Enhancing Intrinsic Reactivity and Durability of Zn‐Doped Cobalt Carbonate Hydroxide via d‐ d Interaction Modulation for Alkaline Zinc Batteries

Abstract The development of high‐performance cathodes for aqueous alkaline Zn//Co batteries (AAZBs) is hindered by the limited intrinsic reactivity and poor cycling stability of cobalt‐based materials. Herein, a Zn‐doping strategy is proposed to tailor the d – d interaction in cobalt carbonate hydroxide (CCH), effectively modulating the spin state of Co species from high spin (HS) to intermediate spin (IS). This electronic structure engineering optimizes the redox activity of Co sites while suppressing parasitic oxygen evolution reactions (OER). The resulting Zn‐doped CCH (ZCCH) cathode delivers an ultrahigh areal capacity of 1.52 mAh cm −2 at 2 mA cm −2 , outperforming pristine CCH (0.97 mAh cm −2 ) and state‐of‐the‐art cathodes. Remarkably, ZCCH exhibits superior durability with 88.4% capacity retention after 4500 cycles at −20 °C and enhanced energy efficiency (83.7% vs 77.3% for CCH). When integrated into a practical pouch cell, the ZCCH//ZnO configuration achieves a cumulative capacity of 17 393 mAh over 366 h. Density functional theory (DFT) calculations reveal that Zn doping elevates the Co d‐band center, weakening the adsorption of OER intermediate and stabilizing the redox process. This work establishes a universal paradigm for designing durable and high‐efficiency cathodes via orbital‐level modulation, advancing the practical deployment of alkaline Zn‐based batteries.