石墨烯
超级电容器
材料科学
三元运算
纳米技术
功率密度
碳纤维
电化学
石墨烯量子点
复合材料
化学工程
复合数
电容
电极
化学
功率(物理)
物理化学
工程类
物理
量子力学
程序设计语言
计算机科学
作者
Zhen Li,Junjie Wei,Jing Ren,Xiaomin Wu,Liang Wang,Dengyu Pan,Minghong Wu
出处
期刊:Carbon
[Elsevier]
日期:2019-12-01
卷期号:154: 410-419
被引量:57
标识
DOI:10.1016/j.carbon.2019.08.040
摘要
Carbon-based flexible fiber-based supercapacitors (FFSCs) are promising power sources for portable and wearable electronics, but their applications are limited by low energy density due to a lower specific capacitance of common carbon materials. We fabricated ternary all-carbon fiber electrodes (N-GQD/GH/CF) with improved electrochemical performance. In this structure, graphene hydrogel (GH) was grown on carbon fibers (CFs) to form a 3D interconnected porous network (GH/CF), and nitrogen-doped graphene quantum dots (N-GQDs) with high pseudocapacitive activity were electrodeposited into the GH/CF network. The ternary N-GQD/GH/CF hybrid electrode delivered a volumetric capacitance of 93.7 F cm−3 at 20 mA cm−3, which was around 7 times higher than that of the GH/CF, while the capacitance retention after 5000 cycles reached 87.9%, which was only a little lower than that of the GH/CF electrode (90.2%). It indicates the introduction of N-GQDs drastically improves the capacitance of the FFSCs without sacrificing the cycle stability. All-carbon asymmetric FFSCs were assembled using N-GQD/GH/CF as positive electrode and GH/CF as negative electrode. The assembled FFSCs exhibited a high energy density of 3.6 mW h cm−3 at power density of 35.6 mW cm−3 owing to the wider potential window (2 V) and the higher volumetric capacitance as well as excellent flexibility and cycling stability.
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