Performance and Safety Behavior of Sulfide Electrolyte-based Solid-state Lithium Batteries PDF Download
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Author: Tongjie Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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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.
Author: Tongjie Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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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.
Author: Diane Houtarde
Publisher:
ISBN:
Category : Electric batteries
Languages : en
Pages : 89
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Book Description
Lithium-sulfur batteries are a promising candidate to support the demand for high energy density storage systems. The active material is sulfur, which presents the advantages of being abundant on earth, thus inexpensive, and environmentally friendly. However the use of conventional organic liquid electrolytes in these batteries prevents them from being commercialized, because of many technical problems that have yet to be overcome. One of the major issues is the polysulfide shuttle which leads to fast decay of cell performance. A solution is to use all-solid-state batteries instead, thus removing the inherent hazards to liquid batteries such as flammability and leakages. The drawbacks for all-solid-state are the increase in resistance of the electrolytes, the deterioration of the electronic and ionic pathways at the solid/solid interfaces, and the expensive processes and designs for their manufacture. In this thesis, research is carried out in an attempt to find new superionic conductors for solid electrolytes, improve on known conductors, and investigate the performance of all-solid-state cells using different fabrication methods and morphologies. In the first part of this thesis, the parameters influencing the synthesis of the well-known super-ionic conductor Li7P3S11are studied, in order to establish a more systematic method to produce this metastable phase at larger scales. Then, new crystal structures are uncovered in the 67.Na2S-33.P2S5 glass system. After thermal and spectroscopic analyses, it seems that these phases might be polymorphs of the known phase Na4P2S7, although its crystal structure has never been reported before. Finally, a completely new phase, Li2NaPS4, is synthesized and characterized by XRD, Raman spectroscopy, and electrochemical impedance spectroscopy. In the second part, the performance of all-solid-state batteries is analyzed depending on the solid electrolyte used, and the composition and architecture of the composite cathode. First, two batteries are compared- using Li7P3S11 and Li10GeP2S12 (LGPS) solid electrolyte respectively. The Li10GeP2S12-based cell proved superior capacity, but poor cyclability and rate capability, and investigation showed that the material decomposes in side reactions providing extra capacity. Then in the composite cathode, two different carbons, Activated Carbon (AC) and KetjenBlack (KB), and two different ionic conductors, Li1.5PS3.25 and LGPS, are compared with each other respectively. At low cycling rate, the best performance is obtained for materials which achieve higher contact area (higher surface area for carbon: AC, and higher coating and ductility for solid electrolyte: Li1.5PS3.25). However, for high rates and high rate change, conductivities are the most important characteristic to enable fast transfer of the carriers at the interface of the active material. Thus, better performance was observed for KB for the electronic conductors, and for LGPS for the ionic conductors.
Author: Darren Huan Shen Tan
Publisher:
ISBN:
Category :
Languages : en
Pages : 151
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Book Description
All solid-state batteries (ASSBs) show great promise toward becoming the dominant next-generation energy storage technology. Compared to conventional liquid electrolyte-based lithium ion batteries, ASSBs utilize nonflammable inorganic solid-state electrolytes (SSEs), which translate to improved safety and the ability to operate over a wider temperature range. Although the recent discoveries of highly conductive SSEs led to tremendous progress in ASSB's development, they still face barriers that limit their practical application, such as poor interfacial stability, scalability challenges and limited performance at high current densities. Additionally, efforts to develop sustainable manufacturing of lithium ion batteries are still lacking, with no prevailing strategy developed yet to handle recyclability of ASSBs. Recognizing this, this dissertation seeks to evaluate SSEs beyond conventional factors and offer a perspective on various bulk/interface and chemical/electrochemical phenomena that are of interest to both the scientific community and the industry. Beginning from an introduction to the current state-of-the-art, rational solutions to overcome some major fundamental obstacles faced by the ASSBs will be discussed, strategies toward enabling scalability as well as potential designs for sustainable ASSB recycling models will be discussed. Specifically, lithium solid-state battery systems were studied using sulfide based SSEs. The electrochemical reactivity of the argyrodite Li6PS5Cl system was studied, to gain insight into its reaction mechanisms, products, and reversible redox behavior. In terms of scalability, binder-solvent-sulfide compatibility was evaluated, in order to enable scalable roll to roll processability of thin and flexible sulfide SSEs. To overcome performance limitations at the anode, carbon free alloys electrodes were enabled, achieving high critical current densities and low temperature operation of ASSB full cells, addressing a key bottleneck in ASSB development. Finally, a fully recyclable ASSB model was designed, incorporating direct recycling approaches that reduce energy and greenhouse gas emissions compared to conventional recycling technologies. Overall, this dissertation offers a deepened understanding of interfacial phenomena, and improved design strategies that translates into better material selection for high performance and sustainable ASSBs.
Author: Christopher Kompella
Publisher:
ISBN:
Category :
Languages : en
Pages : 62
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Book Description
All-solid-state sodium-ion batteries are promising candidates for large-scale energy storage applications. The key enabler for an all-solid-state architecture is a sodium solid electrolyte that exhibits high Na+ conductivity at ambient temperatures, as well as excellent phase and electrochemical stability. In this work, we present the synthesis of a novel Cl-doped tetragonal Na3PS4 (t-Na3-xPS4-xClx) solid electrolyte with a room-temperature Na+ conductivity exceeding 1 mS cm-1. We demonstrate that an all-solid-state TiS2/ t-Na3-xPS4-xClx/Na cell utilizing this solid electrolyte can be cycled at room-temperature at a rate of C/10 with a capacity of over 100 mAh g-1 over 10 cycles. We provide experimental evidence that this excellent electrochemical performance is not only due to the high Na+ conductivity of the solid electrolyte, but also due to the effect that "salting" Na3PS4 has on the formation of an electronically insulating, ionically conducting solid electrolyte interphase.
Author: Tushar Swamy
Publisher:
ISBN:
Category :
Languages : en
Pages : 115
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Book Description
Inorganic solid-state electrolytes (SSEs) could replace flammable liquid electrolytes and improve the safety of Li-ion batteries. Furthermore, these SSEs could enable metal anodes, providing a significant improvement in cell-level energy density compared to the state-of-the-art. Recent improvements in the ionic conductivity of ceramic SSEs have invigorated commercial interest, prompting investigations into SSE/electrode interfacial properties. However, these investigations have revealed several challenges preventing the widespread adoption of all-solid-state Li-ion batteries. SSEs experience Li dendrite propagation and short circuit above a critical current density, similar to liquid electrolytes. While the pathways for Li penetration through a ceramic SSE such as grain boundaries and surface pores have been identified, the Li penetration mechanism is unclear. In addition, most SSEs experience detrimental redox reactions at the Li anode and 4 V cathode interface. The interfacial redox behavior of inorganic SSEs isn't well understood and requires further investigation. This thesis investigates the Li penetration mechanism into sulfide-based amorphous and polycrystalline SSEs, and garnet oxide-based single-crystal and polycrystalline SSEs. It also investigates the electrochemical redox behavior of sulfide-based SSEs. Experimental results show that Li can penetrate into single crystal SSEs devoid of grain boundaries and surface pores. Above a critical current density, the mechanical stress at a critically-sized Li-filled flaw tip at the SSE surface can breach the SSE fracture stress to initiate and propagate a crack through which Li penetrates the SSE, until a short circuit occurs. An electrochemo- mechanical model based on the Griffith theory of brittle ceramic fracture was developed, which relates the SSE fracture stress to SSE fracture toughness and surface flaw size. Experimental determination of the fracture toughness of sulfide-based SSEs revealed that these SSEs are compliant yet significantly more brittle than oxide-based SSEs. In addition, a cyclic-voltammetry based technique was developed to show that a sulfide-based SSE electrochemically decomposes to produce a redox-active interphase at the SSE/electrode interface. This is unlike in case of liquid electrolytes which decompose into an electrochemically irreversible interphase.
Author: Yasmine Benabed
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Lithium-ion batteries (LIBs) are considered the most promising energy storage technology. LIBs electrode materials have the highest known energy densities, allowing the constant miniaturization of commercial electronic devices. Research in the field of LIBs has more recently turned to their implementation in electric vehicles, which will require higher energy and power densities . A concrete way to increase the energy density of LIBs is to increase the cell voltage. To do so, the new generation of batteries will be composed of high potential positive electrode materials (such as LiMn1.5Ni0.5O4 with a potential of 4.7 V vs. Li+/Li) and metallic lithium in the negative electrode. Nevertheless, the introduction of these high potential positive electrode materials is limited by the electrochemical stability of conventional liquid electrolytes, composed of a lithium salt and organic solvents (LiPF6 + EC/DEC), which gets oxidized around 4.2 V vs. Li+/Li , . The use of metallic lithium as the negative electrode is also hindered by the liquid nature of the conventional electrolyte, which does not offer enough mechanical resistance to prevent the formation of lithium dendrites, ultimately causing a short-circuit of the battery. Such short-circuits are likely to lead to thermal runaway because liquid electrolytes are composed of organic solvents that are flammable at low temperature, posing a serious safety issue. Solid electrolytes, based on ceramics or polymers, are developed as an alternative to liquid electrolytes. They contain no flammable solvents and are stable at high temperatures. They are the key element of a new generation of lithium batteries called all-solid-state lithium batteries. These are developed to meet high expectations in terms of safety, stability and high energy density. Solid electrolytes must satisfy a number of requirements before they can be commercialized, including possessing a high ionic conductivity, a wide electrochemical stability window and negligible electronic conductivity. These properties are the most important criteria to consider when selecting solid electrolyte materials. However, the majority of studies found in the literature focuses on the ionic conductivity of solid electrolytes, overshadowing the exploration of their electrochemical stability and electronic conductivity. The electrochemical stability window has long been reported to be very wide in ceramic solid electrolytes (at least from 0 to 5 V vs. Li+/Li). Nevertheless, more recent studies tend to show that the value of this window depends greatly on the electrochemical method used to measure it, and that it is often overestimated. In this context, the first objective of this thesis was to develop a relevant method to determine the stability window of solid electrolytes with precision. This method was optimized and validated on flagship ceramic solid electrolytes such as Li1.5Al0.5Ge1.5(PO4)3, Li1.3Al0.3Ti1.7(PO4)3 and Li7La3Zr2O12. As for the electronic conductivity, it is scarcely studied in solid electrolytes, which are considered as electronic insulators given their wide band gaps. That being said, more recent studies on this subject proved that despite their band gap, solid electrolytes can generate electronic conductivity through defects, and that electronic conductivity, even if it is weak, can eventually cause the failure of the electrolyte. For this reason, the second objective of this thesis project was to explore the formation of defects in solid electrolytes in order to determine their effect on the generation of electronic conductivity. To get a better overview, first-principles were used to investigate six widely used ceramic solid electrolytes, including LiGe2(PO4)3, LiTi2(PO4)3, Li7La3Zr2O12, and Li3PS4.
Author: Han Quoc Nguyen
Publisher:
ISBN:
Category :
Languages : en
Pages : 208
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Book Description
Current state of the art commercial lithium ion batteries (LIB) have been successful power sources for portable electronics. The success of this battery has led to its penetration into electric vehicle and grid-scale storage markets. However, large quantities of LIB batteries pose a threat to public safety, as they are capable of explosive results due to the flammability of the electrolyte. All-solid-state battery (ASSB) technology is gaining attention because it has properties that can address all the shortcomings of LIB, such as: improved safe battery operations using non-volatile and non-flammable components, enabling the Li metal anode, preventing dendrite propagation, high voltage operation, suitable mechanical properties, and high transference number. Among the known solid electrolytes, sulfides have shown promise due to their processibility at lower temperatures, high ionic conductivity, and ductility compared to their oxide analogs. Herein, we investigate new SSE material and evaluate their structure and properties. The crystal structure of the SSE is solved through x-ray diffraction. The performance of the SSE is evaluated through electrochemical means such as: electrochemical impedance spectroscopy, Arrhenius behavior, electrochemical stability window, and galvanostatic charge and discharge performance in a battery. SSE for ASSB is demonstrated to have comparable room temperature ionic conductivity as their LE counterparts. Their performance can be further improved through post-processing reducing grain boundary impedance and defect engineering. The interface of the SSE and electrodes are a formidable technical hurdle to understand and overcome due to their buried nature in the ASSB configuration. The most complex of interface is the cathode/SSE interface where parasitic reaction products are formed by chemical and electrochemical means occurs. Through proper interface engineering, the stability of the interface can be improved. A lithium metal anode is demonstrated to reversibly cycle with high voltage cathodes and Li-S chemistries shorting and showing a pathway to safe and high energy density ASSB.
Author: Sujoy Saha
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Growing needs for energy storage applications require continuous improvement of the lithium ion batteries (LIB). The anionic redox chemistry has emerged recently as a new paradigm to design high-energy positive electrodes of LIBs, however with some issues (i.e., voltage hysteresis and fading, sluggish kinetics, etc.) that remained to be solved. In addition, the safety of the LIBs can be improved by designing all-solid-state batteries (ASSB). In this thesis, we first focused on the development of new oxide-based solid electrolytes (SE) for applications in ASSBs. We explored the influence of disorder on the ionic conductivity of SEs and demonstrated how to increase the conductivity by stabilizing disordered high-temperature phases. Furthermore, we designed Li-rich layered sulfide electrodes that undergo anionic sulfur redox, with excellent reversibility. Thus, the newly designed electrode materials show a possible direction to mitigate the issues related to anionic redox. Lastly, we used the Li-rich sulfides as positive electrode in ASSB with sulfide-based SEs that demonstrate excellent cyclability, thereby highlighting the importance of interfacial compatibility in ASSBs.
Author: Frank Patrick McGrogan (IV.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 270
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Book Description
In Li-ion batteries (LIBs), electrochemically driven dimensional changes in the electrodes lead to mechanical stress buildup during operation. Electrochemomechanical fatigue refers to both mechanical degradation (fracture) and the associated chemical degradation that is exacerbated by fracture as a result of this stress, accumulated during repeated electrochemical cycling. Such fracture can have serious consequences for the performance of LIBs over time in terms of capacity loss, growth of electrochemical impedance, and in all-solid-state batteries (ASSBs) even failure via short-circuiting. To better understand and predict mechanisms for electrochemically-induced fracture, we measured elastic, plastic, and fracture properties of electrode and solid electrolyte materials, focusing especially on sulfide electrolytes for ASSBs. We found that these electrolytes are extremely brittle and therefore vulnerable to fracture-assisted internal electrical shorting, an issue that currently limits commercialization of ASSBs. We built on these results with finite element modeling of electrolyte fracture in ASSBs, thus finding a strong dependence of fracture conditions on both electrolyte fracture toughness and plastic behavior of lithium metal. Using these results, we constructed electrochemomechanical failure maps to establish how microstructure, processing, and mechanical properties influence electrolyte fracture. We also studied how electrochemically induced fracture in turn affects battery performance, particularly for electrode materials. We implemented controlled fracture events in Li[subscript X]Mn2O4 cells employing liquid electrolytes and lithium anodes, and used acoustic emissions monitoring to confirm the timing of the fractures. We then used electrochemical impedance spectroscopy based on a distribution of relaxation times analysis method to isolate the fracture-based mechanisms leading to impedance growth, thereby observing sudden increases in electronic contact resistance concurrent with crack formation within the active particles. We also observed an increased rate of capacity fade following each fracture event, consistent with increased exposure of electrode surfaces to liquid electrolyte that promotes active material dissolution. Thus, within this thesis, we address complementary aspects of electrochemomechanical fatigue: how electrochemical changes promote fracture in electrodes and solid electrolytes, and how this fracture in turn affects electrochemical performance of LIB devices.
Author: Christian Julien
Publisher: Springer Science & Business Media
ISBN: 9780792366508
Category : Technology & Engineering
Languages : en
Pages : 658
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Book Description
A lithium-ion battery comprises essentially three components: two intercalation compounds as positive and negative electrodes, separated by an ionic-electronic electrolyte. Each component is discussed in sufficient detail to give the practising engineer an understanding of the subject, providing guidance on the selection of suitable materials in actual applications. Each topic covered is written by an expert, reflecting many years of experience in research and applications. Each topic is provided with an extensive list of references, allowing easy access to further information. Readership: Research students and engineers seeking an expert review. Graduate courses in electrical drives can also be designed around the book by selecting sections for discussion. The coverage and treatment make the book indispensable for the lithium battery community.
