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Over the past decades, great achievements of supercapacitor positive electrode materials have been developed, but the exploration of negative electrode materials is obviously lagging and mainly focuses on low-capacity electrochemical double-layer capacitor-based carbon materials (≤300 F g −1 , commonly), which limits the overall capacitance of supercapacitor devices for further application. In this work, using the gifted MIL-88A@GO as a precursor, we fabricate a FeS 2 /Fe 2 O 3 heterostructure-coupled S-functionalized 3D rGO network (FeS 2 /Fe 2 O 3 @S-rGO) by a diffusion-controlled etching and vulcanizing process. The formation of heterogeneous interfaces and the strongly coupled interaction between the FeS 2 /Fe 2 O 3 heterostructure and 3D S-rGO can provide high surface area for more electrochemical active sites, a rich pathway for the rapid transmission of the electron and electrolyte, and effectively alleviate the volume variation in the charging and discharging process. Therefore, the as-obtained FeS 2 /Fe 2 O 3 @S-rGO presents an outstanding capacity of 219.4 mA h g −1 (790 F g −1 ) at a current density of 2 A g −1 , which is higher than that of most reported Fe-based negative materials. Then, a positive electrode of hierarchical 2D/3D Ni 3 S 2 /Co 3 S 4 (NCS) is prepared and further fabricated with a FeS 2 /Fe 2 O 3 @S-rGO electrode to obtain a hybrid supercapacitor device (NCS//FeS 2 /Fe 2 O 3 @S-rGO), which delivers an outstanding overall capacitance value of 114.2 mA h g −1 (274 F g −1 ) at 1 A g −1 and provides a remarkable energy density of 85.63 Wh kg −1 corresponding to a power density of 0.75 kW kg −1 .

No abstract

Using a coordination polymer as the template, the porous rose-shaped Co₂P₂O₇/C-X were fabricated by in situ hybrid Co₂P₂O₇ nanoparticles and nanocarbon for supercapacitor applications.