MG Motor has announced that the second generation of its MG4 hatchback will feature a semi-solid-state battery. Solid-state batteries are the holy grail of EVs, a much more energy-dense construction that allows for all the things you ever wanted — faster charging, more range for the same weight, less risk of fire, you name it. Mercedes has already begun testing an EQS prototype with the technology. Big questions surrounding solid-state batteries, though, have been the price and whether or not they would be the exclusive domain of luxury brands.
The originally British but now Chinese-owned brand appears to have found a way to bring costs way, way down. Debuting August 4 in China, the MG4 will start at just $11,000 in that market, per InsideEVs. How did MG do it? By not making the solid-state pack entirely solid. The batteries, developed by QingTao Energy, still feature about 5% liquid electrolyte, resulting in a gel rather than a pure fluid like in a traditional lithium-ion battery. It’s also not the world’s greatest battery; it’s actually less energy dense than Tesla’s current batteries and even the semi-solid designs from the emerging American battery manufacturer Factorial.
That may sound like a downgrade, but the semi-solid battery still has one advantage: It doesn’t lose performance in cold weather, an Achilles heel of the lithium-ion type. The new battery operates at full capacity all the way down to 19 degrees fahrenheit, and at this price, that makes the MG4 a pretty great EV option for daily use.
Metal block solid
A traditional lithium-ion battery features both a cathode (a positively charged half) and an anode (negatively charged), which are awash in a liquid electrolyte that allows charged particles to move from one to the other, creating an electrical current. Solid-state batteries do away with the liquid, and the entire anode. Instead, when plugged in, the charged particles coming out of the solid lithium block pass through a ceramic separator and build themselves up into their own, temporary anode. When that’s discharged by turning the car on, the anode particles flow back through the circuit, eventually depleting the anode altogether.
This design allows the overall size of the battery to be much smaller and lighter, as you don’t have to lug an anode around everywhere. Weight, as we all know, is one of the big downsides of EVs. Get the weight down, and suddenly range gets way better even for the same amount of electrical storage.
That technology is coming soon; in addition to Mercedes, other companies like Volkswagen and Honda are developing solid-state batteries. But they require more pure lithium than a traditional battery, and given supply chain issues, that presents a problem of its own. Semi-solid-state is literally a halfway point between the two, and somewhat like PHEVs may provide a “best of both worlds” solution, at least for the near-term. MG wants to prove that’s the case, and what’s more, it can be done on the cheap. If it can, that’s a big step forward for EVs as a whole.
MG