Alternately-Dipping Method to Prepare Graphene Fiber Electrodes for Ultrahigh-Capacitance Fiber Supercapacitors

Summary Flexible Fiber supercapacitors are a promising candidate for the power supply of wearable electronics. Fabrication of high-performance fibers are in progress yet challenging. The currently available graphene fibers made from wet-spinning or electro-deposition technologies are far away from the practical applications for the unsatisfactory capacitance. Here we report a facile alternately-dipping (AD) method to coat graphene on wire-like substrates. The excellent mechanical properties of the substrate with a greatly diverse choices, can be carried over to the fiber supercapacitors. Under such guideline, the graphene fiber with a titanium core made by our AD method (AD:Ti@RGO) shows an ultra-high specific capacitance of up to 1722.1 mF cm-2, which is ∼1000 times that of wet-spinning and electro-deposition fabricated neat graphene fibers and presents the highest specific capacitance to date. With excellent mechanical properties and the striking electrochemical performances, the AD:Ti@RGO-based supercapacitors light the path to the next generation technologies for wearable devices.