Systematically increased surface area of amorphous sulfurized cobalt-based alloy as a substrate-free electrode for energy application

Abstract Having high energy density, high electrical conductivity and at the same time inexpensive and abundance material are key parameters to build an electrode for energy storage applications. Here, we construct sulfurized amorphous cobalt-based alloy with facile and a low-priced method. Samples were etched in H2SO4 with different molarities. Then, it was sulfurized using chemical vapor deposition technique. Existence of sulfur and its combination with Co was confirmed by Raman spectroscopy and X-ray Photoelectron Spectroscopy. Electrochemical properties were investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge methods. The sample etched in an 8 M H2SO4 had specific capacity of 135 C/g measured at scan rate of 5 mV/s in 1 M KOH. Our results suggest promising application of surface treated amorphous alloy for substrate-free electrodes.