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.