Synthesis Of PANI/RGO Composites And Their Performances In Supercapacitor

As a kind of clean and efficient new energy storage components, supercapacitors have a great application potential and good prospects for development. The properties of the supercapacitors mainly depend on the electrode materials. There are two main kinds of electrode materials for supercapacitors:conductive polymers or metal oxides, corresponding to the energy storage mechanism of pseudocapacitance; and carbon materials, corresponding to the energy storage mechanism of electric double layer. Each of these materials has its merits and defects. Graphene, as a new carbon material, has good stability, high specific surface area and conductivity. But its theoretical capacitance is much lower than the conductive polymer. The theoretical capacitance of conductive polymer is higher, but its conductivity and stability is poor compared with carbon materials. Polyaniline (PANI), relative to other polymer, is materials accessible, cheap and having better stability. In order to get the ideal supercapacitors’ electrode materials, the composite consisting of two or three kinds of the materials above has become the research focus in recent years.Polyaniline and graphene oxide composites (PANI/GO) were prepared by in situ polymerization of aniline monomers in the presence of graphene oxide using chemical oxidation method, then restoring. The end product polyaniline/reducted graphite oxide (PANI/RGO) was prepared by reoxidation. We characterized all samples by SEM, XRD, FT-IR, and tested their electrochemical performance by CV, charging and discharging test. The main results are as following:(1) We compared characteristics and electrochemical performance of PANI, RGO and PANI/RGO composite, and investigated the influence of RGO amount (mass ratio, GO:aniline=1:9,2:8,5:5,8:2,9:1) in the composite on the electrochemical properties of PANI/RGO. Whether to join a small amount of PANI in the RGO, or add a small amount of RGO in PANI, the capacitance of PANI/RGO is greater than the single component PANI or RGO. The capacitance of1165.06F/g was achieved at2mV/s for PANI/RGOio (10%GO).(2) PANI/RGO was restored after the preparation of the PANI/GO composites. In this process, PANI was affected by the reduction reaction, and its electrochemical performance becomes poor. In order to alleviate the influence, we added the reoxidation process, and analyzed the influence of the different dosage of APS (0.00g、0.05g、0.10g、0.15g、0.20g、0.30g) on the electrochemical performance of final products. It was found that too much or too little oxidant can both have a negative effect. When the dosage of APS is0.15g (concentration for3g/L), the PANI/RGO20(GO contents20%) has1018.77F.g-1at2mV/s. By charge and discharge testin at the current density of0.1A/g, PANI/RGO20has58.81%retention of the original capacitance after1000cycles. PANI/RGO has an enhanced electrochemical capacitance and good stability by reoxidation process.