Effective incorporation of nitrogen and boron in worm-like carbon foam for confining polysulfides. (December 2019)

• Record Type: Journal Article
• Authors: Xu, Jijian; Li, Zhi; Sun, Peng; Liu, Kun; Liu, Zhanqiang; Hong, Zhanglian; Huang, Fuqiang
• Is Part Of: Carbon. Volume 155(2019)
• Page Start: 379
• Page End: 385
• Publication Date: 2019-12
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2019.08.088
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Flexible electrode materials toward rational design and low-cost fabrication are crucial to energy storage applications. Herein, a three-dimensional (3D) flexible N, B co-doped carbon foam (NBC) is developed, enabling efficient polysulfides confinement. N, B co-doping is employed to overcome the conflict between heteroatom doping and stability of carbon lattice, because one B and one N atoms are isoelectronic to two C atoms. B atoms in such a carbon structure possess positive charge which can interact with S n 2− anions in forming S n 2− … B while N atoms form negative charge which construct a strong-couple interaction with Li + cations in forming N⋯Li2 S n . Moreover, the fabrication approach of corresponding flexible 3D carbon form is extremely facile derived from the self-gelation of agar. When used as the host for S, such a 3D carbon foam provides a continuous conductive structure, accommodates the volume change during long-term cycling and serves as a barrier for polysulfides dissolution. As a result, cycling performance of high sulfur loading (5.8 mg cm −2 ) NBC-S electrode exhibits high areal capacity of 5.6 mA h cm −2 (965 mA h g −1 ) with a very small capacity decay of 0.03% per cycle over 350 cycles at 0.2 C. Graphical abstract: Image 1