Ultrafast and Facile Synthesis of Three‐Dimensional Graphene‐Metal Oxide Aerogels Toward High‐Performance Hybrid Supercapacitors

Ultrafine amorphous nanoparticles emerge as promising candidates for energy storage applications due to their large specific surface area, high dispersion, short ion diffusion paths, abundant defect sites, and excellent chemical stability. We present high‐performance electrode materials synthesized via an ultrafast and eco‐friendly microwave‐assisted method that enables synergistic electrochemical effects. Iron oxide and nickel–cobalt oxide nanoparticles are incorporated into a graphene aerogel (GA) to serve as the anode and cathode, respectively, forming a high‐performance hybrid supercapacitor (HSC). The thermal sintering step, typically the most time‐consuming stage in conventional synthesis, is completed within 1 min using a household microwave oven. The resulting three‐electrode system achieves specific capacities of 714.4 and 521.4 C g −1 at 1 A g −1 for the anode and cathode, respectively. The assembled device delivers an areal capacity of 0.36 C cm −2 and retains 90% of its capacity after 13,000 cycles at a current density of 50 mA cm −2 . This ultrafast and facile approach enables the scalable fabrication of macroporous GAs embedded with ultrafine amorphous particles, offering strong potential for next‐generation high‐performance energy storage devices.