Creasing Highly Porous V₂O₅ Scaffolds for High Energy Density Aluminum-Ion Batteries

The growing demand for rechargeable metal-ion batteries with high energy densities requires innovative electrode design strategies. We address this challenge by exploring light and highly porous, binder-free scaffolds comprised of vanadium pentoxide (V2O5) nanofibers as the cathode material for aluminum-ion batteries (AIBs). The V2O5 scaffolds are fabricated by unidirectional ice-templating that gives the structure its anisotropic property of ordered channels for facilitated ion diffusion. The unique structure of the scaffolds provides high mechanical stability, despite their porosity of 99.9%. Creasing of such scaffolds results in a corrugated lamella arrangement and formation of contact points, yielding a significant enhancement of the electrical conductivity. The synergy of the electrical conductivity and the high specific surface area renders the creased scaffolds as a promising cathode material for AIBs, demonstrated by the reversible intercalation of Al3+. Particularly, at high current densities of 500 mA g–1, specific storage capacities up to 105 mAh g–1 are achieved, providing an energy density of 52 Wh kg–1, which outperforms other V2O5- and carbon-based cathodes. Our results offer guidelines for the structuring of advanced electrode materials for high energy density metal-ion batteries, which boosts areal and gravimetric capacities.