Encapsulated Strong‐Coupled Cu 2 S/CoNi‐LDH Heterojunction in Mesoporous Carbon for Advanced Aqueous Alkaline Zinc Batteries

ABSTRACT Although the carbon matrix encapsulated functioned LDH should be an ideal model to solve the kinetics and durability issues of cathode materials of aqueous alkaline zinc batteries (AAZBs), the construction of this target structure remains synthetically challenging, due to the thermal instability of LDH. In this work, we develop a redox‐driven in situ etching strategy to construct a strongly coupled Cu 2 S/CoNi‐LDH heterojunction within an octahedral carbon matrix (Cu 2 S/LDH@C). The strong coupled Cu 2 S/LDH hetero‐interface builds a robust built‐in electric field (BEF) with 2.39 electrons transferred from LDH to Cu 2 S, which is beneficial for enhanced reaction kinetics. Furthermore, the 3D carbon network serves as a confined framework that mitigates the volume effect during the charging/discharging process. The optimized Cu 2 S/LDH@C electrode delivers a high specific capacity of 235.6 mAh g −1 (1696.0 F g −1 ) at 1 A g −1 , and maintains 82.1% of its initial capacity after 10,000 cycles. The assembled Cu 2 S/LDH@C//rGO‐Zn device achieves a remarkable energy density of 254.7 Wh kg −1 at 0.45 kW kg −1 power density. This redox‐driven in situ etching strategy provides a general and reliable pathway for constructing carbon‐encapsulated heterostructures, opening a possible pathway for electrode design that simultaneously addresses kinetics and stability issues in advanced energy storage systems.