Polyaniline batteries

Batteries Lithium-ion battery, Polyaniline/Ti02 composite in rechargeable battery [310-324]... 

For the synthesis of polyaniline designed for battery electrodes, Fe(C104)3 and Cu(BF4)2 are preferable as oxidizing agents, because the products contain CIO 4 or BFi anions, which are commonly used in lithium secondary batteries. Polyaniline synthesized by Cu(Bp4)2 has a fibrous morphology [57],... 

A considerabel numbers of papers on fundamental studies of polymer-coated electrodes were published in various journals (e.g., Synth. Met., J. Chem. Soc., J. Electro-anal. Chem., Electrochim. Acta, Makromol. Chem., Macromol. Symp. 8 (1987)) in the year after this manuscript was completed. In several companies applied research works are on the way to realize application of these unconventional materials. Recently secondary batteries (polyaniline/Li, polypyrrole/Li) were commercialized. Developments for practical uses on electrochromic display and sensors are also underway. 

Polypyrrole has been used in the construction of an all-plastic battery. Polyaniline has become a popular conducting polymer. 

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). 

Lithium-Vanadium Oxide 2.5.3 Lithium-Polyaniline Secondary Batteries Batteries... 

Table 12. Specifications of secondary lithium-polyaniline batteries...

Catalogue of lithium-polyaniline batteries, Seiko Instruments Inc., 1996. 

Other materials which appear to be suitable as active battery el trodes are polyazulene poly (A-vinylcarbazole) polyquinolines and, most recently, polyaniline (PANI) panI, in particular, is a promising material for the... 

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. 

As to anodes, in most of the research work a generously dimensioned sheet of lithium metal has been used. Such an electrode is rather irreversible, but this is not noticed when a large excess of lithium is employed. Li-Al alloys and carbon materials inserting lithium cathodically during recharging can be used as anodes in nonaqueous solutions. Zinc has been used in polymer batteries with aqueous electrolyte (on the basis of polyaniline). 

The mechanisms and reasons of catalytic activity of polyaniline (PANI)-type conducting polymers toward oxygen reduction in acidic and saline solutions are investigated by electrochemical and quantum-chemical methods. The PANI/thermally expanded graphite compositions were developed for realization of fully functional air gas-diffusion electrodes. Principally new concept for creation of rechargeable metal-air batteries with such type of catalysts is proposed. The mockups of primary and rechargeable metal-air batteries with new type of polymer composite catalysts were developed and tested. 

Conducting polymers, polyaniline, catalytic activity, PANI/expanded graphite composites, metal-air batteries, primary rechargeable cells. 

The benefit of a hybrid phase for the intercalation-deintercalation of mobile species such as Li+ cations is well illustrated by the study of conductive polymers such as polyaniline or polypyrrole intercalated into a V2O5 framework as potential electrode materials in lithium batteries [34]. For PANI/V2O5, an oxidative post-treatment performed under an oxygen atmosphere allowed the authors to compare the conductivity attributed to the polymer, as in absence of reduced cations, there was no electronic hopping between ions, and the conductive state was due only to the... 

There is a large potential for conducting polymers as corrosion-inhibiting coatings. For instance, the corrosion protection ability of polyaniline is pH-dependent. At lower pH polyaniline-coated steel corrodes about 100 times more slowly than noncoated steel. By comparison, at a pH of about 7 the corrosion protection time is only twice for polyaniline-coated steel. Another area of application involves creation of solid state rechargeable batteries and electrochromic cells. Polyheterocycles have been cycled thousands of times with retention of over 50% of the electrochromic activity for some materials after 10,000 cycles. IR polarizers based on polyaniline have been shown to be as good as metal wire polarizers. 

ZnO displays similar redox and alloying chemistry to the tin oxides on Li insertion [353]. Therefore, it may be an interesting network modifier for tin oxides. Also, ZnSnOs was proposed as a new anode material for lithium-ion batteries [354]. It was prepared as the amorphous product by pyrolysis of ZnSn(OH)6. The reversible capacity of the ZnSn03 electrode was found to be more than 0.8 Ah/g. Zhao and Cao [356] studied antimony-zinc alloy as a potential material for such batteries. Also, zinc-graphite composite was investigated [357] as a candidate for an electrode in lithium-ion batteries. Zinc parhcles were deposited mainly onto graphite surfaces. Also, zinc-polyaniline batteries were developed [358]. The authors examined the parameters that affect the life cycle of such batteries. They found that Zn passivahon is the main factor of the life cycle of zinc-polyaniline batteries. In recent times [359], zinc-poly(anihne-co-o-aminophenol) rechargeable battery was also studied. Other types of batteries based on zinc were of some interest [360]. 

Recently, new types of organic positives, formed by a mixture of dimercaptan with polyaniline, have been reported. These composite materials appear to have an energy density higher than that of most inorganic intercalation oxides and good cyclability. However, use of these materials in practical rechargeable lithium batteries has still to be confirmed. 

A polypyrrole-electrolyte-polypyrrole battery has been described 611) but the n-doped polypyrrole is unstable. This can be avoided by using a polypyrrole-polyanion anode, where the charge and discharge depend upon small cations moving into and out of the electrode612). A polythiophene-polythiophene battery has also been described 135). Polyaniline has been studied as a potential battery cathode, for use with an aqueous electrolyte 613,6I4). 

As a conducting polymer, polyaniline has many electronics-related applications, such as rechargeable batteries (Tsutsumi et al. 1995), multilayer heterostructure light-emitting diode devices (Onoda Yoshino 1995), biosensors (Bartlett Whitaker 1987), elec-trochromic windows (Nguyen Dao 1989), and nonlinear optical materials (Papacostadi-nou Theophilou 1991). Polyaniline may be prepared from aniline by both electrochemi-... 

Work with PPy and PAni has reached the industrial stage. Bridgestone-Seiko has been selling coin-shaped 3-V polyaniline-based batteries for 5 years (1987-1992), and polypyrrole-based batteries were developed by Varta/BASF in the same period. Such batteries have lower energy densities than those of conventional batteries, but they are superior in terms of selfdischarge. The main characteristics of a typical PAni battery are compared to those of lead and Cd-Ni batteries in Table 4. The values mentioned for energy density and electric capacity density refer to the active material alone. 

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