摘要
制备了NH4FePO4·H2O,再用半固相法制得LiFePO4/C。用XRD、SEM、恒流充放电测试及交流阻抗谱等方法,研究了样品的结构、形貌及电化学性能。样品的结晶度高、粒径均匀,含碳量为1.09%;0.2C循环的最高放电比容量为139.5mAh/g,放电平台为3.2V,循环性能良好。增大极化电压(2.7~4.1V),正极反应由扩散控制逐渐转向动力学控制。
NH4FePO4· H2O was prepared, then LiFePO4/C was synthesized by quasi solid-state reaction. The structure, morphology and electrochemical performance of the sample were tested by XRD, SEM, galvanostatic charge-discharge test and AC impedance methods. The sample had high crystallinity degree, uniform particle size, the carbon content was 1.09% ; the highest specific discharge capacity was 139.5mAh/g at 0.2 C cycle, the discharge plateau was 3.2 V,the cycle performance was fine. The cathode reaction controlling step changed from diffusion control to kinetic control with the increasing of nolarization voltage (2 .7 - 4. 1 V)
出处
《电池》
CAS
CSCD
北大核心
2008年第4期201-203,共3页
Battery Bimonthly
基金
青海省重点科技攻关项目(2006-G-168)