Journal of Power Sources, Vol.344, 25-31, 2017
Novel cathode materials LixNa2-xV2O6 (x=2, 1.4, 1, 0) for high-performance lithium-ion batteries
In this work, sodium doped LiVO3 cathode is proposed to achieve enhanced cycling performance for lithium ion battery (LIB) application. LixNa2-xV2O6 (x = 2, 1.4, 1, 0) compounds have been prepared and characterized, and X-ray diffraction patterns confirmed the successful Na doping with various amounts in the LiVO3. The electrochemical performances of the various Na doped compounds LiVO3, Li1.4Na0.6V2O6, LiNaV2O6, and NaVO3 are evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results reveal that Na-doping amount strongly affects the electrochemical performance, and LiNaV2O6 (x = 1) is considered as the optimized Na doped compound for LIB cathodes. The LiNaV2O6 cathode displays enhanced cycling and rate performances as a specific capacity of 193 mAh g(-1) at 0.5 C after 100 cycles is delivered. The enhanced performance is explained that the doping of Na can provide good channels and increase Li+ diffusion coefficient for lithium ion intercalation/deintercalation. (C) 2017 Elsevier B.V. All rights reserved.