Pitch-derived Multifunctional Carbon and Bimetallic Sulfide Composite Electrodes for Aqueous Energy Storage

Abstract

With the rapid development of society, people's requirements for the ecological environment have become increasingly stringent. Coal tar pitch is a by-product of coal processing, which has low value and serious pollution. Under the circumstance, coal tar pitch-derived carbon materials (CTPC) was successfully prepared with the interconnected three-dimensional porous structure, and then NiCo2S4/CTPC composite materials were obtained. CTPC exhibits high conductivity (15.59 S m-1), large specific surface area (614.9 m2 g-1), and rich porous structure of connected carbon nanosheets. Among composite materials with different CTPC contents, the NiCo2S4/CTPC material exhibits the highest specific capacities under the same conditions. Notably, the capacity of NiCo2S4/CTPC is up to 689.6F·g-1 at 1A·g-1. The assembled asymmetrical supercapacitor (NiCo2S4/CTPC//CTPC) exhibits a long cyclic stability of 4000 cycles at 4A·g-1. When the power density is 3616.44Wkg-1, the energy density is as high as 22Whkg-1. Meanwhile, NiCo2S4/CTPC was used as cathode material to assemble an alkaline battery (NiCo2S4/CTPC//Bi2O3) and then its electrochemical properties were systematically analyzed.