In situ visualization by X-Ray computed tomography on sulfur stabilization and lithium polysulfides immobilization in S@HCS/MnO cathode

DOI: 10.1016/j.ensm.2020.06.011

Authors: Ruoyu Xu (University College London (UCL)) , Jingwei Xiang (Huazhong University of Science and Technology) , Junrun Feng (University College London (UCL)) , Xuekun Lu (University College London) , Zhangxiang Hao (University College London (UCL)) , Liqun Kang (University College London (UCL)) , Ming Li (Huazhong University of Science and Technology) , Yunsong Wu (University College London) , Chun Tan (University College London (UCL)) , Yiyun Liu (University College London) , Guanjie He (University College London) , Dan J. L. Brett (University College London) , Paul R. Shearing (University College London) , Lixia Yuan (Huazhong University of Science and Technology) , Yunhui Huang (Huazhong University of Science and Technology) , Feng Ryan Wang (University College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Energy Storage Materials , VOL 31 , PAGES 164 - 171

State: Published (Approved)
Published: October 2020
Diamond Proposal Number(s): 17559 , 19318 , 19246 , 20643

Abstract: The lithium-sulfur (Li-S) batteries have high theoretical energy density, exceeding that of the lithium-ion batteries. However, their practical applications are hindered by the capacity decay due to lithium polysulfide shuttle effect and sulfur volume expansion. Here, we design a S@hollow carbon with porous shell/MnOx (S@HCS/MnOx) cathode to accommodate and immobilize sulfur and polysulfides, and develop a non-destructive technique X-ray computed tomography (X-ray CT) to in situ visualize the volume expansion of Li-S cathode. The designed cathode achieves a specific capacity of ~1100 mAh g-1 at 0.2 ​C with a fade rate of 0.18% per cycle over 300 cycles. The X-ray CT shows that only 16% volume expansion and 70% volume fraction of solid sulfur remaining in the S@HCS/MnOx cathode, superior to the commercial cathode with 40% volume expansion and 5% volume remaining of solid sulfur particles. This is the first reported visualization evidence for the effectiveness of hollow carbon structure in accommodating cathode volume expansion and immobilizing sulfur shuttling. X-ray CT can serve as a powerful in situ tool to trace the active materials and then feedback to the structure design, which helps develop efficient and reliable energy storage systems.

Journal Keywords: Lithium-sulfur battery; X-ray computed tomography; In situ visualization; Designed sulfur cathode; Electrochemical performance

Diamond Keywords: Batteries; Lithium-Sulphur

Subject Areas: Chemistry, Energy, Materials

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E01-JEM ARM 200CF

Added On: 11/08/2020 23:00

Discipline Tags:

Energy Storage Energy Physical Chemistry Energy Materials Chemistry Materials Science

Technical Tags:

Microscopy Electron Microscopy (EM) Transmission Electron Microscopy (TEM)