Electricity storage cell

Abstract

To promote flow of electrolyte in a case.SOLUTION: An electricity storage cell includes: a case; an electrode boy; and electrolyte. The case houses the electrode boy and the electrolyte. The case includes: a main body; and at least one lid. The main body includes an opening. The lid closes the opening. The case has an outer shape having a rectangular parallelepiped shape. A surface of the case with the minimum area out of six surfaces of the case is constructed by the lid. Two or more liquid injection ports are provided in the lid. The two or more liquid injection ports are dispersed in a length direction of the lid. A first groove is formed onto the surface with the maximum area from an internal surface of the main body. The first groove is extended to a vertical direction with respect to the internal surface of the lid. The electrode body includes: a first electrode; and a second electrode. In at least one front surface of the first electrode and the second electrode, a second groove is formed. The second groove is faced to the first groove. The second groove is extended in parallel to the first groove along the first groove. The second groove has a width larger than that of the first groove.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Japanese Patent Application Laid-Open No. 2002-008634 discloses providing a case with two or more liquid injection ports. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-008634 A Summary of the Invention [Problem to be solved by the invention]

[0004] The energy storage cell includes a case and an electrode assembly. The case houses the electrode assembly. After the electrode assembly is housed, an electrolyte is injected into the case. In general, the electrolyte is injected through an injection port provided in the case. To facilitate the injection of the electrolyte, it is considered to provide a plurality of injection ports.

[0005] For example, from the viewpoint of energy density, it is necessary to reduce the clearance between the case and the electrode assembly, and the smaller the clearance, the more likely it is that the flow of electrolyte within the case is hindered.

[0006] An object of the present disclosure is to promote the flow of electrolyte within the case. [Means for solving the problem]

[0007] The technical configuration and the effects of the present disclosure will be described below. However, the mechanism of action includes assumptions. The mechanism of action does not limit the technical scope of the present disclosure.

[0008] The energy storage cell includes a case, an electrode body, and an electrolyte. The case houses the electrode body and the electrolyte. The case includes a main body and at least one lid. The main body has an opening. The lid closes the opening. The case has a rectangular parallelepiped shape. Of the six faces of the case, the face with the smallest area is formed by the lid. The lid is provided with two or more liquid injection ports. The two or more liquid injection ports are distributed in the length direction of the lid. Of the inner faces of the main body, a first groove is formed in a face with the largest area. The first groove extends in a direction perpendicular to the inner face of the lid. The electrode body includes a first electrode and a second electrode. A second groove is formed in a surface of at least one of the first electrode and the second electrode. The second groove faces the first groove. The second groove extends parallel to the first groove along the first groove. The second groove has a width larger than that of the first groove.

[0009] The first groove and the second groove can promote the flow of the electrolyte. The storage cell may be used with pressure applied to the electrode body. This pressure may also be referred to as "confining pressure." The confining pressure is applied through the case. Since the width of the second groove is larger than the width of the first groove, the confining pressure applied to the case can act efficiently on the power generation portion (active material layer) of the electrode body.

[0010] For example, an elastic porous body may be disposed in the first groove. By disposing an elastic porous body in the first groove, it is expected that the confining pressure will be dispersed in the in-plane direction.

[0011] Hereinafter, an embodiment of the present disclosure (hereinafter, may be abbreviated as "the present embodiment") will be described. However, the present embodiment does not limit the technical scope of the present disclosure. The present embodiment is illustrative in all respects. The present embodiment is non-restrictive. The technical scope of the present disclosure includes all modifications within the meaning and scope equivalent to the description of the claims. For example, it is also originally intended that any configuration may be extracted from the present embodiment and arbitrarily combined. [Brief description of the drawings]

[0012] [Figure 1]FIG. 4 is a schematic diagram showing an example of a case in the present embodiment. [Diagram 2] 2 is a schematic diagram illustrating an example of a first storage cell in the present embodiment. FIG. [Diagram 3] FIG. 2 is a schematic diagram showing an example of an electrode body in the present embodiment. [Figure 4] 2 is a schematic cross-sectional view illustrating an example of a first storage cell in the present embodiment. FIG. [Diagram 5] 4 is a schematic diagram illustrating an example of a second storage cell in the present embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Fig. 1 is a schematic diagram showing an example of a case in this embodiment. Fig. 2 is a schematic diagram showing an example of a first storage cell in this embodiment. The first storage cell 1 includes a case 200. The case 200 may be made of, for example, a metal. The case 200 may be made of, for example, an Al alloy.

[0014] The case 200 has a rectangular parallelepiped shape. The case 200 has a height direction (H direction), a width direction (W direction), and a thickness direction (T direction). The H direction, W direction, and T direction are mutually perpendicular. The "first aspect ratio" indicates the ratio of the dimension of the case 200 in the W direction to the dimension of the case 200 in the H direction. The first aspect ratio may be, for example, 1 or more, 1.5 or more, 2 or more, 2.5 or more, 3 or more, 5 or more, or 10 or more. The first aspect ratio may be, for example, 10 or less, 5 or less, 3 or less, 2.5 or less, 2 or less, or 1.5 or less. The "second aspect ratio" indicates the ratio of the dimension of the case 200 in the T direction to the dimension of the case 200 in the H direction. The second aspect ratio may be, for example, 0.1 or more, 0.2 or more, 0.3 or more, 0.5 or more, or 1 or more. The second aspect ratio may be, for example, any one of 1 or less, 0.5 or less, 0.3 or less, or 0.2 or less.

[0015] The case 200 includes a main body 210 and at least one lid 220. The lid 220 may be, for example, one or two. The main body 210 has four faces. The main body 210 is in the shape of a rectangular tube. The main body 210 includes a main wall 211 and a bottom wall 212. The main wall 211 includes the face with the largest area among the six faces of the rectangular parallelepiped. The lid 220 forms a side wall 221. The side wall 221 includes the face with the smallest area among the six faces of the rectangular parallelepiped. The main body 210 has an opening 213. The opening 213 opens in the W direction. The electrode body 100 is inserted into the main body 210 from the opening 213.

[0016] The lid 220 closes the opening 213. For example, the lid 220 may be welded to the body 210 by laser processing. The lid 220 is provided with two or more liquid inlets 222. The number of liquid inlets 222 may be, for example, three or more, four or more, or five or more. The number of liquid inlets 222 may be, for example, five or less, four or less, or three or less. The multiple liquid inlets 222 are distributed in the length direction (H direction) of the lid 220. The liquid inlets 222 may be arranged at both ends in the H direction.

[0017] The electrolyte is injected through the injection hole 222. After the electrolyte is injected, the injection hole 222 is closed with a sealing plug (not shown). That is, the first power storage cell 1 contains the electrolyte. The electrolyte is a liquid electrolyte. The electrolyte may contain, for example, an organic solvent and a lithium salt.

[0018] The lid 220 may include a terminal portion 223. The terminal portion 223 may be insulated from the sidewall 221 by, for example, a gasket 224. The terminal portion 223 is connected to the electrode tab 101. For example, a bus bar (not shown) may connect the terminal portion 223 and the electrode tab 101.

[0019] The first groove 11 is formed on the inner surface of the main wall 211. The first groove 11 extends in a direction perpendicular to the inner surface of the lid 220 (W direction). The first groove 11 extends parallel to the axial direction of the liquid inlet 222. For example, the first groove 11 may be formed by subjecting the inner surface of the main wall 211 to laser processing. The ratio of the depth of the first groove 11 to the thickness of the main wall 211 may be, for example, any of 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, or 0.2 or less. The ratio of the depth of the first groove 11 to the thickness of the main wall 211 may be, for example, any of 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, or 0.8 or more.

[0020] FIG. 3 is a schematic diagram showing an example of an electrode body in this embodiment. The electrode body 100 may be, for example, a laminated type. The electrode body 100 may be, for example, a wound type. The electrode body 100 includes a first electrode 110, a second electrode 120, and a separator 130. The first electrode 110, the second electrode 120, and the separator 130 may each be independently singular or plural. The second electrode 120 has a polarity different from that of the first electrode 110. For example, the first electrode 110 may be a positive electrode, and the second electrode 120 may be a negative electrode. For example, the first electrode 110 may be a negative electrode, and the second electrode 120 may be a positive electrode.

[0021] The separator 130 separates the first electrode 110 from the second electrode 120. The separator 130 is electrically insulating. The separator 130 is porous. The separator 130 allows the electrolyte to pass through. The separator 130 may be disposed between the first electrode 110 and the second electrode 120 one by one. For example, a strip-shaped separator may be folded in a zigzag shape. The zigzag shape may also be expressed as a bellows shape, an accordion shape, or the like. The electrode body 100 (laminate) may be formed by inserting the first electrode 110 or the second electrode 120 each time the separator 130 is folded.

[0022] The first electrode 110 includes a first current collector 111 and a first active material layer 112. The first active material layer 112 includes a positive electrode active material or a negative electrode active material. The positive electrode active material may include, for example, a lithium nickel composite oxide or the like. The negative electrode active material may include, for example, graphite, SiO, Si or the like. The first active material layer 112 may be disposed on only one side of the first current collector 111. The first active material layer 112 may be disposed on both sides of the first current collector 111. The first current collector 111 may include, for example, a metal foil or the like. The metal foil may include, for example, an Al foil, a Cu foil or the like. A portion of the first current collector 111 protruding in the W direction may function as an electrode tab 101.

[0023] The second electrode 120 includes a second current collector 121 and a second active material layer 122. The second active material layer 122 includes a positive electrode active material or a negative electrode active material. The second active material layer 122 may be disposed on only one side of the second current collector 121. The second active material layer 122 may be disposed on both sides of the second current collector 121. The second current collector 121 may include, for example, a metal foil. A portion of the second current collector 121 protruding in the W direction may function as an electrode tab 101.

[0024] The second groove 12 is formed in at least one of the first electrode 110 and the second electrode 120. The second groove 12 may be formed in the first electrode 110 or the second electrode 120. The second groove 12 may be formed in both the first electrode 110 and the second electrode 120. Hereinafter, the first active material layer 112 and the second active material layer 122 may be collectively referred to as "active material layers". The first current collector 111 and the second current collector 121 may be collectively referred to as "current collectors".

[0025] For example, the second grooves 12 may be formed by subjecting the active material layer to laser processing. The bottom surface of the second grooves 12 may be in the active material layer. The bottom surface of the second grooves 12 may be the surface of the current collector. The ratio of the depth of the second grooves 12 to the thickness of the active material layer may be, for example, 1 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less. The ratio of the depth of the second grooves 12 to the thickness of the active material layer may be, for example, more than 0, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more.

[0026] 4 is a schematic cross-sectional view showing an example of a first storage cell in this embodiment. The second groove 12 faces the first groove 11. The second groove 12 extends parallel to the first groove 11 along the first groove 11. In FIG. 4, the first groove 11 and the second groove 12 extend in the depth direction of the page (W direction in FIG. 2, etc.).

[0027] The second groove 12 has a width larger than that of the first groove 11. The width of each groove indicates the dimension in a direction perpendicular to the extension direction of the groove. In FIG. 4, the width of the groove is the dimension in the H direction. The ratio of the width of the second groove 12 to the width of the first groove 11 may be, for example, any of more than 1, 1.1 or more, 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, or 2.0 or more. The ratio of the width of the second groove 12 to the width of the first groove 11 may be, for example, any of 2.0 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, or 1.1 or less.

[0028] An elastic porous body 20 may be disposed in the first groove 11. The elastic porous body 20 may fill a part of the first groove 11, or may fill the entirety of the first groove 11. The elastic porous body 20 may be made of, for example, a resin. The elastic porous body 20 may be made of, for example, a rubber. The elastic porous body 20 may be, for example, sponge-like. The elastic porous body 20 may include, for example, a rubber sponge or the like.

[0029] 5 is a schematic diagram showing an example of a second storage cell in this embodiment. In the second storage cell 2, a plurality of first grooves 11 and a plurality of second grooves 12 are formed. Each of the plurality of first grooves 11 and the plurality of second grooves 12 may be provided at a position corresponding to each liquid injection port 222. In the H direction, the positions of the first groove 11 and the second groove 12 may coincide with the position of the liquid injection port 222. [Explanation of symbols]

[0030] 1 first storage cell, 2 second storage cell, 11 first groove, 12 second groove, 20 elastic porous body, 100 electrode body, 101 electrode tab, 110 first electrode, 111 first current collector, 112 first active material layer, 120 second electrode, 121 second current collector, 122 second active material layer, 130 separator, 200 case, 210 body, 211 main wall, 212 bottom wall, 213 opening, 220 lid, 221 side wall, 222 liquid inlet, 223 terminal portion, 224 gasket.

Claims

[Claim 1] The battery includes a case, an electrode body, and an electrolyte. The case accommodates the electrode body and the electrolyte, The case includes a body and at least one lid; The body has an opening, The lid closes the opening, The case has a rectangular parallelepiped outer shape, Among the six faces of the case, the face having the smallest area is constituted by the lid, The lid is provided with two or more liquid injection ports, The two or more liquid injection ports are distributed in a longitudinal direction of the lid, A first groove is formed in a surface of the inner surface of the body that has a maximum area, The first groove extends perpendicular to the inner surface of the lid, The electrode body includes a first electrode and a second electrode, a second groove is formed in a surface of at least one of the first electrode and the second electrode; The second groove faces the first groove, the second groove extends along and parallel to the first groove; and The second groove has a width greater than that of the first groove. Energy storage cell.

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