Rohstoffe für Flüssigmetallbatterien - Lithium-Ionen-Batterieausrüstung

Donald Sadowy, a professor of materials chemistry at the Massachusetts Institute of Technology, and his students invented a large-capacity liquid metal battery. Now, his team has discovered a new chemical component -- calcium -- that could make the technology cheaper and more practical, opening the way for large-scale applications of liquid metal batteries. Their latest study, published in the journal Nature Communications, shows that calcium -- an abundant and cheap chemical element -- could be an important raw material for three-layer liquid metal batteries.

The discovery was unexpected, Sadowi said, because calcium's properties make it an unlikely ingredient for liquid metal batteries. On the one hand, calcium is easily dissolved in salt solution, but one of the important characteristics of liquid metal batteries is that its three key components form independent layers; on the other hand, calcium has a very high melting point. If it is used as a raw material, liquid metal batteries have to work at a high temperature of 900 degrees Celsius.(Lithium - Ion Battery Equipment)

However, this seemingly most uninteresting material has piqued the interest of researchers. Because cheap calcium can greatly reduce the cost of liquid metal batteries, and its inherent high-voltage performance makes it an excellent "candidate" for the negative electrode layer of liquid metal batteries.

To solve the problem of calcium's melting point, the researchers alloyed calcium with magnesium, which is cheap and has a much lower melting point than calcium. The combination of the two lowers the original melting point by 300 degrees Celsius, while still maintaining the high-pressure properties of calcium.

Another innovation is in the design of the liquid metal battery's middle layer, the electrolyte. When the battery is in use, ions will swim in the electrolyte, and as they swim, current will pass through the wires connecting the two poles of the liquid metal battery.

The newly designed electrolyte contains a mixture of lithium chloride and calcium chloride, and the calcium-magnesium alloy used as the negative electrode layer is not easy to dissolve in this electrolyte. This design also brings new surprises. Normally, in a powered battery, the swimming ions act alone. For example, only lithium ions will swim in a lithium-ion battery, and only sodium ions will swim in a sodium-sulfur battery. But the researchers found that in the latest design, multiple ions swim through the electrolyte, adding to the battery's overall energy output.

The serendipitous discovery could open new avenues for battery design, Sadowi said. "Over time, you can explore more elements on the periodic table to find better battery formulations," he said.