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The fundamental understanding of the relationship between ion transport and segmental dynamics of polymer chains in polymer electrolytes is crucial for achieving high ionic conductivity at room temperature for technological applications in supercapacitors, batteries, etc. In this work, the ion dynamics and relaxation have been studied for gel polymer electrolytes (GPEs) containing P(VdF-HFP) as host polymer, adiponitrile as a plasticizer, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide as ionic liquid, and diphenylamine and copper iodide redox additives as fillers. The crystallization temperature of the ionic liquid and the melting temperature of the plasticizer play important roles in ion dynamics. The highest room-temperature ionic conductivity (3.3 × 10−3 S/cm) was obtained for the GPE filled with dual redox additives. The broadband ac conductivity spectra have been analyzed by using the Universal Power law model coupled with the Poisson–Nernst–Planck (PNP) model. The solid–solid phase transition of the ionic liquid affects the grain and grain boundary regions of the GPEs due to the presence of redox fillers. The temperature dependence of the dielectric spectra of the GPEs containing redox fillers confirms the phase transition at the crystallization temperature. The electric modulus and dielectric spectra have been analyzed by using the Havrilliak–Nigami, Kohlrausch–Williams–Watts, and derivative dielectric constant functions. The scaling of ac conductivity and modulus spectra confirms a common ion conduction and relaxation mechanism for the GPEs. The influence of dual redox additives is clearly observed in the values of ionic conductivity, ion diffusivity, and relaxation time. [ABSTRACT FROM AUTHOR]

Even though dilute (unentangled) polymer solutions cannot act as gel-like sieving media, it has been shown that they can be used to separate DNA molecules in capillary electrophoresis. The separation then comes from sporadic, independent DNA–polymer collisions. We study polymer–polymer collisions in nanochannels (i.e., channels that are smaller than the normal size of the polymers), a situation where a polyelectrolyte is forced to migrate "through" isolated uncharged molecules during electrophoresis. We use Langevin dynamics simulations to explore the nature of these collisions and their effect on the net motion of the two polymer chains. We identify several types of collisions, including some that are unique to nanochannels. When the uncharged polymer is much larger than the polyelectrolyte, the system is reminiscent of gel electrophoresis, and we propose a modified empirical reptation model to explain the data, with an orientation factor that depends on the tube diameter. We also observe that the duration of a collision is a non-monotonic function of the polymer size ratio when the two chains are of comparable size, a surprising resonance-like phenomenon, which, combined with the asymmetric nature of molecular conformations during collision, suggests possible ratchet-like mechanisms that could be used to sort polyelectrolytes in nanodevices. [ABSTRACT FROM AUTHOR]

The effects of the solution's dielectric properties on the conformation and dynamics of star-shaped polyelectrolytes in shear flow are investigated using a hybrid simulation method coupling multi-particle collision dynamics and molecular dynamics. The simulation results showed that by modulating the dielectric properties of the solution, star-shaped polyelectrolytes showed a three-step dynamic behavior transition from tumbling to tank-treading to tumbling dynamics under shear flow. The analysis indicated that this distinct transition in dynamics could be attributed to the uneven distribution of counterions induced by shear on the chain, resulting in a change in the polyelectrolyte conformation and degree of segmental alignment in arms. These findings contribute to a comprehensive understanding of the non-equilibrium dynamics of star-shaped polyelectrolytes in shear flow and offer a viable approach for controlling the dynamic behavior of star-shaped polyelectrolytes by adjusting the dielectric properties of the solution. [ABSTRACT FROM AUTHOR]

In this paper, the responses of assembled behaviors of block polyelectrolytes (PEs) to the strength of electrostatic interactions are studied through molecular dynamic simulations. The results show that the assembled structures closely depend on the electrostatic strength. It should be noted that PE coacervation can outweigh the nucleation of hydrophobic blocks and invert the micelle structures at strong electrostatic strengths, leading to the formation of inverted micelles of PE cores and hydrophobic coronas. In the poor solvent condition for neutral block, diverse anisotropic micelles are presented; candy-like conventional micelles of hydrophobic cores and PE patches coexist with inverted candy-like micelles of PE cores and hydrophobic patches and with Janus micelles of semi-neutral aggregate and semi-PE cluster in the presence of divalent and trivalent counterions. The formation of conventional or inverted micelle is largely determined by the type of micellar fusion, which results from the nucleation competition between electrostatic correlation and hydrophobic interaction. The merge of micelles mediated by hydrophobic attraction leads to conventional hydrophobic cores, and the fusion induced by electrostatic correlations results in PE cores micelles. At strong electrostatic strengths, the PE chains exhibit rich conformations at trivalent counterions, ranging from a fully collapsed state to a rod-like state, and parallel alignment of PE chains is found. [ABSTRACT FROM AUTHOR]

Despite the potential use of polyelectrolyte multilayers for biomedical, separation, and energy applications, their dynamic properties are not sufficiently understood. In this work, center-of-mass diffusion of a weak polyacid—poly(methacrylic acid) (PMAA) of linear and 8-arm architecture (L-PMAA and 8-PMAA, respectively) and matched molecular weight—was studied in layer-by-layer (LbL) assemblies with poly(diallyldimethylammonium) chloride (PDADMAC) of varied molecular weight. The film deposition at low-salt, acidic conditions when PMAA was only partially ionized yielded thicker, more diffused layers with shorter PDADMAC chains, and bilayer thickness decreased for multilayers constructed with longer PDADMAC. The molecular architecture of PMAA had a weak effect on film growth, with bilayer thickness being ∼20% larger for L-PMAA for the films constructed with the shortest PDADMAC (35 kDa) and identical film growth for L-PMAA and 8-PMAA with the longest PDADMAC (300 kDa). The exposure of the multilayer films to 0.2M NaCl triggered a reduction in PMAA ionization and significant lateral diffusivity of fluorescently labeled PMAA molecules (PMAA*), with diffusion coefficients D ranging from 10−13 to 10−12 cm2/s, as determined by the fluorescence recovery after photobleaching technique. For all the films, polymer mobility was higher for star polyacids as compared to their linear counterparts, and the dependence of PMAA diffusion coefficient D on PDADMAC molecular weight (D ∼ M−n) was relatively weak (n < 0.6). However, 8-PMAA demonstrated an approximately doubled power exponent compared to the L-PMAA chains, suggesting a stronger effect of the molecular connectivity of the partner polycation molecules on the diffusion of star polyelectrolytes. [ABSTRACT FROM AUTHOR]

Recent experimental results have demonstrated that zwitterionic ionogel comprised of polyzwitterion (polyZI)-supported lithium salt-doped ionic liquid exhibits improved conductivities and lithium transference numbers than the salt-doped base ionic liquid electrolyte (ILE). However, the underlying mechanisms of such observations remain unresolved. In this work, we pursued a systematic investigation to understand the impact of the polyZI content and salt concentration on the structural and dynamic properties of the poly(MPC) ionogel of our model polyZI ionogel, poly(2-methacryloyloxyethyl phosphorylcholine) [poly(MPC)] supported LiTFSI/N-butyl-N-methylpyrrolidinium TFSI base ionic liquid electrolyte. Our structural analyses show strong lithium–ZI interaction consistent with the physical network characteristic observed in the experiments. An increase in polyZI content leads to an increased fraction of Li+ ions coordinated with the polyZI. In contrast, an increase in salt concentration leads to a decreased fraction of Li+ ions coordinated with the polyZI. The diffusivities of the mobile ions in the poly(MPC) ionogel were found to be lower than the base ILE in agreement with experiments at T > 300 K. Analysis of ion transport mechanisms shows that lithium ions within the poly(MPC) ionogel travel via a combination of structural, vehicular diffusion, as well as hopping mechanism. Finally, the conductivity trend crossover between the poly(MPC) ionogel and the base ILE was rationalized via a temperature study that showed that the base ILE ions are influenced more by the variation of temperature when compared to the poly(MPC) ions. [ABSTRACT FROM AUTHOR]

In recent years, ionic microgels have garnered much attention due to their unique properties, especially their stimulus-sensitive swelling behavior. The tunable response of these soft, permeable, compressible, charged colloidal particles is increasingly attractive for applications in medicine and biotechnologies, such as controlled drug delivery, tissue engineering, and biosensing. The ability to model and predict variation of the osmotic pressure of a single microgel with respect to changes in particle properties and environmental conditions proves vital to such applications. In this work, we apply both nonlinear Poisson–Boltzmann theory and molecular dynamics simulation to ionic microgels (macroions) in the cell model to compute density profiles of microions (counterions, coions), single-microgel osmotic pressure, and equilibrium swelling ratios of spherical microgels whose fixed charge is confined to the macroion surface. The basis of our approach is an exact theorem that relates the electrostatic component of the osmotic pressure to the microion density profiles. Close agreement between theory and simulation serves as a consistency check to validate our approach. We predict that surface-charged microgels progressively deswell with increasing microgel concentration, starting well below close packing, and with increasing salt concentration, in qualitative agreement with experiments. Comparison with previous results for microgels with fixed charge uniformly distributed over their volume demonstrates that surface-charged microgels deswell more rapidly than volume-charged microgels. We conclude that swelling behavior of ionic microgels in solution is sensitive to the distribution of fixed charge within the polymer-network gel and strongly depends on bulk concentrations of both microgels and salt ions. [ABSTRACT FROM AUTHOR]

We present a strategic approach for enhancing the ionic conductivity of block copolymer electrolytes. This was achieved by introducing mixed ionic liquids (ILs) with varying molar ratios, wherein the imidazolium cation was paired with either tetrafluoroborate (BF4) anion or bis(trifluoromethylsulfonyl)imide (TFSI) anion. Two polymer matrices, poly(4-styrenesulfonate)-b-polymethylbutylene (SSMB) and poly(4-styrenesulfonyl (trifluoromethanesulfonyl)imide)-b-polymethylbutylene (STMB), were synthesized for this purpose. All the SSMB and STMB containing mixed ILs showed hexagonal cylindrical structures, but the type of tethered acid group significantly influenced the interfacial properties. STMB electrolytes demonstrated enhanced segregation strength, which was attributed to strengthened Coulomb and hydrogen bonding interactions in the ionic domains, where the ILs were uniformly distributed. In contrast, the SSMB electrolytes exhibited increased concentration fluctuations because the BF4 anions were selectively sequestered at the block interfaces. This resulted in the effective confinement of imidazolium TFSI along the ionic domains, thereby preventing ion trapping in dead zones and facilitating rapid ion diffusion. Consequently, the SSMB electrolytes with mixed ILs demonstrated significantly improved ionic conductivities, surpassing the expected values based on the arithmetic average of the conductivities of each IL, whereas the ionic conductivity of the STMB was aligned with the expected average. The methodology explored in this study holds great promise for the development of solid-state polymer electrolytes. [ABSTRACT FROM AUTHOR]

Due to the importance of supercapacitors in electronic storage devices, improving their efficiency is one of the topics that has attracted the attention of many researchers. Choosing the proper electrolyte for supercapacitors is one of the most significant factors affecting supercapacitors' performance. In the present paper, we compare liquid electrolytes (ionic liquid electrolytes) and solid electrolytes (polymer electrolytes) by molecular dynamics simulation to summarize their pros and cons. We consider polymer electrolytes in linear and network configurations. The results show that although ionic liquid-based supercapacitors have a larger differential capacitance since they have a smaller operation voltage, the energy stored is less than polymer electrolyte-based supercapacitors. Also, our investigations indicate that polymer electrolyte-based supercapacitors have more mechanical stability. Therefore, they can be considered a very suitable alternative to liquid electrolyte-based supercapacitors since they do not have known liquid electrolyte problems and display better performance. [ABSTRACT FROM AUTHOR]

The aluminum ion battery (AIB) is a promising technology, but there is a lack of understanding of the desired nature of the batteries' electrolytes. The ionic charge carriers in these batteries are not simply Al3+ ions but the anionic AlCl4− and Al2Cl7−, which form in the electrolyte. Using computational analysis, this study illustrates the effect of mole ratios and organic solvents to improve the AIB electrolytes. To this end, molecular dynamics simulations were conducted on varying ratios forming acidic, neutral, and basic mixtures of the AlCl3 salt with 1-ethyl-3-methylimidazolium chloride (EMImCl) ionic liquid (IL) and an organic solvent electrolyte [dichloromethane (DCM) or toluene]. The data obtained from diffusion calculations indicates that the solvents could improve the transport properties. Both DCM and toluene lead to higher diffusion coefficients, and higher conductivity. Detailed calculations demonstrated solvents can effectively improve the formation of AlCl3⋯Cl (AlCl4−) and AlCl4−···AlCl4− (Al2Cl7−) especially in acidic mixtures. The densities, around 1.25 g/cm3 for electrolyte mixtures of AlCl3-EMImCl, were consistent with experiment. These results, in agreement with experimental findings, strongly suggest that DCM in acidic media with AlCl3 and EMImCl might provide a promising basis for battery development. [ABSTRACT FROM AUTHOR]

We present a simulation method that allows us to calculate the titration curves for systems undergoing protonation/deprotonation reactions—such as charged colloidal suspensions with acidic/basic surface groups, polyelectrolytes, polyampholytes, and proteins. The new approach allows us to simultaneously obtain titration curves both for systems in contact with salt and acid reservoir (semi-grand canonical ensemble) and for isolated suspensions (canonical ensemble). To treat the electrostatic interactions, we present a new method based on Ewald summation—which accounts for the existence of both Bethe and Donnan potentials within the simulation cell. We show that the Donnan potential dramatically affects the pH of a suspension. Counterintuitively, we find that in suspensions with a large volume fraction of nanoparticles and low ionic strength, the number of deprotonated groups can be 100% larger in an isolated system, compared to a system connected to a reservoir by a semi-permeable membrane—both systems being at exactly the same pH. [ABSTRACT FROM AUTHOR]

Polymer gel electrolytes (PGE) have seen a renewed interest in their development because they have high ionic conductivities but low electrochemical degradation and flammability. PGEs are formed by mixing a liquid lithium-ion electrolyte with a polymer at a sufficiently large concentration to form a gel. PGEs have been extensively studied, but the direct connection between their microscopic structure and macroscopic properties remains controversial. For example, it is still unknown whether the polymer in the PGE acts as an inert, stabilizing scaffold for the electrolyte or it interacts with the ionic components. Here, a PGE composed of a prototypical lithium-carbonate electrolyte and polyacrylonitrile (PAN) is pursued at both microscopic and macroscopic levels. Specifically, this study focused on describing the microscopic and macroscopic changes in the PGE at different polymer concentrations. The results indicated that the polymer-ion and polymer–polymer interactions are strongly dependent on the concentration of the polymer and the lithium salt. In particular, the polymer interacts with itself at very high PAN concentrations (10% weight) resulting in a viscous gel. However, the conductivity and dynamics of the electrolyte liquid components are significantly less affected by the addition of the polymer. The observations are explained in terms of the PGE structure, which transitions from a polymer solution to a gel, containing a polymer matrix and disperse electrolyte, at low and high PAN concentrations, respectively. The results highlight the critical role that the polymer concentration plays in determining both the macroscopic properties of the system and the molecular structure of the PGE. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) exhibit comparable thermal and chemical stability to ionic liquids, coupled with excellent ionic conductivity. Moreover, they boast a higher degree of safety owing to lower toxicity and increased accessibility. Hence, the utilization of DES in gel preparation emerges as an effective solution to address the challenges associated with the inadequate stability of traditional hydrogels and the heightened toxicity of gels composed of ionic liquids. In this paper, eutectogels with excellent low-temperature sensing properties were prepared by using methacrylic acid (MAA) and pyrrole (Py) as monomers and DES as solvent. The eutectogel exhibits excellent sensing capability, with a gauge factor reaching 5.21. Additionally, DES prepared using choline chloride and urea endows the eutectogel with good freeze resistance, enabling sensing at −20 °C while maintaining stability. Moreover, the eutectogel accurately monitors changes in environmental temperature, providing a promising material for temperature-measuring flexible wearable sensor applications. [ABSTRACT FROM AUTHOR]

Li+ ion conduction in two aligned liquid crystalline electrolytes consisting of 10 mol% Li+ salt of a pro-mesogenic anion derived from [closo-1-CB11H12]− in non-ionic hosts was investigated. Using electrochemical impedance spectroscopy (EIS), the ionic conductivity in the parallel (σ‖) and perpendicular (σ⊥) directions of the electrolyte samples was determined using two types of cells: an interdigitated gold electrode and a nylon 6-coated ITO cell. The ratio of ionic conductivities σ⊥/σ‖ in the electrolyte with a nona(ethylene oxide) spacer was about 3 in the entire SmA phase, while in the shorter homologue, the ratio monotonically increases from about 0.4 to 2.9. The liquid crystalline behavior of the hosts and the electrolytes was investigated by optical, thermal, and powder XRD methods. [ABSTRACT FROM AUTHOR]

The polymer electrolyte membrane fuel cells are proven to be clean renewable energy conversion systems; however, the cylindrical structures have numerous potentials in low-power applications owing to their higher gravimetric and volumetric power densities. In this study, a three-dimensional axisymmetric computational fluid dynamics model is developed for a cylindrical structure and is further validated for cell performance at different clamping pressures (0.5–2.5 MPa). The optimum contact resistance for the cell is observed to be 0.40 Ω-cm2 for a clamping pressure of 1.5 MPa at the interface of the cathode gas diffusion layer and cathode current collector. In addition, a structural model is developed with the variation in thickness of the cathode current collector (0.25–1.5 mm) and gas pressure (0.5–3.0 bar) for different clamping systems. The results indicate an enhancement in the cell performance (58.58 W/m2 to 138.96 W/m2 at 0.6 V) with optimum clamping (1.5 MPa) and gas pressure (1 bar) due to better contact pressure distribution at the interface. The thickness of the cathode current collector is also optimized to 1.0 mm for a new (spring) clamping system owing to ∼1.6 times better contact and 66% less resistance to that of conventional (strap) clamping mechanism. • A cylindrical polymer electrolyte membrane fuel cell is modelled using an axisymmetric approach. • Effect of thickness of cathode current collector with strap and spring clamping method is analysed. • Interfacial contact resistance and its effect on cell performance due to clamping and gas pressure are estimated [ABSTRACT FROM AUTHOR]

The in situ‐formed polymer electrolytes provide a vital solution for improving both safety and performance in the high‐voltage lithium metal batteries. This study reports new poly(ester‐alt‐acetal) (PEA) electrolytes, synthesized through in situ alternating copolymerization of glutaric anhydride and 1,3‐dioxane. In the presence of 25 wt.% lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), three lithium salts, lithium difluoro(oxalate)borate (LiDFOB), lithium hexafluorophosphate (LiPF6), and lithium tetrafluoroborate (LiBF4) are employed as the catalysts for the copolymerization. These lithium salts can modulate the compositions of the solid‐electrolyte interphase (SEI) layer. PEA‐LiPF6 exhibits outstanding SEI chemistry, with observing the highest LiF content, thereby achieving a remarkable critical current density of up to 2.5 mA cm−2, a Li+ transference number of 0.81, and an expansive electrochemical stability window of 6.0 V. Furthermore, PEA‐LiPF6 demonstrates noteworthy capacity retention rates of 96.6% (0.5 C, 200th/first cycle in LiFePO4||Li), 95.6% (0.5 C, 100th/first cycle in LiMn0.6Fe0.4PO4||Li), 95.1% (1 C, 100th/first cycle in LiCoO2||Li), and 87.0% (1 C, 100th/first cycle in LiNi0.6Co0.2Mn0.2O2||Li full‐cells). This work demonstrates a facile in situ route to fabricate polymer electrolytes for high‐voltage lithium‐metal batteries with balanced and comprehensive performance. [ABSTRACT FROM AUTHOR]

Ice‐templating is a versatile method for constructing macro‐porous hydrophilic polymer materials. However, the ice‐templating method is generally limited by high energy cost and low efficiency for large‐scale fabrication. Further, due to its hydrophilic nature, the constructed materials are vulnerable to water swelling and have poor structural stability. Here, an Ice‐Dissolving‐Crosslinking (IDCr) method is developed for efficient and large‐scale preparation of polyelectrolyte monoliths with ultra‐stability in aqueous environment. Specifically, Ice‐Dissolving in water‐miscible organic solvent is responsible for pore creation, while subsequent Crosslinking ensures pore structures stabilization. The macro‐porous architecture of materials, taking sodium carboxymethyl cellulose (CMC) as a polyelectrolyte example and trimesoyl chloride (TMC) as the crosslinker, CMC‐TMCIDCr is made much stabler as compared with the case of conventional Lyophilization‐Crosslinking technique (CMC‐TMCLC). The IDCr method is applicable to various hydrophilic polyelectrolytes and hybrids for long‐time use in water and brines, as exemplified by CMC‐TMC‐carbon nanotubes monolith, which exhibits high performance in solar thermal desalination process. This novel approach opens up new opportunities for the construction of porous monoliths with efficient preparation and excellent water stability. [ABSTRACT FROM AUTHOR]

A high concentration gel polymer electrolyte (GPE) was prepared by simply using LiFSI–LiNO3 dissolved in 1,3-dioxolane. The Li‖Li cell achieves stable battery cycling for over 3200 h. Furthermore, the Li‖Cu cell demonstrates a high CE of 99.2%. Even at a high current density of 8 mA cm−2, a high CE of 98.5% was still achieved. Notably, in a Li‖LiFePO4 cell, this electrolyte enables high capacity retention of 94.5% and an average CE of 99.8% over 500 cycles, showing promising prospects for high-performance lithium metal batteries. [ABSTRACT FROM AUTHOR]

Dramatic growth of lithium dendrite, structural deterioration of LiCoO2 (LCO) cathode at high voltages, and unstable electrode/electrolyte interfaces pose significant obstacles to the practical application of high‐energy‐density LCO||Li batteries. In this work, a novel eutectogel electrolyte is developed by confining the nonflammable eutectic electrolyte in a polymer matrix. The eutectogel electrolyte can construct a robust solid electrolyte interphase (SEI) with inorganic‐rich LiF and Li3N, contributing to a uniform Li deposition. Besides, the severe interface side reactions between LCO cathode and electrolyte can be retarded with an in situ formed protective layer. Correspondingly, Li||Li symmetrical cells achieve highly reversible Li plating/stripping over 1000 h. The LCO||Li full cell can maintain 72.5% capacity after 1500 cycles with a decay rate of only 0.018% per cycle at a high charging voltage of 4.45 V. Moreover, the well‐designed eutectogel electrolyte can even enable the stable operation of LCO at an extremely high cutoff voltage of 4.6 V. This work introduces a promising avenue for the advancement of eutectogel electrolytes, the nonflammable nature and well‐regulated interphase significantly push forward the future application of lithium metal batteries and high‐voltage utilization of LCO cathode. [ABSTRACT FROM AUTHOR]

Physical hydrogels crosslinked by noncovalent interactions are promising in flexible zinc–metal batteries for their component controllability and environmental friendliness. However, the compatibility of PVA‐based electrolyte and kosmotropic salt remains a challenge, which shows an unclear mechanism. Here, a "good‐to‐poor" solvent substitution strategy is adopted to develop a PVA hydrogel electrolyte with good compatibility with kosmotropic salt (ZnSO4). Stretching the polymer conformation by preshielding the strong intrachain hydrogen bonds with good solvents and activating the polymer interchain interaction in situ with poor solvents will induce the formation of a homogeneous polymer network and the release of hydrated hydroxyl groups for fast ion transport. This multiscale microstructure improves the ionic conductivity and liquid retention of PVA hydrogels with kosmotropic salt. Additionally, this strong hydrogen bonds preshielded hydrogel electrolyte offers great battery performance, with 1300 h of stable cycling at 1 mA cm−2 with low voltage hysteresis; and an extended cycle life of 220 h at 68.4% zinc utilization. Importantly, the Zn//MnO2 pouch cell maintains 98.4% capacity after 100 cycles at 0.2 A g−1 and features strong environmental reliability. These concepts address the inherent barriers of kosmotropic salt‐based hydrogel electrolytes and advance their development in soft electronics. [ABSTRACT FROM AUTHOR]

Operation at high current density of polymer electrolyte membrane electrolysis cell (PEMEC) can reduce its electrode area and capital expense. The high current density operation is limited by the limiting current density (LCD), where electrolysis voltage abruptly increases. Effects of operating temperature and pressure on the LCD were evaluated in a lab-scale PEMEC within a range from 70 to 90 °C and from 0.1 to 0.3 MPa. Also, a theoretical model was developed to predict the LCD, and to clarify what determines LCD and how the operating conditions influence the LCD. The theoretical analysis suggests that when current density is close to the LCD, water mass transport at anode reaches a limitation, which indicates that water saturation reaches almost zero at anodic catalyst layer. The analysis also finds that lower operating temperature and higher operating pressure can reduce oxygen gas saturation and raise the water saturation in porous transport layer at anode, and finally enlarge the LCD. • Limiting current density (LCD) is decided by mass transport limitation. • Oxygen gas saturation near catalyst layer is close to 1 at LCD. • Bubble overvoltage abruptly rises at LCD. • Lower temperature and higher pressure enlarge LCD. [ABSTRACT FROM AUTHOR]

The present study reports on the development of a new binary filler system for rubber composites, SiO2@Al2O3, where Al2O3 sheets are grown onto SiO2 nanoparticles aggregates by a sustainable water‐based soft‐chemistry approach. The aim is to synergistically integrate the intrinsic thermal conductivity properties of Al2O3 with the peculiar reinforcement ability of SiO2 in an easy one‐pot solution, which has been exploited to prepare polybutadiene (PB) model composites by a simple solvent casting technique. More in detail, the binary filler was used as‐prepared or suitably surface functionalized with 3‐(Trimethoxysilyl)propylmethacrylate (TMSPM). The filler compatibilization and interplay with the polymeric matrix have been inspected by solid state NMR in conjunction with scanning electron microscopy. These investigations highlighted that the presence of alumina in the binary filler does not undermine the capability of silica in generating polymer chains stiffening and indicated a significant effect of the silanization in providing better filler networking and interaction with the PB host ensuring, in principle, an enhanced thermal transport. Accordingly, thermal conductivity measurements revealed that SiO2@Al2O3 introduction in PB induces a remarkable upgrade of the heat transfer, which becomes much more relevant upon surface modification with TMSPM. These results appear encouraging, paving the possibility of applying SiO2@Al2O3 model system to more complex case studies, where both improved thermal conductivity and enhanced reinforcement are required, such as tires tread formulations. Highlights: A new SiO2@Al2O3 binary filler system was proposed following a soft‐chemistry approach.The binary filler was functionalized to enhance its compatibilization.Fillers were dispersed in polybutadiene by a simple solvent casting technique.Thermal conductivity measurements revealed a remarkable upgrade of the heat transfer ability. [ABSTRACT FROM AUTHOR]

Many crucial components inside electronic devices are made from non‐renewable, non‐biodegradable, and potentially toxic materials, leading to environmental damage. Finding alternative green dielectric materials is mandatory to align with global sustainable goals. Carboxymethyl cellulose (CMC) is a bio‐polymer derived from cellulose and has outstanding properties. Herein, citric acid, dextrin, and CMC based hydrogels are prepared, which are biocompatible and biodegradable and exhibit rubber‐like mechanical properties, with Young modulus values of 0.89 MPa. Hence, thin film CMC‐based hydrogel is explored as a suitable green high‐k dielectric candidate for operation at low voltages, demonstrating a high dielectric constant of up to 78. These fabricated transistors reveal stable high capacitance (2090 nF cm−2) for ≈±3 V operation. Using a polyelectrolyte‐type approach and poly‐(2‐vinyl anthracene) (PVAn) surface modification, this study demonstrates a thin dielectric layer (d ≈30 nm) with a small voltage threshold (Vth ≈−0.8 V), moderate transconductance (gm ≈65 nS), and high ON–OFF ratio (≈105). Furthermore, the dielectric layer exhibits stable performance under bias stress of ± 3.5 V and 100 cycles of switching tests. The modified CMC‐based hydrogel demonstrates desirable performance as a green dielectric for low‐voltage operation, further highlighting its biocompatibility. [ABSTRACT FROM AUTHOR]

Conjugated polymers (CPs) have been developed quickly as an emerging functional material with applications in optical and electronic devices, owing to their highly electron‐delocalized backbones and versatile side groups for facile processibility, high mechanical strength, and environmental stability. CPs exhibit multistimuli responsive behavior and fluorescence quenching properties by incorporating azobenzene functionality into their molecular structures. Over the past few decades, significant progress has been made in developing functional azobenzene‐based conjugated polymers (azo‐CPs), utilizing diverse molecular design strategies and synthetic pathways. This article comprehensively reviews the rapidly evolving research field of azo‐CPs, focusing on the structural characteristics and synthesis methods of general azo‐CPs, as well as the applications of charged azo‐CPs, specifically azobenzene‐based conjugated polyelectrolytes (azo‐CPEs). Based on their molecular structures, azo‐CPs can be broadly categorized into three primary types: linear CPs with azobenzene incorporated into the side chain, linear CPs with azobenzene integrated into the main chain, and branched CPs containing azobenzene moieties. These systems are promising for biomedical applications in biosensing, bioimaging, targeted protein degradation, and cellular apoptosis. [ABSTRACT FROM AUTHOR]

[Display omitted] Traditional dual-ion lithium salts have been widely used in solid polymer lithium-metal batteries (LMBs). Nevertheless, concentration polarization caused by uncontrolled migration of free anions has severely caused the growth of lithium dendrites. Although single-ion conductor polymers (SICP) have been developed to reduce concentration polarization, the poor ionic conductivity caused by low carrier concentration limits their application. Herein, a dual-salt quasi-solid polymer electrolyte (QSPE), containing the SICP network as a salt and traditional dual-ion lithium salt, is designed for retarding the movement of free anions and simultaneously providing sufficient effective carriers to alleviate concentration polarization. The dual salt network of this designed QSPE is prepared through in-situ crosslinking copolymerization of SICP monomer, regular ionic conductor, crosslinker with the presence of the dual-ion lithium salt, delivering a high lithium-ion transference number (0.75) and satisfactory ionic conductivity (1.16 × 10−3 S cm−1 at 30 °C). Comprehensive characterizations combined with theoretical calculation demonstrate that polyanions from SICP exerts a potential repulsive effect on the transport of free anions to reduce concentration polarization inhibiting lithium dendrites. As a consequence, the Li||LiFePO 4 cell achieves a long-cycle stability for 2000 cycles and a 90% capacity retention at 30 °C. This work provides a new perspective for reducing concentration polarization and simultaneously enabling enough lithium-ions migration for high-performance polymer LMBs. [ABSTRACT FROM AUTHOR]

Recently, halide solid state electrolytes (SSEs) have received great attention owing to their fast ionic conductivity, high oxidation potential, and good chemical and electrochemical compatibility with high voltage cathode materials. However, most of reported halide SSEs contain rather rare and expensive elements, which hinders their sustainable utilizations in practical batteries. Here in this work, under the guidance of systematic modelling based on the density functional theory (DFT), a low‐cost alternative is developed through optimizing the lattice chemistry in a recently identified spinel‐like chloride Li2CrCl4 into Li5/3Cr1/3Zr1/3Cl4 for remarkably enhanced ionic conductivity and stable electrochemical window with respect to the Li‐anode. This new phase has then been synthesized successfully, delivering an ionic conductivity over 1200 times of that of the pristine phase Li2CrCl4, in addition to a high oxidation potential (up to 4.1 V vs Li/Li+) to enable outstanding interfacial compatibility with high voltage cathodes. Such a high‐voltage and fast Li‐ion conducting solid‐state electrolyte is expected to provide a highly desirable basis toward developing high energy‐density all solid‐state batteries (ASSBs) using economical and Earth‐rich elements. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO) solid electrolytes are regarded as a promising candidate for all‐solid‐state lithium batteries owing to their high safety and interfacial compatibility. However, PEO electrolyte is plagued by relatively weak structural strength and unsatisfactory Li+ conductivity. Herein, a mechanically strong and Li+ conductively favorable cellulosic scaffold of PEO is fabricated through amino (‐NH2) modification and g‐C3N4 (CN) incorporation of bacterial cellulose (BC) under a microbial circumstance. The biologically ‐NH2 modified BC (B‐NBC) is entangled with CN nanosheets (CN@B‐NBC) through an in situ secretion of nanocellulose followed by hydrogen bond‐induced self‐assembly. The ‐NH2 groups from B‐NBC weaken the complexation of Li+ with its counterpart, thus facilitating the release of more free Li+. CN with strong C‐N covalence and extra lone electrons of N further strengthens the BC skeleton and meanwhile offers sufficient anchors for Li+ migration. After infiltrating by LiTFSI/PEO (LP), the LP/CN@B‐NBC composite solid electrolyte (CSE) exhibits high lithium transference number and ionic conductivity. Upon coupling with LiFePO4 cathode, the full battery exhibits a remarkably high specific capacity, superior rate capability, and decent cycling stability. This work pioneers the attempts of chemical decoration and ingredient incorporation of BC architecture in CSE with the aid of a bottom‐up biosynthetic avenue. [ABSTRACT FROM AUTHOR]

The electrochemical performance of supercapacitors drops precipitously at extreme low temperatures due to a multitude of reasons, which includes electrolyte freezing, sluggish ion transport in the electrode and electrolyte, and high charge transfer resistance at electrode–electrolyte interfaces. To address high interface resistance, a new supercapacitor architecture is reported, in which MXene/carbon nanotube electrodes with vertically aligned channels are synthesized to reduce tortuosity and maximize the electrode–electrolyte contact area. These electrodes are fabricated using a directional‐freezing strategy, generating direct and fast ion transport pathways. Further, a freeze‐resistant electrolyte which shows high ionic conductivity is synthesized by designing a double‐crosslinked polymer network in a binary solvent consisting of ionic liquid and water, which exhibits an ultralow freezing temperature of −54 °C. An all‐in‐one supercapacitor is assembled by an integrated polymerization strategy to minimize interfacial resistances. The resulting device delivers a specific capacitance of 231 F g−1 at 2 mV s−1 and a maximum energy density of 10.17 Wh kg−1, while maintaining a capacitance retention of 92%, even at an extreme low temperature of −50 °C. The supercapacitor architecture developed in this study, demonstrates the feasibility of electrochemical energy storage at extreme low temperatures. [ABSTRACT FROM AUTHOR]

Aqueous zinc (Zn)‐based structural batteries capable of both electrochemical energy storage and mechanical load‐bearing capabilities are attractive for next‐generation energy storage for future electric vehicles due to their eco‐friendliness, non‐toxic, and safe nature. However, parasitic free water activities plague aqueous Zn‐based batteries, detrimental to the electrochemical performance and longevity of the cell. Developing polymer gel electrolytes is a notable potential solution, but they usually have poor electrode interfacial interactions and inadequate mechanical properties. This article introduces a novel non‐fibrous highly amorphous cellulose polymer electrolyte "Cellyte" for aqueous structural Zn‐based batteries. Cellyte exhibits a high strength of ≈24 MPa and Young's modulus of ≈380 MPa, along with the ability to suppress parasitic water activity. The symmetric Zn||Cellyte||Zn cell therefore demonstrates excellent cycling stability of over ≈3000 h. Cellyte can also serve as the binder for the structural cathode material, creating a continuous polymer electrolyte–cathode interface, thereby increasing mechanical robustness and decreasing interfacial resistances of the battery, allowing the structural Zn||Cellyte||LMO‐CF battery to achieve high electrochemical performance with excellent cycling stability over 1200 h with ≈91.5% capacity retention. This provides a pathway to design mechanically robust, electrochemically performing, and safe structural batteries. [ABSTRACT FROM AUTHOR]

We formed core–shell‐like polyelectrolyte complexes (PECs) from an anionic bottlebrush polymer with poly (acrylic acid) side chains with a cationic linear poly (allylamine hydrochloride). By varying the pH, the number of side chains of the polyanionic BB polymers (Nbb), the charge density of the polyelectrolytes, and the salt concentration, the phase separation behavior and salt resistance of the complexes could be tuned by the conformation of the BBs. By combining the linear/bottlebrush polyelectrolyte complexation with all‐liquid 3D printing, flow‐through tubular constructs were produced that showed selective transport across the PEC membrane comprising the walls of the tubules. These tubular constructs afford a new platform for flow‐through delivery systems. [ABSTRACT FROM AUTHOR]

Quasi‐solid polymer electrolyte (QPE) lithium (Li)‐metal battery holds significant promise in the application of high‐energy‐density batteries, yet it suffers from low ionic conductivity and poor oxidation stability. Herein, a novel self‐built electric field (SBEF) strategy is proposed to enhance Li+ transportation and accelerate the degradation dynamics of carbon‐fluorine bond cleavage in LiTFSI by optimizing the termination of MXene. Among them, the SBEF induced by dielectric Nb4C3F2 MXene effectively constructs highly conductive LiF‐enriched SEI and CEI stable interfaces, moreover, enhances the electrochemical performance of the QPE. The related Li‐ion transfer mechanism and dual‐reinforced stable interface are thoroughly investigated using ab initio molecular dynamics, COMSOL, XPS depth profiling, and ToF‐SIMS. This comprehensive approach results in a high conductivity of 1.34 mS cm−1, leading to a small polarization of approximately 25 mV for Li//Li symmetric cell after 6000 h. Furthermore, it enables a prolonged cycle life at a high voltage of up to 4.6 V. Overall, this work not only broadens the application of MXene for QPE but also inspires the great potential of the self‐built electric field in QPE‐based high‐voltage batteries. [ABSTRACT FROM AUTHOR]

We formed core–shell‐like polyelectrolyte complexes (PECs) from an anionic bottlebrush polymer with poly (acrylic acid) side chains with a cationic linear poly (allylamine hydrochloride). By varying the pH, the number of side chains of the polyanionic BB polymers (Nbb), the charge density of the polyelectrolytes, and the salt concentration, the phase separation behavior and salt resistance of the complexes could be tuned by the conformation of the BBs. By combining the linear/bottlebrush polyelectrolyte complexation with all‐liquid 3D printing, flow‐through tubular constructs were produced that showed selective transport across the PEC membrane comprising the walls of the tubules. These tubular constructs afford a new platform for flow‐through delivery systems. [ABSTRACT FROM AUTHOR]

Quasi‐solid polymer electrolyte (QPE) lithium (Li)‐metal battery holds significant promise in the application of high‐energy‐density batteries, yet it suffers from low ionic conductivity and poor oxidation stability. Herein, a novel self‐built electric field (SBEF) strategy is proposed to enhance Li+ transportation and accelerate the degradation dynamics of carbon‐fluorine bond cleavage in LiTFSI by optimizing the termination of MXene. Among them, the SBEF induced by dielectric Nb4C3F2 MXene effectively constructs highly conductive LiF‐enriched SEI and CEI stable interfaces, moreover, enhances the electrochemical performance of the QPE. The related Li‐ion transfer mechanism and dual‐reinforced stable interface are thoroughly investigated using ab initio molecular dynamics, COMSOL, XPS depth profiling, and ToF‐SIMS. This comprehensive approach results in a high conductivity of 1.34 mS cm−1, leading to a small polarization of approximately 25 mV for Li//Li symmetric cell after 6000 h. Furthermore, it enables a prolonged cycle life at a high voltage of up to 4.6 V. Overall, this work not only broadens the application of MXene for QPE but also inspires the great potential of the self‐built electric field in QPE‐based high‐voltage batteries. [ABSTRACT FROM AUTHOR]

Inferior air stability is a primary barrier for large‐scale applications of garnet electrolytes in energy storage systems. Herein, a deeply hydrated hydrogarnet electrolyte generated by a simple ion‐exchange‐induced phase transition from conventional garnet, realizing a record‐long air stability of more than two years when exposed to ambient air is proposed. Benefited from the elimination of air‐sensitive lithium ions at 96 h/48e sites and unobstructed lithium conduction path along tetragonal sites (12a) and vacancies (12b), the hydrogarnet electrolyte exhibits intrinsic air stability and comparable ion conductivity to that of traditional garnet. Moreover, the unique properties of hydrogarnet pave the way for a brand‐new aqueous route to prepare lithium metal stable composite electrolyte on a large‐scale, with high ionic conductivity (8.04 × 10−4 S cm−1), wide electrochemical windows (4.95 V), and a high lithium transference number (0.43). When applied in solid‐state lithium batteries (SSLBs), the batteries present impressive capacity and cycle life (164 mAh g−1 with capacity retention of 89.6% after 180 cycles at 1.0C under 50 °C). This work not only designs a new sort of hydrogarnet electrolyte, which is stable to both air and lithium metal but also provides an eco‐friendly and large‐scale fabrication route for SSLBs. [ABSTRACT FROM AUTHOR]

The development of highly producible and interfacial compatible in situ polymerized electrolytes for solid‐state lithium metal batteries (SSLMBs) have been plagued by insufficient transport kinetics and uncontrollable dendrite propagation. Herein, we seek to explore a rationally designed nanofiber architecture to balance all the criteria of SSLMBs, in which La0.6Sr0.4CoO3−δ (LSC) enriched with high valence‐state Co species and oxygen vacancies is developed as electronically conductive nanofillers embedded within ZnO/Zn3N2‐functionalized polyimide (Zn‐PI) nanofiber framework for the first time, to establish Li+ transport highways for poly vinylene carbonate (PVC) electrolyte and eliminate nonuniform Li deposits. Revealed by characterization and theoretical calculation under electric field, the positive‐negative electrical dipole layer in LSC derived from electron migration between Co and O atoms aids in accelerating Li+ diffusion kinetics through densified electric field around filler particle, featuring a remarkable ionic conductivity of 1.50 mS cm−1 at 25 °C and a high Li+ transference number of 0.91 without the risk of electron leakage. Integrating with the preferential sacrifice of ZnO/Zn3N2 on PI nanofiber upon immediate detection of dendritic Li, which takes part in reconfiguring hierarchical SEI chemistry dominated by LixNy/Li−Zn alloy inner layer and LiF outer layer, SSLMBs are further endowed with prolonged cycling lifespan and exceptional rate capability. [ABSTRACT FROM AUTHOR]

The development of highly producible and interfacial compatible in situ polymerized electrolytes for solid‐state lithium metal batteries (SSLMBs) have been plagued by insufficient transport kinetics and uncontrollable dendrite propagation. Herein, we seek to explore a rationally designed nanofiber architecture to balance all the criteria of SSLMBs, in which La0.6Sr0.4CoO3−δ (LSC) enriched with high valence‐state Co species and oxygen vacancies is developed as electronically conductive nanofillers embedded within ZnO/Zn3N2‐functionalized polyimide (Zn‐PI) nanofiber framework for the first time, to establish Li+ transport highways for poly vinylene carbonate (PVC) electrolyte and eliminate nonuniform Li deposits. Revealed by characterization and theoretical calculation under electric field, the positive‐negative electrical dipole layer in LSC derived from electron migration between Co and O atoms aids in accelerating Li+ diffusion kinetics through densified electric field around filler particle, featuring a remarkable ionic conductivity of 1.50 mS cm−1 at 25 °C and a high Li+ transference number of 0.91 without the risk of electron leakage. Integrating with the preferential sacrifice of ZnO/Zn3N2 on PI nanofiber upon immediate detection of dendritic Li, which takes part in reconfiguring hierarchical SEI chemistry dominated by LixNy/Li−Zn alloy inner layer and LiF outer layer, SSLMBs are further endowed with prolonged cycling lifespan and exceptional rate capability. [ABSTRACT FROM AUTHOR]

The practical application of polymer electrolytes is hindered due to the low ionic conductivity and the interfacial instability between the electrodes. Herein, a strategy for designing solid polymer electrolytes is developed that facilitates the rapid lithium‐ion migration through weak coordination with polymer chain segments, as well as the fast ion channel transport of oligomers. Moreover, the in situ‐produced solid polymer electrolyte (PFVS) can form stable LiF‐rich interfaces with both the lithium metal anode and different cathodes. When the PFVS is applied in Li‐metal batteries, excellent properties are achieved at room temperature. A Li||Li symmetric cell can be stably cycled for 4000 h at a current density of 0.1 mA cm−1, a Li||LiFePO4 full cell can maintain capacity retention as high as still 94.4% after 600 cycles at 1 C, and a Li||NCM811 full cell can retain 80% capacity after 180 cycles at 1 C. A 2.6 Ah Graphite|PFVS|NCM90 pouch cell is made for demonstrating the practical application potential, and it can be also stably cycled. The developed strategy provides a promising path for designing solid polymer electrolytes that can effectively extend the lifespan of Li metal batteries. [ABSTRACT FROM AUTHOR]

Although the flexibility of the quasi−solid polymer electrolyte favors its surface conformal to the electrode, interfacial damage originating from side reactions between the electrolyte and the electrode remains dominant for battery failure. The design of quasi−solid electrolytes compatible with both aggressive nickel−rich cathode and lithium metal anode persists critical to the application of quasi−solid high−voltage lithium metal batteries (LMBs). Herein, a chemical/electrochemical response strategy is proposed to construct simultaneously stable cathodic and anodic interfaces relying on the synergistic effect of 1,4,7,10,13,16−hexaoxacyclooctadecane (18C6) and LiNO3. The distinctive [18C6Li]+NO3− cluster modifies electric double layer structure by specific adsorption on the electrode, thereby regulating the interfacial layer composition and construction. The NO3− on electrode preferentially decomposes to improve the interfacial performances, leaving the [18C6Li]+ to cut off the side reaction. Furthermore, the 18C6 coordinates with detrimental transition metal ions from NMC811 cathode and converts into useful clusters alleviating the knock−on effect. Thus, the quasi−solid electrolyte with 18C6 and LiNO3 enables Li||NMC811 coin cell to cycle stably over wide operation temperature (0−55 °C), especially, achieving high capacity retention of 79.2% after 300 cycles at 30 °C. This chemical/electrochemical response strategy projects new insights into the design of smart reactive electrolytes for high−voltage LMBs. [ABSTRACT FROM AUTHOR]

Anion exchange polymers (AEPs) play a crucial role in green hydrogen production through anion exchange membrane water electrolysis. The chemical stability of AEPs is paramount for stable system operation in electrolysers and other electrochemical devices. Given the instability of aryl ether-containing AEPs under high pH conditions, recent research has focused on quaternized aryl ether-free variants. The primary goal of this review is to provide a greater depth of knowledge on the synthesis of aryl ether-free AEPs targeted for electrochemical devices. Synthetic pathways that yield polyaromatic AEPs include acid-catalysed polyhydroxyalkylation, metal-promoted coupling reactions, ionene synthesis via nucleophilic substitution, alkylation of polybenzimidazole, and Diels–Alder polymerization. Polyolefinic AEPs are prepared through addition polymerization, ring-opening metathesis, radiation grafting reactions, and anionic polymerization. Discussions cover structure–property–performance relationships of AEPs in fuel cells, redox flow batteries, and water and CO2 electrolysers, along with the current status of scale-up synthesis and commercialization. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (ZIBs) offer numerous advantages, such as high energy density, enhanced safety, and low cost, making them an ideal choice for energy storage and conversion applications in the “postlithium” era. Hydrogel electrolytes, as the key component of flexible ZIBs, combine the ionic conductivity of traditional water electrolytes with the dimensional stability of solid polymer electrolytes. However, it remains a challenge to design comprehensive and appropriate hydrogel electrolytes to provide flexible ZIBs with good reversibility and versatility. This review discusses the engineering design of hydrogel electrolytes required for flexible ZIBs from the viewpoint of an electrolyte designer. The basic properties of the hydrogel electrolytes, zinc anodes, cathodes and electrolyte stabilization effects are described in detail. Furthermore, we explore the various challenges faced by hydrogel electrolytes and propose corresponding strategies. Finally, the review offers insights into the future development of hydrogel-stabilized ZIBs. [ABSTRACT FROM AUTHOR]

Difunctional devices have great potential in the application of many areas, they can perform two functions simultaneously, and structural difunctional supercapacitor is one of them. The difunctional supercapacitor can carry out bearing capacity and storge electric energy, but it's difficult to keep the balance between bearing capacity and energy storage capacity. In this work, the montmorillonite based geopolymer has a compressive strength of 31.6 MPa after curing for 28 days, and a compressive strength of 30.5 MPa after repolymerization. We use the geopolymer as the framework, and inject 0.5 M Na 2 SO 4 into the geopolymer to prepared a structural electrolyte. Then, the structural electrolyte membrane, electrodeposited MnO 2 , and an activated carbon are assembled into a difunctional supercapacitor. The maximum specific capacity reaches 2216.7 mF cm−2 at 1 mA cm−2 under 15 MPa, achieving a good balance between compressive strength and energy storage capacity. [ABSTRACT FROM AUTHOR]

Aqueous zinc metal batteries are regarded as one of the most promising alternatives to lithium–ion batteries for large‐scale energy storage due to the abundant zinc resources, high safety, and low cost. Herein, an ionic self‐concentrated electrolyte (ISCE) is proposed to enable uniform Zn deposition and reversible reaction of MnO2 cathode. Benefitting from the compatibility of ISCE with electrodes and its adsorption on the electrode surface for guidance, the Zn/Zn symmetrical batteries exhibit the long‐life cycle stability with more than 5000 and 1500 h at 0.2 and 5 mA cm−2, respectively. The Zn/MnO2 battery also exhibits a high capacity of 351 mA h g−1 at 0.1 A g−1 and can enable a stability over 2000 cycles at 1 A g−1. This work provides a new insight into electrolyte design for stable aqueous Zn–MnO2 battery. [ABSTRACT FROM AUTHOR]

Although disubstituted imidazolium cation is sterically crowded, hundreds of ionic liquids based on this cation have been reported as electrolytes for energy storage devices. In contrast to disubstituted imidazolium, non-substituted imidazolium is uncrowded sterically and has not yet been investigated as an electrolyte, to the best of our knowledge. Hence, imidazolium hydrogen sulfate [Imi][HSO4], in mixture with water, was studied as an electrolyte for PANI-based electrode materials. For comparison, pyrrolidinium with hydrogen sulfate or p-toluene sulfonate ([Pyrr][HSO4] or [Pyrr][PTS]), in mixture with water, were also investigated as alternatives to the conventional electrolyte (i.e., aqueous H2SO4) for PANI electrodes. Walden plots of binary mixture ionic liquid–water weight ratios with the optimal ionic conductivity (i.e., [Imi][HSO4]/water 48/52 wt% (195.1 mS/cm), [Pyrr][HSO4]/water 41/59 wt% (186.6 mS/cm), and [Pyrr][PTS]/water 48/52 wt% (43.4 mS/cm) along with the electrochemical performances of PANI in these binary mixtures showed that [Pyrr][HSO4]aq or [Imi][HSO4]aq are convenient electrolytes for PANI/PIL, as opposed to [Pyrr][PTS]aq. Furthermore, replacing the conventional aqueous electrolyte H2SO4 with [Imi][HSO4] aq increased the specific capacitance of PANI/PIL from 249.8 to 268.5 F/g at 15 mV/s. Moreover, PANI/PIL electrodes displayed a quasi-ideal capacitive behavior in [Imi][HSO4]aq (the correction factor of CPE4 was 0.99). This primary study has shown that non-substituted imidazolium as an electrolyte could enhance the electrochemical performances of PANI electrodes and could be a good alternative to the conventional electrolyte. [ABSTRACT FROM AUTHOR]

To realize high-energy-density Li metal batteries at low temperatures, a new electrolyte is needed to solve the high-voltage compatibility and fast lithium-ion de-solvation process. A gel polymer electrolyte with a small-molecular-weight polymer is widely investigated by combining the merits of a solid polymer electrolyte (SPE) and liquid electrolyte (LE). Herein, we present a new gel polymer electrolyte (P-DOL) by the lithium difluoro(oxalate)borate (LiDFOB)-initiated polymerization process using 1,3-dioxolane (DOL) as a monomer solvent. The P-DOL presents excellent ionic conductivity (1.12 × 10−4 S cm−1) at −20 °C, with an oxidation potential of 4.8 V. The Li‖LiCoO2 cell stably cycled at 4.3 V under room temperature, with a discharge capacity of 130 mAh g−1 at 0.5 C and a capacity retention rate of 86.4% after 50 cycles. Moreover, a high-Ni-content LiNi0.8Co0.1Mn0.1O2 (NCM811) cell can steadily run for 120 cycles at −20 °C, with a capacity retention of 88.4%. The underlying mechanism of high-voltage compatibility originates from the dense and robust B- and F-rich cathode interface layer (CEI) formed at the cathode interface. Our report will shed light on the real application of Li metal batteries under all-climate conditions in the future. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes (SPEs) are the key components of lithium metal batteries to overcome the obstacle of insecurity in conventional liquid electrolytes; however, the trade-off between their ionic conductivity and mechanical properties remains a significant challenge. In this work, two-dimensional ZSM-5 nanosheets as fillers are incorporated into a poly(ethylene oxide) (PEO) matrix and lithium salts to obtain composite polymer electrolytes (CPEs). The improved physicochemical and electrochemical properties of the CPE membranes are characterized in full detail. Stripping/plating measurements in symmetric Li/Li cells and cyclic charge/discharge tests are performed to investigate the cyclability and stability of the CPEs. All-solid-state LiFePO4/Li batteries deliver excellent cycling performance with an initial discharge capacity of 152.3 mAh g−1 and 91.4% capacity retention after 200 cycles at 0.2 C, with a discharge specific capacity of 118.8 mAh g−1 remaining after 350 cycles at 0.5 C. Therefore, CPEs containing ZSM-5 nanosheets are a promising option for all-solid-state lithium-ion batteries. [ABSTRACT FROM AUTHOR]