Monodisperse porous LiFePO4/C microspheres derived by microwave-assisted hydrothermal process combined with carbothermal reduction for high power lithium-ion batteries
Monodisperse porous LiFePO4/C microspheres derived by microwave-assisted hydrothermal process combined with carbothermal reduction for high power lithium-ion batteries
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DOI：
10.1016/j.jpowsour.2014.02.068
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发表时间：
2014-07-15
影响因子：
9.2
通讯作者：
Kong, Xiang Yang
中科院分区：
文献类型：
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作者：
Chen, Rongrong;Wu, Yixiong;Kong, Xiang Yang
采用微波辅助水热法结合碳热还原法制备单分散多孔LiFePO4/C微球，其粒径范围为1.0~1.5µm，振实密度约为1.3 g cm(-3)，具有介孔特性，Brunauer-Emmett-Teller(BET)比表面积为30.6 m(2)g(-1)。所得微球呈肉丸状，由碳包覆的LiFePO4纳米粒子聚集而成。电化学阻抗谱(EIS)结果表明，碳包覆能有效地提高LiFePO4/C微球的电子和离子电导。由循环伏安(CV)曲线计算得到LiFePO4/C微球的锂离子扩散系数与6.25×10~(-9)cm~(-2)S(~(-1))相近。在5C和10C充放电倍率下，其电化学性能分别达到约100和90mAHg(-1)。制备的LiFePO4/C微球作为正极材料具有优异的倍率性能和循环稳定性，有望用于高功率锂离子电池。(C)2014爱思唯尔B.V.保留所有权利。
A microwave-assisted hydrothermal approach combined with carbothermal reduction has been developed to synthesize monodisperse porous LiFePO4/C microspheres, which possess the diameter range of 1.0-1.5 mu m, high tap density of similar to 1.3 g cm(-3), and mesoporous characteristic with Brunauer-Emmett-Teller (BET) surface area of 30.6 m(2) g(-1). The obtained microspheres show meatball-like morphology aggregated by the carbon-coated LiFePO4 nanoparticles. The electrochemical impedance spectra (EIS) results indicate that carbon coating can effectively enhance both of the electronic and ionic conductivities for LiFePO4/C microspheres. The Li-ion diffusion coefficient of the LiFePO4/C microspheres calculated from the cyclic voltammetry (CV) curves is similar to 6.25 x 10(-9) cm(2) s(-1). The electrochemical performance can achieve about 100 and 90 mAh g(-1) at 5C and 10C charge/discharge rates, respectively. As cathode material, the as-prepared LiFePO4/C microspheres show excellent rate capability and cycle stability, promising for high power lithium-ion batteries. (C) 2014 Elsevier B.V. All rights reserved.