CuFeS2/Carbon Sphere Nanocomposites for Improved Capacitive Performance

Abstract

CuFeS2 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 CuFeS2. The prepared CuFeS2/CS shows special structures with the CS as the core and CuFeS2 as the shell. These CuFeS2/CS nanocomposites show improved capacitive performance. CuFeS2/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 CuFeS2 (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 CuFeS2 to 90.5% of the CuFeS2/CS nanocomposites due to the rigid structure of both crystal CuFeS2 and firm CS. These CuFeS2/CS nanocomposites are expected to be used in high-performance supercapacitor applications.