Turbulent Flow‐Driven Synthesis of Graphene‐Skinned Boron Nitride Heterostructures for Dendrite‐Free Potassium Metal Batteries

Potassium metal batteries are considered as promising candidates for next-generation energy storage systems. However, their practical development is hindered by the insufficient capacity output and persistent dendritic proliferation at the anode side. Here graphene-skinned hexagonal boron nitride powder is demonstrated synthesized via fluidized bed-chemical vapor deposition, realizing conformal growth of layer-controlled graphene (5-90 layers) over h-BN with atomically coupled heterointerfaces. Fluid dynamic simulations of fluidization environments in fluidized-bed reactors reveal that localized turbulence-driven precursor transport enables uniform powder fluidization and homogeneous graphene formation. Potassium metal electrodes fabricated with Gr-skinned h-BN powder modified Al current collector exhibit favorable cyclic stability (1050 h at 0.5 mA cm^-2) and low nucleation overpotential (<7 mV). The polar hexagonal lattice of h-BN and high surface energy (43.27 mJ m^-2) of graphene readily promote uniform potassium deposition via Frank-van der Merwe mode. This dual-scale approach, which integrates atomic-scale interface engineering with reactor-scale manufacture innovation, offers an appealing pathway toward industrial-level production of high-performance metal batteries.