Fabrication of nanosized cobalt powder from Cobalt(II) hydroxide of spent lithium ion battery

Abstract This study was investigated to fabricate nanosized cobalt (Co) powder from cobalt hydroxide Co(OH) 2 recovered from spent lithium ion battery. Direct process newly proposed was attempted to transform phases as follow: Co(OH) 2  → Co 3 O 4  → Co. The variation of weight with time of the sample was measured using thermogravimetric analysis (TGA) and it was found that weight loss was observed over 500 °C. Thermal treatment was conducted to determine proper operating time for phase transformation of Co 3 O 4 at 500 °C. Subsequently, hydrogen reduction was carried out on the effect of temperature, reaction time and flowrate. In the long run, nanosized cobalt powder was successfully fabricated with a mean particle size of 100–500 nm as well as purity of 99.21 wt.%.