A flexible mesofiber-based fast current collector

Light-weight flexible materials are needed to enable batteries that are safer, flexible, and smaller. However, the metal current collectors that are employed in current batteries are rigid, heavy, and slow in transporting electrons and ions. In this work, we demonstrate a flexible mesofiber that features an ordered mesoporous carbon scaffold threading a carbon nanotube. A facile hydrothermal synthesis method was developed to directly grow the highly ordered mesoporous carbon layer onto the surface of carbon nanotubes. The synergistic effect of these two materials in the designed meso-architecture yields excellent electrical conductivity, fast ion diffusion, and good mass loading of high-capacity active materials. We show that MnO 2 -loaded-mesofiber electrodes can achieve a capacitance of 160 F g −1 at a current density of 0.2 A g −1 and a capacitance retention of 58% after being cycled between 0.2 and 100 A g −1 . The enhanced performance persists even at a scan rate as high as 2000 mV s −1 . This fast current collector may find applications in flexible, wearable batteries and electronics.