N‑Doped Hollow Carbon Spheres/Sheets Composite for Electrochemical Capacitor

• Published in: ACS applied materials & interfaces 2018-11, Vol.10 (46), p.40062-40069
• Main Authors: Du, Juan, Liu, Lei, Yu, Yifeng, Hu, Zepeng, Liu, Beibei, Chen, Aibing
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b16921

Functional carbon materials with a combination of 0 dimension and 2 dimension are particularly interesting in the electrochemical field owing to the low density, high surface area, and strong ion-bearing capacity. Especially, hollow mesoporous carbon spheres (0 dimension) and nanosheet (2 dimension) composite hollow porous carbon spheres and nanosheet (HMCS/S) have received much attention as electrochemical capacitor electrode materials. However, it is challenging for effective preparation of this complex composite structure. In this work, a novel and simple procedure to prepare N-doping HMCS/S (N-HMCS/S) is presented. This approach adopted silica spheres as the core and employed [C18Mim]Br and tetraethyl orthosilicate as the structural directing agent for the formation of the flaky/spherical hybrid structure. The unique structure of nanosheets embedded by hollow carbon spheres and N-doping characteristics endow N-HMCS/S with good performance in electrochemical capacitor with high specific capacity (196.5 F g–1) in the three-electrode system and excellent high-rate capability with retention of 61.5% in the two-electrode system.