Facile synthesis of strontium oxide/polyaniline/graphene composite for the high-performance supercapattery devices

Abstract

Abstract In this work, we have demonstrated, a facile synthesis of the ternary composite of strontium oxide-polyaniline-graphene (SrO-PANI-Gr) for hybrid energy storage applications. The electrochemical performance of the synthesized material is initially characterized in three electrode assembly. This nanomaterial indicates a specific capacity of 164C/g. In order to enhance the electrochemical performance of pristine SrO (S1), it is further physically blended with polyaniline in a 50/50% mass ratio which shows a specific capacity of 200C/g with lower rate capability. To further improve electrochemical performance with no compromise on rate capability, the material (S2) is further blended with graphene and this composition indicates an excellent specific capacity of 296C/g with better rate capability than the S2. To investigate the real device performance, a supercapattery device (S3//activated carbon) is fabricated which exhibits a maximum specific capacity of 151.66C/g. The assembled supercapattery device yields a maximum specific energy of 33.8 Wh.kg-1 along with maximum specific power of 3962.13 W.kg-1. Moreover, the supercapattery device demonstrated an excellent capacity retention of 80% after continuous 3000 charge discharge cycles. To further investigate the performance evaluation a theoretical model proposed by Dunn and co-workers is applied to investigate the capacitive (non-faradaic) and diffusive (faradaic) contribution in the charge storage of the supercapattery. The diffusive contribution is found dominant at lower scan rates whereas the capacitive contribution is dominant at higher scan rates. This variation in the contribution is attributed to the interaction time of the electrolyte charge with the electrode material.