The microstructure and electrochemical behavior of MnOx@reduced graphene oxide (rGO) composites derived from a MnO2/GO template are thoroughly investigated. An as-prepared MnO2/GO mixture is gradually converted to MnO2/rGO in a reduction process and is subsequently annealed under specific conditions to form the Mn3O4/rGO composites. The overall Li+ conversion reactions are visualized and the stability of the transformed MnOx phases is evaluated using density function theory calculations. The semispherical Mn3O4 anchored composite exhibits stable electrode performances, including both the Li+ anode and the Li+-air cathode catalyst, induced by the electrochemically favorable composite with an effective large contact area between the active materials and the electronic conductive rGO. This provides a comparative way of designing the electrode for multiphase metal oxide-based composite electrodes considering the specific electrochemical reactions in view of materials engineering.