Synthesis of LiFePO_4 /C as cathode material by a novel optimized hydrothermal method

作     者：GAO Ge LIU Aifang HU Zhonghua XU Yuanyuan LIU Yafei 

作者机构：Department of Chemistry Tongii University Shanghai 200092 China 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2011年第30卷第5期

页      面：433-438页

核心收录：

学科分类：0808[工学-电气工程] 07[理学] 0806[工学-冶金工程] 08[工学] 070205[理学-凝聚态物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (No. 50472089) 

主　　题：lithium ion batteries cathode materials phosphates olivine carbon deposition hydrothermal synthesis 

摘      要：Olivine LiFePO 4 , as a cathode material for lithium ion batteries, was prepared by a novel optimized hydrothermal method; afterwards, the product mixed with glucose was two-step （350℃ and 700℃） calcinated under high-purity N 2 atmosphere to obtain the LiFePO 4 /C composite. The study on the hydrothermal preparation method, which focused on the influences of molar ratios, initial pH value, reaction temperature, and duration, was made to promote the resultant performances and to investigate the relations between the performances and the reaction conditions. The resultant samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and electrochemical tests, which include charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry. The result shows that the optimal hydrothermal condition is to set the Li：Fe：P molar ratio at 3：1：1 and the reaction temperature at 180℃ for 5 h duration with an initial pH value of 7. The optimized sample, with an average particle size of 100 to 300 nm and a discharge capacity of 118.2 mAh·g-1 at 0.1C, exhibits a stable and narrow-gapped charge-discharge platform and small capacity losses after cycles.