Lawrence Berkeley National Laboratory

The authors regret that a technical mistake has been discovered, which impacts the current density and power density reported in this article. Briefly, the mistake was caused by catalyst solution leaking out of the intended 1 cm2 catalyzed area and depositing catalyst over the whole cell. As a result, the calculated current and power densities (total divided by the catalyzed area) were higher than reality because the measured current and power were dividing by the intended 1 cm2 instead of the actual area including the leakage, which was approximately 5 cm2. This issue is presented, analysed, and discussed in further detail in the supporting information of Reference [1]. Note that this issue does not impact other reported data, including OCV, flame and cell temperature, comparison of various operating conditions, durability, thermal cycling stability, and general trends and conclusions. The authors would like to apologise for any inconvenience caused.