Electrochemical performance of supercapacitor electrodes based on carbon aerogel-reinforced spread tow carbon fiber fabrics
Electrochemical performance of supercapacitor electrodes based on carbon aerogel-reinforced spread tow carbon fiber fabrics
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DOI：
10.1016/j.compscitech.2023.110042
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发表时间：
2023-04
影响因子：
9.1
通讯作者：
H. D. Asfaw;A. Kucernak;E. Greenhalgh;M. Shaffer
中科院分区：
文献类型：
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作者：
H. D. Asfaw;A. Kucernak;E. Greenhalgh;M. Shaffer
采用单片双连续碳气凝胶（CAG）包埋铺束碳纤维织物，制备了基于织物的超级电容器电极。CAG在不到30% wt%的掺入量下，将CAG- cf织物的比表面积增加到230 m2g−1以上，孔隙体积增加到约0.35 cm3−1，比接收的碳纤维高出几个数量级。CAG的存在不仅改善了复合电极的电化学性能，而且由于气凝胶结构的高刚度，可以增强复合电极的力学响应。采用循环伏安法、恒流充放电法和电化学阻抗法对离子液体电解质中由两种cag增强织物组成的对称超级电容器进行了测量。对称超级电容器的比电容在3-5 F g−1范围内，大大高于普通碳纤维的比电容。由于目前还没有最佳的结构电解质，因此将该值归一化为两个电极的总质量，从而为使用这种扩展式CAG-CF系统的未来结构超级电容器设定一个上限。电极总质量归一化后的最大比能量和比功率分别约为2.64 W h kg - 1和0.44 kW kg - 1。这些性能指标表明，薄cag改性展束织物是未来在结构超级电容器中应用的有前途的电极。原则上，在未来的器件中，减少的厚度提供了改进的机械性能和更短的离子扩散距离，以及在给定组件几何形状内制造更高电压的多电池组件的机会。
Fabric-based supercapacitor electrodes were fabricated by embedding spread tow carbon fiber fabrics, in monolithic, bicontinuous carbon aerogels (CAG). The incorporation of CAG, at less than 30 wt%, increased the specific surface area of the CAG-CF fabric to above 230 m2g−1and the pore volume to about 0.35 cm3g−1, orders of magnitude higher than that for the as-received carbon fibres. The presence of the CAG not only improves the electrochemical performance of the composite electrodes but may enhance the mechanical response due to the high stiffness of the aerogel structure. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance measurements were performed on symmetric supercapacitor cells consisting of two CAG-reinforced fabrics in an ionic liquid electrolyte. The specific capacitance of the symmetric supercapacitor was determined to be in the range 3–5 F g−1, considerably higher than that for the plain carbon fibers. Since optimum structural electrolytes are not yet available, this value was normalized to the total mass of both electrodes to place an upper bound on future structural supercapacitors using this spread tow CAG-CF system. The maximum specific energy and specific power, normalized to the total mass of the electrodes, were around 2.64 W h kg−1and 0.44 kW kg−1, respectively. These performance metrics demonstrate that the thin CAG-modified spread tow fabrics are promising electrodes for future use in structural supercapacitors. In principle, in future devices, the reduced ply thickness offers both improved mechanical properties and shorter ion diffusion distance, as well as opportunities to fabricate higher voltage multicell assemblies within a given component geometry.