Aerosol-deposited freestanding Na3V2(PO4)3 thin-film microbattery

High energy density on chip microbatteries that can provide necessary power capability is highly sought to power miniaturized and smart electronics. Currently, various thin-film electrode fabrication methods are struggling to upscale the production. Herein, a thin all-electrochemical-active sodium-ion electrode consisting of Na3V2(PO4)3 and carbon is prepared using aerosol deposition method without postthermal treatment. The freestanding Na3V2(PO4)3 thin film exhibits an increase in charge transfer efficiency, higher sodium ions diffusion coefficient, and a smaller overpotential than conventional bulk electrode. Consequently, the thin-film half-cell delivers a high reversible areal capacity of 32.2 mAh/cm2, a high energy density of 0.106 mWh/cm2, at 96.4 mA/cm2, and an excellent cyclic stability (88.6% after 1000 cycles at 100 mA/cm2). In addition, the full cell delivers a high initial energy density of 213.6 Wh/kg at 15.8 W/kg. This work presents a viable process to prepare a high-performance electrode thin film for practical application.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This study presents a thin all-electrochemical-active sodium-ion electrode prepared by aerosol deposition method, which exhibits high charge transfer efficiency, sodium ions diffusion coefficient, and low overpotential. The thin-film half-cell and full cell show high reversible capacity and energy density, as well as excellent cyclic stability, providing a viable method for preparing high-performance electrode thin film for practical applications.