International news within the industry of mining and metal, Sep, 23 2018
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Cheap energy storage with sodium and potassium batteries

Sodium Battery. Photo: Freedomsphoenix Credit: Readerfour
Sodium Battery. Photo: Freedomsphoenix Credit: Readerfour
Published by
Markku Björkman - 21 Jun 2018

American researchers have found new evidence that sodium and potassium based batteries can be a promising alternative to lithium-based batteries.

Every year more and more products are released, which take advantage of the progress made in battery technology. This has led to concerns that the world's lithium reserves, used in many of the new rechargeable batteries that are manufactured, will end.

Researchers at the Georgia Institute of Technology in the United States have now found evidence that sodium and potassium batteries can be a promising alternative to lithium-based batteries.

"One of the biggest barriers to sodium and potassium batteries has been that they tend to break down and deteriorate faster and save less energy than the alternatives. But we have found that it is not always the case, "said Matthew McDowell of the Georgia Institute of Technology.

The researchers were able to observe, using an electron microscope, how ions of lithium, sodium, and potassium react with an electrode of iron sulfide inside a battery. Although sodium and potassium ions are larger than lithium ions, and therefore, they break down the electrode more when they react with it, they discovered that the iron sulfide was more stable in reactions with sodium and potassium than with lithium. This suggests that a battery of this kind based on sodium or potassium could have a much longer life than expected.

- Lithium batteries are still most attractive right now because they have the highest energy density. Sodium and potassium batteries do not currently have higher density, but they are based on elements that are a thousand times more common in the Earth's crust than lithium. They could, therefore, be much cheaper in the future, which is important in large-scale energy storage, explains Matthew McDowell.