Battery injection structure and injection method

Abstract

The present application relates to the technical field of battery production, and specifically discloses a battery injection structure and injection method, including: a battery core assembly, the battery core assembly is provided with a first injection port and a second injection port connected to the injection cavity; an injection assembly, including an injection cup, the injection cup is provided with an inner cavity and an outer cavity, the upper end of the injection cup is provided with a liquid inlet connected to the inner cavity, and a first plugging member is provided in the liquid inlet; the lower end of the inner cavity is provided with a first liquid outlet connected to the outer cavity, and a second plugging member is provided in the first liquid outlet; the lower end of the injection cup is provided with a second liquid outlet connected to the outer cavity, and the second liquid outlet is connected to the first injection port; the inner cavity is connected to a positive pressure device through a first channel; the outer cavity is connected to a negative pressure device through a second channel; an auxiliary assembly, including a third channel, the first end of the third channel is connected to the second injection port, and the second end of the third channel is used to connect to the negative pressure device. The present application achieves the purpose of improving the injection efficiency of the electrolyte and reducing the production cost and difficulty of the battery.

Description

Technical Field

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

[0002] With the popularity of new energy vehicles in recent years, consumers have not set new requirements for driving range. At the same time, with the rapid development of new energy and the rise of smart grids, green energy has become popular, especially in the new energy industry, which mainly includes lithium-ion batteries, sodium-ion batteries, flow batteries, supercapacitors, etc. These technologies have significantly improved in charging and discharging efficiency, energy density, usage time, product safety, etc., thus further expanding their application scope.

[0003] The rapid development of the new energy industry has also put forward more specific demands on battery cells. The demands for performance indicators such as capacity, energy density, power density and cell volume of battery cells for new energy power and energy storage devices such as lithium batteries, sodium batteries, supercapacitors, etc. are further increasing.

[0004] At present, the mainstream method of battery filling in the market is to have a filling port on the battery, control the pressure change between the battery cell and the filling cup, and use the pressure difference between the inside and outside of the battery cell to drive the electrolyte to flow into the battery cell. The specific process is to draw negative pressure into the filling cup and the battery cell, and then inject the electrolyte into the filling cup. Under the action of the pressure difference between the inside and outside, the electrolyte flows into the battery cell.

[0005] However, this injection method has the following disadvantages: 1. The injection cup is connected to the negative pressure pipeline, and liquid cannot be prepared during the negative pressure extraction process, affecting the entire injection time; 2. High negative pressure extraction can easily cause product deformation, but when low negative pressure is extracted, the electrolyte cannot completely flow from the injection cup into the battery cell.

[0006] Another method of liquid injection also has a liquid injection port on the battery. The battery is placed in a closed environment, and the liquid is injected by controlling the pressure change between the battery cell and the liquid injection cup. The pressure of the environment in which the battery cell is located needs to be controlled to be consistent with the pressure inside the battery cell, so as to avoid deformation of the battery cell during the process of pumping negative pressure and applying positive pressure. The principle of liquid injection is to use the pressure difference between the inside and outside of the battery cell to drive the electrolyte to flow into the battery cell. The specific process is to pump negative pressure on the liquid injection cup and the battery cell, then prepare the liquid in the liquid injection cup, use the environmental pressure and the pressure difference between the liquid injection cup and the battery cell to drive the electrolyte to flow into the battery cell, and then perform high / low pressure cycles.

[0007] However, the disadvantages of this injection method are: 1. There are strict requirements on the sealing of the environment in which the battery cell is located, and the battery cell environment occupies a large space; 2. Frequent switching between pumping negative pressure and applying positive pressure causes waste of gas and increases manufacturing costs; 3. During the high and low pressure cycle process, negative pressure is directly applied to the injection cup, and the electrolyte that has not flowed into the battery cell is affected by the pressure first, which easily draws away the solvent in the electrolyte, affecting the concentration of the electrolyte in a small range.

[0008] In summary, the injection method in the related art has the problem of slow cell injection speed, the need to control the ambient pressure during the injection process, high control requirements for the ambient pressure, and difficulty in controlling the pressure of the cell during the injection process. It is also easy to cause electrolyte loss during the application of negative pressure. Summary of the invention

[0009] The main purpose of the present application is to provide a battery injection structure and injection method to solve the problems of slow cell injection speed, the need to control the ambient pressure during the injection process, high control requirements for the ambient pressure, and the difficulty in controlling the pressure of the battery cell during the injection process, and the easy loss of electrolyte during the application of negative pressure.

[0010] In order to achieve the above-mentioned object, the present application provides a battery injection structure, comprising:

[0011] A battery cell assembly, wherein the battery cell assembly is provided with a first liquid injection port and a second liquid injection port communicating with the liquid injection cavity;

[0012] The liquid injection assembly comprises a liquid injection cup, wherein the liquid injection cup is provided with an inner cavity and an outer cavity isolated from each other, the upper end of the liquid injection cup is provided with a liquid inlet connected with the inner cavity, and the liquid inlet is provided with a first blocking member that can be opened and closed;

[0013] The lower end of the inner cavity is provided with a first liquid outlet communicating with the outer cavity, and a second closing member that can be opened and closed is provided in the first liquid outlet; the lower end of the liquid injection cup is provided with a second liquid outlet communicating with the outer cavity, and the second liquid outlet is communicated with the first liquid injection outlet;

[0014] The inner cavity is connected to a positive pressure device through a first channel to apply positive pressure to the inner cavity; the outer cavity is connected to a negative pressure device through a second channel to apply negative pressure to the outer cavity and the injection cavity;

[0015] The auxiliary component includes a third channel, a first end of the third channel is connected to the second injection port, and a second end of the third channel is used to communicate with a negative pressure device to apply negative pressure to the injection cavity.

[0016] Further, the first channel includes a first control valve communicating with the inner cavity, and the second channel includes a second control valve communicating with the outer cavity.

[0017] Furthermore, the third channel includes a connecting pipe and a third control valve and a fourth control valve connected to the connecting pipe, the connecting pipe is connected to the second liquid injection port, the third control valve is located between the battery cell assembly and the fourth control valve, and the third control valve and the fourth control valve are both used to connect to the negative pressure equipment.

[0018] Furthermore, the first liquid injection port and the second liquid injection port are located on the same side of the battery cell assembly.

[0019] Furthermore, the first liquid injection port and the second liquid injection port are respectively located on two sides of the battery cell assembly.

[0020] Furthermore, the horizontal height of the second liquid injection port is the same as the horizontal height of the first liquid injection port.

[0021] Furthermore, the first liquid injection port is close to the lower part of the liquid injection cavity, and the second liquid injection port is close to the upper part of the liquid injection cavity.

[0022] Furthermore, the second injection port corresponds to the upper free space in the injection cavity, and the upper free space is the space remaining in the injection cavity after a set amount of electrolyte is injected.

[0023] Furthermore, the third channel also includes an electrolyte overflow prevention container, and the connecting pipe includes a main pipe, a first branch pipe, and a second branch pipe;

[0024] The first end of the main pipe is connected to the second liquid filling port, the second end of the main pipe is connected to the fourth control valve, the first end of the first branch pipe is connected to the main pipe and is located at the front end of the fourth control valve, the second end of the first branch pipe is connected to the electrolyte overflow prevention container, the first end of the second branch pipe is connected to the third control valve, and the second end of the second branch pipe is connected to the electrolyte overflow prevention container.

[0025] According to another aspect of the present application, a battery injection method is provided, which adopts the above-mentioned battery injection structure and the following steps:

[0026] Step 1: closing the first channel and the first liquid outlet, opening the second channel and the third channel, using a negative pressure device connected to the second channel and the third channel to form a first negative pressure in the outer cavity and the liquid injection cavity, and in the process opening the liquid inlet to inject the electrolyte into the inner cavity;

[0027] Step 2: closing the second channel and the third channel, keeping the liquid inlet open, and then opening the first liquid outlet, so that the electrolyte in the inner cavity flows into the liquid injection cavity under the pressure difference between the inner cavity and the liquid injection cavity, and maintaining this state for t1 time;

[0028] Step 3: close the liquid inlet, open the first channel and the third channel, apply positive pressure to the inner cavity through the positive pressure device connected to the first channel, apply negative pressure to the injection cavity through the negative pressure device connected to the third channel, and maintain this state for t2 time;

[0029] Step 4: depressurizing the inner cavity and the injection cavity.

[0030] Furthermore, the negative pressure device connected to the third channel is controlled to apply a negative pressure value to the injection cavity, so that the effective substances in the electrolyte in the injection cavity will not enter the third channel.

[0031] Furthermore, the pressure value of the first negative pressure is -0.9 to -1.0 MPa, the pressure value of the positive pressure applied to the inner cavity by the positive pressure device connected to the first channel is 0.3 to 0.6 MPa, and the negative pressure value applied to the injection cavity by the negative pressure device connected to the third channel is 0 to -0.07 MPa.

[0032] Furthermore, during the process of step three, an electrolyte overflow prevention module arranged on the third channel is used to observe whether the electrolyte in the injection chamber overflows, and prevent the electrolyte from being sucked into the vacuum pipe through the third channel.

[0033] In the present application, on the one hand, after the first liquid outlet is blocked by the second blocking member, the first blocking member can be opened to inject electrolyte into the inner cavity when negative pressure is applied to the outer cavity and the liquid injection cavity through the second channel and the third channel, thereby accelerating the liquid injection speed, improving production efficiency, and reducing production costs. The technical effect solves the technical problem in the related art that negative pressure extraction and liquid preparation cannot be performed at the same time, resulting in reduced production efficiency; and, since the inner cavity of the liquid injection cup can directly form a pressure difference with the liquid injection cavity, the electrolyte in the inner cavity can naturally flow into the liquid injection cavity under the action of the pressure difference, so there is no need to control the ambient pressure;

[0034] On the other hand, in the process of pumping negative pressure, the first liquid injection port and the second liquid injection port are used to simultaneously apply negative pressure to the liquid injection cavity, shortening the time for the liquid injection cavity to reach the set pressure value, thereby further improving production efficiency;

[0035] On the other hand, after the electrolyte is injected through the pressure difference between the inner cavity and the injection cavity, positive pressure can be applied to the inner cavity through the first channel, forcing the electrolyte in the inner cavity to flow into the injection cavity under the action of the pressure difference, and negative pressure is applied to the injection cavity through the second injection port of the third channel to draw the airflow out, continuously create a negative pressure environment in the injection cavity, promote the electrolyte to flow in, further improve the injection effect, and in this process, continuously create a pressure difference in the injection cavity, abandon the control of the ambient pressure, and reduce the difficulty of controlling the ambient pressure;

[0036] On the other hand, during the entire injection process, negative pressure will not be applied to the inner cavity of the injection cup, so the electrolyte in the injection cavity will not flow into the inner cavity, so that the electrolyte will not be lost, reducing the material use cost; and there is no high and low pressure circulation in the entire injection process, which will not cause gas waste, further reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0038] Figure 1 is a schematic cross-sectional structural diagram of a liquid injection structure according to an embodiment of the present application;

[0039] Figure 2 is an isometric structural schematic diagram of a liquid injection structure according to an embodiment of the present application;

[0040] Figure 3 is a schematic diagram of the exploded structure of a battery cell assembly according to an embodiment of the present application;

[0041] Figure 4 is a schematic cross-sectional view of the electrolyte overflow prevention container after connection according to an embodiment of the present application;

[0042] Among them, 1 is a liquid injection component, 111 is a liquid injection cup, 112 is a second liquid outlet, 2 is an inner cavity, 3 is an outer cavity, 4 is a first channel, 41 is a first control valve, 5 is a second channel, 51 is a second control valve, 6 is a liquid inlet, 7 is a first blocking piece, 8 is a first liquid outlet, 9 is a second blocking piece, 10 is a battery cell component, 101 is a cover plate, 102 is a fluid, 103 is a winding core, 104 is a shell, 11 is a first liquid injection port, 12 is a second liquid injection port, 13 is a liquid injection cavity, 14 is an auxiliary component, 140 is a third channel, 1401 is a connecting pipe, 14010 is a main pipe, 14011 is a first branch pipe, 14012 is a second branch pipe, 1402 is a third control valve, 1403 is a fourth control valve, and 15 is an electrolyte overflow prevention container. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so as to describe the embodiments of the present application described herein.

[0045] In this application, the terms "upper", "lower", "inner", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0046] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0047] In addition, the terms "disposed", "provided with", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] In addition, the term "plurality" shall mean two or more.

[0049] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0050] To solve relevant technical problems, such as Figure 1 and Figure 2 As shown, the embodiment of the present application provides a battery injection structure, including:

[0051] The battery cell assembly 10 is provided with a first liquid injection port 11 and a second liquid injection port 12 which are in communication with the liquid injection cavity 13;

[0052] The liquid injection assembly 1 includes a liquid injection cup 111, wherein the liquid injection cup 111 is provided with an inner cavity 2 and an outer cavity 3 which are isolated from each other, and an upper end of the liquid injection cup 111 is provided with a liquid inlet 6 which is connected with the inner cavity 2, and an openable and closable first blocking member 7 is provided in the liquid inlet 6;

[0053] The lower end of the inner cavity 2 is provided with a first liquid outlet 8 communicating with the outer cavity 3, and a second blocking member 9 that can be opened and closed is provided in the first liquid outlet 8; the lower end of the liquid injection cup 111 is provided with a second liquid outlet 112 communicating with the outer cavity 3, and the second liquid outlet 112 is communicated with the first liquid injection port 11;

[0054] The inner cavity 2 is connected to the positive pressure device through the first channel 4 to apply positive pressure to the inner cavity 2; the outer cavity 3 is connected to the negative pressure device through the second channel 5 to apply negative pressure to the outer cavity 3 and the injection cavity 13;

[0055] The auxiliary component 14 includes a third channel 140 , a first end of the third channel 140 is connected to the second injection port 12 , and a second end of the third channel 140 is used to communicate with a negative pressure device to apply negative pressure to the injection cavity 13 .

[0056] In this embodiment, the battery cell assembly 10 includes a shell 104, and the shell 104 has a hollow liquid injection cavity 13. The liquid injection cavity 13 is provided with a winding core 103, and the winding core 103 is a structure including a positive electrode, a negative electrode, a separator and a core rod. The battery cell assembly 10 is provided with a first liquid injection port 11 and a second liquid injection port 12 connected to the liquid injection cavity 13. The first liquid injection port 11 and the second liquid injection port 12 can be provided on the shell 104, or on the cover plate 101 located at the end of the shell 104, and this embodiment does not limit it here.

[0057] The liquid injection assembly 1 is used to inject electrolyte into the liquid injection cavity 13 of the battery cell assembly 10, and mainly includes a liquid injection cup 111, and the liquid injection cup 111 has an inner cavity 2 and an outer cavity 3 that are isolated from each other. Figure 1As shown, the liquid injection cup 111 in this embodiment is a nested cup, which includes two cup bodies that are nested with each other, with a gap between the two cup bodies to form an outer cavity 3, and the interior of the cup body located in the middle forms an inner cavity 2, and the upper ends of the two cup bodies can be fixed together to a cup cover structure to close the upper ends of the inner cavity 2 and the upper ends of the outer cavity 3. A liquid inlet 6 communicating with the inner cavity 2 is provided at the upper end of the liquid injection cup 111, and a reserve liquid container can be connected externally through the liquid inlet 6, so that the electrolyte in the reserve liquid container can flow into the inner cavity 2 through the liquid inlet 6. In order to facilitate the blocking and opening of the liquid inlet 6, a first blocking member 7 is provided in the liquid inlet 6 in this embodiment. The first blocking member 7 can be a sealing plug, a sealing rod or other sealing structure blocked in the liquid inlet 6, and this embodiment does not limit it here.

[0058] In order to allow the electrolyte in the inner cavity 2 to flow into the injection cavity 13 of the battery cell assembly 10, a first liquid outlet 8 is provided at the lower end of the inner cavity 2, and the first liquid outlet 8 is connected to the lower end of the outer cavity 3. At the same time, a second liquid outlet 112 is provided at the lower end of the injection cup 111, and the second liquid outlet 112 is also connected to the lower end of the outer cavity 3 and connected to the first liquid injection port 11 on the battery cell assembly 10. When the first liquid outlet 8 is opened, the first liquid outlet 8, the lower end of the outer cavity 3 and the second liquid outlet 112 form an outflow channel for the electrolyte. In order to block and open the first liquid outlet 8, in this embodiment, a second blocking member 9 is provided in the first liquid outlet 8. The second blocking member 9 can be a sealing plug or a long sealing rod structure. Since the position of the first liquid outlet 8 is relatively low, it is preferably adopted as follows Figure 1 The sealing rod structure shown in the figure has an upper end that can extend out of the upper end of the liquid injection cup 111 , and the upper end of the sealing rod can be operated to control the blocking and opening of the first liquid outlet 8 .

[0059] In order to apply positive pressure to the inner cavity 2 and negative pressure to the outer cavity 3 and the injection cavity 13, in this embodiment, a first channel 4 communicating with the inner cavity 2 and a second channel 5 communicating with the inner cavity 2 are provided on the outer side of the injection cup 111. The first channel 4 can be connected to a positive pressure device, and after the positive pressure device is turned on, positive pressure can be applied to the inner cavity 2 through the first channel 4. The second channel 5 can be connected to a negative pressure device, and after the negative pressure device is turned on, negative pressure can be applied to the outer cavity 3 through the second channel 5.

[0060] In this embodiment, on the basis of arranging the liquid injection component 1, an auxiliary component 14 is also connected to the second liquid injection port 12 of the battery cell component 10. The auxiliary component 14 mainly includes a third channel 140, and the third channel 140 can be connected to the negative pressure device. After the negative pressure device is turned on, negative pressure can be generated in the liquid injection cavity 13 through the third channel 140, so as to better cooperate with the liquid injection process.

[0061] In this embodiment, the opening and closing of the first channel 4, the second channel 5 and the third channel 140 can be achieved through corresponding valves, or through the opening and closing of corresponding positive pressure equipment and negative pressure equipment, which is not limited in this embodiment.

[0062] The liquid injection method using the liquid injection structure in the present application is as follows: first, close the first channel 4 and the first liquid outlet 8, open the second channel 5 and the third channel 140, at this time, the inner cavity 2 of the liquid injection cup 111 is completely isolated from the outer cavity 3, and the second channel 5, the outer cavity 3, the liquid injection cavity 13 and the third channel 140 remain connected. Start the negative pressure device connected to the second channel 5 and the negative pressure device connected to the third channel 140 to simultaneously apply negative pressure to the liquid injection cavity 13, so that the liquid injection cavity 13 quickly reaches the set pressure value. Since the inner cavity 2 is completely isolated from the outer cavity 3 during this process, the process of applying negative pressure to the outer cavity 3 and the liquid injection cavity 13 does not affect the inner cavity 2, so that the liquid inlet 6 can be opened synchronously during this process to inject the electrolyte into the inner cavity 2 for temporary storage.

[0063] When the pressure value in the injection cavity 13 reaches the set value, the second channel 5 and the third channel 140 can be closed, and the negative pressure applied to the injection cavity 13 is stopped, and the negative pressure of the injection cavity 13 is kept at the set value. At this time, there is a pressure difference between the injection cavity 13 and the inner cavity 2 of the injection cup 111. Therefore, the first liquid outlet 8 can be opened, and the electrolyte in the inner cavity 2 will flow into the injection cavity 13 through the lower part of the outer cavity 3, the second liquid outlet 112, and the first liquid injection port 11 under the action of the pressure difference. In this process, the liquid inlet 6 on the injection cup 111 can be kept open, so as to keep the inner cavity 2 at a constant positive pressure, so that the electrolyte can flow smoothly.

[0064] During the above-mentioned liquid injection process, the electrolyte in the inner cavity 2 may flow completely into the liquid injection cavity 13, or may flow partially into the liquid injection cavity 13. In order to further promote and guide the flow of the electrolyte, the liquid inlet 6 can be closed, the first channel 4 and the third channel 140 can be opened, the positive pressure device connected to the first channel 4 can be started to apply positive pressure to the inner cavity 2, and the negative pressure device connected to the third channel 140 can be started to apply negative pressure to the liquid injection cavity 13. The electrolyte is pushed to flow continuously into the liquid injection cavity 13 by the positive pressure in the inner cavity 2, and the gas in the liquid injection cavity 13 is pulled out by the negative pressure in the liquid injection cavity 13, and the internal and external pressure difference is continuously created, so that the electrolyte can fully flow into the set position in the liquid injection cavity 13. After the liquid injection is completed, the inner cavity 2 and the liquid injection cavity 13 can be depressurized.

[0065] On the one hand, the present application achieves the technical effect that after the first liquid outlet 8 is blocked by the second blocking member 9, the first blocking member 7 can be opened to inject electrolyte into the inner cavity 2 when negative pressure is applied to the outer cavity 3 and the liquid injection cavity 13 through the second channel 5 and the third channel 140, thereby accelerating the liquid injection speed, improving production efficiency, and reducing production manufacturing costs, thereby solving the technical problem in the related art that negative pressure extraction and liquid preparation cannot be performed at the same time, resulting in reduced production efficiency; and, since the inner cavity 2 of the liquid injection cup 111 can directly form a pressure difference with the liquid injection cavity 13, the electrolyte in the inner cavity 2 can naturally flow into the liquid injection cavity 13 under the action of the pressure difference, so there is no need to control the ambient pressure;

[0066] On the other hand, in the process of pumping negative pressure, the first liquid injection port 11 and the second liquid injection port 12 are used to simultaneously apply negative pressure to the liquid injection cavity 13, shortening the time for the liquid injection cavity 13 to reach the set pressure value, thereby further improving production efficiency;

[0067] On the other hand, after the electrolyte is injected through the pressure difference between the inner cavity 2 and the injection cavity 13, positive pressure can be applied to the inner cavity 2 through the first channel 4, forcing the electrolyte in the inner cavity 2 to flow into the injection cavity 13 under the action of the pressure difference, and at the same time, negative pressure is applied to the injection cavity 13 through the second injection port 12 of the third channel 140, pulling the air flow out, continuously creating a negative pressure environment in the injection cavity 13, prompting the electrolyte to flow in, and further improving the injection effect. In addition, in this process, a pressure difference can be continuously created in the injection cavity 13, giving up the control of the ambient pressure, reducing the difficulty of controlling the ambient pressure;

[0068] On the other hand, during the entire injection process, negative pressure will not be applied to the inner cavity 2 of the injection cup 111, so the electrolyte in the injection cavity 13 will not flow into the inner cavity 2, so that the electrolyte will not be lost, reducing the material use cost; and there is no high and low pressure circulation in the entire injection process, which will not cause gas waste, further reducing manufacturing costs.

[0069] In one embodiment of the battery cell assembly 10, Figure 3 As shown, it includes a shell 104, a cover plate 101, a core 103 and a fluid 102, wherein the core 103 includes a positive electrode, a negative electrode, a diaphragm and a core rod, and the core 103 is rolled into the shell 104, the fluid 102 is installed at both ends of the shell 104, and the cover plate 101 is installed at the end of the shell 104. The shape of the entire battery cell assembly 10 can be cylindrical, square, polygonal, annular, etc. The height of the battery cell assembly 10 can be between 60mm and 500mm, and the diameter can be between 30mm and 250mm. It should be noted that the above description of the specific structure of the battery cell assembly 10 is not restrictive, and those skilled in the art can design it according to needs.

[0070] To facilitate the control of the opening and closing of the first channel 4 and the second channel 5, as Figure 1 and Figure 2 As shown, the first channel 4 in this embodiment includes a first control valve 41 connected to the inner cavity 2, and the second channel 5 includes a second control valve 51 connected to the outer cavity 3. Specifically, it should be noted that the first end of the first control valve 41 is connected to the inner cavity 2 after passing through the outer cavity 3, and the first control valve 41 is partially sealed in contact with the side wall of the outer cavity 3. The second end of the first control valve 41 can be connected to the positive pressure device through a pipeline. Similarly, the first end of the second control valve 51 is connected to the outer cavity 3, and the second end can be connected to the negative pressure device through a pipeline. During the injection process, the opening and closing of the first control valve 41 and the second control valve 51 are respectively controlled according to the injection process, and the positive pressure control of the inner cavity 2 and the negative pressure control of the outer cavity 3 are realized with the cooperation of the corresponding positive pressure device and negative pressure device.

[0071] During the injection process, the third channel 140 is always used to apply negative pressure to the injection chamber 13 under the action of the negative pressure device. Specifically, according to the injection process, before the electrolyte enters the injection chamber 13, it is necessary to apply negative pressure to the injection chamber 13 through the third channel 140, and after the electrolyte enters the injection chamber 13, it is also necessary to apply negative pressure to the injection chamber 13 through the third channel 140 to pull the airflow. However, there is a large difference in the pressure values ​​of the two negative pressures. When the negative pressure is applied for the first time, there is no electrolyte in the injection chamber 13, so the negative pressure value can be larger at this time. When the negative pressure is applied for the second time, there is electrolyte in the injection chamber 13. Therefore, in order to avoid the effective substances in the electrolyte being affected by the large negative pressure, the negative pressure applied for the second time in this embodiment is small, and it can play the role of pulling the airflow.

[0072] Therefore, to facilitate control, the third channel 140 in this embodiment includes a connecting pipe 1401 and a third control valve 1402 and a fourth control valve 1403 connected to the connecting pipe 1401. The connecting pipe 1401 is connected to the second liquid injection port 12. The third control valve 1402 is located between the battery cell assembly 10 and the fourth control valve 1403. The third control valve 1402 and the fourth control valve 1403 are both used to connect to the negative pressure equipment.

[0073] Specifically, it should be noted that the third control valve 1402 is closer to the battery cell assembly 10, so the third control valve 1402 is used to open when the negative pressure is applied for the second time, and the fourth control valve 1403 is used to open when the negative pressure is applied for the first time. According to this setting, even if the electrolyte in the injection cavity 13 enters the connecting tube 1401 when the negative pressure is applied for the second time, since the third control valve 1402 is located at the front end of the fourth control valve 1403, the electrolyte will not enter the fourth control valve 1403.

[0074] In one embodiment of the first liquid injection port 11 and the second liquid injection port 12, the first liquid injection port 11 and the second liquid injection port 12 are located on the same side of the battery cell assembly 10. Figure 1 As shown, the first injection port 11 and the second injection port 12 are located on different sides of the battery cell assembly 10, that is, the first injection port 11 and the second injection port 12 are respectively located on both sides of the battery cell assembly 10. Arranging the two injection ports on both sides of the battery cell assembly 10 can improve the efficiency of pumping the negative pressure of the injection cavity 13 to the set pressure value compared to arranging them on the same side, and can better pull the airflow out after the electrolyte enters the injection cavity 13, thereby improving the injection effect of the electrolyte.

[0075] As for the horizontal arrangement of the first liquid injection port 11 and the second liquid injection port 12 , in one embodiment, the horizontal height of the second liquid injection port 12 is the same as the horizontal height of the first liquid injection port 11 .

[0076] In another embodiment, the first injection port 11 is close to the lower part of the injection cavity 13, that is, the distance between the first injection port 11 and the lower edge of the injection cavity 13 is less than the first preset distance, and the second injection port 12 is close to the upper part of the injection cavity 13, that is, the distance between the second injection port 12 and the upper edge of the injection cavity 13 is less than the second preset distance. Here, the first preset distance and the second preset distance can be the same or different, and the upper edge and the lower edge of the injection cavity 13 are the upper and lower edges of the injection cavity 13 viewed from the electrolyte injection direction. In this embodiment, the first injection port 11 is located at a low position, and the second injection port 12 is located at a high position. Since the first injection port 11 is used for the electrolyte to enter the injection cavity 13, the low-positioned first injection port 11 is conducive to the flow of the electrolyte. At the same time, since there is electrolyte in the injection cavity 13 when negative pressure is applied to the injection cavity 13 for the second time through the third channel 140 , the second injection port 12 located at a high position can prevent the electrolyte from flowing out of the injection cavity 13 .

[0077] On the basis that the second injection port 12 is located at a high position, according to the structural characteristics of the battery, the electrolyte in the injection chamber 13 does not need to completely fill the injection chamber 13, but only needs to cover the outermost diaphragm or electrode sheet. Therefore, when the injection amount of the electrolyte meets the demand, there is still a certain amount of free space in the upper part of the injection chamber 13. Therefore, in order to further avoid the electrolyte from flowing out when the negative pressure is applied to the injection chamber 13 for the second time, the second injection port 12 in this embodiment corresponds to the upper free space in the injection chamber 13, and the upper free space is the space remaining in the injection chamber 13 after the set amount of electrolyte is injected.

[0078] Specifically, it should be noted that the height position of the second injection port 12 needs to be determined according to the position of the upper free space after the required amount of electrolyte is injected into the injection cavity 13. Different battery structures have different corresponding upper free space positions and can be designed according to actual needs.

[0079] On the basis of the above-mentioned embodiment, in order to further prevent the electrolyte in the injection chamber 13 from overflowing and affecting the vacuum pipeline, the third channel 140 in this embodiment further includes an electrolyte overflow prevention container 15, through which the overflowed electrolyte can be buffered to prevent the electrolyte from entering the vacuum pipeline with the airflow and further affecting the negative pressure device.

[0080] Specifically, Figure 4 In this embodiment, in order to cooperate with the electrolyte overflow prevention container 15, the connecting pipe 1401 includes a main pipe 14010, a first branch pipe 14011 and a second branch pipe 14012;

[0081] The first end of the main pipe 14010 is connected to the second liquid filling port 12, the second end of the main pipe 14010 is connected to the fourth control valve 1403, the first end of the first branch pipe 14011 is connected to the main pipe 14010 and is located at the front end of the fourth control valve 1403, the second end of the first branch pipe 14011 is connected to the electrolyte overflow prevention container 15, the first end of the second branch pipe 14012 is connected to the third control valve 1402, and the second end of the second branch pipe 14012 is connected to the electrolyte overflow prevention container 15.

[0082] The electrolyte overflow prevention container 15 in this embodiment has a certain volume, and the first branch pipe 14011 and the second branch pipe 14012 are both connected to the electrolyte overflow prevention container 15. After the fourth control valve 1403 is closed and the third control valve 1402 is opened to apply negative pressure to the liquid injection chamber 13, even if the electrolyte flows out of the liquid injection chamber 13 with the airflow under the negative pressure, it will enter the electrolyte overflow prevention container 15 after passing through the first branch pipe 14011. Since the electrolyte is a liquid, it will be separated from the airflow under the action of gravity and buffered in the electrolyte overflow prevention container 15, while the airflow enters the vacuum pipeline through the second branch pipe 14012 under the action of negative pressure. In this embodiment, the electrolyte overflow prevention container 15, the main pipe 14010, the first branch pipe 14011 and the second branch pipe 14012 are arranged so that the electrolyte overflowing from the liquid injection chamber 13 will not enter the vacuum pipeline and affect the vacuum equipment.

[0083] On the basis of the above-mentioned implementation mode, in order to further improve the effect of gas-liquid separation, in this embodiment, the length of the first branch pipe 14011 is longer, and its lower end extends toward the bottom of the electrolyte overflow prevention container 15, and the length of the second branch pipe 14012 is shorter, and its lower end is closer to the upper part of the electrolyte overflow prevention container 15, thereby increasing the flow path of the airflow and requiring the airflow to return, thereby increasing the gas-liquid separation effect.

[0084] In order to intuitively judge whether the electrolyte overflows, the electrolyte overflow prevention container 15 in this embodiment can be made of a transparent material.

[0085] According to another aspect of the present application, a battery injection method is provided, which adopts the above-mentioned battery injection structure and the following steps:

[0086] Step 1: close the first channel 4 and the first liquid outlet 8, open the second channel 5 and the third channel 140, use the negative pressure device connected to the second channel 5 and the third channel 140 to form a first negative pressure in the outer cavity 3 and the liquid injection cavity 13, and in the process open the liquid inlet 6 to inject the electrolyte into the inner cavity 2;

[0087] Step 2: close the second channel 5 and the third channel 140, keep the liquid inlet 6 open, and then open the first liquid outlet 8, so that the electrolyte in the inner cavity 2 flows into the liquid injection cavity 13 under the pressure difference between the inner cavity 2 and the liquid injection cavity 13, and maintain this state for t1 time, the range of t1 can be designed according to actual needs, and can be 5s-300s; after this step is completed, the electrolyte in the inner cavity 2 may flow completely into the liquid injection cavity 13, or may partially flow into the liquid injection cavity 13;

[0088] Step 3: close the liquid inlet 6, open the first channel 4 and the third channel 140, apply positive pressure to the inner cavity 2 through the positive pressure device connected to the first channel 4, and apply negative pressure to the injection cavity 13 through the negative pressure device connected to the third channel 140, and maintain this state for t2 time, the range of t2 can be designed according to actual needs, and can be 5s-300s;

[0089] Step 4: Depressurize the inner cavity 2 and the injection cavity 13 by opening the corresponding channels.

[0090] In this embodiment, before performing step 1, the liquid injection assembly 1 and the auxiliary assembly 14 need to be sealed and connected to the battery cell assembly 10 to avoid electrolyte loss and internal pressure instability. Specifically, the sealing structure at the connection can be deformed by mechanical extrusion, and the deformation can be controlled to be 10-50% to achieve the purpose of sealing connection. The extrusion method can be through rail or cylinder extrusion, etc. After completing step 4, the liquid injection assembly 1 and the auxiliary assembly 14 can be removed, and then the battery cell assembly 10 can be packaged.

[0091] The present application achieves the technical effect of, through the liquid injection method, after the first liquid outlet 8 is blocked by the second blocking member 9, the first blocking member 7 can be opened to inject electrolyte into the inner cavity 2 when negative pressure is applied to the outer cavity 3 and the liquid injection cavity 13 through the second channel 5 and the third channel 140, thereby accelerating the liquid injection speed, improving production efficiency, and reducing production manufacturing costs, thereby solving the technical problem in the related art that negative pressure extraction and liquid preparation cannot be performed at the same time, resulting in reduced production efficiency; and, because the inner cavity 2 of the liquid injection cup 111 can directly form a pressure difference with the liquid injection cavity 13, the electrolyte in the inner cavity 2 can naturally flow into the liquid injection cavity 13 under the action of the pressure difference, so there is no need to control the ambient pressure;

[0092] On the other hand, in the process of pumping negative pressure, the first liquid injection port 11 and the second liquid injection port 12 are used to simultaneously apply negative pressure to the liquid injection cavity 13, shortening the time for the liquid injection cavity 13 to reach the set pressure value, thereby further improving production efficiency;

[0093] On the other hand, after the electrolyte is injected through the pressure difference between the inner cavity 2 and the injection cavity 13, positive pressure can be applied to the inner cavity 2 through the first channel 4, forcing the electrolyte in the inner cavity 2 to flow into the injection cavity 13 under the action of the pressure difference, and at the same time, negative pressure is applied to the injection cavity 13 through the second injection port 12 of the third channel 140, pulling the air flow out, continuously creating a negative pressure environment in the injection cavity 13, prompting the electrolyte to flow in, and further improving the injection effect. In addition, in this process, a pressure difference can be continuously created in the injection cavity 13, giving up the control of the ambient pressure, reducing the difficulty of controlling the ambient pressure;

[0094] On the other hand, during the entire injection process, negative pressure will not be applied to the inner cavity 2 of the injection cup 111, so the electrolyte in the injection cavity 13 will not flow into the inner cavity 2, so that the electrolyte will not be lost, reducing the material use cost; and there is no high and low pressure circulation in the entire injection process, which will not cause gas waste, further reducing manufacturing costs.

[0095] In order to prevent the electrolyte from flowing out under the action of negative pressure when negative pressure is applied to the injection chamber 13 for the second time, in this embodiment, it is necessary to control the pressure value of the negative pressure applied to the injection chamber 13 by the negative pressure device connected to the third channel 140, so that the effective substances in the electrolyte in the injection chamber 13 will not enter the third channel 140.

[0096] During the injection process, the third channel 140 is always used to apply negative pressure to the injection chamber 13 under the action of the negative pressure device. Specifically, according to the injection process, before the electrolyte enters the injection chamber 13, it is necessary to apply negative pressure to the injection chamber 13 through the third channel 140, and after the electrolyte enters the injection chamber 13, it is also necessary to apply negative pressure to the injection chamber 13 through the third channel 140 to pull the airflow. However, there is a large difference in the pressure values ​​of the two negative pressures. When the negative pressure is applied for the first time, there is no electrolyte in the injection chamber 13, so the negative pressure value can be larger at this time. When the negative pressure is applied for the second time, there is electrolyte in the injection chamber 13. Therefore, in order to avoid the effective substances in the electrolyte being affected by the large negative pressure, the negative pressure applied for the second time in this embodiment is small, and it can play the role of pulling the airflow.

[0097] Therefore, for ease of control, in one embodiment, Figure 1 As shown, the third channel 140 includes a connecting pipe 1401 and a third control valve 1402 and a fourth control valve 1403 connected to the connecting pipe 1401. The connecting pipe 1401 is connected to the second liquid injection port 12. The third control valve 1402 is located between the battery cell assembly 10 and the fourth control valve 1403. The third control valve 1402 and the fourth control valve 1403 are both used to connect to the negative pressure equipment.

[0098] Specifically, it should be noted that the third control valve 1402 is closer to the battery cell assembly 10, so the third control valve 1402 is used to open when the negative pressure is applied for the second time, and the fourth control valve 1403 is used to open when the negative pressure is applied for the first time. According to this setting, even if the electrolyte in the injection cavity 13 enters the connecting tube 1401 when the negative pressure is applied for the second time, since the third control valve 1402 is located at the front end of the fourth control valve 1403, the electrolyte will not enter the fourth control valve 1403, that is, it can prevent the electrolyte from entering the high negative pressure device.

[0099] The liquid injection method using the liquid injection structure in this embodiment is as follows: first, close the first channel 4, the third control valve 1402 and the first liquid outlet 8, open the second channel 5 and the fourth control valve 1403, at this time, the inner cavity 2 of the liquid injection cup 111 is completely isolated from the outer cavity 3, and the second channel 5, the outer cavity 3, the liquid injection cavity 13 and the fourth control valve 1403 remain connected. Start the negative pressure device connected to the second channel 5 and the negative pressure device connected to the fourth control valve 1403 to simultaneously apply negative pressure to the liquid injection cavity 13, so that the pressure in the liquid injection cavity 13 quickly reaches the set pressure value. Since the inner cavity 2 is completely isolated from the outer cavity 3 during this process, the process of applying negative pressure to the outer cavity 3 and the liquid injection cavity 13 does not affect the inner cavity 2, so that the liquid inlet 6 can be opened synchronously during this process to inject the electrolyte into the inner cavity 2 for temporary storage.

[0100] When the pressure value in the injection cavity 13 reaches the set value, the second channel 5 and the fourth control valve 1403 can be closed, and the negative pressure applied to the injection cavity 13 is stopped, and the negative pressure of the injection cavity 13 is maintained at the set value. At this time, there is a pressure difference between the injection cavity 13 and the inner cavity 2 of the injection cup 111. Therefore, the first liquid outlet 8 can be opened, and the electrolyte in the inner cavity 2 will flow into the injection cavity 13 through the lower part of the outer cavity 3, the second liquid outlet 112, and the first liquid injection port 11 under the action of the pressure difference. In this process, the liquid inlet 6 on the injection cup 111 can be kept open, so as to keep the inner cavity 2 at a constant positive pressure, so that the electrolyte can flow smoothly.

[0101] During the above-mentioned liquid injection process, the electrolyte in the inner cavity 2 may flow completely into the liquid injection cavity 13, or may flow partially into the liquid injection cavity 13. In order to further promote and guide the flow of the electrolyte, the liquid inlet 6 can be closed, the first channel 4 and the third control valve 1402 can be opened, the positive pressure device connected to the first channel 4 can be started to apply positive pressure to the inner cavity 2, and the negative pressure device connected to the third control valve 1402 can be started to apply negative pressure to the liquid injection cavity 13. The electrolyte is pushed to flow continuously into the liquid injection cavity 13 by the positive pressure in the inner cavity 2, and the gas in the liquid injection cavity 13 is pulled out by the negative pressure in the liquid injection cavity 13, and the internal and external pressure difference is continuously created, so that the electrolyte can fully flow into the set position in the liquid injection cavity 13. After the liquid injection is completed, the inner cavity 2 and the liquid injection cavity 13 can be depressurized.

[0102] In addition, on this basis, in order to further avoid the impact of electrolyte overflow in the injection chamber 13 on the vacuum pipeline. Figure 4 As shown, in this embodiment, an electrolyte overflow prevention container 15 is arranged at the front end of the third control valve 1402. The electrolyte overflow prevention container 15 can be used to buffer the overflowed electrolyte to prevent the electrolyte from entering the vacuum pipeline with the airflow, thereby affecting the negative pressure equipment connected to the third control valve 1402.

[0103] Furthermore, the pressure value of the first negative pressure is -0.9~-1.0Mpa, the pressure value of the positive pressure applied to the inner cavity 2 by the positive pressure device connected to the first channel 4 is 0.3~0.6Mpa, and the negative pressure value applied to the injection cavity 13 by the negative pressure device connected to the third channel 140 is 0~-0.07Mpa.

[0104] Furthermore, during step three, the electrolyte overflow prevention module disposed on the third channel 140 is used to observe whether the electrolyte in the injection cavity 13 overflows, and prevent the electrolyte from being sucked into the vacuum pipe through the third channel 140 .

[0105] In this embodiment, the electrolyte overflow prevention module may be a transparent electrolyte overflow prevention container 15, or other equipment capable of monitoring electrolyte outflow, and this embodiment does not impose any limitation thereto.

[0106] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Within the spirit and principle of the present application, any modification, equivalent replacement, improvement, etc. made shall be included in the protection scope of the present application.

Claims

1. A battery injection method, characterized in that: The injection structures used include: A battery cell assembly, wherein the battery cell assembly is provided with a first liquid injection port and a second liquid injection port communicating with the liquid injection cavity; The liquid injection assembly comprises a liquid injection cup, wherein the liquid injection cup is provided with an inner cavity and an outer cavity isolated from each other, the upper end of the liquid injection cup is provided with a liquid inlet connected with the inner cavity, and the liquid inlet is provided with a first blocking member that can be opened and closed; The lower end of the inner cavity is provided with a first liquid outlet communicating with the outer cavity, and a second closing member that can be opened and closed is provided in the first liquid outlet; the lower end of the liquid injection cup is provided with a second liquid outlet communicating with the outer cavity, and the second liquid outlet is communicated with the first liquid injection outlet; The inner cavity is connected to a positive pressure device through a first channel to apply positive pressure to the inner cavity; the outer cavity is connected to a negative pressure device through a second channel to apply negative pressure to the outer cavity and the injection cavity; an auxiliary component, comprising a third channel, a first end of the third channel being in communication with the second liquid injection port, and a second end of the third channel being in communication with the negative pressure device to apply negative pressure to the liquid injection cavity; The injection structure is used to perform injection according to the following steps: Step 1: closing the first channel and the first liquid outlet, opening the second channel and the third channel, using a negative pressure device connected to the second channel and the third channel to form a first negative pressure in the outer cavity and the liquid injection cavity, and in the process opening the liquid inlet to inject the electrolyte into the inner cavity; Step 2: closing the second channel and the third channel, keeping the liquid inlet open, and then opening the first liquid outlet, so that the electrolyte in the inner cavity flows into the liquid injection cavity under the pressure difference between the inner cavity and the liquid injection cavity, and maintaining this state for t1 time; Step 3: close the liquid inlet, open the first channel and the third channel, apply positive pressure to the inner cavity through a positive pressure device connected to the first channel, and apply negative pressure to the injection cavity through a negative pressure device connected to the third channel, wherein the negative pressure value is less than the first negative pressure value, and maintain this state for t2 time; Step 4: depressurizing the inner cavity and the injection cavity.

2. The liquid injection method according to claim 1, characterized in that: Control the pressure value of the negative pressure applied to the injection cavity by the negative pressure device connected to the third channel.

3. The liquid injection method according to claim 1, characterized in that: The first passage includes a first control valve communicating with the inner cavity, and the second passage includes a second control valve communicating with the outer cavity.

4. The liquid injection method according to claim 1, characterized in that: The third channel includes a connecting pipe and a third control valve and a fourth control valve connected to the connecting pipe. The connecting pipe is connected to the second liquid injection port. The third control valve is located between the battery cell assembly and the fourth control valve. The third control valve and the fourth control valve are both used to connect to the negative pressure device.

5. The liquid injection method according to claim 1, characterized in that: The first liquid injection port and the second liquid injection port are located on the same side of the battery core assembly; or the first liquid injection port and the second liquid injection port are located on two sides of the battery core assembly respectively.

6. The liquid injection method according to any one of claims 1 to 5, characterized in that: The second liquid injection port has the same level as the first liquid injection port.

7. The liquid injection method according to any one of claims 1 to 5, characterized in that: The first liquid injection port is close to the lower part of the liquid injection cavity, and the second liquid injection port is close to the upper part of the liquid injection cavity.

8. The liquid injection method according to claim 7, characterized in that: The second liquid injection port corresponds to an upper free space in the liquid injection cavity, and the upper free space is a space remaining in the liquid injection cavity after a set amount of electrolyte is injected.

9. The liquid injection method according to claim 4, characterized in that: The third channel also includes an electrolyte overflow prevention container, and the connecting pipe includes a main pipe, a first branch pipe, and a second branch pipe; The first end of the main pipe is connected to the second liquid filling port, the second end of the main pipe is connected to the fourth control valve, the first end of the first branch pipe is connected to the main pipe and is located at the front end of the fourth control valve, the second end of the first branch pipe is connected to the electrolyte overflow prevention container, the first end of the second branch pipe is connected to the third control valve, and the second end of the second branch pipe is connected to the electrolyte overflow prevention container.

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