Safety is one of the most important factors in the development of lithium cells. The thermal stability of a-V2O5/Li cells is investigated. Vanadium compound deposition on a lithium anode during charge/discharge cycles is observed. Vanadium compounds dissolve electrochemically and are deposited on the anode. The low reactivity of the vanadium deposited lithium anode is observed by calorimetry. Chemical-state analysis and morphological investigation of the lithium anode suggest that the improvement in stability is primarily due to the passivation film.