WASHINGTON -- Scientists at the Naval Research Laboratory Materials Science and Technology Division are providing solid evidence that there is a new route towards developing novel, lightweight energy storage devices. By moving away from centuries of caustic, hazardous aqueous-based battery cells and instead using non-volatile, thermally-stable ionic liquids, scientists predict multiple new types of batteries. Rather than depend on highly acidic electrolytes, ionic liquids are used to create a solid polymer electrolyte composed of an ionic liquid and polyvinyl alcohol, developing novel types of solid state batteries with discharge voltages ranging up to 1.8 volts.
The unique properties of ionic liquids have fostered this explosive interest in battery applications. Ionic liquids are room temperature molten salts that possess many important characteristics, such as nearly no vapor pressure, non- flammability and lack of reactivity in various electrochemical or industrial applications. "It is the high thermal and electrochemical stability of the ionic liquids which has fostered the growing interest in ionic liquids for use in various electrochemical processes," said Dr. Thomas Sutto. "These new types of solid-state cells mimic standard alkaline cells, but without the need for caustic electrolytes."
Limits imposed by using corrosive electrolytes often result in severe restrictions to standard battery geometry and the need for special corrosive-resistant battery containers. The use of reactive ionic liquids in non-aqueous cells replaces the more hazardous highly alkaline electrolytes such as manganese oxide (MgO) and zinc (Zn) found in traditional batteries.
The root of this work began during standard corrosion studies of different metals in ionic liquids. While working with ionic liquids based on mineral acids, such as hydrogen sulphates, it was observed that Zn metal would react to form zinc sulphate. Since this is similar to that obs
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Naval Research Laboratory