Polyacetylene batteries

Costs of the active materials and, in the case of D/A-systems, of the solvent/ electrolyte system, are for any practical case extremely important, for they are proportional to the charge to be stored. Cost aspects in batteries are comprehensively treated in [477]. The specific cost per Ah is reduced at high cycle numbers. Thus good cyclability is important, too. Graphite, H2SO4, or, with some restrictions, carbon blacks and carlmnaceous materials are inexpensive materials. PANI is an inexpensive ICP, but this does not generally apply for all other ICPs as erroneously stated in the literature [562, 563]. The pure material costs for a lead-acid battery are below 4 DM/ kWh. But it is nearly impossible to meet this cost level in the case of a polyacetylene battery, for the polymer should then be as cheap as < 0.3 DM/kg. 

Nagatomo, T., et aL 1983. A long-lasting polyacetylene battery with high energy density. Jpn J Appl Phys 22 L275. 

MacDiarmid, A.G. 1984. Polyacetylene batteries. Prog Batteries Sol Cells 5 31. 

A second type of soHd ionic conductors based around polyether compounds such as poly(ethylene oxide) [25322-68-3] (PEO) has been discovered (24) and characterized. These materials foUow equations 23—31 as opposed to the electronically conducting polyacetylene [26571-64-2] and polyaniline type materials. The polyethers can complex and stabilize lithium ions in organic media. They also dissolve salts such as LiClO to produce conducting soHd solutions. The use of these materials in rechargeable lithium batteries has been proposed (25). 

Polymer Batteries The discovery that doping of polyacetylene produced a highly conducting material was followed swiftly by the realization that this material was a rechargeable battery material which, optimistically, might lead to lightweight... 

Polyacetylene proved qnite incapable of working in a realistic battery context, and MacDiarmid did not mention this application in his Nobel lectnre of October, 8 2000. However, other materials have proven their worth, and prototype batteries made with polypyrrole and polyaniline as cathodes (positives), and metal or lithiated carbon materials as anodes (negatives), have been demonstrated in dne conrse by the Japanese and German indnstry, for instance. Novdk et al. (1997) have reviewed the field in detail. 

The concept of electrochemical intercalation/insertion of guest ions into the host material is further used in connection with redox processes in electronically conductive polymers (polyacetylene, polypyrrole, etc., see below). The product of the electrochemical insertion reaction should also be an electrical conductor. The latter condition is sometimes by-passed, in systems where the non-conducting host material (e.g. fluorographite) is finely mixed with a conductive binder. All the mentioned host materials (graphite, oxides, sulphides, polymers, fluorographite) are studied as prospective cathodic materials for Li batteries. 

Although the diffusion of the counterion is faster in polypyrrole than in polyacetylene, its value is still low enough to influence the rate of the electrochemical charge and discharge processes of lithium/polymer batteries. Indeed the current output of these batteries is generally confined to a few mA cm . Possibly, improvements in the electrode kinetics, and thus in the battery rates, may be obtained by the replacement of standard ... 

Polyacetylene (n-and p-type doping) Solid state batteries ... 

Most photoeonductive polymers can be used in solar batteries. The high resistivity of the polymers decreases the actual power of the devices. Possibilities may be connected with electron-donor doping of the polymers. As stated earlier some success has been achieved in this field for polyacetylenes and other conjugated polymers. 

Durham polyacetylene has the advantage of being a uniform, dense film and so lends itself much more readiliy to diffusion studies. In addition, the uniform morphology is much better suited to device applications, although the low surface area would limit applications in batteries. We have made extensive measurements on the doping of Durham frans-polyacetylene by gaseous AsF5 514 515), which is believed to dope the polymer to form the hexafluoroarsenate ion and arsenic trifluoride 516 ... 

Another limiting factor is that it may not be possible to use some of these electronically conducting organic compounds in aqueous solutions. This is true of the polymer most used in new polymer batteries, polyacetylene, for which an appropriate solvent is propylene carbonate (see Fig. 4.115). 

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