Research progress of the alkaline-system selective recycling technology in spent lithium-ion batteries Haiqiang Gong,Dezhao Peng,Xing Ou,Jiafeng,Zhang* Abstract:With the gradually depletion of lithium,nickel and other metal resources,lithium ion battery manufacturing can be less add-valued.In addition,the organic electrolyte contained in lithium ion batteries is highly toxic,which can easily cause serious harm on human beings and the environment.The recovery of spent lithium-ion batteries is an unavoidable problem for the development of lithium-ion batteries industry.The effective recovery of spent lithium-ion batteries is of great importance to the sustainable utilization of lithium resources and the positive cycle of industry.At present,the recovery of lithium-ion batteries mainly relies on the hydrometallurgy extraction process.The main metals are extracted from the waste lithium-ion batteries through acid or alkali,and the recovery of metal compounds is realized through further processing,or the re-synthesis of high-performance materials.Among them,acid leaching process is short and high efficiency.However, acid leaching process dissolves all the metal ions in the solution,which is not easy to separate and purify the valuable metals subsequently.On the other hand,the hydroxide of impurity metal in lithium-ion battery shows a low solubility,while lithium,nickel and cobalt have high solubility,or can form complexes with ammonia ions,which can exist in alkali solution in large quantities.Therefore, Alkaline leaching has better selective leaching ability for metal in electrode materials.and it is more efficient and cleaner in the recovery process which has excellent industrialization potential.In addition,a large number of investigations at domestic and overseas are focused on the acid method research,and formed a certain scale and system,but the alkaline recovery process has not been summarized in detail by researchers.In this paper,based on the industrial research status of alkali leaching recovery,four alkali leaching recovery systems were summarized which include ammonia leaching-reductant-hot working system,ammonia leaching-reductant-electrodeposition system,ammonia leaching-reductant-lithium adsorption system and ammonia leaching-reductant-oxidation separation system,and the principles and advantages of different methods were summarized.Finally,a briefly summarize of the recovery methods for spent lithium-ion batteries was expressed. Key words:spent lithium-ion batteries;recovery;alkaline leaching;selectivity;metal-ammonia complex2 Research progress of the alkaline-system selective recycling technology in spent lithium-ion batteries Haiqiang Gong, Dezhao Peng, Xing Ou, Jiafeng, Zhang⁎ Abstract: With the gradually depletion of lithium, nickel and other metal resources, lithium ion battery manufacturing can be less add-valued. In addition, the organic electrolyte contained in lithium ion batteries is highly toxic, which can easily cause serious harm on human beings and the environment. The recovery of spent lithium-ion batteries is an unavoidable problem for the development of lithium-ion batteries industry. The effective recovery of spent lithium-ion batteries is of great importance to the sustainable utilization of lithium resources and the positive cycle of industry. At present, the recovery of lithium-ion batteries mainly relies on the hydrometallurgy extraction process. The main metals are extracted from the waste lithium-ion batteries through acid or alkali, and the recovery of metal compounds is realized through further processing, or the re-synthesis of high-performance materials. Among them, acid leaching process is short and high efficiency. However, the acid leaching process dissolves all the metal ions in the solution, which is not easy to separate and purify the valuable metals subsequently. On the other hand, the hydroxide of impurity metal in lithium-ion battery shows a low solubility, while lithium, nickel and cobalt have high solubility, or can form complexes with ammonia ions, which can exist in alkali solution in large quantities. Therefore, Alkaline leaching has better selective leaching ability for metal in electrode materials, and it is more efficient and cleaner in the recovery process which has excellent industrialization potential. In addition, a large number of investigations at domestic and overseas are focused on the acid method research, and formed a certain scale and system, but the alkaline recovery process has not been summarized in detail by researchers. In this paper, based on the industrial research status of alkali leaching recovery, four alkali leaching recovery systems were summarized which include ammonia leaching-reductant-hot working system, ammonia leaching-reductant-electrodeposition system, ammonia leaching-reductant-lithium adsorption system and ammonia leaching-reductant-oxidation separation system, and the principles and advantages of different methods were summarized. Finally, a briefly summarize of the recovery methods for spent lithium-ion batteries was expressed. Key words: spent lithium-ion batteries; recovery; alkaline leaching; selectivity; metal-ammonia complex 录用稿件，非最终出版稿