Mesoporous LaNiO3/NiO nanostructured thin films for high-performance supercapacitors†
Abstract
Mesoporous LaNiO3 (LNO)/NiO electrodes for thin film supercapacitors have been developed from a sol–gel precursor using polyethylene glycol 1000 (PEG 1000) as a template. It is the first time that the LNO/NiO thin films have been reported as electrochemical electrodes. Electrochemical measurements in an aqueous electrolyte (1 M Na2SO4) show areal specific capacitances of about 9.5 mF cm−2 and 1.85 mF cm−2 at the scan rates of 0.1 V s−1 and 100 V s−1, respectively. The film shows a quasi-rectangular curve even at the ultrahigh scan-rate of 100 V s−1, which is much higher than that of conventional supercapacitors. The specific capacitance is five orders of magnitude higher than most of the micro-/thin films. The cycling tests operated at the potential window of 0 to 1 V with a current density of 1 mA cm−2 suggest that the thin film