According to reports from Electrek and other media,An investigation conducted by battery researcher Ziroth and more than 20 independent battery experts confirmed that the Finnish Donut Lab company's all-solid-state battery, which made a global sensation at CES 2026, is fake and is actually an ordinary lithium-ion battery.The company used this technology to raise approximately US$25 million from more than 1,300 small investors, and its valuation was once pushed to US$1.25 billion.
The investigation began with questions about the startling claims made at CES 2026.At that time, Donut Lab claimed that its battery had an energy density of 400Wh/kg, a cycle life of over 100,000 times, and could be charged within 5 minutes.
However, five rounds of independent tests by the Finnish Technical Research Center VTT never touched the two core indicators of energy density and cycle life. Subsequently, a whistleblower letter from Nordic Nano’s former chief commercial officer further stated that these specifications were never actually achieved.
Ziroth's investigation provided decisive electrochemical evidence. The voltage curve of the VTT test shows that the voltage of the battery is 3.7 to 3.8 volts when the battery is 50% charged, which is completely consistent with the working range of high-nickel ternary lithium ion; the sodium-ion battery usually does not exceed 3.5 volts under the same power.
More critical evidence comes from battery expansion data:During the charging process, the graphite anode will produce a characteristic "inflection point" between 50% and 70% of the charge, which is caused by the rearrangement of lithium ions in the graphite layered structure. Donut Lab's battery shows exactly the same expansion curve, and the sodium ions are too large to be embedded in the graphite layer.
The measured energy density is about 298Wh/kg, which is only the level of ordinary high-quality lithium batteries and far from the claimed 400Wh/kg.
The investigation also traced the true source of the technology. The battery technology actually came from the German company CT Coatings, whose patent portfolio covers "eclectic" areas such as screen-printed paving tiles, menu clips and warning triangles.
What CT Coatings delivered to Donut Lab was actually an ordinary lithium-ion soft pack battery, and the foundry Nordic Nano has never produced a single cell.However, Donut Lab completed its own technical due diligence without independent verification.
In addition to technical fraud, commercial claims are also questionable. Donut Lab claims to have delivered mass-produced vehicles to consumers in the first quarter of 2026, but internal videos show that the first batch of products are actually trial production vehicles used to optimize the manufacturing process, and are not commercial vehicles delivered to customers.
Donut Lab CEO Lehtimaki later admitted to Finnish media,The 400Wh/kg battery cell was not installed in the vehicle, and the battery cell tested by VTT was “not even the final delivery version.” Leaked emails show that Donut Lab requested a specification certificate from CT Coatings but never received it.
The core reason why Donut Company conducts such fraudulent propaganda is to profit from the capital market. Among the company's more than 1,300 shareholders, more than 900 hold no more than 50 shares, and a single investment is estimated to be between US$3,000 and US$23,000 - a typical small and medium-sized retail investor group.
In a letter to investors, Lehtimaki promised "a return of up to 10 times within 12 to 18 months" and urged investors that "it is not too late to get in." After the CES press conference, the company's valuation was speculated to US$1.25 billion.
The investigation believes that the use of self-verification instead of independent third-party technical review as a fundraising method is the result of deliberately avoiding the strict due diligence of venture capital institutions.At present, the Finnish financial regulator and criminal investigation department have reportedly intervened in the investigation.
