Power storage module

Abstract

To provide a technique capable of efficiently cooling a power storage module including a plurality of power storage devices.SOLUTION: A battery module 400 disclosed herein includes a plurality of batteries 100 each having a box-shaped battery case 10 and arranged along a predetermined direction, and a coolant supply means 300 for supplying a liquid coolant O for cooling the batteries 100. The first battery side 100A and the second battery side 100B are disposed such that a battery facing region 12b1 is formed between the first side 12b2 and the second side P1. A refrigerant guide path 22 for pulling up the liquid refrigerant O in the refrigerant holding portion 200 from the P1 of the bottom surface toward the top surface 14 by a capillary phenomenon is present in the battery facing region 12a. The refrigerant guiding path 22 is a space surrounded by the plurality of grooves 13 and a surface facing the plurality of grooves 13.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage module. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2013-161528 discloses a battery pack including a plurality of battery cells, a wick disposed between the battery cells, and a coolant that permeates the wick. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-161528 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, there is a demand for further development of technology that can efficiently cool an electricity storage module that includes a plurality of electricity storage devices. [Means for solving the problem]

[0005] The disclosed energy storage module has a box-shaped case and includes a plurality of energy storage devices arranged in a predetermined direction. The module also includes a refrigerant supply means for supplying a liquid refrigerant for cooling the energy storage devices. The case has at least a bottom surface, a top surface opposite the bottom surface, and a pair of side walls extending from the bottom surface toward the top surface and facing each other. At least one of the pair of side walls has a plurality of grooves. The refrigerant supply means has a refrigerant retaining section for immersing the bottom surface of the case in the liquid refrigerant. The plurality of energy storage devices include a first energy storage device and an adjacent second energy storage device. Of the pair of side walls of the first energy storage device, the side wall facing the second energy storage device is referred to as a first side wall. Of the pair of side walls of the second energy storage device, the side wall facing the first energy storage device is referred to as a second side wall. The first energy storage device and the second energy storage device are arranged such that a device-facing region is formed between the first side wall and the second side wall. In the device-facing region, a refrigerant guide path is present that draws the liquid refrigerant in the refrigerant holding portion from the bottom surface toward the top surface by capillary action. The refrigerant guide path is a space surrounded by the grooves and a surface facing the grooves. With this configuration, it is possible to efficiently cool an energy storage module including a plurality of energy storage devices. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view schematically showing a battery according to one embodiment. [Figure 2] FIG. 2 is a schematic vertical cross-sectional view taken along line II-II shown in FIG. [Figure 3] FIG. 3 is an explanatory diagram for explaining the configuration of the plurality of grooves and evaporation grooves of the battery shown in FIG. [Figure 4] FIG. 4 is a perspective view schematically showing a battery module according to one embodiment. [Figure 5] FIG. 5 is a schematic diagram of the battery module shown in FIG. 4 as viewed from the direction of the white arrow. [Figure 6]FIG. 6 is a schematic diagram showing the first battery, the second battery, and members included in the battery module shown in FIG. [Figure 7] FIG. 7 is a schematic diagram showing how the liquid refrigerant is drawn up from the bottom surface side to the top surface side by capillary action. [Figure 8] FIG. 8 is a schematic diagram of the first battery, the second battery, and the members in FIG. 7 viewed from the bottom side. [Figure 9] FIG. 9 is a view corresponding to FIG. 1 according to the second embodiment. [Figure 10] FIG. 10 is a view corresponding to FIG. 1 according to the third embodiment. [Figure 11] FIG. 11 is a view corresponding to FIG. 1 according to the fourth embodiment. [Figure 12] FIG. 12 is a view corresponding to FIG. 1 according to the fifth embodiment. [Figure 13] FIG. 13 is a view corresponding to FIG. 5, but with the battery shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0007] Several embodiments of the technology disclosed herein will be described below with reference to the drawings. In the following drawings, components and parts that perform the same function are denoted by the same reference numerals. Furthermore, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships. Matters other than those specifically mentioned in this specification that are necessary for implementing the technology disclosed herein (e.g., the general configuration and manufacturing process of an energy storage device or energy storage module that does not characterize this disclosure) can be understood as design matters of a person skilled in the art based on prior art in the relevant field. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the relevant field. Furthermore, the following description is not intended to limit the present disclosure to the following forms.

[0008] In this specification, the notation "A to B" indicating a range means "greater than A and less than B." It also encompasses the meanings of "greater than A" and "less than B." In addition, in this specification, the term "electricity storage device" refers to a device that can charge and discharge. Electricity storage devices include batteries such as primary batteries and secondary batteries (for example, non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries, and nickel-metal hydride batteries), and capacitors (physical batteries) such as electric double layer capacitors. In addition, the electrolyte may be any of a liquid electrolyte (electrolytic solution), a gel electrolyte, and a solid electrolyte.

[0009] Hereinafter, a battery module 400 including a plurality of lithium-ion secondary batteries (hereinafter simply referred to as "batteries 100"), which are an embodiment of a power storage device, will be described as an example of a power storage module. First, the batteries 100 constituting the battery module 400 will be described. In the following description, the symbols L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom, and the symbols X, Y, and Z in the drawings represent the short side direction of the battery 100, the long side direction perpendicular to the short side direction, and the up-down direction perpendicular to the short side direction and the long side direction, respectively. However, these directions are defined for convenience of description and do not limit the installation manner of the batteries 100 or the battery module 400 in any way.

[0010] <Battery configuration> FIG. 1 is a perspective view schematically illustrating a battery 100 according to one embodiment. FIG. 2 is a schematic longitudinal cross-sectional view taken along line II-II in FIG. 1. As shown in FIG. 2, the battery 100 includes a battery case 10, an electrode assembly 20, a positive electrode terminal 30, and a negative electrode terminal 40. The battery 100 further includes a non-aqueous electrolyte (not shown). The battery 100 is configured by accommodating the electrode assembly 20 and the non-aqueous electrolyte in the battery case 10 to which the positive electrode terminal 30 and the negative electrode terminal 40 are attached.

[0011] The electrode assembly 20 may be the same as a conventional one and is not particularly limited. Here, the electrode assembly 20 is a wound electrode assembly formed by stacking a strip-shaped positive electrode and a strip-shaped negative electrode with a strip-shaped separator interposed therebetween and winding them around a winding axis. The electrode assembly 20 has a flat outer shape. Here, the electrode assembly 20 is disposed inside the battery case 10 with the winding axis oriented substantially parallel to the long side direction Y. However, in other embodiments, the electrode assembly 20 may be disposed inside the battery case 10 with the winding axis oriented substantially parallel to the up-down direction Z. Furthermore, the electrode assembly 20 may be a stacked electrode assembly formed by stacking multiple square-shaped (typically rectangular) positive electrodes and multiple square-shaped (typically rectangular) negative electrodes in an insulated state.

[0012] The positive electrode typically includes a positive electrode current collector and a positive electrode active material layer fixed to at least one surface of the positive electrode current collector. The positive electrode current collector is strip-shaped. The positive electrode current collector is made of a conductive metal such as aluminum, an aluminum alloy, nickel, or stainless steel. The positive electrode current collector is a metal foil, specifically an aluminum foil.

[0013] The positive electrode active material layer is provided in a strip-like shape along the longitudinal direction of the strip-shaped positive electrode current collector. The positive electrode active material layer contains a positive electrode active material capable of reversibly absorbing and releasing charge carriers. The positive electrode active material is preferably an oxide containing at least one of Ni, Co, and Mn, such as lithium transition metal composite oxides such as lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel manganese composite oxide, and lithium nickel cobalt composite oxide. The positive electrode active material is preferably, for example, a composite oxide containing Ni and Li, in which the Ni content in the composite oxide is in the range of 70 to 100 mol% relative to the total number of moles of the constituent elements excluding Li and oxygen in the composite oxide. Positive electrode active materials also include those in which a portion of the Ni, Co, and Mn is replaced with Al, Ti, Zr, P, B, Si, Nb, C, etc., or those in which the particle surface is covered with a compound containing Al, Ti, Zr, W, P, B, Si, Nb, C, etc. The total amount of substitution and addition is about 0.1 to 7 mol %.

[0014] The negative electrode typically includes a negative electrode current collector and a negative electrode active material layer fixed to at least one surface of the negative electrode current collector. The negative electrode current collector is strip-shaped. The negative electrode current collector is made of a conductive metal such as copper, a copper alloy, nickel, or stainless steel. The negative electrode current collector is a metal foil, specifically a copper foil.

[0015] The negative electrode active material layer is provided in a strip shape along the longitudinal direction of the strip-shaped negative electrode current collector. The negative electrode active material layer contains a negative electrode active material capable of reversibly absorbing and releasing charge carriers. Examples of the negative electrode active material include carbon materials such as graphite and carbon, and metals capable of absorbing lithium such as Si, SiO, SiC, and Sn, and compounds thereof.

[0016] The separator is a member that insulates the positive electrode active material layer from the negative electrode active material layer. A porous resin sheet made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP) is suitable as the separator. A heat-resistant layer (HRL) containing an inorganic filler may be provided on the surface of the separator. Examples of inorganic fillers that can be used include alumina, boehmite, aluminum hydroxide, and titania.

[0017] Although not shown in the figures, the electrode assembly 20 may be accommodated inside the battery case 10 while covered with a resin insulating sheet (electrode assembly holder). The number of electrode assemblies 20 arranged inside one battery case 10 may be one, or two or more (plural). A positive electrode tab group 23 is attached to the positive electrode of the electrode assembly 20, and is electrically connected to the positive electrode terminal 30 via the positive electrode current collector 50. A negative electrode tab group 25 is attached to the negative electrode of the electrode assembly 20, and is electrically connected to the negative electrode terminal 40 via the negative electrode current collector 60.

[0018] The non-aqueous electrolyte may be the same as conventional ones and is not particularly limited. The non-aqueous electrolyte typically contains a non-aqueous solvent and a supporting salt (electrolyte salt, for example, Li salt or Na salt). The non-aqueous electrolyte is typically liquid, but may also be gel-like. In another embodiment, the battery 100 may include a solid electrolyte instead of the non-aqueous electrolyte. In this case, the separator may be omitted.

[0019] The battery case 10 is a housing that houses the electrode assembly 20 and the nonaqueous electrolyte. As shown in FIG. 1, the battery case 10 has a box-like (hexahedral) outer shape. Here, the battery case 10 has a flat, bottomed, and approximately rectangular parallelepiped (rectangular) outer shape. The material of the battery case 10 may be the same as conventional materials and is not particularly limited. The battery case 10 is preferably made of metal, and more preferably made of, for example, iron, iron alloys such as stainless steel, aluminum, aluminum alloys, etc. From the viewpoint of improving safety, metals with melting points of 1000°C or higher, and even 1200°C or higher, are particularly preferred, and iron alloys, such as stainless steel containing chromium and / or nickel, are particularly preferred. The iron or iron alloy may be nickel-plated.

[0020] As shown in Fig. 2, the battery case 10 includes a case body 12 having an opening 12h and a top surface (lid) 14 that seals the opening 12h. The battery case 10 is integrated by joining (preferably welding) the top surface 14 to the periphery of the opening 12h of the case body 12. The battery case 10 is hermetically sealed (sealed). As shown in Fig. 1, the case body 12 has at least a bottom surface 12a, the top surface 14, and a pair of side walls 12b. The case body 12 further includes another pair of side walls 12c.

[0021] As shown in FIG. 1, the bottom surface 12a is generally rectangular having long and short sides. The bottom surface 12a is flat, and both the inner surface (the surface facing the electrode body 20, the same applies hereinafter) and the outer surface (the surface not facing the electrode body 20, the same applies hereinafter) are flat. In this embodiment, the bottom surface 12a does not have grooves 13 or vaporization grooves 21, which will be described later. In this specification and claims, the term "approximately rectangular" is a term that encompasses not only a perfect rectangular shape (rectangular shape), but also shapes in which the corners connecting the long and short sides of the rectangle are rounded, or shapes in which the corners have notches. The same applies to the following description.

[0022] As shown in Fig. 1, the top surface 14 is generally rectangular having long and short sides. The top surface 14 is flat. The top surface 14 faces the bottom surface 12a. In this embodiment, the top surface 14 does not have grooves 13 or evaporation grooves 21, which will be described later.

[0023] As shown in FIG. 1, the pair of side walls 12b are generally rectangular having long and short sides. The side walls 12b are flat. The side walls 12b extend from the long sides of the bottom surface 12a toward the long sides of the top surface 14. The side walls 12b correspond to the long side walls. In this embodiment, the side walls 12b have grooves 13 and evaporation grooves 21, which will be described later.

[0024] As shown in FIG. 1, the pair of other side walls 12c are generally rectangular having long and short sides. The other side walls 12c are flat, with both the inner and outer surfaces being flat. The other side walls 12c extend from the short sides of the bottom surface 12a toward the short sides of the top surface 14. The other side walls 12c correspond to the short side walls. In a plan view, the area of ​​the long side walls is larger than the area of ​​the short side walls. In this embodiment, the pair of other side walls 12c do not have grooves 13 or evaporation grooves 21, which will be described later.

[0025] In this embodiment, as shown in FIG. 1, a plurality of grooves 13 are present on both of the pair of side walls 12b.

[0026] In a preferred embodiment, as in this embodiment, the plurality of grooves 13 are arranged so as to extend in a direction from the bottom surface 12a toward the top surface 14 (the direction of arrow A in FIG. 1). One preferred embodiment of the arrangement of the plurality of grooves 13 is to arrange them so as to extend in a direction from the bottom surface 12a toward the top surface 14. Note that in other embodiments, the plurality of grooves 13 may be formed so as to draw a curve, or may have a tree-like structure with branched branches. On the other hand, the former is more preferable from the viewpoint of more suitably generating capillary action in the refrigerant guide path 22 described below.

[0027] The number of grooves 13 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. The number of grooves 13 arranged on one side wall 12b is, for example, 5 or more, and from the viewpoint of efficiently cooling the surface of the battery 100, it is preferably 10 or more, more preferably 15 or more, 20 or more, or 30 or more. The upper limit of the number of grooves 13 arranged on one side wall 12b is, for example, 100 or less, and from the viewpoint of facilitating the formation of the grooves 13, it is preferably 90 or less, 80 or less, more preferably 70 or less, 60 or less, 50 or less, or 40 or less. In this embodiment, as shown in FIG. 1 , the number of grooves 13 arranged on one side wall 12b is 15.

[0028] The shape of the groove 13 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. In this embodiment, the cross-sectional shape of the groove 13 (more specifically, the cross-sectional shape when the groove 13 is cut along the opening of the groove 13 that is immersed in the liquid refrigerant O) is rectangular. Meanwhile, in other embodiments, the cross-sectional shape of the groove 13 may be various shapes, such as a triangular shape (V-shape), a trapezoidal shape, or a semicircular shape as described below. Also, in this embodiment, as shown in FIG. 1 , all of the multiple grooves 13 have the same cross-sectional shape, but this is not limited thereto. In other embodiments, the multiple grooves 13 may have different cross-sectional shapes. Meanwhile, from the viewpoint of facilitating the formation of the multiple grooves 13, the former is more preferable.

[0029] The size of the groove 13 is not particularly limited as long as the effects of the technology disclosed herein are achieved. Here, FIG. 3 is an explanatory diagram for explaining the configuration of the multiple grooves 13 and evaporation groove 21 of the battery 100 shown in FIG. 1 . In FIG. 3 , S, T, and U respectively represent the width, depth, and height of the groove 13. The ratio (S / T) of the width S of the groove 13 to the depth T of the groove 13 is not particularly limited as long as the effects of the technology disclosed herein are achieved. The ratio (S / T) is, for example, 0.1 or more, and from the viewpoint of ease of creating the groove 13, it is preferably 0.2 or more, and more preferably 0.5 or more. The upper limit of the ratio (S / T) is, for example, 3 or less, and from the viewpoint of more easily generating capillary action in the refrigerant guide path 22 described below, it is preferably 2 or less, more preferably 1.5 or less, or 1 or less. The width S of the groove 13 can be, for example, within a range of 0.01 mm to 1 mm (preferably 0.5 mm to 1 mm). The depth T of the groove 13 can be set within a range of, for example, 0.01 mm to 1 mm (preferably, 0.5 mm to 1 mm).

[0030] The ratio (U / S) of the height U of groove 13 to the width S of groove 13 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. The ratio (U / S) is, for example, 5 or more, and from the viewpoint of making capillary action more likely to occur in refrigerant guide path 22 described below, is preferably 10 or more, more preferably 20 or more, 30 or more, 40 or more, or 50 or more. The upper limit of the ratio (U / S) is, for example, 100 or less, and from the viewpoint of ease of creating groove 13, is preferably 90 or less, 80 or less, more preferably 70 or less, or 60 or less. The height U of groove 13 can be, for example, within a range of 10 mm to 100 mm (preferably 20 mm to 50 mm).

[0031] In this embodiment, as shown in Fig. 1, the grooves 13 are all the same size, but this is not limiting. In other embodiments, the grooves 13 may be different sizes. On the other hand, from the viewpoint of facilitating the formation of the grooves 13, the former is more preferable.

[0032] In this embodiment, as shown in Fig. 1, the multiple grooves 13 and the evaporation groove 21 are provided over the entire side wall 12b. The multiple grooves 13 are provided over substantially the entire side wall 12b except for the evaporation groove 21. The multiple grooves 13 are arranged at regular intervals and extend in a direction from the bottom surface 12a of the battery case 10 toward the top surface 14 (corresponding to the vertical direction Z in Fig. 1). In other words, the multiple grooves 13 are arranged in a stripe pattern (stripe pattern) in a direction from the bottom surface 12a of the battery case 10 toward the top surface 14.

[0033] The grooves 13 can be formed by a conventionally known method, such as press working, die casting, forging, casting, photolithography, laser processing, etc. In one example, a single metal plate used to manufacture the battery case 10 is prepared, and the plurality of grooves 13 can be formed by press working the portions that will become the pair of side walls 12b when assembled into the battery case 10.

[0034] 1, evaporation grooves 21 are arranged in at least one (here, both) of the pair of side walls 12b, extending so as to intersect with the plurality of grooves 13. The evaporation grooves 21 extend to the ends (here, the ends in the long side direction Y) of the side walls 12b having the plurality of grooves 13. The evaporation grooves 21 stop the liquid refrigerant O that has been pulled up from the bottom surface 12a side to the top surface 14 side in the refrigerant guide paths 22 described below, and allow the liquid refrigerant O to evaporate in an appropriate manner. This allows new liquid refrigerant O to be guided into the refrigerant guide paths 22, thereby enabling the battery module 400 to be cooled more efficiently.

[0035] The number of vaporization grooves 21 is not particularly limited as long as the effects of the technology disclosed herein are achieved. The number of vaporization grooves 21 may be one on one sidewall 12b, as in the present embodiment, or two or more (plural) in other embodiments. In the present embodiment, the cross-sectional shape of vaporization groove 21 (more specifically, the cross-sectional shape when vaporization groove 21 is cut along an opening present in a direction intersecting with the plurality of grooves 13 of vaporization groove 21) is rectangular, but is not limited thereto. In other embodiments, the cross-sectional shape of vaporization groove 21 may be various shapes, such as a triangular (V-shaped), trapezoidal, or semicircular shape.

[0036] The size of the evaporation groove 21 is not particularly limited as long as the effects of the technology disclosed herein are achieved. In FIG. 3, s, t, and u respectively represent the width, depth, and height of the evaporation groove 21. The ratio (u / t) of the height u of the groove 13 to the depth t of the evaporation groove 21 is not particularly limited as long as the effects of the technology disclosed herein are achieved. The ratio (u / t) is, for example, 1 or more, and from the viewpoint of more suitably evaporating the liquid refrigerant O in the evaporation groove 21, it is preferably 2 or more, and more preferably 3 or more. The upper limit of the ratio (u / t) is, for example, 10 or less, and from the viewpoint of ease of creating the evaporation groove 21, it is preferably 8 or less, and more preferably 5 or less. The depth t of the evaporation groove 21 can be, for example, within a range of 0.5 mm to 10 mm (preferably 0.5 mm to 1 mm). Furthermore, the height u of vaporization groove 21 can be set within a range of, for example, 5 mm to 20 mm (preferably, 10 mm to 15 mm).

[0037] The ratio (s / u) of the width s of the vaporization groove 21 to the height u of the vaporization groove 21 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. 5From the viewpoint of more suitably evaporating the liquid refrigerant O in evaporation groove 21, the ratio is preferably 10 or more, more preferably 15 or more, or 20 or more. The upper limit of the ratio (s / u) is, for example, 50 or less, and from the viewpoint of making it easier to form evaporation groove 21, the upper limit is preferably 40 or less, more preferably 30 or less. Width s of evaporation groove 21 can be set within a range of, for example, 100 mm to 200 mm (preferably, 100 mm to 150 mm).

[0038] As described above, in this embodiment, as shown in FIG. 1 , the vaporization groove 21 is arranged on the sidewall 12b so as to intersect with the plurality of grooves 13. More specifically, the vaporization groove 21 is arranged on the sidewall 12b so as to be approximately perpendicular to the plurality of grooves 13. In this embodiment, the vaporization groove 21 is arranged continuously from one end to the other end of the sidewall 12b in a direction approximately perpendicular to the plurality of grooves 13 (corresponding to the Y direction in FIG. 1 ). Note that "approximately perpendicular to the plurality of grooves 13" does not require the angle at which the vaporization groove 21 intersects with the plurality of grooves 13 to be strictly 90° (a right angle). In other words, "approximately perpendicular" can include any substantial angle that can achieve the effects of the present disclosure. For example, the intersecting angle may be 80° to 100°, more preferably 85° to 95°, and particularly preferably 90°. In other embodiments, the vaporization groove 21 may be arranged on the sidewall 12b so as to intersect with the plurality of grooves 13 at an angle other than approximately perpendicular.

[0039] The vaporization groove 21 can be formed by a conventionally known method, such as press working, die casting, forging, casting, photolithography, laser processing, etc. In one example, a metal plate used to manufacture the battery case 10 is prepared, and the vaporization groove 21 can be formed by press working the portions that will become the pair of side walls 12b when assembled into the battery case 10.

[0040] In a preferred embodiment, as shown in FIG. 1, the battery 100 has electrode terminals (here, a positive electrode terminal 30 and a negative electrode terminal 40) on a surface (here, a top surface 14) different from the bottom surface 12a and the pair of side walls 12b. The refrigerant guide path 22 or the evaporation groove 21 (here, the evaporation groove 21) is provided so as to pass through a portion close to the electrode terminals. The areas of the battery 100 around the electrode terminals are considered to be areas that are particularly prone to heat generation. Therefore, the liquid refrigerant O can be more suitably evaporated in the evaporation groove 21, and the battery module 400 can be cooled more efficiently.

[0041] The top surface 14 is provided with a drain valve 17 and two terminal holes 18 and 19. The drain valve 17 is configured to break when the pressure inside the battery case 10 reaches or exceeds a predetermined value, thereby discharging gas inside the battery case 10 to the outside. The terminal holes 18 and 19 penetrate the top surface 14 in the vertical direction Z. The top surface 14 is also provided with a liquid inlet 15. The liquid inlet 15 is used to inject electrolyte into the battery case 10 after the top surface 14 is assembled to the case main body 12. The liquid inlet 15 is sealed with a sealing member 16 after the electrolyte is injected. Note that, although the liquid inlet 15 is provided on the top surface 14 in the present embodiment, the liquid inlet 15 may be provided on the case main body 12 in other embodiments. Note that, although the liquid inlet 15 is provided on a different surface from the drain valve 17 in the present embodiment, the liquid inlet 15 may be provided on the same surface as the drain valve 17 in other embodiments.

[0042] The positive electrode terminal 30 is electrically connected to the positive electrode tab group 23 of the electrode body 20 via the positive electrode current collector 50 inside the battery case 10. The positive electrode terminal 30 extends from the inside to the outside of the top surface 14 through the terminal pull-out hole 18. The positive electrode terminal 30 is disposed at one end of the top surface 14 in the long side direction Y (the left end in FIGS. 1 and 2). Here, the positive electrode terminal 30 is crimped to the peripheral portion of the top surface 14 that surrounds the terminal pull-out hole 18 by crimping. The positive electrode terminal 30 is fixed to the top surface 14.

[0043] The negative electrode terminal 40 is electrically connected to the negative electrode tab group 25 of the electrode body 20 via the negative electrode current collecting portion 60 inside the battery case 10. The negative electrode terminal 40 extends from the inside to the outside of the top surface 14 through the terminal pull-out hole 19. The negative electrode terminal 40 is disposed at the other end of the top surface 14 in the long side direction Y (the right end in FIGS. 1 and 2). Here, the negative electrode terminal 40 is crimped to the peripheral portion of the top surface 14 that surrounds the terminal pull-out hole 19 by crimping. The negative electrode terminal 40 is fixed to the top surface 14.

[0044] The battery 100 can be manufactured by a conventionally known method except for forming a plurality of grooves 13 and evaporation grooves 21 in a pair of side walls 12b of the case body 12, so details of the manufacturing method will be omitted.

[0045] <Battery module> The battery module 400 according to the present embodiment will be described below. FIG. 4 is a perspective view of the battery module 400 according to the present embodiment. FIG. 5 is a schematic view of the battery module 400 shown in FIG. 4 as viewed from the direction of the outlined arrow. FIG. 6 is a schematic view of the first battery 100A, the second battery 100B, and the component 70 included in the battery module 400 shown in FIG. 5. FIG. 7 is a schematic view of the liquid refrigerant O being drawn up from the bottom surface 12a toward the top surface 14 by capillary action. FIG. 8 is a schematic view of the first battery 100A, the second battery 100B, and the component 70 shown in FIG. 7 as viewed from the bottom side. Note that, for clarity, the liquid refrigerant O present around the first battery 100A, the second battery 100B, and the component 70 is not shown in FIG. 7.

[0046] As shown in FIG. 4 , a battery module 400 according to this embodiment has a box-shaped case (here, a battery case 10) and includes a plurality of batteries 100 (here, 12 batteries) arranged along a predetermined direction (here, the X direction). It also includes a refrigerant supply means 300 that supplies a liquid refrigerant O to cool the batteries 100. As described above, the battery case 10 has at least a bottom surface 12a, a top surface 14 facing the bottom surface 12a, and a pair of opposing side walls 12b extending from the bottom surface 12a toward the top surface 14. At least one (here, both) of the pair of side walls 12b has a plurality of grooves 13. The refrigerant supply means 300 includes a refrigerant retainer 200 that immerses the bottom surface of the battery case 10 in the liquid refrigerant O. The number of batteries 100 included in the battery module 400 may be other than 12.

[0047] 5, in the battery module 400 according to this embodiment, the plurality of batteries 100 are arranged in a first battery 100A and an adjacent second battery 100B. Of the pair of side walls 12b of the first battery 100A, the side wall 12b facing the second battery 100B is designated as a first side wall 12b1. Of the pair of side walls 12b of the second battery 100B, the side wall 12b facing the first battery 100A is designated as a second side wall 12b2. The first battery 100A and the second battery 100B are arranged such that a device-facing region (here, a battery-facing region P1) is formed between the first side wall 12b1 and the second side wall 12b2. In the battery-facing region P1 (here, eleven battery-facing regions P1), a refrigerant guide path 22 is present, which draws the liquid refrigerant O in the refrigerant retainer 200 from the bottom surface 12a toward the top surface 14 by capillary action. The refrigerant guide path 22 is a space surrounded by the plurality of grooves 13 and a surface facing the plurality of grooves 13 (here, the surface 70a of the member 70). In the present disclosure, the "device-facing region" may refer to the region (space) between the first side wall of the first power storage device and the second side wall of the adjacent second power storage device. For example, if a plurality of grooves are formed in the first side wall of the first power storage device or the second side wall of the second power storage device, the device-facing region refers to the region including the plurality of grooves. In the "battery-facing region," the "power storage device" in the above description can be read as "battery."

[0048] In the battery module 400 configured as described above, the liquid refrigerant O is drawn up from the bottom surface 12a to the top surface 14 in the refrigerant guide path 22. Focusing on the second battery 100B, for example, first, as shown in FIG. 5, the bottom surface 12a of the battery case 10 of the second battery 100B (more specifically, the opening of the refrigerant guide path 22 that is immersed in the liquid refrigerant O) is immersed in the liquid refrigerant O. Then, due to capillary action, the liquid refrigerant O permeates toward a position higher than the liquid level Q of the liquid refrigerant O. In the refrigerant guide path 22, the liquid refrigerant O permeates in a direction from the bottom surface 12a of the battery case 10 to the top surface 14 (the direction of arrow A in FIG. 5). Then, as shown in FIG. 7, the liquid refrigerant O permeates up to near the upper end of the refrigerant guide path 22. The same applies to the first battery 100A.

[0049] The refrigerant guide path 22 allows heat-generating components of the battery 100 (e.g., electrode terminals and electrode current collectors) to be cooled at a relatively short distance, thereby enabling efficient cooling of the battery module 400. Furthermore, the wick described above is a cotton-like material that may be crushed by the confinement pressure when the battery module is confined. This may make capillary action less likely to occur, reducing the efficiency of wicking up the liquid refrigerant. In response to this, the battery module 400 has grooves 13 in the sidewalls 12b of the battery 100. These grooves 13 are less likely to be crushed by the confinement pressure when the battery module 400 is confined. This allows capillary action to occur favorably in the refrigerant guide path 22. Therefore, the battery module 400 can be efficiently cooled.

[0050] Furthermore, since there is no need to provide additional components for circulating the liquid refrigerant O, the weight of the battery module 400 can be reduced. Conventionally, water-cooling systems that can efficiently cool battery modules have often made it difficult to design the cooling structure. For example, it was necessary to form flow paths in the narrow gaps between the batteries or to prepare a quantity of refrigerant sufficient to completely cover the entire surface of the batteries with the liquid refrigerant. Furthermore, a structure for fixing the batteries immersed in the liquid refrigerant was also required. In contrast, the battery module 400 disclosed herein can effectively cool the batteries 100 using the refrigerant guide paths 22. This eliminates the need for the complex cooling structure described above, simplifying the configuration of the battery module 400.

[0051] In a preferred embodiment, as in this embodiment, a member 70 is disposed between the arranged batteries 100. The refrigerant guide path 22 is a space surrounded by the surface of the member 70 and the plurality of grooves 13. In this embodiment, as shown in FIG. 6, the member 70 is rectangular and has a pair of wide surfaces. As shown in FIG. 8, the refrigerant guide path 22 is surrounded by the surface 70a (here, the wide surfaces) of the member 70 and the plurality of grooves 13. This configuration facilitates capillary action in the refrigerant guide path 22, thereby enabling more efficient cooling of the battery module 400. Furthermore, such refrigerant guide paths 22 are preferable because they are less likely to collapse due to the restraining pressure when the battery module 400 is restrained. In this embodiment, as shown in FIG. 8, a total of 30 refrigerant guide paths 22 exist in the battery-facing region P1.

[0052] Although not particularly limited, the member 70 may be, for example, an inter-cell separator or spacer disposed between the batteries 100. The member 70 is preferably water-resistant. Such inter-cell separators or spacers are preferably made of, for example, an elastic material. Examples of elastic materials include thermosetting elastomers such as natural rubber, urethane rubber, silicone rubber, ethylene propylene diene rubber, and fluororubber, and thermoplastic elastomers such as polystyrene, polyolefin, polyurethane, polyester, and polyamide. The shape of the member 70 may be a rectangular plate, as in this embodiment, or may be other shapes. The thickness of the member 70 is preferably adjusted depending on the material of the member 70. Such adjustments can be performed through preliminary experiments, etc.

[0053] Although not particularly limited, the area of ​​the opening per refrigerant guide path 22 (see 22A in FIG. 8) is, for example, 0.0001 mm 2 ~1mm 2 From the viewpoint of making it easier for capillary action to occur in the refrigerant guide path 22, it is preferable that the thickness is 0.1 mm. 2 ~1mm 2 and more preferably 0.25 mm 2 ~1mm 2 The opening 22A of the refrigerant guide path 22 can also be said to be an opening into which the liquid refrigerant O is submerged. The same applies to second to sixth embodiments described later.

[0054] As described above, in this embodiment, the evaporation grooves 21 extending to intersect with the plurality of grooves 13 are arranged in at least one (here, both) of the pair of side walls 12b of the battery case 10. The evaporation grooves 21 also extend to the ends of the side walls 12b having the plurality of grooves 13. The evaporation grooves 21 stop the liquid refrigerant O that has been pulled up from the bottom surface 12a side to the top surface 14 side in the refrigerant guide paths 22 from rising, and allow the liquid refrigerant O to evaporate in an appropriate manner. This allows new liquid refrigerant O to be guided into the refrigerant guide paths 22, thereby enabling the battery module 400 to be cooled more efficiently.

[0055] As described above, in this embodiment, the evaporation groove 21 is arranged so as to pass through the portions close to the electrode terminals (here, the positive electrode terminal 30 and the negative electrode terminal 40). The areas around the electrode terminals of the battery 100 are particularly prone to heat generation. Therefore, the liquid refrigerant O can be more suitably evaporated in the evaporation groove 21, and the battery module 400 can be cooled more efficiently.

[0056] As described above, the battery module 400 according to this embodiment includes a plurality of batteries 100 and a refrigerant supply means 300. The refrigerant supply means 300 includes a refrigerant holding unit 200 and a pipe (not shown) configured to supply liquid refrigerant O to the refrigerant holding unit 200. The refrigerant holding unit 200 holds the liquid refrigerant O. The amount of liquid refrigerant O held in the refrigerant holding unit 200 is not particularly limited as long as the effects of the technology disclosed herein are achieved. The liquid refrigerant O is preferably held at a water level equal to or higher than the opening of the refrigerant guide path 22 that is immersed in the liquid refrigerant O (preferably, higher than the opening of the refrigerant guide path 22 that is immersed in the liquid refrigerant O). The cooling method of the refrigerant supply means 300 is not particularly limited as long as the effects of the technology disclosed herein are achieved. The cooling method may be a refrigerant circulation type or a refrigerant retention type. From the viewpoint of more effectively generating capillary action, a refrigerant retention type is more preferable.

[0057] The liquid refrigerant O preferably has a high cooling effect on the battery module 400. For example, it may be water or a mixed solvent of water and a non-flammable, insulating solvent. Examples of non-flammable, insulating solvents include diisopropylnaphthalene, 1-phenyl-1-(3,4-dimethylphenyl)ethane, liquid cellulose, glycols such as ethylene glycol and propylene glycol, and carbon tetrachloride. These may be used alone or in combination. The mixing ratio (mass ratio) of water to the solvent may be 1:9 to 9:1. Furthermore, when the refrigerant is liquid, it may contain various additives such as rust inhibitors. Examples of rust inhibitors include phosphate-based substances (e.g., potassium phosphate, inorganic potassium salt). When a rust inhibitor is included, the rust inhibitor may be contained in a mixed solution of water, a non-flammable, insulating solvent, and the rust inhibitor at a content of 0.5 to 3 mass%. Although not particularly limited, the liquid refrigerant O is preferably liquid at room temperature (approximately 20±5°C). The viscosity of the liquid refrigerant O can be, for example, 0.1 mPa·s to 1000 mPa·s (preferably 1 mPa·s to 500 mPa·s) at 25°C. Such viscosity can be measured using, for example, a commercially available rotational viscometer. Note that, as the water and solvents mentioned above, for example, commercially available products can be used without any particular restrictions.

[0058] As shown in FIG. 4 , in this embodiment, a restraint mechanism is used as the refrigerant retention unit 200. The configuration of the restraint mechanism will be described below. The restraint mechanism is a member that restrains the plurality of batteries 100. The restraint mechanism is configured to apply a specified restraint load to the plurality of batteries 100 in the arrangement direction X. Here, the restraint mechanism includes a pair of end plates 210, a pair of side plates 220, and a plurality of screws 230. The end plates 210 and the side plates 220 are preferably made of metal. Examples of such metals include aluminum, iron, chromium, and alloys thereof (e.g., aluminum alloys and stainless steel). Among these, it is preferable that the restraint mechanism be made primarily of aluminum, and preferably made of aluminum, aluminum alloys, or the like. However, the end plates 210 and the side plates 220 may have portions made of resin.

[0059] The pair of end plates 210 are disposed at both ends of the battery module 400 in the arrangement direction X. The pair of end plates 210 sandwich the plurality of batteries 100 in the arrangement direction X. The pair of side plates 220 bridge the pair of end plates 210. The pair of side plates 220 are fixed to the end plates 210 with a plurality of screws 230 so that a restraining load is, for example, 3 kN to 15 kN, preferably approximately 5 kN to 10 kN. This applies a restraining load to the plurality of batteries 100 in the arrangement direction X, holding the battery module 400 together. However, the configuration of the restraining mechanism is not limited to this. The restraining mechanism may include, for example, a plurality of restraining bands or bind bars instead of the side plates 220 and the plurality of screws 230.

[0060] As shown in Fig. 4, the plurality of batteries 100 are arranged between a pair of end plates 210 along the arrangement direction X (in other words, the thickness direction X of the batteries 100). Note that Fig. 4 is merely an example, and the shape, size, number, arrangement, etc. of the plurality of batteries 100 are not limited to the embodiment disclosed in Fig. 4 and can be changed as appropriate. Furthermore, the battery module 400 may further include other components as long as the effects of the technology disclosed herein are not significantly impaired.

[0061] Although not shown here, when the battery module 400 is in use, the multiple batteries 100 are electrically connected to each other by conductive members such as bus bars. The connection method is not particularly limited, and may be, for example, series, parallel, or multi-series / multi-parallel. For example, in this embodiment, the multiple batteries 100 are connected in series. In the case of a series connection, deterioration in the performance of some of the batteries 100 is likely to lead to deterioration in the performance of the entire battery module 400. For this reason, applying the technology disclosed herein is particularly effective.

[0062] The battery module 400 can be manufactured using the battery 100 by a conventionally known method, and therefore details of the manufacturing method will be omitted.

[0063] The battery module 400 can be used for a variety of purposes, but because it has high heat dissipation properties and can be lightweight, it can be suitably used, for example, as a power source (driving power source) for a motor mounted on a vehicle such as a passenger car, truck, etc. The type of vehicle is not particularly limited, but examples include a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), and a battery electric vehicle (BEV).

[0064] Although a preferred embodiment of the present invention has been described above, the above embodiment (first embodiment) is merely an example. The present invention can be embodied in various other forms. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in the relevant field. The technology described in the claims includes various modifications and alterations of the above-exemplified embodiment. For example, it is possible to replace part of the above-described embodiment with other modifications, and it is also possible to add other modifications to the above-described embodiment. Furthermore, if a technical feature is not described as essential, it can be deleted as appropriate.

[0065] For example, in the above embodiment, the positive electrode terminal 30 and the negative electrode terminal 40 are provided on the top surface 14, but this is not limiting. In other embodiments, the positive electrode terminal 30 and the negative electrode terminal 40 may be provided on a side wall of the case body 12. For example, both the positive electrode terminal 30 and the negative electrode terminal 40 may be provided on one of the other pair of side walls 12c. Alternatively, the positive electrode terminal 30 and the negative electrode terminal 40 may be provided on each of the other pair of side walls 12c. In these cases, the multiple grooves 13 and the evaporation groove 21 can be arranged on at least one of the pair of side walls 12b. Furthermore, when the evaporation groove 21 is formed, it is preferably formed around the electrode terminal.

[0066] For example, in the above embodiment, the member 70 is disposed between the batteries 100, but this is not limiting. In other embodiments, the member 70 may not be disposed between the batteries 100. In such a case, the refrigerant guide path 22 may be a space surrounded by the plurality of grooves 13 in the first side wall 12b1 of the first battery 100A and a surface facing the plurality of grooves 13 (here, the second side wall 12b2 of the adjacent second battery 100B). The surface facing the plurality of grooves 13 may be the first side wall of the first power storage device, the second side wall of the second power storage device, a surface (side surface) of another member, or a side wall of a power storage device other than the power storage device of the present disclosure. Furthermore, in other embodiments, there may be a mixture of locations between the plurality of batteries 100 where the member 70 is disposed and locations where the member 70 is not disposed.

[0067] For example, in the above embodiment, the plurality of grooves 13 are formed in the pair of side walls 12b, but this is not limiting. In other embodiments, the plurality of grooves 13 can be formed by depositing particles (for example, porous sintered metal particles or inorganic particles) on the outer surfaces of the side walls 12b. Capillary action allows the liquid refrigerant O to permeate between the deposited particles from the bottom surface 12a toward the top surface 14. This allows the battery module 400 to be cooled efficiently.

[0068] For example, in the above embodiment, the pair of side walls 12b have multiple grooves 13 and evaporation grooves 21, but this is not limiting. Here, FIG. 9 is a view corresponding to FIG. 1 according to the second embodiment. In FIG. 9, 500, 512, 512a, 512b, 513, 514, 516, 517, 530, and 540 represent the battery, case body, bottom surface, side walls, grooves, top surface, sealing member, discharge valve, positive electrode terminal, and negative electrode terminal, respectively. As shown in FIG. 9, in the second embodiment, the pair of side walls 12b of the battery 500 only have multiple grooves 512. The multiple grooves 513 are continuously arranged on the side walls 512b from the end on the bottom surface 12a side to the end on the top surface 514 side. The cross-sectional shape of the grooves 513 is rectangular. The multiple grooves 513 (more specifically, the openings of the multiple grooves 513 on the top surface 514 side) are arranged to pass through the portions adjacent to the electrode terminals. The grooves 513 are arranged so as to pass through the portions close to the electrode terminals, thereby allowing the liquid refrigerant O to evaporate more efficiently. This allows the battery module to be cooled more efficiently. Note that the number and size of the grooves 513, the area of ​​the openings of the refrigerant guide paths formed, and the like can be determined by referring to the corresponding descriptions in the first embodiment.

[0069] In the above embodiment, the plurality of grooves 13 and the vaporization groove 21 are formed directly on the pair of side walls 12b, but this is not limiting. Here, FIG. 10 is a diagram corresponding to FIG. 1 of the third embodiment. In FIG. 10, 600, 612, 612a, 612b, 613, 614, 616, 617, 630, and 640 denote the battery, case body, bottom surface, side walls, grooves, top surface, sealing member, discharge valve, positive electrode terminal, and negative electrode terminal, respectively. As shown in FIG. 10, in the third embodiment, the pair of side walls 612b of the battery 600 only have the plurality of grooves 612. The plurality of grooves 613 are continuously arranged on the side walls 612b from the end on the bottom surface 612a side to the end on the top surface 614 side. The cross-sectional shape of the grooves 613 is semicircular. The plurality of grooves 613 are arranged so as to pass through the portion adjacent to the electrode terminals. The grooves 613 are arranged to pass through the portions close to the electrode terminals, which allows the liquid refrigerant O to evaporate more efficiently. This allows the battery module to be cooled more efficiently. Note that the number and size of the grooves 613, the area of ​​the openings of the refrigerant guide paths formed, and the like can be determined by referring to the corresponding descriptions in the first embodiment.

[0070] For example, in the above embodiment, the plurality of grooves 13 and the evaporation groove 21 are formed directly on the pair of side walls 12b, but this is not limited thereto. Here, FIG. 11 is a view corresponding to FIG. 1 of the fourth embodiment. In FIG. 11, 700, 712, 712a, 712b, 713, 714, 716, 717, 721, 730, and 740 respectively denote the battery, case body, bottom surface, side walls, groove, top surface, sealing member, exhaust valve, evaporation groove, positive electrode terminal, and negative electrode terminal. As shown in FIG. 11, in the fourth embodiment, an attachment member W having the plurality of grooves 713 and the evaporation groove 721 is attached to the outer surface of the pair of side walls 712b of the battery 700. This attachment can be performed using an adhesive. Examples of such adhesives include those containing epoxy resin, acrylic resin, and silicone resin. Furthermore, the attachment member W can be, for example, the inter-cell separator or spacer described above. The post-installation member W is obtained by forming grooves 713 and evaporation grooves 721 in inter-cell separators, spacers, or the like by a conventionally known method such as laser processing or cutting. In this case, a liquid refrigerant O is supplied near the surface of the battery case 710 of the batteries 700, thereby cooling the plurality of batteries 700. Note that the thickness of the post-installation member W from the surface of the side wall 712b to the grooves 713 is preferably adjusted appropriately depending on the material of the post-installation member W. Such adjustment can be performed through a preliminary experiment or the like. Note that the number, shape, and size of the plurality of grooves 713 and evaporation grooves 721, the area of ​​the opening of the refrigerant guide path to be formed, and the like can be determined by referring to the corresponding descriptions in the first embodiment.

[0071] For example, in the above embodiment, both of the pair of side walls 12b have multiple grooves 13 and evaporation grooves 21, but this is not limiting. Here, Fig. 12 is a view corresponding to Fig. 1 according to the fifth embodiment. Also, Fig. 13 is a view corresponding to Fig. 5, which includes the battery shown in Fig. 12. In Figs. 12 and 13, 800, 812, 812a, 812b, 813, 814, 816, 817, 821, 830, and 840 represent the battery, case body, bottom surface, side wall, groove, top surface, sealing member, exhaust valve, evaporation groove, positive electrode terminal, and negative electrode terminal, respectively. In addition, in FIG. 13, 800A, 800B, 812b1, 812b2, 821, 822, 840, 870, 900, and P2 respectively indicate the battery, the first battery, the second battery, the first side wall, the second side wall, the evaporation groove, the refrigerant guide path, the negative electrode terminal, the member, the battery module, and the battery-facing region.

[0072] As shown in FIG. 12, in the fifth embodiment, multiple grooves 813 and evaporation grooves 821 are arranged on only one of a pair of side walls 812b. In this case, as shown in FIG. 13, a first side wall 812b1 of a first battery 800A that does not have multiple grooves 813 and a second side wall 812b2 of a second battery 800B that has multiple grooves 813 can be arranged to face each other. Multiple batteries 100 can be connected in parallel. In this case, the refrigerant guide path 822 is a space surrounded by the multiple grooves 813 and the surface facing the multiple grooves 813 (here, the surface 70a of the member 70). Note that the number, shape, and size of the multiple grooves 813 and evaporation grooves 821, as well as the area of ​​the opening of the refrigerant guide path 822, can be determined by referring to the corresponding descriptions in the first embodiment.

[0073] As in the fifth embodiment, in the first to fourth embodiments, the plurality of grooves or vaporization grooves may be formed on only one of the pair of side walls.

[0074] As described above, specific aspects of the technology disclosed herein include those described in the following sections.

[0075] Section 1: a plurality of power storage devices each having a box-shaped case and arranged along a predetermined direction; a refrigerant supply means for supplying a liquid refrigerant for cooling the electricity storage device; Equipped with The case is The bottom and a top surface opposite to the bottom surface; a pair of side walls extending from the bottom surface toward the top surface and facing each other; and At least one of the pair of side walls has a plurality of grooves, the refrigerant supply means has a refrigerant holding portion that immerses the bottom surface of the case in the liquid refrigerant, The plurality of power storage devices include a first power storage device and an adjacent second power storage device, one of the pair of side walls of the first power storage device that faces the second power storage device is a first side wall; When the side wall of the pair of side walls of the second power storage device that faces the first power storage device is defined as a second side wall, the first power storage device and the second power storage device are arranged such that a device-facing region is formed between the first side wall and the second side wall; a refrigerant guide path is present in the device-facing region, which draws the liquid refrigerant in the refrigerant holding portion from the bottom surface toward the top surface by capillary action; The refrigerant guide path is a space surrounded by the plurality of grooves and a surface facing the plurality of grooves. Energy storage module.

[0076] Section 2: Item 2. The energy storage module according to item 1, wherein the plurality of grooves are arranged to extend in a direction from the bottom surface toward the top surface.

[0077] Section 3: a member is disposed between the arranged power storage devices, Item 3. The energy storage module according to item 1 or 2, wherein the coolant guide path is a space surrounded by the surface of the member and the plurality of grooves.

[0078] Section 4: a vaporization groove is disposed on at least one of the pair of side walls, the vaporization groove extending to intersect with the plurality of grooves; the vaporization groove extends to an end of the sidewall having the plurality of grooves; Item 4. The electricity storage module according to any one of Items 1 to 3.

[0079] Section 5: the power storage device has electrode terminals on a surface different from the bottom surface and the pair of side walls, the refrigerant guide path or the evaporation groove passes through a portion close to the electrode terminal; Item 5. The storage module according to item 4. [Explanation of symbols]

[0080] 10 Battery case 12 Case body 13 Groove 14 Top 15 Liquid injection hole 16 Sealing member 17 Discharge valve 18, 19 Terminal extraction hole 20 Electrode body 21 Vaporization groove 22 Refrigerant induction path 23 Positive electrode tab group 25 Negative electrode tab group 30 Positive terminal 40 Negative terminal 50 Positive electrode current collector 60 Negative electrode current collector 70 components 100 batteries 200 Refrigerant storage section 210 End Plate 220 Side Plate 230 bis 300 Refrigerant supply means 400 battery module

Claims

1. a plurality of power storage devices each having a box-shaped case and arranged along a predetermined direction; a refrigerant supply means for supplying a liquid refrigerant for cooling the electricity storage device; Equipped with The case is The bottom and a top surface opposite to the bottom surface; a pair of side walls extending from the bottom surface toward the top surface and facing each other; and At least one of the pair of side walls has a plurality of grooves, the refrigerant supply means has a refrigerant holding portion that immerses the bottom surface of the case in the liquid refrigerant, The plurality of power storage devices include a first power storage device and an adjacent second power storage device, one of the pair of side walls of the first power storage device that faces the second power storage device is a first side wall; When the side wall of the pair of side walls of the second power storage device that faces the first power storage device is defined as a second side wall, the first power storage device and the second power storage device are arranged such that a device-facing region is formed between the first side wall and the second side wall; a refrigerant guide path is present in the device-facing region, which draws the liquid refrigerant in the refrigerant holding portion from the bottom surface toward the top surface by capillary action; The refrigerant guide path is a space surrounded by the plurality of grooves and a surface facing the plurality of grooves. Energy storage module.

2. The energy storage module according to claim 1 , wherein the plurality of grooves are arranged to extend in a direction from the bottom surface toward the top surface.

3. a member is disposed between the arranged power storage devices, The energy storage module according to claim 1 , wherein the coolant guide path is a space surrounded by the surface of the member and the plurality of grooves.

4. a vaporization groove is disposed on at least one of the pair of side walls, the vaporization groove extending to intersect with the plurality of grooves; the vaporization groove extends to an end of the sidewall having the plurality of grooves; The energy storage module according to claim 1 or 2.

5. the power storage device has electrode terminals on a surface different from the bottom surface and the pair of side walls, the refrigerant guide path or the evaporation groove passes through a portion close to the electrode terminal; The energy storage module according to claim 4 .

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