High-Purity Graphitic Carbon for Energy Storage: Sustainable Electrochemical Conversion from Petroleum Coke.

The petroleum coke (PC) has been widely used as raw materials for the preparation of electrodes in aluminium electrolysis and lithium-ion batteries (LIB), during which massive CO ₂ gases are produced. To meet global CO ₂ reduction, an environmentally friendly route for utilizing PC is highly required. Here, a simple, scalable, catalyst-free process that can directly convert high-sulfur PC into graphitic nanomaterials under cathodic polarization in molten CaCl ₂ -LiCl at mild temperatures is proposed. The energy consumption of the proposed process is calculated to be 3 627.08 kWh t ^-1 , half that of the traditional graphitization process (≈7,825.21 kWh t ^-1 graphite). When applied as a negative electrode for LIBs, the as-converted graphite materials deliver a competitive specific capacity of ≈360 mAh g ^-1 (0.2 C) compared with commercial graphite. This approach has great potential to scale up for sustainably converting low-value PC into high-quality graphite for energy storage.
(© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)