ETH Zurich spin-offs develop high performance batteries

In order to reduce our CO₂ emissions, we need to electrify many areas of life and store renewable wind and solar energy. Batteries that are not only efficient but also recyclable and sustainable are an essential requirement for achieving this, as the rapidly growing demand for batteries is also pushing up the consumption of scarce raw materials such as lithium. ETH spin-offs BTRY and 8inks have recognised this problem and are working on the battery of the future by applying innovative production methods and manufacturing techniques.

Thinner than a hair

Conventional lithium-ion batteries of the sort currently used in smartphones and notebooks have a liquid electrolyte inside them. This makes the batteries sensitive to temperature fluctuations, meaning that they are easily inflammable at excessive temperatures, for example. Moreover, conventional batteries take some time to recharge.

Moritz Futscher and Abdessalem Aribia, the two founders of BTRY, have therefore developed a solid-state battery that consists of thin layers, which can shorten the charging time many times over. The two researchers entirely forego liquids both during the manufacturing process and for the components of their battery. The solid-state batteries that are currently being developed by BTRY have the major advantage of being very resistant to temperature fluctuations. They can therefore be used both at very high temperatures, such as in sensors that detect vapour leaks, and at very low temperatures, for example during the transportation of medicines.

The spin-off manufactures the battery with a special coating technique originally used for the semiconductor production. Wafer-thin battery cells are placed on top of each other in a vacuum. This unique method enables the finished battery to be recharged quickly in about one minute. Furthermore, the structure of the battery promises a lifetime around ten times longer than that of a conventional battery. The coats are so thin that the finished product, which looks like a foil, is thinner than a hair. “We are currently still using machines on a laboratory scale for the production of our batteries, and in the laboratories our batteries were the size of a pinhead. However, our goal is to establish our own pilot production in Switzerland in around two years and to develop into a global manufacturer of batteries in the long term,” explains Moritz Futscher. The batteries are to be used in many different areas, for example in IoT-sensors, in consumer electronics or in space operations.

New coating technique as industry standard

ETH spin-off 8inks stands out from other battery manufacturers with its innovative production technology. It aims to use this to replace the manufacturing standard for lithium-ion batteries that has remained largely unchanged for the last 30 years – the so-called slot die technique. Paul Baade, founder of 8inks, has developed a technique called “multilayer curtain coating”. By applying several thin coats of the active material in which the lithium-ion is stored, the coating technique can be tailored to the applicable requirements. Owing to the variety in terms of the thickness and material properties of the individual layers, the technique supports, among other things, the scaling of solid-state batteries. Another advantage of the technique is that the coating speed of the battery electrodes can be vastly accelerated and is therefore optimally suited to meet the rising demand.

The staff of 8inks are currently testing various formats, from coin batteries to pouch cells of the sort used in smartphones. The technology is to be scalable up to a larger industrial scale, for instance, for batteries in electric cars. “We aim to use our manufacturing technique to develop solutions for the storage of renewable energies. This is the only way of meeting the enormous rise in demand for high-performance batteries in the long term,” says Baade. 8inks wishes to become so firmly established on the market in the future that its technology is recognised as a new standard in the manufacture of batteries.

Exploiting the potential of the Swiss battery market

Both spin-offs are planning their future in Switzerland. Thanks to the proximity to research and well-qualified graduates, battery manufacturers here are able to launch high-quality (niche) products on the market.

For BTRY, which produces its batteries in a vacuum with a manufacturing technique used in semiconductor production, Switzerland is particularly attractive as a location because the country is renowned for its vacuum industry. “There is even the expression ‘Vacuum Valley’ used to refer to the St Gallen Rhine Valley. There are many companies located there that are active in the vacuum technology, semiconductor production and coating technique segments. This will enable us to make use of synergies and existing know-how,” says Moritz Futscher.

Paul Baade from 8inks also sees the future of his company in Switzerland: “When it comes to excellent production techniques, we can build on a very good foundation here in Switzerland. There are numerous companies developing precisely the high-quality hardware and components that will enable us to establish and market our production systems in the long term.”

Resource-efficient production

Sustainability plays a core role for both spin-offs. This includes a CO₂-neutral manufacturing process, keeping the use of raw materials such as cobalt and lithium to a minimum. As Abdessalem Aribia, co-founder of BTRY, explains: “There are certain dependences on countries abroad, for instance, with regard to limited raw materials such as lithium. At the same time, we at BTRY aspire to use more sustainable materials in the medium term in order also to reduce our dependence on foreign producers.” Meanwhile, ETH spin-off 8inks keeps its energy outlay as low as possible by means of customised production and is simultaneously able to avoid unnecessary material wastage. It is also endeavouring to reduce the share of solvents as much as possible. Both spin-offs successfully demonstrate that sustainability and efficiency can go hand in hand – a promising path into the future.