A Micelle Electrolyte Enabled by Fluorinated Ether Additives for Polysulfide Suppression and Li Metal Stabilization in Li-S Battery
The Li-S battery is a promising next-generation technology due to its high theoretical energy density (2600 Wh kg−1) and low active material cost. However, poor cycling stability and coulombic efficiency caused by polysulfide dissolution have proven to be major obstacles for a practical Li-S battery implementation. In this work, we develop a novel strategy to suppress polysulfide dissolution using hydrofluoroethers (HFEs) with bi-functional, amphiphlic surfactant-like design: a polar lithiophilic “head” attached to a fluorinated lithiophobic “tail.” A unique solvation mechanism is proposed for these solvents whereby dissociated lithium ions are readily coordinated with lithiophilic “head” to induce self-assembly into micelle-like complex structures. Complex formation is verified experimentally by changing the additive structure and concentration using small angle X-ray scattering (SAXS). These HFE-based electrolytes are found to prevent polysulfide dissolution and to have excellent chemical compatibility with lithium metal: Li||Cu stripping/plating tests reveal high coulombic efficiency (>99.5%), modest polarization, and smooth surface morphology of the uniformly deposited lithium. Li-S cells are demonstrated with 1395 mAh g−1 initial capacity and 71.9% retention over 100 cycles at >99.5% efficiency—evidence that the micelle structure of the amphiphilic additives in HFEs can prohibit polysulfide dissolution while enabling facile Li+ transport and anode passivation.
CITE THIS COLLECTION
REFERENCES
- https://doi.org//10.1149/1.3148721
- https://doi.org//10.1021/acsami.5b01412
- https://doi.org//10.1021/la0477183
- https://doi.org//10.1039/C4EE00372A
- https://doi.org//10.1149/2.111308jes
- https://doi.org//10.1149/2.0051706jes
- https://doi.org//10.1038/s41565-018-0183-2
- https://doi.org//10.1063/1.5110525
- https://doi.org//10.1002/ente.201900183
- https://doi.org//10.1021/acs.iecr.8b01600
- https://doi.org//10.1039/C6TA08572E
- https://doi.org//10.1107/S0021889812004037
- https://doi.org//10.1107/S0021889809002222
- https://doi.org//10.1021/acscentsci.7b00123
SHARE
Usage metrics
Read the peer-reviewed publication
AUTHORS (11)
CATEGORIES
- Geochemistry
- Biochemistry
- Organic Chemistry
- Medical Biochemistry: Proteins and Peptides (incl. Medical Proteomics)
- Nuclear Chemistry
- Medical Biochemistry and Metabolomics not elsewhere classified
- Analytical Biochemistry
- Cell Neurochemistry
- Physical Organic Chemistry
- Enzymes
- Organic Green Chemistry
- Environmental Chemistry (incl. Atmospheric Chemistry)
- Catalysis and Mechanisms of Reactions
- Electroanalytical Chemistry
- Analytical Chemistry not elsewhere classified
- Environmental Chemistry
- Food Chemistry and Molecular Gastronomy (excl. Wine)
- Inorganic Chemistry