| In energy storage devices, Lithium-ion batteries have the characteristics of high energy density, long service time, and environmental friendly, super capacitor has the characteristics of high power density, rapid charge and discharge, and environment-friendly. Both of them have been widely used in electric vehicles, electronic devices, and power system in recent years. The raw materials of phenolic are cheap and easy to get. The phenolic has been widely used in the construction industry, chemical industry, and military. As one of the hard carbon precursors, the phenolic can be used as the electrode materials of these energy storage devices.Phenolic resin carbon microspheres were prepared by carbonization after the condensation polymerization of resorcinol and formaldehyde in an ethanol aqueous hydrothermal system using hexadecyl trimethyl ammonium bromide as surfactant, and sodium chloride as additive. The influences of the hydrothermal temperature, hydrothermal time, reactants concentration, the amount of catalyst, surfactant and the addition of sodium chloride on the morphology, particle size, and distribution of the microspheres were investigated. Then by different temperature of carbonization and graphitization treatment, carbon microspheres were obtained. The energy storage properties of the carbon microspheres under different temperature treatment were discussed; The spherical and wormlike phenolic resin were carbonized under the same temperature, and the energy storage properties of phenolic resin-based carbons with different morphologies were discussed. (The testing method mainly involved SEM, IR, TG, XRD, BET, Raman and electrochemical workstation.)It was found that the different amount of surfactant can not only control the particle size, but also change the morphology of the particles in a way of "spherical-vermicular-spherical"; Carbon microspheres prepared by a moderate amount of sodium chloride were monodispersed. After the graphitization treatment, surface of the samples were rough but still maintained a certain degree of sphericity. When the concentration of reactants was 2%,the amount of catalyst was 0.5%, the molar ratio of CTAB to resorcinol was 1:3, the molar ratio of sodium chloride to resorcinol was 1:1, the resorcinol-formaldehyde carbon microspheres prepared under 100?,24 h and carbonization were well monodispersed with an average size of 150 nm. The wormlike phenolic resin carbon was prepared under the same condition, but the molar ratio of CTAB to resorcinol was 1:10.The resorcinol-formaldehyde carbon microspheres were carbonized under 600??700??1000? for 2 hours, were graphitized under 2800?, respectively. When used as electrode materials for LIBs, the microspheres prepared under 700? had a better lithium storage capacity and specific surface area of 503.44m2 g-1. The capacity under 50mA g-1 after 50 times was 333.8mAh g-1; the microspheres prepared under 2800? had a decreased specific surface area of 18.79 m2g-1 and capacity of 207.3 mAh g-1,which were mainly mesopores. Both of them had a good cycle and rate performance. When used as electrode materials for EDLC, the carbon microspheres prepared in 700? and 2800?, had a specific capacity of 125.2 F g-1 and 45.2 F g-1 under 100mAg-1 after 100 times, respectively. The capacity retention rate was 90% and 83.8% under 1A g-1, respectively. Both of them had a stable cycle performance and a good rate performance.The spherical and wormlike phenolic resin carbonized under 700? for 2 hours had different morphology. When used as electrode materials for LIBs, the wormlike carbon had a specific surface area of 417.22 m2 g-1 and capacity of 302.1 mAh g-1,which were mainly micropores. The spherical and wormlike carbon still had a specific capacity of 115.2 mAh g-1 and 81.8 mAh g-1 under 1 Ag-1, respectively; When used as electrode materials for EDLC, the wormlike carbon had a specific capacity of 96.9 F g-1 under 100 mA g-1 after 100 times and a capacity retention rate of 90.5% under 1A g-1. And it had a good cycle and rate performance. |
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