Template Fabrication of Amorphous Co 2 SiO 4 Nanobelts/Graphene Oxide Composites with Enhanced Electrochemical Performances for Hybrid Supercapacitors

The evolution of newfangled supercapacitor electrode materials has always been a task full of opportunities and challenges. In this work, we synthesized amorphous Co 2 SiO 4 nanobelts by a template method to construct the nanostructure and combined Co 2 SiO 4 nanobelts with graphene oxide (GO) to improve their electrochemical properties. The one-dimensional nanostructure enhanced the transport of electrons along the long axis, which facilitated current collection during cycling, thereby improving the electrochemical performances. At the same time, GO not only formed a good charge-transfer network but also prevented the aggregation and accumulation of Co 2 SiO 4 nanobelts. After optimizing the ratio of Co 2 SiO 4 to GO in the composites, the specific capacitance of Co 2 SiO 4 /GO composites totaled 511 F g –1 (332 C g –1 ) at 0.5 A g –1, and the capacitance retention rate measured 84% after 10 000 cycles. The excellent electrochemical performances of Co 2 SiO 4 /GO composites were further demonstrated by assembling a hybrid supercapacitor (HSC) device. The HSC device was assembled by Co 2 SiO 4 /GO composites and activated carbon (AC) with the maximum specific capacitance of 229 mF cm –2 (183 mC cm –2 ) at 3 mA cm –2, and 49% initial capacitance was maintained after 5000 cycles. Furthermore, the HSC exhibited a maximum energy density of 0.41 W h m –2 and a maximum power density of 96 W m –2, demonstrating the potential of Co 2 SiO 4 nanobelts/GO composites applied to hybrid supercapacitors.