The electrochemical performance of RGO-Co(mqph) electrocatalyst for Li–air batteries with hybrid electrolyte was investigated. The RGO-Co(mqph) showed high onset potential (−0.09 V vs. Ag/AgCl) under oxygen condition in the rotating disk electrode system for oxygen reduction reaction, which was higher than that of RGO (−0.17 V vs. Ag/AgCl). Furthermore, the ORR mechanism of RGO-Co(mqph) showed 3.52 electron pathway. On the other hand, the RGO only exhibited the electron transfer number of 2.22 for ORR. Moreover, the electrochemical performance of Li–air batteries with hybrid electrolyte showed that the RGO-Co(mqph) provided good discharge performance and cycle performance. It was thus considered that the Co(mqph) strongly affected ORR activity for cathode electrode. This was ascribed to synergic effect due to combination between RGO and Co(mqph).