尖晶石型LiMn1.9Al0.1O3.95F0.05材料的制备及其增强的倍率性能

通过溶胶-凝胶和高温固相掺杂反应可控合成了形貌均匀、结晶性好的尖晶石型LiMn_1.9Al_0.1O_3.95F_0.05正极材料，探究了Al部分取代Mn、F部分取代O后对结构的影响，测试并比较了电极材料的倍率性能和循环充放电性能. 结果表明，尖晶石型LiMn_1.9Al_0.1O_3.95F_0.05和LiMn₂O₄有同样的晶型，但电极较传统的LiMn2O4电极倍率稳定性有显著提高. 在连续混合（如0.1C、0.5C和1C）充放电150次后，LiMn_1.9Al_0.1O_3.95F_0.05电极的容量仍能保持90%以上.

Preparation and Enhanced Rate Capability of Spinel LiMn1.9Al0.1O3.95F0.05

Spinel LiMn_1.9Al_0.1O_3.95F_0.05 cathode materials with good crystallinity were synthesized by a sol-gel process followed with a high-temperature solid reaction. The effects of partial substitution of Al for Mn, and F for O on the structure and the electrochemical performance were investigated. The results showed that LiMn_1.9Al_0.1O_3.95F_0.05 exhibited the same crystalline state as LiMn₂O₄, but much better electrochemical stability at higher rate cycling. As a result, LiMn_1.9Al_0.1O_3.95F_0.05 could maintain stable electrochemical lithium storage even suffering from different rate currents that retains over 90% of the initial capacity after 150 cycles at continuously varying currents (i.e. 0.1C, 0.5C, and 1C).