As a potential cathode material for the ICD lithium battery, one advantage of Ag6Mo2O7F3Cl (SMOFC) is its enhanced gravimetric capacity of ca. 133 mAh/g above 3 V (vs Li+/Li) delivered by two biphasic transitions at 3.46 and 3.39 V (vs Li+/Li). The unique crystal structure of SMOFC enables a high silver ion conduction: sigma(perpendicular to[001]) = 3.10(-2) S/cm (+/-2.10(-2) S/cm) and sigma(//[001]) = 4.10(-3) S/cm (+/-2.10(-3) S/cm) and, hence, an excellent discharge rate capability. Lithium insertion has been monitored by in situ XRD measurements with HRTEM investigations. There is a linear isotropic collapse of the structure leading to a fully amorphous structure beyond four inserted lithiums.