Fabrication of nickel manganese cobalt oxide (NMCO) anodes for lithium-ion batteries via hydrothermal process

Abstract

Nickel manganese cobalt oxide (NMCO) powders have been fabricated by hydrothermal method followed by a calcination. The present work reports for the first time in the open literature, the effects of ammonium fluoride (NH4F) amount and calcination temperature on the NMCO powder's size and morphology. In this regard, the NMCO composite powders are designed to optimize their performances as anode materials for lithium ion batteries. The morphology, composition and structure of powders have been characterized by scanning electron microscopy, X-ray fluorescence and X-ray diffractometry, respectively. Cyclic voltammetry, galvanostatic and impedance spectroscopy tests have been employed to investigate the lithiation mechanism of the composite electrode. The results reveal that the lowest amount of NH4F (1.5 mmol) in the precursor solution and the lowest calcination temperature (250 degrees C) lead to form NMCO rods with 100 nm diameter and 3-5 mu m length. This newly designed rod-shaped NMCO powder presents a high rate performance. The average discharge/charge capacities are 1224/1129, 968/939, 856/826, and 744/712 mAh g(-1)when the current load increases from 50 to 100, 200 and 400 mA g(-1), respectively.