High‐performance graphene microwave absorption materials are highly desirable in daily life and some extreme situations. A simple technique for the direct growth of graphene as absorption fillers in wave‐transmitting matrices is of paramount importance to bring it to real‐world application. Herein, a simple chemical vapor deposition (CVD) route for the direct growth of edge‐rich graphene (ERG) with tailored structures and tunable dielectric properties in porous Si3N4 ceramics using only methyl alcohol (CH3OH) as precursor is reported. The large O/C atomic ratio of CH3OH helps to build a mild oxidizing atmosphere and leads to a unique structure featuring open graphite nanosteps and freestanding nanoplanes, endowing the ERG/Si3N4 hybrid with an appropriate balance between good impedance matching and strong loss capacity. Accordingly, the prepared materials exhibit superior electromagnetic wave absorption, far surpassing that of traditional CVD graphene and reduced graphene oxide‐based materials, achieving an effective absorption bandwidth of 4.2 GHz covering the entire X band, with a thickness of 3.75 mm and a negligibly low loading content of absorbents. The results provide new insights for developing novel microwave absorption materials with strong reflection loss and wide absorption frequency range.

Inhomogeneous mass and charge transfers induce severe Li dendrite formation, impeding the service of Li metal anodes in rechargeable batteries. Various 3D hosts are proposed to address the related issues. To enable better progress, hybrid micro/nanostructures with the ability to realize spatial control of Li deposition over nucleation should be developed. Here, it is demonstrated that edge‐rich graphene (ERG), which is vertically grown on a 3D carbon nanofiber (CNF) substrate via a simple chemical vapor deposition method, can serve as nanoseeds to reduce the nucleation overpotential of Li effectively and guide the Li deposition on the 3D CNF substrate uniformly, free from dendrites. Different from the case in other sp2 carbon featuring interconnected graphitic structures such as planar graphene, the zero nucleation overpotential presented by ERG is attributed to its unique electron properties (i.e., the enhanced surface electronegativity) and its open architecture. Compared to the pristine CNF host, the ERG‐hybridized one resolves the problems of the Li metal anode better, endowing a practical Li battery with a long lifespan of 1000 cycles with a Coulombic efficiency of 99.7%. The results present novel sights for developing next‐generation Li‐carbon anodes with high cycling stability.

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