摘要
采用两步固相法反应制备LiFePO4/C和LiFePO3.92F0.08/C。采用XRD对样品的结构进行分析。结果表明LiFePO3.92F0.08/C仍然具有橄榄石结构,但是相比于未掺杂的磷酸铁锂其具有更好的倍率性能和循环性能。LiFePO3.92F0.08/C在不同倍率下的放电比容量分别为141.7mAh/g(0.2 C)、113.2 mAh/g(1 C)、70.4 mAh/g(10 C)。尤其是在1 C倍率下循环30圈后,放电比容量仍达115.6 mAh/g。研究显示,F掺杂能够提高电子电导率进而显著改善其电化学性能。
LiFePO4/C and LiFePO3.92Fo.08/C had been prepared by two-step solid-state reaction. The structure of the samples was analyzed by X-ray diffractometry (XRD). The results verified that LiFePO3.92F0.08/C still maintained the olivine structure of LiFePOdC, but had better rate performance and cyclic stability than those of LiFePO4/C. The corresponding specific discharge capacities of LiFePO3.92Fo.os/C was 141.7 mAh/g at 0.2 C rate, 113.2 mAh/g at 1 C rate, and 70.4 mAh/g at 10 C rate, respectively. Specially, the specific discharge capacity of LiFePO3.92F0.05/C was 115.6 mAh/g at I C after 30 cycles. In this research, we can summarize that F-doping can help improve electrochemical performance by increasing electrical conductivity of LiFePO4/C.
出处
《广东化工》
CAS
2014年第7期22-23,共2页
Guangdong Chemical Industry