Study on electrochemical deintercalation to enhance the high-efficiency purification of metallurgical graphite residue from spent lithium battery materials
A large amount of waste graphite generated in the recycling process of spent lithium-ion battery is difficult to be recycled.Waste graphite generated in the metallurgical process of spent electrode material was used as sample,this study putted forward a new method of impurity removal and purification of waste graphite,which combined impurity pretreatment,alkali leaching and electrochemical de-intercalation,to achieve efficient removal of impurities in waste graphite.The results showed that the sulfur content has decreased from 3.47％to 0.32％in the pre-treating process.The optimal conditions of alkali leaching were as follows:sodium hydroxide solution concentration was 2 mol·L-1,liquid-solid ratio was 15:1,temperature was 60 ℃,leaching time was 90 min.On this condition,the removal rate of aluminum was up to 97.13％while the phosphorus content decreased from 4.20％to 0.043％.The best electrochemical de-intercalation efficiency was achieved at electrolyte concentration of 0.5 mol·L-1,voltage of 3.6 V,temperature of 80 ℃ and treating time of 60 min.The removal rates of lithium,nickel,cobalt,manganese,iron and copper were up to 95.68％,91.58％,93.53％,92.34％,96.69％,and 84.17％,respectively.The residual metals in the metallurgical waste graphite were efficiently removed by pretreatment and the degree of graphitization was effectively restored,alkali leaching and electrochemical de-intercalation,which provided high quality materials for the subsequent high-value reuse of waste graphite.
spent lithium-ion batteriesgraphite wasteimpurity removal and purificationalkali washelectrochemical removal
万方数据
维普
