Triphasic interface engineering of V2O3/Co/VC0.7 coupled networks for high-rate and long-cycling aqueous zinc-ion batteries.

Abstract

Aqueous zinc-ion batteries (AZIBs) have great application potential due to their high safety and low cost. However, the vanadium-based cathode faces problems such as poor conductivity, unstable structure, and vanadium dissolution. In this paper, a ternary coupled network cathode composed of V2O3/Co/VC0.7 (VZC-700) was constructed through a ZIF-67 derivative strategy. The metal Co enhances conductivity and catalyzes the formation of the carbon framework, while VC0.7 acts as a physical barrier to effectively inhibit vanadium dissolution. V2O3 transforms into a highly active layered zinc storage phase in situ during activation. On this basis, 5 M glucose was introduced as a green interface stabilizer. The optimized system achieved a first-cycle discharge specific capacity of 85.3 mAh g-1 at 10 A g-1, and still maintained 111.65 mAh g-1 after 1000 cycles. Notably, even when subjected to a high current density of 20 A g-1, as the current gradually decreases back to 5 A g-1, the specific discharge capacity can recover to more than 99.2% of its initial value, highlighting its excellent rate reversibility. This work offers an effective pathway towards the design of advanced cathode materials for high-performance aqueous zinc-ion batteries.