Controlled Air‐Etching Synthesis of Porous‐Carbon Nanotube Aerogels with Ultrafast Charging at 1000 A g−1. Issue 40 (10th September 2018)

• Record Type: Journal Article
• Authors: Zhao, Wenqi; Zhang, Hui; Liu, Jie; Xu, Lu; Wu, Huaisheng; Zou, Mingchu; Wang, Qian; He, Xiaodong; Li, Yibin; Cao, Anyuan
• Is Part Of: Small. Volume 14:Issue 40(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-09-10
• Subjects: air etching -- HNO3 treatment -- porous‐carbon nanotube -- supercapacitor electrode -- ultrafast charging; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201802394
• Languages: English
• ISSNs: 1613-6810

Abstract

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 10 5 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. Abstract : 3D aerogels consisting of interconnected 1D porous‐carbon nanotubes are capable of ultrafast charging and exhibit excellent rate performance as freestanding supercapacitor electrodes.