Lithium Ion Conductivity Research Articles

Screening of Lithium Ionic Conductors in Reference to the Formation of Interface with Lithium Anode

Screening of Lithium Ionic Conductors in Reference to the Formation of Interface with Lithium Anode

Lithium ionic conductivity and structural studies of NASICON structured Li0.4Sr0.3Zr0.5Ti1.5(PO4)3

Stable solid electrolytes have been the subject of intense research due to the growing demand for energy storage and portable energy sources in rechargeable Li-ion batteries. Sodium (NA) super (S) ionic (I) conductor (CON) abbreviated as NASICON are suitable for use as solid electrolytes due to their excellent ionic conductivity and chemical stability. We have reported the effect of partial doping of Sr at Li and Zr4+ at Ti4+ position on the structure and ionic conductivity of composition Li0.4Sr0.3Ti2(PO4)3 (LSTP). The composition with formula Li0.4Sr0.3Ti2−xZrx(PO4)3 (x = 0.0, 0.5, 2.0) were prepared by solid state reaction method. The phase and crystal structure were examined using X-ray diffraction (XRD) patterns. The compositions were in rhombohedral phase with the space group R 3¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline{3}$$\\end{document} c. The doping of Zr4+ in LSTP causes the peaks in the XRD spectra for doped composition (x = 0.5, 2.0) to move towards lower angle. The displacement of the XRD peaks towards lower angle side show the expansion in the lattice of the Zr doped compositions Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 and Li0.4Sr0.3Zr2(PO4)3. The presence of stretching and bending modes of PO4 groups in the prepared compositions was identified by FTIR spectra. The enhanced bulk conductivity of 4.32 × 10–5 S/cm for Zr doped composition Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 and 3.20 × 10–5 S/cm for composition Li0.4Sr0.3Zr2(PO4)3 is observed at 25 °C. The modulus peaks in the Zr doped composition Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 is displaced towards higher frequencies at 450 °C, indicating the presence of the thermally produced dielectric relaxation phenomenon and charge carrier hopping. The cole cole plot consisting of one semicircle in case of Li0.4Sr0.3Ti1.5Zr0.5(PO4)3 discusses the contribution of bulk and grain boundary resistances and is fitted by equivalent circuit consisting of CPE and R element joined in parallel.

Exploiting the Mixed Entropy Strategy for the Design of Fast Ion Conductors

AbstractThe inorganic solid‐state electrolytes play a crucial role in all‐solid‐state batteries. The entropy of solid‐state electrolytes has a significant impact on ion transport. It has been reported that ionic conductivity can be enhanced by increasing the entropy by adding multiple atoms to the materials. However, there is a lack of understanding regarding the potential mechanism between entropy and ion transport in the atomic‐level microstructure of materials. Herein, a new point of view is brought up to understand the influence of entropy on lithium ionic conductivity at an atomic level only by adding one element at a time inspired by the diagonal relationship. A series of materials is designed, including Li1.75Zr0.75Ta0.25Cl6, Li1.75Zr0.75Nb0.25Cl6, Li1.75Zr0.75Mo0.25Cl6, and Li1.75Zr0.75W0.25Cl6, with various mixed entropy, directed by diagonal relationship. It reveals that the substitution increases the mixed entropy, alters the disorder degree of cations around lithium ions, and improves ionic conductivity. Highlighting the importance of mixed entropy in ion migration and establishing the close connection between mixed entropy and ion conduction could provide new insights into the design and development of solid‐state electrolytes.

Exploring high-valence element doping in LLZO electrolytes: Effects on phase transition and lithium-ion conductivity

The increasing popularity of electric vehicles and the emergence of 5G technology have created a demand for high-energy-density and safe batteries. Among various solid-state electrolytes, crystalline Li7La3Zr2O12 (c-LLZO) has garnered significant attention due to its exceptional properties. Researchers have explored doping in LLZO to modulate its phase transition and enhance lithium-ion conductivity. However, the mechanism by which doping induces a phase change and affects lithium-ion conductivity is currently unclear. In this study, we investigated LLZO doping and discovered that high-valence-element doping introduces vacancies, destabilizing the tetragonal phase and promoting the formation of the stable cubic phase. Moreover, we found that the introduction of lithium-ion vacancies significantly enhances lithium-ion conductivity. Nevertheless, doping also has adverse effects. Ga and Al dopants occupy the crucial Li24d sites, impeding lithium-ion diffusion and resulting in the closure of diffusion channels. Additionally, doping reduces the effective vacancy concentration within the structure, further restricting lithium-ion conductivity. In summary, our work elucidates the mechanism behind the influence of dopants on lithium-ion diffusion in LLZO.

Cetyltrimethylammonium bromide induced generation of highly (200) planes-exposed LiMnPO4 nanosheets coated by nitrogen-doped carbon for high-performance batteries

A simple solvothermal method is designed to synthesize LiMnPO4/N-doped C composites with core-shell structure using cetyltrimethylammonium bromide (CTAB) as surfactant and nitrogen source. The effectively growth of (200) planes and nitrogen-doped carbon layer coated LiMnPO4 nanosheets are obtained. The doped nitrogen induces the generation of active defect sites, which changes the cell electronic layer structure, and improve the electronic conductivity and diffusion rate of lithium ions. Thus, the electrochemical performance is beneficial from the synergistic effect of specific planar exposure and particular interfacial modifications. The optimal sample shows the supreme electrochemical performance at 0.1C, 1C and 5C with capacities of 159.1, 122.6 and 83.1 mAh g−1, respectively. The capacity retention can achieve 98 % even after 200 cycles at 1C. This work provides a simple but effective strategy to design polyanion cathode materials with enhanced electrochemical performance.

Solid-state electrolytes: a way to increase the power of lithium-ion batteries

Currently, all-solid-state lithium metal batteries are considered among the most promising energy storage devices, due to their safety and high energy density. Solid-state electrolytes, the key components of the batteries, are attracting increasing attention. This review presents an analysis of important recent advances in the field of lithium conducting solid-state electrolytes, including the mechanisms of conductivity, the main approaches to increase the conductivity, optimization of interfaces and ways to improve the stability for the main types of electrolytes, <i>i.e.</i>, inorganic, polymer and composite materials. For solid inorganic electrolytes, high conductivity and stability have been achieved; however, the problems related the formation of dense thin films and formation of a reliable contact with electrode materials are still unsolved. Polymer electrolytes are characterized by lower conductivity, which is improved upon plasticization with aprotic solvents. Composite electrolytes, for which it is possible to achieve a combination of high conductivity and good mechanical properties along with stability, are considered as the most promising. The main problems in the field of solid electrolytes for all-solid-state lithium metal batteries and possible ways to solve them are outlined.<Br>The bibliography includes 661 references.<Br> Key words: solid-state lithium battery, inorganic electrolyte, polymer electrolyte, composite electrolyte, ionic conductivity, lithium conductivity, transference numbers

Discovering virtual antiperovskites as solid-state electrolytes through active learning

In surveying an extensive library of 18,133 hypothetical antiperovskites (X3BA), we address the challenges posed by conventional experimental and computational screening methods. We introduce a novel computational approach, leveraging an active learning framework that synergistically integrates genetic algorithms with Bayesian optimization. This method efficiently discerns thermodynamically stable antiperovskites, narrowing down the vast initial set to 43 compounds characterized by minimal energy above the hull (Eh<150 meV/atom). Subsequent evaluations of their band structure (Eg), electrochemical stability window (Vw), and room-temperature lithium ion conductivity (σRT), alongside the construction of a 4-dimensional Pareto frontier for Eh, Eg, Vw, and σRT, refined this list to 22 promising candidates, seven of which exhibit outstanding room-temperature ionic conductivity (>4 mS cm−1), marking them as potential candidates. Our methodology not only expedites the identification of superior antiperovskites but also establishes a groundbreaking paradigm for computational exploration in materials science.

Boosting lithium-ion conductivity of polymer electrolyte by selective introduction of covalent organic frameworks for safe lithium metal batteries

The demand for high-energy-density batteries has prompted exploration into advanced materials for enhancing the safety and performance of lithium metal batteries (LMBs). This study introduces a novel approach, incorporating two-dimensional (2D) pyrazine and imine-linked covalent organic frameworks (COFs) into a polyethylene oxide (PEO)-based solid electrolyte matrix. The synthesized COFs act as multifunctional additives, improving mechanical strength, ionic conductivity (reaching 1.86 ×10−3 S/cm at room temperature), electrochemical window (oxidation resistance up to 5 V vs. Li/Li+), and thermal stability (up to 400 °C). The unique electron-rich and polar functionalities of pyrazine and imine linkages facilitate strong interactions with lithium ions (Li+), resulting in a flexible composite solid electrolyte that mitigates dendrite formation and interface instability. Electrochemical performance of LMBs with LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode further confirm the enhanced Li+ conductivity, prolonged cycling stability, and a stable solid electrolyte interface, showcasing the potential of COFs in improving LMB performance. Overall, this study highlights the promising role of pyrazine and imine-linked COFs as effective additives for polymer-based solid electrolytes and their potential for developing safer and more efficient LMBs in the future.

Halloysite nanotubes enhanced polyimide/oxidized-lignin nanofiber separators for long-cycling lithium metal batteries

The high energy density and robust cycle properties of lithium-ion batteries contribute to their extensive range of applications. Polyolefin separators are often used for the purpose of storing electrolytes, hence ensuring the efficient internal ion transport. Nevertheless, the electrochemical performance of lithium-ion batteries is constrained by its limited interaction with electrolytes and poor capacity for cation transport. This work presents the preparation of a new bio-based nanofiber separator by combining oxidized lignin (OL) and halloysite nanotubes (HNTs) with polyimide (PI) using an electrospinning technique. Analysis was conducted to examine and compare the structure, morphology, thermal characteristics, and EIS of the separator with those of commercially available polypropylene separator (PP). The results indicate that the PI@OL and PI-OL@ 10 % HNTs separators exhibit higher lithium ion transference number and ionic conductivity. Moreover, the use of HNTs successfully impeded the proliferation of lithium dendrites, hence exerting a beneficial impact on both the cycle performance and multiplier performance of the battery. Consequently, after undergoing 300 iterations, the battery capacity of LiFePO4|PI-OL@ 10 % HNTs|Li stays at 92.1 %, surpassing that of PP (86.8 %) and PI@OL (89.6 %). These findings indicate that this new bio-based battery separator (PI-OL@HNTs) has the great potential to serve as a substitute for the commonly used PP separator in lithium metal batteries.

Fast lithium-ion conductor LiTi2(PO4)3 coating modified LiNi0.8Co0.15Al0.05O2 as cathode material for lithium-ion batteries

Fast lithium-ion conductor LiTi2(PO4)3 coating modified LiNi0.8Co0.15Al0.05O2 as cathode material for lithium-ion batteries

Development of low-viscosity phosphonium-based ionic liquid electrolytes for lithium-ion batteries: Charge–discharge performance and ionic transport properties

Phosphonium cation-based ionic liquids (phosphonium ILs) have several advantages for electrochemical device applications compared with ammonium cation-based ionic liquids because of their unique features, such as higher ionic conductivity and a larger electrochemical potential window. In this study, we prepared various phosphonium ILs with different substituents (alkyl, alkyl ether, or allyl) on the cation, and bis(fluorosulfonyl)amide (FSA) or bis(trifluoromethanesulfonyl)amide (TFSA) as the anion. This study describes these phosphonium ILs used as electrolytes for lithium-ion batteries and investigates their performance as typical Li/LiCoO2 cells. We demonstrate that discharge capacity increases with increasing lithium-ion conductivity determined by electrochemical impedance and pulsed-field gradient nuclear magnetic resonance. A discharging rate test conducted in constant current (CC) mode also displays good high conductivity phosphonium IL electrolyte performance. Furthermore, the difference in cycle performance between FSA-based and TFSA-based phosphonium IL electrolytes is explained in terms of solid electrolyte interphase formation, similar to the performance of other cation-based ILs.

Influence of Microwave Sintering and Pellet Pressure on the Phase Formation, Microstructure and Lithium-Ion Conductivity of the Li6.28Al0.24La3Zr2O12 Solid Electrolyte

Influence of Microwave Sintering and Pellet Pressure on the Phase Formation, Microstructure and Lithium-Ion Conductivity of the Li6.28Al0.24La3Zr2O12 Solid Electrolyte

Influence of Screw Design and Process Parameters on the Product Quality of PEO:LiTFSI Solid Electrolytes Using Solvent-Free Melt Extrusion

All-solid-state battery (ASSB) technology is a new energy system that reduces the safety concerns and improves the battery performance of conventional lithium-ion batteries (LIB). The increasing demand for such new energy systems makes the transition from laboratory scale production of ASSB components to larger scale essential. Therefore, this study investigates the dry extrusion of poly(ethylene oxide):lithium bis (trifluoromethylsulfonyl)imide (PEO:LiTFSI) all-solid-state electrolytes at a ratio of 20:1 (EO:Li). We investigated the influence of different extruder setups on the product quality. For this purpose, different screw designs consisting of conveying, kneading and mixing elements are evaluated. To do so, a completely dry and solvent-free production of PEO:LiTFSI electrolytes using a co-rotating, intermeshing, twin-screw extruder under an inert condition was successfully carried out. The experiments showed that the screw design consisting of kneading elements gives the best results in terms of process stability and homogeneous mixing of the electrolyte components. Electrochemical impedance spectroscopy was used to determine the lithium-ion conductivity. All electrolytes produced had an ionic conductivity (σionic) of (1.1–1.8) × 10−4 S cm−1 at 80 °C.

High-throughput investigation of stability and Li diffusion of doped solid electrolytes via neural network potential without configurational knowledge

Solid electrolytes hold substantial promise as vital components of all-solid-state batteries. Enhancing their performance necessitates simultaneous improvements in their stability and lithium conductivity. These properties can be calculated using first-principles simulations, provided that the crystal structure of the material and the diffusion pathway through the material are known. However, solid electrolytes typically incorporate dopants to enhance their properties, necessitating the optimization of the dopant configuration for the simulations. Yet, performing such calculations via the first-principles approach is so costly that existing approaches usually rely on predetermined dopant configurations informed by existing knowledge or are limited to systems doped with only a few atoms. The proposed method enables the optimization of the dopant configuration with the support of neural network potential (NNP). Our approach entails the use of molecular dynamics to analyze the diffusion after the optimization of the dopant configuration. The application of our approach to Li10\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{10}}$$\\end{document}MP2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{2}}$$\\end{document}S12-x\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{12-x}}$$\\end{document}Ox\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${_{x}}$$\\end{document} (M = Ge, Si, or Sn) reproduce the experimental results well. Furthermore, analysis of the lithium diffusion pathways suggests that the activation energy of diffusion undergoes a percolation transition. This study demonstrates the effectiveness of NNPs in the systematic exploration of solid electrolytes.

Effects of Nd and Al co-doping on the microstructure and lithium-ion transport in Li7La3Zr2O12 solid-state batteries

In this study, we synthesized co-doped Li6.25Al0.25La3-yNdyZr2O12 (LALNZO) solid-state electrolytes with varying Nd contents to investigate the influence Nd plays on phase evolution, microstructure, and lithium-ion conductivity. It was found that incorporating Nd ions into the lattice reduced bulk resistance by controlling Li+ concentration. However, X-ray diffraction analysis revealed that excessive Nd content led to the formation of Nd2O3, which negatively impacted ion transport and increased grain boundary resistance. It is noteworthy that the LALNZO (y = 0.2) ceramic exhibited outstanding performance, with 94% relative density, and ionic conductivity of 4.7 × 10−4 S/cm. The activation energy was 0.32 eV. Further, Li6.25Al0.25La2.8Nd0.2Zr2O12 was able to demonstrate a stable capacity of 103 mA.h. g−1 after 50 cycles at a current density of 0.1C when used as an electrolyte in lithium-ion batteries. The findings of this study provide valuable insights for developing advanced solid-state electrolytes for lithium-ion batteries.

High Performance Lithium Ion-Conducting Plasticized Biopolymer Electrolyte for Supercapacitor Application

High Performance Lithium Ion-Conducting Plasticized Biopolymer Electrolyte for Supercapacitor Application

Enhancing ionic conductivity and controlling lithium dendrite growth via ferroelectric ceramic Bi4Ti3O12

BackgroundSolid polymer electrolytes (SPEs) have gained numerous research interest in the field of lithium metal batteries. Solid polymer electrolytes have improved safety compared to liquid electrolytes. Despite this, their low ionic conductivity remains a major barrier to practical applications. To overcome the challenge of low ionic conductivity in SPEs, our study introduces a novel approach that integrates ferroelectric ceramics with polymer solid electrolytes. MethodsWe used a one-step molten salt method to synthesize Bi4Ti3O12 (BIT), combined with a poly (vinylidene difluoride) matrix to form the composite solid-state electrolyte. Through various electrochemical characterizations and COMSOL Multiphysics simulations, we discovered that the ferroelectric properties of BIT significantly increase the dissociation of lithium salts, leading to a greater concentration of mobile lithium ions and more efficient ion transport. Significant findingsThis electrolyte showed a remarkable improvement in lithium-ion conductivity, reaching a value of 8.5 × 10−4 S cm−1 at room temperature. Batteries made with these composite electrolytes demonstrate superior cycling stability, the capacity retention rates for LFP/SPEs/Li cells remain high, reaching 95 % even after 1,000 cycles at room temperature (25 °C). These findings highlight the promising applications of ferroelectric ceramics in solid-state batteries.

Understanding Lithium-Ion Conductivity in NASICON-Type Polymer-in-Ceramic Composite Electrolytes

Understanding Lithium-Ion Conductivity in NASICON-Type Polymer-in-Ceramic Composite Electrolytes

Boosting the Ionic Conductivity of Pyrrolidinium-Based Ionic Plastic Crystals by LLZO Fillers.

Organic ionic plastic crystals (OIPCs) have attracted attention as novel organic solid electrolyte materials, but their insufficient mechanical strength and ionic conductivity have prevented their application. In this study, a lithium salt, lithium bis(fluorosulfonyl)amide (LiFSA), and an inorganic solid electrolyte, Li7La3Zr2O12 (LLZO), were added to an OIPC, N,N-diethylpyrrolidinium bis(fluorosulfonyl)amide ([C2epyr][FSA]). The fabricated organic-inorganic hybrid solid electrolytes were evaluated thermally, mechanically, and electrochemically to reveal which factors affect the properties of the electrolytes. All samples showed excellent thermal stability regardless of LiFSA or LLZO concentration, and they were found to be highly plastic and ion-conductive solids at a wide range of temperatures. It was also revealed that the addition of LLZO raised the nanoindentation stiffness (HIT) of the [C2epyr][FSA]/LiFSA composites. The ionic conductivity of the hybrid electrolytes was higher than that of the pristine OIPC, reaching a value of 2.1 × 10-4 S cm-1 at 25 °C upon addition of appropriate amounts of LiFSA and LLZO. Overall, samples with higher LiFSA concentration and moderate LLZO concentration exhibited higher ionic conductivity. Cyclic voltammetry results showed that the [C2epyr][FSA]/LiFSA/LLZO composites were lithium-ion conductors. These findings indicate that by optimizing the concentrations of lithium salt and LLZO, it would be possible to realize their applications as solid electrolytes.

Flexible lithium selective composite membrane for direct lithium extraction from high Na/Li ratio brine

Monovalent selective ion-exchange membranes have been widely used for lithium extraction from brine with a high Mg/Li ratio. However, extracting Li+ directly from raw brine with high Na/Li ratio remains a significant challenge. This study introduces a flexible lithium selective composite membrane by incorporating lithium-ion conductor with a quaternized polymer. The lithium-ion conductor provides pathways for lithium transmission, while the quaternized polymer effectively hinders the leakage of impurity cations. As a result, with the applied voltage of 2.0 V, the membrane achieved a high Li+/Na+ separation coefficient of 35.48 with a Li+ flux of 8.33 × 10−10 mol cm−2 s−1 in the simulated Yiliping brine, which are 56.3 and 2.8 times higher than that of commercial monovalent selective cation exchange membrane (CIMS). We proposed a lithium transport mechanism involving an adsorption-dehydration-diffusion process through the membrane. Theoretical calculations indicate that the combined effects of significant adsorption energy (−0.47 eV), low dehydration energy (515 kJ mol−1), and low diffusion barrier (0.37 eV) leads to the high selectivity for lithium. These findings provide promising prospects for the large-scale preparation of lithium ion-selective membranes, enabling the direct lithium extraction from raw brine.