Amorphous-crystalline TiO2/carbon nanofibers composite electrode by one-step electrospinning for symmetric supercapacitor

Abstract

In this study, the effects of titanium oxycompound templates on carbon nanofibers electrodes for supercapacitors application were investigated. Meanwhile, hybrid titanium that contains organic and inorganic titanium templates acted as another modification method. The organic and inorganic titanium oxycompounds referred to titanium (IV) oxy-acetylacetonate and titanium dioxide nanopowder, respectively. The morphology structure, and electrochemical properties of the three composite electrodes (TiO2@CNFs, OCTi@CNFs, HybTi@CNFs) were studied. Hierarchical pore structure with specific surface area of 697m2g−1 was achieved in HybTi@CNFs, in which TiO2 revealed amorphous, tetragonal rutile and anatase structure. The electron charge transfer resistance and specific capacitance of HybTi@CNFs were calculated to be 0.34Ω and 280.3Fg−1 (at current density of 1Ag−1), respectively. After 4000 cycles with galvanostatic charge/discharge, HybTi@CNFs can maintain 97.5% of its initial capacitance under 8Ag−1 in a symmetric two-electrode system (6M KOH). These results indicate that OCTi@CNFs is superior to TiO2@CNFs, and HybTi@CNFs has combined the advantages of OCTi@CNFs and TiO2@CNFs, suggesting HybTi@CNFs is an excellent electrode material for supercapacitors.