A novel mixed ether-based electrolyte for lithium–sulfur batteries with Li anode protection by dual salts. Issue 15 (6th July 2022)

• Record Type: Journal Article
• Authors: Kong, Xirui; Kong, Yichen; Liao, Xiaobin; Liu, Sheng; Zhao, Yan
• Is Part Of: Sustainable energy & fuels. Volume 6:Issue 15(2022)
• Page Start: 3658
• Page End: 3668
• Publication Date: 2022-07-06
• Subjects: Renewable energy sources -- Periodicals; Fuel cells -- Periodicals; Electric batteries -- Periodicals; Electrochemistry -- Periodicals; 660.297
• DOI: 10.1039/d2se00647b
• Languages: English
• ISSNs: 2398-4902

Abstract

Abstract : The medium concentration electrolyte with lower-solvating-power ether solvents is more suitable for lithium–sulfur batteries. Abstract : Lithium–sulfur batteries (LSB) are regarded as one of the next-generation energy storage systems with a high energy density. However, the shuttle effect of lithium polysulfides (LiPSs) and irreversible consumption of the Li anode prevent the practical application of Li–S batteries. In this work, a mixed tetrahydrofuran (THF) and dipropyl ether (DPE) based electrolyte has been optimized for Li–S batteries. Due to the common-ion effect, the LiPS solubility has been significantly inhibited when the sulfur cathode is operating in a concentrated electrolyte containing an optimized solvent system with weak dissolving power. And no self-discharge effect occurred in the cells with these electrolytes during a 10 day storage. Besides, the coulombic efficiency (CE) for Li deposition/stripping has been improved by optimizing the ratio of dual lithium salts. Impressively, Li‖Cu half-cells can run stably for more than 500 cycles with a high CE (>99.3%). For these reasons, a Li–SeSPAN cell with a L1L2TE-1382 electrolyte demonstrates an excellent capacity retention (>94% after 500 cycles) with an ultrathin (50 μm) Li metal anode. With a good compatibility of the optimized electrolyte for both the Li metal anode and sulfur cathode, this work provides a new design strategy for the electrolyte for lithium–sulfur batteries.