Lithium-oxygen battery has been studied as a hot spot because of its high theoretical specific capacity. But its severe discharge/charge polarization and poor cycle stability greatly hinder its large-scale applications at current stage. The rational design of cathodic catalysts for the oxygen reduction/evolution reaction (ORR/OER) is thus essential to reduce overpotential and extend cycling stability. Three kinds of multi-metal oxides Li_xMO (x=0.79, 0.30, 0.08; M=Ni/Co/Mn) with different lithium contents, which were recycled from the cathodes of spent lithium-ion batteries in different charging states, were explored as cathodic catalysts for lithium-oxygen batteries, respectively. The lithium content and phase structure of these multi-metal oxides Li_xMO were determined by inductive coupled plasma emission spectrometer (ICP) and X-ray diffraction (XRD). Phase transformation from layer to NiO-like rock-salt was observed upon continuous deintercalation of Li⁺ in Li_xMO materials (0.79→0.30→0.08). The dependence of the electrochemical behaviors on the lithium content and lattice structure of the Li_xMO catalysts was also investigated systematically. Compared to that of Li_0.79MO and Li_0.08MO, lithium-oxygen batteries with Li_0.30MO catalyst have delivered a higher specific capacity of 14655.9 mAh•g^–1, a lower charge potential of 3.83 V, and a higher round-trip efficiency of 72.2% under the limited capacity of 800 mAh•g^–1 and current density of 100 mA•g^–1. Moreover, the charge terminal voltage of Li_0.30MO catalyst is stable lower than 4.3 V even after 140 cycles. Furthermore, the ex-situ scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) techniques were used to elucidate the reaction mechanisms with different Li_xMO catalysts. The superior catalytic activity of Li_0.30MO cathode can be mainly attributed to the synergistic effect between its layered/NiO-like rock-salt complex structure and oxygen vacancy formed, which can promote the reversible formation and decomposition of discharge product and improve the cycling stability of lithium-oxygen battery. Hence, the result corroborates that recycling of spent cathodes from lithium-ion batteries can serve as novel strategy to design large-scale and effective catalysts for lithium-oxygen battery.