Nucleation-Controlled Synthesis and a Unified Descriptor for Rational Interlayer Design of Vanadium-Oxide Cathodes toward High-Performance Zinc-Ion Batteries.

Abstract

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage, yet their development is constrained by the cathode that suffers from energy-intensive synthesis and poorly understood interlayer-ion chemistry. NH₄V₄O₁₀ (NVO) exemplifies these challenges, as hydrothermal preparation hampers scalability and the stabilizing role of intercalated cations remains ambiguous. Here, by revisiting vanadium-oxide synthesis history and nucleation mechanisms, we establish a nucleation-kinetics-driven, pH-controlled supersaturation strategy that enables mild and scalable NVO synthesis. Moreover, this method provides a reliable platform for systematic interlayer chemistry studies. A comparative investigation of cations-intercalated NVO establishes a unified descriptor, weighted ionic potential, δ = Z/r × EN( (valence/radius) × electronegativity), which quantifies the effective polarizing power and metal-oxygen interaction of interlayer cations. Experimental correlation and theory analysis identify the most effective stabilizing species. To further enhance capacity without sacrificing stability, redox-active molecules are co-intercalated into Al³⁺-stabilized NVO. The resulting cathode exhibits accelerated Zn²⁺ transport, modified redox chemistry, and additional charge storage, delivering high specific capacities of ∼420 mAh g^-1 at 0.1 A g^-1, 248 mAh g^-1 at 5 A g^-1, and ∼83% retention over 8000 cycles. Overall, this work integrates scalable synthesis and descriptor-guided interlayer design to advance high-performance vanadium-oxide cathodes toward practical AZIBs.