Highly stable self-charging piezoelectric (Rochelle salt) driven supercapacitor based on Ni nanowires

Abstract

In this work, an asymmetric piezo-supercapacitor device is fabricated using Nickel/Rochelle Salt (Ni/RS) nanowires array as cathode, Polypyrrole/Nickel/Rochelle (PPy/Ni/RS) nanowires array as anode and rochelle salt based filter paper as a separator and energy harvester. The fabricated device demonstrates self-charging phenomenon due to piezoelectric effect upto 700 mV under a compressive force of 30 N in just 15 s. Moreover, the electrochemical results reveal tremendous cyclic stability with capacitive retention of 99% and 96% for PPy/Ni/RS and Ni/RS nanowires array based electrodes even after 10,000 repeated GCD cycles. In addition, the fabricated Ni/RS//PPy/Ni/RS based asymmetric device shows a high energy density of 166.23 Wh/kg at 0.24 KW/kg. The practical demonstration of the asymmetric supercapacitor is also given by lighting up a green LED. The proposed facile as well as cost-effective approach for smart self-chargeable power package supercapacitor provides new insights for developing next generation all-in-one energy harvesting and storage devices.