Strategies to enhance the electrochemical performance of strontium-based electrode materials for battery-supercapacitor applications

•Sonochemical approach was employed for synthesis of sulfides-based electrode materials.•The optimized electrodes show excellent specific capacity and rate capability.•Hybrid device (SrS//AC) was assembled revealing remarkable energy density (44.39 Whkg−1).•Capacitive and diffusive contribution was investigated through Dunn’s model. Asymmetric supercapacitors (SCs) have gained peculiar attention in energy storage domain. However, they still lack to accommodate high specific energy (Es) and power (Ps) demands. Therefore, the performance enhancement of supercapacitors by utilizing various electrode materials with superior electrochemical activities is desired. Herein, we have studied various strontium-based materials for asymmetric device applications. Initially, strontium oxide (SrO), phosphide (Sr3P2), and sulfides (SrS) were sonochemically synthesized. The structural, morphological, and elemental study were performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). At first, three electrode system was used to execute electrochemical testing, which revealed SrS to hold prime performance compared to SrO and Sr3P2. The SrS sample obtained high specific capacity (Qs) of 451.7C/g (3 mV/s) and 202.5C/g (0.5 A/g). The electrochemical analysis of the aforementioned SrS electrode was further investigated in two electrode configuration with activated carbon (AC). The device exhibited 44.39 Wh/kg Es and Ps of 595 W/kg and attained power of 8400 W/kg while having Es of 12.9 Wh/kg with significant capacity retention of 89.6 % over 5000 cycles. Furthermore, a simulation approach was scrutinized to verify the capacitive and diffusive contributions. The results obtained predicts strontium sulfides to be efficient materials for asymmetric supercapacitor applications.