Benchmarking the Performance of Moisture-Sensitive Battery Materials: the Importance of the Electrode Preparation Method

Many promising electrode materials for next-generationbatteriesare moisture-sensitive, resulting in various challenging issues. Here,we demonstrate the vital importance of the electrode preparation methodin benchmarking their performance reliably using the O3-type NaNi1/3Fe1/3Mn1/3O2 (NFM111) asa model material. We show that the conventional slurry-based methodleads to poor-quality electrodes, whereas those prepared by a drymethod in argon exhibit a remarkable capacity which is significantlyhigher than previously reported values, highlighting that the energydensity of layered sodium cathodes has been systematically underestimated.Collectively, we propose a general electrode preparation protocolfor benchmarking moisture-sensitive battery materials.