Solid-state symmetric supercapacitor based on Y doped Sr(OH)2 using SILAR method

Supercapacitor is one of the most promising and emerging type of energy storage devices having the merits of both conventional battery and traditional capacitor. In this regard, we have deposited Yttrium doped Strontium hydroxide thin films on stainless steel substrate with the help of a facile, cost-effective successive ionic layer adsorption and reaction technique at room temperature without using any binder. Doping of Yttrium into Strontium hydroxide enhances both electronic conductivity and electrochemical performance of the electrode for energy storage. Nanorods like structure with the tuberose morphology has been obtained with the help of field emission scanning electron microscopy. The cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy measurements show the pseudocapacitive battery like response. Among all the synthesised materials, 1.0 at. % Yttrium doped Strontium hydroxide shows a high specific capacity of 705.3 C g−1 at 0.4 mA current rate and stability of ∼82% at 2.5 mA current rate. The prototype light-weight solid-state symmetric supercapacitor device of Yttrium doped Strontium hydroxide electrodes has been fabricated by sandwiching PVA-Na2SO4 gel. Thus, we observe that this device has potential applications for the next-generation cost effective energy storage system. [Display omitted] •Y doped Sr(OH)2 electrode has been prepared using SILAR deposition method.•The nanorod like structure with tuberose morphology has been observed.•Enhanced applied potential window for Y:Sr(OH)2 shows high capacity.•High stability of 1 at. % Y:Sr(OH)2–85% at 2.5 mA current rate.•A prototype symmetric supercapacitor of Y Sr device has been assembled.