Synthesis and modification of non-stoichiometric spinel (Li1.02Mn1.90Y0.02O4-yF0.08) for lithium-ion batteries

Authors

Chuanqi FengFollow
Hua Li, Hubei University, China
Peng Zhang, University of Wollongong
Zaiping Guo, University of WollongongFollow
Hua-Kun Liu, University of WollongongFollow

RIS ID

31890

Publication Details

Liu, H. K., Feng, C., Li, H., Zhang, P. Guo, Z. (2010). Synthesis and modification of non-stoichiometric spinel (Li_1.02Mn_1.90Y_0.02O_4−yF_0.08)for lithium-ion batteries. Materials Chemistry and Physics, 119 (1-2), 82-85.

Abstract

A non-stoichiometric spinel phase (Li_1.02Mn_1.90Y_0.02O_4−yF_0.08) was synthesized using a natural polymer sol–gel method. It was characterized by X-ray diffraction. The particle size and shape of the as-prepared compounds were observed by scanning electron microscope. The new compound was coated with LiBO₂, and the effects of the LiBO₂ coating on Li_1.02Mn_1.90Y_0.02O_4−yF_0.08 spinel phase were investigated. The results showed that pure Li_1.02Mn_1.90Y_0.02O_4−yF_0.08 had good electrochemical properties, however, the non-stoichiometric spinel coated with LiBO₂ showed better electrochemical performance at both room temperature and high temperature (50 °C) than pure Li_1.02Mn_1.90Y_0.02O_4−yF_0.08. The initial discharge capacity of the LiBO₂-coated non-stoichiometric spinel was 118 mAh g⁻¹ at a current density of 1 mA cm⁻² over the voltage range from 3.0 to 4.4 V. The discharge capacity was about 99.2% of the initial capacity after 100 cycles at room temperature and about 95.2% after 50 cycles at high temperature (50 °C). The modification of spinel with LiBO₂ effectively improved the electrochemical properties of non-stoichiometric spinel as a cathode material.