In-situ deposition of sodium titanate thin film as anode for sodium-ion micro-batteries developed by pulsed laser deposition.

Sodium-ion thin-film micro-batteries form a niche sector of energy storage devices. Sodium titanate, NaTiO (NTO) thin films were deposited by pulsed laser deposition (PLD) using solid-state synthesized polycrystalline NaTiO compound. The phase-purity and crystallinity of NTO in bulk and thin-film forms were confirmed by Rietveld refinement. Electron microscopy and atomic force microscopy revealed the formation of uniform ∼100 nm thin film with roughness of ∼4 nm consisting of homogeneous nanoscale grains. These PLD-deposited NTO thin-films, when tested in Na-half cell architecture, delivered a near theoretical reversible capacity close to 42 mA h g involving Ti/Ti redox activity along with good cycling stability and rate kinetics. NaTiO can work as an efficient and safe anode in designing sodium-ion thin-film micro-batteries.