Download or read book Studies on Ionic Conductivity and Electrochemical Stability of Plasticized Photopolymerized Polymer Electrolyte Membranes for Solid State Lithium Ion Batteries written by Ruixuan He and published by . This book was released on 2016 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: In pursuit of safer and more flexible solid-state lithium ion batteries, solid polymer electrolytes have emerged as a promising candidate. The present dissertation entails exploration of solid plasticized, photopolymerized (i.e. ultraviolet-cured) polymer electrolyte membranes (PEM) for fulfilling the critical requirements of electrolytes, such as high ionic conductivity and good thermal and electrochemical stability, among others. Electrochemical performance of PEMs containing lithium ion half-cells was also investigated at different two temperatures.Phase diagram approach was adopted to guide the fabrication of two types of plasticized PEMs. Prepolymer poly (ethylene glycol) diacrylate (PEGDA) was used as a matrix for building an ionic conductive and mechanically sturdy network. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was incorporated as a source of lithium ions, while a solid plasticizer succinonitrile (SCN) and a liquid plasticizer tetraethylene glycol dimethyl ether (TEGDME) were incorporated in the respective systems. The important role of plasticizer on the enhancement of ionic conductivity (s) to the superionic conductive level (10−3 S/cm) was revealed in both systems. It is worth noting that photopolymerization induced crystallization (PIC) occurred during UV-curing in the SCN-rich region of the ternary PEGDA/LiTFSI/SCN ternary mixtures. The PEM thus formed contained a plastic crystal phase, which showed lower s relative to their amorphous PEGDA/LiTFSI/TEGDME counterpart. Comparisons on other thermal and electrochemical properties of the two types of PEMs are presented in Chapter IV. For the PEGDA/LiTFSI/SCN PEMs, fundamental study was carried out to clarify the relationship between s and glass transition temperature (Tg). In lithium salt/polymer binary PEMs, increase in Tg and reduction in s were observed; these may be attributed to ion-dipole complexation between dissociated lithium cations and ether oxygen upon salt addition. Notably, above the threshold salt concentration of 7 mol %, dual loss tangent peaks were observed in dynamic mechanical studies. These might be ascribed to segmental relaxations of ion-dipole complexed networks and that of polymer chains surrounding the undissociated lithium salt acting like "fillers". Upon SCN incorporation, these two peaks merged into one that was further suppressed below the Tg of the pure network, whereas s improved to the superionic conductor level. The role of SCN on the s enhancement as both plasticizer for the polymer network and ionizer for the salt is discussed in Chapter V. In order to improve the mechanical toughness of the highly conductive PEGDA/LiTFSI/SCN PEM, effects of prepolymer molecular weight on mechanical and electrochemical properties of PEMs were further investigated. By increasing molecular weight of PEGDA from 700 to 6000 g/mol, toughness and elongation at break were enhanced as expected. Interestingly, improved ionic conductivity was achieved simultaneously. The dual improvement may be attributed to the less chemical crosslinked points and the more flexible chain motion in the looser network of PEGDA6000-PEM relative to its PEGDA700 counterpart. Subsequently, high thermal stability and electrochemical stability of both types of PEMs, as well as the satisfactory room temperature charge/discharge cycling performance of PEM containing lithium ion half-cells were observed. The pertinent information is documented in Chapter VI. Finally, the investigation of the charge/discharge cycling performance of solid-state LiFePO4 half-cells at an elevated temperature of 60° C is discussed in Chapter VII. In the half-cells, particularly, SCN plasticized PEMs with and without electrolyte modifier lithium bis(oxalato)borate (LiBOB) were respectively employed. Rapid decline of capacity and increase of cell resistance were found in the unmodified PEM containing cell; however, these deteriorations were greatly suppressed upon LiBOB modification. Electrochemical and thermal compatibility of PEMs towards different electrodes were examined in several symmetric cells and half-cells. Detailed characterization on LiFePO4 electrodes and PEMs retrieved from these cells implied that the observed battery failure might be triggered by an amide-forming side reaction that took place at the interface of a SCN plasticized PEM and a lithium electrode at high temperature. Of particular importance is the fact that this detrimental side reaction was effectively suppressed upon LiBOB electrolyte modifier addition. Plausible mechanisms are discussed.

Download or read book Investigation on the Structure property Relationships in Highly Ion conductive Polymer Electrolyte Membranes for All solid state Lithium Ion Batteries written by Guopeng Fu and published by . This book was released on 2017 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present dissertation is focused on development of the highly ion-conductive polymer electrolyte membrane (PEM) for all-solid-state lithium ion batteries. The organic molecule urea was found to be good additives to enhance the ionic conductive PEM. However, it phase-separated from the electrolyte during the charging/discharging process and harm the performance of the batteries. In order to improve the ionic conductivity as well as stabilize the electrolyte, polyethylene glycol bis-carbamate (PEGBC) was synthesized via a condensation reaction between polyethylene glycol diamine and ethylene carbonate. The PEGBC and lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) salt binary mixture exhibits an enhanced ionic conductivity by virtue of the complexation of the carbamate group and lithium ion.Subsequently, dimethacrylate groups were chemically attached to both ends of PEGBC to afford polyethylene glycol-bis-carbamate dimethacrylate (PEGBCDMA) precursor having crosslinking capability. The melt-mixed ternary mixtures consisting of PEGBCDMA, succinonitrile (SCN) plasticizer, and LiTFSI were completely miscible in a wide compositional range. Upon photo-crosslinking, the neat PEGBCDMA network was completely amorphous exhibiting higher tensile strength, modulus, and extensibility relative to polyethylene glycol diacrylate (PEGDA) counterpart. The succinonitrile-plasticized PEM network containing PEGBCDMA remained completely amorphous and transparent upon photo-crosslinking, showing superionic conductivity, improved thermal stability, and superior tensile properties with improved capacity retention during charge/discharge cycling as compared to the PEGDA-based PEM.By mixing PEGBCDMA, LiTFSI and ethylene carbonate, a flammable retardant and PEM can be fabricated. This transparent PEM is bendable and twistable, which makes it an ideal candidate for a flexible battery application. Moreover, the PEM also exhibits high ionic conductivity and large electrochemical stability windows. The PEM shows impressive performance in the coin-cell battery test. Over 80% of the initial capacity can be retained after 250 cycles in LiFePO4/PEM/graphite full cells. A proof-of-concept flexible all solid-state lithium ion battery has been built based on this PEM.The relationship between the ionic conductivity, glass transition temperature (T [subscript g]) and crosslink density has been studied in the branched copolymer system. PEGDA and monofunctional PEGMEA were copolymerized to afford PEGDA network attached with PEGMEA side chains. Attaching PEGMEA side branches to the PEGDA network backbone is to provide greater free volume afforded by lowering the T [subscript g]. The network flexibility is further manipulated by varying relative amounts of PEGMEA and PEGDA. Concurrently, the ionic conductivity of copolymer electrolyte membrane (co-PEM) consisting of LiTFSI salt and SCN plasticizer in the PEGMEA-co-PEGDA copolymer network is enhanced with increasing PEGMEA side branching. The relationship between the network T [subscript g] and ionic conductivity of the branched co-PEM has been analyzed in the context of Vogel-Tammann-Fulcher (VTF) equation. The plasticized branched co-PEM network exhibits room temperature ionic conductivity at a superionic conductor level of 10−3 S/cm as well as excellent capacity retention in charge/discharge cycling of Li4Ti5O12/co-PEM/Li and LiFePO4/co-PEM/Li half-cells.

Download or read book Composite Electrolyte amp Electrode Membranes for Electrochemical Energy Storage amp Conversion Devices written by Giovanni Battista Appetecchi and published by MDPI. This book was released on 2021-05-05 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemical energy systems can successfully exploit beneficial characteristics of electrolyte and/or electrode membranes due to their intriguing peculiarities that make them well-established, standard components in devices such as fuel cells, electrolyzers, and flow batteries. Therefore, more and more researchers are attracted by these challenging yet important issues regarding the performance and behavior of the final device. This Special Issue of Membranes offers scientists and readers involved in these topics an appealing forum to bring and summarize the forthcoming Research & Development results, which stipulates that the composite electrolyte/electrode membranes should be tailored for lithium batteries and fuel cells. Various key aspects, such as synthesis/preparation of materials/components, investigation of the physicochemical and electrochemical properties, understanding of phenomena within the materials and electrolyte/electrode interface, and device manufacturing and performance, were presented and discussed using key research teams from internationally recognized experts in these fields.

Download or read book Phase Diagram Approach to Control of Ionic Conductivity and Electrochemical Stability of Solid Polymer Electrolyte Membrane for Li ion Battery Application written by Jinwei Cao and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Binary and ternary phase diagram of poly(ethylene glycol) dimethacrylate (PEGDMA), bis(trifluoromethane)sulfonimide (LiTFSI), and succinonitrile (SCN) blends have been established by means of differential scanning calorimetry and polarized optical microscopy. The binary phase diagram of PEGDMA/SCN mixture is of typical eutectic type, whereas the binary phase diagram of PEGDMA/LiTFSI mixture exhibits a wide single-phase region at the intermediate compositions. The ternary phase diagram of PEGDMA/SCN/LiTFSI mixture shows a wide isotropic region. The polymer electrolyte membrane (PEM), which is formed by ternary blends in this region after UV-crosslinking, remains in the isotropic phase and performs. The room temperature ion conductivity as evidenced in AC impedance measurement, was found to be extremely high (i.e., 10−3 S/cm). This ionic conductivity increases to 10−2 S/cm at 60 °C that continues to improve further up to 135 °C investigated. More importantly, the high ionic conductivity behavior is reproducible in repeated heating/cooling cycles. Those PEM are solid-state, stretchable, nonflammable, and light weight, which may be applicable to lithium ion battery as a replacement of commercial liquid electrolyte. SCN in ternary blends affords not only dissociation of the lithium salt, but also plasticization to the cross-linked PEGDMA network. Last not least, thermal and electrochemical stability of these membranes were examined for further application probability.

Download or read book Study of Highly Conductive Flexible Polymer Electrolyte Membranes and Their Novel Flexoelectric Effect written by Camilo Rendon Piedrahita and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Present dissertation outlines a study of the basic important physicochemical properties of photo-cured polymer electrolyte membranes (PEM) that can be enhanced and optimized in order to be implemented as electrolyte in solid-state Li-ion batteries. The studied properties include mechanical integrity, ionic conductivity, thermal and electrochemical stability, etc. This dissertation also introduces and characterizes a novel application of PEMs as energy harvesting materials, due to their capability to transform mechanical stimuli into an electrical signal and vice versa. Chapter I provides a brief overview of the general content of the dissertation. Chapter II presents the material that was taken as the basis for the study. It contains essential information related to the battery principles, operation, development and applications. In addition, it encompasses the description of electroactive polymers, which are in principle, equivalent to the discovered flexoelectric PEMs that are as well introduced in this work. Chapter III illustrates the materials, methods and calculations utilized to perform and analyze the data collected for the purpose of the study. Chapter IV describes an incorporation of mercaptopropyl methyl siloxane homopolymer (thiosiloxane) as a co-component to the matrix of the PEM, which in result enables enhancement of the polymer segmental motion and hence, the ionic conductivity. UV irradiation was applied to various thiosiloxane and poly(ethylene glycol) diacrylate (PEGDA) mixtures to get the `thio-ene' reaction between the thiol functionality and the double bonds of the PEGDA precursor, which formed a complete amorphous self-standing PEM. The thiosiloxane modified PEM film exhibits higher extension-at-break in comparison to the PEM containing only PEGDA such as PEGDA700/SCN/LiTFSI 20/40/40, FTIR and Raman spectroscopy techniques were employed to detect the thiol (SH) groups consumed after performing the so-called thiol-ene reaction. It was found that there is a direct relationship between the level of the thiosiloxane content and the resulting ionic conductivity of the PEM. Discovered PEMs were also analyzed via thermal and electrochemical techniques in order to determine their implementation as electrolyte in solid-state Li-ion batteries. Chapter V presents the implementation of different PEG-based macromolecules with different chemical architectures. Different chemical architectures increase the mechanical strength of the PEMs without affecting drastically the ionic conductivity. PEMs are fabricated by exposing the mixtures of PEGnA/SCN/LiTFSI 20/40/40 to UV irradiation. Following the photo-curing process, FITR spectroscopy was utilized to detect the consumption of acrylate groups. It is believed that succinonitrile (SCN) increases the diffusion of the solutions and therefore improves the probability of acrylate groups to react. PEG4A, PEG3A and PEG2A PEMs were analyzed with the stress-strain curve test in order to determine the influence of different architectures on the mechanical properties and their relationship with the glass transition temperature (Tg) Other important properties, such as thermal stability and optimal electrochemical window were also studied. Chapter VI introduces an innovative way to create electrical potential as a consequence of ionic polarization. Generated electrical potential can be used to design sensors and energy harvesting devices. This section presents the application of passive and active ion transports found in neuron cells to the solid-state PEM (PEGnA/SC/LiTFSI 20/40/40) system. The application of passive ion transport was studied by fabricating a bilayer PEM system where ion diffusion was induced along the concentration gradient. The study didn't provide proper results for further investigation. For the application of active ion transport, an external stimulus was utilized, such as pressure and temperature gradient, to a single layer PEM system. This application revealed mechanoelectric and pyroelectric properties in PEM. In other words, when pressure gradient (bending deformation) is applied to a PEM, ionic polarization takes place within the PEM, resulting in an electrical output in a form of voltage or current. These properties indicate that PEMs are "smart" materials that can sense and harvest energy via mechano and pyroelectricity. Chapter VII presents the flexoelectric effect on ion conductive PEMs composed of poly(ethylene glycol) diacrylate (PEGDA) - thiosiloxane (TS) copolymer and Ionic liquid (IL). These flexoelectric PEMs operate based on the principle of ion polarization of dissociated ions to transform input deformation into electrical output. Electrical outputs are collected by monitoring voltage (Voc) and current (Isc) signals while the sample is deformed (square wave mode) by utilizing a Solartron Galvanostat/Potentiostat. The voltage is directly related to the modulus of the PEM, whereas the current is directly correlated with the ionic conductivity of the PEM. Flexoelectric coefficients were calculated for all the composition in correlation to the above-mentioned properties. The magnitude of the calculated flexoelectric coefficients outperforms those reported in the literature for other materials such as some ceramics, PVDF and bent-core liquid crystals. Similarly, Chapter VIII complements the previous work of flexoelectric PEMs. In this case, the deformation of the sample was performed via sinusoidal wave at different amplitudes. The efficiency of the samples has been studied by calculating flexoelectric coefficients. These were found to be of much lower magnitude compared with those from square wave input. The reason lies in the lack of charge relaxation when the sample is being deformed. The effect of frequency on the amplitude of the current, voltage and magnitude of flexoelectric coefficients is also analyzed. Due to the rubber-like nature of these types of PEMs, they can be potentially applied in rubber based materials as sensors or energy harvesting devices from dynamic deformations.

Download or read book Physical and Electrochemical Investigation of Various Dinitrile Plasticizers in Highly Conductive Polymer Electrolyte Membranes for Lithium Ion Battery Application written by Chenrun Feng and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: To investigate physical and electrochemical properties of polymer electrolyte membranes (PEMs) containing various dinitriles such as succinonitrile (SCN), glutaronitrile (GLN) and adiponitrile (ADN), binary and ternary phase diagrams of poly(ethylene glycol) diacrylate (PEGDA), GLN and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) blends were firstly established in this thesis. The binary phase diagram of PEGDA/GLN system was self-consistently solved based on the combined free energies of Flory-Huggins theory for liquid-liquid demixing and phase field theory for crystal solidification. Computed liquidus and solidus lines were compared with crystal melting temperatures of the binary pairs, obtained by differential scanning calorimetry (DSC) measurement. The binary phase diagram of LiTFSI/GLN system was drawn according to crystal melting temperatures of the binary pairs determined by DSC measurement. Then coexistence regions of each binary phase diagram were verified by polarized optical microscopy. Subsequently, the ternary phase diagram of PEGDA/GLN/LiTFSI at 25 °C were established. Guided by isotropic regions within ternary phase diagrams established in this thesis and previous studies, polymer electrolyte membranes (PEMs) plasticized by various dinitriles thus fabricated via photo-polymerization afforded transparent, homogeneous films. The ionic conductivity of these PEMs was determined by AC impendence spectrometer, which showed high ionic conductivity up to 10−3 S/cm at room temperature. Of particular interest is that GLN-PEM reveals the highest ion conductivity among the three PEMs tested. To analyze the electrochemical performance of PEMs used in lithium-ion batteries, SCN-PEM, GLN-PEM, and ADN-PEM were assembled into Li4Ti5O12/PEM/Li and LiFePO4/PEM/Li half-cells. The half-cell containing GLN-PEM exhibits the best charge-discharge cycling performance, which is consistent with the highest ionic conductivity of the GLN plasticized PEM.

Download or read book Hybrid Organic inorganic Polymer Electrolyte for Lithium Battery Application written by Kuan-Lun Chu and published by . This book was released on 2001 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design of Advanced Polymer Electrolyte for High Performance Lithium and Sodium Batteries written by Wenfeng Liang and published by . This book was released on 2020 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy density of lithium ion batteries (LIBs) is limited by the capacities of the electrode materials. Lithium metal is a promising anode material for future LIBs due to its high theoretical specific capacity (3,860 mAh/g) and low redox potential (-3.04 V vs. standard hydrogen electrode). However, lithium plating in liquid electrolyte will form Li dendritic structure and subsequently penetrate the porous polymeric separator, resulting in battery short circuiting. A straightforward method to suppress the growth of lithium dendrites is to replace the liquid phase electrolyte with a solid-state one. Among different solid-state electrolyte candidates, solid polymer electrolyte (SPE) is advantageous due to its flexible nature and low-cost raw material. However, SPE typically exhibits low ionic conductivity compared to its liquid electrolyte counterpart, which thus could result in restricted use in battery applications. In this work, a rational approach to achieve highly ionic conductive and electrochemically stable SPEs will be discussed. A phase-diagram was firstly mapped out to provide guidance in designing a composite electrolyte with high ionic conductivity at room temperature. The thermal and electrochemical stability of SPE were then characterized. A dual-salt base electrolyte with lithium bis(oxalate)borate (LiBOB) and bis(trifluoromethanesulphonyl)imide (LiTFSI) exhibited excellent electrochemical stability from the passivation layer formed between the electrode/electrolyte interface. In addition, SPEs based on crosslinked fluoropolymer and poly(ethylene glycol) diacrylate (PEGDA) were investigated. Those properties of SPE enable the fabrication of solid-state batteries with lithium metal as an anode. Lithium plating/striping experiments and battery tests were conducted, and the results indicated that the dual-salt SPE could be a promising candidate electrolyte for next generation solid-state rechargeable battery. Sodium ion batteries display good performance yet with limited protection for the inevitable sodium dendrite growth if coupled with metallic sodium electrode, which is an adverse phenomenon that would eventually result in the deterioration of the battery. SPEs with superior ionic conductivity and outstanding electrochemical stability are promising for the all solid-state sodium batteries in grid-storage applications. In this study, a transparent free-standing SPE membrane comprising sodium perchlorate (NaClO4), PEGDA and plastic crystal molecules was fabricated. This sodium based SPE exhibits high sodium-ion conductive property (over 0.925 mS/cm at 30 oC) while being electrochemically stable. A rational approach has also been designed and achieved by using the phase diagram. The NaClO4-based SPE can not only exhibit excellent electrochemical stability with metallic sodium electrode, but also provide remarkable current rate and long-term cycling performance for the solid-state sodium metal batteries (SMB).

Download or read book Theoretical Insights into the Electrochemical Properties of Ionic Liquid Electrolytes in Lithium Ion Batteries written by Leila Maftoon-Azad and published by CRC Press. This book was released on 2024-09-17 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise overview of the use of ionic liquids as electrolytes in lithium-ion batteries (LIBs) from a theoretical and computational perspective. It focuses on computational studies to understand the behavior of lithium ions in different ionic liquids and to optimize the performance of ionic liquid-based electrolytes. The main features of the book are as follows: • Provides a thorough understanding of the theoretical and computational aspects of using ionic liquids as electrolytes in LIBs, including the evaluation and reproducibility of the theoretical paths. • Covers various computational methods such as density functional theory, molecular dynamics, and quantum mechanics that have been used to study the behavior of lithium ions in different solvents and to optimize the performance of ionic liquid-based electrolytes. • Discusses recent advances such as new computational methods for predicting the properties of ionic liquid-based electrolytes, new strategies for improving the stability and conductivity of these electrolytes, and new approaches for understanding the kinetics and thermodynamics of redox reactions with ionic liquids. • Suggests how theoretical insights can be translated into practical applications for improving performance and safety. This monograph will be of interest to engineers working on LIB optimization.

Download or read book Fabrication and Evaluation on Electrochemical Performance of Solid Polymer Electrolyte Membreane for Lithium ion Battery written by Tianli Ren and published by . This book was released on 2017 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the ternary phase diagram of polyethylene (glycol) diacrylate (PEGDA), ethylene carbonate (EC) and lithium bis-(trifluoromethane sulfonyl) imide (LiTFSI), polymer electrolyte membranes (PEMs) were fabricated in various proportions via photo-polymerization. Ionic conductivities of PEMs containing various ratios of three constitutes were measured by means of AC Impedance spectroscopy. Solid polymer electrolyte membrane, consisting of 20/40/40 PEGDA/EC/LiTFSI, was chosen as the appropriate solid PEM that afforded high ionic conductivity and good mechanical properties. The ionic conductivity of such PEM at 25 °C was found to reach a superionic level of 10-3 S cm-1, which is rather difficult to come by for a conventional solid-state electrolyte. More importantly, the present PEM was compatible with conventional electrodes such as LiFePO4 (LFP), Li4Ti5O12 (LTO) and graphite. The Li/PEM/LTO cell was found to achieve the capacity value of 180 mAh/g at a current rate of 0.2 C for both room temperature and 60 °C, which was even higher than the theoretical capacity of LTO of 170 mAh/g. What is more, the capacity of Li/PEM/LTO cell at 2 C, which was rather a high speed for a solid electrolyte membrane, could reach 140 mAh/g, indicating that the PEM was truly compatible with LTO electrode at both high cycling speed and high temperature. In addition, the LTO half-cell was found to survive charge/discharge cycling for more than 200 cycles with 95% retention, which implied that little or no degradation of the electrode occurred during the charge/discharge cycling. The Li/PEM/LFP half-cell and Li/PEM/graphite half-cell also reached the capacity close to the theoretical value. The high thermal and chemical stability of PEM confirmed that the present solid PEM could be a great alternative to the liquid electrolyte having advantages of non-flammable, solvent free, flexible, light weight, low cost and easy processing.

Download or read book Rational Design of Nanostructured Polymer Electrolytes and Solid Liquid Interphases for Lithium Batteries written by Snehashis Choudhury and published by Springer Nature. This book was released on 2019-09-25 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis makes significant advances in the design of electrolytes and interfaces in electrochemical cells that utilize reactive metals as anodes. Such cells are of contemporary interest because they offer substantially higher charge storage capacity than state-of-the-art lithium-ion battery technology. Batteries based on metallic anodes are currently considered impractical and unsafe because recharge of the anode causes physical and chemical instabilities that produce dendritic deposition of the metal leading to catastrophic failure via thermal runaway. This thesis utilizes a combination of chemical synthesis, physical & electrochemical analysis, and materials theory to investigate structure, ion transport properties, and electrochemical behaviors of hybrid electrolytes and interfacial phases designed to prevent such instabilities. In particular, it demonstrates that relatively low-modulus electrolytes composed of cross-linked networks of polymer-grafted nanoparticles stabilize electrodeposition of reactive metals by multiple processes, including screening electrode electrolyte interactions at electrochemical interfaces and by regulating ion transport in tortuous nanopores. This discovery is significant because it overturns a longstanding perception in the field of nanoparticle-polymer hybrid electrolytes that only solid electrolytes with mechanical modulus higher than that of the metal electrode are able to stabilize electrodeposition of reactive metals.

Download or read book Fast Ion Transport in Solids written by B. Scrosati and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main motivation for the organization of the Advanced Research Workshop in Belgirate was the promotion of discussions on the most recent issues and the future perspectives in the field of Solid State lonics. The location was chosen on purpose since Belgirate was the place were twenty years ago, also then under the sponsorship of NATO, the very first international meeting on this important and interdisciplinary field took place. That meeting was named "Fast Ion Transport in Solids" and gathered virtually everybody at that time having been active in any aspect of motion of ions in solids. The original Belgirate Meeting made for the first time visible the technological potential related to the phenomenon of the fast ionic transport in solids and, accordingly, the field was given the name "Solid State lonics". This field is now expanded to cover a wide range of technologies which includes chemical sensors for environmental and process control, electrochromic windows, mirrors and displays, fuel cells, high performance rechargeable batteries for stationary applications and electrotraction, chemotronics, semiconductor ionics, water electrolysis cells for hydrogen economy and other applications. The main idea for holding an anniversary meeting was that of discussing the most recent issues and the future perspectives of Solid State lonics just twenty years after it has started at the same location on the lake Maggiore in North Italy.

Download or read book Strategies to Improve the Electrochemical Performance of Lithium ion Batteries by Stabilizing the Interface of Electrode electrolyte written by Ye Jin and published by . This book was released on 2020 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Lithium-ion batteries (LIBs) provide great potential for electric vehicles, and smart grids as future energy-storage devices. However, there are many challenges in the development of the LIB industry, including low energy and power density of electrode materials, poor rate performance, short cycle life of electrode materials, and safety issues caused by the flammability of the conventional organic liquid electrolytes. In this research, we were committed to using general approach to efficiently and economically synthesize or modify LIB materials by stabilizing the interface between electrode and electrolyte. Atomic layer deposition (ALD) method was used to coat metal oxide thin films on commercial electrode materials, which assisted the electrodes to form a beneficial interface layer and protected the active materials from organic liquid electrolyte, improved the conductivity of the active material, and led to an improved electrochemical performance of the material. The problem of uneven distribution of polyvinylidene fluoride (PVDF) binder had been solved using an extremely simple heat treatment method, which led to a stable and inorganic-riched solid electrolyte interphase (SEI) layer that improved the specific capacities and capacity retentions of the anode electrodes. A low liquid leakage ceramic polymer electrolyte (CPE) with high porosity, thermal and electrochemical stability, and ionic conductivity was synthesized to solve the safety issue of the uncontrolled growth of lithium dendrites in the conventional LIBs. Ultra-thin ZrO2 films were coated on cathode particles by ALD to reduce the interfacial resistance for all-solid-state battery, which improved lithium ions transport and suppressed undesirable interfacial side reactions"--Abstract, page

Download or read book Exploring the Relationship Between Polymer Topology and Ionic Conductivity written by Nam Quang Hai Nguyen and published by . This book was released on 2021 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation will be mainly exploring the relationship between polymer topology and ion transport properties of single-ion conductors (SICs) in lithium-ion battery application. Specifically, we strive to understand the impact of precise 5-carbon spacing on ion transports behavior of precision single-ion conductor. In chapter 2, the investigation was conducted on blending lithium sulfonate salt of precise 5-carbon spacing polymer electrolyte (p5PhS-Li) with poly(ethylene oxide) (PEO), a popular solvating polymer. The highest ionic conductivity of this type of SIC was achieved on the order of 10-7 S/cm at 90 °C. Results from differential scanning calorimetry (DSC) also indicated that polymer blends are at least partial miscible. The conclusion was made due to strong ionic interactions between sulfonate anions and lithium cations that lead to small magnitude of interaction parameter as well as melting point depression in PEO with complicating interpretation of transference number. We were strived to improve the ionic conductivity of single-ion conductors by altering the chemical structures of anions from sulfonate to trifluoromethylsulfonylimide salt (TFSI) that has been shown to increase electrochemical, thermal stabilities and ionic conductivity in chapter 3. Upon characterizing with 1H NMR, 19F NMR and 13C NMR, the efficiency of post polymerization reaction was obtained as high as 90 %. The conversion of sulfonated into TFSI-containing SIC (p5PhTFSI-Li) was shown to improve thermal stability as well as plasticize by an appearance of glass transition temperature (Tg) with higher TFSI content corresponds to lower (Tg). The ionic conductivity of true SIC p5PhTFSI-Li was lower than previously studied p5PhS-Li which contradicted to our hypothesis. The improvement in ionic conductivity was only observed when p5PhTFSI-Li was doped with PEO. Study by DSC also revealed that no crystallinity in PEO was detected, and these blends exhibited a single Tg which is attributed to the miscible behavior of the components. X-ray scattering also complemented with DSC study as ionic aggregates are diluted by the introduction of PEO. Realizing the immediate effect of PEO addition on the ionic conductivity of SICs, chapter 4 of the thesis further expands wider range of blend composition between PEO and p5PhTFSI-Li. Study by DSC reveals one single Tg for every blend composition which is consistent with results obtained from chapter 3. The addition of p5PhTFSI-Li retarded crystallization kinetics of PEO until it fully disrupted the crystalline phase of PEO, which proves that these two components provide greater compatibility than PEO/p5PhS-Li. Highest ionic conductivity of 6.37 x 10-4 S cm-1 was also obtained at 42 wt% of p5PhTFSI-Li, which is on par with that observed in literature TFSI-based SICs. Transference number was also observed to approach unity for experimented compositions. The future of p5PhTFSI-Li is wide open as the material will be investigated in block polymer as well as electrochemical stability. Last but not least, a side project was researched on catechol-containing precision polymer in underwater adhesion applications in chapter 5. Even though the research was not timely done, the synthesis of catechol-containing precision polymer was investigated on monomer synthesis, thermodynamics of polymerization, efficiency of polymerization and copolymerization with a similar comonomer structure. This project will leave opportunities for incoming graduate student to take over and analyze the adhesion performance the catechol-containing precision polymer.

Download or read book Polymer Electrolyte Reviews written by J.R. MacCallum and published by Springer Science & Business Media. This book was released on 1989-10-31 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Impact of Polymer Electrolyte Properties on Lithium Ion Batteries written by Nacer Badi and published by Eliva Press. This book was released on 2022-08-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this review, different types of electrolytes and their electrical and mechanical properties have been reported and studied to evaluate their effect on LIB performance. It was noticed that the electrolyte component and solvent in polymer electrolytes have a great influence on the ionic conductivity, Li+ migration, interfacial contact between electrolyte and electrode, mechanical properties, and the performance of the entire battery. The morphology of incorporated additive materials (nanoparticles, nanowires, nanofillers, salt, etc.) may well contribute to the amelioration of the ion transport pathway, which raises the lithium-ion conductivity. A basic understanding of the chemical reaction routes and the electrolyte structure would facilitate innovation in the battery. The structural, electrochemical, and mechanical properties of new promising materials should be investigated in advance for application in advanced lithium-ion batteries. The electrochemical behavior is inextricably related to the structure. IL-based solid polymer electrolytes appear as a promising material for long-term lithium-ion batteries despite showing low ionic conductivity but exhibiting more advantages than conventional carbonate electrolytes such as good safety, stability, good electrochemical performance, good mechanical stability, and enhanced energy density. Since solid electrolytes exhibit low ionic conductivity, ILs used in SPEs increased their conductivity. In a battery, porous materials appear to offer good properties in terms of lithium ionic conductivity, with no leakage and low interface resistance, and gel-based LIBs demonstrate a good working performance, long cycling life, and high energy density. Good polymer electrolytes need to be highly conductive, safe, highly mechanically and thermally stable, and easy for film formation.

Download or read book Ionic Liquid Based Gel Polymer Electrolytes for Application in Rechargeable Lithium Batteries written by Rajendra K. Singh and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Depleting fossil fuels has put pressing need for the search of alternative energy resources. Solar and wind energy resources are being considered one of the viable solutions. However, these intermittent sources require efficient energy storage systems in terms of rechargeable Li batteries. In Li batteries, electrolyte is one of the most important components to determine the performance, as it conducts the ions between the electrodes. In battery, mostly liquid electrolyte is used as it shows high ionic conductivity and electrode/electrolyte contact which help to reduce the internal resistance. But these are not electrochemically very stable and raised some major problems such as reactivity with electrode, dissolution of electrode ions, leakage, volatility, fast Li dendrite growth, etc. Therefore, in order to improve its electrochemical performance, selection of electrolyte is an important issue. In the present study, ionic liquid (IL)-based polymer electrolyte is used over liquid electrolyte in which IL acts as a plasticizer and improves ionic conductivity and amorphicity. These electrolytes have high thermal and electrochemical stability, therefore, can be used in high voltage Li battery. Also, their mechanical stability helps to suppress Li dendrites growth. Therefore, polymer electrolytes can open a new way in the progression of battery application.