Strong and Robust Polyaniline‐Based Supramolecular Hydrogels for Flexible Supercapacitors

Abstract

We report a supramolecular strategy to prepare conductive hydrogels with outstanding mechanical and electrochemical properties, which are utilized for flexible solid-state supercapacitors (SCs) with high performance. The supramolecular assembly of polyaniline and polyvinyl alcohol through dynamic boronate bond yields the polyaniline-polyvinyl alcohol hydrogel (PPH), which shows remarkable tensile strength (5.3 MPa) and electrochemical capacitance (928 F g(-1) ). The flexible solid-state supercapacitor based on PPH provides a large capacitance (306 mF cm(-2) and 153 F g(-1) ) and a high energy density of 13.6 Wh kg(-1) , superior to other flexible supercapacitors. The robustness of the PPH-based supercapacitor is demonstrated by the 100 % capacitance retention after 1000 mechanical folding cycles, and the 90 % capacitance retention after 1000 galvanostatic charge-discharge cycles. The high activity and robustness enable the PPH-based supercapacitor as a promising power device for flexible electronics.

Bioinspired Nanocomposite Hydrogels with Highly Ordered Structures

“…[22] The mechanical strength of the abovementioned strong hydrogels can be comparable with that of biological soft tissues. [23][24][25] Researchers have also focused on the highly ordered structures within hydrogels. Many biological soft tissues in nature, such as cartilage, skeletal muscles, corneas, and blood vessels, are natural hydrogel materials that exhibit anisotropic mechanical performances due to their highly ordered hierarchical nanocomposite structures.…”

Soft‐Template Construction of 3D Macroporous Polypyrrole Scaffolds

“…However, the building blocks for those 3D materials have been limited so far in a narrow range of 2D nanosheets based on inorganic metal oxides, nitrides, sulfides, and graphene (oxides) . Although conducting polymers with conjugated backbones have been extensively explored for the utilization as energy storage materials due to their relatively low cost, easy fabrication, high electrical conductivity, and excellent electrochemical behavior, direct bottom‐up construction of 3D macroporous materials employing ultrathin conducting polymer nanosheets has remained unrealized …”

Conducting Polymers for Flexible Supercapacitors

“…To improve the mechanical properties and flexibility of the pristine CP‐based conductive hydrogels, various hybrid CP hydrogels have been developed as electrode materials for flexible supercapacitors. So far, PVA is the most commonly used flexible substrate for CPs hybrid hydrogels while PAAM, graphene oxide/graphene, sodium alginate and G‐Zn‐tPy have also been used for the same purpose. These hybrid hydrogels can be highly stretchable, foldable, compressible, and even self‐healable, promising for applications in portable/wearable electronics.…”

“…Due to the introduction of the non‐conducting substrate, it is still a big challenge to design and develop hybrid hydrogels with a high conductivity and high surface area. Nevertheless, a supramolecular strategy has been developed to crosslink PANI and PVA through dynamic bonding, in which a functional monomer (i.e., 3‐aminophenylboric acid, ABA) bearing both amino and boronic acid groups was used to copolymerize with aniline and crosslink with PVA by the condensation reaction of –OH ( Figure ). The optimal molar ratio of ABA to aniline for preparing the PVA/PANI hybrid hydrogel is 0.07:1 with no hydrogel formation at ABA:aniline < 0.03:1.…”

“…Vial 1 has no APS; vial 3 has no PVA; vial 4 has no ABA; vial 5 has no aniline. Reproduced with permission . Copyright 2016, Wiley‐VCH.…”