Even Affordable EVs Are Getting Solid-State Batteries Now 

• A new MG4 electric hatchback will debut in China on August 4.
• It’s expected to become the world’s first small mass-market EV equipped with a semi-solid-state battery.
• The estimated range is 537 kilometers (333 miles) on China’s Light-Duty Test Cycle.

Solid-state batteries have long been regarded as the crown jewel of EV tech—offering the promise of more range, faster charging, better cold-weather performance and lower fire risk thanks to superior thermal stability.

But a single solid-state battery that delivers all of those benefits and remains affordable is unlikely to materialize anytime soon. Like today’s lithium-ion batteries, different flavors of solid-state tech will likely emerge, each optimized for specific use cases.

Now, in the world’s largest EV market, we’re seeing the first signs of that future coming to life. China is already the hotbed of battery manufacturing and innovation and it’s now about to bring a semi–solid-state battery to an affordable mass-market vehicle.

British carmaker MG Motor—owned by China’s state-backed SAIC Motor—has announced that its compact MG4 hatchback, priced between 80,000 yuan and 120,000 yuan (around $11,000 to $16,500), will soon come with a semi–solid-state battery.

If so, it would be the first truly budget EV in the world to use the technology, CarNewsChina reported.

Photo by: MG

It’s an early sign that this next-gen tech won’t be limited to expensive cars or performance-focused models. It can be engineered for affordable EVs also and maybe even serve as a better alternative to lithium-iron phosphate (LFP) batteries.

In a conventional EV battery, a liquid electrolyte allows ions to move between electrodes during charging and discharging. Solid-state batteries swap the liquid for a solid electrolyte. Semi–solid-state batteries, as the name suggests, use a gel-like electrolyte, offering a hybrid solution that mixes the aspects of both designs. MG’s battery will use only 5% liquid electrolyte.

As with all battery chemistries, it’s about tradeoffs. The pack going into the MG4, supplied by Chinese battery maker QingTao Energy, has an energy density of around 180 watt hours per kilogram. That’s significantly lower than Tesla’s 4680 lithium-ion cells, which are estimated at 272–296 Wh/kg. They’re also far behind American startup Factorial’s semi–solid-state cells rated at 375 Wh/kg.

Photo by: MG

But it seems like this battery wasn’t built to win range contests. The goal here appears to be affordability, cold-weather performance and safety—especially compared to LFP batteries, which dominate the Chinese EV market.

The MG4 is expected to deliver 537 kilometers of range on the China Light-Duty Test Cycle, which translates to roughly 217 miles under the stricter EPA test (assuming a 35% reduction). For a $16,500 compact hatch, that’s impressive. It outpaces the BYD Seagull’s 415 km CLTC range. It may be a perfect daily driver or even a road tripper, thanks to China’s excellent charging infrastructure.

MG says the battery maintains its range and performance even at -7°C (19°F) and has passed rigorous safety tests, including puncture torture tests. The pack’s 70 kWh capacity—larger than the Seagull’s 30–43.2 kWh LFP battery—also helps explain its superior range.

Too bad it won’t come to the U.S. This is the type of EV that’s actually been missing stateside and something EV fans have been clamoring for.

Semi-solid-state batteries are being developed in the U.S., too. But the development here seems to be focused more on longer range and performance, not much on affordability—not in the short-term at least.

Stellantis will start testing the Dodge Charger Daytona EV with a solid-state battery next year. Mercedes-Benz and BMW have already installed solid-state batteries in a prototype EQS and an i7.

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