A Cheaper, Greener, More Efficient Alternative to Lithium-ion Batteries - Tech Briefs

Nov 05, 2024

Swiss Federal Laboratories for Materials Science and Technology (Empa), Dübendorf, Switzerland

Lithium-ion (Li-ion) batteries are everywhere, and they are currently our most mature battery technology. Yet they are not ideal for many applications. Li-ion batteries lose capacity with every charge and discharge cycle, charge relatively slowly, and only work well in a narrow temperature range.

According to Empa researchers Abdessalem Aribia and Moritz Futscher, it is time to rethink battery technology. Compared to other existing or developing technologies, their lithium metal-based solid-state battery brings some significant advantages: It can be charged and discharged within one minute, lasts about 10 times as long as a Li-ion battery, and is insensitive to temperature fluctuations.

In addition, unlike Li-ion batteries, it is not flammable. Incorrect handling or damage to a conventional Li-ion cell can lead to a fire that releases toxic gases and is extremely difficult to extinguish. “By contrast, if you cut our battery with scissors,” Aribia said, “you will simply get two batteries that are half as good.”

Together with lab head Yaroslav Romanyuk, the two have founded a spin-off called BTRY (pronounced “battery”). Aribia, BTRY CTO, had never previously thought of starting his own company. CEO Moritz Futscher, on the other hand, has been interested in startups since he was a student. The two researchers have been working together on the battery project for years and are a well-established team.

The new battery is a so-called thin-film solid-state battery, which has been around since the 1980s. However, due to the very low mass of their thin-film components — the entire cell is only a few micrometers thick — they have been able to store very little energy so far. Futscher and Aribia have succeeded in stacking the thin-film cells on top of each other, increasing their capacity. This makes the battery very promising for commercial applications.

The thin-film cells are manufactured using vacuum coating: The desired materials are atomized in a vacuum chamber to form individual atoms, which are then deposited in a precisely controlled layer on the target substrate.

“Such manufacturing methods are currently used on a large scale in the production of semiconductor chips and glass coatings,” Futscher said. “That’s an advantage for us, because the machines and know-how to manufacture our battery are largely in place already.”

“In contrast to the traditional method of battery production, our method does not use toxic solvents,” Aribia said. However, that also makes the thin-film battery more expensive. The researchers therefore see its application primarily in products where the battery only accounts for a small part of the overall cost of the device — e.g., smartphones, smartwatches, or satellites. “There, the advantages of our technology more than make up for the higher price,” Aribia said.

The researchers are not the only ones who believe their product has a lot of potential. BTRY was supported by Innosuisse and made it into the business incubator of the European Space Agency. In addition, Aribia received an Empa Entrepreneur Fellowship, which supports young researchers who want to found a company.

But before the first thin-film batteries launch into space or supply smartphones with electricity, there is still a lot of work to do, both on the administrative and on the technical side. In the meantime, the two founders are using the equipment and facilities at Empa’s Coating Competence Center to create bigger and more powerful battery prototypes to show potential investors that the technology is worth backing.

“Currently, our batteries consist of only two layers of about 1×3 millimeters,” Aribia said. “Next, we want to make a battery of about one square centimeter with two to three layers. We can’t power a satellite with that yet — but we can very well show that our technology is scalable,” he added.

For more information, contact Anna Ettlin at This email address is being protected from spambots. You need JavaScript enabled to view it.; +41 58-765-4733.

This article first appeared in the November, 2024 issue of Tech Briefs Magazine (Vol. 48 No. 11).

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