Vertical-Aligned and Ordered-Active Architecture of Heterostructured Fibers for High Electrochemical Capacitance

Abstract

Architecture of fibrous building blocks with ordered structure and high electroactivity that enables quick charge kinetic transport/intercalation is necessary for high-energy-density electrochemical supercapacitors. Herein, we report a heterostructured molybdenum disulfide@vertically aligned graphene fiber (MoS₂@VA-GF), wherein well-defined MoS₂ nanosheets are decorated on vertical graphene fibers by C–O–Mo covalent bonds. Benefiting from uniform microfluidic self-assembly and confined reactions, it is realized that the unique characteristics of a vertical-aligned skeleton, large faradic activity, in situ interfacial connectivity and high-exposed surface/porosity remarkably create efficiently directional ionic pathways, interfacial electron mobility and pseudocapacitive accessibility for accelerating charge transport and intercalation/de-intercalation. Resultant MoS₂@VA-GF exhibits large gravimetric capacitance (564 F g⁻¹) and reversible redox transitions in 1 M H₂SO₄ electrolyte. Furthermore, the MoS₂@VA-GF-based solid-state supercapacitors deliver high energy density (45.57 Wh kg⁻¹), good cycling stability (20,000 cycles) and deformable/temperature-tolerant capability. Beyond that, supercapacitors can realize actual applications of powering multicolored optical fiber lamps, wearable watch, electric fans and sunflower toys.

Funding

Innovative Research Group Project of the National Natural Science Foundation of China(22278378); Natural Science Foundation of Jiangsu Province(BK20211592); Science and Technology Program of Zhejiang Province(22212011-Y)