A Co-intercalation enhanced V-based cathode material for fast charge aqueous zinc ion batteries

Abstract

H₂O–H–Na co-intercalation is beneficial to enhance the structure of open framework V-based materials, leading to the improvement of Zn²⁺ transport kinetics and solid-state solubility in V-based electrodes. Zn|Zn(CF₃SO₃)₂|HNaV₆O₁₆·4H₂O exhibits an excellent specific capacity of 432.4 mA h g⁻¹ and a long-term cyclic performance up to 800 cycles at 2.0 A g⁻¹ with a reversible phase transformation. For the fast charge capability, a high specific capacity of 411.2 mA h g⁻¹ is achieved with a coulomb efficiency of 100%. The co-intercalation structure can provide a new strategy for the design of fast charge cathode materials in aqueous zinc ion batteries (AZIBs).