Liquid injection process of pre-injecting electrolyte into battery housing

Abstract

The present invention discloses a liquid injection process for pre-injecting electrolyte into a battery case, comprising the following steps: Step S1: Inject the electrolyte into a storage container; Step S2: Place the storage container containing the electrolyte into a liquid nitrogen environment / dry ice environment for freezing to solidify the electrolyte into a solid state; Step S3: Take out the solid electrolyte from the storage container; Place the storage container on a vibration platform; Step S4: Pre-place the solid electrolyte into the battery case; Step S5: Place the battery cell into the battery case and fill the battery case with a protective gas; Step S6: Weld the battery top cover and the battery case together to form a battery; Step S7: Test the sealing performance of the battery; Step S8: Place the battery into a high-temperature static chamber. The present invention has the advantages that are not possessed by existing methods, such as high liquid injection efficiency, high safety, and low cost.

Description

Technical Field

[0001] The present invention relates to the field of batteries. More specifically, the present invention relates to a liquid injection process in which electrolyte is pre-injected into a battery housing. Background Art

[0002] As a small and convenient mobile power source, batteries have become a necessity in people's lives. In particular, lithium batteries have become the dominant products in the battery market at present because of their advantages such as high voltage platform, high discharge specific capacity, long life, light volume and no pollution.

[0003] The main task of the electrolyte in the battery is to transfer charge through the migration of ions, so as to realize the normal operation of the battery. Especially in the case of high-current discharge, a large amount of electrolyte is required inside the battery to provide enough ions for charge transfer between the positive and negative electrodes of the battery.

[0004] There are mainly the following problems in the existing lithium battery liquid injection process: First, the liquid injection time is long, which greatly reduces the liquid injection speed; Second, the liquid injection machine equipment is too large, occupying a large space and having a high equipment cost; Third, the liquid injection pressure is too high, resulting in danger during the liquid injection process and having high requirements for the equipment. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a liquid injection process in which electrolyte is pre-injected into a battery housing, which has the characteristics of short liquid injection time, fast liquid injection speed, low cost and high safety during the liquid injection process.

[0006] The technical solution adopted by the present invention to solve its technical problems is:

[0007] A liquid injection process in which electrolyte is pre-injected into a battery housing includes the following steps:

[0008] Step S1: Inject the electrolyte into a storage container;

[0009] Step S2: Place the storage container containing the electrolyte into a liquid nitrogen environment / dry ice environment for freezing to solidify the electrolyte into a solid state;

[0010] Step S3: Take out the solid electrolyte from the storage container; place the storage container on a vibration platform;

[0011] Step S4: Pre-place the solid electrolyte into the battery housing;

[0012] Step S5: Place the battery cell into the battery housing and fill the battery housing with a protective gas;

[0013] Step S6: Weld the battery top cover and the battery housing together to form a battery;

[0014] Step S7: Test the battery's seal tightness;

[0015] Step S8: Place the battery into the high - temperature static chamber.

[0016] Further, the specific method of injecting the electrolyte into the storage container in step S1 is as follows: The storage container is set as a tray; the tray is made by welding / die - casting with SUS316 material / PP material; the side wall of the tray is set to be inclined outward; the inclination angle of the side wall is set to 2 - 5 degrees to facilitate the removal of the electrolyte; the roughness of the inner wall of the tray is ≤0.4 microns to prevent the adhesion of the electrolyte.

[0017] Further, the specific method of solidifying the electrolyte into a solid state in step S2 is as follows: The temperature of the freezing environment is < 10°C, and the environmental dew point is ≤ - 28°C.

[0018] Further, the specific method of taking out the solid electrolyte from the storage container in step S3 is as follows: Place the tray on a vibration platform / a knocking platform / an ultrasonic vibration platform, and through vibration, the solid electrolyte can be separated from the tray, and the environmental dew point is ≤ - 28°C.

[0019] Further, the specific method of pre - placing the solid electrolyte into the battery housing in step S4 is as follows: Use a suction cup to take out the solid electrolyte from the tray; the environmental temperature is < 20°C, and the environmental dew point is ≤ - 28°C.

[0020] Further, the specific method of putting the battery core into the battery housing in step S5 is as follows: After putting in the battery core, fill the protective gas inside the housing; cool down the battery housing to prevent the electrolyte from melting.

[0021] Further, the specific method of welding the battery top cover to the battery housing in step S6 is as follows: Use the ultrasonic welding process to weld the battery top cover to the battery housing.

[0022] Further, the specific method of testing the battery seal tightness in step S7 is as follows: Test the seal tightness of the battery through positive pressure / negative pressure. Under a positive pressure of 200 kPa or a negative pressure of - 98 kPa, the leakage rate of the battery is ≤2 kPa / min; there is a liquid injection port on the battery housing; and there is a sealing nail on the liquid injection port.

[0023] Further, the specific method of placing the battery into the high - temperature static chamber in step S8 is as follows: The battery's terminal posts face downwards, the temperature of the high - temperature static chamber can be gradually increased from 25 - 150°C, and the battery is static in the high - temperature static chamber for 5 - 24 h.

[0024] The beneficial effects of the present invention are as follows: A liquid injection process for pre-injecting electrolyte into a battery case includes the following steps: Step S1: Inject the electrolyte into a storage container; Step S2: Place the storage container containing the electrolyte into a liquid nitrogen environment / dry ice environment for freezing to solidify the electrolyte; Step S3: Take out the solid electrolyte from the storage container and place the storage container on a vibration platform; Step S4: Pre-place the solid electrolyte into the battery case; Step S5: Place the battery cell into the battery case and fill the battery case with nitrogen or other protective gases; Step S6: Weld the battery top cover and the battery case together to form a battery; Step S7: Test the sealing performance of the battery; Step S8: Place the battery into a high-temperature static chamber. The present invention realizes efficient, safe and low-cost injection of electrolyte into the battery case, solves the problems of long injection time, large floor area of injection equipment, high cost of injection equipment, high injection pressure and low safety in the existing liquid injection process, and can greatly improve the efficiency and safety of battery liquid injection and reduce costs during application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the drawings and embodiments.

[0026] Figure 1 is the process flow chart of the present invention;

[0027] Figure 2 is the structural decomposition diagram of the battery in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The concept, specific structure and technical effects generated by the present invention will be clearly and completely described below in conjunction with the embodiments and the drawings to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components alone, but refer to the more optimal connection structure that can be formed by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the present invention can be interactively combined without conflicting with each other.

[0029] Referring to Figure 1 and Figure 2 , a liquid injection process for pre-injecting electrolyte into a battery case includes the following steps:

[0030] Step S1: Inject the electrolyte into the storage container; the storage container is set as a tray; the tray is made by welding / die-casting with SUS316 material; the material used for the tray is not limited to SUS316 material, and the material needs to have the performance of being resistant to electrolyte corrosion. For example, PP material can also be used to make the tray;

[0031] The side wall of the tray is set to be inclined outward, presenting an upward flared shape; the inclination angle of the side wall is set to 2-5 degrees to facilitate the removal of the electrolyte; the roughness of the inner wall of the tray ≤ 0.4 microns to ensure that when the solid electrolyte is taken out, the electrolyte will not adhere to the inner wall of the tray.

[0032] Step S2: Place the storage container containing the electrolyte into a liquid nitrogen environment / dry ice environment for freezing to solidify the electrolyte; multiple portions of electrolyte can be frozen in batches and taken out as needed; the temperature of the freezing environment < 10°C, and the environmental dew point ≤ -28°C.

[0033] Step S3: Take out the solid electrolyte 02 from the storage container; place the storage container on the vibration platform; place the tray on the vibration platform / tapping platform / ultrasonic vibration platform, and through vibration, the solid electrolyte can be separated from the tray, and the environmental dew point ≤ -28°C.

[0034] Step S4: Pre-place the solid electrolyte 02 into the battery housing 01; use a suction cup to take out the solid electrolyte 02 from the tray; the environmental temperature < 20°C, and the environmental dew point ≤ -28°C.

[0035] Step S5: Place the battery cell 03 into the battery housing 01, and fill the battery housing 01 with nitrogen or other protective gases; cool down the battery housing 01 to prevent the solid electrolyte 02 from melting.

[0036] The order of Step S4 and Step S5 can be swapped without affecting the overall process effect.

[0037] Step S6: Weld the battery top cover 04 and the battery housing 01 together to form a battery; use ultrasonic welding technology to weld the battery top cover 04 to the battery housing 01.

[0038] Step S7: Test the sealing performance of the battery; test the sealing performance of the battery through positive pressure / negative pressure. Under positive pressure of 200 kPa or negative pressure of -98 kPa, the leakage rate of the battery ≤ 2 kPa / min; a liquid injection port is provided on the battery housing 01; a sealing nail is provided on the liquid injection port.

[0039] Step S8: Place the battery into the high-temperature static chamber; the pole column of the battery is downward, and the temperature of the high-temperature static chamber can be gradually increased from 25 - 150°C, and the battery is static in the high-temperature static chamber for 5 - 24 h.

[0040] Between step S7 and step S8, the battery is heated to make the electrolyte heated to a liquid state, which can be heated directly or indirectly, and the heating temperature ≤ 120°C; the battery is vibrated to make the electrolyte infiltrate into the inside of the battery cell 03 as soon as possible. The vibration method adopts horizontal vibration and vertical vibration, the vibration frequency is within 30HZ, and the vibration amplitude is within 30mm.

[0041] In a liquid injection process where the electrolyte is pre-injected into the battery case, the solid electrolyte 02 is pre-placed into the battery case 01, which reduces the pollution of the electrolyte to the liquid injection equipment, can also greatly shorten the liquid injection time, and greatly improves the production efficiency;

[0042] Moreover, this liquid injection process can be carried out under normal pressure with high safety; the traditional breathing and standing method is cancelled, which reduces the complexity of the gas circuit and liquid circuit of the process, requires simple equipment, reduces the floor area of the equipment, and reduces the equipment cost of battery production;

[0043] Moreover, in this process, the vibration and standing method is adopted to accelerate the diffusion and infiltration of the electrolyte into the battery cell, and the infiltration efficiency is higher than that of the traditional breathing method.

[0044] A liquid injection process for pre-injecting the electrolyte into the battery case decomposes the liquid injection process: the process is divided into processes such as freezing the electrolyte, taking out and pre-placing the electrolyte, sealing the battery case, and inspecting the sealing performance of the battery, vibration infiltration, etc., which greatly improves the production efficiency of the battery.

[0045] The above is a specific description of the preferred embodiment of the present invention, but the present invention is not limited to the described embodiment. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A liquid injection process for pre-injecting electrolyte into a battery case, characterized in that: It includes the following steps: Step S1: Inject the electrolyte into a storage container; Step S2: Place the storage container containing the electrolyte into a liquid nitrogen environment / dry ice environment for freezing to solidify the electrolyte into a solid state; Step S3: Place the storage container containing the solid electrolyte on a vibration platform, and through the vibration of the vibration platform, make the solid electrolyte separate from the storage container, and take out the solid electrolyte separated from the storage container from the storage container; Step S4: Pre-place the solid electrolyte into the battery case; Step S5: Place the battery cell into the battery case, fill the battery case with a protective gas, and cool the battery case to prevent the electrolyte from melting; Step S6: Weld the battery top cover to the battery case to form a battery; Step S7: Test the sealing performance of the battery; Step S8: Place the battery into a high-temperature static chamber; The specific method of placing the battery into the high-temperature static chamber in Step S8 is: the pole column of the battery is downward, the temperature of the high-temperature static chamber gradually rises within 25 - 150 °C, and the battery is static in the high-temperature static chamber for 5 - 24 h.

2. A liquid injection process for pre-injecting electrolyte into a battery case according to Claim 1, characterized in that: The specific method of injecting the electrolyte into the storage container in Step S1 is: the storage container is set as a tray; the tray is made by welding / die-casting with SUS316 material / PP material; the side wall of the tray is set to be inclined outward; the inclination angle of the side wall is set to 2 - 5 degrees to facilitate taking out the electrolyte; the roughness of the inner wall of the tray ≤ 0.4 microns to prevent adhesion of the electrolyte.

3. A liquid injection process for pre-injecting electrolyte into a battery case according to Claim 1, characterized in that: The specific method of solidifying the electrolyte into a solid state in Step S2 is: the temperature of the freezing environment < 10 °C, and the environmental dew point ≤ -28 °C.

4. A liquid injection process for pre-injecting electrolyte into a battery case according to Claim 1, characterized in that: The specific method of taking out the solid electrolyte from the storage container in Step S3 is: place the tray on a vibration platform / tapping platform / ultrasonic vibration platform, and through vibration, make the solid electrolyte able to separate from the tray, and the environmental dew point ≤ -28 °C.

5. A liquid injection process for pre-injecting electrolyte into a battery case according to Claim 1, characterized in that: The specific method of pre-placing the solid electrolyte into the battery case in Step S4 is: use a suction cup to take out the solid electrolyte from the tray; the environmental temperature < 20 °C, and the environmental dew point ≤ -28 °C.

6. A liquid injection process for pre-injecting electrolyte into a battery case according to Claim 1, characterized in that: The specific method of welding the battery top cover to the battery case in Step S6 is: use ultrasonic welding technology to weld the battery top cover to the battery case.

7. A liquid injection process for pre-injecting electrolyte into a battery case according to Claim 1, characterized in that: The specific method for the battery sealing test in step S7 is as follows: The sealing performance of the battery is tested through positive pressure / negative pressure. Under a positive pressure of 200 kPa or a negative pressure of -98 kPa, the leakage rate of the battery is ≤ 2 kPa / min. A liquid injection port is provided on the battery housing, and a sealing nail is provided on the liquid injection port.

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