This book contains a novel combination of experimentaland model-based investigations, elucidating the complex processes inside zincair batteries. The work presented helps to answer which battery composition andwhich air-composition should be adjusted to maintain stable and efficientcharge/discharge cycling.In detail, electrochemical investigations and X-raytransmission tomography are applied on button cell zinc air batteries andin-house set-ups. Moreover, model-based investigations of the battery anode andthe impact of relative humidity, active operation, carbon dioxide and oxygen onzinc air battery operation are presented. Thetechniques used in this work complement each other well and yield an unprecedented understanding of zinc airbatteries. The methods applied are adaptable and can potentially be applied togain further understanding of other metal air batteries.