Environmentally friendly method for efficiently recycling LiMn2O4 cathode materials

Abstract

The recycling of cathode materials from batteries has an impact on reducing energy consumption. In this study, a green recycling method without secondary pollution was adopted to directly reutilize spent lithium manganate materials. The stripping rate achieved for these spent materials reached 91.1%. This excellent stripping rate was attributed to the synergistic effects of stirring and sonication. The molecular formula of the stripped cathode materials was determined to be LiMn_1.85O₄. Infrared spectroscopy was used to demonstrate that the organic adhesive in the cathode materials was completely removed after calcination and that the asymmetric stretching peak of the MO₆ groups was enhanced. Comparative experiments showed that the electrochemical properties of the re-utilized materials were dramatically improved. The discharge capacity of the sample calcined at 800 °C for 12 h was 131.7 mAh g⁻¹ at the first cycle, and 91.7% of the capacity was maintained after 200 cycles at 0.2C (1C = 148 mAh g⁻¹). Importantly, this recycling strategy not only requires no toxic or hazardous solvents but also has no harmful effects on the environment and reduces waste accumulation effectively, thus providing a new possibility for the recycling of similar batteries.