Reviving Graphite Anode from Spent Li-Ion Batteries via Acid Leaching and Carbonization Methodology

Abstract

We demonstrated the regeneration of a graphite anode from spent lithium-ion batteries and reused the same as energy storage material. The disordered graphite material is regenerated by inert atmosphere carbonization at high temperatures. Raman and XPS analyses confirm the morphological improvement of the carbonized graphite compared to spent and acid-treated graphite. Acid-treated graphite exhibited discharge and charge capacities of 428 and 364 mAh/g, respectively, in the first cycle at a 0.1C rate, and discharge and charge capacities decreased to 319 and 318 mAh/g, respectively, after 50 cycles at a 0.1C rate, whereas the carbonized graphite exhibited a discharge capacity of 444 mAh/g in the first cycle, 396 mAh/g in the second cycle, 388 mAh/g in third cycle, and 364 mAh/g after 50 cycles at a 0.1C rate. Incremental capacity analysis revealed that the state of health of the cell is restored, and performance increases when the C rate is decreased to C/10 from 1C after 100 cycles. The calculated apparent diffusion coefficients of lithium ions (DLi) corresponding to anodic and cathodic electrochemical reactions were found to be 2.27 × 10–7and 1.36 × 10–7cm2/s, respectively, comparable with the literature’s reported values.