Li/Ag2VO2PO4 cells exhibit high power output and a 15000 fold decrease in impedance upon initial discharge. Energy dispersive X-ray diffraction (EDXRD) allows dimensional resolution of the reaction progress in situ, revealing that silver metal (Ag0) initially forms at the electrode–electrolyte interface. This report contains the first description of an in situ EDXRD analysis of a cathode located within an intact Li-anode cell.
