“…4 In the former category, MnO x without any doping have been directly used as electrode materials, including MnO, MnO 2 , Mn 2 O 3 , Mn 3 O 4 . The materials used to dope MnO x are mainly in three cases: carbon materials such as carbon black, acetylene black, CNTs and exfoliated graphite; 12-14 metal oxides including oxides of Ni, Ru, Cu, Fe, Co, Mo and Ag; 15,16 and conducting polymers e.g. Therefore, various hybrid composites of MnO x have been synthesized to overcome this shortage.…”