Enhanced Li Storage Performance of LiNi0.5Mn1.5O4–Coated 0.4Li2MnO3·0.6LiNi1/3Co1/3Mn1/3O2 Cathode Materials for Li-Ion Batteries

• Published in: ACS applied materials & interfaces Vol. 6; no. 19; pp. 16888 - 16894
• Main Authors: Chen, Yufang, Xie, Kai, Zheng, Chunman, Ma, Zhongyun, Chen, Zhongxue
• Format: Journal Article
• Language: English
• Published: American Chemical Society 08.10.2014
• Subjects: cathodes; coatings; electrochemistry; electrolytes; formaldehyde; lithium; lithium batteries; resorcinol; sol-gel processing; transportation; spinel; Li-rich cathode; Li storage; rate capability; surface modification
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/am504412n

In this study, Li-rich cathode, 0.4Li2MnO3·0.6LiNi1/3Co1/3Mn1/3O2 was synthesized by a resorcinol formaldehyde assisted sol–gel method for the first time. Then, the surface of the as-prepared Li-rich cathode was modified with different amounts of LiNi0.5Mn1.5O4 (5, 10, and 20 wt %) through a simple dip-dry approach. The structural and electrochemical characterizations revealed that the spinel LiNi0.5Mn1.5O4 coating not only can prevent electrolytes from eroding the Li-rich core but also can facilitate fast lithium ion transportation. As a result, the 20 wt % coated sample delivered an initial discharge capacity of 298.6 mAh g–1 with a Coulombic efficiency of 84.8%, compared to 281.1 mAh g–1 and 70.2%, respectively, for the bare sample. Particularly, the coated sample demonstrates a Li storage capacity of 170.7 mAh g–1 and capacity retention of 94.4% after 100 cycles at a high rate of 5 C (1250 mA g–1), showing a prospect for practical lithium battery applications. More significantly, the synthetic method proposed in this work is facile and low-cost and possibly could be adopted for large-scale production of surface-modified cathode materials.