Critical Role of Cation Exchange in Hierarchical Hollow NiCoCe‐Hydroxides Cathode with Multi‐Effects for High‐Performance Alkaline Zn Battery

Abstract Despite their high theoretical capacity, nickel‐based hydroxides also suffer from low electron conductivity, insufficient reactive sites and poor structural stability, causing the unsatisfactory electrochemical performance during energy storage. Herein, hierarchical hollow spheres constructed by nickel/cobalt hydroxides nanosheets with cerium ions decoration (NiCoCe‐OH) are designed through a coupling strategy of self‐templates hydrolysis and cation exchange. The rational construction exposes more reactive sites, creates abundant transfer channels, reinforces electrode‐electrolyte affinity, improves electron conductivity and relieves structural collapse during charge/discharge processes. Impressively, incorporating Ce ions not only promotes redistribution of electron density and regulates coordination environment on metal sites, but optimizes the ions adsorption behavior with the help of strong orbital hybridization, in favor of enhancing reaction kinetics and facilitating phases transformation. Thus, the NiCoCe‐OH‐4 reveals a high specific capacity of 283.4 mAh g −1 at 1 A g −1 and retains 223.1 mAh g −1 after enlarging to 30 A g −1 , along with satisfied cycling durability. Moreover, the aqueous alkaline Zn battery with NiCoCe‐OH‐4 cathode achieves outstanding energy density of 508.4 Wh kg −1 at a power density of 1.56 kW kg −1 and rate capability. This work is supposed to provide valuable insights for tailoring the structure and composition of nickel‐based hydroxides in alkaline energy systems.