Homogeneous intercalated graphene/manganic oxide hybrid fiber electrode assembly by non-liquid-crystal spinning for wearable energy storage

Reduced graphene oxide (rGO)-based fibers with high electrochemical performance have recently showed great potential in the field of flexible energy storage devices. However, they still suffer from low capacitance due to the severe stacking of graphene sheets. Hybrids with nanofillers are an efficient way to improve the electrochemical performance of rGO fibers. Nevertheless, controlling the distribution of nanoparticles in the matrix is still an enormous challenge due to the strong attraction among these nanoparticles which results into agglomeration. Here, we continually prepared rGO hybrid fibers via non-liquid-crystal spinning, accompanied by chemical reduction. Manganic oxide (MnOX) nanoparticles remained well-dispersed in GO dispersion during the continuous spinning of rGO/MnOX hybrid fibers. Results showed that rGO/MnOX-20 hybrid fibers possessed the best capacitance of 123.3 F g−1 (87.6 F cm−3) and 97.1 F g−1 (68.9 F cm−3) at the current density of 0.2 A g−1, and 0.5 A g−1 respectively. Furthermore, a fiber-shaped all-solid-state supercapacitor assembly from the optimized hybrid fibers demonstrated an energy density of 2.67 mWh cm−3 (3.76 mWh g−1) at the power density of 24.76 mWh cm−3 (34.89 mWh g−1). These fiber-based devices show great potential for application in the fields of wearable electronics and energy storage devices.