Ionic Conductivity Of Electrolyte Research Articles

Selective Covalent Basal Plane Modification as a Probe of Hydroxide Ion Conduction Pathways in Magnesium Aluminum Layered Double Hydroxides.

Understanding ionic conduction in layered double hydroxides (LDHs) is a crucial step towards utilizing them as solid, hydroxide ion-conducting electrolytes in energy conversion applications. We selectively modified the interlayer and external surfaces of MgAl LDHs with tris(hydroxymethyl)aminomethane (TRIS) ligands. By adjusting the concentration of the TRIS surface modifier, the LDH basal plane surfaces could be functionalized everywhere (internally and externally) or only externally. External modification resulted in loss of OH-conductivity compared to pristine LDHs, confirming that external platelet surfaces are the primary ion conduction pathway.

A Fully Methylated Cyclic Ether Solvent Enables Graphite Anode Cycling at Low Temperatures.

Graphite anode suffers from great capacity loss and larger cell polarization under low-temperature conditions in lithium-ion batteries (LIBs), which are mainly caused by the high energy barrier for the Li+ desolvation process and sluggish Li+ transfer rate across the solid electrolyte interface (SEI). Regulating an electrolyte with an anion-dominated solvation structure could synchronously stabilize the interface and boost the reaction kinetics of the graphite anode. Herein, a highly ionic conductive electrolyte consisting of a fully methylated cyclic ether solvent of 2,2,4,4,5,5-hexamethyl-1,3-dioxolane (HMD) and fluoroethylene carbonate (FEC) cosolvent was designed. The high electron-donating effect and steric hindrance of -(CH3)2 in HMD endow the HMD-based electrolyte with high ionic conductivity but lower coordination numbers with Li+, and an anion-dominated solvation structure was formed. Such configuration can accelerate the desolvation process and induce the forming of a LiF-rich SEI film on the anode, avoiding the solvent coembedding into graphite and enhancing the ion migration rate under low temperatures. The assembled Li||graphite cell with the tame electrolyte outperformed the conventional carbonates-based cell, showing 93.8% capacity retention after 227 cycles for the DF-based cell compared to 64.7% after 150 cycles. It also exhibited a prolonged cycle life for 200 rounds with 81% capacity retention under -20 °C. Therefore, this work offers a valuable thought for solvent design and provides approaches to electrolyte design for low-temperature LIBs.

Asymmetric ionogel electrolyte with an ultrathin metal–organic framework layer for lithium dendrite inhibition in solid-state lithium-metal batteries

Solid-state electrolytes (SSEs) are used to prevent internal short circuits caused by the growth of lithium dendrites in solid-state lithium-metal batteries (SSLMBs). Ionogel electrolytes are new polymeric SSEs with outstanding processability, excellent flexibility, and superior ionic conductivity. Lithium-ion transport in ionogel electrolytes depends on ionic liquid (IL) content; however, increasing the IL content improves ionic conductivity but sharply decreases mechanical properties, thus limiting the ability to resist lithium dendrites. Thus, ionogel electrolytes must strike a balance between ionic conductivity and mechanical properties. Herein, we adopt a new strategy to suppress the growth of lithium dendrites by in situ polymerizing an ultrathin metal–organic framework (MOF) layer (9.8 μm) onto a highly ionic conductive ionogel electrolyte. The ionogel electrolyte provides an asymmetric SSE (ASSE) with a remarkable ionic conductivity of 4.8 × 10−4 S cm−1 (30 °C), whereas the ultrathin MOF layer regulates uniform dissolution/deposition of lithium and inhibits lithium dendrite growth, thereby increasing critical current density of the ASSE to 0.65 mA cm−2. An SSLMB assembled with the ASSE and LiFePO4 exhibits excellent performance and cycling stability, maintaining a specific capacity of 125.4 mAh g−1 after 500 cycles at 0.3C.

Investigating sulfide-based all solid-state cells performance through P2D modelling

All solid-state batteries, combining metallic lithium with a solid-state electrolyte, are now considered as a very promising answer to the growing need for higher energy density in safer batteries. While research interests are quickly raising on this topic, the number of experiments to perform in order to find the best combination of active material and solid electrolyte composition could be infinite. Therefore, an easy and low computational-cost model forecasting all solid-state cells performance could accelerate the optimization and lower the number of experiments, reaching more rapidly an up scalable solution.In this work, an innovative electrochemical model for a metallic lithium – argyrodite Li6PS5Cl – NMC622 cell is developed. In particular, two important aspects, characterizing this new battery generation, are implemented inside a P2D model.The first aspect is the implementation of a solid-state electrolyte, in substitution to liquid electrolyte, which means using the single ion conducting electrolyte theory, according to which Ohm's law is the only equation to be solved in the electrolyte domain. This reduces the number of parameters characterizing the electrolyte from three, for the liquid electrolyte (ionic conductivity, transference number, and mean molar activity coefficient), to only one, for the solid electrolyte (ionic conductivity). The second aspect regards the anode side, lithium metal is chosen, in substitution to graphite, and this implies a different treatment from an electrochemical point of view, which is to consider the anode as a boundary condition instead of a porous electrode. Such drastic simplification of the P2D model allows, after careful calibration and validation based on experimental data, to obtain reliable charge/discharge profiles at C/10 and C/5 for lithium – argyrodite Li6PS5Cl – NMC622 cells.

Triboelectrically active hydrogel drives self-charging zinc-ion battery and human motion sensing

The fast advancement of flexible electronic technology hastens an ever-growing demand for power sources that are adaptable and flexible, and the arrival of innovative energy harvesting technologies such as triboelectric nanogenerator (TENG) further endow the potable electronics with versatility and sustainability. Herein, polyvinyl alcohol/ polyacrylamide/ zinc sulfate (PPZ) hydrogel was synthesized via an one-step UV-initiated polymerization. The hydrogel demonstrates exceptional tensile properties (with a large strain of 915 % and a corresponding tensile strength of 231 KPa), excellent electrical conductivity and light transmittance. A highly flexible and easily adaptable single-electrode TENG was thus fabricated on the base of the as-synthetized PPZ (PPZ-TENG), where the PPZ hydrogel functions as both the charging layer and current collector. While promoting a high electrical output performance of the PPZ-TENG (an open circuit voltage of 176 V and a power density of 328 mW/m2), the PPZ hydrogel also serves as an efficient ion-conductive electrolyte to construct highly flexible self-charging zinc ion batteries (ZIBs). Besides, highly sensitive strain response toward environmental stimuli was also demonstrated, which makes the integration strategy a promising solution for future development self-powered flexible wearable electronics toward the sustainable monitoring of human vital signs such as pulse and limb movement.

Insights into Lithium Sulfide Glass Electrolyte Structures and Ionic Conductivity via Machine Learning Force Field Simulations.

Sulfide-based solid electrolytes (SEs) are important for advancing all-solid-state batteries (ASSBs), primarily due to their high ionic conductivities and robust mechanical stability. Glassy SEs (GSEs) comprising mixed Si and P glass formers are particularly promising for their synthesis process and their ability to prevent lithium dendrite growth. However, to date, the complexity of their glassy structures hinders a complete understanding of the relationships between their structures and properties. This study introduces a new machine learning force field (ML-FF) tailored for lithium sulfide-based GSEs, enabling the exploration of their structural characteristics, mechanical properties, and lithium ionic conductivities. Using molecular dynamic (MD) simulations with this ML-FF, we explore the glass structures in varying compositions, including binary Li2S-SiS2 and Li2S-P2S5 as well as ternary Li2S-SiS2-P2S5. Our simulations yielded consistent results in terms of density, elastic modulus, radial distribution functions, and neutron structure factors compared to DFT and experimental work. Our findings reveal distinct local environments for Si and P within these glasses, with most Si atoms in edge-sharing configurations in Li2S-SiS2 and a mix of corner- and edge-sharing tetrahedra in the ternary Li2S-SiS2-P2S5 composition. For lithium ionic conductivity at 300 K, the 50Li2S-50SiS2 glass displayed the lowest conductivity at 2.1 mS/cm, while the 75Li2S-25P2S5 composition exhibited the highest conductivity at 3.6 mS/cm. The ternary glass showed a conductivity of 2.6 mS/cm, sitting between the two. Moreover, an in-depth analysis of lithium ion diffusion over the MD trajectory in the ternary glass demonstrated a significant correlation between diffusion pathways and the rotational dynamics of nearby SiS4 or PS4 tetrahedra. The ML-FF developed in this study provides an important tool for exploring a broad spectrum of solid-state and mixed former sulfide-based electrolytes.

Structural and Electrochemical Performance of Sr0.9La0.1WO4 Electrolyte Materials for Solid Oxide Fuel Cells

A possible component of power generation technologies, solid oxide fuel cells (SOFCs) offer a high fuel-to-power conversion efficiency and no negative environmental impact. The solid-state sintering process was used to synthesize the scheelite-structured Sr0.9La0.1WO4 (SLW1) electrolyte material, and phase stability and ionic conductivity were evaluated for their technological applicability for SOFC applications. The resulting mixture, which was a single phase in a tetragonal crystal system, produced a scheelite structure of the space group I41/a. Its symmetry, space group, and structural characteristics are confirmed by X-ray diffraction (XRD) at room temperature and the Rietveld analysis that follows. A highly dense crystal structure was revealed by SEM examination. The ionic conductivity of the SLW1 sample is higher than SBW materials and lower than the conventional BCZY perovskite structure. At 900°C in both the wet Ar and dry Ar conditions, the SLW1 sample’s ionic conductivity was 2.41 × 10−5 S cm-1 and 1.76 × 10−5 Scm−1. This scheelite-like compound showed a thick microstructure and substantial conductivity, making it a potential mixed ion-conducting electrolyte for SOFC.

Development and Characterization of Highly Ionic Conductive Hydrogel Electrolytes for Supercapacitors

Development and Characterization of Highly Ionic Conductive Hydrogel Electrolytes for Supercapacitors

Preparation of cellulose acetate based flexible separator and its application in zinc–air batteries

Flexible solid-state zinc–air batteries as a wearable energy storage device with great potential, and their separators, which control ion permeability, inhibit zinc dendrite generation, and regulate catalytic active sites, have been developed as gel electrolyte separators with high retention of electrolyte uptake. However, the gel electrolyte separator still has problems such as poor affinity with the electrolyte and poor ionic conductivity, which limits its further application. In order to further improve the electrolyte absorption, ionic conductivity and mechanical strength of cellulose acetate(CA)/polyvinyl alcohol (PVA) nanofibers, TiO2 was added to CA/PVA to increase the porosity, and glutaraldehyde (GA) was used to modify the CA/PVA/TiO2 separator by acetal reaction with CA and PVA to make the molecules closely linked. The results shows that the optimal mass fractions of TiO2 and GA were 2% and 5%, respectively. At this time, the porosity and absorption rate of the separator increased from 48% to 68.2% and 142.4% to 285.3%, respectively. The discharge capacity reached 179 mA cm−3, and the cycle stability rate was 89% after 7 stable constant current charge/discharge cycles.

Synthesis of High Na+ Ion-Conducting NASICON-Based Electrolytes and Insights from Diffraction and Positron Annihilation Lifetime Spectroscopy Studies

Synthesis of High Na⁺ Ion-Conducting NASICON-Based Electrolytes and Insights from Diffraction and Positron Annihilation Lifetime Spectroscopy Studies

Structural regulation of halide superionic conductors for all-solid-state lithium batteries

Metal halide solid-state electrolytes have gained widespread attention due to their high ionic conductivities, wide electrochemical stability windows, and good compatibility with oxide cathode materials. The exploration of highly ionic conductive halide electrolytes is actively ongoing. Thus, understanding the relationship between composition and crystal structure can be a critical guide for designing better halide electrolytes, which still remains obscure for reliable prediction. Here we show that the cationic polarization factor, which describes the geometric and ionic conditions, is effective in predicting the stacking structure of halide electrolytes formation. By supplementing this principle with rational design and preparation of more than 10 lithium halide electrolytes with high conductivity over 10−3 S cm−1 at 25 °C, we establish that there should be a variety of promising halide electrolytes that have yet to be discovered and developed. This methodology may enable the systematic screening of various potential halide electrolytes and demonstrate an approach to the design of halide electrolytes with superionic conductivity beyond the structure and stability predictions.

Review of recent progress in the development of electrolytes for Cd/Pb-based quantum dot-sensitized solar cells: performance and stability.

Quantum dot-sensitized solar cells (QDSSCs) represent an exciting advancement in third-generation photovoltaic solar cells owing to their ability to generate multiple electron-hole pairs per photon, high stability under light and moisture exposure, and flexibility in size and composition tuning. Although these cells have achieved power conversion efficiencies exceeding 15%, there remains a challenge in enhancing both their efficiency and stability for practical large-scale applications. Therefore, in this review, we aimed to investigate recent progress in improving the long-term stability, analyzing the impact of advanced quantum dot properties on charge-transport optimization, and assessing the role of interface engineering in reducing recombination losses to maximize QDSSC performance and stability. Additionally, this review delves into key elements such as the electrolyte composition, ionic conductivity, and compatibility with counter electrodes and photoanodes to understand their influence on power conversion efficiencies and stability. Finally, potential directions for advancing QDSC development in future are discussed to provide insights into the obstacles and opportunities for achieving high-efficiency QDSSCs.

Development of composite separators by coating hydrochloric acid-treated halloysite nanotubes on polypropylene separators for lithium-ion batteries.

In this study, polypropylene/halloysite nanotube (PP/HNT) composite separators were prepared by coating HNTs treated with hydrochloric acid (HCl) of different concentrations on both sides of a PP separator. The effect of HNTs treated with hydrochloric acid (HCl) of different concentrations on the properties of PP/HNT composite separators was investigated. The results indicate that the PP/HNT composite separator exhibits higher electrolyte uptake and wettability than a commercial PP separator, resulting in a better electrochemical performance in Li/LiFePO4 cells. In particular, the PP/HNTs-1.2 M composite separator with HNTs treated with 1.2 M HCl exhibits the highest electrolyte uptake (384%) and ionic conductivity (1.03 mS cm-1). The cells assembled with a PP/HNTs-1.2 M composite separator deliver discharge capacities of 166 mA h g-1 (0.5 C) and 131 mA h g-1 (3 C) with attractive cycling performance (87.6% capacity retention after 100 cycles). HNTs treated with HCl of appropriate concentrations can significantly improve the properties of PP/HNT composite separators for application in lithium-ion batteries.

Understanding the role of aliovalent cation substitution on the li-ion diffusion mechanism in Li6+xP1-xSixS5Br argyrodites.

Due to their high ionic conductivity, lithium-ion conducting argyrodites show promise as solid electrolytes for solid-state batteries. Aliovalent substitution is an effective technique to enhance the transport properties of Li6PS5Br, where aliovalent Si substitution triples ionic conductivity. However, the origin of this experimentally observed increase is not fully understood. Our density functional theory (DFT) study reveals that Si4+ substitution increases Li diffusion by activating Li occupancy in the T4 sites. Redistribution of Li-ions within the lattice results in a more uniform distribution of Li around the T4 and neighboring T5 sites, flattening the energy landscape for diffusion. Since the T4 site is positioned in the intercage jump pathway, an increase in the intercage jump rate is found, which is directly related to the macroscopic diffusion and bulk conductivity. Analysis of neutron diffraction experiments confirms partial T4 site occupancy, in agreement with the computational findings. Understanding the aliovalent substitution effect on interstitials is crucial for improving solid electrolyte ionic conductivity and advancing solid-state battery performance.

Mg2+ ion-conducting ceramic solid electrolytes based on Moringa oleifera seed and magnesium nitrate for secondary magnesium battery applications

Mg2+ ion-conducting ceramic solid electrolytes based on Moringa oleifera seed and magnesium nitrate for secondary magnesium battery applications

Innovative Investigation of Ordered Mesoporous Carbon Modified Separator for High Performance Lithium-Sulfur Batteries

These days, many portable electronic devices are used widely, and it makes secondary batteries important for future innovation. Li-ion battery which is most commonly used has the high specific energy and long cycle life. But it has problems with high price and possibility of explosion. Also it reaches the limitations of energy density for electric vehicles (EVs) and energy storage systems (ESS). Lithium-Sulfur battery is becoming a one of the promising alternatives. It has high theoretical capacity (1,675 mAh g-1) and specific energy density (~2600 Wh kg-1) and low cost. Also it is eco-friendly and safe. However, there is the primary problem to be commercialized. That one is called shuttle effect, which means dissolution of polysulfide into the electrolyte in the repetitive charging and discharging. It makes capacity decrease and internal resistance increase. And the active material and the discharge products, which are sulfur and Li2S2, Li2S, have low conductivity. The irreversible volume expansion during electrochemical reaction reaches to 80%. [1,2] To alleviate these problems, various sulfur host materials and modified separators have been investigated. [3,4] One of the representative approach is to apply carbon materials as sulfur hosts. Sulfur must be dispersed throughout the carbon conductor because of its low intrinsic electrical conductivity. The carbon matrix functions as a network for rapid electron transport. Various carbon materials, such as porous carbons, carbon nanotubes, or carbon materials with heteroatoms or chemical groups such as N, O, and S, have been employed to minimize polysulfide migration. One of the most effective sulfur hosts for limiting polysulfide diffusion is mesoporous carbon. By virtue of their inherent porosity and conductive carbon architecture, mesoporous carbon hosts have demonstrated better cycling performance. Another method for dealing with the shuttle effect is to form an interlayer between the cathode and the separator. Because the separator is an important role in battery safety and electrochemical performance, designing a high quality separator is critical for the development of high performance Li-S batteries. Separators made of polypropylene (PP) or polyethylene (PE) are commercially used and have some physical and electrochemical advantages. However, these separators have drawbacks such as low ionic conductivity and poor electrolyte compatibility. Various materials have been studied and used for modifying materials on the separator. For example, carbon materials, graphene oxides, and metal-organic frameworks are excellent at suppressing the shuttle effect of polysulfide. On the other hand, characterizing these structures and comprehending polysulfide behavior in these systems during electrochemical reaction, remain substantial challenges. Herein, we report on a dual-functional modified separator by applying ordered mesoporous carbon (OMC) on a commercial separator.The mesopores and the micropores of the OMC own a specific physical adsorption capability for polysulfide, thus it can adsorb a large amount of polysulfide. In addition, it is thermally and chemically stable. Also, the OMC can be detected by operando small-angle scattering (SAXS). In recent years, SAXS approach was applied to explain the ordered porous structure of sulfur host materials for Li-S batteries. These research provide information on how sulfur is adsorbed by porous carbon. This analysis identifies the changes of sulfur species as to whether polysulfide is adsorbed in mesopores or solid discharge products are formed on the surface, or infiltrated into micropores. The use of in-depth characterization techniques allows for more precise and independent assessment of the rapid electrochemical reactions in Li-S batteries. In brief, the highly ordered mesoporous carbon was synthesized, and it was used as an interlayer that served not only as a physical barrier to limit the polysulfide shuttle phenomena but also as an additional current collector to reuse active materials. By promoting the electrochemical reaction of active materials, it exhibited better electrochemical performance such as high capacity, stable cycle performance, and improved rate performance. The adsorbed polysufide and the behavior of sulfur species in the OMC during cycling were investigated using operando SAXS to acquire insight into the role of the OMC modified separator.[1] Li, Z.; He, Q.; Xu, X.; Zhao, Y.; Liu, X.; Zhou, C.; Ai, D.; Xia, L.; Mai, L. Adv. Mater. 2018, 30 (45), 1804089.[2] Zeng, L.-C.; Li, W.-H.; Jiang, Y.; Yu, Y. Rare Met. 2017, 36 (5), 339-364.[3] Liu, Z.; Liu, B.; Guo, P.; Shang, X.; Lv, M.; Liu, D.; He, D. Electrochim. Acta 2018, 269, 180-187.[4] Schuster, J.; He, G.; Mandlmeier, B.; Yim, T.; Lee, K. T.; Bein, T.; Nazar, L. F. Angew. Chem. 2012, 124 (15), 3651-3655. Figure 1

Polysiloxane-Coated PI Nonwoven Separators with Higher Thermal and Electrochemical Stability for Lithium Ion Battery Application

Polyolefin separators are widely used for most of commercial application owing to their excellent mechanical properties, electrical insulation, and internal porous structures. The raw polyolefin materials have economic viability and possess facile mechanical extension suitable for processing as a film [1]. However, the inherent thermal property of polyolefin inevitably results in the severe thermal deformation of the separators upon the elevation of LiB temperature that has been pointed out as a major cause of fire in LiBs with the possibility of short circuits caused by lithium dendrites [2]. There have been trials to secure cycle characteristics by preventing LiB separators from shrinkage. But, even the coated polyolefin separator couldn’t have thermal stability at high temperatures above 180 oC, since the polyolefin was the base film material.Many studies have been performed to achieve high temperature stability with engineering plastics, including polyimide (PI) [1]. As PI has superior thermal stability, it has been widely applied as nonwoven separators. PI nonwoven fabric separators exhibit stability usually above 200 oC. As PI nonwoven separators have also high ionic conductivity and good electrolyte wettability, it is therefore expected to show excellent rate capability and cyclability [3]. Despite those advantages, however, PI nonwoven separators still have several issues to resolve before application of them to LiBs. One of the problems is the existence of large pores [4]. Pores over a certain size is thought to render particles in cathode active materials pass through or Li dendrites penetrate upon overcharging. Then, it can result in leakage current and internal short circuit eventually. Various studies such as particle-coating or ceramic-coating have been studied in order to figure out this problem [26].Other than pore-size distribution or existence of large pores, it must be the electrochemical stability of PI nonwoven separator and the electrochemical cell performance with the separator at high voltage that needs to be studied and examined for the potential application to LiBs [3]. In accordance with the strong demand on high power LiB development, study on the electrochemical resistance of materials and components is highly required [5]. As PI has polar chemical structure in contrast to non-polar chemical structure of polyolefin, it would be worthy to investigate the electrochemical nature and stability under high current or high voltage. In this study, a PI nonwoven separator is modified by coating of polysiloxane to improve its electrochemical stability and properties as well as its porous structure. As the coated PI nonwoven separator should be stable up to 200 oC due to the robust PI frame and the modification via polysilicon-coating is rather simple, the feasibility of this chemical approach is demonstrated and studied including its electrochemical behaviors. Ionic conductivity, electrolyte wettability, and gas permeability of the modified separator is also examined as a set of tests for LiB application. It was electrochemically stable during LSV even at 5 V vs Li+/Li. The polysiloxane-coating maintains or improves the excellent thermal and electrical stability of the PI nonwoven separators. The full cell test demonstrated that the polysiloxane-coating enabled a cyclability of 98.6% after 100 cycles, while the PI nonwoven could not be charged due to an internal short circuit.[1] H. Lee, M. Yanilmaz, O. Toprakci, K. Fu, X. Zhang, A review of recent developments in membrane separators for rechargeable lithium-ion batteries, Energy Environ. Sci, 7, 2014, 3857.[2] X. Zhang, E. Sahraei, K. Wang, Li-ion Battery Separators, Mechanical Integrity and Failure Mechanisms Leading to Soft and Hard Internal Shorts, Sci. Rep., 6, 2016, 32578.[3] Z. Lu, F. Sui, Y. Miao, G. Liu, C. Li, W. Dong, J. Cui, T. Liu, J. Wu, C. Yang, Polyimide separators for rechargeable batteries, J. Energy Chem., 58, 2021, 170.[4] G. Dong, B. Liu, G. Sun, G. Tian, S. Qi, D. Wu, TiO2 nanoshell@polyimide nanofiber membrane prepared via a surface-alkaline-etching and in-situ complexation-hydrolysis strategy for advanced and safe LIB separator, J. Membr. Sci., 577, 2019, 249.[5] Y. Xiang, J. Li, J. Lei, D. Liu, Z. Xie, D. Qu, K. Li, T. Deng, H. Tang, Advanced Separators for Lithium-Ion and Lithium-Sulfur Batteries: A Review of Recent Progress, ChemSusChem, 9, 2016, 1. Figure 1

Polymer/ceramic gel electrolyte with in-situ interface forming enhances the performance of lithium metal batteries

With the introduction of solid-state electrolytes, solid-state lithium-metal batteries face enormous challenges of low electrolyte ion conductivity and high electrode electrolyte interface impedance. Here, we adopt a strategy of combining rigidity and flexibility to design a polymer/ceramic composite gel electrolyte films (CSEs) with a fiber like structure and local defect channels for rechargeable lithium metal batteries. The CSEs synthesized in situ on LiFePO4 electrode by ultraviolet (UV) curing method, which combines the high ionic conductivity of Li6.5La3Zr1.5Ta0.5O12 (LLZTO) ceramic particles and the flexibility of poly(vinylidene fluoride-co -hexafluoropropylene) (PVDF-HFP) polymer electrolyte. In order to investigate the effect of crosslinker on the performance of electrolytes, 1,6-hexanediol diacrylate (HDDA) and ethoxylated trimethylolpropane triacrylate (ETPTA) were used in the preparation process of ultraviolet (UV) curing method. A comparison was made between gel electrolytes using HDDA and ETPTA crosslinkers, electrolytes containing ETPTA exhibited good overall performance in terms of ion conductivity (7.89 × 10−4 S cm−1), Li+ transference number (0.63), glass transition temperature (−26.2 °C), good flexibility, thermal stability. As a result, the assembled LiFePO4||electrolytes containing ETPTA||Li batteries exhibit excellent the first discharge capacity (151.9 mAh g−1 with 0.1C), good rate performance and its capacity retention rate is 93.1 % after 300 cycles. This study provides a new strategy for the rational design and process method of high-performance CSEs for rechargeable solid lithium metal batteries.

Rechargeable Li/Cl2 Battery Down to -80°C.

Low temperature rechargeable batteries are important to life in cold climates, polar/deep-sea expeditions, and space explorations. Here, this work reports 3.5-4V rechargeable lithium/chlorine (Li/Cl2 ) batteries operating down to -80 °C, employing Li metal negative electrode, a novel carbon dioxide (CO2 ) activated porous carbon (KJCO2 ) as the positive electrode, and a high ionic conductivity (≈5-20 mS cm-1 from -80 °C to room-temperature) electrolyte comprised of aluminum chloride (AlCl3 ), lithium chloride (LiCl), and lithium bis(fluorosulfonyl)imide (LiFSI) in low-melting-point (-104.5 °C) thionyl chloride (SOCl2 ). Between room-temperature and -80 °C, the Li/Cl2 battery delivers up to ≈29100-4500 mAh g-1 first discharge capacity (based on carbon mass) and a 1200-5000 mAh g-1 reversible capacity over up to 130 charge-discharge cycles. Mass spectrometry and X-ray photoelectron spectroscopy probe Cl2 trapped in the porous carbon upon LiCl electro-oxidation during charging. At -80 °C, Cl2 /SCl2 /S2 Cl2 generated by electro-oxidation in the charging step are trapped in porous KJCO2 carbon, allowing for reversible reduction to afford a high discharge voltage plateau near ≈4V with up to ≈1000 mAh g-1 capacity for SCl2 /S2 Cl2 reduction and up to ≈4000 mAh g-1 capacity at ≈3.1V plateau for Cl2 reduction.

ИССЛЕДОВАНИЕ ТВЕРДЫХ ЭЛЕКТРОЛИТОВ НА ОСНОВЕ СМЕСИ ПОЛИМЕРОВ ПОЛИВИНИЛИДЕНФТОРИДА И ГИДРИРОВАННОГО БУТАДИЕН-НИТРИЛЬНОГО КАУЧУКА

The paper discusses the preparation of solid polymer electrolytes based on a blend of polyvinylidene fluoride and hydrogenated butadiene nitrile rubber with lithium bis(trifluorosulfonyl)imide prepared by solution casting technique. The films were characterized by X-ray diffraction analysis, FTIR spectroscopy, scanning electron microscopy, and differential scanning calorimetry. The influence of the polymer blend composition on the ionic conductivity of electrolytes was studied. According to the impedance spectroscopy data, it was found that the ionic conductivity of solid polymer electrolytes increases from 10-5 to 10-4 S/cm at room temperature with increasing the content of hydrogenated butadiene nitrile rubber up to 50 wt. % in the polymer blend matrix.