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Download fileDesigning Anion-Derived Solid Electrolyte Interphase in a Siloxane-Based Electrolyte for Lithium-Metal Batteries
journal contribution
posted on 2022-06-07, 15:36 authored by Jianyang Wu, Tianyi Zhou, Bing Zhong, Qian Wang, Wen Liu, Henghui ZhouThe
rational electrolyte design with weak solvation is regarded
as an effective way to regulate the electrolyte/electrode interface
(SEI) that profoundly affects the performance of Li-metal batteries.
Herein, we propose a newly developed siloxane-based weakly solvating
electrolyte (SiBE) with contact ion pairs (CIPs) or aggregates (AGGs)
dominating the solution structure, which enables the dendrite-free
Li deposition and long cycle stability of Li-metal batteries. By altering
the combination of Li salts, the SiBE leads to the formation of an
inorganic anion-derived solid electrolyte interphase, which is highly
stable and Li+-conductive. Based on SiBE, the Li||LiFePO4 (LFP) full cell can stably cycle for 1000 cycles at a 2C
rate with a capacity retention of 76.9%. Even with a limited Li-metal
anode, it can maintain a capacity retention of 80% after 110 cycles
with a high average Coulombic efficiency of 99.8%. This work reveals
that siloxane can be a promising solvent to obtain weakly solvating
electrolytes, which opens a new avenue for SEI composition regulation
of Li-metal batteries.
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contact ion pairslong cycle stabilityli || lifepofree li depositionsei composition regulationrational electrolyte designnewly developed siloxane4 substably cyclelimited lili saltswork revealsweak solvationsolution structurepromising solventprofoundly affectsnew avenuemetal batteriesmetal anodeinorganic anionhighly stablefull cellelectrode interfaceeffective waydesigning anioncapacity retention9 %.8 %.2c rate110 cycles1000 cycles