Multifunctional Carbon Felt Electrode with N‐Rich Defects Enables a Long‐Cycle Zinc‐Bromine Flow Battery with Ultrahigh Power Density. (19th May 2021)

• Record Type: Journal Article
• Authors: Lu, Wenjing; Xu, Pengcheng; Shao, Siyuan; Li, Tianyu; Zhang, Huamin; Li, Xianfeng
• Is Part Of: Advanced functional materials. Volume 31:Number 30(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-19
• Subjects: carbon felt‐based electrodes -- high power density -- long cycle life -- N‐rich defects -- zinc‐bromine flow batteries; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202102913
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Zinc‐bromine flow batteries (ZBFBs) are regarded as one of the most promising technologies for energy storage owing to high energy density and low cost. However, the sluggish reaction kinetics of Br2 /Br − couples and zinc dendrite issue lead to low power density and poor cycle stability. Herein, a multifunctional carbon felt‐based electrode (NTCF) with N‐rich defects is fabricated for ZBFBs. The defects with abundant N‐containing groups on carbon fibers of NTCF provide high catalytic activity on Br2 /Br − reactions. Simultaneously, the lower energy barrier of N‐rich defects to adsorb zinc atoms, and more deposition sites on NTCF induce more uniform zinc deposition. Thus, a ZBFB using NTCF as both the anode and cathode can stably operate at an unprecedentedly high current density of 180 mA cm −2 with a coulombic efficiency of 97.25%. Moreover, a long cycle life of over 140 cycles with a coulombic efficiency of 98.93% for a Zn symmetric flow battery at 80 mA cm −2 is achieved under a high areal capacity of 40 mAh cm −2 . This current density and areal capacity are by far the highest values ever reported for Zn symmetry flow batteries. Therefore, this work provides an available approach to improve the power density and cycle life of ZBFBs. Abstract : A multifunctional carbon felt‐based electrode (NTCF) having plentiful N‐rich defects with high catalytic activity and ability to regulate zinc deposition is prepared. A zinc‐bromine flow battery (ZBFB) using NTCF electrodes exhibits an unprecedentedly high current density of 180 mA cm −2, and a long cycle life of over 140 cycles for a Zn symmetric flow battery is achieved, enabling high‐power density and long‐cycle life ZBFBs.