| 초록 |
Lithium ion hybrid supercapacitors (Li-HSCs, combined with battery and supercapacitor system) are attractive as next generation energy storage devices because of their fascinating properties such as high energy and power density with stable cyclability. However, one of the problems in HSCs is kinetic imbalance between the rapid non-faradaic reaction on cathodic parts and the slow faradaic reaction on anodic parts. In this work, we applied nanosized niobium pentoxide (Nb2O5)@carbon core-shell to anode of Li-HSC. It could be synthesized through facile one pot method (water-in-oil microemulsion synthesis). It can be controlled the crystal structures (orthorhombic (T) phase and pseudohexagonal (TT) phase) using different pH. The orthorhombic Nb2O5@carbon core-shell electrode shows superior rate capability (~98 mA h g-1 at 5 A g-1) within voltage range from 1.1 to 3.0 V (vs. Li/Li+) and high specific capacity (~180 mA h g-1 at 0.05 A g-1) due to the orthorhombic crystal structure Nb2O5 and nanosized Nb2O5@carbon core-shell structure. |
