A device for injecting electrolyte and activating the opening of a lithium-ion electrode sheet battery pack

Abstract

The present invention discloses a device for injecting liquid and activating the opening of a lithium-ion electrode sheet battery pack, which includes a first pressurizing die, a pressurizer, an air inlet and outlet, a first pressure tank housing, a liquid level sensor, a sealing and clamping member, a DC power integrated control box, a second pressure tank housing, a heat medium inlet and outlet pipe, an electrolyte inlet and outlet, a temperature sensor, a refrigerant inlet and outlet pipe, a second pressurizing die, and a gas pressure sensor. This device is aimed at the stacked and welded lithium-ion electrode capacity units, rather than the single cells in the traditional process. Through structural design, it provides a sealed protective gas environment with controllable environmental conditions such as temperature and air pressure, injects liquid into the battery pack and activates the opening. After this process, it is hermetically sealed to form a finished battery pack, solving the problem that there is no device for injecting liquid and activating the opening of a lithium-ion electrode sheet battery pack in the current existing technology.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and specifically to a device for injecting liquid and opening and activating a lithium-ion pole piece battery pack. Background Art

[0002] With the popularization and application of new energy vehicles and 5G technology, the intelligent society has entered people's daily lives, and the demand for off-grid energy storage power sources is increasing in number and the quality requirements are getting higher and higher. As an energy storage device, the safety, service life, and full-life cost of the battery have attracted much attention. Problems such as leakage, fire, attenuation, low energy density, and high cost exposed by liquid lithium-ion batteries have become important bottlenecks in their applications.

[0003] The ultimate application of battery products, especially power sources and energy storage power sources, is the battery pack. The current production of battery packs includes processes such as the production of battery cells, the grouping of battery cells, and the formation of modules into PACKs. The production of battery cells is divided into multiple steps such as mixing, coating, rolling, drying, stacking, injecting liquid, forming, sealing, aging, grading, and sorting. The current liquid injection and activation steps in the preparation process of battery packs are for single battery cells. The preparation of single battery cells is divided into two types: one is a single battery cell encapsulated by an aluminum-plastic film, which needs to go through pre-sealing, vacuum liquid injection, sealing, activation, and secondary sealing; since gas is generated during the activation process, the process steps of the liquid injection activation encapsulation process of the battery cell are cumbersome and require multiple sealings. The second is a single battery cell encapsulated by a steel shell. Since the steel shell itself has structural strength, it generally uses vacuum pumping, injecting electrolyte, open activation, and finally completing the encapsulation. After the liquid injection is completed, the open activation requires controlling the water and oxygen values of the large environment, with cumbersome process steps and great difficulty. The traditional activation method has caused inconsistencies in single battery cells, resulting in disadvantages such as low grouping rate of single battery cells, low production efficiency, and high manufacturing cost. After the single battery cells are each prepared through processes such as liquid injection activation, they are aged, graded, and sorted, and then the single battery cells are assembled into a module through series and parallel connections using connectors, and then the modules are assembled into a finished battery pack through connectors. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a device for injecting liquid and opening and activating a lithium-ion pole piece battery pack.

[0005] The technical solution for the present invention to solve the above technical problem is to provide a device for injecting liquid and opening and activating a lithium-ion pole piece battery pack, which is characterized in that the device includes a pressure die one, a pressure intensifier, an air inlet and outlet, a pressure tank housing one, a liquid level sensor, a sealing and clamping member, a DC power integrated control box, a pressure tank housing two, a heat medium inlet and outlet pipe, an electrolyte inlet and outlet, a temperature sensor, a refrigerant inlet and outlet pipe, a pressure die two, and a gas pressure sensor;

[0006] The pressure tank housing 1 and the pressure tank housing 2 are hermetically clamped and connected through a sealing clamp to form a detachable pressure tank; the pressurizing die 1 and the pressurizing die 2 are placed inside the pressure tank; the pressurizer is arranged on the outer wall of the pressure tank, and its output end extends into the pressure tank and contacts one of the pressurizing die 1 and the pressurizing die 2 for applying pressure; the other of the pressurizing die 1 and the pressurizing die 2 is arranged on the inner wall of the pressure tank, and this inner wall is opposite to the pressurizer; the lithium-ion pole piece battery pack to be injected with liquid and activated is placed between the pressurizing die 1 and the pressurizing die 2, and the pressurizing die 1 and the pressurizing die 2 clamp or grip the battery pack through the pressurization of the pressurizer; the liquid level sensor is arranged on the inner wall of the pressure tank, above the battery pack, for measuring the liquid level of the electrolyte in the pressure tank; a transparent air inlet and outlet is arranged at the top of the pressure tank, above the liquid level sensor, for evacuating the pressure tank and introducing a protective gas to form a specific air pressure; a transparent electrolyte inlet and outlet is arranged at the bottom of the pressure tank for introducing and discharging the electrolyte; the gas pressure sensor is arranged on the inner wall of the pressure tank, above the liquid level sensor, for measuring the ambient vacuum degree and the ambient air pressure after introducing the protective gas;

[0007] The heat medium inlet and outlet pipe and the refrigerant inlet and outlet pipe are used to provide a hot and cold environment for the battery pack; the temperature sensor is arranged inside the pressure tank for measuring the ambient temperature of the battery pack in the pressure tank and the temperature of the battery pack itself.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0009] (1) This device is aimed at the stacked and welded lithium-ion pole piece capacity units, rather than the single cells in the traditional process. Through structural design, a sealed protective gas environment with controllable environmental conditions such as temperature and air pressure is provided to inject liquid and activate the battery pack with an open mouth. After this process, it is hermetically packaged to form a finished battery pack, solving the problem that there is no device for injecting liquid and activating the lithium-ion pole piece battery pack in the current prior art.

[0010] (2) Using this device shortens the process flow of battery pack manufacturing, eliminates the need for grading and grouping, and the environment is controllable. The same environment and process flow among the battery cells greatly improve the consistency of the battery, improve production efficiency, and reduce manufacturing costs. Description of the Drawings

[0011] Figure 1 It is a schematic internal view of the overall structure of the device according to an embodiment of the present invention;

[0012] Figure 2 It is a schematic internal view of the overall structure of the lithium-ion pole piece battery pack to be injected with liquid and activated according to an embodiment of the present invention;

[0013] In the figure: 1. Lithium-ion pole piece battery pack to be filled with liquid and activated; 2. First pressure die; 3. Pressurizer; 4. Air inlet and outlet; 5. First pressure tank housing; 6. Liquid level sensor; 7. Sealing and clamping part; 8. DC power integrated control box; 9. Voltage acquisition wire harness; 10. Positive bus; 11. Second pressure tank housing; 12. Heat medium inlet and outlet pipe; 13. Electrolyte inlet and outlet; 14. Temperature sensor; 15. Refrigerant inlet and outlet pipe; 16. Pressure tank base; 17. Second pressure die; 18. Gas pressure sensor; 19. Negative bus. Detailed implementation mode

[0014] The following are specific embodiments of the present invention. The specific embodiments are only used to further elaborate the present invention in detail and do not limit the protection scope of the claims of this application.

[0015] The present invention provides a device for injecting liquid and activating the opening of a lithium-ion pole piece battery pack (hereinafter referred to as the device, see Figure 1 ), which is characterized in that the device includes a first pressure die 2, a pressurizer 3, an air inlet and outlet 4, a first pressure tank housing 5, a liquid level sensor 6, a sealing and clamping part 7, a DC power integrated control box 8, a second pressure tank housing 11, a heat medium inlet and outlet pipe 12, an electrolyte inlet and outlet 13, a temperature sensor 14, a refrigerant inlet and outlet pipe 15, a second pressure die 17 and a gas pressure sensor 18;

[0016] The pressure tank housing one 5 and the pressure tank housing two 11 are hermetically clamped and connected through a sealing clamp 7 to form a detachable pressure tank; the pressurizing die one 2 and the pressurizing die two 17 are placed inside the pressure tank; the pressurizer 3 is arranged on the outer wall of the pressure tank, and its output end extends into the pressure tank and contacts one of the pressurizing die one 2 and the pressurizing die two 17 for applying pressure, and the pressure of the pressurizer 3 can be set; the other of the pressurizing die one 2 and the pressurizing die two 17 is arranged on the inner wall of the pressure tank, and this inner wall is opposite to the pressurizer 3 (in this embodiment, the pressurizer 3 is arranged on the outer wall of the top of the pressure tank, and its output end extends into the pressure tank and contacts the pressurizing die one 2; the pressurizing die two 17 is fixed on the inner wall of the bottom of the pressure tank); the lithium-ion pole piece battery pack to be injected with liquid (referred to as the battery pack) 1 is placed between the pressurizing die one 2 and the pressurizing die two 17, and the pressurizing die one 2 and the pressurizing die two 17 clamp or hold the battery pack 1 through the pressurization of the pressurizer 3; the liquid level sensor 6 is arranged on the inner wall of the pressure tank, above the battery pack 1, for measuring the liquid level of the electrolyte in the pressure tank so that the electrolyte can completely immerse the battery pack 1 and judge whether the liquid injection is completed; a transparent air inlet and outlet 4 is arranged at the top of the pressure tank, above the liquid level sensor 6, for evacuating the gas in the pressure tank and introducing protective gases such as nitrogen (preferably inert gas) to form a specific air pressure; a transparent electrolyte inlet and outlet 13 is arranged at the bottom of the pressure tank for the inlet and outlet of the electrolyte; the gas pressure sensor 18 is arranged on the inner wall of the pressure tank, above the liquid level sensor 6, for measuring the ambient vacuum degree and the ambient air pressure after introducing the protective gas;

[0017] The heat medium inlet and outlet pipe 12 and the refrigerant inlet and outlet pipe 15 are used to provide a hot and cold environment for the battery pack 1 for cooling or heating (in Embodiment 1, the heat medium inlet and outlet pipe 12 and the refrigerant inlet and outlet pipe 15 pass through the housing of the pressure tank, and the ends are located in one or both of the pressurizing die one 2 and the pressurizing die two 17; in Embodiment 2, the ends of the heat medium inlet and outlet pipe 12 and the refrigerant inlet and outlet pipe 15 are located in one or both of the pressure tank housing one 5 and the pressure tank housing two 11; in Embodiment 3, the ends of the heat medium inlet and outlet pipe 12 and the refrigerant inlet and outlet pipe 15 are in the temperature control pipeline inside the pressure tank, and the temperature control pipeline is arranged outside the battery pack 1); the temperature sensor 14 is arranged inside the pressure tank for measuring the ambient temperature of the battery pack 1 in the pressure tank and the temperature of the battery pack 1 itself;

[0018] Preferably, the device further includes a pressure tank base 16; the pressure tank base 16 is arranged at the bottom of the pressure tank for adjusting the levelness and stably supporting the pressure tank.

[0019] The lithium-ion pole piece battery pack 1 to be activated by liquid injection has a voltage acquisition harness 9, a positive bus 10, and a negative bus 19; the DC power supply integrated control box 8 is connected to the battery pack 1 through the voltage acquisition harness 9, the positive bus 10, and the negative bus 19, and charges and discharges the battery pack 1 through the positive bus 10 and the negative bus 19 and realizes the acquisition of data such as voltage through the voltage acquisition harness 9; the voltage acquisition harness 9 is led out from the side of the battery pack 1 and is used to collect and transmit the voltage signal of the battery pack 1, passes through the shell of the pressure tank and is electrically connected to the DC power supply integrated control box 8; the positive bus 10 and the negative bus 19 are located on both sides of the battery pack 1 and are used to charge and discharge the battery pack 1, pass through the shell of the pressure tank and are electrically connected to the DC power supply integrated control box 8; the DC power supply integrated control box 8 controls the voltage of the parallel capacity unit of the battery pack 1 through the voltage acquisition harness 9, and the DC power supply integrated control box 8 controls the input voltage and current of the battery pack 1 through the positive bus 10 and the negative bus 19.

[0020] The DC power supply integrated control box 8 is respectively connected to the pressure booster 3, the valves of the air inlet and outlet 4, the liquid level sensor 6, the valves of the heat medium inlet and outlet pipe 12, the valves of the electrolyte inlet and outlet 13, the temperature sensor 14, the valves of the refrigerant inlet and outlet pipe 15, the gas pressure sensor 18, the voltage acquisition harness 9 of the battery pack 1, the positive bus 10 of the battery pack 1, and the negative bus 19 of the battery pack 1, and is used to collect the liquid level signal of the electrolyte in the pressure tank, the ambient temperature signal and the ambient air pressure signal in the pressure tank, and control the pressure value of the pressure booster 3, the electrolyte inflow and outflow, the heat medium inflow and outflow, the refrigerant inflow and outflow, the protective gas inflow and outflow, the voltage and current magnitude, etc.

[0021] The DC power supply integrated control box 8 integrates an automatically adjustable constant current and constant voltage DC power supply (preferably a high-voltage equalizing constant current and constant voltage DC power supply).

[0022] The to-be-injected and activated lithium-ion pole piece battery pack 1 is obtained by cutting and stacking pole pieces to obtain a pole piece capacity unit 101 and then welding the pole piece capacity units 101. The specific preparation process is as follows: After cutting a plurality of positive pole pieces, a plurality of negative pole pieces, and a plurality of separator films, a separator film is adhesively disposed between each positive pole piece and each negative pole piece, and the stacking unit is obtained by stacking in this way; a plurality of stacking units are connected in parallel to form a pole piece capacity unit 101; a plurality of pole piece capacity units 101 are obtained according to this method; the positive pole ears of the pole pieces of all the stacking units of each pole piece capacity unit 101 are connected into a capacity unit positive pole ear 103 through an ultrasonic welding process, and the negative pole ears of all the pole pieces of each pole piece capacity unit 101 are connected into a capacity unit negative pole ear 102 through an ultrasonic welding process; the capacity unit negative pole ear 102 of a pole piece capacity unit 101 is connected to the capacity unit positive pole ear 103 of the previous or next pole piece capacity unit 101 through an ultrasonic welding process, and then all the pole piece capacity units 101 are sequentially connected end to end one by one to form a series structure with positive and negative connections, so as to improve the output voltage level of the battery pack; the capacity unit positive pole ear 103 of the first pole piece capacity unit 101 leads out the battery pack total positive connection terminal 105; the capacity unit negative pole ear 102 of the last pole piece capacity unit 101 leads out the battery pack total negative connection terminal 106; a voltage acquisition wire harness 9 is connected to the capacity unit positive pole ear 103 or the capacity unit negative pole ear 102 between two adjacent pole piece capacity units 101 through an ultrasonic welding process; a voltage acquisition wire harness 9 is connected to the capacity unit positive pole ear 103 of the first pole piece capacity unit 101 through an ultrasonic welding process, and a voltage acquisition wire harness 9 is connected to the capacity unit negative pole ear 102 of the last pole piece capacity unit 101 through an ultrasonic welding process; an insulating and anti-seepage film 104 is disposed between two adjacent pole piece capacity units 101, and then each pole piece capacity unit 101 is separately separated to form an independent unit, ensuring that the electrolytes of each pole piece capacity unit 101 do not communicate with each other, and the to-be-injected and activated lithium-ion pole piece battery pack 1 is obtained;

[0023] The battery pack total positive connection terminal 105 is connected to the positive bus 10 through a welding fixture, and the battery pack total negative connection terminal 106 is connected to the negative bus 19 through a welding fixture.

[0024] The working principle and working process of the present invention are as follows:

[0025] Step 1, drying: Place the lithium-ion pole piece battery pack 1 to be injected with liquid and activated between the pressure die 2 and the pressure die 17, apply pressure through the pressure applicator 3 to clamp it, so that the position of the battery pack 1 is fixed; then lead out the external connection terminals of the voltage acquisition wire harness 9, the positive bus 10 and the negative bus 19 of the battery pack 1 outside the pressure tank; then combine the pressure tank housing 5 and the pressure tank housing 11 into a sealed pressure tank through the sealing and clamping member 7; then pass the heat medium through the heat medium inlet and outlet pipe 12 to raise the ambient temperature in the pressure tank to the temperature required for drying to dry the battery pack 1; connect external equipment through the air inlet and outlet 4 to evacuate the air and introduce protective gases such as nitrogen to purify the environment in the tank, discharge the water vapor, so that the environment in the pressure tank is pure, ensuring that water, oxygen, etc. do not contact the lithium-ion electrolyte to be injected and do not contaminate the electrolyte; preferably, introduce the protective gas through the air inlet and outlet 4 and collect the air pressure signal through the gas pressure sensor 18 until the ambient air pressure required for drying the battery pack 1 is reached;

[0026] Step 2, liquid injection: After drying is completed, cooperate with each other through the heat medium inlet and outlet pipe 12, the refrigerant inlet and outlet pipe 15 and the temperature sensor 14 to adjust the ambient temperature in the pressure tank to the temperature required for the battery pack 1 to soak the electrolyte, and accelerate the flow rate of the electrolyte; inject the electrolyte through the electrolyte inlet and outlet 13 and measure the liquid level position of the electrolyte through the liquid level sensor 6, and stop injecting the electrolyte until the electrolyte completely submerges the battery pack 1; connect external equipment through the air inlet and outlet 4 to control the amount of evacuated air and the intake amount of the protective gas and collect the air pressure signal through the gas pressure sensor 18 until the ambient air pressure required for the battery pack 1 to soak the electrolyte (maintaining positive pressure) is reached, and the air pressure helps the electrolyte to infiltrate into the pole piece; the battery pack 1 is soaked in the electrolyte and left standing to fully infiltrate and absorb enough liquid; after infiltration is completed, drain the excess electrolyte through the electrolyte inlet and outlet 13;

[0027] Preferably, the infiltration amount of the electrolyte entering the pole piece of the battery pack 1 can be obtained by detecting the liquid level difference of the electrolyte in the pressure tank through the liquid level sensor 6, and the liquid injection is judged to be completed by the infiltration amount or the infiltration time;

[0028] Step 3, opening activation: After the excess electrolyte is emptied, the ambient temperature in the pressure tank is adjusted to the temperature required for the opening activation of the battery pack 1 (30 - 65°C, preferably 45°C - 60°C) through the cooperation of the heat medium inlet and outlet pipe 12, the refrigerant inlet and outlet pipe 15, and the temperature sensor 14; the vacuum pumping air volume and the protective gas inlet volume are controlled by an external device through the air inlet and outlet 4, and the air pressure signal is collected by the gas pressure sensor 18 until the ambient air pressure required for the opening activation of the battery pack 1 (150 kPa - 250 kPa); the clamping force required for the opening activation of the battery pack 1 is achieved by applying pressure through the pressure applicator 3 to clamp the battery pack 1; then, the battery pack 1 is activated by high-voltage constant current and constant voltage segmented charge and discharge through the automatic adjustable constant current and constant voltage DC power supply of the DC power integration control box 8 connected by the positive bus 10, the negative bus 19, and the voltage acquisition wire harness 9 of the battery pack 1; the activation DC voltage is 5 V - 1000 V (preferably 5 V - 750 V);

[0029] Preferably, after the opening activation, the battery pack is integrally filled and hermetically sealed. The positive bus 10, the negative bus 19, and the voltage acquisition wire harness 9 of the battery pack 1 are positioned through the filled hermetic seal, and external connection terminals are reserved outside the filled hermetic seal. After connecting the electrical appliance and the battery management system, a charge and discharge energy storage power supply can be made.

[0030] The parts not described in the present invention are applicable to the prior art.

Claims

1. A liquid injection and opening activation device for a lithium-ion electrode sheet battery pack, characterized in that The device includes a first pressurizing die, a pressurizer, an air inlet / outlet, a first pressure tank housing, a liquid level sensor, a sealing and clamping member, a DC power integrated control box, a second pressure tank housing, a heat medium inlet / outlet pipe, an electrolyte inlet / outlet, a temperature sensor, a refrigerant inlet / outlet pipe, a second pressurizing die, and a gas pressure sensor; The first pressure tank housing and the second pressure tank housing are hermetically and detachably connected by a sealing and clamping member to form a detachable pressure tank; the first pressurizing die and the second pressurizing die are placed inside the pressure tank; the pressurizer is arranged on the outer wall of the pressure tank, and its output end extends into the pressure tank and contacts one of the first pressurizing die and the second pressurizing die for applying pressure; the other of the first pressurizing die and the second pressurizing die is arranged on the inner wall of the pressure tank, and this inner wall is opposite to the pressurizer; the lithium-ion pole piece battery pack to be filled and activated is placed between the first pressurizing die and the second pressurizing die, and the first pressurizing die and the second pressurizing die clamp or hold the battery pack through the pressurization of the pressurizer; the liquid level sensor is arranged on the inner wall of the pressure tank above the battery pack for measuring the liquid level of the electrolyte in the pressure tank; a transparent air inlet / outlet is provided at the top of the pressure tank above the liquid level sensor for evacuating the pressure tank and introducing a protective gas to form a specific air pressure; a transparent electrolyte inlet / outlet is provided at the bottom of the pressure tank for introducing and discharging the electrolyte; the gas pressure sensor is arranged on the inner wall of the pressure tank above the liquid level sensor for measuring the ambient vacuum degree and the ambient air pressure after introducing the protective gas; The heat medium inlet / outlet pipe and the refrigerant inlet / outlet pipe are used to provide a hot and cold environment for the battery pack; the temperature sensor is arranged inside the pressure tank for measuring the temperature of the environment where the battery pack is located in the pressure tank and the temperature of the battery pack itself; The DC power integrated control box is respectively connected to the pressurizer, the valve of the air inlet / outlet, the liquid level sensor, the valve of the heat medium inlet / outlet pipe, the valve of the electrolyte inlet / outlet, the temperature sensor, the valve of the refrigerant inlet / outlet pipe, the gas pressure sensor, the voltage acquisition wire harness of the battery pack, the positive bus of the battery pack, and the negative bus of the battery pack.

2. The liquid injection and opening activation device for the lithium-ion electrode sheet battery pack according to claim 1, wherein The heat medium inlet / outlet pipe and the refrigerant inlet / outlet pipe pass through the housing of the pressure tank, and the ends are located in one or both of the first pressurizing die and the second pressurizing die.

3. The lithium-ion electrode sheet battery pack liquid injection and opening activation device according to claim 1, characterized in that The ends of the heat medium inlet / outlet pipe and the refrigerant inlet / outlet pipe are located in one or both of the first pressure tank housing and the second pressure tank housing.

4. The liquid injection and opening activation device for a lithium-ion electrode sheet battery pack according to claim 1, wherein The ends of the heat medium inlet / outlet pipe and the refrigerant inlet / outlet pipe are in the temperature control pipeline inside the pressure tank, and the temperature control pipeline is arranged outside the battery pack.

5. The liquid injection and opening activation device for a lithium-ion electrode sheet battery pack according to claim 1, wherein The device further includes a pressure tank base; the pressure tank base is arranged at the bottom of the pressure tank for adjusting the levelness and stably supporting the pressure tank.

6. The lithium-ion electrode sheet battery pack liquid injection and opening activation device according to claim 1, characterized in that The DC power integrated control box integrates an automatically adjustable constant current and constant voltage DC power supply.

7. The liquid injection and opening activation device for a lithium-ion electrode sheet battery pack according to claim 6, wherein The DC power integrated control box integrates a high-voltage equalizing constant current and constant voltage DC power supply.

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