Quasi-honeycomb graphene architectures enabling geometry-adaptive thermal regulation for high-density electronics

The relentless pursuit of higher power density and miniaturization of modern electronics demand have exposed the limitations of conventional passive cooling systems. This study presents an innovative quasi-honeycomb architecture composed of vertically aligned and interconnected graphene nanosheet arrays (VIG) synthesized via plasma-enhanced chemical vapor deposition (PECVD) on copper substrates, achieving dual-mode heat dissipation through synergistic radiative and convective enhancement. The engineered graphene-copper hybrid interface demonstrates exceptional thermal performance, achieving an enhanced heat transfer coefficient of 35.6 W m^-2 K^-1 through synergistic optimization of infrared emissivity and specific surface area. Systematic evaluations reveal a 21.6% improvement in cooling efficiency compared to pristine copper substrates. Practical implementation as a conformal passive heat sink effectively suppresses temperature rise in high-power LED arrays (ΔT reduction: 28.1 °C at 2.7 W) and lithium-ion battery modules (thermal mitigation: 7.0 °C under 3C discharge). Notably, the ultrathin (≈2.5 μm) and ultralight (≈0.073 mg cm^-2) structure enables spontaneous self-assembly on sub-100 μm metallic foils, providing geometrically adaptive heat dissipation for irregular surfaces. This work establishes a universal paradigm for developing conformal thermal management solutions compatible with geometrically complex surfaces in next-generation compact electronics.