Surface Chemistry and Electrochemistry at Electrode-Ionic Liquid Interfaces
Abstract
The overall project goal was to understand and optimize electrode processes in nonflammable ionic liquid electrolytes for application in safe, reliable batteries. For anode development, the nucleation-growth mechanisms and the formation of the solid electrolyte interfaces during lithium and sodium electrodepositions were evaluated. while sodium exhibited classic instantaneous nucleation-growth behavior, lithium electrodeposition consisted of two sequential nucleation-growth steps and was consistent with the substrate electrode surface being heterogeneous towards lithium nucleation. Also, impedance studies confirmed the formation of a solid electrolyte interface at both lithium and sodium electrodeposits; however, the interface at sodium was approximately ten times more resistive than the lithium interface. For cathode development, spin- coated vanadium oxide xerogel films were prepared using sequential casting techniques and were seen, using scanning electron microscopy, to possess a layered structure with thin sheets running parallel to the casting surface. Finally, novel ionic liquid-polymer gel electrolytes, composed of a perfluoroanion ionic liquid and a poly(vinylidene fluoride) hexafluoropropylene, copolymer were developed and characterized during this project. The ionic conductivities of these nonvolatile, nonflammable solid-state electrolytes were measured from room-temperature to 100 deg C and found to increase from Ca. 1 mS /cm to Ca. 13 mS/cm over this temperature range.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 25, 1997
- Accession Number
- ADA339928
Entities
People
- J. Fuller
- R. T. Carlin