Prussian Blue@C Composite as an Ultrahigh‐Rate and Long‐Life Sodium‐Ion Battery Cathode. (20th May 2016)

• Record Type: Journal Article
• Authors: Jiang, Yinzhu; Yu, Shenglan; Wang, Baoqi; Li, Yong; Sun, Wenping; Lu, Yunhao; Yan, Mi; Song, Bin; Dou, Shixue
• Is Part Of: Advanced functional materials. Volume 26:Number 29(2016)
• Page Start: 5315
• Page End: 5321
• Publication Date: 2016-05-20
• Subjects: sodium‐ion batteries -- cathode -- carbon -- prussian blue -- composite materials; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201600747
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract : Rechargeable sodium ion batteries (SIBs) are surfacing as promising candidates for applications in large‐scale energy‐storage systems. Prussian blue (PB) and its analogues (PBAs) have been considered as potential cathodes because of their rigid open framework and low‐cost synthesis. Nevertheless, PBAs suffer from inferior rate capability and poor cycling stability resulting from the low electronic conductivity and deficiencies in the PBAs framework. Herein, to understand the vacancy‐impacted sodium storage and Na‐insertion reaction kinetics, we report on an in‐situ synthesized PB@C composite as a high‐performance SIB cathode. Perfectly shaped, nanosized PB cubes were grown directly on carbon chains, assuring fast charge transfer and Na‐ion diffusion. The existence of [Fe(CN)6 ] vacancies in the PB crystal is found to greatly degrade the electrochemical activity of the Fe LS (C) redox couple via first‐principles computation. Superior reaction kinetics are demonstrated for the redox reactions of the Fe HS (N) couple, which rely on the partial insertion of Na ions to enhance the electron conduction. The synergistic effects of the structure and morphology results in the PB@C composite achieving an unprecedented rate capability and outstanding cycling stability (77.5 mAh g −1 at 90 C, 90 mAh g− 1 after 2000 cycles at 20 C with 90% capacity retention). Abstract : To understand vacancy‐impacted sodium storage and Na‐inserted reaction kinetics, a PB@C composite is demonstrated as a sodium ion battery cathode with an ultrahigh rate and long life. The electrochemical activity and reaction kinetics are closely associated with the [Fe(CN)6 ] vacancies and Na intercalation. Such electrochemical relationship gives new insight into designing high‐performance PB‐based cathodes for rechargeable sodium ion batteries.