A complementary metal-oxide-semiconductor (CMOS) compatible process for fabricating on-chip microbatteries based on nanostructures has been developed by growing manganese dioxide nanowires on silicon dioxide (SiO2)/silicon (Si) substrate as a cathode material for lithium rechargeable batteries. High aspect-ratio anodized aluminum oxide (AAO) template integrated on SiO2/Si substrates can be exploited for fabrication of a vertical array of nanowires having high surface area. The electrolytic manganese dioxide (EMD) nanowires are galvanostatically synthesized by direct current (dc) electrodeposition. The microstructure of these nanowire arrays is investigated by scanning electron microscopy and X-ray diffraction. Their electrochemical tests show that the discharge capacity of about 150mAhg−1 is maintained during a few cycles at the high discharge/charge rate of 300mAg−1.