Molecular Design of Nitrile Electrolytes Enabling Lithiated Silicon–Sulfur Batteries with Quasi‐Solid‐State Sulfur Reaction
Abstract
Abstract The development of lithium–sulfur (Li−S) batteries is hindered by the polysulfide dissolving, cross‐over and the inherent lithium metal anode instability. We herein instead describe a lithiated silicon−sulfur (LiSi−S) battery enabled by molecular engineering of highly solvating nitrile electrolytes toward weakly solvating to fundamentally decouple the reactions of the two electrodes and eliminate their cross‐talk. Specifically, by controlled fluorination of the ethoxy‐nitrile base solvent, the charge distribution on the solvent is manipulated which suppresses the solvation for polysulfides promoting a quasi‐solid‐state sulfur reaction (QSSSR) mechanism. The promoted anion participation in Li + solvation, along with the fluoroethylene carbonate additive, further stabilizes the interphases at both sulfur cathode and LiSi anode mitigating the mechanical degradations. The QSSSR‐based LiSi−S cell shows a high capacity of 1499.0 mA h g sulfur −1 at 0.1C, and achieves a high capacity retention of 90.2% over 100 cycles at 0.2C with an average Coulombic efficiency of 99.9%. This work highlights the essence of molecular engineering for manipulating the primary reactions and interphasial behaviors at both electrodes toward high performance sulfur batteries.
Article Details
Authors (15)
Mengxue He
Yunpeng Fu
Key Laboratory of Theoretical Organic Chemistry and Functional Molecule, Ministry of Education; School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan 411201 China
Lujun Zhu
Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, School of Materials Science and Engineering
Yue Ma
Chenxi Zheng
International Center for Quantum Materials, School of Physics
Guo Ye
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China
Zhitong Xiao
Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, School of Materials Science and Engineering
Yongfeng Jia
Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, School of Materials Science and Engineering
Xin Gao
Mingchuan Luo
Peking University , , ,
Kenneth Ozoemena
Molecular Sciences Institute School of Chemistry University of the Witwatersrand Private Bag 3, P O Wits Johannesburg 2050 South Africa
Mohammadhosein Safari
Institute for Materials Research (IMO-imomec), Hasselt University, Martelarenlaan 42, Hasselt 3500, Belgium
Shaojun Qiu
Key Laboratory of Theoretical Organic Chemistry and Functional Molecule, Ministry of Education; School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan 411201 China
Jinglun Wang
Quanquan Pang