Ralf. B. Wehrspohn

Silicon–air batteries (SABs) are attracting significant attention for their potential as high‐energy‐density electrochemical storage devices. One of the main limitations for the commercial use of alkaline SABs is the high corrosion, which results in a low conversion efficiency. Herein, the aim is to examine the influence of polyethylene glycol (PEG) on the conversion efficiency of SABs, shedding light on key factors affecting their performance. SABs using KOH as electrolyte at two concentrations, 0.5 and 2.0 mol L −1 , are investigated. The results show that replacing part of the water in the alkaline electrolyte with PEG changes the etching behavior from anisotropic to polishing and increases the specific energy density by 53% and 123% in 0.5 and 2 mol L −1 KOH electrolytes, respectively.