Facile synthesis of strontium ferrite nanorods/graphene composites as advanced electrode materials for...

The exploration of efficient and stable electrode materials is important for supercapacitors. Composite electrode materials are promising candidates for supercapacitors since single component materials cannot satisfy the dual needs of high energy density and power density. In this study, uniform strontium ferrite nanorods are grown on graphene by a facile surfactant assisted hydrothermal method. The resultant SrFe₁₂O₁₉ nanorods/graphene (SrFe₁₂O₁₉ NR/G) composites combine the merits of both SrFe₁₂O₁₉ and graphene, and the SrFe₁₂O₁₉ NR/G based supercapacitors exhibit specific capacitances of 681.2 and 450.9 F g^-1 at 1 and 20 A g^-1, respectively, and 95.5% of capacitance retention after 10,000 cycles at 1 A g^-1. Moreover, they exhibit outstanding energy density and power density characteristics (47.3 Wh kg^-1 at 500.9 W kg^-1 and 31.3 Wh kg^-1 at 10247.7 W kg^-1). In addition, the influence of component ratio on the electrochemical performances of SrFe₁₂O₁₉ NR/G composites is thoroughly studied. Finally, the energy storage behavior and mechanism of as-obtained SrFe₁₂O₁₉ NR/G composites are investigated to further understand their enhanced capacitive performances. This work not only provides a new supercapacitor electrode material, but also offers an idea that can be used for the construction of composite electrode materials.