锂离子电池电解液的绿色处理研究

Study on Green Treatment for Electrolyte of Lithium Ion Batteries

通过化学沉淀方法对锂离子电池电解液进行处理,探究了不同浓度氢氧化钠和温度条件下电解液中六氟磷酸锂(LiPF 6)、碳酸二甲酯(DMC)和碳酸乙烯酯(EC)的反应情况.NaOH既能和LiPF 6反应产生氟化锂沉淀、氟化钠和磷酸钠,又能和DMC、EC反应产生醇和碳酸盐.通过分析不同条件下三者的反应效率,找出反应效率高的NaOH浓度和温度条件,并在此条件下处理电解液,然后向滤液中加入澄清石灰水调节pH值,收集出氟化钙.先后通过NaOH和澄清石灰水对电解液进行两步除杂,实现了对电解液的绿色处理,并能够收集出LiF和CaF 2,实现资源的回收利用.

The reaction of lithium hexafluorophosphate(LiPF 6),dimethyl carbonate(DMC)and ethylene carbonate(EC)in electrolyte was investigated by chemical precipitation method for lithium-ion battery electrolyte under different concentrations of sodium hydroxide and temperature conditions.NaOH can not only react with LiPF 6 to produce lithium fluoride precipitates,sodium fluoride and sodium phosphate,but also react with DMC and EC to produce alcohols and carbonates.By analyzing the reaction efficiency of the three under different conditions,the NaOH concentration and temperature conditions with high reaction efficiency were identified,and the electrolyte was treated under these conditions,after which the pH value was adjusted by adding clarified lime water to the filtrate and calcium fluoride was collected.By using NaOH and clarified lime water to remove impurities in two steps,the green treatment of electrolyte was realized,and LiF and CaF 2 could be collected to realize resource recovery.