Battery formation apparatus, formation system and formation method

Abstract

This application relates to battery formation apparatus, formation system, and formation method. The battery formation apparatus of this application includes a reservoir cup, which includes a receiving cavity and an inlet and an outlet communicating with the receiving cavity. The inlet communicates with the interior of a battery cell, and the outlet communicates with an external negative pressure device, allowing gas from the battery cell to flow out of the reservoir cup through the inlet, receiving cavity, and outlet. It also includes a coating, which is disposed on the cavity wall of the receiving cavity. One of the coating and the electrolyte is oleophilic, and the other is oleophobic, to reduce electrolyte adhesion to the cavity wall when gas carries the electrolyte from the battery cell into the receiving cavity. This battery formation apparatus can reduce the possibility of electrolyte crystallization clogging the battery formation apparatus, thereby ensuring the normal operation of the battery formation process and improving battery formation efficiency.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to a battery formation apparatus, formation system, and formation method. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the production process of battery cells, the formation process plays a crucial role in the quality of the battery cells, and how to improve the efficiency of the formation process is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a battery formation apparatus, formation system, and formation method, aimed at improving the efficiency of the formation process.

[0005] The first aspect of this application discloses a battery formation apparatus, including a reservoir cup, which includes a receiving cavity and an inlet and an outlet communicating with the receiving cavity. The inlet is used to communicate with the interior of a battery cell, and the outlet is used to communicate with an external negative pressure device, so that gas in the battery cell can flow out of the reservoir cup through the inlet, the receiving cavity, and the outlet, wherein the gas carries electrolyte; and a coating, which is disposed on the cavity wall of the receiving cavity, wherein one of the coating and the electrolyte is oleophilic and the other is oleophobic, so as to reduce the electrolyte adhering to the cavity wall of the receiving cavity when the gas carries the electrolyte in the battery cell into the receiving cavity.

[0006] The cavity wall of the receiving cavity in this embodiment is coated with a coating. One of the coating and the electrolyte is oleophilic, and the other is oleophobic. The electrolyte has poor wetting properties to the coating, making it difficult for the electrolyte to adhere to the cavity wall. Consequently, electrolyte salts in the electrolyte are less likely to crystallize on the cavity wall, reducing the possibility of electrolyte crystallization clogging the battery formation device. This ensures the normal progress of the battery formation process and improves battery formation efficiency. Furthermore, because the gas generated by the battery cell during formation is promptly extracted, the gas does not remain inside the battery cell, effectively improving the safety performance of the battery cell. It also avoids lithium plating and black spots, improving the cycle life and charge / discharge rate performance of the battery cell.

[0007] In some embodiments, the cavity wall includes a side wall and a bottom wall, which together form a receiving cavity; the inlet is located on the side wall, and / or the inlet is located on the bottom wall. The location of the inlet can be flexibly selected according to production needs.

[0008] In some embodiments, the inlet includes a first inlet disposed on the bottom wall;

[0009] The battery formation apparatus also includes a first inlet pipe extending into the receiving cavity through a first inlet port. The first inlet pipe includes a first end and a second end that are opposite to each other. The first end is used to connect to the battery cell, and the second end protrudes from the bottom wall to facilitate the return of electrolyte to the battery cell.

[0010] In some embodiments, the second end is located at the geometric center of the containment cavity in the radial direction. The electrolyte near the geometric center of the containment cavity is generally in a liquid state and does not easily crystallize. In the embodiments of this application, the second end is in contact with the liquid electrolyte, which is more conducive to the liquid electrolyte in the containment cavity being guided into the battery cell through the first inlet pipe.

[0011] In some embodiments, the first inlet pipe includes a first switch for controlling the opening and closing of the containment cavity and the battery cell, facilitating the control of electrolyte reflux and electrolyte extraction from the gas.

[0012] In some embodiments, the inlet includes a second inlet disposed on the sidewall;

[0013] The battery formation apparatus further includes a second inlet pipe, which has a third end and a fourth end opposite to each other. The third end is connected to the first inlet pipe, and the fourth end is connected to the receiving cavity through a second inlet port. In this embodiment, when the electrolyte level in the receiving cavity is high, it can flow out through the fourth end of the second inlet pipe and then out through the third end to the first inlet pipe.

[0014] In some embodiments, the fourth end extends into the receiving cavity through the second inlet and protrudes from the sidewall. The electrolyte near the radial geometric center of the receiving cavity is generally in a liquid state, and the fourth end being positioned near the radial geometric center of the receiving cavity facilitates the diversion of the liquid electrolyte and its return to the battery cell.

[0015] In some embodiments, the reservoir cup further includes a cleaning port disposed on the bottom wall; the battery formation device further includes a cleaning tube communicating with the cleaning port, the cleaning tube including a fifth end and a sixth end opposite to each other, the fifth end communicating with the cleaning port, the sixth end being used to connect to a negative pressure device, and the cleaning tube further including a second switch for controlling the on / off connection between the receiving cavity and the negative pressure device. In the embodiments of this application, under the negative pressure drainage of the negative pressure device, the cleaning tube can extract the non-volatile solvents and electrolyte salts in the electrolyte located on the cavity wall from the receiving cavity, reducing the risk of electrolyte crystallization on the bottom wall.

[0016] In some embodiments, the wetting properties of the electrolyte on the coating are less than the wetting properties of the electrolyte on the cavity wall of the reservoir. The electrolyte is less likely to adhere to the surface of the coating, thereby reducing the risk of electrolyte crystallization on the coating surface and, to some extent, preventing crystallized electrolyte from clogging the battery formation device.

[0017] In some embodiments, the coating is made of metal, natural resin, synthetic resin, ceramic, or drying oil. The coating surface formed by the above materials is smooth, which can reduce the amount of electrolyte residue and friction on the cavity wall, accelerate the electrolyte reflux speed, and prevent non-volatile solvents and electrolyte salts in the electrolyte from clogging the reservoir cup; and the electrolyte does not easily wet the coating surface, further reducing the risk of electrolyte adhering to the cavity wall surface.

[0018] A second aspect of this application provides a formation system for the formation of battery cells. The formation system includes: a battery formation apparatus according to the first aspect of this application, with an inlet for communication with the battery cell; and a negative pressure device connected to the outlet of the battery formation apparatus. The formation system provided according to the embodiments of this application can, to a certain extent, avoid the possibility of crystallized electrolyte clogging the formation system, ensuring the normal progress of the formation process, guaranteeing the safety of battery cell production, and improving formation efficiency.

[0019] A third aspect of this application provides a formation method, comprising: providing a battery formation apparatus, the battery formation apparatus including an inlet and an outlet, the inlet being connected to a battery cell; and providing a negative pressure device, the negative pressure device being connected to the outlet, the negative pressure device driving gas containing electrolyte in the battery cell to flow out of the battery formation apparatus through the inlet and outlet. The formation system provided according to the embodiments of this application can, to a certain extent, avoid the possibility of crystallized electrolyte clogging the formation system, ensuring the normal progress of the formation process, ensuring the safety of battery cell production, and improving formation efficiency.

[0020] According to the battery formation apparatus of this application embodiment, the electrolyte has poor wetting performance on the coating, and the electrolyte does not easily adhere to the cavity wall. Consequently, the electrolyte salts in the electrolyte do not easily crystallize on the cavity wall, reducing the possibility of electrolyte crystallization clogging the battery formation apparatus. This ensures the normal operation of the battery formation process and improves the battery formation efficiency. Attached Figure Description

[0021] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the structure of a battery formation apparatus provided in some embodiments of this application;

[0023] Figure 2 yes Figure 1 A schematic cross-sectional view of the battery formation device shown along line AA;

[0024] Figure 3 yes Figure 1 Another cross-sectional view of the battery formation device shown along line AA;

[0025] Figure 4 This is a schematic diagram of the structure of a battery formation apparatus provided in other embodiments of this application;

[0026] Figure 5 These are schematic diagrams of the formation system provided in some embodiments of this application;

[0027] Figure 6 This is a schematic flowchart of a formation method provided in some embodiments of this application;

[0028] The accompanying drawings are not necessarily drawn to scale.

[0029] The following are the labeling elements in the figure:

[0030] X, axial direction; Y, radial direction; B, cell; J, electrolyte;

[0031] 1. Battery formation device;

[0032] 11. Liquid reservoir; 111. Receiving cavity; 1111. Side wall; 1112. Bottom wall;

[0033] 112. Inlet; 1121. First inlet; 1122. Second inlet; 113. Outlet; 114. Cleaning port;

[0034] 12. Coating;

[0035] 13. First inlet pipe; 131. First end; 132. Second end; 133. First switch;

[0036] 14. Second inlet pipe; 141. Third end; 142. Fourth end;

[0037] 15. Cleaning pipe; 151. Fifth terminal; 152. Sixth terminal; 153. Second switch;

[0038] 2. Negative pressure device. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0041] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0043] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0044] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0045] In this application, "multiple" means two or more (including two).

[0046] In this application, the battery cell may include lithium-ion secondary battery cells, lithium-ion primary battery cells, and other lithium-ion battery cells, but this application is not limited in this respect. The battery cell may be cylindrical, flat, cuboid, or other shapes, and this application is not limited in this respect either. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, cuboid / square battery cells, and pouch battery cells, and this application is not limited in this respect either.

[0047] A single battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of lithium ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer, the positive active material layer being coated on the surface of the positive current collector. The positive current collector includes a positive current collection portion and a positive electrode tab protruding from the current collection portion. The positive current collection portion is coated with the positive active material layer, while at least a portion of the positive electrode tab is not coated with the positive active material layer. The material of the positive current collector can be aluminum, and the positive active material layer includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector. The negative current collector includes a negative current collection portion and a negative electrode tab protruding from the negative current collection portion. The negative current collection portion is coated with the negative active material layer, and at least a portion of the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, which can be carbon or silicon, etc. To ensure that a large current can pass through without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited to these.

[0048] The battery cell may also include a housing assembly with an internal cavity that provides a sealed space for the electrode assembly and electrolyte. The housing assembly includes a shell and an end cap assembly. The shell is a hollow structure with an opening on one side, and the end cap assembly closes to the opening of the shell to form a sealed connection, thereby forming a cavity for accommodating the electrode assembly and electrolyte.

[0049] Electrolytes typically consist of an electrolyte salt and a solvent. The electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0050] The solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0051] In the production of battery cells, a battery formation process is required. This process uses chemical and electrochemical reactions to activate the active materials on the electrode components, transforming them into positive and negative electrodes with electrochemical properties. During formation, the solvent in the electrolyte decomposes, and the decomposed solvent molecules react chemically with electrons and lithium ions, forming a passivation film, namely the solid electrolyte interphase (SEI) film, on the surface of the negative electrode active material layer. This process also generates a certain amount of gas. This gas increases the internal pressure of the battery cell, causing it to expand and increasing its volume. Furthermore, the gas obstructs the lithium-ion transport path, preventing lithium ions from migrating smoothly to the negative electrode, leading to lithium plating and black spots. Because lithium plating reduces the number of lithium ions migrating to the negative electrode, the charging capacity of the battery cell decreases; the discharge capacity decreases as fewer lithium ions escape from the negative electrode back to the positive electrode; and the cycle performance of the battery cell also deteriorates.

[0052] Therefore, a formation system is typically used to extract the gas and remove it in a timely manner to avoid adverse effects from the gas inside the battery cell.

[0053] The inventors discovered that during the gas extraction process, some electrolyte is carried into the storage cup of the formation system. Volatile solvents in the electrolyte, such as linear esters, evaporate, while non-volatile solvents, such as cyclic esters, remain in the storage cup. Electrolyte salts are retained in the storage cup along with the non-volatile solvents. Since the electrolyte salts may be in a supersaturated state, the electrolyte salts remaining in the storage cup may adhere to the cavity wall of the storage cup along with the non-volatile solvents, potentially causing crystallization. These crystals may clog the pipelines of the formation system, preventing the formation process from proceeding normally and reducing formation efficiency. Examples of linear esters include dimethyl carbonate (DMC); examples of cyclic esters include ethylene carbonate (EC).

[0054] Blockage in the pipeline will cause the gas generated during the battery formation process to remain inside the battery cell, which may lead to the expansion of the battery cell or even the explosion of the battery cell, posing a safety risk; and it will also reduce the electrochemical performance of the battery cell.

[0055] When the electrolyte is carried out by the gas, the electrolyte content inside the battery cell decreases, failing to meet usage requirements. Therefore, the electrolyte extracted by the gas needs to be returned to the battery cell. After formation is complete, the electrolyte in the reservoir cavity flows back into the battery cell through pipelines.

[0056] In view of this, the inventors improved the structure of the formation system by incorporating a battery formation device. This device includes a reservoir and a coating. The reservoir includes a cavity and an inlet and an outlet connected to it. The inlet communicates with the interior of the battery cell, and the outlet communicates with an external negative pressure device, allowing gas from the battery cell to flow out of the reservoir through the inlet, cavity, and outlet, carrying electrolyte. The coating is applied to the cavity wall, and one of the coating and the electrolyte is oleophilic while the other is oleophobic, reducing electrolyte adhesion to the cavity wall. This battery formation device reduces the wetting properties of the electrolyte on the cavity wall, preventing electrolyte from easily adhering to the cavity wall and thus preventing electrolyte crystallization. This reduces the possibility of electrolyte crystallization clogging the battery formation device, ensuring the normal operation of the formation process and improving formation efficiency.

[0057] To better understand this application, the following will be combined with... Figures 1 to 6 The embodiments of this application are described below.

[0058] Figure 1 This is a schematic diagram of the structure of a battery formation apparatus provided in some embodiments of this application. Figure 2 yes Figure 1 The diagram shows a cross-sectional view of the battery formation device along line AA.

[0059] like Figure 1 and Figure 2 As shown, the battery formation apparatus 1 provided in this embodiment includes a reservoir 11 and a coating 12. The reservoir 11 includes a receiving cavity 111 and an inlet 112 and an outlet 113 communicating with the receiving cavity 111. The inlet 112 is used to communicate with the interior of the battery cell, and the outlet 113 is used to communicate with an external negative pressure device, so that the gas in the battery cell can flow out of the reservoir 11 through the inlet 112, the receiving cavity 111 and the outlet 113, wherein the gas carries electrolyte. The coating 12 is disposed on the cavity wall of the receiving cavity 111, and one of the coating 12 and the electrolyte is oleophilic and the other is oleophobic, so as to reduce the electrolyte adhering to the cavity wall of the receiving cavity 111 when the gas carries the electrolyte in the battery cell into the receiving cavity 111.

[0060] The liquid storage cup 11 is used to store the electrolyte carried during the gas extraction process, which can prevent the loss of electrolyte to a certain extent.

[0061] The coating 12 is disposed on the cavity wall of the receiving cavity 111. The coating 12 is in direct contact with the electrolyte. The wetting effect between the electrolyte and the coating 12 is poor, and the electrolyte does not easily adhere to the coating 12.

[0062] The battery formation apparatus 1 of this application embodiment includes a storage cup 11. When the negative pressure device extracts the gas inside the battery cell, the gas carries the electrolyte from the battery cell out. When the gas flows through the receiving cavity 111 of the storage cup 11, the electrolyte is temporarily stored in the storage cup 11. The volatile solvent in the electrolyte evaporates, while the non-volatile solvent and electrolyte salt remain in the storage cup 11. A coating 12 is provided on the cavity wall of the receiving cavity 111. One of the coating 12 and the electrolyte is oleophilic, and the other is oleophobic. The electrolyte has poor wetting performance on the coating 12, and the electrolyte does not easily adhere to the cavity wall. Consequently, the electrolyte salt in the electrolyte does not easily crystallize on the cavity wall, reducing the possibility of electrolyte crystallization clogging the battery formation apparatus 1. This ensures the normal progress of the battery formation process and improves the battery formation efficiency. Furthermore, because the gas generated during the formation process of the battery cell is promptly removed, the gas will not remain inside the battery cell, thereby effectively improving the safety performance of the battery cell. It can also prevent lithium plating and black spots, and improve the cycle life and charge / discharge rate performance of the battery cell.

[0063] In this embodiment, oleophilicity refers to a substance whose molecular ends or branches contain lipophilic groups, such as hydrocarbon groups; oleophobicity refers to a substance whose molecular ends or branches do not contain hydrophilic groups. The wetting performance between lipophilic and oleophobic substances is poor. Wetting performance can be measured by testing the contact angle. For example, the wetting performance of the electrolyte on the coating 12 can be reflected by testing the contact angle of the electrolyte on the surface of the coating 12. A smaller contact angle indicates better wetting performance of the electrolyte on the coating 12; a larger contact angle indicates poorer wetting performance of the electrolyte on the coating 12. The contact angle can be tested using conventional techniques in the art.

[0064] like Figure 2 As shown, one of the coating 12 and the electrolyte J is oleophilic and the other is oleophobic. This can be because coating 12 is oleophilic and electrolyte J is oleophobic; alternatively, coating 12 can be oleophobic and electrolyte J can be oleophilic. For example, due to the evaporation of volatile solvents in electrolyte J, the containment cavity 111 mainly retains non-volatile solvents, which are oleophilic substances. In this case, coating 12 can be provided with an oleophobic substance.

[0065] As some examples of coating 12, the material of coating 12 can be selected from metal, natural resin, synthetic resin, ceramic or drying oil. The surface of coating 12 formed by the above materials is smooth, which can reduce the residual amount of electrolyte J on the cavity wall of receiving cavity 111 and reduce friction, accelerate the return speed of electrolyte J, and prevent non-volatile solvents and electrolyte salts in electrolyte J from clogging the reservoir cup 11; and the electrolyte J is not easily wetted by the surface of coating 12, further reducing the risk of electrolyte adhering to the cavity wall surface.

[0066] For example, the metal is selected from at least one of chromium, copper, cadmium, tin, and zinc. For instance, the material of coating 12 can be a high-entropy alloy, which refers to an alloy formed from five or more metals in equal or approximately equal amounts. The natural resin is selected from rosin resin or lacquer, etc.; wherein, lacquer is a gelatinous liquid harvested from lacquer trees, containing urushiol, gum, etc. The synthetic resin is selected from epoxy resin or polyurethane resin, etc. The drying oil is a mixture containing triglycerides and free fatty acids. For example, the drying oil is selected from tung oil or linseed oil, etc. The ceramic is selected from Ti4O7 or CrO2, etc.

[0067] In this embodiment, the wetting performance of the electrolyte on the coating 12 is less than that on the cavity wall of the reservoir 11. The electrolyte is less likely to adhere to the surface of the coating 12, thereby reducing the risk of electrolyte crystallization on the surface of the coating 12 and, to a certain extent, preventing the crystallized electrolyte from clogging the battery formation device 1.

[0068] like Figure 2 As shown in the embodiment of this application, the cavity wall of the receiving cavity 111 may include a side wall 1111 and a bottom wall 1112, which together form the receiving cavity 111. Of course, the cavity wall may also include a top wall, which is disposed opposite to the bottom wall 1112.

[0069] In some embodiments, the size of the receiving cavity 111 in the radial Y direction gradually decreases from the top wall to the bottom wall 1112. The gradual change in size of the receiving cavity 111 in the radial Y direction facilitates the flow of electrolyte from the top wall to the bottom wall 1112 under gravity and back into the interior of the battery cell.

[0070] It should be noted here that... Figure 2 The X direction shown represents the axial direction of the receiving cavity 111, the Y direction represents the radial direction of the receiving cavity 111, and the X direction is perpendicular to the Y direction.

[0071] After the negative pressure device removes the gas, the electrolyte in the storage cup 11 needs to be returned to the battery cell. This is typically done via a pipe, such as the first inlet pipe. The first inlet pipe 13 can be located on the side wall 1111, the bottom wall 1112, or both. Correspondingly, the inlet 112 can be located on the side wall 1111, the bottom wall 1112, or both. The location of the inlet 112 can be flexibly selected according to production needs.

[0072] Please continue reading. Figure 2 In some embodiments, the inlet 112 includes a first inlet 1121 disposed on the bottom wall 1112; the battery formation apparatus 1 further includes a first inlet pipe 13, which includes a first end 131 and a second end 132 opposite to each other. The first end 131 is used to connect to a battery cell, and the second end 132 is connected to the first inlet 1121. When it is necessary to extract gas, the gas in the battery cell carrying electrolyte flows through the first end 131 and the second end 132 into the receiving cavity 111; when it is necessary to return electrolyte, the electrolyte in the receiving cavity 111 flows back into the battery cell through the second end 132 and the first end 131.

[0073] Figure 3 yes Figure 1 Another cross-sectional view of the battery formation apparatus shown along line AA. (See diagram below.) Figure 3 As shown, in some embodiments, the first inlet pipe 13 extends into the receiving cavity 111 through the first inlet port 1121, and the second end 132 protrudes from the bottom wall 1112. The height of the second end 132 protruding from the bottom wall 1112 can be set according to production requirements. If the electrolyte accumulates on the bottom wall of the receiving cavity, there is still a possibility of crystallization on the bottom wall. The electrolyte located above the bottom wall is in a liquid state, and the crystallized electrolyte may block the first inlet pipe. In the embodiments of this application, the second end 132 of the first inlet pipe 13 is extended into the receiving cavity 111. The second end 132 is higher than the bottom wall 1112, so the crystallized electrolyte is less likely to block the second end 132. The second end 132 is in contact with the liquid electrolyte, which can guide the electrolyte in the receiving cavity 111 to the inside of the battery cell through the first inlet pipe 13.

[0074] If a small amount of electrolyte crystallizes on the sidewall of the cavity, there is a risk of clogging the first inlet pipe if it is located close to the sidewall. The electrolyte near the geometric center in the radial direction of the cavity is generally in a liquid state and is not prone to crystallization. In some examples, the second end 132 of the first inlet pipe 13 is located at the geometric center in the radial direction Y of the cavity 111. The second end 132 is in contact with the liquid electrolyte, which is more conducive to the liquid electrolyte in the cavity 111 being guided into the battery cell through the first inlet pipe 13.

[0075] To facilitate the control of electrolyte reflux and electrolyte extraction from gas, a first switch 133 may be optionally provided on the first inlet pipe 13. The first switch 133 is used to control the on / off state of the receiving cavity 111 and the battery cell.

[0076] Please continue reading. Figure 3 To further reduce the risk of electrolyte crystallization on the bottom wall, in some embodiments, the reservoir 11 also includes a cleaning port 114 disposed on the bottom wall 1112. Accordingly, the battery formation apparatus 1 also includes a cleaning tube 15 communicating with the cleaning port 114. The cleaning tube 15 includes a fifth end 151 and a sixth end 152 opposite to each other. The fifth end 151 communicates with the cleaning port 114, and the sixth end 152 is used to connect to a negative pressure device. The cleaning tube 15 also includes a second switch 153, which is used to control the on / off connection between the receiving cavity 111 and the negative pressure device.

[0077] Under the negative pressure of the negative pressure device, the cleaning tube 15 can extract the non-volatile solvents and electrolyte salts in the electrolyte located on the cavity wall from the containment cavity 111 and store them in the residual liquid recovery system, which can reduce the risk of electrolyte crystallization on the bottom wall 1112.

[0078] The specific cleaning process is as follows:

[0079] When the first switch 133 is turned on, the negative pressure system extracts the gas from the battery cell, and the gas carrying the electrolyte is extracted into the receiving cavity 111; the electrolyte located in the upper part of the bottom wall 1112 flows back into the battery cell.

[0080] When the first switch 133 is closed and the second switch 153 is opened, the electrolyte (non-volatile solvent and electrolyte salt) on the bottom wall 1112 of the receiving cavity 111 is extracted from the receiving cavity 111 under the action of the negative pressure system.

[0081] When the electrolyte level in the containment cavity is high, the contact area between the electrolyte and the cavity wall increases, increasing the risk of electrolyte crystallization on the cavity wall.

[0082] Figure 4 These are schematic diagrams illustrating the structure of a battery formation apparatus provided in other embodiments of this application. For example... Figure 4 As shown, in some embodiments, the battery formation apparatus 1 further includes a second inlet pipe 14. The inlet includes a second inlet port 1122 disposed on the side wall 1111. The second inlet pipe 14 includes a third end 141 and a fourth end 142 opposite to each other. The third end 141 communicates with the first inlet pipe 13, and the fourth end 142 communicates with the receiving cavity through the second inlet port 1122. When the electrolyte level in the receiving cavity is high, it can flow out through the fourth end 142 of the second inlet pipe 14 and then flow out through the third end 141 to the first inlet pipe 13.

[0083] Optionally, the third end 141 can be located between the first switch 133 and the second end 132, so that the first switch 133 can control the return flow of the electrolyte. Of course, the third end 141 can also be located between the first switch 133 and the first end 131. When the electrolyte level in the receiving cavity 111 is too high, it can flow directly out of the second inlet pipe 14 through the fourth end 142 and the third end 141 and return to the battery cell without being interfered with by the first switch 133. This can, to a certain extent, avoid the situation where the electrolyte cannot return normally due to a malfunction of the first switch 133.

[0084] If the electrolyte crystallizes on the sidewall of the containment cavity, it may clog the fourth end. Optionally, the fourth end 142 extends into the containment cavity 111 through the second inlet 1122 and protrudes beyond the height of the sidewall 1111. The height of the fourth end 142 protruding beyond the sidewall 1111 can be flexibly set according to production requirements. The electrolyte near the geometric center in the radial Y direction of the containment cavity is generally in a liquid state. The placement of the fourth end 142 near the geometric center in the radial Y direction of the containment cavity facilitates the diversion of the liquid electrolyte and its return to the battery cell.

[0085] Figure 5 These are schematic diagrams of the formation system provided in some embodiments of this application. For example... Figure 5 As shown, the formation system provided in this application embodiment is used for the formation of battery cell B. The formation system includes a battery formation device 1, the inlet of which is connected to the battery cell B; and a negative pressure device 2, which is connected to the outlet of the battery formation device 1.

[0086] According to the formation system provided in the embodiments of this application, the electrolyte is less likely to adhere to the battery formation device 1, which can reduce the risk of electrolyte crystallization in the battery formation device 1, thereby avoiding the possibility of crystallized electrolyte clogging the formation system to a certain extent, ensuring the normal progress of the formation process, ensuring the safety of battery cell B production, and improving formation efficiency.

[0087] Based on the formation system provided in the above embodiments, this application also provides a formation method.

[0088] Figure 6 This is a schematic flowchart of the formation method provided in some embodiments of this application, such as... Figure 6 As shown, the method includes:

[0089] S100 provides a battery formation device, which includes an inlet and an outlet, the inlet being used to connect with a single battery cell;

[0090] S200 provides a negative pressure device, which is connected to the outlet. The negative pressure device drives the gas containing electrolyte in the battery cell to flow out of the battery formation device through the inlet and outlet.

[0091] According to the formation method provided in the embodiments of this application, the electrolyte is less likely to adhere to the battery formation device, which can reduce the risk of electrolyte crystallization in the battery formation device, thereby avoiding the possibility of crystallized electrolyte clogging the formation system to a certain extent, ensuring the normal progress of the formation process, ensuring the safety of battery cell production, and improving formation efficiency.

[0092] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery formation apparatus, characterized in that, include: A liquid storage cup (11) includes a receiving cavity (111) and an inlet (112) and an outlet (113) communicating with the receiving cavity (111). The inlet (112) is used to communicate with the interior of a battery cell, and the outlet (113) is used to communicate with an external negative pressure device, so that gas in the battery cell can flow out of the liquid storage cup (11) through the inlet (112), the receiving cavity (111), and the outlet (113); and A coating (12) is provided on the cavity wall of the receiving cavity (111), and one of the coating (12) and the electrolyte is oleophilic and the other is oleophobic, so as to reduce the electrolyte adhering to the cavity wall of the receiving cavity (111) when the gas carries the electrolyte in the battery cell into the receiving cavity (111). The cavity wall of the receiving cavity (111) includes a side wall (1111) and a bottom wall (1112), which together form the receiving cavity (111). The inlet (112) is provided on the side wall (1111), and the inlet (112) is also provided on the bottom wall (1112). The battery formation apparatus further includes a first inlet pipe (13), which includes a first end (131) and a second end (132) opposite to each other. The first end (131) is used to connect to the battery cell, and the second end (132) is connected to the inlet (112) provided on the bottom wall (1112). The second end (132) protrudes from the bottom wall (1112). The battery formation device further includes a second inlet pipe (14), which includes a third end (141) and a fourth end (142) opposite to each other. The third end (141) is connected to the first inlet pipe (13), and the fourth end (142) is connected to the receiving cavity (111) through the inlet (112) provided on the side wall (1111).

2. The battery formation apparatus according to claim 1, characterized in that, The inlet (112) includes a first inlet (1121) disposed on the bottom wall (1112). The first inlet pipe (13) extends into the receiving cavity (111) through the first inlet port (1121).

3. The battery formation apparatus according to claim 1, characterized in that, The second end (132) is located at the geometric center in the radial (Y) direction of the receiving cavity (111).

4. The battery formation apparatus according to claim 1, characterized in that, The first inlet pipe (13) includes a first switch (133), which is used to control the opening and closing of the receiving cavity (111) and the battery cell.

5. The battery formation apparatus according to claim 1, characterized in that, The inlet (112) also includes a second inlet (1122) disposed on the side wall (1111). The fourth end (142) is connected to the receiving cavity (111) through the second inlet (1122).

6. The battery formation apparatus according to claim 5, characterized in that, The fourth end (142) extends into the receiving cavity (111) through the second inlet (1122) and protrudes from the side wall (1111).

7. The battery formation apparatus according to claim 1, characterized in that, The liquid storage cup (11) also includes a cleaning port (114) disposed on the bottom wall (1112). The battery formation device further includes a cleaning pipe (15) connected to the cleaning port (114). The cleaning pipe (15) includes a fifth end (151) and a sixth end (152) opposite to each other. The fifth end (151) is connected to the cleaning port (114), and the sixth end (152) is used to connect to the negative pressure device. The cleaning pipe (15) also includes a second switch (153) for controlling the connection and disconnection between the receiving cavity (111) and the negative pressure device.

8. The battery formation apparatus according to any one of claims 1 to 7, characterized in that, The wetting performance of the electrolyte on the coating (12) is less than that of the electrolyte on the cavity wall of the reservoir (11).

9. The battery formation apparatus according to any one of claims 1 to 7, characterized in that, The coating (12) is made of metal, natural resin, synthetic resin, ceramic or drying oil.

10. A formation system for the formation of a battery cell (B), characterized in that, include: The battery formation apparatus (1) as described in any one of claims 1 to 9, wherein the inlet (112) of the battery formation apparatus (1) is configured to communicate with the battery cell (B); and The negative pressure device (2) is connected to the outlet (113) of the battery formation device (1).

11. A formation method, characterized in that, include: A battery formation apparatus (1) is provided as described in any one of claims 1 to 9, the battery formation apparatus (1) comprising an inlet (112) and an outlet (113), the inlet (112) being used to communicate with a battery cell (B); A negative pressure device (2) is provided, which is connected to the outlet (113). The negative pressure device (2) drives the gas containing electrolyte (J) in the battery cell (B) to flow out of the battery formation device (1) through the inlet (112) and the outlet (113).

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