Battery module

Abstract

The present disclosure pertains to a battery module provided with battery cells, a heat-insulating member, and a first heat-dissipating member as a heat-dissipating member, the battery module being provided with at least a first battery cell and a second battery cell as the battery cells, the first heat-dissipating member being disposed adjacent to each of the battery cells, and the second heat-dissipating member being disposed adjacent to each of the battery cells. The heat-insulating member is disposed between the first battery cell and the second battery cell, and the ratio of the thermal resistance of the heat-insulating member to the thermal resistance of the heat-dissipating member, i.e., the thermal resistance of the heat-insulating member / the thermal resistance of the heat-dissipating member, is 0.0102 or more.

Description

Technical Field

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

[0002] Various technologies have been proposed regarding a battery module such as that disclosed in Japanese Patent Publication No. 2022-549926. Summary of the Invention

[0003] Conventional battery modules include thermal insulation between multiple battery cells, heat dissipation members sandwiched between the insulation members, and a heat sink connected to the heat dissipation members. However, there is room for improvement in terms of preventing heat from being transferred from one battery cell to adjacent cells.

[0004] The present disclosure has been made in view of the above-mentioned actual situation, and a main object thereof is to provide a battery module that can suppress the transfer of heat generated by a single cell to adjacent single cells.

[0005] That is, the present disclosure includes the following aspects.

[0006] <1> A battery module,

[0007] The battery module includes a battery cell, a heat insulating member, and a first heat dissipating member serving as a heat dissipating member.

[0008] The battery module includes at least a first battery cell and a second battery cell as the battery cells.

[0009] The first heat dissipation member is arranged adjacent to each of the battery cells.

[0010] The heat insulating member is disposed between the first battery cell and the second battery cell.

[0011] The ratio of the thermal resistance of the heat insulating member to the thermal resistance of the heat dissipating member, that is, thermal resistance of the heat insulating member / thermal resistance of the heat dissipating member, is 0.0102 or more.

[0012] <2> A battery module,

[0013] The battery module includes a battery cell, two heat insulating members, and a first heat dissipating member and a second heat dissipating member as heat dissipating members.

[0014] The battery module includes at least a first battery cell and a second battery cell as the battery cells.

[0015] The first heat dissipation member is arranged adjacent to each of the battery cells.

[0016] The two heat insulating members are arranged between the first battery cell and the second battery cell,

[0017] The second heat dissipating member is disposed so as to be sandwiched between the two heat insulating members.

[0018] <3> according to <1> or <2> The battery module,

[0019] The heat dissipation member has a thickness smaller than that of the first battery cell and the second battery cell.

[0020] <4> according to <1> ~ <3> The battery module according to any one of the preceding claims,

[0021] The heat dissipation component is composed of a heat dissipation plate and a heat conducting member.

[0022] <5> A battery pack comprising:

[0023] <1> ~ <4> The battery module described in any one of the preceding claims, a stack case accommodating the battery module, and a cooler for cooling the battery module.

[0024] According to the present disclosure, it is possible to provide a battery module that can suppress the transfer of heat generated from a single cell to an adjacent single cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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 numerals represent like elements, and in which:

[0026] Figure 1 It is a schematic cross-sectional view showing an example of the first embodiment of the battery pack of the present disclosure.

[0027] Figure 2 It is a schematic cross-sectional view showing an example of a second embodiment of the battery pack of the present disclosure.

[0028] Figure 3 This is a graph showing the relationship between the thermal resistance ratio (thermal resistance of the heat insulating member / thermal resistance of the first heat dissipating member) and the ultimate temperature of the adjacent battery cell (second battery unit) sandwiched between the heat insulating member.

[0029] Figure 4 This is a graph showing the relationship between the thickness of the heat insulating member and the peak temperature of the adjacent battery cell (second battery unit) sandwiching the heat insulating member. DETAILED DESCRIPTION

[0030] The following describes embodiments of the present disclosure. Furthermore, matters necessary for implementing the present disclosure (e.g., battery modules that do not contribute to the present disclosure) other than those specifically mentioned in this specification can be considered design considerations by those skilled in the art based on existing technologies in the field. The present disclosure can be implemented based on the contents disclosed in this specification and common technical knowledge in the field.

[0031] In a first embodiment of the present disclosure, a battery module is provided.

[0032] The battery module includes a battery cell, a heat insulating member, and a first heat dissipating member serving as a heat dissipating member.

[0033] The battery module includes at least a first battery cell and a second battery cell as the battery cells.

[0034] The first heat dissipation member is arranged adjacent to each of the battery cells.

[0035] The heat insulating member is disposed between the first battery cell and the second battery cell.

[0036] The ratio of the thermal resistance of the heat insulating member to the thermal resistance of the heat dissipating member, that is, thermal resistance of the heat insulating member / thermal resistance of the heat dissipating member, is 0.0102 or more.

[0037] In a second embodiment of the present disclosure, a battery module is provided.

[0038] The battery module includes a battery cell, two heat insulating members, and a first heat dissipating member and a second heat dissipating member as heat dissipating members.

[0039] The battery module includes at least a first battery cell and a second battery cell as the battery cells.

[0040] The first heat dissipation member is arranged adjacent to each of the battery cells.

[0041] The two heat insulating members are arranged between the first battery cell and the second battery cell,

[0042] The second heat dissipating member is disposed so as to be sandwiched between the two heat insulating members.

[0043] The battery module of the present disclosure includes a first battery cell, a second battery cell, at least one heat insulating member, and at least a first heat dissipating member serving as a heat dissipating member.

[0044] The first battery cell and the second battery cell are collectively referred to as a battery cell (sometimes simply referred to as a single cell).

[0045] The second battery cell is arranged adjacent to the first battery cell.

[0046] The battery module only needs to include at least two battery cells, namely a first battery cell and a second battery cell, as battery cells, but may also include three or more battery cells.

[0047] The battery cell may include a positive electrode including a positive electrode current collector and a positive electrode layer, an electrolyte layer, and a negative electrode including a negative electrode layer and a negative electrode current collector.

[0048] The battery cell may include a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector in this order.

[0049] The battery cell may be a conventionally known battery, a liquid battery, or a solid battery.

[0050] In this disclosure, a solid-state battery refers to a battery containing a solid electrolyte. A solid-state battery may be a semi-solid battery, which is a solid battery containing a solid electrolyte and a liquid material, or a fully solid-state battery, which is a solid battery containing no liquid material. The battery may be a primary battery or a secondary battery.

[0051] The thermal insulation member is disposed between the first battery cell and the second battery cell. When the battery module has three or more battery cells, the thermal insulation member may be disposed between each of the three or more battery cells. In the first embodiment of the present disclosure, at least one thermal insulation member may be disposed between each battery cell. In the second embodiment of the present disclosure, at least two thermal insulation members (a first thermal insulation member and a second thermal insulation member) may be disposed between each battery cell.

[0052] When the battery module includes two or more heat insulating members, the heat insulating members may be made of the same material or different materials.

[0053] The heat insulating member may be made of a conventionally known material.

[0054] In the first embodiment of the present disclosure, a first heat dissipation member is provided as a heat dissipation member. In the second embodiment of the present disclosure, a first heat dissipation member and a second heat dissipation member are provided as heat dissipation members. In the present disclosure, the first heat dissipation member and the second heat dissipation member are collectively referred to as heat dissipation members.

[0055] The heat dissipating member may be made of a conventionally known material, or may be made of a metal material such as aluminum, or a carbon material such as carbon.

[0056] To reduce thermal resistance, the heat dissipation member may be thinner than the first and second battery cells. If the battery module has three or more battery cells, the heat dissipation member may be thinner than the thickness of each battery cell in the three or more battery cells.

[0057] The heat dissipation component includes a heat dissipation plate and, if necessary, a heat conducting member. The heat dissipation plate and the heat conducting member can be made of the same material or different materials.

[0058] The heat conducting member may be a heat conducting sheet.

[0059] The first heat dissipating member is arranged adjacent to each battery cell.

[0060] The first heat dissipating member may be disposed between each battery cell and the heat insulating member, or may be disposed on a surface of each battery cell opposite to a surface adjacent to the heat insulating member.

[0061] The heat dissipation plate of the first heat dissipation member may be arranged between each battery cell and the heat insulating member, or may be arranged on the surface of each battery cell opposite to the surface adjacent to the heat insulating member.

[0062] The heat conducting material of the first heat dissipating member may be arranged between the heat dissipating plate of the first heat dissipating member and the cooler. The heat conducting material of the first heat dissipating member may be arranged between the heat dissipating plate of the first heat dissipating member and the assembly case.

[0063] The second heat dissipating member is disposed so as to be sandwiched between the two heat insulating members.

[0064] The heat dissipation plate of the second heat dissipation member may be arranged between the two heat insulating members.

[0065] The heat conducting material of the second heat dissipating member may be arranged between the heat dissipating plate of the second heat dissipating member and the cooler. The heat conducting material of the second heat dissipating member may be arranged between the heat dissipating plate of the second heat dissipating member and the stack case.

[0066] Since the thermal conductor of the second heat dissipating member is insulated from the battery cells by the heat insulating member, it is not necessary to ensure insulation, and therefore measures are taken to reduce thermal resistance.

[0067] The thickness of the second heat dissipation member may be smaller than the thickness of the battery cell, may be the same as the thickness of the first heat dissipation member, or may be smaller than the thickness of the first heat dissipation member.

[0068] The thickness of the heat dissipation plate and the heat conduction member of the second heat dissipation member may be smaller than the thickness of the battery cell, and may be the same as or smaller than the thickness of the heat dissipation plate and the heat conduction member of the first heat dissipation member.

[0069] The thermal conductivity of the heat conductive material of the second heat dissipation member can be greater than that of the heat conductive material of the first heat dissipation member. By making the thermal resistance of the second heat dissipation member lower than the thermal resistance of the heat insulating member, heat conduction to adjacent battery cells can be suppressed, allowing heat to be efficiently dissipated to the cooler and / or the stack case, thereby achieving space savings.

[0070] In the first embodiment of the present disclosure, the ratio of the thermal resistance of the thermal insulation member to the thermal resistance of the heat dissipation member (thermal resistance of the thermal insulation member / thermal resistance of the heat dissipation member) can be 0.0102 or more. In the second embodiment of the present disclosure, the ratio of the thermal resistance of the thermal insulation member to the thermal resistance of the heat dissipation member (thermal resistance of the thermal insulation member / thermal resistance of the heat dissipation member) can be 0.0102 or more. In the present disclosure, from the viewpoint of further suppressing the transfer of heat generated by a single cell to an adjacent single cell, the lower limit can be 0.0308 or more, 0.0925 or more, 0.1542 or more, 0.3084 or more, or 0.8325 or more.

[0071] In the present disclosure, the upper limit of the ratio of the thermal resistance of the heat insulating member to the thermal resistance of the heat dissipating member (thermal resistance of the heat insulating member / thermal resistance of the heat dissipating member) can be 30.8400 or less, 15.4200 or less, 7.4925 or less, or 2.4975 or less, from the perspective of suppressing the increase in the thickness of the heat insulating member, achieving space saving, and improving the energy density of the battery module. The thermal resistance of the heat dissipating member and the thermal resistance of the heat insulating member can be calculated according to the following formula (1).

[0072] (1 / thermal conductivity) × distance ÷ cross-sectional area ... formula (1)

[0073] Since heat moves in the thickness direction of the thermal insulation member, the distance used when calculating the thermal resistance of the thermal insulation member is the thickness of the thermal insulation member.

[0074] Since heat moves from the heat dissipation plate of the heat dissipation member to the heat conductor of the heat dissipation member disposed between the heat dissipation plate and the cooler or the stack case, the distance used to calculate the thermal resistance of the heat dissipation member is the distance from the center to the end of the cross section of the heat dissipation member.

[0075] A battery pack according to the present disclosure includes the battery module according to the present disclosure, a pack case that houses the battery module, and a cooler that cools the battery module.

[0076] The stack case is not particularly limited as long as it can accommodate the battery modules.

[0077] At least one of the cooler and the stack case may be arranged adjacent to the heat conductor of the heat dissipation member.

[0078] The cooler may be housed in the stack casing, may be arranged outside the stack casing, or may be arranged adjacent to the stack casing.

[0079] The cooler may be a conventionally known cooler as appropriate, and may be a heat spreader.

[0080] As applications of the battery module disclosed herein, for example, power sources for hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), electric vehicles (BEV), fuel vehicles, diesel vehicles, and the like can be cited. Among them, it can also be used as a driving power source for hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), or electric vehicles (BEV). In addition, the battery module can be used as a power source for mobile objects other than vehicles (such as railways, ships, and aircraft), and can also be used as a power source for electrical products such as information processing devices.

[0081] Figure 1 It is a schematic cross-sectional view showing an example of the first embodiment of the battery pack of the present disclosure.

[0082] The battery pack 100 includes a cooler 40 and a battery module 50. The battery module 50 is housed in a pack case (not shown).

[0083] The battery module 50 includes a first battery cell 10 , a second battery cell 12 , a heat insulating member 20 , and a first heat dissipating member 32 including a heat dissipating plate 30 and a heat conductor 31 .

[0084] The second battery cell 12 is disposed adjacent to the first battery cell 10 , and the heat insulating member 20 is disposed between the first battery cell 10 and the second battery cell 12 .

[0085] One first heat dissipating member 32 is disposed on the surface of the first battery cell 10 opposite to the surface in contact with the heat insulating member 20 , and one is disposed between the second battery cell 12 and the heat insulating member 20 .

[0086] The heat conductor 31 of the first heat dissipating member 32 is disposed below the heat dissipating plate 30 and between the heat dissipating plate 30 and the cooler 40 .

[0087] The cooler 40 is disposed below the heat conductor 31 of the first heat dissipating member 32 .

[0088] The thickness of the first heat dissipating member 32 is smaller than the thickness of the first battery cell 10 and the second battery cell 12 .

[0089] The heat conductor 31 serves as a heat path for the heat sink 30 .

[0090] The heat 60 moves from the heat dissipation plate 30 of the first heat dissipation member 32 to the heat conductor 31 disposed below the heat dissipation plate 30 .

[0091] Figure 2 It is a schematic cross-sectional view showing an example of a second embodiment of the battery pack of the present disclosure.

[0092] The battery pack 200 includes a cooler 40 and a battery module 50. The battery module 50 is housed in a pack case (not shown).

[0093] The battery module 50 includes a first battery cell 10 , a second battery cell 12 , two heat insulating members 20 (a first heat insulating member and a second heat insulating member), a first heat dissipating member 32 including a heat dissipating plate 30 and a heat conducting member 31 , and a second heat dissipating member 35 including a heat dissipating plate 33 and a heat conducting member 34 .

[0094] The second battery unit 12 is arranged adjacent to the first battery unit 10 .

[0095] The two heat insulating members 20 are arranged between the first battery cell 10 and the second battery cell 12 .

[0096] One first heat dissipating member 32 is disposed on the surface of the first battery cell 10 opposite to the surface in contact with the heat insulating member 20 , and one is disposed between the second battery cell 12 and the heat insulating member 20 .

[0097] The heat conductor 31 of the first heat dissipating member 32 is disposed below the heat dissipating plate 30 and between the heat dissipating plate 30 and the cooler 40 .

[0098] The second heat dissipating member 35 is disposed so as to be sandwiched between the two heat insulating members 20 .

[0099] The heat conductor 34 of the second heat dissipating member 35 is disposed below the heat dissipating plate 33 and between the heat dissipating plate 33 and the cooler 40 .

[0100] The cooler 40 is disposed below the heat conductor 31 of the first heat dissipating member 32 and the heat conductor 34 of the second heat dissipating member 35 .

[0101] The thickness of the first heat dissipating member 32 and the second heat dissipating member 35 is smaller than the thickness of the first battery cell 10 and the second battery cell 12 .

[0102] The heat conductor 31 forms a heat path for the heat sink 30 , and the heat conductor 34 forms a heat path for the heat sink 33 .

[0103] The heat 60 moves from the heat dissipation plate 30 of the first heat dissipation member 32 to the heat conductor 31 disposed below the heat dissipation plate 30 .

[0104] Heat 60 also moves in the thickness direction of heat insulating member 20, and moves from heat dissipation plate 33 of second heat dissipation member 35 to heat conductor 34 disposed below heat dissipation plate 33. Thus, movement of heat 60 to second battery cell 12 can be suppressed.

[0105] (Examples 1 to 19, Comparative Example 1)

[0106] [First embodiment]

[0107] In Examples 1 to 19 and Comparative Example 1, a battery module is used that includes a predetermined first battery cell, a predetermined second battery cell, a first heat dissipation member (including a heat dissipation plate and a heat conductor) arranged adjacent to each of the battery cells, and an insulating member arranged between the first battery cell and the second battery cell.

[0108] Four types of thermal insulation members having different thermal resistances as shown in Table 1 were prepared.

[0109] The thermal resistance of the heat insulating member of 0.1200 K / W is the thermal resistance of the heat insulating member having a thickness of 0.1200 mm.

[0110] The thermal resistance of the heat insulating member of 0.3700 K / W is the thermal resistance of the heat insulating member having a thickness of 0.3700 mm.

[0111] The thermal resistance of the heat insulating member of 1.1100 K / W is the thermal resistance of the heat insulating member having a thickness of 1.1100 mm.

[0112] The thermal resistance of the heat insulating member, 3.3300 K / W, is the thermal resistance of the heat insulating member having a thickness of 3.3300 mm.

[0113] Battery modules of Examples 1 to 19 and Comparative Example 1 were prepared using one of four types of thermal insulation members and one of a plurality of first heat dissipating members having different thermal resistances, and having different thermal resistances of the thermal insulation members and at least one of the thermal resistance of the thermal insulation members and the thermal resistance of the first heat dissipating members.

[0114] A predetermined first battery cell of the battery modules of Examples 1 to 19 and Comparative Example 1 was heated to 898° C., and the peak temperature of the adjacent battery cell (predetermined second battery cell) with the insulating member interposed therebetween was measured.

[0115] Table 1 shows the thermal resistance of the heat insulating member, the thermal resistance of the first heat dissipating member, the thermal resistance of the heat insulating member / the thermal resistance of the first heat dissipating member, and the reaching temperature of the adjacent cells with the heat insulating member interposed therebetween in Examples 1 to 19 and Comparative Example 1.

[0116]

Table 1

[0117] Table 1

[0118]

[0119] Figure 3 This is a graph showing the relationship between the thermal resistance ratio (thermal resistance of the heat insulating member / thermal resistance of the first heat dissipating member) and the ultimate temperature of the adjacent battery cell (second battery unit) sandwiched between the heat insulating member.

[0120] According to Table 1, Figure 3As shown, the ratio of the thermal resistance of the insulating component to the thermal resistance of the first heat dissipation component (thermal resistance of the insulating component / thermal resistance of the first heat dissipation component) only needs to be 0.0102 or above, which can reduce the reaching temperature of adjacent single cells separated by the insulating component. If it reaches 0.0925 or above, the reaching temperature of the adjacent single cells is significantly reduced. If it reaches 0.8325 or above, the effect of reducing the reaching temperature of the adjacent single cells is better and more stable.

[0121] (Examples 20 to 34)

[0122] [Second embodiment]

[0123] In Examples 20 to 24, a battery module is used that includes a predetermined first battery cell, a predetermined second battery cell, a first heat dissipation member (including a heat dissipation plate and a heat conductor) having a predetermined thermal resistance (satisfying the thermal resistance of the insulation member / the thermal resistance of the first heat dissipation member is greater than 0.0102) arranged adjacent to each of the battery cells, two insulation members arranged between the first battery cell and the second battery cell, and a second heat dissipation member (including only the heat dissipation plate, not including the heat conductor) arranged between the two insulation members.

[0124] In Examples 25 to 34, a battery module is used that includes a predetermined first battery cell, a predetermined second battery cell, a first heat dissipation component (including a heat dissipation plate and a heat conductor) having a predetermined thermal resistance (satisfying the thermal resistance of the insulation component / the thermal resistance of the first heat dissipation component is greater than 0.0102) arranged adjacent to each of the battery cells, two insulation components arranged between the first battery cell and the second battery cell, and a second heat dissipation component (including a heat dissipation plate and a heat conductor) arranged between the two insulation components.

[0125] Five types of thermal insulation members having different thicknesses (thermal resistances) as shown in Table 2 were prepared.

[0126] Battery modules of Examples 20 to 24 having different thermal resistances of the thermal insulating members were prepared using one of the five types of thermal insulating members and a second heat dissipating member including only a heat dissipating plate but no heat conductor.

[0127] Battery modules of Examples 25 to 34 were prepared using one of five types of thermal insulation members and one of a plurality of second heat dissipation members (including heat dissipation plates and heat conductors) having different thermal resistances, and having different thermal resistances of the thermal insulation members and at least one of the thermal resistance of the thermal insulation members and the thermal resistance of the second heat dissipation members.

[0128] A predetermined first battery cell of the battery modules of Examples 20 to 34 was heated to 898° C., and the peak temperature of an adjacent battery cell (predetermined second battery cell) separated by two heat insulating members was measured.

[0129] Table 2 shows the thermal resistance of the heat insulating member, the thermal resistance of the second heat dissipating member, the thermal resistance of the heat insulating member / the thermal resistance of the second heat dissipating member, and the reaching temperature of the adjacent cells with the heat insulating member interposed therebetween in Examples 20 to 34.

[0130]

Table 2

[0131] Table 2

[0132]

[0133] Figure 4 This is a graph showing the relationship between the thickness of the heat insulating member and the peak temperature of the adjacent battery cell (second battery unit) sandwiching the heat insulating member.

[0134] According to Table 2, Figure 4 As shown, in Examples 20 to 24, increasing the thickness of the heat insulating member can reduce the reaching temperature of adjacent cells. On the other hand, a comparison of Example 20 with Examples 25 to 29, and a comparison of Example 21 with Examples 30 to 34, shows that by including a heat conductor in the second heat dissipating member and ensuring that the ratio of the thermal resistance of the heat insulating member to the thermal resistance of the heat dissipating member (heat insulating member thermal resistance / heat dissipating member thermal resistance) satisfies a predetermined value, it is possible to reduce the reaching temperature of adjacent cells even without increasing the thickness of the heat insulating member as in Examples 22 to 24.

Claims

1. A battery module, The battery module includes a battery cell, a heat insulating member, and a first heat dissipating member serving as a heat dissipating member. The battery module includes at least a first battery cell and a second battery cell as the battery cells. The first heat dissipation member is arranged adjacent to each of the battery cells. The heat insulating member is disposed between the first battery cell and the second battery cell. The ratio of the thermal resistance of the heat insulating member to the thermal resistance of the heat dissipating member, that is, thermal resistance of the heat insulating member / thermal resistance of the heat dissipating member, is 0.0102 or more.

2. A battery module, The battery module includes a battery cell, two heat insulating members, and a first heat dissipating member and a second heat dissipating member as heat dissipating members. The battery module includes at least a first battery cell and a second battery cell as the battery cells. The first heat dissipation member is arranged adjacent to each of the battery cells. The two heat insulating members are arranged between the first battery cell and the second battery cell, The second heat dissipating member is disposed so as to be sandwiched between the two heat insulating members.

3. The battery module according to claim 1 or 2, The heat dissipation member has a thickness smaller than that of the first battery cell and the second battery cell.

4. The battery module according to claim 1 or 2, The heat dissipation component is composed of a heat dissipation plate and a heat conducting member.

5. A battery pack, The battery pack includes the battery module according to claim 1 or 2, a pack case that houses the battery module, and a cooler that cools the battery module.

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