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As stretchable conductive materials, ionogels have gained increasing attention. However, it still remains crucial to integrate multiple functions including mechanically robust, room temperature self‐healing capacity, facile processing, and recyclability into an ionogel‐based device with high potential for applications such as soft robots, electronic skins, and wearable electronics. Herein, inspired by the structure of spider silk, a multilevel hydrogen bonding strategy to effectively produce multi‐functional ionogels is proposed with a combination of the desirable properties. The ionogels are synthesized based on N‐isopropylacrylamide (NIPAM), N, N‐dimethylacrylamide (DMA), and ionic liquids (ILs) 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]). The synergistic hydrogen bonding interactions between PNIPAM chains, PDMA chains, and ILs endow the ionogels with improved mechanical strength along with fast self‐healing ability at ambient conditions. Furthermore, the synthesized ionogels show great capability for the continuous fabrication of the ionogel‐based fibers using the melt‐spinning process. The ionogel fibers exhibit spider‐silk‐like features with hysteresis behavior, indicating their excellent energy dissipation performance. Moreover, an interwoven network of ionogel fibers with strain and thermal sensing performance can accurately sense the location of objects. In addition, the ionogels show great recyclability and processability into different shapes using 3D printing. This work provides a new strategy to design superior ionogels for diverse applications. Inspired by the structure of spider silk, a multilevel hydrogen bonding strategy is proposed to effectively produce multi‐functional ionogels with a combination of mechanically robust, room‐temperature self‐healing capacity, facile processing, and recyclable properties. The ionogels have shown great potential for use in wearable electronics, electronic skins, and soft robotics. The molecular strategy will be powerful tools to develop high‐performance materials.

Hydrogel‐based zinc‐air batteries (ZABs) are promising flexible rechargeable batteries. However, the practical application of hydrogel‐based ZABs is limited by their short service life, narrow operating temperature range, and repair difficulty. Herein, a self‐healing ionogel is synthesized by the photopolymerization of acrylamide and poly(ethylene glycol) monomethyl ether acrylate in 1‐ethyl‐3‐methylimidazolium dicyanamide with zinc acetate dihydrate and first used as an electrolyte to fabricate self‐healing ZABs. The obtained self‐healing ionogel has a wide operating temperature range, good environmental and electrochemical stability, high ionic conductivity, satisfactory mechanical strength, repeatable and efficient self‐healing properties enabled by the reversibility of hydrogen bonding, and the ability to inhibit the production of dendrites and by‐products. Notably, the self‐healing ionogel has the highest ionic conductivity and toughness compared to other reported self‐healing ionogels. The prepared self‐healing ionogel is used to assemble self‐healing flexible ZABs with a wide operating temperature range. These ZABs have ultra‐long cycling lives and excellent stability under harsh conditions. After being damaged, the ZABs can repeatedly self‐heal to recover their battery performance, providing a long‐lasting and reliable power supply for wearable devices. This work opens new opportunities for the development of electrolytes for ZABs. Self‐healing ionogels with high ionic conductivity and good mechanical properties are synthesized and used to fabricate self‐healing and wide‐temperature flexible ZABs with ultra‐long cycling lives for the first time. These ZABs have excellent stability under harsh conditions. After being damaged, the ZABs can repeatedly self‐heal to recover their battery performance, providing a long‐lasting and reliable power supply for wearable devices.

Although highly desired, it is difficult to develop mechanically robust and room temperature self‐healing ionic liquid‐based gels (ionogels), which are very promising for next‐generation stretchable electronic devices. Herein, it is discovered that the ionic liquid significantly reduces the reversible reaction rate of disulfide bonds without altering its thermodynamic equilibrium constant via small molecule model reaction and activation energy evolution of the dissociation of the dynamic network. This inhibitory effect would reduce the dissociated units in the dynamic polymeric network, beneficial for the strength of the ionogel. Furthermore, aromatic disulfide bonds with high reversibility are embedded in the polyurethane to endow the ionogel with superior room temperature self‐healing performance. Isocyanates with an asymmetric alicyclic structure are chosen to provide optimal exchange efficiencies for the embedded disulfide bonds relative to aromatic and linear aliphatic. Carbonyl‐rich poly(ethylene‐glycol‐adipate) diols are selected as soft segments to provide sufficient interaction sites for ionic liquids to endow the ionogel with high transparency, stretchability, and elasticity. Finally, a self‐healing ionogel with a tensile strength of 1.65 ± 0.08 MPa is successfully developed, which is significantly higher than all the reported transparent room temperature self‐healing ionogel and its application in a 3D printed stretchable numeric keyboard is exemplified. First the authors discovered that the ionic liquid significantly reduces the reversible reaction rate of disulfide bonds without altering its thermodynamic equilibrium constant. This inhibitory effect reduces the dissociated units in the dynamic polymeric network, critical for enhancing the strength of the ionogel. Accordingly, a room temperature self‐healing ionogel with a word record tensile strength of 1.65 ± 0.08 MPa is developed.

Since the last decade, the need for deformable electronics exponentially increased, requiring adaptive energy storage systems, especially batteries and supercapacitors. Thus, the conception and elaboration of new deformable electrolytes becomes more crucial than ever. Among diverse materials, gel polymer electrolytes (hydrogels, organogels, and ionogels) remain the most studied thanks to the ability to tune the physicochemical and mechanical properties by changing the nature of the precursors, the type of interactions, and the formulation. Nevertheless, the exploitation of this category of electrolyte as a possible commercial product is still restrained, due to different issues related to the nature of the gels (ionic conductivity, evaporation of filling solvent, toxicity, etc.). Therefore, this review aims to resume different strategies to tailor the properties of the gel polymer electrolytes as well as to provide recent advancements in the field toward the elaboration of deformable batteries and supercapacitors.

A flexible and stable power supply is essential to the rapid development of wearable electronic devices. In this work, a transparent, flexible, temperature-stable and ionogel electrode-based self-healing triboelectric nanogenerator (IS-TENG) was developed. The ionogel with excellent stretchability (1,012%), high ionic conductivity (0.3 S·m −1 ) and high-temperature stability (temperature range of −77 to 250 °C) was used as the electrode of the IS-TENG. The IS-TENG exhibited excellent transparency (92.1%) and stability. The output performance did not decrease when placed in a 60 °C oven for 48 h. In addition, the IS-TENG behaved like a stable output in the range of −20 to 60 °C. More importantly, the IS-TENG could also achieve self-healing of electrical performance at temperatures between −20 and 60 °C and its output can be restored to its original state after healing. When the single-electrode IS-TENG with an area of 3 cm × 3 cm was conducted under the working frequency of 1.5 Hz, the output values for open-circuit voltage, short-circuit current, short-circuit transferred charge, and maximum peak power density were 189 V, 6.2 µA, 57 nC, and 2.17 W·m −2 , respectively. The IS-TENG enables to harvest biomechanical energy, and drive electronic devices. Furthermore, the application of IS-TENGs as self-driven sensors for detecting human behavior was also demonstrated, showing good application prospects in the field of wearable power technology and self-driven sensing.

Ionogels with high transparency, stretchability and self-healing capability show great potential for wearable electronics. Here, a kind of highly transparent, stretchable and self-healable ionogels are designed using double physical cross-linking including hydrogen bonding and dipole–dipole interaction. Owing to the dynamic and reversible nature of the ion–dipole interaction and hydrogen bonds of polymeric chains, the ionogel possesses good self-healing capability. The multifunctional sensors for strain and temperature are fabricated based on ionogel. The ionogel can serve as strain sensor that exhibited high sensitivity [gauge factor (GF) = 3.06] and durability (1000 cycles) to a wide range of strains (0–300%). Meanwhile, the ionogel shows rapid response to temperature, due to the temperature dependence of its ionic conductivity. Furthermore, the ionogel fibers with excellent antifreezing (− 20 °C) capability are fabricated, and the fibers show the good sensing performance to human motions and temperature. Importantly, the antifreezing ionogel-based triboelectric nanogenerator (ITENG) is assembled for efficient energy harvesting. The ITENG shows a short circuit current ( I SC ) of 6.1 μA, open circuit voltage ( V OC ) of 115 V, and instantaneous peak power density of 334 mW m −2 . This work provides a new strategy to design ionogels for the advancement of wearable electronics. Graphic Abstract

Developing flexible electrochemical devices with high-performance electrolytes by using natural renewable polymer is of great significance for meeting green and sustainable energy requirements. Here, a new type of chemically cross-linked ionogel based on natural chitosan and cellulose with good self-healability has been designed by a two-step method in ionic liquid. The rheological and dynamic mechanical analysis tests revealed that the as-prepared ionogel exhibited excellent thermo-mechanical stability even when the temperature was as high as 150 °C. Furthermore, the obtained ionogels showed good frost resistance, and still could maintain excellent flexibility even when the temperature was as low as − 20 °C. More importantly, the ionogel showed superior room temperature ionic conductivity (up to 2.1 mS/cm) and retained high electrical performance over a temperature range from − 50 to 120 °C. Additionally, the ionogel was used as electrolyte for preparing flexible supercapacitors and showed good performance under high temperature and harsh mechanical conditions. Such an ionogel, based on natural polymers with robust mechanical properties, high ionic conductivity, self-healability, and wide working temperature range, could be very useful for next-generation sustainable electrochemical devices.Graphic abstract

Inspired by the multi-layer architecture of mammal skins, interfacial robust, stretchable, and entirely healable gel-elastomer hybrids hold great potential in diverse fields including biomedical devices, wearable electrical devices, and soft robotics. However, existing gel-elastomer hybrids have numerous limitations including low interfacial bonding toughness, complex and time-consuming preparation process, unhealable, and non-reconfiguration. Herein, we propose a simple and general chemical strategy through the interfacial dynamic bonding between gel and elastomer to simultaneously address the abovementioned obstacles. Dynamic covalent bonds readily and repeatably covalent bonding ionogel and elastomer (interfacial toughness: 390 J m −2 ), endowed the hybrids with entire self-healing features like skin and enabled discretionary assembly and reconfiguration. Moreover, this strategy resolved the troublesome contradiction between interfacial stability and reconfiguration. Taking advantage of the aforementioned features, we readily constructed a multi-module, self-healing, self-powered, and realtime monitoring of personal status integrated elastic electronics, which could simply reconfigure the output signal of elastic electronics into an input signal of the devices-braille keyboard.

The biocompatible strechable ionogels were prepared by a facile solution-processed method. The ionogels showed outstanding stretchable and self-healing properties. The electrical property could revert to its original state after 4 s. The repaired ionogels could still bear stretching about 150%. Moreover, the ionogels exhibited high sensitivity and wide-detection range to temperature. The temperature-sensitive sensor could detect the human breath frequency and intensity, showing potential application in detecting disease.

Ionogels are solid polymer gel networks loaded with ionic liquid (IL) percolating throughout each other, giving rise to ionically conducting solid electrolytes. They combine the mechanical properties of polymer networks with the ionic conductivity, non-volatility, and non-flammability of ILs. In the frame of their applications in electrochemical-based flexible electronics, ionogels are usually subjected to repeated deformation, making them susceptible to damage. It appears critical to devise a simple and effective strategy to improve their durability and lifespan by imparting them with healing ability through vitrimer chemistry. In this work, we report the original in situ synthesis of polythioether (PTE)-based vitrimer ionogels using fast photopolymerization through thiol-acrylate Michael addition. PTE-based vitrimer was prepared with a constant amount of the trithiol crosslinker and varied proportions of static dithiol spacers and dynamic chain extender BDB containing dynamic exchangeable boronic ester groups. The dynamic ionogels were prepared using 50 wt% of either 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide or 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate, both of which were selected for their high ionic conductivity. They are completely amorphous (Tg below −30 °C), suggesting they can be used at low temperatures. They are stretchable with an elongation at break around 60%, soft with Young’s modulus between 0.4 and 0.6 MPa, and they have high ionic conductivities for solid state electrolytes in the order of 10−4 S·cm−1 at room temperature. They display dynamic properties typical of the vitrimer network, such as stress relaxation and healing, retained despite the large quantity of IL. The design concept illustrated in this work further enlarges the library of vitrimer ionogels and could potentially open a new path for the development of more sustainable, flexible electrochemical-based electronics with extended service life through repair or reprocessing.