Epitaxial Growth and Confinement of Graphene‐Skinned Cu Powders: A Comprehensive Assessment of Crystallization Thermodynamics and Kinetics on Spherical Surfaces

As a promising member of the graphene‐skinned Cu powder family, this material integrates the properties of graphene with the inherent advantages of Cu. However, controlled growth on curved surfaces remains challenging due to curvature‐induced stress, catalytic heterogeneity of molten Cu, and limited carbon migration. Using DFT, AIMD, LS‐DYNA, and experimental verification, we show that curvature introduces a size‐dependent energy barrier (181.87 eV for 10 nm vs. 21.40 eV for 10 µm) and elastic instability, triggering six‐branched domains when the branch length exceeds a critical value l c = 0.0092 R (where R is the powder radius). Surface premelting lowers the CH 4 decomposition barrier to 1.10 eV, boosting carbon supply by 10 3 ‐fold, yet simultaneously suppresses carbon surface diffusion by 10 4 times. Consequently, powders ≤10 µm exhibit ultrahigh nucleation density (up to 7.27 × 10 5 N/mm 2 ) and low growth rates (0.92–3.64 µm/min). These effects intensify with decreasing particle size, whereas powders ≥50 µm behave similarly to flat foils. This work clarifies the synergy between curvature‐induced elastic instability and premelting‐mediated kinetics, identifies suitable Cu powder sizes for CVD graphene growth, and provides a theoretical foundation for optimizing CVD parameters (e.g., temperature and carbon flux) to obtain high‐quality graphene coatings for high‐performance composites.