Different assembled nano-MnO₂ fiber supercapacitors applied for smart wearable clothing

With rapid development in the smart wearable field, new-style flexible energy storage devices are necessary to satisfy the demands of flexible smart clothing. Thereinto, fiber supercapacitors present promising application prospects. This work puts forward a facile and reliable strategy to fabricate coaxial fiber electrodes via binary wet spinning, and further assembles them into parallel or twisted nano-MnO 2 fiber supercapacitors. In the obtained fiber electrode, a carboxymethylcellulose layer onto nano-MnO 2 not only allows the requisite ion exchange between the electrochemical active materials and gel electrolyte, but also plays the role of separator to protect the two fiber electrodes effectively from contacting a short circuit, greatly ensuring the electrochemical stability of the nano-MnO 2 fiber supercapacitors. The parallel nano-MnO 2 fiber supercapacitor reaches a maximum C L of 19.7 μF/cm, E L of 0.0027 μWh/cm and P L of 1.49 μW/cm; the twisted MnO 2 fiber supercapacitor achieves maximum C L , E L and P L of 49 μF/cm, 0.0053 μWh/cm and 1.0 μW/cm, respectively. Besides, the outstanding softness and tensile properties of the obtained nano-MnO 2 fiber supercapacitors also guarantee stable electrochemical performance under bending, knotting or other large-distortion situations, which is beneficial to develop a new generation of metal oxide fiber supercapacitors for smart wearable clothing.