Active material layer, method for manufacturing battery, electrode laminate, and battery

Abstract

According to the method of the present application, an active material layer having a groove portion of an arbitrary shape can be formed. The method of the present application for manufacturing an active material layer includes: applying ethylene carbonate (200) in a prescribed pattern on a positive electrode composite layer (140) and / or a negative electrode composite layer (160); and pressing the positive electrode composite layer (140) and / or the negative electrode composite layer (160) to which the ethylene carbonate (200) is applied to obtain a positive active material layer and / or a negative active material layer having a groove portion corresponding to the prescribed pattern.

Description

Technical Field

[0001] This invention relates to a method for manufacturing an active material layer and a battery, an electrode stack, and a battery. Background Technology

[0002] The electrode stack, for example, sequentially comprises a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer or a separator, a negative electrode active material layer, and a negative electrode current collector layer. The battery is formed by housing this electrode stack in an outer container or the like. In the case of a battery containing an electrolyte, in order to improve the diffusion of the electrolyte during injection and the gas expulsion during charging and discharging, it has been disclosed to provide slits or grooves on the active material layer or the separator (Patent Documents 1-6).

[0003] For example, Patent Document 1 discloses a secondary battery comprising an electrode assembly formed by winding or stacking a positive electrode plate and a negative electrode plate on the surface of a current collector having an agent layer containing an active material formed thereon, separated by a separator. Multiple grooves are formed on the surface of the agent layer in at least one of the positive and negative electrode plates, and each groove has a curved portion at its side end and bottom center. It is claimed that the electrolyte in the secondary battery described in Patent Document 1 has excellent impregnation properties and excellent cycle characteristics and reliability.

[0004] Patent Document 2 discloses a non-aqueous electrolyte secondary battery, characterized by forming a groove on the surface of the active material layer, extending from one edge of an electrode plate along its length to another edge, with the cross-sectional area of ​​the groove gradually increasing from the center of the electrode plate to the edge. It is claimed that, according to the non-aqueous electrolyte secondary battery described in Patent Document 2, by forming a groove on the surface of the electrode, the diffusion rate of the injected electrolyte into the power generation element, the exhaust rate from the power generation element, and the solvent removal rate can be increased.

[0005] Patent Document 3 discloses a non-aqueous electrolyte secondary battery comprising an electrode assembly having: a high-density positive electrode with a positive active material layer formed on at least one side of a positive current collector; a high-density negative electrode with a negative active material layer formed on at least one side of a negative current collector; and a separator between the positive and negative electrodes. The electrode assembly is impregnated with a non-aqueous electrolyte, wherein the specific surface area per unit area of ​​the positive active material layer of the positive electrode is 0.5 to 1.0 times that of the specific surface area per unit area of ​​the negative active material layer of the negative electrode, which is sandwiched between the positive electrode and the separator. It is claimed that the non-aqueous electrolyte secondary battery described in Patent Document 3 can achieve stabilization of initial characteristics, particularly discharge characteristics under high current discharge, and improvement of charge-discharge cycle characteristics.

[0006] Patent Document 4 discloses a non-aqueous electrolyte battery, which is constructed by sealing an outer casing containing an electrode body formed with a separator between the positive and negative electrodes and a non-aqueous electrolyte. The battery is characterized by having an electrode mixture layer containing an active material on one or both sides of a current collector. The thickness of the electrode mixture layer on at least one surface of at least one of the positive and negative electrodes is 100 μm or more, and the surface opposite to the current collector has multiple grooves with openings. The width L1 of each groove is 100–800 μm, and the spacing L2 between adjacent grooves is 2–5 mm. It is claimed that the non-aqueous electrolyte battery described in Patent Document 4 achieves high power generation efficiency while using electrodes with thick electrode mixture layers.

[0007] Patent Document 5 discloses a separator for an energy storage device, which includes: an electrode body having a positive and negative electrode stacked structure with a separator separating the positive and negative electrodes, a housing containing the electrode body, and an electrolyte, wherein the separator has one or more grooves extending from one end of the separator constituting the positive and negative electrode stacked structure toward the other end. It is claimed that the separator described in Patent Document 5 can appropriately improve the electrolyte impregnation.

[0008] Patent Document 6 discloses a non-aqueous electrolyte battery, which is a non-aqueous electrolyte battery in which a positive electrode and a negative electrode are stacked together with a separator in between, and a non-aqueous electrolyte is injected. The battery is characterized by having at least one side of the separator roughened. It is claimed that the non-aqueous electrolyte battery described in Patent Document 6 is a non-aqueous electrolyte battery that shortens the electrolyte penetration time into the electrode assembly and has good mass production capabilities.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: International Publication No. 2008 / 053880

[0012] Patent Document 2: Japanese Patent Application Publication No. 2004-207253

[0013] Patent Document 3: Japanese Patent Application Publication No. 2004-006275

[0014] Patent Document 4: Japanese Patent Application Publication No. 2012-181978

[0015] Patent Document 5: Japanese Patent Application Publication No. 2024-092439

[0016] Patent Document 6: Japanese Patent Application Publication No. 06-333550 Summary of the Invention

[0017] The problem that the invention aims to solve

[0018] In the methods described in Patent Documents 1 to 6, the groove is formed by pressing with a roller having protrusions or a rough surface for roughening treatment. When using this method, a groove with a pattern corresponding to the protrusions on the roller surface can be formed. However, the patterns of the grooves that can be formed by roller pressing are limited, and in particular, they tend to be repetitive patterns.

[0019] Therefore, the object of the present invention is to provide a method for forming grooves of arbitrary shapes.

[0020] Methods for solving problems

[0021] The present invention achieves the above objectives through the following means.

[0022] (Method 1)

[0023] A method for manufacturing an active material layer, comprising:

[0024] Ethylene carbonate is coated onto the electrode composite layer in a specified pattern; and

[0025] The electrode composite material layer coated with the above-mentioned ethylene carbonate is pressed to obtain an active material layer having a groove corresponding to the above-mentioned specified pattern.

[0026] (Method 2)

[0027] According to the method of method 1, the groove portion has at least one of the following structures:

[0028] (i) The groove extends in a generally radial manner from the end face near the injection hole of the active material layer toward the other end face of the active material layer.

[0029] (ii) The above-mentioned groove forms a branch flow path extending in the surface direction;

[0030] (iii) The structure in which the above-mentioned groove does not reach at least one edge of the active material layer;

[0031] (iv) The grooves described above have a spiral or spider web-like structure.

[0032] (Method 3)

[0033] A method for manufacturing a battery, wherein,

[0034] The aforementioned battery sequentially comprises a first current collector layer, a first active material layer, a solid electrolyte layer or separator, a second active material layer, and a second current collector layer, and

[0035] The manufacturing method includes manufacturing the first and / or second active material layers described above by means of method 1 or 2.

[0036] (Method 4)

[0037] An electrode stack has an active material layer and a current collector layer in contact with the active material layer, wherein...

[0038] The surface of the active material layer on the side opposite to the current collector layer has a groove, and

[0039] The aforementioned groove has at least one of the following structures:

[0040] (i) The groove extends in a generally radial manner from the end face near the injection hole of the active material layer toward the other end face of the active material layer.

[0041] (ii) The above-mentioned groove forms a branch flow path extending in the surface direction;

[0042] (iii) The structure in which the above-mentioned groove does not reach at least one edge of the active material layer;

[0043] (iv) The grooves described above have a spiral or spider web-like structure.

[0044] (Method 5)

[0045] A battery, comprising, in sequence, a first current collector layer, a first active material layer, a solid electrolyte layer or a separator, a second active material layer, and a second current collector layer, and

[0046] The combination of the first current collector layer and the first active material layer, and / or the combination of the second current collector layer and the second active material layer constitutes the electrode stack described in embodiment 4.

[0047] Invention Effects

[0048] According to the method of the present invention, it is possible to form grooves of any shape. Attached Figure Description

[0049] Figure 1 This is a schematic diagram illustrating the coating process of ethylene carbonate.

[0050] Figure 2 This is a schematic diagram used to illustrate the pressing process.

[0051] Figure 3 This is a schematic diagram used to illustrate the pattern of the groove.

[0052] Figure 4 This is an image of the active material layer in an embodiment of the present invention. Detailed Implementation

[0053] Methods for manufacturing active substance layers

[0054] The method of the present invention for manufacturing an active material layer includes: coating an electrode composite material layer with ethylene carbonate in a predetermined pattern; and pressing the electrode composite material layer coated with the ethylene carbonate to obtain an active material layer having grooves corresponding to the predetermined pattern.

[0055] According to the above method, grooves of any shape can be formed.

[0056] As described above, a conventional method discloses that, in order to improve the diffusion of the electrolyte during injection and the gas expulsion during charging and discharging, slits or grooves are provided on the active material layer. In this case, the shape (pattern) of the slits and grooves is formed by transferring a pattern onto the pressure roller, thus becoming a repeating pattern.

[0057] In contrast, in the method of the present invention, ethylene carbonate is coated onto an electrode composite material layer in a predetermined pattern, and then the electrode composite material layer coated with ethylene carbonate is pressed to obtain an active material layer having grooves corresponding to the predetermined pattern. This allows for the formation of grooves with arbitrary patterns, thus enabling the formation of patterns that cannot be formed by transfer printing with a pressure roller.

[0058] Furthermore, since ethylene carbonate is a solid at room temperature (25°C) and is an electrolyte component, it is not necessary to dry and remove ethylene carbonate after film formation. Therefore, the method of the present invention can be used even when the entire film formation process is carried out in a dry film formation manner.

[0059] The embodiments of the present invention will now be described in detail. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the spirit of the invention. Furthermore, in the accompanying drawings, the same elements are labeled with the same symbols, and repeated descriptions are omitted.

[0060] <Coating process of ethylene carbonate>

[0061] In the method of the present invention for manufacturing the active material layer, firstly, ethylene carbonate is coated on the electrode composite material layer in a prescribed pattern.

[0062] Figure 1 One embodiment of the present invention is shown, but it is not limited thereto. Figure 1 A cross-sectional view of the active material layer is shown. A negative electrode composite material layer 160 is disposed on the upper surface of the current collector layer 120, and a positive electrode composite material layer 140 is disposed on the lower surface. Ethylene carbonate 200 is disposed on a portion of the surface of the negative electrode composite material layer 160.

[0063] Ethylene carbonate can be coated with a specified pattern. At least a portion of the pattern of the coated ethylene carbonate corresponds to the pattern of the groove formed after pressing.

[0064] In this invention, the specified pattern is not particularly limited, and examples include striped patterns, grid patterns, and the following shapes:

[0065] (i) The pattern is defined as a structure that extends in a generally radial manner from the end face near the injection hole of the active material layer toward the other end faces of the active material layer.

[0066] (ii) Specify the structure of the branch flow path that extends along the surface direction in the drawing.

[0067] (iii) Specify a structure in which the pattern does not reach at least one edge of the active material layer.

[0068] (iv) The pattern shall be a spiral or spider web structure.

[0069] (Active substance layer)

[0070] In this invention, the active material layer is made by pressing the electrode composite material layer, etc., and has a void with a specified pattern.

[0071] There are no particular limitations on the thickness of the active material layer. For example, it can be 0.1μm or more, 1μm or more, 3μm or more, 5μm or more, or 10μm or less, or less than 1mm, 700μm or less, 500μm or less, 300μm or less, or 100μm or less.

[0072] (Electrode composite material layer)

[0073] In this invention, the electrode composite material layer contains at least active material particles. Additionally, the active material layer may further contain at least one of a solid electrolyte, a conductive additive, and a binder, as needed.

[0074] There are no particular restrictions on the types of solid electrolytes, conductive additives, and binders that may be included in the active material layer. Furthermore, there are no particular restrictions on the content of solid electrolytes, conductive additives, and binders in the active material layer.

[0075] <Pressing Process>

[0076] In the method of the present invention for manufacturing the active material layer, the electrode composite material layer coated with ethylene carbonate is then pressed to obtain an active material layer having a groove corresponding to a specified pattern.

[0077] Figure 2One embodiment of the present invention is shown, but it is not limited thereto. By pressing the electrode composite material layer, ethylene carbonate 200 disposed on the surface of the negative electrode composite material layer 160 forms a groove on the surface of the negative electrode composite material layer and enters the groove.

[0078] In this invention, pressing methods include, but are not limited to, roll pressing using rollers with smooth surfaces, surface pressing, etc.

[0079] In this invention, the pressure of the roller pressing is not particularly limited and can be above 5kN / cm, above 10kN / cm, above 50kN / cm, above 80kN / cm, or above 100kN / cm, or below 500kN / cm, below 300kN / cm, below 200kN / cm, or below 100kN / cm.

[0080] The shape of the groove can be arbitrary, for example, such as Figure 3 The striped, grid-like, etc. patterns shown are examples. In particular, grooves of the shapes described below are difficult to form using pressure rollers, therefore the method of the present invention can be more preferably utilized:

[0081] (i) The groove extends in a generally radial manner from the end face near the injection hole of the active material layer toward the other end face of the active material layer.

[0082] (ii) The above-mentioned groove forms a branch flow path extending in the surface direction;

[0083] (iii) The structure in which the above-mentioned groove does not reach at least one edge of the active material layer;

[0084] (iv) The grooves described above have a spiral or spider web-like structure.

[0085] For example, the groove portion of the structure described in (iii) above can improve the impregnation of the electrolyte while making the active material layer less susceptible to damage, thus the method of the present invention can be used more preferably.

[0086] In this invention, grooves on the surface of the active material layer can be formed by removing ethylene carbonate from the surface of the active material layer after the pressing process. Methods for removing ethylene carbonate include, but are not limited to, heating it to above its melting point (approximately 36.4°C) to melt it, or dissolving it in an electrolyte.

[0087] Furthermore, as mentioned above, ethylene carbonate is a component that may be included in the electrolyte. Therefore, the step of drying and removing the ethylene carbonate used to form the tank after the active material layer is formed is not required. In particular, since a drying step after the formation of the active material layer is not required, the method of the present invention can be effectively utilized even if the active material layer is formed by dry film formation.

[0088] Battery Manufacturing Methods

[0089] In the method of manufacturing a battery according to the present invention, the battery sequentially comprises a first current collector layer, a first active material layer, a solid electrolyte layer or a separator, a second active material layer, and a second current collector layer, and includes manufacturing the first and / or second active material layers by the method described in the present invention.

[0090] <Injection Process>

[0091] In this invention, the battery manufacturing method may include an electrolyte injection process, i.e., an electrolyte filling process. By injecting the electrolyte, the ethylene carbonate on the surface of the active material layer can dissolve into the electrolyte over a sufficient period of time, thereby removing the ethylene carbonate from the surface of the active material layer and forming a groove on the surface of the active material layer.

[0092] There are no particular restrictions on the electrolyte injected during the electrolyte injection process. Even if the ethylene carbonate content of the electrolyte injected during the electrolyte injection process is less than the amount configured in the electrode stack, an electrolyte with the desired ethylene carbonate content can still be formed within the electrode stack module.

[0093] Electrode Laminates

[0094] The electrode stack of the present invention is an electrode stack having an active material layer and a current collector layer in contact with the active material layer, wherein a groove is provided on the surface of the active material on the side opposite to the current collector layer side, and the groove has at least one of the following structures:

[0095] (i) The groove extends in a generally radial manner from the end face near the injection hole of the active material layer toward the other end face of the active material layer.

[0096] (ii) The above-mentioned groove forms a branch flow path extending in the surface direction;

[0097] (iii) The structure in which the above-mentioned groove does not reach at least one edge of the active material layer;

[0098] (iv) The grooves described above have a spiral or spider web-like structure.

[0099] "Battery"

[0100] The battery of the present invention comprises, in sequence, a first current collector layer, a first active material layer, a solid electrolyte layer or a separator, a second active material layer and a second current collector layer, and the combination of the first current collector layer and the first active material layer, and / or the combination of the second current collector layer and the second active material layer constitutes the electrode stack described in the present invention.

[0101] The present invention will be described in more detail below with reference to the embodiments, but the scope of the invention is not limited to these embodiments.

[0102] Example

[0103] (Ethylene carbonate coating)

[0104] Ethylene carbonate, heated above its melting point and molten, was applied in a stripe pattern to the negative electrode composite material layer. The coated negative electrode composite material layer is shown below. Figure 4 (a) The coated ethylene carbonate was cooled to room temperature (25°C) and maintained a striped pattern on the surface of the negative electrode composite layer.

[0105] (suppress)

[0106] The coated negative electrode composite material layer was rolled at room temperature (25℃) and 14 kN / cm. The rolled negative electrode active material layer is shown below. Figure 4 (b). Ethylene carbonate forms grooves on the negative electrode composite layer while maintaining the striped coating.

[0107] (Melting of ethylene carbonate)

[0108] By heating the pressed electrode at 37.0°C, ethylene carbonate is melted and impregnated into the negative electrode composite material layer. The negative electrode active material layer after molten ethylene carbonate is shown in the figure. Figure 4 (c). For example Figure 4 As shown in (c), grooves formed by ethylene carbonate were observed on the surface of the negative electrode composite material layer.

[0109] (evaluate)

[0110] like Figure 4 As shown in (a) to (c), it can be confirmed that grooves can be formed that correspond to any shape of the ethylene carbonate coating.

[0111] Symbol Explanation

[0112] 120 collector layer

[0113] 140 Positive electrode composite material layer

[0114] 160 Negative Electrode Composite Material Layer

[0115] 200 Ethyl carbonate

Claims

1. A method for manufacturing an active material layer, comprising: Ethylene carbonate is coated onto the electrode composite material layer in a specified pattern; as well as The electrode composite material layer coated with ethylene carbonate is pressed to obtain an active material layer with a groove corresponding to the specified pattern.

2. The method according to claim 1, wherein, The groove has at least one of the following structures: (i) The groove extends in a generally radial manner from the end face side near the injection hole of the active material layer toward the other end face side of the active material layer; (ii) The groove forms a branch flow path extending along the surface direction; (iii) The structure in which the groove does not reach at least one edge of the active material layer; (iv) The groove has a spiral or spider web-like structure.

3. A method for manufacturing a battery, wherein, The battery sequentially comprises a first current collector layer, a first active material layer, a solid electrolyte layer or separator, a second active material layer, and a second current collector layer, and The manufacturing method includes manufacturing the first and / or second active material layer by means of the method of claim 1 or 2.

4. An electrode stack having an active material layer and a current collector layer in contact with the active material layer, wherein, The surface of the active material layer on the side opposite to the current collector layer has a groove, and The groove has at least one of the following structures: (i) The groove extends in a generally radial manner from the end face side near the injection hole of the active material layer toward the other end face side of the active material layer; (ii) The groove forms a branch flow path extending along the surface direction; (iii) The structure in which the groove does not reach at least one edge of the active material layer; (iv) The groove has a spiral or spider web-like structure.

5. A battery, comprising, in sequence, a first current collector layer, a first active material layer, a solid electrolyte layer or a separator, a second active material layer, and a second current collector layer, and The combination of the first current collector layer and the first active material layer, and / or the combination of the second current collector layer and the second active material layer constitutes the electrode stack as described in claim 4.

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