title: Sulphur-impregnated flow cathode to enable high-energy-density lithium flow batteries.
abstract: Redox flow batteries are promising technologies for large-scale electricity storage, but have been suffering from low energy density and low volumetric capacity. Here we report a flow cathode that exploits highly concentrated sulphur-impregnated carbon composite, to achieve a catholyte volumetric capacity 294 Ah l(-1) with long cycle life (>100 cycles), high columbic efficiency (>90%, 100 cycles) and high energy efficiency (>80%, 100 cycles). The demonstrated catholyte volumetric capacity is five times higher than the all-vanadium flow batteries (60 Ah l(-1)) and 3-6 times higher than the demonstrated lithium-polysulphide approaches (50-117 Ah l(-1)). Pseudo-in situ impedance and microscopy characterizations reveal superior electrochemical and morphological reversibility of the sulphur redox reactions. Our approach of exploiting sulphur-impregnated carbon composite in the flow cathode creates effective interfaces between the insulating sulphur and conductive carbon-percolating network and offers a promising direction to develop high-energy-density flow batteries.
authors.affiliation: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
authors.forename: Hongning
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
authors.forename: Qingli
authors.initials: Q
authors.lastname: Zou
authors.affiliation: 1] Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China [2] Shun Hing Institute of Advanced Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
authors.forename: Zhuojian
authors.initials: Z
authors.lastname: Liang
authors.affiliation: Department of Physics, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Physics, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Li
authors.affiliation: 1] Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China [2] Shun Hing Institute of Advanced Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Lu