碳源对LiFePO_4/C正极材料性能的影响  

Effects of carbon source on the performance of LiFePO_4/C cathode material

作　　者：王小娟[1] 李新海[1] 王志兴[1] 郭华军[1] 彭文杰[1] 

机构地区：[1]中南大学冶金科学与工程学院,湖南长沙410083

出　　处：《功能材料》2009年第12期1996-1999,2003,共5页Journal of Functional Materials

基　　金：国家重点基础研究发展计划(973计划)资助项目(2007CB613607)

摘　　要：以FePO4.2H2O、Li2CO3和柠檬酸/酒石酸/抗坏血酸为原料,经机械球磨后在惰性气氛中高温煅烧合成LiFePO4/C正极材料。研究了不同碳源对LiFePO4结构、形貌及电化学性能的影响。重点考察了碳源为酒石酸时,不同合成温度对材料性能的影响。采用XRD、SEM以及电化学测试等手段对目标产物进行了结构表征和性能测试。结果表明,以酒石酸做碳源时,合成的正极材料物相单一,颗粒细小,粒度均匀,并且具有优良的电化学性能。在室温下以0.1C倍率充放电,首次放电比容量可达155mAh/g,1.0C首次放电比容量为120mAh/g,经过100次循环以后容量仍有109mAh/g。LiFePO4/C cathode material was synthesized by ball-milling and then sintering at high temperature under the protection of the inert gas with precursor FePO4 · 2H2O, Li2CO3 and monohydrate acid/tartaric acid/ ascorbie acid as raw materials. The effects of different carbon source on the structure, morphology and electro- chemical performance of as-synthesized cathode materials were investigated, especially, the effects of different temperatures with tartaric acid as carbon source. The crystal structure and the eleetrochemical performance were characterized by XRD, SEM, and electrochemical performance testing. The results show that the as-synthesized cathode materials with tartaric acid as carbon source are pure and have excellent electrochemical performance. The particles are small and the distribution of particle size is uniform. At room temperature, the specific discharge capacity reaches 155mAh/g at 0. 1C, 91.18% of the theoretical capacity. The specific discharge capacity at 1.0C reaches 120mAh/g and remains 109mAh/g after 100 cycles.

关 键 词：磷酸铁锂 碳源 柠檬酸 酒石酸 抗坏血酸 

分 类 号：TM912.9[电气工程—电力电子与电力传动]