He Xiangming, Wang Jixian, Dai Zhongjia, Wang Li, Tian Guangyu
Institute of Nuclear & New Energy Technology, Tsinghua University, Beijing 100084, China.
State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China.
Materials (Basel). 2016 Sep 8;9(9):766. doi: 10.3390/ma9090766.
LiMnFePO₄/C material has been synthesized through a facile solid-state reaction under the condition of carbon coating, using solvothermal-prepared LiMnPO₄ and LiFePO₄ as precursors and sucrose as a carbon resource. XRD and element distribution analysis reveal completed solid-state reaction of precursors. LiMnFePO₄/C composites inherit the morphology of precursors after heat treatment without obvious agglomeration and size increase. LiMnFePO₄ solid solution forms at low temperature around 350 °C, and Mn/Fe diffuse completely within 1 h at 650 °C. The LiMnFePO₄/C ( < 0.8) composite exhibits a high-discharge capacity of over 120 mAh·g (500 Wh·kg) at low C-rates. This paves a way to synthesize the crystal-optimized LiMnFePO₄/C materials for high performance Li-ion batteries.
采用溶剂热法制备的LiMnPO₄和LiFePO₄作为前驱体，蔗糖作为碳源，通过简便的固态反应在碳包覆条件下合成了LiMnFePO₄/C材料。XRD和元素分布分析表明前驱体发生了完全的固态反应。LiMnFePO₄/C复合材料在热处理后继承了前驱体的形貌，没有明显的团聚和尺寸增加。LiMnFePO₄固溶体在350℃左右的低温下形成，Mn/Fe在650℃下1小时内完全扩散。LiMnFePO₄/C（<0.8）复合材料在低倍率下表现出超过120 mAh·g（500 Wh·kg）的高放电容量。这为合成用于高性能锂离子电池的晶体优化LiMnFePO₄/C材料铺平了道路。
