Ceria is a very important catalytic material for fuel reforming in SOFCs and CO poisoning in PEM fuel cells. Especially, the design of a new generation SOFC requires the in-situ reforming of hydrocarbon fuels. In this work, nanostructured ceria was developed via a controlled hydrothermal process in a mixed water-ethanol medium. The microstructure, formation mechanism, and their surface catalytic properties were investigated.

Solid-state electrochemical devices, such as batteries, fuel cells, membranes, and sensors, are critical components of technologically advanced societies in the 21st Century and beyond. The development of these devices involves common research themes such as ion transport, interfacial phenomena, and device design and performance, regardless of the class of materials or whether the solid state is amorphous or crystalline. The intent of this international symposia series is to provide a forum for recent advances in solid-state ion conducting materials and the design, fabrication, and performance of devices that utilize them. The papers in this issue of ECS Transactions were presented at the 6th Solid State Ionic Devices symposium, at the 214th meeting of The Electrochemical Society, October 12-17, 2008 in Honolulu, Hawaii.

The book is about the studies that have been focused on the synthesis and characterization of transition metal oxides as anode materials in lithium ion batteries. The synthesis methods were the hydrothermal method, the electrospinning method, and electrostatic spray deposition (ESD). By controlling the synthesis conditions, different morphologies can be obtained, which result in different electrochemical performances. All of these studies provide a fundamental basis for the development of high performance lithium ion batteries.

The book highlights applications of hybrid materials in solar energy systems, lithium ion batteries, electromagnetic shielding, sensing of pollutants and water purification. 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: 3D hybrid nanomaterials nanofillers Hybrid nanostructured materials for development of advanced lithium batteries High performing hybrid nanomaterials for supercapacitor applications Nano-hybrid 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

Reducing fabrication and operation costs while maintaining high performance is a major consideration for the design of a new generation of solid-state ionic devices such as fuel cells, batteries, and sensors. The objective of this research is to fabricate nanostructured materials for energy storage and conversion, particularly porous electrodes with nanostructured features for solid oxide fuel cells (SOFCs) and high surface area films for gas sensing using a combustion CVD process. This research started with the evaluation of the most important deposition parameters: deposition temperature, deposition time, precursor concentration, and substrate. With the optimum deposition parameters, highly porous and nanostructured electrodes for low-temperature SOFCs have been then fabricated. Further, nanostructured and functionally graded La[subscript0.8]Sr[subscript0.2]MnO[supscript2] (LSM)-La[subscript0.8]SrCoO[subscript3] (LSC)-GDC composite cathodes were fabricated on 240 [micro]m thick YSZ electrolyte supports. Extremely low interfacial polarization resistances (i.e. 0.43 [omega]cm2 at 700[degree]C) and high power densities (i.e. 481 mW/cm2 at 800[degrees]C) were generated at operating temperature range of 600[degrees]C-850[degrees]C. The original combustion CVD process is modified to directly employ solid ceramic powder instead of clear solution for fabrication of porous electrodes for solid oxide fuel cells. Solid particles of SOFC electrode materials suspended in an organic solvent were burned in a combustion flame, depositing a porous cathode on an anode supported electrolyte. Combustion CVD was also employed to fabricate highly porous and nanostructured SnO2 thin film gas sensors with Pt interdigitated electrodes. The as-prepared SnO2 gas sensors were tested for ethanol vapor sensing behavior in the temperature range of 200-500[degrees]C and showed excellent sensitivity, selectivity, and speed of response. Moreover, several novel nanostructures were synthesized using a combustion CVD process, including SnO2 nanotubes with square-shaped or rectangular cross sections, well-aligned ZnO nanorods, and two-dimensional ZnO flakes. Solid-state gas sensors based on single piece of these nanostructures demonstrated superior gas sensing performances. These size-tunable nanostructures could be the building blocks of or a template for fabrication of functional devices. In summary, this research has developed new ways for fabrication of high-performance solid-state ionic devices and has helped generating fundamental understanding of the correlation between processing conditions, microstructure, and properties of the synthesized structures.

With the rapidly increasing demand for better energy sources, material development for alternative energy storage and conversion systems has become extremely important. Among those, lithium ion batteries have achieved huge success in commercial use; however, progress still needs to be made to improve the performance. Toward this end, nanostructured materials have emerged as potential solutions toward smaller, cheaper, safer, and longer lasting batteries. One part of this dissertation focuses on the synthesis and characterization of nanostructured carbon materials for lithium ion batteries using electrospinning and nanoimprint lithography as primary synthesis methods. By appropriate nanostructuring, we have achieved improvement in electrochemical performance compared to that of the current state-of-art graphite anode, yet more effort is needed for further advancement. The other major portion of this dissertation is on the use of various scanning probe microscopy techniques to thoroughly characterize synthetic ferroelectrics for solar cell applications, and biological ferroelectrics for bio-compatible molecular electronics. The fundamentals of each scanning probe microscopy technique are first introduced, followed by a description of how they are applied to the ferroelectric materials to study different properties and behaviors. By combining piezoresponse force microscopy (PFM) and Kelvin probe force microscopy, we are able to establish solid proof that the perovskite is indeed ferroelectric, and also to observe the charge separation process when used as the light absorber layer in solar cells. More importantly, we investigated how the external light illumination interacts with the intrinsic ferroelectricity, to help understand the role of ferroelectricity in its superior performance in solar cells. PFM and conductive atomic force microscopy (c-AFM) also applied to study the ferroelectric resistive switching behavior in the biological ferroelectric elastin and its monomer level tropoelastin. Experimentally, we observed switchable diode-like conductance behavior and strong correlation to ferroelectric polarization which opens up new applications for those biological tissues.