A Finnish startup, Donut Labs, promising solid-state battery technology is facing increasing skepticism. Initial optimism surrounding the company is waning due to conflicting test results and altered promises regarding the battery’s capabilities. Concerns have also emerged regarding the background and role of the company’s inventor. These developments are casting doubt on the viability of Donut Labs’ claims and the potential of their technology. The situation highlights the challenges in developing and commercializing next-generation battery solutions. Further investigation is needed to determine the accuracy of the company’s assertions and the future of the project.