Battery pack

Abstract

To provide a battery pack in which the thermal conduction between battery modules can be suppressed even if the number of components is reduced.SOLUTION: A battery pack according to the present disclosure includes a plurality of battery modules, at least one bracket, at least one heat insulating member, and a battery pack container. The battery module includes a plurality of battery cells, and a battery module container that accommodates the battery cells. The bracket is attached to the battery module container, and connects the adjacent battery modules among the plurality of battery modules. The heat insulating member is disposed between the adjacent battery modules. The battery pack container accommodates the battery modules, the at least one bracket, and the at least one heat insulating member. The heat insulating member is held in the bracket.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a battery pack. [Background technology]

[0002] For battery packs using lithium-ion batteries, technology is being developed to prevent heat conduction between battery modules when thermal runaway occurs in the lithium-ion batteries.

[0003] Patent Document 1 discloses a battery pack (hereinafter also referred to as "battery pack"). The battery pack includes a plurality of battery modules (hereinafter also referred to as "battery modules"). The plurality of battery modules are housed in a battery pack housing. Fireproof material is arranged between adjacent battery modules. As methods for installing and fixing the fireproof material in a housing (hereinafter also referred to as "battery module container") that forms a battery module, the patent document discloses two methods: a method for fixing the fireproof material to the battery module container via an adhesive material, and a method for fixing the fireproof material using a frame after stacking the fireproof material on the battery module container. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-206604 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the battery pack disclosed in Patent Document 1 requires fixing parts (e.g., adhesive or a frame) for fixing the fire-resistant material in addition to brackets that connect adjacent battery modules. Therefore, there is a demand for a battery pack that can suppress heat conduction between battery modules even without fixing parts (i.e., even if the number of parts is reduced).

[0006] The present disclosure has been made in consideration of the above circumstances. An object of one embodiment of the present disclosure is to provide a battery pack that can suppress heat conduction between battery modules even when the number of parts is reduced. [Means for solving the problem]

[0007] The means for solving the above problems include the following embodiments.

[0008] <1> The battery pack of the first aspect comprises: a plurality of battery modules each having a plurality of battery cells and a battery module container for accommodating the plurality of battery cells; at least one bracket attached to the battery module container and connecting adjacent battery modules among the plurality of battery modules; at least one heat insulating member disposed between the adjacent battery modules; a battery pack container that houses the plurality of battery modules, the at least one bracket, and the at least one heat insulating member; The heat insulating member is held by the bracket in the battery pack.

[0009] In the first aspect, the heat insulating member is held by a bracket. That is, unlike conventional brackets, the bracket of the first aspect has the function of holding the heat insulating member. This allows the heat insulating member to be disposed in the space between adjacent battery modules without the need for conventional fixing parts. As a result, the battery pack of the first aspect can suppress heat conduction between battery modules even with a reduced number of parts.

[0010] <2> The battery pack of the second aspect is the heat insulating member has a heat insulating plate that partitions at least a part of the space between the adjacent battery modules, The bracket has a through hole, The heat insulating plate is fitted into the through hole. <1> 2. The battery pack according to claim 1.

[0011] This allows the heat insulating plate of the second aspect to be reliably fixed by the bracket, and as a result, the battery pack of the second aspect can suppress heat conduction between the battery modules for a long period of time.

[0012] <3> The battery pack of the third aspect is the heat insulating member further includes a cover plate attached to the bracket and closing at least a portion of the space between the adjacent battery modules; The heat insulating plate has a first cutout portion, the cover plate has a second cutout portion, the first cutout portion and the second cutout portion are fitted together; <2> 2. The battery pack according to claim 1.

[0013] This allows the battery pack of the third aspect to suppress heat conduction due to gas between the battery modules more effectively than when the heat insulating member does not have a cover plate. As a result, the battery pack of the third aspect can further suppress heat conduction between the battery modules.

[0014] <4> The battery pack of the fourth aspect is the heat insulating member has a heat insulating plate that partitions at least a part of the space between the adjacent battery modules, the bracket has a groove; The heat insulating plate is fitted into the groove. <1> 2. The battery pack according to claim 1.

[0015] This allows the heat insulating plate of the fourth aspect to be reliably fixed by the bracket, and as a result, the battery pack of the fourth aspect can suppress heat conduction between the battery modules for a long period of time.

[0016] <5> A fifth aspect of the battery pack is the battery cell includes a laminated lithium ion secondary battery; <1> ~ <4> The battery pack according to any one of the above items.

[0017] The term "laminated lithium ion secondary battery" refers to a lithium ion secondary battery that includes a laminate film container.

[0018] The battery pack of the fifth aspect can suppress heat conduction between battery modules including laminated lithium secondary batteries. [Effects of the Invention]

[0019] According to an embodiment of the present disclosure, a battery pack is provided that has a small number of parts and is capable of suppressing heat conduction between battery modules. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view of a battery pack according to a first embodiment. [Figure 2] FIG. 2 is a front view of the battery pack according to the first embodiment. [Figure 3] FIG. 3 shows a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is an exploded perspective view of the heat insulating member according to the first embodiment. [Figure 5] FIG. 5 is a front view of the battery pack according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

[0022] Hereinafter, embodiments of the battery pack of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0023] (1) First embodiment As shown in Fig. 1, the battery pack 1A of the first embodiment includes a plurality of heat insulating members 10A, a plurality of brackets 20A, four battery modules 30, a battery pack container 40, and a plurality of fastening bolts 50. The battery module 30 is a rectangular parallelepiped object. The battery pack container 40 houses the plurality of heat insulating members 10A, the plurality of brackets 20A, the four battery modules 30, and the plurality of fastening bolts 50.

[0024] In the first embodiment, the longitudinal direction of the main surface of the battery module 30 is the X-axis direction, the lateral direction of the main surface of the battery module 30 is the Y-axis direction, and the thickness direction of the battery module 30 is the Z-axis direction. The X-axis, Y-axis, and Z-axis are perpendicular to each other. Note that these directions do not limit the orientation of the battery pack of the present disclosure during use.

[0025] The four battery modules 30 are arranged in two rows aligned in the Y-axis direction. Each row is made up of two battery modules 30 arranged along the X-axis direction. A pair of brackets 20A is disposed between the battery modules 30 adjacent to each other in the X-axis direction. The heat insulating member 10A is held by the pair of brackets 20A.

[0026] (1.1) Heat insulating materials 2 to 4, the heat insulating member 10A includes a heat insulating plate 11A and a cover plate 12. The heat insulating plate 11A is a flat plate-like object and is attached to a pair of brackets 20A.

[0027] The heat insulating plate 11A partitions a part of the space R30 (see FIGS. 2 and 3) between adjacent battery modules 30. As shown in FIG. 4, the heat insulating plate 11A has a first cutout portion C11 formed along the Y-axis direction. The cover plate 12 is a flat plate. As shown in FIG. 3, the cover plate 12 closes the opening on the positive side of the Z-axis of the space R30 between adjacent battery modules 30.

[0028] 4, the cover plate 12 has four through holes H12 into which the fastening bolts 50 are inserted, and second cutout portions C12 formed along the Y-axis direction. The first cutout portions C11 and the second cutout portions C12 fit together.

[0029] The material of the heat insulating member 10A may be any known material that provides heat resistance and flame retardancy to the heat insulating member 10A, such as mica, glass wool, silica, aerogel, etc. These materials may be used alone or in combination.

[0030] (1.2) Bracket The bracket 20A connects the battery modules 30 adjacent to each other in the X-axis direction. As shown in FIG. 4, the bracket 20A is a long plate-like object. The longitudinal direction of the bracket 20A is the Y-axis direction. The length of the bracket 20A in the Y-axis direction is approximately the same as the length of the battery modules 30 in the Y-axis direction. As shown in FIG. 2, the bracket 20A closes the opening on the positive side of the Z-axis of the space R30 between the adjacent battery modules 30.

[0031] The bracket 20A has one through hole H20A into which the heat insulating plate 11A is inserted, and four through holes H20B into which the fastening bolts 50 are inserted. The heat insulating plate 11A is fitted into the through holes H20A of the pair of brackets 20A. The material of the bracket 20A is not particularly limited, and may be metal or resin.

[0032] (1.3) Battery module The battery module 30 includes a plurality of battery cells 31 and a battery module container 32. The battery module container 32 houses the plurality of battery cells 31. The battery module 30 may be a known battery module.

[0033] The battery cells 31 function as power-generating elements. The type of battery cell 31 is not particularly limited, and examples thereof include primary batteries (e.g., manganese batteries, alkaline manganese batteries, lithium graphite fluoride batteries, lithium manganese dioxide batteries, solid electrolyte batteries, flooded batteries, and thermal batteries) and secondary batteries (e.g., lithium ion batteries, lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-iron batteries, silver oxide-zinc batteries, lithium manganese dioxide secondary batteries, lithium cobaltate carbonate secondary batteries, and vanadium lithium secondary batteries). The lithium ion secondary battery may be a lithium ion secondary battery using a nonaqueous electrolyte or a lithium ion secondary battery using a solid electrolyte.

[0034] The battery cells 31 may be of a laminated type or a metal container type. "Laminated type" refers to a battery cell having a laminated film container. "Metal container type" refers to a battery cell having a metal container. The metal container may be rectangular or cylindrical. The battery cells 31 preferably include laminated lithium-ion secondary batteries. The number of battery cells 31 housed in one battery module 30 is selected appropriately depending on the application of the battery pack 1A, etc. Multiple battery cells 31 may be stacked along one of the X-axis direction, Y-axis direction, and Z-axis direction.

[0035] The battery module container 32 is a rectangular parallelepiped container. As shown in Fig. 3, the battery module container 32 has two through holes H12 into which the fastening bolts 50 are inserted. The material of the battery module container 32 is not particularly limited, and may be metal or resin.

[0036] (1.4) Battery pack container The battery pack container 40 houses a plurality of heat insulating members 10A, a plurality of brackets 20A, four battery modules 30, and a plurality of fastening bolts 50. The battery pack container 40 may include a lower tray 41 and a cover (not shown). The lower tray 41 houses a plurality of battery modules 30. The lower tray 41 is a container-like object that opens in the positive direction of the Z axis. The cover covers the opening of the lower tray 41. The material of the battery pack container 40 is not particularly limited and may be metal or resin. The battery pack container 40 may be a known battery pack container. The battery pack container 40 may include a known cooling device for cooling the battery modules 30.

[0037] (1.5) Fastening bolts The fastening bolt 50 unites the heat insulating member 10A, the bracket 20A, and the battery module 30. The fastening bolt 50 is inserted into the through-hole H12 of the heat insulating member 10A and the through-hole H20B of the bracket 20A. This attaches the bracket 20A to the battery module 30. The material of the fastening bolt 50 is not particularly limited and may be metal or resin. The fastening bolt 50 may be a known fastening bolt.

[0038] (1.6)Applications The battery pack 1A can be used, for example, as a power source for devices (such as electric four-wheeled vehicles, electric two-wheeled vehicles, portable devices, and power storage systems). Examples of electric four-wheeled vehicles include battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and hybrid electric vehicles (HEVs). Examples of electric two-wheeled vehicles include electric motorcycles and electrically assisted bicycles. Examples of portable devices include smartphones, tablet computers, notebook computers, power tools, and video cameras. Examples of power storage systems include household power storage systems, industrial power storage systems, and energy storage systems (ESSs).

[0039] (1.7) Action and Effect 1 to 4, the battery pack 1A includes a plurality of battery modules 30, a plurality of brackets 20A, a plurality of heat insulating members 10A, and a battery pack container 40. The heat insulating members 10A are held by the brackets 20A. Unlike conventional brackets, the bracket 20A has the function of holding the heat insulating member 10A. This allows the heat insulating member 10A to be disposed in the space R30 between the battery modules 30 adjacent to each other in the X-axis direction, without the need for conventional fixing parts. As a result, the battery pack 1A can suppress heat conduction between the battery modules 30 even with a reduced number of parts.

[0040] As described with reference to Figures 1 to 4, in the battery pack 1A, the heat insulating member 10A has the heat insulating plate 11A. The bracket 20A has a through hole H20A. The heat insulating plate 11A is fitted into the through hole H20A. This allows the heat insulating plate 11A to be reliably fixed by the bracket 20A. As a result, the battery pack 1A can suppress heat conduction between the battery modules 30 for a long period of time.

[0041] As described with reference to FIGS. 1 to 4, in the battery pack 1A, the heat insulating member 10A further has a cover plate 12. The heat insulating plate 11A has a first cutout portion C11. The cover plate 12 has a second cutout portion C12. The first cutout portion C11 and the second cutout portion C12 fit together. This allows the battery pack 1A to suppress heat conduction due to gas between the battery modules 30 more effectively than when the heat insulating member 10A does not have the cover plate 12. As a result, the battery pack 1A can further suppress heat conduction between the battery modules 30.

[0042] As described with reference to FIGS. 1 to 4, in the battery pack 1A, the battery cells 31 preferably include laminated lithium ion secondary batteries. This allows the battery pack 1A to suppress heat conduction between the battery modules 30 including the laminated lithium secondary batteries.

[0043] (2) Second embodiment The battery pack 1B of the second embodiment is similar to the battery pack 1A of the first embodiment except that the heat insulating member 10A and the bracket 20A are different.

[0044] The battery pack 1B includes a plurality of battery modules 30, a plurality of brackets 20B, a plurality of heat insulating members 10B, and a battery pack container 40. The heat insulating members 10B are held by the brackets 20B.

[0045] (2.1) Bracket Bracket 20B is similar to bracket 20A, except that it has a groove G20 instead of through-hole H20A. Bracket 20B has groove G20 into which heat insulating plate 11B fits. Groove G20 is formed along the Y-axis direction. As shown in FIG. 6, bracket 20B closes the opening on the positive Z-axis side of space R30 between adjacent battery modules 30.

[0046] (2.2) Heat insulating materials The heat insulating member 10B has a heat insulating plate 11B. The heat insulating plate 11B is attached to a pair of brackets 20B. More specifically, the heat insulating plate 11B fits into each groove G20 of the pair of brackets 20B. The heat insulating plate 11B is similar to the heat insulating plate 11A except that it does not have the first cutout portion C11 and is a different size.

[0047] (2.3) Action and Effect 5 and 6, the battery pack 1B includes a plurality of battery modules 30, a plurality of brackets 20B, a plurality of heat insulating members 10B, and a battery pack container 40. The heat insulating members 10B are held by the brackets 20B. Unlike conventional brackets, the bracket 20B has the function of holding the heat insulating member 10B. This allows the heat insulating member 10B to be disposed in the space R30 between the battery modules 30 adjacent to each other in the X-axis direction, without the need for conventional fixing parts. As a result, the battery pack 1B can suppress heat conduction between the battery modules 30 even with a reduced number of parts.

[0048] 5 and 6, in the battery pack 1B, the heat insulating member 10B has the heat insulating plate 11B. The bracket 20B has a groove G20. The heat insulating plate 11B is fitted into the groove G20. This allows the heat insulating plate 11B to be reliably fixed to the bracket 20B, thereby preventing heat conduction between the battery modules 30 in the battery pack 1B for a long period of time.

[0049] (3) Variations In the first embodiment, the heat insulating member 10A includes the heat insulating plate 11A, but the present disclosure is not limited to this. The heat insulating member 10A does not need to include the heat insulating plate 11A as long as it can insulate adjacent battery modules from each other. In the second embodiment, the heat insulating member 10B includes a heat insulating plate 11B, but the present disclosure is not limited to this. The heat insulating member 10B does not need to include a heat insulating plate 11B as long as it can insulate adjacent battery modules from each other.

[0050] In the first embodiment, the heat insulating member 10A further includes a cover plate 12, but the present disclosure is not limited to this. The heat insulating member 10A does not necessarily have to include the cover plate 12.

[0051] In the first embodiment, a pair of brackets 20A are arranged between adjacent battery modules 30 in the X-axis direction, but the present disclosure is not limited to this. One bracket 20A or three or more brackets 20A may be arranged between adjacent battery modules 30 in the X-axis direction. In the second embodiment, a pair of brackets 20B are arranged between the battery modules 30 adjacent to each other in the X-axis direction, but the present disclosure is not limited to this. One bracket 20B or three or more brackets 20B may be arranged between the battery modules 30 adjacent to each other in the X-axis direction.

[0052] In the first embodiment, the heat insulating member 10A and the bracket 20A are disposed between the battery modules 30 adjacent in the X-axis direction, but the present disclosure is not limited to this. The heat insulating member 10A and the bracket 20A may be disposed between the battery modules 30 adjacent in the Y-axis direction, or may be disposed between the battery modules 30 adjacent in both the X-axis direction and the Y-axis direction. In the second embodiment, the heat insulating member 10B and the bracket 20B are disposed between the battery modules 30 adjacent in the X-axis direction, but the present disclosure is not limited to this. The heat insulating member 10B and the bracket 20B may be disposed between the battery modules 30 adjacent in the Y-axis direction, or may be disposed between the battery modules 30 adjacent in both the X-axis direction and the Y-axis direction.

[0053] In the first and second embodiments, the number of battery modules 30 is four, but the present disclosure is not limited to this. The number of battery modules 30 may be two, three, or five or more. The multiple battery modules 30 may be arranged in three or more rows. [Explanation of symbols]

[0054] 1A, 1B: battery pack, 10A, 10B: heat insulating member, 11A, 11B: heat insulating plate, 12: cover plate, 20A, 20B: bracket, 30: battery module, 31: battery cell, 40: battery pack container, 41: lower tray, 50: fastening bolt, C11: first notch, C12: second notch, G20: groove, H20A: through hole, R30: space

Claims

1. a plurality of battery modules each having a plurality of battery cells and a battery module container for accommodating the plurality of battery cells; at least one bracket attached to the battery module container and connecting adjacent battery modules among the plurality of battery modules; at least one thermal insulating member; a battery pack container that houses the plurality of battery modules, the at least one bracket, and the at least one heat insulating member; The heat insulating member is held by the bracket.

2. the heat insulating member has a heat insulating plate that partitions at least a part of the space between the adjacent battery modules, The bracket has a through hole, The battery pack according to claim 1 , wherein the heat insulating plate is fitted into the through hole.

3. the heat insulating member further includes a cover plate attached to the bracket and closing at least a portion of the space between the adjacent battery modules; the heat insulating plate has a first notch portion, the cover plate has a second cutout portion, The battery pack according to claim 2 , wherein the first cutout portion and the second cutout portion are fitted together.

4. the heat insulating member has a heat insulating plate that partitions at least a part of the space between the adjacent battery modules, the bracket has a groove; The battery pack according to claim 1 , wherein the heat insulating plate is fitted into the groove.

5. The battery pack according to any one of claims 1 to 4, wherein the battery cells include laminated lithium ion secondary batteries.

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