Fabrication of porous Cu_2S nanosheets for high performance hybrid supercapacitor

摘要

Cu2S powders are synthesized by a facile combustion method using copper nitrate as oxidant and a mixture of thiourea and glycine as fuel. The structural, microstructural, and electrochemical properties are analyzed by X-ray diffractometry, scanning and transmission electron microscopy, cyclic voltammetry, and galvanic charge/discharge tests. The Cu2S powders are crystallized in cubic phase. The combusted powders are composed of sheetlike Cu2S particles with some micropores (similar to 1-2 nm). The electron diffraction patterns show that the Cu2S nanosheets are single crystal nature with 002 crystal facets, leading to the high specific capacitance of 677 F g(-1) at the current density of 1 A g(-1). Furthermore, the Cu2S//MnO2 hybrid capacitor exhibit a high energy density of 42.3 Wh kg(-1) at the current density of 1 A g(-1) and high cycling stability of 86 at 3 A g(-1) following 6500 cycles.