Pre-extraction of Li from spent lithium-ion batteries through an Ethanol-Water vapor thermal reduction approach

Abstract

Pre-extraction of lithium from spent lithium-ion batteries (LIBs) is highly required to obtain a high recovery rate of lithium. Here, we report an ethanol–water vapor thermal reduction approach in a sealed reactor to selectively recycle lithium and transition metal oxides (TMOs) from spent LIBs. Spent cathode materials were converted to LiOH and TMO by the reduction of water-alcohol vapor at a temperature of 350–400 °C. More than 99 % of the Li in LiCoO2 was selectively extracted from LiCoO2 at 370 °C for 2 h and at 400 °C for 0.8 h. The selective extraction is co-driven by water and alcohol that enable the reduction of LiCoO2 and release water-soluble LiOH and water-insoluble TMOs. In addition, the water–vapor thermal reduction method is applicable to selectively recovery Li from different types of cathode materials such as NCMs and lithium manganese oxide. The pre-selective extraction ensures a high lithium recovery rate and a reagent-saving manner. We envision that the vapor thermal recovery method could help recycle spent LIBs by an environmentally friendly and economically reasonable way.