Study On Ascorbic Acid Leaching Of Valuable Metals From Spent Nickel-Cobalt Manganese Ternary Batteries

With the shortage of global stone resources and the increasing awareness of environmental protection,the development of new energy vehicles is gradually becoming the consensus of people,and power batteries are an important part of new energy vehicles.When the power battery is used in new energy vehicles,the service life is generally about 5 years.According to the corresponding scrapping standards,The China Automotive Technology and Research Center predicted that the power battery capacity of China's new energy vehicles would reach 170,000 tons in 2020.In the technical direction of power batteries,lithium nickel cobalt manganese ternary?NCM?cathode materials gradually replace lithium cobalt oxide?LiCoO₂?with its unique low cost,high performance,light pollution,etc.,and become a power lithium ion battery.One of the most widely used positive electrode active materials.The harm Less and resourceful recycling of spent ternary power batteries has become a hot topic at home and abroad.Acid leaching is the most common method for recovering metal elements in cathode materials,and it is also a valuable metal element in spent NCM batteries.The key steps in recycling that determine the efficiency of recovery make it necessary to study the leaching process to determine the optimum process conditions for selective recovery.With the shortage of global stone resources and the increasing awareness of environmental protection,the development of new energy vehicles is gradually becoming a consensus.As an important part of new energy vehicles,power batteries are used in new energy vehicles,and their service life is generally about 5 years.According to the corresponding scrapping standards,The China Automotive Technology and Research Center predicted that the power battery capacity of China's new energy vehicles would reach 170,000 tons in 2020.In the technical direction of power batteries,lithium nickel cobalt manganese ternary?NCM?cathode materials gradually replace lithium cobalt oxide?LiCoO₂?with its unique low cost,high performance,light pollution,etc.,and become one of the most widely used positive electrode active materials for power batteries.The harm Less and resourceful recycling of spent ternary power batteries has become a hot topic at home and abroad.Acid leaching is the most common method for recovering metal elements in cathode materials,and also a key step in determining the recycling efficiency of the recovery of valuable metal elements in spent NCM batteries.It is necessary to study the leaching process to determine the optimum process conditions for selective recovery.In the research of this subject,the spent NCM batteries were firstly discharged and disassembled,then the disassembled positive electrode materials were subjected to shear drying treatment.The positive electrode material was subjected to digestion treatment,and the positive electrode piece was qualitatively and quantitatively analyzed by Inductively coupled plasma atomic emission spectrometer?ICP-AES?.Then,the research on the leaching process of the positive electrode material of the discarded NCM battery was carried out,and the positive electrode waste was directly treated with the reducing organic acid ascorbic acid.The effects of reaction temperature,ascorbic acid concentration,solid-liquid ratio and reaction time on the leaching rate of each metal were explored,combined with response surface analysis,the best experimental conditions were as follows: reaction temperature 70 ?,ascorbic acid concentration 1.25 mol/L,solid-liquid 30 g /L,reaction time 60 min.Finally,the kinetic analysis of the leaching process yields were explored the best kinetic model were found.The economics of this research system and the traditional recycling system are analyzed,and the economic advantages of the research system in terms of equipment and electricity consumption are obtained.In comparison,the ascorbic acid system process saves 1,760,683.29 yuan in equipment and electricity costs,and has an advantage in equipment investment and energy consumption.In this study,the ternary power battery of spent automobiles were used as raw material,which utilized the acidity and reducing property of ascorbic acid and low selectivity to aluminum foil current collector,avoided the use of organic solvent,and does not involve calcination and ball milling,which greatly simplified the recycling process,reduced recycling costs.It did not produce secondary pollution during the recycling process,and were very friendly to the environment,which provided theoretical guidance for the high-value resource recycling and comprehensive utilization of the anode material for spent NCM batteries.