Donut Lab’s Solid-State Battery Survives Extreme Heat Tests
▼ Summary
– Finnish startup Donut Lab’s solid-state battery was tested under extreme heat and not only functioned but gained capacity, delivering over 107% of its room-temperature performance at 100°C.
– The battery’s improved performance at high temperatures is attributed to lower internal resistance in its solid electrolyte, allowing ions to move more easily compared to traditional liquid-electrolyte batteries.
– Solid-state batteries use a solid conductive material instead of flammable liquid electrolytes, which could lead to EVs with longer range, faster charging, and better safety by avoiding thermal runaway.
– Traditional lithium-ion batteries with liquid electrolytes are vulnerable to extreme heat, which can cause dangerous degradation, swelling, or fires, highlighting a key advantage of solid-state designs.
– The test results, while promising, leave unanswered questions about the battery’s specific chemistry and its long-term resilience to issues like dendrite growth, which can cause electrical shorts.
A Finnish company is making significant strides in battery technology, demonstrating a solid-state cell that not only withstands extreme heat but actually performs better under those punishing conditions. Donut Lab’s recent testing, conducted by the state-owned VTT Technical Research Centre of Finland, revealed its battery could operate and even gain capacity at temperatures reaching 100 degrees Celsius (212°F). This performance directly challenges a major weakness of conventional lithium-ion batteries, which often degrade or become hazardous in high heat.
The research team subjected a 3.6-volt, 26 amp-hour solid-state battery to a rigorous thermal examination. They established a baseline at a comfortable 20°C, then pushed the limits to 80°C and finally an extreme 100°C. To simulate real-world conditions, the battery was placed under physical pressure on a heatsink inside a precisely controlled chamber. The outcomes were striking. While the cell delivered 24.9Ah at room temperature, its output jumped to 27.5Ah at 80°C, roughly 110.5% of its baseline capacity. Even at the scorching 100°C mark, it maintained a robust 27.6Ah, or 107.1% of its room-temperature performance.
This counterintuitive improvement stems from the fundamental physics of solid-state design. Unlike standard “wet” lithium-ion batteries that rely on liquid electrolytes, solid-state batteries use a dry conductive material. In VTT’s study, the heat actually reduced the internal resistance within this solid electrolyte, allowing ions to move with greater ease and efficiency. This explains the observed capacity increase. While the physical battery pouch did lose its vacuum seal at the highest temperature, the cell itself continued to function and could be recharged afterward, a critical safety indicator.
The pursuit of a reliable solid-state battery has long been a focus for researchers, often dubbed the industry’s “holy grail.” Traditional lithium-ion packs, while prevalent, come with notable drawbacks: slower charging speeds, vulnerability to freezing temperatures, and the inherent risk of thermal runaway due to their flammable liquid components. Solid-state technology promises a path to electric vehicles with longer range, drastically reduced charging times, and superior resilience in both hot and cold climates. For liquid batteries, extreme heat can cause the electrolyte to vaporize or degrade, leading to potential fires, swelling, or a shortened lifespan.
It is important to view these promising results with measured optimism. The VTT report leaves several pivotal questions unanswered. The exact chemical composition of Donut Lab’s battery pack was not independently verified but was accepted as presented. Furthermore, the testing did not investigate the persistent “dendrite issue,” a known challenge where microscopic lithium growths can form inside solid-state cells, potentially causing short circuits. Donut Lab has indicated that future independent tests, part of its ongoing “I Donut Believe” campaign, will aim to address these and other critical performance parameters.
(Source: The Verge)
