Semiconductor oxides like ZnO, TiO2, etc. used as anode materials but why not used as cathode materials? But coatings of cathode materials with semiconductor oxides were done.what is the reason? similarly p-type semiconductor Co3o4, NiO, CuO etc. can be used as anode material but not as cathode...kindly guide me... coatings of cathode materials with semiconductor oxides were done but why not used as composite materials with cathode electrodes in Li ion batteries?