LiFe_1-xMg_xPO₄锂离子电池正极材料的电化学性能

来源期刊：中南大学学报(自然科学版)2006年第6期

论文作者：张宝 李新海 罗文斌 王志兴

文章页码：1094 - 1097

关键词：锂离子电池;正极材料;磷酸铁锂;镁掺杂

Key words：Li-ion battery; cathode material; lithium iron phosphate; Mg doping

摘    要：采用体相掺杂法对LiFePO₄进行改性,采用Mg对LiFePO₄进行掺杂,研究Mg的掺杂量对LiFePO₄材料电化学性能的影响。研究结果表明,经掺杂改性后的LiFe_1-xMg_xPO₄(x=0.01, 0.05, 0.10, 0.15)材料的充放电容量和循环性能均有所提高,其中,样品LiFe_0.85Mg_0.15PO₄的性能最佳,其首次放电容量为125.6 mA·h/g,循环6次后容量仍达123.0 mA·h/g; Mg部分取代LiFePO₄材料中的Fe后所得材料的电子电导率提高了1×10⁶倍,从而提高了材料的电化学性能。

Abstract: LiFe_1-xMg_xPO₄(x=0.01, 0.05, 0.10, 0.15) was synthesized by Mg doping. The effect of amount of doped-Mg on the electrochemical performances of LiFe_1-xMg_xPO₄ was investigated. The results show that the Mg-doped LiFePO₄ has higher charge and discharge capacities and better cycling behavior than LiFePO₄. The first specific discharge capacity of the LiFe_0.85Mg_0.15PO₄ is 125.6 mA·h/g and the discharge capacitty remains 123.0 mA·h/g after 6 cycles.The electronic conductivity can be increased by a factor of 1×10⁶ after Mg doping. Compared with pristine LiFePO₄, the electrochemical performances of Mg-doped sample are greatly improved.

基金信息：国家自然科学基金资助项目