Facile synthesis of TiO2/Mn3O4 hierarchical structures for fiber-shaped flexible asymmetric supercapacitors with ultrahigh stability and tailorable performance

A rapidly developing area of the electronics industry is devoted to manufacturing miniaturized electronic devices with flexible, portable and wearable characteristics, which require high-performance energy storage apparatus with tailorable and restructurable properties as well as excellent bending resistance. Herein, we successfully fabricated a flexible fiber-shaped electrode based on a hierarchical TiO2/Mn3O4 structure via a facile synthesis method. The formation of TiO2 arrays effectively boosts the electrodeposition of Mn3O4 and also improves the capacitive properties. The capacitance of the fiber-shaped electrodes reached the high value of 22.69 mF cm(-1)/72.26 F cm(-3) under a scan rate of 10 mV s(-1), with excellent cycling stability (over 92% retention after 20 000 cycles). Furthermore, a fiber-shaped flexible asymmetric supercapacitor was assembled based on the resulting hierarchical TiO2/Mn3O4 structure and MoS2 nanoflakes (negative electrode), and it showed tailorable properties and ultrahigh bending stability without any apparent degradation. Our work provides an effective strategy to fabricate ultrahigh bending resistance fiber electrodes through a facile and low-cost method, illustrating the great potential for the application of portable and wearable energy storage devices.