Unlocking the versatility of V2O5 thin films for next-generation batteries: A binder-free approach

Microbatteries are poised to revolutionize the landscape of portable and flexible electronics and IoT devices. However, their development highly relies on the advancement of cathode materials. In response to this demand, Vanadium pentoxide (V₂O₅) stands out due to its ability to undergo multiple oxidation-reduction states during electrochemical reactions. In this work, we present the binder-free synthesis of V₂O₅ using reactive magnetron sputtering on a battery-grade aluminum foil substrate. Highly ordered brick-like nanostructures are observed during microscopic analysis having high wettability (contact angle ∼ 33°) to the electrolyte, achieving a potentially high-quality cathode-electrolyte interface. As a result, the V₂O₅ thin film cathode shows a capacity of 23 μAh/cm² μm (for standard LiPF₆ electrolyte) and 54 μAh/cm² μm (for quasi–solid electrolyte) at 0.05C rate with excellent rate capability after 100 cycles. The post-electrochemical analysis showed that the electrode is more stable in the solid electrolyte. As a result, it can be interpreted that this binder-free V₂O₅ thin film can be used as a versatile electrode to fabricate efficient lithium-free cathodes for new-generation batteries.