Electrolytes For Lithium Batteries Research Articles

Ionic Gel Chemical Sensors with Damage Tolerance for Monitoring Lithium‐ion Battery Electrolyte Leakage and Battery Safety

AbstractGiven the frequent occurrence of lithium‐ion battery (LIB) incidents, gas sensors monitoring LIB safety are imperative yet deficient. Here, a new class of LIB electrolyte sensors based on ionic gels is presented, in which ions instead of electrons act as charge carriers and interact with analyte molecules for improved sensitivity. The ionic gels are readily synthesized through the photopolymerization of ionic liquids (ILs) incorporating C═C bonds with structurally analogous ILs devoid of C═C bonds. Through systematic investigation, PF6− is identified as the optimal ion carrier for LIB electrolyte sensing. Trace amounts of LIB electrolyte (20 nL) leakage can be detected within seconds. Interestingly, the devices exhibit decent damage tolerance. More importantly, multiple sensors with decent consistency can be batch‐fabricated on a large scale, which is essential for practical applications. Remarkably, the devices exhibit an extended operational lifespan, endowing them with significant potential for long‐term safety monitoring. The sensors are integrated into a monitoring system and demonstrate exceptional capability in differentiating the various stages of LIB thermal runaway, which paves the way for their potential applications in power storage stations and electric vehicles.

Organic-Inorganic Hybrid Solid Composite Electrolytes for High Energy Density Lithium Batteries: Combining Manufacturability, Conductivity, and Stability.

The deployment of solid and quasi-solid electrolytes in lithium metal batteries is envisioned to push their energy densities to even higher levels, in addition to providing enhanced safety. This article discusses a set of hybrid solid composite electrolytes which combine functional properties with electrode compatibility and manufacturability. Their anodic stability >5V versus Li+/Li and compatibility with lithium metal stem from the incorporated ionic liquid electrolyte, whereas the organic-inorganic hybrid host structure boosts their conductivity up to 2.7mScm-1 at room temperature. The absence of strong acids enables compatibility with porous NMC811 electrodes. Liquid precursor solutions can be readily impregnated into porous electrodes, facilitating cell assembly. Electrolytes containing TFSI- as the only anion have a superior compatibility toward high-voltage positive electrode materials, whereas electrolytes containing both FSI- and TFSI- have a better compatibility toward lithium metal. Using the former as catholyte and the latter as anolyte, NMC811/Li coin cells retain up to 100% of their initial capacity after 100 cycles (0.2C, 3.0-4.4V vs Li+/Li). Because of their unprecedented combination of functional properties, electrode compatibility, and manufacturability, these hybrid solid composite electrolytes are potential candidates for the further development of lithium metal battery technology.

Nanofillers modified with aluminum carboxylate for application in Polymer composite electrolytes for lithium-ion batteries

AbstractOne of the additives that positively influence the parameters of the electrolyte for lithium-ion cells are ceramic nanoparticles, such as SiO2 and α-Al2O3. However, they tend to agglomerate and sediment, which is an unfavorable phenomenon. An effective strategy to prevent this is to modify the surface of the particles with polymeric compounds, which can increase compatibility and stability in the electrolyte system. To reduce agglomeration and sedimentation, a method was developed to modify aluminum oxide and silica particles using aluminum carboxylate, which chemically combines with inorganic particles that have hydroxyl groups on their surface through an alkoxide bond. This method allows the introduction of oligooxyethylene groups to the ceramic surface, thus obtaining more stable systems. The effectiveness of this modification was confirmed through dynamic light scattering (DLS) measurements of particle size in liquid organic solvents, which are potential solvents for liquid electrolytes in lithium-ion cells. The modified nanosilica and aluminum oxide particles were then used as additives to solid polymer electrolytes made of poly(ethylene oxide) (PEO). This led to higher conductivity values compared to the use of unmodified fillers. The obtained values of lithium transference number for solid polymer electrolyte with PEO/CF3SO3Li and nanosilica or aluminum oxide modified with aluminum carboxylate are equal to 0.32–0.40.

Research on the Current Status and Improvement Methods of Electrolytes for Lithium ion Batteries

Owing to their high energy density among other beneficial features, lithium-ion batteries (LIBs) enjoy extensive application across sectors including aerospace engineering, civil transportation, and electronic device manufacturing. Nonetheless, the LIBs electrolyte presents certain drawbacks, which contribute to the diminishing performance of these batteries and pose risks to environmental safety. Considering these issues, the paper begins by presenting the operational principles of LIBs and examining the constituents of the electrolyte and discusses the roles of the individual components. Then, the causes of the problems and proposes improvement strategies are summarized. The working stability of LIBs at extreme temperatures can be improved by a series of measures, such as adding flame retardants and optimizing the composition of electrolytes. The aim of the research is to resolve the current problems with LIBs electrolytes and enhance the applicability and stability of LIBs in various practical situations.

Simultaneous measurement of temperature and refractive index based on fiber optic Fabry–Pérot cavity in batteries

Abstract A Fabry-Pérot (FP) sensor for simultaneous measurement of refractive index and temperature of an all-fiber synchronous liquid based on the Vernier effect is proposed, special application for internal monitoring of lithium-ion battery electrolytes. The theoretical model of high sensitivity cascade Fabry-Pérot interferometer (PFPI) is established, the sensitivity amplification mechanism of PFPI is analyzed in detail, the perfect matching scheme for measuring the refractive index of the electrolyte inside the battery is designed according to the matching conditions of the optical path, and the corresponding sensors for simultaneous measurement of the temperature and the refractive index are fabricated. The experimental results show that the sensor has a maximum refractive index sensitivity of 15391.5033 nm/RIU, a good linear fit, and can effectively monitor the refractive index change of the electrolyte by 10-4 orders of magnitude during normal charging and discharging of lithium-ion batteries. Compared to traditional epoxy adhesive bonded or laser processed FP sensors, this all-fibre optic structure not only improves temperature and corrosion resistance, but also significantly reduces temperature cross-sensitivity. Its small size and excellent resistance to high temperature and corrosion ensure the sensor's excellent response and broad application prospects in monitoring the refractive index of the electrolyte in 18650 lithium-ion batteries, which provides effective technical support for monitoring the health status of batteries and detecting early safety issues.

Research Progress on Solid-State Electrolytes in Solid-State Lithium Batteries: Classification, Ionic Conductive Mechanism, Interfacial Challenges

Solid-state lithium batteries exhibit high-energy density and exceptional safety performance, thereby enabling an extended driving range for electric vehicles in the future. Solid-state electrolytes (SSEs) are the key materials in solid-state batteries that guarantee the safety performance of the battery. This review assesses the research progress on solid-state electrolytes, including polymers, inorganic compounds (oxides, sulfides, halides), and organic–inorganic composites, the challenges related to solid-state batteries in terms of their interfaces, and the status of industrialization research on solid-state electrolytes. For each kind of solid-state electrolytes, details on the preparation, properties, composition, ionic conductivity, ionic migration mechanism, and structure–activity relationship, are collected. For the challenges faced by solid-state batteries, the high interfacial resistance, the side reactions between solid-state electrolytes and electrodes, and interface instability, are mainly discussed. The current industrialization research status of various solid electrolytes is analyzed in regard to relevant enterprises from different countries. Finally, the potential development directions and prospects of high-energy density solid-state batteries are discussed. This review provides a comprehensive reference for SSE researchers and paves the way for innovative advancements in regard to solid-state lithium batteries.

Electroplating of Lithium-metal electrode in different electrolyte for lithium batteries

Electroplating of Lithium-metal electrode in different electrolyte for lithium batteries

A moisture/acid-purified and thermoregulatory separator promises hygroscopic electrolytes in lithium-ion batteries

A moisture/acid-purified and thermoregulatory separator promises hygroscopic electrolytes in lithium-ion batteries

Structural Engineering Developments in Sulfide Solid-State Electrolytes for Lithium and Sodium Solid-State Batteries

Solid-state batteries (SSBs), especially those derived from lithium and sodium, show great promise as the next generation of energy storage devices due to their remarkable energy density, compact electrode architecture, nonflammability, and the use of metallic anodes. The solid-state electrolytes (SSEs), a significant part of SSBs, are essential to their functionality. A family of SSEs known as sulfide-based has been extensively studied for many years as a potential SSE for sodium and lithium SSBs. It offers excellent ionic conductivity, favorable mechanical properties, and ease of manufacturing. Notwithstanding its advantages, it also presents several problems, which require careful consideration for it to be successfully commercialized. This review summarizes the recent advancements in SSEs for lithium and sodium SSBs. It explores how structural engineering strategies impact the electrochemical properties of argyrodites SSEs for lithium SSBs and Na3PS4-based SSEs for sodium SSBs. The review provides comprehensive information on successful structural engineering approaches, such as introducing vacancies, mobile ions stuffing, and doping, for both lithium and sodium SSEs. It also discusses the air stability and electrochemical stability against electrodes, offering insights for designing and synthesizing next-generation SSEs that can lead to more durable and efficient energy storage systems.

Chitosan-based gel polymer electrolytes for high performance Li-ion battery

This study explores the use of glutaraldehyde-crosslinked chitosan-based gel polymer electrolytes (GPEs) in lithium-ion batteries (LIBs). GPEs are prepared by solution casting using two different molecular weights of chitosan including 150 kDa as medium and 400 kDa as high molecular weight (MMWCS and HMWCS, respectively) with varying amounts of crosslinker. Degree of crystallinity was 25.9 and 24.1 % for HMWCS and MMWCS, respectively that was decreased to 18.3 and 22.7 % by using 5 % crosslinker and 17.8 and 21.1 % by using 10 % crosslinker, and 17.2 and 17.6 % by using 20 % crosslinker. The obtained ionic conductivity for HMWCS and MMWCS was 3.1 × 10−3 and 2.9 × 10−3 S.cm−1. After crosslinking by 5, 10, and 20 % crosslinker, the ionic conductivity was obtained to 0.9 × 10−3 and 0.3 × 10−3 S.cm−1, 6.3 × 10−3 and 5 × 10−3 S.cm−1, and 1.1 × 10−3 and 0.5 × 10−3 S.cm−1 for high and medium molecular weight, respectively. Lithium-ion transfer number was obtained between 0.34 and 0.83 and the highest t+ value was obtained for the MMWCS-GA10. Electrochemical stability window of the prepared polymer electrolytes was >5 V and samples showed no remarkable dendrite growth after cycling analyses. The symmetric cells demonstrated reliable performance, operating for over 300 h without any short-circuiting, which indicates excellent reversible cycling stability for chitosan-based lithium-ion batteries. Furthermore, the Gr/GPE cell exhibited very low voltage polarization, with the over-potential decreasing from 10 mV initially to 6 mV after 300 h at the same current density. Discharge capacity was obtained higher than 170 mAh/g at 0.2C with CE = 97 % for both HMWCS-GA20 and HMWCS-GA20.

Outer Helmholtz plane adsorption regulation to achieve low-concentration of pure propylene carbonate solvent electrolytes compatible with graphite anode

The low melting point and high polarity of propylene carbonate (PC) make it an ideal solvent for electrolytes of lithium-ion batteries (LIBs), but the incompatibility with graphite anode hinders the application. In the present study, a new method is developed to solve this problem from a new viewpoint. Introduction of saturated LiNO3 (0.14 mol L‒1) into pure PC electrolyte containing lithium salt with normal concentration (1.38 mol L‒1) leads to a perfect compatibility with graphite anode. Li/Graphite cell using this pure PC electrolyte shows a reversible capacity of 350.0 mAh g‒1 and a 200-cycle capacity retention of 96.3 %. Further mechanism study and theoretical computation indicate that the NO3‒ anions are adsorbed to outer Helmholtz plane of the electric double layer at the graphite anode interface. This changes the Li+ solvation structure in the electric double layer, facilitating the Li+ desolvation process hence resulting in high compatibility with the graphite anode. The most prominent advantage of the present strategy is that, because of the adsorption of NO3‒ anions to the outer Helmholtz plane, the compatibility with graphite anode could be improved by introduction of tiny amount of Li salt without large change of the bulk phase properties of the electrolyte. This work provides a new understanding of the compatibility from the viewpoint of outer Helmholtz plane, which might deliver new insights for the optimization of electrolytes for LIBs.

Role of Anion Flexibility on Graphite Electrode Reactions in Bis(fluorosulfonyl)amide-Based Ionic Liquid Electrolytes for Lithium-Ion Batteries

Role of Anion Flexibility on Graphite Electrode Reactions in Bis(fluorosulfonyl)amide-Based Ionic Liquid Electrolytes for Lithium-Ion Batteries

Advances in inorganic solid electrolytes for lithium-ion batteries

Advances in inorganic solid electrolytes for lithium-ion batteries

Tailored PEO/PEG-PPG Polymer Electrolyte for Solid-State Lithium-Ion Battery

Abstract Solid polymer electrolytes (SPEs) offer a promising avenue for advancing the performance and safety of all-solid-state batteries. In this study, we investigated the effects of blending poly(ethylene oxide) (PEO) with amorphous poly(propylene glycol) (PPG) or poly(ethylene glycol-ran-propylene glycol) (PEG-PPG) to engineer SPEs with enhanced electrochemical properties. By blending PEO with PEG-PPG or PPG, we effectively lowered the crystallinity of PEO, facilitating the diffusion of lithium ions through the SPE and broadening its operational temperature range. This optimization strategy enhanced ionic conductivity and significantly reduced the interfacial resistance between the electrolyte and electrode, thus improving electrochemical stability. The solid-state lithium/lithium iron phosphate (LiFePO4 or LFP) with PEO blended with 7% PEG-PPG showed excellent charge/discharge cycling stability, with maximal discharge capacities of 165 mAh g-1 and 162 mAh g-1 at a current rate of 0.2 C at 60 and 125°C, respectively. The PEG-PPG-based SPE outperformed the PPG polymer-based SPE in terms of better electrochemical performance and a wider temperature range due to its longer polymer chain. This combination offered improved ionic conductivity, interface stability, and electrolyte compatibility with electrodes, making it highly suitable for high-demand applications of lithium-ion batteries.

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.