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Increasing energy demands and worsening environmental issues have stimulated intense research on alternative energy storage and conversion systems including supercapacitors and fuel cells.Mixed transition-metal oxides(MTMOs),typically designated as AxB3-xO4(A,B = Co,Ni,Zn,Mn,Fe,etc.)with stoichiometric or non-stoichiometric compositions,have recently captured worldwide interests due to their unlimited potentials in energy storage and conversion applications in terms of remarkable electrochemical properties,low cost and environmental friendliness.[1-3] Among various MTMOs,spinel nickel cobaltite(NiCo2O4)has been suggested as a promising alternative candidate for pseudocapacitors and ORR catalyst because of its better electrical conductivity and richer redox chemical valences over its two corresponding singlecomponent oxides.[4,5] Despite all the merits delivered by MTMOs,the relative poor electrical conductivity,low surface area and large volume change during chargedischarge processes are still great challenges limiting their capacitive behavior and ORR catalytic activity.