Battery and electrode

Abstract

To provide a battery and an electrode capable of suppressing deterioration of battery performance.SOLUTION: A battery according to an aspect of the present disclosure includes an electrode layer having groove structures G, and a current collector C having the electrode layer having the groove structures on at least one surface. The current collector C includes two plate-shaped members C1 and support columns C2. One surfaces of the plate-shaped members C1 have electrode layers, and the other surfaces face each other. The support columns C2 are disposed at positions along the groove structures G and connect the other surfaces of the two plate-shaped members C1 to each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a battery and an electrode.

Background Art

[0002] Patent Document 1 describes a power storage device including a power storage module in which bipolar electrodes are stacked, a restraint plate that restrains the power storage module in the stacking direction, and an elastic body disposed between the power storage module and the restraint plate. The power storage device described in Patent Document 1 equalizes the surface pressure applied to the power storage module by a configuration in which an elastic body is disposed between the power storage module and the restraint plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a bipolar electrode as described in Patent Document 1, the positive electrode layer may have a groove structure in order to discharge gas generated during manufacturing. In this case, the positive electrode layer tends to be thinner in the stacking direction near the groove structure than at other positions.

[0005] When the height in the stacking direction varies in the positive electrode layer depending on the position, a non-uniform surface pressure is applied to the positive electrode layer. When a non-uniform surface pressure is applied to the positive electrode layer, gas generated during manufacturing may accumulate at positions where the surface pressure is low, which may cause a decrease in battery performance. Patent Document 1 does not disclose a technique capable of solving the above problems.

[0006] The present disclosure has been made to solve such problems, and an object thereof is to provide a battery and an electrode capable of suppressing a decrease in battery performance.

Means for Solving the Problems

[0007] A battery according to one aspect of the present disclosure includes an electrode layer having a groove structure, and a current collector having the electrode layer having the groove structure on at least one surface. The current collector has two plate-like members having an electrode layer on one surface and facing each other on the other surface, and a support column disposed at a position along the groove structure and connecting the other surfaces of the two plate-like members. It is a battery.

[0008] According to such a configuration, even in the vicinity of the groove structure where the thickness of the electrode layer becomes thin, the surface pressure applied by the current collector to the electrode layer is maintained. Therefore, the battery according to one aspect of the present disclosure can suppress the generation of gas accumulation. As a result, the battery according to one aspect of the present disclosure can suppress a decrease in battery performance.

[0009] In the battery according to one aspect of the present disclosure, the plate-like member may be an elastic body. According to such a configuration, the surface pressure of the contact surface between the electrode layer and the current collector increases. Therefore, the battery according to one aspect of the present disclosure can more effectively suppress the generation of gas accumulation.

[0010] In the battery according to one aspect of the present disclosure, the width of the support column may be shorter than the width of the groove structure. According to such a configuration, the surface pressure of the contact surface between the electrode layer and the current collector increases. Therefore, the battery according to one aspect of the present disclosure can more effectively suppress the generation of gas accumulation.

[0011] In the battery according to one aspect of the present disclosure, the configuration may be such that a coolant flows inside the current collector. According to such a configuration, the battery according to one aspect of the present disclosure can suppress the temperature rise during operation, and thus can suppress the deterioration of battery performance.

[0012] The battery according to one aspect of the present disclosure includes an electrode layer having a groove structure, and a current collector having the electrode layer having the groove structure on at least one surface. The current collector has one surface having an electrode layer and the other surface having two plate-like members facing each other, and a support column disposed along the groove structure and connecting the other surfaces of the two plate-like members. It is an electrode.

Advantages of the Invention

[0013] According to the present disclosure, it is possible to provide a battery and an electrode capable of suppressing the deterioration of battery performance.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0015] (First Embodiment) <Configuration of the Battery> Hereinafter, with reference to the drawings, the first embodiment according to the present disclosure will be described in detail. First, the configuration of the power storage device according to the present embodiment will be described in detail. FIG. 1 is a schematic cross-sectional view showing the configuration of the battery according to the first embodiment.

[0016] Of course, the right-handed xyz orthogonal coordinates shown in FIG. 1 and other drawings are for convenience in explaining the positional relationship of the components. Usually, the positive direction of the z-axis is vertically upward, the xy plane is the horizontal plane, and they are common among the drawings.

[0017] As shown in FIG. 1, the battery E according to the first embodiment has a structure in which bipolar electrodes BE and separator layers SL are alternately laminated. The bipolar electrodes BE and the separator layers SL are constrained in the lamination direction, that is, the positive direction of the z-axis, by a restraining jig (not shown). Further, the bipolar electrodes BE and the separator layers SL are applied with surface pressure in the positive direction of the z-axis by the restraining jig.

[0018] The separator layer SL prevents a short circuit between the bipolar electrodes BE. As the material of the separator layer SL, any material may be used as long as it functions as a separator of the battery. Specific examples of the material of the separator layer SL include, for example, a porous film or non-woven fabric mainly composed of a polyolefin resin such as polyethylene (PE, PolyEthylene) or polypropylene (PP, PolyPropylene).

[0019] Further, the separator layer SL contains an electrolytic solution and also functions as an electrolyte layer. The electrolytic solution contained in the separator layer SL may be any solution as long as it functions as an electrolytic solution of the battery. Specific examples of the solvent of the electrolytic solution contained in the separator layer SL include cyclic carbonates, cyclic esters, chain carbonates, chain esters, ethers, and mixtures thereof. Specific examples of the solute of the electrolytic solution contained in the separator layer SL include LiBF4, LiPF6, LiN(FSO2)2, LiN(SO2CF3)2, LiN(SO2C2F5)2, and mixtures thereof.

[0020] The bipolar electrode BE includes a current collector C, a positive electrode layer PL, a positive electrode foil PF, a negative electrode layer NL, and a negative electrode foil NL. Note that the positive electrode layer PL and the negative electrode layer NL may be collectively referred to as an electrode layer.

[0021] The electrode according to the present disclosure includes an electrode layer having a groove structure and a current collector having the electrode layer having the groove structure on at least one surface. In the present embodiment, the positive electrode layer PL corresponds to the electrode layer having the groove structure. Also, in the present embodiment, the current collector C corresponds to the current collector having the electrode layer having the groove structure on at least one surface.

[0022] The positive electrode layer PL is a layer formed on the surface of the current collector C via the positive electrode foil PF and has a groove structure G. FIG. 2 is a schematic plan view showing the configuration of the battery according to the first embodiment, and is a view of the positive electrode layer PL and the positive electrode foil PF seen from the negative z-axis direction. As shown in FIG. 2, the positive electrode layer PL is formed in a plurality of regions on the positive electrode foil PF. And between the regions where the positive electrode layer PL is formed, there is a groove structure G which is a portion where the positive electrode layer PL is not formed.

[0023] Note that the groove structure G may be regarded as a part of the electrode layer. Also, the groove structure G is provided to discharge the gas generated from the positive electrode layer PL to the outside during the manufacture of the battery E.

[0024] The positive electrode layer PL may be formed, for example, by applying a positive electrode slurry onto the current collector C via the positive electrode foil PF and drying it. Also, the groove structure G may be formed, for example, by applying the positive electrode slurry only to the above-mentioned plurality of regions during the film formation of the positive electrode layer PL. Also, the groove structure G may be formed, for example, by peeling off a part of the formed positive electrode layer PL and applying it.

[0025] The positive electrode layer PL has a thickness in the z-axis direction near the groove structure G that is thinner than the thickness at other positions. That is, the positive electrode layer PL has a non-uniform thickness. Although details will be described later, the positive electrode layer PL is subjected to surface pressure from a plate-shaped member C1 that is curved according to the thickness of the positive electrode layer PL.

[0026] The positive electrode layer PL contains a positive electrode active material. The positive electrode active material contained in the positive electrode layer PL may be any material as long as it can be used as the positive electrode active material of the battery. Specific examples of the positive electrode active material contained in the positive electrode layer PL include LiCoO2, LiNiO2, LiMn2O4, LiNi x Co y O2, LiNi x Co y Al z O2, LiNi x Co y Mn z O2, LiFePO4, etc. However, in the above composition formulas, x, y, and z are real numbers of 0 or more.

[0027] Also, the positive electrode layer PL may contain a conductive assistant. The conductive assistant contained in the positive electrode layer PL may be any material as long as it can be used as the conductive assistant of the battery. Specific examples of the conductive assistant contained in the positive electrode layer PL include carbon materials such as acetylene black, carbon black, and graphite.

[0028] Also, the positive electrode layer PL may contain a binder. The binder contained in the positive electrode layer PL may be any material as long as it can be used as the binder of the battery. Specific examples of the binder contained in the positive electrode layer PL include fluorine-containing resins, thermoplastic resins, imide-based resins, alkoxysilyl group-containing resins, acrylic resins, etc.

[0029] The positive electrode foil PF is a thin film located on the surface of the current collector C and is typically a metal layer. A positive electrode layer PL is formed on the positive electrode foil PF. The positive electrode foil PF is a thin film located on the surface of the plate-like member C1 described later and bends according to the bending of the plate-like member C1. Note that the positive electrode foil PF may be omitted. That is, the positive electrode layer PL may be directly formed on the current collector C.

[0030] The negative electrode layer NL is a layer formed on the surface of the current collector C via the negative electrode foil NF and contains a negative electrode active material. The negative electrode active material contained in the negative electrode layer NL may be any material as long as it can be used as the negative electrode active material of the battery. Specific examples of the negative electrode active material contained in the negative electrode layer NL include carbon such as graphite, graphite, mesocarbon microbeads, hard carbon, and soft carbon, metal compounds, elements or their compounds that can be alloyed with lithium, boron-added carbon, and the like. Specific examples of the elements that can be alloyed with lithium include silicon and tin.

[0031] The negative electrode layer NL may contain a conductive assistant. The conductive assistant contained in the negative electrode layer NL may be any material as long as it can be used as the conductive assistant of the battery. Note that the specific examples of the conductive assistant contained in the negative electrode layer NL are the same as those of the conductive assistant contained in the positive electrode layer PL.

[0032] The negative electrode layer NL may optionally contain a binder. The binder contained in the negative electrode layer NL may be any material as long as it can be used as the binder of the battery. Note that the specific examples of the binder contained in the negative electrode layer NL are the same as those of the conductive assistant contained in the positive electrode layer PL.

[0033] The negative electrode foil NF is a thin film located on the surface of the current collector C and is typically a metal layer. A negative electrode layer NL is formed on the negative electrode foil NF. Note that the negative electrode foil NF may be omitted. That is, the negative electrode foil NF may be directly formed on the current collector C.

[0034] The current collector C includes two plate-like members C1 and a support C2. The current collector C has a positive electrode layer PL on one surface via a positive electrode foil PF. Also, the current collector C has a negative electrode layer NL on one surface via a negative electrode foil NF. The current collector C outputs the electric power generated by the positive electrode layer PL and the negative electrode layer NL to the outside.

[0035] The plate-like member C1 is a conductive member, one surface has an electrode layer, and the other surfaces face each other. Also, the opposing surfaces are connected by the support C2 described later. That is, the current collector C is composed of two laminated plate-like members C1, and the two plate-like members C1 are connected by the support C2.

[0036] One of the plate-like members C1 according to the present embodiment has a positive electrode layer PL on the surface via a positive electrode foil PF, and the other has a negative electrode layer NL on the surface via a negative electrode foil NF. More specifically, the plate-like member C1 located on the positive side of the z-axis has the positive electrode layer PL, and the plate-like member C1 located on the negative side of the z-axis has the negative electrode layer NL.

[0037] The plate-like member C1 is bent by receiving a force in the z-axis direction from the support C2 and applies a surface pressure to the electrode layer. Therefore, the plate-like member C1 is preferably an elastic body having conductivity. Examples of the elastic body having conductivity include a thin metal plate. Specific examples of the material of the thin metal plate that can be used as the plate-like member C1 include stainless steel, iron, copper, aluminum, titanium, nickel, and alloys containing two or more of these.

[0038] Note that the two plate-like members C1 may be made of different materials. In addition, in the present embodiment, the plate-like member C1 having the electrode layer, that is, the positive electrode layer PL, in which the groove structure G is formed may be curved, and the other plate-like member C1 may be a rigid body.

[0039] The support column C2 is disposed on the surface of the plate-like member C1 that does not have the electrode layer, and connects the two plate-like members C1. Further, the support column C2 is made of a conductive material and also electrically connects the two plate-like members C1.

[0040] FIG. 3 is a schematic cross-sectional view showing the configuration of the battery according to the first embodiment. More specifically, FIG. 3 is a view of the plate-like member C1 on the negative z-axis side and the support column C2 as seen from the positive z-axis direction, with the support column C2 cut along a plane parallel to the xy plane. It can be said that FIG. 3 shows the configuration of the back surface of the surface shown in FIG. 2.

[0041] FIG. 4 is a schematic cross-sectional view showing the configuration of the battery according to the first embodiment. More specifically, FIG. 4 is a view of the plate-like member C1 on the negative z-axis side, the support column C2, the positive electrode foil PF, the positive electrode layer PL, and the separator layer SL on the negative z-axis side as seen from the positive x-axis direction, with the battery 1 cut along a plane parallel to the yz plane.

[0042] As shown in FIGS. 3 and 4, the support column C2 is disposed at a position along the groove structure G provided on the back surface. As shown in FIG. 3, the support column C2 is configured as a linear member extending in one direction parallel to the main surface of the plate-like member C1, that is, the y-axis direction.

[0043] As described above, the thickness of the positive electrode layer PL becomes thinner in the vicinity of the groove structure G. Therefore, the support column C2 according to the present embodiment applies a force to the plate-like member C1 and curves the plate-like member C1 and the positive electrode foil PF so as to sink into the groove structure G, as shown in FIG. 4. According to such a configuration, the surface pressure applied by the plate-like member C1 to the positive electrode layer PL is maintained even in the vicinity of the groove structure G where the thickness of the positive electrode layer PL becomes thinner. When the surface pressure applied to the positive electrode layer PL is maintained, the generation of gas accumulation between the positive electrode layer PL and the current collector C is suppressed. As a result, the battery E can suppress the degradation of performance.

[0044] Here, the width of the support C2 in the direction perpendicular to the stacking direction, that is, the width in the y-axis direction, may be configured to be shorter than the width of the groove structure G in the y-axis direction, as shown in FIG. 4. Also, as shown in FIG. 4, the position of the support C2 may be adjusted so as not to exist on the back surface of the position where the positive electrode layer PL is formed. According to such a configuration, since the surface pressure of the contact surface between the positive electrode layer PL and the positive electrode foil PF increases, the battery E can more effectively suppress the generation of gas accumulation.

[0045] As described above, in the battery E according to the present embodiment, the support C2 disposed at a position along the groove structure G curves the plate-like member C1 so as to sink into the groove structure G. According to such a configuration, even in the vicinity of the groove structure G where the thickness of the positive electrode layer PL becomes thin, the surface pressure applied by the plate-like member C1 to the positive electrode layer PL is maintained. Since the surface pressure applied to the positive electrode layer PL is maintained even in the vicinity of the groove structure G, the battery E according to the present embodiment can suppress the generation of gas accumulation. As a result, the battery E according to the present embodiment can suppress the degradation of battery performance.

[0046] (Other Embodiments) Also, the battery E according to the first embodiment includes a bipolar electrode, but the battery according to the present disclosure is not limited thereto. For example, the battery E may have a configuration in which an electrode provided with a positive electrode layer PL on both sides of a current collector C and an electrode provided with a negative electrode layer NL on both sides of the current collector C are alternately stacked via a separator layer SL.

[0047] In the battery E according to the first embodiment, only the positive electrode layer PL has the groove structure G, but only the negative electrode layer NL may have the groove structure G, or both the positive electrode layer PL and the negative electrode layer NL may have the groove structure G.

[0048] In the battery E according to the first embodiment, an electrode layer having a groove structure was provided only on one side of the current collector C. However, the current collector C may be provided with electrode layers having a groove structure on both sides. That is, the current collector C only needs to be provided with an electrode layer having a groove structure on at least one side.

[0049] The battery E according to the first embodiment was configured using only an electrode composed of an electrode layer having a groove structure G and a current collector C including a plate-like member C1 and a support C2. However, the configuration of the battery according to the present disclosure is not limited to this. For example, the battery according to the present disclosure may be configured by combining the electrode disclosed in the present application and a generally used electrode.

[0050] In the battery E according to the present disclosure, a coolant may be caused to flow inside the current collector C, that is, in a space surrounded by the two plate-like members C1 and the support C2. According to such a configuration, heat generation of the battery during operation can be suppressed. As a result, the battery E can suppress a decrease in battery performance.

[0051] As described above, the present invention has been described in accordance with the above embodiments. However, the present invention is not limited only to the configurations of the above embodiments, and of course includes various modifications, corrections, and combinations that can be made by those skilled in the art within the scope of the invention of the claims of the present patent application.

Explanation of Reference Numerals

[0052] E Battery BE Bipolar Electrode PL Positive Electrode Layer PF Positive Electrode Foil NL Negative Electrode Layer NF Negative Electrode Foil C Current Collector C1 Plate-Like Member C2 Support SL Separator Layer

Claims

1. An electrode layer having a groove structure, A current collector having the electrode layer with the groove structure on at least one surface, and The current collector Has one surface having an electrode layer and the other surface having two plate-like members facing each other, And a support column disposed at a position along the groove structure and connecting the other surfaces of the two plate-like members, A battery.

2. The battery according to claim 1, wherein the plate-like member is an elastic body.

3. The battery according to claim 1 or 2, wherein the width of the support column is shorter than the width of the groove structure.

4. The battery according to claim 1 or 2, wherein a coolant flows inside the current collector.

5. An electrode layer having a groove structure, A current collector having the electrode layer with the groove structure on at least one surface, and The current collector Has one surface having an electrode layer and the other surface having two plate-like members facing each other, And a support column disposed at a position along the groove structure and connecting the other surfaces of the two plate-like members, An electrode. ​ ​ ​

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