电化学还原技术从废旧锂离子电池中浸出LiCoO_2  

Leaching LiCoO_2 from spent lithium-ion batteries by electrochemical reduction

作　　者：常伟[1] 满瑞林[1] 尹晓莹[1] 张建[1] 

机构地区：[1]中南大学化学化工学院,长沙410083

出　　处：《中国有色金属学报》2014年第3期787-792,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(21046007)

摘　　要：基于电化学还原技术,提出在低酸度溶液中电解浸出废旧锂离子电池正极片(LiCoO2)的新方法。线性伏安扫描结果表明:LiCoO2的还原峰电位为0.30 V(vs SCE),验证了此方法的可行性。通过条件实验对影响钴和铝浸出率的各因素进行考察,得到电解浸出的最佳条件:电流密度15.6 mA/cm2、硫酸浓度40 g/L、柠檬酸浓度36 g/L、温度45℃、时间120 min。在此优化条件下,钴和铝的浸出率分别为90.8%和7.9%。电解浸出后,可直接回收铝箔,用扫描电子显微镜(SEM)对铝箔表面进行观察,结果表明:铝箔在浸出过程中的腐蚀深度远小于其表面原有点蚀坑的深度。Based on the electrochemical reduction technique, a novel process was developed for leaching LiCoO2 in the low acidity medium by electrolysis from spent lithium-ion secondary batteries. The electrochemical deoxidizing of LiCoO2 was characterized by linear sweeping voltammetry. The results show that the cathodic peak potential of LiCoO2 is 0.30 V（vs SCE）, which verifies the possibility of the process. The related factors on the leaching rates of Co and Al were investigated by single factor experimental method, and the optimal parameters are as follows： current density 15.6 mA/cm2, concentration of H2SO4 40 g/L, concentration of C6H8O7？H2O 36 g/L, reaction temperature 45 ℃, electrolysis time 120 min. Under the optimal conditions, the leaching rates of Co and Al are 90.8% and 7.9%, respectively. After leaching, the aluminum foil can be recovered in their metallic forms. The surface morphology of the aluminum foil was examined by scanning electron microscopy （SEM）. The results indicate that the corrosion depth of aluminum foil under leaching conditions is much smaller than the corrosive pit depth of aluminum foil without leaching in the sulfuric acid solution.

关 键 词：废旧锂离子电池 LICOO2 电化学还原 电解浸出 阴极保护 

分 类 号：X705[环境科学与工程—环境工程]