以废旧锂离子电池正极材料还原产物为原料熔盐合成钴酸锂循环利用

Performance of Recycled Lithium Cobalt Oxide Synthesized with Molten Salt of Cathode Material Reduction Product of Waste Lithium Battery

基于一种创新的废旧锂离子电池回收再合成的绿色循环路线,以熔融LiCl·KCl作为熔盐介质,废旧锂电池正极材料热还原转型产物LiOH·H_(2)O与Co_(2)O_(3)为原料,通过熔盐法合成了锂离子电池正极材料钴酸锂LiCoO_(2),进而制备纽扣电池用以资源的循环利用。主要研究钴酸锂合成的反应动力学及反应条件对产物钴酸锂LiCoO_(2)的材料结构、形貌结构的影响;通过电化学分析手段对钴酸锂LiCoO_(2)的电池性能进行测试表征。结果表明:运用Kissinger法计算合成过程中的3个吸热反应过程的活化能依次为34.21200、168.53925、221.26181 kJ·mol^(-1);在750℃焙烧6 h,产物LiCoO_(2)具有良好的六方晶格结构;在0.2 C倍率、测试电压范围在2.4~4.2 V的条件下对电池进行充放电及循环性能测试,得出在750℃焙烧6 h合成的LiCoO_(2)制备出的实验电池,其首次充放电比容量分别为150 mA·h/g和147 mA·h/g,Coulombic效率为98%,循环充放电50次之后的放电比容量仍有129 mA·h/g;经过倍率循环后电池仍有较好的充放电性能。

Based on an innovative green recycling route for recycling and re-synthesis of spent lithium-ion batteries,LiCoO_(2)was synthesized by a molten salt method with LiCl-KCl as a molten salt medium and LiOH·H_(2)O and Co_(2)O_(3) as raw materials,and then the button batteries were prepared for resource recycling.The reaction kinetics of lithium cobalt oxide synthesis and the effect of reaction conditions on the structure and morphology of LiCoO_(2)were investigated.The battery performance of LiCoO_(2)was characterized by electrochemical analysis.The results show that the activation energies of the three endothermic reaction processes in the synthesis calculated by the Kissinger model are 34.21200,168.53925 kJ/mol and 221.26181 kJ/mol,respectively.The product of LiCoO_(2)has a good hexagonal lattice structure when calcined at 750℃for 6 h.The charge-discharge and cycle performance of the battery were tested at 0.2 C rate and 2.4‒4.2 V.The experimental battery prepared by LiCoO_(2)calcined at 750℃for 6 h has the first charge-discharge specific capacity of 150 mA·h/g and 147 mA·h/g,the Coulombic efficiency is 98%,and the discharge specific capacity after 50 cycles of charge and discharge is still 129 mA·h/g.The battery still has a good charge and discharge performance after rate cycle.