期刊
JOURNAL OF MATERIALS CHEMISTRY A
卷 1, 期 8, 页码 2886-2895出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c2ta01190e
关键词
-
资金
- National Science Council, Taiwan [NSC 99-2113-M-007-007-MY3]
- Delta Electronics Inc. [99F2289A8I]
The rate capability of carbon-based electrochemical capacitors (ECs) is an important issue for applications and the three-dimensional (3D) hierarchically ordered porous carbon (HOPC) can reduce the diffusion length to improve the rate performance by the unique architectural design. In this study, a modified dual-templating strategy for architectural design of 3D HOPC as a promising electrode material for high-rate EC applications was developed by using polystyrene and Pluronic F127 as macro-and meso-porous templates, respectively. Tetraethyl orthosilicate was also added as the silica precursor, and then the solgel-derived SiO2 was removed by sodium hydroxide to form the second mesopore in HOPC (HOPC-s) for enhancing the accessible surface areas and pore structures. The HOPC-s formed by the templating strategy is composed of highly ordered macropores, macroporous windows, bimodal mesopores, and micropores, resulting in high specific surface area (1112 m(2) g(-1)), high total pore volume (1.18 cm(3) g(-1)) and an easily accessible environment for fast electrolyte ion transport. The specific capacitance of the HOPC-s electrodes can reach 316 F g(-1) at 25 mV s(-1) and maintain excellent capacitive retention at a high scan rate of 1000 mV s(-1) when compared with that of ordered mesoporous carbon (OMC-s). Electrochemical impedance spectroscopy fitting shows that the pore electrolyte resistance of HOPC-s is 3 times lower than that of OMC-s, which is attributed to the hierarchical macroporous structures and short mesoporous channels. In the symmetric capacitor test, the HOPC-s also shows excellent power capability, and the energy density of 4-10 W h kg(-1) can be maintained over the power density range of 1-14 kW kg(-1). In addition, the capacitance of HOPC-s in the polycarbonate-containing ionic liquid shows 80% retention at a scan rate of 500 mV s(-1), indicating that the unique hierarchical structure can provide efficient ion-buffering capacity for high-rate performance. These exceptional electrochemical performances clearly demonstrate that 3D HOPC-s is a superior material to solve the poor ion transport limitation, which can open an avenue to fabricate high-rate ECs with high power and energy densities for energy storage.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据