Jian-Hua Wang, Yu Wang, Yu-zhong Guo
Apr 25, 2014
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Influential Citations
26
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Journal
Rare Metals
Abstract
Aluminum phosphate (AlPO 4 ) was used to modify the surface of LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM) cathode material. The surface structure and electrochemical properties of the coated materials were investigated by X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The results confirm the formation of aluminum-containing solid solution on the surface of NCM particles. An aluminum phosphate coating blocks the Li + insertion-extraction process in cells charged at high rates at room temperature, increasing surface film resistance and decreasing discharge capacity. However, an aluminum phosphate aids the formation of a stable solid electrolyte interface film on NCM surface and stabilizes the R ct of cell as samples electrochemically cycled at 55 °C. The electrochemical studies suggest that the initial columbic efficiency is significantly enhanced. An NCM sample coated with 1.0 wt% AlPO 4 delivers a higher discharge capacity and shows excellent capacity retention ability.