A Fluidized Bed Chemical Vapor Deposition (FB-CVD) Furnace is the premium hardware solution for the uniform, high-throughput coating of micro- and nano-powders. Unlike rotary or static furnaces, FB-CVD suspends the particles in an upward stream of precursor gas, turning the entire powder bed into a "fluid."

The core of the system is the Gas Distributor (typically a porous quartz or metal frit) at the bottom of a vertical furnace tube. (1) Gas Entrance: Precursor and carrier gases (CH4, Ar, H2) enter from the bottom. (2) Fluidization: When the gas velocity reaches the "Minimum Fluidization Velocity" (Umf), the aerodynamic drag counteracts the weight of the particles. The bed expands, and particles begin to move turbulently. (3) Uniform Reaction: Every single particle is surrounded by the precursor gas. This eliminates the "shielding effect" found in tray-based furnaces, ensuring 100% conformal coating across the entire batch.  Heat Transfer: Fluidized beds have exceptionally high heat transfer coefficients, preventing "hot spots" that could cause phase changes in delicate SIB cathodes.

References:

S. Aslam, et al., A new route to apply nanometric alumina coating on powders by fluidized bed chemical vapor deposition, Chemical Engineering Journal Advances, 2023,16, 100554

B. Li, et al., The Fluidized Bed-Chemical Vapor Deposition Coating Technology of Micro-Nano Particles: Status and Prospective, Coatings 2025, 15(3), 322