A green electrochemical transformation of inferior coals to crystalline graphite for stable Li-ion storage

With the increasing demand for the efficient utilization of global resources, green strategies for the transformation of inferior coals to highly value-added products are largely required. In this study, a green approach was demonstrated for the conversion of inferior coals into crystalline graphite using a simple purification and high-efficiency electrochemical method. After being processed in the molten CaCl₂ salt under 2.6 V at 950 °C for 6 h, the products presented a highly graphitic structure with high degree of graphitization. The as-prepared graphite was employed as a negative electrode material for lithium-ion batteries, delivering a highly reversible capacity of 510 mA h g⁻¹ at 1C. High-performance lithium-ion storage represents an efficient green strategy to reuse inferior coals for conversion into value-added products via a more sustainable route.