Designing amorphous additive of cathode for stable zinc-ion storage

Due to the safety, high energy density, and rapid charging feature, aqueous zinc-ion batteries (AZIBs) have attracted great attention in large-scale energy storage systems. Although excellent electrochemical performances have been achieved, the cycling stabilities of AZIBs are still unsatisfactory, especially at low current densities, because the cathode materials are prone to being dissolved into electrolytes. Here we develop a unique zincophilic and hydrophobic amorphous additive of ZnSnO₃ (ZSO), which effectively prevents the irreversible dissolution and deamination of NH₄V₄O₁₀ (NVO) cathode. Benefiting from the ingenious design, NVO@ZSO cathode delivers the best cycling stability at a low current density (0.1 A·g⁻¹), with an ultrahigh capacity retention of 98.8% after 300 cycles. Besides, at a high current density of 5 A·g⁻¹, the NVO@ZSO cathode still possesses excellent cycling performance, and a reversible capacity of 284.6 mAh·g⁻¹ is achieved even after 7000 cycles. The mechanism is clarified with the aid of density function theory calculations and molecular dynamics simulations. These findings provide a new paradigm for designing stable cathodes by introducing amorphous additive, which should promote further application exploration of AZIBs at low current densities.