Cosolvent Systems Research Articles

Fluorinated co-solvent electrolytes enable lithium metal batteries to operate at low temperatures

Enhancing the energy output of batteries in low temperatures is critical to broadening the application areas of advanced electronic devices, which can be accomplished by utilizing high-voltage cathodes to match lithium metal anode, optimizing electrolyte electrochemical windows and forming stable solid electrolyte interphases to provide facile ion-transmission kinetics at low temperature. Herein, we demonstrate a fluorinated ester co-solvent electrolyte, which applies 1 M LiPF6 in an ethyl 4,4,4-trifluoro butyrate/fluoroethylene carbonate (FEC) (4/1 by volume ratio) that jointly satisfies high voltage cathode and lithium metal anode reversibility at required ambient. The performance of the battery is due to the rapid dissociation of Li+ and the formation of a fluorine-rich inorganic electrolyte interface in the fluorinated solvent. Therefore, the fluorinated ester co-solvent electrolyte system can provide 209.9 mAh g−1, 194.8 mAh g−1, and 175.5 mAh g−1 when discharged at room temperature, −20 ℃ and −40 ℃, respectively, those far exceeds the performance of carbonate electrolytes. This work advances the development of low-temperature lithium metal batteries.

Harnessing the potential of deep eutectic solvents in biocatalysis: design strategies using CO2 to formate reduction as a case study

IntroductionDeep eutectic solvents (DESs) have emerged as green solvents with versatile applications, demonstrating significant potential in biocatalysis. They often increase the solubility of poorly water-soluble substrates, serve as smart co-substrates, modulate enzyme stereoselectivity, and potentially improve enzyme activity and stability. Despite these advantages, screening for an optimal DES and determining the appropriate water content for a given biocatalytic reaction remains a complex and time-consuming process, posing a significant challenge.MethodsThis paper discusses the rational design of DES tailored to a given biocatalytic system through a combination of experimental screening and computational tools, guided by performance targets defined by solvent properties and process constraints. The efficacy of this approach is demonstrated by the reduction of CO2 to formate catalyzed by NADH-dependent formate dehydrogenase (FDH). By systematically analyzing FDH activity and stability, NADH stability (both long-term and short-term stability after solvent saturation with CO2), and CO2 solubility in initially selected glycerol-based DESs, we were able to skillfully guide the DES screening process.Results and discussionConsidering trade-offs between experimentally determined performance metrics of DESs, 20% solution of choline chloride:glycerol in phosphate buffer (ChCl:Gly80%B) was identified as the most promising solvent system for a given reaction. Using ChCl:Gly as a co-solvent resulted in an almost 15-fold increase in FDH half-life compared to the reference buffer and stabilized the coenzyme after the addition of CO2. Moreover, the 20% addition of ChCl:Gly to the buffer improved the volumetric productivity of FDH-catalyzed CO2 reduction in a batch system compared to the reference buffer. The exceptional stability of the enzyme in this co-solvent system shows great potential for application in continuous operation, which can significantly improve process productivity. Additionally, based on easily measurable physicochemical solvent properties and molecular descriptors derived from COSMO-RS, QSAR models were developed, which successfully predicted enzyme activity and stability, as well as coenzyme stability in selected solvent systems with DESs.

Facile Synthesis and Characterization of Fluorescent Polystyrene Nanospheres for Homogeneous Light-Initiated Chemiluminescence Immunoassay.

Homogeneous light-initiated chemiluminescence technology (LICA) is widely used in clinical diagnostics due to the advantages of high sensitivity, minimal reagent usage, and no need for washing. Luminescent microspheres receive singlet oxygen emitted by photosensitive microspheres to generate optical signals. Therefore,1O2-initiated luminescent nanospheres are crucial, but there are few reports on the preparation of 1O2-initiated luminescent nanospheres. Herein, monodisperse luminescent Eu/C-28@PS (Eps) nanospheres were prepared and optimized using chelate Eu (TTA)3phen and 4-(2-phenyl-5,6-dihydro1,4-oxathiin-3-yl)-N, N-ditetradecylbenzenamine (C-28) as probe dye via THF/water swelling-shrinking procedure. Various swelling parameters were studied to obtain the swelling conditions that produce the minimum particle size and narrow size distribution, which shows good results in uniform particle size distribution (~ 250nm, a PDI of 0.03), surface carboxylate content (1.18mmol/g), and BSA loading capability (129.8mg/g) in the case of 20mg total probe dosage and 2h of incubation at 40°C using 14% THF/water mixture as a co-solvent system. The composition of the entrapped probe has a gain effect on the 1O2-initiated fluorescent signal and the optimal ratio of Eu (TTA)3phen: C-28 (1:1) was obtained on a commercial analyzer using IgG and anti-human IgG as models in PBS buffer. These results indicate that monodisperse luminescent Eps nanospheres are suitable as light-initiated chemiluminescence sensors and have great application potential in early detection, screening tests, and prognostic evaluation of patients.

Water as Dual-Function Plasticizer and Cosolvent in Gel Electrolytes for Dye-Sensitized Solar Cells.

This study presents a novel approach to developing eco-friendly dye-sensitized solar cells (DSSCs) using natural and renewable materials for gel polymer electrolytes (GPEs), reducing reliance on unsustainable solvents. Water is added to polar aprotic solvents, specifically ethylene carbonate/propylene carbonate (EC/PC), across various mass fractions (0:100 to 100:0). An amphiphilic hydroxypropyl cellulose (HPC) natural polymer is employed to formulate GPEs within this water-EC/PC cosolvent system, achieving successful gelation up to 50:50 mass fractions. Incorporating water reduced the gel strength and viscosity of the GPEs. Water acted as a plasticizer, enhancing the polymer chains mobility, and creating a more flexible and permeable structure. This increased ion diffusion coefficients and ion mobility, resulting in a maximum ionic conductivity of 18.17 mS cm-1. The highest efficiency achieved in DSSCs using these GPEs is 5.81%, with elevated short-circuit current density and reduced recombination losses. However, some compositions experienced syneresis, affecting their stability. The GPE with a 40:60 mass fraction exhibited superior long-term stability because it is free from syneresis, though it achieved a lower efficiency (4.83%), making it the best-performing sample. This work demonstrates the feasibility and benefits of using gel polymer electrolytes in an aqueous system, improving DSSC efficiency and sustainability.

Facile synthesis of multifunctional zeolitic imidazolate framework-8 coatings on diverse bare substrates using a one-step strategy

Rational growth of metal–organic frameworks (MOFs) with controllable morphology and surface properties has been challenging. In this study, facile synthesis of zeolitic imidazolate framework-8 (ZIF-8) in solutions as well as direct in-situ growth of ZIF-8 on various untreated substrates was studied systematically. ZIF crystals with controllable morphology and size were prepared by simply adjusting the ethanol content in the co-solvent system, achieving a rational synthesis of ZIFs in controlled environments. More importantly, co-solvent content was proved to be crucial in the inter-dimensional topotactic phase transformation from a 2-dimensional ZIF-L to a three-dimensional ZIF-8. Then, the facile in-situ crystallization of ZIF-8 on a variety of untreated substrates was studied. With the use of co-solvents, ZIF-8 crystals were formed uniformly and continuously on all substrates regardless of the nature of the support material, including organic supports such as nylon membranes, 3D printed meshes, melamine sponges, mask filter layers, fabric, metallic support stainless-steel meshes, and ceramic pellet. This facile coating strategy provided controllable crystal coating morphology, size, and coating density, without surface modification/pre-treatment steps which are commonly used in the synthesis of high-quality ZIF coatings/membranes. The ZIF-8 coated substrates prepared in a co-solvent system displayed superior performance in some environmental remediation and biomedical applications. For example, the ZIF-8-coated nylon membrane achieved an impressive 96 ∼ 98 % small oil droplet removal from emulsions while maintaining a high water flux of ∼ 1200 L m−2h−1 bar−1. The superhydrophobic ZIF-8-coated melamine sponges were effective for fast oil adsorption. Last but not least, the ZIF-8-coated masks demonstrated greatly improved antibacterial activities. Overall, the co-solvent synthesis method reported in this work has enabled a one-step universal strategy for the direct growth of zeolitic imidazolate framework coating on diverse bare substrates with controlled surface properties and thus showed significant commercial potential in environmental and biological applications.

Development of a dexamethasone-hyaluronic acid conjugate with selective targeting effect for acute lung injury therapy

Acute lung injury (ALI), a critical complication of COVID-19, is characterized by widespread inflammation and severe pulmonary damage, necessitating intensive care for those affected. Although glucocorticoids (GCs), such as dexamethasone (Dex), have been employed clinically to lower mortality, their nonspecific systemic distribution has led to significant side effects, limiting their use in ALI treatment. In this study, we explored the conjugation of Dex to hyaluronic acid (HA) to achieve targeted delivery to inflamed lung tissues. We achieved a conjugation efficiency exceeding 98 % using a cosolvent system, with subsequent ester bond cleavage releasing the active Dex, as verified by liquid chromatography. Biodistribution and cellular uptake studies indicated the potential of the HA conjugate for cluster of differentiation 44 (CD44)-mediated targeting and accumulation. In a lipopolysaccharide-induced ALI mouse model, intravenous (IV) HA-Dex administration showed superior anti-inflammatory effects compared to free Dex administration. Flow cytometry analysis suggested that the HA conjugate preferentially accumulated in lung macrophages, suggesting the possibility of reducing clinical Dex dosages through this targeted delivery approach.

Enhancing the Separation Performance of Cellulose Membranes Fabricated from 1-Ethyl-3-methylimidazolium Acetate by Introducing Acetone as a Co-Solvent

Cellulose, a sustainable raw material, holds great promise as an ideal candidate for membrane materials. In this work, we focused on establishing a low-cost route for producing cellulose microfiltration membranes by adopting a co-solvent system comprising the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) and acetone. The introduction of acetone as a co-solvent into the casting solution allowed control over the viscosity, thereby significantly enhancing the morphologies and filtration performances of the resulting cellulose membranes. Indeed, applying this co-solvent allowed the water permeability to be significantly increased, while maintaining high rejections. Furthermore, the prepared cellulose membrane demonstrated excellent fouling resistance behavior and flux recovery behavior during a challenging oil-in-water emulsion filtration. These results highlight a promising approach to fabricate high-performance cellulose membranes.

Advancing Towards Commercialization with Enhanced Stability and Efficiency in Lithium Metal Batteries Using TTE as a Co-Solvent in Carbonate Electrolytes

Lithium metal batteries are considered ideal anode materials for next-generation battery systems due to their high theoretical specific capacity (3,860 mAh g-1) and low negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode), which are essential for high energy density. However, the fatal dendritic growth on the lithium metal surface, which occurs during repetitive cycling, acts as a significant barrier to commercially successful lithium metal battery application. Therefore, regulating the morphology of lithium plating in commercial carbonate-based electrolytes is a critical challenge for the stable operation of lithium metal batteries. Additionally, this leads to the formation of inhomogeneous lithium dendrites in carbonate-based electrolytes, manifesting as uneven current density and lithium-ion concentration gradients. The uneven current leads to inconsistent charging/discharging rates in the corresponding Ni-rich cathode, which in turn causes overpotentials and deteriorates cell safety, culminating in a reduction of capacity. this has been clarified through Kelvin probe force microscopy analysis to demonstrate an uneven state of charge distribution in the Ni-rich cathode.In this work, we propose a new strategy for high-performance lithium metal batteries, utilizing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) as a co-solvent with carbonate electrolytes. By using TTE as a co-solvent, we observed a reduction in the viscosity of the electrolyte, leading to improved ionic conductivity and a decrease in the overpotential during the lithium plating/stripping process via in-situ electrochemical atomic force microscopy. This resulted in more uniform Li deposition compared to conventional carbonate-based electrolytes, forming a dense and stable Li metal layer. Furthermore, by leveraging our control over stable lithium plating morphologies via TTE co-solvent system, we observed long-term cycling stability (capacity retention of 78% at 300 cycles) with the use of an ultra-thin Li layer (40 µm). Through these results, we have effectively enhanced the stability and efficiency of high-energy-density (380 Wh kg-1) electrodes based on carbonate electrolytes, and we believe that this study can contribute to the commercialization of lithium metal batteries. Figure 1

Realizing rechargeable cathode-free aluminum-ion batteries via regulating solvation structure in aqueous-aprotic electrolytes

Aqueous aluminum-ion batteries (AIBs) are promising candidates for large-scale energy storage due to the abundant resource reserve, high theoretical capacity, intrinsic safety, and low cost of Al. However, the development of aqueous AIBs is constrained by the inefficient Al plating, inevitable parasitic side reactions, and the collapse of the cathode materials. Herein, we propose a novel Al3+/Mn2+ hybrid electrolyte in a water-acetonitrile co-solvent system with a regulated solvation structure to realize cathode-free AIBs. The inclusion of acetonitrile as a co-solvent plays a crucial role in reducing the desolvation energy and suppressing side reactions. The introduction of Mn2+ can enable the reversible plating/stripping of Al-Mn alloy with reduced overpotentials on the anode and deposition/stripping of AlxMnO2 on the cathodic current collector to realize cathode-free AIBs. The architected AIB delivers a high discharge capacity of 397.9 mAh g−1, coupled with superior rate capability and stable cycling performance. Moreover, the cathode-free AIB shows superior low-temperature performance and can operate at −20 °C for over 120 cycles. This work provides new ideas for developing high-performance and low-cost aqueous AIBs.

Highly uncondensed lignin extraction in the novel green L-cysteine/lactic acid cosolvent system

Enhancing the efficient isolation of proto-lignin from lignocellulose using sustainable, environmentally friendly solvents has consistently been a key focus in the lignin-first biorefinery strategy for the past years. At the same time, achieving efficient extraction of highly uncondensed active lignin under acidic conditions has posed an insurmountable challenge. In this study, we develop an L-cysteine-assisted binary acidic cosolvent that efficiently separates the uncondensed lignin under 80 ∼ 90 °C treatment, resulting in a lighter color and a recovery yield of up to 60 %. The corresponding delignification rate reached 82.6 %. The obtained lignin exhibited an ideal retention rate (maximum 84.5 %) of alkyl aryl ether bonds (β–O–4) relative to the native lignin in raw material. The resulting residue was free from cellulose decomposition and yielded over 90 % cellulose with a surface-esterified structure. This study establishes a one-step L-cysteine-assisted stabilization methodology that overcomes the challenges of lignin condensation and allows for the fractionation of lignocellulose into highly uncondensed lignin and high-quality cellulose, thus offering new solutions for biorefinery.

Injectable Hydrogel of Chitosan-Octyl Itaconate Conjugate Modulates Inflammatory Response.

Itaconic acid and its derivative 4-octyl itaconate (OI) represent a novel anti-inflammatory medication that has demonstrated efficacy in multiple inflammation models because of its minimal side effects. Recently, natural polymers conjugated with small molecule drugs, known as polymer-drug conjugates (PDCs), have emerged as a promising approach to sustained drug release. In this work, we reported an approach to prepare a PDC containing an OI and make it into an injectable hydrogel. Chitosan (CS) was selected for PDC synthesis because of its abundant free amino groups that can be conjugated with molecules containing carboxyl groups by carbodiimide chemistry. We used an ethanol/water cosolvent system to synthesize a CS-OI conjugate via EDC/NHS catalysis. The CS-OI conjugate had improved water solubility and unique anti-inflammatory activity and did not show compromised antibacterial activity compared with unmodified CS. Beta-glycerophosphate (β-GP) cross-linked CS-OI hydrogel exhibited good injectability with sustainable OI release and effectively modulated inflammatory response in a rat model. Therefore, this study provides valuable insights into the design of PDC hydrogels with inflammatory modulatory properties.

Freeze-drying cycle optimization of an amorphous solid dispersion of resveratrol

Resveratrol (RES) has demonstrated advantages as anti-cancer, anti-inflammatory, blood sugar-lowering agent and as cardioprotective agent, among others. Despite RES therapeutic advantages its use in pharmaceutical applications is limited by its low oral bioavailability, mainly due to its poor water solubility. Formulation of poorly water-soluble compound as solid dispersion (SD) converts a crystalline into a more soluble in water amorphous drug. Lyophilization or freeze-drying is a process in which water, an organic solvent, or a co-solvent system is frozen, followed by its removal from the sample, initially by sublimation (primary drying) and then by desorption (secondary drying). This study aimed the development and optimization of a bulk freeze-drying cycle by critical process parameters assessment in each phase to prepare a RES third-generation SD, containing Eudragit E PO as hydrophilic polymer at 1:2 ratio, and Gelucire 44/14 as surfactant at 16 % (w/w) to RES, using a tert-butanol (TBA)/Acetate buffer pH 4.5 (75:25) co-solvent system. A RES third-generation SD with good appearance, not cracked, collapsed, or melted was prepared by an optimized and robust bulk lyophilization process. A physicochemical characterization confirmed the conversion of RES to the amorphous state in the SD and formulation stability after 1 month at 40 °C/75 % RH. Increased solubility and higher dissolution rate compared with pure RES were also obtained.

Enzymatic Desymmetrisation of Prochiral meso-1,2-Disubstituted-1,2-Diaminoethane for the Synthesis of Key Enantioenriched (-)-Nutlin-3 Precursor.

Herein we present the biocatalysed preparation of a mono-N-carbamate-protected precursor of antitumoral Nutlin-3a through enantioselective alkoxycarbonylation of meso-1,2-disubstituted-1,2-diaminoethane using enzyme lipases and dialkyl carbonates as acylating agents. A series of supported or free lipase enzymes were screened in combination with commercially available diallyl, diethyl and dimethyl carbonates. The reactions were conducted at different temperatures, for different reaction times and with variable co-solvent systems to evaluate the effects on the enzyme catalytic activity. The best results in terms of conversion, enantiomeric excess and yield were obtained when lipase from Candida antarctica B (CAL-B) was used with diallyl carbonate (DAC) when conducting the reaction solventless at 75 °C.

Supramolecular assembled macroscopic soft scaffolds of thioindigo amphiphiles as cell-material interfaces

Biocompatible synthetic supramolecular systems have been proven success in fabricating regenerative biomedical materials with intrinsic functionality, tunability, and stimuli-responsiveness. However, it remains highly challenging to develop a supramolecular soft scaffold that allows transferring intrinsic microscopic aligned structural properties to cell attachments. Herein, we report a thioindigo bola-amphiphile (TIA) that is equipped with long alkyl-linker to connect the carboxylic acid end-group on the opposite side. Though photoresponsiveness of TIA is hindered in aqueous medium, it can be slightly improved by utilizing a co-solvent system or doping TIA with other amphiphiles. Electron microscopies and X-ray diffraction analysis suggest that a large aspect ratio of TIA nanostructures assembled into macroscopic soft scaffold with high degree of unidirectional alignment. The fabricated TIA macroscopic soft scaffold is further incubated with hMSCs, in revealing unidirectional aligned cell attachments. This work could provide an alternative strategy towards development of next-generation biocompatible soft functional materials.

Dissolution Thermodynamics and Preferential Solvation of Phenothiazine in Some Aqueous Cosolvent Systems

Dissolution Thermodynamics and Preferential Solvation of Phenothiazine in Some Aqueous Cosolvent Systems

Date palm wood-derived cellulose aerogel dissolved in ionic liquids as a green thermal insulation construction material

Heat insulation materials used in the construction industry are essential for energy conservation. Nonetheless, the majority of current commercial heat insulators are fossil-fuel derived materials; thus, it is vital to provide sustainable, biodegradable, and environmentally friendly alternatives. In this work, an innovative method for producing cellulose II aerogels extracted from date palm waste and from microcrystalline lab-grade cellulose, targeting thermal insulation applications in the construction industry was introduced. A key aspect of the investigated approach is the use of a co-solvent system that combines 1-butyl-3-methylimidazolium chloride (Bmim)Cl and dimethylformamide (DMF), chosen for its efficiency in dissolving cellulose. The cellulose (at 3, 5, 7, and 9 wt%) was dissolved in a co-solvent system of 70 wt% (Bmim)Cl ionic liquid and 30 wt% DMF, saving costs associated with using purely ionic liquid solvents. The prepared aerogels exhibited low thermal conductivity (0.033–0.065 W/m⋅K), low densities (0.08–0.15 g/cm3), high porosity (89.85–94.69 %) and good thermal diffusivity (0.06–0.022 mm2/s). Furthermore, the developed insulators required a compressive strength of 75 kPa to reach 50 % strain and exhibited a sound absorption coefficient of 0.9. Structural characterization of the materials, including X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis, highlights the prospect of cellulose extracted from date palm wood in aerogel preparation and the potential for the (Bmim)Cl/DMF co-solvent system in dissolving cellulose.

Synthesis of microalgae-based methyl ester using calcium glyceroxide catalyst derived from duck eggshells and crude glycerol in the n-hexane co-solvent system

Abstract The synthesis of microalgae-based methyl ester has attracted the interest of researchers since microalgae have a high lipid content and can proliferate. Chlorella vulgaris, with its 63% lipid content on a dry basis, holds promise for methyl ester production. Heterogeneous catalysts, particularly calcium glyceroxide (Ca[O(OH)2C3H5]), play a crucial role in ester manufacturing due to their high catalytic activity. The synthesis of the calcium glyceroxide catalyst involves duck eggshells as a calcium source and crude glycerol. Optimal methyl ester production is achieved by employing n-hexane as a co-solvent for efficient microalgae oil dissolution. This research focuses on synthesizing and characterizing the calcium glyceroxide catalyst derived from duck eggshells and crude glycerol, emphasizing its application in manufacturing microalgae-based methyl esters with n-hexane as the co-solvent. Methyl ester synthesis variables include a 55°C reaction temperature, a 1.5% microalgae-derived catalyst, and a 9:1 methanol to microalgae ratio. FTIR functional group analysis identifies hydroxyl (O-H) groups from crude glycerol bound to calcium at 3345.71 cm−1, along with C-H group vibrations from crude glycerol bound to calcium at 2941.80 cm−1. SEM morphological analysis reveals aggregate formation on the calcium glyceroxide catalyst, indicating potential active sites. Utilizing the calcium glyceroxide catalyst for methyl ester synthesis yields a promising 62.42% yield. GC characterization demonstrates a methyl ester purity of 72.09%, with methyl palmitate as the predominant component at 30.927%. This study underscores the efficient use of the synthesized calcium glyceroxide catalyst for microalgae-based methyl ester production, showcasing its potential for sustainable biodiesel synthesis.

Development of Perfluoro Decalin/Fluorinated Polyimide Core-Shell Microparticles via SPG Membrane Emulsification Using Methyl Perfluoropropyl Ether Cosolvent.

Red blood cell-inspired perfluorocarbon-encapsulated core-shell particles have been developed for biomedical applications. Although the use of perfluorodecalin (FDC) is expected for core-shell particles owing to its high oxygen solubility, the low solubility of FDC in any organic solvent, owing to its fluorous properties, prevents its use in core-shell particles. In this study, a new cosolvent system composed of dichloromethane (DCM) and heptafluoropropyl methyl ether (HFPME) was found to dissolve both FDC and fluorinated polyimide (FPI) based on a systematic study using a phase diagram, achieving a homogeneous disperse phase for emulsification composed of oxygen-permeable FPI and oxygen-soluble FDC. Using this novel cosolvent system and Shirasu porous glass (SPG) membrane emulsification, FDC-encapsulated FPI shell microparticles were successfully prepared for the first time. In addition to oxygenation, demonstrated using hypoxia-responsive HeLa cells, the fabricated core-shell microparticles exhibited monodispersity, excellent stability, biocompatibility, and oxygen capacity.

Resource Recovery of Spent Lithium-Ion Battery Cathode Materials by a Supercritical Carbon Dioxide System.

The increasing global market size of high-energy storage devices due to the boom in electric vehicles and portable electronics has caused the battery industry to produce a lot of waste lithium-ion batteries. The liberation and de-agglomeration of cathode material are the necessary procedures to improve the recycling derived from spent lithium-ion batteries, as well as enabling the direct recycling pathway. In this study, the supercritical (SC) CO2 was innovatively adapted to enable the recycling of spent lithium-ion batteries (LIBs) based on facilitating the interaction with a binder and dimethyl sulfoxide (DMSO) co-solvent. The results show that the optimum experimental conditions to liberate the cathode particles are processing at a temperature of 70 °C and 80 bar pressure for a duration of 20 min. During the treatment, polyvinylidene fluoride (PVDF) was dissolved in the SC fluid system and collected in the dimethyl sulfoxide (DMSO), as detected by the Fourier Transform Infrared Spectrometer (FTIR). The liberation yield of the cathode from the current collector reaches 96.7% under optimal conditions and thus, the cathode particles are dispersed into smaller fragments. Afterwards, PVDF can be precipitated and reused. In addition, there is no hydrogen fluoride (HF) gas emission due to binder decomposition in the suggested process. The proposed SC-CO2 and co-solvent system effectively separate the PVDF from Li-ion battery electrodes. Thus, this approach is promising as an alternative pre-treatment method due to its efficiency, relatively low energy consumption, and environmental benign features.

Optimizing electrolyte systems for stable and low-temperature zinc-ion batteries via efficient coordinator

Aqueous zinc-ion battery suffers poor cycling stability due to uneven Zn2+ deposition and serious dendrite growth. To effectively protect the Zn metal anode, diglyme (G2) is added as the co-solvent. Adding G2 can reconstruct the Zn2+ solvation structure and reduce the water molecule content of [Zn(H2O)6]2+ sheath. Theoretical calculations confirm that by adding G2, the triflate group OTF− ion shows greater interaction with Zn, and the water molecules from the [Zn(H2O)6]2+ solvation structure are replaced by OTF− ions. Benefitted from this, an organic-inorganic SEI layer is formed on the Zn anode, which isolates the Zn anode from the bulk electrolyte, and allows/suppresses Zn2+ diffusion. As well, Zn corrosion and side reactions are inhibited in this system. This co-solvent electrolyte system has a high Coulombic efficiency of 99.7%. A long cycling life of 1000 cycles with capacity retention of 80% is demonstrated by Zn//iodine (I2) - Activated Carbon (AC) full cell at room temperature. Even under a low-temperature condition (−18 °C), Zn//I2 - AC full cell shows a long lifespan of 1000 cycles with capacity retention of 65%. This work demonstrates a new direction and unparalleled insight into electrolyte engineering with solvation structure regeneration and SEI player formation for aqueous zinc-ion batteries.