Lithium diffusion behavior and improved high rate capacity of LiNi1/3Co1/3Mn1/3O2 as cathode material for lithium batteries

Homogeneous particles of LiNi1/3Co1/3Mn1/3O2 are synthesized at 900 degrees C for 24 h (LNCM-24H) based on the precursors formed in ethanol. Cyclic voltammetry (CVs) profiles of the sample LNCM-24H have been recorded under various scan rates. The calculated diffusion coefficients of Li+ in solid-state electrode well explain the kinetic process of the oxidation/reduction reactions. Based on the simulated data of electrochemical impedance spectroscopy (EIS). Li+ diffusion through the electrode surface is relatively faster than that in the lattice of cathode material which present relative smaller R-f and R-Li appear compared with W-R and W-T. The big capacitances CPE1P and CPE2P are attributable to positive charges that accumulate on the interfaces which involve the phase changes of Li+. The sample LNCM-24H worked at the cut-off voltage 4.4 V exhibits an improved discharge capacity of 197.9 mAh g(-1) at 0.1 C, and can remain 95% capacity after 50 cycles. For the usage of energy storage device, the sample LNCM-24H presents very good in-situ electrochemical performance under various temperature and current rates. Under the cut-off voltage 4.4 V. the sample LNCM-24H presents a high discharge capacity of 243 mAh g(-1) and very good cycleability after 50 cycles at 50 degrees C. Under a continuous changing temperature (range from 0 to 50 degrees C), higher and stable discharge capacity still remains. (C) 2011 Elsevier B.V. All rights reserved.