Controlled Air‐Etching Synthesis of Porous‐Carbon Nanotube Aerogels with Ultrafast Charging at 1000 A g−1 |
| |
Authors: | Wenqi Zhao Hui Zhang Jie Liu Lu Xu Huaisheng Wu Mingchu Zou Qian Wang Xiaodong He Yibin Li Anyuan Cao |
| |
Affiliation: | 1. Centre for Composite Materials and Structures, Harbin Institute of Technology, Harbin, P. R. China;2. Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, P. R. China |
| |
Abstract: | Supercapacitors are energy storage systems capable of fast charging and discharging, thus generating superior power density. Porous carbon with high surface area and tunable pore size represents a promising candidate to construct ultrafast supercapacitors; so far, most porous carbon–based electrodes can only be charged to a moderate current density (100–200 A g?1), also with significant capacitance loss at increasing rate. Here, it is shown that a 3D aerogel consisting of interconnected 1D porous‐carbon nanotubes (PCNs) can serve as a freestanding supercapacitor electrode with excellent rate performance. As a result, the PCN aerogel electrodes achieve 1) ultrafast charging at current densities up to 1000 A g?1 (corresponding to a charge period of 16 ms), which is the highest value among other porous carbon–based supercapacitors, 2) superior cycling stability at high charging rates (88% capacitance retention after 105 cycles at 1000 A g?1). Mechanism study reveals favorable kinetics including a centralized pore size distribution at 0.8 nm which is a dominant factor to allow high‐rate charging, a low and linear IR drop, and a metallic feature of 1D PCNs by theoretical calculation. The results indicate that 1D PCNs with controlled porous structures have potential applications in ultrafast energy conversion and storage. |
| |
Keywords: | air etching HNO3 treatment porous‐carbon nanotube supercapacitor electrode ultrafast charging |
|
|