The Zn anode/electrolyte interface faces critical challenges, including hydrogen evolution reaction, corrosion, and dendrite growth that degrade battery performance. This study employs 1 mol% N-(2-hydroxyethyl) succinimide (NHS) as a multifunctional electrolyte additive to address these issues. The carbonyl groups (C=O) in NHS can strongly coordinate with Zn atoms and water molecules, selectively adhering to the Zn anode surface to displace H2O, thereby suppressing parasitic reactions while simultaneously reducing water activity in the electrolyte. The NHS can regulate Zn2+ solvation by replacing water molecules in the primary solvation sheath, thereby further facilitating Zn2+ desolvation by reducing the number of bound water molecules. Additionally, the NHS on the anode surface enables a homogeneous Zn2+ flux, resulting in uniform zinc deposition. As a result, the NHS enables a Zn||Zn symmetric cell to achieve 7,500 h cycling at 1 mAcm-2, and a Zn||Cu cell to maintain 99.8% Coulombic efficiency over 3200 cycles. The Zn||V2O5 full cell retains 82.5% capacity after 7,000 cycles. These findings highlight the proficiency of the NHS in securing Zn anodes for enhanced battery performance.

Viologens exhibit reversible redox properties and remarkable color response, making them core materials in electrochromism. However, their low conjugation compromises charge transfer efficiency, undermines redox reversibility, and causes fluorescence quenching, thereby limiting their applications. This study addresses this challenge by proposing a synergistic design strategy of 'aromatic bridging-flexible side chains.' Incorporating electron-rich carbazole groups into the viologen backbone as a rigid bridging structure expands the molecular conjugation network; while tuning the length of the alkyl side chains on both sides suppresses molecular aggregation. Following this strategy, we designed and synthesized carbazole-viologen derivatives substituted with hydroxypropyl (HICDP) and hydroxyhexyl (HICDH) groups. A systematic investigation revealed how the carbazole unit and side-chain length regulate their electrochromic and photoluminescent properties. Experiments showed that the carbazole bridging unit expanded the conjugation system, enabling HICDH to achieve an optical contrast of Delta T = 77.4 % at 700 nm. Even after 100 cycles, HICDH retained approximately 70 % of its optical contrast. The increased side-chain length in carbazole-viologen derivatives increased the distance between radicals, suppressed dimer formation, and enhanced stability. Meanwhile, the material exhibited excellent photoluminescent properties. Theoretical calculations further confirmed that the side-chain extension strategy suppressed radical dimerization through steric hindrance. The hexyl side chain reduced the HOMO-LUMO bandgap to facilitate electron transitions while increasing the molecular dihedral angle to minimize non-radiative recombination. The extension of the side chains effectively suppressed non-radiative transition pathways, ultimately enhanced both the photochromic and electrochromic performance.

A designed zwitterionic group APS (amino-1-propanesulfonate) is grafted onto the metal-carboxylate framework to investigate its strategic and promising function for the melting of metal-carboxylate MOFs and glass formation. Such APS groups on 1,4-dicarboxybenzene ligand (BDC) composite with Bro/nsted acids to form a binary ionic liquid subsystem within the UiO-66, one well-known nonmeltable MOF in coordination chemistry community, and thus readily lead to the melt at moderate temperature (<160 degrees C) and melt-quenched glass formation. The synergic effects of suppressed charge transition from ligand to metal ion, protonation of carboxylate COO- and multiple H-bonding interactions well account for the weakened coordination bond and unmeltable-to-meltable transform of the metal-carboxylate framework. The structure before and after vitrification and melt mechanism are systemically investigated through experiment and computer calculation study. High anhydrous proton conduction (10 degrees C, similar to 10(-3) S cm(-1)) and meltability enable the materials to be facilely fabricated into a high-performance supercapacitor with a stable electrolyte-electrode interface via a melt-infiltration method. We hope this work would point an expressway of exploring various meltable MOFs materials with different zwitterions and carboxylate ligands. It may mean the numerous function materials of MOFs with easy processability toward large areas without grain boundary and structure fragility is desirable in future.

Viologen has become a prominent focus of research in electrochromism due to its facile molecular structure modification, diverse color transitions, low driving voltage, and high coloration efficiency. In this study, asymmetric viologen derivatives (Pentyl-V and Heptyl-V) were synthesized through N-alkylation reactions using 1,2-bis(4-pyridyl) ethylene as the pyridine backbone. Subsequently, these derivatives were used to fabricate electrochromic gels, which were integrated with ITO-coated conductive glass to assemble electrochromic devices. Finally, the spectroelectrochemical, and electrochromic properties of the devices were comprehensively studied. Among these two electrochromic devices based on asymmetric viologen derivatives, the viologen derivative Heptyl-V, which has a longer alkyl chain substituent, demonstrates a significant optical contrast (30.3

Aqueous zinc-iodine batteries (ZIBs) are a promising energy storage technology due to the abundance of iodine, environmental friendliness, and low cost. This study introduces a multifunctional additive, l-lysine hydrochloride (LLH), designed to activate the four-electron transfer chemistry between I+ and I- species, significantly boosting energy density. LLH stabilizes I+ via dual coordination from the amino groups and chloride ion, effectively suppressing hydrolysis and enabling reversible 2I-/I0 2/2I+ conversion. The preferential adsorption of the carboxyl group of protonated l-lysine at the zinc anode promotes uniform zinc deposition while inhibiting the hydrogen evolution reaction. Additionally, the incorporation of LLH effectively suppresses the shuttle effect by interacting with iodine species through its carboxyl and amino groups. LLH-modified Zn‖Zn symmetric batteries demonstrate extended cycling stability, operating beyond 4000 hours, while Zn‖I2 full batteries deliver a high specific capacity of 502 mAh g-1 at 1 A g-1. This additive strategy renders a facile and efficient approach to realizing high-capacity and durable ZIBs.

Four-electron iodine cathodes () promise high-capacity zinc-iodine batteries, yet stabilizing the high-valence couple has so far remained a challenge. Here, we propose a low-concentration eutectic electrolyte that, for the first time, enables fully reversible redox chemistry at only 1 M ZnCl2 concentration in ethylene glycol by constructing a water-free eutectic solvation environment. At the molecular level, the eutectic electrolyte realizes dual regulation of iodine chemistry that ethylene glycol coordinates with high-valence iodine species to suppress hydrolysis and stabilize reactive intermediates, and meanwhile, its hydroxyl groups hydrogen-bond with I-/ to inhibit polyiodide diffusion. Furthermore, ethylene glycol participates in Zn2+ solvation and promotes the formation of an O/Cl-rich hybrid interphase on Zn, enabling uniform deposition. The battery delivers 386 mAh g-1 at 1 A g-1 with over 5000 stable cycles, a 2.15 V stability window, and operation from -20 to 40 degrees C. This work establishes a low-threshold eutectic solvation strategy to unlock high-valence iodine chemistry, offering a new electrolyte paradigm for high-capacity zinc-iodine batteries.

Organic electrochromic materials have shown considerable potential for applications in smart windows, biosensors, and energy-storage devices owing to their tunable molecular structures, facile preparation, and rich color variation. Conventional viologen compounds are susceptible to over-reduction in their reduced states, which induces irreversible structural changes and limits their application in bifunctional electrochromic-photoluminescent devices. Viologen molecules possess excellent structural designability, and their optical and electrochemical properties can be precisely modulated by modifying substituent structures, counterions, and conjugation lengths, giving them irreplaceable advantages in electrochromic applications. In this study, an aromatic-bridging strategy was adopted, in which dibenzo[b,d]thiophene and dimethoxybenzene units were introduced between pyridine rings to modulate molecular conjugation and charge transport, while hydroxyhexyl side chains were incorporated to improve molecular solubility and intermolecular interactions. The experimental results demonstrate that the successfully prepared 4,4′-(2,5-dimethoxy-1,4-phenylene)bis(1-(6-hydroxyhexyl)pyridin-1-ium) dibromide (DMBBH) exhibits outstanding performance. DMBBH enables a reversible transition from a transparent state to a deep-red state, with an optical contrast of ΔT = 72.0%, a high coloration efficiency of η = 183.90 cm2/C, coloration (τc)/bleaching (τb) response times of 9.5 s and 51 s, respectively, and an optical contrast that remains at 61.8% after 10000 s of cycling. This work demonstrates the key role of aromatic bridging structures in stabilizing the excited states of viologen molecules and optimizing charge-transport pathways, providing a new design strategy for future high-performance bifunctional organic optoelectronic devices.

Structural degradation and rapid capacity decay of MnO2 cathodes significantly limit the battery lifespan of aqueous zinc-ion batteries (AZIBs). Herein, an ion-enriched and multifunctional composite film is developed through a controllable and mature layer-by-layer (LbL) self-assembly technique for stabilizing MnO2 cathodes. The multilayer consists of two bio-macromolecules of chitosan (CS) and sodium alginate (SA). It is shown that this LbL film can optimize the ion distribution on the MnO2 cathode due to the presence of a large amount of polar functional groups. This can promote the Mn2+ <-> Mn3+ <-> Mn4+ two-step redox process and the reversible deposition of Zn4(OH)6SO4xH2O. It is also shown that the dissolved Mn2+ can be immobilized to prevent capacity decay. Full cells with the double layer of SA/CS exhibit maximum reversible capacity of 604.3 mAh g-1 at 0.3 A g-1. The cathode maintains the capacity retention of 86.96% after 1000 stable cycles at 2 A g-1. Given the facile and cost-effective material and production of the LbL films, this cathode-modified strategy may boost the industrial application of high-capacity AZIBs.

In this study, fluorene was integrated as a bridging moiety within the pyridine ring to synthesize a bifunctional viologen derivative exhibiting both electrochromic and photoluminescent properties. The impact of substituents on the performance of the viologen derivative was also investigated. Upon application of an external voltage, electrochromic devices based on the viologen derivative demonstrated reversible switching between colorless and green states, achieving a remarkable optical contrast of Delta T = 70.2 %. The coloring duration is remarkably brief, measured at tic = 6.5 s, while the optical contrast (Delta T) consistently maintains a value of approximately 70.2 % even after an extended period of 3000 s, indicating exceptional stability. Additionally, the incorporation of the fluorene bridging group endows the viologen with enhanced fluorescence properties. It is noteworthy that both solvent polarity and standing time exert significant influences on the fluorescence intensity of the fluoreneviologen. As the solvent polarity increases, the fluorescence intensity of the fluorene-viologen derivative initially enhances and subsequently diminishes. After a period of 5 days, the fluorescence intensity of this derivative reaches its peak, approximately five times greater than its initial value. This fluorene-viologen derivative exhibits promising potential for applications in areas such as smart windows, flexible displays, energy storage, and beyond.

Realizing stable four-electron reactions ( ) is the key to boosting the energy density of aqueous zinc-iodine batteries (ZIBs). In most of the traditional studies, the four-electron reactions are realized by catalytic halogen ions as electrolyte additives. Herein, we utilize commercial polyacrylamide (PAM) powder as a cost-friendly electrode binder to catalyze the stable interconversion between I 0 and I + , enabling a four-electron reaction in the absence of halogen ions. We show that PAM obtained from various suppliers can serve as a catalytic binder and induce the 4e reactions due to the presence of a large amount of nucleophilic −CONH 2 group, which strongly binds with I + . Furthermore, PAM also exhibits a strong affinity to polyiodide species, which suppresses the polyiodide shuttling and thus mitigates the anode side reactions between polyiodide and Zn. As a result of the above two beneficial effects, the Zn-I 2 battery demonstrates a high capacity of 416 mAh g −1 (calculated from available iodine mass in electrolyte) and an extended cycle life of over 10 000 cycles at 5 A g −1 . This low-cost and fluorine-free commercial binder for four-electron iodine reaction will boost the progress of high-energy-density aqueous Zn batteries.

A wearable health monitoring sensor based on flexible fibers with high sensitivity capable of detecting various limb movements and monitoring different physiological signals was developed using a coaxial co-injection capillary microfluidic device.

In order to tackle the known challenges faced by aqueous zinc-based batteries (AZBs), including dendrite growth, hydrogen evolution, and parasitic side reactions, we employed a N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES) as a dual-functional electrolyte additive. The rational is as follows. Firstly, the sulfonic acid groups on BES molecules adsorb onto the zinc anode surface, modulating the inner Helmholtz plane and guiding uniform Zn deposition. This adsorption increases the nucleation overpotential, yielding a compact and dendrite-free morphology after cycling while improving Coulombic efficiency. Second, BES buffers electrolyte pH fluctuations, suppressing anode corrosion and hydrogen evolution. As a result, the BES-modified electrolyte renders Zn|| Zn symmetric cells with stable cycles of exceeding 4300 h (1 mA cm- 2 and 1 mA h cm- 2) without distinct dendrites or gas evolution. Consequently, Zn||I2 full cells with BES retain high-capacity retention of 83.14 % after 50000 cycles. As a biocompatible and cost-effective buffering agent, the BES additive provides a sustainable strategy for developing safe, low-cost, and environmentally friendly energy storage systems.

Structural degradation and rapid capacity decay of MnO 2 cathodes significantly limit the battery lifespan of aqueous zinc‐ion batteries (AZIBs). Herein, an ion‐enriched and multifunctional composite film is developed through a controllable and mature layer‐by‐layer (LbL) self‐assembly technique for stabilizing MnO 2 cathodes. The multilayer consists of two bio‐macromolecules of chitosan (CS) and sodium alginate (SA). It is shown that this LbL film can optimize the ion distribution on the MnO 2 cathode due to the presence of a large amount of polar functional groups. This can promote the Mn 2+ ↔ Mn 3+ ↔ Mn 4+ two‐step redox process and the reversible deposition of Zn 4 (OH) 6 SO 4 ·xH 2 O. It is also shown that the dissolved Mn 2+ can be immobilized to prevent capacity decay. Full cells with the double layer of SA/CS exhibit maximum reversible capacity of 604.3 mAh g −1 at 0.3 A g −1 . The cathode maintains the capacity retention of 86.96% after 1000 stable cycles at 2 A g −1 . Given the facile and cost‐effective material and production of the LbL films, this cathode‐modified strategy may boost the industrial application of high‐capacity AZIBs.

The development of high-energy-density aqueous zinc-ion batteries requires the preparation of cathodes with a thick layer of active material. However, the insulating nature and dissolution of vanadium-based oxides lead to low areal capacity (0.1,1 mA h cm-2) during the charge/discharge cycle. Herein, V2O5 nanospheres are generated by anchoring onto the laser-induced graphene (LIG) conductive network through defect-induced adsorption, resulting in the formation of pomegranate-like V2O5@LIG composites. The unique and abundant defect structure in the honeycomb LIG can trigger the formation of uniform V2O5 nanospheres with high specific surface area and interact electronically with V2O5 to enhance the electrical conductivity of the cathode materials up to four orders of magnitude. In contrast to conventional carbon materials that can cause steric hindrance for ion transport, the micropores within LIG shorten the ion transport path through the cathode. Concurrently, the pomegranate-like encapsulated structure effectively prevents cathode material corrosion. Under a high-loading mass of 17.1 mg cm-2, the full cell is stably cycled for 200 cycles, possessing a 92.5% capacity retention, and achieving a high areal capacity of 6.05 mA h cm-2. Pomegranate-liked V2O5@LIG composites are formed by anchoring V2O5 nanospheres onto laser-induced graphene (LIG) networks via defects-triggered adsorption. The numerous defects and micropores of LIG endow the cathode material with enhanced electron conduction pathways and ionic conductivity, achieving 6.05 mA h cm-2 under high-loading mass (17.1 mg cm-2) and demonstrating a high-capacity contribution of vanadium (34.98 A h mol-1). image

The zinc metal anodes are liable to experience detrimental dendrite growth and side reactions, thereby limiting the lifespan of aqueous Zn-ion batteries. Here, a readily available supramolecule, dimethoxypillar[5]arene (DP[5]), is utilized as a shielding layer to stabilize the Zn anode by exploiting its zincophilicity derived from the & horbar;OCH3 functional groups and its hydrophobicity from the hydrophobic backbone. The DP[5] shielding layer regulates the solvation sheath of Zn2+ and facilitates uniform zinc deposition. Swelling and dendrite formation are obviously suppressed in both the symmetric and full cells. The DP[5]-Zn symmetrical cell cycles stably for 5500 h, and achieves a coulombic efficiency of 99.76% in a DP[5]-Zn||Cu half-cell after 2200 cycles. The DP[5]-Zn||V2O5 full cell maintains 92.03% of initial capacity after 6000 cycles. Given the cost-effective fabrication and environmental friendliness of DP[5] films, this material may pave the way for practical applications of zinc anodes.

Triboelectric nanogenerator (TENG) represents an effective approach for the conversion of mechanical energy into electrical energy and has been explored to combine multiple technologies in past years. Self-powered sensors are not only free from the constraints of mechanical energy in the environment but also capable of efficiently harvesting ambient energy to sustain continuous operation. In this review, the remarkable development of TENG-based human body sensing achieved in recent years is presented, with a specific focus on human health sensing solutions, such as body motion and physiological signal detection. The movements originating from different parts of the body, such as body, touch, sound, and eyes, are systematically classified, and a thorough review of sensor structures and materials is conducted. Physiological signal sensors are categorized into non-implantable and implantable biomedical sensors for discussion. Suggestions for future applications of TENG-based biomedical sensors are also indicated, highlighting the associated challenges. This review comprehensively introduces the remarkable achievements of triboelectric nanogenerators-based human sensing devices in recent years, focusing on human health sensing solutions such as human motion and physiological signal detection. Systematically categorizes movements from different parts of the body, touch, sound, and eyes, and provides a comprehensive review of the sensors' structure and materials. image

Cracking caused by aging or repeated bending can severely affect the lifetime of electrochromic devices. In this work, a self-healing electrochromic hydrogel was developed with poly (vinyl alcohol) (PVA)-sodium carboxymethyl chitosan (SCC) semi-inter transfer network as the matrix, viologen bromide (HPV2+2Br-) as the electrochromic substance, and borax as the cross-linking agent. The self-healing properties of hydrogel stem from the dynamic and reversible borate bonds between borax and PVA molecular chains. As the voltage changes, the color of the device transitions from colorless to light purple and then to dark purple. The optical contrast at 600 nm reaches approximately 51 %. At room temperature, the disconnected hydrogel can fully restore its original state after 30 minutes of contact, effectively addressing issues related to cracks and damage in flexible electrochromic devices. This research holds significant implications for enhancing the reliability and stability of flexible electrochromic devices. Electrochromic hydrogels exhibit rapid response speed, consistent color change, excellent reversibility. The dynamic reversible borate bond formed between borax and PVA molecular chains confers the hydrogel with robust self-repairing properties. image

Hybrid zinc-ion capacitors combine the energy storage capabilities of zinc-ion batteries with the high-power output of supercapacitors. However, the limited cycle life and narrow electrochemical window of hybrid zinc-ion capacitors currently restrict their potential applications. Herein, a hybrid zinc-ion capacitor is fabricated on laser-induced graphene (LIG) based on in situ electropolymerization of organic compound poly(8-amino-2-naphthol). The electropolymerized long-conjugated chain polymers on the 3D conductive framework of LIG can enhance reaction kinetics, suppress the dissolution of organic compounds, and boost capacity. Simultaneously, hydrogen bonds form between polymer chains, aiding in proton transport. The assembled Zn//carbon cloth/LIG/poly(8-amino-2-naphthol) hybrid zinc-ion capacitors possess a high specific capacity of 308 mAh g-1 at 0.1 mA cm-2, which is twice as much as that of the batteries without LIG. Additionally, these hybrid capacitors can stably endure 10 000 cycles at a current density of 5 mA cm-2. The hybrid zinc-ion capacitor, utilizing poly(8-amino-2-naphthol) on laser-induced graphene network presents a high specific capacity of 308 mAh g-1 at 0.1 mA cm-2, and demonstrates an exceptional cycling performance over 10 000 cycles with a retention rate of 99.98%. image

With the increase in people’s concern for personal health, the demand for convenient health monitoring electronics has grown noticeably. Wearable physiological sensors with multi-functionality and continuous power supply are constructed through system-level integration and delicate circuit design for energy management and low-power sensing. Energy harvested from body motion and solar or domestic lighting has great potential in powering wearable electronics, eliminating the need of batteries or plug-in power sources. Triboelectric nanogenerators readily fabricated with digital ink-jet printing display a high-power output of 30.96 mW/cm2 after integration with a flexible thin-film solar cell, which ensures unremitting work of the sensors. The self-powered physiological monitoring system can continuously monitor and wirelessly transmit the electrocardiogram, blood pressure, temperature, and motion parameters of the human in real-time without the need for an external power source, providing the wearer with a reliable monitoring means.

Wearable hydrogel sensors provide a user-friendly option for wearable electronics and align well with the existing manufacturing strategy for connecting and communicating with large numbers of Internet of Things devices. This is attributed to their components and structures, which exhibit exceptional adaptability, scalability, bio-compatibility, and self-healing properties, reminiscent of human skin. This review focuses on the recent research on principal structural elements of wearable hydrogels: toughening networks and conductive networks, highlighting the strategies for enhancing mechanical and electrical properties. Wearable hydrogel sensors are categorized for an extensive exploration of their composition, mechanism, and design approach. This review provides a comprehensive understanding of wearable hydrogels and offers guidance for the design of components and structures in order to develop high-performance wearable hydrogel sensors.