Battery module

Abstract

To provide a battery module which can efficiently release heat generated from an electrode body.SOLUTION: The battery module includes: a battery cell having an electrode body and a battery cell case in which the electrode body is sealed, the electrode body being formed of laminate structures deposited on each other and each laminate structure including a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; and a heat release member in contact with the battery cell case. The battery module also includes an exposure part having a metal layer and a fusion resin layer arranged in the inner surface side of the metal layer, the metal layer being exposed to at least a part of the outer surface. The heat release member is in contact with the exposure part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a battery module.

Background Art

[0002] Conventionally, a battery cell in which an electrode body in which a plurality of positive electrodes, negative electrodes, and separators are stacked is enclosed inside a battery cell case has been used. Since heat is generated from the electrode body during charging / discharging or short-circuiting, etc., means for dissipating heat from this electrode body to the outside has been conventionally studied.

[0003] For example, Patent Document 1 discloses a battery module formed in a structure in which a plurality of plate-shaped battery cells are continuously stacked in a module case, and each of the plate-shaped battery cells includes a cathode / separator / anode structure electrode assembly attached in a battery case formed from a laminate sheet including a resin layer and a metal layer, and a plurality of heat dissipation members are disposed at two or more interfaces between the battery cells, and a heat exchange member integrally interconnecting the heat dissipation members is attached to one side of the stacked structure of the battery cells, whereby heat generated from the battery cells during charging and discharging of the battery cells is removed by the heat exchange member. Further, Patent Document 2 discloses a battery module including a module case having a lower plate and side walls forming an internal space, a plurality of battery cells present in the internal space of the module case, and a resin layer present in the internal space of the module case, the resin layer being in contact with the plurality of battery cells and also in contact with the lower plate or side wall of the module case. Furthermore, Patent Document 3 discloses a battery having a structure in which a positive electrode member having a positive electrode active material and a current collector and a negative electrode member having a negative electrode active material and a current collector are stacked facing each other via a separator member, housed together with an electrolyte in a housing, and a heat transfer plate is disposed so as to be joined to the outer surface of the housing, wherein the heat transfer plate has a region that is in direct contact with the outer surface of the housing and a region in which a bonding material for joining the heat transfer plate to the outer surface of the housing is disposed. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2012-511802 [Patent Document 2] Special Publication No. 2018-510463 [Patent Document 3] International Publication No. 2012 / 081311 [Overview of the project] [Problems that the invention aims to solve]

[0005] Heat is generated in the electrode body within a battery module during charging, discharging, and short circuits. Therefore, it is necessary to efficiently dissipate this heat generated from the electrode body to the outside. From the standpoint of achieving this heat dissipation, the battery module disclosed in Patent Document 1 has a configuration in which a heat dissipation member is arranged between multiple battery modules, each having a battery case formed from a laminate sheet, and the battery disclosed in Patent Document 3 also has a configuration in which a heat transfer plate for heat dissipation is arranged. On the other hand, the battery module disclosed in Patent Document 2 has a configuration in which multiple battery cells and a resin layer are located in the internal space of the module case, and the resin layer is in contact with the battery cells and the lower plate or side wall of the module case. However, there is a need to dissipate heat from the electrode more efficiently.

[0006] This disclosure is made in view of the above circumstances and aims to provide a battery module that can efficiently dissipate heat generated from the electrode body. [Means for solving the problem]

[0007] <1> A battery cell comprising an electrode body having a stacked structure in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are further stacked, and a battery cell case that encloses the electrode body inside, A battery module including a heat dissipation member that contacts the battery cell case, The battery cell case has at least a metal layer and a fusion resin layer disposed on the inner surface side of the metal layer, and has an exposed portion on at least a part of the outer surface where the metal layer is exposed. The heat dissipation member is a battery module that contacts the exposed portion. <2> The electrode surface of the electrode body is rectangular in shape, and the exposed portion is located at the end of the longer side of the rectangular shape. <1> The battery module described above. <3> The battery cell case has the exposed portion on the outer surface side of region E, where the inner surface side contacts the electrode body, and the heat dissipation member contacts the exposed portion in region E. <1> or <2> The battery module described above. <4> The battery cell case includes a first sheet having the exposed portion and a second sheet not having the exposed portion, wherein the average thickness of the metal layer in the first sheet is greater than the average thickness of the metal layer in the second sheet. <1> ~ <3> A battery module as described in any one of the items. <5> The heat dissipation member comprises at least one of a battery module case and a cooler, wherein at least one of the battery module case and the cooler is in contact with the exposed portion. <1> ~ <4> A battery module as described in any one of the items. <6> Having at least one of a battery module case and a cooler, and having a resin member that joins at least one of the battery module case and the cooler as the heat dissipation member to the battery cell case, and the resin member contacts the exposed portion, the battery module according to any one of <1> to <4>.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a battery module that can efficiently dissipate heat generated from the electrode body.

Brief Description of the Drawings

[0009] [Figure 1] It is a schematic cross-sectional view illustrating a battery cell used in a battery module according to an embodiment of the present disclosure. [Figure 2] It is a schematic cross-sectional view illustrating a battery module according to an embodiment of the present disclosure. [Figure 3] It is a schematic cross-sectional view illustrating another aspect of a battery module according to an embodiment of the present disclosure. [Figure 4] It is a schematic cross-sectional view illustrating another aspect of a battery module according to an embodiment of the present disclosure. [Figure 5] It is a schematic perspective view showing a cross-section and a surface in a perspective direction of a battery cell used in a battery module according to an embodiment of the present disclosure. [Figure 6] It is a schematic perspective view showing a cross-section and a surface in a perspective direction of a battery cell used in a battery module according to an embodiment of the present disclosure. [Figure 7] It is a schematic plan view showing a main part of a vehicle. [Figure 8] It is a schematic perspective view of a battery module. [Figure 9] It is a plan view of a battery module with the upper lid removed. [Figure 10] It is a schematic view of a battery cell housed in a battery module as seen from the thickness direction.

Embodiments for Carrying Out the Invention

[0010] <Battery module> The battery module according to an embodiment of the present disclosure includes a battery cell and a heat dissipation member. The battery cell has a laminated structure having a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and further includes a plurality of laminated electrode bodies, and a battery cell case that encloses the electrode bodies therein. The heat dissipation member is disposed so as to contact the battery cell case. The battery cell case has at least a metal layer and a fusion resin layer disposed on the inner surface side of the metal layer. The battery cell case has an exposed portion where at least a part of the outer surface side of the metal layer is exposed. Note that a protective resin layer may be disposed on a part of the outer surface side of the metal layer. And the heat dissipation member contacts the exposed portion.

[0011] Hereinafter, an embodiment of the battery module according to an embodiment of the present disclosure will be described with reference to the drawings. Each of the drawings shown below is schematically shown, and the size and shape of each part are exaggerated as appropriate for easy understanding.

[0012] First, the battery module used in the battery module according to an embodiment of the present disclosure will be described. FIG. 1 is a schematic cross-sectional view illustrating a battery cell used in the battery module according to an embodiment of the present disclosure. The battery cell 20 shown in FIG. 1 has an electrode body 8 and a battery cell case that encloses the electrode body 8 therein and is composed of a first sheet 210 and a second sheet 220. The electrode body 8 is formed by further laminating a laminated structure having a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode.

[0013] The first sheet 210 and the second sheet 220, which constitute the battery cell case, form a housing portion 20D that encloses the electrode body 8 by fusing their ends together. The first sheet 210, which constitutes the battery cell case, has a metal layer 214 and a fusion resin layer 212 disposed on the inner surface side of the metal layer 214. The second sheet 220, which constitutes the battery cell case, has a metal layer 224 and a fusion resin layer 222 disposed on the inner surface side of the metal layer 224, and further has a protective resin layer 226 disposed on the outer surface side of the metal layer 224. The first sheet 210 has an exposed portion 214A on its entire outer surface 20A where the metal layer 214 is exposed. On the other hand, the second sheet 220 does not have the metal layer 224 exposed on its outer surface.

[0014] Here, "exposed area" refers to the region on the outer surface of the battery cell case where the metal layer is exposed. Therefore, even if the metal layer is exposed on the inner surface (for example, the inner surface 20B of the first sheet 210 in Figure 1) or the side surface (for example, the side surface 20C of the first sheet 210 in Figure 1, such as the cut end surface formed after the fused portion is trimmed following the fusion of the ends of the first sheet 210 and the second sheet 220), these regions do not constitute an exposed area.

[0015] • First battery module Next, a battery module according to an embodiment of this disclosure will be described. Figure 2 is a schematic cross-sectional view illustrating a battery module according to an embodiment of this disclosure. The battery module 11A shown in Figure 2 has the battery cells 20 shown in Figure 1. Multiple battery cells 20 are stacked in the battery module 11A, and Figure 2 shows a magnified view of four of the stacked battery cells 20. In addition, other battery cells are stacked on the upper and lower sides of Figure 2.

[0016] The battery module 11A has a battery module case 40, which is an example of a heat dissipation member, and houses battery cells 20 stacked inside the battery module case 40. The battery module case 40 is positioned to contact the exposed portion 214A of the first sheet 210 that constitutes the battery cell case. The fused portion where the ends of the first sheet 210 and the second sheet 220 are fused together is bent in a curved shape, and the exposed portion 214A at the tip of the fused portion is positioned to make surface contact with the battery module case 40.

[0017] The battery module according to the embodiment of this disclosure, having the above configuration, can efficiently dissipate heat generated from the electrode body.

[0018] In electrode bodies, heat is generated during charging, discharging, and short circuits. Conventionally, in order to dissipate the heat generated from the electrode body to the outside, the battery cell case was positioned so that it was in contact with a heat dissipation member provided on the outside of the battery cell (for example, the battery module case or a resin layer interposed between the battery module case and the battery cell case). In other words, a heat transfer path was formed from the electrode body inside the battery cell through the battery cell case to the heat dissipation member. However, in conventional battery modules, a three-layer sheet having a metal layer and resin layers arranged on both sides of the metal layer (specifically, a fused resin layer arranged on the inner side of the metal layer and a protective resin layer arranged on the outer side of the metal layer) is generally used as the battery cell case. For example, a battery cell is formed by using two of these three-layer sheets, fusing the ends of both sheets together, and sealing the electrode body inside. However, in a battery cell case with this configuration, the metal layer is exposed only on the side (for example, the cut end formed by trimming the fused portion where the ends of two sheets are fused together), and the exposed area is limited to a region equal to the thickness of the metal layer. Therefore, the part of the battery cell case that is in direct contact with the heat dissipation member provided outside the battery cell is either the resin layer or the metal layer exposed on the side, and the area in contact between the metal layer and the heat dissipation member is limited to a small area where it is almost line contact. Here, when the battery cell case is used as a heat transfer path, the metal layer is the main contributor to electrical heating during heat dissipation. For this reason, conventionally, the contact area between the battery cell case and the heat dissipation member became the rate-limiting process of the heat transfer path, and heat transfer was not performed efficiently.

[0019] In contrast, the battery module according to the embodiment of this disclosure has an exposed portion on the outer surface of the battery cell case where a metal layer is exposed, and this exposed portion is in contact with the heat dissipation member. In other words, because the area in direct contact between the metal layer and the heat dissipation member is large, the rate-limiting process in the heat transfer path can be reduced, and heat transfer during heat dissipation can be performed efficiently. As a result, the heat generated from the electrode body can be efficiently dissipated.

[0020] Furthermore, since the battery cell does not require a separate component for heat dissipation and uses the battery cell case as the heat transfer path, the number of parts is reduced, and structural efficiency is also improved.

[0021] In Figure 2, the battery module 11A is shown having a battery module case 40 as a heat dissipation member, with the exposed portion 214A in contact with the battery module case 40. However, it is not limited to this configuration, and the heat dissipation member may also include a cooler (for example, a cooling plate with a refrigerant inside), with the exposed portion in contact with the cooler. Alternatively, the heat dissipation member may include both a battery module case and a cooler, with the exposed portion in contact with both the battery module case and the cooler.

[0022] Furthermore, the device may have at least one of a battery module case and a cooler, and may also have a resin member as a heat dissipation member that joins at least one of the battery module case and the cooler to the battery cell case, and the resin member may be in contact with the exposed portion. The following describes, with reference to the diagram, a configuration in which a resin member serves as a heat dissipation component and the resin member is in contact with the exposed portion.

[0023] • Second battery module Figure 3 is a schematic cross-sectional view illustrating another example of a battery module according to the embodiments of this disclosure. The battery module 11B shown in Figure 3 has the battery cells 20 shown in Figure 1. Multiple battery cells 20 are stacked in the battery module 11B, and Figure 3 shows a magnified view of four of the stacked battery cells 20. In addition, other battery cells are stacked on the upper and lower sides of Figure 3.

[0024] The battery module 11B has a battery module case 40, which houses stacked battery cells 20. A resin member 42, which is an example of a heat dissipation member, is placed in the gap between the battery module case 40 and the battery cells 20, filling the gap and fixing the battery cells 20. The resin member 42 joins the battery module case 40 and the battery cell case, and is positioned so that the resin member 42 is in contact with the exposed portion 20A of the battery cell case.

[0025] Thus, the battery cell case has an exposed portion on its outer surface where a metal layer is exposed. This exposed portion contacts a resin component, which is an example of a heat dissipation member, and the resin component contacts the battery module case. This reduces the rate-limiting process in the heat transfer path, allowing for efficient heat transfer during heat dissipation. As a result, heat generated from the electrode body can be efficiently dissipated. Furthermore, since the battery cell does not require a separate component for heat dissipation and uses the battery cell case as the heat transfer path, the number of parts is reduced, and structural efficiency is also improved.

[0026] • Third battery module Further embodiments of battery modules will be described. Figure 4 is a schematic cross-sectional view illustrating another example of a battery module according to the embodiments of this disclosure. The battery module 11C shown in Figure 4 has the battery cells 20 shown in Figure 1. Multiple battery cells 20 are stacked in the battery module 11C, and Figure 4 shows a magnified view of four of the stacked battery cells 20. In addition, other battery cells are stacked on the upper and lower sides of Figure 4. Furthermore, in Figure 4, the stacked battery cells 20 are not in contact with each other, and inter-cell gaps are formed between the battery cells 20.

[0027] The battery module 11C has a battery module case 40, which houses stacked battery cells 20. A resin member 42, which is an example of a heat dissipation member, is placed in the gap between the battery module case 40 and the battery cells 20, and the gap is filled with the resin member 42, fixing the battery cells 20 in place. Therefore, the gaps between the battery cells 20 that are not in contact with each other are also filled with the resin member 42. The resin member 42 joins the battery module case 40 and the battery cell case, and is positioned so as to contact the exposed portion 20A of the battery cell case.

[0028] Thus, the battery cell case has an exposed portion on its outer surface where a metal layer is exposed. This exposed portion contacts a resin component, which is an example of a heat dissipation member, and the resin component contacts the battery module case. This reduces the rate-limiting process in the heat transfer path, allowing for efficient heat transfer during heat dissipation. As a result, heat generated from the electrode body can be efficiently dissipated. Furthermore, since the battery cell does not require a separate component for heat dissipation and uses the battery cell case as the heat transfer path, the number of parts is reduced, and structural efficiency is also improved.

[0029] Furthermore, the battery cell case has an exposed portion 20A on the outer surface of the region 20E on its inner side that contacts the electrode body 8, and a resin member 42, which is an example of a heat dissipation member, is in contact with the exposed portion 20A in region 20E. As a result, heat from the electrode body, which is the heat-generating part, can be transferred more efficiently, and heat dissipation can be performed more efficiently. Furthermore, from the viewpoint of more efficient heat dissipation, it is preferable that all exposed surfaces of the battery cell case are covered with a resin material (the resin material is in direct contact with the surface).

[0030] In Figure 3, the battery module 11B, and in Figure 4, the battery module 11C, show a configuration in which the resin member, which is a heat dissipation component, is joined to the battery module case 40. However, the configuration is not limited to this, and it may also include a cooler (for example, a cooling plate with a refrigerant inside), in which the resin member is joined to the cooler. Alternatively, it may include both a battery module case and a cooler, in which the resin member as a heat dissipation component is joined to both the battery module case and the cooler.

[0031] (Resin component) Here, we will explain the resin components shown in Figures 3 and 4. A resin member, which is an example of a heat dissipation component and joins at least one of the battery module case and the cooler to the battery cell case, is required to have thermal conductivity.

[0032] The thermal conductivity of the resin component is preferably, for example, 1.5 W / mk or higher. On the other hand, there is no particular upper limit to the thermal conductivity, but it can be, for example, 50 W / mk or less. The thermal conductivity of the resin component is measured according to the ASTM D5470 standard or the ISO 22007-2 standard.

[0033] As the resin in the resin component, for example, known curable resins can be used. Examples of curable resins include acrylic resins, epoxy resins, urethane resins, olefin resins, EVA (ethylene vinyl acetate) resins, and silicone resins. Furthermore, from the viewpoint of improving thermal conductivity, fillers can be added to the resin component. Examples of fillers include ceramic fillers such as alumina, AlN (aluminum nitride), BN (boron nitride), silicon nitride, ZnO, SiC, and BeO, and carbon fillers such as graphite.

[0034] (Roughening treatment and carbon coating treatment) In the area where the exposed portion of the battery cell case and the heat dissipation member (especially when the heat dissipation member includes at least one of the battery module case and the cooler) are in contact, it is preferable that at least one of the treatments, roughening treatment and carbon coating treatment, is applied to the surface of at least one of the metal layer on the exposed portion and the surface of at least one of the heat dissipation member. This allows for more efficient heat dissipation. In the case where carbon coating treatment is applied, the heat dissipation member and the exposed portion are considered to be in direct contact. Furthermore, if the heat dissipation member is a resin member, it is preferable that at least one of the following treatments—roughening treatment and carbon coating treatment—is applied to the surface of either or both of the battery module case and the cooler, at the point where the resin member that is the heat dissipation member is in contact with at least one of the battery module case and the cooler.

[0035] (Position of exposed area) In the battery module 11A shown in Figure 1, the battery module 11B shown in Figure 3, and the battery module 11C shown in Figure 4, the exposed portion 214A is shown where the metal layer 214 is exposed over the entire outer surface of the first sheet 210 constituting the battery cell case. However, it is not limited to this, and the exposed portion may be formed only on a part of the outer surface. For example, as shown in Figure 5, the electrode surface of the electrode body 8 may be rectangular, and the exposed portion may be located at the ends 214B and 214C on the longer sides of the rectangular shape. In Figure 5, the exposed portion is shown as being formed at both ends 214B and 214C on the longer sides of the rectangular shape, but the exposed portion may be formed at only one end on the longer side. Furthermore, as shown in Figure 6, the electrode surface of the electrode body 8 may be rectangular in shape, and the exposed portion may be located at the end 214D on the shorter side of the rectangular shape. In Figure 6, the exposed portion is shown as being formed at one end 214D on the shorter side of the rectangular shape, but exposed portions may also be formed at both ends on the shorter side (in Figure 6, the other end is located further forward relative to the cross-section in Figure 6). Figures 5 and 6 are schematic perspective views showing a cross-section and a view from the oblique direction of a battery cell used in a battery module according to the embodiment of this disclosure.

[0036] However, if the electrode surface of the electrode body is rectangular in shape, it is preferable that the exposed portion be located at least at the end of the longer side of the rectangular shape (i.e., the battery module 202 shown in Figure 5 is preferable to the battery module 200 shown in Figure 6). By having the exposed portion located at least at the end of the longer side of the rectangular shape, the distance between the central part of the electrode body, where heat tends to accumulate in particular, and the exposed portion of the battery cell case can be reduced compared to the case where the exposed portion is located only at the end of the shorter side, and the cross-sectional area of ​​the heat transfer path during heat dissipation can be increased. This allows for more efficient heat dissipation.

[0037] (Thickness of the metal layer) The thickness of the metal layer in a battery cell case is not particularly limited. However, when a battery cell case is composed of two or more sheets, including a first sheet with an exposed portion (for example, the first sheet 210 shown in Figure 1) and a second sheet without an exposed portion (for example, the second sheet 220 shown in Figure 1), it is preferable that the average thickness of the metal layer in the first sheet (for example, the average thickness L1 of the metal layer 214 shown in Figure 1) is greater than the average thickness of the metal layer in the second sheet (for example, the average thickness L2 of the metal layer 224 shown in Figure 1). A larger average thickness of the metal layer in the first sheet than in the second sheet allows for a larger cross-sectional area of ​​the heat transfer path during heat dissipation, enabling more efficient heat dissipation. Note that the average thickness refers to the arithmetic mean of the thickness of the metal layer at 10 arbitrarily selected locations.

[0038] Next, a battery module, a battery pack having the battery module, and a vehicle according to the embodiments of this disclosure will be described with reference to the figures.

[0039] (Overall configuration of vehicle 100) Figure 7 is a schematic plan view showing the main parts of a vehicle 100 to which the battery pack 10 according to the embodiment is applied. As shown in Figure 7, the vehicle 100 is a battery electric vehicle (BEV) with the battery pack 10 mounted under the floor. In each figure, the arrows UP, FR, and LH indicate the upper side in the vertical direction of the vehicle, the front side in the longitudinal direction of the vehicle, and the left side in the width direction of the vehicle, respectively. When describing the directions of front, rear, left, right, up, and down, unless otherwise specified, they refer to the front and rear in the longitudinal direction of the vehicle, the left and right in the width direction of the vehicle, and the up and down in the vertical direction of the vehicle.

[0040] In this embodiment, the vehicle 100, as an example, has a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 positioned in front of the battery pack 10. The motor 108, gearbox 110, inverter 112, and charger 114 are positioned behind the battery pack 10.

[0041] The DC current output from the battery pack 10 is voltage-adjusted by the DC / DC converter 102 and then supplied to the electric compressor 104, PTC heater 106, inverter 112, etc. Power is also supplied to the motor 108 via the inverter 112, causing the rear wheels to rotate and the vehicle 100 to move.

[0042] A charging port 116 is provided on the right side of the rear of the vehicle 100. By connecting a charging plug from an external charging device (not shown) to the charging port 116, power can be stored in the battery pack 10 via the onboard charger 114.

[0043] The arrangement and structure of the components constituting the vehicle 100 are not limited to the configuration described above. For example, it may be applied to a hybrid vehicle (HV) or a plug-in hybrid electric vehicle (PHEV) equipped with an engine. In this embodiment, the motor 108 is mounted at the rear of the vehicle and it is a rear-wheel drive vehicle, but it is not limited to this, and it may be a front-wheel drive vehicle with the motor 108 mounted at the front of the vehicle, or a pair of motors 108 may be mounted at the front and rear of the vehicle. Furthermore, it may be a vehicle equipped with in-wheel motors for each wheel.

[0044] Here, the battery pack 10 is composed of multiple battery modules 11. In this embodiment, as an example, 10 battery modules 11 are provided. Specifically, 5 battery modules 11 are arranged in the longitudinal direction of the vehicle on the right side of the vehicle 100, and 5 battery modules 11 are arranged in the longitudinal direction of the vehicle on the left side of the vehicle 100. Furthermore, each battery module 11 is electrically connected.

[0045] Figure 8 is a schematic perspective view of the battery module 11. As shown in Figure 8, the battery module 11 is formed in a roughly rectangular parallelepiped shape with the vehicle width direction as its longitudinal direction. The outer shell of the battery module 11 is made of aluminum alloy. For example, the outer shell of the battery module 11 is formed by joining aluminum die-cast parts to both ends of an aluminum alloy extruded material by laser welding or the like.

[0046] A pair of voltage terminals 12 and a connector 14 are provided at both ends of the battery module 11 in the vehicle width direction. A flexible printed circuit board 22, which will be described later, is connected to the connector 14. In addition, busbars (not shown) are welded to both ends of the battery module 11 in the vehicle width direction.

[0047] The length MW of the battery module 11 in the vehicle width direction is, for example, 350 mm to 600 mm, the length ML in the vehicle longitudinal direction is, for example, 150 mm to 250 mm, and the height MH in the vehicle vertical direction is, for example, 80 mm to 110 mm.

[0048] Figure 9 is a plan view of the battery module 11 with the top cover removed. As shown in Figure 9, multiple battery modules 20 are housed inside the battery module 11 in an arranged state. In this embodiment, as an example, 24 battery modules 20 are arranged in the front-rear direction of the vehicle and bonded to each other.

[0049] A flexible printed circuit board (FPC) 22 is placed on top of the battery module 20. The flexible printed circuit board 22 is formed in a strip shape with the vehicle width direction as its longitudinal direction, and thermistors 24 are provided at both ends of the flexible printed circuit board 22. The thermistors 24 are not bonded to the battery module 20, but are pressed toward the battery module 20 by the top cover of the battery module 11.

[0050] Furthermore, one or more cushioning materials (not shown) are housed inside the battery module 11. For example, the cushioning material is a thin, elastically deformable plate-like member, and is arranged between adjacent battery modules 20 with the arrangement direction of the battery modules 20 as the thickness direction. In this embodiment, as an example, cushioning material is arranged at both ends in the longitudinal direction and in the longitudinal center of the battery module 11.

[0051] Figure 10 is a schematic view of the battery module 20 housed in the battery module 11, viewed from the thickness direction. As shown in Figure 10, the battery module 20 is formed in a roughly rectangular plate shape, and an electrode body (not shown) is housed inside. The electrode body is composed of a positive electrode, a negative electrode, and a separator stacked together, and is sealed with a laminate film 28.

[0052] In this embodiment, as an example, the electrode housing is formed by folding and bonding an embossed sheet-like laminate film 28. While both a single-cup embossed structure with one embossed area and a double-cup embossed structure with two embossed areas can be employed, this embodiment uses a single-cup embossed structure with a fold depth of approximately 8mm to 10mm.

[0053] The upper ends of both longitudinal ends of the battery module 20 are bent, and the corners form the outer shape. In addition, the upper end of the battery module 20 is bent, and fixing tape 30 is wrapped around the upper end of the battery module 20 along the longitudinal direction.

[0054] Here, terminals (tabs) 26 are provided at both longitudinal ends of the battery module 20. In this embodiment, as an example, the terminals 26 are provided at a position offset below the vertical center of the battery module 20. The terminals 26 are joined to a busbar (not shown) by laser welding or the like.

[0055] The length CW1 of the battery module 20 in the vehicle width direction is, for example, 530mm to 600mm, the length CW2 of the area where the electrode body is housed is, for example, 500mm to 520mm, and the height CH of the battery module 20 is, for example, 80mm to 110mm. The thickness of the battery module 20 is 7.0mm to 9.0mm, and the height TH of the terminal 26 is 40mm to 50mm. [Explanation of symbols]

[0056] 20A Outer side, 20B Inner side, 20C Side side, 210 First sheet, 220 Second sheet, 212, 222 Fused resin layer, 214, 224 Metal layer, 214A, 214B, 214C, 214D Exposed part, 216, 226 Protective resin layer, 40 Battery module case, 42 Resin component, 8 Electrode body, 10 Battery pack, 11, 11A, 11B, 11C Battery module, 12 Voltage terminal, 14 Connector, 20 Battery cell, 22 Flexible printed circuit board, 24 Thermistor, 26 Terminal, 28 Laminate film, 30 Fixing tape, 100 Vehicle, 102 Converter, 104 Electric compressor, 106 Heater, 108 Motor, 110 Gearbox, 112 Inverter, 114 On-board charger, 114 Charger, 116 charging port

Claims

1. A battery cell comprising an electrode body having a stacked structure in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are further stacked, and a battery cell case that encloses the electrode body inside, A battery module including a heat dissipation member that contacts the battery cell case, The battery cell case has at least a metal layer and a fusion resin layer disposed on the inner side of the metal layer, and has an exposed portion on at least a part of the outer surface in which the metal layer is exposed. The battery module wherein the battery cell case has the exposed portion on the outer surface side of a region E whose inner surface contacts the electrode body, and the heat dissipation member contacts the exposed portion in the region E.

2. The battery module according to claim 1, wherein the electrode surface of the electrode body is rectangular in shape, and the exposed portion is located at the end of the longer side of the rectangular shape.

3. The battery module according to claim 1, wherein the battery cell case includes a first sheet having the exposed portion and a second sheet not having the exposed portion, and the average thickness of the metal layer in the first sheet is greater than the average thickness of the metal layer in the second sheet.

4. The battery module according to claim 1, comprising at least one of a battery module case and a cooler as the heat dissipation member, wherein at least one of the battery module case and the cooler is in contact with the exposed portion.

5. The battery module according to claim 1, comprising at least one of a battery module case and a cooler, and having a resin member that joins at least one of the battery module case and cooler, which serves as a heat dissipation member, to the battery cell case, wherein the resin member is in contact with the exposed portion.

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