Atomic layer deposition-based synthesis of TiO2 and Al2O3 thin-film coatings on nanoparticle powders for sodium-ion batteries with enhanced cyclic stability

Despite it being the leading technology for fabricating uniform-thickness metal and metal-oxide thin films on wafer-based substrates, atomic layer deposition (ALD) is yet to be utilized with powder-based substrates. Via the successful deposition of TiO2 and Al2O3 thin films on the surfaces of silica (SiO2) nanospheres, Prussian blue (PB) nanocubes, and NaTi2(PO4)(3) (NTP) nanocubes using a home-built ALD system, this study demonstrates that ALD is a viable technique for depositing thin films on powdered substrates. Furthermore, amorphous TiO2 thin films are used as a protective layer to enhance the electrochemical properties of NTP nanocubes, which have application prospects in sodium-ion batteries. Whereas uncoated NTP nanocubes loses 67.9% of its initial charge capacity within 100 charge discharge cycles, TiO2-coated (thickness: similar to 3 nm) NTP nanocubes reduces this capacity loss to 22.1%. This strongly suggests that powder-optimized ALD can be used to fabricate thin films for multiple applications that use powder-type nanoparticles, such as electrode materials and catalysts. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study demonstrates that atomic layer deposition (ALD) can be used to deposit thin films on powdered substrates, providing potential applications for powder-type nanoparticles.