BMW tests solid state batteries

BMW has started testing solid state batteries in earnest in one of its BMW i7 cars.

The motor manufacturer has been cooperating with Solid Power, a US-based technology partner.

Solid-state batteries offer several significant benefits for electric cars, making them a highly anticipated "game-changer" in the EV industry.

Conventional electric car batteries are lithium-ion, but a solid state battery - or an all-solid-state battery (ASSB) as BMW calls them - provides a greater amount of energy density than a traditional lithium-ion battery.

What does this mean to EV drivers?

More energy density translates immediately to a longer range, potentially exceeding 600 miles on a single charge providing the range of an equivalent diesel car and eliminating the range anxiety fear.

Another advantage is that the cells themselves are smaller and lighter allowing greater vehicle efficiency and better, more agile performance.

One disadvantage of conventional batteries is that the larger they are (and therefore have greater range), the longer they take to charge - although new 800v architecture on the latest cars is changing this.

But solid state batteries will enable much faster charging times. Some research and manufacturer claims suggest charging from 10% to 80% in as little as 9-15 minutes, making EV "refueling" comparable to filling up a normal petrol or diesel combustion engine. This is due to the solid electrolyte being more stable and less prone to overheating during rapid charging.

How is the BMW testing of ASSB going?

BMW Group says the higher energy density compared to current battery technologies have the potential to achieve longer ranges in vehicles without the disadvantages of greater weight.

The current ASSB battery pack is being tested for thermal balance and power consistency as BMW Group continues to test the technology with Solid State.

“Solid Power is extremely proud that our partnership with BMW has resulted in the first demonstration of truly all-solid-state battery cells in a vehicle,” said John Van Scoter, President and Chief Executive Officer of Solid Power. “We believe in the promise of ASSB’s and continue to drive innovation of our sulfide electrolyte in support of that future for EV’s.”

Martin Schuster, Vice President Battery Cell and Cell Module at the BMW Group, added:

“Our BMW i7 ASSB test vehicle on the road is a perfect example of the BMW Group's technology-open mindset. We are continuously advancing the development of new battery cell technologies and are constantly expanding our know-how with valuable partners such as Solid Power. ”

When will we see solid state batteries on sale?

Solid state batteries still have some way to go before they become ready for production series cars - and BMW isn’t the only manufacturer working on the technology. Chinese maker BYD is aiming to have a demonstration solid state car by 2027, but the most likely date for series production will be the turn of the decade.

In the meantime, there are plenty of brilliant new electric cars available to lease using conventional battery technology - and now with an average of 300 miles on a charge (up from 235 in 2024) the advancement of the technology is ever increasing. Is now the time for you to go electric?