Development of Cathode Materials and Electrolytes for High-energy Lithium-sulfur Batteries

Development of Cathode Materials and Electrolytes for High-energy Lithium-sulfur Batteries PDF Author: Shuru Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Rechargeable lithium-sulfur (Li-S) batteries have attracted great attentionbecause they promise an energy density 3-5 times higher than that of currentstate-of-the-art lithium ion batteries at lower cost. However, current Li-S frequently suffer from low practical energy density, poor cycle life, low efficiency, and high self-discharge. Those issues mainly stem from the poorconductivity of sulfur and its lithiated products, the dissolution and side-reactions of intermediate lithium polysulfides, and the unstable lithium-electrolyte interface.This dissertation focuses on development of high-sulfur-fraction carbon/sulfur composite cathode materials and efficient electrolyte systems for Li-S batteries, aiming to improve both their practical energy densities and electrochemical performance. In Chapter 3, hollow carbon (HC) spheres with extremely high specific volume (>10 cm3 g-1) are shown to accommodate ultrahigh sulfur fraction (~90 wt%) in their nano-scale pores. The obtained HC/S composites enable high areal sulfur loading of up to 6.9 mg cm-2 in the cathode electrode using industry-adopted coating techniques. In addition, a new hydrofluoroether-based electrolyte is shown to significantly mitigate polysulfide dissolution and also to facilitate the electrochemicalreactions of sulfur cathodes. Combined with this new electrolyte, thehigh-sulfur-fraction and high-areal-loading HC/S composite cathode can achieve exceptional performance, which can significantly improve both the cyclability and the practical energy density of the Li-S batteries. In chapter 4, substituting soluble Li polysulfides for conventional Li salts in the commonly used Li-S electrolyte is found to not only contribute extra capacity but also significantly improve the cycling performance of Li-S cells. In chapter 5, a new functional electrolyte system using electrochemically active organosulfides (e.g., dimethyl disulfide) as co-solvents is shown to reduce the required electrolyte amount while at the same time increasing cell capacity. The organosulfides lead to a new reaction pathway for sulfur cathodes, which involves the chemical reactions between organosulfides and sulfur to new intermediate organopolysulfides, followed by their subsequent electrochemical reactions during cell cycling. Through this new mechanism, the functional organosulfide electrolyte not only contributes a significant amount of capacity, but also enables good cathode cyclability by way of an automatic discharge shutoff mechanism. This new functional electrolyte system thus promises high energy density for Li-S batteries.In the appendix, the development of silicon-carbon yolk-shell nanocomposite materials is discussed. These high-performance silicon anode materials can potentially be used to replace the Li anode, which in the long term can improve the cycle life and safety of Li-S batteries.

Development of Cathode Materials and Electrolytes for High-energy Lithium-sulfur Batteries

Development of Cathode Materials and Electrolytes for High-energy Lithium-sulfur Batteries PDF Author: Shuru Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Rechargeable lithium-sulfur (Li-S) batteries have attracted great attentionbecause they promise an energy density 3-5 times higher than that of currentstate-of-the-art lithium ion batteries at lower cost. However, current Li-S frequently suffer from low practical energy density, poor cycle life, low efficiency, and high self-discharge. Those issues mainly stem from the poorconductivity of sulfur and its lithiated products, the dissolution and side-reactions of intermediate lithium polysulfides, and the unstable lithium-electrolyte interface.This dissertation focuses on development of high-sulfur-fraction carbon/sulfur composite cathode materials and efficient electrolyte systems for Li-S batteries, aiming to improve both their practical energy densities and electrochemical performance. In Chapter 3, hollow carbon (HC) spheres with extremely high specific volume (>10 cm3 g-1) are shown to accommodate ultrahigh sulfur fraction (~90 wt%) in their nano-scale pores. The obtained HC/S composites enable high areal sulfur loading of up to 6.9 mg cm-2 in the cathode electrode using industry-adopted coating techniques. In addition, a new hydrofluoroether-based electrolyte is shown to significantly mitigate polysulfide dissolution and also to facilitate the electrochemicalreactions of sulfur cathodes. Combined with this new electrolyte, thehigh-sulfur-fraction and high-areal-loading HC/S composite cathode can achieve exceptional performance, which can significantly improve both the cyclability and the practical energy density of the Li-S batteries. In chapter 4, substituting soluble Li polysulfides for conventional Li salts in the commonly used Li-S electrolyte is found to not only contribute extra capacity but also significantly improve the cycling performance of Li-S cells. In chapter 5, a new functional electrolyte system using electrochemically active organosulfides (e.g., dimethyl disulfide) as co-solvents is shown to reduce the required electrolyte amount while at the same time increasing cell capacity. The organosulfides lead to a new reaction pathway for sulfur cathodes, which involves the chemical reactions between organosulfides and sulfur to new intermediate organopolysulfides, followed by their subsequent electrochemical reactions during cell cycling. Through this new mechanism, the functional organosulfide electrolyte not only contributes a significant amount of capacity, but also enables good cathode cyclability by way of an automatic discharge shutoff mechanism. This new functional electrolyte system thus promises high energy density for Li-S batteries.In the appendix, the development of silicon-carbon yolk-shell nanocomposite materials is discussed. These high-performance silicon anode materials can potentially be used to replace the Li anode, which in the long term can improve the cycle life and safety of Li-S batteries.

High Energy Density Lithium Batteries

High Energy Density Lithium Batteries PDF Author: Katerina E. Aifantis
Publisher: John Wiley & Sons
ISBN: 9783527630028
Category : Technology & Engineering
Languages : en
Pages : 296

Get Book Here

Book Description
Materials Engineering for High Density Energy Storage provides first-hand knowledge about the design of safe and powerful batteries and the methods and approaches for enhancing the performance of next-generation batteries. The book explores how the innovative approaches currently employed, including thin films, nanoparticles and nanocomposites, are paving new ways to performance improvement. The topic's tremendous application potential will appeal to a broad audience, including materials scientists, physicists, electrochemists, libraries, and graduate students.

Lithium-Sulfur Batteries

Lithium-Sulfur Batteries PDF Author: Ram Gupta
Publisher: Elsevier
ISBN: 0323919324
Category : Technology & Engineering
Languages : en
Pages : 710

Get Book Here

Book Description
Lithium-Sulfur Batteries: Materials, Challenges, and Applications presents the advantages of lithium-sulfur batteries, such as high theoretical capacity, low cost, and stability, while also addressing some of the existing challenges. Some of the challenges are low electrical conductivity, the possible reaction of sulfur with lithium to form a soluble lithium salt, the formation of the dendrimer, large volume variation of cathode materials during the electrochemical reaction, and shuttle behavior of highly soluble intermediate polysulfides in the electrolyte. This book provides some possible solutions to these issues through novel architecture, using composite materials, doping to improve low conductivity, etc., as well as emphasizing novel materials, architectural concepts, and methods to improve the performance of lithium-sulfur batteries. Covers the state-of-the-art progress on materials, technology, and challenges for lithium-sulfur batteries Presents novel synthetic approaches, characterizations, and applications of nanostructured and 2D nanomaterials for energy applications Provides fundamentals of electrochemical behavior and their understanding at nanoscale for emerging applications in lithium-sulfur batteries

Lithium-Sulfur Batteries

Lithium-Sulfur Batteries PDF Author: Prashant Kumta
Publisher: Elsevier
ISBN: 0128231696
Category : Technology & Engineering
Languages : en
Pages : 624

Get Book Here

Book Description
Lithium-sulfur (Li-S) batteries provide an alternative to lithium-ion (Li-ion) batteries and are showing promise for providing much higher energy densities. Systems utilizing Li-S batteries are presently under development and early stages of commercialization. This technology is being developed in order to provide higher, safer levels of energy at significantly lower costs. Lithium-Sulfur Batteries: Advances in High-Energy Density Batteries addresses various aspects of the current research in the field of sulfur cathodes and lithium metal anode including abundance, system voltage, and capacity. In addition, it provides insights into the basic challenges faced by the system. The book includes novel strategies to prevent polysulfide dissolution in sulfur-based systems while also exploring new materials systems as anodes preventing dendrite formation in Li metal anodes. Provides insight into the basic challenges faced by the materials system Discusses additives and suppressants to prevent dissolution of electrolyes Includes a review of the safety limitations associated with this technology Incorporates a historical perspective into the development of lithium-sulfur batteries

Development of High-energy Cathode Materials for Lithium-sulfur Batteries

Development of High-energy Cathode Materials for Lithium-sulfur Batteries PDF Author: Tianren Xu
Publisher:
ISBN:
Category :
Languages : en
Pages : 121

Get Book Here

Book Description


Electrolytes for Lithium and Lithium-Ion Batteries

Electrolytes for Lithium and Lithium-Ion Batteries PDF Author: T. Richard Jow
Publisher: Springer
ISBN: 1493903020
Category : Technology & Engineering
Languages : en
Pages : 488

Get Book Here

Book Description
Electrolytes for Lithium and Lithium-ion Batteries provides a comprehensive overview of the scientific understanding and technological development of electrolyte materials in the last several years. This book covers key electrolytes such as LiPF6 salt in mixed-carbonate solvents with additives for the state-of-the-art Li-ion batteries as well as new electrolyte materials developed recently that lay the foundation for future advances. This book also reviews the characterization of electrolyte materials for their transport properties, structures, phase relationships, stabilities, and impurities. The book discusses in-depth the electrode-electrolyte interactions and interphasial chemistries that are key for the successful use of the electrolyte in practical devices. The Quantum Mechanical and Molecular Dynamical calculations that has proved to be so powerful in understanding and predicating behavior and properties of materials is also reviewed in this book. Electrolytes for Lithium and Lithium-ion Batteries is ideal for electrochemists, engineers, researchers interested in energy science and technology, material scientists, and physicists working on energy.

Toward High Energy and High Efficiency Secondary Lithium Batteries

Toward High Energy and High Efficiency Secondary Lithium Batteries PDF Author: Rui Xu
Publisher:
ISBN:
Category :
Languages : en
Pages : 179

Get Book Here

Book Description
"Energy storage systems play an important role nowadays. Developing batteries with high energy and long cycle life has been an important research part in scientific and engineering field. Lithium ion batteries and the recent rising lithium sulfur batteries demonstrate a huge potential to be the next generation energy storage devices and being substitutes for fossil fuels in electric cars. This dissertation focuses on the development of cathode materials for lithium ion batteries with advanced electrochemical performances, and then on the design of novel lithium sulfur systems which can deliver a capacity five times as much as lithium ion batteries offer. In the first part of the dissertation, advanced cathode materials for lithium-ion batteries were investigated in the aspects of material synthesis and performance test. Li-Mn-rich composite materials have high theoretical capacities (200 - 300 mAh/g). High energy composite material 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2, or written as Li1.5Ni0.25Mn0.75O2.5, was synthesized through a polymer-assisted method and a coprecipitation method in a continuous stirred tank reactor (CSTR). The as-synthesized powder using the polymer-assisted method has a primary particle size in the range of 100-300 nm, and can reach a discharge capacity of around 230 mAh/g at the current density of 5 mA/g, and 170 mAh/g at 20 mA/g. The secondary particles of the composite material synthesized through co-precipitation method were spheres with diameters of around 10 [mu]m, and has an initial capacity of 295 mAh/g. 0.5Li2MnO3·0.5LiMn1/3Ni1/3Co1/3O2 powder was synthesized via a spray pyrolysis method. The as-prepared material was spheres with a high porosity. The first discharge capacity of the material was over 300 mAh/g. High voltage spinel cathode material has a high working potential and thus can generate a high energy. LiNi0.24Mn1.76O4 was prepared through a simple solid state method and the as-prepared material was tested between 3 - 4.8 V. The material has excellent rate capabilities and cycling stabilities. Nanofiber cathode materials were successfully produced using the electrospinning method. Through controlling a series of electrospinning parameters, LiFePO4 and high voltage spinel LiNi0.5Mn1.5O4 (LMNO) nanofibers with a diameter as thin as 50 - 100 nm were fabricated followed by a subsequent heat-treating procedure. The well-separated nanofiber precursors supress LiNi0.5Mn1.5O4 particles' growth and aggregation during the heating procedure, and led to good performances of high capacities and excellent rate capabilities of the final LMNO nanofibers. At a current density of 27 mA g−1, the initial discharge capacity of the cell was 130 mAh g−1 (charge-discharge between 3.5 - 4.8 V) and 300 mAh g−1 (2.0 - 4.8 V). In the second part of the dissertation, lithium sulfur systems were investigated due to their high theoretical capacity and the use of abundant and safe sulfur cathode material. To understand the chemistry and problems within a lithium-sulfur cell, various techniques were applied to study the system including SEM, TEM, XRD, Raman spectroscopy and etc. It was identified that one of the main problems in a Li-S cell that hinders its achieving a high performance is the so-called 'shuttle reactions'. It was resulted from the dissolution of lithium polysulfides into the electrolyte and migration to the lithium anode. Another issue was the difficulty of fully discharge a sulfur cathode due to the low conductivity of reduction product, lithium sulfide. Several approaches aiming to resolve the problems were designed to improve the cell's coulombic efficiency, capacity and cycle life. The electrochemical performances of lithium sulfur batteries and electrochemistry mechanisms within the cell system were investigated in the following aspects: 1) Impact of liquid electrolytes (including carbonate-based electrolytes and ether-based electrolytes) 2) Impact of the LiNO3 additive as a shuttle inhibitor 3) Impact of the sulfur/carbon ratio in the electrode 4) Impact of different carbon forms in the electrode 5) Impact of impregnating sulfur in the carbon pores in the electrode 6) Impact of adding polysulfide adsorbents 7) Surface morphology change of the lithium anode and the sulfur cathode 8) Composition of lithium polysulfide solution and powder 9) Self-discharge phenomenon 10) Cell intermediate and interface characterization. Last but not least, we developed a novel polysulfide-based electrolyte that prevents the performance degradation inherent to Li-S batteries by self-healing. By creating a dynamic equilibrium between the dissolution and precipitation of lithium polysulfides at the sulfur/electrolyte interface, the Li-S cells were capable of delivering a superior capacity (1450 mAh/g, sulfur), which along with the high coulombic efficiency and excellent cycle life make our cells among the best performing Li-S cells. In addition, the present technology eliminates the need for complicated and costly electrode preparation. The polysulfides in the electrolyte eliminate the need for traditional lithium salts"--Pages vi-ix.

Performance and Safety Behavior of Sulfide Electrolyte-based Solid-state Lithium Batteries

Performance and Safety Behavior of Sulfide Electrolyte-based Solid-state Lithium Batteries PDF Author: Tongjie Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
The lithium-ion batteries (LIBs) are the most researched battery system nowadays. LIBs, since their commercialization in the 1990s, provide better gravimetric/volumetric energy density, higher voltage, and cycle life with lower self-discharge than previously developed battery systems. All those advantages made the LIB systems an excellent candidate as the power source for portable electronic devices, electric-powered vehicles, space vehicles, electricity grid storage, and future electric aviation. However, there is a limitation to developing higher-capacity lithium-ion batteries as we approach the practical limit of the presently used cathodes, which makes today's high-energy LIBs. Moreover, small-form-factor portable electric devices and large-scale applications of LIB systems for electric vehicles, space vehicles, electric and hybrid aircraft, and grid storage are all facing challenges of lower than required safety levels in today's LIBs. Thus, developing new technologies and components of batteries with higher energy density and safety levels is the most desirable research & development topic. In this case, the lithium-sulfur battery (LSB) system is an excellent candidate for increasing the battery system's energy, beyond the energy storage limit of today's LIBs. With ~650 Wh kg-1 of gravimetric energy density, Li-S battery (LSB) achieved more than two times the energy density of state-of-art LIBs (~250 Wh kg-1). Organic liquid electrolyte (OLE) is one of the essential components in LIBs due to its high ionic conductivity (10-2-10-1 S cm-1) and electrode wettability at ambient conditions. As the temperature rises, the lack of thermal stability and high flammability of OLEs becomes a significant challenge in designing a safe operable LIB. Even a moderately elevated temperature (>65℗ʻC) can severely diminish the useful capacity and cycle life and can pose thermal safety issues (such as fire and explosions). Pursuing safer electrolytes led battery researchers and manufacturers around the globe to a significant task in developing a high-conductivity, thermally-stable solid-state electrolyte (SE). Depending on material selection (polymer or inorganic ceramics or polymer-ceramic composite), the solid electrolyte can be incombustible, nonvolatile, nonflammable, and stable at elevated temperatures. Combining the concept of LSB (high energy) and SE (enhanced safety), researchers introduced high energy density, high safety all-solid-state batteries, particularly all-solid-state lithium metal batteries. My research involves understanding the performance and safety behavior of next-generation, high-energy, high-safety all-solid-state lithium batteries, including LSB and LIBs. In my study, we experimented with sulfur-infused carbon as high-capacity cathode materials. We infused the sulfur at different temperatures. We utilized carbon cloth, activated carbon on carbon cloth, and hierarchical porous carbon on carbon cloth as substrate. The cathodes were tested in the baseline liquid electrolyte-based lithium-sulfur battery. To increase the safety of the lithium-sulfur battery, we synthesized different solid electrolytes based on sulfides, such as lithium phosphorous sulfur bromine iodine (LPSBI) and lithium phosphorous sulfur chlorine (LPSCl). The selection of these Li+ conducting sulfides was based on different useful properties such as i) high Li+ conductivity, ii) high interfacial stability with lithium anodes, and iii) high compressibility required for cell fabrication at room temperature. For the synthesis of Li+ conducting sulfide solid electrolyte, we have developed a scalable synthesis route that includes material sintering in a furnace in an Ar glovebox and eliminated the risk of letting the material contact with air compared to the state-of-the-art procedure that involves sintering the materials in a volume constraint quartz tube. Learned the challenges of state-of-the-art rechargeable and primary LSBs. For the first time, we constructed and studied the performance of sulfide SE-based primary (non-rechargeable) LSBs. My research suggests that future research should address optimizing i) sulfur cathode loading, ii) stack pressure, iii) electrode kinetics to make solid-state lithium-sulfur a secondary battery. The lithium (Li) anode can undergo infinite volume change during the charge-discharge of LSBs. For example, if one starts with a Li thickness of 100 ℗æm, during discharge thickness of the Li anode can vary from 100 ℗æm to 0. This kind of Li volume change, especially when using SEs makes the pressure applied on the battery critical. Without proper pressure, the connectivity of LSB components (viz., anode, electrolyte, and cathode) will falter and make the battery dysfunctional. Thus, understanding the effect of pressure on the battery plays an important role in solid-state LSBs. So we studied the effect of pressure on lithium deposition (charge) and strapping (discharge) against an important sulfide SE (Lithium Phosphorus Sulfur Bromine Iodide, LPSBI). We adopted a unique charge/discharge protocol using asymmetric cell configuration and determined the maximum allowed stripping and deposition current density at various pressures. This research will facilitate future progress on rechargeable solid-state LSBs and other rechargeable solid-state LIBs. Finally, my research focused on understanding the safety (thermal, electrochemical, and environmental) of sulfide SE-based all-solid-state LIBs using high voltage cathode (lithium cobalt oxide, LiCoO2 and low voltage anode (graphite, C). Thermal safety has been evaluated using Differential Scanning Calorimetry (DSC) and electrical safety by monitoring the open circuit voltage of a fully charged battery at different temperatures up to 170℗ʻC. Environmental safety has been evaluated by measuring the quantity of released H2S gas. The thermal, electrochemical, and environmental safety data obtained on sulfide SE-based all-solid-state LIBs has been found superior to commercial-type organic LE-based LIBs.

Li-S and Li-O2 Batteries with High Specific Energy

Li-S and Li-O2 Batteries with High Specific Energy PDF Author: Huamin Zhang
Publisher: Springer
ISBN: 9811007462
Category : Technology & Engineering
Languages : en
Pages : 55

Get Book Here

Book Description
This brief reviews the fundamentals, recent developments, challenges and prospects of Li-S and Li-O2 batteries, including fundamental research and potential applications. It starts with a brief overview encompassing the current state of Li-S and Li-O2 battery technology. It then provides general information on Li-S and Li-O2 batteries, including the electrochemical processes and battery components. The following sections focus on the historical and recent development of Li-S and Li-O2 batteries respectively, offering detailed insights into the key material development, cell assembly, diagnostic test and mechanism of electrolyte decomposition. Lastly, it focuses on the main promising applications of Li-S and Li-O2 batteries together with their challenges and potential

Room-temperature Sodium-Sulfur Batteries

Room-temperature Sodium-Sulfur Batteries PDF Author: Vipin Kumar
Publisher: CRC Press
ISBN: 1003803229
Category : Technology & Engineering
Languages : en
Pages : 177

Get Book Here

Book Description
Highlights scientific challenges in developing room-temperature sodium-sulfur batteries Covers pertinent anode, cathode, and electrolyte engineering Provides scientific and technical interpretation for each of the cell components Discusses how Na-S batteries relate to the more extensively researched Li-S batteries Explores importance of the SEI and CEI in developing stable sodium-sulfur batteries