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 °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 Rf and RLi 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 °C. Under a continuous changing temperature (range from 0 to 50 °C), higher and stable discharge capacity still remains.

► LNM-24H presents lower degree of cation mixing and highly ordered layered structure.
► Diffusion coefficients Ds and Dl of Li+ well explain kinetic process of battery.
► The resistance and capacitance of battery well simulated based on the EIS results.
► LNCM-24H exhibit discharge capacity 197.9 mAh g-1 and remain 95% after 50 cycles.
► LNCM-24H delivers capacity of 243.2 mAh g-1 and very well cycleability at 50 ºC.