多级结构水滑石薄膜电容器正负极的构筑及性能研究

发布时间：2018-07-03 15:56

  本文选题：水滑石复合物 + 碳纳米管　； 参考：《北京化工大学》2015年硕士论文

【摘要】：赝电容的性能依赖于多级结构的构筑和复合。通过在泡沫镍基体的表面原位生长NiAl水滑石薄膜,之后直接采用气相沉积法(CVD)在水滑石薄膜表面原位生长多壁碳纳米管薄膜,最后在碳纳米管薄膜的表面再次原位生长NiAl水滑石薄膜,获得了三维镍铝水滑石/多壁碳纳米管/泡沫镍(NiAl-LDH/MWCNT/NF)多级结构薄膜。第一步,采用溶胶凝胶法,泡沫镍提供镍源,铝溶胶提供铝源,使用氨水调节pH值,在泡沫镍的表面原位生长镍铝水滑石薄膜(NiAl-LDH/NF),第二步,采用上一步制备的薄膜做基体和催化剂,乙炔气体提供碳源,通过化学气相沉积法(CVD)在泡沫镍表面原位生长多壁碳纳米管薄膜(MWCNT/NF)。第三步,采用尿素水热分解法,硝酸镍,硝酸铝的混合溶液提供镍源和铝源,加入适量的十二烷基硫酸钠(SDS),在MWCNT/NF的表面原位生长镍铝水滑石。最终获得了多级结构的薄膜。采用XRD, SEM, ICP, RAMAN等测试结果表明,在MWCNT/NF表面获得了均匀致密的镍铝水滑石薄膜。活性物质(NiAl-LDH)负载量为5.8 mg cm-2。电化学性能测试结果表明该电极的面积比电容值约为7.5 F cm-2,换算为质量比电容为1293 F g-1,在30 mA cm-1电流密度下,充放电1000个循环后,其循环稳定性达83%。与第一步制备NiAl-LDH/NF薄膜电极(面积比电容5.6 F cm-2,质量比电容938Fg-1和69%的循环稳定性)相比,电化学性能明显提高。说明这种将碳纳米管生长在导电基体,再原位生长镍铝水滑石薄膜的多级结构构筑方式,提高了电极的比表面积和电导率,进而提高了其赝电容性能。采用共沉淀法,以FeS04和Fe2(S04)3提供铁源,氢氧化钠作为沉淀剂,添加多壁碳纳米管,制备了FeⅡFeⅢ-LDH/MWCNT复合电极,XRD、SEM等测试结果表明FeⅡFeⅢ-LDH成功复合到MWCNT的表面。电化学性能测试表明,在电流密度1 A g-1时,FeⅡFeⅢ-LDH和FeⅡFeⅢ-LDH/MWCNT的质量比电容分别为461 F g-1和980 F g-1,说明将FeⅡFeⅢ-LDH直接复合在MWCNT的表面,增加了FeⅡFeⅢ-LDH导电性,暴露出了更多的电化学活性位点,提高了FeⅡFeⅢ-LDH的赝电容性能。该方法构筑的多级结构NiAl-LDH/MWCNT/NF和FeⅡFeⅢ-LDH/MWCNT电极材料在电化学储能方面有着潜在的应用价值。
[Abstract]:The performance of pseudo-capacitance depends on the construction and composition of multilevel structure. Nial hydrotalcite films were grown on the surface of nickel foams in situ, and then multiwalled carbon nanotube films were directly grown on the surface of hydrotalcite films by vapor deposition (CVD). Finally, nial hydrotalcite thin films were grown in situ on the surface of carbon nanotube films, and three dimensional Ni-Al hydrotalcite / multi-wall carbon nanotubes / foamed nickel (NiAl-LDH / MWCNT / NF) multilevel structure films were obtained. In the first step, Ni-Al hydrotalcite film (NiAl-LDH / NF) was grown in situ on the surface of nickel foam by sol-gel method, nickel source was provided by foamed nickel, aluminum sol provided aluminum source, pH value was adjusted by ammonia water, and NiAl-LDH / NF film was grown on the surface of foamed nickel in situ. Multiwalled carbon nanotubes (MWCNT / NF) films were grown on the surface of nickel foam by chemical vapor deposition (CVD), using the films prepared by the previous step as the substrate and catalyst, and the carbon source was provided by acetylene gas. In the third step, nickel-aluminum hydrotalcite was grown in situ on the surface of MWCNT / NF by urea hydrothermal decomposition, nickel and aluminum sources were provided by mixed solution of nickel nitrate and aluminum nitrate, and appropriate amount of sodium dodecyl sulfate (SDS) was added. Finally, multilevel structure films were obtained. The results of XRD, SEM, ICP and Raman measurements show that uniform and dense Ni-Al hydrotalcite films were obtained on the surface of MWCNT / NF. The loading amount of the active substance (NiAl-LDH) was 5.8 mg cm-2. The electrochemical performance test results show that the area specific capacitance of the electrode is about 7.5F cm-2, which is converted to the mass specific capacitance of 1293 F g -1. At 30 Ma cm-1 current density, after charging and discharging 1000 cycles, the cyclic stability of the electrode reaches 83%. Compared with the first step, the electrochemical performance of NiAl-LDH / NF thin film electrode (area specific capacitance 5.6 F cm-2, mass specific capacitance 938 Fg-1 and 69% cycle stability) was significantly improved. The results show that the multistage structure of nickel aluminum hydrotalcite films grown on conductive substrates and in situ by carbon nanotubes can improve the specific surface area and conductivity of the electrodes and further improve their pseudo-capacitance properties. Fe 鈪，

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