MnO2/煤基碳纳米纤维的制备及其在柔性超级电容器中的应用

采用静电纺丝技术制备了柔性煤基碳纳米纤维(CBCNFs)。利用低温等离子体技术对CBCNFs进行改性,并将改性后的CBCNFs作为还原剂与KMn O4反应,以实现Mn O2的原位还原负载制备CBCNFs/Mn O2复合材料。通过X射线衍射、扫描电镜和透射电镜等手段对复合材料的结构与形貌进行了表征;另外,研究了其作为柔性超级电容器电极材料的性能。结果表明,KMn O4∶CBCNFs=2∶1(质量比)条件下制备的复合材料(CBCNFs/Mn O2-2)具有良好的电化学性能。在0.1A·g-1电流密度下,CBCNFs/Mn O2-2的比电容高达118F·g-1,为CBCNFs比电容(26F·g-1)的4.5倍,在1A·g-1电流密度下,循环1000次后比容量保持率为97%,表现出良好的循环稳定性。

Preparation of MnO2/CBCNFs composite materials and its electrochemical performance for flexible supercapacitor

The flexible coal based carbon nanofibers (CBCNFs) were prepared by electrospinning technique. The CBCNFs were well modified by using the low temperature plasma surface modification technology. The CBCNFs/MnO2 composite was prepared by in situ reduction reaction using plasma-modified CBCNFs as reductant to react with potassium permanganate (KMnO4). The morphology and structure of the obtained CBCNFs/MnO2 composites were investigated by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, TEM). The results showed that the nanoflakes of MnO2 well coated on the CBCNFs. Furthermore, the electrochemical performance of the electrode material as flexible supercapacitor was investigated. It was found that the CBCNFs/MnO2-2 electrodes showed a specific capacitance of 118 F g-1 at a current density of 0.1 A g-1, which is 4.5 times higher than that of the CBCNFs (26 F g-1). The capacitance retention ratio of the CBCNFs/MnO2-2 remained 97% after 1000 cycles at a current density of 1 A g-1.