高级检索

    离子键和氢键连接的PANI/GO的制备及倍率充放电性能

    The preparation and rate charge/discharge performance of PANI/GO connected by ionic and hydrogen bonds

    • 摘要: 为了提高氧化石墨的倍率充放电性能和循环使用性能,通过离子键和氢键将聚苯胺(PANI)接枝到氧化石墨(GO)上,制备了具有优异充放电性能的PANI/GO复合材料。利用X射线衍射、红外光谱、X射线光电子能谱、扫描电子显微镜、能量色散谱和N2吸附/脱附技术分析PANI/GO的物理特性。此外,使用对称电容器探究PANI/GO在KOH电解液中的充放电行为。结果表明:GO具有六方相晶体结构。改性后,GO被PANI颗粒包覆,N原子含量增加5倍。PANI/GO中,PANI和GO通过离子键和氢键连接,并且N原子以─ \textNH_2^+ ─、─NH─和═N─的形式存在于骨架之中。在KOH溶液中,PANI/GO的电化学特性由双电层电容(EDLC)和赝电容同时决定。0.2 A·g−1时,PANI/GO的放电比容量为99.1 F·g−1,是GO的2.1倍。电流密度提高至10 A·g−1时,容量保持率是GO的1.15倍。循环5 000次后,PANI/GO的容量保持率比GO高4.9%。研究结果可为低电导率多孔材料的倍率充放电性能和循环使用性能的提高提供参考。

       

      Abstract: In order to improve the rate charge/discharge performance and cyclic performance of graphite oxide (GO), PANI/GO composites with excellent charge/discharge performance were prepared by grafting polyaniline (PANI) on GO through ionic and hydrogen bonds. The physical characteristics of PANI/GO were analyzed by X-ray diffraction, infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersion spectrum and N2 adsorption/desorption techniques. Besides, the charging/discharge performance of PANI/GO in KOH electrolyte was evaluated using a symmetrical capacitor. The results show that GO has a hexagonal phase crystalline structure. After the modification, GO is coated with PANI particles and the content of N atoms is increased by 5 times. In PANI/GO, PANI and GO are connected by ionic and hydrogen bonds and N exists in the framework as ─ \textNH_2^+ ─, ─NH─ and ═N─ species. In KOH solution, the electrochemical feature of PANI/GO is dominated by both electrical double-layer capacitance (EDLC) and pseudocapacitance. At 0.2 A·g−1, the specific discharge capacity of PANI/GO is 99.1 F·g−1, which is 2.1 times that of GO. When the current density is enhanced to 10 A·g−1, the capacitance retention rate is 1.15 times that of GO. After 5 000 cycles, the capacity retention of PANI/GO is 4.9% higher than that of GO. The research results could provide reference for the improvement of rate charge/discharge properties and cyclic feature of low conductivity porous materials.

       

    /

    返回文章
    返回