Li-O₂ batteries have the potential to be the candidate for the power source to drive electric-vehicles and portable electronics. Recent studies have been focused on searching for stable electrode materials for rechargeable Li-O₂ batteries with high efficiency and long cycle life. Here Pd-functionalized MnO_x-GeO_y nanomembranes were fabricated as the cathode materials of Li-O₂ batteries. The incorporation of Pd nanoparticles on the nanomembranes matrix enables the fast transportation of both electrons and lithium ions as well as oxygen-containing species, thus efficiently lowering the charge voltage and greatly prolonging the cycle life of Li-O₂ batteries to 160 cycles without apparent degradation. More importantly, Li-O₂ batteries using such as-prepared Pd-functionalized MnO_x-GeO_y nanomembranes can be cycled repeatedly with extremely low charge voltage of only ~3.14V. The presence of small amounts of Pd nanoparticles contributes to the formation of toroid-like Li₂O₂ during the oxygen reduction reaction which is efficiently decomposed afterwards by the oxygen evolution reaction. The encouraging performance suggests that such nanomembrane-based materials are promising cathode architectures for the future Li-O₂ batteries.