, penetrates the adjacent separator 25 and contacts the collector foil 18-1 of the collector 18D, the distance between the short-circuit portion of the collectors 18U and 18D and the negative electrode active material layer 19 and the positive electrode active material layer 21 becomes longer, so the possibility of the negative electrode active material layer 19 and the positive electrode active material layer 21 being heated to high temperature due to the heat generated at the short-circuit portion is small.

[0055] Furthermore, when the distance 27LT in the front-to-back direction between the rear end face of the rear portion 27B and the rear end face of the negative electrode active material layer 19 is made to be more than 10 times the distance 18DL in the stacking direction between adjacent collectors 18, the possibility of the negative electrode active material layer 19 and the positive electrode active material layer 21 becoming hot due to the heat generated at the short-circuit location becomes smaller than when the distance 27LT is less than 10 times the distance 18DL.

[0056] Furthermore, the upper and lower dimensions (thickness) of each separator 27 are the same as the upper and lower dimensions (thickness) of each positive electrode active material layer 21. That is, at a time point before an external force is applied to the battery 10, the upper surface of the separator 27 is in contact with the lower surface of the collector foil 18-1 and the lower surface of the separator 27 is in contact with the upper surface of the separator 25. Therefore, at a time point before an external force is applied to the battery 10, the separator 27 is more likely to prevent the two collector foils 18-1 from short-circuiting each other, compared with a case where the separator 27 is not in contact with the lower surface of the collector foil 18-1 or the upper surface of the separator 25.

[0057] As mentioned above, the battery 10 according to the embodiment has been described, but the design thereof can be appropriately changed within the scope not departing from the gist of the present invention.

[0058] Figure 4 The battery 50 of the first modified example shown is similar in structure to the battery 10 of the embodiment except that the dimensions of the separator 51 in the front-to-back direction and the left-to-right direction are different from those of the separator 27. The rear portion 51SR of the inner peripheral surface of the separator 51 is aligned with the rear end face of the negative electrode active material layer 19 in the vertical direction. That is, the rear portion 51SR of the inner peripheral surface of the separator 51 and the rear end face of the negative electrode active material layer 19 are positioned in the same front-to-back direction. Although not shown in the figure, the front portion of the inner peripheral surface of the separator 51 is aligned with the front end face of the negative electrode active material layer 19 in the vertical direction. The left side portion of the inner peripheral surface of the separator 51 is aligned with the left end face of the negative electrode active material layer 19 in the vertical direction. The right side portion of the inner peripheral surface of the separator 51 is aligned with the right end face of the negative electrode active material layer 19 in the vertical direction. Furthermore, the distance 51LT in the front-to-back direction between the front end face of the front portion of the separator 51 and the front end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The distance 51LT in the front-to-back direction between the rear end face of the rear portion 51R of the separator 51 and the rear end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The distance 51LT in the left-to-right direction between the left side face of the left side portion of the separator 51 and the left end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The distance 51LT in the left-to-right direction between the right side face of the right side portion of the separator 51 and the right end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. Furthermore, each distance 51LT is preferably at least 10 times the length of the distance 18DL. Figure 4 In the battery 50 of the first modified example shown, when an external force is applied to the battery 50, the separator 51 (rear portion 51R) prevents the collector foil 18-1 of the current collector 18U from contacting the collector foil 18-1 of the current collector 18D at a portion where the distance in the front-back direction between the collector foil 18-1 of the current collector 18U and the negative electrode active material layer 19 and the positive electrode active material layer 21 is short. Therefore, when an external force is applied to the battery 50, a short circuit that makes it easy for the negative electrode active material layer 19 and the positive electrode active material layer 21 to heat up is unlikely to occur between the two collector foils 18-1.

[0059] Figure 5 The battery 60 of the second modified example shown is similar in structure to the battery 10 of the embodiment except that the dimensions of the separator 61 in the front-to-back direction and the left-to-right direction are different from those of the separator 27. The rear portion 61SR of the inner peripheral surface of the separator 61 contacts the rear end surface of the positive electrode active material layer 21. Although not shown in the figure, the front portion of the inner peripheral surface of the separator 61 contacts the front end surface of the positive electrode active material layer 21, the left portion of the inner peripheral surface of the separator 61 contacts the left end surface of the positive electrode active material layer 21, and the right portion of the inner peripheral surface of the separator 61 contacts the right end surface of the positive electrode active material layer 21. Furthermore, the distance 61LT in the front-to-back direction between the front end surface of the front portion of the separator 61 and the front end surface of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The distance 61LT in the front-to-back direction between the rear end surface of the rear portion 61R of the separator 61 and the rear end surface of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The left-right distance 61LT between the left side surface of the left side portion of the separator 61 and the left end surface of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The left-right distance 61LT between the right side surface of the right side portion of the separator 61 and the right end surface of the negative electrode active material layer 19 is significantly longer than the distance 18DL. Furthermore, each distance 61LT is preferably at least 10 times the length of the distance 18DL. Figure 5 In the battery 60 of the second modified example shown, the separator 61 (rear portion 61R) prevents the portion of the collector foil 18-1 of the collector 18U, which is short in the front-back direction to the negative electrode active material layer 19 and the positive electrode active material layer 21, from contacting the collector foil 18-1 of the collector 18D. Therefore, when an external force is applied to the battery 60, it is difficult for a short circuit to occur between the two collector foils 18-1, which makes the negative electrode active material layer 19 and the positive electrode active material layer 21 easily heated. Furthermore, the inner peripheral end of the separator 61 is located further inward (on the positive electrode active material layer 21 side) than the inner peripheral end of the separators 27 and 51, so the mechanical strength of the battery 60 is higher than that of the batteries 10 and 50.

[0060] Figure 6The battery 70 of the third modified example shown is similar in structure to the battery 10 of the embodiment except that the dimensions of the separator 71 in the front-back direction and the left-right direction are different from those of the separator 27 and that the separator 72 is provided. The rear portion 71SR of the inner peripheral surface of the separator 71, which is orthogonal to the positive electrode active material layer 21, contacts the rear end surface of the positive electrode active material layer 21. Although not shown in the figure, the front portion of the inner peripheral surface of the separator 71 contacts the front end surface of the positive electrode active material layer 21, the left side portion of the inner peripheral surface of the separator 71 contacts the left end surface of the positive electrode active material layer 21, and the right side portion of the inner peripheral surface of the separator 71 contacts the right end surface of the positive electrode active material layer 21. Furthermore, the rear portion 71TR of the outer peripheral surface of the separator 71 contacts the rear portion of the inner peripheral surface of the central opening 30S of the resin member 30. Although not shown in the figure, the front portion of the outer peripheral surface of the separator 71 contacts the front portion of the inner peripheral surface of the central opening 30S. The left side portion of the outer peripheral surface of the spacer 71 contacts the left side portion of the inner peripheral surface of the central opening 30S. The right side portion of the outer peripheral surface of the spacer 71 contacts the right side portion of the inner peripheral surface of the central opening 30S.

[0061] The battery 70 includes a separator 72 that is opposed to the negative electrode active material layer 19 in a direction orthogonal to each other. The shape of the separator 72 when viewed in the stacking direction is also a rectangular frame body, similar to the separators 27, 51, 61, and 71. The vertical dimension (thickness) of the separator 72 is the same as the vertical dimension (thickness) of each negative electrode active material layer 19. The rear portion 72SR of the inner peripheral surface of the separator 72 is in contact with the rear end surface of the negative electrode active material layer 19. Although omitted in the figure, the front portion of the inner peripheral surface of the separator 72 is in contact with the front end surface of the negative electrode active material layer 19, the left side portion of the inner peripheral surface of the separator 72 is in contact with the left end surface of the negative electrode active material layer 19, and the right side portion of the inner peripheral surface of the separator 72 is in contact with the right end surface of the negative electrode active material layer 19. Furthermore, the rear portion 72TR of the outer peripheral surface of the separator 72 is in contact with the rear portion of the inner peripheral surface of the central opening 30S of the resin component 30. The front portion of the outer peripheral surface of the partition 72 contacts the front end surface of the inner peripheral surface of the central opening portion 30S, the left side portion of the outer peripheral surface of the partition 72 contacts the left end surface of the inner peripheral surface of the central opening portion 30S, and the right side portion of the outer peripheral surface of the partition 72 contacts the right end surface of the inner peripheral surface of the central opening portion 30S.

[0062] Furthermore, the distance 712LT in the front-to-back direction between the front end face of the front portion of the separator 71, 72 and the front end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The distance 712LT in the front-to-back direction between the rear end face of the rear portion 71R, 72R and the rear end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The distance 712LT in the left-to-right direction between the left side face of the left portion of the separator 71, 72 and the left end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. The distance 712LT in the left-to-right direction between the right side face of the right portion of the separator 71, 72 and the right end face of the negative electrode active material layer 19 is significantly longer than the distance 18DL. Furthermore, each distance 712LT is preferably a length that is 10 times or more of the distance 18DL.

[0063] In this way, the annular space between the outer peripheral surface of the positive electrode active material layer 21 and the inner peripheral surface of the central opening 30S of the resin component 30 is completely blocked by the separator 71, and the annular space between the outer peripheral surface of the negative electrode active material layer 19 and the inner peripheral surface of the central opening 30S of the resin component 30 is completely blocked by the separator 72. Therefore, when an external force is applied to the battery 70, there is almost no possibility of a short circuit between the two collector foils 18-1. In addition, when the rear part 30R is damaged due to a collision, there is a possibility that the parts of the collectors 18U and 18D located further back than the rear parts 71TR and 72TR are short-circuited to each other. However, in this case, the distance between the short-circuited parts of the collectors 18U and 18D and the front-to-back direction of the negative electrode active material layer 19 and the positive electrode active material layer 21 becomes longer, so the possibility of the negative electrode active material layer 19 and the positive electrode active material layer 21 being heated to a high temperature due to the heat generated at the short-circuited parts is small.

[0064] The vertical dimension (thickness) of the separators 27 , 51 , 61 , and 71 may be smaller than that of the positive electrode active material layer 21 . The vertical dimension (thickness) of the separator 72 may be smaller than that of the negative electrode active material layer 19 .

[0065] The battery of the present invention may include only one of a separator facing the positive electrode active material layer 21 in the direction perpendicular to the positive electrode active material layer 21 and a separator facing the negative electrode active material layer 19 in the direction perpendicular to the positive electrode active material layer 19 .

[0066] The number of electrodes provided in the battery 10 may be any number as long as it is plural.

[0067] The battery 10 may be provided in a device different from the battery electric vehicle.

Claims

1. A battery, A stacked body comprising a plurality of bipolar electrodes and a plurality of spacers stacked in a predetermined stacking direction, The plurality of bipolar electrodes have: Current collector; a positive electrode active material layer formed on one surface of the current collector and having an outer peripheral end portion located further inward than an outer peripheral end portion of the current collector; and a negative electrode active material layer formed on the other surface of the current collector and having an outer peripheral end located further inward than an outer peripheral end of the current collector, The plurality of separators are located between the positive electrode active material layer and the negative electrode active material layer. The battery has: a resin frame provided on the outer periphery of the stacked body so as to be connected to a portion of each of the current collectors where the positive electrode active material layer and the negative electrode active material layer are not formed, that is, a current collector foil; and A separator made of an insulating material is located between the collector foil and the separator such that a distance to the positive electrode active material layer and the negative electrode active material layer in a direction perpendicular to the stacking direction is longer than a distance to the frame in the direction perpendicular to the stacking direction.

2. The battery according to claim 1, wherein The outer peripheral end of the negative electrode active material layer is located further outward than the outer peripheral end of the positive electrode active material layer. The separator is provided on the current collector so as to face the positive electrode active material layer from the outer peripheral side in the orthogonal direction. At least a portion of the separator and the outer peripheral end of the negative electrode active material layer are aligned in the stacking direction.

3. The battery according to claim 1 or 2, wherein: The separator and the positive electrode active material layer have the same dimensions in the stacking direction.

4. The battery according to claim 1 or 2, wherein: A sealing material independent of the separator is provided between a part of the current collector and the frame to seal the space between the current collector and the frame in a liquid-tight state.

5. The battery according to claim 1 or 2, wherein: When observing the battery along the stacking direction, the distance in the orthogonal direction between the outer peripheral surface of the separator located between the positive electrode active material layer or the negative electrode active material layer and the frame and the outer peripheral surface of the negative electrode active material layer is more than 10 times the distance in the stacking direction between adjacent collectors.

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