Ga3+ modulated V10O24·nH2O cathode with tailored electron structure for durable zinc-ion batteries

The advancement of aqueous zinc-ion batteries (ZIBs) has long been hindered by critical limitations in cathode materials, especially their insufficient electronic conductivity and structural instability. The pursuit of cathode materials that simultaneously exhibit high electrical conductivity with robust structural stability remains a paramount challenge. In this work, Ga 3+ -modified V 10 O 24 ·nH 2 O (GVO-0.5) was synthesized as a cathode material for aqueous zinc-ion batteries. Density Functional Theory (DFT) calculations and experimental characterization demonstrate that the incorporated Ga 3+ forms a stable bonding network with oxygen, thereby optimizing the layered structure and effectively mitigating structural collapse during cycling. Additionally, Ga 3+ modulates the electronic structure, which not only significantly enhances the electrical conductivity but also reduces the Zn 2+ diffusion barrier. GVO-0.5 delivers extraordinary zinc-storage performance and ultra-high cycling stability, achieving a high capacity of 208.92 mAh g −1 at 10 A g −1 and maintaining 97.13% capacity retention after 8000 cycles. In particular, the H + /Zn 2+ co-intercalation mechanism behind the excellent performance was studied in depth using ex-situ testing and kinetic analysis. This work elucidates the fundamental role of Ga 3+ in enhancing cathode performance via DFT simulations, offering a strategic approach for designing high-rate and ultra-stable ZIB cathodes. In this study, Ga 3+ was doped into the layered vanadium oxide Ga x V 10 O 24 ·H 2 O to enhance the ion storage performance of the resulting Ga x V 10 O 24 ·H 2 O material. Owing to its strong electronegativity, Ga 3+ forms a more stable Ga O bonding network with lattice oxygen, significantly enhancing the stability of the layered structure. Meanwhile, the introduction of Ga 3+ effectively induces the generation of oxygen vacancies, optimizes the electronic structure of the material, and thus significantly enhances its intrinsic electrical conductivity. Both experimental results and DFT consistently demonstrate that the introduction of Ga 3+ induces charge redistribution in Ga x V 10 O 24 ·H 2 O, induces p-d hybridization reduces the Zn 2+ diffusion energy barrier, and accelerates the Zn 2+ diffusion kinetics. This straightforward modification strategy provides profound theoretical insights and a unique design approach for the rational design of high-rate and long-cycle-life cathodes for zinc-ion batteries. • Ga 3+ forms stable bonds with oxygen atoms and interacts with interlayer water, significantly enhancing the overall structural stability. • The introduction of Ga 3+ broads the Zn 2+ transport channels, significantly improving its intrinsic conductivity. • DFT reveal that Ga 3+ induces p-d hybridization, reduces the energy barrier for Zn 2+ diffusion, thereby significantly enhancing the electrochemical performance.