Calcium-Metal Liquid Battery Demonstrated At MIT
A calcium-metal-based liquid rechargeable battery was recently demonstrated by MIT professor Donald Sadoway and his team of researchers. The battery is intended for grid-scale storage and a long cycle life. Calcium was blended with magnesium to make it usable, and these two elements are often found together during mining operations, so there could be a convenience and lower cost if they can be used effectively to make these kinds of batteries.
The MIT team had to overcome some problems with using calcium: high solubility in molten salts, high reactivity, and high melting temperature. This last problem was solved by mixing calcium with magnesium. This attempt was successful and lowered the melting temperature by about 300 degrees. They also made a new molten salt formulation to decrease solubility by blending calcium chloride with lithium chloride.
MIT liquid metal battery
“Schematic of cell with the negative current collector consisting of a stainless steel rod and Fe–Ni foam and the positive current collector made of mild steel or graphite. The foam contains the negative electrode. Current collectors are electrically isolated by means of an alumina insulator.”
MIT battery
“Charge–discharge voltage time traces of Ca–Mg (20–80 mol%)||Bi, Ca–Mg (90–10 mol%)||Bi, and Ca–Mg (90–10 mol%)||Sb operated at current density 200 mA cm 2 and temperature 650 C. The theoretical capacities of Ca–Mg (20–80 mol%)||Bi, Ca–Mg (90–10 mol%)||Bi, and Ca–Mg (90–10 mol%)||Sb cells were 0.569, 1.33 and 1.08 Ah, respectively. The results of measurements were replicated more than five times, four times and twice, respectively.”
“This paper brings together innovative engineering advances in cell design and component materials within a strategic framework of ‘cost-based discovery’ that is amenable to the massive scale-up required of grid-scale applications,” said Richard Alkire, University of Illinois professor of Chemical and Biomolecular Engineering.
Advantages of this type of battery are the use of earth-abundant materials and that it employs a scalable kind of construction.
The DOE’s Advanced Research Projects Energy (ARPA-E) and the French energy company Total S.A. supported the research.
Clean energy technology such as solar and wind power have become so affordable that more and more people are able to purchase them in some form. Energy storage is growing in parallel, and it is just as exciting, though it doesn’t get much press.
