Metal Coated Fabric Based Asymmetric Supercapacitor for Wearable Applications

Abstract

This paper presents a fabric based asymmetric supercapacitor (ASC) with metal coated cloths as the electrode and the current collector. Graphite paste printed on silver coated textile (Berlin) is used as the negative electrode and nickel/copper/silver plated fabric (Nora Dell) as the positive electrode. Biocompatible polyvinyl alcohol (PVA)-potassium chloride (KCl) gel is used as the electrolyte for ASC fabrication. During the electrochemical process, the metal oxides formed on the Nora Dell fabric contributes to the pseudocapacitance, whereas the graphite electrode forms the electric double layer capacitance. Compared to the Berlin/graphite based symmetric SC, the fabricated ASC shows enhanced performance with an areal capacitance and energy density of 32 mF.cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.8~\mu $ </tex-math></inline-formula> Wh.cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> respectively at a scan rate of 25 mV. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{s}^{\mathbf {-1}}$ </tex-math></inline-formula> . The cyclic stability and self-charging capability of the device with flexible solar cells are also demonstrated as a proof of concept for use in practical applications. The presented energy storage device has potential to be used as a safe and sustainable alternative needed to meet the rapid growth in the field of wearable electronics.