Solid state electrochemistry device, electrochemical

This volume contains four chapters. The topics covered are solid state electrochemistry devices and techniques nanoporous carbon and its electrochemical application to electrode materials for supercapacitors the analysis of variance and covariance in electrochemical science and engineering and the last chapter presents the use of graphs in electrochemical reaction networks. 

The principles behind this membrane technology originate from solid-state electrochemistry. Conventional electrochemical halfceU reactions can be written for chemical processes occurring on each respective membrane surface. Since the general chemistry under discussion here is thermodynamically downhill, one might view these devices as short-circuited solid oxide fuel cells (SOFCs), although the ceramics used for oxygen transport are often quite different. SOFCs most frequently use fluorite-based solid electrolytes - often yttria stabUized zirco-nia (YSZ) and sometimes ceria. In comparison, dense ceramics for membrane applications most often possess a perovskite-related lattice. The key fundamental... 

There is an extended special literature3,10-16 on applications of solid state electrochemistry and even more on electrochemical devices. According to our objective, in this section applications will be emphasized in which migration and diffusion in the solid state are decisive processes (as discussed in Part I2). We intend to subsume such applications under the headlines composition sensors, composition actors, and energy storage or conversion devices. 

Chapter 1 by Joachim Maier continues the solid state electrochemistry discussion that he began in Volume 39 of the Modem Aspects of Electrochemistry. He begins by introducing the reader to the major electrochemical parameters needed for the treatment of electrochemical cells. In section 2 he discusses various sensors electrochemical (composition), bulk conductivity, surface conductivity, galvanic. He also discusses electrochemical energy storage and conversion devices such as fuel cells. 

With the development of solid-state semiconductor devices (diodes, transistors), semiconductor/solution interfaces [24] became a subject of scientific interest. Since the 1960s, semiconductor electrochemistry and photo-electrochemistry has become established as an independent subdiscipline in electrochemical science. The basic principles and summaries of experimental results can be found in review papers and textbooks [25]. Here, we will introduce the subject by comparing simple electron transfer at a metal with that at a semiconductor electrode. 

Solid State Electrochemistry, including the major electrochemical parameters needed for die treatment of electrochemical cells as well as the discussion of electrochemical energy storage and conversion devices such as fuel cells... 

Solid-state electrochemistry is an important and rapidly developing scientific field that integrates many aspects of classical electrochemical science and engineering, materials science, solid-state chemistry and physics, heterogeneous catalysis, and other areas of physical chemistry. This field comprises - but is not limited to - the electrochemistry of solid materials, the thermodynamics and kinetics of electrochemical reactions involving at least one solid phase, and also the transport of ions and electrons in solids and interactions between solid, liquid and/or gaseous phases, whenever these processes are essentially determined by the properties of solids and are relevant to the electrochemical reactions. The range of applications includes many types of batteries and fuel cells, a variety of sensors and analytical appliances, electrochemical pumps and compressors, ceramic membranes with ionic or mixed ionic-electronic conductivity, solid-state electrolyzers and electrocatalytic reactors, the synthesis of new materials with improved properties and corrosion protection, supercapacitors, and electrochromic and memory devices. 

Conway, B. E., and W. G. Pell. 2003. Double-layer and pseudocapacitance types of electrochemical capacitors and their applications to the development of hybrid devices. Journal of Solid State Electrochemistry 7 637-644. 

Photovoltaic (PV) cells are physical devices that operate on the principles of solid-state physics. Another class of device - one that is capable of splitting water - is based on photo-electrochemical reactions, which take place at electrodes that are light-sensitive. Photo-electrochemistry may serve to generate d.c. electricity (via dye-sensitized solar cells) and this can then be used to electrolyze water (as with PV cells). Alternatively, light illuminating an electrode may reduce water directly to hydrogen - a process known as photolysis . These two processes are described next. 

The electrochemical behavior of redox molecules in polymer films and gels has been investigated [4,7,18,23,61-66], but such behavior has usually been studied by using a modified electrode coated with a polymer film or gel in the presence of an outer electrolyte solution. In a few examples, entirely solid-state voltammetry was also achieved, but by using a microelectrode array [65,66] composed of working, counter, and reference electrodes because of the slow ionic or molecular diffusion in the soHd matrices. The apparent diffusion coefficient (Dapp) of a redox substrate in the films or solids coated on an electrode was very small [4,7,18,23,62-66], usually of the order of less than 10 cm s Another example of solid state votammetry is a report on the electrochemistry of Prussian blue in silica sol-gel electrolytes [67], but only Pt gauze working and counter electrodes for a - 1 mm-thick silica solid were used. Moreover, it is well known that solid electrolytes have been used on various sensors, electro chromic devices, etc. [68,69]. However, in spite... 

All the electrochemical devices that will be introduced in this chapter are constituted by a central membrane, the electrolyte, and they involve an electrochemical circuit. The role of fuel cells will be detailed because, under this name, different systems are involved with varied features and scientific technical aspects, for example, according to the temperature and the electrolyte, different kinds of electrochemistry can be seen solid-state, molten salt, ionic liquids and more common aqueous solutions. Furthermore, fuel cells have reached a state of maturity and are excellent examples for understanding the behaviour of membranes in electrochemical devices. As electrolysis is constituted of similar elements to fuel cells, we will be much more synthetic with respect to this thematic. 

As one of the first applications in electrochemistry toward AP-XPS, solid oxide fuel cells (SOCs) have been chosen and tested successfully [77-80]. SOCs, as one of the solid state electrochemical devices for electrochemical power, operate under gaseous fuel condition to generate the electrical power at relatively high temperature condition (>700 °C). And, these operating conditions of SOCs, e.g., high temperature and elevated pressure, have been the hurdle for the in situ characterization of surface/interface properties of SOCs. 

The future prospects for polymer electrolytes look promising because it has been appreciated that they form an ideal medium for a wide range of electrochemical processes. Other than primary and secondary batteries, and high and low temperature fuel cells, practical applications for polymer electrolytes that are under consideration include electrochromic devices, modified electrode/sensors, solid-state reference electrode systems, supercapacitors, thermoelectric generators, high-vacuum electrochemistry and electrochemical switching. Device applications that have been the main driving force behind the development of polymer electrolytes are treated hereafter. 

Xhe principal audience that will benefit from this book are M.Sc. and Ph.D. students with speciahzation in physical chemistry, elecdochemistry, or physics, as well as researchers and engineers in the field of electrochemistry, particularly in areas of semiconductors, solid electrolytes, corrosion, sohd state devices, and electrochemical power sources. Impedance spectroscopy has firmly established itself as one of the most informative and irreplaceable investigation methods in these areas of research. In addition, the book provides a valuable source of information and resource for established researchers and engineers working in one or more of the above fields. 

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