Selective Recovery of Nickel from Precipitates of NCA Battery Cathodes Through Leaching Process Using Oxalic Acid

Abstract

Lithium ion battery (LIB) currently becomes of important aspect in modern life, especifically due to demands from electronic devices and e-vehicle industries. Because of its superlative performance, among various types of LIB, NCA battery has widely used in many applications. Nickel in the battery cathode contributes up to 48% and tends to shift towards higher nickel content due to its superior energy density. However, the battery will come to an end after a certain period of usage and the waste might cause environmental problem in the future. Due to its valuable metal content, a recovery unit is needed in order to recycle the metals including nickel. The present work focused on recovery of nickel from the remaining precipitates through a leaching process in oxalic acid following lithium recovery from NCA battery cathode. The research aimed to investigate the effect of temperature, S/L ratio, pH, and reaction time on the nickel recovery. Experimental result showed that lower pH and S/L ratio values as well as temperature rise to 60°C could improve the recovery. Meanwhile, above 60°C recovery seemed to decrease due to the rate of deposition of nickel is higher than the rate of leaching. The optimum leaching conditions was reached after 30 minute with S/L ratio of 5, at 57.68°C, pH 1 with the optimum recovery value of 63.34% analyzed using RSM method. The kinetics parameters were studied at the optimum condition and the data was used for kinetic model evaluation. The proposed kinetic model was suitable to approach the experimental data with a rate constant of leaching (k') of 0.9674 men-1 and rate constant of deposition (k2) of 0.0556 men-1