Batteries applications composites

The composition of lithium-manga-nese-oxide spinel electrodes that are of interest for lithium battery applications fall within the Li[Mn2]04 - Li4Mn5Ot2 -Li2[Mn4]0() tie-triangle of the Li-Mn-0... 

In general, we believe that new types of batteries with composite PANI/TEG catalysts can find their own diapason of practical applications depending on concrete conditions of application. 

An up-date of the status of EB curing of carbon fiber composites was presented by A. Berejka. Developments proven successful for aerospace applications are now being seriously scrutinized for automotive use. The diversity of proven uses of radiation grafting for uses in batteries, porous film and non-woven filters, and release coated films and papers was also presented. Opportunities for use of grafting in biomedical applications, composites technology, and fuel cell membrane development were also discussed. 

Silicon sulfide is the base material for a novel class of fast Li conductors for use in solid state battery applications [124, 125]. The material also can be used in infrared transparent fibers and films [126, 127]. A compound of the composition SiS iH (j =... 

Peled and co-workers [54-56] have reported another interesting battery application of the PEO-based composite electrolytes in a cell of the following structure ... 

Other desirable features include low cost and low toxicity. Eailure to meet one or more of these criterions prevents the practical use of a salt in lithium and Li-ion batteries. It is important to note, however, that many of these properties are strongly dependent upon the electrolyte formulation (e.g., solvents used, salt concentration, additives). Thus, electrolyte compositions need to be tailored to specific battery applications/demands. 

For battery applications, high conductivity of the electrolyte must be complemented by good mechanical strength. Composite electrolytes derived from a rigid polymer and a fluid polymer host and, plasticized by high permittivity organic solvents, often have both the mechanical strength and conductivity necessary for the fabrication of room temperature batteries. 

For any battery applications, the separator should have uniform pore distribution to avoid performance losses arising from nonuniform current densities. The submicron pore dimensions are critical for preventing internal shorts between the anode and the cathode of the lithium-ion cell, particularly since these separators tend to be as thin as 25 pm or less. This feature will be increasingly important as battery manufacturers continue to increase the cell capacity with thinner separators. The pore structure is usually influenced by polymer composition, and stretching conditions, such as drawing temperature, drawing speed, and draw ratio. In the wet process, the separators produced by the process of drawing after extractirai... 

Both of the above systems show the enhanced cycling and enhanced capacity of composite anode materials. There are a variety of metals that might he used to intercalate lithium or incorporate hthium. Several studies are currently underway in these areas in our lahs and in others. Some objectives include 35-Ah cells for aerospace applications, development of batteries for electric vehicles, and batteries for hybrid electric vehicles. Improved lithium ion technology, as regards improved performance, decreased cost, and more viable technology is mandatory for synthesis and use of such materials in novel secondary battery applications. 

The PEO-PVA-H2O alkaline SPE was further developed and applied in the Zn/air and Ni/MH batteries [35], It was found that the new alkaline SPE with the composition of PEO PVA = 2 8 had the higher ionie eonductivity of 0.0608 S cm. For the Ni/MH battery, after 40 cycles of charge/discharge tests, the Ni(OH)2 aetive material still had an average capacity density of 250 mAh g. However, the PVA-PEO blend could form a porous and brittle structure membrane. This is not favorable for Zn/air battery application, because the zinc dendrite would penetrate through the air cathode and cause short-circuit dming the discharge. 

Carbon fibers are also produced from the catalytic decomposition of hydrocarbon gases. These vapor-grown fibers can be prodnced at snbmicrometer diameters and show great potential in battery applications. Larger vapor-grown fibers can be produced rapidly by pulse injection and show promise as filler material in composites. 

Mohammadi T, Skyllas-Kazacos M. Use of polyelectrolyte for incorporation of ion-exchange groups in composite membranes for vanadium redox flow battery applications. J Power Sources 1995 56 91-6. 

The high temperature electrolytes are mostly oxides of composition MO based upon the fluorite, structure. The best investigated is "calcia stabilized zirconia (CSZ) which consists of a solid solution of 12-15% CaO in ZrO. The addition of calcia transforms ZrO from the monoclinic to tne cubic (fluorite) structure and also introduces anion vacancies for charge compensation. Conduction is by 0 ion diffusion through anion vacancies and ZrO -CaO has a resistivity of 30 ohm-cm at 950 C. Trivalent cations may also be used to stabilise ZrO with resistivities at 950 C of 12 ohm-cm for ZrO -Y 0 and - 6 ohm-cm for ZrO -Yb O or ZrO -Sc O (Figure l). Staoilized zirconia is of interest as an electrolyte for fuel cells, but no battery applications have been proposed and the temperature of conduction is too high to be of real interest. 

Figure 20. Doped olivines of stoichiometry Lii xMxFeP04 show electrical conductivity at room temperature that is a factor of ca. 10 greater than in undoped LiFeP04, and absolute values > 10 S cm" over the temperature range -20 °C to +150 °C of interest for battery applications. Results are for polyciystals fired at 700-850 °C and measured by two-point d.c. and four-point van der Pauw methods. Inset shows expanded plot for series of dense, single-phase samples fired at 800 °C, showing lower activation energy of the doped compositions. [122]...

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