Anode materials oxide-based

Subcategory A encompasses the manufacture of all batteries in which cadmium is the reactive anode material. Cadmium anode batteries currently manufactured are based on nickel-cadmium, silver-cadmium, and mercury-cadmium couples (Table 32.1). The manufacture of cadmium anode batteries uses various raw materials, which comprises cadmium or cadmium salts (mainly nitrates and oxides) to produce cell cathodes nickel powder and either nickel or nickel-plated steel screen to make the electrode support structures nylon and polypropylene, for use in manufacturing the cell separators and either sodium or potassium hydroxide, for use as process chemicals and as the cell electrolyte. Cobalt salts may be added to some electrodes. Batteries of this subcategory are predominantly rechargeable and find application in calculators, cell phones, laptops, and other portable electronic devices, in addition to a variety of industrial applications.1-4 A typical example is the nickel-cadmium battery described below. 

Similarly to the case of direct-oxidation anode materials, sulfur-tolerant anode materials based on sulfides [6, 7] or double-perovskite oxides have special requirements for their processing into SOFC layers. For example, nickel sulfide-promoted molybdenum sulfide is tolerant to high sulfur levels [7], However, it has a low melting temperature [6] that has resulted in the development of cobalt sulfide as a stabilizer of the molybdenum sulfide catalyst [6], CoS-MoS2 admixed with Ag has an even higher performance in H2S-containing fuels than in pure H2 [6]. However, processing methods such as PS, infiltration, or sol-gel techniques that can process... 

The data in Table 6-1 provide a chronology of the evolution in cell component technology for MCFCs. In the mid-1960s, electrode materials were, in many cases, precious metals, but the technology soon evolved to the use of Ni-based alloys at the anode and oxides at the cathode. 

Figure 51. Cathodic and anodic stability of LiBOB-based electrolytes on metal oxide cathode and graphitic anode materials Slow scan cyclic voltammetry of these electrode materials in LiBOB/EC/EMC electrolyte. The scan number and Coulombic efficiency (CE) for each scan are indicated in the graph. (Reproduced with permission from ref 155 (Eigure 2). Copyright 2002 The Electrochemical Society.)...

The previous discussion has focused on the properties of perovskite materials rather than on their performance as anodes. The number of actual fuel-cell studies is more limited, but this literature has been reviewed recently by Irvine. Various perovskites have been investigated as potential SOFC anode materials however, these early efforts were hampered by low electrochemical activity toward methane oxidation,poor anode structure,or insufficient electrode conductivity. Most recently, Tao and Irvine demonstrated that an anode based on (Lao.75Sro.25)o.9Cro.5Mno.503 can provide reasonable power densities at 1173 K in 3% humidified CH4. Barnett and co-workers also reported stable power generation with methane and propane fuels on an anode based on LaCr03 however, they reported that the addition of Ni, in levels too small to affect the conductivity, was crucial in providing activity for the electrochemical oxidation reactions. 

ZnO displays similar redox and alloying chemistry to the tin oxides on Li insertion [353]. Therefore, it may be an interesting network modifier for tin oxides. Also, ZnSnOs was proposed as a new anode material for lithium-ion batteries [354]. It was prepared as the amorphous product by pyrolysis of ZnSn(OH)6. The reversible capacity of the ZnSn03 electrode was found to be more than 0.8 Ah/g. Zhao and Cao [356] studied antimony-zinc alloy as a potential material for such batteries. Also, zinc-graphite composite was investigated [357] as a candidate for an electrode in lithium-ion batteries. Zinc parhcles were deposited mainly onto graphite surfaces. Also, zinc-polyaniline batteries were developed [358]. The authors examined the parameters that affect the life cycle of such batteries. They found that Zn passivahon is the main factor of the life cycle of zinc-polyaniline batteries. In recent times [359], zinc-poly(anihne-co-o-aminophenol) rechargeable battery was also studied. Other types of batteries based on zinc were of some interest [360]. 

Other common anode materials for thermal batteries are lithium alloys, such as Li/Al and Li/B, lithium metal in a porous nickel or iron matrix, magnesium and calcium. Alternative cathode constituents include CaCr04 and the oxides of copper, iron or vanadium. Other electrolytes used are binary KBr-LiBr mixtures, ternary LiF-LiCl-LiBr mixtures and, more generally, all lithium halide systems, which are used particularly to prevent electrolyte composition changes and freezing out at high rates when lithium-based anodes are employed. 

Primary alkaline cells use sodium hydroxide or potassium hydroxide as tlie electrolyte. They can be made using a variety of chemistries and physical constructions. The alkaline cells of the 1990s are mostly of the limited electrolyte, dry cell type. Most primary alkaline cells are made sing zinc as the anode material a variety of cathode materials can be used. Primary alkaline cells are commonly divided into tW o classes, based on type of construction the larger, cylindrically shaped batteries, and the miniature, button-type cells. Cylindrical alkaline batteries are mainly produced using zinc-manganese dioxide chemistry, although some cylindrical zinc-mercury oxide cells are made. 

Since ionic radii and valences of iron and chromium ions are similar to gallium ion, substitution of these cations with gallium ion may result in powders with similar crystal structure and properties to LSGM. Moreover, LaFe03- and LaCr03-based oxides are candidate cathode and anode materials for SOFC, respectively. 

As well-known, Mn02 finds wide-spread applications in the classical Leclanche cell in which, put simply, Zn is oxidized to ZnO by Mn02. Zn is a cheap anode material which is also employed in the Zn-air battery.7 This intriguing battery concept represents a primary battery but exhibits similarities with a fuel cell.63 64 69 Table 6 gives an overview on zinc-based primary elements. 

An investigation of the anodic oxidation of mesitylene in nitrate-ion based electrolytes but with aprotic solvents revealed little more to illuminate the mechanistic picture (Nyberg, 1971d). Again, a very pronounced shift of the voltammetric curve was observed upon addition of the substrate when platinum was the anode material, whereas on graphite a small shift toward less positive potentials was noted. Product distributions are shown below eqn (67). The forma-... 

Huang, K.G. et al.. Increasing power density of LSGM-based solid oxide fuel cells using new anode materials, J. Electrochem. Soc., 148, A788-A794 (2001). 

The specific systems selected for this study are described later. The major problem of TCO is the first irreversible capacity loss, resulting from the reaction of lithium with SnO and the formation of Li20. Nevertheless, the development of TCO was the first demonstration of the potential for creating the so-called active-inactive nanocomposite anode materials by the electrochemical insertion of lithium into the tin oxide-based amorphous glass. 

Processes analogous to the well-known electrochemical synthesis of tetraethyllead (Et4Pb) from sacrificial Pb electrodes have been described for Sb and Bi. EtjBi is formed in good yields (94% based on the current passed) when an aqueous solution of NaBEt4 is oxidized at a Bi anode . If the anode material is changed to Sb, EtjSb is formed in moderate yields based on the current passed (25-50% dependent on the current density) . The lower yields at the Sb anode were ascribed to passivation of the electrode . 

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