Self-Healing, Flexible and Smart 3D Hydrogel Electrolytes Based on Alginate/PEDOT:PSS for Supercapacitor Applications

Abstract

Hydrogel electrolytes for energy storage devices have made great progress, yet they present a major challenge in the assembly of flexible supercapacitors with high ionic conductivity and self-healing properties. Herein, a smart self-healing hydrogel electrolyte based on alginate/poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (alginate/PEDOT:PSS)(A/P:P) was prepared, wherein H2SO4 was employed as a polymeric initiator, as well as a source of ions. PEDOT:PSS is a semi-interpenetrating network (IPN) that has been used in recent studies to exhibit quick self-healing properties with the H₂SO₃ additive, which further improves its mechanical strength and self-healing performance. A moderate amount of PEDOT:PSS in the hydrogel (5 mL) was found to significantly improve the ionic conductivity compared to the pure hydrogel of alginate. Interestingly, the alginate/PEDOT:PSS composite hydrogel exhibited an excellent ability to self-heal and repair its original composition within 10 min of cutting. Furthermore, the graphite conductive substrate-based supercapacitor with the alginate/PEDOT:PSS hydrogel electrolyte provided a high specific capacitance of 356 F g−1 at 100 mV/s g−1. The results demonstrate that the A/P:P ratio with 5 mL PEDOT:PSS had a base sheet resistance of 0.9 Ω/square. This work provides a new strategy for designing flexible self-healing hydrogels for application in smart wearable electronics.

Biomass‐based materials for advanced supercapacitor: principles, progress, and perspectives

“…Alginate serves as the foundation of the electrolyte, while the incorporation of PEDOT:PSS imparts flexibility and self-healing properties to the electrolyte. This hydrogel has an ionic conductivity of 13.7 × 10 −3 S cm −1 at 25 • C. [128] Mondal et al prepared polyacrylic acid (PAA) (SL-g-PAA-Ni) hydrogels containing sulfonated lignin (SL) under high concentration of nickel chloride (NiCl 2 ). The presence of phenolic hydroxyl and methoxyl groups on the SL enabled the formation of a hydroquinone/quinone redox system with Ni 2+ /Ni 3+ pairs, thereby promoting the polymerization reaction.…”

Research progress of self‐healing polymer materials for flexible electronic devices

“…Sodium alginate/PEDOT:PSS composite hydrogel has good electrical conductivity and self‐healing ability within 10 min of cutting. In addition, the graphite conductive substrate supercapacitor with the sodium alginate /PEDOT:PSS hydrogel electrolytes provide a high specific capacitance of 356 F g −1 at 100 mV/s g −1 54 …”

“…In addition, the graphite conductive substrate supercapacitor with the sodium alginate /PEDOT:PSS hydrogel electrolytes provide a high specific capacitance of 356 F g À1 at 100 mV/s g À1 . 54 Not only at room temperature, Li and his colleagues also reported a flexible self-healing water-based supercapacitor at low temperatures. The capacitor uses biochar and polyelectrolyte as the electrodes and gel electrolyte substrate.…”

Mechanical and Electrical Dual-Repairing Agents for Flexible Conductors Based on Biphasic Liquid Metal–Polymer Composites

“…31−34 Naturally, the combination of LMs with selfhealing polymers presents a viable approach for simultaneously repairing the mechanical and electrical properties of MBFCs. 35−37 However, the practical application of such a combined method is notorious for the tedious repair conditions including extended repair time (>12 h), 38,39 required external stimuli (light, heat, or pressure), 5,40,41 low repair efficiency, 42 and high cost. 43 Hence, there is an urgent demand to develop FCRAs to address the dilemma presently existing in repairing MBFCs.…”

“…Currently, self-healing polymers are functionalized as the substrate materials of MBFCs to achieve the autonomous repair of the mechanical performance of damaged MBFCs. − Nevertheless, the self-healing strategy has fatal issues in restoring the conductive network in damaged MBFCs due to the inferior electrical conductivity of self-healing polymers, failing to repair the electrical conductivity of broken MBFCs. , Meanwhile, liquid metals (LMs) have been increasingly adapted to incorporate silicon rubbers (such as PDMS) for designing wearable electronics, soft robotics, and human–computer interactions. − Recent studies have highlighted the exceptional self-repair capabilities of LMs due to their integrated merits of superior fluidity and metallic conductivity. − Naturally, the combination of LMs with self-healing polymers presents a viable approach for simultaneously repairing the mechanical and electrical properties of MBFCs. − However, the practical application of such a combined method is notorious for the tedious repair conditions including extended repair time (>12 h), , required external stimuli (light, heat, or pressure), ,, low repair efficiency, and high cost . Hence, there is an urgent demand to develop FCRAs to address the dilemma presently existing in repairing MBFCs.…”