Waste lithium battery recovery system based on water electrolysis device

Abstract

The utility model discloses a waste lithium battery recovery system based on a water electrolysis device, and belongs to the technical field of waste lithium battery recovery. Comprising an electrolytic tank, the electrolytic tank comprises an electrolytic tank cathode and an electrolytic tank anode, and the electrolytic tank is connected with a hydrogen separator used for separating hydrogen and high-temperature electrolyte through the electrolytic tank cathode. The electrolytic cell is connected with an oxygen separator for separating oxygen from high-temperature electrolyte through an electrolytic cell anode, a hydrogen outlet of the hydrogen separator is connected with a waste lithium iron phosphate battery positive electrode material recovery system, and an oxygen outlet of the oxygen separator is connected with a waste ternary lithium battery positive electrode material recovery system. The lithium leaching rate of the waste lithium batteries is increased, environmental pollution is reduced, and efficient recovery of lithium resources is facilitated. High-efficiency and high-quality recovery of important components of the waste lithium battery is really realized, and the goal of'double carbon 'is helped to be realized early.

Description

Technical Field

[0001] This utility model relates to a waste lithium battery recycling system based on an electrolysis water device, belonging to the field of waste lithium battery recycling technology. Background Technology

[0002] Hydrogen has a wide range of applications as a clean energy source. Using hydrogen as a reducing agent to reduce the cathode material of spent ternary lithium batteries, compared with carbothermal reduction, not only reduces energy consumption and is more environmentally friendly, but also has a higher subsequent lithium leaching rate, which is conducive to improving recycling efficiency and achieving sustainable development.

[0003] Oxygen, when used as an oxidant, not only does not produce any toxic or harmful gases, but also exhibits excellent oxidation effects, making it a green and environmentally friendly oxidant. Current research indicates that the efficiency of oxygen oxidation in waste lithium iron phosphate batteries is not yet high enough, but this can be improved by adding oxidants such as hydrogen peroxide, increasing the reaction temperature, and increasing the oxygen flow rate. These are key areas for future research and have broad application prospects.

[0004] Currently, the reduction roasting of spent ternary lithium battery cathode materials generally uses carbon as a reducing agent. However, the lithium leaching rate of carbothermic reduction water leaching is lower than that of hydrogen reduction roasting, and hydrogen reduction roasting requires a lower temperature, reducing energy consumption and increasing efficiency. Currently, the oxidation of spent lithium iron phosphate battery cathode materials is mainly achieved by adding oxidants such as H₂O₂ and Na₂S₂O₈. However, using oxygen for oxidation is not only convenient and fast, but also safer, producing no toxic gases and reducing costs. Therefore, using hydrogen and oxygen generated from water electrolysis to perform reduction and oxidation reactions on spent ternary lithium battery cathode materials and spent lithium iron phosphate battery cathode materials, respectively, can achieve a green and convenient recovery of the precious metal lithium, which is of great significance to addressing my country's lithium resource shortage.

[0005] Prior art, disclosed in CN209104306U, is a waste lithium battery recycling system, including a protective atmosphere dismantling device, an electrolyte heating and evaporation device, and an electrolyte condensation and recovery device. The electrolyte heating and evaporation device is located inside the protective atmosphere dismantling device, and its outlet is connected to the inlet of the electrolyte condensation and recovery device. This system can only dismantle lithium batteries and recover some compounds, but it does not provide a solution for the rapid recovery of the positive and negative electrodes.

[0006] The prior art disclosed in CN210816681U is a waste lithium battery recycling system, relating to the field of battery recycling. It includes a frame on which a feeding platform, a dual-shaft shredder, a hammer crusher, a magnetic conveyor, and a gravity separator are sequentially connected. A discharge mechanism is also installed on the feeding platform. The discharge mechanism includes a storage tank, a pusher plate, and a sliding plate. The storage tank is filled with brine, with a feeding port at the top and a discharge port on the top. A carrying plate is movably installed inside the storage tank, with evenly distributed leakage holes at the bottom. Multiple guide grooves are provided on the inner sidewall of the storage tank, and a convex strip is provided on the outer sidewall of the carrying plate. An electric push rod is installed inside the storage tank, and a pusher plate is movably installed inside the storage tank. An electric push rod is connected to the back of the pusher plate. A sliding plate is inclinedly installed on the frame between the storage tank and the dual-shaft shredder. It can only treat one type of waste battery electrode material, and the reagents used are expensive and highly polluting. Utility Model Content

[0007] To address the shortcomings of existing technologies, this utility model provides a waste lithium battery recycling system based on an electrolysis water device. It combines the system with a system for producing hydrogen and oxygen through water electrolysis, and uses the generated hydrogen to carry out the reduction reaction of the cathode material of waste ternary lithium batteries. The system has a simple structure, is easy to use, has high processing efficiency, and high energy utilization rate.

[0008] To achieve the above objectives, this utility model provides a waste lithium battery recycling system based on a water electrolysis device, including a water electrolysis device for generating oxygen and hydrogen through water electrolysis. The water electrolysis device includes an electrolysis cell, which includes an electrolysis cell cathode and an electrolysis cell anode. The electrolysis cell is connected to a hydrogen separator for separating hydrogen and high-temperature electrolyte through the electrolysis cell cathode. The electrolysis cell is connected to an oxygen separator for separating oxygen and high-temperature electrolyte through the electrolysis cell anode. The hydrogen outlet of the hydrogen separator is connected to a waste lithium iron phosphate battery cathode material recycling system, and the oxygen outlet of the oxygen separator is connected to a waste ternary lithium battery cathode material recycling system.

[0009] The waste lithium iron phosphate battery cathode material recycling system includes a reduction reactor connected to an oxygen separator. The reduction reactor is equipped with an inlet a for feeding crushed waste lithium iron phosphate battery cathode material. The outlet of the reduction reactor is sequentially connected to a leaching tank a, a suction flask a, an oven a, and a product collection tank a.

[0010] The waste ternary lithium battery cathode material recycling system includes an oxidation reactor, which is equipped with an inlet b for feeding crushed waste ternary lithium battery cathode material and oxygen. The outlet of the oxidation reactor is sequentially connected to a leaching tank b, a vacuum filtration flask b, an oven b, and a product collection tank b.

[0011] Furthermore, the electrolyzer is connected to renewable energy sources such as wind and solar power via an energy converter.

[0012] Furthermore, the high-temperature electrolyte outlets of both the hydrogen separator and the oxygen separator are connected to radiators via pipelines, and the radiators are connected to the electrolytic cell via circulating pump pipelines.

[0013] Furthermore, both the high-temperature electrolyte outlets of the hydrogen separator and the oxygen separator are connected to radiators via pipelines, and the radiators are connected to the electrolytic cell via circulating pump pipelines.

[0014] Furthermore, the operating temperature of the reduction reactor is 500℃.

[0015] Beneficial Effects: This device uses renewable energy sources such as solar and wind power as electrolysis power sources. It combines the hydrogen and oxygen generated from water electrolysis with a waste lithium battery recycling system, achieving clean and efficient utilization. Compared to traditional waste lithium battery recycling methods, it improves the lithium leaching rate, reduces environmental pollution, and facilitates the efficient recovery of lithium resources. It truly achieves high-efficiency and high-quality recycling of key components from waste lithium batteries, contributing to the early realization of the "dual-carbon" goal.

[0016] Water is decomposed into hydrogen and oxygen in an electrolyzer, and the hydrogen is separated from the high-temperature electrolyte by a hydrogen separator. The collected hydrogen is used in the reduction process of cathode materials from spent ternary lithium batteries, achieving material recycling. Oxygen is extracted from the high-temperature electrolyte by an oxygen separator. The collected oxygen is used in the oxidation process of cathode materials from spent lithium iron phosphate batteries, improving the efficiency of material recycling. The system can process two different types of spent lithium batteries simultaneously. By precisely controlling the supply rates of hydrogen and oxygen, the system optimizes the reaction speed of the recycling process and improves the overall recycling efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the waste lithium battery recycling system based on the water electrolysis device of this utility model.

[0018] In the diagram: 1-Electrolytic cell, 2-Radiator, 3-Circulating pump, 4-Hydrogen separator, 5-Oxygen separator, 6-Renewable energy source such as wind and solar power, 7-Energy converter, 8-Inlet a, 9-Reduction reactor, 10-Leaching tank a, 11-Filter flask a, 12-Oven a, 13-Product collection tank a, 14-Inlet b, 15-Oxidation reactor, 16-Leaching tank b, 17-Filter flask b, 18-Oven b, 19-Product collection tank b. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] like Figure 1As shown, this utility model proposes a waste lithium battery recycling system based on an electrolysis water device, including an electrolysis water device for generating oxygen and hydrogen, utilizing renewable energy sources such as wind and solar energy 6 as energy sources, and supplying power to the electrolysis water device through an energy converter 7. The electrolysis water device includes an electrolysis cell 1, which is connected to a hydrogen separator 4 for separating hydrogen and high-temperature electrolyte and an oxygen separator 5 for separating oxygen and high-temperature electrolyte. The hydrogen outlet of the hydrogen separator 4 is connected to a waste lithium iron phosphate battery cathode material recycling system, and the oxygen outlet of the oxygen separator 5 is connected to a waste ternary lithium battery cathode material recycling system.

[0021] The waste lithium iron phosphate battery cathode material recycling system includes a reduction reactor 9 connected to an oxygen separator 5. The reduction reactor 9 is provided with an inlet a8 for feeding crushed waste lithium iron phosphate battery cathode material. The outlet of the reduction reactor 9 is sequentially connected to a leaching tank a10, a filtration flask a11, an oven a12, and a product collection tank a13.

[0022] The waste ternary lithium battery cathode material recycling system includes an oxidation reactor 15, which is equipped with an inlet b14 for feeding crushed waste ternary lithium battery cathode material and oxygen. The outlet of the oxidation reactor 15 is sequentially connected to a leaching tank b16, a filtration flask b17, an oven b18, and a product collection tank b19.

[0023] After being softened by the pretreatment system, tap water enters the water pressure stabilization system, and is then pressurized by the water pump and mixed with electrolyte before being fed into the electrolytic cell 2. The water undergoes electrolysis in the electrolytic cell 2, producing hydrogen and oxygen at the cathode and anode of the electrolytic cell 2, respectively.

[0024] The hydrogen separator 4 receives the hydrogen mixture generated at the cathode of the electrolytic cell 1. The hydrogen separator 4 is equipped with a hydrogen-permeable membrane. When hydrogen molecules in the hydrogen mixture pass through the hydrogen-permeable membrane, other gas molecules have relatively less chance of passing through, thus separating the hydrogen from the high-temperature electrolyte. The oxygen separator 5 receives the oxygen mixture generated at the anode of the electrolytic cell 1. The oxygen and high-temperature electrolyte mixture enters the oxygen separator 5. The oxygen separator 5 is equipped with an oxygen-permeable membrane. When oxygen molecules in the mixture pass through the oxygen-permeable membrane, other gas molecules have relatively less chance of passing through, thus separating the oxygen from the high-temperature electrolyte.

[0025] The end of the hydrogen separator 5 is connected to one end of the radiator 2, and the hydrogen separator 5 separates the high-temperature electrolyte in the hydrogen mixture into the radiator 2 for heat dissipation. The end of the oxygen separator 5 is connected to one end of the radiator 2, and separates the high-temperature electrolyte in the oxygen mixture into the radiator 2 for heat dissipation.

[0026] The hydrogen obtained after separation in hydrogen separator 4 is connected to the waste ternary lithium battery cathode material recycling system to reduce the waste ternary lithium cathode material; the oxygen obtained after separation in oxygen separator 5 is connected to the waste lithium iron phosphate battery cathode material recycling system to oxidize the waste lithium iron phosphate cathode material.

[0027] The radiator 2 receives the high-temperature electrolyte from the hydrogen separator 4 and the oxygen separator 5. After being cooled, the electrolyte is enriched together. The other end of the radiator 2 is connected to the circulation pump 3. The high-temperature electrolyte after being cooled is drawn out by the circulation pump 3 and then returned to the electrolytic cell 1 for recycling.

[0028] The working steps of the waste ternary lithium battery cathode material recycling system are as follows:

[0029] a1. Pre-treat waste ternary lithium batteries by removing the negative electrode material, outer shell and separator, leaving only the ternary lithium positive electrode material.

[0030] a2. Reduce and roast the ternary lithium cathode material. During the reduction and roasting process, hydrogen is introduced as a reducing agent to recover elements such as nickel, cobalt, and manganese in a low-valence state. The specific method is to first fill the reaction vessel with hydrogen, and then continuously introduce hydrogen at the required flow rate to meet the consumption requirements of the reaction. The roasting temperature is 500℃, and the roasting duration is determined according to the amount of waste lithium batteries.

[0031] a3. The calcined ternary lithium cathode material is subjected to water leaching for lithium extraction. After the leaching residue is discharged, an alkaline agent is added, and lithium dioxide is obtained by lithium precipitation process.

[0032] The working steps of the waste lithium iron phosphate battery cathode material recycling system are as follows:

[0033] b1. Pre-treat the waste lithium iron phosphate batteries by removing the negative electrode material, casing and separator, leaving only the positive electrode material.

[0034] b2. Using oxygen as an oxidant to oxidize the cathode material of waste lithium iron phosphate batteries improves reaction efficiency and selectivity, and reduces pollution and the generation of by-products.

[0035] b3. After the cathode material that has undergone oxidation treatment is subjected to water leaching to extract lithium, after the leaching residue is discharged, an alkaline agent is added, and lithium carbonate is obtained by lithium precipitation process.

[0036] After reduction and oxidation treatment, the spent lithium battery cathode material undergoes a series of subsequent processing steps (water immersion, lithium precipitation, filtration, and drying) to obtain battery-grade Li2CO3, which can be used in the direct regeneration process of lithium batteries. The high-temperature electrolyte obtained from the hydrogen separator and oxygen separator is passed together into a radiator for heat dissipation and then pumped back into the electrolyzer by a circulation pump to participate in the next cycle.

[0037] Hydrogen and oxygen generated from water electrolysis are used in recycling systems for spent ternary lithium-ion battery cathode materials and spent lithium iron phosphate battery cathode materials, respectively. Combining these two systems and their synergistic effect improves the recycling efficiency of spent lithium batteries, promoting the green and sustainable recycling of lithium resources. Advanced hydrogen-permeable membrane and oxygen-permeable membrane technologies achieve efficient separation of hydrogen and oxygen from the high-temperature electrolyte, improving gas purity and providing a high-quality gas source for subsequent reduction and oxidation reactions. Furthermore, an intelligent control system is introduced to dynamically adjust the flow rates of hydrogen and oxygen based on the characteristics of the spent lithium-ion battery cathode materials and the requirements of the redox reaction, optimizing the reduction and oxidation processes and improving reaction efficiency and material utilization.

Claims

1. A waste lithium battery recycling system based on a water electrolysis device, characterized in that, The device includes an electrolysis unit for generating oxygen and hydrogen by electrolyzing water. The electrolysis unit includes an electrolysis cell (1), which includes an electrolysis cell cathode and an electrolysis cell anode. The electrolysis cell (1) is connected to a hydrogen separator (4) for separating hydrogen and high-temperature electrolyte through the electrolysis cell cathode. The electrolysis cell (1) is connected to an oxygen separator (5) for separating oxygen and high-temperature electrolyte through the electrolysis cell anode. The hydrogen outlet of the hydrogen separator (4) is connected to a waste lithium iron phosphate battery cathode material recycling system, and the oxygen outlet of the oxygen separator (5) is connected to a waste ternary lithium battery cathode material recycling system. The waste lithium iron phosphate battery cathode material recycling system includes a reduction reactor (9) connected to an oxygen separator (5). The reduction reactor (9) is provided with an inlet a (8) for feeding the crushed waste lithium iron phosphate battery cathode material. The outlet of the reduction reactor (9) is sequentially connected to a leaching tank a (10), a filtration flask a (11), an oven a (12), and a product collection tank a (13). The waste ternary lithium battery cathode material recycling system includes an oxidation reactor (15), which is provided with an inlet b (14) for feeding crushed waste ternary lithium battery cathode material and oxygen. The outlet of the oxidation reactor (15) is sequentially connected to a leaching tank b (16), a filtration flask b (17), an oven b (18), and a product collection tank b (19).

2. The waste lithium battery recycling system based on a water electrolysis device according to claim 1, characterized in that: The electrolytic cell (1) is connected to a renewable energy source (6) via an energy converter (7).

3. The waste lithium battery recycling system based on a water electrolysis device according to claim 1, characterized in that: The hydrogen separator (4) is equipped with a hydrogen-permeable membrane for separating hydrogen, and the oxygen separator (5) is equipped with an oxygen-permeable membrane for separating oxygen.

4. The waste lithium battery recycling system based on a water electrolysis device according to claim 1, characterized in that: The high-temperature electrolyte outlets of the hydrogen separator (4) and the oxygen separator (5) are both connected to radiators (2) via pipelines. The radiators (2) are connected to the electrolytic cell (1) via the circulation pump (3) pipeline.

5. The waste lithium battery recycling system based on a water electrolysis device according to claim 1, characterized in that: The working temperature of the reduction reactor (9) is 500℃.

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