Earlier this year, Finnish start-up Donut Lab officially announced the launch of the world's first all-solid-state battery that is ready for commercial mass production. The specifications of this battery are explosive: the energy density reaches 400Wh/kg, it can be fully charged in 5 minutes, and the number of charge and discharge cycles is up to 100,000 times, far exceeding the "5,000 upper limit" of traditional lithium-ion batteries. In the extreme range of -30°C to 100°C, the capacity retention rate is still over 99%, and the charging efficiency is not affected by temperature.
Recently, the all-solid-state battery was independently tested by VTT Technology Research Center, a Finnish state-owned research institution, and the results showed:
11C rate + double radiator: the battery cell is charged to 80% in 4.5 minutes, and the surface temperature rises from 26.5°C to a peak temperature of 63°C; 5C rate + single radiator: the battery cell is fully charged, and the temperature rises from 27°C to 61.5°C; 5C rate + double radiator: the starting temperature is 23.4°C, and the peak temperature is only 47°C.
According to reports, this solid-state battery uses a high-ion conductivity solid electrolyte and a special electrode structure to achieve an extreme charging rate of 11C, solving the contradiction between fast charging and capacity fading of solid-state batteries.
Even under 11C fast charging, the maximum battery surface temperature is only 63°C, which is far lower than the thermal runaway threshold of lithium batteries (usually >100°C), and the dual radiator configuration can further reduce the temperature to 47°C, meeting vehicle safety standards.
Moreover, there is no need for the complex cooling system and pressure maintenance device of traditional lithium batteries, which greatly reduces the complexity and cost of battery pack design while improving safety.
However, it should be pointed out that in the test with 11C rate + only a single radiator (the configuration closest to minimalist thermal management), the surface temperature of the cell reached the 90°C safety cut-off threshold, and VTT was forced to interrupt the test. After 4 minutes of cooling, the researchers fixed the cell more tightly to the radiator to improve heat conduction, and the test was restarted.
There are reports that the 90°C trigger protection is critical this time. Donut Lab previously promoted that this battery does not require active cooling, but under 11C fast charging, even passive thermal management with a single radiator is obviously not enough. In real vehicle scenarios, continuous 11C fast charging will inevitably require a certain thermal management design.
According to the plan, Donut Lab solid-state batteries will be commercialized for the first time on the Verge TS Pro electric motorcycle in the first quarter of this year, and have negotiated cooperation with a number of automobile manufacturers, aiming to achieve automotive-grade mass production in 2027.
