Role of Ag and Cu as an interfacial layer on the electrochemical performance of Ni/Ag/ Co3(PO4)2 and Ni/Cu/Co3(PO4)2 electrodes for hybrid energy storage devices

Abstract

Hybrid energy storage devices unifying the effect of both batteries (high specific energy) and capacitors (high specific power) have emerged in recent years due to their admirable cyclic stability and charge storage capability. Considerable amount of research has been conducted to optimize the electrode materials capable of showing good electrochemical characteristics. Here, we report the influence of interfacial layer of Ag and Cu on the electrochemical performance of cobalt phosphate electrode. Sputtering of Ag and Cu has been amalgamated to improve the interfacial properties of the current collector. After initial structural and morphological study, detailed electrochemical characterizations have been employed for Ni/Ag/Co3(PO4)2 and Ni/Cu/Co3(PO4)2 have been investigated by utilizing various characterizations. Hybrid device was fabricated using the combination Ni/Ag/Co3(PO4)2 since, Ag possess impressive electrochemical characteristics and electrical conductivity. The fabricated device has achieved the energy density of 65.8 Whkg−1 and power density of 6012 Wkg-1 along with the 85.6% retention after 1000 GCD cycles showing the device is stable enough. These results make the hybrid device a potential candidate for supercapattery applications.