SILAR synthesized dysprosium selenide (Dy2Se3) thin films for hybrid electrochemical capacitors

As the necessity of energy storage is continuously increasing, new materials have been investigated for electrochemical energy storage, especially for electrochemical capacitors. These storage devices are rapidly convertible as well as air pollution free. Therefore, a number of materials have been explored as electrode materials for supercapacitors to fulfill different requirements of electrochemical energy storage. Herewith, dysprosium selenide (Dy2Se3) films were prepared using the simple successive ionic layer adsorption and reaction (SILAR) method and characterized using different physico-chemical techniques. The specific capacitance (Cs) of 92 F g−1 was obtained at the current density of 2.85 A g−1 in 1 M LiClO4 electrolyte with a retention of 85% over 5000 galvanostatic charge-discharge (GCD) cycles performed at a current density of 4 A g−1. The flexible solid-state hybrid electrochemical capacitor of configuration Dy2Se3/LiClO4-PVA/MnO2 showed Cs of 83 F g−1 and specific energy of 18 Wh kg−1 at a specific power of 2.7 kW kg−1. This hybrid device retained 92% of capacitance at a device bending angle of 160°. These results demonstrate the facile synthesis of Dy2Se3 and its possible use in electrochemical energy storage applications. [Display omitted] •The novel Dy2Se3 thin films were synthesized using successive ionic layer adsorption and reaction method.•Dy2Se3 electrode exhibits specific capacitance of 92 F g−1 at current density of 2.85 A g−1.•Hybrid device delivers 18 Wh kg−1 specific energy at 2.668 kW kg−1.•This hybrid device retained 92.82% of capacitance at a device bending angle of 160°.