Download or read book Non precious Cathode Electrocatalytic Materials for Zinc air Battery written by Baejung Kim and published by . This book was released on 2013 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past decade, rechargeable batteries attracted the attention from the researchers in search for renewable and sustainable energy sources. Up to date, lithium-ion battery is the most commercialized and has been supplying power to electronic devices and hybrid and electric vehicles. Lithium-ion battery, however, does not satisfy the expectations of ever-increasing energy and power density, which of their limits owes to its intercalation chemistry and the safety.1-2 Therefore, metal-air battery drew much attention as an alternative for its high energy density and a simple cell configuration.1 There are several different types of metal-air batteries that convey different viable reaction mechanisms depending on the anode metals; such as Li, Al, Ca, Cd, and Zn. Redox reactions take place in a metal-air cell regardless of the anode metal; oxidation reaction at the anode and reduction reaction at the air electrode. Between the two reaction, the oxygen reduction reaction (ORR) at the air electrode is the relatively the limiting factor within the overall cell reactions. The sluggish ORR kinetics greatly affects the performance of the battery system in terms of power output, efficiency, and durability. Therefore, researchers have put tremendous efforts in developing highly efficient metal air batteries and fuel cells, especially for high capacity applications such as electric vehicles. Currently, the catalyst with platinum nanoparticles supported on carbon material (Pt-C) is considered to exhibit the best ORR activities. Despite of the admirable electrocatalytic performance, Pt-C suffers from its lack of practicality in commercialization due to their prohibitively high cost and scarcity as of being a precious metal. Thus, there is increasing demand for replacing Pt with more abundant metals due economic feasibility and sustainability of this noble metal.3-5 Two different attitudes are taken for solution. The first approach is by optimizing the platinum loading in the formulation, or the alternatively the platinum can be replaced with non-precious materials. The purpose of this work is to discover and synthesize alternative catalysts for metal-air battery applications through optimized method without addition of precious metals. Different non-precious metals are investigated as the replacement of the precious metal including transition metal alloys, transition metal or mixed metal oxides, and chalcogenides. These types of metals, alone, still exhibits unsatisfying, yet worse, kinetics in comparison to the precious metals. Nitrogen-doped carbon material is a recently well studied carbon based material that exhibits great potential towards the cathodic reaction.6 Nitrogen-doped carbon materials are found to exhibit higher catalytic activity compared to the mentioned types of metals for its improved conductivity. Benefits of the carbon based materials are in its abundance and minimal environmental footprints. However, the degradation of these materials has demonstrated loss of catalytic activity through destruction of active sites containing the transition metal centre, ultimately causing infeasible stability. To compensate for these drawbacks and other limits of the nitrogen-doped carbon based catalysts, nitrogen-doped carbon nanotubes (NCNT) are also investigated in the series of study. The first investigation focuses on a development of a simple method to thermally synthesize a non-precious metal based nitrogen-doped graphene (NG) electrocatalyst using exfoliated graphene (Ex-G) and urea with varying amounts of iron (Fe) precursor. The morphology and structural features of the synthesized electrocatalyst (Fe-NG) were characterized by SEM and TEM, revealing the existence of graphitic nanoshells that potentially contribute to the ORR activity by providing a higher degree of edge plane exposure. The surface elemental composition of the catalyst was analyzed through XPS, which showed high content of a total N species (~8 at.%) indicative of the effective N-doping, present mostly in the form of pyridinic nitrogen groups. The oxygen reduction reaction (ORR) performance of the catalyst was evaluated by rotating disk electrode voltammetry in alkaline electrolyte and in a zinc-air battery cell. Fe-NG demonstrated high onset and half-wave potentials of -0.023 V (vs. SCE) and -0.110 V (vs. SCE), respectively. This excellent ORR activity is translated into practical zinc-air battery performance capabilities approaching that of commercial platinum based catalyst. Another approach was made in the carbon materials to further improve the cost of the electrode. Popular carbon allotropes, CNT and graphene, are combined as a composite (GC) and heteroatoms, nitrogen and sulfur, are introduced in order to improve the charge distribution of the graphitic network. Dopants were doped through two step processes; nitrogen dopant was introduced into the graphitic framework followed by the sulfur dopant. The coexistence of the two heteroatoms as dopants demonstrated outstanding ORR performance to those of reported as metal free catalysts. Furthermore, effects of temperature were investigated through comparing ORR performances of the catalysts synthesized in two different temperatures (500 ??? and 900 ???) during the N-doping process (consistent temperature was used for S-doping). Through XPS analysis of the surface chemistry of catalysts produced with high temperature during the N-doping step showed absence of N-species after the subsequent S-doping process (GC-NHS). Thus, the synergetic effects of the two heteroatoms were not revealed during the half-cell testing. Meanwhile, the two heteroatoms were verified in the catalyst synthesized though using low temperature during the N-doping process followed by the S-doping step (GC-NLS). Consequently, ORR activity of the resulting material demonstrated promising onset and half-wave potentials of -0.117 V (vs. SCE) and -0.193 V (vs. SCE). In combination of these investigations, this document introduces thorough study of novel materials and their performance in its application as ORR catalyst in metal air batteries. Moreover, this report provides detailed fundamental insights of carbon allotropes, and their properties as potential elecrocatalysts and essential concepts in electrochemistry that lies behind zinc-air batteries. The outstanding performances of carbon based electrocatalyst are reviewed and used as the guides for further direction in the development of metal-air batteries as a promising sustainable energy resource in the future.
Download or read book Zinc Air Batteries written by Zongping Shao and published by John Wiley & Sons. This book was released on 2023-01-04 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc–Air Batteries Authoritative and comprehensive resource covering foundational knowledge of zinc–air batteries as well as their practical applications Zinc–Air Batteries provides a comprehensive understanding of the history and development of Zn–air batteries, with a systematic overview of components, design, and device innovation, along with recent advances in the field, especially with regards to the cathode catalyst design made by cutting-edge materials, engineering processes, and technologies. In particular, design principles regarding the key components of Zn–air batteries, ranging from air cathode, to zinc anode, and to electrolyte, are emphasized. Furthermore, industrial developments of Zn–air batteries are discussed and emerging new designs of Zn–air batteries are also introduced. The authors argue that designing advanced Zn–air battery technologies is important to the realization of efficient energy storage and conversion—and, going further, eventually holds the key to a sustainable energy future and a carbon-neutral goal. Edited and contributed to by leading professionals and researchers in the field, Zinc–Air Batteries also contains information regarding: Design of oxygen reduction catalysts in primary zinc–air batteries, including precious metals, single-atoms, carbons, and transition metal oxides Design of bifunctional oxygen catalysts in rechargeable zinc–air batteries, covering specific oxygen redox reactions and catalyst candidates Design of three-dimensional air cathode in zinc–air batteries, covering loading of carbon-based and transition metal catalysts, plus design of the three-phase interface Design of electrolyte for zinc–air batteries, including liquid electrolytes (e.g., alkaline) and gel polymer electrolytes (e.g., PVA hydrogel) For students, researchers, and instructors working in battery technologies, materials science, and electrochemistry, and for industry and government representatives for decision making associated with energy and transportation, Zinc–Air Batteries summarizes the research results on Zn–air batteries and thereby helps researchers and developers to implement the technology in practice.
Download or read book Zinc Batteries written by Rajender Boddula and published by John Wiley & Sons. This book was released on 2020-05-05 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Battery technology is constantly changing, and the concepts and applications of these changes are rapidly becoming increasingly more important as more and more industries and individuals continue to make “greener” choices in their energy sources. As global dependence on fossil fuels slowly wanes, there is a heavier and heavier importance placed on cleaner power sources and methods for storing and transporting that power. Battery technology is a huge part of this global energy revolution. Zinc batteries are an advantageous choice over lithium-based batteries, which have dominated the market for years in multiple areas, most specifically in electric vehicles and other battery-powered devices. Zinc is the fourth most abundant metal in the world, which is influential in its lower cost, making it a very attractive material for use in batteries. Zinc-based batteries have been around since the 1930s, but only now are they taking center stage in the energy, automotive, and other industries. Zinc Batteries: Basics, Developments, and Applicationsis intended as a discussion of the different zinc batteries for energy storage applications. It also provides an in-depth description of various energy storage materials for Zinc (Zn) batteries. This book is an invaluable reference guide for electrochemists, chemical engineers, students, faculty, and R&D professionals in energy storage science, material science, and renewable energy.
Download or read book Design and Engineering of Hierarchically Porous Transition Metal based Electrocatalysts for Rechargeable Zn air Batteries written by Moon Gyu Park and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemical oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the critical cathodic and anodic reactions, respectively, in electrically rechargeable Zn-air battery. With a variety of advantages including relatively high energy density (1218 Wh kg-1), the abundance of zinc in the earth, and secure handling and safe operation, electrically rechargeable (secondary) Zn-air battery technology has been regarded as highly promising energy applications in consumer electronics, electric vehicles, and smart grid storage. Zn-air batteries consist of not only zinc anode, polymer separator, and an alkaline electrolyte that are typical battery components, but also air-breathing cathode that makes Zn-"air" battery unique technology. Unlike other general battery systems such as lithium-ion batteries, there is no active material stored in cathode, but gaseous oxygen molecules in the air are used as the fuel for energy-generating reaction in the air cathode of Zn-air technology. The reactions occurring during battery discharge and charge are ORR and OER, respectively, which are mostly dominating the overall energy efficiency of the Zn-air battery system due to their intrinsically sluggish kinetics. The high energy barrier attributed to conversions between oxygen molecules diffused from the air and hydroxide ions in the electrolyte at the thin layer of the electrode leads to low charge/discharge energy efficiency and insufficient cycle stability hindering the commercialization of rechargeable Zn-air batteries to the market. Therefore, it is necessarily required to facilitate the slow kinetics of oxygen electrocatalytic reactions by using bifunctionally active and durable oxygen electrocatalyst materials to progress the reactions at practically viable and stable rates. With the use of bifunctional oxygen catalysts, kinetics of ORR and OER can be improved, leading to enhancement of Zn-air battery performances such as higher operating voltage and longer battery cycling life. The current best-known catalysts for ORR and OER are noble metals, including platinum (Pt) and iridium (Ir), respectively. However, high cost and scarcity of the precious metal-based catalysts hinder their employment in large scale energy applications. Furthermore, the electrochemical stability of these materials is well known to be very insufficient for long term usage even under typical device operating conditions. Therefore, the development of non-precious transition metal-based electrocatalysts has significantly been a momentous research field. Along with this movement, the facile synthesis and inexpensive preparation of highly active and durable electrocatalysts will take the top priority for the fulfillment of practically available rechargeable Zn-air battery technology in a variety of energy applications from portable electronics to electric vehicles and smart grid storage systems. In this work, novel design strategies of bifunctionally active and durable electrocatalysts possessing robust three-dimensional framework with hierarchical porosity are presented. A porous structure with a large surface area is essential to improve the oxygen electrocatalysis since the oxygen reactions take place at the surface of materials, where active sites reside, and thereby the large surface indicating plenty of catalytically active sites enhances kinetics of the reactions. Additionally, the porous architecture facilitates diffusion of oxygen gas molecules during the oxygen electrocatalysis, leading to enhanced mass transport of reactants and reduced overpotentials for ORR and OER polarizations, eventually resulting in improved activities. In addition to the improvement of activities, electrochemical stability is an essential fundamental property for the rational design of electrocatalysts. Thus, the 3D porous structure must have robust framework which can endure the highly oxidative environment in OER potential range. Therefore, the work presented in this thesis is aiming for the design and engineering of hierarchically porous transition metal-based electrocatalysts involving high porosity as well as electrocatalytically robust frameworks to improve the oxygen electrocatalytic activities and durability and thereby put the rechargeable Zn-air battery technology at a commercially viable level. In the first study, a facile polymer template-derived method has been used to synthesize three-dimensionally ordered meso/macro-porous (3DOM) spinel cobalt oxide as a bifunctional oxygen electrocatalyst. Physicochemical characterizations have revealed the morphology of the designed electrocatalyst to be a hierarchically meso/macro-porous metal oxide framework. As investigated by electrochemical characterizations, 3DOM Co3O4 shows far enhanced ORR and OER activities with improved kinetics compared to the bulk material. The enhancement is majorly attributed to the five times higher specific surface area and significantly greater pore volume, leading to the increased number of catalytic active sites and facilitated diffusion of oxygen molecules into and out of the structure, respectively. Moreover, the robust frameworks of 3DOM Co3O4 helps to withstand harsh cycling environments by exhibiting significantly small performance reduction and retaining the original morphology. The improved oxygen electrocatalytic activity and durability have been well demonstrated in the rechargeable Zn-air battery system. 3DOM Co3O4 presents remarkably enhanced rechargeability over 200 cycles while retaining quite comparable operating voltage gap in comparison with the precious benchmark catalyst. In the second study, palladium (Pd) nanoparticle is deposited on the surface of 3DOM Co3O4 via a simple chemical reduction process. The morphological advantages of the 3DOM framework, as confirmed in the previous study, are expected to facilitate diffusion of oxygen molecules into and out of the structure leading to the decreased overpotentials during ORR and OER. However, using metal oxides as electrocatalysts restricts fast electron transfer leading to limited activity for oxygen catalysis due to their intrinsically low electrical conductivity. Therefore, Pd nanoparticles are introduced into 3DOM Co3O4 by expecting synergy from the combination of the morphological advantage of 3DOM architecture and the significant thermodynamic stability as well as the excellent ORR activity of palladium metal. Electrochemical characterizations have revealed that the combination demonstrates synergistically improved bifunctional electrocatalytic activity and durability. Moreover, computational simulation via density-functional-theory (DFT) verifies Pd@Co3O4(3DOM) is superior in two ways; (i) Activity-wise: the d-band center of Pd deposited on 3DOM Co3O4 was found to decrease significantly, resulting in increased electron abundance at the Fermi level, which in turn enhanced the overall electrical conductivity; (ii) Durability-wise: synergistic hybrid of Pd and 3DOM Co3O4 resulted in a significantly improved corrosion resistance, due to the much higher carbon oxidation potential and bulk-like dissolution potential of Pd nanoparticles on 3DOM Co3O4. The remarkable electrochemical activities and stabilities of Pd@3DOM-Co3O4 obtained from the half-cell testing resulted in excellent rechargeability of a prototype Zn-air battery, demonstrating the synergistic introduction of Pd into 3DOM Co3O4. In the last study, a type of metal-organic-framework (MOF) is selected as a template to synthesize MOF-based electrocatalyst possessing robust framework with multi-level porosity. Typically, MOF materials consist of metal centers linked by functional organic ligands, which gives them unique material characteristics such as high porosity and surface area, morphological and compositional flexibility, and high crystallinity. Especially, transition metal-based Prussian blue analogue (PBA) nanocubes with a chemical formula MxII[MyIII(CN)6]z▪H2O, where MII and MIII are divalent and trivalent transition metal cations, respectively, are employed as the MOF precursors due to a several material advantages such as simple precipitation synthesis, various possible compositions, and robust structure with high porosity
Download or read book Novel Non Precious Metal Electrocatalysts for Oxygen Electrode Reactions written by Hui Yang and published by MDPI. This book was released on 2019-11-01 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on alternative energy harvesting technologies, conversion and storage systems with high efficiency, cost-effective and environmentally friendly systems, such as fuel cells, rechargeable metal-air batteries, unitized regenerative cells, and water electrolyzers has been stimulated by the global demand on energy. The conversion between oxygen and water plays a key step in the development of oxygen electrodes: oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), processes activated mostly by precious metals, like platinum. Their scarcity, their prohibitive cost, and declining activity greatly hamper large-scale applications. This issue reports on novel non-precious metal electrocatalysts based on the innovative design in chemical compositions, structure, and morphology, and supports for the oxygen reaction.
Download or read book Nanostructured Spinel Oxides as Bi functional Electrocatalysts for Rechargeable Metal air Batteries written by Dong Un Lee and published by . This book was released on 2017 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to continuously increasing energy demands, particularly with the emergence of electric vehicles (EV), smart energy grids, and portable electronics, advanced energy conversion and storage systems such as fuel-cells and metal-air batteries have drawn tremendous research and industrial attention. Even though the lithium-ion battery technology is the most developed and widely distributed energy device for a wide range of applications, some researchers view its energy density insufficient for fulfilling the ultimate requirements of highly energy intensive applications such as EVs. Recently, zinc-air batteries have re-gained research attention since the initial development in the 1970s due to their remarkably highly energy density and the potential to be electrically rechargeable. However, some technological hurdles such as low charge/discharge energy efficiency, and insufficient cycle stability have hampered commercialization and introduction of rechargeable zinc-air batteries to the market. The mentioned hurdles are currently the main challenges of rechargeable zinc-air battery developed, and they stem from the fact that the reaction kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are intrinsically very sluggish. The two are the main electrochemical reactions that govern the charge and discharge processes of a rechargeable metal-air battery at the air electrode, and these oxygen reactions must be facilitated by active electrocatalysts in order to progress them at practically viable and stable rates. Currently, the best known catalysts for ORR and OER are carbon supported platinum (Pt/C) and iridium (Ir/C), respectively. However, the use of these precious metal based catalysts for large scale applications like EVs and energy storage systems is prohibitively expensive. Additionally, the durability of these catalysts have been reported to be insufficient for long-term usage under normal device operating conditions. Perhaps most importantly, the precious metal based catalysts are strongly active towards only one of the two oxygen reactions required for rechargeable applications. For example, Pt/C is a strong ORR active catalyst, while Ir/C is a strong OER active catalyst. Recently in the literature, a simple physical mixture of these two catalysts have been used to render bi-functionality, but this method is very rudimentary and still requires two separate syntheses for each catalyst. This suggests that future bi-functionally active catalysts must not only be non-precious (inexpensive), but also a single active material capable of catalyzing both ORR and OER over the same active surface. Having said above, non-precious catalyst research, specifically for bi-functional ORR and OER electrocatalyses, has increased dramatically beginning in the 90's with a very popular and positive belief in the energy community that rechargeable lithium-air batteries could potentially replace lithium-ion batteries. This wave of interest has also picked up research in rechargeable zinc-air batteries since the electrochemical oxygen reactions that take place at the air electrodes are fundamentally very similar. Additionally, the use of zinc metal as the anode, which is one of Earth's most abundant elements, and the water-based (aqueous) solutions as the electrolyte (as opposed to organic ones) made the rechargeable zinc-air battery development very attractive and seemingly easy to scale-up. Moreover, primary (non-rechargeable) zinc-air batteries have already been commercialized and are available in the market as hearing aid batteries, leading many researchers to believe that a simple tuning of the current technology would lead to a successful secondary (rechargeable) zinc-air battery development. However, there are a set of technical difficulties specific to rechargeable zinc-air batteries that have slowed the development for the past few decades. Therefore, the work presented in this thesis aims to address the challenges of rechargeable zinc-air batteries particularly from the active bi-functional electrocatalyst standpoint to make them as commercially viable as possible.
Download or read book Zinc Air Batteries written by Shengjie Peng and published by Springer Nature. This book was released on 2023-01-01 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims to discuss the cutting-edge materials and technologies for zinc-air batteries. From the perspective of basic research and engineering application, the principle innovation, research progress, and technical breakthrough of key materials such as positive and negative electrodes, electrolytes, and separators of zinc-air batteries are discussed systematically, which can be used to guide and promote the development of zinc-air battery technology. We do believe that our experiences and in-depth discussions would make this book useful for researchers at all levels in the energy area and provide them with a quick way of understanding the development of zinc-air batteries.
Download or read book Advanced Nanostructured Electrode and Materials Design for Zinc Air Batteries written by Jordan Scott and published by . This book was released on 2013 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc air batteries have great promise as a new age energy storage device due to their environmental benignity, high energy density in terms of both mass and volume, and low cost Zinc air batteries get their high energy density by using oxygen from the air as the active material. This means that all the mass and volume that are normally required for active material in a battery are replaced by a thin gas diffusion electrode which allows for oxygen from the air to diffuse into the cell. Although this seems ideal, there are many technical challenges associated with the cell being open to the atmosphere. Some of these issues include electrolyte and electrode drying out, poor reaction kinetics involving sluggish reaction, the need for bifunctional catalysts to charge and discharge, and durability of the gas diffusion electrode itself. The bifuntional catalysts used in these systems are often platinum or other precious metals since these are commonly known to have the highest performance, however the inherent cost of these materials limits the feasibility of zinc air systems. Thus, there is a need to limit or remove the necessity for platinum carbon catalysts. There are many types of non precious metal catalysts which can be used in place of platinum, however their performance is often not as high, and the durability of these catalysts is also weak. Similar limitations on feasibility are invoked by the poor durability of the gas diffusion electrodes. Carbon corrosion occurs at the harsh caustic conditions present at the gas diffusion electrodes, and this corrosion causes catalyst dissolution. Moreover, many issues with zinc electrode fabrication limit durability and usable anode surface area within these systems. There is a need for a stable, porous, high surface area anode with good structural integrity. These issues are addressed in this work by three studies which each focuses on solving some of the issues pertaining to a crucial component of zinc air batteries, those being the gas diffusion electrode, the zinc electrode, and the bifunctional catalyst necessary for oxygen reduction reactions (ORR) and oxygen evolution reactions (OER).
Download or read book Design of Efficient Cobalt based Bi functional Catalysts for Zinc air Batteries written by Guihua Liu and published by . This book was released on 2019 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to its high theoretical specific energy and low-cost, rechargeable zinc-air batteries have attracted tremendous attention as a promising next-generation energy conversion system. However, there are some challenges that need to overcome before its practical application. One of the key issues is the slow reaction kinetics in the air cathode of the batteries towards the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). This would cause insufficient charge/discharge efficiency and poor cycle stability of the batteries. Therefore, the development of efficient ORR-OER bi-functional electrocatalysts with high catalytic activity and durability is essential for the development of rechargeable zinc-air batteries. In this work, a series of catalyst design strategies have been explored to improve the activity and durability of cobalt-based bi-functional catalysts especially under the oxidative condition of OER reaction. The latter would cause catalyst oxidation and aggregation, and therefore deteriorate the cycling performance of the bi-functional catalysts in zinc-air batteries. In the first study, a surface engineering approach was adopted to prepare efficient bi-functional catalyst consists of mildly oxidized, N-doped Co9S8 catalyst supported on N-doped reduce graphite oxide (O-N-Co9S8@N-RGO). The surface decorated electrocatalyst shows excellent activity for both ORR and OER, and maintains good stability over 900 charge-discharge cycles at 10 mA cm-2 in zinc-air battery. Interestedly, it was found that O-N-Co9S8 nanoparticles responsible for the OER reaction were completely converted into Co3O4 after OER reaction, indicating Co3O4 is the actual active phase for OER. On the basis of this observation, we propose and demonstrate that oxides in-situ generated cobalt oxides during OER reaction are more active than the directly calcined oxides. This work advances fundamental insight and the design of metal chalcogenides-based bi-functional "catalysts". On the recognition of the high catalytic activity of surface-engineered Co9S8 material, a three-dimensionally ordered mesoporous (3DOM) structured surface-engineered Co9S8 catalyst was developed to explore the benefits of the 3DOM structural design for its catalytic performance. Different from the N-RGO supported O-N-Co9S8, the 3DOM-Co9S8 catalyst is self-supported, which contains only an inner carbon layer within its mesoporous structure. Due to the 3D interconnected architecture and large surface area, the air electrode delivers excellent cell performance and cycling durability. However, the partial structure crush of N-Co9S8 after long-time OER testing was observed, demonstrating that the highly oxidative operating condition of rechargeable zinc-air batteries could cause significant structural integrity issues of porous chalcogenide electrocatalysts. Thus, in the last study, a new strategy focusing on the oxidation-resistive catalyst support design using oxygen vacancy (OV)-rich, low-bandgap semiconductor was proposed. The OVs promote the electrical conductivity of the semiconductor support, and at the same time offer a strong metal-support interaction (SMSI). The SMSI enables the catalysts with small metal size, high catalytic activity, and high stability. This strategy is demonstrated by successfully synthesizing ultrafine Co metal decorated 3DOM titanium oxynitride (3DOM-Co@TiOxNy). The catalyst not only exhibits good ORR-OER activities, but also shows excellent cycling stability in alkaline conditions, e.g. less than 1% energy efficiency loss over 900 charge-discharge cycles at 20 mA cm-2. Theoretical calculation confirmed that the high stability of this catalyst is attributed to the strong SMSI between Co and 3DOM-TiOxNy. This study will provide an alternative strategy for the design of efficient and durable non-precious electrocatalysts using OV-rich semiconductors as support materials. In summary, a series of catalyst design strategies for efficient and durable bi-functional ORR-OER catalyst were developed in this work. It was found that NH3 treatment is an effective surface-engineering approach to develop highly active ORR-OER catalysts. The in-situ transformation or oxidation of Co9S8 into Co3O4 observed in post-OER analysis advanced our understanding of the chemical, structural transformation and real catalytic phase for OER "catalyst". Moreover, the results show that the 3DOM design of self-supported Co9S8 catalyst could also benefits the catalytic performance by facilitating the mass and electronic transportation within the 3DOM framework. Finally, based on our up-to-date understanding of the OV in semiconductor physics and heterogeneous catalysis, a novel bi-functional catalyst support design strategy was proposed and demonstrated using OV-rich TiOxNy semiconductor. Excellent cycling stability and activity performance of such semiconductor supported cobalt catalyst in rechargeable zinc-air batteries is achieved.
Download or read book Zinc Batteries written by Rajender Boddula and published by John Wiley & Sons. This book was released on 2020-04-10 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Battery technology is constantly changing, and the concepts and applications of these changes are rapidly becoming increasingly more important as more and more industries and individuals continue to make “greener” choices in their energy sources. As global dependence on fossil fuels slowly wanes, there is a heavier and heavier importance placed on cleaner power sources and methods for storing and transporting that power. Battery technology is a huge part of this global energy revolution. Zinc batteries are an advantageous choice over lithium-based batteries, which have dominated the market for years in multiple areas, most specifically in electric vehicles and other battery-powered devices. Zinc is the fourth most abundant metal in the world, which is influential in its lower cost, making it a very attractive material for use in batteries. Zinc-based batteries have been around since the 1930s, but only now are they taking center stage in the energy, automotive, and other industries. Zinc Batteries: Basics, Developments, and Applicationsis intended as a discussion of the different zinc batteries for energy storage applications. It also provides an in-depth description of various energy storage materials for Zinc (Zn) batteries. This book is an invaluable reference guide for electrochemists, chemical engineers, students, faculty, and R&D professionals in energy storage science, material science, and renewable energy.
Download or read book Non noble metal oxygen electrocatalysts for zinc air batteries written by Zhan Yi and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal Air and Metal Sulfur Batteries written by Vladimir Neburchilov and published by CRC Press. This book was released on 2016-09-19 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal–air and metal–sulfur batteries (MABs/MSBs) represent one of the most efficient-energy storage technologies, with high round trip efficiency, a long life cycle, fast response at peak demand/supply of electricity, and decreased weight due to the use of atmospheric oxygen as one of the main reactants. This book presents an overview of the main MABs/MSBs from fundamentals to applications. Recent technological trends in their development are reviewed. It also offers a detailed analysis of these batteries at the material, component, and system levels, allowing the reader to evaluate the different approaches of their integration. The book provides a systematic overview of the components, design, and integration, and discusses current technologies, achievements, and challenges, as well as future directions. Each chapter focuses on a particular battery type including zinc–air batteries, lithium–air batteries, aluminum–air batteries, magnesium–air batteries, lithium–sulfur batteries, and vanadium–air redox flow batteries, and metal–sulfur batteries. Features the most recent advances made in metal–air/metal–sulfur batteries. Describes cutting-edge materials and technology for metal–air/metal–sulfur batteries. Includes both fundamentals and applications, which can be used to guide and promote materials as well as technology development for metal–air/metal–sulfur batteries. Provides a systematic overview of the components, design, and integration, and discusses current technologies, achievements, and challenges, as well as future directions. Covers a variety of battery types in depth, such as zinc–air batteries, lithium–air batteries, aluminum–air batteries, magnesium–air batteries, lithium–sulfur batteries, vanadium–air redox flow batteries, and metal–sulfur batteries.
Download or read book Spinel Oxides and Heteroatom doped Carbon Nano composite as Bi functional Oxygen Electrocatalyst for Rechargeable Zinc air Battery written by Moon Gyu Park and published by . This book was released on 2015 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: With continued increase in energy demand for high energy-required devices such as portable electronics and electric vehicles, development of innovative energy conversion and storage systems has attracted tremendous attention. Even though lithium-ion battery technology is currently the most developed energy storage technology and employed for multiple applications, their insufficient energy density and critical problem in intrinsic chemistry limit their further development for fulfilling the ultimate requirements. As an attractive alternative technology, metal-air battery has recently captured the spotlight as promising sustainable energy conversion and storage technology. Metal-air batteries with the open architecture provide many attractive characteristics containing environmental benignity, high power and energy densities. In addition, with a wide range of selection in different metals determines different energy capacity and efficiency. Among a various types of metal-air batteries, zinc-air battery system has especially been considered as the most mature technology due to its abundance, low cost, ease handling, and safe operation as well as high energy efficiency. However, some technological challenges of zinc-air batteries such as insufficient cycling durability, low charge/discharge activity and efficiency, and poor rate capability still must be addressed for future commercialization. These main challenges interrupting the development of electrically rechargeable zinc-air batteries are primarily due to very sluggish oxygen reduction and evolution reactions generated during discharge and charge processes on air electrode. The slow oxygen reactions create large overpotentials during both discharge and charge processes, which significantly decrease energy efficiency of zinc-air battery. Accordingly, the use of electrocatalysts in air electrode has been highly required to facilitate the reactions and even propel the zinc-air batteries to practical energy applications. Therefore, it is considerably necessary to develop highly active and durable bi-functional electrocatalysts toward both ORR and OER for the sake of successful commercialization of electrically rechargeable zinc-air batteries. In this point of view, design and synthesis of advanced oxygen electrocatalysts at low cost has been favorably considered. Despite extensive efforts made, however, developing air electrode catalysts with the high activity and the long durability at low cost remain a huge challenge because mostly precious metal-based catalysts such as platinum (Pt) and iridium (Ir) show greatly high activities toward ORR and OER, respectively. However, the use of the materials as electrocatalysts for zinc-air battery is highly challengeable in that they are extremely scarce, expensive, and unstable during the oxygen reactions. Therefore, it is significantly important to develop proper materials which are inexpensive, abundant, and stable during the oxygen reactions, where they are called “non-precious catalysts” primarily composed of transition metals or metal oxides, nano-carbons, and their hybrids. The strong objectives make us focus on the design of a class of novel composite architecture for high-performance electrochemical energy storage, electrically rechargeable zinc-air battery. In this work, the strategy is based on a fast solvation-induced assembly that directly exploits strong hydrophobicity of both cobalt oxide nanocrystals (Co3O4 NCs) and Nitrogen-doped carbon nanotubes (N-CNTs). A two-phase method is exploited to prepare the nearly mono-dispersed, highly crystalline, nano-sized cobalt oxide. The reaction of the two-phase system happens at the interface between the oil (nonpolar) and water (polar) phases and the interface is an exclusive site for both nucleation and growth. N-CNTs were synthesized by a single step chemical vapor deposition technique using either ferrocene as a catalyst and etylenediamine as a carbon source. Simply at first, cobalt oxide NCs and N-CNTs are dispersed in nonpolar solvent (e.g., toluene). Upon addition of polar solvent (e.g., methanol), solvation forces induce the hydrophobic cobalt oxide NCs to assemble around the hydrophobic CNTs, which leads to the formation of cobalt oxide NCs-decorated on the N-CNTs. As an electrochemical catalyst for air electrode, Co3O4 nanoparticle is a material with little ORR activity by itself. However, when it is decorated on Nitrogen-doped carbon nanotubes, their hybrid shows unexpected, surprisingly high performance in ORR that is further enhanced by nitrogen doping of N-CNTs. The Co3O4 NC/N-CNT hybrid exhibits comparable ORR catalytic activity but superior stability to a commercial carbon-supported Pt catalyst in alkaline solutions, thus leading to a novel bi-functional catalyst for ORR. The same hybrid is also highly active for OER, making it a high-performance non-precious metal-based bi-functional catalyst for both ORR and OER. The unusual catalytic activity arises from synergetic coupling effects between Co3O4 and N-CNTs. The full cell electrochemical catalytic activity is evaluated by preparing air electrodes of rechargeable zinc-air batteries utilizing ambient air to emphasize practicality. The galvanodynamic charge and discharge behaviors are superior to Pt/Carbon and N-CNT counterparts particularly at high applied current densities. Electrochemical impedance spectroscopy reveals that Co3O4 NC/N-CNT hybrid electrode results in significantly less internal, solid-electrolyte interface, and charge transfer resistances which lead to highly efficient electrochemical reactions. Superior rechargeability has also been confirmed where virtually no voltage drops are observed over 200 pulse cycles. The practicality of Co3O4 NC/N-CNT hybrid is highlighted by demonstrating comparable discharge voltages and greatly outperforming charge voltages with excellent electrochemical stability than commercial Pt/Carbon catalyst.
Download or read book PEM Fuel Cell Electrocatalysts and Catalyst Layers written by Jiujun Zhang and published by Springer Science & Business Media. This book was released on 2008-08-26 with total page 1147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proton exchange membrane (PEM) fuel cells are promising clean energy converting devices with high efficiency and low to zero emissions. Such power sources can be used in transportation, stationary, portable and micro power applications. The key components of these fuel cells are catalysts and catalyst layers. “PEM Fuel Cell Electrocatalysts and Catalyst Layers” provides a comprehensive, in-depth survey of the field, presented by internationally renowned fuel cell scientists. The opening chapters introduce the fundamentals of electrochemical theory and fuel cell catalysis. Later chapters investigate the synthesis, characterization, and activity validation of PEM fuel cell catalysts. Further chapters describe in detail the integration of the electrocatalyst/catalyst layers into the fuel cell, and their performance validation. Researchers and engineers in the fuel cell industry will find this book a valuable resource, as will students of electrochemical engineering and catalyst synthesis.
Download or read book Encyclopedia of Electrochemical Power Sources written by Jürgen Garche and published by Newnes. This book was released on 2013-05-20 with total page 4532 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Encyclopedia of Electrochemical Power Sources is a truly interdisciplinary reference for those working with batteries, fuel cells, electrolyzers, supercapacitors, and photo-electrochemical cells. With a focus on the environmental and economic impact of electrochemical power sources, this five-volume work consolidates coverage of the field and serves as an entry point to the literature for professionals and students alike. Covers the main types of power sources, including their operating principles, systems, materials, and applications Serves as a primary source of information for electrochemists, materials scientists, energy technologists, and engineers Incorporates nearly 350 articles, with timely coverage of such topics as environmental and sustainability considerations
Download or read book Photo and Electro Catalytic Processes written by Jianmin Ma and published by John Wiley & Sons. This book was released on 2022-01-25 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore green catalytic reactions with this reference from a renowned leader in the field Green reactions—like photo-, photoelectro-, and electro-catalytic reactions—offer viable technologies to solve difficult problems without significant damage to the environment. In particular, some gas-involved reactions are especially useful in the creation of liquid fuels and cost-effective products. In Photo- and Electro-Catalytic Processes: Water Splitting, N2 Fixing, CO2 Reduction, award-winning researcher Jianmin Ma delivers a comprehensive overview of photo-, electro-, and photoelectron-catalysts in a variety of processes, including O2 reduction, CO2 reduction, N2 reduction, H2 production, water oxidation, oxygen evolution, and hydrogen evolution. The book offers detailed information on the underlying mechanisms, costs, and synthetic methods of catalysts. Filled with authoritative and critical information on green catalytic processes that promise to answer many of our most pressing energy and environmental questions, this book also includes: Thorough introductions to electrocatalytic oxygen reduction and evolution reactions, as well as electrocatalytic hydrogen evolution reactions Comprehensive explorations of electrocatalytic water splitting, CO2 reduction, and N2 reduction Practical discussions of photoelectrocatalytic H2 production, water splitting, and CO2 reduction In-depth examinations of photoelectrochemical oxygen evolution and nitrogen reduction Perfect for catalytic chemists and photochemists, Photo- and Electro-Catalytic Processes: Water Splitting, N2 Fixing, CO2 Reduction also belongs in the libraries of materials scientists and inorganic chemists seeking a one-stop resource on the novel aspects of photo-, electro-, and photoelectro-catalytic reactions.
Download or read book Sustainable Green Chemical Processes and their Allied Applications written by Inamuddin and published by Springer Nature. This book was released on 2020-05-30 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: Urbanization, industrialization, and unethical agricultural practices have considerably negative effects on the environment, flora, fauna, and the health and safety of humanity. Over the last decade, green chemistry research has focused on discovering and utilizing safer, more environmentally friendly processes to synthesize products like organic compounds, inorganic compounds, medicines, proteins, enzymes, and food supplements. These green processes exist in other interdisciplinary fields of science and technology, like chemistry, physics, biology, and biotechnology, Still the majority of processes in these fields use and generate toxic raw materials, resulting in techniques and byproducts which damage the environment. Green chemistry principles, alternatively, consider preventing waste generation altogether, the atom economy, using less toxic raw materials and solvents, and opting for reducing environmentally damaging byproducts through energy efficiency. Green chemistry is, therefore, the most important field relating to the sustainable development of resources without harmfully impacting the environment. This book provides in-depth research on the use of green chemistry principles for a number of applications.
