Simultaneous Improvement in Ionic Conductivity and Flexibility of Solid Polymer Electrolytes for Thin Film Lithium Ion Batteries PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Simultaneous Improvement in Ionic Conductivity and Flexibility of Solid Polymer Electrolytes for Thin Film Lithium Ion Batteries PDF full book. Access full book title Simultaneous Improvement in Ionic Conductivity and Flexibility of Solid Polymer Electrolytes for Thin Film Lithium Ion Batteries by Jianying Ji. Download full books in PDF and EPUB format.
Author: Jianying Ji
Publisher:
ISBN: 9781303465529
Category :
Languages : en
Pages :
Get Book Here
Book Description
A rubber-like, soy protein-based SPE (s-SPE)was obtained by employing soy protein isolate (SPI), a soy product usually used as rigid fillers for enhancing mechanical properties of polymers, blended with poly(ethylene oxide)(PEO). The results indicated that the s-SPE with 55 wt% of SPI possesses a fully amorphous uniform structure having low Tg, in contrast with crystalline PEO-based SPE having discernable Tg and Tm. The conductivity and elasticity are both significantly improved with SPI involvement. Remarkably, this film has been elongated up to 100% without loss of ionic conductivity and 700% without mechanical damage.
Author: Jianying Ji
Publisher:
ISBN: 9781303465529
Category :
Languages : en
Pages :
Get Book Here
Book Description
A rubber-like, soy protein-based SPE (s-SPE)was obtained by employing soy protein isolate (SPI), a soy product usually used as rigid fillers for enhancing mechanical properties of polymers, blended with poly(ethylene oxide)(PEO). The results indicated that the s-SPE with 55 wt% of SPI possesses a fully amorphous uniform structure having low Tg, in contrast with crystalline PEO-based SPE having discernable Tg and Tm. The conductivity and elasticity are both significantly improved with SPI involvement. Remarkably, this film has been elongated up to 100% without loss of ionic conductivity and 700% without mechanical damage.
Author: Ruixuan He
Publisher:
ISBN:
Category : Glass transition temperature
Languages : en
Pages : 198
Get Book Here
Book Description
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.
Author: Yukyung Jung
Publisher:
ISBN:
Category :
Languages : en
Pages : 430
Get Book Here
Book Description
Lithium-ion batteries are important in many aspects of modern life from portable electronics to electric vehicles. Their high specific energy, light weight, and design flexibility make them especially useful compared to other types of battery technologies. However, there remains room for improvement with regards to battery stability, safety, and increased capacity. One strategy for making lithium batteries both safer and more practical is by using solid polymer electrolytes (SPEs). Not only does the replacement of small molecule liquid electrolytes by SPEs significantly reduce the flammability of the battery, SPEs also make possible the construction of lighter weight batteries with increased flexibility in form factor. However, SPEs have not been widely incorporated into commercial batteries at the current time. Their applications are limited primarily due to their relatively low conductivities (~10-5 S/cm) at ambient temperatures. The first project describes the synthesis and characterization of a set of polyester-based polymer electrolytes. The polyesters were synthesized using transition metal-catalyzed alternating copolymerization of epoxides and anhydrides, which allowed the incorporation of a variety of Li+ ion coordinating functional groups including allyl ethers, pendant oligo(ethylene glycol), and esters. The bulk properties of the polymers and polymer-salt mixtures were investigated and compared to results from molecular dynamics (MD) simulations. The simulations were also used to probe the mechanism of Li + binding and transport in the polyesters. The simulations suggested that the relatively low Li + conductivity of the polyesters compared to PEO was most likely due to a lower than optimal density and spacing of the Li + binding sites in the polyesters. The insights from the polyester study were used to design a set of polyethers to further elucidate the source of PEO's unusually high ionic conductivity, as well as potentially improve the conductivity by further optimizing binding site connectivity. The polyethers were synthesized using acyclic diene metathesis (ADMET) polymerization, and a set of polymers was made with very specific and systematic alterations in structure. By studying the ionic conductivity as a function of temperature, we were able to analyze the effect of binding group density and pattern on the ionic conductivity and Li + ion transport mechanism in polyethers. The third project was inspired by the search for catalysts to develop novel high performance materials. Enantioselective [beta]-diiminate zinc catalysts were designed for the synthesis of highly isotactic polycarbonates from CO2 and meso epoxides. The ligand optimization process is described, as well as the characterization of the catalyst and isotactic poly(cyclohexene carbonate).
Author: Sanaz Momeni Boroujeni
Publisher: Cuvillier Verlag
ISBN: 3736967098
Category : Technology & Engineering
Languages : en
Pages : 176
Get Book Here
Book Description
Lithium (Li) deposition is a problem in Li batteries (LB) – both Li metal (LMB) and Li-ion (LIB) batteries – which limits their performance in terms of power and energy density. Two trends can be identified in the advancement of LBs concerning the problem of Li deposition: optimization of the existing system (the state-of-the-art LIBs) and further development of cell components such as electrolytes. This work addresses both approaches. In the first part, this study investigates Li deposition in LMB and LIBs. A novel method to study the Li-based transport mechanisms in LIBs is introduced. Later the kinetic deviations between anode and cathode as a consequence of aging and the relation of these deviations to the occurrence of Li-plating are discussed. In the second part, the applicability of PEO-based solid polymer electrolytes for LMBs to overcome the Li plating issue is investigated. The introduction of various interfacial interlayers at the cathode/electrolyte interphase was studied to improve the electrochemical stability of the cells. Cells with an in-situ electro-deposited interlayer showed the best cyclability.
Author: Prasanth Raghavan
Publisher: CRC Press
ISBN: 1000351807
Category : Technology & Engineering
Languages : en
Pages : 335
Get Book Here
Book Description
Ceramic and Specialty Electrolytes for Energy Storage Devices, Volume II, investigates recent progress and challenges in a wide range of ceramic solid and quasi-solid electrolytes and specialty electrolytes for energy storage devices. The influence of these electrolyte properties on the performance of different energy storage devices is discussed in detail. Features: • Offers a detailed outlook on the performance requirements and ion transportation mechanism in solid polymer electrolytes • Covers solid-state electrolytes based on oxides (perovskite, anti-perovskite) and sulfide-type ion conductor electrolytes for lithium-ion batteries followed by solid-state electrolytes based on NASICON and garnet-type ionic conductors • Discusses electrolytes employed for high-temperature lithium-ion batteries, low-temperature lithium-ion batteries, and magnesium-ion batteries • Describes sodium-ion batteries, transparent electrolytes for energy storage devices, non-platinum-based cathode electrocatalyst for direct methanol fuel cells, non-platinum-based anode electrocatalyst for direct methanol fuel cells, and ionic liquid-based electrolytes for supercapacitor applications • Suitable for readers with experience in batteries as well as newcomers to the field This book will be invaluable to researchers and engineers working on the development of next-generation energy storage devices, including materials and chemical engineers, as well as those involved in related disciplines.
Author: B. Scrosati
Publisher: Springer Science & Business Media
ISBN: 9401119163
Category : Science
Languages : en
Pages : 375
Get Book Here
Book Description
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.
Author: Chunyi Zhi
Publisher: John Wiley & Sons
ISBN: 3527342532
Category : Technology & Engineering
Languages : en
Pages : 512
Get Book Here
Book Description
Provides in-depth knowledge of flexible energy conversion and storage devices-covering aspects from materials to technologies Written by leading experts on various critical issues in this emerging field, this book reviews the recent progresses on flexible energy conversion and storage devices, such as batteries, supercapacitors, solar cells, and fuel cells. It introduces not only the basic principles and strategies to make a device flexible, but also the applicable materials and technologies, such as polymers, carbon materials, nanotechnologies and textile technologies. It also discusses the perspectives for different devices. Flexible Energy Conversion and Storage Devices contains chapters, which are all written by top researchers who have been actively working in the field to deliver recent advances in areas from materials syntheses, through fundamental principles, to device applications. It covers flexible all-solid state supercapacitors; fiber/yarn based flexible supercapacitors; flexible lithium and sodium ion batteries; flexible diversified and zinc ion batteries; flexible Mg, alkaline, silver-zinc, and lithium sulfur batteries; flexible fuel cells; flexible nanodielectric materials with high permittivity for power energy storage; flexible dye sensitized solar cells; flexible perovskite solar cells; flexible organic solar cells; flexible quantum dot-sensitized solar cells; flexible triboelectric nanogenerators; flexible thermoelectric devices; and flexible electrodes for water-splitting. -Covers the timely and innovative field of flexible devices which are regarded as the next generation of electronic devices -Provides a highly application-oriented approach that covers various flexible devices used for energy conversion and storage -Fosters an understanding of the scientific basis of flexible energy devices, and extends this knowledge to the development, construction, and application of functional energy systems -Stimulates and advances the research and development of this intriguing field Flexible Energy Conversion and Storage Devices is an excellent book for scientists, electrochemists, solid state chemists, solid state physicists, polymer chemists, and electronics engineers.
Author: Guang Yang
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Rechargeable lithium ion batteries are revolutionary energy storage systems widely used in portable electronic devices (e.g., mobile phones, laptops) and more recently electrical vehicles. The conventional liquid electrolytes in the lithium ion battery brought about safety problems such as fire and explosion. Related safety accidents (e.g., cell phone explosion, laptop fire, plane smoldering, etc.) have been reported many times. This also eliminates the possibility of using lithium metal as anode material which has much higher theoretical specific capacity in comparison with commercial graphite electrode because of the growth of uncontrolled lithium dendrites can lead to short circuit and other serious accidents. Solid polymer electrolytes have many advantages over conventional liquid electrolytes. They are light-weighted, non-volatile and have much better safety features than liquid electrolyte. Meanwhile, they are also better than the ceramic electrolyte in terms of their excellent flexibility and processability. Currently, low ionic conductivity of solid polymer electrolytes (e.g., polyethylene oxide (PEO)) at ambient temperature still hinders their practical application. Ionic liquids (ILs) are non-flammable and have negligible volatility. Its ionic conductive nature, excellent chemical stability, and good electrochemical stability enable them to be regarded as useful components for next generation battery electrolytes. In this thesis work, focus will be placed on synthesis and characterization of ionic liquid tethered organic/inorganic hybrid polymer electrolyte with high room temperature ionic conductivity. Moreover, their electrochemical properties and prototype battery performances were also looked into. The use of highly conductive solid-state electrolytes to replace conventional liquid organic electrolytes enables radical improvements in reliability, safety and performance of lithium batteries. Here in chapter 2, we report the synthesis and characterization of a new class of nonflammable solid electrolytes based on the grafting of ionic liquids onto octa-silsesquioxane. The electrolyte exhibits outstanding room-temperature ionic conductivity (~4.8 10-4 S/cm), excellent electrochemical stability (up to 5 V relative to Li+/Li) and high thermal stability. All-solid-state Li metal batteries using the prepared electrolyte membrane are successfully cycled with high coulombic efficiencies at ambient temperature. Good cycling stability of the electrolyte against lithium has been demonstrated. This work provides a new platform of solid polymer electrolyte for the application of room-temperature lithium batteries. In chapter 3, an organic-inorganic hybrid solid electrolyte with ionic liquid moieties tethered onto dumbbell-shaped octasilsesquioxanes through oligo(ethylene glycol) spacers was synthesized. The hybrid electrolyte is featured by its high room-temperature ionic conductivity (1.210-4 S/cm at 20 oC with LiTFSI salt), excellent electrochemical stability (4.6 V vs Li+/Li), and great thermal stability. Excellent capability of the hybrid electrolyte to mediate electrochemical deposition and dissolution of lithium has been demonstrated in the symmetrical lithium cells. No short circuit has been observed after more than 500 hrs in the polarization tests. Decent charge/discharge performance has been obtained in the prepared electrolyte based all-solid-state lithium battery cells at ambient temperature. In chapter 4, hybrid polymer electrolyte network (XPOSS-IL) synthesized by crosslinking the individual dendritic POSS-IL was investigated. To be specific, after grafting mono-broninated hexaethylene glycol to the POSS cage, 1-vinyl imidazole was adopted for the subsequent quarternization reaction. Then the chain end double bonds underwent free radical crosslinking process to produce XPOSS-IL. The ionic conductivity of LiTFSI dissolved XPOSS-IL is 5.4 10-5 S/cm at 30 . By adding a small fraction of ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI), the ionic conductivity increases to 1.4 10-4 S/cm at room temperature. It is also found that EMITFSI will enhance the anodic stability of XPOSS-IL. The Li/LTO and Li/LFP cell assembled with X-POSS-IL-LiTFSI/EMITFSI demonstrates capability of delivering high specific capacities at room temperature and elevated temperature.
Author: Guopeng Fu
Publisher:
ISBN:
Category : Lithium ion batteries
Languages : en
Pages : 179
Get Book Here
Book Description
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.
Author: Ye Jin
Publisher:
ISBN:
Category :
Languages : en
Pages : 199
Get Book Here
Book Description
"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
