Kilogram-Scale Synthesis of Few-Layer Graphene-Skinned Copper Powders via Pulsed-Pressure Chemical Vapor Deposition

Copper powders are essential components in electronics and manufacturing but suffer from rapid surface oxidation. Graphene encapsulation offers an effective protective strategy; however, conventional chemical vapor deposition (CVD) methods face challenges such as particle sintering, poor coverage due to inefficient precursor transport, and self-limited monolayer growth. Here, we report a scalable pulsed-pressure CVD strategy for kilogram-scale preparation of few-layer graphene-skinned copper powders. This method employs graphite powder as a physical spacer to prevent sintering, while a unique cyclic pressure modulation actively enhances precursor penetration throughout the powder bed. The resulting powders feature a conformal few-layer graphene skin (3-5 layers) with 98.2% surface coverage and high crystallinity. They exhibit exceptional oxidation resistance, showing an approximately 20‑fold lower oxygen uptake than bare copper after 30 min at 190°C in air. The graphene-copper composites consolidated from these powders show an ∼8% higher thermal conductivity and an ∼3% higher electrical conductivity than pure copper. This work provides a viable pathway for large-scale production of high-performance graphene-metal composites, opening new opportunities for advanced conductive and thermal management applications.