Energy Storage Module

Abstract

To provide a power storage module capable of suppressing short circuits between adjacent storage cells even when the liquid reaches between adjacent storage cells.SOLUTION: Each power storage module 100 includes a housing 22 having an upper surface 22a and external terminals 23, 24 provided on the upper surface 22a. The power storage module includes a first storage cell 21a and a second storage cell arranged adjacent to each other; and a spacer 30 having insulation disposed between the housings 22 adjacent to each other. The spacer 30 has a discharge part 35 formed for discharging a liquid reaching the spacer 30 from above out of the spacer 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage module mounted on a vehicle. [Background technology]

[0002] As a conventional energy storage module, Japanese Patent Application Laid-Open No. 2013-041708 (Patent Document 1) discloses a technology in which a spacer arranged between adjacent energy storage cells has a protruding portion protruding laterally at the upper end of the side surface of the spacer, and the upper surface of the protruding portion has an inclined surface that slopes downward as it moves away from the side surface of the spacer. This allows foreign matter that falls on the protruding portion to fall along the inclined surface, making it possible to prevent foreign matter from accumulating on the protruding portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-041708 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the energy storage module disclosed in Patent Document 1, the protrusion has an inclined surface, which can prevent foreign matter such as dust from accumulating on the protrusion, but the top surface of the spacer is flat. Therefore, when liquid such as condensed water on the top surface of the spacer reaches the protrusion, the liquid cannot be moved and remains on the top surface of the spacer. In this case, adjacent energy storage cells may short-circuit.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide a storage module that can prevent adjacent storage cells from short-circuiting when liquid reaches between the adjacent storage cells. [Means for solving the problem]

[0006] The energy storage module according to the present disclosure includes a first energy storage cell and a second energy storage cell arranged adjacent to each other, each of which includes a housing having an upper surface and an external terminal provided on the upper surface, and an insulating spacer arranged between the adjacent housings. The spacer is provided with a discharge portion for discharging liquid that reaches the spacer from above to the outside of the spacer.

[0007] According to the above configuration, by providing the spacer with a discharge portion, liquid that reaches the spacer from the upper side of the spacer can be discharged to the outside of the spacer by the discharge portion. This makes it possible to prevent the creepage distance between the external terminals of adjacent storage cells from being reduced due to the accumulation of liquid. As a result, insulation between the external terminals of adjacent storage cells can be ensured, and adjacent storage cells can be prevented from being short-circuited.

[0008] In the energy storage module according to the present disclosure, the spacer has an upper surface portion located at a position lower than the upper surface of the housing. The upper surface portion may have an inclined surface that inclines downward toward one side of a direction perpendicular to an arrangement direction in which the first energy storage cells and the second energy storage cells are arranged and a vertical direction. In this case, the discharge portion is constituted by the inclined surface.

[0009] According to the above-described configuration, by providing an inclined surface on the upper surface of the spacer, even if liquid reaches the upper surface of the spacer, the liquid can be discharged to the outside of the spacer by the inclined surface.

[0010] In the energy storage module according to the present disclosure, the spacer may include one or more exhaust flow paths communicating in the vertical direction. In this case, the exhaust section is configured by the one or more exhaust flow paths, and the length of the housing in the arrangement direction in which the first storage cell and the second storage cell are arranged and in the direction perpendicular to the vertical direction is A (mm), the distance between the housings adjacent to each other is B (mm), and the total flow path area of ​​the one or more exhaust flow paths in a cross section of the spacer perpendicular to the vertical direction is C (mm 2 ), it is preferable that C / (A×B) is 1% or more and 50% or less.

[0011] According to the above configuration, by setting C / (A×B) to be greater than or equal to 1% and less than or equal to 50% as described above, liquid that has reached the spacer from above can be discharged outside the spacer via the discharge path, and damage to the spacer can be suppressed when an impact is applied to the spacer from the outside. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide an energy storage module that can prevent adjacent energy storage cells from short-circuiting due to liquid when the liquid reaches a gap between the adjacent energy storage cells. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a top view of the electricity storage module according to the first embodiment. [Diagram 2] 3 is a front view of a spacer provided in the energy storage module in accordance with the first embodiment and an energy storage cell located behind the spacer. FIG. [Diagram 3] 13 is a front view of a spacer provided in an electricity storage module according to a comparative example and an electricity storage cell located behind the spacer. FIG. [Figure 4] 10A and 10B are diagrams for explaining a creepage distance between adjacent external terminals in an electricity storage module according to a comparative example. [Diagram 5]13 is a diagram showing a state in which liquid is stored on the upper surface of a spacer in an electricity storage module according to a comparative example. FIG. [Figure 6] 13 is a front view of a spacer provided in an electricity storage module according to a second embodiment and an electricity storage cell located behind the spacer. FIG. [Figure 7] 13 is a front view of a spacer provided in an electricity storage module according to Embodiment 3 and an electricity storage cell located behind the spacer. FIG. [Figure 8] FIG. 11 is a top view partially showing the electricity storage module according to the third embodiment. [Figure 9] 13 is a front view of a spacer provided in an electricity storage module according to embodiment 4 and an electricity storage cell located behind the spacer. FIG. [Figure 10] FIG. 11 is a top view partially showing the electricity storage module according to the fourth embodiment. [Figure 11] 13 is a front view of a spacer provided in an electricity storage module according to Embodiment 5 and an electricity storage cell located behind the spacer. FIG. [Figure 12] 13 is a front view of a spacer provided in an electricity storage module according to a reference example and an electricity storage cell located behind the spacer. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference characters in the drawings, and the description thereof will not be repeated.

[0015] (Embodiment 1) Fig. 1 is a top view of an electricity storage module according to embodiment 1. With reference to Fig. 1, an electricity storage module 100 according to the embodiment will be described.

[0016] The electricity storage module 100 according to the first embodiment is mounted on a hybrid vehicle capable of running using at least one of the power of a motor and an engine, or an electrically powered vehicle that runs using driving force obtained from electric energy.

[0017] The energy storage module 100 includes a plurality of energy storage cells 21 and a plurality of spacers 30. The plurality of energy storage cells 21 and the plurality of spacers 30 are alternately arranged along a predetermined arrangement direction.

[0018] The storage cell 21 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The single cell has, for example, a rectangular shape. The secondary battery may use a liquid electrolyte or a solid electrolyte. The storage cell may also be a unit capacitor configured to be capable of storing electricity.

[0019] The storage cell 21 has a housing 22, and a positive terminal 23 and a negative terminal 24 as external terminals. A battery element (not shown) is housed inside the housing 22. The positive terminal 23 and the negative terminal 24 are provided on an upper surface 22a of the housing 22. The positive terminal 23 is electrically connected to the positive electrode side of the battery element. The negative terminal 24 is electrically connected to the negative electrode side of the battery element. The positive terminal 23 and the negative terminal 24 are insulated from the housing 22 by an insulator (not shown).

[0020] The multiple storage cells 21 include a first storage cell 21a and a second storage cell 21b adjacent to each other in the arrangement direction. The first storage cell 21a and the second storage cell 21b are arranged such that the positive electrode terminals 23 and the negative electrode terminals 24 are arranged alternately in the arrangement direction.

[0021] The spacer 30 is disposed between adjacent power storage cells 21. The spacer 30 is disposed between the first power storage cell 21a and the second power storage cell 21b. More specifically, the spacer 30 is disposed between the housing 22 of the first power storage cell 21a and the housing 22 of the second power storage cell 21b.

[0022] The spacer 30 has insulating properties. The spacer 30 is made of an insulating resin member. As the resin member, polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS), polycarbonate (PC), or the like can be used.

[0023] FIG. 2 is a front view of a spacer provided in the energy storage module according to the first embodiment and an energy storage cell located behind the spacer.

[0024] 1 and 2, the spacer 30 has a plate-like shape. The spacer 30 is provided with a discharge portion 35 for discharging liquid that has reached the spacer 30 from above to the outside of the spacer.

[0025] The spacer 30 has an upper surface portion 30a and a bottom surface portion 30b. The upper surface portion 30a is located on the upper end side of the spacer 30 in the vertical direction (DR1 direction in FIG. 2). The upper surface portion 30a is located at a position lower than the upper surface 22a of the housing 22 of the storage cell 21. The contact angle between the upper surface portion 30a and water is, for example, about 80 degrees. The bottom surface portion 30b is located on the lower end side of the spacer 30 in the vertical direction.

[0026] In the first embodiment, the upper surface portion 30a has an inclined surface that inclines downward from one side to the other side in a width direction (direction DR2 in FIG. 2) perpendicular to the arrangement direction and the up-down direction. The inclined surface constitutes the discharge portion 35. The inclination angle θ of the inclined surface intersecting the width direction is preferably 1 degree or more. By setting the inclination angle θ to 1 degree or more, the liquid can be moved more reliably along the inclined surface.

[0027] The power storage module 100 is housed in a housing case (not shown), and when the inside of the housing case is cooled, condensation water may occur. Liquid may also seep into the housing case. In such a case, liquid may reach the spacer 30 from the upper side of the spacer 30.

[0028] When liquid reaches the spacer 30 from above the spacer 30, the discharge portion 35 can discharge the liquid to the outside of the spacer 30. Specifically, the liquid flows along the inclined surface of the upper surface portion 30a, and the liquid is discharged to the outside of the spacer 30. This can prevent the creepage distance between the external terminals of the adjacent storage cells 21 from becoming smaller due to the accumulation of liquid. As a result, insulation between the external terminals of the adjacent storage cells 21 can be ensured, and adjacent storage cells 21 can be prevented from being short-circuited.

[0029] The creepage distance between the external terminals of adjacent power storage cells 21 will be described later with reference to FIGS.

[0030] (Comparative Example) Fig. 3 is a front view of a spacer provided in a power storage module according to a comparative example and a power storage cell located behind the spacer. Referring to Fig. 3, a power storage module 100X according to a comparative example will be described.

[0031] 3, the energy storage module 100X according to the comparative example is different from the energy storage module 100 according to the first embodiment in the shape of a spacer 30X. The other configurations are almost the same. In the spacer 30X, an upper surface portion 30a is formed flat.

[0032] FIG. 4 is a diagram for explaining the creepage distance between adjacent external terminals in an electricity storage module according to a comparative example.

[0033] If the length from the positive electrode terminal 23 to the top surface 22a of the casing 22 in the vertical direction is b (mm), the length from the top surface 22a of the casing 22 to the top surface 30a of the spacer 30X in the vertical direction is a (mm), the distance from the side of the casing 22 to the side of the positive electrode terminal 23 in the arrangement direction is c (mm), and the distance from the center of the spacer 30X to the side of the casing 22 in the arrangement direction is d (mm), the insulation between the external terminals of adjacent storage cells 21 depends on the creepage distance (a+b+c+d) at the closest point between the external terminals.

[0034] FIG. 5 is a diagram showing a state in which liquid is stored on the upper surface of the spacer in the electricity storage module according to the comparative example.

[0035] 5, in the comparative example, the upper surface 30a of the spacer 30X is configured to be flat, so that the liquid L that reaches the spacer 30X from above remains on the upper surface 30a. In such a case, when the length from the liquid level to the upper surface 22a of the housing 22 in the vertical direction is a1 (mm), the creepage distance is a1+b+c+d.

[0036] a1 (mm) is smaller than the above-mentioned a (mm), and the creepage distance (a1+b+c+d) when liquid accumulates on the upper surface portion 30a is smaller than when no liquid accumulates on the upper surface portion 30a as shown in Fig. 4. As a result, in the energy storage module 100X according to the comparative example, the accumulation of liquid L on the upper surface portion 30a of the spacer 30X reduces the insulation between adjacent external terminals, which can cause adjacent energy storage cells 21 to short-circuit.

[0037] (Embodiment 2) Fig. 6 is a front view of a spacer provided in the power storage module according to embodiment 2 and a power storage cell located behind the spacer. The power storage module 100A according to embodiment 2 will be described with reference to Fig. 6.

[0038] 6, the energy storage module 100A according to the second embodiment differs from the energy storage module 100 according to the first embodiment in the shape of a spacer 30A. The other configurations are substantially the same.

[0039] 6, the upper surface 30a of the spacer 30A has a first inclined surface 30a1 and a second inclined surface 30a2. In the second embodiment, the discharge portion 35 is constituted by the first inclined surface 30a1 and the second inclined surface 30a2.

[0040] The first inclined surface 30a1 is inclined downward from the center of the spacer 30A in the width direction toward one side in the width direction. An inclination angle θ1 of the first inclined surface 30a1 intersecting the width direction is preferably 1 degree or more.

[0041] The second inclined surface 30a2 is inclined downward from the center of the spacer 30A in the width direction toward the other side in the width direction. An inclination angle θ2 of the second inclined surface 30a2 intersecting the width direction is preferably 1 degree or more.

[0042] By setting the inclination angles θ1 and θ2 to 1 degree or more, the liquid can be moved more reliably along the inclined surface.

[0043] Even when configured in this manner, the power storage module 100A according to the second embodiment has substantially the same effects as the power storage module 100 according to the first embodiment.

[0044] (Embodiment 3) Fig. 7 is a front view of a spacer provided in an energy storage module according to embodiment 3 and an energy storage cell located behind the spacer. Fig. 8 is a top view partially showing the energy storage module according to embodiment 3. A power storage module 100B according to embodiment 3 will be described with reference to Figs. 7 and 8.

[0045] 7 and 8, the energy storage module 100B according to the third embodiment differs from the energy storage module 100 according to the first embodiment in the shape of the spacer 30B. The other configurations are substantially the same.

[0046] The spacer 30B includes a flat plate portion 31 and a plurality of protruding portions 32. The flat plate portion 31 is approximately parallel to the up-down direction and the width direction. The upper surface of the flat plate portion 31 is approximately parallel to the width direction. The flat plate portion 31 abuts against the housing 22 of one of the adjacent storage cells 21 (first storage cell 21a). The flat plate portion 31 has a substantially rectangular shape when viewed from the front (when viewed from the arrangement direction).

[0047] The multiple protrusions 32 protrude from the flat plate portion 31 toward the other of the adjacent storage cells 21 (the second storage cell 21b). The multiple protrusions 32 are provided to extend in the up-down direction and are arranged at intervals in the width direction. The multiple protrusions 32 have a columnar shape having a top surface and a bottom surface at both ends in the up-down direction. Specifically, the multiple protrusions 32 have a quadrangular column shape. Ends of the multiple protrusions 32 in the arrangement direction abut against the housing 22 of the second storage cell 21b.

[0048] By forming the multiple protrusions 32 in this manner, multiple discharge flow paths 33 that communicate in the vertical direction are formed in the spacer 30. In this embodiment, the one or more discharge flow paths 33 constitute a discharge section 35.

[0049] In this case, the length of the housing 22 in the width direction is A (mm), the distance between adjacent housings 22 in the arrangement direction is B (mm), and the total flow path area of ​​the multiple discharge flow paths 33 in the cross section of the spacer 30B perpendicular to the up-down direction is C (mm 2 ), it is preferable that C / (A×B) is 1% or more and 50% or less.

[0050] When liquid reaches the spacer 30B from above, the liquid can be discharged below the spacer 30B by the plurality of discharge flow paths 33. In addition, by setting C / (A×B to be 1% or more and 50% or less, damage to the spacer 30B can be suppressed when an impact is applied to the spacer 30B from the outside.

[0051] In this way, the power storage module 100B according to the third embodiment provides substantially the same effects as the power storage module 100 according to the first embodiment.

[0052] In the above-mentioned embodiment 3, an example was given of a case where a plurality of discharge flow paths 33 are provided in the spacer 30B, but this is not limited thereto, and it is sufficient that one or more discharge flow paths 33 are provided as long as the liquid can be discharged.

[0053] (Embodiment 4) Fig. 9 is a front view of a spacer provided in the energy storage module according to embodiment 4 and an energy storage cell located behind the spacer. Fig. 10 is a top view partially showing the energy storage module according to embodiment 4. A power storage module 100C according to embodiment 4 will be described with reference to Figs. 9 and 10.

[0054] 9 and 10, an energy storage module 100C according to embodiment 4 differs from an energy storage module 100B according to embodiment 3 in the shape of a spacer 30C. The other configurations are substantially the same.

[0055] The spacer 30C is different from the spacer 30B according to the second embodiment in the shape of the multiple protrusions 32C. The multiple protrusions 32C have a columnar shape with a top surface and a bottom surface at both ends in the arrangement direction. Specifically, the multiple protrusions 32C have a cylindrical shape.

[0056] The multiple protrusions 32C are arranged in a staggered pattern with a gap between them. By forming the multiple protrusions 32C in this manner, multiple discharge flow paths that communicate in the vertical direction are formed in the spacer 30. The multiple discharge flow paths form a discharge section 35.

[0057] In the present embodiment, the length of the housing 22 in the width direction is also defined as A (mm), the distance between adjacent housings 22 in the arrangement direction is defined as B (mm), and the total flow path area of ​​the plurality of discharge flow paths 33 in a cross section of the spacer 30B perpendicular to the vertical direction is defined as C (mm 2 ), it is preferable that C / (A×B) is 1% or more and 50% or less.

[0058] Even when configured in this way, the power storage module 100C according to the fourth embodiment can achieve substantially the same effects as the power storage module 100B according to the third embodiment.

[0059] (Embodiment 5) Fig. 11 is a front view of a spacer provided in the power storage module according to embodiment 5 and a power storage cell located behind the spacer. With reference to Fig. 11, a power storage module 100D according to embodiment 5 will be described.

[0060] 11, an energy storage module 100D according to embodiment 5 differs from the energy storage module 100 according to embodiment 1 in the shape of an upper surface portion 30a of a spacer 30D. The other configurations are substantially the same.

[0061] The upper surface 30a of the spacer 30D has a curved surface in which the central portion in the width direction bulges upward more than both ends in the width direction. In this case, the discharge portion 35 is formed by the curved surface.

[0062] Even when the upper surface portion 30a is curved in this way, the liquid flows along the curved surface, and the liquid can be discharged to the outside of the spacer 30D. Note that the radius of curvature of the curved surface is preferably, for example, R1000 or less. By setting the radius of curvature in this way, the liquid can be moved along the curved surface, and the liquid can be more reliably discharged to the outside of the spacer 30D.

[0063] Even when configured as described above, the power storage module 100D according to the fifth embodiment can achieve substantially the same effects as the power storage module 100 according to the first embodiment.

[0064] (Reference example) Fig. 12 is a front view of a spacer provided in a power storage module according to a reference example and a power storage cell located behind the spacer. Referring to Fig. 12, a power storage module 100E according to a reference example will be described.

[0065] 12, the power storage module 100E according to the reference example differs from the power storage module 100X according to the comparative example in that a water-repellent treatment is applied to the upper surface portion 30a of the spacer 30E. As a result of the water-repellent treatment, the contact angle between the upper surface portion 30a and water is approximately 150 degrees or more.

[0066] Even in this case, liquid that reaches the spacer 30E from above can be discharged to the outside of the spacer 30 due to the water-repellent treatment.

[0067] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0068] 21 storage cell, 21a first storage cell, 21b second storage cell, 22 housing, 22a upper surface, 23 positive electrode terminal, 24 negative electrode terminal, 30, 30A, 30B, 30C, 30D, 30E, 30X spacer, 30a1 first inclined surface, 30a2 second inclined surface, 30a upper surface portion, 30b bottom surface portion, 31 flat plate portion, 32, 32C protruding portion, 33 discharge flow path, 35 discharge portion, 100, 100A, 100B, 100C, 100D, 100E, 100X storage module.

Claims

1. A first storage cell and a second storage cell, each of which includes a housing having an upper surface and an external terminal provided on the upper surface, and which are arranged adjacent to each other; a spacer having insulating properties and disposed between the adjacent housings; the spacer has an upper surface portion located at a position lower than the upper surface of the housing, the upper surface portion has an inclined surface that is inclined downward toward one side in a width direction perpendicular to an arrangement direction in which the first storage cells and the second storage cells are arranged and perpendicular to a vertical direction, the spacer is provided with a discharge portion for discharging liquid that has reached the spacer from above to an outside of the spacer in the width direction, The discharge portion is constituted by the inclined surface, the upper surface portion has a lower end located on the one side in the width direction and an upper end located on the other side in the width direction, The inclined surface connects the lower end and the upper end of the energy storage module.

2. A first storage cell and a second storage cell, each of which includes a housing having an upper surface and an external terminal provided on the upper surface, and which are arranged adjacent to each other; a spacer having insulating properties and disposed between the adjacent housings; the spacer has an upper surface portion located at a position lower than the upper surface of the housing, the upper surface portion has an inclined surface that is inclined downward toward one side in a width direction perpendicular to an arrangement direction in which the first storage cells and the second storage cells are arranged and perpendicular to a vertical direction, the spacer is provided with a discharge portion for discharging liquid that has reached the spacer from above to an outside of the spacer in the width direction, The discharge portion is constituted by the inclined surface, The upper surface portion includes a first inclined surface extending from a center portion in the width direction toward the one side in the width direction, and a second inclined surface extending from the center portion toward the other side in the width direction.

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