A hybrid material is defined as a material composed of an intimate mixture of inorganic components, organic components, or both types of components. In the last few years, a tremendous amount of attention has been given towards the development of materials for efficient energy harvesting; nanostructured hybrid materials have also been gaining significant advances to provide pollutant free drinking water, sensing of environmental pollutants, energy storage and conservation. Separately, intensive work on high performing polymer nanocomposites for applications in the automotive, aerospace and construction industries has been carried out, but the aggregation of many fillers, such as clay, LDH, CNT, graphene, represented a major barrier in their development. Only very recently has this problem been overcome by fabrication and applications of 3D hybrid nanomaterials as nanofillers in a variety of polymers.
This book, Hybrid Nanomaterials, examines all the recent developments in the research and specially covers the following subjects:
* Hybrid nanostructured materials for development of advanced lithium batteries
* High performing hybrid nanomaterials for supercapacitor applications
* Nanohybrid materials in the development of solar energy applications
* Application of hybrid nanomaterials in water purification
* Advanced nanostructured materials in electromagnetic shielding of radiations
* Preparation, properties and application of hybrid nanomaterials in sensing of environmental pollutants
* Development of hybrid fillers/polymer nanocomposites for electronic applications
* High performance hybrid filler reinforced epoxy nanocomposites
* State-of-the-art overview of elastomer/hybrid filler nanocomposites
Suneel Kumar Srivastava received MSc, DIIT and PhD from Lucknow University and the Indian Institute of Technology, Kharagpur in 1976, 1979 and 1986 respectively. He is Professor in the Department of Chemistry and Acting Head in the School of Energy Science and Engineering of the Indian Institute of Technology, Kharagpur. His research interests are in the fields of zero, one and two dimensional semiconducting and magnetic nanomaterials and their applications in energy and the environment, polymers and polymer blends. He has guided 16 PhD students and published about 135 research papers in referred journals.
Vikas Mittal received his BTech, MTech and PhD degree from Punjab Technical University, Jalandhar, Indian Institute of Technology, Delhi, India, Swiss Federal Institute of Technology, Zurich, Switzerland respectively. He is currently the Department Deputy Chair and an Associate Professor of Chemical Engineering at the Petroleum Institute in Abu Dhabi. Dr. Mittal has earlier worked in Polymer Research section of BASF, Ludwigshafen, Germany. His main research interest is in the areas of polymer membranes, polymer processing and nanotechnology and graphene-based nanomaterials. He has published more than 80 articles in refereed journals and conference proceedings and has authored and edited more than 30 books of which 7 are with the Wiley-Scrivener imprint.
Hybrid Nanostructured Materials for Advanced Lithium Batteries
Soumyadip Choudhury* and Manfred Stamm*
Leibniz Institute of Polymer Research, Dresden, Dresden, Germany
*Corresponding authors: firstname.lastname@example.org; email@example.com
Efficient energy storage devices are progressively gaining importance due to the limited reserve of fossil fuels and advancement of alternative energy sources. Lithium-based battery systems have acquired a leading position in electrochemical energy storage and have become an important element in the replacement of conventional gasoline-driven vehicles with electrically driven ones. State-of-the-art lithium-ion batteries still cannot fulfill capacity requirements, and lithium-sulfur and lithium-air batteries might be promising for the high-energy-density batteries of the future. In this chapter, a brief overview of common lithium-ion batteries as well as of advanced battery systems is provided, including principles of operation, methods of fabrication utilizing nanohybrids for improved performance, and some aspects for further improvements.
Keywords: Nanostructured materials, hybrid materials, lithium-ion batteries, lithium-sulfur batteries, lithium-air batteries
In our society, the worldwide demand for electric energy consumption is progressively increasing day by day, and energy is being exploited in everything from mobile electronics to portable electronic gadgets and, ultimately, electrically driven vehicles. This increasing demand has caused a rapid rise of both primary and secondary batteries. In the 21st century, the steep growth of energy demand and environmental concerns associated with global warming, and a limited reserve of fossil fuels, has brought a serious note to the work of politicians and researchers in finding alternatives to the sole dependency on fossil fuels. Energy resources, such as hydroelectric, nuclear, and renewable resources like sun, wind, biological and tidal powers, are competing candidates as alternatives to fossil fuels. Hydroelectric power is a clean source of energy that requires storage of the potential energy of water in dams in suitable regions which are not available everywhere. Nuclear power, although used in different countries at large scale, causes radioactive hazards associated with long-term storage of radioactive wastes, and safety aspects are primary hindrances to be taken care of, especially in the wake of the Fukushima disaster. Although renewable sources offer clean energy, the intermittent nature of sources like the sun, wind or tidal waves practically restricts the continuous production of energy from these sources . In that case, the renewable energies have to be stored when they are available and supplied on demand. These systems can only be operated reasonably with powerful energy storage units, like thermal or chemical storage units including high-energy batteries, to strategically balance source variability and power requirement.
The accumulators (or secondary or rechargeable batteries) can be exploited as a component of energy storage system for giant electric grids, but mostly for local energy storage for smart grids in localized communities; in addition, they are used in consumer electronics to a large extent and are essential for the progress of e-mobility. Nowadays, the rechargeable batteries find applications in laptops, cell phones, medical implants, power tools, toys and many different portable electronic gadgets. In recent years, there has been a strong drive towards research and development to replace gasoline-driven cars with e-cars with rechargeable batteries. So, secondary batteries are now being exploited in high-end applications; for example, in transportation sectors, defense, or aerospace applications as well. State-of-the-art lithium-ion battery technology suffices for batteries for electronic gadgets, but to broaden the prospects of batteries in transportation sectors, a dramatic boost in the current battery technology has to be executed .
In particular, to bring the global electrified transportation venture to reality, development of cheap, environmentally friendly, safe, and high-energy-density batteries is the challenge for the near future. However, the state-of-the-art Li-ion batteries presently existing in the market are limited to the energy density of 150 Wh/kg which is, taking weight limitations into account, below the performance of the gasoline-driven vehicles (Figure 1.1). Most advanced e-cars like Tesla Model S have now extended the range with a big battery pack to 500 km. Significant uplift of energy densities by a factor of 2-5 are required to reach the desired performance of plug-in hybrid-electric vehicles (PHEVs) with approx. 100 km all-electric range and all-electric vehicles (EVs) with a range exceeding 600 km at reasonable weight and price, respectively [2, 3]. The recent advancements of next-generation lithium-ion batteries start to approach the performance requirements of PHEVs, but new electrochemical systems such as lithium-sulfur (Li-S) or lithium-air (oxygen) (or Li-air) can have the potential to meet the performance and cost requirements for EVs. In principle, Li-S and Li-air batteries offer at least five times the practical specific energy of present day lithium-ion batteries, use better available and cheaper constituents, and promise to be more environmentally friendly. This chapter covers the rise of lithium battery technology, and it provides some concepts for this technology to overcome the technological challenges to meet the performance matrices of electrically powered transportation sectors. Efficient electrical energy storage systems such as batteries have now become a key issue of national and strategic importance in a highly competitive international platform [4, 5]. The progress of electrical energy storage in that respect constitutes a challenging scientific and technological task that directly addresses critical economic, social and environmental needs. More specifically, revolutionary development of safe operating, pocket friendly, high-energy-density batteries at reasonable cost could bring the global electrified transportation industry to the market. Those challenges and future opportunities are outlined in several books, reviews and reports [6-15].
Figure 1.1 (a) Practical driving ranges of a present typical electrically driven vehicle (the values for driving ranges are based on the minimum specific energy for each technology and scaled on the specific energy of the Li-ion cells (140 Wh/kg) and a driving range (160 km) of the Nissan Leaf). The specific energies are given for some rechargeable batteries, along with estimated driving distances and pack prices. For future technologies, a range of anticipated specific energies are shown by the lighter shaded region on the bars in the chart for rechargeable batteries under development and for R&D. (Reprinted with permission from ; Copyright © 2012 Macmillan Publishers Ltd). (b) Drive range of all electrically driven cars as per U.S. Environmental Protection Agency (EPA) rating. (Source: Wikimedia Commons, "Electric Car," 12/2016).
This chapter briefly outlines the current development strategies adopted for lithium-based batteries, different chemistries behind the operation of lithium-based batteries and electrode nanostructures, challenges associated with the nanostructure design and their remedies. It includes an overview of the importance of nanostructured materials over bulk battery materials and their advancements so far as well as important aspects on lithium-based batteries. So we briefly introduce the working principles of lithium-based batteries (Li-ion, Li-air, and Li-S) and cover the various challenges associated with lithium-based batteries. In this chapter, the importance of controlled synthesis strategies will be outlined, thus providing an ideal platform to study synergistic effects of various hybrid structures for enhanced performance.
1.2 Battery Requirements
Before continuing the discussion about batteries, one must recall why we need batteries and what the requirements for the batteries are. It is obvious that we need batteries for mobile energy supply and storage but batteries have been classified as per their cell voltage, capacity, energy density, and whether they are rechargeable or for single use. In a battery the electrical energy is generated from the chemical reaction of two components, often referred to as Faradaic reactions. On the contrary, supercapacitors are operated mostly by ion electrosorption [16, 17]. So there is no change of oxidation state of the acting ions. In a battery, one electrode is referred to as the anode, which releases electrons and thereby generates ions, and another is referred to as the cathode, which accepts electrons . The flow of electrons is possible due to the change of oxidation state of the reactants. This produces current and hence capacity. The anode and cathode are separated by a separator which is soaked with electrolyte and also acts as electrolyte reservoir . Principally, all batteries are of two types: primary and secondary.
1.2.1 Primary and Secondary Batteries
Primary batteries are those which can be used only once and which are discarded after a single use. The reason behind this is that the chemical reactions which are responsible for the production of electrical energy cannot be easily reversed. Still, their ease of fabrication, low cost, simple design, and high energy output for a short period of time...