Synthesis cathode material LiNi_0.80Co_0.15Al_0.05O₂ with two step solid-state method under air stream

¹ Faculty of Chemistry & Chemical Engineering, Qujing Normal University, Qujing 655011, P.R. China
² Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, P.R. China

^a e-mail: xiashubiao401@163.com

Received: 12 July 2013
Revised: 16 November 2013
Accepted: 18 November 2013
Published online: 6 January 2014

Abstract

A facile generic strategy of solid-state reaction under air atmosphere is employed to prepare LiNi_0.8Co_0.15Al_0.05O₂ layer structure micro-sphere as cathodes for Li-ion batteries. The impurity phase has been eliminated wholly without changing the R-3m space group of LiNi_0.8Co_0.15Al_0.05O₂. The electrochemical performance of LiNi_0.8Co_0.15Al_0.05O₂ cathodes depend on the sintering step, temperature, particle size and uniformity. The sample pre-sintered at 540 °C for 12 h and then sintered at 720 °C for 28 h exhibits the best electrochemical performance, which delivers a reversible capacity of 180.4, 165.8, 154.7 and 135.6 mAhg⁻¹ at 0.2 C, 1 C, 2 C and 5 C, respectively. The capacity retention keeps over 87% after 76 cycles at 1 C. This method is simple, cheap and mass-productive, and thus suitable to large scale production of NCA cathodes directly used for lithium ion batteries.