Enormous ranges and no risk of fire are promised by the manufacturers of solid-state batteries. While the US and China are now reporting great successes in this field, Germany has some bad news.
Solid-State Battery
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Developments in the field of batteries in recent years have impressively demonstrated the potential of battery-electric drives. Ranges of over 600 km on a single charge are no longer uncommon – for example, according to the manufacturer, the current ID.7 with the 86 kWh battery from Volkswagen only needs to be charged after 709 km (WLTP). This takes the fear of range anxiety out of the equation for concerned customers – thanks in part to the ever-improving energy density of the traction batteries used. Within the past ten years, this has increased from 140 Wh/kg (2014) to 300 Wh/kg. And that's with lithium-ion technology.
According to an estimate by the Volkswagen Group, as much as 350 Wh/kg will be available for e-mobility from 2030. At this point, however, it should be mentioned that at the end of last year, the CEO of Nio undertook a journey from Shanghai to Xiamen (1,044 km) with the ET7. On board was a battery from Welion Co. Ltd. with an energy density of 360 Wh/kg – the highest value for mass production to date. About half a year later, scientists at the Institute of Physics (IOP), who were conducting research on the battery alongside Nio, succeeded in developing a rechargeable lithium battery in pocket form that boasts an impressive record with an energy density of 711 Wh/kg.
Solid-state Battery: From the Lab to the Fast Lane?
Despite this enormous progress, the question nevertheless arises as to whether lithium-ion technology has a future in electric mobility. And whether the solid-state battery, which is more advantageous in some respects, is better suited for the drive change. After all, the solid-state battery has a number of advantages that have already convinced some automobile manufacturers – including the German OEMs BMW, Mercedes-Benz and Volkswagen. According to their own information, the Wolfsburg-based company, for example, is planning to develop a solid-state battery with the US company QuantumScape, which is to go into series production from 2026.
And BMW wants to work with Solid Power to advance the industrialization of solid-state batteries and equip the first demo vehicles with them next year. Mercedes, on the other hand, is already on the road with the Vision EQXX. The technology demonstrator recently managed a journey of over 1,000 km on a single charge. Toyota wants to outdo that and has announced that it will bring a solid-state battery to market in 2027 that will enable a range of up to 1,200 km. Nissan, Ford, Nio and, above all, MG should also be mentioned.
The Long-Range Accumulator
Just a few weeks ago, Yu Jingmin, deputy general manager of SAIC Passenger Vehicles, to which the MG brand belongs, announced at the Chengdu Motor Show that the company intends to launch a vehicle with a solid-state battery as early as next year. This is a year earlier than previously intended. The push is likely to be based on corporate strategy: The Asians plan to increase production in order to be able to use economies of scale. SAIC hopes to achieve a cost advantage of around 30% for solid-state batteries compared to current lithium iron phosphate (LFP) batteries. This is an important step towards the democratization of electric mobility.
In Europe, research is also focusing on significantly reducing the costs per kWh. The Solidify consortium, for example, has just developed a lithium-metal battery with a solid electrolyte – with the special feature that the concept is based on a solid nanocomposite electrolyte. According to the consortium, it is "made by a sol-gel reaction that is favorably used for a liquid-to-solid approach in the production of the composite cathode and the solid electrolyte separator".
Higher Energy Density for Lower Costs
The aim is to achieve a target energy density of 1,200 Wh/L (400 Wh/kg) in 20 minutes of charging time. The consortium partners still have to address a number of weaknesses, such as mechanical strength and cathode impregnation. However, if they succeed, a kWh for under 150 euros would be possible. Nissan even sees a price of around 75 US dollars per kWh as feasible – by 2028. In addition to the potential for lower costs per kWh, the automotive industry hopes that the solid-state battery will offer further advantages.
However, the article also mentions that, among other things, so-called dendrite formation limits the lifespan. The focus of research is therefore on the essential components such as the anode material. Research laboratories, especially in the United States and Asia, are working hard on solutions. One solution seems to be within reach: at least that is the message conveyed by the research article published by several authors from the University of Science and Technology of China (USTC) in the journal Angewandte Chemie in June 2024.
Are the USA and China Outpacing Germany?
A new LPSO solid electrolyte (Li7 P3 S7.5 O3.5) has been developed there, in which "this material does not require the expensive Li2S" for synthesis. According to the research team, the raw material costs are "only 14.42 US dollars/kg – which, unlike most solid electrolytes, is below the commercialization threshold of 50 US dollars/kg". At around the same time, the US company Adden Energy developed an all-solid-state pouch cell battery (ASSB) with lithium metal anodes and high-nickel NMC cathodes. This makes energy densities of over 500 Wh/kg possible. According to Luhan Ye, CTO of Adden Energy, the "porous anode technologies enable high cathode charges of over 4 mAh/cm2 and the multi-electrolyte separators completely prevent dendrite formation even at such high current densities".
This makes solid-state batteries "the most promising energy storage option if done right", says Xin Li, co-founder and chairman of Adden Energy. The Fraunhofer Institute for Systems and Innovation Research (ISI) also sees considerable potential for SSB batteries in e-mobility. However, they believe that "the roadmap for the broader introduction of SSB batteries in electric vehicles remains speculative." At least that was the state of knowledge in June 2024.
Germany Cuts Back on Battery Research
Another finding of the Fraunhofer researchers, on the other hand, is even more disturbing. A glance at the publications "from the past five years that contain the term solid state batteries" reveals that China is currently dominating research and development of SSB batteries. The largest number of publications come from Chinese authors (55 %), followed by North America (16 %), Europe (14 %), and Asia (14 %). While US research laboratories are trying to catch up on research and development, the FDP-led Federal Ministry of Education and Research (BMBF) plans to discontinue funding for battery research.
According to the BMBF, around 30 % of public research and development spending in battery technology in Germany is funded – that's over 150 million euros annually, which is used to finance the development of research capacities at universities and institutes. "An attack on competitiveness" is how Kai-Christian Möller, who works for the Battery Alliance of the Fraunhofer Institutes, explains it. The German Association of the Automotive Industry (VDA) has therefore also voiced strong criticism. VDA President Hildegard Müller is quoted as saying that this is a "contradiction between the set goals and actual policy".
This is a partly automated translation of this German article.
