A new sodium-metal battery has posted a charging number that makes today’s EVs look painfully slow. In laboratory testing, the cell operated at a 15C rate, equivalent to completing a charge or discharge in roughly four minutes.
That doesn’t mean researchers plugged in an electric car and watched it fill up before the driver finished buying coffee. The result came from a small experimental cell using a new quasi-solid electrolyte, while the larger pouch-cell prototype delivered far less dramatic performance.
How did it reach four minutes
The battery uses a gel electrolyte called Sn-FB QSE, which helps sodium ions move more evenly and keeps the metal surface stable during charging.
That stability addresses one of the biggest problems facing sodium-metal batteries. Sodium can form sharp deposits called dendrites, which may grow through the cell and cause a short circuit. The tougher gel structure reduced the weak spots where those deposits usually begin.
At 15C, the full cell still delivered 80.1 mAh per gram. It’s an impressive laboratory result, but a four-minute test rate isn’t the same as charging an EV pack from empty under real-world heat, power, and safety constraints.
Where the longevity claim changes
The battery’s strongest durability result came at a slower 3C rate, equivalent to about 20 minutes. Under those conditions, the full cell retained 90% of its capacity after 2,000 cycles.
A separate sodium-to-sodium test ran for more than 6,000 hours without failing. That simplified setup checks whether sodium deposits evenly, though it isn’t a complete battery powering a device.
These results show that the electrolyte improved stability across several experiments. They don’t show one cell combining four-minute charging, 2,000-cycle retention, and 6,000-hour endurance in a single test.
Why an EV is still far away
The researchers also built a small pouch-cell prototype, which is closer to the battery format used in real products. It retained 84% capacity after 19 cycles at a slow 0.1C rate. Another version held 60% after 100 cycles at 0.2C under light pressure.
Neither pouch cell matched the headline charging speed or lifespan. The next meaningful milestone is a larger pouch cell that can maintain fast charging without rapid degradation across hundreds of cycles without pressure or punctures.