Synergistic Redox Modulation in Hollow Mesoporous Frameworks for High-Performance Symmetric and Asymmetric Supercapacitors

Transition metal vanadates (TMVs) are promising candidates for high-performance supercapacitor electrode materials owing to their rich redox chemistry, synergistic interactions and cost-effectiveness. However, their practical application is still limited by poor intrinsic conductivity, sluggish ion transport, restricted accessibility of redox-active sites, and structural instability, which collectively hinder the simultaneous attainment of high energy density and long-cycle-life.Herein, an approach based on the “mesopore-confined synergistic redox modulation” is proposed to concurrently enhance conductivity, increase the density of accessible redox-active sites, and improve structural stability. This is achieved by synthesizing a cerium-incorporated cobalt vanadate (CVO@3Ce) hollow mesoporous structure via a glycerol-assisted soft template method. The resulting material, when employed in both aqueous symmetric supercapacitors (ASS) and asymmetric supercapacitors (AAS), delivers energy densities of 34.72 and 47.77 Wh kg–1, respectively, with capacitance retention of 75.08% (ASS) and 81.20% (AAS) after 10,000 cycles. This work demonstrates an effective strategy for designing high-energy, long-cycle-life electrodematerials for high-performance supercapacitors.