A surprising breakthrough could help sodium-ion batteries rival lithium—and even turn seawater into drinking water. Scientists discovered that keeping water inside a key battery material, instead of removing it as traditionally done, dramatically boosts performance. The “wet” version stores nearly twice as much charge, charges faster, and remains stable for hundreds of cycles, placing it among the top-performing sodium battery materials ever reported.
Lithium Iron Phosphate (LiFe-PO) are actually really stable. Way less likely to catch fire in thermal runaway and don’t lose capacity as easily.
They just aren’t very energy dense, so you need more weight per wh. They also operate at a lower voltage per cell which means they charge slower.
They are used in short to med range EVs already, but the lower capacity makes it impractical to put enough for longer range EVs.
As an aside, I would argue that for the majority of people a large capacity EV battery is a bit of a waste. Mine is ~70Kwh, give or take. In optimal conditions my car estimates 240-250mi at 100%. Over the winter it’s showing anywhere from 140-180mi at 80%.
I moved cross country right after getting it and drove it 1000 miles. It took a bit longer, than it would in a gas car, but it was doable. Just have to plan segments to get to the next charger and try to charge to 100% with level 2 charging (240v AC) if you can when you stop for the night.