Transition metals recovery from organic acid leachate of spent lithium-ion battery cathode via oxalic acid co-precipitation

Abstract

Li-ion batteries (LIBs) have been widely used in almost every aspect of human life. Not only for portable electronics but also envisioned to be used as energy storage of most vehicles in the future. However, as their usage increases, the environmental problem caused by the piling up of the battery waste cannot be avoided. Recycling is considered the best option to mitigate this problem while ensuring the sustainability of battery production as the battery constituent materials, especially the transition metals, are quite expensive and scarce. Among various methods, the hydrometallurgy technique through organic acid leaching and co-precipitation is considered a good recovery method of transition metals. It produces high efficiency with a minimum environmental hazard. This work investigated the recovery process of transition metals using oxalic acid from previously obtained cathode leached solution via DL-malic leaching procedure. Characterization of the sample using XRF shows that reaction time and oxalic acid concentration plays an important role in determining the quantity of successfully recovered transition metals. Samples that were recovered by adding 1M oxalic acid with 120 min reaction time show the highest recovery efficiency with the composition of recovered Ni, Co, and Mn match the actual composition of the spent cathode, i.e. Li(Ni1/3Co1/3Mn1/3)O2 with Ni:Co:Mn ratio of 1:1:1.