Suchergebnisse

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 S2-) 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. ; U.S. Department of Energy (DOE), Vehicle Technologies OfficeUnited States Department of Energy (DOE); DOEUnited States Department of Energy (DOE) [DE-AC02-06CH11357]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [21903001]; Natural Science Foundation of Anhui ProvinceNatural Science Foundation of Anhui Province [1908085QB58]; University of Jeddah, Saudi Arabia [UJ-07-18-ICP]; European Commission under the European Union's Horizon 2020 Research and Innovation Programme [GA 759603]; European Research Council under the European Union's Horizon 2020 Research and Innovation ProgrammeEuropean Research Council (ERC) [GA 759603]; Polish Ministry of Science and EducationMinistry of Science and Higher Education, Poland [3787/E-138/S/2017] ; R.A. and J.L. contributed equally to this work. Research at the Argonne National Laboratory was funded by the U.S. Department of Energy (DOE), Vehicle Technologies Office. Support from Tien Duong of the U.S. DOE's Office of Vehicle Technologies Program is gratefully acknowledged. Use of the Advanced Photon Source (APS), an Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory, was supported by DOE under Contract No. DE-AC02-06CH11357. The authors also acknowledge the support from National Natural Science Foundation of China (21903001) and Natural Science Foundation of Anhui Province (1908085QB58) for the AIMD simulation. Saudi contribution was funded by the University of Jeddah, Saudi Arabia, under grant no. (UJ-07-18-ICP). K.F. acknowledges the European Commission and the European Research Council for financial support within the Starting Grant project (GA 759603) under the European Union's Horizon 2020 Research and Innovation Programme. I.A. and K.L. acknowledge the financial support from the Polish Ministry of Science and Education -Grant No 3787/E-138/S/2017.