MoCl5 as a dual-function redox mediator for Li–O2 batteries. Issue 23 (30th May 2019)

• Record Type: Journal Article
• Authors: Wang, Xin-Gai; Zhang, Zihe; Zhang, Qinming; Wang, Chengyi; Zhang, Xin; Xie, Zhaojun; Zhou, Zhen
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 23(2019)
• Page Start: 14239
• Page End: 14243
• Publication Date: 2019-05-30
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta03628h
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Li–O2 batteries suffer from high polarization and low energy density partly due to the film-like insulating product of Li2 O2 . These problems could be alleviated by a dual-function redox mediator, MoCl5, which promotes both discharge and charge processes. Abstract : Li–O2 batteries suffer from high polarization and low energy density partly due to the film-like insulating product of Li2 O2 . These problems can be alleviated by a redox mediator, which usually catalyses either the formation or decomposition of solid Li2 O2 . However, few redox mediators have dual functions and catalyse both discharge and charge processes. Here, we propose MoCl5 as a dual-function redox mediator for Li–O2 batteries. In the discharge process, with MoCl5, Li2 O2 is initially formed in the solution and then deposited on the cathode surface in toroidal morphology, leading to a discharge capacity 2.6 times that without MoCl5 . In the charge process, MoCl5 could help oxidize Li2 O2 effectively, resulting in an extremely high coulombic efficiency and long cycling lifespan. Therefore, both oxygen reduction and evolution reactions could be promoted greatly for Li–O2 batteries with MoCl5 as the dual-function redox mediator.