UNCLASSIFIED: Distribution Statement A. Approved for public release UNCLASSIFIED: Distribution Statement A. Approved for public release LiSICON-Ionic Liquid Electrolyte for Lithium ion Battery

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. Current lithium?ion batteries (LiB) have limited usefulness in high temperature applications due to the flammable of the organic electrolyte. Alternatively, solid electrolytes can mitigate safety issues and enable high temperature applications. Here, a new solid-state lithium ion battery design is investigated using LiSICON as the electrolyte. To reduce the interfacial resistance between the solid electrolyte and graphite electrode, an ionic liquid was used as the ionic conductor. N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR13+FSI-) was used as the ionic liquid due to its high efficiency for lithiation/delithiaion. The cell capacity and efficiency was measured at temperatures from 25?C to 120?C.