Regulating the Hidden Solvation‐Ion‐Exchange in Concentrated Electrolytes for Stable and Safe Lithium Metal Batteries. Issue 25 (2nd June 2020)

• Record Type: Journal Article
• Authors: Amine, Rachid; Liu, Jianzhao; Acznik, Ilona; Sheng, Tian; Lota, Katarzyna; Sun, Hui; Sun, Cheng‐Jun; Fic, Krzysztof; Zuo, Xiaobing; Ren, Yang; EI‐Hady, Deia Abd; Alshitari, Wael; Al‐Bogami, Abdullah S.; Chen, Zonghai; Amine, Khalil; Xu, Gui‐Liang
• Is Part Of: Advanced energy materials. Volume 10:Issue 25(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-06-02
• Subjects: concentrated electrolytes -- lithium metal batteries -- siloxanes -- solvation‐ion‐exchange -- sulfur; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202000901
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Lithium–sulfur batteries are attractive for automobile and grid applications due to their high theoretical energy density and the abundance of sulfur. Despite the significant progress in cathode development, lithium metal degradation and the polysulfide shuttle remain two critical challenges in the practical application of Li–S batteries. Development of advanced electrolytes has become a promising strategy to simultaneously suppress lithium dendrite formation and prevent polysulfide dissolution. Here, a new class of concentrated siloxane‐based electrolytes, demonstrating significantly improved performance over the widely investigated ether‐based electrolytes are reported in terms of stabilizing the sulfur cathode and Li metal anode as well as minimizing flammability. Through a combination of experimental and computational investigation, it is found that siloxane solvents can effectively regulate a hidden solvation‐ion‐exchange process in the concentrated electrolytes that results from the interactions between cations/anions (e.g., Li +, TFSI −, and S 2− ) and solvents. As a result, it could invoke a quasi‐solid‐solid lithiation and enable reversible Li plating/stripping and robust solid‐electrolyte interphase chemistries. The solvation‐ion‐exchange process in the concentrated electrolytes is a key factor in understanding and designing electrolytes for other high‐energy lithium metal batteries. Abstract : Parasitic reactions between polysulfides, electrolytes, and Li metal need to be mitigated in Li–S batteries. Here, a new class of concentrated siloxane‐based electrolytes is reported, which can regulate the hidden solvation‐ion‐exchange process and thus simultaneously suppress Li dendrite and polysulfides dissolution, demonstrating significant improvement over the widely reported ether‐based electrolytes in terms of cycle stability, coulombic efficiency, and flammability.