Exploring　composite　materials　with　ideal　structures　is　an　effective　way　to　achieve　synergy　among　different　functional　components.　In　this　paper,　a　thermal　decomposition　method　was　adopted　to　prepared　IrO2–CeO2-graphene/Ti　composite　electrodes.　The　influence　of　adding　graphene　on　the　composite　material＇s　electronic　structure　was　analyzed　by　first-principles　calculations,　and　its　microstructure　and　electrochemical　performance　were　also　observed　though　various　tests.　The　results　indicated　that　coatings　containing　graphene　exhibited　a　hierarchical　porous　structure,　which　could　enlarge　the　specific　surface　area　effectively.　The　band　gaps　of　the　IrO2–CeO2　composite　oxides　were　filled　by　the　energy　level　of　C,　which　reduced　the　electron-transfer　resistance.　With　amorphous　CeO2　and　the　graphene　acting　as　highly　efficient　ion-diffusion　and　electron-transfer　channels　respectively,　the　electrodes＇　charge　storage　performances　were　improved.　The　electrodes＇　specific　capacitance　values　rose　at　first,　then　decreased　as　the　graphene　contents　increased,　reaching　a　maximum　of　368　F　g−1　when　the　content　was　2　mg　mL−1.　However,　adding　graphene　could　harm　the　electrodes＇　cycling　stability;　excessive　graphene　could　also　encapsulate　IrO2　nanoparticle　and　hinder　contact　with　the　electrolyte,　thus　reducing　the　electrodes＇　specific　capacitances.　©　2020　Elsevier　Ltd　and　Techna　Group　S.r.l.