No abstract

No abstract

With high electrical conductivity, good mechanical strength, and excellent multidimensional flexibility, graphene fibers are more suitable for wearable devices than other flexible materials. However, challenges still exist in increasing their energy density. Here, we overcome this disadvantage by developing a fibrous supercapacitor loaded with battery-type active material. First, reduced-graphene-oxide fibers (rGOFs) with high conductivity and high toughness are fabricated from flake graphite by a series of redox reactions and wet-spinning processes. Second, Co-based zeolite imidazole framework (Co-ZIF) nanosheets are grown in situ on the surfaces of the rGOFs at room temperature and then converted into nickel cobalt layered double hydroxide (NCLDH) nanosheets by an etching codeposition method. The as-prepared NCLDH@rGOFs with a unique one-dimensional cladding structure exhibit an outstanding area specific capacitance of 2020 mF cm −2 at 5 mA cm −2 in a three-electrode system. When the NCLDH@ rGOFs and FeOOH@rGOFs are assembled into a flexible asymmetric supercapacitor (NF-FASC), the NF-FASC shows high area specific capacitance (351.6 mF cm −2 ), high energy density (max. 117.3 μWh cm −2 ), excellent power density (max. 34 000 μW cm −2 ), and acceptable cycle stability (75.5% capacitance retention after 5000 cycles).

No abstract

No abstract

No abstract

No abstract

As an Mn+1AXn phase ternary layered carbide, Ti3SiC2 possesses the advantages of both excellent stability and high electrical conductivity, which are considered to be promising electrode materials for supercapacitors. Ti3SiC2/Carbon nanofiber composites with one-dimensional nanostructures were successfully synthesized via electrospinning. Systematic electrochemical tests showed that the Ti3SiC2/Carbon composite possesses a large specific capacitance of 133.1 F/g at the current density of 1 A/g, high rate capability of 113.7% capacitance retention from 1 to 10 A/g, and low resistance of 1.07 Ω. After assembling the asymmetrical supercapacitor, Ti3SiC2/Carbon provides the energy density of 7.02 Wh/kg at the power density of 140 W/kg. In addition, Ti3SiC2/Carbon composite is highly stable, with 74.6% capacity retention after 4000 cycles. Ti3SiC2/Carbon’s superior electrochemical properties are ascribed to the 1D nanowire structure and the high specific surface area. Ti3SiC2/Carbon is a prospective electrode material for future supercapacitors.