Direct fabrication of two-dimensional copper sulfide nanoplates on transparent conducting glass for planar supercapacitor

An in-planar two-dimensional supercapacitor was fabricated utilizing chemically deposited copper sulfide (CuS) nanoplates on patterned fluorine doped tin oxide (FTO) glass substrate. The morphology and structural properties of the CuS thin films were analyzed using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The fabricated CuS planar supercapacitor device demonstrated a promising electrochemical performance due to the pseudocapacitance induced by Li + ions intercalation/deintercalation process on the electrode surface. A maximum areal capacitance of 4.9 mF cm −2 was delivered by the CuS thin film device with an energy and power density of 4 x 10 −7 W h cm −2 and 2 mW cm −2 respectively. Moreover, the planar supercapacitor exhibited an excellent cyclic stability of ∼94% capacitance retention after 5000 charge/discharge cycles