Ksp-Regulated Electrochemically Etching Strategy: BaSO4-Decorated NiCo-LDH with Strong Built-in Electric Field for High-Performance Aqueous Alkaline Zinc Batteries

Although layered double hydroxides (LDHs) provide structural advantages for alkaline zinc-ion battery (AZIB) cathodes via their inherent layered architecture, their intrinsic low electrical conductivity and anisotropic ion transport limits charge transfer kinetics. A Ksp -regulated electrochemical etching strategy is first proposed to solve this challenge by exploiting the dramatic solubility difference between BaSO 4 and Co/NiSO 4 . The thermodynamic selectivity enables the precise construction of BaSO 4 nanodot-anchored NiCo-LDH heterostructures (BS@CN-LDH) within a rapid minute-scale process, achieving atomic-level control over heterointerface architecture. Density functional theory (DFT) calculations coupled with UPS analysis reveal a strong built-in electric field (BEF) at the heterointerface (ΔΦ = 0.70 eV), driving interfacial charge redistribution of 0.013 e from NiCo-LDH to BaSO 4 . The optimized BS@CN-LDH electrode material exhibits a high specific capacity of 450.5 mAh g −1 at a current density of 2 mA cm −2 , maintaining 83.3% excellent cycling stability after 10 000 cycles. Moreover, the as-fabricated BS@CN-LDH//rGO-Zn AAZB cell achieves a record energy density of 747.9 Wh kg −1 at a power density of 0.27 kW kg −1 , surpassing most reported zinc-based energy storage devices. This Ksp -regulated etching strategy provides critical insights into electric field engineering of heterostructured materials to resolve the persistent electron/ions transfer kinetics for dramatically increased energy storage performance.