Energy storage device

Abstract

Even when the pressure inside the energy storage module is reduced to a level lower than atmospheric pressure, the non-opposing electrode region is prevented from sinking inward towards the inside of the energy storage module in the first direction. [Solution] The energy storage device 10 comprises at least one energy storage module 12 and a case. Each of the at least one energy storage module 12 includes a plurality of electrode sheets, including a bipolar electrode sheet 16, and sealants 36, 38. The bipolar electrode sheet 16 has a current collector foil 22, a positive electrode active material layer 24, and a negative electrode active material layer 26. Each end face of the energy storage module 12 in a first direction has an electrode-facing region A1 and an electrode-non-facing region A2. At each end face of the energy storage module 12 in a first direction, at least a portion of the electrode-non-facing region A2 is bonded to an adjacent energy storage module or case via an adhesive.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a power storage device.

Background Art

[0002] Patent Document 1 describes a power storage device. The power storage device includes at least one power storage module stacked along a first direction. Each of the at least one power storage module is stacked along the first direction and includes a plurality of electrode sheets including bipolar electrode sheets, and a sealing body disposed at the periphery of the plurality of electrode sheets and sealing an electrolyte between the plurality of electrode sheets. The bipolar electrode sheet has a current collector foil, a positive electrode active material layer provided on one surface of the current collector foil, and a negative electrode active material layer provided on the other surface of the current collector foil. Each end face in the stacking direction of the power storage module has an electrode facing region facing at least one of the positive electrode active material layer and the negative electrode active material layer when viewed along the first direction, and an electrode non-facing region located outside the electrode facing region and inside the sealing body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When constraining the energy storage module as described above in the first direction (i.e., the stacking direction), it is conceivable to constrain the region excluding the electrode-facing region. However, since the electrode-facing region is present over a relatively wide area on each end face in the stacking direction of the energy storage module, constraining only the region excluding the electrode-facing region is not sufficient to adequately constrain the energy storage module. To avoid this problem, for example, it is conceivable to reduce the pressure inside the energy storage module to a pressure lower than atmospheric pressure. In this case, the electrode-non-facing regions on each end face in the stacking direction of the energy storage module may sink inward due to the pressure difference between the inside and outside of the energy storage module.

[0005] In light of the above circumstances, this specification provides a technique for avoiding or suppressing the inward recession of the non-opposing electrode region in the first direction of the energy storage module, even when the pressure inside the energy storage module is reduced to a pressure lower than atmospheric pressure. [Means for solving the problem]

[0006] The technology disclosed herein is embodied in an energy storage device. In a first embodiment thereof, the energy storage device comprises at least one energy storage module stacked along a first direction, and a case housing the at least one energy storage module. Each of the at least one energy storage module is stacked along the first direction and includes a plurality of electrode sheets, including a bipolar electrode sheet, and a sealant positioned around the periphery of the plurality of electrode sheets, sealing an electrolyte between the plurality of electrode sheets. The bipolar electrode sheet has a current collector foil, a positive electrode active material layer provided on one side of the current collector foil, and a negative electrode active material layer provided on the other side of the current collector foil. Each end face of the energy storage module in the first direction has, when viewed along the first direction, an electrode-facing region facing at least one of the positive electrode active material layer and the negative electrode active material layer, and an electrode-non-facing region located outside the electrode-facing region and inside the sealant. At each end face of the energy storage module in the first direction, at least a portion of the non-electrode-facing region is bonded to an adjacent energy storage module or the case via an adhesive.

[0007] In the energy storage device described above, at least a portion of the non-electrode-facing region at each end face in the first direction of the energy storage module is bonded to an adjacent energy storage module or case via adhesive. When the non-electrode-facing region of the energy storage module is bonded to an adjacent energy storage module or case in this way, even when the pressure inside the energy storage module is reduced to a pressure lower than atmospheric pressure, it is possible to avoid or suppress the non-electrode-facing region from sinking inward into the energy storage module.

[0008] In a second embodiment, in the first embodiment, at each end face of the energy storage module in a first direction, the portion of the non-electrode-facing region that includes the central line between the outer edge of the electrode-facing region and the inner edge of the seal may be bonded to an adjacent energy storage module or case via adhesive. When the pressure inside the energy storage module is reduced, the portion of the non-electrode-facing region that includes the central line between the outer edge of the electrode-facing region and the inner edge of the seal tends to sink inward into the energy storage module. Therefore, if the portion including the central line is bonded to an adjacent energy storage module or case, it is possible to effectively avoid or suppress the sinking of the non-electrode-facing region inward into the energy storage module when the pressure inside the energy storage module is reduced to a pressure lower than atmospheric pressure.

[0009] In a third embodiment, the first or second embodiment may further include at least one plate material laminated together with at least one energy storage module along a first direction. In this case, each of the at least one plate material is conductive and may be in contact with the electrode-facing region of the end face of the energy storage module in the first direction. With this configuration, the end face of one energy storage module and the end face of another adjacent energy storage module are electrically connected via the plate material. In this case, the adhesive will be placed around the plate material, so the thickness of the adhesive should be designed to match the thickness of the plate material.

[0010] In a fourth embodiment, the plate material may be provided with cooling channels through which a cooling medium flows, as in the third embodiment. With this configuration, the plate material can cool the energy storage module.

[0011] In a fifth embodiment, in any of the first to fourth embodiments, the adhesive may comprise a sheet-like substrate and adhesive layers provided on both sides of the substrate. With this configuration, the thickness of the substrate and the thickness of the adhesive layer can be appropriately changed to match the distance between the electrode-facing regions of two adjacent energy storage modules. [Brief explanation of the drawing]

[0012] [Figure 1] A diagram schematically showing the configuration of the energy storage device 10 in the embodiment. [Figure 2] Cross-sectional view along line II-II in Figure 1. [Figure 3] Enlarged view of part III in Figure 2. [Figure 4] A diagram illustrating the central line CT between the outer edge L1 of the electrode-facing region A1 and the inner edges L2 of the sealants 36 and 38. [Modes for carrying out the invention]

[0013] The embodiment of the energy storage device 10 will be described with reference to the drawings. In this embodiment, the energy storage device 10 is a bipolar lithium-ion secondary battery. The energy storage device 10 can be mounted on a vehicle and used as a power source to drive the vehicle's wheels. In other embodiments, the energy storage device 10 may be a secondary battery other than a lithium-ion secondary battery (for example, a nickel-metal hydride secondary battery). In yet another embodiment, the energy storage device 10 may be an all-solid-state battery.

[0014] As shown in Figures 1 and 2, the energy storage device 10 comprises a plurality of energy storage modules 12 and a case 14 that houses the plurality of energy storage modules 12.

[0015] As shown in Figure 2-4, the multiple energy storage modules 12 comprise two energy storage modules 12a and 12b. The two energy storage modules 12a and 12b include a first energy storage module 12a and a second energy storage module 12b. Each of the two energy storage modules 12 is arranged parallel to the X and Y axes. The two energy storage modules 12 are stacked along the Z axis. That is, the first energy storage module 12a and the second energy storage module 12b are stacked in order from the positive Z direction toward the negative Z direction. Here, the X, Y, and Z axes are orthogonal to each other.

[0016] As shown in FIGS. 1 and 2, the case 14 includes an upper wall 14a, four side walls 14b, and a lower wall 14c. Each of the upper wall 14a and the lower wall 14c is arranged parallel to the X-axis and the Y-axis. The upper wall 14a is arranged on the positive Z-axis side of the first power storage module 12a, and the lower wall 14c is arranged on the negative Z-axis side of the second power storage module 12b. Each of the four side walls 14b extends in the positive Z-axis direction from the lower wall 14c.

[0017] As shown in FIGS. 2 and 3, each of the two power storage modules 12 includes a plurality of electrode sheets 16, 18, 20. Each of the plurality of electrode sheets 16, 18, 20 is arranged parallel to the X-axis and the Y-axis. The plurality of electrode sheets 16, 18, 20 are laminated along the Z-axis direction.

[0018] The plurality of electrode sheets 16, 18, 20 include a bipolar electrode sheet 16, a positive electrode side end electrode sheet 18, and a negative electrode side end electrode sheet 20. The bipolar electrode sheet 16 is arranged between the positive electrode side end electrode sheet 18 and the negative electrode side end electrode sheet 20.

[0019] The bipolar electrode sheet 16 includes a current collector foil 22, a positive electrode active material layer 24, and a negative electrode active material layer 26. The current collector foil 22 is a conductive sheet. The current collector foil 22 is, for example, a laminate of a copper foil and an aluminum foil, and the aluminum foil is joined to one surface of the copper foil. The positive electrode active material layer 24 is provided on one surface of the current collector foil 22 (i.e., the surface in the negative Z-axis direction). The negative electrode active material layer 26 is provided on the other surface of the current collector foil 22 (i.e., the surface in the positive Z-axis direction).

[0020] The positive electrode active material layer 24 contains a positive electrode active material. Examples of the positive electrode active material include lithium nickel-based composite oxides, lithium cobalt-based composite oxides, lithium manganese-based composite oxides, lithium nickel manganese-based composite oxides (e.g., LiNi 1 / 2 Mn 3 / 2 O4), lithium nickel manganese cobalt-based composite oxides (e.g., LiNi 1 / 3 Mn 1 / 3 Co 1 / 3Examples of the cathode active materials include rock salt layer-type active materials such as O2), spinel-type active materials such as lithium manganese oxide, olivine-type active materials such as lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), etc. The negative electrode active material layer 26 contains a negative electrode active material. Examples of the negative electrode active material include carbon materials such as graphite (graphite), hard carbon, soft carbon, etc., materials that form an alloy with lithium such as silicon (Si), and these lithium alloys (for example, Li X M, where M is C, Si, Sn, Sb, Al, Mg, Ti, Bi, Ge, Pb, or P, etc., and X is a natural number), etc. Each active material may be composed of a single type of material or a plurality of types of materials. Further, each of the active material layers 24 and 26 may further contain a conductive assistant, a binder, etc.

[0021] The positive electrode side end electrode sheet 18 includes a positive electrode side end current collector foil 28 and a positive electrode side end active material layer 30. The positive electrode side end current collector foil 28 is a sheet having conductivity. The positive electrode side end current collector foil 28 is, for example, an aluminum foil. The positive electrode side end active material layer 30 is provided on one surface of the positive electrode side end current collector foil 28 (that is, the surface on the negative Z-axis direction side). The positive electrode side end active material layer 30 faces the negative electrode active material layer 26 of the bipolar electrode sheet 16.

[0022] The negative electrode side end electrode sheet 20 includes a negative electrode side end current collector foil 32 and a negative electrode side end active material layer 34. The negative electrode side end current collector foil 32 is a sheet having conductivity. The negative electrode side end current collector foil 32 is, for example, a copper foil. The negative electrode side end active material layer 34 is provided on one surface of the negative electrode side end current collector foil 32 (that is, the surface on the positive Z-axis direction side). The negative electrode side end active material layer 34 faces the positive electrode active material layer 24 of the bipolar electrode sheet 16.

[0023] As shown in Figures 2 and 3, each of the two energy storage modules 12 further comprises a sealing body 36, 38. The sealing bodies 36, 38 have a frame shape. The sealing bodies 36, 38 include a plurality of sheet materials 36 and a plurality of spacers 38. Each of the plurality of sheet materials 36 is positioned on the periphery of one of the bipolar electrode sheet 16, positive electrode end electrode sheet 18, and negative electrode end electrode sheet 20. Each of the plurality of spacers 38 is positioned on the periphery of one of the bipolar electrode sheet 16, positive electrode end electrode sheet 18, or negative electrode end electrode sheet 20 between two sheet materials 36 adjacent to each other in the stacking direction (i.e., the Z-axis direction). This allows the sealing bodies 36, 38 to seal the electrolyte between the plurality of electrode sheets 16, 18, and 20. Although not particularly limited, each energy storage module 12 may further comprise a separator positioned between the bipolar electrode sheet 16 and each of the end electrode sheets 18, 20.

[0024] As shown in Figures 3 and 4, each end face of each energy storage module 12 in the stacking direction (i.e., the Z-axis positive side of the positive electrode end current collector foil 28 and the Z-axis negative side of the negative electrode end current collector foil 32) has an electrode-facing region A1 and an electrode-non-facing region A2. The electrode-facing region A1 faces at least one of the positive electrode active material layer 24 and the negative electrode active material layer 26 when viewed along the stacking direction. The electrode-non-facing region A2 is located outside the electrode-facing region A1 and inside the sealants 36 and 38 when viewed along the stacking direction.

[0025] As shown in Figures 2 and 3, the energy storage device 10 further comprises two current collection terminals 40 and 42. The two current collection terminals 40 and 42 are conductive. The two current collection terminals 40 and 42 are stacked along the Z-axis direction together with the two energy storage modules 12. Although not shown, a portion of each current collection terminal 40 and 42 is exposed from the case 14 of the energy storage device 10, and the remainder of each current collection terminal 40 and 42 is housed within the case 14 of the energy storage device 10. The two current collection terminals 40 and 42 include a positive electrode side current collection terminal 40 and a negative electrode side current collection terminal 42. The positive electrode side current collection terminal 40 is in contact with the electrode-facing region A1 of the positive electrode side end current collection foil 28 of the first energy storage module 12a. The negative electrode side current collection terminal 42 is in contact with the electrode-facing region A1 of the negative electrode side end current collection foil 32 of the second energy storage module 12b. Therefore, when external devices are attached to the two current collection terminals 40 and 42, the two energy storage modules 12 and the external devices are electrically connected. This allows power to be supplied from the energy storage device 10 to the external devices, or the energy storage device 10 to be charged by the external devices.

[0026] As shown in Figure 2-4, the energy storage device 10 further includes a cooling plate 46. The cooling plate 46 is stacked along the Z-axis direction together with the two energy storage modules 12. The cooling plate 46 is provided with a cooling channel 46a through which a cooling medium (e.g., air) flows. The cooling plate 46 is positioned between the first energy storage module 12a and the second energy storage module 12b. The cooling plate 46 is in contact with the electrode-facing region A1 of the negative electrode end current collector foil 32 of the first energy storage module 12a, and also in contact with the electrode-facing region A1 of the positive electrode end current collector foil 28 of the second energy storage module 12b. As a result, the electrode-facing regions A1 of the two energy storage modules 12a and 12b in contact with the cooling plate 46 are cooled as the cooling medium flows through the cooling channel 46a. The cooling plate 46 is also conductive. Therefore, the negative electrode end current collector foil 32 of the first energy storage module 12a is electrically connected to the positive electrode end current collector foil 28 of the second energy storage module 12b via the cooling plate 46.

[0027] As shown in Figure 2-4, the energy storage device 10 further comprises a plurality of adhesive members 50. Each of the plurality of adhesive members 50 has a frame shape. The plurality of adhesive members 50 are stacked together with the two energy storage modules 12 along the Z-axis direction. That is, one of the plurality of adhesive members 50 is positioned between the first energy storage module 12a and the upper wall 14a of the case 14. Another of the plurality of adhesive members 50 is positioned between the first energy storage module 12a and the second energy storage module 12b. And another of the plurality of adhesive members 50 is positioned between the second energy storage module 12b and the lower wall 14c of the case 14.

[0028] Each of the multiple adhesives 50 comprises a base material 52 and two adhesive layers 54a and 54b. The two adhesive layers 54a and 54b include a first adhesive layer 54a and a second adhesive layer 54b. The first adhesive layer 54a is provided on one surface of the base material 52 (here, the surface on the positive Z-axis side). The second adhesive layer 54b is provided on the other surface of the base material 52 (here, the surface on the negative Z-axis side). Each adhesive layer 54a and 54b is composed of, for example, epoxy resin, acrylic resin, silicone resin, etc. The adhesive strength of each adhesive layer 54a and 54b is, for example, 101 kPa or more. The adhesive strength of each adhesive layer 54a and 54b referred to here is the tensile adhesive strength measured in accordance with JIS K6849 (1994). Furthermore, each adhesive layer 54a and 54b has lower conductivity than the two current collection terminals 40 and 42 and the cooling plate 46.

[0029] As shown in Figures 3 and 4, each adhesive 50 is positioned in the non-electrode opposing region A2 when viewed along the lamination direction. Each adhesive 50 may be positioned over the entire non-electrode opposing region A2, or only in a part of the non-electrode opposing region A2. In this example, each adhesive 50 is positioned in the non-electrode opposing region A2, including the central line CT. The central line CT is the central line between the outer peripheral edge L1 of the electrode opposing region A1 and the inner peripheral edges L2 of the sealants 36 and 38. As a result, the area of ​​the non-electrode opposing region A2 of the positive electrode end current collector foil 28 of the first energy storage module 12a, including the central line CT, is bonded to the upper wall 14a of the case 14 via the adhesive 50. The portion of the non-opposing electrode region A2 of the negative electrode end current collector foil 32 of the first energy storage module 12a that includes the central line CT is bonded via adhesive 50 to the portion of the non-opposing electrode region A2 of the positive electrode end current collector foil 28 of the second energy storage module 12b that includes the central line CT. The portion of the non-opposing electrode region A2 of the negative electrode end current collector foil 32 of the second energy storage module 12b that includes the central line CT is bonded via adhesive 50 to the lower wall 14c of the case 14.

[0030] In the energy storage device 10 described above, the non-opposing electrode region A2 at each end face in the stacking direction of the energy storage module 12 (i.e., the Z-axis positive side of the positive electrode end current collector foil 28 and the Z-axis negative side of the negative electrode end current collector foil 32) is bonded to an adjacent energy storage module 12 or case 14 via adhesive 50. By bonding the non-opposing electrode region A2 of the energy storage module 12 to an adjacent energy storage module 12 or case 14 in this way, even when the pressure inside the energy storage module 12 is reduced to a pressure lower than atmospheric pressure, it is possible to avoid or suppress the non-opposing electrode region A2 from sinking inward towards the energy storage module 12.

[0031] In the above-described embodiment, at each end face in the stacking direction of the energy storage module 12, the area of ​​the non-electrode-facing region A2 that includes the aforementioned central line CT is bonded to an adjacent energy storage module 12 or case 14 via adhesive 50. When the pressure inside the energy storage module 12 is reduced, the area of ​​the non-electrode-facing region A2, in particular, that includes the central line CT tends to sink inward towards the energy storage module 12. Therefore, if the area including the central line CT is bonded to an adjacent energy storage module 12 or case 14, it is possible to effectively avoid or suppress the sinking of the non-electrode-facing region A2 inward towards the energy storage module 12 when the pressure inside the energy storage module 12 is reduced to a pressure lower than atmospheric pressure.

[0032] However, at each end face in the stacking direction of the energy storage module 12, it is not necessarily required that the area of ​​the non-electrode-facing region A2 that includes the central line CT between the outer peripheral edge L1 of the electrode-facing region A1 and the inner peripheral edges L2 of the sealants 36 and 38 be bonded to an adjacent energy storage module 12 or case 14 via adhesive 50. That is, at each end face in the stacking direction of the energy storage module 12, it is sufficient that at least a portion of the non-electrode-facing region A2 is bonded to an adjacent energy storage module 12 or case 14 via adhesive 50.

[0033] In the above-described embodiment, the energy storage device 10 includes two current collection terminals 40, 42 and a cooling plate 46. Each of the two current collection terminals 40, 42 and the cooling plate 46 is stacked together with the two energy storage modules 12 along the stacking direction. Each of the two current collection terminals 40, 42 and the cooling plate 46 is conductive and in contact with the electrode-facing region A1 on the end face of each energy storage module 12 in the stacking direction. With this configuration, the positive electrode end current collection foil 28 of the first energy storage module 12a and the negative electrode end current collection foil 32 of the second energy storage module 12b are electrically connected via either of the two current collection terminals 40, 42 and the cooling plate 46. In this case, the adhesive 50 will be placed around each of the two current collection terminals 40, 42 and the cooling plate 46, so it is preferable to design the thickness of the adhesive 50 to match the thickness of each of the two current collection terminals 40, 42 and the cooling plate 46.

[0034] In this embodiment, the two current collection terminals 40 and 42, and the cooling plate 46 are examples of plate materials in this technology. The energy storage device 10 does not necessarily need to include all two current collection terminals 40 and 42, and the cooling plate 46. That is, the energy storage device 10 may include at least one of the two current collection terminals 40 and 42, and the cooling plates 46 and 48.

[0035] In the above-described embodiment, the cooling plate 46 is provided with a cooling channel 46a through which a cooling medium flows. With this configuration, the cooling plate 46 can cool the energy storage module 12 that is in contact with the cooling plate 46.

[0036] In other embodiments, the energy storage device 10 may be provided with a connecting plate instead of the cooling plate 46. The connecting plate has the same configuration as the cooling plate 46, except that it does not have a cooling channel 46a. That is, the connecting plate is conductive. The connecting plate is in contact with the electrode-facing region A1 of the negative electrode end current collector foil 32 of the first energy storage module 12a, and also in contact with the electrode-facing region A1 of the positive electrode end current collector foil 28 of the second energy storage module 12b. As a result, the negative electrode end current collector foil 32 of the first energy storage module 12a is electrically connected to the positive electrode end current collector foil 28 of the second energy storage module 12b via the connecting plate. The connecting plate in this embodiment is also an example of a plate material in this technology.

[0037] In the above-described embodiment, the adhesive 50 comprises a sheet-like base material 52 and adhesive layers 54a and 54b provided on both sides of the base material 52 (here, the side facing the positive Z-axis and the side facing the negative Z-axis). With this configuration, for example, the thickness of the base material 52 and the thickness of the adhesive layers 54a and 54b can be appropriately changed to match the distance between the electrode-facing regions A1 of two adjacent energy storage modules 12. However, each of the multiple adhesives 50 does not necessarily need to include a base material 52. In another embodiment, each adhesive 50 may consist of a single layer made of adhesive.

[0038] In the embodiment described above, the energy storage device 10 comprises two energy storage modules 12. However, the number of energy storage modules 12 does not necessarily have to be two; at least one is sufficient. For example, if there is only one energy storage module 12, at least a portion of the non-electrode-facing region A2 at each end face in the stacking direction of the energy storage module 12 may be bonded to the case 14 via adhesive 50. Alternatively, if there are three or more energy storage modules 12, at least a portion of the non-electrode-facing region A2 at each end face in the stacking direction of each energy storage module 12 may be bonded to other adjacent energy storage modules 12 via adhesive 50. In this case, a cooling plate 46 (or the connecting plate described above) may be provided between each adjacent energy storage module 12.

[0039] In the embodiment described above, the plurality of electrode sheets 16, 18, and 20 include one bipolar electrode sheet 16, a positive electrode end electrode sheet 18, and a negative electrode end electrode sheet 20. However, the number of bipolar electrode sheets 16 does not necessarily have to be one; at least one is sufficient. That is, in other embodiments, the plurality of electrode sheets 16, 18, and 20 may include two or more bipolar electrode sheets 16, a positive electrode end electrode sheet 18, and a negative electrode end electrode sheet 20.

[0040] Although several specific examples have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or in the drawings exhibit technical usefulness individually or in combination. [Explanation of symbols]

[0041] 10: Energy storage device, 12a, 12b: Energy storage module, 14: Case, 16: Bipolar electrode sheet, 18: Positive electrode end electrode sheet, 20: Negative electrode end electrode sheet, 22: Current collector foil, 24: Positive electrode active material layer, 26: Negative electrode active material layer, 28: Positive electrode end current collector foil, 30: Positive electrode end active material layer, 32: Negative electrode end current collector foil, 34: Negative electrode end active material layer, 36, 38: Encapsulation body, 40, 42: Current collector terminals, 46: Cooling plate, 46a: Cooling channel, 50: Adhesive, 52: Substrate, 54a, 54b: Adhesive layer, A1: Electrode opposing region, A2: Electrode non-opposing region, CT: Center line, L1: Outer edge, L2: Inner edge

Claims

1. It is an energy storage device, At least one energy storage module stacked along a first direction, A case housing at least one of the aforementioned energy storage modules, Equipped with, Each of the at least one energy storage module is Multiple electrode sheets, including a bipolar electrode sheet, are stacked along the first direction, The set includes a sealant disposed around the periphery of the plurality of electrode sheets and sealing an electrolyte between the plurality of electrode sheets, The bipolar electrode sheet comprises a current collector foil, a positive electrode active material layer provided on one side of the current collector foil, and a negative electrode active material layer provided on the other side of the current collector foil. Each end face of the energy storage module in the first direction has, when viewed along the first direction, an electrode-facing region that faces at least one of the positive electrode active material layer and the negative electrode active material layer, and an electrode-non-facing region that is located outside the electrode-facing region and inside the sealant, At each end face of the energy storage module in the first direction, at least a portion of the non-electrode-facing region is bonded to an adjacent energy storage module or the case via an adhesive. Energy storage device.

2. The energy storage device according to claim 1, wherein at each end face of the energy storage module in the first direction, a portion of the non-electrode-facing region, including the central line between the outer peripheral edge of the electrode-facing region and the inner peripheral edge of the sealant, is bonded to the adjacent energy storage module or the case via the adhesive.

3. The system further comprises at least one plate material stacked along the first direction together with the at least one energy storage module, The energy storage device according to claim 1, wherein each of the at least one plate material is conductive and is in contact with the electrode-facing region of the end face of the energy storage module in the first direction.

4. The energy storage device according to claim 3, wherein the plate material is provided with a cooling channel through which a cooling medium flows.

5. The energy storage device according to any one of claims 1 to 4, wherein the adhesive comprises a sheet-like base material and adhesive layers provided on both sides of the base material.

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