Evaluation and realization of safer Mg-S battery: The decisive role of the electrolyte. (May 2021)

• Record Type: Journal Article
• Authors: Sheng, Lin; Hao, Zhangxiang; Feng, Junrun; Du, Wenjia; Gong, Manxi; Kang, Liqun; Shearing, Paul R.; Brett, Dan J.L.; Huang, Yunhui; Wang, Feng Ryan
• Is Part Of: Nano energy. Volume 83(2021)
• Publication Date: 2021-05
• Subjects: Magnesium-sulfur battery -- Electrolyte -- Safety -- Vapour pressure -- Thermal runaway; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2021.105832
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The magnesium–sulfur (Mg-S) battery may be a safer alternative for the lithium-sulfur battery because Mg plating usually proceeds without dendrite formation. Here, we correlate the thermal runaway of Mg-S battery with the associated change of electrolyte vapour pressure via battery testing calorimetry. Over-pressure builds up along with the programmed heating of the cell, and as a result, the thermal runaway is triggered at 20–45 K over the electrolyte boiling point, corresponding to 70–150 kPa pressure difference between the cell and the environment. The distinct performance-safety-cost behaviours of three ether type of electrolytes stems from the different CH2 CH2 O chain lengths. Such molecular insight will serve as a fundamental guideline in choosing and designing the desired electrolyte that simultaneously achieves a high explosion limit and good electrochemical performance . Graphical Abstract: The safety of the MgS battery is mainly related to the vapour pressure of the electrolyte. The over-pressure builds up along with heating of the cell and triggers the battery explosion. The subsequent exothermic reaction between MgS and H2 O caused a sudden temperature jump of the battery. A modified DME with higher boiling point will be ideal of the MgS battery. ga1 Highlights: A novel method of safety evaluation is introduced to the Mg-S system. The thermal runaway of Mg-S battery is correlated with the associated change of electrolyte vapour pressure. The distinct performance-safety-cost relationship of ether electrolytes with different degree of polymerisation.