Cryopolymerization‐enabled self‐wrinkled polyaniline‐based hydrogels for highly stretchable all‐in‐one supercapacitors

Abstract

Conductive polymer hydrogels are attractive due to their combination of high theoretical capacitance, intrinsic electrical conductivity, fast ion transport, and high flexibility for supercapacitor electrodes. However, it is challenging to integrate conductive polymer hydrogels into an all-in-one supercapacitor (A-SC) simultaneously with large stretchability and superior energy density. Here, a self-wrinkled polyaniline (PANI)-based composite hydrogel (SPCH) with an electrolytic hydrogel and a PANI composite hydrogel as the core and sheath, respectively, was prepared through a stretching/cryopolymerization/releasing strategy. The self-wrinkled PANI-based hydrogel exhibited large stretchability (∼970%) and high fatigue resistance (∼100% retention of tensile strength after 1200 cycles at a 200% strain) ascribing to the formation of the self-wrinkled surfaces and the intrinsic stretchability of hydrogels. Upon cutting off the edge connections, the SPCH could directly work as an intrinsically stretchable A-SC maintaining high energy density (70 μW h cm −2 ) and stable electrochemical outputs under a stretchability of 500% strain and a full-scale bending of 180 • . After 1000 cycles of 100% strain stretching and releasing processes, the A-SC device could deliver highly stable outputs with high capacitance retention of 92%. This study might provide a straightforward method for fabricating self-wrinkled conductive polymer-based hydrogels for A-SCs with highly deformation-tolerant energy storage.

Injectable smart stimuli-responsive hydrogels: pioneering advancements in biomedical applications

“…The most common conductive polymers are polypyrrole (PPy), polyaniline (PANI), polythiophene, and polyacrylamide (PAAm). 358 Their conductivity typically depends on the conjugated system and orbital overlap. Under electrical stimulation, these electricity-responsive hydrogels achieve controlled drug release through two main mechanisms: drug expulsion from the contracting hydrogel network and drug migration in the direction of the opposite charge.…”

Flexible Energy Storage Devices to Power the Future

“…There have been numerous studies on optimizing materials for components such as electrodes and electrolytes. [81] To meet the specific requirements of wearable, skin-applicable or integrated energy storage or to fulfill the general needs of planar electrodes in flexible batteries or flexible supercapacitors, three FESD structures have been developed. These structures differ in terms of dimensionality and include fiber-type energy storage devices, thin-film energy storage devices, and 3D energy storage devices, as shown in Figure 3.…”

“…There have been numerous studies on optimizing materials for components such as electrodes and electrolytes. [ 81 ]…”

Three-Dimensional Carbon Nanomaterial/Aluminum Oxide/Aluminum Composite Current Collectors for Flexible Supercapacitors

“…The current collectors for FSSCs need to meet the following requirements: (i) good electrical conductivity, (ii) chemically stable and not reacting with active materials, adhesives, and electrolytes, (iii) good connection with electrode materials, (iv) good flexibility, and (v) cost-effective and easy to mass produce. − Aluminum (Al) foil is one of the most commonly used current collectors for energy storage devices, especially in supercapacitors and sodium-ion batteries, due to its flexibility, low price, and lightweight. However, the biggest problem with Al foil current collectors is the poor connection between the Al foil and active materials, which can lead to a decrease in the stability of the supercapacitor.…”