Low-Cost Cathode

Aside from the high energy density, metal-air batteries have other advantages. 

The reagent at the cathode, oxygen, is free, and the cathode is composed mostly of porous carbon, which is less expensive than cathodes such as UC0O2 that are used in lithium-ion cells. 

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Wang L, Chen Y, Ye Y, Lu B, Zhu S, Shen S (2011) Evaluation of low-cost cathode catalysts for high yield biohydrogen production in microbial electrolysis cell. Water Sci Technol 63(3) 440-448. doi 10.2166/wst.2011.241... 

The cathode is the main bottleneck of current MFC development. Development of high-performance, low-cost cathode material is critical for the successful application of MFC technology, especially for wastewater treatment. A typical air cathode includes a carbon base layer, a catalyst coating on the water feeing side, and several diffusion layers (DLs) on the air-fecing side [48]. 

Recent developments demonstrated the great potential of activated carbon as low-cost cathode material, which can be formed by cold pressing-activated carbon with a PTFE binder around a Ni mesh current collector. Such a cathode structure avoided the need for carbon cloth or a metal catalyst, and produced a cathode with high activity for oxygen reduction at typical MFC current densities [72]. Tests with the AC cathode produced a maximum power density of 1220 mW m , compared with 1060 mW m obtained by Pt-catalyzed carbon cloth cathode. Other carbon material, including activated carbon fiber felt [56] and HNOs-treated carbon powder (Vulcan XC-72R) [73], also demonstrated good performance for oxygen reduction reaction in MFCs. 

The low cost, light weight, and exceUent electrical conductivity of graphite anodes have made this impressed current protection system valuable for cathodic protection of pipelines, storage vessels, process equipment, and also for weU casings both on- and offshore. 

Conceptually elegant, the SOFC nonetheless contains inherently expensive materials, such as an electrolyte made from zirconium dioxide stabilized with yttrium oxide, a strontium-doped lanthanum man-gaiiite cathode, and a nickel-doped stabilized zirconia anode. Moreover, no low-cost fabrication methods have yet been devised. 

Alkaline batteries were introduced in the early 1960s they last two to five times longer than Zn-carbon cells on continuous discharge and command two or three times the price in the USA (far more in Europe and the East). Alkaline cells became a necessary invention and they succeeded as a result of the requirements of the electronic devices. The essential improvement was the change from ammonium chloride and/or zinc chloride electrolyte to alkaline (KOH) electrolyte, the steel can construction, the outside cathode, and the zinc powder (large surface) anode. A main low-cost feature is that they use pressed cathodes and do not need to follow "jellyroll"... 

A fuel cell is an electrochemical reactor with an anodic compartment for the fuel oxidation giving a proton and a cathodic compartment for the reaction of the proton with oxygen. Two scientific problems must be solved finding a low-cost efficient catalyst and finding a membrane for the separation of anodic and cathodic compartments. The membrane is a poly electrolyte allowing the transfer of hydrated proton but being barrier for the gases. 

Aqueous cathodic electrodeposition has been shown to offer a low-cost route for the fabrication of large surface n-CdS/p-CdTe solar cells. In a typical procedure, CdTe films, 1-2 xm thick, are electrodeposited from common acidic tellurite bath over a thin window layer of a CdS-coated substrate under potential-controlled conditions. The as-deposited CdTe films are stoichiometric, exhibit strong preferential (111) orientation, and have n-type conductivity (doping density typically... 

Recently, rhodium and ruthenium-based carbon-supported sulfide electrocatalysts were synthesized by different established methods and evaluated as ODP cathodic catalysts in a chlorine-saturated hydrochloric acid environment with respect to both economic and industrial considerations [46]. In particular, patented E-TEK methods as well as a non-aqueous method were used to produce binary RhjcSy and Ru Sy in addition, some of the more popular Mo, Co, Rh, and Redoped RuxSy catalysts for acid electrolyte fuel cell ORR applications were also prepared. The roles of both crystallinity and morphology of the electrocatalysts were investigated. Their activity for ORR was compared to state-of-the-art Pt/C and Rh/C systems. The Rh Sy/C, CojcRuyS /C, and Ru Sy/C materials synthesized by the E-TEK methods exhibited appreciable stability and activity for ORR under these conditions. The Ru-based materials showed good depolarizing behavior. Considering that ruthenium is about seven times less expensive than rhodium, these Ru-based electrocatalysts may prove to be a viable low-cost alternative to Rh Sy systems for the ODC HCl electrolysis industry. 

Aluminum foil capacitors occupy an important position in circuit applications due to their unsurpassed volumetric efficiency of capacitance and low cost per unit of capacitance.328 Together with tantalum electrolytic capacitors, they are leaders in the electronic discrete parts market. Large capacitance is provided by the presence of extremely thin oxide layers on anodes and cathodes, and high surface areas of electrodes could be achieved by chemical or electrochemical tunnel etching of aluminum foils. The capacitance of etched eluminum can exceed that of unetched metal by as much as a factor of 50.328... 

Doped Nickel Cathode Alloy Anode Low Cost... 

Adsorptive cathodic stripping voltammetry has an advantage over graphite furnace atomic absorption spectrometry in that the metal preconcentration is performed in situ, hence reducing analysis time and risk of contamination. Additional advantages are low cost of instrumentation and maintenance, and the possibility to use adapted instrumentation for online and shipboard monitoring. 

Liquid Crystal Displays (LCD). Liquid crystal displays, once limited to small devices such as calculators, are now displacing color CRT (cathode ray tube) displays in commercial quantities. The ability to fabricate these display devices at high quality and at low cost is partially due to the wider spread use of photopolymer-based materials. Photopolymer technology is being used for the alignment of liquid crystal (LC) elements (49), the orientation of ferroelectric materials (50), the synthesis of LC polymers (57) and the manufacture of color filters for liquid crystal display applications (52). 

A significant cost advantage of alkaline fuel cells is that both anode and cathode reactions can be effectively catalyzed with nonprecious, relatively inexpensive metals. To date, most low cost catalyst development work has been directed towards Raney nickel powders for anodes and silver-based powders for cathodes. The essential characteristics of the catalyst structure are high electronic conductivity and stability (mechanical, chemical, and electrochemical). 

Despite all of these merits, the application of Lilm in lithium ion cells never materialized because it caused severe A1 corrosion in electrolytes based on it. " In situ surface studies using EQCM established a reaction between the Im anion and the A1 substrate in which Al(Im)3 is produced and adsorbed on the A1 surface. Undoubtedly, this corrosion of a key component of the cell by Im greatly restricts the possible application of Lilm, because the role of A1 as a cathode substrate in the lithium-based battery industry is hard to replace, due to its light weight, resistance to oxidation at high potential, excellent processability, and low cost. 

This chapter considers photoanodes comprised of metal oxide semiconductors, which are of relatively low cost and relatively greater stability than their non-oxide counterparts. In 1972 Fujishima and Honda [1] first used a crystal wafer of n-type Ti02 (rutile) as a photoanode. A photoelectrochemical cell was constructed for the decomposition of water in which the Ti02 photoanode was connected with a Ft cathode through an external circuit. With illumination of the Ti02 current flowed from the Ft electrode to the... 

Aluminum, a highly electropositive metal similar to the aUcaline earth metals, can be useful in deposition of low work function cathode metal electrodes in OLEDs and OELDs, and is preferred for many electronics applications because of its low cost and high conductivity, although it is somewhat prone to electro migration [8, 65]. Since A1 is an important metal for device applications its deposition on SAMs has been extensively studied [20, 21, 23, 32, 33,41, 50, 65-69]. The critical problem for Al, however, is its facility in penetration along with filament growth. 

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