Mechanical Force Provoking Oxygen Vacancies and Pyrolysis Gas Reduction Activity for the Efficient Valorization of Waste Biomass and Li-ion Batteries

Abstract

Pyrolysis, thermal reduction, and mechanochemical force are commonly used for biomass utilization, materials synthesis, and spent Li-ion batteries recycling. However, the effect of mechanical treatment on pyrolysis gas generation and thermal reduction remains unclear. Herein, we study the effect of mechanical treatment on the biomass pyrolysis reduction of LiCoO2. The mechanical milling generates oxygen vacancies in the LiCoO2 lattice. In addition, the mechanical treatment can regulate the pyrolysis gas of sawdust in terms of increasing the content of H2, CH4, and CO while decreasing the CO2 content. The oxygen vacancies and pyrolysis gas are beneficial for the thermal collapse of the LiCoO2 structure, leading to the rapid and complete separation of Li and Co, thereby increasing the recovery efficiency to above 98%. The understanding of the interplay of mechanical force, oxide structure, and pyrolysis gas composition helps design green approaches to enabling metal and organic resource recovery and utilization.