Graphene-amorphous carbon with interwoven networks for enhanced strength.

Abstract

High-strength, high-conductivity graphite-based carbon materials (GCMs) are widely explored for diverse applications. Designing and regulating the graphitic phase microstructure is essential for simultaneously enhancing mechanical and electrical properties, particularly mechanical strength. Here, we propose a two-step strategy to synthesize graphene-amorphous carbon (GAC) with interwoven graphene networks. By leveraging the different graphitization tendencies between polyacrylamide and glucose, we obtained GAC with a microscale structure in which few-layers graphene and amorphous carbon are uniformly interwoven. Therefore, the GAC exhibits exceptional compressive and flexural strengths of 303 MPa and 203 MPa, respectively, greatly exceeding previously reported performance benchmarks. Microscopic studies reveal that crack propagation is significantly impeded by the network of cross-cutting few-layer graphene, resulting in continuous crack deflections, which account for the outstanding mechanical performance of the GAC. This microstructure design strategy provides the rationale for developing ultrahigh-strength GCMs.