Gels that are freeze-resistant and heat-resistant and have high ultimate tensile strength are desirable in practical applications owing to their potential in designing flexible energy storage devices, actuators, and sensors. Here, a simple method for fabricating ionic liquid (IL)–based click-ionogels using thiol-ene click chemistry under mild condition is reported. These click-ionogels continue to exhibit excellent mechanical properties and resilience after 10,000 fatigue cycles. Moreover, due to several unique properties of ILs, these click-ionogels exhibit high ionic conductivity, transparency, and nonflammability performance over a wide temperature range (−75° to 340°C). Click-ionogel–based triboelectric nanogenerators exhibit excellent mechanical, freeze-thaw, and heat stability. These promising features of click-ionogels will promote innovative applications in flexible and safe device design.

Alkaline anion‐exchange membrane fuel cells (AEMFCs) are attracting much attention because of their potential use of nonprecious electrocatalysts. The anion‐exchange membrane (AEM) is one of the key components of AEMFCs. An ideal AEM should possess high hydroxide conductivity and sufficient long‐term durability at elevated temperatures in high‐pH solutions. Herein, recent progress in research into the alkaline stability behavior of cations (including quaternary ammonium, imidazolium, guanidinium, pyridinium, tertiary sulfonium, phosphonium, benzimidazolium, and pyrrolidinium) and their analogous AEMs, which have been investigated by both experimental studies and theoretical calculations, is reviewed. Effects, including conjugation, steric hindrance e, σ–π hyperconjugation, and electrons, on the alkaline stability of cations and their analogous AEMs have been discussed. The aim of this article is to provide an overview of some key factors for the future design of novel cations and their analogous AEMs with high alkaline stability.

The synthesis and characterization of pyrrolidinium cation based anion exchange membranes (AEMs) are reported. Pyrrolidinium cations with various N-substituents (including methyl, ethyl, butyl, octyl, isopropyl, 2-hydroxylethyl, benzyl, and cyclohexylmethyl groups) were synthesized and investigated with respect to their chemical stability in alkaline media. The influence of substitutions on alkaline stability of pyrrolidinium cations was investigated by quantitative 1H nuclear magnetic resonance spectroscopy (NMR) and theoretical approaches. N,N-Ethylmethyl-substituted pyrrolidinium cation ([EMPy]+) exhibited the highest alkaline stability in this study. The synthesized AEMs based on [EMPy]+ show promising alkaline stability in strongly basic solution. The study of this work should provide a feasible way for improving the alkaline stability of pyrrolidinium cation based AEMs.

In practical applications, long-term load cycles tend to cause fatigue damage to the ionogels and induce cracks, reduce their stability and accuracy, greatly decrease their service life, and increase operating costs. At present, no effective strategy has been developed to fundamentally solve the problem of crack propagation sensitivity of ionogels. For example, double network (DN) gels (such as poly(1-acrylamido-2-methylpropane sulfonic acid) (PAMPS)/ polyacrylamide (PAAM) hydrogel [18] ) prevent crack propagation through the fracture of primary and sacrificial networks. However, covalent crosslinking network is usually irreversible, and fatigue resistance is limited under long-term cyclic loading. [9,[18][19][20][21][22] Moreover, introducing reversible dynamic bonds (such as ionic and hydrogen bonds) into polymer networks can effectively enhance the selfhealing ability during fatigue damage or crack propagation. [13,[23][24][25][26][27] However, due to the lack of an additional energy dissipation mechanism, irreversible fatigue damage can be caused by crack propagation during long-term cyclic loading. Furthermore, reversible bonds cannot dissipate the stress concentration at the pre-cut crack tip and are unable to prevent crack propagation. [21] Microgels have been used as DN structure to enhance the mechanical properties of hydrogels. [21,28,29] The matrix polymers are chemically crosslinked rather than linear polymer segments, which greatly limits the deformability of the hydrogels. In addition, the chemically crosslinked single network outside the microgels leads to the catastrophic expansion of the crack at the notch of the hydrogels. Therefore, the crack propagation insensitivity and fatigue resistance were sacrificed. Addition of nanocomposites improved the toughness and strength of the hydrogels through the interaction between surface functional groups and external polymer matrix (hydrophobic association by amphiphilic triblock copolymer, strong hydrogen bond, and coordination bond). [19,22,[30][31][32][33] The hydrogels need residence time to recover the damaged mechanical properties under cyclic load due to the unstable mechanical properties of reversible bonds.Recyclability and mechanical stability of polymer networks are contradictory properties. The covalently crosslinked rigid network ensures the stability of the polymer framework at the expense of the regeneration and recycling capacity. The noncovalent bond in the reversible dynamic bond system is a weak Most gels and elastomers introduce sacrificial bonds in the covalent network to dissipate energy. However, long-term cyclic loading caused irreversible fatigue damage and crack propagation cannot be prevented. Furthermore, because of the irreversible covalent crosslinked networks, it is a huge challenge to implement reversible mechanical interlocking and reorganize the polymer segments to realize the recycling and reuse of ionogels. Here, covalent crosslinking of host materials is replaced with entanglement. The entangled microdomains are used as...

Electronic skin can detect minute electrical potential changes in the human skin and represent the body's state, which is critical for medical diagnostics and human–computer interface development. On the other hand, sweat has a significant effect on the signal stability, comfort, and safety of electronic skin in a real‐world application. In this study, by modifying the cation and anion of a poly(ionic liquid) (PIL) and employing a spinning process, a PIL‐based multilayer nanofiber membrane (PIL membrane) electronic skin with a dual gradient is created. The PIL electronic skin is moisture‐wicking and breathable due to the hydrophilicity and pore size‐gradients. The intrinsically antimicrobial activities of PILs allow the safe collection of bioelectrical signals from the human body, such as electrocardiography (ECG) and electromyography (EMG). In addition, a robotic hand may be operated in real‐time, and a preliminary human–computer interface can be accomplished by simple processing of the collected EMG signal. This study establishes a novel practical approach for monitoring and using bioelectrical signals in real‐world circumstances via the multifunctional electronic skin.