Donut Lab’s Solid-State Battery Achieves Breakthrough in First Test Results
Finnish startup Donut Lab has made significant strides in solid-state battery technology. The company recently unveiled promising results from independent tests on its innovative battery, conducted by the VTT Technical Research Centre of Finland.
Breakthrough Test Results
The test showcased the battery’s remarkable charging speed and thermal performance. Donut Lab’s solid-state battery charged from 0 to 80 percent in about 9.5 minutes, retaining 100 percent of its capacity. In a separate test, it achieved the same charge in just 4.5 minutes while still maintaining 99 percent capacity.
Advantages of Solid-State Batteries
- Solid-state batteries have a higher energy density compared to traditional lithium-ion batteries.
- They avoid hazards associated with liquid electrolytes, such as flammability, and perform better in extreme temperatures.
- The battery structure does not require the extensive cooling systems that most lithium-ion variants need.
Typically, electric vehicle (EV) batteries using traditional lithium-ion technology charge slowly and can take 30 to 40 minutes for a full charge. Donut Lab aims to reduce that time to about 5 minutes, similar to refueling a gasoline vehicle.
Testing Methodology and Results
The VTT team employed a passive cooling system during testing. They conducted the evaluation under two configurations: the battery was either sandwiched between aluminum plates or placed on a single metal surface. This method ensured efficient thermal management without relying on conventional liquid cooling systems.
The researchers utilized “C-rate” measurements to determine charging speed relative to capacity. Traditional lithium-ion batteries charge at rates between 1C and 3C, while Donut Lab’s battery achieved charging rates of 5C and 11C during tests.
Under these conditions, the battery reached 80 percent charge in approximately 9.5 minutes and a full charge in just over 12 minutes. Importantly, it delivered 100 percent of the charged capacity upon discharge.
Key Specifications
- Charging time: 0-80% in 4.5 to 9.5 minutes
- Full charge time: Approximately 12 minutes
- Battery capacity: 26Ah
- Nominal energy: 94Wh
- Expected lifespan: 100,000 cycles
For context, current lithium-ion batteries typically last between 1,500 and 3,000 cycles and have energy densities ranging from 200 to 300 watt-hours per kilogram (Wh/kg). Donut Lab claims its battery achieves 400 Wh/kg.
Potential Challenges Ahead
Despite the positive test outcomes, some critical questions remain. The VTT report did not confirm the exact chemistry of Donut Lab’s battery. Additionally, issues such as the “dendrite problem” could present risks, where microscopic structures form between the anode and cathode, potentially leading to electrical shorts.
Moving forward, Donut Lab anticipates releasing further independent test results as part of its ongoing “I Donut Believe” initiative. As the company continues its research, it may address these unresolved concerns and further substantiate its claims.
