Mordant inspired wet-spinning of graphene fibers for high performance flexible supercapacitors
Mordant inspired wet-spinning of graphene fibers for high performance flexible supercapacitors
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DOI：
10.1039/c8ta12337c
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发表时间：
2019-03-28
影响因子：
11.9
通讯作者：
Gao, Wei
中科院分区：
文献类型：
--
作者：
He, Nanfei;Shan, Weitao;Gao, Wei
最近，衍生自氧化石墨烯（GO）分散体的湿纺的石墨烯纤维已经成为用于纤维形超级电容器（FSC）和/或电池的可行电极，其中期望大的表面积、高的电导率和足够的机械强度/韧性。然而，对于迄今为止报道的大多数纤维电极，必须在能量存储容量和机械/电气性能之间进行折衷，而具有高容量和足够韧性的石墨烯纤维尚未被开发用于直接机器编织或针织。受传统纺织品染色工业中用于天然染料的明矾媒染剂的启发，我们的研究小组合成了湿纺GO纤维，并将其与不同的多价阳离子（例如Ca 2+，Fe 3+和Al 3+）进行凝固，其中观察到了显着不同的纤维形态和性能。第一性原理密度泛函理论已被进一步解释所观察到的差异，通过阳离子-GO结合能计算。当组装成固态FSC时，基于Al 3+的还原GO（rGO）纤维提供优异的抗弯曲稳定性，并且在40 mV s（-1）下的比电容为148.5 mF cm（-2），分别是基于其他三种凝固体系（Fe 3+、Ca 2+和乙酸）的rGO纤维的比电容的1.4、4.8和6.8倍。Al 3+基FSC的体积能量密度高达13.26 mW·h·cm ~（-3），同时保持了250.87 mW·cm ~（-3）的高功率密度。
Recently, graphene fibers derived from wet-spinning of graphene oxide (GO) dispersions have emerged as viable electrodes for fiber-shaped supercapacitors (FSCs) and/or batteries, wherein large surface area, high electrical conductivity, and sufficient mechanical strength/toughness are desired. However, for most fiber electrodes reported so far, compromises have to be made between energy-storage capacity and mechanical/electrical performance, whereas a graphene fiber with high capacity and sufficient toughness for direct machine weaving or knitting is yet to be developed. Inspired by the alum mordant used for natural dyes in the traditional textile dyeing industry, our research group has synthesized wet-spun GO fibers and coagulated them with different multivalent cations (e.g. Ca2+, Fe3+, and Al3+), where dramatically different fiber morphologies and properties have been observed. The first principles density functional theory has been further employed to explain the observed disparities via cation-GO binding energy calculation. When assembled into solid-state FSCs, Al3+-based reduced GO (rGO) fibers offer excellent stability against bending, and a specific capacitance of 148.5 mF cm(-2) at 40 mV s(-1), 1.4, 4.8, and 6.8 times higher than that of the rGO fibers based on other three coagulation systems (Fe3+, Ca2+ and acetic acid), respectively. The volumetric energy density of the Al3+-based FSC is up to 13.26 mW h cm(-3), while a high power density of 250.87 mW cm(-3) is maintained.