Chemical technologist Harry Pratt synthesizes a copper-based ionic liquid. (Randy Montoya)
Sandia National Laboratory researchers have developed a family of liquid salt electrolytes - known as MetILs - that could lead to better batteries and well as devices that can help incorporate large-scale intermittent renewable energy sources, like solar and wind, into the nation’s electric grid.

“MetILs are a new, promising battery chemistry that might provide the next generation of stationary storage battery technology, replacing lead-acid and lithium-ion batteries and providing significantly higher energy storage density for these applications,” said Anthony Medina, director of Sandia’s Energetic Components Realization program.

Sandia researcher and inorganic chemist Travis Anderson is leading a team developing the next generation of flow batteries. A flow battery pumps a solution of free-floating charged metal ions, dissolved in an electrolyte — substance with free-floating ions that conducts electricity — from an external tank through an electrochemical cell to convert chemical energy into electricity. Flow batteries are rapidly charged and discharged by changing the charge state of the electrolyte, and the electroactive material can be easily re-used many times. Anderson said flow batteries can sustain more than 14,000 cycles in the lab, equivalent to more than 20 years of energy storage, which would be unusual in a lithium-ion battery.

Anderson assembled a multidisciplinary team of experts including electrochemist David Ingersoll, organic chemist Chad Staiger, and chemical technologists Harry Pratt and Jonathan Leonard. What they’ve designed is a new family of electrochemically reversible, metal-based ionic liquids, or MetILs, which are based on inexpensive, non-toxic materials that are readily available within the U.S., such as iron, copper and manganese.