电池级四氟硼酸锂制备工艺的优化及电化学性能研究

Optimization of the preparation process and research of electrochemical performance of battery grade lithium tetrafluoroborate

以氢氟酸、硼酸和碳酸锂为原料,溶液法新工艺制备电池级四氟硼酸锂。采用正交试验对工艺参数进行优化,通过电池测试系统及电化学工作站测试产物的电化学性能。确定最佳工艺参数为:反应温度7.5℃,原料摩尔比n(氢氟酸)∶n(硼酸)∶n(碳酸锂)=4.05∶1.00∶0.55,乙醇蒸发量为溶剂质量的65%,重结晶温度15℃。在此条件下获得的四氟硼酸锂纯度为99.59%,收率为90.08%。电化学性能测定结果:配制的电解液电导率为10.1ms/cm,组装的纽扣电池首次放电容量为152.9mAh/g,放电容量为139.9mAh/g,在1.0C的倍率下循环30次后其容量保持率达84.74%,循环效率维持在98.00%。

LiBF4of battery level was prepared by adopting solution method and taking hydrofluoric acid,boric acid and lithium carbonate as the raw materials.Technological parameters were optimized by conducting orthogonal experiment.The optimal technological parameters were determined as about 7.5℃ of reaction temperature,the mole ration 4.05∶1.00∶0.55 of raw material of HF∶H3BO3∶Li2CO3,65% of the quality of resolvent alcohol evaporation capacity,15℃recrystallization temperature.LiBF4 prepared under such conditions had the purity of 99.59%and yield of 90.08%.The electrochemical properties of products were tested by battery cell test systems and electrochemical workstations.The electrical conductivity was 10.1ms/cm,the first discharge capacities could reach 152.9mAh/g,and the first discharge capacities was139.9mAh/g.After 30 cycles at a rate of 1.0C,the capacity retention and the cycling efficiency of samples were 84.74%and 98.00%.