沸石咪唑酯骨架衍生碳基复合材料的结构及其超级电容器的性能

Structure of Zeolitic Imidazolate Frameworks Derived Carbon-based Composite and Properties of Its Supercapacitor

通过原位生长方法将沸石咪唑酯骨架颗粒镶嵌在聚吡咯管(质量分别为30,60,120 mg)上,再经一步热处理法碳化和活化后制备得到碳基复合材料,研究了该材料的微观结构和电化学性能,以及其组装的双电层超级电容器的电化学性能。结果表明:复合材料由碳纳米管和管外表面的氮掺杂碳颗粒组成,具有较大的比表面积和高的氮元素含量,微孔孔径集中分布在1 nm左右;复合材料具有良好的充放电可逆性和倍率性能,并表现出典型的双电层电容行为。在相同条件下,聚吡咯管质量为60 mg时复合材料的电化学性能最优,其在1 A·g^(-1)电流密度下的比电容最大,为283 F·g^(-1);由该复合材料组装的对称型超级电容器具有优异的循环稳定性,在2 A·g^(-1)充放电电流密度下循环3 000次后,其比电容保持率为91.5%,能量密度高达9.15 Wh·kg^(-1)。

Zeolite imidazolate framework particles were embedded into polypyrrole tubes(mass of 30,60,120 mg) by in-situ growth method, and then carbon-based composites were prepared by carbonization and activation with one-step heat treatment. The microstructure and electrochemical properties of the materials and the electrochemical performance of the assembled double-layer supercapacitor were studied. The results show that the composites were composed of carbon nanotubes and nitrogen-doped carbon particles on the outer surface of the tubes;the composites had large specific surface area and high nitrogen content, and the micropore diameter was concentrated at about 1 nm. The composites had good charge-discharge reversibility and rate performance, and exhibited typical double-layer capacitance behavior. The electrochemical performance of the composites with 60 mg polypyrrole tubes was the best under the same condition, and the composite had the largest specific capacitance of 283 F·g^(-1) at current density of 1 A·g^(-1). The symmetrical supercapacitor assembled by the composite had excellent cycle stability with specific capacitance retention rate of 91.5% after 3 000 cycles at charge-discharge current density of 2 A·g^(-1) and with energy density of 9.15 Wh·kg^(-1).