Boosting Zn²⁺ Intercalation in High-Performance Aqueous Zinc-Ion Batteries with Coupling-Induced Biphase Interface

Effectively addressing the trade-off between fast charging kinetics and long cycle life of aqueous zinc ion batteries (AZIBs) has proven challenging due to JahnTeller distortion and high lattice strain induced by inserted Zn²⁺ ions in cathode structures. Herein, a hybrid cathode of NiCo₂O₄-MnO₂ with abundant electrochemical phase interfaces and interface coupling induced defects is developed via a simple electrochemical oxidation strategy to boost rich redox reactions. The formation of Ni─O─Mn and Co─O─Mn bonds promoted the electron transfer between the biphase interface, adjusted the electron density of the material body, effectively alleviated the electrostatic effect between Zn²⁺ embedding and the main frame, and further maintained the stability of the structure and alleviated the dissolution of manganese. The resulting NiCo₂O₄-MnO₂ cathode exhibited a high reversible specific capacity of 343.5 mA h g^-1 at a current density of 100 mA g^-1 and retained 95.5 % of its initial capacity after 1000 cycles at a current density of 1 A g^-1. This discovery enriches insights into performance mechanisms at interfaces and paves the way for designing advanced energy storage materials.