Sulfonic Acid Groups Research Articles

Exploring the role of SAP chemical composition in the internal curing of high-performance cementitious materials

This study investigates the impact of the chemical composition of superabsorbent polymers (SAPs) on their effectiveness in internal curing within high-performance cementitious materials. Although the use of commercial SAPs in cementitious systems has been widely researched, there is still no consensus on how different SAP structures influence material properties. For the first time, this research employs photoinitiated free radical polymerization technology to synthesize three structurally distinct SAPs: SAP with sulfonic acid groups (PAMPS), SAP with amide groups (PAM), and SAP with carboxyl groups (PAAs). The effects of these SAPs on the cement hydration process and microstructure were examined by analyzing their water absorption behavior in cement filtrate. The residual cation content on the SAP surface was evaluated using EDS, while XRD and TGA were used to study how SAP structure affects cement hydration products. Furthermore, the impact of these SAPs on the strength and autogenous shrinkage of the material was investigated. The results indicate that PAMPS, with its sulfonic acid groups, exhibited stable water absorption performance in the alkaline cement environment, promoting hydration reactions and increasing the formation of needle-shaped C-S-H. This stability contributed to mitigating the negative effects on mechanical properties. While the inclusion of SAPs generally reduced the strength of the cement matrix, PAMPS was the most effective in mitigating autogenous shrinkage, achieving a shrinkage mitigation efficiency of 86 %. These findings highlight the importance of SAP chemical structure in influencing cement hydration and material performance, offering insights for the development of effective internal curing agents to enhance high-performance concrete.

Sulfonated Covalent Organic Frameworks Anchoring Cobalt as High-Efficient and Stable Catalysts for Peroxymonosulfate Activation.

Heterogeneous cobalt-based catalysts are highly effective in activing peroxymonosulfate (PMS) and produce free radicals to deal with recalcitrant organic pollutants in water. However, unfeasible recyclability and gradual performance degradation remain challenging due to the easy agglomeration and leaching of active cobalt species. Herein, a strategy is proposed to construct stably anchored and highly dispersed Co2+ sites on dual functional sulfonated covalent organic frameworks (COF-Co). The sulfonic acid groups are able to realize the targeted binding with cobalt ions through a two-step cation-exchange method, leading to strong combination with active Co2+ sites and utmost utilization efficiencies. Moreover, the super-hydrophility of sulfonic acid groups favors the rapid accessibility of organic molecules to the catalyst and accelerates the degradation. Remarkably, COF-Co exhibits high activity in PMS activation, effective oxidation for tetracycline degradation (92% within 30min at 30mg L-1) and other coloring contaminants, and excellent recycle stability. This work can guide the rational design of efficient and environmentally friendly PMS-activated catalyst with great potential for application in wastewater treatment.

A low-impedance cation exchange membrane for extending the voltage window of a BiFeO3-based hybrid supercapacitor through the pH-decoupling strategy

Aqueous hybrid supercapacitors usually suffer from narrow voltage window and poor energy density limited by the thermodynamic decomposition of water. Based on necessary ion exchange membranes, the pH-decoupling strategy can be employed to extend the voltage windows of hybrid supercapacitors. We propose a novel low-impedance cation exchange membrane (CEM) with the interpenetrating network structure for the pH-decoupling strategy, which can be served as the separator for a AC//BiFeO3 supercapacitor to enhance its electrochemical performances. Two CEMs (CEM-1 and CEM-2) with different contents of the sulfonic acid (-SO3H) groups, are fabricated through the copolymerization of various monomers according to the predetermined stoichiometric ratios. FTIR, Raman and XPS spectra reflect that the CEM-2 has the higher content of the -SO3H groups than the CEM-1. The membrane parameter measurements confirm that the CEM-2 has the higher water content, lower membrane resistance and smaller membrane thickness than the CEM-1. The AC//BiFeO3 supercapacitor with the CEM-2 separator provides the higher gravimetric specific capacitance of 61 F g−1 at 1 A g−1, better coulombic efficiencies (97 % ∼ 103 %) and lower Rs value (39.74 Ω) than the AC//BiFeO3 supercapacitors with the CEM-1 separator. Moreover, the AC//BiFeO3 supercapacitor with the CEM-2 separator delivers the maximum energy density of 41.0 Wh kg−1 at the power density of 1.1 kW kg−1. The pH-decoupling strategy with this low-impedance CEM, opens up a new avenue for developing high-performance aqueous electrochemical energy storage devices.

Corn Stover Lignin as a Solid Acid Catalyst for the Esterification of Oleic Acid

AbstractThe catastrophic ramifications of fossil fuels on the environment have prompted the search for renewable energy sources. Over the recent decades, biodiesel has garnered attention as a promising direct alternative to diesel fuel; however, reliance on homogeneous catalysts and the requirement for refined vegetable oil feedstocks present financial and sustainability concerns. Thus, there exists a need for the development of sustainable and cost‐effective catalytic solutions. Herein, the application of lignin, an abundant and renewable biomass, as an effective heterogeneous catalyst is reported for biodiesel production via the esterification of oleic acid. Lignin is extracted from corn straw using sulfuric acid, which endows sulfonic acid groups (0.85 mmol g−1) to its structure allowing it to act as an acid catalyst without additional post‐treatments. Conversion of oleic oil to biodiesel is achieved at 97% using a 1:3 oleic acid to methanol molar ratio with a 5 wt.% catalyst loading at 90 °C after only 30 min. Moreover, the catalyst exhibits a remarkable turnover frequency of 2.61 min−1 proving its efficiency. These findings demonstrate that heterogeneous catalysts can be prepared from biomass waste offering a significantly cheaper and less intensive synthesis process and allowing for a paradigm shift to non‐edible and waste cooking oils.

Heat-Resistant Covalent Organic Framework (COF) PVA-Hybridized Gel Electrolyte for the Preparation of Dendrite-Free Zinc-Ion Batteries.

High-performance zinc-ion batteries (ZIBs) have attracted a great deal of attention due to their high theoretical capacity and high level of safety. Herein, we propose a covalent organic framework (COF) hybrid poly(vinyl alcohol) (PVA)-based gel electrolyte, which can induce the uniform deposition of Zn2+ and achieve dendrite-free formation. By grafting sulfonic acid groups on the surface of COFs to absorb Zn2+, we can strengthen the interaction between strong ions and dipoles in the electrolyte, improve the ionic conductivity, and achieve stable Zn2+ electroplating and stripping. Due to the good thermal stability of the COF material itself, the gel electrolyte hybrid with the PVA hydrogel shows high mechanical strength and good heat resistance and is capable of stable cycling for >1000 h at 50 °C, with a capacity retention rate of ≤75%. This study provides a new approach for developing high-temperature-resistant and highly stable dendrite-free ZIBs.

Investigation of hydrolysis of sugarcane bagasse into glucose over solid acid HSO3-ZSM-5 zeolite for fermentation to bioethanol

ABSTRACT In the pursuit of sustainable energy sources, biomass has emerged as a promising alternative to fossil fuels due to its renewability and carbon neutrality. This current work presents the application of solid acid zeolite catalyst for biomass hydrolysis into reducing sugar for fermentation. Sulfonated ZSM-5 zeolite was prepared by grafting sulfonic acid group on the surface and/or into the pores of porous ZSM-5 zeolite and characterized by several analyses. The as-synthesized HSO3-ZSM-5 zeolite was then investigated as a solid acid catalyst for the hydrolysis of alkaline pretreated sugarcane bagasse (SB). Containing sulfonic acid groups – a very strong acid – on the surface, HSO3-ZSM-5 zeolite presented high catalytic activity and high efficiency in the hydrolysis of SB biomass. When the hydrolysis was carried out under optimal conditions, approximately 106.8 g/L of reducing sugar including of glucose, xylose, arabinose, and cellobiose was recovered. 86.65% fermentable sugars could be achieved after catalytic hydrolysis, and 48.7% of SB in total was converted to reducing sugar and others. Moreover, this solid acid catalyst can be reused impressively several times with no significant loss in catalytic activity. The sugar hydrolyzate could be used for fermentative production of bio-ethanol. Results indicated the possibility of using solid acid zeolite in the hydrolysis of lignocellulose to generate sugars that can be further applied in biofuel or chemical manufacturing.

Enhanced Hydrophilicity of DAAQ-TFP COFs via Sulfonate Modification for Air Water Harvesting in Arid Environment.

The poor ability of covalent organic frameworks (COFs) based adsorbents at low relative humidity (RH) conditions limits their applications for air-water harvesting in arid environments. In the present work, the sulfonated COFs (DAAQ-TFP-SO3H@LiCl) composites are prepared through the functionalization of sulfonic acid and LiCl composite to improve its hydrophilicity. TheDAAQ-TFP-SO3H@LiCl composites exhibit a good adsorption performance, outperforming many other COF adsorbents developed so far. It can absorb 0.22±0.005g g-1 and 1.01±0.027g g-1 of water at room temperature under 20% RH and 90% RH, respectively while demonstrating good cyclic stability. Compared with the isotherm of the DAAQ-TFP, the introduction of the sulfonic acid group shifts the inflection point of the water isotherm toward low humidity, indicating that the sulfonic acid group effectively expends the working humidity range of the adsorbent and enables the effective water adsorption in an arid environment. Furthermore, the DAAQ-TFP-SO3H@LiCl composites display rapid kinetics during both the adsorption and desorption processes, reaching saturation within 60min in the equilibrium adsorption test and completing desorption within 12min at 50°C. This innovative approach provides a new method for designing adsorbent materials with low energy input requirements and high daily water consumption capabilities.

Enhanced proton transfer in proton exchange membrane fuel cells via novel nanocomposite membrane incorporating (3-Mercaptopropyl)trimethoxysilane-graphene oxide and basic amino ligands: A synergistic acid-base approach

A nanocomposite polymer electrolyte membrane (MGC) was synthesized by blending MPTS (HS(CH2)3Si(OCH3)3) and graphene oxide (GO) nanosheets at varying weight ratios (91.5 to 9.5, respectively) for proton exchange membrane fuel cell (PEMFC) applications. By covalently modifying the GO support with MPTS through a silane modification process, the acidic MGC matrix is formed. The blending process, with ultrasonication and vigorous stirring, initiates two significant reactions in reactive MPTS: first, the conversion of methoxy groups (Si–OCH3) to silanols (Si-OH); second, the potential condensation of silanol groups to form siloxane bonds (Si–O–Si), followed by oxidation of sulfhydryl groups to sulfonic acid (-SO3H) groups by hydrogen peroxide. The resulting -SO3H groups connected to the siloxane network (Si-O-Si) adjacent to the GO. Two basic amino ligands – dopamine, and aminopropyl trimethoxysilane (APTES) were incorporated into the MGC matrix to establish acid-base pairs, promoting swift proton transport. These additions, at weight ratios of (0.5, 1, 2, and 7) wt%, synergistically contributed to the MGC matrix, forming effective proton channels. Various analytical techniques, including field emission-scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Raman spectroscopy, X-ray diffraction (XRD), and electrochemical impedance spectroscopy (EIS), were employed to assess the impact of functionalized basic amino groups on the MGC matrix. Notably, the MGC membrane containing 2 wt% of PDA as basic amino ligands exhibited optimal performance, showcasing an in-plane proton conductivity of 115.10 mS cm-1 under fully hydrated conditions at 90 °C, and the maximum power density (MPD) of 170.74 mW cm-2 with a current density of 1051.46 mA cm-2 at 60 °C and 100 % relative humidity (RH). In contrast, the MGC membrane, devoid of amino ligands, exhibited a comparatively low in-plane conductivity of 44.32 mS cm⁻¹ under identical conditions at 90 °C. Additionally, it recorded the MPD of 48.5 mW cm⁻², corresponding to a current density of 313.25 mA cm⁻² at 60 °C and 100 % RH. This study introduces an innovative approach for developing high-performance nanocomposite membranes for PEMs and related applications.

Effect of ANSA as an additive on electrodeposited Sn-Ag-Cu alloy coatings in deep eutectic solvent

This study investigates the electrodeposition of Sn-Ag-Cu ternary solder coating in a choline chloride-ethylene glycol DES using 1-amino-2-naphthol-4-sulfonic acid (ANSA) as an additive. The mechanism of ANSA was evaluated through UV–visible absorption spectroscopy, infrared spectroscopy, and CV. The results demonstrate that ANSA, as a multifunctional organic compound, influences the electrodeposition process through its sulfonic acid, amino, and naphthyl groups. When the ANSA concentration is below 600 ppm, its primary action is through an interfacial adsorption mechanism, where lone pairs of electrons on nitrogen and oxygen atoms adsorb onto the electrode surface, and the bulky naphthyl ring inhibits the formation of large deposits. As the ANSA concentration exceeds 600 ppm, complexation becomes the dominant mechanism, competing with the complexation of chloride ions (Cl−) in the choline chloride electrolyte. SEM analysis indicates that as the ANSA concentration increases, the deposited coatings become smoother, denser, and exhibit finer grain sizes. The Scharifker-Hills model was employed to analyze the CA curves before and after the addition of ANSA, revealing that the nucleation mechanism of Sn-Ag-Cu alloy deposition gradually transitions from instantaneous nucleation to progressive nucleation with increasing ANSA concentration.

Preparation and ferroelectric properties of metal-organic frame lithium ion liquid crystal composites

ABSTRACT Two series of lithium ion liquid-crystalline composites (LCCs) containing metal-organic frame (MOF) materials were fabricated via a self-assembly process by use of poly(4-styrenesulfonic acid) lithium polymers, a cholesteryl-based liquid-crystalline monomer with terminal sulphonic acid group, and Fe-MIL-53_NH2. The chemical structure, chiral smectic C mesophase and ferroelectric property of the LCCs were characterised by various instruments, and the effect of liquid crystal monomer and lithium polymers on the ferroelectric property were investigated. The cholesteryl-based liquid crystal monomer presents a dominant role in the ferroelectric property of the LCCs, in which the asymmetric carbon atoms are responsible for the spontaneous polarisation. For the LCCs, the mechanical properties and porous loading characteristics of liquid crystal polymer are improved by the MOF materials, and the lithium-ion polymer connects the liquid crystal monomer with the MOF by ionic bond and improves the polarity of the material. When the electric field changed from −10 V and 10 V, the maximum residual polarisation strength (Pr) of the LCCs reached 74.82 nC/cm2. Because the LCCs showed excellent ferroelectric and mechanical properties, it has some potentials of application in the field of ferroelectric materials.

Graphene/polyaniline waterborne composite coatings for metallic bipolar plates

Waterborne composite coatings were formulated for protection of metallic bipolar plates. The challenges lied in two aspects, one was the confliction between high electrical conductivity and good corrosion protection properties; the other was the water dispersibility of the constituent phases. Water-solubility of polyaniline (PANI) were controlled by adding polystyrene sulfonic acid during the polymerization of aniline. Graphene was functionalized by p-aminobenzoic acid and p-phenylenediamine to enhance the compatibility with PANI, while keeping the electrical conductivity of graphene at around 169 S/cm. Upon in-situ polymerization of the functionalized graphene/PANI composites, the electrical conductivity varied significantly from 41 S/cm to 91 S/cm with the surface functionality of graphene. The composite coatings were prepared thereafter with functionalized graphene/PANI/carbon black on the surface of 316 L stainless steel by centrifugal spraying coating. The interfacial contact resistance of the coatings reached 4 mΩ·cm2, comparable to Au coatings, but the corrosion current density was 4.37 μA/cm2 due to the existence of the hydrophilic groups in waterborne coatings, like amino groups and sulfonic acid groups. A post-treatment was carried out to consume some of the amino groups, so that the corrosion current density was decreased to 0.88 μA/cm2.

Porous polymeric materials prepared via pickering emulsion templating targeted as a bronsted acid catalyst in room-temperature biodiesel production

The present work is about preparing a set of magnetic macroporous polymers using the Pickering high internal phase w/o emulsions (HIPEs) templating method. The octyl-modified core-shell magnetic nanoparticles (Fe3O4@SiO2-Octyl) were used as a solid stabilizer and Span 80 surfactant to stabilize the HIPEs. The effect of Fe3O4@SiO2-Octyl content, Span 80 content, and molar ratio of styrene/divinylbenzene (St/DVB) on physical properties, morphology, pore size, and void size of the macroporous polyHIPEs was precisely evaluated. The optimized polyHIPE prepared by 2 wt% of Fe3O4@SiO2-Octyl nanoparticles, 9 wt% of Span 80, and St/DVB molar ratio of 8 with the porosity of 86±1.1 % and an average pore size of 4.1 µm was selected as catalyst support to functionalize with sulfonic acid groups. The resulting catalyst (polyHIPE–SO3H) showed excellent performance in reacting long-chain free fatty acids (FFA) with methanol to give fatty acid monoalkyl esters (FAMEs) at room temperature. In this way, the polyHIPE–SO3H was found to be very active and reusable in the mentioned process, giving high yields (∼92–98 %) of various biodiesel compounds under very mild reaction conditions and recycling in the next subsequent runs without significant loss of activity.

A novel macromolecular flame retardant based on sulfonyl diphenol monomer for simultaneous fire safety, transparency and high performance of thin-walled polycarbonate

In order to further advance the development of transparency, fire safety, and high-performance thin-walled polycarbonate (PC), it is essential to avoid the negative impact of traditional flame retardants on the overall performance of PC. In this work, a new copolymer polycarbonate (ASPC) containing sulfonyl diphenol monomer was synthesized by interfacial polycondensation, and it was used as a flame retardant for PC. Due to the fact that the compounds containing sulfonic acid groups produced by the decomposition of ASPC in a high temperature environment promote the crosslinking and rearrangement of PC, the PC can generate a denser char layer during combustion, thus effectively preventing the exchange of heat and gas inside and outside the matrix. To addition of 20 wt% ASPC can make PC with a thickness of 1.5 mm to pass the UL 94 V-0 rating and LOI increased to 33.5 %. The peak of heat release rate (PHRR) and smoke produce rate (PSPR) of PC/ASPC-20 was decreased by 32.4 % and 38.4 %, respectively. More importantly, the addition of ASPC can delay the speed of flame spread, provide people with more escape time and reduce the fire hazard. Furthermore, the ASPC is good compatibility with PC due to the structural similarity between ASPC and PC. Therefore, PC/ASPC maintains the comparable transparency and tensile properties of PC. The transmittance of PC/ASPC-20 is 87.7 %, and the elongation at break is 32.5 % higher than that of PC. This work provides a new solution for the preparation of flame-retardant modification of transparent and thin-walled PC, and expands the application scope of PC composites.

Biomimetic Channels Design in Metal-Organic Framework Enabling Highly Lithium-Ion Conduction for Lithium-Metal Batteries.

Solid-state electrolytes (SSEs) based on metal-organic frameworks (MOFs) are an ideal material for constructing high-performance lithium metal batteries (LMBs). However, the low ion conductivity and poor interface contact (especially at low temperatures) still seriously hinder its further application. Herein, inspired by the Na+/K+ conduction in biology systems, a series (NH2, OH, NH-(CH2)3-SO3H)-modified MIL-53-X as SSEs is reported. These functional groups are similar to anions suspended in biological ion channels, partially repelling anions while allowing cations to be effectively transported through pore channels. Subsequently, MIL-53-X with hierarchical pore structure (H-MIL-53-X) is obtained by introducing lauric acid as a regulator, and then the effects of structural design and morphology control on its performance are explored. The conductivity of H-MIL-53-NH-SO3Li with multi-level pore structure and modified by sulfonic acid groups reached 2.2×10-3Scm-1 at 25°C, lithium-ion transference number of 0.78. Besides, the H-MIL-53-NH-SO3Li still has an excellent conductivity of 10-4Scm-1 at -40°C. Additionally, LiFePO4/Li batteries equipped with H-MIL-53-NH-SO3Li SSEs could operate stably for over 200 cycles at 0.1C. The strategy of combining structural and morphological design of MOFs with biomimetic ion channels opens new avenues for the design of high-performance SSEs.

The adsorption of cesium by sulfonic acid functionalized hollow mesoporous silica microspheres

With the development of nuclear industry, radioactive elements such as 137Cs put a threat on the water environment. It is a challenging task to remove the Cs+ in the nuclear wastewater. In the current study, we prepared a new Cs+-adsorbing material by introducing sulfhydryl group onto the surface of hollow mesoporous silica microspheres, then oxidizing the sulfhydryl group to sulfonic acid group. The obtained HMSS-SO3H material had an excellent adsorption capacity for Cs+ in the aqueous solution, with an adsorption capacity of 51.53 mg g−1 in 30 min. Characterization approaches, such as FT-IR and EDS, were used to confirm the result of modification. Adsorption experiments were carried out under. The influence of various parameters on the adsorption process was investigated under the conditions of changing pH, temperature, and time. The effect of competitive ions was also explored. The results indicated that the adsorption process followed the pseudo-second-order model and the main adsorption mechanisms are electrostatic interaction and coordination. The material had a best adsorption performance at a neutral pH. The adsorption process could well-fit the Langmuir's model, with a theoretical maximum adsorption capacity of 81.31 mg g−1. And the adsorption capacity was slightly affected by competing ions such as Mg2+ and Ca2+. The results indicate that the HMSS-SO3H prepared in this study is a promising adsorbent for Cs+, with the advantages of high adsorption capacity, fast adsorption rate and high selectivity.

Cross-linked proton exchange membrane covalently bonded with silicotungstic acid for enhanced proton conductivity

Proton exchange membranes with cross-linked structures often showed excellent mechanical and chemical stability, but their water absorption and proton conductivity were restricted. This study reported a convenient and efficient thermal cross-linking reaction of sulfonic acid groups and benzene rings using dimethyl sulfoxide and sulfolane mixed solvents to prepare the membrane. To further illustrate, phenoxyphenyl-attached silicotungstic acid (POP-SiWA) was incorporated in the sulfonated poly(ether ether ketone) membrane and covalently bonded with the polymer by thermal cross-linking reaction. The immobilization ratio for the membranes prepared with 10∼30 wt% POP-SiWA addition was 88.0–63.7%. The modified membranes exhibited high hydrophilicity and improved proton conductivity under hydrated or low relative humidity conditions due to the strong acidity and water-retaining properties of silicotungstic acid. Specifically, the proton conductivity of the modified membrane with 30 wt% POP-SiWA reached 212 mS/cm. It exhibited a fuel cell power density of 629 mW/cm2 at 80 °C and 100% relative humidity, which were 1.90 and 2.67 times higher than the pristine membrane.

Evaluating Effects of Cerium Concentration and Water Content on Diffusivity of Cerium Ions in PEFC Using Molecular Dynamics Simulations

We investigated effects of cerium concentrations and water content on diffusivity of cerium ions in Nafion membrane. The diffusion coefficients of cerium ions were taken, and the structural features that could change diffusivity were analyzed. Results show that difference in concentrations in this study is independent of diffusivity. Although there was a slight difference in structure depending on the concentration, it was suggested that this depended on the initial position of the cerium ion. The diffusion of cerium ions was found to be greatly affected by water content. When water content is 3, cerium ions coordinate with sulfonic acid group because of luck of water around cerium ion. As water content increase, cerium ions are fully hydrated, and they may have high diffusivity. The growth of water clusters, which are the transport pathway for the ions, is also thought to be the cause of the significantly larger diffusion coefficient.

Effects of Ionomer Film Thickness and Water Content on Oxygen Permeation Properties of PEFC Cathode Catalyst

In order to promote the widespread use of Polymer Electrolyte Fuel Cell (PEFC), enhancing cell performance is necessary. One significant factor affecting cell performance is the oxygen permeability in the ionomer, which depends on its nano-scale structure. In this study, to investigate the relationship between structures of catalyst layers and cell performances, we analyzed the effects of film thickness and water content on the oxygen permeation properties of ionomer in the cathode catalyst layer of PEFC using molecular dynamics simulations. We constructed a system in which oxygen molecules permeated ionomer on a platinum (Pt) surface. We found that sulfonic acid groups have a significant effect on oxygen permeation in low water content conditions.

Supramolecular polymer cross-linking gel electrolyte for highly stable quasi-solid-state lithium metal batteries

Lithium (Li) metal batteries have the advantage of high energy density, but the Li dendrites risk piercing the separator and causing a short circuit in the battery. Replacing the liquid electrolytes with gel electrolytes is considered an effective strategy to solve the issues. Herein, a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based gel electrolyte, improved with multifunctional supramolecular polymer (MSP), was prepared to enhance the cycling stability and energy density of quasi-solid-state Li metal batteries. The MSP addictive constructs a cross-linked network structure with PVDF-HFP matrix and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) through hydrogen bonding, improving the mechanical strength of the composite gel electrolyte (PH-10%MSP-GE) to against the growth of Li dendrites. Moreover, the pre-lithiated sulfonic acid groups, conductive polyether groups of MSP, and the attraction of TFSI– anions, promote the Li-ion transportation of the composite gel electrolyte. Finally, the Li||Li symmetric cell cycle stably for over 450 h. The Li||LiFePO4 full cell demonstrates a high energy density and excellent cycling stability for over 600 cycles, with a capacity retention rate of up to 98.7%. This work provides valuable insights into the preparation of multifunctional composite gel polymer electrolytes and competitive quasi-solid-state Li metal batteries.

Facile In Situ Building of Sulfonated SiO2 Coating on Porous Skeletons of Lithium-Ion Battery Separators.

Polyolefin separators with worse porous structures and compatibilities mismatch the internal environment and deteriorate lithium-ion battery (LIB) combination properties. In this study, a sulfonated SiO2 (SSD) composited polypropylene separator (PP@SSD) is prepared to homogenize pore sizes and in situ-built SSD coatings on porous skeletons. Imported SSD uniformizes pore sizes owing to centralized interface distributions within casting films. Meanwhile, abundant cavitations enable the in situ SSD coating to facilely fix onto porous skeleton surfaces during separator fabrications, which feature simple techniques, low cost, environmental friendliness, and the capability for continuous fabrications. A sturdy SSD coating on the porous skeleton confines thermal shrinkages and offers a superior safety guarantee for LIBs. The abundant sulfonic acid groups of SSD endow PP@SSD with excellent electrolyte affinity, which lowers Li+ transfer barriers and optimizes interfacial compatibility. Therefore, assembled LIBs give the optimal C-rate capacity and cycling stability, holding a capacity retention of 82.7% after the 400th cycle at 0.5 C.