Ultrasonic renovating and coating modifying spent lithium cobalt oxide from the cathode for the recovery and sustainable utilization of lithium-ion battery

Abstract

This research presented a sustainable recycling method for the separation and renovation of spent lithium-ion batteries (LIBs) based on the ultrasonic effects. Lithium cobalt oxide (LiCoO2) and aluminum foils were separated sufficiently under the effect of ultrasonic cavitation. The lithium in anode materials was directly reused as lithium leaching solution and applied in the ultrasonic renovation of spent LiCoO2. Thereby solving the problem of wastewater discharge and realizing the whole material circulation. The optimal separation rate was 99.98% under the ultrasonic power of 270 W, the temperature of 75 °C, the ultrasonic time of 120 min, the stirring speed of 200 r·min−1, the solid-liquid (S/L) ratio of 1/140 g mL−1 and 1 mL H2O2 solution. The pH range of the lithium leaching solution were within 10.10–10.64 to realize the optimal renovation effect. Argon (Ar) atmosphere was used as cavitation gas to improve the cavitation effect and increase the renovation efficiency. Nano-Al2O3 was applied for coating modification to improve the electrochemical properties. The first charge and discharge capacity of the modified battery was 167.0 mAh·g−1 and 166.3 mAh·g−1. The process introduced no secondary pollution and showed a high reaction efficiency, which meet the journal scope of sustainable development. This study comprehensively improved the utilized efficiency and provided a theoretical basis for the technical upgrading of the spent LIBs industry.