Electrochemical capacitor performance of TiO2 nanostructures and porous MnO2 composite supported on carbon fiber paper.

Titania-based nanostructures and porous MnO 2 layer are deposited onto carbon fiber paper (CFP) conductive support using hydrothermal method. TiO 2 nanoparticles and leaf-like Na 2 Ti 3 O 7 nanosheets are synthesized through the hydrolysis of TiF 4 and post-treatment in NaOH aqueous solution. Electrochemical tests reveal that CFP@TiO 2 @MnO 2 has a better performance with areal specific capacitance of 744 mF cm −2 at 0.25 mA cm −2 , compared with that (600 mF cm −2 ) of CFP@Na 2 Ti 3 O 7 @MnO 2 . The possible mechanism is that TiO 2 has higher surface area and better electronic conductivity than those of Na 2 Ti 3 O 7 . However, the cycling performance of CFP@TiO 2 @MnO 2 is limited with capacitance retention of 17.7% after 1000 cycles while CFP@Na 2 Ti 3 O 7 @MnO 2 keeps this retention up to 59.9%. [ABSTRACT FROM AUTHOR]