Al2O3 surface coating on LiCoO2 through a facile and scalable wet-chemical method towards high-energy cathode materials withstanding high cutoff voltages. Issue 46 (15th November 2017)

• Record Type: Journal Article
• Authors: Zhou, Aijun; Liu, Qin; Wang, Yi; Wang, Weihang; Yao, Xu; Hu, Wentao; Zhang, Long; Yu, Xiqian; Li, Jingze; Li, Hong
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 46(2017)
• Page Start: 24361
• Page End: 24370
• Publication Date: 2017-11-15
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta07312g
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A low-cost and eco-friendly solution coating of nanoscale Al2 O3 addresses the high-voltage fast degradation of LiCoO2 . Abstract : With the increasing demand for high energy density in portable-device Li-ion batteries (LIBs), efforts are devoted to increase and stabilize the capacity of LiCoO2 at high operation voltages. Herein, we report a low-cost and eco-friendly wet-chemical method to coat Al2 O3 on LiCoO2, using only aluminium sulphate and water as source materials. A nanoscale oxide layer is coated on the surface of LiCoO2 particles through hydrogen-bonding assisted adsorption of the hydrolysed Al(OH)3 nanoparticles. The as-proposed Al2 O3 -coating provides excellent physico-chemical protection and kinetically-favourable interfaces for the LiCoO2 electrode, resulting in remarkable improvements of the electrode's cycling stability and rate capability when tested at high cutoff voltages up to 4.7 V ( vs. Li/Li + ). The synergetic effects of the oxide coating, e.g. alleviated electrolyte decomposition and reduced generation of irreversible solid electrolyte interphase (SEI) constituents (LiF/Li2 CO3 and organics), are attributed to the improvements. At the cutoff voltage of 4.5 V, the modified LiCoO2 electrode in this work exhibits excellent cycling stability (147 mA h g −1, 82.6% retention after 500 cycles at 1C) and competitive rate capability (130 mA h g −1 at 10C), which are some of the best results reported so far. The outstanding high-voltage electrode performance and the simple and scalable coating approach show great promise of LiCoO2 cathodes in future high-energy and high-power LIBs.