碳热还原法制备LiFePO_4/C锂电池正极材料的研究

Synthesis of LiFePO_4/C Cathode Material by Carbothermal Reduction Method

以Fe2O3为铁源,NH4H2PO4为磷源,Li2CO3为锂源,蔗糖为碳添加剂,应用碳热还原一步烧结法制备了LiFePO4/C复合粉体材料,系统的研究了烧结温度、烧结时间和锂铁比对样品电化学性能的影响。研究结果表明,对电化学性能影响因素最大的是烧结温度、其次是锂铁比,最后是烧结时间。当烧结温度为700℃、锂铁比为1.00、烧结时间为12 h时样品所得的电化学性能最佳,它在0.1C,0.5C和1.0C倍率下的首次放电比容量分别为130.1,118.2和105.6 mAh.g-1,经20次循环后,不同倍率下样品的容量的保持率分别为99.8%,98.9%和97.5%。

Abstract： The LiFePOJC cathode material was synthesized by carbothermal reduction method, using Fe203, NH4H2PO4 and Li2 CO3 as raw materials and sucrose as reduction reagent. The effects of sintering temperature, sintering time, molar ratio of Li to Fe on the electrochemical properties of LiFePO4 for lithium ion battery were studied. The results showed that the optimized synthesis process of LiFePO4 was sintering temperature of 700℃, molar ratio of Li to Fe of 1.00 and sintering time of 12 h. The results showed that the LiFePO4/C powders achieved a high initial discharge capacity of 130.1, 118.2 and 105.6 mAh.g^-1 at 0.1C, 0.5C and 1.0C rate and after 20 cycles discharges, the capacity retention rate Was 99.8%, 98.9% and 97.5%, respectively.