Suddenly, solid state batteries — the technology that is supposed to give us lower priced electric vehicles with more range and faster charging times — are like Chicken Man. They’re everywhere! They’re everywhere! Conventional lithium-ion batteries use a semi-liquid electrolyte between the anode and the cathode. That electrolyte can catch fire or explode if it gets too hot or if the battery is punctured.
Solid state batteries replace the semi-liquid electrolyte with a solid substance that is far more tolerant of high heat and less susceptible to damage in the event of a collision. In the lab, they have a higher energy density, can charge faster, and weigh less than traditional lithium-ion batteries. Not only do they cost less, they may require simpler, less costly cooling systems and could allow automakers to dispense with the heavy, bank vault quality safety cages used today to prevent damage to traction batteries in the event of a collision. Those two factors alone could lower the cost of manufacturing electric vehicles, making them affordable for more drivers.
There is theory and then there is reality. What works in the lab may not translate easily to commercial production. As high tech as today’s battery cells are, the manufacturing process used to make them harks back to the days of 8-tracks and cassettes. The machines that apply the semi-liquid electrolyte for battery cells today trace their origins to the roll-to-roll machines that applied a ferric oxide coating to plastic tape. Any new product that employs existing manufacturing techniques has a higher likelihood of success than one that requires all the old production equipment be scrapped and replaced with new machines.
So far this week — and it’s only Friday — there are announcements from Ford, BMW, Toyota, and Solid Power claiming solid state battery technology is just around the corner. Here’s the latest.
Ford/BMW Collaboration With Solid Power
Over the past several years, both Ford and BMW have invested in Colorado based Solid Power. In a press release dated December 10, the company said it is now producing 20 amp-hour (Ah) multi-layer solid state lithium metal batteries. The 330 Wh/kg, 22-layer cells have higher energy density than any commercially available lithium-ion battery manufactured today according to the company. It says it expects its batteries to exceed 400 Wh/kg by 2022.
That’s great news, but here’s the exciting part. Solid Power solid state cells can be manufactured at commercial scale using industry standard lithium-ion roll-to-roll production equipment. The 20 Ah cells are currently being validated by Solid Power’s automotive partners, including Ford and BMW. Other investors in the company include Hyundai, Volta Energy, Solvay, and Samsung. Solid Power has already shipped more than 400 prototype solid state cells to external parties for independent performance validation and expects to begin the formal automotive qualification process with even larger capacity solid state battery cells in early 2022.
“Solid Power has shown that our all solid state cell design can be produced using scalable processes on industry standard lithium ion equipment, and early multi-layer prototype cells using a highly conservative cell design have already exceeded the energy performance of today’s lithium ion cells,” says CEO and co-founder Doug Campbell. “Proof of successful scale-up is key to realizing the potential of any next generation battery technology, which is why lithium ion roll to roll compatibility has been our mission since day one.”
Here are some specs for you to consider:
- -10° C operation
- 50% fast charge in 15 minutes at room temperature
- Separator thickness as low as 25 microns
When it comes to battery life, the company says its solid state cells are capable of continuous discharge rates of up to 5C. Its early 10-layer 2 Ah pouch cells are showing stable early cycling at near room temperature while the corresponding double layer pouch cells have already surpassed 250 stable cycles. Further advancements are anticipated. The transition of the company’s new electrolytes, binders, and electrode designs to the continuous roll to roll production line will result in improvements to specific energy, energy density, cycle life, and charge rates and culminate in a full scale cell demonstration by the end of 2021.
“Solid Power is proving that an all solid-state platform can excel in environments ranging from below freezing to 70°C with an inherently safer chemistry that is free of flammable liquids or gels,” said Josh Buettner-Garrett, the company’s Chief Technology Officer. “Solid Power has now demonstrated feasibility of large format cells produced on the same equipment used for conventional lithium ion and we are excited to push the performance further as we move toward automotive qualification.”
After we slammed Toyota twice this week for its tepid embrace of the EV revolution, the company announced on Thursday that it is having success with its own solid state battery program. According to Nikkei Asia, Toyota plans to be the first company to sell an electric vehicle equipped with a solid state battery and will unveil a prototype next year. Curiously, the company’s global media center makes no mention of this news.
The Nikkei Asia account extols the virtues of solid state batteries, but provides no technical details about any battery under development by Toyota. It does say such batteries can be recharged in 10 minutes (maybe) and have a reduced risk of fires. It adds the electric vehicles being developed by Toyota will have twice the range of a vehicle using a conventional lithium ion battery under the same conditions without sacrificing interior space. Around the CleanTechnica jacuzzi and sushi bar this morning, the general feeling was that this is more happy talk from Toyota. Suffice to say we are skeptical.
But Toyota is said to have over 1,000 solid state battery patents and has already convinced Mitsui Mining and Smelting to create a pilot facility to manufacture solid electrolytes for its batteries. If the research is having an impact on Toyota’s supply chain, that is a sign that things are getting serious. The pilot plant should be able to provide enough electrolytes to begin manufacturing prototype batteries by next year. The Japanese government is said to be working to secure access to sufficient supplies of lithium for the country’s nascent electric car manufacturing sector.
Just this week, QuantumScape announced its solid state battery technology is coming along nicely. Now Solid Power and Toyota say they can see the day when solid state batteries are in general production is not far away. For EV owners, all these news reports add up to a sense that lighter, less expensive electric cars with more range and shorter charging times are on the horizon. We can’t wait!