A new roadmap from Fraunhofer ISI looks at alternatives to lithium-ion batteries for the period up to 2045. These are the key findings of the study at a glance.
Lithium-ion batteries (LIBs for short) are currently the dominant battery technology on the market due to their wide range of applications, for example in electric cars and trucks as well as in stationary and mobile devices. According to forecasts by the Fraunhofer Institute for Systems and Innovation Research (ISI), global market demand is expected to reach a capacity of almost one TWh by 2023. Due to the increasing market penetration of electric vehicles, the demand for batteries will continue to rise significantly and multiply, according to the institute.
With this enormous demand on the one hand and only one battery technology available on a large scale on the other, the question arises as to alternative battery technologies that should also achieve economic, ecological or technological advantages over the dominant LIBs. In order to find out which alternative battery technologies are available and suitable, Fraunhofer ISI has drawn up the "Alternative Battery Technologies Roadmap 2030+". It looks in particular at metal-ion, metal-sulphur, metal-air and redox flow batteries for the period up to 2045. These are the most important results at a glance.
What are the technological advantages of alternative battery technologies?
Many alternative battery types such as metal-ion (e.g. sodium-ion or zinc-ion batteries) or metal-air batteries (e.g. zinc-air batteries) are said to offer great potential for greater sustainability, lower costs or less resource consumption, but some of them would also have disadvantages such as lower energy density or low technological maturity, according to the Fraunhofer ISI. Metal-sulphur batteries, for example, could have a higher energy density and their costs are likely to be significantly lower than those of LIBs due to the low sulphur costs per kWh. Redox-flow batteries are already available on the market, but still need to improve in terms of cost and carbon footprint, the researchers say.
Which applications are suitable for alternative battery technologies?
According to the Fraunhofer researchers, sodium-ion batteries are on the verge of widespread commercialization for mobile applications; the first sodium-ion batteries are already being used in electric two-wheelers and small cars. Lithium-sulphur batteries could be used in larger drones from 2035 and in other electric aircraft from 2040, the study predicts. The requirements for stationary applications are lower, for example in terms of energy density, and storage systems such as redox flow batteries, saltwater or high-temperature sodium-sulphur batteries, some of which are already available on the market, could become more relevant in the near future – just like sodium-ion batteries, which are characterized by good resource availability, safety and deep discharge capability, as well as zinc or aluminium-ion batteries.
Are there alternative battery technologies that significantly reduce dependence on raw materials?
As the Fraunhofer researchers explain, some promising alternative battery technologies require larger quantities of raw materials in order to achieve the same storage capacity due to their lower energy density compared to LIBs. However, many of the non-lithium-based technologies require fewer critical raw materials than LIBs. However, due to a lack of large application areas and markets, the production and supply of lithium, nickel and cobalt will remain critical for the time being – especially in the next 5 to 10 years.
Are alternative battery technologies foreseeable that can be produced and scaled in a similar way to LIBs?
According to the Fraunhofer ISI, metal-ion batteries, which are not classified as LIBs, are very promising in the coming decade because their production steps are very similar to those of LIBs. Existing production technologies and environments could be used directly (drop-in technologies) or would only need to be adapted to a limited extent.
Can alternative battery technologies become cheaper than LIBs?
Although alternative battery technologies have potentially lower material costs than LIBs, according to the study, their cell costs are likely to be higher initially due to the low production volume. According to the scientists, scaling up production would bring considerable cost benefits, but this would require sufficiently large markets and applications on a GWh scale.
How is Europe positioned when it comes to alternative battery technologies?
According to the study, patent and publication analyses show that the EU countries are better positioned for redox flow batteries, lithium-air or aluminum-ion batteries, for example, than they currently are for LIBs. However, Japan and China remain the leaders here. For some alternative battery technologies, the EU countries are showing strong momentum with annual growth rates of between 10 % and 50 %, while growth for LIBs is around 10 %. Dr. Annegret Stephan, scientific coordinator of the roadmap at Fraunhofer ISI, also points out the need for political support in order to tap into the potential of alternative battery technologies.
The Fraunhofer ISI concludes that LIBs will continue to dominate the market, but that selected alternative battery technologies could provide relief from raw material, production and supply dependencies in certain markets and applications and thus contribute to technological sovereignty. However, further efforts in the area of research and development in Germany and the EU are necessary and worthwhile.