Dual-Ion "Rocking-Chair" Chemistry: A Vanadium Dioxide Anode with Pre-Intercalated Zinc Ions and Protons for Zinc Metal-Free Zinc-Ion Batteries

Abstract

Abstract: Rechargeable zinc-ion batteries (ZIBs) have gained significant attention due to their high theoretical capacity, low cost, and inherent safety. However, ZIBs with zinc metal anodes suffer from critical issues such as gas evolution, zinc dendrite formation, and low utilization of anode materials, which hinder their large-scale applications. To address these challenges, we report a vanadium dioxide anode with pre-intercalated zinc ions and protons (VO2(B)) as a promising alternative to zinc metal. The VO2(B) anode exhibits a zinc and proton co-insertion mechanism, enabling a high. capacity of 360 mAh g-1, excellent rate capability, and superior cycling stability over 10,000 cycles. We further assembled a "rocking-chair" full-battery by pairing VO2(B) anode with α-MnO2 cathode, which operates based on the reversible migration of both protons and zinc ions between the anode and cathode. The zinc metal-free full battery demonstrates a high specific energy density while completely avoiding the fatal issues associated with zinc metal anodes. This work provides new insights for the development of zinc metal-free ZIBs for energy storage applications.

Keywords: Zinc metal-free anode, Vanadium dioxide, Battery chemistry, Zinc-ion battery