High-pressure liquid injection control equipment and control system

Abstract

The utility model discloses high-pressure liquid injection control equipment and a high-pressure liquid injection control system. The high-pressure liquid injection control equipment comprises a vacuum and pressure relief device, a liquid supply device, a liquid injection control device and a positive pressure device, the vacuum and pressure relief device is connected with the liquid injection control device, and the vacuum and pressure relief device is used for pressure relief of the liquid injection control device during positive and negative pressure circulation liquid injection; the liquid injection control device comprises a cavity, a retainer cup and a battery cell, wherein the retainer cup and the battery cell are arranged in the cavity; the retainer cup is arranged right above the battery cell; the vacuum and pressure relief device comprises a second switch valve, a second pressure gauge and a third pressure gauge; the second switch valve is connected with the retainer cup through a pipeline; the second pressure gauge is arranged on the pipeline between the second switch valve and the retainer cup and used for monitoring the pressure of the retainer cup, and the third pressure gauge is arranged on the pipeline between the second switch valve and the cavity and used for monitoring the pressure of the cavity. According to the utility model, the internal and external pressure difference value during battery cell liquid injection control is reduced, battery cell shell deformation is avoided, and battery cell liquid leakage is prevented.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing and processing technology, and in particular to a high-pressure liquid injection control device and control system. Background Technology

[0002] Lithium-ion power batteries consist of positive and negative electrodes, electrolyte, and an aluminum casing. Common electrolyte filling equipment falls into two categories: isobaric filling and differential pressure filling. Isobaric filling is further divided into confinement-type and bell-type isobaric filling, with the bell-type currently being more prevalent in the industry. During the filling process, the electrolyte is quantitatively delivered from a storage tank to a filling cup, which then circulates the electrolyte into the battery cell using positive and negative pressure. The filling pressure for square batteries is typically 0.2–0.6 MPa, approaching a bottleneck. With increasing market demand for capacity, larger cell sizes, and larger electrolyte volumes, the overall difficulty and time of filling have increased. Simultaneously, to improve the specific energy of the cells, the positive and negative electrode materials are evolving towards smaller particles, larger specific surface areas, thicker electrodes, and higher compaction. The filling time and the degree of electrode wetting are gradually becoming bottlenecks in cell manufacturing.

[0003] Currently, industry understanding of accelerating liquid injection largely focuses on increasing pressure, typically to 1.5 MPa. However, increasing pressure is challenging, and maintaining and releasing pressure are difficult. In particular, there's no clear method for controlling pressure during high-pressure liquid injection. Most methods involve a direct connection between the gas storage tank and the cavity, and a direct connection between the sleeve cup and the cavity's pressure relief pipe, allowing them to open and close together. However, during liquid injection, the cavity's pressure relief pipe is over 12mm in diameter and unobstructed, while the sleeve cup's pressure relief pipe connects to the cell's 3mm diameter injection hole. Furthermore, the sleeve cup above the cell contains electrolyte, creating a liquid seal that hinders gas pressure release. Consequently, during the positive and negative pressure cycles of liquid injection control, the pressure in the cavity and sleeve cup becomes inconsistent. The sudden pressure change within the cavity causes instantaneous pressure inequality inside and outside the cell, leading to irreversible deformation of the cell. This can result in metal fatigue at the cell cover weld, causing cracks and potential leakage. Utility Model Content

[0004] This utility model provides a high-pressure liquid injection control device and control system. During the liquid injection control process, it reduces the pressure difference between the inside and outside of the battery cell, avoids deformation of the battery cell shell, prevents cracks from occurring at the welding position of the battery cell cover plate due to metal fatigue, and prevents liquid leakage from the battery cell.

[0005] According to one aspect of the present invention, a high-pressure liquid injection control device is provided, comprising: a vacuum and pressure relief device, a liquid supply device, a liquid injection control device, and a positive pressure device, wherein the vacuum and pressure relief device is connected to the liquid injection control device, and the vacuum and pressure relief device is used to relieve pressure of the liquid injection control device during positive and negative pressure cyclic liquid injection.

[0006] The liquid supply device is connected to the liquid injection control device, and the liquid supply device is used to provide electrolyte to the liquid injection control device. The positive pressure device is connected to the liquid injection control device, and the positive pressure device is used to provide nitrogen to the liquid injection control device.

[0007] The liquid injection control device includes: a cavity and a sleeve cup and a battery cell disposed in the cavity, wherein the sleeve cup is disposed directly above the battery cell;

[0008] The vacuum and pressure relief device includes: a second switching valve, a second pressure gauge, and a third pressure gauge, wherein the second switching valve is connected to the sleeve cup via a pipeline;

[0009] The second pressure gauge is installed on the pipeline between the second switching valve and the sleeve cup, and is used to monitor the pressure of the sleeve cup. The third pressure gauge is installed on the pipeline between the second switching valve and the cavity, and is used to monitor the pressure of the cavity.

[0010] Optionally, the positive pressure device includes: a pressure pump, an air tank, a first switching valve, and a first pressure gauge;

[0011] The pressure pump is connected to the gas storage tank, which is connected to the cavity and the sleeve cup via a gas pipeline. The gas storage tank is used to store nitrogen gas, and the pressure pump is used to deliver the nitrogen gas to the cavity and the sleeve cup via the gas pipeline.

[0012] The first pressure gauge is installed on the gas pipeline and located above the cavity; the first pressure gauge is used to monitor the pressure of the sleeve cup and the cavity.

[0013] The first switching valve is installed on the gas pipeline between the gas storage tank and the first pressure gauge, and the first switching valve is used to control the flow of nitrogen gas.

[0014] Optionally, the first switching valve includes a solenoid switching valve.

[0015] Optionally, the liquid supply device includes: a liquid pump and a liquid storage tank;

[0016] The storage tank is connected to the liquid pump, and the liquid pump is connected to the cup via a liquid pipeline. The storage tank is used to store electrolyte, and the liquid pump is used to deliver the electrolyte to the inside of the cup via the liquid pipeline.

[0017] Optionally, the vacuum and pressure relief device further includes a fourth switching valve, which is connected to the second pressure gauge and is used for normal pressure leak testing of the cavity.

[0018] Optionally, the fourth switching valve includes a solenoid switching valve.

[0019] Optionally, the vacuum and pressure relief device further includes: a communicating vessel;

[0020] The first end of the communicating vessel is connected to the second pressure gauge, the second end of the communicating vessel is connected to the second switching valve, and the third end of the communicating vessel is connected to the third pressure gauge.

[0021] Optionally, the cavity includes an upper cavity and a lower cavity, wherein the upper cavity and the lower cavity are integrally formed.

[0022] Optionally, the second switching valve includes a solenoid switching valve.

[0023] According to another aspect of the present invention, a high-pressure liquid injection control system is provided, which includes the high-pressure liquid injection control device described in any one of the preceding aspects.

[0024] The technical solution of this utility model embodiment monitors the pressure difference between the sleeve cup and the cavity using a second pressure gauge and a third pressure gauge, respectively, and controls the intermittent opening and closing of the second switching valve. When the second switching valve is closed, the sleeve cup and the cavity form a communicating vessel, achieving pressure balance. Opening the second switching valve then reduces the pressure difference between the inside and outside of the battery cell, preventing deformation of the battery cell shell and avoiding cracks at the welded position of the battery cell cover due to metal fatigue, thus preventing leakage. In summary, this utility model solves the problem of inconsistent pressure between the cavity and the sleeve cup during the positive and negative pressure cycle of the battery cell under liquid injection control. Sudden pressure changes within the cavity and instantaneous pressure inequality between the inside and outside of the battery cell cause irreversible deformation, leading to metal fatigue and cracks at the welded position of the battery cell cover, resulting in leakage.

[0025] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of a high-pressure liquid injection control device according to an embodiment of the present utility model;

[0028] Figure 2 This is a structural schematic diagram of another high-pressure liquid injection control device provided according to an embodiment of the present utility model. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] Figure 1 This is a structural schematic diagram of a high-pressure liquid injection control device according to an embodiment of the present utility model, with reference to... Figure 1 The present invention provides a high-pressure liquid injection control device, which includes: a vacuum and pressure relief device 10, a liquid supply device 20, a liquid injection control device 30, and a positive pressure device 40. The vacuum and pressure relief device 10 is connected to the liquid injection control device 30 and is used to relieve pressure of the liquid injection control device 30 during positive and negative pressure cyclic liquid injection.

[0032] The liquid supply device 20 is connected to the liquid injection control device 30. The liquid supply device 20 is used to provide electrolyte to the liquid injection control device 30. The positive pressure device 40 is connected to the liquid injection control device 30. The positive pressure device 40 is used to provide nitrogen to the liquid injection control device 30.

[0033] The liquid injection control device 30 includes: a cavity 31 and a sleeve cup 32 and a battery cell 33 disposed in the cavity 31, with the sleeve cup 32 disposed directly above the battery cell 33;

[0034] The vacuum and pressure relief device 10 includes: a second switching valve 11, a second pressure gauge 12 and a third pressure gauge 13. The second switching valve 11 is connected to the sleeve cup 32 through a pipe.

[0035] The second pressure gauge 12 is installed on the pipeline between the second switch valve 11 and the sleeve cup 32. The second pressure gauge 12 is used to monitor the pressure of the sleeve cup 32. The third pressure gauge 13 is installed on the pipeline between the second switch valve 11 and the cavity 31. The third pressure gauge 13 is used to monitor the pressure of the cavity 31.

[0036] Specifically, the operation process of the high-pressure liquid injection control equipment is as follows: the battery cell 33 is placed inside the cavity 31, the cavity 31 is closed, the sleeve cup 32 is drawn under negative pressure, and the cavity 31 is tested for leaks at normal pressure. A certain amount of electrolyte is pumped into the sleeve cup 32, the liquid delivery pipe at the top of the sleeve cup 32 is closed, the valve connecting the sleeve cup 32 and the battery cell 33 is opened, and nitrogen gas at a specified pressure is input into the cavity 31 and the sleeve cup 32 to make them reach a certain high-pressure state. The air inlet valve in the positive pressure device 40 is closed and maintained for a certain period of time. The second switch valve 11 is opened, the second pressure gauge 12 is used to monitor the sleeve cup 32, and the third pressure gauge 13 is used to monitor the pressure inside the cavity 31. When the pressure difference is >2 kPa, the second switch valve 11 is closed.

[0037] After the pressure is balanced (i.e., the readings of the second pressure gauge 12 and the third pressure gauge 13 are equal), open the second switch valve 11 and repeat until the pressure equals atmospheric pressure (the readings of the second pressure gauge 12 and the third pressure gauge 13 are equal to atmospheric pressure). Then, draw negative pressure through the vacuum pipe to bring both gauges to a certain pressure. Close the second switch valve 11 and maintain this pressure for a certain period. The depressurization process is the same as the above steps: recharge with positive pressure – depressurize – depressurize, repeating this process multiple times until the electrolyte completely enters the battery cell 33. Depressurize to atmospheric pressure, open the cover, and remove the battery cell 33.

[0038] This embodiment provides a high-pressure liquid injection control device. A pressure gauge is installed on each pressure pipeline, and an electromagnetic switching valve is set at each pipeline connection node. By monitoring the pressure difference between the sleeve cup and the cavity during the liquid injection process, the switching valve is controlled to intermittently open and close, thereby reducing the local pressure difference inside and outside the battery cell, reducing the degree of battery cell deformation, avoiding irreversible deformation of the battery cell, and preventing problems such as leakage that could damage other battery cells in the liquid injection device.

[0039] High-pressure liquid injection control equipment is not limited to lithium batteries; it can also be applied to liquid injection control in other products. Compared to existing equipment, pressure control via pressure gauges allows for pressure variation control at a lower cost, preventing irreversible cell deformation and potentially more serious leakage risks.

[0040] The technical solution of this utility model embodiment monitors the pressure difference between the sleeve cup and the cavity using a second pressure gauge and a third pressure gauge, respectively, and controls the intermittent opening and closing of the second switching valve. When the second switching valve is closed, the sleeve cup and the cavity form a communicating vessel, achieving pressure balance. Opening the second switching valve then reduces the pressure difference between the inside and outside of the battery cell, preventing deformation of the battery cell shell and avoiding cracks at the welded position of the battery cell cover due to metal fatigue, thus preventing leakage. In summary, this utility model solves the problem of inconsistent pressure between the cavity and the sleeve cup during the positive and negative pressure cycle of the battery cell under liquid injection control. Sudden pressure changes within the cavity and instantaneous pressure inequality between the inside and outside of the battery cell cause irreversible deformation, leading to metal fatigue and cracks at the welded position of the battery cell cover, resulting in leakage.

[0041] Figure 2 This is a structural schematic diagram of another high-pressure liquid injection control device according to an embodiment of the present invention, with reference to... Figure 2 Optionally, the positive pressure device 40 includes: a pressure pump 41, an air tank 42, a first switching valve 43, and a first pressure gauge 44;

[0042] The pressure pump 41 is connected to the gas storage tank 42. The gas storage tank 42 is connected to the cavity 31 and the cup 32 through a gas pipeline. The gas storage tank 42 is used to store nitrogen. The pressure pump 41 is used to deliver nitrogen to the cavity 31 and the cup 32 through the gas pipeline.

[0043] The first pressure gauge 44 is installed on the gas pipeline and located above the cavity 31. The first pressure gauge 44 is used to monitor the pressure of the sleeve cup 32 and the cavity 31.

[0044] The first switching valve 43 is installed on the gas pipeline between the gas storage tank 42 and the first pressure gauge 44. The first switching valve 43 is used to control the flow of nitrogen.

[0045] Specifically, the operation process of the high-pressure liquid injection control device is as follows: the battery cell 33 is placed inside the cavity 31, the cavity 31 is closed, the sleeve cup 32 is drawn under negative pressure, and the cavity 31 is tested for leaks under normal pressure. A certain amount of electrolyte is pumped into the sleeve cup 32, the liquid delivery pipe at the top of the sleeve cup 32 is closed, the valve connecting the sleeve cup 32 and the battery cell 33 is opened, and nitrogen gas at a specified pressure is input into the cavity 31 and the sleeve cup 32 (the first switch valve 43 is opened, and the pressure of nitrogen gas is 0.8MPa), so that both reach a certain high-pressure state. The first switch valve 43 in the positive pressure device 40 is closed and maintained for a certain period of time. The second switch valve 11 is opened, the second pressure gauge 12 is used to monitor the sleeve cup 32, and the third pressure gauge 13 is used to monitor the pressure in the cavity 31. When the pressure difference is >2Kpa, the second switch valve 11 is closed.

[0046] Optionally, the first switching valve includes a solenoid switching valve.

[0047] Continue to refer to Figure 2 Optionally, the liquid supply device 20 includes: a liquid pump 21 and a liquid storage tank 22;

[0048] The storage tank 22 is connected to the liquid pump 21, and the liquid pump 21 is connected to the cup 32 through a liquid pipeline. The storage tank 22 is used to store the electrolyte, and the liquid pump 21 is used to transport the electrolyte to the inside of the cup 32 through the liquid pipeline.

[0049] Continue to refer to Figure 2 Optionally, the vacuum and pressure relief device 10 further includes a fourth switching valve 14, which is connected to the second pressure gauge 12 and is used for normal pressure leak testing of the cavity 31.

[0050] Specifically, the cavity 31 is tested for leaks at normal pressure: a vacuum is drawn through the passage of the second pressure gauge 12 and the fourth switch valve 14.

[0051] Optionally, the fourth switching valve includes a solenoid switching valve.

[0052] Continue to refer to Figure 2 Optionally, the vacuum and pressure relief device 10 further includes: a communicating vessel 15;

[0053] The first end of the communicating vessel 15 is connected to the second pressure gauge 12, the second end of the communicating vessel 15 is connected to the second switching valve 11, and the third end of the communicating vessel 15 is connected to the third pressure gauge 13.

[0054] Optionally, the cavity includes an upper cavity and a lower cavity, which are integrally formed.

[0055] Optionally, the second switching valve includes a solenoid switching valve.

[0056] The embodiments of this utility model also provide a high-pressure liquid injection control system, which includes the high-pressure liquid injection control device provided in any embodiment of this utility model.

[0057] Since the high-pressure injection control system includes the high-pressure injection control device provided in any embodiment of this utility model, the beneficial effects of the high-pressure injection control system and the high-pressure injection control device are the same, and will not be repeated here.

[0058] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A high-pressure liquid injection control device, characterized in that, include: The device includes a vacuum and pressure relief device, a liquid supply device, a liquid injection control device, and a positive pressure device. The vacuum and pressure relief device is connected to the liquid injection control device, and the vacuum and pressure relief device is used to relieve pressure when the liquid injection control device is injecting liquid in a positive and negative pressure cycle. The liquid supply device is connected to the liquid injection control device, and the liquid supply device is used to provide electrolyte to the liquid injection control device. The positive pressure device is connected to the liquid injection control device, and the positive pressure device is used to provide nitrogen to the liquid injection control device. The liquid injection control device includes: a cavity and a sleeve cup and a battery cell disposed in the cavity, wherein the sleeve cup is disposed directly above the battery cell; The vacuum and pressure relief device includes: a second switching valve, a second pressure gauge, and a third pressure gauge, wherein the second switching valve is connected to the sleeve cup via a pipeline; The second pressure gauge is installed on the pipeline between the second switching valve and the sleeve cup, and is used to monitor the pressure of the sleeve cup. The third pressure gauge is installed on the pipeline between the second switching valve and the cavity, and is used to monitor the pressure of the cavity.

2. The device according to claim 1, characterized in that, The positive pressure device includes: a pressure pump, an air tank, a first switching valve, and a first pressure gauge; The pressure pump is connected to the gas storage tank, which is connected to the cavity and the sleeve cup via a gas pipeline. The gas storage tank is used to store nitrogen gas, and the pressure pump is used to deliver the nitrogen gas to the cavity and the sleeve cup via the gas pipeline. The first pressure gauge is installed on the gas pipeline and located above the cavity; the first pressure gauge is used to monitor the pressure of the sleeve cup and the cavity. The first switching valve is installed on the gas pipeline between the gas storage tank and the first pressure gauge, and the first switching valve is used to control the flow of nitrogen gas.

3. The device according to claim 2, characterized in that, The first switching valve includes a solenoid switching valve.

4. The device according to claim 1, characterized in that, The liquid supply device includes: a liquid pump and a liquid storage tank; The storage tank is connected to the liquid pump, and the liquid pump is connected to the cup via a liquid pipeline. The storage tank is used to store electrolyte, and the liquid pump is used to deliver the electrolyte to the inside of the cup via the liquid pipeline.

5. The device according to claim 1, characterized in that, The vacuum and pressure relief device further includes a fourth switching valve, which is connected to the second pressure gauge and is used for normal pressure leak testing of the cavity.

6. The device according to claim 5, characterized in that, The fourth switching valve includes an electromagnetic switching valve.

7. The device according to claim 1, characterized in that, The vacuum and pressure relief device further includes: a communicating vessel; The first end of the communicating vessel is connected to the second pressure gauge, the second end of the communicating vessel is connected to the second switching valve, and the third end of the communicating vessel is connected to the third pressure gauge.

8. The device according to claim 1, characterized in that, The cavity includes an upper cavity and a lower cavity, which are integrally formed.

9. The device according to claim 1, characterized in that, The second switching valve includes a solenoid switching valve.

10. A high-pressure liquid injection control system, characterized in that, Includes the high-pressure liquid injection control device as described in any one of claims 1-9.

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