Environmentally friendly recycling of energy storage functional materials from hazardous waste lithium-containing aluminum electrolytes

Abstract

Low energy consumption and environmentally friendly extraction of high value-added elements from waste aluminum electrolytes are crucial for developing potential mineral resources and reducing environmental hazards. This study aims to propose a new method for resource utilization of retired aluminum electrolytes by combining NH4Cl with CaO-assisted low-temperature calcination. The leaching rates of Li and Na exceed 94.67 % and 98.12 %, respectively. The optimal conditions for roasting transformation were determined to be NH4Cl/CaO: 2, CaO/LWE@Al: 2, T: 550 ℃, t: 1 h. In the leaching stage, liquid–solid ratio: 5, T: 45 ℃, t: 1.0 h were proved to be the most suitable experimental condition. An evaluation was conducted on the economic benefits and creativity of the process. Finally, the regenerated LiCoO2 prepared from recycled Li2CO3 has been proven to have better electrochemical performance than commercial LiCoO2, demonstrating the feasibility of energy storage use. The economic accounting results indicate that this novel process demonstrates significant financial and environmental benefits through high-value lithium recovery. Compared with traditional concentrated acid roasting, this low-temperature roasting method has lower energy consumption, higher element conversion rate, lower corrosiveness, and lower operational difficulty (without the involvement of strong acids/bases). Therefore, this process has been proven to be a green, environmentally friendly, low energy consumption, and high value-added method for comprehensive utilization of waste electrolytes.