细菌纤维素/碳纳米管/MnO2复合超级电容器电极

Electrochemical properties of bacterial cellulose/carbon nanotubes/ MnO2 composite membrane electrode

摘要:

基于细菌纤维素(BC)的三维多孔及柔性支架结构和碳纳米管(MWCNT)的优良导电性,构筑起BC/MWCNT自支撑导电基底。其中,二者通过氢键紧密结合,协同赋予复合基底优良的电导率和机械性能。然后将二氧化锰(MnO₂)电沉积在该基底上,构建了一种新型的BC/MWCNT/MnO₂薄膜电极。BC/MWCNT复合膜的多孔结构、电解质吸收特性及蜂窝状活性MnO₂纳米片的桥连结构,赋予其出色的电化学性能(在1 mA cm_-2^{的电流密度下},其面积比电容和质量比电容分别达到1.17 F cm_-2^和200 F g_-1⁾和显著的循环稳定性(在20 mA cm_-2^{的电流密度下进行}10000次循环后,其比电容保留率稳定在96%)。这种无粘合剂的薄膜电极制备简便且成本低廉,在开发柔性储能器件方面具有巨大潜力。关键词：细菌纤维素(BC)；碳纳米管(MWCNT)；二氧化锰(MnO₂)；膜电极；电化学性能中图分类号：TQ630 文献标识码： A 文章编号：1003-5214 (2020) 01-0000-00

Abstract:

Based on the three-dimensional porous and flexible scaffold structure of bacterial cellulose (BC) and the excellent conductivity of carbon nanotubes (MWCNT), a self-supporting conductive substrate was fabricated, and then manganese dioxide (MnO2) was electrodeposited on the substrate to construct a novel BC/MWCNT/MnO2 thin film electrode. Among them, the two components are closely combined through hydrogen bonds, synergistically endowing the composite substrate with excellent electrical conductivity and mechanical properties. The porous structure, electrolyte absorption characteristics and bridging structure of the honeycomb active MnO2 nanosheets of the BC/MWCNT composite membrane endow it with excellent electrochemical performance (at a current density of 1 mA cm-2^, its areal and mass specific capacitances reach 1.17 F cm-2 ^{and 200 F g}-1^, respectively) and remarkable cycling stability (the specific capacitance retention is stable at 96% after 10,000 cycles at a current density of 20 mA cm^-2). Such binder-free thin-film electrodes are facile and inexpensive to prepare, and have great potential in the development of flexible energy storage devices.