All major European car makers have embraced batteries as they scramble to meet deadlines for EU regulation 2035 of phasing out the combustion engine.

Mercedes, BMW and Volkswagen are all currently employing the use of standard Lithium batteries. But they're also throwing significant money into research and development of the so-called solid-state battery.

With the auto industry looking to cut carbon emissions by doing away with the combustion engine, the battery has been the go-to power source to replace petrol, a fossil fuel. The development of the electric vehicle (EV) has created a demand for automobile batteries with greater driving range.

Solid-state batteries could offer this advantage over the batteries currently in use, along with higher energy density and faster charging. They could prove both lighter and safer.

From single-use to solid-state 

From simple, single-use cells like the AA and AAA to rechargeable battery cells like those used in EVs, battery usage has also evolved significantly since they were invented in the 1800s. 

‘'I think the battery is the greatest innovation of the 21st century and it's changing our world totally," Professor Ferdinand Dudenhoeffer, director at the Center for Automotive Research in Duisburg, Germany, told DW. 

There are two main kinds of batteries: primary and secondary. Primary batteries, also known as one-use batteries, cannot be recharged. They provide steady energy throughout their lifespan but cannot be reversed to produce more energy. The most popular type is the Alkaline battery, widely used in low-power standalone devices.

Secondary batteries, meanwhile, allow for chemical reactions to be reversed through voltage application, making them rechargeable. The lead acid, nickel metal hydride and lithium ion batteries are all used in the auto industry, particularly the lightweight lithium batteries. Tesla relies heavily on lithium batteries for their electric cars.

New batteries could solve electric vehicle woes

Lithium batteries rely on a liquid electrolyte solution, which allows lithium ions to move as needed for the battery to function. With solid-state batteries, scientists have managed to replace this liquid electrolyte with a solid electrolyte. This makes it possible to do away with the heavy separator component needed to keep the positive electrode from coming into contact with the negative electrode. 

The absence of a flammable liquid electrolyte reduces the risk of fire, making the battery safer compared to the liquid-state battery.

Tests in labs both in Japan and Europe have shown much potential in the battery, with Toyota recently announcing a breakthrough with the solid-state battery.  In early July, the Japanese carmaker said it had simplified the production process for materials used to make them. Toyota, the world's second-largest car manufacturer, has said it plans to produce cars with solid-state batteries by 2025. 

Due to a higher energy density, the solid-state battery will power the car over longer distances, hence improving range, a key issue for both consumers and manufacturers when it comes to EVs. 

So important is the solid-state battery technology that Volkswagen has become the biggest shareholder in QuantamScape, a solid-state battery company founded in 2010. In late July, the company's stock soared on the news that it was working with a partner in the automotive industry on a potential launch of its first commercial product. 

Mercedes Benz, for its part, plans to go all-electric by 2030. They've also signed partnerships with companies like Prologium, a Taiwanese developer and manufacturer of solid-state batteries.

But alongside the numerous advantages, the solid-state battery is also thought to have a shorter battery life. Cracks can form and grow in these batteries, Lorenz Olbrich, a doctoral student in Materials Science at Oxford University told DW, "hence providing a shorter lifetime for the battery."

Scalability still in question

Although the solid-state battery is thought to be lighter, more powerful with shorter charging times and safer, experts remain skeptical about the mass production costs and how much consumers will need to pay for it.

Tim Wicke, a researcher at the Fraunhofer Institute for Systems and Innovation Research, said that demand for these new batteries will be limited to niche markets at first. 

"Those solid-state batteries will be more expensive when they start to be industrialized because the production scale will be much smaller," he told DW. 

The European Union has declared battery cell production to be an important project of common European interest. That means the government can offer subsidies for auto makers investing in battery technology. The EU has already offered grants to several battery makers in different countries.

Governments have also funded automakers who have in turn funded companies and start-ups working on solid-state batteries and other battery technologies currently in the research and development phase in different labs across Europe.

China's headstart poses a threat to the West

Chinese researchers at the University of Science and Technology of China have announced the development of a solid-state battery that could be produced at cheaper rates. This development might slow the efforts of the West to scour Chinese dependence on EV batteries.

With China miles ahead technology-wise and in production capacity compared to Europe, many European automakers have depended on Chinese companies to supply traditional batteries for their EVs.

Chinese battery companies account for over 70% of global manufacturing, with companies like BYD, CATL and Tritek among others supplying Western automakers.

China also possesses a vast treasure trove of natural resources, like lithium, cobalt, manganese, graphite and nickel, which are used in the making of battery components. Several European and American companies depend on supplies of these from China.

China currently enjoys great control of the supply chain. With the changing geopolitical arena, auto makers in the West are trying to find ways to rid themselves of Chinese dependence. 

"There is a lot of fear in the West due to strong dependence on China with raw materials," Oxford's Olbrich said. "It is not only the raw materials, but the biggest cell producers come from China."

Along with looking towards investing and building up new battery production plants, efforts to recycle old batteries are being stepped up across Europe and the US. In Europe for instance, EU regulations on batteries put a strong emphasis on recycling as a source of the much needed raw materials in order to ensure sustainability and cost-cutting in battery production.

"Even though Europe lacks raw materials currently, there is another way of getting them apart from mining," said Wicke. "We can get the materials through recycling. It is important to recycle materials from batteries which have finished their lifecycle.''

Edited by: Kristie Pladson