Preparation of Ti~(3+) self-doped TiO_xNRs/rGO composite: application in supercapacitors

摘要

The characteristics of large surface area, high conductivity and mechanical flexibility performances make graphene suitable for high power next-generation energy storage devices. However, it only stores charge through double-layer capacitors, which limits its energy storage mechanism, resulting in a limited specific capacitance of graphene. In this paper, black Ti~(3+) self-doped nano titanium dioxide rods (TiO_xNRs) were introduced into graphene nanosheets to improve capacitor performance. The results manifest that when 20 wt% TiO_x-NRs were added into the TiO_xNRs/rGO composite, the capacitance performance is the best and the specific capacitance value is 149.5 F g~(-1) at the scanning speed of 40 mV s~(-1). In addition, the specific capacitance of the electrode prepared with the TiO_xNRs/rGO composite still maintains the original 89.57% after 2000 charge-discharge cycles and has a good cycle life at a current density of 1 A g~(-1). In short, the TiO_xNRs/rGO composite is a prospect and potential material for supercapacitor electrodes in the future.