Enhanced electrochemical performance of V2O5 prepared by spray drying process as cathode material for Zinc-ion batteries

The search for alternatives to lithium-ion battery (LIB) is mainly driven through some inherent disadvantages like cost or safety and through a predicted energy supply problem that is just around the corner. The rechargeable aqueous zinc-ion battery (ZIB) is seen as a sustainable, safe, low cost and ecological alternative to LIBs. The cathode is currently the limitation component of this energy storage technology, using metallic zinc as anode material and aqueous electrolytes. For instance, only a few cathode materials have been investigated as suitable hosts for Zn2+: manganese-based, vanadium-based, prussian blue analogs, and more recently organic materials.
Our research focus on vanadium pentoxide V2O5 because it can deliver a high theoretical capacity of 589 mAh.g-1 based on the two-electron redox centers. Nevertheless, vanadium-based materials are affected by poor electrical conductivity and volume changes caused by Zn2+ insertion/extraction during cycling. Several strategies can be used to improve electrochemical performance: insertion of metal ions or structural water in cathode material, optimization of architecture design and selection of conductive additives. The main objective of this study was to tailor the morphological design through a one-step spray-drying process at pilot scale. The results demonstrate the strong influence of this process on morphological and electrochemical properties. Spray-dried V2O5 exhibit remarkably high capacities of 495 mAh.g-1 and 240 mAh.g-1 at low (0.1 A g-1) and high current density (5 A g-1) respectively, excellent rate capability and good stability. Therefore, the V2O5 prepared by spray drying offers good qualities to be used as cathode material in ZIBs.