June 29, 2022

Solid-state batteries for electric vehicles leap to mass production

This piece originally appeared on Inside climate news. It is republished with permission. Sign up for their newsletter here.


At some point, the development of solid-state batteries – in which electrons flow through a solid material instead of a liquid or gel – will lead to electric vehicles that can go much farther on a charging and battery storage systems that can hold more power while taking up less space. We just don’t know when that will happen.

But in the past 10 days, two announcements offer reason to believe the answer is “as soon as possible.”

First, Solid Power, a Colorado-based company that develops solid-state EV batteries for partners including Ford and BMW, said it had completed installing a “pilot production line” capable of manufacturing about 300 battery cells per week. This signals that the technology is now moving from the lab to the factory.

Second, researchers from the University of Houston published a paper showing how they developed a glass-like material that is highly effective as an electrolyte – the part of a battery that electrons pass through during charge and discharge cycles. – for use in a sodium-sulfur battery for energy storage. The research is notable because it is a solid-state battery and because it shows the promise of sodium-sulfur batteries as an alternative to lithium-ion batteries for long-term energy storage.

Let’s step back for a solid-state battery 101. I contacted George Crabtree, director of the Joint Center for Energy Storage Research, based at Argonne National Laboratory near Chicago, to help explain why these batteries are special. .

“I would say, first of all, solid-state batteries are very likely to be the next big thing commercially,” he said.

They would be the biggest leap forward in battery technology since 1991, he said. It was then that Sony introduced the first commercial lithium-ion battery.

Solid-state batteries are capable of holding much more energy per unit mass than today’s lithium-ion batteries, meaning an electric vehicle could run much longer before needing to be recharged, did he declare. Even though the electrolyte is solid, it is porous at the microscopic level, allowing electrons to pass through it.

Researchers have long known that a solid-state design has advantages over batteries that use liquid or gel, including lithium-ion batteries. One big advantage is that solid electrolytes can be lighter and take up less space than liquids or gels. But there are major engineering challenges that have slowed this technology from reaching consumers.

Data source: Toyota [Image: Paul Horn/courtesy Inside Climate News]

One issue is dendrites, the spiny fibers that can build up in a battery during charging, decreasing battery performance. Dendrites are not alive, although they sometimes look like tree branches, or even clumps of wild mushrooms. They are a problem for many battery types, including lithium-ion, and have been particularly frustrating for researchers designing solid-state batteries. Newer semiconductor designs have a variety of approaches to dealing with the problem, including the use of an electrolyte that resists or otherwise limits dendrite growth.

Researchers have developed solid electrolytes made of ceramics, glass, and mixtures of ceramics and glass.

Solid Power, based in Louisville, Colorado, is a spinoff of research started at the University of Colorado at Boulder. It was founded in 2011 and is now publicly traded with a market capitalization of $1.3 billion. The company’s battery uses a ceramic glass electrolyte.

Together with its partners Ford and BMW, Solid Power is one of the leading players in the race to develop a consumer electric vehicle running on a solid-state battery system.

Among the main competitors is QuantumScape of San Jose, Calif., which has a market capitalization of $5.1 billion and works with Volkswagen.

Almost every automaker develops solid-state batteries, either with an outside partner like Solid Power or QuantumScape, or through in-house research and development.

Announcing its new production line, Solid Power says it is on track to produce its systems on a much larger scale by the mid-2020s.

“With the pilot line of EV cells now installed, our next big challenge is to begin full-scale production and build cells that meet the requirements necessary for us to enter automotive qualification later this year,” said Derek Johnson, COO of Solid Power. in a report.

It refers to the years-long process of working with automakers to validate the safety and efficiency of the systems before the batteries can be sold to the public.

In addition to improving the performance of electric vehicles, solid-state batteries could be part of a new generation of energy storage systems.

Research findings from the University of Houston, published in the journal Nature Communications, show the results of a project to develop a solid-state battery for use in grid-scale energy storage.

The researchers say their battery is inexpensive, easy to build, has a high degree of mechanical stability, and is chemically stable – four important factors for market viability.

“To date, no solid sodium electrolyte has been able to meet all four of these requirements at the same time,” Yan Yao, professor of electrical and computer engineering and co-author of the paper, said in a statement. .

The key component is the glassy electrolyte which uniquely combines the properties of oxygen and sulfur, Yao said in an email. It also resists the formation of dendrites.

His team is trying to develop a battery that has the potential to combine low costs and a discharge capacity of up to 12 hours on a single charge. The key to low costs is that one of its main materials, sodium, is widely available and affordable, unlike lithium.

I asked Crabtree how these recent developments in research and manufacturing fit into the larger picture of the clean energy transition.

“Lithium-ion is the best battery we’ve ever had,” he said. “However, he can’t do everything.”

Lithium-ion batteries have been very successful for the current generation of electric vehicles, but are not well suited for long-haul land vehicles, trains, ships, or planes. Lithium-ion batteries are also not well suited for grid-scale energy storage of more than four hours.

Much of the current battery research focuses on what materials and designs will be most effective for these other applications, he said. The development of solid-state batteries is only a small part of this larger picture.

So solid-state batteries can make electric vehicles and energy storage systems capable of holding more energy than today’s batteries, but that’s just the start of something bigger. large and transformer for energy saving.