有机酸浸法绿色回收废旧磷酸铁锂电池正极金属的研究  

Green recovery of metals from spent lithium iron phosphate cathode by organic acid leaching

作　　者：罗家玲 刘昕烨 刘思怡 何嘉成 文婕 LUO Jia-ling;LIU Xin-ye;LIU Si-yi;HE Jia-cheng;WEN Jie(Sichuan Provincial Key Laboratory of Oil&Gas Field Applied Chemistry,College of Chemistry&Chemical Engineering,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学化学化工学院,油气田应用化学四川省重点实验室,四川成都610500

出　　处：《现代化工》2024年第11期202-207,共6页Modern Chemical Industry

基　　金：四川省2023年大学生创新创业训练计划项目(S202310615151);四川省产教融合示范项目“四川省光伏产业产教融合综合示范基地”(川财教[2022]106号);油气田应用化学四川省重点实验室开放基金(YQKF202115)。

摘　　要：采用绿色有机酸对磷酸铁锂电池正极粉末进行回收,考察了浸出过程的影响因素。结果表明,柠檬酸+抗坏血酸体系对Li浸出率最高可达92.7%,最佳反应条件为:柠檬酸浓度为1.5 mol/L、抗坏血酸浓度为0.3 mol/L、酸浸温度为80℃、酸浸时间为60 min、固液比为1∶20。采用液体边界层传质控制模型和化学反应控制模型对浸出过程进行分析,结果表明,Li的浸出过程符合化学反应控制模型,反应活化能为30.56 kJ/mol。SEM和XRD表征结果表明,在浸出反应过程中,Li以Li_(3)Cit的形式释放到溶液中,LiFePO_(4)正极粉末中的Fe^(2+)被氧化为Fe^(3+),酸浸反应后LiFePO_(4)可以直接转化为FePO_(4),而不需要形成其他铁化合物。A sustainable approach is explored for recovering lithium from lithium iron phosphate(LiFePO4)cathode powder by green organic acids,and the effectiveness at various leaching parameter is evaluated.It is revealed that the highest extraction rate of lithium reaches 92.7%under a combination of citric acid(1.5 mol·L^(-1))and ascorbic acid(0.3 mol·L^(-1))system.The optimal reaction conditions are obtained as follows:citric acid concentration is 1.5 mol·L^(-1),ascorbic acid concentration is 0.3 mol·L^(-1),leaching temperature is 80℃,leaching time is 60 minutes,and solid-liquid ratio is 1∶20.The leaching process is analyzed by using liquid boundary layer mass transfer controlling model and chemical reaction controlling model.Results indicate that the extraction process of lithium conforms to the chemical reaction control model,with an activation energy of 30.56 kJ·mol^(-1).SEM and XRD characterization analysis confirms that Li in the form of Li3Cit is released into the solution during the leaching reaction process.Fe^(2+)in LiFePO_(4) cathode powder is oxidized to Fe^(3+).After the leaching reaction,LiFePO4 can be directly converted to FePO_(4) without forming other iron compounds.

关 键 词：锂离子电池 磷酸铁锂 正极粉末 酸浸 机理 动力学 

分 类 号：TQ150.9[化学工程—电化学工业]