Solid-state batteries could be a breakthrough for electric vehicles (EVs) by storing more energy, charging faster and offering greater safety than liquid lithium-ion batteries, accelerating the shift of cars to fossil fuels.
How do they differ from liquid lithium-ion batteries?
Solid-state batteries use thin layers of solid electrolytes, which carry lithium ions between electrodes.
Lithium-ion (li-ion) batteries use liquid electrolytes and have separators that prevent the positive electrode from coming into contact with the negative electrode.
Currently, solid-state batteries are used in devices such as pacemakers and smart watches.
Mass-market production of these batteries for EVs will take three to five years, experts say.
What are the advantages of solid state batteries?
They are probably safer and more stable than liquid Li-ion batteries in which the electrolyte is volatile and flammable at high temperatures. This makes electric vehicles using Li-ion batteries more vulnerable to fires and chemical leaks.
Increased stability means faster charging and reduces the need for bulky safety equipment.
They can hold more energy than liquid Li-ion batteries, speeding up the transition from petrol vehicles to electric vehicles as drivers don’t have to stop as often to recharge their cars.
Why is it difficult to mass-produce solid-state batteries?
Automakers and technology companies have been producing solid-state Li-ion battery cells one by one in a lab, but have so far failed to scale that up to mass production.
It is difficult to design a solid electrolyte that is stable, chemically inert and yet a good ion conductor between the electrodes. They are expensive to manufacture and prone to cracking due to the brittleness of the electrolytes as they expand and contract during use.
Currently, a solid-state cell costs about eight times more to make than a liquid Li-ion battery, experts say.
Who is trying to make them?
Japan’s Toyota is one of the frontrunners in the mass production of solid-state batteries. It has said it struggles with their short lifespan but still plans to start making them in mid-2020.
In addition to Toyota’s internal research, Toyota has partnered with Japan’s Panasonic to develop these power packs with their Prime Planet Energy & Solutions business.
On its heels, German Volkswagen has invested in Bill Gates-backed US battery company QuantumScape, which aims to introduce its battery for VW’s EVs and eventually other automakers by 2024.
VW says the battery will provide about 30 percent more range than a liquid battery and charge to 80 percent capacity in 12 minutes, which is less than half the time the fastest-charging Li-ion cells available today.
Stellantis, formed in January through the merger of Italian-American automaker Fiat Chrysler and French PSA, has a venture called Automotive Cells Co with TotalEnergies and a partnership with China’s Contemporary Amperex Technology (CATL). Stellaantis plans to introduce solid-state batteries by 2026.
Ford Motor and BMW AG have invested in the startup Solid Power, which says its solid-state technology can deliver 50 percent more energy density than current lithium-ion batteries. Ford expects to cut battery costs by 40 percent by the middle of the decade.
South Korean Hyundai Motor, which has invested in the start-up of SolidEnergy Systems, plans to mass produce solid-state batteries by 2030.
Samsung SDI, a subsidiary of Samsung, is developing solid-state batteries.
EV market leader Tesla has so far not said it plans to develop or use solid-state cells in its cars.
© Thomson Reuters 2021