Zhao Jing, Zhu Jiayao, Li Yutong, Wang Luxiang, Dong Yue, Jiang Zimu, Fan Chengwei, Cao Yali, Sheng Rui, Liu Anjie, Zhang Su, Song Huaihe, Jia Dianzeng, Fan Zhuangjun
Key Laboratory of Energy Materials Chemistry, Ministry of Education; Key Laboratory of Advanced Functional Materials, Autonomous Region; Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, P. R. China.
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):11669-11678. doi: 10.1021/acsami.9b22408. Epub 2020 Feb 26.
High surface area, good conductivity, and high mechanical strength are important for carbon nanofiber fabrics (CNFs) as high-performance supercapacitor electrodes. However, it remains a big challenge because of the trade-off between the strong and continuous conductive network and a well-developed porous structure. Herein, we report a simple strategy to integrate these properties into the electrospun CNFs by adding graphene quantum dots (GQDs). The uniformly embedded GQDs play a crucial bifunctional role in constructing an entire reinforcing phase and conductive network. Compared with the pure CNF, the GQD-reinforced activated CNF exhibits a greatly enlarged surface area from 140 to 2032 m g as well as a significantly improved conductivity and strength of 5.5 and 2.5 times, respectively. The mechanism of the robust reinforcing effect is deeply investigated. As a freestanding supercapacitor electrode, the fabric performs a high capacitance of 335 F g at 1 A g and extremely high capacitance retentions of 77% at 100 A g and 45% at 500 A g. Importantly, the symmetric device can be charged to 80% capacitance within only 2.2 s, showing great potential for high-power startup supplies.
高比表面积、良好的导电性和高机械强度对于作为高性能超级电容器电极的碳纳米纤维织物（CNF）而言至关重要。然而，由于在强连续导电网络和发达的多孔结构之间存在权衡，这仍然是一个巨大的挑战。在此，我们报告了一种通过添加石墨烯量子点（GQD）将这些特性整合到电纺CNF中的简单策略。均匀嵌入的GQD在构建整个增强相和导电网络中发挥着关键的双功能作用。与纯CNF相比，GQD增强的活性CNF的表面积从140大幅增加到2032 m²/g，同时导电性和强度分别显著提高了5.5倍和2.5倍。对这种强大增强效果的机制进行了深入研究。作为独立的超级电容器电极，该织物在1 A/g时表现出335 F/g的高电容，在100 A/g时具有77%的极高电容保持率，在500 A/g时具有45%的电容保持率。重要的是，对称器件仅需2.2秒即可充电至80%的电容，显示出在高功率启动电源方面的巨大潜力。
