A multifunctional silicotungstic acid-modified Li-rich manganese-based cathode material with excellent electrochemical properties

作者：Geng, Tianfeng; Du, Chunyu^*; Cheng, Xinqun^*; Xu, Xing; Jian, Jiyuan; He, Xiaoshu; Zuo, Pengjian; Yin, Geping

来源：Journal of Solid State Electrochemistry, 2019, 23(1): 101-108.

DOI：10.1007/s10008-018-4113-x

• Lithium-ion battery
• Li-rich layered oxide
• Silicotungstic acid coating
• Electronic and ionic conductivity

Li-rich layered oxide (LrLO) cathode has attracted much attention for Li-ion batteries in recent years due to its superior capacity of exceeding 250mAhg(-1). However, these materials still have some inherent drawbacks such as poor rate stability and cycle performance. In this paper, Li-rich cathode material Li1.2Mn0.54Ni0.13Co0.13O2 was modified by silicotungstic acid (HSW) with high electronic and ionic conductivity via a facile approach. The material was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and electrochemical tests. The results showed that the thickness of HSW coating was about 5nm. HSW coating could supply a transfer pathway for Li ions and electrons, resulting in the superior discharge capacity and rate capability. The HSW-LrLO could deliver 158.38mAhg(-1) even at high current density of 500mAg(-1), which was 26.9% higher than that of pristine LrLO. In addition, HSW-LrLO exhibited excellent cycling performance with the capacity retention over 90% at 1 and 5C. These results were useful to develop effective surface modification for LrLO materials.

• 出版日期2019-1
• 单位哈尔滨工业大学