Vanadium bronzes have been well-demonstrated as promising cathode materials for aqueous zinc-ion batteries. However, conventional single-ion pre-intercalated V_(4)O_(9)nearly reached its energy/power ceiling due to the nature of micro/electronic structures and unfavourable phase transition during Zn;storage processes. Here, a simple and universal in-situ anodic oxidation method of quasi-layered Ca V_(4)O_(9)in a tailored electrolyte was developed to introduce dual ions(Ca^(2+) and Zn^(2+)) into bilayer δ-V_(4)O_(9)frameworks forming crystallographic ultra-thin vanadium bronzes,Ca^(2+)Zn^(2+)V_(4)O_(9)·n H;O. The materials deliver transcendental maximum energy and power densities of 366 W h kg-1(478 m A h g^(-1)@ 0.2 A g^(-1)) and 6627 W kg-1(245 m A h g^(-1)@10 A g^(-1)), respectively, and the long cycling stability with a high specific capacity up to 205 m A h g^(-1)after 3000 cycles at10 A g^(-1). The synergistic contributions of dual ions and Ca^(2+) electrolyte additives on battery performances were systematically investigated by multiple in-/ex-situ characterisations to reveal reversible structural/chemical evolutions and enhanced electrochemical kinetics, highlighting the significance of electrolyte-governed conversion reaction process. Through the computational approach, reinforced “pillar” effects,charge screening effects and regulated electronic structures derived from pre-intercalated dual ions were elucidated for contributing to boosted charge storage properties.
