Flexible carbon@graphene composite cloth for advanced lithium-sulfur batteries and supercapacitors with enhanced energy storage capability

Flexible carbon@graphene composite cloth was fabricated, and the resultant composite cloth consists of core-shell hollow structured carbon/graphene hybrid fibers with abundant micro- and mesoporosity and hydrophilic functionality. These unique features enable the composite cloth to be a promising material for energy storage application. As an efficient polysulfide adsorbent, the composite can be applied in lithium-sulfur batteries by being sandwiched between the sulfur cathode and polymeric separator. With this novel configuration, a high reversible capacity of ca. 900 mAh g(-1) and excellent cycle-life has been achieved, which is ascribed to the excellent polysulfides adsorption and confinement capability of the special core-shell and hollow structured porous hybrid fibers. Additionally, the composite cloth can be applied in supercapacitors as a flexible binder-free electrode, exhibiting a high specific capacitance of 271 F g(-1) (360 F cm(-3)) at 0.1 A g(-1) in 6 M KOH, as well as excellent rate capability and cycling stability. The assembled symmetric supercapacitor supplies a high energy density of up to 9.4 Wh kg(-1) (12.5 Wh L-1) with a power density of 25.0 W kg(-1) (33.3 W L-1) and remains 5.7 Wh kg(-1) (7.6 Wh L-1) with 4.5 kW kg(-1) (6.0 kW L-1).