Power storage module

Abstract

The invention relates to a power storage module. A power storage module includes a first active material layer, a second active material layer, a separator disposed between the first active material layer and the second active material layer, and a gas discharge tube portion. The second active material layer includes a main surface located on the first active material layer side. The main surface includes a facing region facing the first active material layer. The gas discharge control section is provided on the main surface at a position adjacent to the opposing region and outside the opposing region.

Description

Technical Field

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

[0002] For example, Japanese Patent Application Laid-Open No. 2020-177761 discloses a power storage module including an electrode stack formed of a plurality of unit cells and a resin material provided around a side surface of the electrode stack. Summary of the Invention

[0003] The power storage module includes a resin frame and an electrode stack disposed within the resin frame. The electrode stack includes a plurality of unit cells.

[0004] The plurality of unit cells include a first current collecting plate (collector plate), a first active material layer, a separator, a second active material layer, and a second current collecting plate. The separator is disposed between the first and second active material layers. For adjacent unit cells in the stacking direction, the first current collecting plate of one unit cell contacts the second current collecting plate of another unit cell, forming a stacked current collecting plate using the contacting first and second current collecting plates.

[0005] The battery module is sealed by a resin frame, a first current collecting plate, and a second current collecting plate. An electrolyte is enclosed in the battery module. The first active material layer, the second active material layer, and the separator are impregnated (immersed) in the electrolyte.

[0006] In a battery module constructed as described above, if the separator loses its insulating function, a short circuit occurs between the first and second active material layers, which face each other across the separator, generating a short-circuit current. This short-circuit current generates Joule heat, heating the electrolyte. The heated electrolyte gasifies. This gas increases the internal pressure of the battery module, causing it to expand. This gas can then no longer be contained within the battery module, potentially breaking through the module's resin frame and erupting.

[0007] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a power storage module capable of suppressing adverse effects caused by expansion of gas generated by vaporization of a high-temperature (elevated) electrolyte.

[0008] A first aspect of the present disclosure relates to a battery module comprising a first active material layer, a second active material layer, a separator disposed between the first and second active material layers, and a protrusion. The second active material layer includes a main surface located on the first active material layer side. The main surface includes an opposing region facing the first active material layer. The protrusion is provided on the main surface and is disposed outside of and adjacent to the opposing region.

[0009] The power storage module according to the first aspect of the present disclosure has a protruding portion provided so as to extend annularly along the outer peripheral edge portion of the facing region.

[0010] The convex portion of the electricity storage module according to the first aspect of the present disclosure has a height of 50 μm or more from the main surface.

[0011] The battery module according to the first aspect of the present disclosure further includes a current collecting plate provided with a first active material layer. The current collecting plate is located on an opposite side of the separator from the first active material layer. The first active material layer includes at least one groove. The current collecting plate is exposed from the first active material layer at the at least one groove.

[0012] In the first aspect of the present disclosure, the length of the first active material layer and the second active material layer in either the longitudinal direction or the width direction is at least 1 m.

[0013] In the electricity storage module according to the first aspect of the present disclosure, at least one groove portion has a width of 0.5 mm to 20 mm.

[0014] In the electricity storage module according to the first aspect of the present disclosure, a distance between at least one groove portion is 40 mm or more and 350 mm or less.

[0015] The second aspect of the present disclosure relates to a storage module comprising a plurality of bipolar electrodes stacked in a stacking direction and a separator arranged between the plurality of bipolar electrodes. Each of the plurality of bipolar electrodes comprises a current collecting plate, a first active material layer, a second active material layer, and a protrusion. The current collecting plate has a first coating surface and a second coating surface in the stacking direction. The first active material layer is coated on the first coating surface of the current collecting plate. The second active material layer is coated on the second coating surface of the current collecting plate and has a main surface. The main surface is covered by a separator. The main surface has a relative region opposite to the first active material layer of the bipolar electrode adjacent to the bipolar electrode with the separator sandwiched therebetween. The protrusion is provided on the main surface and is provided on the outside of the relative region and at a position adjacent to the relative region.

[0016] The power storage module according to the second aspect of the present disclosure has a convex portion provided so as to extend annularly along the outer peripheral edge portion of the facing region.

[0017] A second aspect of the present disclosure relates to a power storage module having at least one groove provided in a first active material layer, and a current collecting plate exposed from the first active material layer at the at least one groove.

[0018] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A diagram schematically showing a power storage module according to an embodiment of the present disclosure.

[0020] Figure 2 For Figure 1 The illustrated power storage module is an end view viewed from the direction of the arrow on line II-II.

[0021] Figure 3 To illustrate Figure 2 Figure 2 shows a diagram of the first active material layer.

[0022] Figure 4 It is a graph showing the conditions of the comparative test and the evaluation results of each condition.

[0023] Figure 5 This is a diagram showing the classification of the degree of high temperature. DETAILED DESCRIPTION

[0024] The embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings referred to below, the same components or corresponding components are given the same reference numerals.

[0025] <Electricity Storage Module Configuration>

[0026] Figure 1 Schematically shows a power storage module according to an embodiment of the present disclosure. Figure 1 In the figures, the stacking direction H indicates the stacking direction of the power storage modules 1 . Figure 1 In FIG. 1 , the width direction W indicates the width direction of the electricity storage module 1 , and the length direction L indicates the length direction of the electricity storage module 1 .

[0027] like Figure 1 As shown, the electricity storage module 1 is formed in a rectangular parallelepiped shape. The electricity storage module 1 has a first main surface 1 a and a second main surface 1 b arranged at intervals in the stacking direction H. The electricity storage module 1 includes an electrode stack 10 and a resin portion 500 .

[0028] Figure 2 For Figure 1 The battery module shown is an end view viewed from the direction of the arrow on the II-II line. The electrode stack 10 includes a plurality of unit cells 100. The plurality of unit cells 100 are stacked in a stacking direction H.

[0029] Each unit cell 100 includes a first current collecting plate 112 , a first active material layer 120 , a separator 400 , a second active material layer 130 , and a second current collecting plate 113 .

[0030] The first active material layer 120 is, for example, a positive electrode active material layer and is formed on the first coating surface 112 a of the first current collecting plate 112 . The first coating surface 112 a is the lower surface of the first current collecting plate 112 .

[0031] The second active material layer 130 is, for example, a negative electrode active material layer and is formed on the second coating surface 113 a of the second current collecting plate 113 . The second coating surface 113 a is the upper surface of the second current collecting plate 113 .

[0032] The separator 400 is disposed between the first active material layer 120 and the second active material layer 130 .

[0033] In adjacent unit cells 100 in the stacking direction H, the first current collecting plate 112 of one unit cell 100 contacts the second current collecting plate 113 of another unit cell 100. The stacked current collecting plates 110 are formed with the contacting first and second current collecting plates 112 and 113.

[0034] While the example in which the first current collecting plate 112 and the second current collecting plate 113 are in contact is shown, the present disclosure is not limited thereto. The first current collecting plate 112 and the second current collecting plate 113 may be at least electrically connected. For example, the first current collecting plate 112 and the second current collecting plate 113 may be stacked with a conductive adhesive, a conductive material, a conductive resin, or a combination thereof to achieve electrical connection. Alternatively, the first and second current collecting plates may be electrically connected using wires or terminals.

[0035] When viewed from a position away from the stacking direction H, the stacking current collecting plates 110 are formed into a rectangular shape. The stacking current collecting plates 110 include a first current collecting plate 112 and a second current collecting plate 113. The first current collecting plate 112 is made of, for example, aluminum. The second current collecting plate 113 is made of, for example, copper. The stacking current collecting plates 110 have a first coated surface 112a, which is the surface of the first current collecting plate 112, and a second coated surface 113a, which is the surface of the second current collecting plate 113, in the stacking direction H.

[0036] Figure 3 To illustrate Figure 2 The first active material layer 120 is shown in FIG. For example, when viewed from a position away from the first active material layer 120 in the stacking direction H, the first active material layer 120 is formed into a rectangular shape. The first active material layer 120 is formed so that its length in either the longitudinal direction L or the width direction W is at least 1.0 m. At least one groove 121 is formed in the first active material layer 120.

[0037] The grooves 121 are formed to extend in the longitudinal direction L. The ends of the grooves 121 reach the outer peripheral edge 120a of the first active material layer 120, and the first active material layer 120 is divided into multiple sections by the plurality of grooves 121. The groove width t of the grooves 121 is, for example, 0.5 mm or greater, and for example, 20.0 mm or less. The grooves 121 are arranged with a gap g between adjacent grooves 121 in the width direction W. The gap g is, for example, 40 mm or greater, and for example, 350 mm or less.

[0038] See again Figure 2 In the groove portion 121 , the first coated surface 112 a of the first current collecting plate 112 is exposed from the first active material layer 120 .

[0039] When viewed from a position away from the second active material layer 130 in the stacking direction H, the second active material layer 130 is formed into a rectangular shape. Furthermore, it is formed to extend from the first active material layer 120. Specifically, the outer peripheral edge 130a of the second active material layer 130 extends outward by a phase difference d compared to the outer peripheral edge 120a of the first active material layer 120. The phase difference d is, for example, 0.5 mm or greater. The second active material layer 130 is formed to have a length of at least 1.0 m in either the longitudinal direction L or the width direction W.

[0040] In the unit cell 100 , the second active material layer 130 has a main surface 130 b located on the first active material layer 120 side.

[0041] The main surface 130b includes an opposing region 130c, which is an area facing the first active material layer 120. When the second active material layer 130 and the first active material layer 120 are viewed from a distance in the stacking direction H, the outer peripheral portion 120a is located inward of the outer peripheral portion 130a. Therefore, the opposing region 130c is a portion of the main surface 130b.

[0042] The second active material layer 130 includes a gas exhaust control portion 131. The gas exhaust control portion 131 is a protrusion formed integrally with the second active material layer 130. The gas exhaust control portion 131 is provided on the main surface 130b. More specifically, the gas exhaust control portion 131 is formed outside the opposing region 130c and adjacent to the opposing region 130c. The gas exhaust control portion 131 is formed to extend annularly along the outer peripheral edge of the opposing region 130c. The gas exhaust control portion 131 is formed to protrude from the main surface 130b by a height h. The height h is not less than 50 μm. The cross-sectional shape of the gas exhaust control portion 131 is semicircular, but may also be rectangular, trapezoidal, or elliptical.

[0043] In addition, the gas exhaust control portion 131 is an example of a convex portion in the present disclosure.

[0044] The separator 400 is formed in a rectangular shape when viewed from a position away from the separator 400 in the stacking direction H. The separator 400 is formed so as to protrude from the outer peripheral edge portion 130 a.

[0045] Separator 400 is formed into a sheet, for example. Separator 400 may be a porous sheet or nonwoven fabric. Separator 400 may contain, for example, a polymer that absorbs and retains electrolytes. Examples of materials constituting separator 400 include polypropylene (PP), polyethylene (PE), polyolefins, and polyesters.

[0046] The separator 400 may have a single-layer structure or a multi-layer structure. For example, in order to improve heat resistance and insulation properties, the separator 400 may have a multi-layer structure formed of a porous resin layer and a ceramic layer.

[0047] The resin portion 500 is formed in an annular shape so as to surround (encircle) the electrode stack 10. The outer peripheral ends of the stacked current collecting plates 110 and the outer peripheral ends of the separators 400 are embedded in the resin portion 500. The resin portion 500 and the stacked current collecting plates 110 embedded in the resin portion 500 form a sealed space R. An electrolyte is disposed in the sealed space R.

[0048] The first current collecting plates 112 and the second current collecting plates 113 are exposed at both ends of the electricity storage modules 1 in the stacking direction H. By disposing conductive members (current collecting plates, etc.) at these exposed portions, a plurality of electricity storage modules 1 can be electrically connected in series.

[0049] In the above description, the configuration of the power storage module 1 is described with a focus on the unit cell 100. On the other hand, the power storage module 1 is a bipolar battery including a plurality of bipolar electrodes 101. This will be described in detail below.

[0050] The electricity storage module 1 includes a plurality of bipolar electrodes 101 stacked in a stacking direction H, and separators 400 . The separators 400 are arranged between the bipolar electrodes 101 .

[0051] The bipolar electrode 101 includes a second active material layer 130, a laminated current collecting plate 110, and a first active material layer 120. The laminated current collecting plate 110 includes a first coated surface 112a and a second coated surface 113a. The first coated surface 112a and the second coated surface 113a are spaced apart in the stacking direction H. The second active material layer 130 is applied to the second coated surface 113a. The first active material layer 120 is applied to the first coated surface 112a. Thus, the laminated current collecting plate 110 is located on the opposite side of the separator 400 relative to the first active material layer 120.

[0052] The second active material layer 130 has a main surface 130b. In the bipolar electrode 101, the main surface 130b is the surface of the second active material layer 130 and is covered by the separator 400. The main surface 130b also has a facing region 130c.

[0053] In the bipolar electrode 101 , the opposing region 130 c is a region opposing the first active material layer 120 of the bipolar electrode 101 adjacent in the stacking direction H with the separator 400 interposed therebetween.

[0054] <Comparative Test>

[0055] Figure 4 This is a diagram showing conditions of each power storage module used as the subject of the comparative test and evaluation results of the degree of temperature increase in each power storage module. Figure 5 This is a diagram showing the classification of high temperature components. Figure 4 and Figure 5 The comparative test is described.

[0056] In the comparative test, Figure 4 The storage modules shown in Example 1 and Example 2 are evaluated for their respective high temperature levels. Figure 4 The evaluation of the degree of temperature increase of the storage module according to the comparison reference (not shown) is compared to confirm the effectiveness of suppressing the temperature increase of the gas exhaust control portion 131 and the groove portion 121. Unless otherwise specified, the storage module according to the comparison reference, the storage module shown in the first embodiment, and the storage module shown in the second embodiment have a common configuration and are the same as the storage module 1 according to the embodiment of the present disclosure.

[0057] The following describes the common configuration of each power storage module. Each power storage module includes 30 cells 100 and has an outer shape with a length L of 1535 mm and a width W of 1210 mm.

[0058] The unique configuration of each power storage module will be described.

[0059] In the battery module according to the comparative reference, the groove portion 121 and the gas release regulating portion 131 are not formed in the first active material layer 120 and the second active material layer 130 .

[0060] The storage module according to Example 1 lacked grooves 121 in its first active material layer 120. Meanwhile, the storage module according to Example 1 had nine different types of second active material layers 130. Specifically, these second active material layers 130 had a phase difference d of 0.5 mm, 1.0 mm, or 2.0 mm, and a gas exhaust control portion 131 height h of 50 μm, 100 μm, or 200 μm.

[0061] The storage module according to Example 2 includes a second active material layer 130 with a phase difference d of 2.0 mm and a gas exhaust control portion 131 with a height h of 50 μm. There are ten types of first active material layers 120 in the storage module according to Example 2. Specifically, the first type includes two grooves 121 with a width t of 0.5 mm, 0.8 mm, 1.2 mm, 2.5 mm, or 10.0 mm. The second type includes four, six, or eight grooves 121 with a width t of 0.5 mm. The third type includes ten grooves 121 with a width t of 2.5 mm or 20.0 mm.

[0062] A comparative test was conducted to evaluate the degree of high temperature of each storage module involved in the comparison benchmark, each storage module involved in Example 1, and each storage module involved in Example 2. The specific method of the comparative test is described below. First, the first main surface 1a of the storage module is heated using a heater, and the heating is terminated when the second main surface 1b reaches 300°C. After the heating is completed, the self-heating caused by the high temperature of the storage module is observed to stop, as well as the interior of the storage module after the self-heating stops. Based on the observation results, the degree of high temperature of each storage module is evaluated using 5 stages (5 levels).

[0063] Figure 5 Shows the classification of high temperature degree. Figure 5 As shown, the degree of high temperature is classified into the following five categories: Category 1: Global high temperature, with large amounts of gas ejected from the battery; Category 2: Global high temperature, with gas ejected from the battery; Category 3: Local high temperature, with gas ejected from the battery; Category 4: Local high temperature, with gas ejected from the battery; and Category 5: Local high temperature, with gas ejected from the battery. It should be noted that global high temperature (temperature rise across the entire region) refers to all cells within the battery module reaching high temperatures. Local high temperature refers to only a portion of the cells within the battery module reaching high temperatures.

[0064] Each category is evaluated in five stages, with evaluation 1 being the most severe high temperature increase and a low evaluation, and evaluation 5 being the least severe high temperature increase and a high evaluation. The first category is evaluated as 1, and the fifth category is evaluated as 5 in order.

[0065] After evaluating the degree of high temperature of each storage module, the evaluation of the degree of high temperature of each storage module according to the comparison base, the evaluation of the degree of high temperature of each storage module according to the first embodiment, and the evaluation of the degree of high temperature of each storage module according to the second embodiment are compared. The configuration of the storage module that has a higher evaluation of the degree of high temperature than the evaluation of the degree of high temperature of the storage module according to the comparison base is determined to have achieved the effect of suppressing high temperature.

[0066] The following describes the results of the comparative test. Figure 4 The evaluation results of the degree of temperature increase of each power storage module will be described.

[0067] When the battery module according to the comparative standard was heated using the above-mentioned heating method, the inventors found that a large amount of gas was ejected from the battery module, causing the entire module to heat up. Therefore, the degree of temperature increase of the battery module according to the comparative standard was rated as 1.

[0068] The evaluation of the degree of high temperature of each of the electricity storage modules according to the Example 1 group was 3.

[0069] The degree of high temperature rise of each of the storage modules according to the Example 2 group was rated between 3 and 5. More specifically, the storage module having first active material layer 120 with two grooves 121 having a groove width t of 10.0 mm had a degree of high temperature rise rated at 4. Furthermore, the storage module having first active material layer 120 with eight grooves 121 having a groove width t of 0.5 mm had a degree of high temperature rise rated at 4. Furthermore, the storage module according to the Example 2 group having first active material layer 120 with ten grooves 121 having a groove width t of 2.5 mm or 20.0 mm had a degree of high temperature rise rated at 5. The other storage modules according to the Example 2 group had a degree of high temperature rise rated at 3.

[0070] Next, the results of comparison of evaluations of the degree of temperature increase of each power storage module will be described.

[0071] First, the evaluation of the degree of temperature increase of the electricity storage module according to the comparison standard and the evaluation of the degree of temperature increase of the electricity storage module according to the Example 1 group were compared.

[0072] As a result, the evaluation of the degree of high temperature in all the storage modules in the Example 1 group was higher than that in the storage modules in the comparative group. This confirms that the high temperature suppression effect can be achieved by forming the annularly extending gas exhaust control portion 131 adjacent to the opposing region 130c of the second active material layer 130.

[0073] Second, the evaluations of the degree of temperature increase of the power storage modules in the Example 1 group were compared with each other.

[0074] As a result, the evaluation results of the degree of temperature increase of all the power storage modules in the Example 1 group were the same. Figure 4 Within the range of the combination of the phase difference d and the height h of the gas exhaust control portion 131 shown in Example 1, there is no difference in the effect of suppressing high temperature increase obtained by forming the gas exhaust control portion 131 in the second active material layer 130 .

[0075] Third, the evaluation of the degree of temperature increase of the electricity storage module according to the comparison standard and the evaluation of the degree of temperature increase of the electricity storage modules according to the second embodiment are compared.

[0076] The results showed that the temperature rise degree of all the storage modules in Example 2 was higher than that of the storage modules in the comparison group. This confirms that the formation of grooves 121 in the first active material layer 120 and gas exhaust control portions 131 in the second active material layer 130 can effectively suppress temperature rise.

[0077] Fourth, the degree of temperature increase of the storage modules of Example 1 was evaluated and compared with the degree of temperature increase of the storage modules of Example 2. Specifically, the storage modules of Example 1, which had a second active material layer 130 formed with a gas discharge control portion 131 having a phase difference d of 2.0 mm and a height h of 50 μm, were compared with the storage modules of Example 2, which had a second active material layer 130 formed with a gas discharge control portion 131 having a phase difference d of 2.0 mm and a height h of 50 μm, and a first active material layer 120 formed with a groove 121 having a groove width t of 0.5 mm.

[0078] As a result, the evaluation of the degree of temperature increase of the storage battery module having the first active material layer 120 without grooves 121 was the same as the evaluation of the degree of temperature increase of the storage battery module having the first active material layer 120 with two, four, or six grooves 121 with a groove width t of 0.5 mm.

[0079] On the other hand, the battery module having first active material layer 120 with eight grooves 121 having a width t of 0.5 mm was evaluated as having a higher degree of temperature increase than the battery module having first active material layer 120 with six grooves 121 having a width t of 0.5 mm.

[0080] This confirms that the first active material layer 120 having a predetermined number of grooves 121 has a higher high-temperature suppression effect than the first active material layer 120 without grooves 121. The "predetermined number" refers to the number of grooves 121, each with a groove width t of 0.5 mm, being 8 or more.

[0081] Fifth, the evaluations of the degree of temperature increase of the power storage modules in the Example 2 group were compared with each other.

[0082] The results showed that the battery module having first active material layer 120 with two grooves 121 having a width t of 10.0 mm had a higher evaluation of the degree of high temperature than the battery module having first active material layer 120 with two grooves 121 having a width t of 2.5 mm. This confirmed that increasing the groove width t can achieve a higher effect in suppressing high temperature.

[0083] On the other hand, the evaluation of the degree of temperature increase in the battery module formed with ten grooves 121 having a groove width t of 20.0 mm was similar to the evaluation of the degree of temperature increase in the battery module formed with ten grooves 121 having a groove width t of 2.5 mm. This confirms that the effect of suppressing temperature increase by increasing the groove width t has a limit (upper limit).

[0084] Sixth, the evaluation of the temperature increase degree of the power storage module according to the comparison standard, the evaluation of the temperature increase degree of each power storage module according to the first embodiment, and the evaluation of the temperature increase degree of each power storage module according to the second embodiment were compared.

[0085] The results showed that the storage module in Example 2, in which ten grooves 121 with a width t of 2.5 mm or 20.0 mm were formed in the first active material layer 120, had the highest evaluation of the degree of high temperature rise. This confirms that within the test conditions of this comparative test, the storage module comprising a second active material layer 130 with a gas release control portion 131 having a phase difference d of 2.0 mm and a height h of 50 μm, and a first active material layer 120 with ten grooves 121 having a width t of 2.5 mm or 20.0 mm, had the highest high temperature suppression effect. Furthermore, from the perspective of ensuring the coating area of the first active material layer 120, the storage module comprising a second active material layer 130 with a gas release control portion 131 having a phase difference d of 2.0 mm and a height h of 50 μm, and a first active material layer 120 with ten grooves 121 having a width t of 2.5 mm, was found to be the most optimal condition.

[0086] In this test, when the gap g was 40 mm or more and 350 mm or less, the effect of suppressing high temperature increase was obtained.

[0087] In the embodiment of the present disclosure, separator 400 is a porous body formed, for example, from a porous sheet. Gas exhaust control section 131 is formed adjacent to opposing region 130c. This configuration allows separator 400 to follow the shape of gas exhaust control section 131, forming a curved portion within separator 400.

[0088] A short circuit occurs between the first and second active material layers, generating a short-circuit current. This short-circuit current generates Joule heat, causing the electrolyte to heat up, gasify, and expand in volume, creating a tiny space between the first and second active material layers. The gas moves horizontally within this space. The protrusions act as a physical barrier to this horizontally moving gas, preventing it from escaping outside the gas discharge control unit.

[0089] This can suppress the internal pressure of the space R from rising and can prevent the resin portion 500 from partially breaking. If the resin portion 500 is partially broken, adjacent stacked current collecting plates 110 in the stacking direction H may contact each other and cause a short circuit.

[0090] On the other hand, the electricity storage module 1 according to the embodiment of the present disclosure described above can suppress the breakage of the resin portion 500 and can suppress the occurrence of the above-mentioned adverse effects.

[0091] In an embodiment of the present disclosure, a groove 121 is formed in the first active material layer 120. With this configuration, gas generated by vaporization of the electrolyte between the separators 400 rises through the groove 121 and reaches the stacked current collecting plate 110. The gas reaching the stacked current collecting plate 110 releases heat to the stacked current collecting plate 110, lowering the gas temperature. This lowering of the gas temperature can suppress melting of the separator 400 and prevent short circuits between the first active material layer 120 and the second active material layer 130. Furthermore, the lowering of the gas temperature reduces the volume of the gas, which can reduce the pressure within the space R.

[0092] In particular, in a bipolar electrode 101 having stacked current collecting plates 110 in which first and second current collecting plates 112 and 113 are in direct contact, heat from gas reaching the current collecting plates through grooves 121 is more easily dissipated (dissipated) through the current collecting plates, compared to a battery in which first and second current collecting plates 112 and 113 are electrically connected via a wire or terminal. As a result, the gas temperature decreases, the gas volume decreases, and the pressure within space R can be lowered.

[0093] In the above embodiment, the gas exhaust control portion 131 is integrally formed with the second active material layer 130, but the present disclosure is not limited thereto. For example, the gas exhaust control portion 131 may be formed separately from the second active material layer 130 and positioned outside and adjacent to the opposing region 130c included in the main surface 130b.

[0094] The gas exhaust control portion 131 may be formed of a material different from that of the second active material layer 130. For example, the gas exhaust control portion 131 may be formed by forming a resin or the like in an annular shape along the outer periphery of the facing region 130c on the main surface 130b.

[0095] In the above embodiment, the grooves 121 are formed to extend along the longitudinal direction L, but the present disclosure is not limited thereto. For example, when viewed from the stacking direction H, the grooves 121 may be formed in a grid pattern, or may be partially formed in a grid pattern. Furthermore, the grooves 121 may not be straight lines.

[0096] While the embodiments of the present invention have been described above, the embodiments disclosed herein are to be construed as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be encompassed.

Claims

1. A power storage module comprising: a first active material layer and a second active material layer, a separator disposed between the first active material layer and the second active material layer, and convex part, The second active material layer includes a main surface located on the first active material layer side. The main surface includes a region facing the first active material layer. The convex portion is provided on the main surface and is provided at a position outside the opposing region and adjacent to the opposing region.

2. The power storage module according to claim 1, wherein The convex portion is provided so as to extend annularly along the outer peripheral edge portion of the opposing region.

3. The power storage module according to claim 1, wherein The protrusion has a height of 50 μm or more from the main surface.

4. The power storage module according to claim 1, wherein It also includes a current collecting plate provided with the first active material layer, The current collecting plate is located on the opposite side of the separator relative to the first active material layer. At least one groove is provided in the first active material layer. The current collecting plate is exposed from the first active material layer at the at least one groove portion.

5. The power storage module according to claim 4, wherein The length of the first active material layer and the second active material layer in either the longitudinal direction or the width direction is at least 1 m.

6. The power storage module according to claim 4 or 5, wherein: The at least one groove has a width of 0.5 mm or more and 20 mm or less.

7. The power storage module according to claim 4 or 5, wherein: The interval between the at least one groove portion is 40 mm or more and 350 mm or less.

8. A power storage module comprising: A plurality of bipolar electrodes stacked in a stacking direction, and a separator disposed between the plurality of bipolar electrodes, Each of the plurality of bipolar electrodes includes a current collecting plate, a first active material layer, a second active material layer, and a protrusion. The current collecting plate has a first coating surface and a second coating surface in the stacking direction, The first active material layer is coated on the first coating surface of the current collecting plate, The second active material layer is coated on the second coating surface of the current collecting plate and has a main surface. said main surface being covered by said separator, The main surface includes a region facing the first active material layer of one of the plurality of bipolar electrodes adjacent to each other with the separator interposed therebetween. The convex portion is provided on the main surface and is provided at a position outside the opposing region and adjacent to the opposing region.

9. The power storage module according to claim 8, wherein The convex portion is provided so as to extend annularly along the outer peripheral edge portion of the opposing region.

10. The power storage module according to claim 8 or 9, wherein: At least one groove is provided in the first active material layer. The current collecting plate is exposed from the first active material layer at the at least one groove portion.

Images