Yolk–shell vanadium pentoxide integrated electrode for high-performance stretchable lithium metal battery

Vanadium pentoxide (V2O5) stands out as a preferred cathode material for stretchable lithium-ion batteries due to its high specific capacity, robust structural stability, cost-effectiveness, and ease of synthesis. However, its practical application is limited by a low Li+ diffusion coefficient (10−12–10−13 cm2 s−1) and poor electrical conductivity. To address these challenges, we have developed an innovative yolk-shell V2O5 architecture using a facile synthesis method involving spray pyrolysis followed by thermal treatment. This yolk-shell V2O5 is coated with a poly(ethylene oxide) (PEO) electrolyte to enhance ion transport contact areas and flexibility. The yolk-shell V2O5@PEO is then integrated with a PEO-based polymer electrolyte in a thin film configuration, paired with zig-zag truncated lithium metal anodes for stretchable lithium metal batteries. The integrated film demonstrates superior electrochemical performance due to highly reversible Li+ insertion/extraction and enhanced Li ion diffusion. The unique design of the stretchable Li-yolk-shell V2O5@PEO battery achieves an excellent specific discharge capacity of 261 mAh g−1, compared to 158 mAh g−1 for pure V2O5 at 0.1C. Additionally, the stretchable Li-yolk-shell V2O5@PEO cell exhibits a discharge capacity of 250 mAh g−1 under zero-strain conditions and 233.7 mAh g−1 under 40 % strain at 0.1C and 40 °C. Characterization through X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirms the nano-sized morphology and high crystallinity of the yolk-shell V2O5. X-ray photoelectron spectroscopy (XPS) analysis reveals the transformation of yolk-shell V2O5@PEO into α-V2O5, ε-Li0.5V2O5, δ-LiV2O5, and γ-Li2V2O5 phases during lithium-ion (de)intercalation. This cutting-edge battery design paves the way for the development of high-performance, stretchable, and flexible batteries, ideal for next-generation portable electronic devices. [Display omitted] •Yolk–shell V2O5@PEO powders were successfully prepared for stretchable lithium metal battery.•Yolk-shell V2O5@PEO is integrated with a PEO-based polymer electrolyte in a thin film.•The stretchable lithium metal battery delivers a capacity of 250 mAh g−1 at 0.1C.•The yolk-shell V2O5@PEO integrated film exhibits high electrochemical performance.