Nitrogen-doped rock-salt Li3V2O5 nanosheet arrays with improved rate capability as an anode for thin film lithium-ion microbatteries

Abstract

Disordered rock-salt Li₃V₂O₅ (LVO) is a promising anode for all-solid-state thin film lithium-ion microbatteries (TFBs) due to its high specific capacity, low operating voltage, and good structural stability. However, its intrinsic poor electrical and ionic conductivities degrade its rate performance and restrain its application in TFBs. In this work, a nitrogen-doped rock-salt LVO (N–LVO) thin-film anode is prepared via the in situ electrochemical transition of nitrogen-doped layered V₂O₅ nanosheet arrays, which are deposited by reactive magnetron sputtering at room temperature. The incorporation of nitrogen into N–LVO can significantly increase its electrical conductivity and Li⁺ diffusion coefficient, facilitating fast electrode kinetics. Consequently, the N–LVO electrode delivers a large capacity (350.1 mA h g⁻¹ at 0.1C), good rate capability (160.7 mA h g⁻¹ at 10C), and excellent cycling stability (80% capacity retention after 2000 cycles), outperforming the LVO electrode. This work offers a valuable structural regulation approach to develop advanced thin-film electrodes for TFBs.