Multi-phase conversion pathways towards porous but graphitized carbon structures for energy storage and conversion

Abstract

Carbon materials, especially porous carbon materials, have been widely used in energy storage and conversion due to their rich and adjustable pore configuration and parameters; however, porous skeletons often exhibit amorphous carbon nature, resulting in a trade-off between porosity and graphitization. Designing porous graphitized carbon (PGC) materials that combine developed porosity and long-range graphitic crystalline structures is crucial for achieving simultaneously high activity and stability in energy storage and conversion systems, thereby ensuring all-round performance improvement. Efforts so far to design and prepare such carbon materials have included screening suitable carbon sources (such as natural carbon precursors, polymers, and molecular architectures) and selecting strategies for activation and graphitization. From the perspective of evolutionary pathways and environmental conditions, regardless of the type of carbon source or the methods used for pore formation and graphitization, the growth and regulation of the carbon structure can be achieved through three conversion pathways including solid-, liquid-, and gas-phase conversion processes. Therefore, this review summarizes the past and recent progress in this class of carbon materials based on the multi-phase conversion pathways, with the emphasis on the evolution picture and synergistic regulation mechanism of the two contradictory variables of porous and graphitized structures. The enhanced effects of PGC on the activity and stability in energy storage and conversion applications were also discussed. In addition, the latest research progress on the synthesis of PGC through precursor engineering strategies based on multi-phase conversion pathways has also been reviewed. Finally, a perspective on the design principles and practical development trends of PGC is presented with the aim of inspiring innovations in PGC manufacturing and expanding its potential application scenarios.