Advances in atmospheric-pressure particle atomic layer deposition

Atmospheric pressure particle atomic layer deposition (AP-PALD) shows promising potentials in the fields of energy and catalytic materials due to its ability in precisely modifying the surfaces of functional materials operated at atmospheric or near-atmospheric pressure. This technique eliminates the need for a vacuum system, reducing the equipment and maintenance costs, and thereby exhibits great advantages for scaling up processes. This paper reviews the fundamentals of self-terminating surface reactions on particles via ALD, challenges needing to be overcome, and pros and cons of AP-PALD. The conformality of ALD has been overviewed briefly, followed by the development of reactor designs for temporal ALD (t-ALD) and spatial ALD (s-ALD) under atmospheric pressure together with the comparison about processing of high-throughput particles using t-ALD and s-ALD. The applications of AP-PALD used in catalytic materials, drug delivery, Li-ion batteries, and other areas are summarized. Future perspectives of AP-PALD are also addressed.