Probing the Influence of Steric Hindrance in Nonfluorinated Ether Electrolytes for Lithium Metal Batteries
Year: 2024
Type: article
Abstract: Lithium metal batteries (LMBs), especially “anode-free“ LMBs, promise much higher energy density than current lithium-ion batteries but suffer from poor capacity retention. While novel electrolytes have been designed to extend cycle life in anode free LMBs, most of them contain a high fraction of fluorinated solvents or diluents that may cause environmental concerns. Herein, we report the design and synthesis of a group of nonfluorinated ether solvents (termed xME solvents). By substituting the methyl terminal group of 1,2-dimethoxy ethane (DME) with different alkyl groups, the solvation power of xME solvents was tuned to be weaker, leading to more ion pairing in electrolyte solvation structure. In anode free type Cu/LiFePO4 (Cu/LFP) cells, xME electrolytes in general show better capacity retention than DME-based electrolyte. Some xME electrolytes also show better oxidative stability than DME against aluminum and LiNi0.8Mn0.1Co0.1O2 (NMC811) electrodes. While the general improvement in LMB cycle life and oxidative stability can be attributed to more ion pairing, the local variation within xME electrolytes indicates other factors are also important. Our work proposes a molecular design strategy to fine-tune ion solvation structure of nonfluorinated ether electrolytes for LMBs.
Authors: Peiyuan Ma, Uyen Le, Ke-Hsin Wang, Minh Canh Vu, Priyadarshini Mirmira, Chibueze V. Amanchukwu
Institution: University of Chicago
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $1,855
OpenAlex ID: W4405222806