What Are Solid-State Batteries, and Why Is BMW Betting Big on Them?

Matt Bubbers February 9, 2023

As far as drivers are concerned, solid-state batteries are a bit like the Holy Grail for electric vehicles. These batteries promise to be something of a miracle cure for everything that ails the modern EV: more range, less weight, lower cost, faster charging, improved safety and better long-term performance. Too good to be true, you say? Read on.

Cars powered by all-solid-state batteries (ASSBs) are elusive, always seemingly just around the corner. Then, earlier this year, BMW announced it was taking a big step forward on its way to putting these batteries in real cars that we can actually buy. We’re (patiently) stoked about it.

Why Should Drivers Care About Solid-State Batteries?

For drivers of electric vehicles, the most obvious benefit of ASSBs is way more driving range. (Kiss range anxiety goodbye!) Estimates vary, but EVs powered by solid-state batteries could go 1.5 times or even twice as far as current EVs that use lithium-ion batteries.

In the real world, that means a compact sport sedan like the BMW i4 M50, which has an official range of 435 kilometres, could go 800 km on a single charge if it were stuffed with ASSBs. For a big, flagship luxury sedan like the BMW i7, you could be looking at a range of 1,000 km. That’s Vancouver to Banff in one shot, with range to spare.

More driving range, but what else?

Since these batteries are more energy-dense, which means you get more kilometres of driving per pound of battery. As a result, cars could make do with smaller battery packs without sacrificing driving range or performance, as Automotive News reports.

Not only would that make EVs significantly more affordable. Batteries are the reason EVs cost more to purchase than conventional cars. Solid Power, the Colorado-based startup working with BMW to commercialize this technology, estimates its batteries will be 15 to 35 per cent cheaper than current lithium-ion cells. Lowering the cost of batteries, and therefore EVs, would surely spur adoption, helping Canada hit its target of having 395,000 new electrified vehicles sold in 2026, 1.2 million in 2030, and 2.0 million in 2035.

Solid-state batteries wouldn’t just make EVs cheaper, it’d make them lighter as well. They open up more possibilities for different types of electric vehicles.

For example, in a sports car, weight is enemy No.1, and current batteries are monstrously heavy. That’s why there are hardly any electric sports cars on the market yet. Solid-state batteries could solve that problem; imagine a featherweight sports car the size of a Porsche 718 Cayman with quad-motor electric drive and 800 horsepower.

Not only that, but solid-state batteries wouldn’t degrade as quickly as the lithium-ion batteries we’re accustomed to in our cellphones and laptops. Notice how your iPhone just doesn’t last through the day after a couple years? That’s less of a concern with solid-state batteries, which have a much longer life expectancy.

In terms of mileage, Solid Power predicts its EV batteries would be good for nearly 600,000 km. In other words, they’ll probably outlast your car.

Your EV Would Recharge Faster Too

Solid Power claims its EV’s battery could recharge from 10 to 90 per cent in as little as 20 minutes. With the best current lithium-ion batteries, it’d take roughly twice as long to do the same charge, or probably longer.

Okay, so how do solid-state batteries work?

Without forcing you to remember your high school chemistry lessons, solid-state batteries are, well, solid. Where lithium-ion batteries use a liquid to manage the flow of energy, solid-state batteries don’t.

“By doing away with the sloshing, flammable liquid electrolyte, solid-state batteries are, by default, more stable and compact. The solid electrolyte can be composed of any number of everyday materials, like ceramics and glass,” J.D. Power explains.

Today, solid-state batteries are usually only found in small devices, like pacemakers.

What Big Step Is BMW Taking With Its Solid-State Batteries?

At its battery cell manufacturing centre in Germany, BMW is installing a prototype production line for Solid Power’s solid-state batteries. The car company plans to start testing full-scale automotive-grade battery cells from Solid Power later this year. After that, a BMW prototype vehicle powered by solid-state batteries is due out before 2025.

BMW has been working with Solid Power since 2016, so this has been a long time coming.

“BMW remains committed to the pursuit of all-solid-state batteries, a technology which we believe has significant potential for the future,” said Frank Weber, the BMW board member responsible for development. “We expect this agreement to accelerate the installation of our solid-state prototype line and our companies’ mutual goal of commercializing this promising cell technology.”

Of course, BMW and Solid Power aren’t the only companies working to get solid-state batteries into your driveway. Volkswagen, Mercedes-Benz and some Japanese car companies are hoping to roll out solid-state EVs in the second half of the decade. Samsung and Panasonic are working on this technology as well; so, it’s a race to the finish line.