Alcohol molecule coupling: A universal approach to modulating amorphousness in vanadium-based cathodes for high-rate and durable aqueous zinc-ion batteries.

Abstract

Vanadium oxides (VOs) are promising cathode materials for aqueous batteries due to their high theoretical capacity, but they face challenges such as sluggish kinetics and V dissolution. To overcome these issues, we introduce a universal alcohol-based molecule coupling (AMC) method to regulate amorphousness and inhibit V dissolution in VOs (VO₂, V₂O₅, and V₆O₁₃), resulting in high-performance cathodes. The strategy enables alcohol molecules with different chain lengths (ethanol, isopropanol, and isobutanol) to couple with VOs by forming V─OH bonds under Lewis acid-based interactions, inducing controlled amorphization. Among these, isopropanol coupling stands out by enabling the formation of short-range ordered amorphous structure (SOA-VO/Ipr). This structure enhances the reaction kinetics and suppresses V dissolution. As a result, the SOA-VO/Ipr cathode achieves 219.4 mAh g^-1 at 100 A g^-1, retains 92.6% capacity over 10,000 cycles, and delivers 228.8 mAh g^-1 at 9.1 A g^-1 under high loading (21.9 mg cm^-2) over 3500 cycles, demonstrating a promising method for durable zinc-ion batteries.