Safe and longlasting: solid-state batteries of the future

The further development of batteries to make them even more powerful, durable, safe and environmentally friendly is a high priority worldwide. Batteries are an essential cornerstone for the transformation of the energy and mobility system – they are needed, for example, to buffer the fluctuations of renewable energy sources, for the decarbonisation of industry and for more environmentally friendly road and air traffic.
 

‘The AIT Austrian Institute of Technology has been established in battery research for many years and plays a leading role in Europe,’ emphasises Christian Chimani, head of the AIT Center for Transport Technology. AIT researchers lead numerous major EU projects in this area, covering the entire value chain – from materials research and the development of production processes to integration into industrial applications.
 

Three main research areas are being pursued:

• In the area of materials development, research is being conducted into new materials that will make batteries more efficient and sustainable. The main focus here is on the replacement of critical raw materials (such as lithium or cobalt), recyclability and the circular economy.
   
• In the area of sustainable production processes, the focus is on environmentally friendly, resource-conserving and energy-efficient manufacturing technologies – such as replacing toxic solvents with harmless substances.
   
• The solid-state batteries focus area is dedicated to developing the next generation of batteries with higher safety, energy density and lifespan. Solid-state batteries do not contain any liquid electrolytes, which are flammable and contribute to the aging process in batteries.

This third research focus is the core of the new Solid State Battery Lab at the AIT headquarters in Giefinggasse, Vienna. ‘This new infrastructure perfectly complements our existing expertise and offers us new opportunities to reach the next level in battery research. With the lab, we can close a crucial gap between lab development and industrial application,’ explains Chimani.
A new building directly adjacent to the existing Battery Lab has already been completed. However, the spacious, state-of-the-art laboratories are not yet fully equipped with the necessary apparatus – these are now being installed step by step. The reason for this is that solid-state batteries are still such a new topic that no ‘off-the-shelf’ machines are available. Rather, the equipment is being developed together with the manufacturers and customised for AIT's purposes. This applies, for example, to the centrepiece of the future pilot production line: the coating system. It currently exists only as a small prototype; the larger system, on which small series will be produced in the future and the production processes further developed and optimised, is still under construction.

There are no industry standards for solid-state batteries yet. A number of suitable materials for solid-state batteries are already known, such as polymers, ceramics and glasses or sulfide-based substances. These each have their own advantages and disadvantages in terms of processability, performance or safety. Based on this knowledge, new battery types must now be designed and optimised, and completely new manufacturing processes must be developed. Only then can solid-state batteries become ready for practical use in a few years' time. “To better understand these systems, fundamental questions still need to be answered,” explains Marcus Jahn, head of the AIT Competence Unit “Battery Technologies”. 

An increasingly important chapter in battery technology is the construction of so-called ‘smart cells’. These are battery cells and modules that are equipped with sensors that monitor their ‘state of health’. This provides important information for battery management, in order to further increase performance, lifespan and safety.
AIT researchers are also breaking new ground in a completely new field of application for batteries: they are working on electric drives for aircraft to make them more climate-friendly. Since weight plays a central role in flying, some EU projects are working with partners to research batteries that can be integrated into structural components of an aircraft, such as wings.
At AIT, battery development is closely linked to other key technologies for the mobility sector, especially innovative drive technologies and microelectronics, lightweight construction and sustainable, intelligent and safe transport infrastructure, including charging infrastructure for electric cars.

‘First-class research infrastructure is an important basis for our cooperation with partners and key customers,’ emphasised Alexander Svejkovsky, AIT Managing Director Finance, Processes and Administration, during an on-site inspection of the new laboratory. ‘AIT is at the interface between universities and industry, driving technological development and transferring knowledge from basic research to practical applications. Cooperation with key customers is a basis for application-oriented research,’ said Svejkovsky.