Review on recycling of graphite anode from spent lithium-ion batteries
Lithium-ion battery capacity will reduce to a certain extent after used for 6-8 years and a large amount of waste are generated.The graphite anode accounts for 12%—21%of battery and its recycling is beneficial to the environment protection and economic development.In this paper,the regenerating methods of spent graphite anode into battery-grade graphite are summarized,which include the combination of leaching and calcination,graphite surface coating,preparation of composite materials and heteroatom doping.A brief comparison of these methods is also presented in terms of energy consumption and electrochemical performance.At present,direct regeneration for lithium-ion batteries is considered as the most suitable method for the regeneration of anode materials.In the future,more efficient and eco-friendly leaching agents and the multi-path low-temperature calcination methods should be investigated.In addition,high-capacity anode materials should be studied to composite with spent graphite,as well as the development of low-cost coating on the surface of graphite.Furthermore,the doping mechanism of heteroatoms in graphite is a direction worthy of research.