Preparation and Energy Storage Properties of Copper-Based Electrode on Silicon Substrate

Purposes Transition element oxides, sulfides, and hydroxides are widely used as a kind of pseudocapacitance materials owing to their excellent theoretical specific capacitance, high power density, and low cost. However, most of the transition element-based electrodes are fabricated under abnormal temperatures combined with conductive agent and binder, which deeply restricts their application towards silicon-based micro-supercapacitor (MSC). Methods In this research, one layer of titanium collector was deposited on the silicon substrate followed by the sputtering of copper film. The copper hydroxide nanowire was fabricated through an in-situ wet oxidation method at room temperature. The copper sulfide was further synthetized by soaking above product in sodium sulfide solution for enhancing energy storage properties. The synthetise method showed a good compatibility with traditional silicon micro fabrication. Conclusion The results showed that in 1.0 mol/L sodium sulfate electrolyte, the copper sulfide electrode exhibited high average areal capacitance of 166.98 mF/cm2 at the current density of 1 mA/cm2, which was 6.68 times than that of copper hydroxide electrode. After 500 cycles, 74.2% of the areal capacitance was preserved. The copper-based electrodes reported here could have a wide application prospect in silicon-based micro-supercapacitor.