ETH Zurich spin-offs develop high performance batteries

The electrification of many areas of life is leading to an increased demand for high-​performance batteries. Two ETH spin-​offs are making waves in this field: while BTRY develops high-​performance solid-​state batteries, 8inks is working on a new standard for production.

In brief

• The ETH and Empa spin-​off BTRY develops fast-​charging batteries that are resistant to temperature fluctuations and suitable for a wide range of applications.
• 8inks, also an ETH spin-​off, wishes to establish an innovative manufacturing technology as the industry standard, enabling it to produce customised batteries.
• Both companies see major potential on the Swiss market and are focusing on efficient battery production with maximum sustainability.

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.

This article was first published on 29 April by ETH Zurich.