Fabrication Of N,S Co-doped Graphene Aerogel And Its Application In Supercapacitor

Supercapacitor(SC)is deemed as a promising energy storage device due to its attracting unique properties.Hydrothermal method is a simple and feasible way to prepare three-dimensional(3D)porous graphene aerogels(GAs)which are often applied as electrode materials for SC.Here we presented a novel fabrication strategy for sandwich-like N,S co-doped graphene aerogels(NSGAs)via one-pot hydrothermal method,which could effectively inhabit the restacking of graphene sheets and improve the doping amount of S atom when N,S co-doped in graphene lattice.The unique advantage of the proposed synthesis strategy is the applications of 2,5-Dimercapto-1,3,4-thiadiazole(DMTD),connected by N and S atoms via novalent interactions,as pillared agents,the source of N,S atoms and S doping promoter.The planar DMTD molecules had shown strong supramolecular π-π and H-bonding interactions with graphene oxide(GO),which effectively avoid the restacking of graphene sheets and enhance the doping efficiency and amount of S atoms.The synthesized NSGA samples(DMTD:0.75 mg/mL)exhibit the atomic content of S(2.39 at.%),high surface area(366.0 m2/g),and relatively good gravimetric specific capacitance(321 F/g at a current density of 1 A/g)at 180℃.More significantly,symmetric supercapacitor assembled based on the NSGA displays a maximum energy density of 10.52 Wh/kg at a power density of 500 W/kg,which reaches the top level for graphene-based SC systems.The relatively high tandem and parallel device performance(the supercapacitor exhibits remarkable current response,even at 2000 mV/s)suggests the potential of NSGA in practical applications.The proposed simple fabrication strategy and attracting good performance of NSGA material shed light on the potential practical applications of graphene-based material as SCs,and the observed structure-function relations also provides physical-chemical insight into the function principle of heteroatom doped graphene in SCs.