| Fossil energy shortage and increasingly serious environmental pollution have been the puzzle for us. Many countries are trying to find new green energy and advanced energy storage technology to achieve sustainable development. Among which, in China, new energy and new material have been included in Seven Strategic New Industry. Supercapacitors（SCs）, as a new type of energy storage devices between electrolytic capacitors and batteries, have been a research hotspot in the field of new energy. SCs have improved specific capacity and energy density compared with conventional capacitors,and have higher power density, longer cycle life, as well as faster chargedischarge at a large current in comparison with rechargeable batteries, which show broad applying prospects in varies fields of national defense, aerospace, transportation, electronic information technology and instrumentation, et.al.The main contents of this paper are as follows:1. Mo S2 nanosheets（NSs） were successfully synthesized through hydrothermal method by ammonium molybdate [（NH4）6Mo7O24? 4H2O and thiourea（CH4N2S） as raw material. And Mo S2 performances based on distinct hydrothermal conditions were analyzed to discuss the influences of each parameters containing concentration, temperature and time. The optimized synthesis parameters are: concentration of（4）6724? 42（0.01 M） and 42（0.13 M）, temperature of 200 oC, reaction time of 9 h. All the below-mentioned Mo S2 were prepared in this condition without special instructions. Moreover, Mo S2 typical lamellar structures were characterized by SEM, TEM and Raman. As indicated, the thickness of Mo S2 NSs are 10 nm and the layer spacing is 0.65 nm.2. Ti wires was selected as backbones to support Mo S2 NSs active layer. Surface of Ti was modified respectively by introduction of Ti O2 buffer-layer, which is beneficial for subsequent growth of Mo S2 NSs. Compared with the backbone not being modified, Mo S2 NSs were anchored on backbones more uniformly, more completely, and more tightly, which was verified by SEM, BET, XPS, and FTIR spectrometer. After loading of Mo S2 active layer, coaxial cable-like fiber electrodes（Ti/Ti O2/Mo S2） were prepared. The coaxial nature of fiber electrode were identified by the cross-sectional SEM image and EDX elemental mapping. Modification treatment plays a crucial role for the improved specific capacitance, because of uniform Mo S2 NSs anchored more tightly on the surface of backbone, leading to faster electron transfer and lower electron resistance. Specifically, the specific capacitance of Ti/Ti O2/Mo S2 electrode is increased by 88%, comparing with that of Ti/Mo S2.3. As the electrochemical properties of Mo S2 were explored in this paper. The specific capacity of Ti/Ti O2/Mo S2 fiber electrode is 230.2 F g-1（70.6 F cm-3）. Ti/Ti O2/Mo S2 fiber SCs were further assembled by two fiber electrodes with energy density of 2.70 Wh kg-1（4.98 m Wh cm-3）, power density is 530.9 W kg cm-1（977.4 m W cm-3）. In terms of cycle performances, Ti/Ti O2/Mo S2 SCs retain 89% specific capacitance after 2000 cycles.4. A single fiber capacitors with high specific capacity and long cycle life, however, limited output voltage and lower energy provided by a single device may not meet the power and energy requirements for most practical micro-electronics applications. Thus, multiple SCs may have to be connected together in series and/or in parallel configurations to produce reasonable output potential and rational specific capacitance for supplying power. The applicability and stability of the combinations of multiple SCs were exploited. Eight fiber SCs with four in series and four in parallel can be readily used for lighting five light-emitting diodes that operated at a minimum voltage of 2.0 V.5. Remarkably, the flexible and mechanically stable fiber SCs show outstanding processability in well-controlled ways, including being assembled into a stretchable, spring-shaped device and knitted into the fabric to lighten light-emitting diodes. In addition, the fiber SCs have been integrated in a self-powered photodetecting system and power the ultraviolet（UV） photodetector steadily, demonstrating that the fiber SCs can be easily integrated into future sustainable selfsufficient sensor networks. |
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