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 wetspinning. 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.