Lithium battery drying and gas collecting device

Abstract

The utility model belongs to the technical field of lithium battery manufacturing, and particularly relates to a lithium battery drying and gas collecting device. Comprising a battery cell, an upper base and a lower base, a vertical rod is fixed to the upper end of the lower base, and the upper end of the vertical rod is slidably connected with an upper base. The upper end of the upper base is connected with a power system; a drying unit and a gas collecting unit are arranged at the lower end of the upper base; the gas collecting unit comprises a gas collecting box, the gas collecting box is installed on the upper base, the gas collecting box is communicated with one end of a gas conveying guide pipe, and the other end of the gas conveying guide pipe is provided with a sealing plug; a liquid injection opening is formed in the battery cell, and the sealing plug is connected with the liquid injection opening; the gas production rate of the lithium ion battery can be detected anytime and anywhere, the battery state is not changed in the whole testing process, and the gas production condition can be truly and accurately reflected.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium battery manufacturing, and particularly relates to a lithium battery drying and gas collecting device. Background Art

[0002] Lithium-ion batteries have been widely used in many mobile devices in the defense, industrial, and civilian fields due to their high energy density, small size, long service life, and low self-discharge. During the charging and discharging process of lithium-ion batteries, the electrode material and the electrolyte react at the solid-liquid interface to form a passivation layer covering the surface of the electrode material. This passivation layer has the characteristics of a solid electrolyte, is an electronic insulator and is also an excellent conductor of Li+. This passivation layer is called a "solid electrolyte interface film," or SEI film for short.

[0003] The transport performance of the SEI film will affect the battery's charge and discharge characteristics, and have a direct impact on the battery's rate performance and cycle performance. The water content in the battery plays a decisive role in the quality and consistency of the SEI film. On the one hand, the water content directly affects the composition of the SEI film; on the other hand, if the water content in the battery is too much, a large amount of gas will be generated during the battery formation process, which will hinder the formation of the SEI film and affect the consistency of the SEI film.

[0004] Therefore, moisture control and battery drying in the production environment are key processes in the production of lithium-ion batteries. Battery drying means volatilizing the internal moisture of the battery at a certain temperature to achieve the purpose of removing the internal moisture of the battery as much as possible. In the process of battery drying, temperature and environmental vacuum have a decisive influence on the drying effect and drying efficiency. The existing drying process generally heats the battery with high-temperature dry air or nitrogen first, and then vacuumizes and pressurizes the battery to gradually remove moisture. However, this drying method has the following defects: first, the heating effect of batteries at different positions in the drying furnace is inconsistent; second, the heat is conducted from the outside of the battery cell to the inside of the battery cell, which is inefficient, especially for laminated batteries, where the heat conduction from the outer electrode to the inner electrode is slow and the consistency is poor; third, the heat transfer medium such as air has a low specific heat capacity, slow heat conduction speed, and slow heating speed for the battery. The presence of gas will cause performance degradation, increased internal resistance, expansion and deformation of lithium-ion batteries. Different positive and negative electrode material systems, different electrolytes, different battery structures, and different pre-formation electrode moisture content have different gas production rules, and the gas composition and volume produced are different. The study of gas production can help in the selection of positive and negative electrode materials for batteries, the identification of electrolyte quality, and the optimization of battery manufacturing processes, and will have an important impact on the electrochemical properties, cycle performance, and safety performance of batteries.

[0005] Therefore, the research on rapid drying and gas collection is of great significance. However, the existing drying devices and gas collection devices are relatively complex and difficult to operate, and the gas collection experimental cells used need to be immersed in the electrolyte, which is inconsistent with the state of the production battery during formation, and cannot fully and accurately reflect the actual gas production conditions. Therefore, a simple, effective, accurate, and instant detection device is needed. Utility Model Content

[0006] In view of the above problems, the utility model proposes a lithium battery drying and gas collection device, comprising a battery cell, an upper base and a lower base; a vertical pole is fixed to the upper end of the lower base, and the upper end of the vertical pole is slidably connected to the upper base; the upper end of the upper base is connected to a power system; a drying unit and a gas collection unit are provided at the lower end of the upper base; the gas collection unit comprises a gas collection box, which is installed on the upper base, the gas collection box is connected to one end of a gas supply conduit, and a sealing plug is provided at the other end of the gas supply conduit; a liquid injection port is opened on the battery cell, and the sealing plug is connected to the liquid injection port.

[0007] Furthermore, the drying unit comprises a heating plate, a positive electrode heat conducting rod and a negative electrode heat conducting rod are arranged at the lower end of the heating plate, a positive electrode heat conducting rod is sleeved with a positive electrode compression spring, and a negative electrode heat conducting rod is sleeved with a negative electrode compression spring.

[0008] Furthermore, a guide groove is provided at the lower end of the lower base, a guide block is slidably connected in the guide groove, a through groove is provided on the heating plate, the upper ends of the positive electrode heat conducting rod and the negative electrode heat conducting rod respectively pass through the through grooves and are connected to the guide block; the middle part of the gas supply conduit is connected to the guide block.

[0009] Furthermore, a groove is provided at the upper end of the upper base, a positioning hole is provided at the bottom of the groove, and a positioning plate is inserted into the positioning hole; the battery cell is placed in the groove, and cell positioning blocks are slidably provided on both sides of the lower base.

[0010] Furthermore, the number of the grooves is ≥2.

[0011] Furthermore, a heating module is arranged in the groove.

[0012] Furthermore, a temperature sensing module is provided on the upper base.

[0013] Furthermore, a check valve is provided on the gas recovery box.

[0014] Furthermore, a limiting block is arranged at the upper end of the vertical pole.

[0015] Furthermore, a buffer spring is sleeved on the vertical pole.

[0016] The present invention is provided with a drying unit and a gas collection unit, which can keep the battery temperature constant, thereby improving the consistency of the battery moisture content. At the same time, the battery gas production measurement system has a simple structure, is easy to operate, safe and effective, and can detect the gas production of lithium-ion batteries anytime and anywhere. The entire test process does not change the battery state, and can truly and accurately reflect the gas production status.

[0017] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by implementing the utility model. The purpose and other advantages of the utility model can be realized and obtained by the structures indicated in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 Shown is a front view of the present invention.

[0020] Figure 2 A top view of the present invention is shown.

[0021] In the figure, 1, upper base; 2, lower base; 3, vertical pole; 4, temperature sensing module; 5, check valve; 6, limit block; 7, buffer spring; 201, heating plate; 10, battery cell; 202, positive electrode thermal conductive rod; 203, negative electrode thermal conductive rod; 204, positive electrode compression spring; 205, negative electrode compression spring; 301, gas collection box; 302, gas transmission duct; 303, sealing plug; 304, liquid filling port; 50, guide block; 70, groove; 80, positioning hole; 90, positioning plate; 100, battery cell positioning block. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The utility model embodiment provides a lithium battery drying and gas collection device, referring to Figure 1 , Figure 1 The invention comprises a battery cell 10, an upper base 1 and a lower base 2; a vertical pole 3 is fixed to the upper end of the lower base 2, and the upper end of the vertical pole 3 is slidably connected to the upper base 1; the upper end of the upper base 1 is connected to the power system; a drying unit and a gas collecting unit are arranged at the lower end of the upper base 1; the gas collecting unit comprises a gas collecting box 301, which is installed on the upper base 1, and the gas collecting box 301 is connected to one end of a gas supply conduit 302, and a sealing plug 303 is arranged at the other end of the gas supply conduit 302; a liquid injection port 304 is opened on the battery cell 10, and the sealing plug 303 is connected to the liquid injection port 304.

[0024] The drying unit comprises a heating plate 201 , a positive heat conducting rod 202 and a negative heat conducting rod 203 are arranged at the lower end of the heating plate 201 , a positive compression spring 204 is sleeved on the positive heat conducting rod 202 , and a negative compression spring 205 is sleeved on the negative heat conducting rod 203 .

[0025] A guide groove is provided at the lower end of the lower base 2, and a guide block 50 is slidably connected in the guide groove. A through groove is provided on the heating plate 201, and the upper ends of the positive electrode heat conducting rod 202 and the negative electrode heat conducting rod 203 pass through the through grooves respectively and are connected to the guide block 50; the middle part of the gas delivery conduit 302 is connected to the guide block 50.

[0026] In a specific implementation, the battery cell 10 is first placed on the lower base 2, and then the guide block 50 is adjusted according to the specifications of the placed battery cell 10 through the positions of the positive pole column, the negative pole column and the injection port 304 on the battery cell 10, so that the guide block 50 moves in the guide groove, so that the guide block 50 drives the positive guide rod and the negative guide rod to move in the through groove, so that the positive thermal conductive rod 202 and the negative thermal conductive rod 203 are respectively moved to the positions opposite to the positive pole column and the negative pole column; at the same time, the guide block 50 on the gas transmission conduit 302 can also be moved. Drive the gas delivery pipe to move to a position corresponding to the liquid injection port 304; wherein the positive electrode heat conducting rod 202 and the negative electrode heat conducting rod 203 can be integrally slidably matched with the through groove of the heating plate 201 to ensure the heat conduction effect, and at the same time, the upper part of the positive electrode heat conducting rod 202 and the negative electrode heat conducting rod 203 can also be slidably matched with the through groove, and the diameter of the lower part of the heat conducting rod is larger than the upper part and also larger than the diameter of the through groove, so that when the heating plate 201 slides to the lower part along the heat conducting rod, the cross section of the lower part of the heat conducting rod is also in contact with the heating plate 201, thereby further increasing the heat conduction effect;

[0027] Then preheat the heating plate 201 to a specified temperature; then drive the upper base 1 to move downward along the vertical rod 3 through the power system, so that the upper base 1 drops to a specified pressure range, driving the positive electrode heat conductive rod 202 and the negative electrode heat conductive rod 203 to move downward to align with the positive electrode column and the negative electrode column; the power system can be a pneumatic cylinder, etc.; under the action of the compression spring, the positive electrode heat conductive rod 202 and the negative electrode heat conductive rod 203 are connected to the positive electrode column and the negative electrode column due to their own heat conduction and the elastic effect of the compression spring, thereby completing the heat transfer effect on the entire battery cell 10; through The temperature rises rapidly and the heat conduction is uniform, which effectively accelerates the drying level of the lithium-ion battery. At the same time, when used in the formation tooling, before the battery cell 10 is formed, the stainless steel needle is inserted into the battery filling port 304 and plugged in tightly, and the sealing plug 303 is fixed at the same time, and a layer of vaseline is applied around the sealing plug 303, wherein the sealing plug 303 can be a solid rubber plug with a sealing lip. For the gas generated by the formation, it flows into the gas delivery conduit 302 through the liquid injection port 304, and then flows into the gas collection box 301 through the gas delivery conduit 302, waiting for test analysis.

[0028] The utility model can maintain a constant battery temperature by arranging a drying unit and a gas collection unit, thereby improving the consistency of the battery's moisture content. At the same time, the battery gas production measurement system has a simple structure, is easy to operate, safe and effective, and can detect the gas production of lithium-ion batteries anytime and anywhere. The entire test process does not change the battery state, and can truly and accurately reflect the gas production status.

[0029] In one embodiment, reference Figure 2 , Figure 2 A groove 70 is formed at the upper end of the upper base 1, a positioning hole 80 is formed at the bottom of the groove 70, and a positioning plate 90 is inserted into the positioning hole 80; the battery cell 10 is placed in the groove 70, and cell positioning blocks 100 are slidably provided on both sides of the lower base 2.

[0030] The number of the grooves 70 is ≥2.

[0031] A heating module is disposed in the groove 70 .

[0032] In a specific implementation, the battery cell 10 is first placed in the groove 70, and then a positioning plate 90 of a corresponding size is selected according to the size of the battery cell 10, and the positioning plate 90 is inserted into the positioning hole 80 at the corresponding position, so that the positioning plate 90 is close to the side wall of the battery cell 10; wherein the positioning holes 80 are provided in multiple groups in the horizontal and vertical directions, and the positioning plate 90 can be a flat plate or an L-shaped plate, and if it is a flat plate, it is formed by splicing four flat plates to fit the four side walls of the battery cell 10, and if it is an L-shaped plate, it is formed by splicing two L-shaped plates; then the cell positioning block 100 is moved to fit the side wall of the battery cell 10; there can be multiple grooves 70, and multiple battery cells 10 can be dried and gas collected at the same time;

[0033] A heating module is arranged at the bottom of the groove 70. The heating module may be a heating plate or other structure. The heating module heats the bottom of the battery cell 10. At the same time, the heating module heats the cell positioning block 100 and the positioning plate 90 through the lower base 2, thereby heating the side of the battery cell 10 to accelerate the drying process.

[0034] In one embodiment, a temperature sensing module 4 is disposed on the upper base 1 .

[0035] A check valve 5 is provided on the gas recovery box.

[0036] A limiting block 6 is provided at the upper end of the vertical rod 3 .

[0037] The vertical rod 3 is sleeved with a buffer spring 7 .

[0038] By setting a temperature sensing module 4 on the upper base 1, the temperatures of the heating plate 201, the positive electrode thermal conductive rod 202 and the negative electrode thermal conductive rod 203 are monitored in real time to keep the temperature of the battery constant, thereby improving the consistency of the battery's moisture content; by installing a check valve 5, gas backflow is avoided, so that the gas in the gas collection box 301 flows out for testing and analysis; a limit block 6 is installed at the upper end of the vertical pole 3 to prevent the upper base 1 from separating from the vertical pole 3 during movement; a buffer spring 7 is mounted on the vertical pole 3, and when the upper base 1 moves up and down, the stability of the movement of the upper base 1 is guaranteed by the buffering effect of the spring.

[0039] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lithium battery drying and gas collection device, comprising a battery cell (10), characterized in that: The battery cell (10) further comprises an upper base (1) and a lower base (2); a vertical pole (3) is fixed to the upper end of the lower base (2), and the upper end of the vertical pole (3) is slidably connected to the upper base (1); the upper end of the upper base (1) is connected to a power system; a drying unit and a gas collection unit are arranged at the lower end of the upper base (1); the gas collection unit comprises a gas collection box (301), the gas collection box (301) is mounted on the upper base (1), the gas collection box (301) is connected to one end of a gas delivery conduit (302), and a sealing plug (303) is arranged at the other end of the gas delivery conduit (302); a liquid injection port (304) is provided on the battery cell (10), and the sealing plug (303) is connected to the liquid injection port (304).

2. A lithium battery drying and gas collection device according to claim 1, characterized in that: The drying unit comprises a heating plate (201), a positive electrode heat conducting rod (202) and a negative electrode heat conducting rod (203) are arranged at the lower end of the heating plate (201), a positive electrode compression spring (204) is sleeved on the positive electrode heat conducting rod (202), and a negative electrode compression spring (205) is sleeved on the negative electrode heat conducting rod (203).

3. A lithium battery drying and gas collection device according to claim 2, characterized in that: A guide groove is provided at the lower end of the lower base (2), a guide block (50) is slidably connected in the guide groove, a through groove is provided on the heating plate (201), the upper ends of the positive electrode heat conducting rod (202) and the negative electrode heat conducting rod (203) respectively pass through the through grooves and are connected to the guide block (50); the middle part of the gas delivery conduit (302) is connected to the guide block (50).

4. A lithium battery drying and gas collection device according to claim 3, characterized in that: The upper end of the upper base (1) is provided with a groove (70), the bottom of the groove (70) is provided with a positioning hole (80), and a positioning plate (90) is inserted into the positioning hole (80); the battery cell (10) is placed in the groove (70), and cell positioning blocks (100) are slidably provided on both sides of the lower base (2).

5. A lithium battery drying and gas collection device according to claim 4, characterized in that: The number of the grooves (70) is ≥2.

6. A lithium battery drying and gas collection device according to claim 5, characterized in that: A heating module is arranged in the groove (70).

7. A lithium battery drying and gas collection device according to claim 5, characterized in that: A temperature sensing module (4) is provided on the upper base (1).

8. A lithium battery drying and gas collection device according to claim 6, characterized in that: The gas collection box (301) is provided with a check valve (5).

9. A lithium battery drying and gas collection device according to claim 8, characterized in that: A limiting block (6) is arranged at the upper end of the vertical rod (3).

10. A lithium battery drying and gas collection device according to claim 9, characterized in that: A buffer spring (7) is sleeved on the vertical rod (3).

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