Electrochemical pre-lithiation device for lithium battery

Abstract

The utility model discloses an electrochemical pre-lithiation device for a lithium battery. The electrochemical pre-lithiation device comprises a shell, the cover plate is arranged at the top end of the shell; the mounting frame is fixed on the inner side of the shell, and a lithium-plated copper sheet is fixed on the mounting frame through a clamp assembly; the pressure sensor is arranged on the inner side wall of the mounting frame so as to detect the pressing force on the lithium-plated copper sheet, and the pressure sensor is connected with a pressure gauge terminal through a wire; the gas regulation and control assembly is arranged on one side wall of the shell so as to discharge gas on the inner side of the shell; by arranging the shell, the clamp assembly, the pressure sensor and the gas regulation and control assembly, gas can be conveniently released and discharged, proper constraining force is applied to a lithium-plated copper sheet in the pre-lithium process, and an electrolyte can be put into the other shell after pre-lithium, so that cyclic utilization is realized, the waste of the electrolyte is reduced, and the production cost is reduced. The pre-lithium of the battery can be simply, conveniently and stably realized.

Description

Technical Field

[0001] The utility model specifically relates to an electrochemical pre-lithiation device for a lithium battery. Background Art

[0002] During the first charging process of a lithium-ion battery, the surface of the negative electrode reacts with the electrolyte to form a solid electrolyte membrane (SEI). Although this electrolyte membrane is beneficial to the cycle stability of the lithium-ion battery, it will consume the lithium ions of the positive electrode, and this reaction is irreversible, resulting in a decrease in the battery's initial coulombic efficiency (ICE) and a reduction in the battery's capacity. At present, in order to solve the problem of low initial coulombic efficiency of negative electrode materials, people have developed chemical reduction methods, artificial SEI membrane methods, and electrochemical pre-lithiation methods. Among them, the electrochemical pre-lithiation method is the most direct method to solve the low ICE of lithium-ion negative electrode materials.

[0003] The existing electrochemical pre-lithiation method is to place lithium metal on the side of the battery cell and place them together in the electrolytic cell. The lithium metal lead-out wire serves as the negative electrode of the original battery, and the negative electrode of the battery cell serves as the positive electrode of the original battery. A battery tester is used to discharge the negative electrode of the battery cell to the lithium metal. The lithium ions will fall off the lithium metal and embed into the surface of the negative electrode sheet. However, during the pre-lithiation process, gas will be produced, causing spots on the negative electrode interface, and a large amount of electrolyte will be wasted. The lack of restraint during the pre-lithiation process will also cause other adverse effects on the negative electrode interface. For this reason, we propose a lithium battery electrochemical pre-lithiation device. Utility Model Content

[0004] The purpose of the present invention is to provide a lithium battery electrochemical pre-lithiation device to solve the problems raised in the above background technology that gas is produced in the existing pre-lithiation process, causing spots on the negative electrode interface, wasting electrolyte, and having no restraint during the pre-lithiation process.

[0005] To achieve the above objectives, the present invention provides the following technical solutions: a lithium battery electrochemical pre-lithiation device, comprising:

[0006] case;

[0007] A cover plate is arranged on the top of the shell;

[0008] A mounting frame is fixed to the inner side of the housing, and a lithium-plated copper sheet is fixed to the mounting frame via a clamp assembly;

[0009] A pressure sensor is provided on the inner side wall of the mounting frame to detect the pressing force on the lithium-plated copper sheet, and the pressure sensor is connected to a pressure gauge terminal via a wire;

[0010] A gas regulating assembly is provided on a side wall of the shell to discharge the gas inside the shell;

[0011] The drain valve body is installed at the lower end of the inner side of the shell through the threaded portion to discharge the electrolyte downward after pre-lithiation.

[0012] It is convenient to apply appropriate pressure to the lithium-plated copper sheet during the pre-lithiation process to improve the restraint effect on it, and at the same time it is convenient to discharge the gas to reduce the mottling effect caused by the gas. In the later stage, the electrolyte is injected into the inner side of another shell by opening the drain valve body to realize the recycling of the electrolyte to reduce waste.

[0013] Preferably, a copper busbar is fixed to the upper end of one side wall of the mounting frame, and a lithium metal terminal is connected to one side of the copper busbar through a wire. A spring sheet electrically connected to the copper busbar is provided on the mounting frame, and the spring sheet is in contact with the lithium-plated copper sheet. A negative terminal is provided on the front surface of the shell, and one end of the negative terminal is provided with a connecting wire electrically connected to the upper end of the lithium-plated copper sheet.

[0014] During pre-lithiation, the lithium metal is connected to the negative electrode of the external battery tester through the copper bus and the lithium metal terminal, and the negative electrode of the battery cell is connected to the negative and positive electrodes of the external battery tester through the spring pin and the negative terminal. Discharge is carried out during pre-lithiation. At this time, the lithium on the lithium-plated copper sheet will lose electrons and become lithium ions, which will gradually be embedded in the negative electrode sheet from the side of the battery cell, thereby realizing pre-lithiation of the battery cell.

[0015] Preferably, the clamp assembly includes a guide rod, a clamping screw and a clamping plate. The guide rod is fixed to the inner side of the mounting frame. There are multiple clamping plates evenly distributed along the axial direction of the guide rod, and a sliding hole that cooperates with the guide rod is opened on the inner side of the clamping plate. A clamping space for accommodating a lithium-plated copper sheet is formed between each two clamping plates. The clamping screw is installed on a side wall of the mounting frame through a threaded portion, and one end of the clamping screw is in conflict with the clamping plate.

[0016] It is convenient to press and restrain the lithium-plated copper sheet.

[0017] Preferably, four guide rods are provided, and springs are sleeved on the outer surfaces of the guide rods corresponding to the clamping spaces.

[0018] When restraint is no longer required, the two splints are separated from each other.

[0019] Preferably, the gas regulating assembly includes a negative pressure valve and a pressure gauge, the negative pressure valve and the pressure gauge are arranged side by side on a side wall of the shell, and the negative pressure valve and the pressure gauge are both connected to the interior of the shell.

[0020] It is convenient to detect the pressure inside the shell so as to discharge the gas in time.

[0021] Preferably, a drainage hole is formed on the inner side of the drainage valve body, and the drainage hole passes through both side walls of the drainage valve body.

[0022] It is convenient to release the electrolyte into the inner side of another shell, so as to realize the recycling of the electrode liquid.

[0023] Preferably, the cross section of the drain valve body is T-shaped.

[0024] This facilitates better release of the electrode liquid to the inside of the other shell.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This patent is equipped with a shell, a clamp assembly, a pressure sensor and a gas control assembly to facilitate the release and discharge of gas, apply appropriate restraint force to the lithium-plated copper sheet during the pre-lithiation process, and can place the electrolyte into another shell after pre-lithiation to achieve recycling, reducing the waste of electrolyte. It can easily and stably achieve battery pre-lithiation, and through the precise control of the battery tester, it can increase the consistency of the pre-lithiation battery cell while improving the battery capacity and cycle life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram of the utility model;

[0028] Figure 2 This is a schematic diagram of the mounting frame structure of the utility model;

[0029] Figure 3 This is a schematic diagram of the plywood structure of the present utility model;

[0030] Figure 4 This is a schematic diagram of the spring structure of the utility model;

[0031] Figure 5 This is a schematic diagram of the structure of the liquid discharge valve body of the utility model;

[0032] Figure 6 This is a schematic diagram of the drainage hole structure of the present utility model.

[0033] In the figure: 1. Shell; 2. Negative terminal; 3. Cover; 4. Negative pressure valve; 5. Pressure gauge; 6. Mounting bracket; 7. Guide rod; 8. Compression screw; 9. Clamp; 10. Lithium-plated copper sheet; 11. Copper busbar; 12. Lithium metal terminal; 13. Pressure gauge terminal; 14. Spring; 15. Drain valve body; 16. Drain hole. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] See also Figures 1-6 The present invention provides a technical solution: a lithium battery electrochemical pre-lithiation device, comprising:

[0036] Shell 1;

[0037] The cover plate 3 is arranged on the top of the housing 1;

[0038] The mounting frame 6 is fixed to the inner side of the housing 1, and a lithium-plated copper sheet 10 is fixed to the mounting frame 6 via a clamp assembly;

[0039] A pressure sensor is provided on the inner wall of the mounting frame 6 to detect the pressing force on the lithium-plated copper sheet 10, and the pressure sensor is connected to a pressure gauge terminal 13 via a wire, so as to apply appropriate pressure to the lithium-plated copper sheet 10 during the pre-lithiation process to improve the restraint effect on it;

[0040] The gas regulating component is arranged on a side wall of the shell 1 to discharge the gas inside the shell 1, so as to facilitate the discharge of the gas and reduce the effect of the gas on the mottling;

[0041] The drain valve body 15 is installed at the lower end of the inner side of the shell 1 through the threaded portion to discharge the electrolyte downward after pre-lithiation, so as to facilitate the injection of electrolyte into the inner side of another shell 1, thereby realizing the recycling of electrolyte and reducing waste.

[0042] In this embodiment, preferably, a copper busbar 11 is fixed to the upper end of one side wall of the mounting frame 6, and a lithium metal terminal 12 is connected to one side of the copper busbar 11 through a wire. A spring piece 14 electrically connected to the copper busbar 11 is provided on the mounting frame 6, and the spring piece 14 is in contact with the lithium-plated copper sheet 10. A negative terminal 2 is provided on the front surface of the shell 1, and a connecting line electrically connected to the upper end of the lithium-plated copper sheet 10 is provided at one end of the negative terminal 2. During pre-lithiation, the lithium metal is connected to the negative electrode of the external battery tester through the copper busbar 11 and the lithium metal terminal 12, and the negative electrode of the battery cell is connected to the negative positive electrode of the external battery tester through the spring pin and the negative terminal 2. Discharge is performed during pre-lithiation. At this time, the lithium in the lithium-plated copper sheet 10 will lose electrons and become lithium ions, which are gradually embedded in the negative electrode sheet from the side of the battery cell, thereby realizing pre-lithiation of the battery cell.

[0043] In this embodiment, preferably, the clamp assembly includes a guide rod 7, a clamping screw 8 and a splint 9. The guide rod 7 is fixed to the inner side of the mounting frame 6. There are multiple splints 9 evenly distributed along the axial direction of the guide rod 7, and a sliding hole that cooperates with the guide rod 7 is opened on the inner side of the splint 9. A clamping space for accommodating the lithium-plated copper sheet 10 is formed between each two splints 9. The clamping screw 8 is installed on a side wall of the mounting frame 6 through a threaded portion, and one end of the clamping screw 8 is in conflict with the splint 9, which is convenient for clamping and restraining the lithium-plated copper sheet 10.

[0044] In this embodiment, preferably, four guide rods 7 are provided, and springs are sleeved on the outer surfaces of the guide rods 7 corresponding to the clamping spaces, so as to separate the two clamping plates 9 from each other when no constraint is required.

[0045] In this embodiment, preferably, the gas control component includes a negative pressure valve 4 and a pressure gauge 5, and the negative pressure valve 4 and the pressure gauge 5 are arranged side by side on a side wall of the shell 1, and the negative pressure valve 4 and the pressure gauge 5 are both connected to the inside of the shell 1, so as to facilitate the detection of the pressure inside the shell 1 and to discharge the gas in time.

[0046] In this embodiment, preferably, a drainage hole 16 is opened inside the drainage valve body 15, and the drainage hole 16 passes through the two side walls of the drainage valve body 15, so as to release the electrolyte into the inside of another shell 1, thereby realizing the recycling of the electrode liquid.

[0047] In this embodiment, preferably, the cross section of the drain valve body 15 is T-shaped to facilitate draining.

[0048] The working principle and use process of the present invention: When in use, the device is mainly divided into a shell 1 and a clamp assembly. The shell 1 is a multi-layer stacking design. The top layer has a cover plate 3. The side has a negative pressure valve 4 that can be connected to a vacuum pipe to achieve negative pressure control on the inside of the shell 1. The lower surface of each shell 1 has a movable drain valve body 15 for draining. The side of the shell 1 is equipped with three types of terminals for current control and pressure transmission; the clamp assembly is a retractable pressure plate structure, which is fixed to the inside of the shell 1. Lithium-plated copper sheets 10 are installed on the sides of the corresponding battery cells between the splints 9. The lower end of the lithium-plated copper sheet 10 contacts the conductive spring 14 and is then electrically connected to the lithium metal terminal 12 on the shell 1 through the copper bus 11. A probe is fixed at the corresponding negative ear position to contact the negative electrode and then conduct with the negative terminal 2 on the shell 1 respectively; during pre-lithiation, the battery cells to be pre-lithiumed are placed in the middle of the splint 9, the compression screw 8 is tightened until the specified pressure, and the lithium-plated copper sheet 10 is installed and then the liquid is injected. Finally, the negative electrode sheet is controlled by the test cabinet to discharge the lithium metal to realize the pre-lithiation of the battery cell. After the pre-lithiation is completed, the drain valve body 15 can be opened for drainage, and the electrolyte can be directly discharged into another shell 1 below to realize the recycling of the electrolyte. The utility model can realize the pre-lithiation of the battery simply and stably. Through the precise control of the battery tester, the consistency of the pre-lithium battery cell is increased while improving the battery capacity and cycle life. The recycling of the electrolyte can also reduce the pre-lithiation cost.

[0049] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lithium battery electrochemical pre-lithiation device, characterized in that: include: Housing (1); A cover plate (3) is arranged on the top of the housing (1); A mounting frame (6) is fixed to the inner side of the housing (1), and a lithium-plated copper sheet (10) is fixed to the mounting frame (6) via a clamp assembly; A pressure sensor is arranged on the inner side wall of the mounting frame (6) to detect the pressing force on the lithium-plated copper sheet (10), and the pressure sensor is connected to a pressure gauge terminal (13) via a wire; A gas regulating component is arranged on a side wall of the shell (1) to discharge the gas inside the shell (1); The drain valve body (15) is installed on the lower end of the inner side of the shell (1) through the threaded portion to discharge the electrolyte downward after pre-lithiation.

2. The lithium battery electrochemical pre-lithiation device according to claim 1, characterized in that: A copper busbar (11) is fixed to the upper end of one side wall of the mounting frame (6), and a lithium metal terminal (12) is connected to one side of the copper busbar (11) via a wire. A spring piece (14) electrically connected to the copper busbar (11) is provided on the mounting frame (6), and the spring piece (14) is in contact with the lithium-plated copper sheet (10). A negative terminal (2) is provided on the front surface of the housing (1), and a connecting wire electrically connected to the upper end of the lithium-plated copper sheet (10) is provided at one end of the negative terminal (2).

3. The lithium battery electrochemical pre-lithiation device according to claim 1, characterized in that: The clamp assembly includes a guide rod (7), a clamping screw (8) and a clamping plate (9). The guide rod (7) is fixed to the inner side of the mounting frame (6). There are multiple clamping plates (9) evenly distributed along the axial direction of the guide rod (7), and a sliding hole that matches the guide rod (7) is opened on the inner side of the clamping plate (9). A clamping space for accommodating a lithium-plated copper sheet (10) is formed between each two clamping plates (9). The clamping screw (8) is installed on a side wall of the mounting frame (6) through a threaded portion, and one end of the clamping screw (8) is in conflict with the clamping plate (9).

4. The lithium battery electrochemical pre-lithiation device according to claim 3, characterized in that: Four guide rods (7) are provided, and springs are sleeved on the outer surfaces of the guide rods (7) corresponding to the clamping spaces.

5. The lithium battery electrochemical pre-lithiation device according to claim 1, characterized in that: The gas control component comprises a negative pressure valve (4) and a pressure gauge (5), wherein the negative pressure valve (4) and the pressure gauge (5) are arranged side by side on a side wall of the housing (1), and the negative pressure valve (4) and the pressure gauge (5) are both connected to the interior of the housing (1).

6. The lithium battery electrochemical pre-lithiation device according to claim 1, characterized in that: A drainage hole (16) is provided on the inner side of the drainage valve body (15), and the drainage hole (16) passes through both side walls of the drainage valve body (15).

7. The lithium battery electrochemical pre-lithiation device according to claim 1, characterized in that: The cross section of the drain valve body (15) is in a T-shape.

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