A hierarchical porous carbon derived from gas-exfoliation activation of lignin for high-energy lithium-ion batteries

A large scale hierarchical porous carbon was developed by a cheaper and environmentally friendly activation approach from the most abundant aromatic polymer in plants, lignin using ZnCO3 as a non-corrosive and recyclable activator. The three-dimensional (3D) novelty hierarchical lignin-derived porous carbon (HLPC) possesses a desirable microstructure and a large number of mesoporous based on activation that gas released by ZnCO3 can gas-exfoliation of lignin and nano-sized ZnO particles (10-20 nm) in-situ generated form ZnCO3 have an in-situ templating effect. As a result, the resulting HLPC based achieved simultaneously excellent volume/mass energy density (730 mAh·cm-3/550 mAh·g-1 after 200 cycles at 0.2 A·g-1) with excellent cycling performance (~99% retention after 10,000 cycles), especially the volume capacitances obtained in our work are the highest among the reported lignin-based carbon. Compared to conventional activators, ZnCO3 as a green, non-corrosive, low cost and recyclable activator has a broad prospect in the preparation of biomass-based carbon materials. Our work demonstrates the successful and large-scale conversion of industrial lignin into high-performance carbon-based material, and the promising mass/volumetric performances further suggest the method developed may provide an available pathway for improving the energy density of energy storage materials.