Vertically Aligned Co S Nanotube Arrays onto Graphene Papers as High-Performance Flexible Electrodes for Supercapacitors.

Paper-like electrodes are emerging as a new category of advanced electrodes for flexible supercapacitors (SCs). Graphene, a promising two-dimensional material with high conductivity, can be easily processed into papers. Here, we report a rational design of flexible architecture with Co S nanotube arrays (NAs) grown onto graphene paper (GP) via a facile two-step hydrothermal method. When employed as flexible free-standing electrode for SCs, the proposed architectured Co S /GPs exhibits superior electrochemical performance with ultrahigh capacitance and outstanding rate capability (469 F g at 10 A g ). These results demonstrate that the new nanostructured Co S /GPs can be potentially applied in high performance flexible supercapacitors.