Battery cell liquid injection device and liquid injection system

Abstract

The utility model discloses a battery cell liquid injection device and a liquid injection system, and belongs to the technical field of battery production. An accommodating cavity for accommodating electrolyte is formed in the liquid injection cup, one end of the first pipeline is communicated with the accommodating cavity, and the other end of the first pipeline is communicated with a battery cell; the second pipeline is provided with a first valve and communicates with the first pipeline, and the connecting position of the second pipeline and the first pipeline is located on the side, away from the liquid injection cup, of the first valve. When liquid injection operation is carried out on the battery cell, the first valve is firstly closed, the battery cell is vacuumized through the second pipeline, meanwhile, electrolyte is added into the liquid injection cup, vacuumizing is stopped, the first valve is opened, the electrolyte in the liquid injection cup is injected into the battery cell through the first pipeline under the action of the internal and external pressure difference of the battery cell, and the operation is repeated, so that multiple quantitative liquid injection operation can be realized; the electrolyte can be in full contact with a pole piece and a diaphragm in the battery cell, so that the wettability is improved; and the vacuumizing of the battery core and the addition of the electrolyte into the electrolyte injection cup can be simultaneously carried out, so that the operation time can be saved, and the total electrolyte injection time is further reduced.

Description

Technical Field

[0001] The present application belongs to the field of battery production technology, and specifically relates to a battery cell liquid injection device and a liquid injection system. Background Art

[0002] In the battery manufacturing process, electrolyte injection is a critical step in adding electrolyte to the battery. The electrolyte transports ions within the battery, directly impacting its performance and cycle life. Therefore, as a critical step in the battery manufacturing process, the effectiveness of this process not only affects battery performance but also restricts production efficiency. In related technologies, direct electrolyte injection using an injection cup is often employed, but this can result in long injection times and poor electrolyte penetration. Utility Model Content

[0003] The present application aims to provide a battery cell liquid injection device and liquid injection system, which can solve the problems of long liquid injection time and poor electrolyte infiltration when liquid is directly injected using a liquid injection cup.

[0004] In order to solve the above technical problems, this application is implemented as follows:

[0005] In the first aspect, an embodiment of the present application proposes a battery cell filling device, comprising: a filling cup, a first pipe, a second pipe and a first valve, wherein the filling cup is provided with a accommodating chamber for accommodating electrolyte, one end of the first pipe is connected to the accommodating chamber, and the other end is used to communicate with the battery cell; the first valve is provided in the first pipe, the second pipe is connected to the first pipe, and the connection position of the second pipe and the first pipe is located on the side of the first valve away from the filling cup, and the second pipe is used to vacuum the battery cell.

[0006] Optionally, the battery cell liquid injection device further includes a second valve, which is provided in the second pipeline and is used to control the conduction or disconnection of the second pipeline.

[0007] Optionally, the battery cell liquid injection device includes a vacuum state and a liquid injection state. When the battery cell liquid injection device is in the vacuum state, the first valve is closed and the second valve is opened; when the battery cell liquid injection device is in the liquid injection state, the first valve is opened and the second valve is closed.

[0008] Optionally, the battery cell injection device further includes a buffer cup, in which a buffer cavity is provided, and the end of the second pipe away from the first pipe is connected to the buffer cavity, and the buffer cup is used to buffer overflowed electrolyte when the battery cell is vacuumed.

[0009] Optionally, a vacuum tube is provided on the buffer cup; the vacuum tube is used to connect to a vacuum pumping mechanism so that the vacuum pumping mechanism can vacuum the battery cell through the buffer cup.

[0010] Optionally, the cache cup is further provided with a first positive pressure tube, which is used to connect to a positive pressure mechanism to pressurize the cache cavity so that the overflowed electrolyte in the cache flows back into the battery cell.

[0011] Optionally, the filling cup is provided with an injection tube and a second positive pressure tube connected to the accommodating cavity, the injection tube is used to connect to the injection mechanism to inject electrolyte into the accommodating cavity; the second positive pressure tube is used to connect to the positive pressure mechanism to pressurize the accommodating cavity so that the electrolyte is injected into the battery cell.

[0012] Optionally, the accommodating chamber includes a first injection chamber and a second injection chamber that are connected to each other, the first pipe is connected to the end of the second injection chamber that is away from the first injection chamber, and the second injection chamber gradually shrinks from the first injection chamber to the first pipe.

[0013] Optionally, the liquid injection cup is arranged in the cache cavity, and the first pipe passes through the cavity wall of the cache cavity.

[0014] In the second aspect, an embodiment of the present application proposes a liquid injection system, comprising: a liquid injection mechanism, a vacuum pumping mechanism and a battery cell liquid injection device as described in any one of the above items, wherein the liquid injection mechanism is connected to the accommodating cavity and is used to inject electrolyte into the accommodating cavity, and the vacuum pumping mechanism is connected to the second pipe and is used to vacuum the battery cell.

[0015] In an embodiment of the present application, a cavity for accommodating electrolyte is provided in the liquid injection cup, one end of the first pipe is connected to the cavity, and the other end is used to communicate with the battery cell; a first valve is provided in the first pipe, a second pipe is connected to the first pipe, and the connection position of the second pipe and the first pipe is located on the side of the first valve away from the liquid injection cup, and the second pipe is used to evacuate the battery cell. When injecting liquid into the battery cell, the first valve is first closed, the battery cell is evacuated through the second pipe, and electrolyte is added to the liquid injection cup at the same time, then the vacuuming is stopped and the first valve is opened. Under the action of the pressure difference between the inside and outside of the battery cell, the electrolyte in the liquid injection cup is injected into the battery cell through the first pipe. Repeating this operation can achieve multiple quantitative liquid injection operations, so that the electrolyte can fully contact the internal electrode and diaphragm of the battery cell, thereby improving the wettability. At the same time, vacuuming the battery cell and adding electrolyte to the liquid injection cup can be performed simultaneously, which can save operation time and thus reduce the total liquid injection time.

[0016] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 is a schematic diagram of a battery cell liquid injection device according to an embodiment of the present application;

[0019] Figure 2 is a schematic diagram of another battery cell liquid injection device according to an embodiment of the present application;

[0020] Figure 3 This is a schematic diagram of a liquid filling cup according to an embodiment of the present application.

[0021] Reference numerals:

[0022] 1: Liquid filling cup; 11: Receiving chamber; 12: Liquid filling tube; 13: Second positive pressure tube; 14: First liquid filling chamber; 15: Second liquid filling chamber; 2: First pipeline; 3: Second pipeline; 4: First valve; 5: Second valve; 6: Buffer cup; 61: Buffer chamber; 62: Vacuum tube; 63: First positive pressure tube; 64: First mounting hole; 65: Second mounting hole; 66: Third mounting hole; 7: Battery cell. DETAILED DESCRIPTION

[0023] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly refer to one or more of the features. Throughout the description of this application, unless otherwise specified, "plurality" means two or more. Furthermore, "and / or" in the specification and claims refers to at least one of the connected entities, and the character " / " generally indicates an "or" relationship between the connected entities.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0027] Before introducing the battery cell liquid injection device provided in the embodiment of the present application in detail, the specific scenario of the battery cell liquid injection device is first described in detail:

[0028] In the related art, when the battery cell is injected with liquid, the injection cup 1 is connected to the battery cell 7. The injection cup 1 is provided with a vacuum tube, an injection tube and a positive pressure port. The battery cell 7 is first evacuated through the vacuum tube. After the vacuum is completed, the battery cell 7 and the injection cup 1 are closed by the sealing rod. A certain amount of electrolyte is injected into the injection cup 1 through the injection tube, taking 300g as an example. Then, the electrolyte in the injection cup is pressurized through the positive pressure port, and all 300g of electrolyte is injected into the battery cell 7. Then, the battery cell 7 is evacuated again through the vacuum tube, and the electrolyte extracted from the injection cup 1 during vacuum is pressurized through the positive pressure port and injected into the battery cell 7 again. This cycle is repeated many times to inject all 300g of electrolyte into the battery cell. However, this method, on the one hand, cannot simultaneously inject electrolyte during vacuuming, making the operation time-consuming; on the other hand, injecting all the electrolyte into the battery cell at once results in poor electrolyte infiltration, and the electrolyte can easily impact the electrode, causing wrinkles on the electrode. To solve this problem, this application proposes a battery cell injection device and injection system.

[0029] The battery cell liquid injection device and liquid injection system provided in the embodiments of the present application are described in detail below with reference to specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0030] refer to Figure 1 and Figure 2According to some embodiments of the present application, the battery cell liquid injection device includes a liquid injection cup 1, a first pipe 2, a second pipe 3 and a first valve 4. The liquid injection cup 1 is provided with a accommodating chamber 11 for accommodating electrolyte, one end of the first pipe 2 is connected to the accommodating chamber 11, and the other end is used to communicate with the battery cell 7; the first valve 4 is provided in the first pipe 2, the second pipe 3 is connected to the first pipe 2, and the connection position of the second pipe 3 and the first pipe 2 is located on the side of the first valve 4 away from the liquid injection cup 1, and the second pipe 3 is used to vacuum the battery cell 7.

[0031] In the embodiment of the present application, the electrolyte can be contained in the receiving chamber 11 of the liquid filling cup 1. One end of the first pipe 2 is connected to the receiving chamber 11, and the other end is used to communicate with the battery cell 7. The first valve 4 is set in the first pipe 2, and the second pipe 3 is connected to the first pipe 2. The connection position of the second pipe 2 and the first pipe 1 is located on the side of the first valve 4 away from the liquid filling cup 1. The second pipe 3 is used to evacuate the battery cell 7. When the battery cell is injected, the first valve 4 is first closed, and the battery cell 7 is evacuated through the second pipe 3. At the same time, electrolyte is added to the liquid filling cup 1. Then, the vacuum is stopped and the first valve 4 is opened. Under the action of the pressure difference between the inside and outside of the battery cell 7, the electrolyte in the liquid filling cup 1 is injected into the battery cell 7 through the first pipe 2. Repeating this operation can achieve multiple quantitative injection operations, so that the electrolyte can fully contact the internal electrode and diaphragm of the battery cell, improving the wettability. At the same time, evacuating the battery cell and adding electrolyte to the liquid filling cup can be performed simultaneously, which can save operation time and thus reduce the total injection time.

[0032] In specific applications, refer to Figure 1 and Figure 2 Taking the injection of 300g of electrolyte into the battery cell 7 as an example, 60g of electrolyte is injected into the injection cup 1 each time. When injecting the electrolyte into the injection cup 1, the battery cell 7 is evacuated through the second channel 3. Then, under the action of the pressure difference between the inside and outside of the battery cell, 60g of electrolyte is injected into the battery cell 7. This cycle is repeated 5 times until all 300g of electrolyte is injected into the battery cell 7. Since the amount of electrolyte injected each time is small, it is not easy to impact the electrode sheet, thus preventing the electrode sheet from being impacted by the electrolyte and forming wrinkles.

[0033] It is understandable that when the battery cell 7 is vacuumed, the air pressure during the vacuuming mechanism extraction depends on the specific specifications of the battery cell 7. For example, the vacuum degree of the vacuuming can be set to: -10 to -99 MPa. Specifically, the air pressure value of the vacuuming can be set to any value such as -10 MPa, -20 MPa, -30 MPa, -40 MPa, -50 MPa, -60 MPa, -70 MPa, -80 MPa, -90 MPa, -99 MPa, or a range between any two values. Those skilled in the art can select according to actual needs, and the embodiments of the present application are not limited to this.

[0034] Specifically, the first valve 4 can be a control valve, including but not limited to: a pneumatic valve, an electric valve, a hydraulic valve, etc., and technicians in this field can select it according to actual needs. The embodiment of the present application does not limit this.

[0035] Optionally, the first valve 4 can also be a one-way valve, so that when the filling cup 1 needs to be filled, the electrolyte can smoothly pass through the one-way valve into the battery cell 7, and when vacuuming, it will not affect the filling cup 1.

[0036] refer to Figure 1 and Figure 2 In some embodiments of the present application, the battery cell liquid injection device further includes a second valve 5 , which is disposed in the second pipe 3 and is used to control the conduction or disconnection of the second pipe 3 .

[0037] In the embodiment of the present application, a second valve 5 is provided on the second pipe 3 to control the conduction or disconnection of the second pipe 3, thereby preventing the electrolyte from flowing out along the second pipe 3 during injection, resulting in insufficient electrolyte injected into the battery cell 7, thereby improving the injection quality of the battery cell injection device.

[0038] In specific applications, the second valve 5 includes but is not limited to: a pneumatic valve, an electric valve, a hydraulic valve, etc., and those skilled in the art can select one according to actual needs. The embodiment of the present application does not impose any restrictions on this.

[0039] refer to Figure 1 and Figure 2 In some embodiments of the present application, the battery cell liquid injection device includes a vacuum state and a liquid injection state. When the battery cell liquid injection device is in the vacuum state, the first valve 4 is closed and the second valve 5 is opened; when the battery cell liquid injection device is in the liquid injection state, the first valve 4 is opened and the second valve 5 is closed.

[0040] In an embodiment of the present application, the battery cell liquid injection device includes a vacuum state and a liquid injection state. When the battery cell liquid injection device is in the vacuum state, the first valve 4 is closed and the second valve 5 is opened. At this time, the battery cell 7 is vacuumed through the second pipe 3 while the electrolyte is injected into the liquid injection cup 1 to save time; after the liquid injection and vacuuming are completed, the first valve 4 is opened and the second valve 5 is closed. At this time, under the action of the pressure difference between the inside and outside of the battery cell 7, the electrolyte flows into the battery cell 7 along the first pipe 2, and the closure of the second valve prevents the electrolyte from flowing out along the second pipe, thereby improving the injection quality of the electrolyte.

[0041] refer to Figure 1 and Figure 2In some embodiments of the present application, the battery cell filling device also includes a buffer cup 6, a buffer cavity 61 is provided in the buffer cup 6, and the end of the second pipe 3 away from the first pipe 2 is connected to the buffer cavity 61. The buffer cup 6 is used to buffer the overflowed electrolyte when the battery cell is vacuumed.

[0042] In the embodiment of the present application, the battery cell injection device further includes a buffer cup 6, which is provided with a buffer chamber 61. One end of the second pipe 3 is connected to the buffer chamber 61, and the other end is connected to the first pipe 2. The buffer cup 6 is used to connect to the vacuum pumping mechanism and also to store the electrolyte extracted during the vacuum pumping. This avoids electrolyte waste and saves production costs.

[0043] In specific applications, since vacuuming and liquid injection are carried out in multiple cycles during liquid injection, after the electrolyte is injected into the battery cell 7 several times, the electrolyte injected into the battery cell 7 will be extracted when vacuuming is performed again. Adding a buffer cup 6 can store the electrolyte extracted during vacuuming for continued use in subsequent processes, avoiding waste.

[0044] refer to Figure 1 and Figure 2 In some embodiments of the present application, the buffer cup 6 is provided with a vacuum tube 62 , which is used to connect to a vacuum mechanism to evacuate the battery cell 7 .

[0045] In the embodiment of the present application, a vacuum tube 62 is provided on the buffer cup 6 , so as to be more conveniently connected to the vacuum mechanism, so that the vacuum mechanism can vacuum the battery cell 7 through the buffer cup 6 .

[0046] It can be understood that the vacuum tube 62 can be set as a quick connection interface, or it can be set as a section of pipe extending out of the buffer cup 6. Those skilled in the art can choose according to actual needs, and the embodiments of the present application do not limit this.

[0047] refer to Figure 1 and Figure 2 In some embodiments of the present application, the cache cup 6 is further provided with a first positive pressure tube 63, which is used to connect a positive pressure mechanism to pressurize the cache cavity 61 so that the cached electrolyte overflows and flows back into the battery cell 7.

[0048] In an embodiment of the present application, since the electrolyte injected into the battery cell 7 may be drawn out into the cache cavity 61 when the battery cell 7 is vacuumed through the cache cup 6, a first positive pressure tube 63 is also provided on the cache cup 6, and the first positive pressure tube 63 is connected to the positive pressure mechanism. When the electrolyte is vacuumed out, the electrolyte stored in the cache cavity 61 is re-injected into the battery cell 7 through the positive pressure mechanism, thereby ensuring the total amount of electrolyte in the battery cell 7 and improving the efficiency of electrolyte injection.

[0049] In specific applications, after the battery cell 7 is injected with electrolyte several times, when the battery cell 7 is vacuumed by the vacuum mechanism, part of the electrolyte may be drawn out of the battery cell 7 and flow into the cache cavity 61. In order to ensure that the amount of electrolyte finally injected into the battery cell 7 remains unchanged, a first positive pressure tube 63 is provided on the cache cup 6, and the electrolyte stored in the cache cavity 61 is re-injected into the battery cell 7 through the positive pressure mechanism.

[0050] The air pressure value input to the first positive pressure pipe 63 by the positive pressure mechanism includes but is not limited to: 100-300 MPa. Specifically, the air pressure value for vacuuming can be set to any value such as 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, 260 MPa, 270 MPa, 280 MPa, 290 MPa, 300 MPa, or a range between any two values. Those skilled in the art can select according to actual needs, and the embodiments of the present application are not limited thereto.

[0051] refer to Figure 1 and Figure 2 In some embodiments of the present application, the liquid injection cup 1 is provided with a liquid injection tube 12 and a second positive pressure tube 13 connected to the accommodating cavity 11. The liquid injection tube 12 is used to connect to the liquid injection mechanism to inject electrolyte into the accommodating cavity 11; the second positive pressure tube 13 is used to connect to the positive pressure mechanism to pressurize the accommodating cavity 11 so that the electrolyte is injected into the battery cell 7.

[0052] In an embodiment of the present application, the filling cup 1 is provided with a filling tube 12 and a second positive pressure tube 13 connected to the accommodating cavity 11. The filling tube 12 is used to connect to the filling mechanism, so as to quantitatively inject electrolyte into the accommodating cavity 11; the second positive pressure tube 13 is used to connect to the positive pressure mechanism, so that when part of the electrolyte has been injected into the battery cell 7, the electrolyte in the accommodating cavity 11 is pressurized by the positive pressure mechanism, so that the electrolyte can be injected into the battery cell 7 more smoothly, thereby improving the efficiency of the electrolyte injection.

[0053] In specific applications, after the battery cell 7 has undergone several cycles of vacuuming and filling, electrolyte is retained in the battery cell 7. At this time, when the battery cell 7 is filled with liquid, the electrolyte is not easy to be injected. Therefore, the second positive pressure tube 13 connected to the positive pressure mechanism is provided on the filling cup 1, and the positive pressure mechanism pressurizes the electrolyte in the accommodating cavity 11 to smoothly inject the electrolyte into the battery cell 7, thereby improving the injection efficiency of the electrolyte.

[0054] It can be understood that the injection mechanism can quantitatively input the electrolyte injected each time into the injection cup 1, thereby improving the efficiency of injecting the electrolyte into the injection cup 1.

[0055] It can be understood that the pressurization time of the first positive pressure tube 63 and the second positive pressure tube 13 can be determined according to the filling situation of the battery cell 7. For example, when the electrolyte in the battery cell 7 is not extracted into the buffer cup 6 during vacuum extraction, only the air pressure is input into the filling cup 1 through the second positive pressure tube 13. When the electrolyte in the battery cell 7 has been extracted into the buffer cup 6 during vacuum extraction, air pressure is input into the filling cup 1 and the buffer cup 6 through the first positive pressure tube 63 and the second positive pressure tube 13, so that all the electrolyte in the filling cup 1 and the buffer cup 6 are injected into the battery cell 7, which can effectively utilize the electrolyte.

[0056] refer to Figure 3 In some embodiments of the present application, the accommodating chamber 11 includes a first liquid injection chamber 14 and a second liquid injection chamber 15 that are connected to each other. The first pipe 2 is connected to the end of the second liquid injection chamber 15 that is away from the first liquid injection chamber 14. The second liquid injection chamber 15 gradually shrinks from the first liquid injection chamber 14 to the first pipe 2.

[0057] In the embodiment of the present application, the accommodating chamber 11 includes a first liquid injection chamber 14 and a second liquid injection chamber 15. One end of the second liquid injection chamber 15 is connected to the first liquid injection chamber 14, and the other end is connected to the first pipe 2. From the first liquid injection chamber 14 to the first pipe 2, the second liquid injection chamber 15 gradually shrinks, which is more conducive to the electrolyte flowing from the accommodating chamber 11 to the first pipe 2, and when the positive pressure mechanism pressurizes the liquid injection chamber 11, the electrolyte can flow more smoothly to the first pipe 2 to be injected into the battery cell 7.

[0058] refer to Figure 2 In some embodiments of the present application, the liquid injection cup 1 is disposed in the buffer cavity 61 , and the first pipe 2 passes through the buffer cup 6 and is connected to the liquid injection cup 1 .

[0059] In an embodiment of the present application, the liquid filling cup 1 is arranged in the buffer cavity 61, and the first pipe 2 is connected to the liquid filling cup 1 through the buffer cup 6, so that while the liquid filling is realized, the structure of the battery cell liquid filling device is more compact and convenient for users to use.

[0060] It can be understood that the overall size of the liquid filling cup 1 should be smaller than the size of the buffer cavity 61 so that the liquid filling cup 1 can be set in the buffer cavity 61 and store electrolyte in the buffer cavity 61.

[0061] refer to Figure 2 In some embodiments of the present application, the liquid injection cup 1 is disposed in the buffer chamber 61. The buffer cup 6 is further provided with a first mounting hole 64, a second mounting hole 65, and a third mounting hole 66. The first mounting hole 64 allows the first pipe 2 to pass through the liquid injection cup 1 for communication. The second mounting hole 65 allows the liquid injection pipe 12 to communicate with the liquid injection structure. The third mounting hole 63 allows the second positive pressure pipe 13 to communicate with the positive pressure mechanism. This makes the overall structure of the battery cell liquid injection device more compact and convenient to use.

[0062] In a specific application, when the liquid filling cup 1 is set in the buffer chamber 61, the liquid filling cup 1 needs to be connected with the first pipe 2, the liquid filling mechanism and the positive pressure mechanism. Therefore, a first mounting hole 64, a second mounting hole 65 and a third mounting hole 66 are set on the buffer chamber 61 to facilitate the connection between the liquid filling cup 1 and the first pipe 2, the liquid filling mechanism and the positive pressure mechanism.

[0063] In some embodiments of the present application, a liquid injection system is also proposed, including: a liquid injection mechanism, a vacuum pumping mechanism and the battery cell liquid injection device described in any of the above embodiments, the liquid injection mechanism is connected to the accommodating chamber 11, and is used to inject electrolyte into the accommodating chamber 11, and the vacuum pumping mechanism is connected to the second pipe 3, and is used to vacuum the battery cell 7.

[0064] In an embodiment of the present application, the liquid injection system includes: a liquid injection mechanism, a vacuum pumping mechanism, and the battery cell liquid injection device described in any of the above embodiments. The liquid injection mechanism is in communication with the accommodating chamber 11 and is used to inject electrolyte into the accommodating chamber 11. The vacuum pumping mechanism is in communication with the second pipe 3 and is used to vacuum the battery cell 7. The accommodating chamber 11 provided with the liquid injection cup 1 can contain electrolyte. One end of the first pipe 2 is in communication with the accommodating chamber 11, and the other end is used to communicate with the battery cell 7. The first valve 4 is provided in the first pipe 2, and the second pipe 3 is in communication with the first pipe 2. The connection position of the second pipe 2 and the first pipe 1 is located on the side of the first valve 4 facing away from the liquid injection cup 1. The second pipe 3 is used to vacuum the battery cell 7. When injecting liquid into the battery cell, first close the first valve 4, evacuate the battery cell 7 through the second pipe 3, and add electrolyte to the injection cup 1 at the same time, then stop evacuating the battery cell, and open the first valve 4. Under the action of the pressure difference between the inside and outside of the battery cell 7, the electrolyte in the injection cup 1 is injected into the battery cell 7 through the first pipe 2. Repeat this operation to achieve multiple quantitative injection operations, so that the electrolyte can fully contact the internal electrode and diaphragm of the battery cell, thereby improving the wettability. At the same time, evacuating the battery cell and adding electrolyte to the injection cup can be carried out at the same time, which can save operation time and thus reduce the total injection time.

[0065] In a specific application, the vacuum pump includes a vacuum pump, which is connected to the second pipe 3 or the vacuum tube 62, thereby vacuuming the battery cell 7; the liquid injection mechanism includes a diaphragm pump and a liquid storage tank, which is used to store electrolyte, and the diaphragm pump is connected to the liquid injection tube 12 and the liquid storage tank, and the electrolyte in the liquid storage tank is transported to the liquid injection cup 1 through the liquid injection tube 12; the positive pressure mechanism includes a gas booster pump and a gas tank, which is used to store gas, and the gas booster pump is connected to the gas tank and the first positive pressure tube 63 and the second positive pressure tube 13, and the cache cup 6 and the liquid injection cup 1 are pressurized respectively through the first positive pressure tube 63 and the second positive pressure tube 13.

[0066] Below, taking the injection of 300g of electrolyte into a square aluminum shell battery cell as an example, the use process of the battery cell injection device and injection system is briefly introduced:

[0067] First, close the first valve 4 and open the second valve 5, and inject 60g of electrolyte from the injection tube 12 into the accommodating cavity 11 of the injection cup 1 through the injection mechanism. At the same time, the battery cell 7 is vacuumed from the vacuum tube 62 through the vacuum pumping mechanism. The vacuum pumping mechanism maintains a negative pressure of -90MPa and lasts for 5s; then open the first valve 4, and apply an air pressure of 200MPa to the electrolyte in the accommodating cavity 11 from the second positive pressure tube 13 on the injection cup 1 through the positive pressure mechanism, and last for 15s.

[0068] Then close the first valve 4, open the second valve 5, and inject the second 60g electrolyte into the accommodating chamber 11 through the liquid injection mechanism again. At the same time, the battery cell 7 is vacuumed from the vacuum tube 62 through the vacuum pumping mechanism. The vacuum pumping mechanism maintains a negative pressure of -90MPa and lasts for 5s; then open the first valve 4, close the second valve 5, and apply an air pressure of 200MPa to the electrolyte in the accommodating chamber 11 from the second positive pressure tube 13 on the liquid injection cup 1 through the positive pressure mechanism, and continue for 15s.

[0069] The above steps are repeated in this way to completely inject 300g of electrolyte into the battery cell 7. During this process, if the electrolyte in the battery cell 7 is extracted into the buffer cup 6 when vacuum is applied, when air pressure is applied to the electrolyte in the accommodating chamber 11 from the second positive pressure tube 13 on the injection cup 1 through the positive pressure mechanism, an air pressure of 200MPa is applied to the electrolyte in the buffer chamber 61 from the first positive pressure tube 63 on the buffer cup 6 through the positive pressure mechanism, and the pressure is maintained for 15s. At this time, on the basis of the opening of the first valve 4, the second valve 5 is opened to inject all the electrolyte in the buffer cup 6 and the injection cup 1 into the battery cell 7. Of course, pressurizing the accommodating chamber 11 to inject the electrolyte into the battery cell 7 and pressurizing the buffer chamber 61 to inject the electrolyte into the battery cell 7 can be carried out simultaneously or successively. Therefore, the first valve 4 and the second valve 5 can be opened simultaneously or successively.

[0070] In this way, through multi-stage quantitative injection and adjustable vacuum and positive pressure, the electrolyte infiltration efficiency can be greatly improved, thereby improving production efficiency; at the same time, multi-stage quantitative injection can reduce the impact of the electrolyte on the electrode during injection, reduce the probability of wrinkles on the electrode, and improve the production quality of the battery cell 7.

[0071] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0072] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell injection device, characterized in that: include: A liquid injection cup (1), a first pipe (2), a second pipe (3) and a first valve (4); the liquid injection cup (1) is provided with a receiving chamber (11) for receiving electrolyte; one end of the first pipe (2) is in communication with the receiving chamber (11), and the other end is in communication with the battery cell (7); the first valve (4) is provided in the first pipe (2); the second pipe (3) is in communication with the first pipe (2), and the connection position between the second pipe (3) and the first pipe (2) is located on a side of the first valve (4) away from the liquid injection cup (1); the second pipe (3) is used to evacuate the battery cell (7).

2. The battery cell liquid injection device according to claim 1, characterized in that: The battery cell liquid injection device further comprises a second valve (5), which is arranged in the second pipeline (3) and is used to control the conduction or disconnection of the second pipeline (3).

3. The battery cell liquid injection device according to claim 2, characterized in that: The battery cell liquid injection device includes a vacuum state and a liquid injection state. When the battery cell liquid injection device is in the vacuum state, the first valve (4) is closed and the second valve (5) is opened; when the battery cell liquid injection device is in the liquid injection state, the first valve (4) is opened and the second valve (5) is closed.

4. The battery cell liquid injection device according to claim 1, characterized in that: The battery cell injection device further comprises a buffer cup (6), a buffer cavity (61) being provided in the buffer cup (6), an end of the second pipe (3) away from the first pipe (2) being in communication with the buffer cavity (61), and the buffer cup (6) being used for buffering overflowed electrolyte when the battery cell is evacuated.

5. The battery cell liquid injection device according to claim 4, characterized in that: The buffer cup (6) is provided with a vacuum tube (62), and the vacuum tube (62) is used to connect to a vacuum pumping mechanism so that the vacuum pumping mechanism can vacuum the battery cell (7) through the buffer cup (6).

6. The battery cell liquid injection device according to claim 5, characterized in that: The cache cup (6) is also provided with a first positive pressure tube (63), which is used to connect to a positive pressure mechanism to pressurize the cache cavity (61) so that the cached electrolyte overflows and flows back into the battery core (7).

7. The battery cell liquid injection device according to claim 6, characterized in that: The liquid injection cup (1) is provided with a liquid injection tube (12) and a second positive pressure tube (13) in communication with the accommodating cavity (11). The liquid injection tube (12) is used to connect to a liquid injection mechanism to inject electrolyte into the accommodating cavity (11); the second positive pressure tube (13) is used to connect to the positive pressure mechanism to pressurize the accommodating cavity (11) so that the electrolyte is injected into the battery core (7).

8. The battery cell liquid injection device according to claim 1, characterized in that: The accommodating chamber (11) comprises a first liquid injection chamber (14) and a second liquid injection chamber (15) which are connected to each other. The first pipe (2) is connected to an end of the second liquid injection chamber (15) which is away from the first liquid injection chamber (14). The second liquid injection chamber (15) gradually contracts in the direction from the first liquid injection chamber (14) to the first pipe (2).

9. The battery cell liquid injection device according to claim 4, characterized in that: The liquid injection cup (1) is arranged in the cache cavity (61), and the first pipe (2) is passed through the cavity wall of the cache cavity (61).

10. A liquid injection system, characterized in that: include: A liquid injection mechanism, a vacuum pumping mechanism, and a battery cell liquid injection device as described in any one of claims 1 to 9, wherein the liquid injection mechanism is connected to the accommodating chamber (11) and is used to inject electrolyte into the accommodating chamber (11), and the vacuum pumping mechanism is connected to the second pipe (3) and is used to vacuum the battery cell (7).

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