Battery cell liquid injection device and battery cell liquid injection method

Abstract

The embodiment of the invention provides a battery cell liquid injection device and a battery cell liquid injection method. Relates to the technical field of batteries. The battery cell liquid injection device comprises a butt joint piece, a liquid injection piece and an air exhaust piece, the butt joint piece is provided with a first butt joint end and a second butt joint end. The first butt joint end is used for being communicated with a liquid storage cavity of the battery cell. The liquid injection part is connected to the second butt joint end of the butt joint part. The air exhaust piece is connected to the second butt joint end of the butt joint piece. And when the battery cell liquid injection device is in a vacuumizing state, the air exhaust piece is communicated with the liquid storage cavity of the battery cell through the butt joint piece. And when the battery cell liquid injection device is in a liquid injection state, the liquid injection piece is communicated with the liquid storage cavity of the battery cell through the butt joint piece. And when the battery cell liquid injection device is in a non-liquid injection state and a non-vacuumizing state, the first butt joint end is closed. And the air exhaust piece and the liquid injection piece are both disconnected with the liquid storage cavity of the battery cell. According to the battery cell liquid injection device and the battery cell liquid injection method provided by the embodiment of the invention, the infiltration uniformity of the electrolyte in the battery cell is improved, and the use performance of the battery cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular to a battery cell injection device and a battery cell injection method. Background Art

[0002] The chemical reaction inside the battery requires the transfer of ions between the electrode and the electrolyte, so the selection and concentration of the electrolyte are crucial to the battery performance. Filling is the process of contacting the battery cell with the electrolyte, allowing the electrolyte to fully penetrate the electrode structure and form the electrolyte medium required for the chemical reaction.

[0003] In the related art, the electrolyte infiltration methods of the battery cell include vacuum cavity pressurized infiltration, breathing infiltration, and step infiltration. Vacuum cavity pressurized infiltration means: after the air is exhausted from the gap between the positive and negative electrodes, the pre-mixed electrolyte is added to the battery cell. Breathing infiltration means: vacuuming the inside of the battery shell; then maintaining the pressure of the battery shell, then injecting the electrolyte, and then depressurizing the battery shell; then continue to pressurize, depressurize, vacuumize, and depressurize the battery shell and let it stand in a cycle.

[0004] However, existing battery cells have the problem of poor electrolyte wetting effect. Summary of the invention

[0005] The embodiments of the present application provide a battery cell liquid injection device and a battery cell liquid injection method, which improve the wetting uniformity of the electrolyte in the battery cell and improve the performance of the battery cell.

[0006] In a first aspect, an embodiment of the present application provides a battery cell liquid injection device, which includes a docking piece, a liquid injection piece, and an air extraction piece.

[0007] The docking piece has a first docking end and a second docking end. The first docking end is used to communicate with the liquid storage cavity of the battery core.

[0008] The liquid injection piece is connected to the second docking end of the docking piece.

[0009] The suction member is connected to the second butt end of the butt joint member.

[0010] When the battery core liquid injection device is in a vacuum state, the vacuum pump is connected to the liquid storage cavity of the battery core through the docking member, and the liquid injection member is disconnected from the liquid storage cavity of the battery core.

[0011] When the battery cell liquid injection device is in the liquid injection state, the liquid injection piece is connected to the liquid storage cavity of the battery cell through the docking piece, and the air extraction piece is disconnected from the liquid storage cavity of the battery cell.

[0012] When the battery cell liquid injection device is in a non-liquid injection and non-vacuum pumping state, the vacuuming component is disconnected from the liquid storage cavity of the battery cell; the liquid injection component is disconnected from the liquid storage cavity of the battery cell.

[0013] In some embodiments of the present application, the docking piece includes a first docking piece and a second docking piece.

[0014] The first docking piece is connected with the liquid injection piece and the air extraction piece.

[0015] The second docking piece is used to connect with the battery core, and a normally closed stop valve is arranged in the second docking piece.

[0016] When the battery cell injection device is in a vacuum state, the normally closed stop valve is in an open state, and the first docking piece is connected to the second docking piece. The vacuum pump is connected to the liquid storage cavity of the battery cell through the first docking piece and the second docking piece. The injection piece is disconnected from the liquid storage cavity of the battery cell.

[0017] When the battery cell injection device is in the injection state, the normally closed stop valve is in the open state, and the first docking piece is connected to the second docking piece. The injection piece is connected to the liquid storage cavity of the battery cell through the first docking piece and the second docking piece. The air extraction piece is disconnected from the liquid storage cavity of the battery cell.

[0018] When the battery cell injection device is in a non-injection and non-vacuuming state, the normally closed stop valve is in a disconnected state, the first docking piece and the second docking piece are disconnected, the vacuum piece is disconnected from the liquid storage cavity of the battery cell, and the injection piece is disconnected from the liquid storage cavity of the battery cell.

[0019] In some embodiments of the present application, the docking member includes a valve body and a valve core. A first channel, a second channel, and a third channel are constructed in the cavity of the valve body. The first end of the first channel is connected to the liquid injection member. The first end of the second channel is connected to the air extraction member. The first end of the third channel is used to communicate with the liquid storage cavity of the battery cell.

[0020] The valve core is movably arranged in the cavity, and the valve core switches among a first position, a neutral position and a second position.

[0021] When the valve core is in the first position, the second end of the first channel is connected to the second end of the third channel, and the second end of the second channel is disconnected from the second end of the third channel, forming the injection state of the battery cell injection device.

[0022] When the valve core is in the second position, the second end of the second channel is connected to the second end of the third channel, and the second end of the first channel is disconnected from the second end of the third channel, forming a vacuum state of the battery cell injection device.

[0023] When the valve core is in a neutral position, the second end of the second channel and the second end of the third channel are disconnected, and the second end of the first channel and the second end of the third channel are disconnected, forming a non-injection and non-vacuuming state of the battery cell injection device.

[0024] In some embodiments of the present application, the battery cell injection device further includes an injection needle, a first end of the injection needle is connected to the liquid storage chamber of the battery cell, and a second end of the injection needle is connected to the first docking end.

[0025] In some embodiments of the present application, the battery cell injection device further includes a base having a supporting platform, and the supporting platform is used to place the battery cell.

[0026] In some embodiments of the present application, the base further includes a clamping section, the clamping section is located on the supporting platform, the clamping end of the clamping section forms a clamping area, and the clamping area is used to clamp and fix the battery cell.

[0027] In some embodiments of the present application, the battery cell injection device also includes an injection pipeline, a first end of the injection pipeline is connected to the injection piece, a second end of the injection pipeline is connected to the docking piece, and an injection valve is arranged on the injection pipeline.

[0028] In some embodiments of the present application, the battery cell liquid filling device also includes an exhaust pipeline, a first end of the exhaust pipeline is connected to the exhaust piece, a second end of the exhaust pipeline is connected to the docking piece, and an exhaust valve is arranged on the exhaust pipeline.

[0029] In a second aspect, an embodiment of the present application provides a cell injection method, which is applied to a cell injection device. The cell injection method includes:

[0030] The liquid storage chamber of the battery cell is evacuated by using a vacuum element;

[0031] When the vacuuming is completed, the vacuuming member and the liquid storage chamber of the battery cell are disconnected;

[0032] Using a liquid injection piece to inject liquid into the liquid storage cavity of the battery cell;

[0033] When the liquid injection is completed, the liquid injection piece and the liquid storage chamber of the battery cell are disconnected.

[0034] In some embodiments of the present application, a vacuum pump is used to vacuumize the liquid storage chamber of the battery cell; when the vacuum pumping of the battery cell is completed, the vacuum pump and the liquid storage chamber of the battery cell are disconnected; and further comprising:

[0035] When the vacuum degree of the liquid storage chamber of the battery cell is less than the preset vacuum degree, the vacuum pump and the liquid storage chamber of the battery cell are disconnected; and the first docking end of the docking member of the battery cell liquid injection device is closed.

[0036] The preset vacuum degree is P, and P satisfies: P≤300Pa.

[0037] In some embodiments of the present application, when the vacuum degree of the liquid storage chamber of the battery cell is less than the preset vacuum degree, the vacuum pump and the liquid storage chamber of the battery cell are disconnected; the first docking end of the docking member of the battery cell injection device is closed; and further comprising:

[0038] Within a preset time period, when the preset vacuum degree P satisfies: P≤300Pa, the vacuum component and the liquid storage chamber of the battery cell are disconnected; and the first docking end of the docking component is closed.

[0039] In some embodiments of the present application, when the vacuum degree of the liquid storage chamber of the battery cell is less than the preset vacuum degree, the vacuum pump and the liquid storage chamber of the battery cell are disconnected; the first docking end of the docking member of the battery cell injection device is closed; and further comprising:

[0040] Within a preset time period, when the change value of the vacuum degree of the battery cell is less than or equal to 1 Pa / s, the liquid injection port of the battery cell is closed.

[0041] In some embodiments of the present application, the preset vacuum degree P satisfies: 30Pa≤P≤70Pa.

[0042] In some embodiments of the present application, the preset time period is T, and T satisfies: T≥1Os.

[0043] The battery cell injection device and battery cell injection method provided in the embodiment of the present application are characterized in that the vacuuming and injection processes of the battery cell are carried out in steps, which is conducive to the balance of the production line rhythm and greatly improves the efficiency of the battery cell vacuuming, electrolyte injection, and electrolyte infiltration processes. At the same time, the battery cell injection method provided in the embodiment of the present application, after the vacuuming process is completed, closes the first docking end to achieve the closure of the battery cell's liquid storage cavity, and after the electrolyte injection process is completed, closes the first docking end to achieve the closure of the battery cell's liquid storage cavity, ensuring that after each process is completed, the battery cell is isolated from the external environment to prevent external air or impurities from entering the battery cell's liquid storage cavity and hindering the subsequent electrolyte infiltration process. Compared with the prior art, the battery cell injection device and battery cell injection method provided in the embodiment of the present application reduce the resistance of the electrolyte when it infiltrates in the battery cell's liquid storage cavity, improve the consistency of the electrolyte infiltration, avoid problems such as black spots and lithium precipitation during battery cell formation, and improve the performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0045] Figure 1 Schematic diagram of the structure of the battery cell injection device provided in the embodiment of the present application Figure 1 ;

[0046] Figure 2 Schematic diagram of the structure of the battery cell injection device provided in the embodiment of the present application Figure 2 ;

[0047] Figure 3 A schematic diagram of the structure of a base and a battery cell from a first perspective provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of the structure of the base and the battery cell from a second perspective provided in an embodiment of the present application;

[0049] Figure 5A schematic diagram of the structure of the base and the battery cell from a third perspective provided in an embodiment of the present application;

[0050] Figure 6 A schematic diagram of a battery cell injection method provided in an embodiment of the present application.

[0051] Description of reference numerals:

[0052] 100: docking piece; 110: first docking piece; 120: second docking piece;

[0053] 200: liquid injection part; 210: liquid injection pipeline;

[0054] 300: exhaust component; 310: exhaust pipeline;

[0055] 400: base; 410: clamping section;

[0056] 500: injection needle;

[0057] 600: Battery cell. DETAILED DESCRIPTION

[0058] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0059] The cell in the battery is the core part of the battery, responsible for storing and releasing electrical energy. The cell includes positive electrode, negative electrode, electrolyte, and separator. The positive electrode material is the main part of the battery that stores lithium ions or other ions. The negative electrode material is another part of the battery that stores lithium ions or other ions. The electrolyte is the medium for ion conduction in the battery, ensuring the ion transmission between the positive and negative electrodes. The separator is a porous membrane placed between the positive and negative electrodes to prevent the electrodes from directly contacting each other and causing a short circuit, while allowing ions to pass through. In addition, the current collector is a conductive material used to collect and conduct current, connecting the positive and negative electrodes respectively. Conductive agents are added to the electrode materials to improve conductivity. Binders are used to bond the electrode materials to the current collector.

[0060] Taking lithium-ion batteries as an example, the working process of the battery is as follows: Charging process: The external power supply applies voltage, lithium ions are released from the positive electrode, migrate to the negative electrode through the electrolyte, and are embedded in the negative electrode material. Discharging process: Lithium ions are released from the negative electrode, migrate to the positive electrode through the electrolyte, and are embedded in the positive electrode material, generating current for use by the external circuit.

[0061] The infiltration of electrolyte inside the battery cell is crucial to the performance and life of the battery. Good infiltration ensures that the electrolyte can fully contact the surface of the electrode material, thereby maximizing the active area of ​​the electrode. This helps to improve the capacity and efficiency of the battery.

[0062] The infiltration and diffusion mechanism of the electrolyte inside the battery cell is mainly determined by three parts: the electrolyte flow pressure, the capillary force generated by the material properties, and the air resistance hidden in the material gaps. The electrolyte flow pressure is consistent in all battery cells because it is basically in a static state after the injection is completed; and the capillary force generated by the material properties is determined based on the previous process and is unique; so for the injection and infiltration process, the universal improvement solution is to solve the air resistance hidden in the gaps of the electrode material, and a large number of studies have found that air resistance will directly cause an infiltration dead zone in the later stage of infiltration, resulting in black spots and lithium precipitation on the electrode interface during subsequent formation.

[0063] In the related art, there are mainly the following ways to infiltrate the electrolyte inside the battery cell: 1. Place the normal pressure battery cell in a high-pressure cavity for infiltration and exhaust. 2. Step-by-step negative pressure infiltration inside the battery cell: let the battery cell after liquid injection stand for a certain period of time at a preset temperature; at the preset temperature, evacuate the battery cell multiple times, and let it stand for a certain period of time after each evacuation. During multiple evacuations, the vacuum pressure inside the battery cell changes from high to low in a step-by-step manner, and the infiltrated battery cell is sealed; 3. Breathing negative pressure infiltration inside the battery cell: evacuate the inside of the battery shell; maintain pressure; inject electrolyte; release pressure; the following pressurization, pressure relief, vacuumization, and pressure relief are one cycle, and the cycle is allowed to stand: fill with nitrogen at a pressure of 0.020 to 0.035 MPa and pressurize for 60 to 80 seconds, release pressure, evacuate to a vacuum degree of -65KPa to -90KPa, release pressure; fill with nitrogen and maintain for 30 to 80 seconds; release pressure, and the liquid injection is completed.

[0064] However, traditional infiltration methods such as vacuum chamber pressurized infiltration, breathing infiltration, and step infiltration all have disadvantages such as slow infiltration speed, long process time, complex process, and expensive equipment. In particular, the battery cell is subjected to negative pressure again after liquid injection. After liquid injection, the battery cell is in a gas-liquid mixed state. Although it has an improving effect on battery infiltration, it is affected by the gas-liquid mixed phase. The negative pressure will bring out the electrolyte and there is liquid-sealed air that cannot escape, and the consistency of infiltration cannot be guaranteed.

[0065] In view of this, an embodiment of the present application provides a battery cell injection device and a battery cell injection method. The battery cell injection device includes a docking piece, a liquid injection piece and an air extraction piece. The docking piece has a first docking end and a second docking end. The first docking end is used to communicate with the liquid storage chamber of the battery cell. The liquid injection piece is connected to the second docking end of the docking piece. The air extraction piece is connected to the second docking end of the docking piece.

[0066] When the battery cell injection device is in a vacuum state, the docking piece is in a docking state, and the first docking end is connected to the second docking end. The vacuum pump is connected to the liquid storage cavity of the battery cell through the docking piece. The injection piece is disconnected from the liquid storage cavity of the battery cell.

[0067] When the battery cell injection device is in the injection state, the docking piece is in the docking state, the first docking end is connected to the second docking end, the injection piece is connected to the liquid storage cavity of the battery cell through the docking piece, and the air extraction piece is disconnected from the liquid storage cavity of the battery cell.

[0068] When the battery cell liquid injection device is in a non-liquid injection and non-vacuum extraction state, the vacuum component is disconnected from the liquid storage cavity of the battery cell; the liquid injection component is disconnected from the liquid storage cavity of the battery cell.

[0069] The battery cell injection device and battery cell injection method provided in the embodiment of the present application are characterized in that the vacuuming and injection processes of the battery cell are carried out in steps, which is conducive to the balance of the production line rhythm and greatly improves the efficiency of the battery cell vacuuming, electrolyte injection, and electrolyte infiltration processes. At the same time, the battery cell injection method provided in the embodiment of the present application, after the vacuuming process is completed, closes the first docking end to achieve the closure of the battery cell's liquid storage cavity, and after the electrolyte injection process is completed, closes the first docking end to achieve the closure of the battery cell's liquid storage cavity, ensuring that after each process is completed, the battery cell is isolated from the external environment to prevent external air or impurities from entering the battery cell's liquid storage cavity and hindering the subsequent electrolyte infiltration process. Compared with the related art, the battery cell injection device and battery cell injection method provided in the embodiment of the present application reduce the resistance of the electrolyte when it is infiltrated in the battery cell's liquid storage cavity, improve the consistency of the electrolyte infiltration, avoid the problems of black spots and lithium precipitation during the battery cell formation, and improve the performance of the battery cell.

[0070] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0071] First, refer to Figure 1 and Figure 2 An embodiment of the present application provides a battery cell liquid injection device, which includes a docking member 100, a liquid injection member 200 and an air extraction member 300.

[0072] The docking member 100 has a first docking end and a second docking end. The first docking end is used to communicate with the liquid storage cavity of the battery cell 600.

[0073] The suction member 300 is connected to the second docking end of the docking member 100. The suction member 300 is used to evacuate the liquid storage chamber of the battery cell 600.

[0074] The liquid injection member 200 is connected to the second docking end of the docking member 100. The liquid injection member 200 is used to inject electrolyte into the liquid storage cavity of the battery cell 600.

[0075] When the battery cell injection device is in a vacuum state, the docking piece 100 is in a docking state, and the first docking end is connected to the second docking end. The vacuum member 300 is connected to the liquid storage chamber of the battery cell 600 through the docking piece 100. The injection piece 200 is disconnected from the liquid storage chamber of the battery cell 600. When the vacuum member 300 vacuums the liquid storage chamber of the battery cell 600, the first docking end and the second docking end are connected, so that the vacuum member 300 can be directly connected to the liquid storage chamber of the battery cell 600, thereby efficiently extracting air or other gases in the liquid storage chamber. This helps to form a low-pressure environment in the liquid storage chamber, preparing for the subsequent injection process.

[0076] When the battery cell injection device is in the injection state, the docking piece 100 is in the docking state, and the first docking end is connected to the second docking end. The injection piece 200 is connected to the liquid storage cavity of the battery cell 600 through the docking piece 100. The vacuum piece 300 is disconnected from the liquid storage cavity of the battery cell 600. In this way, when the injection piece 200 injects electrolyte into the liquid storage cavity of the battery cell 600, the first docking end is connected to the second docking end to ensure that the electrolyte can be accurately delivered to the liquid storage cavity of the battery cell 600. This precise control helps to improve the consistency and quality of battery production and reduce battery performance problems caused by improper injection.

[0077] When the battery cell injection device is in a non-injection and non-vacuuming state, the first docking end is closed. The air extraction member 300 is disconnected from the liquid storage chamber of the battery cell 600; the injection member 200 is disconnected from the liquid storage chamber of the battery cell 600. In this way, when the battery cell injection device is in a non-injection and non-vacuuming state, the liquid storage chamber of the battery cell 600 is in a closed state by closing the first docking end. The liquid storage chamber of the battery cell 600 is in a closed state, which means that the liquid storage chamber of the battery cell 600 is not connected to the outside atmosphere. When the liquid storage chamber of the battery cell 600 is in a closed state, the liquid storage chamber of the battery cell 600 is isolated from the outside air environment, which can prevent the outside air from entering the battery storage chamber again, and prevent the gas in the battery cell 600 from hindering the infiltration process of the electrolyte, thereby improving the infiltration uniformity of the electrolyte inside the battery cell 600. In addition, this design helps to prevent liquid leakage and external gas from entering the liquid storage chamber, ensuring the stability and safety of the liquid storage chamber of the battery cell 600.

[0078] As a feasible implementation method, refer to Figures 3 to 5 The battery cell injection device further includes a base 400 having a support platform for placing the battery cell 600. The support platform provides a stable placement position for the battery cell 600 to prevent unstable operation caused by vibration or movement during the injection or vacuuming process. This helps to ensure the accuracy and consistency of the injection.

[0079] As a feasible implementation, the base 400 further includes a clamping section 410, which is located on the support platform. The clamping end of the clamping section 410 forms a clamping area, which is used to clamp and fix the battery cell 600 to ensure that the battery cell 600 remains stable during the injection process. This helps to improve the accuracy of injection and avoid uneven injection or errors caused by the movement of the battery cell 600. By clamping the battery cell 600, the risk of accidental falling or movement is reduced, especially when handling flammable, explosive or corrosive electrolytes, which significantly improves operational safety.

[0080] As a feasible implementation manner, the battery cell liquid filling device also includes an exhaust pipeline 310, the first end of the exhaust pipeline 310 is connected to the exhaust member 300, the second end of the exhaust pipeline 310 is connected to the docking member 100, and an exhaust valve is provided on the exhaust pipeline 310.

[0081] Exemplarily, the air extraction member 300 may be a vacuum pump. Thus, when the battery cell injection device is in the injection state, the battery cell 600 liquid storage chamber is in a vacuum environment, which can effectively reduce the formation of bubbles in the electrolyte, ensure that the electrolyte can fully infiltrate the electrode material, and improve the performance and consistency of the battery.

[0082] By providing an exhaust valve on the exhaust pipeline 310 , the exhaust valve can accurately control the opening and closing of the exhaust member 300 , thereby accurately controlling the pressure change inside the battery cell 600 .

[0083] As an achievable implementation, the battery cell injection device further includes an injection pipeline 210, a first end of the injection pipeline 210 is connected to the injection member 200, a second end of the injection pipeline 210 is connected to the docking member 100, and an injection valve is provided on the injection pipeline 210. By providing the injection pipeline 210 and the injection valve on the injection pipeline 210, the injection valve can accurately control the opening and closing of the injection member 200, thereby accurately controlling the flow rate and injection time of the electrolyte. This precise control helps to ensure that the injection amount of each battery cell 600 is consistent, thereby improving the consistency and quality of the product.

[0084] Exemplarily, the injection component 200 includes an injection tank and an injection pump. The liquid outlet of the injection tank is connected to the liquid inlet of the pump body of the injection pump, and the liquid outlet of the pump body of the injection pump is connected to the docking component 100 through the injection valve. The injection tank provides a stable electrolyte storage and supply source to ensure a continuous and stable supply of electrolyte during the injection process, avoiding injection interruptions caused by unstable liquid supply. The injection pump can accurately control the flow and pressure of the electrolyte to ensure the accuracy and consistency of each injection. The injection valve remains closed in the non-injection state to prevent backflow and contamination of the electrolyte, ensuring the cleanliness and safety of the injection tank. The injection pump can quickly transport electrolyte to the battery cell 600, improve the injection speed and efficiency, and meet the needs of large-scale production.

[0085] The cell filling device also includes a stirring member, the stirring end of which is located in the filling chamber of the filling tank. The stirring member can effectively destroy and reduce bubbles in the electrolyte through continuous mechanical agitation. The stirring action causes the bubbles to rise to the liquid surface and escape, thereby reducing the bubble content in the electrolyte. By maintaining the fluidity of the liquid, the stirring member can prevent bubbles from gathering in a certain area, thereby reducing the formation and growth of bubbles. The liquid flow and turbulence generated by the stirring helps to bring the bubbles to the surface of the liquid, making it easier for them to escape into the atmosphere.

[0086] The stirring element, through its rotation or vibration action, can evenly mix the various components in the electrolyte, preventing the components from separating or settling. This ensures that the composition of the electrolyte is consistent every time the electrolyte is filled.

[0087] The stirring element can also help evenly distribute the temperature in the electrolyte to prevent local overheating or overcooling, which is especially important for certain temperature-sensitive electrolyte components. Through continuous stirring, the components in the electrolyte are always in a dynamic equilibrium state, ensuring that the chemical and physical properties of the electrolyte remain consistent during the injection process.

[0088] Exemplarily, the stirring member comprises a stirring rod.

[0089] As a realizable implementation manner, the docking component 100 includes a first docking component 110 and a second docking component 120 .

[0090] The first docking member 11v is connected to the liquid injection member 200 and the air extraction member 300.

[0091] The second docking member 120 is used to connect with the battery cell 600 , and a normally closed stop valve is disposed in the second docking member 120 .

[0092] When the battery cell injection device is in a vacuum state, the normally closed stop valve is in an open state, and the first docking piece 110 is connected to the second docking piece 120. The air extraction piece 300 is connected to the liquid storage cavity of the battery cell 600 through the first docking piece 110 and the second docking piece 120. The liquid injection piece 200 is disconnected from the liquid storage cavity of the battery cell 600 to prevent liquid from entering the air extraction system.

[0093] When the battery cell injection device is in the injection state, the normally closed stop valve is in the open state, and the first docking piece 110 is connected to the second docking piece 120. The injection piece 200 is connected to the liquid storage cavity of the battery cell 600 through the first docking piece 110 and the second docking piece 120. The air extraction piece 300 is disconnected from the liquid storage cavity of the battery cell 600.

[0094] When the battery cell injection device is in a non-injection and non-vacuuming state, the normally closed stop valve is in a disconnected state, and the first docking member 110 and the second docking member 120 are disconnected. The first docking end is closed. The air extraction member 300 is disconnected from the liquid storage chamber of the battery cell 600; the liquid injection member 200 is disconnected from the liquid storage chamber of the battery cell 600, and the air extraction member 300 and the liquid injection member 200 are both disconnected from the liquid storage chamber to ensure the sealing and safety of the liquid storage chamber.

[0095] A normally closed globe valve is a valve whose default state is closed and will only open when an external force (such as mechanical force, pneumatic, hydraulic or electric actuation) is applied. This design ensures that the valve remains closed when there is no external operation, thereby preventing the accidental flow of fluid or gas.

[0096] In the non-injection and non-vacuuming state, the normally closed stop valve remains closed to form an effective seal, reducing the risk of leakage and ensuring the integrity and safety of the battery cell filling device.

[0097] Through simple external control (such as manual, pneumatic or electric drive), the normally closed stop valve can be quickly opened or closed, which simplifies the operation process and improves production efficiency.

[0098] By setting a normally closed stop valve in the second docking member 120, the normally closed stop valve is automatically closed when not in the liquid injection and non-vacuuming state, thereby ensuring the sealing of the liquid storage chamber of the battery cell 600, preventing the entry of external air or impurities, and thus avoiding the obstruction of the electrolyte infiltration process by external air or impurities. By controlling the closing of the normally closed stop valve, the liquid injection and vacuuming functions can be quickly switched, which simplifies the liquid injection and vacuuming functions and improves work efficiency. At the same time, when the battery cell liquid injection device is in the liquid injection or vacuuming state, only one of the liquid injection part 200 or the air extraction part 300 is connected to the liquid storage chamber of the battery cell 600, avoiding cross contamination between the liquid injection part 200 and the air extraction part 300, and improving the cleanliness of the battery cell liquid injection device.

[0099] Exemplarily, the first docking member 110 may be a docking joint, and the second docking member 120 may be a docking joint.

[0100] As an achievable implementation, the docking member 100 includes a valve body and a valve core. A first channel, a second channel, and a third channel are configured in the cavity of the valve body. The first end of the first channel is connected to the liquid injection member 200. The first end of the second channel is connected to the air extraction member 300. The first end of the third channel is used to communicate with the liquid storage cavity of the battery cell 600.

[0101] The valve core is movably arranged in the cavity, and the valve core switches between the first position, the neutral position, and the second position. By switching the valve core in different positions, the conversion between the liquid injection, vacuum pumping, and non-liquid injection and non-vacuum pumping states can be quickly realized, which simplifies the operation process of the battery cell liquid injection device and improves the work efficiency.

[0102] When the valve core is in the first position, the second end of the first channel is connected to the second end of the third channel, and the second end of the second channel is disconnected from the second end of the third channel, forming the injection state of the battery cell injection device.

[0103] The second end of the first channel is connected to the second end of the third channel, allowing the injection member 200 to inject the electrolyte into the liquid storage cavity of the battery cell 600 through the first channel. The second end of the second channel is disconnected from the second end of the third channel to ensure that the air extraction member 300 is isolated from the liquid storage cavity to avoid interfering with the injection process.

[0104] When the valve core is in the second position, the second end of the second channel is connected to the second end of the third channel, and the second end of the first channel is disconnected from the second end of the third channel, forming a vacuum state of the battery cell injection device.

[0105] The second end of the second channel is connected to the second end of the third channel, so that the gas extraction member 300 is connected to the liquid storage cavity through the second channel, thereby extracting the gas in the liquid storage cavity. The second end of the first channel is disconnected from the second end of the third channel to ensure that the liquid injection member 200 is isolated from the liquid storage cavity and prevent the electrolyte from entering the liquid storage cavity of the battery cell 600.

[0106] During the injection and vacuuming state, it is ensured that only one function is connected to the liquid storage chamber, thus avoiding cross contamination between the two and improving the purity and reliability of the operation.

[0107] When the valve core is in the neutral position, the second end of the second channel is disconnected from the second end of the third channel, and the second end of the first channel is disconnected from the second end of the third channel, forming a non-liquid injection and non-vacuum pumping state of the battery cell liquid injection device. In this state, the liquid storage chamber is disconnected from the liquid injection member 200 and the air extraction member 300, ensuring the sealing and safety of the liquid storage chamber and preventing external air or impurities from entering.

[0108] Exemplarily, the docking member 100 may be a three-way, three-position valve. The three-way, three-position valve has three channels and three working positions, and can achieve flexible flow direction management in a fluid control system. Since multiple functions can be achieved in one valve body, the three-way, three-position valve can reduce the number of valves required in the battery cell injection device, thereby simplifying the design of the battery cell injection device and reducing complexity and cost.

[0109] The battery cell 600 has a liquid injection port. The liquid injection port of the battery cell 600 is used to connect with the liquid injection part 200. In this way, the liquid injection part 200 injects electrolyte into the liquid storage cavity of the battery cell 600 through the liquid injection port. At the same time, the liquid injection port of the battery cell 600 is also used to connect with testing equipment, such as pressure testing equipment and leakage detectors. In other words, in addition to the liquid injection part 200 injecting electrolyte into the liquid storage cavity and the vacuum part 300 evacuating the liquid storage cavity, the liquid injection port of the battery cell 600 also needs to be connected with other components. In order to achieve the versatility of the battery cell 600 connected via the liquid injection port, the battery cell liquid injection device provided in the embodiment of the present application also includes a liquid injection needle 500.

[0110] As a feasible implementation, the battery cell injection device further includes an injection needle 500, a first end of the injection needle 500 is connected to the liquid storage cavity of the battery cell 600, and a second end of the injection needle 500 is connected to the first docking end.

[0111] The injection needle 500 can be used as a standardized interface, so that the injection port of the battery cell 600 can be flexibly connected to a variety of equipment (such as testing equipment). This versatility reduces the need for different interface adapters and simplifies the operation process.

[0112] The injection needle 500 is generally designed to fit tightly with the injection port to provide good sealing, which helps prevent electrolyte leakage and external air from entering, thereby improving the safety and reliability of the battery cell 600.

[0113] By using the injection needle 500, operators can more easily switch between different devices, reducing the complexity of connection and disconnection. This not only improves operating efficiency, but also reduces the difficulty of maintenance. Since the injection needle 500 can be used as a replaceable interface component, the direct wear on the injection port of the battery cell 600 body is reduced, thereby extending the service life of the battery cell 600.

[0114] Second, refer to Figure 6 The present application embodiment provides a battery cell injection method, which is applied to a battery cell injection device. The battery cell injection method includes:

[0115] S100: Use a vacuum pump to evacuate the liquid storage chamber of the battery cell;

[0116] S200: When the vacuuming is completed, the vacuuming member and the liquid storage chamber of the battery cell are disconnected;

[0117] S300: injecting liquid into the liquid storage cavity of the battery cell using a liquid injection component;

[0118] S400: When the liquid injection is completed, the liquid injection component and the liquid storage chamber of the battery cell are disconnected.

[0119] For example, by evacuating the liquid storage cavity of the battery cell 600 before liquid injection, air and moisture in the liquid storage cavity can be effectively removed, thereby improving the injection efficiency of the electrolyte and ensuring that the electrolyte can fully fill the liquid storage cavity.

[0120] After the vacuuming is completed, ensure that the vacuuming member 300 is disconnected from the liquid storage cavity of the battery cell 600, effectively preventing external air or impurities from entering the liquid storage cavity, thereby improving the sealing of the liquid storage cavity of the battery cell 600.

[0121] Since the liquid storage cavity of the battery cell 600 is in a vacuum environment during the process of the liquid injection part 200 injecting liquid into the liquid storage cavity of the battery cell 600, the electrolyte can enter the interior of the battery cell 600 more quickly, shortening the injection time, improving production efficiency, and improving the uniform distribution of the electrolyte in the liquid storage cavity of the battery cell 600.

[0122] After the vacuuming is completed, ensure that the liquid injection piece 200 is disconnected from the liquid storage cavity of the battery cell 600, which can effectively prevent external air or impurities from entering the liquid storage cavity, while avoiding electrolyte leakage and ensuring the cleanliness of the liquid storage cavity of the battery cell 600.

[0123] Finally, the battery cell 600 is left to stand at a preset temperature, and the electrolyte infiltrates into the liquid storage cavity of the battery cell 600 by capillary action, ensuring that the electrolyte fully infiltrates the surface of the electrode material, thereby improving the infiltration uniformity of the electrolyte in the battery cell 600.

[0124] The above-mentioned battery cell liquid injection device and battery cell liquid injection method can efficiently and conveniently complete the processes of vacuuming, electrolyte injection, electrolyte infiltration, etc. of the battery cell 600. After each process is completed, the first docking end is closed to achieve the closure of the liquid storage cavity of the battery cell 600, thereby ensuring that the actions of each process can isolate the external environment and ensure process consistency. At the same time, the vacuuming-liquid injection process of the above-mentioned battery cell liquid injection device is carried out in steps, which is beneficial to the balance of the production line rhythm and greatly improves the efficiency of the vacuuming, electrolyte injection, and electrolyte infiltration processes of the battery cell 600. Compared with the prior art, the resistance of the electrolyte when infiltrating in the liquid storage cavity of the battery cell 600 is reduced, the infiltration consistency of the electrolyte is improved, and the problems of black spots and lithium precipitation during the formation of the battery cell 600 are avoided.

[0125] As a feasible implementation, the vacuum pump 300 is used to vacuumize the liquid storage chamber of the battery cell 600; when the vacuum pumping of the battery cell 600 is completed, the vacuum pump 300 and the liquid storage chamber of the battery cell 600 are disconnected; and further comprising:

[0126] When the vacuum degree of the liquid storage chamber of the battery cell 600 is less than the preset vacuum degree, the vacuum element 300 and the liquid storage chamber of the battery cell 600 are disconnected: the first docking end of the docking element 100 of the battery cell filling device is closed.

[0127] The preset vacuum degree is P, and P satisfies: P≤≤300Pa.

[0128] Exemplarily, by setting a preset vacuum degree (P≤300Pa), when the vacuum degree inside the battery cell 600 is less than the preset vacuum degree, the first docking end is closed. In this way, before the battery cell filling device injects electrolyte into the battery cell 600, the liquid storage chamber of the battery cell 600 is isolated from the outside world to prevent air from entering the battery cell 600. It also prevents air from entering the battery cell 600 again after the vacuum is evacuated and before the electrolyte is injected into the battery cell 600, which affects the subsequent injection of electrolyte and the infiltration consistency of the electrolyte.

[0129] As an achievable implementation, when the vacuum degree of the liquid storage chamber of the battery cell 600 is less than the preset vacuum degree, the vacuum pump 300 and the liquid storage chamber of the battery cell 600 are disconnected; and the first docking end of the docking member 100 of the battery cell injection device is closed. Also included:

[0130] Within a preset time period, when the preset vacuum degree P satisfies: P≤300Pa, the vacuum member 300 and the liquid storage chamber of the battery cell 600 are disconnected; and the first docking end and the second docking end of the docking member 100 are disconnected.

[0131] By monitoring the vacuum level of the liquid storage chamber of the battery cell 600 within a preset time period, it is ensured that the liquid storage chamber of the battery cell 600 reaches and maintains an ideal vacuum level. This precise control helps optimize the injection conditions of the electrolyte.

[0132] The vacuum degree is kept stable within a preset time, ensuring that each battery cell 600 is injected with liquid under the same vacuum condition, thereby improving the consistency and repeatability of the injection process.

[0133] As an achievable implementation, when the vacuum degree of the liquid storage chamber of the battery cell 600 is less than the preset vacuum degree, the vacuum pump 300 and the liquid storage chamber of the battery cell 600 are disconnected; the first docking end of the docking member 100 of the battery cell liquid injection device is closed; and further comprising:

[0134] When the change value of the vacuum degree of the battery cell 600 is less than or equal to 1 Pa / s within the preset time period, the liquid injection port of the battery cell 600 is closed.

[0135] By monitoring the changes in the vacuum level in the liquid storage chamber of the battery cell 600, it is ensured that the operation is carried out when the vacuum level reaches and maintains a stable state. This helps to provide consistent liquid filling conditions and reduce the formation of bubbles.

[0136] When the vacuum degree of the battery cell 600 changes to less than or equal to 1Pa / s, it is considered that the change in vacuum degree tends to be stable. When the vacuum degree changes to be stable, the injection port is closed to ensure that the electrolyte is injected into the battery cell 600 under stable conditions, thereby improving the uniformity and consistency of the injection. By monitoring the rate of change of vacuum degree, it is possible to more accurately determine when to close the injection port, avoiding process instability caused by closing too early or too late.

[0137] The liquid injection port is closed in time after the vacuum degree changes and stabilizes, thereby reducing the operating time and energy consumption of the vacuum element 300 and reducing the equipment load.

[0138] As a feasible implementation manner, the preset vacuum degree P satisfies: 30Pa≤P≤70Pa.

[0139] In contrast, when the preset vacuum degree P is less than 30Pa, the preset vacuum degree is relatively low, and too low a vacuum degree (i.e., too high a vacuum level) may indeed have an impact on the physical structure of the battery cell 600, especially when the battery cell 600 is made of thinner materials or has a more complex structure. An extremely high vacuum may cause uneven pressure inside the material, thereby increasing the risk of stress and deformation.

[0140] In addition, maintaining a lower vacuum level requires higher energy consumption and equipment load, which may lead to increased equipment wear and maintenance costs.

[0141] Therefore, the preset vacuum degree P of the embodiment of the present application satisfies: 30Pa≤P≤70Pa. Within this vacuum degree range, the air and bubbles inside the battery cell 600 can be effectively removed, ensuring that the electrolyte can fully infiltrate the electrode material, thereby improving the performance and consistency of the battery cell 600. Moreover, the preset vacuum degree will not damage the structure of the battery cell 600, avoiding excessive stress and deformation of the internal structure of the battery cell 600.

[0142] As a feasible implementation method, the preset time period is T, and T satisfies: T≥10s.

[0143] In contrast, when the preset time period T is less than 10s, the preset time period is relatively short, and within the relatively short preset time period, the vacuum degree of the battery cell 600 may be unstable, affecting the infiltration effect of the electrolyte and the performance of the battery cell 600. A stable vacuum degree may not be achieved or maintained within a short period of time, resulting in uneven liquid injection.

[0144] Therefore, in the embodiment of the present application, the preset time period T is ≥ 10s. This helps to ensure the stability of the vacuum degree in the liquid storage chamber of the battery cell 600, helps to ensure that the bubbles inside the battery cell 600 are fully removed, and improves the infiltration effect of the electrolyte and the performance of the battery cell 600.

[0145] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0146] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A battery cell injection device, characterized in that: include: A docking piece (100), the docking piece (100) having a first docking end and a second docking end, the first docking end being used to communicate with the liquid storage cavity of the battery cell (600); A liquid injection piece (200), the liquid injection piece (200) being connected to the second docking end of the docking piece (100); An air suction member (300), the air suction member (300) being connected to the second docking end of the docking member (100); When the liquid injection device of the battery cell (600) is in a vacuum state, the vacuum member (300) is connected to the liquid storage chamber of the battery cell (600) through the docking member (100), and the liquid injection member (200) is disconnected from the liquid storage chamber of the battery cell (600); When the battery cell liquid injection device is in a liquid injection state, the liquid injection component (200) is connected to the liquid storage cavity of the battery cell (600) through the docking component (100), and the air extraction component (300) is disconnected from the liquid storage cavity of the battery cell (600); When the battery cell liquid injection device is in a non-liquid injection and non-vacuum extraction state, the vacuum element (300) is disconnected from the liquid storage chamber of the battery cell (600); and the liquid injection element (200) is disconnected from the liquid storage chamber of the battery cell (600).

2. The battery cell injection device according to claim 1, characterized in that: The docking piece (100) comprises a first docking piece (110) and a second docking piece (120); The first docking member (110) is connected to the liquid injection member (200) and the air extraction member (300); The second docking piece (120) is used to connect to the battery cell (600), and a normally closed stop valve is provided in the second docking piece (120); When the battery cell injection device is in a vacuum state, the normally closed stop valve is in an open state, the first docking piece (110) and the second docking piece (120) are in communication, the vacuum element (300) is in communication with the liquid storage chamber of the battery cell (600) through the first docking piece (110) and the second docking piece (120), and the injection element (200) is disconnected from the liquid storage chamber of the battery cell (600); When the battery cell injection device is in the injection state, the normally closed stop valve is in the open state, the first docking piece (110) and the second docking piece (120) are in communication, the injection piece (200) is in communication with the liquid storage chamber of the battery cell (600) through the first docking piece (110) and the second docking piece (120), and the air extraction piece (300) is disconnected from the liquid storage chamber of the battery cell (600); When the battery cell injection device is in a non-injection and non-vacuum extraction state, the normally closed stop valve is in a disconnected state, the first docking member (110) and the second docking member (120) are disconnected, the vacuum member (300) is disconnected from the liquid storage chamber of the battery cell (600), and the injection member (200) is disconnected from the liquid storage chamber of the battery cell (600).

3. The battery cell injection device according to claim 1, characterized in that: The docking member (100) comprises a valve body and a valve core, a first channel, a second channel and a third channel are configured in the cavity of the valve body, a first end of the first channel is connected to the liquid injection member (200), a first end of the second channel is connected to the air extraction member (300), and a first end of the third channel is used to communicate with the liquid storage cavity of the battery cell (600); The valve core is movably arranged in the cavity, and the valve core switches between a first position, a neutral position, and a second position; When the valve core is in the first position, the second end of the first channel is connected to the second end of the third channel, and the second end of the second channel is disconnected from the second end of the third channel, thereby forming a liquid injection state of the battery cell liquid injection device; When the valve core is in the second position, the second end of the second channel is connected to the second end of the third channel, and the second end of the first channel is disconnected from the second end of the third channel, thereby forming a vacuum state of the battery cell injection device; When the valve core is in a neutral position, the second end of the second channel and the second end of the third channel are disconnected, and the second end of the first channel and the second end of the third channel are disconnected, forming a non-injection and non-vacuum state of the battery cell injection device.

4. The battery cell liquid injection device according to claim 2 or 3, characterized in that: The battery cell injection device further comprises an injection needle (500), a first end of the injection needle (500) being in communication with the liquid storage cavity of the battery cell (600), and a second end of the injection needle (500) being connected to the first docking end.

5. The battery cell injection device according to claim 4, characterized in that: The battery cell liquid injection device also includes a base (400), wherein the base (400) has a support platform, and the support platform is used to place the battery cell (600).

6. The battery cell liquid injection device according to claim 5, characterized in that: The base (400) further comprises a clamping section (410), wherein the clamping section (410) is located on the supporting platform, and a clamping end of the clamping section (410) forms a clamping area, wherein the clamping area is used to clamp and fix the battery cell (600).

7. The battery cell injection device according to claim 4, characterized in that: The battery cell liquid injection device also includes a liquid injection pipeline (210), a first end of the liquid injection pipeline (210) is connected to the liquid injection piece (200), a second end of the liquid injection pipeline (210) is connected to the docking piece (100), and a liquid injection valve is provided on the liquid injection pipeline (210).

8. The battery cell injection device according to claim 4, characterized in that: The battery cell liquid injection device also includes an air extraction pipeline (310), a first end of the air extraction pipeline (310) is connected to the air extraction member (300), a second end of the air extraction pipeline (310) is connected to the docking member (100), and an air extraction valve is provided on the air extraction pipeline (310).

9. A method for injecting liquid into a battery cell, characterized in that: Applicable to the battery cell injection device according to any one of claims 1 to 8, the battery cell injection method comprising: Using a vacuum pump (300) to evacuate the liquid storage chamber of the battery cell (600); When the vacuuming is completed, the vacuuming member (300) and the liquid storage chamber of the battery cell (600) are disconnected; Using a liquid injection piece (200) to inject liquid into the liquid storage cavity of the battery core (600); When the liquid injection is completed, the liquid injection piece (200) and the liquid storage cavity of the battery cell (600) are disconnected.

10. The battery cell injection method according to claim 9, characterized in that: The vacuum pump (300) is used to vacuum the liquid storage chamber of the battery cell (600); after the vacuum pumping is completed, the vacuum pump (300) and the liquid storage chamber of the battery cell (600) are disconnected; and further comprising: When the vacuum degree of the liquid storage chamber of the battery cell (600) is less than a preset vacuum degree, the vacuum pump (300) and the liquid storage chamber of the battery cell (600) are disconnected; and the first docking end of the docking member (100) of the battery cell liquid injection device is closed; The preset vacuum degree is P, and P satisfies: P≤300Pa.

11. The battery cell injection method according to claim 10, characterized in that: When the vacuum degree of the liquid storage chamber of the battery cell (600) is less than a preset vacuum degree, the air extraction member (300) and the liquid storage chamber of the battery cell (600) are disconnected; The first docking end of the docking piece (100) of the battery cell injection device is closed; and further comprises: Within a preset time period, when the preset vacuum degree P satisfies: P<300Pa, the vacuum member (300) and the liquid storage chamber of the battery cell (600) are disconnected; and the first docking end of the docking member (100) is closed.

12. The battery cell injection method according to claim 11, characterized in that: When the vacuum degree of the liquid storage chamber of the battery cell (600) is less than a preset vacuum degree, the air extraction member (300) and the liquid storage chamber of the battery cell (600) are disconnected; The first docking end of the docking piece (100) of the battery cell injection device is closed; and further comprises: Within the preset time period, when the change value of the vacuum degree of the battery cell (600) is less than or equal to 1 Pa / s, the liquid injection port of the battery cell (600) is closed.

13. The battery cell injection method according to claim 10, characterized in that: The preset vacuum degree P satisfies: 30Pa≤P<70Pa.

14. The battery cell injection method according to claim 11, characterized in that: The preset time period is T, and T satisfies: T≥l0s.

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