Rapid synthesis of cobalt phosphate microplates for supercapacitors

Abstract

In this study, cobalt phosphate is synthesized using a step hydrothermal approach on a stainless steel substrate. The effect of sodium dodecyl sulfate (SDS) was studied to tune the morphology of the electrode. The structural confirmation of cobalt phosphate was performed using XRD and FT-Raman studies. The SDS concentration influences the microplate's structure were observed through SEM analysis. Further, elemental mapping was carried out using EDS. The optimized electrode shows a specific capacitance of 3.92 F cm⁻² at 20 mA cm⁻². Additionally, an aqueous hybrid device was assembled and tested using the CPS3//AC configuration. The device shows a specific capacitance of 93.96 mF cm⁻² at 5 mA cm⁻². The cyclic stability of the device was tested for up to 5100 cycles, revealing 99.97% capacitive retention. Furthermore, time series analysis is employed to predict and forecast the cyclic stability data. Thus, the synthesized cobalt phosphate electrode can be used in energy storage devices.