Synthesis and Electrochemical Studies of Carbon-modified LiNiPO4 as the Cathode Material of Li-ion Batteries  

作　　者：ZHANG Ying PAN Yue LIU Jia WANG Guiling CAO Dianxue 

机构地区：[1]Key Laboratory of Superlight Material and Surface Technology of Ministry of Education,College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China

出　　处：《Chemical Research in Chinese Universities》2015年第1期117-122,共6页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China（No.21306033）, the Fundamental Research Funds for the Central Universities of China（No.HEUCF201403019） and the Heilongjiang Postdoctoral Fund, China（No.LBH-Z13059）.

摘　　要：Well-crystallized olivine LiNiPO4 and carbon-modified LiNiPO4（LiNiPO4/C） were synthesized by a combined solvothermal and solid state reaction method using water-benzyl alcohol two-phase solvent. The structure and morphology of the prepared LiNiPO4 were systematically characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The LiNiPO4 particles are up to around 2 μm in diameter while the particle size of LiNiPO4/C is about 100-200 nm. At a current rate of 0.05 C（1.00 C=167 mA/g, corresponding to one Li^＋｜ intercalation/deintercalation）, LiNiPO4 and LiNiPO4/C presented a high initial specific capacity of 157 and 220 mA.h/g, respectively. The capacity of LiNiPO4/C is 72% larger than that of LiNiPO4 at 0.1 C. The LiNiPO4/C cathode exhibits a superior electrochemical performance in comparison with LiNiPO4, revealing that carbon modifying is an effective method to improve the ionic diffusion and electronic conductivity of cathode material LiNiPO4. Furthermore, lithium ion diffusion coefficients of LiNiPO4 and LiNiPO4/C are 1.80× 10^-15 and 1.91×10^-14 cm^2/s, respectively, calculated via the data from electrochemical impedance spectra.Well-crystallized olivine LiNiPO4 and carbon-modified LiNiPO4（LiNiPO4/C） were synthesized by a combined solvothermal and solid state reaction method using water-benzyl alcohol two-phase solvent. The structure and morphology of the prepared LiNiPO4 were systematically characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The LiNiPO4 particles are up to around 2 μm in diameter while the particle size of LiNiPO4/C is about 100-200 nm. At a current rate of 0.05 C（1.00 C=167 mA/g, corresponding to one Li^＋｜ intercalation/deintercalation）, LiNiPO4 and LiNiPO4/C presented a high initial specific capacity of 157 and 220 mA.h/g, respectively. The capacity of LiNiPO4/C is 72% larger than that of LiNiPO4 at 0.1 C. The LiNiPO4/C cathode exhibits a superior electrochemical performance in comparison with LiNiPO4, revealing that carbon modifying is an effective method to improve the ionic diffusion and electronic conductivity of cathode material LiNiPO4. Furthermore, lithium ion diffusion coefficients of LiNiPO4 and LiNiPO4/C are 1.80× 10^-15 and 1.91×10^-14 cm^2/s, respectively, calculated via the data from electrochemical impedance spectra.

关 键 词：Lithium nickel phosphate Carbon-modifying Cathode material Lithium ion battery Lithium ion diffusion coefficient 

分 类 号：TM912[电气工程—电力电子与电力传动] TM912.2