To improve electrode properties of electrical double-layer capacitor(EDLC), carbon material composites prepared using activated carbon fiber and graphene.
First, Boron atoms are doped into graphene for high electrical conductivity and increasing ener...
To improve electrode properties of electrical double-layer capacitor(EDLC), carbon material composites prepared using activated carbon fiber and graphene.
First, Boron atoms are doped into graphene for high electrical conductivity and increasing energy density. Forming boron doped graphene (BRGO) via a catalyst free thermal annealing approach in the presence of boron trioxide. Then, BRGO was dissolved in N,N-dimethylformamide and that was dispersed by ultrasonication. Dispersed BRGO and polyacrylonitrile(PAN) were mixed before electrospinning. BRGO/carbon fiber composites (BRGO/CF) were synthesized by using electrospinning followed by heat treatment. Lastly, in order to improve the redox reaction of electrode, BRGO/CF coated with electrically conducting polymer such as polypyrrole using chemical polymerization.
Successful boron atoms doping into graphene has been identified by XPS. And, the microstructure and morphology of the obtained BRGO/CF was characterized using TEM, SEM. XRD measurements were also carried out to determine the structure of composites. Electrical conductivity of BRGO/CF enhanced compared to initial carbon fiber about 100 times from 0.0006S/cm to 0.096S/cm. Then, BRGO/CF with varying BRGO contents of 2.5% was the best conductivity with 0.196S/cm. Capacity of composites were evaluated in initial charge-discharge curve using cyclic voltammetry equipment. As a result, capacity of BRGO/CF was increased than carbon fiber from 1.3 C/cm² to 3.25 C/cm². Then, BRGO/CF with varying BRGO contents of 2.5% was the best capacity with 2.43C/cm². Capacity of BRGO/CF coated with polypyrrole indicated with BRGO-2.5/CF likewise. In report, coating of polypyrrole not affected for capacity betterment.