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The use of highly conductive solid-state electrolytes to replace conventional liquid organic electrolytes enables radical improvements in the reliability, safety and performance of lithium batteries. Here, we report the synthesis and characterization of a new class of nonflammable solid electrolytes based on the grafting of ionic liquids onto octa-silsesquioxane. The electrolyte exhibits outstanding room-temperature ionic conductivity (∼4.8 × 10 −4 S cm −1 ), excellent electrochemical stability (up to 5 V relative to Li + /Li) and high thermal stability. All-solid-state Li metal batteries using the prepared electrolyte membrane are successfully cycled with high coulombic efficiencies at ambient temperature. The good cycling stability of the electrolyte against lithium has been demonstrated. This work provides a new platform for the development of solid polymer electrolytes for application in room-temperature lithium batteries.
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Lignin‐Based Solid Polymer Electrolytes: Lignin‐Graft‐Poly(ethylene glycol)
Abstract Lignin is an aromatic‐rich biomass polymer that is cheap, abundant, and sustainable. However, its application in the solid electrolyte field is rare due to challenges in well‐defined polymer synthesis. Herein, the synthesis of lignin‐graft‐poly(ethylene glycol) (PEG) and its conductivity test for a solid electrolyte application are demonstrated. The main steps of synthesis include functionalization of natural lignin's hydroxyl to alkene, followed by graft‐copolymerization of PEG thiol to the lignin via photoredox thiol‐ene reaction. Two lignin‐graft‐PEGs are prepared having 22 wt% lignin (lignin‐graft‐PEG 550) and 34 wt% lignin (lignin‐graft‐PEG 2000). Then, new polymer electrolytes for conductivity tests are prepared via addition of lithium bis‐trifluoromethanesulfonimide. The polymer graft electrolytes exhibit ionic conductivity up to 1.4 × 10−4 S cm−1 at 35 °C. The presence of lignin moderately impacts conductivity at elevated temperature compared to homopolymer PEG. Furthermore, the ionic conductivity of lignin‐graft‐PEG at ambient temperature is significantly higher than homopolymer PEG precedents.
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- Award ID(s):
- 1804871
- PAR ID:
- 10453952
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Macromolecular Rapid Communications
- Volume:
- 42
- Issue:
- 3
- ISSN:
- 1022-1336
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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