Defect-engineered CeO2@nitrogen-doped graphene hybrid as an artificial solid-electrolyte interphase for dendrite-free Zn anodes in grid-scale energy storage

A mesoporous cerium oxide@nitrogen-doped graphene (CeO 2 @NG) hybrid is engineered as an artificial solid-electrolyte interphase for dendrite-free zinc (Zn) anodes in aqueous Zn-ion batteries (ZIBs). Integrating hydrothermally derived cerium oxide (CeO 2 ) spheres with defect-engineered nitrogen-doped graphene (NG) yields a three-dimensional conductive scaffold that modulates the interfacial electric field, lowers Zn nucleation overpotential to 30.7 mV, and enables reversible plating/stripping over 2100 h at 2 mA cm −2 . In symmetrical Zn||Zn cells, CeO 2 @NG coating outperforms as compared to bare Zn and CeO 2 , exhibiting minimal voltage hysteresis and suppressed hydrogen evolution. When paired with a vanadium pentoxide (V 2 O 5 ) cathode, the full cell is demonstrated to deliver 335.3 mAh g −1 at 0.1 A g −1 , retain 67.4 % capacity after 800 cycles at 2 A g −1 , and maintain ≈99.5% Coulombic efficiency (CE). Post-mortem characterization confirms that the CeO 2 crystallinity remains intact, the NG conductivity persists, and the structure transforms into a uniform ZnCe-layered double hydroxide layer devoid of dendrites. Theoretical calculations further reveal favorable Zn 2+ adsorption (0.41 eV), reduced diffusion barriers, and enhanced charge transfer kinetics at the CeO 2 @NG interface, underscoring the synergistic roles of Ce 3+ /Ce 4+ redox centers and NG substrate. The CeO 2 @NG strategy thus addresses critical safety and longevity challenges for high-performance and grid-scale aqueous zinc-ion storage.