Graphene Aerogel Armed 3D Ordered Mesoporous Carbon as Versatile Anode Platforms for Sodium‐Ion Storage Devices

Abstract The rise of Na‐storage devices has put forward higher requirements for Na‐storage anode materials with large capacity, long service life, and fast rate capability. Mesoporous carbons, either as active materials or as hosts for guest active nanoparticles, are considered as promising electrode materials. However, addressing the issues of their short lifespan resulting from volume variation and the low coulombic efficiency caused by large surface area via a facile porous structure design still remains a challenge. Herein, a versatile phosphorus‐doped mesoporous carbon (PMC) armed is developed by graphene aerogel (GA) (GA@PMC) for hosting Na‐storage active nanoparticles. As a case study, FeSe ₂ nanoparticles are selectively supported onto this GA@PMC matrix, creating the FeSe ₂ /GA@PMC composite. When employed in typical Na‐storage devices, such as Na‐ion batteries, Na‐ion hybrid capacitors, and Na‐ion based dual‐ion batteries, the FeSe ₂ /GA@PMC electrode consistently demonstrates superior electrochemical performance. In such GA@PMC, the conformal GA can improve the entire conductivity while decreasing the specific surface area that is directly contacting with electrolyte. The interconnected macroporous structure can not only promote the diffusion of Na ⁺ but also buffers the volume change of the guest active nanoparticles. This bespoke carbon platform synergistically endows the electrode material with enhanced rate capability, cyclic stability, and coulombic efficiency, which are being expected in advanced Na‐storage devices.