A hydrogen reduction device and method for recycling battery cathode materials

Abstract

The application relates to a hydrogen reduction device and method for recycling battery positive electrode materials, the device comprising: a hydrogen production device; a plurality of reduction furnaces, the reduction furnace comprising a cooling chamber and a heating furnace, the cooling chamber and the heating furnace being separated by a furnace door, the cooling chamber being further provided with an inlet and outlet, and the heating furnace being further provided with an air inlet and an air outlet; a metal container placed in the reduction furnace and capable of moving between the cooling chamber and the heating furnace when the furnace door is opened; a nickel tray placed in the metal container and used for containing the battery positive electrode materials; a first hydrogen pipeline used for connecting each air inlet with the hydrogen production device; a plurality of first gas valves arranged at the connection between each air inlet and the first hydrogen pipeline; a second hydrogen pipeline connected with each air inlet and each air outlet; and a plurality of second gas valves arranged at the connection between each air inlet and each air outlet and the second hydrogen pipeline. The device has the beneficial effects of reducing the generation of waste liquid and waste gas and improving the recovery rate of valuable metal elements in the battery positive electrode materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery recycling, in particular to a hydrogen reduction device and method for recycling positive electrode materials of batteries. BACKGROUND

[0002] With the development of lithium ion batteries, lithium cobaltate, lithium manganate, lithium nickelate, nickel-cobalt-manganese (ternary material), lithium iron phosphate and other lithium ion batteries are widely used in power battery field.

[0003] After thousands of charge and discharge cycles, the performance of the active material in the ternary lithium battery deteriorates, and the battery is eventually scrapped. The average scrap cycle is generally 5-8 years. Waste ternary lithium batteries contain a large amount of valuable metals, such as Li accounting for 2%-5%, Co accounting for 5%-20%, and Ni accounting for 5%-12%. Comprehensive disassembly and recycling of positive electrode materials of waste ternary lithium batteries not only solves the problem of lack of strategic metals in China, but also helps to improve related environmental problems.

[0004] Since 2013, when the consumer car subsidy policy was officially launched, the new energy vehicle industry has grown rapidly. In the context of the global auto industry being hit and showing signs of weakness, electric vehicle sales have grown against the trend, becoming a bright spot in the industry. China is the world's largest electric vehicle market, accounting for about 50% of global electric vehicle sales. The downstream demand for high growth drives the rapid increase in the installed capacity of power batteries. According to the average 5-8 year scrap cycle of power batteries, the current power battery is now facing a wave of retirement.

[0005] The shortage of lithium, cobalt, nickel and other resources makes the recycling of lithium ion positive electrode materials very economically valuable. For lithium resources, more than 83% of China's lithium resources are salt lake lithium mines, and because of the harsh natural environment, the mining difficulty is great, making China's lithium resources very dependent on imported lithium resources. For cobalt resources, cobalt has a very low content in the earth's crust, with an average abundance of only 17.3 x 10 -6 China is currently the largest consumer of cobalt resources, and the supply of cobalt resources is tight, with cobalt mines relying on imports and import volume increasing year by year. For nickel resources, China's nickel reserves account for only 3% of the world's total. But China is a big consumer of nickel, and since 2015, China's dependence on nickel has remained above 80%. In order to solve this situation, we should consider that waste power batteries are rich in metal content and are high-quality urban mine resources. With the price rising due to the mismatch between upstream metal resource supply and downstream high demand, and the shortage of lithium, cobalt, nickel and other metals, power battery recycling will provide a new supply channel.

[0006] Moreover, since the materials of the waste power battery can react with some substances in the environment to produce pollutants, once entering the soil, water and atmosphere, it will cause serious pollution. In addition, the metals such as cobalt, nickel, copper, aluminum and manganese in the power battery also have the effect of enrichment, which can accumulate in the human body through the food chain and endanger human health. Concentrated harmless treatment of waste lithium ion batteries and recycling of metal materials are important measures to ensure human health and sustainable development of the environment, and are in line with the "double carbon" goal.

[0007] According to the "China Waste Lithium Ion Battery Recycling and Disassembly and Gradual Utilization Industry Development White Paper (2022)", the theoretical waste lithium battery recycling in China in 2021 reached 591,000 tons, and it is expected that the theoretical waste lithium ion battery recycling in China in 2026 will reach 2,312,000 tons.

[0008] At present, the main method for treating waste lithium ion batteries in industry is to recover and recycle resources through wet recovery and fire recovery process.

[0009] Wet recovery technology, as the name implies, is to dissolve the valuable metal oxides in the positive active material into ions through leaching, so as to enter the solution, and then remove impurities or separate metals by methods such as precipitation, ion exchange, solvent extraction and electrolysis, so as to realize the recovery of valuable metals. Wet metallurgy has the advantages of low energy consumption and high recovery purity, but its process is complex and will produce a large amount of harmful emissions such as waste liquid and waste gas. For example, hydrochloric acid, phosphoric acid and other acids used in wet metallurgy will produce corrosive waste gas such as chlorine gas during leaching, which not only requires high equipment but also needs to treat the subsequent waste liquid.

[0010] The main method of fire metallurgy technology is to use physical or chemical conversion at high temperature to recover and extract valuable metals from waste lithium ion battery materials, and finally to treat and further purify the obtained alloy and slag. It is widely used in industry because of its relatively simple operation and large treatment capacity. But also has the defects of high energy consumption and low recovery rate. For example, in the slagging reduction smelting process of fire metallurgy, lithium ions enter the slag phase, and subsequent secondary purification treatment is needed. High energy consumption and low recovery rate are the shortcomings that fire metallurgy cannot avoid.

[0011] Therefore, how to propose a scheme that can reduce waste gas emission and improve recovery rate in the process of recycling waste lithium ion batteries has become a problem to be solved at present. SUMMARY

[0012] (I) Technical problems to be solved

[0013] In view of the above-mentioned defects and disadvantages of the prior art, the present application provides a hydrogen reduction device and method for recycling battery positive electrode materials, which solves the technical problems of low recycling rate of battery positive electrode materials and high exhaust emission in the recycling process.

[0014] (II) Technical solutions

[0015] In order to achieve the above-mentioned purposes, the main technical solutions adopted by the present application include:

[0016] In a first aspect, the present application provides a hydrogen reduction device for recycling battery positive electrode materials, comprising: a hydrogen production device for obtaining hydrogen; a plurality of reduction furnaces are arranged adjacent from left to right, the reduction furnace comprises a cooling chamber and a heating furnace, the cooling chamber and the heating furnace are separated by a furnace door, the cooling chamber is further provided with an inlet and outlet port, and the heating furnace is further provided with an inlet port and an outlet port; a metal container can be placed in the reduction furnace through the inlet and outlet port, and the metal container can move between the cooling chamber and the heating furnace when the furnace door is opened; a nickel tray is placed in the metal container for containing battery positive electrode materials; a first hydrogen gas pipeline is used to communicate each inlet port with the hydrogen production device; a plurality of first gas valves are arranged at the connection between each inlet port and the first hydrogen gas pipeline, and the first gas valve is opened to make the gas enter the heating furnace through the inlet port; a second hydrogen gas pipeline is in communication with each inlet port and each outlet port; a plurality of second gas valves are arranged at the connection between each inlet port and each outlet port and the second hydrogen gas pipeline, and the second gas valve is a three-way valve, in the case of replacing the battery positive electrode materials in the reduction furnace, the three-way valve only closes the valves on the inlet port and outlet port sides of the reduction furnace where the battery positive electrode materials are replaced, without hindering the circulation of the gas in the second hydrogen gas pipeline.

[0017] Optionally, the hydrogen production device comprises an ammonia decomposition hydrogen production device and / or a renewable energy water electrolysis hydrogen production device.

[0018] Optionally, the hydrogen reduction device further comprises a plurality of gas drying devices arranged on the second hydrogen gas pipeline between adjacent reduction furnaces for drying the gas in the pipeline.

[0019] Optionally, in the case of replacing the gas drying device, the three-way valve only closes the valves at both ends of the gas drying device to be replaced, without closing the valves on the inlet port and outlet port sides.

[0020] Optionally, the metal container is a nickel container.

[0021] In a second aspect, the embodiments of the present application provide a method for recycling battery cathode material, which uses the hydrogen reduction device for recycling battery cathode material in the above technical solution, and the method comprises the following steps: opening the inlet and outlet of each reduction furnace cooling chamber, placing a plurality of nickel trays containing battery cathode material in each metal container, and then closing the inlet and outlet after placing each metal container in each cooling chamber; opening each furnace door, moving each metal container into each heating furnace, and then closing each furnace door; controlling each heating furnace to heat to a reduction temperature; opening all first gas valves and all second gas valves; after the reduction of the battery cathode material in one of the heating furnaces is completed, the heating furnace is recorded as a first heating furnace, the first gas valve corresponding to the first heating furnace is closed, and the second gas valve close to the gas inlet and the gas outlet is closed; opening the furnace door of the first heating furnace to move the metal container to the cooling chamber for cooling in a hydrogen atmosphere, closing the furnace door, and taking out the nickel tray in the metal container and placing it in water when the temperature of the metal container cools to a preset temperature; placing a new nickel tray containing battery cathode material in the metal container in the first cooling chamber and closing the inlet and outlet, opening the corresponding furnace door of the first heating furnace, moving the metal container into the first heating furnace, and then closing the furnace door; controlling the first heating furnace to heat to a reduction temperature; opening the closed first gas valve and the second gas valve corresponding to the first heating furnace.

[0022] Optionally, the hydrogen reduction device further comprises a plurality of gas drying devices arranged on the second hydrogen pipeline between adjacent reduction furnaces, for drying the gas in the pipeline, and the method further comprises: in the case of replacing the gas drying device, closing the valves at both ends of the gas drying device to be replaced of the three-way valve, and not closing the valves on the gas inlet and gas outlet sides.

[0023] (Three) beneficial effects

[0024] The beneficial effects of the present application are: the hydrogen reduction device for recycling battery cathode material of the present application, by arranging a plurality of reduction furnaces adjacent to each other, and controlling the opening and closing of the first gas valve and the second gas valve, the gas can flow between the reduction furnaces. In the process of gas flow, the unreacted hydrogen can flow into the next reduction furnace for further reaction, improving the utilization rate of hydrogen. Compared with related technologies, the use of hydrogen reduction can reduce the generation of waste liquid and waste gas, and does not need secondary purification treatment, improving the recovery rate of battery cathode material. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The hydrogen reduction device for recycling battery cathode material provided by the embodiments of the present application is shown in the structural schematic diagram;

[0026] Figure 2 The structural schematic diagram of a single reduction furnace provided by the embodiments of the present application is shown in the structural schematic diagram;

[0027] Figure 3 A single heating furnace structure schematic diagram provided for the embodiment of the present application

[0028] Figure 4 A flowchart schematic diagram of the method for recycling battery positive electrode material provided for the embodiment of the present application.

[0029]

Explanation of reference signs

[0030] 10: hydrogen reduction device for recycling battery positive electrode material;

[0031] 11: ammonia decomposition hydrogen production device;

[0032] 12: reduction furnace;

[0033] 121: cooling chamber;

[0034] 1211: inlet and outlet port

[0035] 122: heating furnace;

[0036] 1221: gas inlet;

[0037] 1222: gas outlet;

[0038] 123: furnace door;

[0039] 13: nickel tray;

[0040] 14: first hydrogen pipeline;

[0041] 15: first gas valve;

[0042] 16: second hydrogen pipeline;

[0043] 17: second gas valve;

[0044] 18: renewable energy water electrolysis hydrogen production device;

[0045] 19: gas drying device;

[0046] 20: metal container. DETAILED DESCRIPTION

[0047] In order to better explain the present application, in order to facilitate understanding, the present application is described in detail by specific embodiments in combination with the accompanying drawings.

[0048] The hydrogen reduction device for recycling battery positive electrode material provided by the embodiment of the present application is characterized in that: a plurality of reduction furnaces are arranged adjacently, and the on-off control of the first gas valve and the second gas valve is combined to enable the gas to flow between the adjacent reduction furnaces. In the gas flow process, the hydrogen gas that is not completely reacted can flow into the next reduction furnace for continuous reaction, thereby improving the utilization rate of the hydrogen gas. Compared with the wet metallurgical technology for recycling battery electrode material, the embodiment can reduce the generation of waste liquid and waste gas. Compared with the pyrometallurgical technology for recycling battery electrode, the embodiment does not need secondary purification treatment, thereby improving the recovery rate of the battery positive electrode material.

[0049] In order to better understand the above technical solutions, the exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided so that the present application can be more clearly, thoroughly understood, and the scope of the present application can be completely conveyed to those skilled in the art.

[0050] Embodiment one

[0051] Reference Figure 1 , Figure 1The left-to-right adjacent multiple reduction furnaces 12 are provided with a cooling chamber 121 and a heating furnace 122, the cooling chamber 121 and the heating furnace 122 are separated by a furnace door 123, the cooling chamber 121 is further provided with an inlet and outlet port 1211, and the heating furnace 122 is further provided with an air inlet 1221 and an air outlet 1222; a metal container 20 can be placed in the reduction furnace 12 through the inlet and outlet port 1211, and the metal container 20 can move between the cooling chamber 121 and the heating furnace 122 when the furnace door 123 is opened; a nickel tray 13 is placed in the metal container 20 and used for containing the battery positive material; a first hydrogen gas pipeline 14 is used for connecting each air inlet 1221 with the hydrogen production device; a plurality of first gas valves 15 are arranged at the connection between each air inlet 1221 and the first hydrogen gas pipeline 14, and the gas enters the heating furnace through the air inlet 1221 by controlling the first gas valve 15 to be opened; a second hydrogen gas pipeline 16 is connected with each air inlet 1221 and each air outlet 1222; a plurality of second gas valves 17 are arranged at the connection between each air inlet 1221 and each air outlet 1222 and the second hydrogen gas pipeline 16, and the second gas valve 17 is a three-way valve, which only closes the valves on the air inlet and air outlet sides of the reduction furnace in which the battery positive material is replaced, without hindering the gas flow in the second hydrogen gas pipeline.

[0052] The hydrogen reduction device for recycling battery positive materials provided in the embodiment can make the gas flow between the adjacent reduction furnaces 12 by arranging multiple reduction furnaces 12 and controlling the on-off of the first gas valve 15 and the second gas valve 17. In the gas flow process, the hydrogen that is not completely reacted can flow into the next reduction furnace 12 for continuous reaction, thereby improving the utilization rate of hydrogen. Compared with the related art, the hydrogen reduction method can reduce the generation of waste liquid and waste gas, and does not need secondary purification treatment, thereby improving the recovery rate of valuable metal elements in the battery positive material. In addition, since nickel has the properties of high temperature resistance, corrosion resistance, high strength and rigidity, anti-adhesion and reusability, the use of the nickel container can not only realize metal recovery, but also effectively reuse the container itself, which meets the principle of sustainable development. Therefore, the use of the nickel tray 14 can provide multiple benefits such as high temperature resistance, corrosion resistance, high strength, anti-adhesion and reusability, which helps to improve the efficiency and safety of the battery material recycling process.

[0053] Optionally, as Figure 3As shown, the heating furnace 122 is a cuboid container, and the gas inlet 1221 and the gas outlet 1222 are respectively arranged on the left and right sides or the front and back sides of the heating furnace 122, and the gas outlet 1222 is located on the opposite side of the gas inlet 1221, which is not shown in the figure.

[0054] Optionally, the hydrogen production device comprises: an ammonia decomposition hydrogen production device 11 and / or a renewable energy water electrolysis hydrogen production device 18.

[0055] Optionally, the hydrogen reduction device further comprises: a plurality of gas drying devices 19 arranged on the second hydrogen pipeline between adjacent reduction furnaces, for drying the gas in the pipeline.

[0056] By increasing the gas drying device 19, the gas entering the next heating furnace 122 from the previous heating furnace 122 is in a dry state, avoiding the influence of water vapor generated during the reduction process on the reduction process. Among them, the gas drying device 19 can adopt adsorption or freezing to dry the gas. The adsorption type is to use a dryer to adsorb the moisture in the air. The freezing type is to cool the gas to make water vapor precipitate from the air to obtain dry gas.

[0057] Optionally, the metal container is a nickel container.

[0058] Because nickel has the following characteristics: 1. High temperature resistance: nickel has good high temperature resistance and can withstand molten metal in high temperature environment. 2. Corrosion resistance: nickel has good corrosion resistance and can remain stable when in contact with various metals and non-metallic substances. 3. High strength and rigidity: nickel has high strength and rigidity, so that the nickel container can maintain its structural integrity in harsh working environments, ensuring the safety and reliability of the metal recovery process. 4. Reusability: Compared with other materials, nickel has good reusability and can be recycled and reused through appropriate treatment methods. Therefore, using a nickel container not only realizes metal recovery, but also effectively recycles the container itself, in line with the principles of sustainable development. Therefore, the heating furnace 122 as a nickel container can provide multiple benefits such as high temperature resistance, corrosion resistance, high strength, anti-adhesion and reusability, which helps to improve the efficiency and safety of the battery material recovery process.

[0059] Example two

[0060] Reference Figure 4 The present embodiment provides a method for recycling battery positive electrode materials, which adopts the hydrogen reduction device for recycling battery positive electrode materials provided in the first embodiment of the present application, and the method comprises:

[0061] S401, open the inlet and outlet of each reduction furnace cooling chamber, place a plurality of nickel trays containing battery positive materials in each metal container, and then close the inlet and outlet after placing each metal container into each cooling chamber.

[0062] S402, open each furnace door, and then close each furnace door after moving each metal container into each heating furnace.

[0063] S403, control each heating furnace to heat to a reduction temperature.

[0064] S404, open all first gas valves and all second gas valves.

[0065] S405, after the reduction of the battery positive material in one of the heating furnaces is completed, the heating furnace is recorded as a first heating furnace, the first gas valve corresponding to the first heating furnace is closed, and the second gas valve close to the inlet and outlet is also closed.

[0066] S406, open the furnace door of the first heating furnace to move the metal container to the cooling chamber for cooling in a hydrogen atmosphere, close the furnace door, and then take out the nickel tray in the metal container and place it in water when the temperature of the metal container cools to a preset temperature.

[0067] S407, place a new nickel tray containing battery positive material in the metal container in the first cooling chamber and close the inlet and outlet, open the corresponding furnace door of the first heating furnace, move the metal container into the first heating furnace, and then close the furnace door; control the first heating furnace to heat to a reduction temperature; open the closed first gas valve and second gas valve corresponding to the first heating furnace.

[0068] The method for recycling battery positive materials provided by the embodiment of the application can make the gas flow between multiple reduction furnaces by controlling the opening and closing of the first gas valve and the second gas valve, and the unreacted hydrogen can flow into the next reduction furnace for further reaction in the gas flow process, thereby improving the utilization rate of hydrogen. Compared with the related art, the hydrogen reduction method can reduce the generation of waste liquid and waste gas, and does not need secondary purification treatment, thereby improving the recycling rate of battery positive materials.

[0069] Optionally, the hydrogen reduction device further comprises a plurality of gas drying devices arranged on the second hydrogen pipeline between adjacent reduction furnaces, for drying the gas in the pipeline, and the method further comprises: in the case of replacing the gas drying device, closing the valves at both ends of the gas drying device to be replaced, and not closing the valves on the inlet and outlet sides.

[0070] By closing only the valves at both ends of the gas drying device, the gas leakage during replacement can be prevented. In addition, the three-way valve can also be completely closed during replacement of the gas drying device.

[0071] Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the spirit and scope of the present application. Accordingly, such modifications and changes should be included within the scope of the present application as defined by the appended claims and their equivalents.

[0072] In the description of the present application, it is to be understood that the terms "first", "second", "third" and the like, merely identify features being described but do not imply or imply relative importance or a number of the features being referred to. Thus, a feature with a "first", "second", or the like designation can implicitly or explicitly include one or more of the features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0073] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A hydrogen reduction device for recycling a cathode material of a battery, characterized by, The application relates to a hydrogen reduction device for recycling battery positive materials. The hydrogen reduction device comprises a hydrogen production device for obtaining hydrogen; a plurality of reduction furnaces are arranged adjacently from left to right, the reduction furnaces comprise cooling chambers and heating furnaces, the cooling chambers and the heating furnaces are separated by furnace doors, the cooling chambers are further provided with inlet and outlet ports, and the heating furnaces are further provided with gas inlets and gas outlets; metal containers can be placed in the reduction furnaces through the inlet and outlet ports, and the metal containers can be moved between the cooling chambers and the heating furnaces when the furnace doors are opened; nickel trays are placed in the metal containers and used for containing battery positive materials; a first hydrogen pipeline is used for connecting each gas inlet with the hydrogen production device; a plurality of first gas valves are arranged at the connection positions of each gas inlet and the first hydrogen pipeline, and gas is allowed to enter the heating furnace through the gas inlet by controlling the first gas valve to be opened; a second hydrogen pipeline is connected with each gas inlet and each gas outlet; a plurality of second gas valves are arranged at the connection positions of each gas inlet and each gas outlet and the second hydrogen pipeline, and the second gas valves are three-way valves; in the case of replacing battery positive materials in the reduction furnaces, the three-way valves only close the valves at the gas inlet and gas outlet sides of the reduction furnace in which the battery positive materials are replaced, and do not hinder the circulation of gas in the second hydrogen pipeline; the hydrogen reduction device further comprises: a plurality of gas drying devices arranged on the second hydrogen pipeline between adjacent reduction furnaces and used for drying the gas in the pipeline; in the case of replacing the gas drying devices, the three-way valves only close the valves at the two ends of the gas drying device to be replaced, and do not close the valves at the gas inlet and gas outlet sides. The hydrogen production device comprises: an ammonia decomposition hydrogen production device and / or a renewable energy water electrolysis hydrogen production device. The metal containers are nickel containers. The application further discloses a method for recycling battery positive materials by using the hydrogen reduction device. The method comprises the following steps: opening the inlet and outlet ports of the cooling chambers of the reduction furnaces, placing a plurality of nickel trays containing battery positive materials in the metal containers respectively, and then closing the inlet and outlet ports after the metal containers are placed in the cooling chambers; opening the furnace doors, and then closing the furnace doors after the metal containers are moved into the heating furnaces; controlling the heating furnaces to be heated to a reduction temperature; opening all the first gas valves and all the second gas valves; after the battery positive materials in one of the heating furnaces are reduced, the heating furnace is recorded as a first heating furnace, the first gas valve corresponding to the first heating furnace is closed, and the second gas valves close to the gas inlet and gas outlet sides are closed; opening the furnace door of the first heating furnace, moving the metal container to the cooling chamber, and then cooling the metal container in a hydrogen atmosphere, closing the furnace door, and then taking out the nickel tray in the metal container and placing the nickel tray in water when the temperature of the metal container is cooled to a preset temperature; placing a new nickel tray containing battery positive materials in the metal container in the first cooling chamber and closing the inlet and outlet ports, opening the furnace door corresponding to the first heating furnace, moving the metal container into the first heating furnace, and then closing the furnace door; controlling the first heating furnace to be heated to a reduction temperature; and opening the closed first gas valve and second gas valve corresponding to the first heating furnace. ​ ​ ​ ​ ​ ​ 2. The hydrogen reduction apparatus for recycling a battery cathode material according to claim 1, characterized by, ​ ​ 3. The hydrogen reduction apparatus for recycling a battery cathode material according to claim 2, characterized by, ​ 4. A method for recycling a cathode material of a battery, characterized by, ​ ​ ​ ​ ​ ​ ​ ​ The hydrogen reduction device further comprises a plurality of gas drying devices arranged on the second hydrogen pipeline between adjacent reduction furnaces, for drying the gas in the pipeline, and the method further comprises: In the case of replacing the gas drying device, the valves at both ends of the gas drying device to be replaced are closed, and the valves on the gas inlet and outlet sides are not closed.

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