Anodes composite

For Sm, Eu, and Yb, on the other hand, nanocapsules containing carbides were not found in the cathode deposit by either TEM or XRD. To see where these elements went, the soot particles deposited on the walls of the reaction chamber was investigated for Sm. XRD of the soot produced from Sm203/C composite anodes showed the presence of oxide (Sm203) and a small amount of carbide (SmC2). TEM, on the other hand, revealed that Sm oxides were naked, while Sm carbides were embedded in flocks of amorphous carbon[12J. The size of these compound particles was in a range from 10 to 50 nm. However, no polyhedral nanocapsules encaging Sm carbides were found so far. 

Seraphin et a/. [39] reported that an arc evaporation of Fe/C composite anode also generated nanochains with similar morphology, described above. 

It is a valve metal and when made anodic in a chloride-containing solution it forms an anodic oxide film of TiOj (rutile form), that thickens with an increase in voltage up to 8-12 V, when localised film breakdown occurs with subsequent pitting. The TiOj film has a high electrical resistivity, and this coupled with the fact that breakdown can occur at the e.m.f. s produced by the transformer rectifiers used in cathodic protection makes it unsuitable for use as an anode material. Nevertheless, it forms a most valuable substrate for platinum, which may be applied to titanium in the form of a thin coating. The composite anode is characterised by the fact that the titanium exposed at discontinuities is protected by the anodically formed dielectric Ti02 film. Platinised titanium therefore provides an economical method of utilising the inertness and electronic conductivity of platinum on a relatively inexpensive, yet inert substrate. 

There have been many attempts to improve the cycling efficiency of lithium anodes. We describe some of them below, by discussing electrolytes, electrolyte additives, the stack pressure on the electrode, composite anodes, and alternatives to the lithium-metal anode anode. 

We believe that the advantage of these composite anodes is that they result in a uniform lithium deposition at the boundaries of two components that may improve the cycling efficiency. 

EMERGING METAL/CARBON COMPOSITE ANODES FOR NEXT GENERATION LITHIUM-ION BATTERIES... 

Holze, R. and Wu, Y. P., Novel composite anode materials for lithium ion batteries with low sensitivity towards humidity, J. Solid State Electrochem. (2003) 8 66-72. 

In addition to the use of composite anodes and cathodes, another commonly used approach to increase the total reaction surface area in SOFC electrodes is to manipulate the particle size distribution of the feedstock materials used to produce the electrodes to create a finer structure in the resulting electrode after consolidation. Various powder production and processing methods have been examined to manipulate the feedstock particle size distribution for the fabrication of SOFCs and their effects on fuel cell performance have also been studied. The effects of other process parameters, such as sintering temperature, on the final microstructural size features in the electrodes have also been examined extensively. 

Yin Y, Li S, Xia C, and Meng G. Electrochemical performance of gel-cast NiO-SDC composite anodes in low-temperature SOFCs. Electrochim. Acta 2006 51 2594-2598. 

The Ba.C) N, nanotubes and fullerene-like structures have been synthesized by various laboratories in recent years. The most popular method is the plasma arc technique. The first report on the synthesis of BN nanotubes was by Zettl and coworkers (55). Since BN is an insulator, a composite anode was prepared from a tungsten rod with an empty bore in the center, which was stuffed with a pressed hexagonal BN powder. For the cathode, a water-cooled Cu rod was used. The collected gray soot contained limited amount of multi wall BN nanotubes. It is possible that in this case, the tungsten serves also as a catalyst. By perfecting this method, macroscopic amounts of double-wall BN nanotubes of a uniform diameter (2 nm)... 

Phenoxanthin, 68 X = S Y = O, is prepared by the electrochemical oxidation of diphenyl ether in dichloromethane and trichloroacetic acid containing tetraethyl-ammonium perchlorate at a composite anode of carbon and sulphur. The anode generates sulphur cations, which carry out electrophilic substitution on the benzene ring [237], Phenoxathiin radical-cation, formed at the potential of the fust oxidation wave, has been characertised by esr spectroscopy [238],... 

Table 5.3 Electrolyte pit and composition, anodization conditions, and size of the resulting nanotubcs.

In an early experiment, metal/graphite composite anodes were made of bored graphite rods that were packed with pressed mixtures of metal oxide powder, graphite powder, and pitch (12,13). The packed graphite rods had to be heated to about 1600°C for several hours under vacuum in order to cure the pitch. Subsequently the preparation of composite anodes was simplified by simply packing with a mixed powder of metal oxide (or metal) and carbon. Several kinds of composite rods, in which metal particles are uniformly dispersed in graphite, are now commercially available (31). 

Nabae Y., Yamanaka I., Hatano M., Otsuka K., 2006. Catalytic behavior of Pd-Ni/composite anode for direct oxidation of methane in SOFCs. Journal of the Electrochemical Society 153(1), A140-A145. 

Li H, Huang X, Chen L, Wu Z, Liang Y. A high capacity nano-Si composite anode material for lithium rechargeable batteries. Electrochem Solid-State Lett 1999 2 547-549. 

Liu WR, Wu NL, Shieh DT, Wu HC, Yang MH, Korepp C, Besenhard JO, Winter M. Synthesis and characterization of nanoporous NiSi-Si composite anode for lithium-ion batteries. J Electrochem Soc 2007 154 A97-A102. 

Lodowicks, E. and Beck, F. (1994), Basic characteristics of spinel type manganese mixed ox-idc/titanium composite anodes for electroorganic redox catalysis. Chem. Eng. Technol., 17(5) 338-347. 

Beck, F. and Schulz, H. (1987) Cr-Ti-Sb oxide composite anodes, electro-organic oxidation. 

PEVD has been applied to deposit auxiliary phases (Na COj, NaNOj and Na SO ) for solid potenfiometric gaseous oxide (CO, NO, and SO ) sensors, as well as a yttria stabilized zirconia (YSZ) ceramic phase to form composite anodes for solid oxide fuel cells. In both cases, the theoretically ideal interfacial microstructures were realized. The performances of these solid state ionic devices improved significantly. Eurthermore, in order to set the foundation for future PEVD applications, a well-defined PEVD system has been studied both thermodynamically and kinetically, indicating that PEVD shows promise for a wide range of technological applications. 

Applying PEVD to Composite Anode Fabrication for Solid Oxide Fuel Cells... 

In searching for the best fabrication techniques for anodes in our laboratory, PEVD was used to fabricate efficient and compatible composite anodes in the hope of lowering polarization loss and simultaneously achieving long term stability in SOFCs. 

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