Solid state batteries? No need: Mercedes

Mercedes-Benz CTO Markus Schäfer says developments in lithium-ion batteries could potentially mean that solid-state batteries “may not be necessary” because “so many people have worked on the conventional cells, making them so much better”. 

While the majority of electric vehicles currently utilise lithium-ion batteries with a liquid electrolyte, the industry has been shifting its focus towards next-generation solid-state batteries, which are expected to bring significant advancements.

Mr Schäfer, however, highlighted the “unexpected” recent progress in lithium-ion technologies, pointing out their comparable energy density to solid-state batteries, and cautioned against expecting immediate cost benefits in the initial production offerings over lithium-ion cells.

“You might get the first batteries in 2025/26, but I don’t think that they come with a major cost advantage,” he predicted.

Mr Schäfer also expressed scepticism about a significant breakthrough in cost reduction for EV batteries in the near future.

“We know the electric drivetrain is still way more expensive than a combustion drivetrain,” he said. “That’s a fact.

We do our battery research; we have our labs. I don’t really see a game changer coming on cost production for batteries, not a significant one.”

Mr Schäfer stressed the challenges in developing a production battery that meets the desired criteria for energy density, cost efficiency, and safety, stating that the development timeline for viable solid-state batteries would still face a “long, long development time”.

“We invested in some cool startups,” said Mr Schäfer, referring to Mercedes’ commitment to advancing solid-state battery technology through its investments in companies like ProLogium, which recently opened the world’s first solid-state lithium ceramic battery plant in Taiwan.

Despite these endeavours, Mercedes maintains a practical stance on the future of electric vehicles, as showcased in the CLA concept car for which the brands plans mild hybrid versions, affirming its commitment to internal combustion powertrains.

“There were some very optimistic forecasts a while ago,” cautioned Mr Schäfer. “It reminds me a little bit of the forecasting of autonomous drive.”

He noted that improvements in lithium-ion tech would continue, leading to a competitive race with solid state, suggesting the latter may not be the breakthrough they were thought to be.

Accepting the benefits of solid-state batteries, Mr Schäfer said: “On the safety side, of course they come with this advantage.” But he pointed out that lithium-ion battery manufacturers have been improving their products with added safety features like impact protection to prevent damage and reduce the risk of fires and injuries.

Mr Schäfer also discounted the idea of ultra-rapid charging as a solution for integrating smaller batteries into electric vehicles, citing persistent range anxiety concerns among consumers.

He highlighted that consumers prioritise occasional lengthy journeys, such as winter skiing getaways or summer road trips, over their regular daily driving habits when evaluating the range requirements of electric cars.

“They think about the one [big] trip they have to do each year, and this is not rational,” he said. 

Despite Mr Schäfer’s cautious stance, other industry players, such as Nissan, remain optimistic about solid-state battery technology, with plans to introduce it into production by 2028.

These companies consider solid-state batteries to be a key breakthrough in battery technology, enabling smaller, more cost-effective, and higher-energy-density cells potentially offering twice the charge at half the weight.

Moving forward, Mr Schäfer did not rule out the potential of solid-state batteries in the near future. 

“It’s a head-to-head race now,” he said, acknowledging that the ultimate winner between solid-state and lithium-ion batteries remains uncertain among automotive experts and stakeholders, emphasising the dynamic nature of battery technology development in the EV industry.