Researchers from the Texas Materials Institute at the University of Texas, Austin pursued the goal of developing batteries that can do without the valuable cobalt and expensive lithium. After a few attempts, the researchers around Arumugam Manthiram found what they were looking for. At its core, the newly developed sulfur-metal battery consists of materials such as sulfur and sodium that are found in abundance around the world. Another advantage of the new battery is that it neither burns nor is subject to decay.
No risk of fire and decay
Although the research team from the University of Texas are not the only ones researching a cheaper and more sustainable battery, the product they have now developed represents an innovation. In their publication, the researchers write that they have succeeded in avoiding dendrites, i.e. deposits which could lead to short circuits and even explosions in batteries. In addition, Manthiram succeeded in preventing the electrode from disintegrating. This was promoted by the electrolytes previously used, which considerably limited the service life of the battery storage system.
So far, the new type of sulfur-metal battery is still quite small. Soon, however, the researchers want to build a larger product in order to be able to store larger amounts of energy. These should then act, for example, as a buffer store for wind and solar power or be used in electric cars. So far, lithium-ion batteries have made up a large proportion of their use in electric cars and also in electricity storage systems for renewable energies. That makes the batteries quite expensive.
Dream technology
“I call it a dream technology because sodium and sulfur are abundant, environmentally friendly, and the cheapest thing imaginable,” said Manthiram, director of the UT’s Texas Materials Institute and professor in the Walker Department of Mechanical Engineering. “With increasing electrification and the increasing need for renewable energy storage, cost and affordability will be the most important factor.”
Amruth Bhargav, a doctoral student in the Arumugam Manthiram team, selected highly concentrated salt solution as the electrolyte for the sulfur-metal batteries. In a further step, he diluted these with a special solvent that does not react with other materials. This solution made the battery fire- and explosion-proof and much more resilient. The first battery in this series withstood 300 charge and discharge cycles without losing its capacity. ”If you put a lot of sugar in water, it becomes syrupy. Not everything is resolved, ”said Bhargav, PhD student in Manthiram’s laboratory. “Some things are half bound and half dissolved. In a battery, we want everything to be half resolved. “
No exploitation of people
The researchers published their results jüngst im Journal of the American Chemical Society. You have created a cheaper battery alternative to the conventional lithium-ion battery, which will definitely have a right to exist in the future. The price of lithium-ion batteries has skyrocketed. Ultimately, this is likely to be due to the mining conditions. The extraction has an enormous negative impact on the environment. Not only is a lot of groundwater consumed, but there is also significant soil and water pollution as well as carbon emissions. Sodium, on the other hand, is available in the sea and is more environmentally friendly and much cheaper.
The new cobalt- and lithium-free batteries ensure a better environmental balance and are more humanitarian. For example, the cobalt found in lithium-ion batteries is mainly mined under inhumane conditions in the Democratic Republic of the Congo in Africa. Manthiram introduced a cobalt-free battery last year.
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