Electrode manufacturing method, battery and electric device

Abstract

An electrode manufacturing method, a battery and an electric device. The electrode manufacturing method comprises the following steps: providing slurry, wherein the slurry is mixed with a pore-forming agent; applying the slurry onto a current collector so as to form an active substance layer on the current collector; and electrifying the active substance layer, so that the pore-forming agent in the active substance layer is subjected to an electrochemical reaction to form pores. Before the step of applying the slurry onto the current collector, the method further comprises the step: providing a roller, wherein the roller is used for coating and traveling of the current collector, conductive pieces are arranged on the surface of the roller, and the conductive pieces are used for being electrically connected to the current collector. The step of electrifying the active substance layer comprises electrifying the current collector with the conductive pieces. The technical solution can improve the pore forming efficiency of an electrode, so that when the electrode is applied to a battery, the battery can have relatively high manufacturing efficiency.

Description

Electrode manufacturing method, battery, and electrical device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410046332.7, filed on January 12, 2024, entitled “Electrode Manufacturing Method, Battery, and Electrical Device,” and the entire contents of the above application are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a method for manufacturing an electrode, a battery, and an electrical device. Background Art

[0004] Electrodes are not only an important component of batteries, but can also be used in electrolysis industry, electrocatalysis, electrochemical analysis and other electrochemical reaction scenarios involving porous electrodes. Therefore, whether in the development of battery technology or other electrochemical reaction technologies, how to improve the pore-forming efficiency of electrodes is a technical problem that needs to be solved urgently.

[0005] Summary of the Invention

[0006] The present application provides an electrode manufacturing method, a battery, and an electrical device. The technical solution provided in the present application can improve the pore-forming efficiency of the electrode, and when the electrode is applied to the battery, the battery can have a higher manufacturing efficiency.

[0007] This application is achieved through the following technical solutions:

[0008] In a first aspect, some embodiments of the present application provide a method for manufacturing an electrode, comprising the following steps: providing a slurry mixed with a pore-forming agent; applying the slurry to a current collector to form an active material layer on the current collector; and applying electricity to the active material layer so that the pore-forming agent in the active material layer undergoes an electrochemical reaction to form pores. Prior to the step of applying the slurry to the current collector, the method further comprises the following steps: providing a roller for coating the current collector, the roller having a conductive member provided on its surface for electrically connecting to the current collector. The step of applying electricity to the active material layer comprises applying electricity to the current collector via the conductive member.

[0009] Some embodiments of the present application provide a method for manufacturing an electrode, wherein a pore-forming agent that undergoes an electrochemical reaction when energized is added to a slurry, and after the slurry mixed with the pore-forming agent is applied to a current collector to form an active material layer, the pore-forming agent is electrochemically reacted by energizing the active material layer, thereby removing the pore-forming agent, and generating gases that can escape due to the electrochemical reaction, or generating substances that can be separated from the active material layer due to the electrochemical reaction, thereby efficiently forming uniform and dense pores in the active material layer. On the one hand, the formation and morphology of the pores in the active material layer can be precisely controlled, and on the other hand, the pore-forming efficiency of the electrode is improved, thereby enabling the battery to have a higher manufacturing efficiency when the electrode is used in a battery. At the same time, by providing a conductive member on a roller, current can be conducted to the active material layer when the current collector is conveyed on the roller, thereby energizing the active material layer, thereby enabling the active material layer to efficiently form pores, thereby improving the pore-forming efficiency of the electrode, thereby enabling the battery to have a higher manufacturing efficiency when the electrode is used in a battery.

[0010] According to some embodiments of the present application, the pore former is configured as a substance that generates gas when electrified.

[0011] In the above scheme, by limiting the pore-forming agent to a substance that can generate gas after being energized, the gas produced by the electrochemical reaction can escape from the active material layer after the active material layer is energized, thereby efficiently forming uniform pores on the active material layer, improving the pore-forming efficiency of the electrode, and then when the electrode is applied to a battery, the battery can have a higher manufacturing efficiency.

[0012] According to some embodiments of the present application, the pore-forming agent includes water, methanol, ethanol, formic acid, ammonium carbamate, or the like.

[0013] In the above scheme, when the pore-forming agent is water, oxygen and hydrogen can be generated by applying electricity to the active material layer. Oxygen and hydrogen quickly escape from the active material layer, and uniform pores can be quickly formed in the active material layer. When the pore-forming agent is methanol, gas such as carbon dioxide can be generated by applying electricity to the active material layer. Carbon dioxide quickly escapes from the active material layer, thereby quickly forming uniform pores in the active material layer. When the pore-forming agent is ethanol, gas such as carbon dioxide and methane can be generated by applying electricity to the active material layer. Carbon dioxide and methane can quickly escape from the active material layer, thereby quickly forming uniform pores in the active material layer. When the pore-forming agent is formic acid, gas such as carbon dioxide can be generated by applying electricity to the active material layer. Carbon dioxide can quickly escape from the active material layer, thereby quickly forming uniform pores in the active material layer, improving the pore-forming efficiency of the electrode, and then when the electrode is applied to a battery, the battery can have a higher manufacturing efficiency.

[0014] According to some embodiments of the present application, the mass ratio of the pore former in the slurry is A, satisfying 0.00001≤A≤0.2.

[0015] In the above scheme, by limiting the mass ratio A of the pore-forming agent in the slurry to greater than or equal to 0.00001, the amount of pores in the active material layer can be increased, resulting in a larger specific surface area for the electrode, which is conducive to improving the electrode's reaction rate. By limiting the mass ratio A of the pore-forming agent in the slurry to less than or equal to 0.2, it is possible to effectively reduce the waste of space in the active material layer caused by the final pores formed due to excessive pore-forming agent, which affects the amount of active material and thus the volume energy density. When 0.00001mm≤A≤2mm, the reaction rate and volume energy density of the electrode can be effectively balanced.

[0016] According to some embodiments of the present application, the pore-forming agent is solid, and the median particle size D50 of the pore-forming agent satisfies 0.001 mm ≤ D50 ≤ 6 mm.

[0017] In the above scheme, by limiting the median particle size D50 of the pore-forming agent to greater than or equal to 0.001 mm, the size of the pores in the active material layer can be increased, which is beneficial to improving the reaction rate of the electrode. By limiting the median particle size D50 of the pore-forming agent to less than or equal to 6 mm, it is possible to effectively reduce the waste of space in the active material layer caused by the use of an overly large pore-forming agent, resulting in excessively large pores in the final mold, which affects the amount of active material and thus the volumetric energy density. When 0.001 mm ≤ D50 ≤ 6 mm, the reaction rate and volumetric energy density of the electrode can be effectively balanced.

[0018] According to some embodiments of the present application, the median particle size D50 of the pore-forming agent satisfies 0.002 mm ≤ D50 ≤ 5 mm.

[0019] In the above scheme, by limiting the median particle size D50 of the pore-forming agent to greater than or equal to 0.002mm, the size of the pores in the active material layer can be further increased, further facilitating an increase in the reaction rate of the electrode. By limiting the median particle size D50 of the pore-forming agent to less than or equal to 5mm, it is possible to more effectively reduce the waste of space in the active material layer caused by excessively large pores in the final molded product, which affects the amount of active material and, consequently, the volumetric energy density. When 0.002mm≤D50≤5mm, the reaction rate and volumetric energy density of the electrode can be further balanced.

[0020] According to some embodiments of the present application, the step of providing the slurry further includes mixing the slurry with a surfactant.

[0021] In the above scheme, by mixing a surfactant into the slurry, it is beneficial to promote the escape of gas generated by the electrochemical reaction of the pore-forming agent, improve the efficiency of pore formation, thereby improving the pore-forming efficiency of the electrode, and then when the electrode is applied to the battery, the battery has a higher manufacturing efficiency.

[0022] According to some embodiments of the present application, before the step of energizing the active material layer, the step of drying the active material layer is further included; or, after the step of energizing the active material layer, the step of drying the active material layer is further included.

[0023] The above scheme provides two options for the order of applying power to the active material layer and drying the active material layer, providing multiple options for electrode manufacturing. For example, in some embodiments, the active material layer can be applied before drying; in other embodiments, the active material layer can be applied after drying.

[0024] According to some embodiments of the present application, the step of applying electricity to the active material layer includes: the pores formed have a pore diameter D that satisfies 0.001 mm ≤ D ≤ 5 mm.

[0025] In the above scheme, by limiting the pore diameter D to greater than or equal to 0.001mm, the diffusion rate of ions can be improved, thereby accelerating the reaction rate of the electrode. By limiting the pore diameter D to less than or equal to 5mm, the waste of active material layer space caused by excessive pore size can be effectively reduced, affecting the amount of active material and thus the volumetric energy density. When 0.001mm≤D≤5mm, the reaction rate and volumetric energy density of the electrode can be effectively balanced.

[0026] According to some embodiments of the present application, the step of energizing the active material layer includes: a distance L between any two adjacent pores formed satisfies 0.01 mm ≤ L ≤ 10.5 mm.

[0027] In the above scheme, by limiting the spacing L between any two adjacent pores to greater than or equal to 0.01mm, the structural stability of the active material layer can be improved, the risk of active material layer collapse can be reduced, and the reliability of the electrode can be improved. By limiting the spacing L between any two adjacent pores to less than or equal to 10.5mm, the waste of active material layer space caused by excessive spacing between two adjacent pores can be effectively reduced, affecting the amount of active material and thus the volume energy density. When 0.01mm≤L≤10.5mm, the reliability and volume energy density of the electrode can be effectively balanced.

[0028] According to some embodiments of the present application, the current collector has an empty foil area and a coating area. Along the width direction of the current collector, empty foil areas are respectively arranged on both sides of the coating area. The number of conductive members is two, and the two conductive members are arranged at intervals along the width direction of the current collector to respectively contact the corresponding empty foil areas.

[0029] In the above solution, by setting the number of conductive members to two to correspond to the two empty foil areas, the current can effectively act on the active material layer, enabling the pore-forming agent in the active material layer to efficiently undergo an electrochemical reaction, thereby enabling the active material layer to efficiently form pores, improving the pore-forming efficiency of the electrode, and further, when the electrode is applied to a battery, enabling the battery to have a high manufacturing efficiency.

[0030] According to some embodiments of the present application, along the width direction of the current collector, the two conductive members are configured to be arranged on the roller in a position-adjustable manner.

[0031] In the above solution, by setting the conductive members to be position-adjustable along the width direction of the current collector, the conductive members can act on current collectors of different specifications to manufacture porous electrodes of different specifications, reducing the impact of waste of manufacturing time caused by replacing the roller to adapt to current collectors of different specifications, and further facilitating the improvement of the manufacturing efficiency of the electrode.

[0032] According to some embodiments of the present application, along the width direction of the current collector, the size of the conductive member is d, and the size of the roller is W, satisfying 0.001 < d / W < 0.5.

[0033] In the above solution, by limiting the ratio d / W of the size d of the conductive member along the width direction of the current collector to the size D of the roller along the width direction of the current collector to be greater than or equal to 0.001, the conductive member can be effectively electrically connected to the empty foil area, facilitating the improvement of the efficiency of the electrochemical reaction of the pore-forming agent and the efficiency of pore formation; by limiting the ratio d / W of the size d of the conductive member along the width direction of the current collector to the size D of the roller along the width direction of the current collector to be less than or equal to 0.5, the interference between the conductive member and the active material layer can be effectively reduced, avoiding wrinkles in the active material layer and reducing the defective rate of the electrode. When 0.001 < d / W < 0.5, the pore formation efficiency of the electrode and the yield rate of the electrode can be effectively balanced.

[0034] According to some embodiments of the present application, the conductive member is connected to a potential controller, and the potential controller is connected to a reference electrode.

[0035] In the above solution, by setting the potential controller and the reference electrode, the voltage intensity applied to the active material layer can be effectively controlled, thereby effectively controlling the efficiency, type, and degree of the electrochemical reaction of the pore-forming agent, and facilitating the improvement of the pore formation efficiency.

[0036] In a second aspect, some embodiments of the present application provide a battery comprising an electrode assembly, the electrode assembly comprising a first electrode, a second electrode, and a separator, wherein the first electrode and the second electrode have opposite polarities, and the separator is disposed between the first electrode and the second electrode. The first electrode and / or the second electrode are obtained by the electrode manufacturing method of the first aspect.

[0037] In a third aspect, the present application provides an electrical device, which includes the battery provided in the second aspect, and the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0039] FIG1 is a schematic diagram of a vehicle in some embodiments of the present application;

[0040] FIG2 is an exploded view of a battery in some embodiments of the present application;

[0041] FIG3 is a schematic diagram of a partial structure of an electrode assembly in some embodiments of the present application;

[0042] FIG4 is a flowchart of a method for manufacturing an electrode in some embodiments of the present application;

[0043] FIG5 is a flowchart of a method for manufacturing an electrode in other embodiments of the present application;

[0044] FIG6 is a flowchart of a method for manufacturing an electrode in other embodiments of the present application;

[0045] FIG7 is a schematic diagram of a current collector and an active material layer in some embodiments of the present application;

[0046] FIG8 is a schematic diagram of an electrode manufacturing apparatus according to some embodiments of the present invention;

[0047] FIG9 is a schematic diagram of a current collector and an active material layer in some embodiments of the present application;

[0048] FIG10 is a schematic diagram of a roller in some embodiments of the present application.

[0049] Icons: 100-battery; 10-housing; 11-shell; 12-end cap; 120-electrode terminal; 121-liquid injection hole; 20-electrode assembly; 21-first electrode; 22-second electrode; 23-diaphragm; 24-current collector; 240-empty foil area; 241-coating area; 25-active material layer; 26-pore; 30-roller; 31-conductive member; 40-trailer; 50-potential controller; 51-reference electrode; x-width direction of current collector; 2000-electrode manufacturing method; 1000-vehicle; 200-controller; 300-motor. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0053] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, C and / or B can represent the following three situations: C exists, C and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0057] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0058] In this application, the battery may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, etc., and the embodiments of this application are not limited thereto. The battery may be a rectangular parallelepiped or other shape, and the embodiments of this application are not limited thereto.

[0059] A battery includes an electrode assembly and an electrolyte, with the electrode assembly consisting of electrodes and a separator. The electrodes include a positive electrode and a negative electrode with opposite polarity. The battery primarily operates by the movement (e.g., deintercalation) of metal ions between the positive and negative electrodes. The electrodes may include a current collector and an active material layer. For example, the positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector not coated with the positive active material layer protrudes from the positive current collector coated with the positive active material layer, and the positive current collector not coated with the positive active material layer serves as the positive tab. For lithium-ion batteries, for example, the positive current collector may be made of aluminum, and the positive active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The negative current collector not coated with the negative active material layer protrudes from the negative current collector coated with the negative active material layer, and the negative current collector not coated with the negative active material layer serves as the negative tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the present invention is not limited thereto.

[0060] In electrochemical reactions, such as battery charging and discharging, electrode porosity is a crucial parameter. Increasing electrode porosity increases the reaction area between the electrode and reactants, thereby accelerating the electrochemical reaction rate. It also promotes the diffusion rate of substances / ions, further accelerating the reaction rate. Therefore, to improve battery performance, electrodes are often porous, meaning that pores are formed in the active material layer of the electrode.

[0061] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the manufacturing efficiency of the battery also needs to be considered.

[0062] Currently, electrode manufacturing methods often involve placing dried electrodes in a polar solvent and using solvent extraction to remove the pore-forming agent to create pores in the electrode. However, the contact area between the electrode and the solvent, as well as the extraction time, affect the efficiency of pore formation, resulting in low electrode pore formation efficiency, which in turn affects battery manufacturing efficiency.

[0063] In view of this, in order to improve the pore forming efficiency and thus improve the manufacturing efficiency of the battery, some embodiments of the present application provide a method for manufacturing an electrode, which includes the following steps:

[0064] A slurry is provided, wherein the slurry is mixed with a pore forming agent.

[0065] The slurry is coated on a current collector to form an active material layer on the current collector.

[0066] Electricity is applied to the active material layer, causing the pore former in the active material layer to undergo an electrochemical reaction to form pores.

[0067] Some embodiments of the present application provide a method for manufacturing an electrode, by adding a pore-forming agent that undergoes an electrochemical reaction when electricity is applied to a slurry. After the slurry mixed with the pore-forming agent is coated on a current collector to form an active material layer, electricity is applied to the active material layer to cause the pore-forming agent to undergo an electrochemical reaction. This can remove the pore-forming agent, gas that can escape due to the electrochemical reaction, or substance that can separate from the active material layer due to the electrochemical reaction, thereby allowing the active material layer to efficiently form uniform and dense pores, thereby improving the pore-forming efficiency of the electrode. When the electrode is applied to a battery, the battery can have a higher manufacturing efficiency.

[0068] The technical solutions described in the embodiments of this application are applicable to electrode manufacturing. The electrodes manufactured using the electrode manufacturing methods described in the embodiments of this application can be used in batteries or other devices that require electrodes for electrochemical reactions, such as electrolyzers and electrochemical sensors. The technical solutions described in the embodiments of this application are applicable to electrical devices that use batteries having the electrodes.

[0069] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include new energy vehicles, which may include pure electric vehicles, hybrid electric vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0070] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0071] FIG1 is a schematic diagram of a vehicle in some embodiments of the present application.

[0072] A controller 200, a motor 300, and a battery 100 may be provided inside the vehicle 1000. The controller 200 is used to control the battery 100 to power the motor 300. For example, the battery 100 may be provided at the bottom, front, or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may serve as an operating power source for the vehicle 1000 and for the circuit system of the vehicle 1000, for example, for the starting, navigation, and operating power requirements of the vehicle 1000. In another embodiment of the present application, the battery 100 may serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0073] In some embodiments, one or more batteries 100 may be part of a battery pack 100. A battery pack 100 may include one or more batteries 100 to provide a single physical module with higher voltage and capacity. A battery pack 100 generally includes a housing for enclosing one or more batteries 100. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the batteries 100.

[0074] Please refer to Figure 2, which is an exploded view of a battery 100 in some embodiments of the present application. The battery 100 includes a housing 10 and an electrode assembly 20 accommodated in the housing 10.

[0075] The outer casing 10 includes a housing 11 and an end cap 12. The housing 11 has a receiving cavity and an opening to accommodate the electrode assembly 20 within the receiving cavity of the housing 11. The end cap 12 is configured to seal the opening of the housing 11. The end cap 12 can be provided with an electrode terminal 120 for electrical connection to the tab of the electrode assembly 20 to enable charging and discharging of the battery 100. After the electrode assembly 20 is accommodated in the outer casing 10, electrolyte can be injected into the receiving cavity through the injection hole 121 provided on the end cap 12.

[0076] The shape of the housing 10 depends on the shape of the electrode assembly 20. For example, the housing 10 can be a hollow cuboid, a hollow cube, or a hollow cylinder. In some embodiments of the present application, the housing 10 can be made of a conductive metal material, such as aluminum or an aluminum alloy. The housing 10 can also be made of plastic.

[0077] As shown in Figure 3, Figure 3 is a schematic diagram of the partial structure of the electrode assembly 20 in some embodiments of the present application. The electrode assembly 20 may include electrodes and a separator 23. The electrodes include a first electrode 21 and a second electrode 22 of opposite polarity. The separator 23 is disposed between the first electrode 21 and the second electrode 22. The first electrode 21 may be a positive electrode, and the second electrode 22 may be a negative electrode. The electrode may include a current collector 24 and an active material layer 25 disposed on the current collector 24. The active material layer 25 may be formed by applying a slurry containing an active material to the surface of the current collector 24.

[0078] According to some embodiments of the present application, a method 2000 for manufacturing an electrode is provided. Please refer to FIG4 , which is a flowchart of the method for manufacturing an electrode in some embodiments of the present application.

[0079] The method for manufacturing an electrode comprises the following steps:

[0080] S1. providing a slurry mixed with a pore-forming agent;

[0081] S2. coating the slurry on a current collector to form an active material layer on the current collector;

[0082] S3. Applying electricity to the active material layer causes the pore-forming agent in the active material layer to undergo an electrochemical reaction to form pores.

[0083] In some embodiments, the "slurry" may be a slurry of active material, which may include active material, conductive agent, binder, and solvent. For example, for the positive electrode, the active material may include lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and ternary materials, the conductive agent may include carbon black, carbon nanotubes, conductive graphite, etc., the binder may be an aqueous or oil-based binder, and the solvent may include deionized water corresponding to the aqueous system and NMP solvent corresponding to the oil system. For the negative electrode, the active material may include various types of graphite, silicon-carbon negative electrode, the conductive agent may include carbon black, carbon nanotubes, conductive graphite, etc., the binder may be an aqueous or oil-based binder, and the solvent may include deionized water corresponding to the aqueous system and NMP solvent corresponding to the oil system.

[0084] In some embodiments, when manufacturing the battery 100 , the slurry may be coated on the current collector 24 during a coating process, and the slurry coated on the current collector 24 forms the active material layer 25 .

[0085] The phrase "the slurry is mixed with a pore-forming agent" can be understood as meaning that the pore-forming agent is mixed into the slurry. For example, during the process of stirring the active material, conductive agent, binder, and solvent to form the slurry, a certain amount of pore-forming agent can be added to the stirring container so that the pore-forming agent is evenly mixed into the slurry. The pore-forming agent can be a substance used to form pores 26 in the active material layer 25. In some embodiments, the pore-forming agent can undergo an electrochemical reaction when energized, thereby forming pores 26 in the active material layer 25. For example, when electricity is applied to the pore-forming agent, the pore-forming agent undergoes an electrochemical reaction, and its product can be a gas that can escape (such as carbon dioxide, hydrogen or oxygen, etc.) to form pores 26 on the active material layer 25; or its product can be a magnetic and non-conductive substance (such as γ'-Fe4N magnetic nanomaterial, which can be found in the literature, Shandong University, "Research and Application of Transition Metal Doped γ'-Fe4N Magnetic Nanomaterials"), which can be carried away by a strong magnetic field to form pores 26 on the active material layer 25, or the product can be a substance that can be dissolved by a specific solution, and after passing through the specific solution, pores 26 can be formed on the active material layer 25.

[0086] “Electrifying the active material layer” can be understood as directly electrifying the active material layer 25 , for example, by inserting an electrified electrode into the active material layer 25 , or indirectly electrifying the active material layer 25 , for example, by supplying power to the current collector 24 .

[0087] In some embodiments, the voltage applied to the active material layer 25 can be controlled to meet the electrochemical reaction requirements of the pore former and to control the electrochemical reaction rate of the pore former in the active material layer 25 .

[0088] Some embodiments of the present application provide a method for manufacturing an electrode, by adding a pore-forming agent that undergoes an electrochemical reaction when an electric current is applied to a slurry. After the slurry mixed with the pore-forming agent is coated on a current collector 24 to form an active material layer 25, the pore-forming agent is electrochemically reacted by applying an electric current to the active material layer 25. This can remove the pore-forming agent, the gas that can escape due to the electrochemical reaction, or the substance that can separate from the active material layer 25 due to the electrochemical reaction, thereby efficiently forming uniform and dense pores 26 in the active material layer 25. On the one hand, by controlling the magnitude of the current and other parameter data, the formation and morphology of the pores 26 in the active material layer 25 can be precisely controlled. On the other hand, the pore-forming efficiency of the electrode can be improved, and thus when the electrode is applied to the battery 100, the manufacturing efficiency of the battery 100 can be improved.

[0089] In some embodiments, the electrode obtained by the electrode manufacturing method 2000 described above can not only be used in batteries, for example, two electrodes with opposite polarities are arranged in conjunction with a diaphragm to constitute an electrode assembly of a battery, but can also be used in electrolysis industry, electrocatalysis, electrochemical analysis and other electrochemical reaction scenarios involving porous electrodes.

[0090] According to some embodiments of the present application, the pore former is configured as a substance that generates gas when electrified.

[0091] “The pore-forming agent is configured to be a substance that produces gas when energized” can be understood as that after a current of a certain voltage is applied to the active material layer 25 , the pore-forming agent in the active material layer 25 can undergo an electrochemical reaction, thereby directly or indirectly producing gas, and forming pores 26 on the active material layer 25 through the escape of the airflow.

[0092] In the above scheme, by limiting the pore-forming agent to a substance that can generate gas after being energized, the gas produced by the electrochemical reaction can escape from the active material layer 25 after the active material layer 25 is energized, thereby efficiently forming uniform pores 26 on the active material layer 25, improving the pore-forming efficiency of the electrode, and then when the electrode is applied to the battery 100, the battery 100 has a higher manufacturing efficiency.

[0093] According to some embodiments of the present application, the pore-forming agent includes at least one of water, methanol, ethanol, formic acid, or ammonium carbamate.

[0094] In some embodiments, the pore former may be one of water, methanol, ethanol, formic acid, or ammonium carbamate.

[0095] In other embodiments, the pore-forming agent may be any two of methanol, ethanol, formic acid, or ammonium carbamate. In other embodiments, the pore-forming agent may be any three of methanol, ethanol, formic acid, or ammonium carbamate. In other embodiments, the pore-forming agent may be methanol, ethanol, formic acid, and ammonium carbamate.

[0096] In the above embodiment, when the pore-forming agent is water, oxygen and hydrogen can be generated by applying electricity to the active material layer 25. The oxygen and hydrogen quickly escape from the active material layer 25, quickly forming uniform pores 26 in the active material layer 25. When the pore-forming agent is methanol, gas such as carbon dioxide can be generated by applying electricity to the active material layer 25. The carbon dioxide quickly escapes from the active material layer 25, quickly forming uniform pores 26 in the active material layer 25. When the pore-forming agent is ethanol, gas such as carbon dioxide and methane can be generated by applying electricity to the active material layer 25. The carbon dioxide and methane quickly escape from the active material layer 25, quickly forming uniform pores 26 in the active material layer 25. When the pore-forming agent is formic acid, by applying electricity to the active material layer 25, gas, such as carbon dioxide, can be generated. The carbon dioxide can quickly escape from the active material layer 25, thereby quickly forming uniform pores 26 in the active material layer 25. When the pore-forming agent is ammonium carbamate, by applying electricity to the active material layer 25, ammonia and carbon dioxide can be generated. The ammonia and carbon dioxide can quickly escape from the active material layer 25, thereby quickly forming uniform pores 26 in the active material layer 25. As a result, when the electrode is applied to the battery 100, the battery 100 has higher manufacturing efficiency.

[0097] In other embodiments, the specific type of the pore-forming agent is not limited, as long as it can form the pores 26 in the active material layer 25 by passing electricity.

[0098] According to some embodiments of the present application, the mass ratio of the pore former in the slurry is A, satisfying 0.00001≤A≤0.2.

[0099] The mass ratio of the pore-forming agent in the slurry is A, which can be understood as the ratio of the mass of the pore-forming agent to the total mass of the slurry and the pore-forming agent, in the same units. In some embodiments, the value of A can be 0.00001, 0.00002, 0.00003, 0.00004, ... 0.008, 0.009, 0.01, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, 0.2, or any value in between.

[0100] In the above scheme, by limiting the mass ratio A of the pore-forming agent in the slurry to greater than or equal to 0.00001, the amount of pores 26 in the active material layer 25 can be increased, resulting in a larger specific surface area for the electrode, which is beneficial for improving the electrode's reaction rate. By limiting the mass ratio A of the pore-forming agent in the slurry to less than or equal to 0.2, it is possible to effectively reduce the waste of space in the active material layer 25 caused by the final pores 26 formed due to excessive pore-forming agent, which affects the amount of active material and thus the volumetric energy density. When 0.00001mm≤A≤2mm, the reaction rate and volumetric energy density of the electrode can be effectively balanced.

[0101] According to some embodiments of the present application, the pore-forming agent is solid, and the median particle size D50 of the pore-forming agent satisfies 0.001 mm ≤ D50 ≤ 6 mm.

[0102] In some embodiments, the pore-forming agent may be solid particles. The particle size of the pore-forming agent may affect the size of the final formed pores 26. For example, the pore-forming agent may be ammonium carbamate.

[0103] The median particle size D50 can be understood as the particle size at which the cumulative particle size distribution of a sample reaches 50%. Its physical meaning is that particles larger than this size account for 50%, and particles smaller than this size also account for 50%. The median particle size D50 can be measured using various methods, including sieving, sedimentation, electrical resistance, laser analysis, and electron microscopy.

[0104] In some embodiments, the median particle size D50 of the pore-forming agent can be 0.001 mm, 0.002 mm, 0.003 mm, 0.004 mm, 0.005 mm, 0.006 mm, 5.7 mm, 5.8 mm, 5.9 mm, 6 mm, or any value between two adjacent values.

[0105] In the above scheme, by limiting the median particle size D50 of the pore-forming agent to greater than or equal to 0.001 mm, the size of the pores 26 in the active material layer 25 can be increased, thereby improving the reaction rate of the electrode. By limiting the median particle size D50 of the pore-forming agent to less than or equal to 6 mm, it is possible to effectively reduce the waste of space in the active material layer 25 caused by excessively large pores 26 in the final mold, which affects the amount of active material and, consequently, the volumetric energy density. When 0.001 mm ≤ D50 ≤ 6 mm, both the reaction rate and the volumetric energy density of the electrode can be effectively balanced.

[0106] In other embodiments, the pore former may be a liquid, or a mixture of a solid and a liquid.

[0107] According to some embodiments of the present application, the median particle size D50 of the pore former satisfies 0.002 mm ≤ D50 ≤ 5 mm.

[0108] In some embodiments, the median particle size D50 of the pore-forming agent can be 0.002 mm, 0.003 mm, 0.004 mm, 0.005 mm, 0.006 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5 mm, or any value between two adjacent values.

[0109] In the above scheme, by limiting the median particle size D50 of the pore-forming agent to greater than or equal to 0.002 mm, the size of the pores 26 in the active material layer 25 can be further increased, further facilitating an increase in the electrode reaction rate. By limiting the median particle size D50 of the pore-forming agent to less than or equal to 5 mm, it is possible to more effectively reduce the waste of space in the active material layer 25 caused by excessively large pore-forming agents, resulting in excessively large pores 26 in the final mold, which affects the amount of active material and, consequently, the volumetric energy density. When 0.002 mm ≤ D50 ≤ 5 mm, both the electrode reaction rate and the volumetric energy density can be further balanced.

[0110] According to some embodiments of the present application, the step of providing the slurry further includes mixing the slurry with a surfactant.

[0111] “The slurry is mixed with a surfactant” can be understood as mixing a surfactant into the slurry. For example, in the process of stirring the active material, the conductive agent, the adhesive and the solvent to form a slurry, a certain amount of a pore-forming agent and a surfactant can be added into the stirring container so that the pore-forming agent and the surfactant are evenly mixed in the slurry.

[0112] Surfactants can be understood as interfacial agents, which are compounds that can significantly reduce the surface tension or interfacial tension between two liquids, between a liquid and a gas, or between a liquid and a solid. For example, the surfactant can be sodium lauryl sulfate.

[0113] For example, the pore-forming agent may include methanol, which reacts when electricity is applied to generate carbon dioxide. By providing the pore-forming agent, the escape of carbon dioxide can be promoted.

[0114] In the above scheme, by mixing a surfactant into the slurry, it is beneficial to promote the escape of gas generated by the electrochemical reaction of the pore-forming agent, improve the efficiency of forming the pores 26, thereby improving the pore-forming efficiency of the electrode, and further when the electrode is applied to the battery 100, it can improve the manufacturing efficiency of the battery 100.

[0115] According to some embodiments of the present application, please refer to FIG5 , which is a flowchart of a method 2000 for manufacturing an electrode in other embodiments of the present application. Before step S3 of energizing the active material layer, the method further includes the following steps:

[0116] S4.1. Dry the active material layer.

[0117] Alternatively, in other embodiments of the present application, please refer to FIG6 , which is a flow chart of a method 2000 for manufacturing an electrode in other embodiments of the present application.

[0118] After step S3 of applying electricity to the active material layer, the method further includes the following steps:

[0119] S4.2. Dry the active material layer.

[0120] In some embodiments, the active material layer 25 on the surface of the current collector 24 may be dried by a drying device.

[0121] In some embodiments, before the active material layer 25 is dried, electricity may be applied to the active material layer 25 to form the pores 26, and then the active material layer 25 with the pores 26 may be energized. In other embodiments, after the active material layer 25 is dried, electricity may be applied to the active material layer 25 to form the pores 26.

[0122] Exemplarily, the pore-forming agent includes methanol, and the method for manufacturing the electrode includes:

[0123] S1. Providing a slurry, wherein the slurry is mixed with a pore-forming agent; in this step S1, the slurry is mixed with methanol and a surfactant.

[0124] S2. Apply the slurry on a current collector to form an active material layer on the current collector.

[0125] S3. Applying electricity to the active material layer causes the pore-forming agent in the active material layer to undergo an electrochemical reaction to form pores.

[0126] S4.2. Dry the active material layer.

[0127] In another exemplary embodiment, the pore-forming agent includes ammonium carbamate, and the method for manufacturing the electrode includes:

[0128] S1. providing a slurry mixed with a pore-forming agent;

[0129] S2. coating the slurry on a current collector to form an active material layer on the current collector;

[0130] S4.1. Drying the active material layer;

[0131] S3. Applying electricity to the active material layer causes the pore-forming agent in the active material layer to undergo an electrochemical reaction to form pores.

[0132] The above scheme provides two options for the order of applying power to the active material layer 25 and drying the active material layer 25, providing multiple options for electrode manufacturing. For example, in some embodiments, the active material layer 25 can be energized before drying; in other embodiments, the active material layer 25 can be energized after drying.

[0133] According to some embodiments of the present application, in conjunction with Figure 7, Figure 7 is a schematic diagram of a current collector 24 and an active material layer 25 in some embodiments of the present application. Figure 7 shows the current collector 24, the active material layer 25, and the pores 26.

[0134] The step S3 of applying electricity to the active material layer 25 includes: forming pores with a pore diameter D satisfying 0.001 mm≤D≤5 mm.

[0135] In some embodiments, the method for measuring the pore size of the pore 26 includes but is not limited to a gas adsorption method or a scanning electron microscopy method.

[0136] In some embodiments, after the active material layer 25 is energized through step S3, the pore size D of the pores 26 formed on the active material layer 25 can be 0.001 mm, 0.002 mm, 0.003 mm, 0.004 mm...4.7 mm, 4.8 mm, 4.9 mm, 5 mm or any value between two adjacent values.

[0137] In some embodiments, the pores 26 in the active material layer 25 may have different sizes. The smallest pore 26 may have a pore diameter D ranging from 0.001 mm to 5 mm, or 0.001 mm or less than 5 mm. The largest pore 26 may have a pore diameter D ranging from 0.001 mm to 5 mm, or greater than 0.001 mm or 5 mm.

[0138] In the above scheme, by limiting the pore diameter D of pores 26 to greater than or equal to 0.001 mm, the diffusion rate of ions is improved, thereby accelerating the reaction rate of the electrode. By limiting the pore diameter D of pores 26 to less than or equal to 5 mm, the space wasted in the active material layer 25 due to excessively large pores 26 can be effectively reduced, which affects the amount of active material and, consequently, the volumetric energy density. When 0.001 mm ≤ D ≤ 5 mm, both the reaction rate and the volumetric energy density of the electrode can be effectively balanced.

[0139] According to some embodiments of the present application, the step of energizing the active material layer includes: a distance L between any two adjacent pores formed satisfies 0.01 mm ≤ L ≤ 10.5 mm.

[0140] “The distance between any two adjacent pores is L” can be understood as the minimum distance between any two adjacent pores 26 being L. In some embodiments, the value of L can be 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 9 mm, 9.1 mm, 9.2 mm, 9.3 mm, 9.4 mm, 9.5 mm, 9.6 mm, 9.7 mm, 9.8 mm, 9.9 mm, 10 mm, 10.1 mm, 10.2 mm, 10.3 mm, 10.4 mm, 10.5 mm, or any value between two adjacent values.

[0141] In the above scheme, by limiting the spacing L between any two adjacent pores 26 to greater than or equal to 0.01 mm, the structural stability of the active material layer 25 is enhanced, the risk of collapse of the active material layer 25 is reduced, and the reliability of the electrode is improved. By limiting the spacing L between any two adjacent pores 26 to less than or equal to 10.5 mm, the waste of space in the active material layer 25 caused by excessive spacing between adjacent pores 26 can be effectively reduced, which affects the amount of active material and thus the volumetric energy density. When 0.01 mm ≤ L ≤ 10.5 mm, both electrode reliability and volumetric energy density can be effectively balanced.

[0142] According to some embodiments of the present application, before step S2 of coating the slurry on the current collector 24, the method further includes:

[0143] Step S1.1: Provide a roller.

[0144] The roller 30 is used for coating the current collector 24 . The surface of the roller 30 is provided with a conductive member 31 , which is used to electrically connect to the current collector 24 . Step S3 of energizing the active material layer 25 includes energizing the current collector 24 through the conductive member 31 .

[0145] Please refer to Figure 8, which is a schematic diagram of the manufacturing equipment of the electrode in some embodiments of the application. During the manufacturing process of the electrode, the current collector 24 is transported by the transport roller and the roller 30. During the transport of the current collector 24, the slurry (the slurry is marked as J in Figure 8) is coated on the current collector 24 by the coating equipment. In some embodiments, there are multiple transport rollers 40, and multiple transport rollers 40 are arranged at intervals along the transport direction of the current collector 24. The roller 30 is arranged on the transport path of the current collector 24, and a conductive part 31 is provided on the roller 30, and the conductive part 31 is connected to an external power supply. When the current collector 24 is transported on the roller 30 with the conductive part 31, the current collector 24 contacts the conductive part 31, so that the current can be transferred to the active material layer 25 through the conductive part 31 and the current collector 24.

[0146] In some embodiments, the conductive member 31 may be a conductive ring mounted on the circumference of the roller 30. The conductive member 31 and the roller 30 may be stationary or rotatable relative to each other. For example, the conductive member 31 and the roller 30 may be stationary relative to each other, and the conductive member 31 may be in contact with and connected to an electrical wire. For another example, the conductive member 31 may be rotatably mounted on the roller 30 and connected to the electrical wire. When the current collector 24 is running, the roller 30 rotates while the conductive member 31 remains stationary, effectively transmitting current.

[0147] In the above scheme, by providing a conductive member 31 on the roller 30, the current can be conducted to the active material layer 25 when the current collector 24 is carried on the roller 30, thereby energizing the active material layer 25, so that the active material layer 25 can efficiently form pores 26, thereby improving the manufacturing efficiency of the battery 100.

[0148] According to some embodiments of the present application, please refer to Figures 9 and 10. Figure 9 is a schematic diagram of the current collector 24 and the active material layer 25 in some embodiments of the present application, and Figure 10 is a schematic diagram of the roller 30 in some embodiments of the present application.

[0149] The current collector 24 has a hollow foil region 240 and a coated region 241. Along the width direction x of the current collector, a hollow foil region 240 is provided on either side of the coated region 241. There are two conductive members 31, which are spaced apart along the width direction x of the current collector to contact corresponding hollow foil regions 240.

[0150] The coated area 241 may be an area on the current collector 24 coated with the slurry to form the active material layer 25. The empty foil area 240 may be an area on the current collector 24 not coated with the slurry. In some embodiments, along the width direction x of the current collector, the coated area 241 is located between two empty foil areas 240.

[0151] There are two conductive members 31 , and the conductive members 31 can be disposed corresponding to the empty foil areas 240 , so that when the current collector 24 is supported on the roller 30 , the conductive members 31 are in contact with the corresponding empty foil areas 240 .

[0152] In some embodiments, the material of the conductive member 31 may be aluminum, copper, or aluminum alloy, etc. In some embodiments, the material of the conductive member 31 may be the same as or different from the material of the current collector 24 .

[0153] In the above scheme, by setting the number of conductive members 31 to two to correspond to the two empty foil areas 240, the current can be effectively applied to the active material layer 25, so that the pore-forming agent in the active material layer 25 can efficiently undergo an electrochemical reaction, thereby enabling the active material layer 25 to efficiently form pores 26. As a result, when the electrode is applied to the battery 100, the manufacturing efficiency of the battery 100 can be improved.

[0154] According to some embodiments of the present application, along the width direction x of the current collector, two conductive members 31 are configured to be arranged on the roller 30 in an adjustable manner.

[0155] In some embodiments, the operator can adjust the position of the conductive member 31 to accommodate current collectors 24 of different specifications. For example, when changing production lines, from a small-sized current collector 24 to a large-sized current collector 24, the empty foil area 240 moves outward. Correspondingly, to make the conductive member 31 correspond to the moved empty foil area 240, the operator adjusts the position of the conductive member 31, and the conductive member 31 also moves outward accordingly.

[0156] The width direction x of the current collector may be parallel to the axial direction of the roller 30 .

[0157] In some embodiments, the circumference of the roller 30 may be provided with a chute extending along the width direction x of the current collector. The conductive member 31 is sleeved within the chute, and the position of the conductive member 31 within the chute is adjusted by sliding the conductive member 31. In some embodiments, the chute has multiple threaded holes spaced apart along the width direction x of the current collector, and the conductive member 31 is connected to any of the threaded holes via threads.

[0158] In the above scheme, by setting the conductive member 31 to be adjustable in position along the width direction x of the current collector, the conductive member 31 can act on current collectors 24 of different specifications to produce porous electrodes of different specifications, thereby reducing the impact of waste of manufacturing time caused by replacing the roller 30 to adapt to current collectors 24 of different specifications, thereby facilitating the improvement of the manufacturing efficiency of the battery 100.

[0159] According to some embodiments of the present application, along the width direction x of the current collector, the size of the conductive member 31 is d, and the size of the roller 30 is D, which satisfies 0.001 <d / D<0.5。

[0160] In some embodiments, the ratio d / D of the dimension d of the conductive member 31 in the width direction x of the current collector to the dimension D of the roller 30 in the width direction x of the current collector can be 0.002, 0.003, 0.004...0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, any value between two adjacent values, any value between 0.001 and 0.002, or any value between 0.49-0.5.

[0161] In the above solution, by defining the ratio d / D of the dimension d of the conductive member 31 in the width direction x of the current collector to the dimension D of the roller 30 in the width direction x of the current collector as greater than or equal to 0.001, the conductive member 31 can be effectively electrically connected to the empty foil area 240, which is beneficial to improving the efficiency of the electrochemical reaction of the pore-forming agent and the efficiency of the formation of the pores 26; by defining the ratio d / D of the dimension d of the conductive member 31 in the width direction x of the current collector to the dimension D of the roller 30 in the width direction x of the current collector as less than or equal to 0.5, the risk that the conductive member 31 interferes with the active material layer 25, causing the active material layer 25 to wrinkle and resulting in a reduction in the yield of the electrode can be effectively reduced. When 0.001 < d / D < 0.5, the formation efficiency of the pores 26 of the electrode and the yield of the electrode can be effectively balanced.

[0162] According to some embodiments of the present application, the conductive member 31 is connected to the potential controller 50, and the potential controller 50 is connected to the reference electrode 51.

[0163] The reference electrode 51 can be an electrode used as a reference comparison when measuring various electrode potentials. In some embodiments, the reference electrode 51 includes, but is not limited to, a grounded electrode, a standard hydrogen electrode, or an Ag / AgCl electrode. The potential controller 50 is a device connected to the conductive member 31. The potential controller 50 can be connected to the conductive member 31 through a wire. The potential controller 50 is connected to the reference electrode 51 and can provide a current with a certain voltage to the conductive member 31 based on the reference electrode 51. Exemplarily, in some embodiments of the present application, the voltage of the current applied by the potential controller 50 to the conductive member 31 and applied to the active material layer 25 relative to the reference electrode 51 is between -500V and 500V.

[0164] In the above solution, by providing the potential controller 50 and the reference electrode 51, the voltage intensity applied to the active material layer 25 can be effectively controlled, thereby effectively controlling the efficiency of the electrochemical reaction of the pore-forming agent and being beneficial to improving the formation efficiency of the pores 26.

[0165] Some embodiments of the present application further provide a battery 100, which includes an electrode assembly 20. The electrode assembly 20 includes a first electrode 21, a second electrode 22, and a separator 23. The polarities of the first electrode 21 and the second electrode 22 are opposite, and the separator 23 is disposed between the first electrode 21 and the second electrode 22. Among them, the first electrode 21 and / or the second electrode 22 are obtained by the electrode manufacturing method provided above.

[0166] In some embodiments, the housing 10 includes a shell 11 and an end cap 12. The shell 11 has a receiving cavity and an opening, so that the electrode assembly 20 can be accommodated in the receiving cavity of the shell 11. The end cap 12 is configured to close the opening of the shell 11. The end cap 12 can be provided with an electrode terminal for electrically connecting to the tab of the electrode assembly 20 to enable charging and discharging of the battery 100. After the electrode assembly 20 is accommodated in the housing 10, the electrolyte can be injected into the receiving cavity through the injection hole provided on the end cap 12.

[0167] The shape of the housing 10 depends on the shape of the electrode assembly 20. For example, the housing 10 can be a hollow cuboid, a hollow cube, or a hollow cylinder. In some embodiments of the present application, the housing 10 can be made of a conductive metal material, such as aluminum or an aluminum alloy. The housing 10 can also be made of plastic.

[0168] According to some embodiments of the present application, an electrical device is provided, which includes the battery 100 provided above, and the battery 100 is used to provide electrical energy.

[0169] According to some embodiments of the present application, referring to FIG. 4 to FIG. 8 , a method 2000 for manufacturing an electrode is provided. The method includes the following steps:

[0170] S1. providing a slurry mixed with a pore-forming agent;

[0171] S1.1. Provide rollers;

[0172] S2. coating the slurry on a current collector to form an active material layer on the current collector;

[0173] S3. Applying electricity to the active material layer causes the pore-forming agent in the active material layer to undergo an electrochemical reaction to form pores.

[0174] In step S1, the pore-forming agent may be a substance used to form pores 26 in the active material layer 25. In some embodiments, the pore-forming agent may undergo an electrochemical reaction when energized, and the reaction may result in the formation of pores 26 in the active material layer 25. For example, when the pore-forming agent is energized, the pore-forming agent undergoes an electrochemical reaction, and the product thereof may be a gas that can escape (e.g., carbon dioxide, hydrogen, or oxygen, etc.), thereby forming pores 26 in the active material layer 25; or the product thereof may be a magnetic and non-conductive substance (e.g., γ'-Fe4N magnetic nanomaterial, which can be found in the literature, Shandong University, "Research and Application of Transition Metal-Doped γ'-Fe4N Magnetic Nanomaterials"), which can be carried away by a strong magnetic field to form pores 26 in the active material layer 25; or the product thereof may be a substance that can be dissolved by a specific solution, and after passing through the specific solution, pores 26 can be formed in the active material layer 25.

[0175] In step S1.1, a conductive member 31 is provided on the surface of roller 30. Conductive member 31 is used to electrically connect to current collector 24 to energize active material layer 25 in step S3. In some embodiments, conductive member 31 is connected to potential controller 50, which is in turn connected to reference electrode 51. Reference electrode 51 includes, but is not limited to, ground, a standard hydrogen electrode, or an Ag / AgCl electrode.

[0176] In some embodiments, the electrode manufacturing method may further include the following step: drying the active material layer 25 .

[0177] By adding a pore-forming agent that undergoes an electrochemical reaction when electricity is applied to the slurry, after the slurry mixed with the pore-forming agent is applied to the current collector 24 to form the active material layer 25, electricity is applied to the active material layer 25 to cause the pore-forming agent to undergo an electrochemical reaction, thereby removing the pore-forming agent, the gas that can escape due to the electrochemical reaction, or the substance that can be separated from the active material layer 25 due to the electrochemical reaction, thereby allowing the active material layer 25 to efficiently form uniform and dense pores 26. On the one hand, by controlling the magnitude of the current and other parameter data, the formation and morphology of the pores 26 in the active material layer 25 can be precisely controlled. On the other hand, the pore-forming efficiency of the electrode can be improved, and thus when the electrode is applied to the battery 100, the manufacturing efficiency of the battery 100 can be improved.

[0178] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for manufacturing an electrode, wherein, It includes the following steps: Provide a slurry, and the slurry is mixed with a pore-forming agent; Coat the slurry on a current collector to form an active material layer on the current collector; Apply an electric current to the active material layer so that the pore-forming agent in the active material layer undergoes an electrochemical reaction to form pores; Wherein, before the step of coating the slurry on the current collector, there is also included a step: Provide a roller, the roller is used for the coating and running of the current collector, and a conductive member is arranged on the surface of the roller, and the conductive member is used for electrically connecting with the current collector; The step of applying an electric current to the active material layer includes applying an electric current to the current collector through the conductive member.

2. The method for manufacturing an electrode according to claim 1, wherein, The pore-forming agent is configured as a substance that generates gas when an electric current is applied.

3. The method for manufacturing an electrode according to claim 2, wherein, The pore-forming agent includes at least one of water, methanol, ethanol, formic acid or ammonium carbamate.

4. The method for manufacturing an electrode according to claim 2 or 3, wherein, The mass ratio of the pore-forming agent in the slurry is A, satisfying 0.00001 ≤ A ≤ 0.

2.

5. The method for manufacturing an electrode according to any one of claims 2-4, wherein, The pore-forming agent is solid, and the median particle size D50 of the pore-forming agent satisfies 0.001 mm ≤ D50 ≤ 6 mm.

6. The method for manufacturing an electrode according to claim 5, wherein, The median particle size D50 of the pore-forming agent satisfies 0.002 mm ≤ D50 ≤ 5 mm.

7. The method for manufacturing an electrode according to any one of claims 2-3, wherein, The step of providing the slurry further includes that the slurry is mixed with a surfactant.

8. The method for manufacturing an electrode according to any one of claims 1-7, wherein, Before the step of applying an electric current to the active material layer, there is also included a step: Dry the active material layer; or, After the step of applying an electric current to the active material layer, there is also included a step: Dry the active material layer.

9. The method for manufacturing an electrode according to any one of claims 1-8, wherein, The step of applying an electric current to the active material layer includes: the aperture of the formed pores is D, satisfying 0.001 mm ≤ D ≤ 5 mm.

10. The method for manufacturing an electrode according to any one of claims 1-9, wherein, The step of applying an electric current to the active material layer includes: the distance between any two adjacent formed pores is L, satisfying 0.01 mm ≤ L ≤ 10.5 mm.

11. The method for manufacturing an electrode according to any one of claims 1-10, wherein, The current collector has an empty foil area and a coating area, and along the width direction of the current collector, empty foil areas are respectively arranged on both sides of the coating area; The number of the conductive members is two, and the two conductive members are arranged at intervals along the width direction of the current collector to respectively contact the corresponding empty foil areas.

12. The method for manufacturing an electrode according to claim 11, wherein, Along the width direction of the current collector, the two conductive members are configured to be arranged on the roller in a position-adjustable manner.

13. The manufacturing method of the electrode according to claim 11 or 12, wherein along the width direction of the current collector, the size of the conductive member is d and the size of the roller is W, satisfying 0.001 < d / W < 0.

5.

14. The manufacturing method of the electrode according to any one of claims 1-13, wherein the conductive member is connected to a potential controller, and the potential controller is connected to a reference electrode.

15. A battery, wherein, The battery includes an electrode assembly, the electrode assembly includes a first electrode, a second electrode, and a separator, the polarities of the first electrode and the second electrode are opposite, and the separator is disposed between the first electrode and the second electrode; wherein, the first electrode and / or the second electrode is obtained by the manufacturing method of the electrode according to any one of claims 1-14.

16. An electrical device, wherein, Including the battery according to claim 15, the battery is used for providing electric energy.

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