CuFeS2/Carbon Sphere Nanocomposites for Improved Capacitive Performance

CuFeS 2 has many advantages, like high electrical conductivity, multiple redox centers, natural abundance and nontoxic. However, the low capacitance limits their application. In this work, we use carbon spheres (CS) prepared from starch to modify CuFeS 2 . The prepared CuFeS 2 /CS shows special structures with the CS as the core and CuFeS 2 as the shell. These CuFeS 2 /CS nanocomposites show improved capacitive performance. CuFeS 2 /CS has a specific capacitance of 349.4[Formula: see text]F[Formula: see text]g[Formula: see text] at 0.5[Formula: see text]A[Formula: see text]g[Formula: see text], four times that of pristine CuFeS 2 (88.8[Formula: see text]F[Formula: see text]g[Formula: see text], which might be attributed to the increased electrolyte diffusion capacity. The cyclic stability is also slightly improved, from 86.4% of the pristine CuFeS 2 to 90.5% of the CuFeS 2 /CS nanocomposites due to the rigid structure of both crystal CuFeS 2 and firm CS. These CuFeS 2 /CS nanocomposites are expected to be used in high-performance supercapacitor applications.