Electron Delocalization‐Driven Dual‐Electron Redox Chemistry in NiCo‐LDH for High‐Capacity Aqueous Ni–Zn Batteries
Ding Zhang, Meiling Zhang, Jiale Dang, Yingjie Hua, Huajie Feng, Bing‐Xin Lei, Ying Xu, Xihong Lu
Abstract
Abstract As a cathode material for alkaline Zn batteries, Ni(OH) 2 shows limited capacity and efficiency due to its single‐electron transfer per redox site and the side reaction of oxygen evolution during charge–discharge processes. Here, we report an electrode material featuring an ultrathin NiCo‐LDH layer coated on hollow carbon shell (NC@HCS). Incorporating Co into the lattice affects the conformation and band structure of adjacent Ni sites via CoO 6 octahedral distortion, leading to the formation of charge‐transfer orbitals through electron delocalization near the Fermi level, which significantly reduces the oxidation potential of Ni(OH) 2 . The ultrathin NC@HCS architecture weakens interlayer hydrogen bonding during the dehydrogenation process (charging), lowering the dehydrogenation energy barrier. This structural feature facilitates the formation of high‐valence states and enables efficient two‐electron transfer. As an efficient cathode material for Zn batteries, the ultrathin NC@HCS cathode exhibits a remarkable capacity of 528 mAh g −1 at 5 A g −1 (0.63 mAh cm −2 ). This strategy provides a pathway for developing high‐performance and durable cathode materials for Ni–Zn batteries.