Recovery nano-flake (100 nm thickness) of zero-valent manganese from spent lithium-ion batteries

Abstract

The recovery of spent Li-ion batteries has drawn many attentions because the recycled metals can be very profitable. The current metal recovery technology of spent Li-ion battery is mainly hydrometallurgical leaching. This technology has a high recovery rate of metals but it employs abundant chemical agents and causes wastewater as well as sludge discharging. Vacuum reduction technology is a new kind of environmentally friendly metal recovery technology because it is waste-free and energy-saving. The recovery of cobalt and nickel by vacuum reduction has been proposed. To further realize the recovery of all metal components in spent Li-ion batteries, we propose a new recovery technology including vacuum reduction process and gasification-condensation process to recover manganese from the cathode materials of spent Li-ion battery. The manganese in cathode materials (LiNix/3Mny/3Coz/3O2) is firstly decomposed to manganese oxide and then reduced by aluminum to zero-valent manganese. Gasification-condensation is an innovative metal separation process. The zero-valent manganese is separated from other substances by gasification in the heating area and condensation in the condensing area. More interestingly, we find that some nano-flakes (100 nm thickness) of zero-valent manganese are produced, it shows that this process has a potential to produce nano-flake materials. There is no refractory wastewater, toxic gas or hazardous solid waste in this recover process. This paper contributed a new technology to the full recovery of metals from spent Li-ion battery.