Abstract
Calcium batteries are next-generation energy storage technologies with promising techno-economic benefits. However, performance bottlenecks associated with conventional electrolytes with oxygen-based coordination chemistries must be overcome to enable faster cation transport. Here, we report an imidazole-based polymer electrolyte with the highest reported conductivity and promising electrochemical properties. The polymerization of vinylimidazole in the presence of calcium bis(trifluoromethanesulfonyl)imide (Ca(TFSI)2) salt creates a gel electrolyte comprising a polyvinyl imidazole (PVIm) host infused with vinylimidazole liquid. Calcium ions effectively coordinate with imidazole groups, and the electrolytes present room temperature conductivities of >1 mS/cm. Reversible redox activity in symmetric Ca cells is demonstrated at 2 V overpotentials, stable cycles at 0.1 mA/cm2, and areal capacities of 0.1 mAh/cm2. Softer coordination, polarizability, and closer coordinating site distances of the imidazole groups can explain the enhanced properties. Hence, imidazole is a suitable chemical benchmark for the future design and advancement of polymer electrolytes for calcium batteries.
Original language | English (US) |
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Pages (from-to) | 6803-6811 |
Number of pages | 9 |
Journal | ACS Applied Polymer Materials |
Volume | 4 |
Issue number | 10 |
DOIs | |
State | Published - Oct 14 2022 |
Externally published | Yes |
Keywords
- batteries
- calcium
- electrolytes
- energy
- polymers
- salts
ASJC Scopus subject areas
- Process Chemistry and Technology
- Polymers and Plastics
- Organic Chemistry