Hydrothermal synthesis of cobalt ruthenium sulfides as promising pseudocapacitor electrode materials

Abstract

In this paper, we report the successful synthesis of cobalt ruthenium sulfides by a facile hydrothermal method. The structural aspects of the as-prepared cobalt ruthenium sulfides were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. All the prepared materials exhibited nanocrystal morphology. The electrochemical performance of the ternary metal sulfides was investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy techniques. Noticeably, the optimized ternary metal sulfide electrode exhibited good specific capacitances of 95 F g-1 at 5 mV s-1 and 75 F g-1 at 1 A g-1, excellent rate capability (48 F g-1 at 5 A g-1), and superior cycling stability (81% capacitance retention after 1000 cycles). Moreover, this electrode demonstrated energy densities of 10.5 and 6.7 Wh kg-1 at power densities of 600 and 3001.5Wkg-1, respectively. These attractive properties endow proposed electrodes with significant potential for high-performance energy storage devices.