Self-Healable Poly(vinyl alcohol)─Metal–Organic Hybrid Gel Electrolyte for Flexible Capacitor Sensors

Abstract

Supramolecular gels based on noncovalent interaction are attractive self-healable polymeric electrolytes due to their repeatable spontaneous recovery of mechanical and electrochemical performance. Herein, we report such a hybrid supramolecular gel electrolyte system composed of a poly­(vinyl alcohol) (PVA)–palladium-coordination metal–organic gel (MOG) by controlling ligand conformation transition from cis to trans. The reversible coordination and hydrogen bonding interactions endow the PVA/MOG hybrid gels with 17 consecutive self-healing in 10000S and ultrafast self-healable ability in both mechanical and electrochemical time scales of 180 and 60 s, respectively. The polyaniline (PANI)-based printed interdigital capacitor (IDC) sensor with the hybrid gel electrolyte exhibits a wide voltage window of 0–2.75 V, stable charge–discharge cycle at a high scan rate of 500 mV/s. When printed onto a glove, our sensor can recognize the hand fist and open with good sensitivity. This work provides a promising direction for designing flexible capacitor sensors with self-healable MOGs.

Metal–organic gels and their derived materials for electrochemical applications

“…When poly(vinyl alcohol) (PVA) was introduced into a coordination polymer gel Pd-MOG, a hybrid gel electrolyte PVA-Pd-MOG was obtained that showed self-healable properties. 101 Pd-MOG was assembled from Pd 2+ and bisbenzimidazole L1 (Scheme 1). The ionic conductivity of the PVA-hybrid gel was 1.5 × 10 −4 S cm −1 .…”