Analysis of the potential of nickel selenide micro-supercapacitors as energy storage device

Microsupercapacitors (MSCs) are emerging as compelling electrochemical energy storage solutions, particularly for miniaturized portable electronics. Their appeal lies in their high-power density and exceptional cycling stability, making them promising alternatives to traditional batteries. However, current microfabrication techniques often involve costly steps that result in materials with structural defects, ultimately limiting their energy density. This research introduces an innovative approach by harnessing screen-printing technology, which offers an additive and cost-effective production process while reducing waste generation. The study centers on the assessment of three distinct electrode materials—NiSe2, Ni3Se4, and NiSe—synthesized via a hydrothermal process for their suitability in supercapacitor applications. Among these materials, NiSe emerges as a standout candidate, showcasing remarkable energy storage capabilities. It achieves an impressive specific capacity of 93.3 mAh g−1 at a current density of 12 A g−1 in three-electrode measurements and demonstrates outstanding cycling stability, retaining 98 % of its capacity over an impressive 30,000 charge-discharge cycles. The resulting flexible symmetric micro-supercapacitor (NiSe-MSC) exhibits a remarkable volumetric capacitance of 81.44 F cm−3 at a current density of 6 A g−1, accompanied by impressive power density (822.86 W cm−3) and energy density (5.28 mWh cm−3).