Effect of doped Mn on improving the electrochemical performance of LiFePO4
Effect of doped Mn on improving the electrochemical performance of LiFePO4
复制标题
掺杂Mn对LiFePO4电化学性能的改善作用
DOI：
10.1007/s10854-019-02833-5
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发表时间：
2020-02-01
影响因子：
2.8
通讯作者：
Li, Jun-Qi
中科院分区：
文献类型：
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作者：
Liu, Yuan;Gu, Yi-Jing;Li, Jun-Qi
采用简单的水热法制备了LiFe1-xMnxPO4/C复合材料。研究了掺杂锰对其微观结构和电化学性能的影响。XRD结果表明Mn掺杂不能改变LiFePO4的橄榄石晶格类型。适当的Mn掺杂可以减小LiFePO4的粒径。电化学性能数据表明，随着Mn掺杂量的增加，复合材料的电化学性能呈现先增强后降低的趋势。CV和EIS结果表明，少量掺杂Mn会降低样品的电极极化和电化学阻抗，同时提高样品的电化学性能。在所有样品中，LiFe0.98Mn0.02PO4/C样品具有理想的电化学性能，在0.1 C的倍率下，其比放电容量达到156.0 mAh g(-1)，即使在5 C的高倍率下，其比放电容量仍可达到110.0 mAh g（-1）。结果表明，适量的Mn掺杂对LiFePO4/C的电化学性能有显著影响。
A series of LiFe1-xMnxPO4/C composites were successfully synthesized through a simple hydrothermal method. The effects of doped Mn on their micro-structures and electrochemical performances were investigated. The XRD results indicate that Mn doping cannot change the olivine lattice type of LiFePO4. Appropriate Mn doping can reduce the particle size of LiFePO4. The electrochemical performance data show that the electrochemical performances of the composite materials are enhanced at first and then decrease as the doping amount of Mn increases. Both the CV and EIS results illustrate that a small amount of doped Mn will reduce the electrode polarization and electrochemical impedance of the samples and simultaneously improve the electrochemical performance. Among all the samples, the LiFe0.98Mn0.02PO4/C sample has a desirable electrochemical performance, with its specific discharge capacity reaching 156.0 mAh g(-1) at a rate of 0.1 C. Even at a high rate of 5 C, it can still reach 110.0 mAh g(-1). All the results indicate that an appropriate amount of doped Mn has an emphatic effect on the electrochemical performance of LiFePO4/C.