Chemical power sources

Many electrochemical devices and plants (chemical power sources, electrolyzers, and others) contain electrolytes which are melts of various metal halides (particularly chlorides), also nitrates, carbonates, and certain other salts with melting points between 150 and 1500°C. The salt melts can be single- (neat) or multicomponent (i.e., consist of mixtures of several salts, for their lower melting points in the eutectic region). Melts are highly valuable as electrolytes, since processes can be realized in them at high temperatures that would be too slow at ordinary temperatures or which yield products that are unstable in aqueous solutions (e.g., electrolytic production of the alkali metals). 

Bagotzky, V. S., and A. M. Skundin, Chemical Power Sources, Academic Press, London, 1980. 

Anodic oxidation of valve metals, particularly, aluminum, has attracted considerable attention because of its wide application in various fields of technology. Traditionally, aluminum is anodized in order to protect the metal against corrosion, to improve its abrasion and adsorption properties, etc.1 The more recent and rapidly growing applications of anodic aluminas in electronics are due to their excellent dielectric properties, perfect planarity, and good reproducibility in production. Finally, ways have recently been found to use the energy potential of aluminum oxidation for chemical power sources of the metal-air type2,3 and other electrochemical applications. 

Bogotzky V.S., Skundin A.M. Chemical Power Sources. London-New York Academic Press, 1980. 

Monomethylhydrazine is a clear, colorless liquid used extensively in military applications as a missile and rocket propellant, in chemical power sources, and as a solvent and chemical intermediate. Upon contact with strong oxidizers (e.g., hydrogen peroxide, nitrogen tetroxide, chlorine, fluorine) spontaneous ignition may occur. 

It has been a long time since the invention of the lead-acid battery, but it still represents the most important secondary chemical power source—both in number of types and diversity of application. The lead-acid battery has maintained its leading role for so many decades due to its competitive electrical characteristics and price and due to its adaptability to new applications. It is manufactured in a variety of sizes and designs, ranging from less than 1 to over 10 000 A h.206... 

The synthesis of polyaniline and copolymers of aniline with o-nitroaniline is aimed at obtaining an electroactive material. This material can be used, for example, as an electrode in conjunction with the magnesium electrode to construct chemical power sources. The polymers were prepared by oxidation of aniline or its mixture with nitroaniline ammonium persulfate in aqueous hydrochloric... 

An ambitious review of carbon applications in chemical power sources (see also Section 5.3.5) was offered by Fialkov [94], It is disconcerting, however, that the author discusses the influence exerted by... surface properties without citing even one of the well-known—or well-cited or more recent—studies on carbon surface chemistry. And yet, in conjunction with the use of carbon in air (oxygen) electrodes, he speculates that the oxygen electroreduction kinetics depend on... the degree to which side faces of carbon crystallites are developed because base groups are formed there and presumably interact (e.g., with HjOj) in the following manner ... 

For use of ionic melts as electrolytes in high-temperature chemical power sources it is necessary to know the metal-oxide s solubilities in these media, since the oxides may be formed as a result of reactions of electrochemically active substances with oxide ions which exist in the pure halide melts. This interaction is especially undesirable for the case of rechargeable high-temperature chemical power sources, since it results in irreversible removal of electrochemically active particles from the reaction sphere. 

Metal-air chemical power sources call also peculiar interest among numerous electrochemical systems that elaborate autonomous power sources. It is connected with high coal energy, simplicity of service, reliability of metal-air power sources. Wide using of such systems are connected with development of active air electrode based on cheap and effective catalyst. 

The combination of polyaniline, nano-Ti02 and other components [34-35] permits to produce the composites with improved physico-chemical properties. Such nanocomposite materials are studied actively and are employed in die different branches of engineering and technics [31, 36], as cathodic materials in the chemical power sources [37], in the electronics [7, 35], chemo- and biosensors [39-40], and also as the components of corrosion protection coverages [41] or protective shades of different assignments [42],... 

The high value of the first dissociation constant maintains high concentration of ions in the solution, and ions have a several-fold higher mobility than all other ions in the solution. This guarantees high electrical conductivity of the H2SO4 electrolyte in the battery, which is a mandatory requirement for any chemical power source. 

Over 95% of failed lead—acid batteries are recycled in these pools, yielding secondary lead which is re-used for the manufacture of new lead—acid batteries. The secondary lead is purified to a degree, allowing its utilization in the production of leady oxide and lead alloys. A certain amount of primary lead extracted from lead ores is also added to the lead pool and used in the manufacture of leady oxide. Thanks to the high percentage of recycled secondary lead and the simple technology of manufacture, the lead—acid battery is the cheapest chemical power source available. 

Bagotsky VS, Skundin AM. Chemical Power Sources. London Academic Press 1980. Daniel C, Besenhard JO, editors. Handbook of Battery Materials. 2nd ed. Chichester, Wein-heim Wiley-VCH 2011. 

The theoretical energy density of a lithium-sulfur electrochemical system is 2500 Wh/kg or 2800 Wh/1, which makes it immensely attractive for the development of a chemical power source. This attractiveness is also enhanced by the ready availability and cheapness of sulfur and the absence of environmentally harmful components. And, indeed, attempts of developing a battery using this electrochemical system were made yet in the end of the 1960s of the previous century, at the rise of the studies of electrochemical lithium systems. It was suggested in the beginning to use the negative electrode made of metallic lithium and the positive one of elementary sulfur supported directly on the current collector. The characteristics of these first layouts were clearly unsatisfactory, partly, because sulfur is an insulator. Later, the positive electrode came to be made of a mixture of sulfur and a carbon material (carbon black). 

In 1980 Academic Press London New York published the book Chemical Power Sources written by two of the authors of this book (V.S. Bagotsky and A.M. Skundin). Now, almost 35 years later, this book is outdated and has become an obsolete rarity. 

Highly energy-intensive chemical power sources (CPSs), such as lithium thionylchloride systems, are known to be subject to thermal destruction during storage [24]. Thermodynamic causes of this phenomenon have been analysed in [25]. Szpak et al. [26] have shown that the self-destmction can be initiated by an external local heat source. Some cases are known, however, in which the self-destruction proceeds without any external action, i.e. only due to internal causes. These causes, which were analysed in [27], are considered below. 

A Model of Chemical Power Source (CPS) Self-Discharge... 

For laser applications that require a very large laser or a laser remote fi om conventional electrical or chemical power sources, a nuclear pumped laser may be an effective alternative to more conventional lasers. Commercial, power reactors routinely operate for months at total fission powers of3000 MW, with corresponding electrical power... 

Greatbatch W, Lee JH, Mathias W, Eldiidge M, Moser JR, Schneider AA (1971) The solid-state lithium battery a new improved chemical power source for implantable cardiac pacemakers. IEEE Trans BioMed Eng BME 18 317-324... 

Methods for electrochemical, catalytic (metal assisted), and deep reactive ion etching (DRIE) of silicon have been developed, which enable fabrication of arrays of deep cylindrical or modulated pores, walls, tubes, combinations of these, and other forms with vertical walls (Wu et al. 2010). As a rule, the regular arrays produced by electrochemical etching are characterized by constant porosity and pore depths (up to 500 pm) and form a planar front propagating into the substrate. Various devices and functional elements for micromechanics, photonics, chemical power sources, microfluidics, photovoltaics, etc. (see Porous Silicon Application Survey chapter), are commonly fabricated on the basis of these arrays by post-anodization treatment intended to modify the structure and properties of macroporous silicon to raise or reduce its porosity, change the shape of pores, transform the pore array into a column array, change the properties of the inner surface of pores, coat it with the film of a metal or insulator, open up pores, fill pores with various fillers, dope the silicon walls, etc. Some procedures can be performed locally, which requires formation of a pattern and subsequent structuring. 

The first was found by Alessandro Volta in 1800 in an investigation of the causes of the well known Galvani frog-leg phenomenon, and the second was the discovery of Michael Faraday in 1831 that a magnet moving near a metal wire induces motion of electrons it it. The latter discovery resulted in the present day production of electrical energy in power plants, while the former enabled. us to obtain electricity independently of the mains supply, from chemical power sources, commonly known as batteries. It may not be common knowledge however, that these two power production methods have developed to a similar level of use. The electric power delivered at the present time by automobile batteries alone amounts to about 1.5 TW and is of the same order as that delivered by all the electric power-plants in the world. 

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