Novel Cathodes

Most of the current cathode materials are based on the perovskite-type ABO3 structure with one of the conventional materials being LSM (Lai- Sr MnOs) as introduced earlier in Section 2.1.3. Other materials currently under development are based on the analogous system 

Lai-xSr CoOs. These are viewed as traditional cathode materials but through substitution, primarily of the La site, several new cathode compositions have been proposed. These are discussed in subsequent sections. 

Further improvements in the performance of cathode materials can be achieved by co-doping on both A and B sites. Phillipps et al. found that 

INORGANIC MATERIALS FOR SOLID OXIDE FUEL CELLS 

Iron-containing oxide phases are stable under SOFC cathodic conditions and exhibit, in general, larger electronic or mixed conductivity than in the LSM system. The highest level of electronic and ionic transport has been found for the Lao.sSro.sFeOs-s composition. An important disadvantage of these perovskite ferrites is their high thermal expansion coefficient (TEC) (a values typically between 15 and 25 x 10 K ) in comparison with the common solid electrolytes (of about 10-11 X 10 1175,176] important 

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Shao et al. [35] not only used a similar Ti mesh to the one presented by Scott s group but also used a Ti mesh as the cathode DL in a DMFC. The main difference between both meshes was that the one used on the cathode side was coated on both sides with carbon black (Vulcan XC-72) and PTFE (i.e., with MPLs on each side). It was shown that this novel cathode DL performed similarly to conventional CFP DLs under comparable conditions. Chetty and Scott [36] also used a catalyzed Ti mesh as the anode DL, but in a direct ethanol fuel cell (DEFC) it performed better compared to a cell with a standard DL (CFP). 

Oyaizu, Kenichi Ikkanda, Koji Kitao, Mizuki Tanaka, Ken Yamaguchi, Aritomo Yuasa, Makoto. Analysis of catalytic activity of novel cathode catalyst for fuel cells using polymer-cobalt complexes. Abstracts of Papers, 229th ACS National Meeting, San Diego. March 13-17, 2005. 

Ishihara, A. et al.. Tantalum oxynitride for a novel cathode of PEFC, Electrochem. Solid-State Lett., 8, A201, 2005. 

Giorgi, L. Carewska, M. Scaccia, S. Simonetti, E. Giacometti, E. Tulli, R. Development of molten carbonate fuel cell using novel cathode material. Int. J. Hydrogen Energy 1996, 21 (6), 491-496. 

Soler, J. Gonzalez, T. Escudero, M.J. Rodrigo, T. Daza, L. Endurance test on a single cell of a novel cathode material for MCFC. J. Power Sources 2002, 106 (1-2), 189-195. 

Another interesting finding based on the thermodynamic data is the low A fH0A (-28.9 kcal/mol or -121.0 kj/mol) of the Ca/CsF system. The combined used of Ca and CsF should conceptually construct a novel cathode configuration in OLEDs. Our device studies in Section 5.5 have clarified this presumption. The device performances are also dependent of other factors, e. g. they may be deteriorated by exciton quenching that arise from the gap-state formation over a rather thick interface region due to the highly exothermic reaction between the Ca and CsF. 

Kawai H, Nagata M, Tukamoto H, West AR (1998) A novel cathode Li2CoMn30g for lithium ion batteries operating over 5V. J Mater Chem 8 837-839... 

Since the focus of this paper is on pollution control applications of metal recovery, the complex and as yet incompletely told story of the early development of electroplating, surface finishing and early electrowinning techniques will not be discussed further. The development of electrolytic cells for pollution control applications of metal recovery dates from the mid-1960 s when several major advances in electrochemical engineering took place. Advances in potential and current distribution theory, mass transfer processes, coupled with the introduction of new materials, created a stimulus for the introduction of novel cathode designs with improved mass transfer characteristics. 

Ishihara A, Lee K, Doi S, Mitsushima S, Kamiya N, Kara M, Domen K, Eukuda K, Ota K (2005) Tantalum oxynitride for a novel cathode of PEEC. Electrochem Solid-State Lett 8(4) A201-A203... 

Jaouen patented a novel cathode structure for a solid polymer fuel cell [96] that cathode structure consisted of a solid polymer anion-exchange membrane surrounding the catalysts particles (entirely within the cathode structure), which was in contact (surrounded) with a cation-conducting polymer membrane. 

Smo.sSro.sCoOa has been used as a cathode material for the LSGM electrolyte, and a low cathodic overpotential of less than 50 mV at 0.5 A/cm was obtained at 873 K [203]. BaCoOa was also investigated as a novel cathode material for the... 

In summary, while fuel ceU/batteiy hybrid systems reduce the degradation from platinum surface area loss from voltage-cycling to an acceptable level, novel cathode catalysts with increased stability toward voltage-cycling would bring significant benefits and are therefore a very active field of research. 

Greiner JC, Bassat JM, Mauvy E (2012) Novel cathodes for solid oxide fuel cells. Eneigy 35 402-444... 

Chen Q, NuLi YN, Guo W, Yang J, Wang JL, Guo YG (2013) PTMA/Graphene as a novel cathode material for rechargeable Magnesium batteries. Acta Phys Chim Sin 29 2295-2299. doi 10.3866/PKU.WHXB201309241... 

Otaa K (2005) Tantalum Oxynitride for a Novel Cathode of PEFC, Electrochemical and Solid-State Letters, 8, A201-A203. 

Voltammetry studies. Voltammetry has various uses, for example to determine the standard redox potentials of redox active components Rabaey et al. 2005a), examine the electrochemical activity of microbial strains or consortia Kim et al. 2002 Niessen et al. 2004 Rabaey et al. 2004 Schroder et al. 2003), and test the performance of novel cathode materials Zhao et al. 2005). A potentiostat is needed to conduct voltammetry studies, of which there are two basic types. In linear sweep voltammetry (LSV) the potential of the working electrode (anode or cathode) is varied at a certain scan rate (expressed in V s" ) in one set direction. For cyclic voltammetry (CV), the scan is... 

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