Graphene/VO2 hybrid material for high performance electrochemical capacitor

High Performance Flexible Supercapacitor Electrodes Composed of Ultralarge Graphene Sheets and Vanadium Dioxide

“…In addition, impedance measurements disclosed that the charge transfer resistance of the VURGO fi lm (0.37 kΩ) was half that of VSRGO (0.73 kΩ), demonstrating the advantage of using ultralarge GO in the VURGO fi lm to reduce the number of intersheet tunneling barriers. It is noteworthy that the hybrid VURGO electrode exhibited remarkable pseudocapacitive performance that was about 3 times higher previously reported values for closely related electrodes including the starfruit-like VO 2 electrode (216 F/g), [ 16 ] starfruitlike VO 2 /graphene electrode (Hummer's method) (200 F/g), [ 17 ] and VO 2 (B)/MWCNT electrode (250 F/g). [ 18 ] The excellent electrochemical properties of the VURGO electrode highlight the potential utility of URGO (as a conductive support) in a hybrid electrode containing VO 2 nanobelts (as an electroactive material) for high performance fl exible hybrid supercapacitor.…”

“…The VURGO hybrid electrode exhibited excellent capacitive performance (769 F/g) that was far superior to that of VSRGO electrode (385 F/g), and was approximately three-fold better than those of previously reported hybrid (200 to 250 F/g). [16][17][18] These results highlight the potential of URGO hybrid electrodes for use in high performance fl exible hybrid supercapacitor.…”

“…The VURGO electrode yielded distorted CV curves and nonlinear GCD curves, indicative of a combination of EDL capacitance and pseudocapacitance, which is a typical feature of hybrid electrodes. [ 17 ] The specifi c capacitance of the VURGO electrode at a current density of 1 A/g (769 F/g) was 3 to 4 times higher than the values obtained previously using a hybrid electrode composed of graphene and starfruit-like VO 2 (200 F/g, 1 A/g) [ 17 ] and a VO 2 (B)/MWCNT composite electrode (250 F/g, 1 A/g) [ 18 ] (Table S1, Supporting Information, listed the specifi c capacitances of the VURGO electrode and the selected VO 2 -based electrodes reported in the literature for comparisons). At the highest discharge current density of 10 A/g, the specifi c capacitance of the VURGO electrode was 95 F/g, which was still signifi cantly higher than those of the VSRGO (53 F/g) and URGO (35 F/g) electrodes (Figure 8 c).…”

“…[ 16 ] Furthermore, blending VO 2 with carbon-based conducting materials did not signifi cantly improve in the electrical conductivity and capacitive performances. A hybrid electrode composed of starfruit-like VO 2 and graphene showed a specifi c capacitance of 200 F/g (current density of 1.0 A/g) and a capacitance retention of 81% after 1000 cycles in 0.5 M K 2 SO 4 solution, [ 17 ] whereas a VO 2 (B)/MWCNT composite electrode exhibited specifi c capacitance of 250 F/g (current density of 1.0 A/g) and a capacitance retention of 71% after 200 cycles in 1 M Na 2 SO 4 solution. [ 18 ] In the present study, we examined the effect of graphene lateral size on the electrochemical performance of a hybrid supercapacitor composed of VO 2 /GO electrodes, in which GO was converted to reduced GO (RGO) by thermal treatment at 250 °C.…”

Graphene/MnO 2 hybrid film with high capacitive performance

“…Research results indicate that the capacitive property of supercapacitors is mainly influenced by the electrode material, electrolyte, and the assembly technology, of which the most important factor is the electrode material [4]. Porous carbon materials, transition metal oxides, and conducting polymers are currently the promising candidates for supercapacitor electrode materials [5].…”