Battery liquid injection device

Abstract

The utility model relates to a battery liquid injection device which comprises a low-concentration electrolyte tank and a high-concentration electrolyte tank, a first valve is mounted at the output end of the low-concentration electrolyte tank, and a second valve is mounted at the output end of the high-concentration electrolyte tank; the output end of the electrolyte recovery tank is provided with a sixth valve; the first pipe body is communicated with the first valve, the second valve and the sixth valve; the three-way valve comprises a main pipe opening and a first branch pipe opening, the main pipe opening of the three-way valve is communicated with the first pipe body, the first branch pipe opening of the three-way valve is communicated with a second pipe body, the second pipe body is provided with a third valve, and one end of the second pipe body is communicated with a battery. According to the present invention, the low-concentration electrolyte can be injected first, the free low-concentration electrolyte can be discharged after the primary formation, and the high-concentration electrolyte can be injected, such that the infiltration time of the battery is reduced, and the compact SEI film (solid electrolyte interface film) can be formed during the formation so as to easily achieve the stability of the battery in the long cycle.

Description

Technical Field

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

[0002] Liquid injection in the secondary battery preparation process refers to the process of controlling the amount of liquid electrolyte and the injection time so that the liquid electrolyte is injected into the battery from the injection port.

[0003] In the related art, the concentration of the electrolyte injected into the battery at one time is too high. As the concentration of lithium salt in the electrolyte increases, the viscosity of the liquid also increases. The increase in viscosity directly leads to a decrease in the wettability of the electrolyte, which prolongs the electrolyte infiltration time of the battery. Summary of the invention

[0004] The present application provides a battery injection device, which can first inject a low-concentration electrolyte, discharge the free low-concentration electrolyte after one-time formation, and then inject a high-concentration electrolyte, so that the battery's immersion time is reduced. At the same time, a denser SEI film (solid electrolyte interface film) will be formed during formation, which is beneficial to the stability of the battery in a long cycle.

[0005] The present application provides a battery liquid injection device, which includes:

[0006] A low-concentration electrolyte tank and a high-concentration electrolyte tank, wherein a first valve is installed at the output end of the low-concentration electrolyte tank, and a second valve is installed at the output end of the high-concentration electrolyte tank;

[0007] An electrolyte recovery tank, wherein a sixth valve is installed at the output end of the electrolyte recovery tank;

[0008] a first tube body, wherein the first tube body is connected to the first valve, the second valve and the sixth valve;

[0009] A three-way valve, comprising a main pipe port and a first branch pipe port; the main pipe port of the three-way valve is connected to the first pipe body, the first branch pipe port of the three-way valve is connected to the second pipe body, the second pipe body is installed with a third valve, and one end of the second pipe body is connected to a battery.

[0010] In one embodiment, the three-way valve further includes a second branch pipe port, and the second branch pipe port is connected to a negative air pressure device.

[0011] In one embodiment, the second branch pipe opening is also connected to a high-pressure gas device.

[0012] In one embodiment, the battery filling device further includes:

[0013] A three-way vent pipe, the main pipeline of which is connected to the second branch pipe opening of the three-way valve;

[0014] The first branch pipe of the three-way air pipe is connected to the negative air pressure device, and the first branch pipe is installed with a fourth valve;

[0015] The second branch pipeline of the three-way air pipe is connected to the high-pressure gas device, and the second branch pipeline is installed with a fifth valve.

[0016] In one embodiment, the second tube body is connected to the liquid filling port of the battery via a hose.

[0017] In one embodiment, the battery filling device further includes:

[0018] An electrolyte recovery tank, wherein a sixth valve is installed at the output end of the electrolyte recovery tank, and the sixth valve is connected to the first pipe body.

[0019] In one embodiment, the battery filling device further includes:

[0020] A rotating device is fixed to the battery, and can drive the horizontally placed battery to rotate.

[0021] In one embodiment, the rotating device comprises:

[0022] A motor, wherein a rotating turntable is installed at the output end of the motor, and the rotating turntable is provided with a clamping assembly, and the clamping assembly is used to clamp and fix the battery.

[0023] In one embodiment, the clamping assembly comprises:

[0024] Two elastic expansion members, the elastic expansion members are parallel to the rotating surface of the rotating turntable and are fixed to the rotating turntable, and the two elastic expansion members are located on the same axis;

[0025] A straight plate is fixed to the telescopic end of the elastic telescopic member, and the two straight plates move and clamp the two sides of the battery through the elastic force of the elastic telescopic member connected to them.

[0026] In one embodiment, the clamping assembly comprises:

[0027] Four elastic expansion members, wherein the elastic expansion members are parallel to the rotating surface of the rotating turntable and are fixed to the rotating turntable, and the four elastic expansion members are located on two axes perpendicular to each other;

[0028] A right-angle plate is fixed to the telescopic end of the elastic telescopic member, and the four right-angle plates are moved to clamp the four corners of the battery through the elastic force of the elastic telescopic member connected to them.

[0029] In one embodiment, the elastic telescopic member includes a spring telescopic rod.

[0030] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0031] First, a low-concentration electrolyte is injected into the battery through a low-concentration electrolyte tank for a primary formation, and then the free low-concentration electrolyte after the primary formation is discharged to the electrolyte recovery tank, and then a high-concentration electrolyte is injected into the battery through a high-concentration electrolyte tank. The low-concentration electrolyte is injected first, the free low-concentration electrolyte is discharged after a primary formation, and then a high-concentration electrolyte is injected, which reduces the battery's immersion time, and uses a low-concentration electrolyte to form a dense and stable SEI film (solid electrolyte interface film), which is beneficial to the stability of the battery in a long cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a structural schematic diagram of a battery liquid injection device;

[0034] Figure 2 It is a structural schematic diagram of the rotating device.

[0035] In the figure: 1. low-concentration electrolyte tank; 101. first valve; 2. high-concentration electrolyte tank; 201. second valve; 3. first tube body; 4. three-way valve; 5. second tube body; 501. third valve; 6. battery; 7. three-way air pipe; 701. main pipeline; 702. first branch pipeline; 703. fourth valve; 704. fifth valve; 705. second branch pipeline; 8. electrolyte recovery tank; 801. sixth valve; 9. rotating device; 901. rotating turntable; 902. clamping assembly; 9021. elastic telescopic member; 9022. right-angle plate. DETAILED DESCRIPTION

[0036] 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 are within the scope of protection of this application.

[0037] The embodiment of the present application provides a battery injection device, which can first inject a low-concentration electrolyte, discharge the free low-concentration electrolyte after one formation, and then inject a high-concentration electrolyte, so as to reduce the battery's immersion time and improve the lithium salt precipitation phenomenon. At the same time, a denser SEI film (solid electrolyte interface film) will be formed during the formation, which is beneficial to the stability of the battery in a long cycle.

[0038] like Figure 1 As shown, an embodiment of the present application provides a battery injection device, which includes: a low-concentration electrolyte tank 1 and a high-concentration electrolyte tank 2, the output end of the low-concentration electrolyte tank 1 is equipped with a first valve 101, and the output end of the high-concentration electrolyte tank 2 is equipped with a second valve 201; an electrolyte recovery tank 8, the output end of the electrolyte recovery tank 8 is equipped with a sixth valve 801; a first tube body 3, the first tube body 3 is connected to the first valve 101, the second valve 201 and the sixth valve 801; a three-way valve 4, the three-way valve 4 includes a main pipe port and a first branch pipe port; the main pipe port of the three-way valve 4 is connected to the first tube body 3, the first branch pipe port of the three-way valve 4 is connected to the second tube body 5, the second tube body 5 is equipped with a third valve 501, and one end of the second tube body 5 is connected to the battery 6.

[0039] It should be noted that the naming meaning of the low-concentration electrolyte tank 1 and the high-concentration electrolyte tank 2 is that the electrolyte concentration of the low-concentration electrolyte tank 1 is lower than the electrolyte concentration of the high-concentration electrolyte tank 2 .

[0040] First, a low-concentration electrolyte is injected into the battery 6 through the low-concentration electrolyte tank 1 to perform a primary formation, and then the free low-concentration electrolyte after the primary formation is discharged to the electrolyte recovery tank 8, and then a high-concentration electrolyte is injected into the battery 6 through the high-concentration electrolyte tank 2. The low-concentration electrolyte is injected first, the free low-concentration electrolyte is discharged after the primary formation, and then the high-concentration electrolyte is injected, so that the immersion time of the battery 6 is reduced, and the lithium salt precipitation phenomenon is improved. At the same time, a more compact SEI film (solid electrolyte interface film) will be formed during the formation, which is beneficial to the stability of the battery 6 in a long cycle.

[0041] Furthermore, the three-way valve 4 also includes a second branch pipe port, and the second branch pipe port is connected to a negative air pressure device.

[0042] Furthermore, the second branch pipe opening is also connected to a high-pressure gas device.

[0043] Further, such as Figure 1As shown, the battery filling device may also include: a three-way air pipe 7, a main pipe 701 of the three-way air pipe 7 is connected to the second branch pipe opening of the three-way valve 4, a first branch pipe 702 of the three-way air pipe 7 is connected to a negative air pressure device (not shown in the figure), and the first branch pipe 702 is installed with a fourth valve 703; the second branch pipe 705 of the three-way air pipe 7 is connected to a high-pressure gas device (not shown in the figure), and the second branch pipe 705 is installed with a fifth valve 704.

[0044] Furthermore, the second tube body 5 is connected to the liquid injection port of the battery 6 via a hose.

[0045] Among them, in actual work, the first branch pipe port and the second branch pipe port of the three-way valve 4 are first connected, and the fourth valve 703 and the third valve 501 are opened, and the negative air pressure device can pump negative pressure to the battery 6; after the negative pressure is pumped, the fourth valve 703 is closed, and then the three-way valve 4 is rotated to make the main pipe port of the three-way valve 4 and the first branch pipe port connected, and the first valve 101 is opened to realize the injection of low-concentration electrolyte. After the injection of low-concentration electrolyte is completed, the first valve 101 and the third valve 501 are closed, and the battery after the low-concentration injection is taken out for a formation. After the formation is completed, the battery is put back to the original position of the battery injection device, and the three-way valve 4 is continued to be rotated so that the first branch pipe port and the second branch pipe port of the three-way valve 4 are in a connected state, and the fifth valve 704 and the third valve 501 are opened. At this time, high-pressure gas is injected into the second branch pipe 705 through the high-pressure gas device, and the high-pressure gas flows to the inside of the battery 6. Then the fifth valve 704 is closed, and the three-way valve 4 is rotated so that the main pipe port of the three-way valve 4 and the first branch pipe port are in a connected state, and the sixth valve 801 is opened to discharge the free low-concentration electrolyte after the formation inside the battery 6 through the second tube body 5 and the first tube body 3 to the electrolyte recovery tank 8. When injecting high-concentration electrolyte for the second time, the part of low-concentration electrolyte injected for the first time that is free after the first formation can be discharged first, so that the concentration of the electrolyte does not need to be too high during the second injection, avoiding the problem of excessive concentration change between two injections and uneven distribution of lithium ions inside the battery, and reducing the situation of lithium salt precipitation of high-concentration electrolyte blocking the injection pipeline. On the other hand, it also realizes resource recycling.

[0046] Further, such as Figure 1As shown, the battery injection device may further include: a rotating device 9, which is fixed to the battery 6, and the rotating device 9 can drive the horizontally placed battery 6 to rotate. Among them, the battery horizontal limit is fixed on the rotating device 9, and the rotating device 9 is driven to drive the battery 6 to rotate 180 degrees, so that the battery rotates from the state where the injection port is facing upward to the state where the injection port is facing downward. On the one hand, the electrolyte can be completely immersed in the battery after injection, and on the other hand, the time for discharging part of the low-concentration electrolyte freed after the primary formation to the electrolyte recovery tank 8 can be shortened, ensuring that the process of recovering the low-concentration electrolyte is fast and convenient.

[0047] Further, such as Figure 2 As shown, the rotating device 9 may include: a motor (not shown in the figure), a rotating turntable 901 is installed at the output end of the motor, and the rotating turntable 901 is provided with a clamping assembly 902, and the clamping assembly 902 is used to clamp and fix the battery 6. The rotating turntable 901 is coaxially fixed at the output end of the motor, and the battery 6 is horizontally fixed to the top of the rotating turntable 901 by using the clamping assembly 902. The rotating turntable 901 is driven by controlling the motor to rotate 180 degrees.

[0048] Further, the clamping assembly 902 may include: two elastic expansion members 9021, the elastic expansion members 9021 are parallel to the rotating surface of the rotating turntable 901, and are fixed to the rotating turntable 901, and the two elastic expansion members 9021 are located on the same axis; the telescopic end of the elastic expansion member 9021 is fixed with a straight plate, and the two straight plates move the two sides (not shown) of the clamping battery 6 through the elastic force of the elastic expansion members 9021 connected by themselves. Wherein, the elastic expansion member 9021 is horizontally fixed to the rotating surface of the rotating turntable 901, and the two elastic expansion members 9021 are located on the same axis, so that the two elastic expansion members 9021 are arranged on both sides of the diameter direction of the battery 6, and the symmetrical clamping is fixed to the two sides of the battery 6, completing the limit fixing work of the battery 6.

[0049] Further, such as Figure 2 As shown, the clamping assembly 902 includes: four elastic telescopic members 9021, which are parallel to the rotating surface of the rotating turntable 901 and fixed to the rotating turntable 901, and the four elastic telescopic members 9021 are located on two mutually perpendicular axes; the telescopic ends of the elastic telescopic members 9021 are fixed with right-angle plates 9022, and the four right-angle plates 9022 move and clamp the four corners of the battery 6 through the elastic force of the elastic telescopic members 9021 connected to them. Among them, each group of elastic telescopic members 9021 and right-angle plates 9022 can limit a corner of the battery 6, and the four corners of the battery 6 are limited and clamped by four groups of elastic telescopic members 9021 and right-angle plates 9022, and the clamping is stable and reliable.

[0050] Furthermore, the elastic telescopic member 9021 includes a spring telescopic rod.

[0051] Furthermore, the electrolyte solubility in the low-concentration electrolyte tank 1 is 0.7-0.9 mol / L.

[0052] Furthermore, the electrolyte solubility in the high-concentration electrolyte tank 2 is 1.1 to 1.3 mol / L.

[0053] The specific working principle is as follows:

[0054] Step 1: Fix the battery 6 to the rotating device 9 in an upright state, so that the first branch pipe port and the second branch pipe port of the three-way valve 4 are in a connected state, open the fourth valve 703 and the third valve 501, and its negative air pressure device can pump negative pressure to the battery 6. After the negative pressure work is completed, close the fourth valve 703, rotate the three-way valve 4, so that the first tube body 3 and the second tube body 5 are connected, open the first valve 101, and inject 0.8mol / L low-concentration electrolyte into the battery 6, and the injection volume is 800g. Among them, the electrolyte concentration range of the first injection is 0.7~0.9mol / L, and the electrolyte volume of the first injection is obtained by the production beat (the more the injection, the slower) and the battery performance (the more the injection volume, the better the infiltration, and the better the battery performance). The first negative pressure range is -4MPa~-5MPa.

[0055] Step 2: After a low-concentration injection is completed, the battery 6 is rotated 180° using the rotating device 9, so that the battery changes from an upright state to an inverted state, that is, rotates from a state with the injection port facing upward to a state with the injection port facing downward, so as to achieve complete immersion of the battery in the electrolyte.

[0056] Step 3: After the injection and soaking of the low-concentration electrolyte are completed, the first valve 101 and the third valve 501 are closed, and the battery after the low-concentration electrolyte injection is taken out from the rotating device 9 for a formation. The conditions for the formation are 12 hours at room temperature (24°C) plus 12 hours at high temperature (45°C).

[0057] Step 4: After the formation is completed, the battery 6 is fixed on the rotating device 9 in an inverted state again, the three-way valve 4 is rotated so that the first branch pipe mouth and the second branch pipe mouth of the three-way valve 4 are in a connected state, the fifth valve 704 and the third valve 501 are opened, and the high-pressure gas device is used to drive the high-pressure gas of 1MPa~2MPa into the battery 6 from the second branch pipe 705, the main pipe 701 and the second pipe body 5. After the punching is completed, the fifth valve 704 is closed, the three-way valve 4 is rotated so that the first pipe body 3 and the second pipe body 5 are connected, and the free part of the low-concentration electrolyte after the formation inside the battery 6 is recovered in the electrolyte recovery tank 8, and its outflow is 100g. Wherein, according to the experience of dissecting the battery, the amount of free electrolyte inside the battery 6 after the formation is between 105-110g. In order to ensure the consistency of battery production, the amount of electrolyte extracted is set to 100g. The setting of the amount of electrolyte extracted is that the total free electrolyte range is 95%~91%. When the liquid is drawn for the first time, high voltage is first injected into the battery 6 to make the free electrolyte after the primary formation flow out of the battery 6, so as to avoid excessive low-concentration electrolyte and high-concentration electrolyte in the battery 6 from being unevenly mixed.

[0058] Step 5: After the low-concentration electrolyte is discharged, the battery 6 is fixed on the rotating device 9 in an upright state again, and the first branch pipe port and the second branch pipe port of the three-way valve 4 are connected again. The fourth valve 703 and the third valve 501 are opened, and the negative air pressure device can pump negative pressure to the battery 6. After the negative pressure work is completed, the fourth valve 703 is closed, and the three-way valve 4 is rotated to connect the first tube body 3 and the second tube body 5. The second valve 201 is opened, and 1.2mol / L high-concentration electrolyte is injected into the battery 6, and the injection volume is 350g. Among them, the concentration range of the high-concentration electrolyte is 1.1-1.3mol / L. If the concentration is too low, the secondary injection volume will be too large, and there is a risk of liquid leakage. If the concentration is too high, the viscosity of the electrolyte increases, and it is difficult to inject. The second injection volume is calculated based on the first injection volume, the first injection concentration, the concentration of the extracted electrolyte, and the second electrolyte concentration.

[0059] In the description of the present application, it should be noted that the terms "upper", "lower", etc. 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, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0060] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0061] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A battery filling device, characterized in that: It includes: A low-concentration electrolyte tank (1) and a high-concentration electrolyte tank (2), wherein the output end of the low-concentration electrolyte tank (1) is provided with a first valve (101), and the output end of the high-concentration electrolyte tank (2) is provided with a second valve (201); An electrolyte recovery tank (8), wherein a sixth valve (801) is installed at the output end of the electrolyte recovery tank (8); a first tube body (3), wherein the first tube body (3) is in communication with the first valve (101), the second valve (201) and the sixth valve (801); A three-way valve (4), the three-way valve (4) comprising a main pipe port and a first branch pipe port; the main pipe port of the three-way valve (4) is connected to the first pipe body (3), the first branch pipe port of the three-way valve (4) is connected to the second pipe body (5), the second pipe body (5) is equipped with a third valve (501), and one end of the second pipe body (5) is connected to a battery (6).

2. The battery liquid injection device according to claim 1, characterized in that: The three-way valve (4) further comprises a second branch pipe opening, wherein the second branch pipe opening is connected to a negative air pressure device.

3. The battery liquid injection device according to claim 2, characterized in that: The second branch pipe opening is also connected to a high-pressure gas device.

4. The battery liquid filling device according to claim 3, characterized in that: The battery injection device also includes: A three-way vent pipe (7), wherein the main pipe (701) of the three-way vent pipe (7) is connected to the second branch pipe opening of the three-way valve (4); The first branch pipe (702) of the three-way pipe (7) is in communication with the negative air pressure device, and the first branch pipe (702) is provided with a fourth valve (703); The second branch pipeline (705) of the three-way pipe (7) is connected to the high-pressure gas device, and the second branch pipeline (705) is installed with a fifth valve (704).

5. The battery liquid filling device according to claim 1, characterized in that: The second tube body (5) is connected to the liquid injection port of the battery (6) via a hose.

6. The battery liquid injection device according to claim 1, characterized in that: The battery injection device also includes: A rotating device (9), wherein the rotating device (9) is fixed to the battery (6), and the rotating device (9) can drive the horizontally placed battery (6) to rotate.

7. The battery liquid injection device according to claim 6, characterized in that: The rotating device (9) comprises: A motor, wherein a rotating disk (901) is installed at the output end of the motor, and the rotating disk (901) is provided with a clamping assembly (902), and the clamping assembly (902) is used to clamp and fix the battery (6).

8. The battery liquid injection device according to claim 7, characterized in that: The clamping assembly (902) comprises: Two elastic and retractable members (9021), wherein the elastic and retractable members (9021) are parallel to the rotating surface of the rotating turntable (901) and are fixed to the rotating turntable (901), and the two elastic and retractable members (9021) are located on the same axis; A straight plate is fixed to the telescopic end of the elastic telescopic member (9021), and the two straight plates move and clamp the two sides of the battery (6) through the elastic force of the elastic telescopic member (9021) to which they are connected.

9. The battery liquid filling device according to claim 7, characterized in that: The clamping assembly (902) comprises: Four elastic and retractable members (9021), wherein the elastic and retractable members (9021) are parallel to the rotating surface of the rotating turntable (901) and are fixed to the rotating turntable (901), and the four elastic and retractable members (9021) are located on two axes that are perpendicular to each other; A right-angle plate (9022) is fixed to the telescopic end of the elastic telescopic member (9021), and the four right-angle plates (9022) move and clamp the four corners of the battery (6) through the elastic force of the elastic telescopic member (9021) to which they are connected.

10. The battery liquid injection device according to claim 8 or 9, characterized in that: The elastic telescopic member (9021) comprises a spring telescopic rod.

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