Fe₃O₄ is a promising pseudocapacitive electrode material, but its poor electrical conductivity limits rate performance. Here, we report a rapid 1-min thermal CVD strategy to synthesize FeO_x/multilayer graphene core–shell nanocomposites. During the process, partial reduction of Fe₃O₄ generated Fe-rich catalytic sites that enabled graphitic carbon shell formation. Temperature-dependent analysis showed that 1000 °C produced uniform multilayer graphene shells with improved crystallinity, whereas lower or higher temperatures resulted in poorly crystalline or defective carbon layers. The optimized electrode delivered a specific capacitance of 267 F g^-1 at 0.5 A g^-1, retained 45% capacitance at 20 A g^-1, and maintained 81% retention after 6000 cycles. The enhanced performance is attributed to combined Fe²⁺/Fe³⁺ pseudocapacitive reactions and efficient electron transport through the conductive graphene network. These findings demonstrate a scalable CVD-based approach for designing high-performance transition-metal-oxide electrodes for energy storage applications. This work has been published in the Journal of Alloys and Compounds (2026), DOI: 10.1016/j.jallcom.2026.189204.