Small-grain SnO2, SnO2/Mo (2%), and SnO2/Mo (30%) samples were prepared by using low-temperature aqueous methods and tested as cathodes in secondary lithium batteries. Cells were cycled between 1.0 and 0.0 V. The best electrochemical performance was obtained from the Li/[SnO2/Mo (2%)] cell, which retained 87% of its initial capacity (510 mAh/g) after 50 cycles; by contrast, the Li/SnO2 cell only retained 60% of its initial capacity (570 mAh/g). Significantly increased Mo contents caused the capacity to fade drastically.