Development of flexible and sustainable all quasi-solid-state supercapacitors based on ecofriendly binders on aluminum foil

Since the beginning of the 21st century, ecological, light weight and low-cost power sources devices with excellent mechanical flexibility are crucial to fulfill the requirements of emerging technologies for the new generation, including robots, foldable phones and wearable electronics. Herein, we report the integration of eco-friendly and biocompatible binders Polyvinyl alcohol (PVA) and Pullulan (Pu) for the straightforward manufacturing of flexible and sustainable carbon-based electrodes for supercapacitors applications. Furthermore, Glycerol (GCy) has been employed as a dual-purpose plasticizer agent for both electrode and electrolyte preparation, thereby minimizing manufacturing costs. Firstly, GCy content influence on the electrochemical performances and PVA-GCy/KOH films quality was investigated. Pullulan/Activated Carbon (Pu/AC) based supercapacitors have shown superior energetic performances in contrast to those achieved by the PVA/AC based ones. The Pu-based device exhibited a maximum aerial capacitance of 155 mF cm−2 at 5 mV s−1, and a maximum energy and power densities of 31.8 μWh cm−2 and 34.3 mW cm−2 respectively at 0.1 A g−1. Furthermore, the device showed excellent stability behavior (>91 % of its initial capacitance after 9000 cycles). More importantly, the fabricated supercapacitor presented acceptable electrochemical performances when folded at different bending angles, opening the way to the practical applications of micro-storage and flexible embedded systems.