Long considered the pinnacle of EV technology, solid-state batteries promise more range, quicker charging, improved performance in cold climates, and a decreased risk of fire due to their exceptional thermal stability.
However, it is unlikely that a single solid-state battery that offers all of those advantages and is still reasonably priced would become available anytime soon. Different types of solid-state technology, each tailored for particular use cases, will probably arise, much like today’s lithium-ion batteries.
We are now witnessing the first indications of that future materialising in the largest EV market in the world. China is already a leader in battery development and production, and it is soon to introduce a semi-solid-state battery into a mass-market automobile at a reasonable price.
Owned by China’s state-backed SAIC Motor, the British automaker MG Motor has revealed that a semi-solid-state battery would soon be included in its small MG4 hatchback, which is priced between 80,000 and 120,000 yuan (about $11,000 and $16,500).
It’s an early indication that next-generation technology won’t be restricted to high-end vehicles or models with a strong emphasis on performance. It can be designed for low-cost EVs as well, and it might even be a better option than lithium-iron phosphate (LFP) batteries.
During charging and discharging, ions can flow between electrodes in a liquid electrolyte found in a traditional EV battery. Solid-state batteries use a solid electrolyte instead of a liquid. As the name implies, semi-solid-state batteries employ an electrolyte that resembles gel, providing a hybrid solution that combines elements of both types. Only 5 per cent liquid electrolyte will be used in MG’s battery.
It involves trade-offs, much like any other battery chemistries. The MG4’s battery pack, which is provided by QingTao Energy, a Chinese battery manufacturer, has an energy density of about 180 watt-hours per kilogram. The estimated 272–296 Wh/kg of Tesla’s 4680 lithium-ion cells is far more than that. Additionally, they lag substantially behind the 375 Wh/kg semi-solid-state cells from American startup Factorial.
However, it appears that this battery was not designed to win range competitions. Affordability, cold-weather performance, and safety seem to be the main objectives here, particularly in contrast to LFP batteries, which control the Chinese EV market.
According to the China Light-Duty Test Cycle, the MG4 should have a range of 537 km, or around 217 miles, under the more stringent EPA test (assuming a 35% reduction). That’s impressive for a tiny hatch that costs $16,500. It surpasses the 415 km CLTC range of the BYD Seagull. Because of China’s first-rate charging infrastructure, it might be the ideal daily driver or even a road tripper.
According to MG, the battery has passed stringent safety tests, including as puncture torture tests, and retains its range and performance even at -7°C (19°F). Another factor contributing to the pack’s longer range is its 70 kWh capacity, which is greater than the Seagull’s 30–43.2 kWh LFP battery.
Unfortunately, the U.S. will not see it. EV enthusiasts have been demanding this kind of EV, which has actually been lacking in the US.
The United States is also developing semi-solid-state batteries. However, it appears that the development here is more concerned with performance and longer range than with price, at least not in the near future.
Next year, Stellantis will begin testing a solid-state battery for the Dodge Charger Daytona EV. Solid-state batteries have already been fitted in an i7 and a prototype EQS by Mercedes-Benz and BMW.