WO2024021084A1

WO2024021084A1 - Plate preparation method, plate preparation device, plate, electrode assembly, battery cell, battery and electric device

Info

Publication number: WO2024021084A1
Application number: PCT/CN2022/109153
Authority: WO
Inventors: 黄彩虾; 陈伟; 葛少兵; 佘扬帆; 梁静冰; 唐鸣浩
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-07-29
Filing date: 2022-07-29
Publication date: 2024-02-01

Abstract

Provided in the present application are a plate preparation method, a plate preparation device, a plate, an electrode assembly, a battery cell, a battery and an electric device. The plate preparation method comprises: adding an active material and a base material into a mold cavity of a mold; covering the active material and the base material with a coverage member; and applying force to the coverage member and/or the mold, and using the coverage member and the mold to jointly extrude the active material and the base material, so as to compound the active material and the base material to form a plate. By means of the plate preparation method in the technical solution of the present application, energy density of the battery can be effectively increased. In addition, working procedures such as plate coating, base material winding and unwinding, and plate cutting are effectively simplified, and working hours of all the working procedures are shortened, thereby effectively increasing the production efficiency of the plate and then effectively increasing the production efficiency of the battery.

Description

Pole piece preparation method, pole piece preparation device, pole piece, electrode assembly, battery cell, battery and electrical device

Technical field

The present application relates to the field of battery technology, specifically, to a pole piece preparation method, pole piece preparation device, pole piece, electrode assembly, battery cell, battery and electrical device.

Background technique

Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

In battery production, how to improve battery production efficiency while increasing battery energy density is an urgent problem that needs to be solved.

Contents of the invention

This application provides a pole piece preparation method, pole piece preparation device, pole piece, electrode assembly, battery cell, battery and electrical device. The pole piece preparation method can effectively simplify the pole piece production process, improve battery production efficiency, and at the same time , this pole piece preparation method facilitates and effectively improves the energy density of the battery.

In a first aspect, this application provides a pole piece preparation method, which includes: adding active material and base material into the mold cavity of the mold; covering the active material and base material with a cover; The cover and/or the mold apply force, and the active material and the base material are co-extruded through the cover and the mold, so that the active material and the base material are composited to form a pole piece.

In the pole piece preparation method of the technical solution of the present application, the pole piece formed by extrusion compounding can effectively improve the compaction and density of the active material on the base material, and can effectively improve its energy density, and the compaction of the pole piece Adjustable, pole pieces with different compaction densities can be obtained by designing molds with different cavity volumes or by controlling different feeding amounts; on the other hand, the method of forming pole pieces through die extrusion and compounding facilitates an increase in the thickness of the active material layer. , thus enabling the preparation of pole pieces with higher thickness requirements to meet the preparation requirements for thick pole pieces, and increasing the thickness of the pole pieces can effectively increase the active material capacity, thereby effectively increasing its energy density. Furthermore, the cavity of the mold plays a role in limiting and shaping the active material. By controlling the shape and size of the mold cavity, pole pieces of the target shape and size can be directly prepared. Compared with the traditional wet coating method, pole piece preparation process, the technical solution of this application can effectively simplify the processes such as coating, substrate rewinding and unwinding, pole piece cutting, etc., and reduce the transfer time between each process, reduce the working hours of coating, drying and other processes, thereby effectively improving Pole piece production efficiency.

According to some embodiments of the present application, the method further includes: drying the pole piece located in the mold cavity; and taking out the dried pole piece from the mold.

In the above technical solution, the pole pieces formed by extrusion and compounding are directly dried in the mold cavity, and then the dried pole pieces are separated from the mold cavity. On the one hand, it can effectively avoid the problem caused by directly demolding the extruded pole pieces. Problems such as pole piece deformation and active material displacement can effectively ensure the structural stability of the pole piece and the production yield of the pole piece. On the other hand, the pole piece compounding and pole piece drying are integrated into the same work station. This further reduces the transportation and transfer time in pole piece production, further improving the pole piece production efficiency.

According to some embodiments of the present application, drying the pole piece located in the mold cavity includes: increasing the temperature of the mold and/or the cover to dry the pole piece .

In the above technical solution, the pole pieces are dried by increasing the temperature of the mold and/or the cover. On the one hand, the extruded pole pieces are located between the mold and the cover, and the temperature of the mold and/or the cover is directly increased to dry the pole pieces. Heating the pole pieces can effectively reduce the heating distance of the pole pieces, improve the uniformity of heating of the pole pieces, and thereby improve the drying efficiency of the pole pieces; on the other hand, the mold and cover play a role in the heating and drying process of the pole pieces. The positioning and shaping effect can effectively reduce the risk of warping and deformation of the pole pieces during the heating process, thereby effectively ensuring the drying quality of the pole pieces; furthermore, compared with traditional pole piece drying through ovens, ovens and other equipment, The method of heating the pole pieces by raising the temperature of the mold and/or cover can provide the pole pieces with a small heating range but more accurate heat source, which is not only conducive to improving the heating and drying efficiency of the pole pieces, but also effectively reduces the drying time. Dry heat energy demand, saving the investment cost of drying equipment, is conducive to significantly reducing the production cost of pole pieces, and has high economic benefits.

According to some embodiments of the present application, the mold is a metal piece, and raising the temperature of the mold and/or the cover includes: energizing the mold to increase the temperature of the mold.

In the above technical solution, the temperature of the mold can be increased by energizing the metal mold. The mold heats up quickly and has a strong temperature rise balance, which is conducive to further improving the pole piece drying efficiency and pole piece drying quality, and is conducive to further reducing the pole piece drying efficiency. Film production costs.

According to some embodiments of the present application, adding the active material and the base material into the mold cavity of the mold includes sequentially adding the active material and the base material into the mold cavity; and covering the cover in the mold cavity. Placing the active material and the base material includes: covering the base material with the covering member.

In the above technical solution, the active material and the base material are added sequentially into the mold cavity, the base material is covered on the active material, and then the cover is covered on the base material, and the cover and the mold jointly extrude the active material and the base material to form The active material is extruded and compounded on the side of the base material away from the cover to form a single-sided coated pole piece.

According to some embodiments of the present application, adding the active material and the base material into the mold cavity of the mold includes: sequentially adding a first layer of the active material, the base material and a second layer into the mold cavity. The active material; covering the covering member on the active material and the base material includes: covering the covering member on the second layer of the active material.

In the above technical solution, the first layer of active material, the base material and the second layer of active material are sequentially added into the mold cavity. The base material is located between the two layers of active material, and then the cover is covered on the second layer of active material. The component and the die co-extrude two layers of active materials and the base material, so that the two layers of active materials are extruded and compounded on both sides of the base material to form a double-sided coated pole piece.

According to some embodiments of the present application, the mold includes a body and a protruding portion, the body has the mold cavity, the protruding portion protrudes from the bottom wall of the mold cavity, and the bottom wall is connected to the mold cavity. The openings of the mold cavity are opposite to each other; and sequentially adding the first layer of the active material, the base material and the second layer of the active material into the mold cavity includes: sequentially adding the first layer into the mold cavity. The active material and the base material; covering the cover on the base material; applying force to the cover and/or the mold, and extruding the first through the cover and the mold together. One layer of the active material and the base material, so that the protrusion penetrates the base material; add a second layer of the active material into the mold cavity.

In the above technical solution, the mold includes a protruding portion provided on the bottom wall of the mold cavity. When the active material and the base material are co-extruded through the cover and the mold, the protruding portion can form a container for accommodating the electrolyte on the active material. cavity to promote the storage and infiltration of electrolyte inside the pole piece, improve the problem of large ionic resistance of the pole piece, and increase the battery cycle life; when the pole piece is a double-sided coated pole piece, the protruding part can penetrate the base material, This is to ensure that the protrusions can form accommodation cavities for the active materials on both sides of the base material.

When adding the first layer of active material, the base material and the second layer of active material into the mold cavity in sequence, first add the first layer of active material and the base material into the mold cavity in sequence. Because there are protrusions in the mold cavity, The base material will resist the end of the protrusion without force, which will affect the addition of the second layer of active material into the mold cavity. At this time, the cover is covered on the base material, and the base material and the first layer of active material are extruded together through the cover and the mold, so that the base material penetrates the protruding portion and moves closer to the first layer of active material. The second layer of active material makes room for filling. After the second layer of active material is added to the mold, the cover is again covered on the second layer of active material and extruded together with the mold, so that the first layer of active material, the base material and the second layer of active material are compositely formed into one body. At the same time, the protruding portion forms accommodating cavities in both the first layer of active material and the second layer of active material.

In a second aspect, the application provides a pole piece preparation device, including: a mold, the mold is provided with a mold cavity, the mold cavity is used to accommodate active materials and base materials; a cover, the cover is configured The purpose is to at least partially extend into the mold cavity through the opening of the mold cavity, so as to co-extrude the active material and the base material with the mold, so that the active material and the base material are composited to form a pole piece.

The pole piece preparation device of the technical solution of the present application includes a mold and a cover. The mold is provided with a mold cavity for accommodating active materials and base materials. When used, the active materials and base materials are added to the mold cavity, and the cover is covered on the mold. On the active material or substrate in the cavity, force is applied to the mold and/or cover so that at least part of the cover extends into the mold cavity, and the cover and the mold jointly squeeze the active material and substrate, so that the active material and The base materials are combined to form pole pieces. On the one hand, the structure in which the mold and the cover are co-extruded can effectively improve the compaction and density of the active material on the substrate, and can effectively increase the energy density of the pole piece. On the other hand, the structure in which the mold and the cover are co-extruded It is convenient to thicken the thickness of the active material layer, so that pole pieces with higher thickness requirements can be stably prepared to meet the preparation needs of thick pole pieces, and it is also convenient to effectively increase the active material capacity by increasing the thickness of the pole piece, thereby effectively increasing its energy density. . Furthermore, by controlling the shape and size of the mold cavity, pole pieces of the target shape and size can be directly prepared, which is beneficial to improving the production efficiency of the pole pieces.

According to some embodiments of the present application, the mold includes a body and a protruding portion, the body has the mold cavity, the protruding portion protrudes from the bottom wall of the mold cavity, and the bottom wall is connected to the mold cavity. The openings of the mold cavity are opposite to each other, and the protruding portion is used to form a receiving cavity for accommodating electrolyte on the active material.

In the above technical solution, the mold includes a protrusion arranged on the bottom wall of the mold cavity. When the active material and the base material are extruded together by the mold and the cover to compositely form the pole piece, the protrusion can be used during the compaction process of the active material. A certain space is reserved on the active material, which forms a holding cavity for accommodating the electrolyte. The thicker the electrode piece, the longer the diffusion path of liquid phase ions, and the greater the diffusion resistance of the electrolyte, which will affect the battery. of magnification. In this application, a receiving cavity for accommodating electrolyte is provided in the active material layer of the pole piece by physically forming holes, which can increase the thickness and compactness of the active material layer of the pole piece and at the same time promote the electrolyte in the pole piece. The storage and infiltration inside the chip improves the problem of large ionic resistance of the electrode piece and effectively increases the cycle life of the battery, which is beneficial to effectively ensure the charge and discharge rate of the battery while ensuring the energy density of the battery.

According to some embodiments of the present application, there are multiple protrusions, and the plurality of protrusions are spaced apart.

In the above technical solution, a plurality of spaced-apart protrusions are provided in the mold cavity to form a plurality of spaced-apart accommodation cavities for accommodating electrolyte on the pole piece, thereby further improving the storage and storage of electrolyte on the pole piece. infiltration amount, and effectively improve the uniformity of electrolyte distribution and penetration.

According to some embodiments of the present application, the cover is provided with an escape hole for the protruding portion to pass through.

In the above technical solution, the cover is provided with an escape hole for the protruding portion to pass through. On the one hand, the arrangement of the escape hole can provide more extension space for the protruding portion, thereby ensuring the depth of the accommodation cavity along the thickness direction of the pole piece. , effectively increasing the volume of the accommodation cavity, and enabling the protruding portion to penetrate the pole piece along the thickness direction of the pole piece. In some embodiments, active materials can be provided on both sides of the thickness direction of the base material, and the protruding portion Penetrating the pole piece along the thickness direction of the pole piece is conducive to forming accommodation cavities for the active materials on both sides of the base material; on the other hand, the setting of the avoidance hole can effectively avoid positional interference between the cover and the protruding portion, which affects the mold and The problem of the extrusion strength of the cover piece can effectively ensure the compactness of the extrusion molding of the pole piece, and ensure the structural stability of the pole piece while ensuring the energy density of the pole piece.

According to some embodiments of the present application, the pole piece preparation device further includes: a drying mechanism for drying the pole piece.

In the above technical solution, the pole piece preparation device is provided with a drying mechanism to dry the extruded pole pieces.

According to some embodiments of the present application, the drying mechanism includes a power supply mechanism, the mold is a metal piece, and the power supply mechanism is used to energize the mold to heat the mold to dry the pole piece; and /Or, the cover is a metal piece, and the power supply mechanism is used to energize the cover to raise the temperature of the cover to dry the pole piece.

In the above technical solution, a power supply mechanism is provided to energize the metal mold and/or the metal cover. After the mold and/or the cover are energized, the temperature rises to directly heat the pole piece located between the mold and the cover. drying. A power supply mechanism is used to supply power to the mold and/or cover. The mold and/or cover heats up quickly and with a strong balance of temperature rise, which is conducive to further improving the pole piece drying efficiency and pole piece drying quality, and is conducive to further reducing the pole piece drying efficiency. Production cost; at the same time, the pole pieces are heated and dried between the mold and the cover. The mold and the cover play a role in clamping and positioning the pole pieces, effectively reducing the risk of pole piece drying deformation, thereby ensuring the pole piece drying quality.

According to some embodiments of the present application, the pole piece preparation device further includes: a pressurizing mechanism connected to the cover, and the pressurizing mechanism is used to apply pressure to the cover so that the cover and The die co-extrudes the active material and substrate in the die cavity.

In the above technical solution, a pressurizing mechanism is provided to apply pressure to the cover, so that the cover and the mold can jointly squeeze the active material and the base material in the mold cavity, so that the active material and the base material can be compositely formed into pole pieces.

In a third aspect, the present application provides a pole piece, including: a base material; a first active material layer disposed on one side of the base material in the thickness direction, and the first active material layer includes a layer facing away from the base material. The first surface; wherein, the first surface is provided with a first accommodation cavity for accommodating electrolyte.

In the above technical solution, the pole piece includes a base material and a first active material layer. The first active material layer is provided with a first accommodation cavity, and the first accommodation cavity is used to accommodate electrolyte. The thicker the pole piece, the longer the diffusion path of liquid ions and the greater the diffusion resistance of the electrolyte. After applying the pole piece to the battery cell, the design of the first accommodation cavity can increase the active material of the pole piece. While improving the layer thickness and pressure tightness, it promotes the storage and infiltration of electrolyte inside the pole piece, improves the problem of large ion resistance of the pole piece, and effectively increases the cycle life of the battery. At the same time, the setting of the first accommodation cavity can assist the electrolyte to penetrate into the interior of the first active material layer, effectively increasing the penetration thickness of the electrolyte, thereby ensuring the full utilization of the pole pieces and reducing insufficient reaction due to thick pole pieces. Therefore, the pole piece of the technical solution of the present application can effectively ensure the battery performance while effectively ensuring the energy density of the battery.

According to some embodiments of the present application, the pole piece further includes: a second active material layer disposed on the other side in the thickness direction of the base material, and the second active material layer includes a third active material layer facing away from the base material. Two surfaces, the second surface is provided with a second accommodation cavity for accommodating electrolyte.

In the above technical solution, the pole piece includes a base material and a first active material layer and a second active material layer coated on both sides in the thickness direction of the base material, which effectively increases the active material passenger capacity of the pole piece, thereby increasing the energy density; first Both the active material layer and the second active material layer are provided with accommodating cavities, which is conducive to further improving the storage capacity and infiltration efficiency of the electrolyte, and effectively improves the uniformity of the distribution and penetration of the electrolyte on the pole piece, ensuring double-sided coated poles. full utilization of the film.

According to some embodiments of the present application, the base material is provided with a through hole, and the first accommodation cavity and the second accommodation cavity are connected to each other through the through hole.

In the above technical solution, the first accommodation cavity and the second accommodation cavity are connected through the through hole on the base material, which can effectively improve the circulation of the electrolyte and further improve the infiltration efficiency of the electrolyte.

According to some embodiments of the present application, the thickness of the second active material layer is H1, satisfying H1≤1500 μm, preferably, 70 μm≤H1≤1500 μm.

Excessive thickness of the pole piece may lead to problems of low reaction adequacy and poor rate capability. However, the thickness of the active material layer of the pole piece provided with the accommodation cavity of the present application can reach 70 μm to 1500 μm, which can effectively increase the thickness of the pole piece and simultaneously Ensure the reaction adequacy and rate capability of the pole piece, thereby effectively ensuring the energy density and charge and discharge rate of the battery using the pole piece.

According to some embodiments of the present application, the thickness of the first active material layer is H2, satisfying H2≤1500 μm, preferably, 70 μm≤H2≤1500 μm.

In the above technical solution, both the first active material layer and the second active material layer are provided with accommodation cavities. The thickness of the first active material layer can reach 70 μm to 1500 μm, which can effectively increase the thickness of the pole piece while ensuring the reaction of the pole piece. Adequacy and rate capability further ensure the energy density of the battery using the pole piece while ensuring its performance.

According to some embodiments of the present application, the first active material layer is provided with a mounting hole penetrating the first active material layer along a first direction, the first direction intersects with the plane of the base material, and the pole The sheet also includes: an electric energy extraction part, which is inserted through the mounting hole. One end of the electric energy extraction part is welded to the base material, and the other end extends out of the outline of the pole piece.

In the above technical solution, the electric energy extraction part of the pole piece is extracted along the first direction that intersects with the surface of the base material. Compared with the structure in which the electric energy extraction part is extracted from the side of the base material, it is more convenient for the base material and active material to be placed in the mold Extrusion molding effectively reduces the risk of bending, deformation or even breakage of the electrical energy extraction part during the extrusion molding of the pole piece.

In a fourth aspect, the present application also provides an electrode assembly, including a positive electrode piece, a negative electrode piece and a separation film. The positive electrode piece, the negative electrode piece and the separation film are stacked to form the electrode assembly, so The isolation film is disposed between the positive electrode piece and the negative electrode piece; wherein at least one of the positive electrode piece and the negative electrode piece is the electrode piece described in any one of the above.

Due to the characteristics of the pole piece proposed in the third aspect of this application, the electrode assembly proposed in the fourth aspect of this application is also beneficial to ensuring the energy density of the battery while ensuring the performance of the battery.

In a fifth aspect, the present application also provides a battery cell, including a case and the electrode assembly described in the above solution, and the electrode assembly is accommodated in the case.

In a sixth aspect, the present application also provides a battery, including a box and the battery cell described in the above solution, and the battery cell is accommodated in the box.

In a seventh aspect, the present application also provides an electrical device, including the battery cell described in the above solution, where the battery cell is used to provide electric energy.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and therefore do not It should be regarded as a limitation of the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic diagram of the overall flow of the pole piece preparation method provided by some embodiments of the present application;

Figure 2 is a schematic diagram of the state in which the cover and the mold co-extrude the active material and the base material provided by some embodiments of the present application;

Figure 3 is a schematic sub-flow diagram of the pole piece preparation method provided by some embodiments of the present application;

Figure 4 is a schematic diagram of the state in which the protrusion penetrates the base material provided in some embodiments of the present application;

Figure 5 is a schematic diagram of the state in which the cover and the mold co-extrude the first layer of active material, the base material and the second layer of active material provided by some embodiments of the present application;

Figure 6 is a schematic structural diagram of a pole piece preparation device provided by some embodiments of the present application;

Figure 7 is a schematic structural diagram of a pole piece preparation device provided by some embodiments of the present application;

Figure 8 is a schematic structural diagram of an electrical device provided by some embodiments of the present application;

Figure 9 is an exploded view of a battery provided by some embodiments of the present application;

Figure 10 is an exploded view of a battery cell provided by some embodiments of the present application;

Figure 11 is an exploded view of a battery cell provided by some embodiments of the present application;

Figure 12 is an isometric view of a pole piece provided by some embodiments of the present application;

Figure 13 is an isometric view of a pole piece provided by some embodiments of the present application;

Figure 14 is a side cross-sectional view of a pole piece provided by some embodiments of the present application;

Figure 15 is an isometric view of a pole piece provided by some embodiments of the present application.

In the drawings, the drawings are not drawn to actual scale.

Marking description: 1000-vehicle; 100-battery; 10-battery cell; 1-casing; 11-case; 12-cover; 2-electrode assembly; 21-pole piece; 21a-positive electrode piece; 21b-negative electrode Pole piece; 211-substrate; 2111-through hole; 2112-pole tab area; 212-first active material layer; 2121-first surface; 2122-first accommodation cavity; 2123-mounting hole; 213-second Active material layer; 2131-second surface; 2132-second accommodation cavity; 214-electric energy extraction part; 214a-positive electrode electric energy extraction part; 214b-negative electrode electric energy extraction part; 22-isolation film; 20-box; 201- The first part; 202-the second part; 200-controller; 300-motor; 2000-pole piece preparation device; 2100-mold; 2110-body; 2120-mold cavity; 2130-protrusion; 2140-avoidance groove; 2200 - cover; 2210-avoidance hole; 2220-extension; 3000-active material; 3100-first layer of active material; 3200-second layer of active material; X-first direction.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments These are part of the embodiments of this application, but not all of them. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the application provided in the appended drawings is not intended to limit the scope of the claimed application, but rather to represent selected embodiments of the application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only used to illustrate the technical solution of the present application more clearly, and are therefore only used as examples and cannot be used to limit the protection scope of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field belonging to this application; the terms used herein are for the purpose of describing specific embodiments only and are not intended to be used in Limitation of this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

In the description of the embodiments of this application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying the relative importance or implicitly indicating the quantity or specificity of the indicated technical features. Sequence or priority relationship. In the description of the embodiments of this application, "plurality" means two or more, unless otherwise explicitly and specifically limited.

Reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of this application, the term "plurality" refers to two or more (including two).

In the description of the embodiments of this application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right" and "vertical" The orientation or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the embodiments of the present application and simplifying the description. It does 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 implementation of the present application. Example limitations.

In the description of the embodiments of the present application, unless otherwise explicitly stated and limited, technical terms such as "setting", "installation", "connecting", "connecting" and "fixing" should be understood in a broad sense. For example, it can be a fixed connection, or a fixed connection. It can be a detachable connection or integrated; it can be a mechanical connection, an electrical connection, or a signal connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an internal connection between two elements. interactive relationship. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of simplicity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only illustrative illustrations and should not constitute any limitation to the present application. .

The battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. Among them, multiple battery cells can be connected in series, parallel or mixed connection to directly form a battery. Mixed connection means that multiple battery cells are connected in series and in parallel. Multiple battery cells can also be connected in series, parallel or mixed to form a battery cell group, and then multiple battery cell groups can be connected in series, parallel or mixed to form a battery. The battery may include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

In this application, the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries or magnesium ion batteries, etc., which are not limited in the embodiments of this application. The battery cell may be in the shape of a flat body, a cylinder, a cuboid, or other shapes, and the embodiments of the present application are not limited to this.

The battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode plate, a negative electrode plate and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work. The positive electrode sheet includes a positive electrode current collector (the current collector is the base material described below) and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector that is not coated with the positive electrode active material layer can be convex. The cathode current collector coated with the cathode active material layer serves as the cathode tab. Taking lithium-ion batteries as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector that is not coated with the negative electrode active material layer can protrude from the negative electrode that is coated with the negative electrode active material layer. The current collector serves as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon. In order to ensure that large currents can pass through without melting, the number of positive electrode tabs can be multiple and stacked together, and the number of negative electrode tabs can be multiple and stacked together. The material of the isolation film can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc. In addition, the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.

The development of battery production technology requires progress in many aspects, such as energy density, production efficiency, etc.

The traditional preparation of pole pieces adopts a wet coating process, which mainly involves making binders, active substances, conductive agents and other materials into a slurry, and then wet-coating the slurry on the surface of the current collector, and then the current collector enters a high-temperature oven. Evaporate the solvent to dryness to obtain the required pole piece.

The inventor found that there are many shortcomings in using the wet coating process to prepare pole pieces, mainly including: (1) The compaction density of the slurry is low, resulting in low energy density, high resistance and low cycle life; (2) The pole pieces are easy to Problems such as cracking occur, which makes it impossible to meet the preparation needs of pole pieces with thick active material layers, and cannot effectively improve the energy density of the battery; (3) the pole piece preparation process is cumbersome and the process cycle is long, which is not conducive to improving the production efficiency of the pole pieces.

Based on the above reasons, in order to improve energy density and production efficiency, the inventor of the present application has conducted in-depth research and provided a pole piece preparation method. The method mainly includes: adding active materials and base materials into the mold cavity of the mold; The active material and the base material are covered with a piece; force is applied to the covering piece and/or the mold, and the active material and the base material are co-extruded through the covering piece and the mold, so that the active material and the base material are compounded to form a pole piece.

On the one hand, the pole pieces formed by extrusion compounding can effectively improve the compaction and density of the active material on the substrate, and can effectively increase its energy density. Moreover, the compaction of the pole pieces can be adjusted by designing different molds. Molds with cavity volumes or by controlling different feeding amounts can obtain pole pieces with different compaction densities; on the other hand, extrusion molding can effectively increase the compaction of the pole pieces, which can effectively reduce the risk of pole piece cracking, thus making it easier to increase The thickness of the active material layer can be used to prepare pole pieces with higher thickness requirements to meet the preparation requirements of thick pole pieces. By increasing the thickness of the pole pieces, the active material passenger capacity can be effectively increased, thereby effectively increasing its energy density. Furthermore, the cavity of the mold plays a role in limiting and shaping the active material. By controlling the shape and size of the mold cavity, pole pieces of the target shape and size can be directly prepared. Compared with the traditional wet coating method, Pole piece preparation process, the technical solution of this application can effectively simplify the processes such as coating, substrate rewinding and unwinding, pole piece cutting, etc., and reduce the transfer time between each process, reduce the coating and drying hours, thereby effectively improving the pole piece production efficiency.

The batteries disclosed in the embodiments of this application can be used in, but are not limited to, electrical equipment such as vehicles, ships, or aircrafts, and the batteries disclosed in this application can be used to form the power supply system of the electrical equipment.

Battery cells suitable for the pole pieces prepared by the pole piece preparation method of the present application may include lithium ion secondary batteries, lithium ion primary batteries, lithium sulfur batteries, sodium lithium ion batteries, sodium ion batteries or magnesium ion batteries, etc., the application implements This example is not limiting.

The pole piece preparation device in this application can, but is not limited to, prepare pole pieces suitable for batteries such as lithium ion secondary batteries, lithium ion primary batteries, lithium sulfur batteries, sodium lithium ion batteries, sodium ion batteries or magnesium ion batteries. This application implements This example is not limiting.

Please refer to Figures 1 and 2. Figure 1 is a schematic diagram of the overall flow of the pole piece preparation method provided by some embodiments of the present application. Figure 2 is a schematic diagram of the active material and base material co-extruded between the cover and the die provided by some embodiments of the present application. Status diagram. Some embodiments of the present application provide a pole piece preparation method, including:

S1: Add the active material 3000 and the base material 211 into the mold cavity 2120 of the mold 2100.

Specifically, the active material 3000 can be added to the mold cavity 2120 first, and then the base material 211 can be covered on the active material 3000. Alternatively, the base material 211 can be added to the mold cavity 2120 first, and then the base material 211 can be covered with the active material 3000. On the other hand, the substrate 211 can even be placed between two layers of active material 3000 .

Among them, the active material 3000 can be a dry powder mixture containing electrode active materials, conductive agents, binders and other materials, or it can be a slurry with a high solid content, or a group-shaped active material with certain viscosity and plasticity. wait.

It can be understood that the base material 211 can be a positive electrode base material or a negative electrode base material. Similarly, with the same polarity as the base material 211, the active material 3000 can be a positive electrode active material or a negative electrode active material.

The shape of the base material 211 can be adapted to the shape and size of the mold cavity 2120. The peripheral dimension of the base material 211 may also be smaller than the inner peripheral dimension of the mold cavity 2120 (that is, there is a gap between the outer periphery of the base material 211 and the inner peripheral surface of the mold cavity 2120).

S2: Cover the covering member 2200 on the active material 3000 or the base material 211.

Specifically, the cover 2200 can cover the active material 3000 or the base material 211. When the base material 211 and the active material 3000 are sequentially added to the mold cavity 2120, the cover 2200 covers the active material 3000, and When the active material 3000 and the base material 211 are sequentially added into the mold cavity 2120, the cover 2200 covers the base material 211.

For example, as shown in FIG. 2 , the active material 3000 and the base material 211 are sequentially added into the mold cavity 2120 , and the cover 2200 covers the base material 211 .

S3: Apply force to the cover 2200 and/or the mold 2100, and jointly extrude the active material 3000 and the base material 211 through the cover 2200 and the mold 2100, so that the active material 3000 and the base material 211 are composited to form the pole piece 21.

Specifically, the active material 3000 is extruded and compounded with the base material 211, and the extruded active material 3000 forms the active material layer of the pole piece 21; force can only be applied to the cover 2200 (the mold 2100 remains stationary), or You can only apply force to the mold 2100 (the cover 2200 remains stationary after covering the active material 3000 or the base material 211), or you can apply force to the mold 2100 and the cover 2200 at the same time, so that the mold 2100 and the cover 2200 move toward each other. Pressing, for example, the mold 2100 remains stationary, applying force to the cover 2200.

Among them, force can be applied to the cover 2200 and/or the mold 2100 manually, or force can be applied to the cover 2200 and/or the mold 2100 through driving components such as a hydraulic system, a pneumatic system, and a servo cylinder. The embodiment of the present application does not apply force to the cover 2200 and/or the mold 2100. It is uniquely qualified.

In the preparation method of the pole piece 21 of the technical solution of the present application, the active material 3000 and the base material 211 are added to the mold cavity 2120 of the mold 2100, and then the cover 2200 and the mold 2100 are matched to jointly extrude the active material 3000 and the base material 211, so that The active material 3000 and the base material 211 are directly compounded to form the pole piece 21. On the one hand, the pole piece 21 formed by extrusion compounding can effectively improve the compaction and density of the active material 3000 on the base material 211, and can effectively increase its energy. Density, and the compaction of the pole piece 21 is adjustable. The pole pieces 21 with different compaction densities can be obtained by designing molds 2100 with different mold cavity 2120 volumes or by controlling different feeding amounts; on the other hand, extrusion through the mold 2100 The method of compositely forming the pole piece 21 facilitates an increase in the thickness of the active material layer, thereby enabling the preparation of a pole piece 21 with a higher thickness requirement to meet the preparation requirements for a thick pole piece 21, and making it easy to effectively increase the activity by increasing the thickness of the pole piece 21 material passenger capacity, thereby effectively increasing its energy density. Furthermore, by controlling the shape and size of the cavity 2120 of the mold 2100, the pole piece 21 of the target shape and size can be directly prepared. Compared with the traditional wet coating pole piece preparation process, the technical solution of the present application can effectively The processes such as coating, substrate 211 rewinding and unwinding, and pole piece 21 cutting are simplified, and the transfer time between each process is reduced, thereby effectively improving the production efficiency of the pole piece 21.

According to some embodiments of the present application, the method further includes: drying the pole piece 21 located in the mold cavity 2120; and taking out the dried pole piece 21 from the mold 2100.

There are many implementation forms for drying the pole pieces 21 located in the mold cavity 2120. For example, the mold 2100 carrying the pole pieces 21 can be sent into a drying equipment such as an oven or oven, so that the pole pieces 21 can be dried. Special drying equipment can also be set up, so that the drying equipment is close to the mold 2100 or extends into the mold cavity 2120 to bake the pole pieces 21 in the mold cavity 2120, and so on.

For example, the mold 2100 carrying the pole piece 21 can be sent into the oven. The mold 2100 enters the oven through the inlet of the oven on the conveyor line, and is discharged through the outlet of the oven, so that the mold 2100 The pole piece 21 is dried during the process of passing through the oven.

After the pole piece 21 is dried, the pole piece 21 in the fixture can be taken out manually or with production equipment. Similarly, there are many ways to take out the pole piece 21. You can use a vacuum nozzle to suck the pole piece 21 out of the mold cavity 2120, or you can invert the jig to discharge the pole piece 21.

The pole piece 21 extruded and compounded in the mold cavity 2120 is directly dried, and then the dried pole piece 21 is separated from the mold cavity 2120. On the one hand, it can effectively avoid the damage caused by directly demolding the extruded pole piece 21. Problems such as the deformation of the pole piece 21 and the displacement of the active material 3000 can effectively ensure the structural stability of the pole piece 21 and the preparation yield of the pole piece 21; on the other hand, the composite of the pole piece 21 and the drying of the pole piece 21 are integrated It is carried out at the same work station, thereby further reducing the transportation and transfer time in the production of the pole piece 21, and further improving the production efficiency of the pole piece 21.

According to some embodiments of the present application, drying the pole piece 21 located in the mold cavity 2120 includes: increasing the temperature of the mold 2100 and/or the cover 2200 to dry the pole piece 21 .

Specifically, the temperature of the mold 2100 or the cover 2200 can be increased individually, or the temperatures of the mold 2100 and the cover 2200 can be increased simultaneously.

For example, the temperature of the mold 2100 or the cover 2200 on the side close to the active material 3000 can be increased. That is, if the active material 3000 is located between the mold 2100 and the substrate 211, the temperature of the mold 2100 can be increased to affect the active material 3000. For heating, if the active material 3000 is located between the substrate 211 and the cover 2200, the temperature of the cover 2200 can be increased to heat the active material 3000.

There are many ways to increase the temperature of the mold 2100 and the cover 2200. For example, the wall of the mold 2100 and the cover 2200 can be a hollow structure containing a heating medium. By raising the temperature of the heating medium, the mold 2100 and the cover 2200 can be raised. Part 2200 temperature.

The pole piece 21 is dried by increasing the temperature of the mold 2100 and/or the cover 2200. On the one hand, the extruded pole piece 21 is located between the mold 2100 and the cover 2200, directly raising the temperature of the mold 2100 and/or the cover 2200. Heating the pole piece 21 at a temperature can effectively reduce the heating distance of the pole piece 21 and improve the heating uniformity of the pole piece 21, thereby improving the drying efficiency of the pole piece 21; on the other hand, the mold 2100 and the cover 2200 are in the pole piece 21 During the heating and drying process, the pole piece 21 plays a positioning and shaping role, which can effectively reduce the risk of warping and deformation of the pole piece 21 during the heating process, thereby effectively ensuring the drying quality of the pole piece 21; furthermore, compared with the traditional The method of drying the pole piece 21 through ovens, ovens and other equipment, and the method of heating the pole piece 21 by raising the temperature of the mold 2100 and/or the cover 2200 can provide the pole piece 21 with a small heating range but more precise heating. The heat source is not only conducive to improving the heating and drying efficiency of the pole piece 21, but also can effectively reduce the drying heat energy demand, save the investment cost of drying equipment, and is conducive to significantly reducing the production cost of the pole piece 21, and has high economic benefits.

According to some embodiments of the present application, the mold 2100 is a metal piece, and increasing the temperature of the mold 2100 and/or the cover 2200 includes: energizing the mold 2100 to increase the temperature of the mold 2100 .

Specifically, the mold 2100 is a metal conductor, and the mold 2100 generates electric heat (when electric current passes through the conductor, the conductor will generate heat, and this heat generated by the electric current is called electric heat) to heat and dry the pole piece 21 in the mold cavity 2120. .

It can be understood that the inner wall of the mold cavity 2120 can be provided with an insulating layer with good thermal conductivity, which can effectively prevent the impact of electricity on the mold 2100 on the active material 3000 and the base material 211.

In some other embodiments, the cover 2200 can also be a metal conductor. By energizing the cover 2200 to increase the temperature of the cover 2200, the pole piece 21 is heated through the cover 2200.

It can be understood that at least the surface of the cover 2200 that is in contact with the mold 2100 and the pole piece 21 can be provided with an insulating layer with good thermal conductivity, which can effectively prevent the mold 2100 from being energized and affecting the active material 3000 and the base material 211 .

By energizing the metal mold 2100, the temperature of the mold 2100 can be increased. The temperature rise speed is fast and the temperature rise balance is strong, which is conducive to further improving the drying efficiency and drying quality of the pole piece 21, and is conducive to further reducing the temperature of the pole piece 21. Cost of production.

According to some embodiments of the present application, please refer to Figure 2 again, adding the active material 3000 and the base material 211 into the mold cavity 2120 of the mold 2100, including sequentially adding the active material 3000 and the base material 211 into the mold cavity 2120; covering the Covering the active material 3000 and the base material 211 with the member 2200 includes: covering the covering member 2200 on the base material 211 .

Specifically, when preparing the pole piece 21, first lay a layer of active material 3000 in the mold cavity 2120, then cover the base material 211 on the active material 3000 in the mold cavity 2120, and then cover the base material 211 with the covering member 2200. The side facing away from the active material 3000 in the thickness direction.

The active material 3000 and the base material 211 are sequentially added into the mold cavity 2120. The base material 211 is covered on the active material 3000, and then the cover 2200 is covered on the base material 211. The cover 2200 and the mold 2100 jointly extrusion the active material 3000. and the base material 211, so that the active material 3000 is extruded and compounded on the side of the base material 211 away from the cover 2200 to form a single-sided coated pole piece 21.

According to some embodiments of the present application, please refer to Figures 3 to 5. Figure 3 is a schematic sub-flow diagram of a pole piece preparation method provided by some embodiments of the present application; Figure 4 is a protrusion penetrating base provided by some embodiments of the present application. Figure 5 is a schematic diagram of the state of the cover and the die co-extruded by some embodiments of the present application to extrudate the first layer of active material, the base material and the second layer of active material. Adding the active material 3000 and the base material 211 to the mold cavity 2120 of the mold 2100 includes: sequentially adding the first layer of active material 3100, the base material 211 and the second layer of active material 3200 into the mold cavity 2120; covering the cover 2200 On the active material 3000 and the base material 211, the method includes: covering the second layer of active material 3200 with the cover 2200.

Specifically, when preparing the pole piece 21, first lay the first layer of active material 3100 into the mold cavity 2120, then cover the base material 211 on the first layer of active material 3100 in the mold cavity 2120, and then lay the first layer of active material 3100 into the mold cavity 2120. Add the second layer of active material 3200, and cover the second layer of active material 3200 with the cover 2200 to co-extrude the first layer of active material 3100, the base material 211 and the second layer of active material 3200 with the mold 2100.

The first layer of active material 3100, the base material 211 and the second layer of active material 3200 are sequentially added into the mold cavity 2120. The base material 211 is located between the two layers of active material 3000, and then the cover 2200 is covered on the second layer of active material 3200. On the top, the cover 2200 and the mold 2100 co-extrude the two layers of active material 3000 and the base material 211, so that the two layers of active material 3000 are extruded and compounded on both sides of the base material 211 to form a double-sided coated pole piece 21.

According to some embodiments of the present application, as shown in Figure 5, the mold 2100 includes a body 2110 and a protruding portion 2130. The body 2110 has a mold cavity 2120. The protruding portion 2130 protrudes from the bottom wall of the mold cavity 2120. The bottom wall is connected to the mold cavity 2120. The openings of the cavity 2120 are opposite; the first layer of active material 3100, the base material 211 and the second layer of active material 3200 are sequentially added into the mold cavity 2120, including:

S11: Add the first layer of active material 3100 and the base material 211 into the mold cavity 2120 in sequence;

S12: Cover the cover 2200 on the base material 211;

S13: Apply force to the cover 2200 and/or the mold 2100, and co-extrude the first layer of active material 3100 and the base material 211 through the cover 2200 and the mold 2100, so that the protruding portion 2130 penetrates the base material 211;

S14: Add the second layer of active material 3200 into the mold cavity 2120.

The protruding part 2130 may be a cylindrical structure, a vertebral structure, or other conventional or special-shaped three-dimensional structure. One protruding part 2130 may be provided, or multiple protruding parts 2130 may be provided. For example, A plurality of protruding parts 2130 are provided, and the plurality of protruding parts 2130 are distributed at scattered points on the bottom wall of the mold cavity 2120. Furthermore, the distances between the plurality of protruding parts 2130 may be equal. Of course, the distances between the plurality of protruding parts 2130 may also be unequal.

The height of the protruding portion 2130 protruding from the bottom wall can be less than the depth of the mold cavity 2120 (the distance between the bottom wall and the opening), or can be equal to the depth of the mold cavity 2120 (that is, the distance between the end surface of the protruding portion 2130 and the distance between the mold cavity 2120 The opening surface is flush). Of course, the height of the protruding portion 2130 protruding from the bottom wall can also be greater than the depth of the mold cavity 2120 (that is, the end surface of the protruding portion 2130 protrudes from the opening surface of the mold cavity 2120). For example, the end surface of the protruding portion 2130 is flush with the opening surface of the mold cavity 2120 .

It can be understood that the cover 2200 can be provided with an escape hole 2210 to avoid the protruding portion 2130 to prevent the protruding portion 2130 from interfering with the extrusion of the mold 2100 and the cover 2200.

Since the protruding portion 2130 is provided in the mold cavity 2120, after the base material 211 is added to the mold cavity 2120, the end of the protruding portion 2130 presses against the base material 211, and the cover 2200 covers the base material 211 and moves toward the base material 211. The cover 2200 and/or the mold 2100 exert force to cause the protruding portion 2130 to exert force on the base material 211 and penetrate the base material 211 . The protruding portion 2130 penetrating the base material 211 enters the filling space of the second layer of active material 3200 .

Among them, the mold 2100 can be exerted to make the protruding portion 2130 directly exert force on the base material 211, or the cover 2200 can be exerted to make the protruding portion 2130 exert a reverse force on the base material 211. Of course, it can also be Force is applied to both the mold 2100 and the base material 211, so that the protruding portion 2130 applies an acting force and a reverse force to the base material 211 at the same time.

After the protruding portion 2130 penetrates the base material 211, the second layer of active material 3200 is added into the mold cavity 2120.

The mold includes a protrusion 2130 disposed on the bottom wall of the mold cavity 2120. When the active material 3000 and the base material 211 are co-extruded through the cover 2200 and the mold 2100, the protrusion 2130 can be formed on the active material 3000 to accommodate the electrolyte. accommodating cavity to promote the storage and infiltration of electrolyte inside the pole piece 21, improve the problem of large ionic resistance of the pole piece 21, and increase the 100 cycle life of the battery; when the pole piece 21 is a double-sided coated pole piece 21, The protruding portion 2130 can penetrate the base material 211 to ensure that the protruding portion 2130 can form accommodating cavities on the active materials 3000 on both sides of the base material 211 . When the first layer of active material 3100, the base material 211 and the second layer of active material 3200 are sequentially added to the mold cavity 2120, first the first layer of active material 3100 and the base material 211 are sequentially added to the mold cavity 2120, through the cover 2200 The base material 211 and the first layer of active material 3100 are extruded together with the mold 2100, so that the base material 211 penetrates the protruding portion 2130 and moves closer to the first layer of active material 3100, freeing up space for the second layer of active material 3200 to be filled. space. After the second layer of active material 3200 is added to the mold 2100, the cover 2200 is again covered on the second layer of active material 3200 and extruded together with the mold 2100, so that the first layer of active material 3100, the base material 211 and the second layer The active material 3200 is compositely molded into one body. At the same time, the protruding portion 2130 forms accommodating cavities in both the first layer of active material 3100 and the second layer of active material 3200 .

Please refer to Figure 6. Figure 6 is a schematic structural diagram of a pole piece preparation device provided by some embodiments of the present application. The present application provides a pole piece preparation device 2000. The pole piece preparation device 2000 includes: a mold 2100 and a cover 2200. The mold 2100 is provided with a mold cavity 2120, which is used to accommodate the active material 3000 and the base material 211. The cover 2200 is configured to at least partially extend into the mold cavity 2120 through the opening of the mold cavity 2120, so as to co-extrude the active material 3000 and the base material 211 with the mold 2100, so that the active material 3000 and the base material 211 are composited to form the pole piece 21.

The mold cavity 2120 of the mold 2100 (a mold and tool used for molding articles) is used to accommodate the active material 3000 and the base material 211, so as to have a limiting and boundary limiting effect on the active material 3000 and the base material 211. It can be understood that, The cross-sectional shape of the mold cavity 2120 can correspond to the shape of the pole piece 21. For example, the cross-sectional shape of the mold cavity 2120 can be circular to extrudate the circular pole piece 21. The cross-sectional shape of the mold cavity 2120 can be It is rectangular, and the rectangular pole piece 21 is extruded. Of course, the cross-sectional shape of the mold cavity 2120 can also be other conventional shapes to prepare pole pieces 21 of different shapes. The overall shape of the mold 2100 may or may not correspond to the shape of the mold cavity 2120 .

At least the part of the cover 2200 that extends into the mold cavity 2120 can match the mold cavity 2120, or the outer circumferential size of the cover 2200 is slightly smaller than the opening size of the mold cavity 2120. For example, the cross section of the mold cavity 2120 is rectangular, and the cover 2200 has a rectangular cross-section. The cross-section of 2200 is also rectangular, and the cover 2200 is adapted to the mold cavity 2120.

The cover 2200 may be a plate-like structure or a block-like structure.

In some embodiments, please refer to FIG. 7 , which is a schematic structural diagram of a pole piece preparation device provided in some embodiments of the present application. An extension 2220 may be provided on one edge of the cover 2200 , and an extension 2220 may be provided on the side wall of the mold 2100 . There is an escape groove 2140 for the extension part 2220 to be inserted. The design of the extension part 2220 and the escape groove 2140 guides the extrusion of the mold 2100 and the cover 2200.

In addition, the edge on one side of the base material 211 can be provided with a blank area that can extend out of the mold cavity 2120. This blank area can eventually become the tab of the pole piece 21. When the base material 211 is placed into the mold cavity 2120, it can be The blank area is inserted into the escape groove 2140. After the mold 2100 and the cover 2200 are pressed toward each other, the blank area extending from the edge of the base material 211 is clamped between the extension part 2220 and the bottom wall of the escape groove 2140, so as to Effectively avoid folding and wrinkles in the blank area.

The pole piece 21 preparation device includes a mold 2100 and a cover 2200. The mold 2100 is provided with a mold cavity 2120 for accommodating the active material 3000 and the base material 211. During use, the active material 3000 and the base material 211 are added to the mold cavity 2120, and the The cover 2200 covers the active material 3000 or the substrate 211 in the mold cavity 2120, and exerts force on the mold 2100 and/or the cover 2200, so that at least part of the cover 2200 extends into the mold cavity 2120, and the cover 2200 and the mold 2100 co-extrudes the active material 3000 and the base material 211, so that the active material 3000 and the base material 211 are composited to form the pole piece 21. On the one hand, the co-extruded structure of the mold 2100 and the cover 2200 can effectively improve the compaction and density of the active material 3000 on the base material 211, and can effectively increase the energy density of the pole piece 21. On the other hand, the mold 2100 and the cover The co-extruded structure of the parts 2200 is convenient for thickening the thickness of the active material layer, so that the pole piece 21 with a higher thickness requirement can be stably prepared to meet the preparation requirements of the thick pole piece 21, and it is easy to effectively increase the activity by increasing the thickness of the pole piece 21 material passenger capacity, thereby effectively increasing its energy density. Furthermore, by controlling the shape and size of the cavity 2120 of the mold 2100, the pole piece 21 of the target shape and size can be directly prepared, which is beneficial to improving the production efficiency of the pole piece 21.

According to some embodiments of the present application, please continue to refer to Figures 6 and 7. The mold 2100 includes a body 2110 and a protruding portion 2130. The body 2110 has a mold cavity 2120. The protruding portion 2130 protrudes from the bottom wall of the mold cavity 2120. The wall is opposite to the opening of the mold cavity 2120, and the protruding portion 2130 is used to form a receiving cavity on the active material 3000 to accommodate the electrolyte.

As mentioned above, the protruding portion 2130 can be a cylindrical structure, a vertebral structure, or other conventional or special-shaped three-dimensional structures. One or more protruding portions 2130 can be provided. Examples Optionally, multiple protrusions 2130 are provided, and the plurality of protrusions 2130 are spacedly distributed on the bottom wall of the mold cavity 2120. The distance between the plurality of protrusions 2130 may be equal or unequal.

The height of the protruding portion 2130 protruding from the bottom wall may be less than, greater than, or equal to the depth of the mold cavity 2120 (the distance between the bottom wall and the opening). For example, the end surface of the protruding portion 2130 and the opening surface of the mold cavity 2120 Flush.

The mold 2100 includes a protruding portion 2130 disposed on the bottom wall of the mold cavity 2120. When the active material 3000 and the base material 211 are co-extruded by the mold 2100 and the cover 2200 to compositely form the pole piece 21, the protruding portion 2130 can move the active material When 3000 is compacted, a certain space is reserved on the active material 3000. This space forms a receiving cavity for accommodating the electrolyte. The thicker the electrode piece 21 is, the longer the diffusion path of liquid phase ions is, and the diffusion of the electrolyte is The greater the impedance, the higher the rate capability of the battery 100 will be affected. By physically forming a hole in the active material layer 3000 of the pole piece 21, a receiving cavity for containing the electrolyte can be provided, which can increase the thickness and compactness of the active material layer 3000 of the pole piece 21 and at the same time promote the electrolyte. The storage and infiltration inside the pole piece 21 improves the problem of large ionic resistance of the pole piece 21 and effectively increases the cycle life of the battery 100, thereby ensuring the energy density of the battery 100 while effectively ensuring the charge and discharge rate of the battery 100.

According to some embodiments of the present application, multiple protrusions 2130 are provided, and the plurality of protrusions 2130 are spaced apart.

As shown in Figures 6 and 7, the plurality of protrusions 2130 can be distributed on the bottom wall of the mold cavity 2120 in a scattered point manner, and the distance between the plurality of protrusions 2130 can be equal or unequal. For example, The distances between the plurality of protrusions 2130 are equal.

A plurality of spaced-apart protrusions 2130 are provided in the mold cavity 2120 to form a plurality of spaced-apart accommodation cavities for accommodating electrolyte on the pole piece 21 , thereby further improving the storage of electrolyte on the pole piece 21 , infiltration amount, and effectively improve the uniformity of electrolyte distribution and penetration.

According to some embodiments of the present application, the cover 2200 is provided with an escape hole 2210 for the protrusion 2130 to pass through.

It can be understood that, as shown in FIGS. 6 and 7 , when multiple protrusions 2130 are provided, the cover 2200 can be provided with multiple escape holes 2210 , and the multiple escape holes 2210 are connected to the multiple protrusions 2130 one by one. correspond.

The cover 2200 is provided with an escape hole 2210 for the protruding portion 2130 to pass through. On the one hand, the arrangement of the escape hole 2210 can provide more extension space for the protruding portion 2130, thereby ensuring that the accommodation cavity is arranged along the thickness direction of the pole piece 21. depth, effectively increasing the volume of the accommodation cavity, and enabling the protruding portion 2130 to penetrate the pole piece 21 along the thickness direction of the pole piece 21. In some embodiments, active elements can be provided on both sides of the substrate 211 in the thickness direction. material 3000, the protruding portion 2130 penetrates the pole piece 21 along the thickness direction of the pole piece 21, which is beneficial to forming accommodation cavities for the active material 3000 on both sides of the base material 211; on the other hand, the setting of the avoidance hole 2210 can effectively avoid covering The problem of positional interference between the member 2200 and the protruding portion 2130 affects the extrusion strength of the mold 2100 and the covering member 2200, thereby effectively ensuring the compactness of the extrusion molding of the pole piece 21, and ensuring the energy density of the pole piece 21 while ensuring the pole piece 21. Structural stability of sheet 21.

According to some embodiments of the present application, the pole piece preparation device 2000 also includes a drying mechanism, which is used to dry the pole piece 21 .

There are many implementation forms of the drying mechanism. As an example, the drying mechanism can use drying equipment used in industrial production (such as ovens, ovens, etc.), and can take out the extruded pole piece 21 from the mold 2100 Then it is sent to the drying equipment, or the mold 2100 carrying the pole piece 21 can be directly sent to the drying equipment, so that the pole piece 21 is dried.

The pole piece preparation device is provided with a drying mechanism to dry and shape the extruded pole piece 21 .

According to some embodiments of the present application, the drying mechanism includes a power supply mechanism. The mold 2100 is a metal part. The power supply mechanism is used to energize the mold 2100 to heat the mold 2100 to dry the pole piece 21; and/or the cover 2200 is metal. The power supply mechanism is used to energize the cover 2200 to heat the cover 2200 to dry the pole piece 21 .

The power supply mechanism generally refers to a mechanism that can energize the mold 2100 and/or the cover 2200. It can use a conventional mains power supply structure or a conventional battery power supply structure, as long as it can energize the metal to make it heat.

The power supply mechanism can energize the mold 2100 to generate electric heat (when current passes through a conductor, the conductor will generate heat, and this heat generated by the current is called electric heat) to heat and dry the pole piece 21 in the mold cavity 2120.

Of course, the power supply mechanism can also energize the cover 2200 alone, or energize the mold 2100 and the cover 2200 at the same time to heat and dry the pole piece 21 in the mold cavity 2120.

It can be understood that the inner wall of the mold cavity 2120 can be provided with an insulating layer with good thermal conductivity, which can effectively prevent the impact of electricity on the mold 2100 on the active material 3000 and the base material 211. Of course, when the cover 2200 is powered on, at least the surface of the cover 2200 that is in contact with the mold 2100 and the pole piece 21 can also be provided with an insulating layer with good thermal conductivity to effectively prevent the impact of the cover 2200 on the active material 3000 and the base material 211 .

A power supply mechanism is used to supply power to the mold 2100 and/or the cover 2200. The mold 2100 and/or the cover 2200 generate electric heat, which has a fast heating speed and strong temperature rise balance, which is conducive to further improving the drying efficiency of the pole piece 21 and the drying efficiency of the pole piece 21. dry quality, and is conducive to further reducing the production cost of the pole piece 21; at the same time, the pole piece 21 is heated and dried between the mold 2100 and the cover 2200, and the mold 2100 and the cover 2200 play a clamping and positioning role for the pole piece 21, effectively The risk of drying deformation of the pole piece 21 is reduced, thereby ensuring the drying quality of the pole piece 21.

According to some embodiments of the present application, the pole piece preparation device 2000 further includes a pressurizing mechanism connected to the cover 2200. The pressurizing mechanism is used to apply pressure to the cover 2200 so that the cover 2200 and the mold 2100 are co-extruded. The active material 3000 and the substrate 211 in the mold cavity 2120 are pressed.

The pressurizing mechanism refers to a structure that can provide pressure drive for the cover 2200. There are many implementation forms of the pressurizing mechanism. For example, the pressurizing mechanism can be a hydraulic press, and the hydraulic press drives the cover 2200 to move. Of course, the pressurizing mechanism can also be a pressure providing mechanism such as a pneumatic press or a servo electric cylinder.

During use, the position of the mold 2100 is fixed, and the cover 2200 is installed at the output end of the pressurizing mechanism. The pressurizing mechanism can drive the cover 2200 to move toward the mold 2100, so that the cover 2200 and the mold 2100 jointly squeeze the material in the mold cavity 2120. The base material 211 and the active material 3000, and the pressing mechanism can also drive the cover 2200 to move away from the mold 2100, so that the cover 2200 is separated from the mold 2100.

A pressurizing mechanism is provided to apply pressure to the cover 2200, so that the cover 2200 and the mold 2100 can jointly squeeze the active material 3000 and the base material 211 in the mold cavity 2120, so that the active material 3000 and the base material 211 can be compositely formed into the pole piece 21 .

Some embodiments of the present application provide an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.

The battery described in the embodiments of the present application is not limited to the above-described electrical devices, but can also be applied to all electrical devices using batteries. However, for the sake of simplicity of description, the following embodiment uses an example of an embodiment of the present application. An electrical device is a vehicle as an example for illustration.

Please refer to FIG. 8 , which is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail 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 . The vehicle 1000 may also include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .

In some other embodiments, the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used 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 .

Please refer to FIG. 9 , which is an exploded view of the battery 100 provided by some embodiments of the present application. The battery 100 may include a box 20 and a battery cell 10 , and the battery cell 10 is accommodated in the box 20 . The box 20 is used to provide an accommodation space for the battery cells 10 , and the box 20 can adopt a variety of structures. In some embodiments, the box 20 may include a first part 201 and a second part 202 , the first part 201 and the second part 202 cover each other, and the first part 201 and the second part 202 jointly define a space for accommodating the battery cell 10 of accommodation space. The second part 202 may be a hollow structure with one end open, and the first part 201 may be a plate-like structure. The first part 201 covers the open side of the second part 202 so that the first part 201 and the second part 202 jointly define a receiving space. ; The first part 201 and the second part 202 may also be hollow structures with one side open, and the open side of the first part 201 is covered with the open side of the second part 202. Of course, the box 20 formed by the first part 201 and the second part 202 can be in various shapes, such as rectangular parallelepiped, cube, etc.

In the battery 100 , there may be a plurality of battery cells 10 , and the plurality of battery cells 10 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 10 are connected in series and in parallel. Multiple battery cells 10 can be directly connected in series or in parallel or mixed together.

Please refer to Figure 10. Figure 10 is an exploded view of a battery cell 10 provided in some embodiments of the present application. The battery cell 10 provided in some embodiments of the present application may include a casing 1, an electrode assembly 2 and an electrolyte. The casing 1 is made of Parts used to accommodate the electrode assembly 2, electrolyte and other components. The housing 1 can be in various shapes, such as rectangular parallelepiped. In some embodiments, please refer to FIG. 11 . FIG. 11 is an exploded view of the battery cell 10 provided in some embodiments of the present application. The casing 1 is in the form of a cylinder. Of course, the shape of the shell is not limited to the above-mentioned rectangular parallelepiped and cylinder, and can also be other shapes.

The housing 1 may include a housing 11 and a cover 12. The cover 12 covers the opening of the housing 11. The cover 12 and the housing 11 jointly define a sealed space for accommodating the electrode assembly 2, electrolyte and other components.

The electrode assembly 2 is a component in the battery cell 10 where electrochemical reactions occur. The electrode assembly 2 may include a positive electrode piece 21a, a negative electrode piece 21b, and a separation film 22. The electrode assembly 2 may be a rolled structure formed by winding the positive electrode piece 21a, the isolation film 22 and the negative electrode piece 21b, or may be a laminate structure. Exemplarily, the electrode assembly 2 is a laminate structure.

Please refer to Figure 12, which is an isometric view of a pole piece provided by some embodiments of the present application. Some embodiments of the present application also provide a pole piece 21. The pole piece 21 includes a base material 211 and a first active material layer 212. The first active material layer 212 is disposed on one side of the base material 211 in the thickness direction. The active material layer 212 includes a first surface 2121 facing away from the substrate 211; wherein the first surface 2121 is provided with a first accommodation cavity 2122 for accommodating electrolyte.

The pole piece 21 can be made by using the aforementioned pole piece preparation method and pole piece preparation device. The base material 211 can be a positive electrode base material or a negative electrode base material. The first active material layer 212 can be extruded and compounded by the active material 3000. formed on the base material 211. Of course, in other embodiments, the first active material layer 212 can also be compounded with the base material 211 by spraying, rolling, or other methods.

The first surface 2121 faces away from the base material 211 , and the first accommodation cavity 2122 may penetrate the first active material layer 212 along the thickness direction of the pole piece 21 , or may not penetrate the first active material layer 212 . One first accommodating cavity 2122 may be provided, or multiple first accommodating cavities 2122 may be provided at intervals. For example, a plurality of first accommodating cavities 2122 may be provided at intervals.

The first receiving cavity 2122 can be directly formed through the protruding portion 2130 in the mold 2100 when the pole piece 21 is extruded. That is, the mold 2100 includes a body 2110 and a protruding portion 2130. The body 2110 has a mold cavity 2120 and a protruding portion 2130. Protruding from the bottom wall of the mold cavity 2120 , the mold 2100 and the cover 2200 jointly squeeze the active material 3000 and the base material 211 , and the protruding portion 2130 forms a first accommodation cavity 2122 on the active material 3000 . Of course, in some other embodiments, the first accommodating cavity 2122 can also be processed on the finished pole piece 21 .

In addition, a blank area that can protrude out of the mold cavity 2120 may be provided on the edge of one side of the base material 211 , and this blank area eventually becomes the tab area 2112 of the pole piece 21 .

The pole piece 21 includes a base material 211 and a first active material layer 212. The first active material layer 212 is provided with a first accommodation cavity 2122, and the first accommodation cavity 2122 is used to accommodate electrolyte. The thicker the electrode piece 21 is, the longer the diffusion path of liquid phase ions is, and the greater the diffusion resistance of the electrolyte is. After applying the electrode piece 21 to the battery cell 10, the design of the first accommodation cavity 2122 can increase the electrode size. The thickness and tightness of the active material layer 3000 of the sheet 21 simultaneously promotes the storage and infiltration of the electrolyte inside the pole piece 21, improves the problem of large ionic impedance of the pole piece 21, and effectively increases the cycle life of the battery 100. At the same time, the setting of the first accommodation cavity 2122 can assist the electrolyte to penetrate into the interior of the first active material layer 212, effectively increasing the penetration thickness of the electrolyte, thereby ensuring the full utilization of the pole piece 21 and reducing the risk of the thick pole piece 21. There is a risk of insufficient reaction. Therefore, the pole piece 21 of the technical solution of the present application can effectively ensure the energy density of the battery 100 and the performance of the battery 100 at the same time.

According to some further embodiments of the present application, please refer to Figures 13 and 14. Figure 13 is an isometric view of a pole piece provided in some further embodiments of the present application, and Figure 14 is a side view of a pole piece provided in some further embodiments of the present application. View section view. The pole piece 21 also includes a second active material layer 213. The second active material layer 213 is disposed on the other side in the thickness direction of the base material 211. The second active material layer 213 includes a second surface 2131 facing away from the base material 211. The surface 2131 is provided with a second containing cavity 2132 for containing electrolyte.

It can be understood that the second active material layer 213 and the first active material layer 212 are made of the same material. Similarly, the second active material layer 213 can be formed by extrusion compounding of the active material 3000 on the base material 211 . Of course, in other embodiments, the second active material layer 213 can also be compounded with the base material 211 by spraying, rolling, or other methods.

The second surface 2131 faces away from the base material 211 , and the second accommodation cavity 2132 may penetrate the second active material layer 213 along the thickness direction of the pole piece 21 , or may not penetrate the second active material layer 213 . One second accommodating cavity 2132 may be provided, or multiple second accommodating cavities 2132 may be provided at intervals. For example, a plurality of second accommodating cavities 2132 may be provided at intervals.

The second accommodating cavity 2132 can be directly formed through the protruding portion 2130 in the mold 2100 when the pole piece 21 is extruded. Of course, in some other embodiments, the second accommodating cavity 2132 can also be formed on the finished pole piece 21 Processed.

The pole piece 21 includes a base material 211 and a first active material layer 212 and a second active material layer 213 coated on both sides of the thickness direction of the base material 211, which effectively increases the active material capacity of the pole piece 21, thereby increasing the energy density; Both the first active material layer 212 and the second active material layer 213 are provided with accommodating cavities, which is conducive to further improving the storage capacity and infiltration efficiency of the electrolyte, and effectively improves the uniformity of the distribution and penetration of the electrolyte on the pole piece 21 to ensure both sides. Full utilization of the surface-coated pole piece 21.

According to some embodiments of the present application, please continue to refer to FIG. 14 , the base material 211 is provided with a through hole 2111 , and the first accommodating cavity 2122 and the second accommodating cavity 2132 are connected to each other through the through hole 2111 .

It can be understood that, based on the implementation form of "the mold 2100 includes a body 2110 and a protruding portion 2130", the through hole 2111 can be directly formed by penetrating the base material 211 through the protruding portion 2130 in the mold 2100 when the pole piece 21 is extruded. , of course, in some other embodiments, the base material 211 can be provided with through holes 2111 in advance before the pole piece 21 is formed, and the through holes 2111 can allow the protruding portion 2130 to pass through.

The number of through holes 2111 may correspond to the first accommodating cavity 2122 and the second accommodating cavity 2132.

The first accommodating cavity 2122 and the second accommodating cavity 2132 are connected through the through hole 2111 on the base material 211, which can effectively improve the circulation of the electrolyte in the pole piece 21, increase the infiltration path of the electrolyte, and further improve the efficiency of the electrolyte. Wetting efficiency and penetration adequacy.

According to some embodiments of the present application, please continue to refer to Figure 14. The thickness of the second active material layer 213 is H1, satisfying H1≤1500 μm, preferably, 70 μm≤H1≤1500 μm.

The thickness H1 of the second active material layer 213 can be any value greater than 0 and less than or equal to 1500 μm. For example, H1 can be 10 μm, 50 μm, 100 μm, 300 μm, 1000 μm, 1500 μm, etc.

Preferably, H1 can be any value greater than or equal to 70 μm and less than or equal to 1500 μm. For example, H1 can be 70 μm, 80 μm, 200 μm, 1200 μm, etc. For example, H1 is 1500 μm.

If the thickness of the pole piece 21 is too large, problems such as low reaction adequacy and poor rate capability may occur. However, the thickness of the active material layer of the pole piece 21 provided with the accommodation cavity of the present application can reach 70 μm to 1500 μm, which effectively increases the thickness of the pole piece 21. At the same time, the reaction adequacy and rate capability of the pole piece 21 can be ensured, thereby effectively ensuring the energy density and charge and discharge rate of the battery using the pole piece 21.

According to some embodiments of the present application, please continue to refer to Figure 14. The thickness of the first active material layer 212 is H2, satisfying H2≤1500 μm, preferably, 70 μm≤H2≤1500 μm.

The thickness H2 of the first active material layer 212 can be any value greater than 0 and less than or equal to 1500 μm. For example, H2 can be 70 μm, 80 μm, 200 μm, 1200 μm, etc.

Preferably, H2 can be any value greater than or equal to 70 μm and less than or equal to 1500 μm. For example, H2 can be 70 μm, 80 μm, 200 μm, 1200 μm, etc. For example, H2 is 1500 μm.

Among them, H1 and H2 may be the same or different. As an example, H1 and H2 are the same.

Both the first active material layer 212 and the second active material layer 213 are provided with accommodating cavities for accommodating the electrolyte. The thickness of the first active material layer 212 can reach 70 μm to 1500 μm, which can effectively increase the thickness of the pole piece 21 while ensuring the electrolyte. The reaction adequacy and rate capability of the pole piece 21 further ensure the energy density of the battery using the pole piece 21 while ensuring its performance.

According to some further embodiments of the present application, please refer to FIG. 15 , which is an isometric view of a pole piece provided in some further embodiments of the present application. The first active material layer 212 is provided with a first active material layer penetrating through the first active material layer 212 along the first direction X. In the mounting hole 2123 of the material layer 212, the first direction 211 welding, the other end extends out of the outline of pole piece 21.

The electric energy extraction part plays an overcurrent role and is used to extract the electric energy from the pole piece 21 . The electric energy extraction part 214 can serve as the pole tab of the pole piece 21 .

The intersection of the first direction X and the plane of the base material 211 means that the angle between the first direction X and the plane of the base material 211 is not zero. The first direction The plane where the base material 211 is located, for example, the first direction X is perpendicular to the plane where the base material 211 is located.

When the pole piece 21 is applied to the battery cell 10, one end of the electric energy extraction part 214 extending out of the outline of the pole piece 21 can be connected to the electrode terminal provided on the casing 1 of the battery cell 10 through an adapter or other current-carrying component. (It is used to draw the electric energy in the battery cell 10 out of the battery cell 10 ). Of course, one end of the electric energy extraction part 214 extending out of the outline of the pole piece 21 can also directly extend out of the casing 1 of the battery cell 10 .

The electric energy extraction part 214 can be welded on the base material 211 in advance, and then the active material and the base material 211 with the electric energy extraction part 214 are added to the mold cavity 2120, and the pole piece 21 is extruded through the cover 2200 and the mold 2100.

Of course, after the pole piece 21 is formed, the mounting hole 2123 can be processed in the first active material layer 212, and then the electric energy extraction part 214 can be welded to the base material 211.

Compared with the structure of leaving a blank area on the side of the base material 211 to form the tabs of the pole piece 21, the pole piece 21 is provided with an electric energy extraction part 214, and the electric energy extraction part 214 is along the first direction that intersects with the surface of the base material 211. X extraction makes it easier for the base material 211 and the active material to be extruded in the mold 2100, effectively reducing the risk of the electrical energy extraction part 214 being bent, deformed or even broken during the extrusion molding of the pole piece 21.

Please refer to Figure 11 again. This application also provides an electrode assembly 2, including a positive electrode piece 21a, a negative electrode piece 21b and an isolation film 22. The positive electrode piece 21a, the negative electrode piece 21b and the isolation film 22 are stacked to form the electrode assembly 2 , the isolation film 22 is disposed between the positive electrode piece 21a and the negative electrode piece 21b; wherein at least one of the positive electrode piece 21a and the negative electrode piece 21b is the pole piece 21 described in any one of the above.

That is to say, both the positive electrode piece 21a and the negative electrode piece 21b can be the pole piece 21 described in the above solution, or only one of them can be the pole piece 21 described in the above solution. For example, both the positive electrode piece 21a and the negative electrode piece 21b are the electrode pieces 21 described in the above solution.

Among them, the positive electrode piece 21a can include a positive electric energy extraction part 214a, and the negative electrode piece 21b can include a negative electrode electric energy extraction part 214b. The positive electrode electric energy extraction part 214a and the negative electrode electric energy extraction part 214b can be distributed between the positive electrode piece 21a and the negative electrode piece 21b. Both sides of the stacking direction.

The electrode assembly 2 is beneficial to ensure the energy density of the battery 100 while ensuring the performance of the battery 100 .

This application also provides a battery cell 10, which includes a case 11 and the electrode assembly 2 described in the above solution. The electrode assembly 2 is accommodated in the case 11.

It can be understood that the housing 1 can be a housing of any structure mentioned above, and the housing 1 can include one aforementioned electrode assembly 2 or multiple aforementioned electrode assemblies 2. When the housing 1 houses multiple electrode assemblies 2 , multiple electrode assemblies 2 may be stacked along the stacking direction of the pole pieces 21 , or may be arranged in a direction perpendicular to the stacking direction of the pole pieces 21 , which is not uniquely limited in this embodiment.

For example, as shown in Figure 11, the housing 1 has a cylindrical structure, and the pole pieces 21 are also circular structures. The housing 1 includes an electrode assembly 2, and the stacking direction of the pole pieces 21 of the electrode assembly 2 is along the direction of the housing 11. Axial extension.

The positive electrode piece 21a and the negative electrode piece 21b of the electrode assembly 2 each include a base material 211, a first active material layer 212 and a second active material layer 213. The first active material layer 212 is provided with a plurality of first accommodation cavities 2122. The second active material layer 213 is provided with a plurality of second accommodating cavities 2132. The base material 211 is provided with a plurality of through holes 2111. The first accommodating cavities 2122 are connected to the second accommodating cavities 2132 through the through holes 2111 in a one-to-one correspondence.

The first active material layer 212 of the positive electrode piece 21a and the negative electrode piece 21b is distributed on both sides of the stacking direction of the electrode piece 21. The positive electrode piece 21a includes a positive electric energy extraction part 214a. One end of the positive electric energy extraction part 214a is connected to the positive electrode piece 21a. The base material 211 is welded, and the other end extends out of the first active material layer 212 of the positive electrode piece 21a along the axial direction of the housing 11. The negative electrode piece 21b includes a negative electrode electric energy extraction part 214b. One end of the negative electrode electric energy extraction part 214b is connected to the negative electrode. The base material 211 of the piece 21b is welded, and the other end extends out of the first active material layer 212 of the negative electrode piece 21b along the axial direction of the housing 11.

Some embodiments of the present application provide a battery 100, including a box 20 and the battery cell 10 described in the above solution, and the battery cell 10 is accommodated in the box 20.

Some embodiments of the present application provide an electrical device, including the battery cell 10 described in the above solution. The battery cell 10 is used to provide electrical energy. The electrical device can be any of the aforementioned electrical devices.

Please refer to Figures 5 to 7. Some embodiments of the present application provide a pole piece preparation device 2000. The pole piece preparation device 2000 includes: a mold 2100, a cover 2200, a power supply mechanism and a pressurizing mechanism. The mold 2100 includes a body 2110 and a The body 2110 has a plurality of protrusions 2130. The body 2110 has a mold cavity 2120. The plurality of protrusions 2130 protrude from the bottom wall of the mold cavity 2120 and are spaced apart from each other. The bottom wall is opposite to the opening of the mold cavity 2120. The mold cavity 2120 is used to accommodate The active material 3000 and the substrate 211 are placed. The cover 2200 is provided with an escape hole 2210 for the protruding portion 2130 to pass through. The output end of the pressurizing mechanism is connected to the cover 2200. The pressurizing mechanism is used to apply pressure to the cover 2200 so that the cover 2200 passes through the mold cavity 2120. The opening at least partially extends into the mold cavity 2120, and the active material 3000 and the base material 211 are extruded together with the mold 2100, so that the active material 3000 and the base material 211 are combined to form the pole piece 21, and the plurality of protrusions 2130 are used to form the pole piece 21 A plurality of accommodation chambers for accommodating electrolyte are formed on the active material 3000.

The mold 2100 is a metal piece, and the power supply mechanism is used to energize the mold 2100 to heat the mold 2100 to dry the pole piece 21 .

Please refer to Figures 14 and 15. Some embodiments of the present application provide a pole piece 21. The pole piece 21 includes a base material 211, a first active material layer 212, a second active material layer 213 and an electric energy extraction part 214. An active material layer 212 is provided on one side of the substrate 211 in the thickness direction, and a second active material layer 213 is provided on the other side of the substrate 211 in the thickness direction. The first active material layer 212 includes a first layer facing away from the substrate 211 . Surface 2121, the second active material layer 213 includes a second surface 2131 facing away from the substrate 211, wherein the first surface 2121 is provided with a first accommodation cavity 2122 for accommodating the electrolyte, and the second surface 2131 is provided with a first accommodation cavity 2122 for accommodating the electrolyte. The second accommodation cavity 2132. The base material 211 is provided with a through hole 2111, and the first accommodating cavity 2122 and the second accommodating cavity 2132 are connected to each other through the through hole 2111.

The first active material layer 212 is provided with a mounting hole 2123 that penetrates the first active material layer 212 along the first direction X. The first direction One end of the portion 214 is welded to the base material 211, and the other end extends out of the outline of the pole piece 21.

It should be noted that, as long as there is no conflict, the features in the embodiments of this application can be combined with each other.

While the present application has been described with reference to preferred embodiments, various modifications may be made and equivalents may be substituted for components thereof without departing from the scope of the application. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any way. The application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

A method for preparing pole pieces, including:

Add active materials and base materials into the cavity of the mold;

Cover the active material and the base material with a covering member;

Applying force to the cover and/or the mold, the active material and the base material are co-extruded through the cover and the mold, so that the active material and the base material are composited to form a pole. piece.
The pole piece preparation method according to claim 1, further comprising:

Drying the pole piece located in the mold cavity;

The dried pole piece is taken out from the mold.
The pole piece preparation method according to claim 2, wherein drying the pole piece located in the mold cavity includes:

The temperature of the mold and/or the cover is increased to dry the pole piece.
The pole piece preparation method according to claim 3, wherein the mold is a metal piece, and increasing the temperature of the mold and/or the cover includes:

The mold is energized to increase the temperature of the mold.
The pole piece preparation method according to any one of claims 1-4, wherein adding the active material and the base material into the mold cavity of the mold includes:

Add the active material and the base material sequentially into the mold cavity;

The covering member on the active material and the base material includes:

The cover is placed on the substrate.
The pole piece preparation method according to any one of claims 1-4, wherein adding the active material and the base material into the mold cavity of the mold includes:

Add the first layer of the active material, the base material and the second layer of the active material into the mold cavity in sequence;

The covering member on the active material and the base material includes:

Cover the second layer of active material with the covering member.
The pole piece preparation method according to claim 6, wherein the mold includes a body and a protruding portion, the body has the mold cavity, and the protruding portion protrudes from the bottom wall of the mold cavity, so The bottom wall is opposite to the opening of the mold cavity;

The step of sequentially adding the first layer of the active material, the base material and the second layer of the active material into the mold cavity includes:

Sequentially adding the first layer of the active material and the base material into the mold cavity;

Cover the covering member on the base material;

Applying force to the cover and/or the mold, the first layer of the active material and the base material are co-extruded through the cover and the mold, so that the protrusion penetrates the base material;

Add a second layer of the active material into the mold cavity.
A pole piece preparation device, including:

Mold, the mold is provided with a mold cavity, and the mold cavity is used to accommodate active materials and base materials;

Cover, the cover is configured to at least partially extend into the mold cavity through the opening of the mold cavity to co-extrude the active material and the base material with the mold, so that the active material and the The base materials are combined to form pole pieces.
The pole piece preparation device according to claim 8, wherein the mold includes a body and a protruding portion, the body has the mold cavity, and the protruding portion protrudes from the bottom wall of the mold cavity, so The bottom wall is opposite to the opening of the mold cavity, and the protruding portion is used to form a receiving cavity for accommodating electrolyte on the active material.
The pole piece preparation device according to claim 9, wherein there are a plurality of protruding parts, and the plurality of protruding parts are arranged at intervals.
The pole piece preparation device according to claim 9 or 10, wherein the cover is provided with an escape hole for the protruding portion to pass through.
The pole piece preparation device according to any one of claims 8-11, wherein the pole piece preparation device further includes:

A drying mechanism is used to dry the pole piece.
The pole piece preparation device according to claim 12, wherein the drying mechanism includes a power supply mechanism, the mold is a metal piece, and the power supply mechanism is used to energize the mold to heat the mold for drying. The pole piece; and/or

The cover is a metal piece, and the power supply mechanism is used to energize the cover to heat the cover to dry the pole piece.
The pole piece preparation device according to any one of claims 8-13, wherein the pole piece preparation device further includes:

A pressurizing mechanism, connected to the cover, is used to apply pressure to the cover so that the cover and the mold jointly squeeze the active material and the active material in the mold cavity. base material.
A pole piece including:

base material;

A first active material layer is disposed on one side of the substrate in the thickness direction, and the first active material layer includes a first surface facing away from the substrate;

Wherein, the first surface is provided with a first accommodation cavity for accommodating electrolyte.
The pole piece according to claim 15, wherein the pole piece further includes:

A second active material layer is disposed on the other side in the thickness direction of the base material. The second active material layer includes a second surface facing away from the base material. The second surface is provided with a hole for accommodating electrolyte. The second accommodation cavity.
The pole piece according to claim 16, wherein the base material is provided with a through hole, and the first accommodating cavity and the second accommodating cavity are connected to each other through the through hole.
The pole piece according to claim 16 or 17, wherein the thickness of the second active material layer is H1, satisfying H1≤1500 μm, preferably, 70 μm≤H1≤1500 μm.
The pole piece according to any one of claims 16 to 18, wherein the thickness of the first active material layer is H2, satisfying H2≤1500 μm, preferably, 70 μm≤H2≤1500 μm.
The pole piece according to any one of claims 15 to 19, wherein the first active material layer is provided with a mounting hole penetrating the first active material layer in a first direction, and the first direction is consistent with the first active material layer. The planes where the base materials are located intersect, and the pole pieces also include:

An electric energy extraction part is inserted through the mounting hole. One end of the electric energy extraction part is welded to the base material, and the other end extends out of the outline of the pole piece.
An electrode assembly, including a positive electrode piece, a negative electrode piece and an isolation film. The positive electrode piece, the negative electrode piece and the isolation film are stacked to form the electrode assembly. The isolation film is disposed on the positive electrode. between the plate and the negative electrode plate;

Wherein, at least one of the positive electrode piece and the negative electrode piece is the electrode piece according to any one of claims 15-20.
A battery cell includes a case and an electrode assembly according to claim 21, and the electrode assembly is accommodated in the case.
A battery includes a box and the battery cell according to claim 22, and the battery cell is accommodated in the box.
An electrical device, comprising the battery cell according to claim 22, wherein the battery cell is used to provide electrical energy.