Ultrathin ZnO coating for improved electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode material

To enhance the electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode, especially at elevated temperature, atomic layer deposition (ALD) technology has facilely used to deposit an ultrathin amorphous ZnO coating onto LiNi0.5Co0.2Mn0.3O2 with precise thickness-control at atomic scale. The coated cathode material with 8 ALD cycles exhibits the significantly improved discharge capacity and cycle-ability, as compared with those of the bare one. Such enhanced electrochemical performance of the coated sample is ascribed to its high-quality ultrathin amorphous ALD oxide coating, which can protect the active material from HF attack, reduce the dissolution of metal ions in the electrode and favor the lithium diffusion of the oxide proved by the electrochemical impedance spectroscopy (EIS) tests. The simple ALD process provides a potential new approach for the battery industry to fabricate novel electrodes with high performances even cycled at high rate at elevated temperature. (C) 2014 Elsevier B.V. All rights reserved.