High-Purity Biomass-Derived Synthetic Graphite: Catalyst-Free Industrial Synthesis and Applications

To support efforts on the graphite industry's defossilization, the pursuit of more sustainable options for synthetic graphite might be in contrast with the high requirements for purity, quantity, and quality of graphite materials. The catalyst-free graphitization of pyrolyzed biomass residues into a synthetic graphite is presented. The resulting biomass-derived graphite is characterized by high purity (>99.9%), high crystallinity with a graphitization degree of >91%, and exhibits electrical and thermal conductivity similar to fossil-based synthetic graphites. Material characterization and application data confirm various possible applications, namely in carbon brushes for electric motors and polymer bipolar plates for fuel cells. Since biomass, as called nongraphitizable carbon, is used as a raw material, the graphitization mechanism in the absence of a metal catalyst is proposed and discussed. The reported process and preparation of biomass-derived graphite are confirmed at the industrial scale and thus provide a more sustainable alternative to fossil-based synthetic graphites.