Study Of PANI/Graphene Composites And N-Doped Graphene

Supercapacitors are kind of high performance and environmental friendly energy store devices. The study of supercapacitors mainly focuses on finding new kinds of electrode materials with higher performance and easier synthesis. Because of its unique structure and excellent electrical properties, graphene has received lots of attention and study as a kind of electrode materials. However, the pure graphene is not suitable for electrode materials, due to the strong interaction force between graphene sheets. The effective ways to solve this problem are forming composites with conducting polymer and synthetic of nitrogen atoms doped graphene. Therefore, in this article, we successfully prepared two kinds of graphene/PANI composites and synthesized N-doped graphene with two different nitrogen sources.(1) The nitrogen doped graphene hydrogels(NGH) were formed through hydrothermal reaction using p-phenylenediamine(PPD) and graphene oxide(GO),which exhibited unique 3D network structure and good electrochemical properties(396.1F/g at 1 A/g and 98.2% capacitance retention after 1000 cycles at 20A/g). Then,PANI was conjugated grafted in NGH that formed N-doped Graphene/PANI hydrogels composites(NGH-PANI). This composite was combined with the synergistic effect between the two components, which further enhanced the performance that the capacitance can reach as high as 685F/g at 2 A/g with 94.4% capacitance retention after 1000 cycles. For that, NGH-PANI composite prepared could be an ideal material for high performance supercapacitor.(2) Graphene/sodium ligninsulfonate hydrogel(GO/SL4) has formed through hydrothermal reaction. Based on this hydrogel, graphene/PANI composite(GO/SL4/PANI0.1) was prepared via in situ polymerization method. XRD, XPS and FT-IR tests showed that the structure of PANI had been improved through sodium ligninsulfonate doping, which make the synergetic effect worked much better. The electrochemical tests illustrated that GO/SL4/PANI0.1 had excellent electrochemical performance. The capacitance can be reach as high as 820F/g at 1A/g and it also can keep 92.49% original capacitance after 1000 cycles.(3) A new N-doped graphene material(GOPD300Ni1.7) was synthesized through simultaneous of nitrogen doping and catalytic carbonization. From the results of TEM,XRD, XPS and Raman tests, we knew that GOPD300Ni1.7 had uniform graphite structure that make it had high volume density. And nitrogen atoms and active oxygengroups in GOPD300Ni1.7 brought high pseudocapacitance. The electrochemical tests showed that the highest gravimetric capacitance of GOPD300Ni1.7 was 443.4F/g and the corresponding volumetric capacitance was 496.6F/cm3 at 0.5A/g. Furthermore, it had no capacitance loss after 1000 cycles.(4) 3D nitrogen-doped graphene(NRG) was prepared through the hydrothermal method with graphene oxide(GO) as raw material and melamine as nitrogenous source and reducing agent. SEM, XPS, Raman and electrochemical tests were used to characterize the morphology, structure, components and supercapacitor performance of as-prepared electrode materials. Results showed that GO can be reduced by melamine efficiently and realized N-doping at the same time. When the mass ratios of GO and melamine was 1:2, the specific capacitance of NRG-2 can achieve 296F/g at the current density of 1A/g and 88.5% capacitance can be remained after 1000 cycles.