The effect of silver co-sputtering on the characteristics of amorphous V2O5 films, grown by dc reactive sputtering, is investigated. The co-sputtering process influences the growth mechanism as well as the characteristics of the V2O5 films. X-ray diffraction (XRD), Inductively coupled plasma-atomic emission spectrometry (ICP-AES), field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared spectrometry (FT-IR) and X-ray photoelectron spectrometry (XPS) results indicate that the microstructure of the V2O5 films is affected by the rf power of the co-sputtered silver. In addition, an all-solid-state thin film battery with full cell structure of Li/LiPON/Ag x V2O5/Pt has been fabricated. It is found that the silver co-sputtered V2O5 cathode film exhibits better cycle performance than an undoped one.