Abstract:

LiFePO₄/C cathode materials were synthsized by improved solid state-carbothermal reactions using LiOH·H₂O and LiCO₃. The electrochemical performance of products synthsized by using lithium hydroxide was better. Using lithium hydroxide as the lithium source and anhydrous glucose as the carbon precursor，preparation of LiFePO₄/C cathode materials were investigated by varying the ratio of Li and Fe，the amount of glucose added，the sintering temperature and sintering time. The structure of the prepared materials was analyzed by using TG/DSC，XRD and SEM，and their electrochemical performance was evaluated. Results illustrated that the sintering temperature showed the largest influence. With 1.05∶1 ratio of Li and Fe and 1.5 g of glucose，the capacity of the product was the highest（135 mAh/g）. The best sintering temperature range was found as 600～650 ℃，and the best sintering time range was 10～15 h. This improved method avoided using ball milling machine and would be beneficial for industrialization.

摘要：

使用改进的固相法，用LiOH·H₂O、LiCO₃作锂源，制备LiFePO₄/C正极材料，得出使用氢氧化锂作为原料合成的产物电化学性能较好。以氢氧化锂为锂源，无水葡萄糖为碳前体，考察锂铁比、葡萄糖加入量、焙烧温度、焙烧时间四因素对LiFePO₄正极材料电化学性能的影响。使用TG/DSC、XRD、SEM、充放电测试对合成产物进行结构及电化学性能分析。结果表明，焙烧温度对于产物的影响最大。锂铁比为1.05∶1，每摩尔铁中加入葡萄糖量为1.50 g时产品容量最高，为135.0 mAh/g。最佳焙烧温度为600～650 ℃，最佳焙烧时间为10～15 h。改进的固相法避免使用球磨机，有利于工业化生产。