Hierarchical MnO2 nanowire/graphene hybrid fibers with excellent electrochemical performance for flexible solid-state supercapacitors
Hierarchical MnO2 nanowire/graphene hybrid fibers with excellent electrochemical performance for flexible solid-state supercapacitors
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DOI：
10.1016/j.jpowsour.2015.12.063
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发表时间：
2016-02-29
影响因子：
9.2
通讯作者：
Zhu, Meifang
中科院分区：
文献类型：
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作者：
Ma, Wujun;Chen, Shaohua;Zhu, Meifang
朝着轻量化、柔性化甚至可穿戴电子产品的快速发展，需要一种高效的能量存储设备来实现其能量供应管理。基于石墨烯纤维的超级电容器由于其优异的力学性能和电学性能而被认为是有前途的候选材料之一。然而，基于裸石墨烯纤维的超级电容器通常具有低电容，这无疑限制了其潜在的广泛应用。在这项工作中，分层结构的二氧化锰纳米线/石墨烯混合纤维是通过一种简单的、可扩展的湿纺方法制造的。杂化纤维形成介孔结构，比表面积达139.9 m(2) g（-1）。MnO2的质量负荷可高达40 wt%。由于MnO2纳米线与石墨烯之间的协同作用，MnO2的主赝电容和石墨烯的双电层电容同时得到改善。从实际演示的角度出发，采用聚乙烯醇/H3PO4电解质包覆两根MnO2/石墨烯纤维，将其扭转制成高柔性的固态超级电容器。超级电容器具有高容量电容（66.1 F cm(-3)，由两个光纤电极的总体积归一化），优异的循环稳定性（在10,000次循环中保持96%的电容），高能量和功率密度（分别为5.8 mWh cm（-3）和0.51 W cm(-3)）。(C) 2015 Elsevier B.V.版权所有
Towards rapid development of lightweight, flexible, and even wearable electronics, a highly efficient energy-storage device is required for their energy supply management. Graphene fiber-based super capacitor is considered as one of the promising candidates because of the remarkable mechanical and electrical properties of graphene fibers. However, supercapacitors based on bare graphene fibers generally suffer a low capacitance, which certainly restricts their potentially wide applications. In this work, hierarchically structured MnO2 nanowire/graphene hybrid fibers are fabricated through a simple, scalable wet-spinning method. The hybrid fibers form mesoporous structure with large specific surface area of 139.9 m(2) g(-1). The mass loading of MnO2 can be as high as 40 wt%. Due to the synergistic effect between MnO2 nanowires and graphene, the main pseudocapacitance of MnO2 and the electric double layer capacitance of graphene are improved simultaneously. In view of the practical demonstration, a highly flexible solid-state supercapacitor is fabricated by twisting of two MnO2/graphene fibers coated by polyvinyl alcohol/H3PO4 electrolyte. The supercapacitor exhibits a high volumetric capacitance (66.1 F cm(-3), normalized by the total volume of two fiber electrodes), excellent cycling stability (96% capacitance retention over 10,000 cycles), high energy and power density (5.8 mWh cm(-3) and 0.51 W cm(-3), respectively). (C) 2015 Elsevier B.V. All rights reserved.