Fiber electrode by one-pot wet-spinning of graphene and manganese oxide nanowires for wearable lithium-ion batteries

Flexible and mechanically robust fiber electrodes, for their application in wearable lithium-ion batteries, are prepared by one‐pot wet‐spinning of a liquid crystal dispersion of graphene oxide and manganese oxide (MnO2) nanowires. MnO2 nanowires, which are synthesized by a microwave-assisted hydrothermal reaction, are mixed with the graphene oxide aqueous dispersion and then assembled into the continuous fibers by the wet-spinning. The nanowire morphology and the high-aspect ratio of MnO2 contribute to maintain structural integrity of the fiber shape during the wet‐spinning process, as well as to achieve a high loading density of the active materials in the fiber. Furthermore, our simple one‐pot fiber electrode fabrication process allows for a more uniform distribution of the active materials throughout the fiber electrode, and a lower contact resistance between the MnO2 and graphene. The resulting fiber electrode delivers a high reversible capacity, excellent cycling performance, and good rate capability. Flexible and mechanically robust fiber electrodes, for their application in wearable lithium ion batteries, were prepared by one-pot wet-spinning of a liquid crystal dispersion of graphene oxide and MnO2 nanowires. The wire-shape with high aspect ratio of MnO2 allows excellent fiber formability as well as high battery capacity and good cycle performance.