Battery module

Abstract

This battery module 1 comprises a plurality of battery cells 12, a holder 11, and blocks 13. The battery cells 12 each have a side surface section 12c and a pair of end surface sections 12a, 12b. The holder 11 is composed of an insulating material and is provided with at least one block housing section 15. The blocks 13 are composed of a material having higher thermal conductivity than the insulating material. The blocks 13 are disposed in the block housing sections 15. The block housing sections 15 are provided with a plurality of cell accommodation sections 16 that respectively accommodate the plurality of battery cells 12 so as to surround at least a portion of the side surface sections 12c, so that the directions that the end surface sections 12a, 12b face are aligned, and so that the end surface sections 12a, 12b are exposed.

Description

Battery Module

[0001] This disclosure relates to a battery module.

[0002] Patent Document 1 discloses a battery module including a plurality of battery cells arranged densely and a heat plate in close contact with a battery cell group composed of these plurality of battery cells.

[0003] Special Table 2023-540075

[0004] The heat plate in the battery module of Patent Document 1 is intended for more efficient dissipation of heat generated by the battery cells. However, since the heat plate only contacts a part of each battery cell (for example, one end of a cylindrical battery cell), its contribution to improving the heat dissipation of the battery module is limited.

[0005] This disclosure aims to improve the heat dissipation of a battery module.

[0006] One aspect of this disclosure provides a battery module including a plurality of battery cells each having a side surface portion and a pair of end surface portions, a holder made of an insulating material and provided with at least one block accommodating portion, and a block made of a material having higher thermal conductivity than the insulating material, disposed within the block accommodating portion, and provided with a plurality of cell accommodating portions for accommodating the plurality of battery cells so as to surround at least a part of the side surface portion, align the opposing directions of the pair of end surface portions, and expose the pair of end surface portions.

[0007] According to the battery module according to this disclosure, the heat dissipation can be improved.

[0008] Exploded perspective view of the battery module according to an embodiment of this disclosure. Exploded perspective view of the battery cell assembly included in the battery module according to an embodiment of this disclosure. Planar view of the battery cell assembly included in the battery module according to an embodiment of this disclosure. Schematic cross-sectional view taken along line IV-IV of FIG. 3. Cross-sectional view similar to FIG. 4 of the first modification of this disclosure. Planar view similar to FIG. 3 of the second modification of this disclosure. Partial perspective view of the battery cell module of the third modification of this disclosure. Cross-sectional view similar to FIG. 4 of the third modification of this disclosure. Cross-sectional view of the fourth modification of this disclosure.

[0009] A battery module according to one embodiment of the present disclosure comprises a plurality of battery cells, each having a side portion and a pair of end portions; a holder made of an insulating material and provided with at least one block housing portion; and a block made of a material having higher thermal conductivity than the insulating material, disposed within the block housing portion, and provided with a plurality of cell housing portions that house the plurality of battery cells, each surrounding at least a portion of the side portions, with the opposing directions of the pair of end portions aligned and the pair of end portions exposed.

[0010] The sides of individual battery cells are not entirely surrounded by a holder made of insulating material, but are at least partially surrounded by a block made of a material with higher thermal conductivity than insulating material. Therefore, individual battery cells can dissipate heat not only from their end faces but also from their sides via the block. As a result, the heat dissipation of the battery module is improved.

[0011] Each of the plurality of battery cells has a pair of end faces, each including a first end face on which at least one of the positive and negative electrodes is provided, and a second end face opposite to the first end face. The battery module may further include a heat transfer layer made of a material with higher thermal conductivity than the insulating material, provided so as to be in contact with at least the individual second end faces of the plurality of battery cells and the block, and a heat dissipation member made of a material with higher thermal conductivity than the insulating material, provided so that one side is in contact with the heat transfer layer on the side opposite to the battery cells and the block, and the other side is exposed to the air.

[0012] The heat generated by the battery cell is released into the air not only from the second end face via the heat transfer layer and heat dissipation member, but also from the side surface via the block, heat transfer layer, and heat dissipation member. In other words, by providing the heat transfer layer and heat dissipation member, a highly efficient heat transfer path is created between the battery cell, particularly the side surface, and the air. As a result, heat dissipation is further improved.

[0013] The block is made of a metal material, the holder has a plurality of block housing sections, the plurality of battery cells housed in the plurality of cell housing sections of one block are connected in parallel, and the holder may further have a partition wall separating two adjacent block housing sections, wherein the height position of the partition wall on the second end face side is higher than the height position of the block on the second end face side.

[0014] By making the blocks from a metal material with high thermal conductivity, heat dissipation can be further enhanced. Although the blocks are made of metal, by setting the height of the partition wall higher than the height of the blocks, insulation can be ensured between multiple battery cells held in a block housed in one block housing and multiple battery cells held in a block housed in another adjacent block housing.

[0015] The heat transfer layer may be made of a heat-conducting and heat-dissipating material.

[0016] Even if there is a difference in height between the second end face of the partition wall and the second end face of the block, the heat transfer layer deforms on the side of the heat transfer layer opposite to the heat dissipation member, causing the heat transfer layer to come into close contact with the second end face of the block. As a result, the heat transfer efficiency from the block to the heat transfer layer increases, further improving the heat transfer efficiency of the heat transfer path, particularly from the side of the battery cell to the air, and thus further improving heat dissipation.

[0017] The heat transfer layer is made of a thermal conductive filler, and the thermal conductive filler may fill at least a portion of the gap between the side portion of the battery cell and the cell housing portion of the block.

[0018] The presence of a heat transfer layer between the side surface of the battery cell and the cell housing of the block improves the heat transfer efficiency from the side surface of the battery cell to the block. This further increases the heat transfer efficiency of the heat transfer path, particularly from the side surface of the battery cell to the air, resulting in improved heat dissipation.

[0019] The plurality of cell housings provided in the block may include those that surround all of the side surfaces of the battery cell and those that surround a portion of the side surfaces of the battery cell when viewed from the opposing directions of the pair of end faces.

[0020] This configuration allows for an increased density of multiple battery cells, thereby increasing the overall volumetric energy density of the battery module.

[0021] The plurality of cell housings provided in the block may surround all of the side surfaces of the battery cells when viewed from the opposing directions of the pair of end faces.

[0022] This configuration allows for an increase in the area of ​​the side surface surrounded by the block for all battery cells, thereby improving the heat transfer efficiency of the heat transfer path from the side surface through the block to the air.

[0023] The following describes specific examples of this disclosure in detail based on the drawings. In the following description, terms indicating specific directions or positions (e.g., "up," "down," and other terms including these) will be used as needed. The use of these terms is for the purpose of facilitating the understanding of the disclosure with reference to the drawings, and the meaning of these terms does not limit the technical scope of this disclosure. Also, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components. Furthermore, the embodiments shown below are examples of the technical idea of ​​this disclosure and do not limit this disclosure to them. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are intended to be illustrative, and not to limit the scope of this disclosure unless specifically stated. Also, the content described in one embodiment or modification is applicable to other embodiments and modifications. Furthermore, the size and positional relationships of the components shown in the drawings may be exaggerated to clarify the explanation.

[0024] The battery module of this disclosure is applicable, for example, to emergency power sources such as battery backup units (BBUs) or to power the drive motors of electric vehicles. However, this disclosure does not specify the application of the battery module, and it can be used as a power source for various other electrical devices.

[0025] Referring to Figure 1, the battery module 1 of this disclosure comprises an outer casing 2, a battery cell assembly 3, a current collection structure 4, a heat transfer layer 5, and a heat sink (heat dissipation member) 6.

[0026] The outer casing 2 is a long rectangular parallelepiped shape and defines an internal space for housing the battery cell assembly 3, the current collection structure 4, the heat transfer layer 5, and the heat sink 6. The outer casing 2 comprises a base 2A and a cover 2B that is separable from the base 2A in the height direction. The base 2A comprises a bottom wall 2a and a pair of end walls 2b provided at both ends of the bottom wall 2a. A fan 7 is positioned on the bottom wall 2a of the base 2A. Each of the pair of end walls 2b is provided with a ventilation opening 2c. Therefore, when the fan 7 is started, an airflow is generated from one end wall 2b to the other end wall 2b.

[0027] In Figure 1, the battery cell assembly 3, current collection structure 4, heat transfer layer 5, and heat sink 6 are arranged in a stacked state between the left end wall 2b and the fan 7. More specifically, the current collection structure 4, battery cell assembly 3, heat transfer layer 5, and heat sink 6 are stacked in this order, starting from the bottom wall 2a of the outer case 2 and moving upward in the height direction.

[0028] Referring also to Figure 2, the battery cell assembly 3 comprises a holder 11, a plurality of battery cells 12, and a plurality of blocks 13.

[0029] Referring to Figure 1, the battery cell 12 is a cylindrical lithium-ion secondary battery and has a pair of end faces 12a and 12b and a side face 12c. The battery cell 12 may be a battery other than a cylindrical type, such as a rectangular battery, or a battery other than a lithium-ion secondary battery, such as an all-solid-state battery. One end face 12a (first end face) is provided with a peripheral electrode 12d as a negative electrode at its periphery and a central electrode 12e as a positive electrode in the center. The polarity of the peripheral electrode 12d and the central electrode 12e may be reversed. In this embodiment, the other end face 12b (second end face) is not provided with an electrode and is generally flat.

[0030] In the battery module 1, multiple battery cell units 14, each composed of multiple battery cells 12 connected in parallel, are connected in series. Specifically, each battery cell unit 14 consists of nine battery cells 12, and eleven battery cell units 14 are connected in series. As will be described later, this connection of multiple battery cells 12 is realized by a current collection structure 4.

[0031] Referring to Figures 1 to 4, the holder 11 is generally a long frame-like structure and is made of insulating resin, which is an example of an insulating material. The holder 11 comprises a bottom wall 11a, a pair of side walls 11b and 11c extending in the longitudinal direction, a pair of end walls 11d and 11e at both ends in the longitudinal direction, and a plurality of partition walls 11f provided at intervals in the longitudinal direction. One end wall 11d, the partition wall 11f adjacent to the end wall 11d, and the pair of side walls 11b and 11c define a block housing section 15, which is an open space at the top in the height direction. Similarly, the other end wall 11e, the partition wall 11f adjacent to the end wall 11e, and the pair of side walls 11b and 11c define a block housing section 15. Furthermore, the block housing section 15 is defined by a pair of adjacent partition walls 11f and a pair of side walls 11b and 11c. Each block housing 15 contains one block 13, and each block housing 15 corresponds to one battery cell unit 14. Specifically, eleven block housings 15 are arranged in a longitudinal direction, and each of them contains a block 13.

[0032] Referring to Figures 2 to 4, block 13 is a solid component and is made of aluminum or an aluminum alloy, which is an example of a material with higher thermal conductivity than the insulating resin that constitutes the holder 11. Block 13 may be made of other metals or other non-metallic materials, as long as they have higher thermal conductivity than the insulating resin that constitutes the holder 11.

[0033] The block 13 is generally rectangular in shape and has a bottom surface 13a, a top surface 13b, a pair of side surfaces 13c facing each other in the longitudinal direction of the holder 11, and a pair of end surfaces 13d facing each other in the width direction of the holder 11. The block 13 is positioned in the block housing section 15 of the holder 11 such that the bottom surface 13a is in close contact with the bottom wall 11a, the side surfaces 13c are in close contact with the end walls 11d, 11e or the partition wall 11f, and the end surfaces 13d are in close contact with the side walls 11b, 11c.

[0034] Block 13 holds multiple (nine in this embodiment) battery cells 12 contained in one battery cell unit 14. Specifically, Block 13 holds the battery cells 12 contained in one battery cell unit 14 in such a position that the end face portion 12a, on which the peripheral electrode 12d and central electrode 12e are provided, is on the lower side in the height direction, and the end face portion 12b opposite to the end face portion 12b is on the upper side in the height direction. Block 13 also holds the battery cells 12 contained in one battery cell unit 14 so that the end face portion 12a is exposed from the bottom surface 13a and the end face portion 12b is exposed from the top surface 13c.

[0035] Block 13 is provided with a cell housing section 16 to hold a battery cell 12 contained in one battery cell unit 14. In this embodiment, block 13 is provided with two types of cell housing sections 16, namely a cell housing hole 16A and a cell housing groove 16B.

[0036] The cell housing hole 16A is an open-ended hole that penetrates between the bottom surface 13a and the top surface 13b of the block 13, and has a cross-sectional shape (circular in this embodiment) that corresponds to the side surface 12c of the battery cell 12. As is most clearly shown in Figure 3, when the battery cell 12 housed in the cell housing hole 16A is viewed from above, that is, from the direction in which the end surfaces 12a and 12b of the battery cell 12 are facing each other, the entire side surface 12c is surrounded by the block 13.

[0037] The cell housing groove 16B is a groove provided on the side surface 13c of the block 13, extending between the bottom surface 13a and the top surface 13b. Together with the cell housing grooves 11g provided on the end walls 11d, 11e and the partition wall 11b, which face each other, it forms a through-hole having a cross-sectional shape corresponding to the side surface 12c of the battery cell 12. As is most clearly shown in Figure 3, in a plan view, a portion of the side surface 12c of the battery cell 12 housed in the cell housing groove 16B is surrounded by the block 13.

[0038] As is most clearly shown in Figure 4, in this embodiment, the side portion 12c of the battery cell 12 housed in the cell housing groove 16B is in close contact with the groove wall of the cell housing groove 16B. Similarly, the side portion 12c of the battery cell 12 housed in the cell housing hole 16A is in close contact with the hole wall of the cell housing hole 16A.

[0039] Referring to Figure 4, the height position Hp of the top surface of the partition wall 11f of the holder 11, that is, the height position Hp on the side of the second end face 12a of the battery cell 12 of the block 13, is set higher than the height position Hb of the top surface 13b of the block 13. As is clear from referring to Figure 2 as well, the height positions of the side walls 11b, 11c and end walls 11d, 11e of the holder 11 on the side of the second end face 12a are also set to a height position Hp higher than the height position Hb of the top surface 13b of the block 13.

[0040] As mentioned above, the block 13 is made of aluminum or an aluminum alloy, which is a highly conductive metallic material. By setting the height position Hp of the partition wall 11f higher than the height position Hb of the top surface 13b of the block 13, insulation can be ensured between the battery cell unit 14 held in a block 13 housed in one block housing section 15 and the battery cell unit 14 held in a block 13 housed in another block housing section 15 adjacent to it.

[0041] Referring to Figure 4, the height position Hc of the second end face 12a of the battery cell 12 is set to be approximately the same as the height position Hb of the top surface 13b of the block 13. In other words, the second end face 12a of the battery cell 12 and the top surface 13b of the block 13 are approximately flush.

[0042] Referring to FIGS. 1 and 4, a heat transfer layer 5 and a heat sink 6 are arranged on the battery cell assembly 3 in a stacked state in this order.

[0043] The heat transfer layer 5 is made of a heat-conductive heat dissipation material (TIM), which is a material having higher thermal conductivity than the insulating resin constituting the holder 11. As the heat-conductive heat dissipation material, an example is a silicon-based material containing a heat-conductive filler. This heat-conductive heat dissipation material has a certain degree of elasticity or flexibility.

[0044] The heat sink 6 in this embodiment is made of aluminum or an aluminum alloy, which is a material having higher thermal conductivity than the insulating resin constituting the holder 11, and has a rigid body or rigidity equivalent thereto. The heat sink 6 may be made of other metals or other non-metallic materials as long as it has higher thermal conductivity than the insulating resin constituting the holder 11. The heat sink 6 in this embodiment is a long plate shape corresponding to the holder 11.

[0045] The heat transfer layer 5 is arranged on the battery cell assembly 3, and the heat sink 6 is arranged on the heat transfer layer 5. The lower surface of the heat sink 6 is in close contact with the heat transfer layer 5 on the side opposite to the battery cell assembly 3, and the upper surface of the heat sink 6 is exposed in the air.

[0046] The heat transfer layer 5 and the heat sink 6 are screwed to the holder 11, and the heat transfer layer 5 is sandwiched between the holder 11 and the heat sink 6 and compressed in the thickness direction. Specifically, female screw holes 11h are provided at a plurality of locations in the holder 11, and through holes 5a and 6a are provided at corresponding positions of the heat transfer layer 5 and the heat sink 6, respectively. Further, the male screw portion 21a of the screw 21 is inserted into the through hole 6a of the heat sink 6 and the through hole 5a of the heat transfer layer 5, and is screwed into the female screw hole 11f of the holder 11. As a result, the heat sink 6 and the heat transfer layer 5 are sandwiched between the head 21b of the screw 21 and the holder 11.

[0047] As shown in FIG. 4, the heat transfer layer 5 pressed against the holder 11 by the heat sink 6 is compressed in the thickness direction and the lower surface side is deformed. Specifically, the lower surface side of the heat transfer layer 5 made of a heat-conductive heat dissipation material having elasticity or flexibility as described above is in close contact with the end surface portion 12b of the battery cell 12, the top surface 13b of the block 13, and the top surface of the partition wall 11f of the holder 11.

[0048] Referring to FIGS. 1 and 4, the current collector structure 4 in this embodiment is disposed below the battery cell assembly 3. The current collector structure 4 has a three-layer structure including a first current collector group 31, an insulating layer 32, and a second current collector group 33. The first current collector group 31 is disposed below the bottom wall 11a of the holder 11, the insulating layer 32 is disposed below the first current collector group 31, and the second current collector group 33 is further disposed below the insulating layer 32.

[0049] The first current collector group 31 includes the same number of first current collectors 31A as the battery cell units 14, that is, 11 first current collectors 31A. Each first current collector 31A extends to the peripheral electrode 12d of the battery cell 12 through a through hole provided in the bottom wall 11a of the holder 11 and is electrically connected to the peripheral electrode 12d. Similarly, the second current collector group 33 includes the same number of second current collectors 33A as the battery cell units 14, that is, 11 second current collectors 33A. Each second current collector 32A extends to the central electrode 12e of the battery cell 12 through a through hole provided in the insulating layer 32, a through hole provided in the first current collector 31A, and a through hole provided in the bottom wall 11a of the holder 11 and is electrically connected to the central electrode 12e.

[0050] The current collector structure 4 is not limited to that of this embodiment. For example, it may be one that collects current from the first end face portion 12a and the side face portion 12c with the central electrode 12 as the positive electrode and the side face portion 12c as the negative electrode of each battery cell 12.

[0051] The heat generated by each battery cell 12 is released into the air from the second end face portion 12b of the battery cell 12 through the heat transfer layer 5 and the heat sink 6, and the air heated by the air flow generated by the fan 7 described above is discharged outside the outer case 2.

[0052] Of the battery cells 12, those housed in cell housing holes 16A have their entire side portion 12a surrounded by block 13, while those housed in cell housing grooves 16B have their side portion 12c partially surrounded by block 13. In other words, the side portion 12c of each battery cell 12 is not entirely surrounded by a holder 11 made of insulating material, but at least a portion of it is surrounded by block 13 made of aluminum or an aluminum alloy, which is a material with higher thermal conductivity than insulating material. Therefore, the air generated by each battery cell 12 is also released from the side portion 12c. Specifically, the heat generated by each battery cell 12 is released into the air from the side portion 12c through block 13, heat transfer layer 5, and heat sink 6.

[0053] As described above, in the battery module 1 of this embodiment, each battery cell 12 can dissipate heat not only from the second end face portion 12b, but also from the side portion 12c via the block 13. As a result, the heat dissipation performance of the battery module is improved.

[0054] Furthermore, by providing the heat transfer layer 5 and the heat dissipation member 16, a highly efficient heat transfer path is formed between the battery cell 12, particularly the side portion 12c, and the air. As a result, heat dissipation is further improved.

[0055] Furthermore, even if there is a difference in height Hp between the partition wall 11f of the holder 11 and the height Hb of the block 13, the lower side of the heat transfer layer 5 deforms, causing the heat transfer layer 5 to come into close contact with the end face of the block 13. As a result, the heat transfer efficiency from the block 13 to the heat transfer layer 5 increases, further improving the heat transfer efficiency of the heat transfer path, particularly from the side portion 12b of the battery cell 12 to the air, and further improving heat dissipation.

[0056] Furthermore, in this embodiment, the cell housing section 16 of the block 13 includes, in plan view, a cell housing hole 16A that surrounds the entire side portion 12c of the battery cell 12 and a cell housing groove 16B that surrounds a part of the side portion 12c of the battery cell 12. This increases the arrangement density of multiple battery cells 12 and increases the overall volumetric energy density of the battery module 1.

[0057] Figures 5 to 9 show modified examples of this embodiment.

[0058] In the first modified example shown in Figure 5, the heat transfer layer 5 is made of a heat conductive filler. An example of a heat conductive filler is one that is liquid when supplied and hardens over time. In this modified example, the heat conductive filler fills the gaps between the side portion 12c of the battery cell 12 and the hole walls of the cell housing hole 16A and the groove walls of the cell housing groove 16B. By interposing the heat transfer layer 5 made of a heat conductive filler between the side portion 12c of the battery cell 12 and the cell housing portion 16 of the block 13 in this way, the heat transfer efficiency from the side portion 12c of the battery cell 12 to the block 13 is improved, so the heat transfer efficiency of the heat transfer path, especially from the side portion 12c of the battery cell 12 to the air, is further increased, and the heat dissipation is further improved.

[0059] As mentioned above, the height position Hp of the partition wall 11 of the holder 11 is higher than the height position Hb of the block 13, and the same applies to the side walls 11b, 11c and end walls 11d, 11e of the holder 11. In other words, the block housing section 15 in which the block 13 is housed is surrounded by multiple walls of the holder 11. Therefore, the amount of liquid heat conductive filler supplied to each block 13 can be easily adjusted.

[0060] In the second modified example shown in Figure 6, all of the cell housing portions 16 of the block 13 are cell housing holes 16A. This increases the area of ​​the portion where the side portion 12c of all battery cells 12 is surrounded by the block 13, thereby further improving the heat transfer efficiency of the heat transfer path from the side portion 12c of the battery cell 12 through the block 13 to the air.

[0061] In the third modified example shown in Figures 7 and 8, an outer peripheral rib 11i of uniform height is provided on the entire outer circumference of the upper part of the holder 11, specifically on the tops of the side walls 11b, 11c and end walls 11d, 11e of the holder, facing upward. The height position Hp of this outer peripheral rib 11i is higher than the height position Hp of the top surface of the partition wall f. With this configuration, the heat transfer layer 5 can be compressed by the heat sink 6 when the heat sink 6 is in contact with the top surface of the outer peripheral rib 11i, making it possible to keep the amount of compression (compression height) of the heat transfer layer 5 constant or uniform.

[0062] The fourth modified example, conceptually shown in Figure 9, will be described below.

[0063] In this modified example, the battery cell 12 has a central electrode 12e at the end face 12a as the positive electrode, and an end face 12b at the bottom of the can as the negative electrode. In each individual battery cell unit 14, the orientation of the battery cell 12 is aligned, that is, whether the positive electrode end face 12a or the negative electrode end face 12b is facing upward. However, the orientation of the battery cells 12 differs between battery cell units 14 located in adjacent blocks 13. The current collection structure 4 is a split structure in which lead plates 34A and 34B are arranged on the upper and lower sides of the battery cell assembly 3, respectively. The upper lead plates 34A and 34B connect the negative electrode of a battery cell 12 constituting a battery cell unit 14 located in one block 13 to the positive electrode of a battery cell 12 constituting a battery cell unit 14 located in a block 13 adjacent to that block 13.

[0064] In this modified example, the heat transfer layer 5 and the heat dissipation layer 6 are also separate structures. Each heat transfer layer 5 and heat dissipation layer 6 is provided on the upper or lower side of the battery cell assembly 3 so as to cover the bottom side of the can, i.e., the end face portion 12b side, of the battery cell 12 that constitutes the corresponding battery cell unit 14. The portions of each lead plate 34A, 34B that are connected to the negative electrode of the battery cell 12 (the end face portion 12b, which is the bottom of the can, as described above) are embedded in the heat transfer layer 5.

[0065] This disclosure may include the following: (Aspect 1) A battery module comprising: a plurality of battery cells, each having a side portion and a pair of end portions; a holder made of an insulating material and provided with at least one block housing portion; and a block made of a material having higher thermal conductivity than the insulating material, disposed within the block housing portion, and provided with a plurality of cell housing portions that house the plurality of battery cells, each surrounding at least a portion of the side portions, with the opposing directions of the pair of end portions aligned and the pair of end portions exposed. (Aspect 2) The battery module according to aspect 1, wherein each of the plurality of battery cells has a pair of end faces, each of which includes a first end face on which at least one of the positive and negative electrodes is provided, and a second end face opposite to the first end face, and further comprises a heat transfer layer made of a material with higher thermal conductivity than the insulating material, provided so as to be in contact with at least the individual second end faces of the plurality of battery cells and the block, and a heat dissipation member made of a material with higher thermal conductivity than the insulating material, provided such that one side is in contact with the heat transfer layer on the side opposite to the battery cells and the block, and the other side is exposed to the air. (Aspect 3) The battery module according to aspect 2, wherein the block is made of a metal material, the holder has a plurality of block housings, the plurality of battery cells housed in the plurality of cell housings of one block are connected in parallel, and the holder further has a partition wall separating two adjacent block housings, wherein the height position of the partition wall on the second end face side is higher than the height position of the block on the second end face side. (Aspect 4) The battery module according to aspect 3, wherein the heat transfer layer is made of a heat-conducting heat dissipation material. (Aspect 5) The battery module according to aspect 3, wherein the heat transfer layer is made of a heat-conducting filler, and the heat-conducting filler fills at least a portion of the gap between the side portion of the battery cell and the cell housing of the block. (Aspect 6) The battery module according to any one of aspects 1 to 5, wherein the plurality of cell housings provided in the block include, when viewed from the opposing directions of the pair of end faces, one that surrounds all of the side surfaces of the battery cell and one that surrounds a portion of the side surfaces of the battery cell.(Aspect 7) The battery module according to any one of aspects 1 to 6, wherein the plurality of cell housings provided in the block surround all of the side surfaces of the battery cells when viewed from the opposing directions of the pair of end faces.

[0066] 1 Battery module 2 Outer case 2A Base 2a Bottom wall 2b End wall 2c Ventilation hole 2B Cover 3 Battery cell assembly 4 Current collection structure 5 Heat transfer layer 5a Through hole 6 Heat sink (heat dissipation member) 6a Through hole 7 Fan 11 Holder 11a Bottom wall 11b, 11c Side walls 11d, 11e End walls 11f Partition wall 11g Cell housing groove 11h Female screw hole 11i Outer circumference rib 12 Battery cell 12a End face (first end face) 12b End face (second end face) 12c Side surface 12d Peripheral electrode 12e Central electrode 13 Block 13a Bottom surface 13b Top surface 13c Side surface 13d End face 14 Battery cell unit 15 Block housing section 16 Cell housing section 16A Cell housing hole 16B Cell housing groove 21 Screw 21a Male screw section 21b Head 31 First current collector group 32 Insulating layer 33 Second current collector group lead plate

Claims

1. A battery module comprising: a plurality of battery cells, each having a side portion and a pair of end portions; a holder made of an insulating material and provided with at least one block housing portion; and a block made of a material with higher thermal conductivity than the insulating material, disposed within the block housing portion, and provided with a plurality of cell housing portions that house the plurality of battery cells, each surrounding at least a portion of the side portions, with the opposing directions of the pair of end portions aligned and the pair of end portions exposed.

2. The battery module according to claim 1, wherein each of the plurality of battery cells has a pair of end faces, each including a first end face on which at least one of the positive and negative electrodes is provided, and a second end face opposite to the first end face, and further comprising a heat transfer layer made of a material with higher thermal conductivity than the insulating material, provided so as to be in contact with at least the individual second end faces of the plurality of battery cells and the block, and a heat dissipation member made of a material with higher thermal conductivity than the insulating material, provided such that one side is in contact with the heat transfer layer on the side opposite to the battery cells and the block, and the other side is exposed to the air.

3. The battery module according to claim 2, wherein the block is made of a metal material, the holder comprises a plurality of block housings, the plurality of battery cells housed in the plurality of cell housings of one block are connected in parallel, and the holder further comprises a partition wall separating two adjacent block housings, wherein the height position of the partition wall on the second end face side is higher than the height position of the block on the second end face side.

4. The battery module according to claim 3, wherein the heat transfer layer is made of a heat-conducting and heat-dissipating material.

5. The battery module according to claim 3, wherein the heat transfer layer is made of a thermal conductive filler, and the thermal conductive filler fills at least a portion of the gap between the side portion of the battery cell and the cell housing portion of the block.

6. The battery module according to any one of claims 1 to 5, wherein the plurality of cell housings provided in the block include, when viewed from the opposing directions of the pair of end faces, one that surrounds all of the side surfaces of the battery cell and one that surrounds a portion of the side surfaces of the battery cell.

7. The battery module according to any one of claims 1 to 6, wherein the plurality of cell housings provided in the block surround all of the side surfaces of the battery cells when viewed from the opposing directions of the pair of end faces.

Images