SBIR-STTR Award

Feasibility of rechargeable lithium-ion cells utilizing two ambient temperature molten salt electrolytes will be investigated. The anions of these electrolytes will be resistant to oxidation; the cation of one of the electrolytes will be resistant to both oxidation and reduction; therefore, in such electrolytes both cathode and anode will be electrochemically stable. The electrolytes will be prepared and their properties will be determined. Stability of cathode and anode in the electrolytes will also be measured. Lithium-ion cells will be fabricated and their performance will be evaluated. It is expected that results obtained will demonstrate low self-discharge, long cycle life, and thermal and electrochemical stability, thus confirming the feasibility of the lithium-ion rechargeable cells constructed with ambient temperature molten salt electrolytes

Keywords:
ambient temperature molten salts lithium-ion rechargeaable batteries

A prototype of lithium-ion rechargeable cell using ambient temperature molten salt electrolytes will be developed. Two types of ambient temperature molten salt electrolytes will be used. These electrolytes show high conductivity, wide electrochemical window, no safety hazard, and operating temperature range form -40C to 300C. One of the melts shows very low glass transition (-85C) and good conductivity. The cell will have a very simple design and charged cell will have open circuit voltage of approximately 3.8 V. The cells employing the proposed ambient temperature melts as electrolytes will show high energy, acceptable self-discharge, long cycle life, excellent safety characteristics and will operate in a wide temperature range (-40C to 100C). Cell components including the melts are not very moisture sensitive thus allowing assembly in a normal atmosphere. Simple cell design and readily available electrode materials will make the cell commercially attractive.

Keywords:
ambient temperature molten salts lithium-ion rechargeaable batteries