Anomalous electrochemical performance of binary silver–strontium phosphate-based electrode material in supercapattery

Abstract

Mesoporous silver strontium phosphate (SSP) was synthesized through a facile hydrothermal technique and utilized as a positive electrode for supercapattery. Material's morphology, crystallinity, elemental composition, and homogeneity were carried out through SEM, TEM, XRD, EDS, XPS, and EDS mapping. Various electrochemical characterizations were performed in three as well as two electrode assemblies to ensure the ability of the material towards electrochemical charge storage. In fact, three-electrode results explore that the material possesses excellent performance in terms of specific capacity, lower series resistance, and negligible charge transfer resistance. After a conclusive three electrode assembly findings, an asymmetric supercapacitor was assembled by utilizing SSP as a positive electrode and as a counterpart carbon nanotube (CNT) as a negative electrode. This hybrid device reveals excellent electrochemical performance and was able to deliver a specific capacity of 240.0 C/g. Indeed, not only higher capacity was delivered by this device, nevertheless, its performance was remarkable in terms of high energy density and excellent power density. Besides, the rate capability for the supercapattery was estimated from GCD which was ∼77% at the highest current density of 12 A/g. The stability has a significant role in energy storage devices and was analyzed by charging and discharging the device, and the results demonstrate the outstanding specific capacity retention of 86.68% after 5000 cycles. Likewise, the device successfully holds coulombic efficiency of 95.79% by the end of 5000 charge-discharge cycles. Our analysis reveals that this material possesses remarkable energy performance which makes it applicable for future supercapattery devices.