Regulation of Oxygen Vacancies in High Entropy Oxides With Multi-Layer Eggshell Architectural Framework for Boosting the Electrochemical Performance of SupercapacitorsOA

High-entropy oxides(HEOs)exhibit great potential as supercapacitor electrode materials,but their practical application is hindered by inherent challenges such as structural instability,insufficient conductivity,and difficulties in regulating oxygen vacancies.To overcome these limitations,we present a dual-defect engineering strategy:tailoring the elemental composition of FeZnCuCoNi-based HEOs to generate abundant oxygen vacancies,and constructing a hierarchical,3D multi-shell porous network structure via an in situ template method.Density functional theory calculations reveal that high-entropy lattice distortion significantly enhances oxygen vacancy concentration while reducing charge transfer barriers.Additionally,the multi-layered eggshell morphology creates interconnected ion diffusion pathways,shortens ion transport distances,and reinforces mechanical integrity.The optimized HEO electrode demonstrates remarkable electrochemical performance,achieving a specific capacitance of 641 F g⁻¹at 1 A g⁻¹,with a 92% electric double-layer contribution at 50 mV s⁻¹.The assembled asymmetric supercapacitor delivers an energy density of 36.7 Wh kg⁻¹ at a power density of 800 W kg⁻¹,while maintaining 92% of its initial capacity after 10000 charge-discharge cycles.Mechanistic studies indicate that oxygen vacancies optimize hydroxyl adsorption kinetics,facilitating surface charge transfer,while the hierarchical porous structure effectively mitigates volumetric expansion stress via a 3D ion transport network.This work offers a strategic framework for designing next-generation high-entropy energy storage materials by providing a synergy between atomic-scale electronic tuning and mesoscale structural design.