Recycling Of Spent Lithium-Ion Batteries And Resource Utilization

With the development of portable electronic devices and new energy vehicles,the usage of lithium-ion batteries（LIBs）shows an explosive growth.However,problems of spent LIBs followed closely,while the cumulative quantity of spent LIBs was expected to be 25 billion by 2020.A large number of spent LIBs not only mean serious environmental pollution,but also mean enormous valuable metal resources waste.For this purpose,this paper reused the spent LIBs and focused on the catalytic performance of its products.Calcinating mechanical separation was involved to compare unscreened rate of cathode materials in various calcinating temperature、calcinating time and crushing time by Na Cl immersive discharge and circuit discharge.Circuit discharge showed low unscreened rate in all conditions,which means better performance for collecting cathode active powder.H₂SO₄-NaHSO₃ leaching method was involved to study the optimum reaction conditions: c（H₂SO₄）= 1.5 mol/L、c（NaHSO₃）= 0.02 mol/L、reaction time=4 h、reaction temperature=90 oC.In the optimum conditions,recovery of Co、Ni、Mn、Li could reach 93.7%、99.3%、93.3% and 95.4%。Hydrothermal method was involved to extract Co、Ni、Mn in the acid leaching solution of spent LIBs preparing composite metal oxides,which mostly were Mn2O3 and utilized as toluene catalysts.This paper researched that the optimum calcination temperature for preparing catalyst was T=600℃ and the best gas hourly space velocity（GHSV）was 60000 m L/（g·h）realizing 95% toluene conversion at 275 ℃.Ferrite process was involved to immobilize residual valuable metals of LIBs wastewater utilizing its products as ozone catalysts,which can accelerate more radicals to enhance the effect of phenol ozonation.The optimum molar rate of Fe/Me=20、pH=11、preparing temperature=90 ℃ and various metal doped ferrites、initial pH、dosage、cycle utilization in phenol degradation were studied.Spent LIBs wastewater ferrite realized phenol degradation of 95% in 30 min,30 min faster than ozonation.Degradation pathway of phenol ozonation was proved to be phenol---1-2-Benzenediol---benzoquinone---low molar acid in order.