Supercritical-hydrothermal accelerated solid state reaction route for synthesis of LiMn_2O_4 cathode material for high-power Li-ion batteries

超临界水热合成结合固相煅烧制备高性能锂离子电池的锰酸锂正极材料(英文)

Synthesis of the spinel structure lithium manganese oxide （LiMn2O4） by supercritical hydrothermal （SH） accelerated solid state reaction （SSR） route was studied. The impacts of the reaction pressure, reaction temperature and reaction time of SH route, and the calcination temperature of SSR route on the purity, particle morphology and electrochemical properties of the prepared LiMn2O4 materials were studied. The experimental results show that after 15 min reaction in SH route at 400 ℃ and 30 MPa, the reaction time of SSR could be significantly decreased, e.g. down to 3 h with the formation temperature of 800 ℃, compared with the conventional solid state reaction method. The prepared LiMn2O4 material exhibits good crystallinity, uniform size distribution and good electrochemical performance, and has an initial specific capacity of 120 mA.h/g at a rate of 0.1C （1C=148 mA/g） and a good rate capability at high rates, even up to 50C.

采用超临界水热合成与高温固相合成相结合的方法制备亚微米级锂离子电池锰酸锂正极材料,研究超临界水热合成过程中的反应压力、反应温度、反应时间和高温固相合成过程中煅烧温度对合成材料的纯度、形貌及电化学特性的影响。结果表明:相对于传统的高温固相合成方法,在400°C和30 MPa的条件下,经过15 min超临界水热反应获得的LiMn2O4电池材料,在后续800°C煅烧温度下的煅烧时间可缩短到3 h。在该条件下合成的LiMn2O4正极材料具有良好的结晶度、均匀的粒度分布和优异的电化学性能,在0.1C下的首次放电比容量达到120 mA·h/g,且在50C的高倍率下仍然表现出良好的放电性能。