Vacancy-Driven Mesoporous CeO2-Based Protective Coatings with Tailored Structure-Morphology for Stable Zn Metal Anodes

Aqueous zinc ion batteries (ZIBs) are poised to become a scalable and safe energy storage technology based on their high theoretical capacity, small redox potential of Zn²⁺/Zn, and nonflammable electrolytes. However, its practical application is hampered by such problems as dendrite formation and zinc corrosion. This study presents a novel approach to enhancing ZIB performance by employing a mesoporous hollow cerium oxide (CeO₂) coating on the zinc anode. The high surface area and porous framework of the CeO₂ significantly mitigate dendrite growth, improve electrolyte wettability, and provide structural stability. Electrochemical analyses reveal improved zinc plating/stripping reversibility behavior, reduced charge transfer resistance, and enhanced long-term cyclic stability, with over 1400 h of stable operation at 2 mA cm^‒2 and a depth of discharge of 1 mAh cm^‒2 (DOD: 1.7%). Moreover, a high coulombic efficiency of 97.49% for 400 cycles is achieved with a reduced nucleation overpotential of 107.7 mV. Density functional theory calculations further demonstrate the electronic and structural benefits of the vacancy-driven CeO₂ coating, including reduced nucleation overpotential and improved charge distribution. These findings demonstrate the possibility of using CeO₂-coated zinc anodes in ZIB technology to develop safer and more efficient energy storage systems.