Electrochemical behavior of nanostructured NiO@C anode in a lithium-ion battery using LiNi⅓Co⅓Mn⅓O2 cathode

Abstract

A NiO@C composite anode is prepared through an alternative synthesis route involving precipitation of a carbon precursor on NiO nanopowder, annealing under argon to form a Ni core, and oxidation at moderate temperature to get metal oxide particles whilst retaining carbon and metallic Ni in traces. The electrode reversibly reacts in lithium cells by the typical conversion process occurring in a wide potential range with the main electrochemical activity at 1.3 V vs. Li+/Li during discharge and at 2.2 V vs. Li+/Li during charge. The NiO@C material exhibits highly improved behavior in a lithium half-cell compared to bare NiO due to faster electrode kinetics and superior stability over electrochemical displacement, leading to a reversible capacity approaching 800 mAh g−1, much enhanced cycle life and promising rate capability. The applicability of the NiO@C anode is further investigated in a lithium-ion NiO@C/LiNi⅓Co⅓Mn⅓O2 cell, which operates at about 2.5 V delivering about 160 mAh g−1 with respect to the cathode mass. The cell exhibits stable response upon 80 cycles at a C/2 rate with coulombic efficiency ranging from 97% to 99%.