A Flexible All-Solid-State Micro Supercapacitor and Its Application in Electrostatic Energy Management System

This paper presents a flexible, all-solid-state micro supercapacitor (MSC) employing a thin parylene-C membrane as the substrate and polyvinyl alcohol-phosphoric acid polymer gel as the solid electrolyte. The MSC is surface mounted on an electrostatic energy management system, which aims to manage the energy collected from an electrostatic energy harvester and then store it in the MSC. The system consists of three parts: an electrostatic energy harvester, a management integrated circuit, and an MSC. The MSC prototype shows a specific capacitance of 31 mF/cm² in the solid electrolyte. The prototype without a separator has also demonstrated that the capacitance changes from 27.7 to 25.4 mF/cm² after more than 40 bending cycles and the capacitance retention is 91.7%, which indicates that the fabricated devices have good mechanical and electrochemical stability. The system can charge a 2.5-mF MSC with the result of 0.7 V output. The flexible all-solid-state MSC has the excellent potential in wearable electronics applications. The system can be used to efficiently collect and store the energy harvested from the environment, which bridges the energy harvesters to the practical applications.