水热法制备树叶状LiFePO4/C复合正极材料(英文)  

Hydrothermal Synthesis of Leaf-like LiFePO_4/C Cathode Composites

作　　者：云强[1,2] 周园[1] 海春喜[1] 申月[1] 李翔[1,2] 张丽娟[1,2] 李松[1,2] 丁秀萍[1] 

机构地区：[1]中国科学院青海盐湖研究所盐湖资源化学重点实验室,西宁810008 [2]中国科学院大学,北京100049

出　　处：《无机化学学报》2015年第5期880-887,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家高技术研究发展计划(863)(No.2013AA110100);国家重点基础研究发展计划(973)(No.2014CB660806);中国科学院“西部之光”人才培养计划(No.Y412041007);2014年西宁市科技项目(No.2014-6-24)资助

摘　　要：采用柠檬酸辅助水热法合成了高分散性树叶状LiFePO4/C复合正极材料。利用X射线衍射、傅里叶红外光谱、扫描电镜、高分辨率透射电镜和选区电子衍射分析了材料的形貌结构。结果表明,柠檬酸对树叶状LiFePO4/C复合材料的形成具有促进作用。该材料的最大暴露晶面为(010)晶面,且分散性较好。与颗粒状LiFePO4/C材料相比,该材料呈现出更高的放电比容量和更好的倍率性能,在0.1C和5C倍率下,放电比容量分别为158和126mAh·g-1,其原因是由于锂离子沿[010]方向的扩散距离缩短,从而使锂离子扩散系数显著增大。Highly-dispersed LiFePO4/C composite with micro-leaf structure was synthesized by a facile citric acid-assisted hydrothermal method in this study. Crystal structure and morphology of samples were investigated by XRD, FTIR, SEM, HR-TEM and selected area electron diffraction（SAED）. The characterization results indicate that citric acid accelerates the formation of leaf-like LiFePO4/C composite. The as-prepared leaf-like LiFePO4/C composite with an enlarged（010） plane has high dispersibility. By comparing the electrochemical properties of the LiFePO4/C particles in our study, the Li Fe PO4/C micro-leaves exhibit larger discharge capacity and better rate performance, which deliver a discharge capacity of 158 m Ah·g^-1at 0.1C and 126 m Ah·g^-1at 5C.The enhanced performance perhaps is attributed to the reduced Li-ion diffusion paths along the [010] direction and larger Li-ion diffusion coefficient.

关 键 词：材料科学 水热合成 电化学 LIFEPO4/C 树叶状 柠檬酸 

分 类 号：O646[理学—物理化学] TM912.9[理学—化学]