Type Of Electrolyte Research Articles

Electrical conductance study of Schiff base in different solvents and temperatures: DFT calculation

The electrical conductivities of the N-(2-chlorobenzylidene)benzylamine (NCB) as Schiff bases (SB) compound in water and methanol were studied in different temperatures, the mixtures of methanol and water studied in various percentages of methanol at 298 K. Initially, the relationship between equivalent conductivity and the square root of molar concentration was plotted to find electrolyte types using Kohlrausch equations. The plot indicates that NCB was weakly associated with water, methanol, and mixtures. Lee-Wheaton equation treated the experimental results of symmetrical electrolytes (1:1) to calculate the conductivity confines: equivalent conductance at infinite dilution Λₒ, association constant KA, and the main distance between ions in solution (R) at best-fit values of (ϬΛ). Thermodynamic quantities for the ion association reaction (∆Go, ∆Ho and ∆So) have been measured. Also, the theoretical calculation was used to optimize the energy of the molecule in the gas phase then measured many descriptors by using (AM1, PM3) then DFT. In addition, recalculated the optimization energy in water, and methanol. After theoretical calculation and analysis, it was found that the Λₒ value is related to the molecular volume of the system (molecules assembled in the solvent). As the molecular volume increases, the Λₒ value decreases due to association. KEY WORDS: Schiff bases, Electrical conductivities, Lee-Wheaton equation, Thermodynamic parameter, DFT Bull. Chem. Soc. Ethiop. 2025, 39(1), 177-187. DOI: https://dx.doi.org/10.4314/bcse.v39i1.15

Effects of fluorine and phosphorus-based flame retardants addition on the lower flammability limit of dimethyl carbonate

This study initially examines the alteration pattern of the lower flammable limit (LFL) of dimethyl carbonate (DMC), a typical electrolyte component in lithium batteries, under the influence of inhibitors, namely di(2,2,2trifluoroethyl) carbonate (DtFEC), perfluorohexanone (C6F12O), and trimethylphosphate (TMP), through experimental investigation. Additionally, the critical inhibitory concentration required for complete inhibition is investigated. Subsequently, numerical simulations and chemical kinetic path analyses reveal how these inhibitors control combustion. Results show that C6F12O and DtFEC initially decrease and then increase the LFL of DMC, while TMP causes a monotonic increase. This is due to the competition between reaction-thermal and reaction-radical effects. Reaction kinetic analysis reveal that when small amounts of C6F12O and DtFEC are added, the fluorine-containing components decomposed by the reaction undergo oxidation, thereby promoting combustion. However, with increased amounts, these components combine with H and OH radicals to form stable substances like HF, inhibiting the combustion process. In the case of TMP, the phosphorus-containing intermediate components produced by cleavage catalyze the recombination of H and OH radicals, thereby inhibiting DMC combustion. The research findings offer a theoretical foundation for the development of safer lithium batteries and provide crucial data references for enhancing battery safety and prevention measures.

Simultaneous determination of chlorides, bromides, and fluorides in ion-conducting electrolyte

There are developed the techniques of determining the content of chlorides, bromides and fluorides at their joint presence in two types of solid electrolytes differing in matrix content: the first type contains lithium, the second one — both lithium and aluminium, simultaneously. Determination of bromides mass fraction is fulfilled using a method of iodometric titration of iodic potassium excess after bromides are oxidized until free bromine. The fluorides mass fraction is measured by the gravimetric method in the form of fluoro-chloride of lead, in this case the aluminium interfering influence is eliminated by its precipitation in the form of hydroxide after it is fused with carbonates of potassium and natrium, as well as by the method of potentiometric titration with a fluoride ion-selective electrode using the nitrate lanthanum solution. The absence of aluminium interfering influence on the result of fluorine determination is estimated by the «input – found» method. The mass fraction of chlorides is determined by calculation by difference between results of determining the sum of chlorides and bromides using the method of mercurometric titration and — separately — the bromides mass fraction. Optimal conditions of samples preparation and analysis for each of mentioned methods of analysis were selected. The limits of the relative total error of determining bromides in the range of mass fractions from 28.0 to 41.0% is ±2.1%, chlorides within the mass fraction range from 8.0 to 15.0% — ±3.6%, fluorides within the mass fraction range from 3.0 to 7.0% — ±3.4% using gravimetric method and within the mass fraction range from 5.0 to 8.0% — ±1.5% using a method of potentiometric titration. The developed techniques were certified by a metrological service of the enterprise and are used to control the chemical composition of the ion-conducting electrolyte. The techniques do not require expensive equipment, and can be used in factory laboratories.

Revealing the Dynamic Evolution of Electrolyte Configuration on the Cathode‐Electrolyte Interface by Visualizing (De) Solvation Processes

AbstractElectrolyte engineering is crucial for improving cathode electrolyte interphase (CEI) to enhance the performance of lithium‐ion batteries, especially at high charging cut‐off voltages. However, typical electrolyte modification strategies always focus on the solvation structure in the bulk region, but consistently neglect the dynamic evolution of electrolyte solvation configuration at the cathode‐electrolyte interface, which directly influences the CEI construction. Herein, we reveal an anti‐synergy effect between Li+‐solvation and interfacial electric field by visualizing the dynamic evolution of electrolyte solvation configuration at the cathode‐electrolyte interface, which determines the concentration of interfacial solvated‐Li+. The Li+ solvation in the charging process facilitates the construction of a concentrated (Li+‐solvent/anion‐rich) interface and anion‐derived CEI, while the repulsive force derived from interfacial electric field induces the formation of a diluted (solvent‐rich) interface and solvent‐derived CEI. Modifying the electrochemical protocols and electrolyte formulation, we regulate the “inflection voltage” arising from the anti‐synergy effect and prolong the lifetime of the concentrated interface, which further improves the functionality of CEI architecture.

Perfluorooctanoic Acids (PFOA) removal using electrochemical oxidation: A machine learning approach

The urgent need to eliminate Perfluorooctanoic Acid (PFOA) has positioned electrooxidation (EO) as a key solution for pollutant degradation. This study evaluates several machine learning (ML) models, including K-Nearest Neighbors (KNN), Decision Tree (DT), Random Forest (RF), Gradient Boosted Decision Trees (GBDT), and Deep Learning (DL), to predict EO efficiency in PFOA removal. Using 10-fold cross-validation, the RF model outperformed others with a root mean square error (RMSE) of 7.7 and a correlation coefficient of 0.965, demonstrating its robustness and accuracy across diverse operational settings. Feature importance within the RF model was analyzed using Gini impurity and Mean Decrease in Accuracy (MDA). Electrolysis Time consistently emerged as the most influential factor in both analyses, underscoring its pivotal role in providing extended exposure of PFOA molecules to reactive species at the electrode surfaces. The study also found strong agreement between Gini and MDA in identifying Current Density and Anode Material as critical factors, although MDA placed slightly more emphasis on Anode Material. Differences between Gini and MDA were more pronounced in the ranking of Electrolyte Type and Concentration, with MDA assigning higher importance to Electrolyte Concentration. In contrast, the Water Matrix was consistently ranked as the least important factor. The strong concordance between Gini and MDA highlights the reliability of the RF model in identifying key drivers of electrochemical degradation. Overall, this work contributes significantly to the advancement of pollutant degradation technologies, presenting a reliable ML-based tool for environmental remediation efforts.

Review of AEM Electrolysis Research from the Perspective of Developing a Reliable Model

This review thoroughly examines recent progress, challenges, and future prospects in the field of alkaline exchange membrane (AEM) electrolysis. This emerging technology holds promise for eco-friendly hydrogen production. It blends the benefits of traditional alkaline and proton-exchange membrane technologies, enhancing affordability and operational efficiencies by utilizing non-precious metal catalysts and operating at reduced temperatures. This study discusses key developments in materials, electrode design, and performance enhancement techniques. It also highlights the strategic role of AEM electrolysis in meeting global energy transition targets, like achieving Net Zero Emissions by 2050. An in-depth exploration of the operational fundamentals of AEM water electrolysis is provided, noting the technology’s early stage development and the ongoing need for research in membrane-electrode assembly assessment, catalyst efficiency, and electrochemical ammonia production. Moreover, this review compiles results on different cell components, electrolyte types, and experimental approaches, providing insights into operational parameters critical to optimizing AEM performance. The conclusion emphasizes the necessity for continuous research and commercialization efforts to exploit AEM electrolysis’s full potential across diverse industries.

Zinc Chemistries of Hybrid Electrolytes in Zinc Metal Batteries: From Solvent Structure to Interfaces.

Along with the booming research on zinc metal batteries (ZMBs) in recent years, operational issues originated from inferior interfacial reversibility have become inevitable. Presently, single-component electrolytes represented by aqueous solution, "water-in-salt," solid, eutectic, ionic liquids, hydrogel, or organic solvent system are hard to undertake independently the task of guiding the practical application of ZMBs due to their specific limitations. The hybrid electrolytes modulate microscopic interaction mode between Zn2+ and other ions/molecules, integrating vantage of respective electrolyte systems. They even demonstrate original Zn2+ mobility pattern or interfacial chemistries mechanism distinct from single-component electrolytes, providing considerable opportunities for solving electromigration and interfacial problems in ZMBs. Therefore, it is urgent to comprehensively summarize the zinc chemistries principles, characteristics, and applications of various hybrid electrolytes employed in ZMBs. This review begins with elucidating the chemical bonding mode of Zn2+ and interfacial physicochemical theory, and then systematically elaborates the microscopic solvent structure, Zn2+ migration forms, physicochemical properties, and the zinc chemistries mechanisms at the anode/cathode interfaces in each type of hybrid electrolytes. Among of which, the scotoma and amelioration strategies for the current hybrid electrolytes are actively exposited, expecting to provide referenceable insights for further progress of future high-quality ZMBs.

Confined Polyethylene Glycol Anchored in Kaolinite as High Ionic Conductivity Solid-State Electrolyte for Lithium Batteries.

Solid-state electrolytes (SSEs) have garnered significant attention as critical materials for enabling safer, energy-dense, and reversible electrochemical energy storage in batteries. Among the various types of solid electrolytes developed, composite polymer electrolytes (CPEs) have stood out as some of the most promising candidates due to their well-rounded performance. In this study, we choose polyethylene glycol (PEG) as the covalent grafting intercalant and lithium perchlorate as carrier source to prepare a fast lithium ion conductor, K-PEG-Li doped with clay-based active filler as a CPE. The CPE exhibits excellent lithium conduction (4.36 × 10-3 S cm-1 at 25 °C and 3.32 × 10-2 S cm-1 at 115 °C), great mechanical performance with good tensile strength (6.07 MPa) and toughness (strain 313%), and convincing flame-retardancy. These outstanding conducting and mechanical functionalities indicate that such a clay-based active filler doped composite polymer electrolyte will find promising application in solid-state lithium batteries.

Enhancing photovoltaic cell design with multilayer sequential neural networks: A study on neodymium-doped ZnO nanoparticles

Multilayer sequential neural networks, a powerful machine learning model, demonstrate the ability to learn intricate relationships between input features and desired outputs. This study focuses on employing such models to design photovoltaic cells. Specifically, neodymium (Nd)-doped ZnO nanoparticles (NPs) were utilized as a photoanode for fabricating dye-sensitized solar cells (DSSCs). A natural dye extracted from Spinacia oleracea was employed, while two types of electrolytes, liquid and gel (polyethylene glycol-based), were used for comparative analysis. Extensive material characterization of the photoanode highlights the impact of Nd content on the physicochemical properties of ZnO. Notably, when the doped photoanode and gel electrolyte were combined, a substantial 110% improvement in power conversion efficiency (PCE) was achieved. Building on these findings, the machine learning model in this research accurately predicts the current-voltage (I-V) curve values for such photoanodes, with an impressive accuracy of 98%. Additionally, the model illuminates the significance of variables like crystal distortion, texture coefficient, and doping concentration, underscoring their importance in the context of photovoltaic cell design.

The Study of Removal of Polyvinyl Chloride (PVC) Particles from Wastewater through Electrocoagulation

Plastic was produced massively, especially using polyvinyl chloride (PVC) as a raw material. Unfortunately, this condition cause affects the environment, which creates a new pollutant issue. It is essential to study the removal of PVC microplastics in current water treatment processes. The study of wastewater treatment can be achieved using electrocoagulation, which has several benefits, including low-cost, simple chemicals, and accessible equipment operation. This research investigated the study of the removal of PVC microplastics from wastewater by electrocoagulation. The new potential of the electrocoagulation technique using Al-Al electrodes was studied systematically at various variations, i.e., electrolysis time, electrolyte concentration, initial pH, coagulation speed, and electrolyte type. The results showed that the PVC microplastics removal efficiency reached 100% after electrolysis for 60 min, electrolyte concentration of 0.01 mol/L, initial pH of 7, coagulation speed of 500 rpm, the type of electrolyte used was NaCl at a flocculation speed. These optimum conditions also reduced the value of turbidity of wastewater samples from 1.39 ± 0.02 to 1.10 ± 0.05 NTU. The results of this study provide an engineering perspective in optimizing operational parameters for removing PVC microplastics in aquatic environments.

Benchmarking the Performance of Lithium and Sodium‐Ion Batteries With Different Electrode and Electrolyte Materials

ABSTRACTSodium‐ion (Na‐ion) batteries are considered a promising alternative to lithium‐ion (Li‐ion) batteries due to the abundant availability of sodium, which helps mitigate supply chain risks associated with Li‐ion batteries. Many studies have focused on the design of Li‐ion batteries, exploring their energy, power, and cost aspects. However, there is still a lack of similar research conducted on Na‐ion batteries. A comparison of the cell voltage characteristics and rate capability of sodium and lithium‐ion batteries using different types of electrodes and electrolytes. For sodium‐ion batteries electrolytes used are NaPF6 and NaClO4 and electrodes used are NaCoO2, NaNiO2, NaFePO4, (Na3V2(PO4)3), graphite, hard carbon, sodium metal, and sodium titanate. For lithium‐ion batteries with LiPF6 and KOH electrolytes and electrodes as LiCoO2, NMC, LVP, Li2MnSiO4, graphite, silicon, lithium titanate (LTO), lithium metal. A thorough analysis of six important performance metrics is part of the investigation: Ragone plots, Electrolyte salt concentration versus spatial coordinate, electrolyte potential versus spatial coordinate, Cell voltage versus battery cell state of charge, Cell voltage versus time, and state variable versus time. Comparing operating voltage and rated capacity NMC and graphite is selected for lithium‐ion batteries as this combination provides operating voltage up to 4.2 V and a rated capacity of 275 Wh/kg, for sodium‐ion for NaCoO2 and hard carbon which has an operating voltage of 2.5–3.8 V and rated capacity around 200 Wh/kg and another combination of electrode as NaFePO4 and sodium metal with NaClO4 electrolyte has a maximum operating voltage of 2.8–3.8 V and rated capacity around 200 Wh/kg. This paper shows significant influence of electrolyte selection on battery performance. The Ragone plots demonstrate that LiPF6 electrolytes in lithium‐ion batteries and NaPF6 electrolytes in sodium‐ion batteries both exhibit superior specific energy densities compared to their KOH and NaClO4 counterparts, respectively. The work presented in this paper encourages researchers to select alternate electrolytes and electrodes for lithium‐ion and sodium‐ion batteries in order to obtain optimal device performance.

A novel strategy inspired by Luban lock towards endowing polyzwitterionic electrolyte hydrogel with UCST behaviors

The electrostatic interaction in polyzwitterionic electrolyte hydrogels is the prerequisite for materials to exhibit temperature-sensitive behaviors. Few reports mention the potential temperature-sensitive properties of these hydrogels, although amounts of polyzwitterionic electrolyte hydrogels with bright prospects in advanced fields have been reported. PMAD (copolymer of AM, AA and DMC) is a typical polyzwitterionic electrolyte, which is taken as an example to elucidate the essential conditions for the UCST behaviors of polyzwitterionic electrolyte hydrogels. The temperature-sensitive properties of PMAD hydrogels depends on the tight stacking of zwitterionic polymer chains, while the introduction of chemical crosslinker could limit the movement of PMAD chains and increase the difficulty of forming effective electrostatic interactions between zwitterionic segments resulting in the disappearance of UCST behaviors. Accordingly, the strategy inspired by the Chinese Luban lock for compressing the distance of PMAD chains by utilizing the “mortise-tenon” structure could recovery the UCST behaviors of PMAD and are expected to endow more polyzwitterionic electrolyte hydrogels with temperature-responsive properties.

Functionalized fillers as “ions relay stations” enabling Li+ ordered transport in quasi-solid electrolytes for high-stability lithium metal batteries

Quasi–solid–state lithium–metal batteries (QSLMBs) are promising candidates for next–generation battery systems due to their high energy density and enhanced safety. However, their practical application has been hindered by low ionic conductivity and the growth of lithium dendrites. To achieve ordered transport of Li+ ions in quasi–solid electrolytes (QSEs), improve ionic conductivity, and homogenize Li+ fluxes on the surface of the lithium metal anode (LMA), we propose a novel method. This method involves constructing “ion relay stations” in QSEs by introducing cyano–functionalized boron nitride nanosheets into pentaerythritol tetraacrylate (PETEA) –based polymer electrolytes. The functionalized boron nitride nanosheets promote the dissociation of lithium salts through ion–dipole interactions, optimizing the solvated structure to facilitate the orderly transport of Li+ ions, resulting in an ionic conductivity of 2.5 × 10−3 S cm−1 at 30 °C. Notably, this strategy regulates the Li+ distribution on the surface of the LMA, effectively inhibiting the growth of lithium dendrites. Li||Li symmetrical cells using this type of electrolyte maintain stability for over 2000 h at 2 mA cm−2 and 2 mAh cm−2. Additionally, with a high LiNi0.8Co0.1Mn0.1O2 (NCM811) loading of 8.5 mg cm−2, the cells exhibit excellent cycling performance, retaining a high capacity after 400 cycles. This innovative QSE design strategy represents a significant advancement towards the development of high–performance QSLMBs.

Role of Acoustic and Volumetric Properties in View to Estimate the Intermolecular Interactions in the Solutions of Electrolytes and l‐Isoleucine

Abstractl‐Isoleucine is subjected to density and sound velocity measurements in aqueous solutions of potassium (KCl) and sodium chlorides (NaCl) as well as water, from 288.15 to 298.15 K. Through the use of these experimental data, a variety of volumetric and acoustical parameters are calculated, including values for molar volume (Vm), available volume (Va), adiabatic compressibility (β), nonlinear parameters (B/A), Wada constant (W), Rao's constant (R), and van der Wall's constant (a). The findings shed light on many electrostatic and hydrophobic interactions within the binary system involving electrolytes, water, and amino acids. The interactions between the electrolytes and l‐isoleucine are thoroughly examined under varying electrolyte concentrations and temperatures, revealing many interactions. Positive transfer quantities demonstrate the ion‐hydrophilic and solute–solvent interaction in the aqueous medium, particularly between l‐isoleucine and NaCl and KCl. The influence of electrolyte type and temperature on these interactions is discernible. The culmination of the study's outcomes is elaborated through analyzing solute–solvent and solute–solute interactions. In particular, the interaction hierarchy is identified as l‐isoleucine + water + KCl > l‐isoleucine + water + NaCl > l‐isoleucine + swater.

Revisiting ether electrolytes for high-voltage sodium-ion batteries

While ether electrolytes show great potential for anode materials of sodium-ion batteries (SIBs), they are perceived to be intolerant to high voltage (4.0 V and above) and are rarely employed in cathode materials. Herein, four typical ether electrolytes are examined and the oxidative stability is demonstrated to be closely related to their solvation structures. The anion-involved solvation structure lowers the tolerance of weakly solvated electrolyte to high voltage, and the resulting inorganics-rich cathode electrolyte interphase is equipped with high resistance and friability, leading to undesired rate and cycle performance. In contras, strongly solvated electrolytes can cycle stably at a high voltage of 4.3 V with high rate performance. As a proof-of-concept, the Graphite//Na3(VOPO4)2F full cell based on G2 electrolyte (1 M NaPF6 in glyme) can deliver a high energy density of 126.3 Wh kg−1 at 61.2 W kg−1 and a desirable power density of 5424.3 W kg−1 at 65.1 Wh kg−1, providing a demonstration for the potential application of ether electrolytes in high-voltage SIBs.

Efficacy of machine learning algorithm in estimating oxyhydrogen gas generation system: Electrolyte concentration and current influence on sustainable energy production

Hydrogen gas has emerged as a promising and ecologically friendly substitute for fossil fuels, providing a long-term energy alternative. This research study applies machine learning regression models for estimating the volume of HHO gas generated using two distinct electrolytes with varying concentrations, namely sodium hydroxide (NaOH) and potassium hydroxide (KOH). The efficiency of the HHO gas production system hinges on various factors, such as the type of electrolyte and electrode, distance between electrodes, applied current and voltage. This investigation employed a comprehensive array of 29 multiple-regression algorithms to predict gas production. Notably, the input data for these algorithms were directly fed from the collected experimental data without any preprocessing. The input variables include the electrolyte concentration, current, and voltage, while the output is the estimated production of HHO gas. The findings of this study revealed that the multilayer perceptron (MLP) regression algorithm yielded the highest correlation coefficients, registering values of 0.9945 for NaOH and 0.9942 for KOH, respectively. Root relative squared error, relative absolute error, root mean squared error, mean fundamental error, and correlation coefficient were the metrics used to determine the model performance in predicting the volume of HHO gas produced. Furthermore, the experimental analysis demonstrated a direct relationship between the concentration of the electrolyte solution and the current with the rate of HHO gas production. Notably, the study identified that operating the cell at 40 A with KOH resulted in the maximum productivity of 0.9 litres per minute (LPM) of HHO gas, representing a 16 % increase compared to NaOH. These findings underscore the potential of machine learning regression models in optimizing hydrogen production and highlight the advantages of KOH as an electrolyte in this context.

VO2·xH2O nanoribbons as high-capacity cathode material for aqueous zinc-ion batteries: Electrolyte selection and performance optimization

In the pursuit of efficient energy storage solutions for renewable energy, aqueous zinc-ion batteries (ZIBs) have emerged as promising contenders, offering high capacity and manufacturability. Among transition metal oxides, vanadium dioxide (VO2) stands out as the synergestic behavior of H+ and Zn2+ ions with the VO2·xH2O ensures high specific capacity in Zn-ion based battery. Here, we present the successful synthesis of hydrated vanadium oxide (VO2·xH2O) nanoribbons via the hydrothermal method, followed by comprehensive characterizations to assess material properties. A systematic study on electrolyte selection, focusing on achieving high capacity and stability, was conducted using varying electrolyte types and concentrations. The superior 3 M Zn(CF3SO3)2 electrolyte was chosen for further electrochemical investigations, leading to the formation of a two-electrode system comprising VO2·xH2O//Zn half-cell ZIB, which lasts more than 1000 cycles at 1 A g−1 in addition to capacity retention of 82.18% while providing a capacity of 235.63 mAh g−1 at 0.1 A g−1, while demonstrating favorable rate capability. Ex-situ XRD analysis unveiled insights into the designed ZIB's charging/discharging mechanism, showcasing variations in cathode crystallinity and the formation of Zn(OH)2 peaks during cycling. To establish the effective usage of this formed ZIB for daily-life applications, the coin cell was effectively used to power an LED and LCD screen, and the subsequently attained value of capacity was compared along with the available literature. This work surpasses existing ZIBs in terms of capacity and cyclability, paving the way for a more sustainable future through efficient energy storage from renewable sources.

A niobium and tantalum co-doped perovskite electrolyte with high ionic conduction for low-temperature Ceramics Fuel cell

In recent studies, fast ionic conduction through surface doping and coating has been a favorite subject and has indicated a promising and stable strategy to optimize ions in the developed electrolytes for low-temperature ceramic fuel cells (LT-CFCs). We have designed co-doped perovskite (Nb/Ta-SrCoO3) to enhance further ionic properties using the Solid-state blending technique. The prepared SCNT (SrCoNb0.3Ta0.3O3) was used as an electrolyte sandwiched between symmetrical electrodes and delivered attractive fuel cell performance (650 mW/cm2) with better stability at the low operating temperature of 520 °C compared to other compositions of SCNT. The low grain boundary resistance manifests SCNT's high ionic conduction + microstructural properties, assisting with higher fuel cell performance. The co-doping enables the fermi-level to move towards the -ive side, establishing a space charge region constituting BIEF (built in electric field) and helping to enhance the ions' transportation through the surface and interface. This work thus points out a new type of electrolyte with a different working mechanism from previous studies. It indicates a feasible approach to developing high-performing and stable electrolytes for LT-CFCs.

Evaluation of Oxide|Sulfide Heteroionic Interface Stability for Developing Solid-State Batteries with a Lithium-Metal Electrode: The Case of LLZO|Li6PS5Cl and LLZO|Li7P3S11.

Developing solid-state batteries (SSB) with a lithium metal electrode (LME) using only one type of solid electrolyte (SE) is a significant challenge since no SE fits all the requirements imposed by both electrodes. A possible solution is using multilayer SSBs with an LME where the drawbacks of each SE are overcome by using layers of different SEs. However, research on inorganic SE1|SE2 heteroionic interfaces is still quite preliminary, especially regarding oxide|sulfide heteroionic interfaces. This work reports the electrochemical investigation of the heteroionic interface between Li6.25Al0.25La3Zr2O12 (Al-LLZO) and two representative materials for sulfide-based SEs: argyrodite-based Li6PS5Cl (LPSCl) and glass-like Li7P3S11 (LPS711). Through in-depth temperature- and pressure-dependent impedance analyses of multilayer symmetric cells at equilibrium (i.e., no current load), the electrical properties of the heteroionic interfaces are assessed. The pressure-dependent kinetic of the Al-LLZO|LPSCl pair is interpreted with the concept of geometric constriction resistance and show that its resistance is lower than for the Al-LLZO|LPS711 pair. Furthermore, the effect of Al-LLZO surface treatment on the electrical properties of the Al-LLZO|LPSCl heteroionic interface is evaluated. Such investigation shows that the value of the interface activation energy decreases when the Al-LLZO surface is heat treated, revealing a significant influence of the carbonate/hydroxide passivation layer on the heteroionic interface. Additionally, by cycling the symmetric cell for 900 h at 1.0 mAh·cm-2, it is revealed that the Al-LLZO|LPSCl interface has a lower impedance increase than the Al-LLZO|LPS711 interface, especially if the Al-LLZO is heat treated. With this work, we highlight that the oxide|argyrodite combination can be a promising candidate for multilayer SSBs with an LME. However, we show that an optimized LLZO surface treatment and chemical analysis of the interface are recommended for future research.

Electrolytes for High-Safety Lithium-Ion Batteries at Low Temperature: A Review.

As the core of modern energy technology, lithium-ion batteries (LIBs) have been widely integrated into many key areas, especially in the automotive industry, particularly represented by electric vehicles (EVs). The spread of LIBs has contributed to the sustainable development of societies, especially in the promotion of green transportation. However, the high demand for battery performance and safety in these fields has made the high viscosity, volatility, and potential leakage inherent in traditional organic liquid electrolytes a constraint on their further expansion. Especially at low temperature, the increased viscosity of the electrolyte, reduced solubility of lithium salts, crystallization or solidification of the electrolyte, increased resistance to charge transfer due to interfacial by-products, and short-circuiting due to the growth of anode lithium dendrites all affect the performance and safety of LIBs. Therefore, improving the safety performance of LIBs under low-temperature environments has become a focus of current research. This paper primarily reviews the progress made in utilizing different types of electrolytes in LIBs to enhance safety and optimize low temperature performance and discusses the current research progress as well as the future development direction of the field.