Electrolytes For Lithium Batteries Research Articles

Phthalocyanine-based solid-state electrolyte for high-capacity and long-life lithium-ion batteries

Phthalocyanine-based solid-state electrolyte for high-capacity and long-life lithium-ion batteries

A Computational Review on Localized High‐Concentration Electrolytes in Lithium Batteries

AbstractElectrolyte engineering plays a vital role in improving the battery performance of lithium batteries. The idea of localized high‐concentration electrolytes that are derived by adding “diluent” in high‐concentration electrolytes has been proposed to retain the merits and alleviate the disadvantages of high‐concentration electrolytes, and it has become the focus of attention in high‐voltage lithium batteries, flame‐retardant lithium batteries, and low‐temperature lithium batteries. Extensive efforts have been made to elucidate the fundamentals of localized high‐concentration electrolytes. This review provides an overview of state‐of‐the‐art computational progress in the studies of localized high‐concentration electrolytes, focusing on the application of computational techniques to analyze the redox stability, solvation structures, and interface characteristics of lithium batteries with localized high‐concentration electrolytes. Integrated with experimental approaches, complementing each other, computational methods are believed to be conducive to understanding the working mechanism and designing localized high‐concentration electrolytes for better lithium batteries in the future.

Recent research progress on Li29Zr9Nb3O40-based solid electrolytes for lithium batteries

All-solid-state batteries have become a research hotspot because of their high specific capacity and safety. Solid-state electrolytes are the key material of all-solid-state lithium-ion batteries, and their properties directly affect the overall performance of lithium-ion batteries. So far, many inorganic solid electrolytes have been reported, such as NASICON, LISICON, perovskite, and garnet-type solid electrolyte. However, some lithium-rich rock salt-structured electrolytes, such as Li2ZrO3, LiNbO4, and Li6Zr2O7, have been underappreciated in the field of solid-state electrolytes due to their lower ionic conductivity at room temperature. While investigating solid solution formation, Li6Zr[Formula: see text][Formula: see text]Nb[Formula: see text]O[Formula: see text][Formula: see text][Formula: see text], a new phase known as Li[Formula: see text]Zr9Nb3O[Formula: see text] with a rock-salt structure was discovered. After decades, it was not until a team prepared Li[Formula: see text]Zr9Nb3O[Formula: see text] ceramics by sol-gel method, which exhibited high ionic conductivity (10[Formula: see text]–10[Formula: see text]S cm[Formula: see text]) at room temperature, that the substance showed great potential as a solid electrolyte in all-solid-state lithium-ion batteries. In this paper, the crystal structure, lithium-ion transport mechanism, preparation method, and element doping of Li[Formula: see text]Zr9Nb3O[Formula: see text] are described comprehensively based on research progress in recent years. Then, development prospects and challenges of the concrete application of Li[Formula: see text]Zr9Nb3O[Formula: see text]in all-solid-state lithium-ion batteries are also discussed.

Effect of SiO2 on the Performance of Cellulose/Poly(Vinylidene Fluoride) Films as Polymer Electrolytes for Lithium Ion Battery

AbstractPolymer electrolytes serve as highly efficient alternatives to liquid electrolytes, especially in terms of safety in lithium ion batteries. Among various polymers, Cellulose contains electron‐donating atoms which can coordinate with lithium salts and be used as polymer electrolyte. Also, cellulose can be blended with other polymers to improve their properties. Polymer electrolytes suffer from poor mechanical properties. Adding nanoparticles not only surmounts the drawback of poor mechanical properties but also improves physical and electrochemical properties. In this study, different weight ratios of PVDF/cellulose blend films containing silicon dioxide (SiO2) are prepared via solution casting method. The results explored ionic conductivity in order of 10−4 S cm−1. In addition, high transfer numbers (0.74<t+<0.98), wide electrochemical window (up to 6 V), acceptable charge capacity, and long cycle stability are attained. In details, for 90/10 (wt./wt.) cellulose/PVDF, the ionic conductivity reached 4.4×10−⁴ S cm−1, and the ion transfer number was obtained 0.98. Additionally, the electrochemical stability window for these gel polymer electrolytes exceeded 5 V. The sample containing 90 % cellulose achieved an optimal charge capacity of 225.3, with 93.4 % capacity retention after 200 cycles at 0.2 C.

Development of the electrolyte in lithium-ion battery: a concise review on its thermal hazards

Development of the electrolyte in lithium-ion battery: a concise review on its thermal hazards

DNA: Novel Crystallization Regulator for Solid Polymer Electrolytes in High-Performance Lithium-Ion Batteries.

In this work, we designed a novel polyvinylidene fluoride (PVDF)@DNA solid polymer electrolyte, wherein DNA, as a plasticizer-like additive, reduced the crystallinity of the solid polymer electrolyte and improved its ionic conductivity. At the same time, due to its Lewis acid effect, DNA promotes the dissociation of lithium salts when interacting with lithium salt anions and can also fix the anions, creating more free lithium ions in the electrolyte and thus improving its ionic conductivity. However, owing to hydrogen bonding between DNA and PVDF, excess DNA occupies the lone pairs of electrons of the fluorine atoms on the PVDF molecular chains, affecting the conduction of lithium ions and the conductivity of the solid electrolyte. Hence, in this study, we investigated the effects of adding different DNA amounts to solid polymer electrolytes. The results show that 1% DNA addition resulted in the best improvement in the electrochemical performance of the electrolyte, demonstrating a high ionic conductivity of 3.74 × 10-5 S/cm (25 °C). The initial capacity reached 120 mAh/g; moreover, after 500 cycles, the all-solid-state batteries exhibited a capacity retention of approximately 71%, showing an outstanding cycling performance.

Recyclable cellulose-based vitrimer electrolytes for lithium ion batteries

Cellulose as polymer electrolytes in lithium-ion batteries (LIBs) has a number of advantages such as low cost, readily available, abundant, environmentally friendly, and contains electron-donating groups within its structure. Beside, vitrimers are a novel class of polymer materials made of dynamic covalent networks that can undergo bond-exchange processes. Beyond cellulose's special qualities, cellulose-based vitrimer production is highly desired for enhancing electrolytes mechanical qualities, thermal stability, cyclability, and ionic conductivity. In this study, cellulose-based vitrimeric polymer electrolytes are prepared. At first, poly(glycidyl methacrylate-co-methyl acrylate) by different ratios of comonomers is prepared and then cellulose is cross-linked by prepared copolymers. Prepared vitrimers are recycled four steps through transesterification reaction and as-prepared and recycled crosslinked celluloses are used as gel polymer electrolytes (GPEs). The results showed the best ionic conductivity of as-prepared samples in order of 10−4 S/cm whereas ionic conductivity increased to order of 10−3 S/cm for recycled samples. Also, high lithium-ion transfer number of >0.8 was achieved for recycled samples. All as-prepared and recycled electrolytes had excellent electrochemical stability window (> 5 V). Also, improved specific capacity (>178 mA h g−1 with capacity retention upper than 90 % after 200 cycles at 0.2C of LiCoO2/GPEs/Gr) was attained.

Lithium ion transportation in lignin infused polyvinyl alcohol based eutectogel: A molecular dynamics framework

Eutectogels are an arising material in the field of energy storage applications like high-energy Lithium-Ion batteries (LIBs) due to their properties like higher ionic conductivity, environment friendly and enhanced safety. However, it is important to understand the working mechanism of eutectogels at an atomistic level with the help of Molecular Dynamics (MD) simulations, in order to enhance their performance as electrolytes for LIBs. Eutectogels are formed by integrating deep eutectic solvent (DES) involving Lithium Chloride (LiCl) and ethylene glycol (EG) in the molar ratio of 1:5 with the polymeric matrix of Polyvinyl alcohol (PVA) chains considered for this study. Thereafter, lignin molecules are induced in the eutectogel system to improve the characteristics of an eutectogel. The elaborate study of the effect of lignin on the lithium ions movement through the lignin-added-eutectogel is involved in this work. The increase in hydrogen bonds among PVA polymeric chains and lignin molecules show the strength enhancement. From the Radial Distribution Function results it is derived that the lithium ions are showing enhanced interactions with chlorine ions than any other component of the system. Mean Square Displacement gives an idea about diffusivity of lithium ions through the systems and it suggests that the Li+ ion diffusivity is improved after Lignin imposition. On the basis of findings from this work, the modified Lignin infused PVA based eutectogel can be the potential candidate for the battery and energy storage applications.

Understanding Li6.24La3Zr2Al0.24O11.98 effect on poly(ionic liquid)-based electrolytes for high voltage solid-state lithium batteries working at room temperature

Hybrid electrolytes composed of poly(ionic liquid), ionic liquids (ILs), and fillers are very promising candidates for solid-state lithium metal batteries (SSLMBs). However, a significant knowledge gap in the field of hybrid electrolytes lies in the understanding of filler effect on properties and performance. Herein, we have investigated hybrid electrolytes based on poly(diallyldimethylammonium) bis(fluorosulfonyl)imide (PDDA-FSI), N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR13FSI), lithium bis(fluorosulfonyl)imide (LiFSI) and different loadings (from 0 to 19.2 vol%) of Li6.24La3Zr2Al0.24O11.98 (Al-LLZO) particles. All the electrolytes present a homogeneous morphology and excellent thermal stability. Moreover, our results demonstrate that Al-LLZO particles do not contribute to the ionic conductivity of the hybrid electrolytes. A 2.6 vol% of Al-LLZO led to the excellent performance in full cells at room temperature. Surprisingly, the battery performance was not correlated with the transport properties. Instead, this study found out a mechanical-performance relationship, which follows a master equation: t = A (−12.48 (1-e(1.53x10-4σy))) / P that enables to correlate the effect Al-LLZO particles on the cell performance, and predicts, for the first time, the lifetime of the battery through the mechanical properties.

Recent Advances in Poly(ethylene oxide)-Based Solid-State Electrolytes for Lithium-Ion Batteries

Recent Advances in Poly(ethylene oxide)-Based Solid-State Electrolytes for Lithium-Ion Batteries

Ethyl Isopropyl Sulfone Modulating to Achieve Stable High-Voltage Electrolyte for Lithium-Ion Batteries.

The demand for efficient large-scale energy storage necessitates high-energy-density batteries, making research on high-voltage electrolytes particularly important. In this article, ethyl isopropyl sulfone (ES), which has a high dielectric constant, is added to traditional carbonate-based electrolyte solvents and analyzed. Based on calculated and analyzed results, different proportions of ES are added to the conventional carbonate-based electrolyte. The high-voltage performance, the influence on the surface of the electrode, the active material structure after cycling, the electrochemical behavior, and the impedance of the electrode were studied systematically. As a result, ES addition is applied in high-voltage lithium-ion batteries and exhibits excellent electrochemical properties. These results will provide support for the research and application of sulfone additives in increasing the decomposition voltage of lithium-ion battery electrolytes and improving battery cycle stability.

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.

A rapid pressureless sintering strategy for LLZTO ceramic solid electrolyte sheets prepared by tape casting

Garnet-type electrolytes are regarded as one of the most promising solid-state electrolytes (SSEs) for lithium-ion batteries due to their potential advantages in terms of energy density, electrochemical stability and safety. To achieve the maximum energy density, it is necessary to ensure that the electrolyte layer is as thin as possible. Nevertheless, thin sheet SSE is more challenging to sinter than pellet due to the greater lithium volatilization from the high surface/volume ratio. Garnet-type SSE (Li6.5La3Zr1.5Ta0.5O12, LLZTO) green tape was prepared by the tape-casting technique. The effects of supporter, sintering temperature and dwell time on the relative density, microstructure and ionic conductivity of thin sheet were investigated. A ceramic SSE sheet with a thickness of 173 μm, a relative density of 97.2 %, an ionic conductivity of 2.02 × 10−4 S/cm at 25 °C and an activation energy of 0.25 eV, was achieved using a rapid pressureless sintering at 1250 °C for 25 min with a MgO supporter. This work offers insights into the practical production of LLZTO sheets.

FFF/FDM 3D-Printed Solid Polymer Electrolytes Based on Acrylonitrile Copolymers for Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) are essential in modern electronics, particularly in portable devices and electric vehicles. However, the limited design flexibility of current battery shapes constrains the development of custom-sized power sources for advanced applications like wearable electronics and medical devices. Additive manufacturing (AM), specifically Fused Filament Fabrication (FFF), presents a promising solution by enabling the creation of batteries with customized shapes. This study explores the use of novel poly(acrylonitrile-co-polyethylene glycol methyl ether acrylate) (poly(AN-co-PEGMEA)) copolymers as solid polymer electrolytes for lithium-ion batteries, optimized for 3D printing using FFF. The copolymers were synthesized with varying AN:PEGMEA ratios, and their physical, thermal, and electrochemical properties were systematically characterized. The study found that a poly(AN-co-PEGMEA) 6:1 copolymer ratio offers an optimal balance between printability and ionic conductivity. The successful extrusion of filaments and subsequent 3D printing of complex shapes demonstrate the potential of these materials for next-generation battery designs. The addition of succinonitrile (SCN) as a plasticizer significantly improved ionic conductivity and lithium cation transference numbers, making these copolymers viable for practical applications. This work highlights the potential of combining polymer chemistry with additive manufacturing to provide new opportunities in lithium-ion battery design and function.

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.

Electrolytes from Alkoxyalkyl-substituted Imidazolium ionic liquids. Synthesis, characterization, properties and cell performance in LiFePO4 half-cells

Electrolytes based on lithium bis(trifluoromethane)sulfonimide (LiTFSI) salt and alkoxyalkyl-substituted imidazolium ionic liquids (ILs) have been studied. We have synthesized three different 1-alkoxyalkyl-3-methylimidazolium TFSI salts with different chain lengths (from 4 to 10 atoms) and with one to three oxygen atoms at position 1- of the imidazole ring. Both the neat ILs as well as the cognate lithium doped electrolytes have been structurally and physicochemically characterized and electrochemically evaluated.Thermal analyses indicate that the glass transition temperature of the electrolytes is displaced to higher temperatures than those of the corresponding neat ILs, being also higher (more positive) upon increasing the number of oxyethylene units. On the other hand, all 1 M LiTFSI doped synthesized electrolytes are thermally stable up to 300 °C.Raman spectroscopy results indicate that the fraction of TFSI anions coordinated to lithium ion decreases on increasing the number of alkoxy units. This finding implies that there is more “free” lithium ion available to link to the ethereal oxygen of the side chain of the imidazolium ring system. This fact influences the ionic conductivity of the neat ILs and their cognate electrolytes.The electrochemical properties —namely high room temperature conductivities as well as wide electrochemical stability windows— indicate that these materials are promising electrolytes for lithium-ion batteries (LIBs). Lithium half-cells using LiFePO4 (LFP) olivine have been assembled in order to assess the electrochemical performance by means of both cyclic voltammetry and galvanostatic charge/discharge tests. Overall, we have found that the electrochemical performance of these cells is better than that reported 1 M LiTFSI [Pyr14][TFSI], a common electrolyte in LIBs. The generated half-cell from the 1-alkoxyalkyl-3-methylimidazolium TFSI salts possess a high capacity up to 145 mAh∙g−1 at a current of 2C.The results reported herein show a striking relationship between structure and properties.

In Situ Fabrication of Solvent-Free Solid Polymer Electrolytes for Wide-Temperature All-Solid-State Lithium Metal Batteries.

All-solid-state lithium metal batteries (ASSLMBs) have been regarded as promising candidates to settle the safety issues of liquid electrolytes for rechargeable lithium batteries. However, the currently reported gel polymer electrolytes still have flammable liquid solvents, thus leading to the potential safety hazard. Here, solvent-free deep eutectic solid polymer electrolytes (SPEs) are designed and fabricated via an in situ polymerization, which are composed of a poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) electrospun membrane, succinonitrile (SN), poly(ethylene glycol) diacrylate (PEGDA200, Mn = 200 g mol-1), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and lithium difluoro(oxalato)borate (LiDFOB). The deep eutectic solvent (DES) with SN/LiTFSI provides a superior room-temperature ionic conductivity, while the PEGDA200 precursor acts as cross-linking network to form SPEs under thermal initiation for free radical polymerization, and LiDFOB can form a stable solid electrolyte interface (SEI) layer. The PVDF-HFP electrospun membrane with a three-dimensional nanofibrous network structure for SN/PEGDA200/LiTFSI/LiDFOB SPEs exhibits a wide electrochemical stability window, high lithium-ion transference number, and good compatibility with the lithium metal anode. Furthermore, the obtained SPEs assembled with Li//LiMn0.6Fe0.4PO4, Li//LiFePO4, and Li//LiNi0.8Co0.1Mn0.1O2 asymmetric cells show excellent cycling performance and rate capability at a wide temperature. This strategy provides a promising path in designing high-energy-density ASSLMBs for practical application.

Rational design of the temperature-responsive nonflammable electrolyte for safe lithium-ion batteries

The development of nonflammable electrolytes is critical for breaking the trade-off between the safety and energy density in Li-ion batteries (LIBs). Here, a rational design strategy of temperature-responsive nonflammable electrolytes (TRNEs) is proposed which are capable to prevent the heat accumulation and extinguish the fire efficiently during thermal runaway. Compared to the conventional phosphate- or halogen-based flame retardants, the TRNE based on low-cost and multifunctional methylurea (MU) was demonstrated with the lowest volatility (11.6 % weight loss) below 250 °C, and the highest efficacy to extinguish the fire at >210.4 °C through heat absorption, inert gases generation and char layer formation. In addition, the developed MU-based TRNEs enable higher stability and rate capability of LIBs compared to various nonflammable electrolytes. A Li||LiFePO4 (LFP) cell employing MU-based TRNE achieved higher stability (94.9 % capacity retention for 1500 cycles) than commercial electrolyte. A Ni-rich Li||LiNi0.8Mn0.1Co0.1O2 (NMC811) system was demonstrated with superior rate capability and high stability for 700 cycles (2.72 months) with the capacity retention of 89.9 %. Combining low cost and volatility, as well as high stability, rate capability and fire extinguishing efficacy, we demonstrate a promising design strategy to improve the battery safety for high-energy-density LIBs.

Ethylene Carbonate-Free Electrolytes for High Voltage Lithium-Ion Batteries: Progress and Perspectives

Ethylene Carbonate-Free Electrolytes for High Voltage Lithium-Ion Batteries: Progress and Perspectives

The research progress on COF solid-state electrolytes for lithium batteries.

Lithium metal batteries have garnered significant attention due to their high energy density and broad application prospects. However, the practical use of traditional liquid electrolytes is constrained by safety and stability challenges. In the exploration of novel electrolytes, solid-state electrolyte materials have emerged as a focal point. Covalent organic frameworks (COFs), with their large conjugated structures and unique electronic properties, are gradually gaining attention as an emerging class of solid-state electrolyte materials. In recent years, outstanding electrochemical performance has been achieved through the design and synthesis of various types of COF-based solid-state electrolytes, along with successful integration with other functional materials. This review will provide an overview of the research progress on COFs as solid-state electrolyte materials for lithium metal batteries and offer insights into their future potential in battery technology.