Designing layered V2O3@C with stable oxygen defects via UV-curing technology for high-performance Zn-ion hybrid supercapacitors

Zn-ion hybrid supercapacitors (ZHSCs) have attracted enormous interest recently due to the perfect integration of superb energy density and power density. However, they are still bottlenecked by the low specific capacities of inadequate carbon cathodes. Herein, a layered carbon cathode embedded with oxygen-deficient V2O3 (OdV2O3@C) is prepared via a UV-curving technology, which endows the super uniform anchoring of Od-V2O3 into the carbon matrix. The stabilities of the crystal phase and oxygen vacancies of Od-V2O3 are significantly improved due to the Od-V2O3 being tightly immobilized in the carbon. Density functional theory (DFT) calculations reveal that introduced oxygen defects enhance the electronic conductivity and reduce the adsorption energy of Zn2+, thus increasing the storage performance. The Od-V2O3@C features both reversible faradic reactions and electric double-layer capacitance, leading to a large capacity of 200.3 mA h g-1 even at 20 A g-1 with a long cycle life (remains 80.6% after 12,000 cycles). Impressively, the ZHSC delivers an exceptional high energy density of 195.0 Wh kg- 1 (363.1 W kg- 1) and a power density of 13959.4 W kg- 1 (162.9 Wh kg- 1). This work provides a novel strategy to construct advanced carbon-coated ultra-small metal-oxides compounds, which can be applied to other energy storage fields.