Donut Lab reports 409 Wh/kg energy density in independent battery test

Donut Lab has released independent test results for its battery technology, conducted by the Finnish research center VTT. The tests on a single cell, designated as 'Donut Battery V1.5' or DL6, showed a gravimetric energy density of 409.3 Wh/kg and a volumetric energy density of 804.7 Wh/l.

According to Donut Lab's CTO Ville Piippokert, the cell was energy-optimized as part of their ongoing development. The testing process involved measuring the cell's mass and volume, charging it fully, and discharging it at 25 degrees Celsius across a voltage range of 2.3 to 4.25 volts.

While the results are significant, technical reports note that the test utilized an optimized scenario with a low discharge rate of 0.1 C, which favors higher energy density readings. Furthermore, the results do not definitively prove the use of solid-state technology or the battery's readiness for mass production, despite previous claims by the company regarding its suitability for series vehicle manufacturing.