US Naval Research Lab scientists developing ionic liquid batteries
15 April 2011
Scientists at the US Naval Research Laboratory (NRL) Materials Science and Technology Division are providing evidence of a viable new route towards developing novel, lightweight energy storage devices using non-volatile, thermally-stable ionic liquids. Rather than depend on 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 use of these electrolytes suggests the potential for new types of rechargeable systems, such as replacement electrolytes in nickel-metal hydride (NiMH) batteries, or even the standard lead-acid battery. Experimental work is currently underway to develop such a rechargeable ionic liquid power source. The ability to create solid separators also allows for the formation of many new types of batteries via a number of fabrication techniques.
The unique properties of ionic liquids have fostered this 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. These new types of solid-state cells mimic standard alkaline cells, but without the need for caustic electrolytes.
—Dr. Thomas Sutto
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 observed for the zinc anode in a standard alkaline cell, a series of experiments were then performed to determine how different metal oxides reacted in these types of ionic liquids.
Electrochemical experiments demonstrate that not only can these reactive ionic liquids act as the electrolyte/separator in both solid state and liquid batteries, but they can also act as a reactive species in the cell’s electrochemical makeup. Using a non-aqueous approach to primary and secondary power sources, batteries are designed using standard cathode and anode materials such as magnesium dioxide (MgO2), lead dioxide (PbO2) and silver oxide (AgO). The ionic liquid that is the main focus of this work is 1-ethyl-3-methylimidazolium hydrogen sulphate (EMIHSO4), however, other ionic liquids such as those based on the nitrate and dihydrogen phosphate anions have also been found to work well in this type of a battery design.
Ionic liquids may be helpful in some battery geometry - but this post claims Zn to be "hazardous." Zn anodes are used extensively in boats and ships to protect prop shaft metals from corrosion.
NRL is the home of far more interesting energy research e.g. the LENR SPAWAR program.
Posted by: Reel$$ | 15 April 2011 at 11:58 AM
Scottsdale/AZ Fluid Energy received a $5.13M grant in Nov 2009 to develop the same thing leading to a rechargeable battery with 11X the energy density. Any results?
Posted by: HarveyD | 15 April 2011 at 03:03 PM
Solid State still sounds pretty good http://www.energy-daily.com/reports/Fast_Recharge_Lithium_Ion_Battery_Could_Be_Perfect_For_Electric_Cars_999.html
Posted by: HealthyBreeze | 15 April 2011 at 03:37 PM
That is an interesting and recent article on 3D batteries.
"The 3-D Li-ion battery recharges in minutes, rather than hours, and could bring closer the day in which electric cars can recharge as quickly as gas-powered vehicles"
Where you will get 440v 3 phase 500 amp service for multiple cars I do not know, but it sounds good.
Posted by: SJC | 16 April 2011 at 01:21 PM
There are already a number of different batteries capable of charging in minutes, Altairnano being one of them, if you can provide the power.
Posted by: JRP3 | 17 April 2011 at 09:25 AM