Research On The Recovery And Reuse Of Waste Nickel-cobalt-manganate Lithium Batteries

In recent years,market of new energy in China has been expanding,and the sales volume of lithium ion batteries has been increasing rapidly,resulting in a large number of retired lithium ion batteries and serious environmental pollution.If the metal in the waste lithium ion battery which is of high value can be recovered efficiently,it will reduce the consumption of mineral resource and the environmental pollution.This paper studied the efficiency recovery of waste lithium ion battery and reuse of cathode materials,including the methods and conditions of the safe disassembly of batteries,metal leaching and regeneration.(1)Firstly,the spent batteries are immersed in 8mol/L sodium solution to realize safe dischange,then the disassembled cathode electrode is treated with ultrasonic heating at 70?for 10min,of maximum efficiency to collect cathode material.Finally,pure spent cathode active material is obtained by heating the active material at 750?for 6h to remove the PVDF and conductive carbon black.(2)This paper uses green organic malic acid as the leaching agent,and the leaching efficiency is greatly enhanced under the synergistic action of H₂O₂.When the malic acid concentration is chosen 1.25mol/L,solid-liquid rate is 40g/L,reaction temperature is 60?,reaction time is 80min and H₂O₂volume is 4%,the maximizing leaching efficiency of Li,Ni,Co,Mn reaches 99.09%,99.08%,98.91%,99.38%.(3)A hydrothermal method using urea as precipitator is used to reuse metal leaching solution and to assist high temperature calcination to regenerate Li Ni_0.5Co_0.2Nn_0.3O₂(NCM523)cathode material.The morphology and electrochemiacl properties of the materials can be affected by adjusting experimental variable.The regenerated samples is synthesized under the conditions of 0.06mol urea,24 h the reaction time and 180?reaction temperature,which has micrometer spherical structure.The initial discharge specific capacity reaches158.2m Ah/g at 0.2C,and the capacity retention rate is 97%after 100 cycles.(4)This paper uses oxalic acid to recycle metal leaching solution,and regenerated materials with excellent electrochemical properties is obtained under the condition that concentration is 0.25mol/L,reaction temperature is 180?,the reaction time is 24h.After comparing with commercial NCM-S,it is found that it has great stability and high capacity retention.The samples have the first discharge specific capacity of 160.8m Ah/g at 0.2C and the capacity retention rate is 94.3%after cycling 100 weeks,which indicate that it has better electrochemical performance.