Synthesis of hierarchical porous carbon from metal carbonates towards high-performance lithium storage

Abstract

Hierarchical porous carbon (HPC) has become increasingly important in tackling global environmental and energy-related challenges. However, its wide utilization is still limited by the complicated and environment-unfriendly synthesis process. Herein, we report a green and facile strategy to synthesize HPC from abundant metal carbonates without any emission of CO₂ or/and noxious gases. The sponge-like HPC synthesized from reacting lithium carbonate (Li₂CO₃) with lithium hydride (LiH) exhibits high specific surface area and porosity, enabling high-performance lithium storage. The Li₂CO₃-derived HPC achieves a reversible capacity of ∼1750 mA h g⁻¹ at a current density of 0.2 A g⁻¹, among the highest reversible lithium storage capacities for HPCs. Moreover, excellent cycling stability and superior rate performance are demonstrated with a high capacity of 505 mA h g⁻¹ even at 4.0 A g⁻¹ over 2000 stable cycles. Such a rational and environment-friendly strategy might pave the way for the large-scale synthesis and utilization of HPCs in high-performance energy storage.