Synthesis and electrochemical studies of novel ionic liquid based electrolytes

<p>"Room temperature ionic liquids (RTILs) have received substantial interest as nonaqueous electrolytes in lithium ion- and metal-air batteries in recent years due to their low volatility, non-flammability, wide liquid range, and thermal stability characteristics. Towards developing a new generation of high specific energy lithium ion batteries, a series of imidazolium and pyrrolidinium based ionic liquids were synthesized and explored as nonaqueous electrolytes in lithium-, lithium ion-, and lithium-air batteries. Pyrrolidinium-TFSI based ionic liquids have wide electrochemical stability (5.7 - 6.2 V vs Li/Li⁺); however, they show limited thermal stabilities and lithium cell discharge characteristics. TFSI-based ionic liquids are thermally and electrochemically more stable when compared with their BF₄-based analogues. A series of fluorinated ionic liquid electrolytes were synthesized and investigated for their use in lithium-air batteries. These ionic liquids have improved the diffusion coefficient and higher solubility of oxygen when compared with currently used nonaqueous electrolytes.</p> <p>Cathode materials, such as LiNi_1/3Mn_1/3Co_1/3O₂ and LiFePO₄, were chemically delithiated using nitronium tetrafluoroborate (NO₂BF₄), or disodium peroxydisulfate (Na₂S₂O₈>), to explore their effect on the oxidative degradation of the carbonate based electrolytes. Using fluoroethylene carbonate as the electrolyte additive, electrolyte degradation was monitored by ¹⁹F NMR spectroscopy. Formation of the solid electrolyte interface (SEI) on the delithiated cathode materials was probed using surface techniques, such as X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM)"--Abstract, page iii.</p>

Name thesis:degree_name

Ph. D. in Chemistry

Grantor

Missouri University of Science and Technology

Year dc:date.available

2016

Author dc:creator

• Vadapalli, Avinash Raju

• Imidazolium
• Ionic Liquids
• Lithium batteries
• Pyrrolidinium
• Chemistry

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2460

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3462