Ultra-Stiff yet Super-Elastic Graphene Aerogels by Topological Cellular Hierarchy.

Lightweight cellular materials with high stiffness and excellent recoverability are critically important in structural engineering applications, but the intrinsic conflict between these two properties presents a significant challenge. Here, a topological cellular hierarchy is presented, designed to fabricate ultra-stiff (>10 MPa modulus) yet super-elastic (>90% recoverable strain) graphene aerogels. This topological cellular hierarchy, composed of massive corrugated pores and nanowalls, is designed to carry high loads through predominantly reversible buckling within the honeycomb framework. The compressive modulus of the as-prepared graphene aerogel is nearly twice that of conventional graphene aerogel. This high-stiff graphene aerogel also exhibits exceptional mechanical recoverability, achieving up to 60% strain recovery over 10 000 fatigue cycles without significant structural failure, outperforming most previously reported porous lattices and monoliths. It is further demonstrated that this graphene aerogel exhibits superior energy dissipation and anti-fatigue dynamic impact properties, with an energy absorption capacity nearly an order of magnitude greater than that of conventional aerogels. These exceptional properties of the topological cellular graphene aerogel open new avenues for high-energy bullet protection, offering great promise for the development of lightweight, armor-like protective materials in transportation and aerospace applications.