Constructing a Hierarchical Ternary Hybrid of PEDOT:PSS/rGO/MoS2 As an Efficient Electrode for a Flexible Fiber-Shaped Supercapacitor

Improving the specific capacitance and energy densityof a fiber-shapedsupercapacitor (FSSC) is critical to its applications as an energystorage device for advanced smart wearable electronics. In this paper,a heterogeneous poly-(3,4-ethylenedioxythiophene):poly-(styrenesulfonate)/reducedgraphene oxide/molybdenum disulfide (PEDOT:PSS/rGO/MoS2) fiber was prepared to achieve a high-performance and durable electrodefor the FSSC. As indicated, pseudocapacitive MoS2 was insitu grown on a highly conductive acid-treated PEDOT:PSS/rGO assemblywith a hierarchical structure. This structural design emphasizes thewrinkled morphology and high conductivity of the PEDOT:PSS/rGO backboneto maximize the MoS2 deposition and accelerate its electrontransfer, which fully utilizes the pseudocapacitance of MoS2 and provides additional capacitance contribution to the obtaineddevice. Attributed to the synergy, the prepared fiber electrode inthe FSSC exhibits high volumetric/areal specific capacitance (325.8F cm(-3)/405.3 mF cm(-2) at 1 A cm(-3) or 1.2 mA cm(-2)) and excellent rateperformance (82%, 1-10 A cm(-3)). The correspondingdevice shows an ultrahigh volumetric energy density of 6.9 mW h cm(-3) at a high power density of 173.6 mW cm(-3) and an areal energy density of 8.5 mu W h cm(-2) at 215.9 mu W cm(-2), together with excellentcycle stability and mechanical flexibility, outperforming most ofthe previously reported FSSCs. Accordingly, the proposed strategyprovides a great opportunity to develop a high-performance FSSC forfurther wearable electronics.