DE3844940C2 - Composite material made of aluminum and an electrically conductive polymer and method for producing the composite body - Google Patents

Abstract

A composite body made of aluminum and an electrically conductive polymer is described, in which the aluminum surface to which the polymer is bound has a (HOO) surface (H = 1, 2, 4) as the main crystal surface. The electrically conductive polymer can be applied to the aluminum surface by chemical polymerization and, if appropriate, additionally carried out electrolytic polymerization.

Description

The invention relates to a composite body made of aluminum and an electrically conductive polymer, e.g. B. polyaniline, and a Process for producing the composite body.

A method of synthesizing an organic polymer by Electrolytic oxidation of organic material has been around has long been known and various polymers have been developed by electro-synthesizing organic polymers chemically controlled.

In particular, it is known that polymers produced by poly merization can be obtained with electrolytic oxidation, such as B. polypyrrole, polythiophene, polyphenylene, and poly aniline (polypyrrole in A. F. Dinz, J. Chem. Soc., Chem. Commun., 1975, 635; Polythiophene in the Japanese Open Application No. 56-47421; Polyphenylene in electrochem., Acta. 27, 61 (1982); Polyaniline in F. Diaz, J. Electroanal. Chem. 111, 1524 (1980)) have electrical conductivities, that of values that of insulators or semiconductors correspond to those of metals, the higher conductivities by doping such Polymers with certain impurities can be achieved. It is also known that the doping is reversible and accompanies a color change. It was because of that intensive studies on the application and use in dis play elements, photoelectronic conversion elements,  Switching elements, electrode materials, secondary lines, electromagnetic shielding materials and various which types of sensors are performed.

Such polymeric materials are usually combined in one composite structure used, d. H. in combination with other conductors (mainly metals), and aluminum minium is preferred as a conductor because it has no adverse effects Effect on the beneficial properties of the polymer Materials (reduced weight, thin film-like shape, etc.) can be used. Because aluminum is a relative light weight and excellent guidance ability compared to other metals (Fe, Ni, Cu, etc.) it became common with such devices and composite materials used, a Ver Strive to reduce weight and thickness. About that in addition, they are also often due to the light bil formation of oxide films and light etching in electrolytic Capacitors have been used, as well as in the manufacture of conductive layers or reflective layers by means of a Schottky connection using a gas phase process, such as. B. Vapor separation on various kinds of materials.

The composite aluminum and polymer Body is functional electrodes for many aspects been proposed. From the inventors of the present Application was also believed to be preferred an electrolytic etching for aluminum to manufacture composite electrodes that form a composite body made of aluminum and polymer, to apply one tight bond between the aluminum and the polymer get an improvement in the charging efficiency of the Polymers, and easy removal of oxide layers of aluminum (Japanese Patent Laid-Open No. 61-133 557). Although the surface of the aluminum ver  is enlarged and the tight bond between the alumi nium and the polymer is improved Electrolytic etching applied to ordinary aluminum however, the disadvantage that the mechanical strength of the Aluminum is significantly reduced.

When using a composite electrode, the a composite body made of aluminum and polymer as one functional electrode in various devices contains, however, is the guarantee of their mechanical Strength one of the requirements from the standpoint the manufacture and also from a functional point of view required are.

In EP-A-183 053 a galvanic element with a Polymer electrode described. As a separation document for the electrochemical polymerisation of the electrode active organic material with its natural oxide skin left aluminum called that with an electron conductive coating from z. B. Au, Pt, Ni, C is provided. Besides aluminum can also be used directly as a separation pad serve if it is used in bright pickled form. Here it is not discussed which crystal surface the Has aluminum surface to which the polymer is bound.

The object of the invention is a composite body made of aluminum to provide nium and an electrically conductive polymer, the ver with regard to interface adhesion and impedance is better and in particular as a composite electrode for different areas of application.

The invention relates to a composite body made of aluminum and an electrically conductive polymer, characterized thereby is that the aluminum surface to which the polymer is bound, a (HOO) surface (H = 1, 2, 4) as the main Has crystal surface.  

With the composite body according to the invention it is possible to to get a composite body in which the tight bond at the interface is improved, the interfaces impedance is improved, and the film thickness of the electrical conductive polymer is uniform, and that as one composite electrode for different types of Elements can be used. The invention electrical cell that such a composite Electrode used has high capacity and high Energy density, and exhibits excellent stability with repeated charging and discharging.

The present invention is based on the discovery that when connecting aluminum and electrically conductive Polymer get a satisfactory composite surface can be, especially when connecting aluminum, the same as the crystal surface on the composite surface has a (HOO) surface (H = 1, 2, 4).

Metals that face-centered a crystal structure have cubic lattice type, such as. B. aluminum or Alkali metals, have a high reactivity at (HOO) - Surfaces, and in the case of connection by a chemical Procedure it is possible to have a satisfactorily dense Get connection. Especially in the case of Her provision of an electrically conductive polymer on Alumi nium as a substrate, this effect is remarkable embossed, in comparison with aluminum, which is not predominantly as a crystal surface on the composite surface a (HOO) - Area (H = 1, 2, 4). This makes the interfaces lower impedance between aluminum and polymer, and thus represents an advantage when using the Composite body made of aluminum and the polymer in various which devices.

The present invention therefore provides a composite body made of aluminum and an electrically conductive  Polymer ready in which the aluminum on the composite surface predominantly a (HOO) surface (H = 1, 2, 4) as a crystal surface has, as well as a method for producing such Body, and an electric cell, such a Composite body used as an electrode.

The polymer which can be used for the composite body according to the invention is a polymer which contains a conjugated double bond in the main chain and / or a heteroatom in the main chain and which is active for electrochemical oxidation and reduction, such an action being reversible, such as, for. B .:

• a) a polymer of a heterocyclic 5-membered Ring connection comprising z. B. furan, pyrrole, thiophene, selenophene Telluphen and derivatives of such monomers,
• b) a polymer of aromatic hydrocarbon compounds comprehensively z. B. benzene, naphthalene, anthracene, pyrene, fluorene, Azulene and derivatives of such monomers, and
• c) a polymer of amine compounds comprising z. B. aniline, p-aminodiphenylamine, N, N'-diphenylbenzidine and Derivatives of such monomers.

As a method for polymerizing such monomers chemical polymerization using an oxi dationsmittel be used, and an electrolytic Polymerization using electrical energy.

The chemical polymerization is carried out by adding of an oxidizing agent in a solution containing a monomer contains, and oxidation of the monomer. The used here oxidizing agents include halogen, such as. B. iodine, bromine, Bromoiodide; Metal halides such as e.g. B. arsenic pentafluoride, Antimony pentafluoride, silicon fluoride and phosphorus penta chloride; Protonic acids, such as B. sulfuric acid, nitrate acid, fluorosulfuric acid, chlorosulfuric acid; Sour Compound containing compounds, such as. B. sulfur trioxide,  Nitrogen dioxide, potassium permanganate or potassium hydrogen chromate; Persulfate, e.g. B. sodium persulfate, potassium persulfate and ammonium persulfate; Peroxides such as B. water peroxide, peracetic acid and difluorosulfonyl peroxide.

Chemical polymerization is when a polymer is synthesized with a high degree of polymerization Polymer insoluble and is synthesized in powder form. In view of the above, it is practical Carrying out the production of a ver according to the invention body, the aluminum and the polymer to connect mechanically tightly, but this method involves holds the disadvantage that the tight bond between aluminum minium and the polymer is bad and the interfaces impedance increases.

Because on the other hand, the composite body made of aluminum and the polymer in the electrolytic polymerization using an electrochemical reaction in one Stage using aluminum as the reaction electrode can be generated and the interface impedance is lowered can be, this is compared to the Polymerisationsver advance using the oxidizing agent trains used. However, it is difficult to electroly table polymerization of the monomer directly on aluminum perform, and uniform formation of a poly meren has generally been difficult.

As a process to get the monomer directly onto aluminum Polymerizing electrolytically was invented by the inventors the present application found that an electroly table polymerization of the monomer directly onto the aluminum nium substrate is possible if you have the surface of a Aluminum electrode of a mechanical polishing treatment with emery paper, and an electrolytic Etching with the purpose of thick oxide films on the surface  remove to a certain extent. The inventors of the present application have further found that if aluminum is used, that on the surface weighing a (HOO) surface (H = 1, 2, 4) as a crystal surface possesses the monomers uniformly on the aluminum upper is polymerized without an etching treatment on the surface Aluminum surface.

That using aluminum as an electrode performed electrolytic polymerization processes is generally z. B. described in J. Electrochem. Soc., Vol. 130, No. 7, 1506-1509 (1983), Electrochem. Acta., Vol. 27, No. 1, 61-65 (1982) J. Chem. Soc. Chem. Commun., 1199 (1984), and the method can be practical be done by finding a solution that is a mono meres and an electrolyte dissolved in a solvent contains an electrode in an electrolysis vessel dips in, and the electrolytic polymerization freak tion by means of anodic oxidation or cathodic reduction tion causes.

As an electrolyte z. B. are called BF ₄ ^- , AsF ₆ ^- , SbF ₆ ^- , PF ₆ ^- , ClO ₄ ^- , HSO ₄ ^- , SO ₄ ^2- and aromatic sulfonic acid anions as anions, and H ⁺ , quaternary ammonium cation, lithium, sodium or Potassium are examples of suitable cations, and there is no particular limitation.

The solvent can e.g. B. include water, acetonitrile, Benzonitrile, propylene carbonate, γ-butyrolactone, dichloro methane, dioxane, dimethylformamide or a nitro solution medium, such as B. nitromethane, nitroethane, nitropropane and Nitrobenzene, with no particular restrictions just insist. For electrolytic polymerization can electrolysis with constant voltage, an electric lysis with constant current, and an electrolysis z. B. with  constant potential can be used.

The polymers which contain the monomers described above and which can be applied with repeated doping and de-doping, and which, for. B. polypyrrole, polythiophene, poly-3-methylthio phen, polyphenylene, polyaniline, diphenylbenzidine polymer, and derivatives thereof, wherein those having an electrical conductivity in the doped state of greater than 10 ^-3 S / cm are preferred.

As the electrically conductive used in the present invention Polymer can be mentioned those described above being polyaniline, which is an excellent chemical stabilizer lity, is preferred.

Polyaniline and substituted polyaniline used in the present invention are polymers of the monomers represented by the following general formula:

wherein R ₁ -R _{5 are} hydrogen, alkyl, alkoxy and silyl, with the measure that R ₂ , R ₃ and R _{4 are} not alkoxy.

Aniline, 4-aminodiphenylamine, N-methylaniline, N-ethylaniline, 4- (N-methylamino) diphenyl amine, diphenylamine, o-methyl-aniline, o-ethyl-aniline, m- Methylaniline, m-ethylaniline, 4- (N-ethylamino) diphenylamine, N, N'-diphenyl-p-phenylenediamine, N-trimethylsilylaniline, o-trimethylsilylaniline, m-trimethylsilylaniline, o-methoxy  aniline, o-ethoxyaniline, m-methoxyaniline, m-ethoxyaniline, 2,5-dimethylaniline, 2,6-dimethylaniline, 2,5-dimethoxy aniline and 2,6-dimethoxyaniline. Among these has aniline with regard to the electrode characteristics for ver preferred properties in electrical cells.

In the electrolytic synthesis of polyaniline, this is synthesized in an aqueous acidic solution, and using a protonic acid, such as. B. H ₂ SO ₄ , HCl, HClO ₄ and HBF ₄ as electrolyte, which is different from the synthesis of many other electrically conductive polymeric materials Ma, which is carried out in a non-aqueous system (Japanese Patent Application Laid-open No. 62-96525, J Electroanal. Chem. 161, 419 (1984)). The effect according to the invention is clearly pronounced in the direct electrolytic synthesis of polyaniline on aluminum. It can e.g. For example, it can be observed that when aniline is polymerized on aluminum in an aqueous sulfuric acid solution, a thin film of polyaniline grows uniformly on the surface of the aluminum when aluminum is used as the electrode which has (HOO) surfaces (H =) on the surface 1, 2, 4) has as the main crystal face, and an electric field is applied while substantially no polymerization occurs, or the polymer only grows in an island-like configuration on the aluminum surface when the polymerization is carried out by applying an electric field Use of aluminum as the electrode applied, which has no (HOO) surface (H = 1, 2, 4) as the main crystal surface. Similarly, this phenomenon also occurs in the synthesis of other electrically conductive polymeric materials on aluminum, and is not limited to the polymerization of aniline, although this phenomenon is particularly remarkable in the synthesis of polyaniline. If the aluminum surface, which has the (HOO) surface (H = 1, 2, 4) as the main crystal surface on the surface, is roughened with emery paper, etc., to the crystal arrangement of the (HOO) surface (H = 1, 2 , 4) to destroy, the growth of the polymer is also extremely uneven.

As another form of manufacturing process for which he composite body according to the invention is considered a method for the aluminum, which is predominantly the (HOO) surface (H = 1, 2, 4) as the crystal surface, applied with etching is, a composite body with the electrically conductive Polymer is produced. Even with this procedure the direction of the crystal face of aluminum extremely significant. That is, it is preferred that the crystal face on the surface of the aluminum, which is an etching treatment is predominantly the (HOO) area (H = 1, 2, 4).

It is known that the crystal structure of aluminum is a face centered cubic lattice structure, and there is a difference in the density of the atoms on the resulting crystal faces, which depend on the arrangement of the Depends on atoms. It is therefore believed that reactions, like oxidation or etching, in the less dense area (100) can run faster than in other denser ones Areas such as B. (110) and (111).

On the (100) crystal surface of aluminum, it is a characteristic that a micro-unevenness of the aluminum surface, which is formed by electrolytic etching, is formed uniformly in the direction perpendicular to the aluminum surface ( Fig. 1). Furthermore, the unevenness on the (100) crystal surface is particularly deep, or penetration holes can be obtained. Because micro-openings are in communication with each other, there is less detachment of aluminum, which results in a lower reduction in strength and less reduction in the specific surface area, and thus fewer disadvantages. On the other hand, the formation of microholes in the aluminum surface in low crystallinity aluminum or aluminum containing a plurality of (110) faces, (111) faces in the crystal face on the surface is not uniform in one by electro-lytic etching Direction perpendicular to the aluminum surface, and individual holes are formed which run in different directions ( Fig. 2). Because the holes communicate with each other in a complicated manner, remarkable disadvantages are caused, e.g. B. a detachment of aluminum, and thus a reduction in strength and a reduction in the specific surface.

In the case of an etching treatment of the aluminum, it can be as an embodiment according to the invention can be considered, the aluminum is first electrochemically in an etching solution to etch, and then the electrically conductive polymer directly to bind to aluminum. In the case of the invention It is also a composite body made of aluminum and polyaniline possible the composite body essentially in one step by making the aluminum an electro using chemical etching in an etching solution subject to an acid capable of directly aniline to electrolytically polymerize on the aluminum rend the aniline monomer to the solution as later described, adds. Because the aniline polymerization is direct on the etched surface, this Ver drive the advantage that the binding of aluminum and Polyaniline is possible, while the oxidation on the ge etched surface is suppressed to a certain extent.

As described above, according to the present The invention used aluminum on the surface the (HOO) surface (H = 1, 2, 4) as the main crystal surface.

The (HOO) area on which in the present invention Is referenced, the (100) face closes, (200) -  Area and the (400) area in the crystallographic sense a, and the crystal structure of the aluminum surface is assessed by X-ray diffraction. The x-ray Diffraction patterns on the aluminum used according to the invention minium surface mainly comprises diffraction lines the (200) area, and in quantitative terms that is Ratio of the integrated intensity of the diffraction lines through the (200) area to the integrated intensity of the total diffraction lines greater than 0.4 and preferably greater than 0.6.

The (HOO) surface was determined by means of electron diffraction (H = 1, 2, 4) of the aluminum an electron diffraction image point shaped shape, which has a high single crystallinity Aluminum on the surface.

The aluminum used according to the invention, which on the upper mainly a (HOO) surface (H = 1, 2, 4) as a crystal has area, z. B. produced by zone melting (W.G. Pfann Trans A.I.M. E. 194, 747 (1952)). By Zone melting can be made of an aluminum that both on the surface and in the mass the (HOO) - Has surface as a crystal surface. Such aluminum can be used according to the invention as it is, or after it is cut open so that it is the (HOO) face on the surface.

Whether in an embodiment of the invention the electro lytic polymerization is carried out directly or the electrolytic polymerization is carried out after or during the etching of aluminum that is on the surface predominantly has the (HOO) surface as the crystal surface, depends on the use of the composite body and can cannot be determined in advance.

But it is generally possible to be electrically conductive  Polymer evenly on aluminum using the as described above aluminum according to the invention to synthesize. When using, e.g. B. as electro chrome electrode, then is a uniform color change, accompanying the change in the electric field may be possible Lich. Used as an electrode for a secondary Cell it is because the film has grown uniformly further possible, an electrode with low internal resistance to get compared to using an electrode island growth, and with that it is possible to be dependent from reducing the voltage z. B. the reduction of Improve energy capacity.

The electrolytic polymerization of aniline is described in performed an acidic aqueous solution, and the Ver use of a specific acid for the synthesis of poly aniline on aluminum is essential. Such acids that a pKS value within a range of -2.5 to +2.5 possess, show satisfactory results.

Such acid can e.g. B. include sulfuric acid, Sulfonic acid such as B. paratoluenesulfonic acid, benzene sulfonic acid and naphthalenesulfonic acid, trifluoroacetic acid acid. If perhydrochloric acid (pKS: approx. -3.1), Tetrafluoroboric acid (pKS: approx. -4.9) or hydrogen chloride acid (pKS: approx. -4) is used, an electroly generating electricity for aluminum during the polymerization process tial of aniline observed, and the polymerization takes place not instead. If further nitric acid (pKS: approx. -3) ver is used, although no electrolysing current at the polymerization potential of aniline flows and Aluminum is not washed out, no polyaniline forms. A similar phenomenon also occurs in the case of Observe the use of hydrofluoric acid (pKS: approx. 3.2) in which no aniline polymerization takes place. It is believed that the washout or oxidation  of aluminum has an effect on these phenomena, and as a result of these studies, it was found that satisfactory results can be obtained at Use of an acid with a pKa value within one Range from -2.5 to +2.5.

In the case of carrying out the electrolytic polymerization using an acid which is not capable of direct polymerization of aniline on aluminum, such as. B. HCl and HBF ₄ , the electrolytic poly merization is made possible by first forming a thin poly aniline film on the aluminum using an acid capable of direct polymerization, such as. B. H ₂ SO ₄ , and then the polymerization in HCl or HBF ₄ , or by first a thin film of z. B. forms polypyrrole on the aluminum by previous chemical polymerization.

In a further embodiment for the invention Composite body it is possible to apply a process where you first have a thin film of polyaniline or another electrically conductive polymer on the aluminum minium forms using an acid suitable for the is capable of direct polymerization on aluminum, such as. B. Sulfuric acid, and then an electrically conductive one Polymer such as B. Polyaniline using chemical Polymerization deposits. As a complex procedure under Using chemical polymerization it is possible to the composite body of the thin polymeric film and the Incorporate aluminum together in a polymerization system gene, which is a protonic acid, an oxidizing agent, Contains water and aniline, or it is also possible to use one to apply an electric field while looking at the composite body made of thin polymer film and aluminum as Reaction electrode in a chemical polymerization system used, causing the polymerization of aniline  on the aluminum created with the one before going synthesized thin polymeric film as the core Is provided. With the latter method it is possible the composite body even under a low electric field that is less than that electric field used for the polymerization of aniline in a system that does not have an oxidizing agent contains, and it is also possible to add more polyaniline the aluminum than in the system that does not contain oxidizing agents.

The oxidizing agent usable in chemical polymerization can e.g. B. include (NH ₄ ) ₂ S ₂ O ₈ , FeCl ₃ , NaClO ₃ , MnO ₂ , H ₂ O ₂ , PbO ₂ , KMnO ₄ and K ₂ Cr ₂ O ₇ . As the protonic acid, the same acids as are used for the electrolytic polymerization of aniline can be used.

That during the electrolytic synthesis of polyaniline potential applied to the electrode is preferred an electrolytic potential within a range from +0.75 to +0.95 V, based on the saturated calomel Electrode (SCE).

If the potential is higher than +0.95 V, the sol sensitivity to doping and de-doping in the Electrolytic solution using e.g. B. PC deteriorate tert, whereby the life of the composite body as Electrode is reduced. If it is lower than +0.75 V is, although the solubility is not as bad becomes bad, the formation of fibrils from polyaniline and, especially if it is lower than +0.7V the value of the current that flows during the polymerization, low, which worsens production efficiency.

The polymerization process is a constant process Potential, but electrolysis can also be constant  Current can be used as long as the potential difference between the reaction electrode (aluminum) and the Reference electrode (SCE) within a range between +0.75 V and +0.95 V.

In the composite body produced according to the invention Polymer on the aluminum together with a doping deposited by ions. The electrolytic poly Mer body manufactured composite is therefore ge forms while remaining in the doped state. To do that One can remove dopants from the composite body the process of the electrochemical de-doping reaction perform by applying a potential that from is far less noble to ions from the polymer To let the ion complex escape in the electrolyte, or by using chemical de-doping a reducing medium.

In the electrochemical process, it is preferred that the electrolyte is a non-aqueous electrolyte. If the doping of the composite body in an aqueous Electrolyte is carried out, then there is concern that the composite body has a mixed electrode potential of aluminum and electrically conductive polymer shows that is unable to adequately reduce the to effect electrically conductive polymer. In particular for a composite body made of aluminum and polyaniline shows the composite because aniline in the aqueous acidic solution is polymerized electrolytically if the doping also in aqueous acidic solution is performed, a potential that is mixed Electrode potential of aluminum and polyaniline is seen, and makes it impossible to de-dope through respectively.

The de-doping from the composite body according to the invention  is therefore preferably in non-aqueous solution guided. As for the polyaniline used in the present invention In terms of chemistry, there is a big difference structure between the synthesized state (doped state) and the de-doped state because the synthesis was carried out in the aqueous acidic solution and unpaired electrons on nitrogen atoms are available. In the case of using polyaniline as electrochromic element, it is e.g. B. possible by pots tial waste cause a color change, even if the composite body made of aluminum and polyaniline in the synthesized state according to the invention directly into a brought non-aqueous solution. In the case of use Form a composite body made of aluminum and polyaniline as an electrode for non-aqueous cells when the Cell function for that by electrolytic polymerisa tion synthesized polyaniline directly in the non-aqueous Electrolytes without de-doping are detected in the cells function somewhat deteriorated and less stable than in the case the application of de-doping. It is believed that this is due to the difference in the chemical structure of the poly anilins between the synthesized state (doped Condition) and the reduced described above Condition. So for polyaniline To expect stable cell function, it is necessary the polyaniline in the aluminum bound by direct electrolytic polymerization synthesized state a de-doping, and then in the to give non-aqueous electrolytes. The aluminum However, polyaniline electrode shows as above wrote the mixed electrode potential of poly aniline and aluminum in an aqueous acidic solution, and therefore makes it impossible to de-dope polyaniline to subjugate.

To overcome these disadvantages, the inventors of  present application various reduction methods for the composite body made of aluminum and polyaniline under was looking for and had success, a composite body made of aluminum and polyaniline in the reduced state by chemical Reduction of the polyaniline in the synthesized state (doped state) in the composite body (1) by contact with one other than metals reducing medium, undergoing a chemical reaction is performed, and / or (2) by contact with a redu decorative metal.

As a reducing medium in process (1), a reducing agent, such as. B. H ₂ , hydrazine and phenylhydrazine used. The use of ammonia is not preferred, and when ammonia is used, the solubility of polyaniline in an organic solvent is increased, and thus significantly deteriorates the repetitive doping / de-doping property of the composite. As a specific reduction method, the reducing agent described above is brought into direct contact with the composite body, or it can be dissolved in the other solvent in which the composite body can be immersed. The concentration of the solution is preferably 20 to 70% by volume. Of these, a method in which the composite body made of aluminum and polyaniline is immersed in a 30 to 60% by volume hydrazine solution is preferred. With regard to the reduction treatment of polyaniline, Japanese Patent Laid-Open No. 62-149724 describes the application of a reduction treatment for polyaniline e.g. B. using hydrazine. It was pointed out that a method for the electrochemical doping of polyaniline in the synthesized (doped) state in an aqueous acidic solution, carrying out the reduction treatment with hydrazine and further alcohol treatment is preferably used. As described above, the de-doping is not carried out in aqueous acid solution in the composite body according to the invention made of aluminum and polyaniline. If a less noble potential is used to carry out the de-doping of the composite body of aluminum and poly aniline in the aqueous acidic solution, the disadvantage arises that the solubility of the polyaniline in the non-aqueous solution is increased, the composite body made of aluminum and Polyaniline is degraded on the composite surface, etc. The use of electrochemical de-doping in combination with the chemical reduction in an aluminum polyaniline electrode according to the invention as a process step for the reduction of poly aniline is therefore not suitable. In this regard, the inventive concept is different from the related inventions. As a further reduction process for the composite body made of aluminum and polyaniline, a reduction process in contact with a reducing metal can be mentioned. The reducing metal specifically includes such alkali metals as Li, Na, K, Mg, Ca, etc. In this method, the doping of the polyaniline can be achieved by a simple method by using the polyaniline produced by electrolytic polymerization and a reducing metal directly into a non-aqueous solvent or solution. From an electrochemical point of view, it appears that this corresponds to the application of the standard electrode potential of an alkali metal to polyaniline in the synthesized state (doped state). However, because the function of the composite body made of aluminum and polyaniline as a cell electrode, produced by de-doping the composite body made of aluminum and polyaniline according to the invention by means of the three-electrode method using the composite body as an operating electrode in a non-aqueous solution, is poorer than that of polyaniline de-doped in contact with the alkali metal, it should be considered that there is another factor besides the potential in the reduction process for the polyaniline of the present invention, but exact reasons for this have not yet been given.

For the use of the composite body according to the invention different types of devices have been considered drawn. In the event that the doping and de-doping Ver keeping the electrically conductive polymer is used the composite body must be in a non-aqueous solvent or used with a solid electrolyte because the de-doping of the electrically conductive polymer of the Composite body according to the invention, as described above ben, not carried out smoothly in an aqueous solution can be.

It is said to be an electrical cell using the he Composite body according to the invention made of aluminum and electrical conductive polymer can be described as an electrode.

The electric cell essentially comprises a positive electrode, a negative electrode and an electrolyte in which between the electrodes Separator can be attached. The electrolyte is out a solvent and an electrolyte, or a solid electrolyte can also be used.

The electrical cell stores energy, by doping with anions or cations, and sets energy through an external current at the De-Dotie free. Because the doping / de-doping is reversible the electrical cell can also be used as a secondary cell.  

The composite body according to the invention made of aluminum and electrically conductive polymer can at least can be used for the positive electrode.

As a dopant for the polymer of the electrode z. B. the following anions or cations are listed, and a cation-doped electrically conductive polymeric complex is an n-type material, while an anion-doped electrically conductive polymeric complex is a p-type material. The p-type material can be used for the positive electrode and the n-type material can be used for the negative electrode. Because polyaniline can also be converted into a stable p-type material by anion doping, it is suitable for the positive electrode.

(1) anion:
Anions of halides of Group Va elements, such as. B. PF ₆ ^- , SbF ₆ ^- , AsF ₆ ^- and SbCl ₆ ^- ; Anions of the halides of Group IIIa elements, such as. B. BF ₄ ^- ; Perchlorate ions such as B. ClO ₄ .

(2) cation:
Ions of alkali metals, such as e.g. B. Li ⁺ , Na ⁺ , K ⁺ , (R ₄ N) ⁺ (wherein R means: hydrocarbon group with 1 to 20 carbon atoms).

Specific examples of compounds of the dopant described above can e.g. B. include LiPF ₆ , LiSbF ₆ , LiAsF ₆ , LiClO ₄ , NaClO ₄ , KJ, KPF ₆ , KSbF ₆ , KAsF ₆ , KClO ₄ , ((n-Bu) ₄ N) ⁺ AsF ₆ ^- , ((n- Bu) ₄ N) ⁺ . ClO ₄ ^- , LiAlCl ₄ , and LiBF ₄ , which are used as electrolyte for the electrical cell. Among them, LiBF ₄ and LiSbF _{6 are} preferred for the electric cell.

As a solvent for the electrolyte in the Cell are preferred those that are not polar  protic solvents that are not called protic solvents with a high specific Dielectric constant are. Specifically, you can e.g. B. used are ketones, nitriles, esters, ethers, Carbonates, nitro compounds, compounds from sulfolane Type, or mixtures of these solvents. Under these are nitriles, carbonates, and sulfolane type compounds prefers. Typical examples of these may include Acetonitrile, propionitrile, butyronitrile, valeronitrile, Benzonitrile, ethylene carbonate, propylene carbonate, γ-butyro lactone, sulfolane, 3-methylsulfolane, tetrahydrofuran and 2- Methyl tetrahydrofuran. Specifically, they have those made on the basis of propy lencarbonate and addition of DME, Sulfolan, THF or Derivatives thereof, excellent properties. Ver You can also improve the processability Polymers added to form a paste-like shape become.

As a negative electrode in the electri according to the invention cell can be in addition to that described above benen polymeric material such metals and alloys used, such as. B. Li, Zn, Cu, Ag, Al, binary Alloy, such as B. Al-Li, ternary alloys such. B. Li-Al-Ag or Li-Al-Mn, or Wood's alloys. Under the Li-Al alloy is a negative electrode in them preferred the electrical cell according to the invention, and a ternary alloy such as B. Li-Al-Mg or Li-Al-Mn, based on Li-Al, is preferably used. For Manufacture of the negative electrodes from these metals and alloys there are several options; a metal itself can function both as an active substance and own as a charge collector; or Ni, Al as charge collecting material (charge carriers) can be used in close ver bond used, or a charge-collecting Material can be used while being active  Substance due to the deposition of cations in the electrolyte provides.

As a separator in the electrical cell such materials are used that are low Resistance to ion movement in the electrolyte solution and an excellent reluctance of the solution demonstrate. It can e.g. B. a glass fiber filter, a polymer Pore filters, such as B. a non-woven fabric made of polyester, Teflon, Polyflon, or polypropylene, or non-woven fabrics, the glass fibers and contain such polymeric materials, ver be applied.

Instead of the electrolyte and the separator, a solid electrolyte can also be used as a component. For example, such inorganic electrolytes can be named, such as. B. metal halides, e.g. B. AgCl, AgBr, AgJ and LiJ, RbAg ₄ J ₅ , and RbAg ₄ J ₄ CN. As organic solid electrolytes, there can be mentioned such composite materials which are produced using polyethylene oxide, polypropylene oxide, polyvinylidene fluoride or polyacrylonitrile as a polymer matrix in which the electrolyte salts described above are dissolved, crosslinked products thereof, and polymeric electrolytes which are graft-polymerized to groups which are less ionizable , such as B. low molecular weight polyethylene oxide, polyethylene imine and crown ether to the polymeric main chain forth.

Brief description of the drawings:

Fig. 1 is a schematic view for explaining the surface state in which an aluminum used according to the invention, which predominantly has a (HOO) surface on the surface as a crystal surface, has been subjected to an electrolytic etching treatment;

Fig. 2 is a schematic view illustrating the surface state in which conventional aluminum has been subjected to an electrolytic etching treatment;

Fig. 3 is a graph showing the electrochemical properties of an aluminum polyaniline electrode according to the present invention (Example 1);

Fig. 4 is a graph showing the switching characteristic of a 3-layer device of the present invention made of aluminum / poly aniline / gold (Example 5); and

Fig. 5 is a view illustrating the peeling test.

Below are preferred embodiments of the above lying invention in the form of examples with reference described on the drawings.

Examples example 1

In order to obtain an aluminum polyaniline electrode, an electrolytic polymerization of 0.5 M aniline in an aqueous 5.0 N sulfuric acid solution was carried out using aluminum with a thickness of 60 µm (ratio of the integrated intensity of the diffraction lines by the ( 200) area / integrated intensity of the entire diffraction lines = 0.9) as an electrode for the electrolysis at 0.8 V vs SCE. In this case, aniline is polymerized uniformly on aluminum. As shown in Fig. 3, the aluminum polyaniline electrode shows repeating electrochemical activity in a non-aqueous electrolyte (solution of 3.0 M LiBF ₄ in a mixed solvent of propylene carbonate and dimethoxyethane (7: 3)), as shown in Fig. 3, and in accordance with the poten tialänderung electrochromism is observed.

The aluminum polyaniline electrode is then immersed in an aqueous 50% by volume hydrazine solution and dried. Then the cell test is carried out by repeatedly charging and discharging a current density of 0.2 mA / cm ² in an electrolyte of 3.0 M LiBF ₄ dissolved in a mixed solvent of propylene carbonate and dimethoxyethane (7: 3) using the aluminum - Polyaniline electrode as positive electrode and Li as negative electrode.

Result

Example 2

In the same way as in Example 1, an aluminum Polyaniline electrode manufactured, with the exception that the Electrode in the electrolyte brought into contact with lithium instead of being immersed in a hydrazine solution becomes. Then the same cell test as in Example 1 carried out.

Result

Example 3

In the same manner as in Example 2, an aluminum minium polyaniline electrode manufactured, with the exception that after contacting lithium one Reduction treatment by immersion in an aqueous 50 vol .-% hydrazine solution is subjected. Then it will be the same cell test as in Example 1 was carried out.

Result

Comparative Example 1

In the same way as in Example 1, an alumi nium polyaniline electrode manufactured, with the exception that the aluminum used has a ratio of inte intensity of the diffraction lines of the (200) surface / integrated intensity of the total diffraction lines = 0.05 and is polished with CW1000 emery paper. The film thickness of the polyaniline is not uniform and the electro caused by potential change chromism shows no uniform color change. Then the same cell test as in Example 1 is carried out.

Result

Comparative Example 2

In the same way as in Example 1, an alumi nium polyaniline electrode manufactured, with the exception that no hydrazine treatment is used. Then it will be the same cell test as in Example 1 was carried out.

Result

Comparative Example 3

In the same way as in Example 1, an aniline polymerization attempted, except that the ver aluminum applied a ratio of integrated inten diffraction lines of the (200) surface / integrated Intensity of the total diffraction lines = 0.05. As a result, the formation of the polymer is extremely uneven shaped.

Comparative Example 4

In the same way as in Example 1, an aniline polymerization attempted, except that the ver aluminum applied a ratio of the integrated inten diffraction lines through the (200) surface / inte The intensity of the total diffraction lines = 0.94 and is polished with CW100 emery paper. in the As a result, the formation of the polymer is extremely uneven moderate.  

Example 4

An acetonitrile solution containing 0.1 mol / l pyrrole and 0.1 mol / l tetraethylammonium paratoluenesulfonate is prepared in a glass reaction vessel under an Ar (argon) atmosphere. Using aluminum with a thickness of 50 µm (ratio of the integrated intensity of the diffraction lines through the (200) surface / integrated intensity of the total diffraction lines = 0.94) as the anode and nickel as the cathode and application of a constant voltage of 5 V. an electrolytic oxidative polymerization of the pyrrole is carried out between the two electrodes. In this case, black poly pyrrole is deposited evenly on aluminum. The dry weight of the electrode is 56.4 mg. Then a 0.75 V vs SCE potential is applied to cause the flow of an electrical charge of 5 C / cm ² in an aqueous solution of 0.5 M aniline in 3 N HBF ₄ using the electrode prepared above as the working electrode, Platinum as counter electrode and SCE as reference electrode. The dry weight is 74.3 mg and aniline could be polymerized without leaching aluminum.

Comparative Example 5

In the same way as in Example 4, an electro lytic oxidative polymerization of pyrrole carried out, with the exception that the aluminum used (one Thickness of 50 µm) a ratio of integrated intensities diffraction lines through the (200) surface / inte The intensity of the total diffraction lines = 0.05 owns. In this case the deposition of pyrrole extremely non-uniform and the dry weight is 54.4 mg. Then the aniline polymerization in the same Way as in Example 1 using the result performed the electrode as a working electrode. The dry  weight of the electrode is 52.0 mg and it is indicated take that the exposure of aluminum is preferred occurs because the pyrrole is not uniform.

Example 5

Gold is vapor-deposited on the polyaniline of the aluminum-polyaniline electrode produced in Example 1 and derivations are carried out to produce a three-layer aluminum / polyaniline / gold device. As a result of testing the current / voltage characteristics thereof, the switching characteristic shown in Fig. 4 is observed.

Example 6

An acetonitrile solution is placed in a glass reaction vessel prepared, the 4.5 mol / l N, N'-diphenylbenzidine, 0.1 mol / l Tetrabutylammonium perchlorate and 0.05 mol / l 2,6-lutidine contains. Using the 3-electrode method using of aluminum used as an anode in Example 1 as working electrode, platinum as counter electrode and one saturated calomel electrode (SCE) as reference electrode and applying a voltage of 1.2 V vs SCE will Polymerization carried out. In this case it turns black shot oxidized polymer uniformly on aluminum the.

Comparative Example 6

The polymerization is carried out in the same way as in Bei game 6 performed, except that the used Aluminum a ratio of integrated intensity of Diffraction lines through the (200) surface / integrated inten of total diffraction lines = 0.05. The Ab Separation of the polymer from aluminum is not uniform.  

Comparative Example 7

In the same manner as in Example 6, the polymer rization carried out, with the exception that the used Aluminum is a ratio of the integrated intensity of the Diffraction lines through the (200) surface / integrated inten of the total diffraction lines = 0.94, and with CW1000 emery paper is polished. The separation of the Polymers on aluminum is extremely uneven.

Example 7

Under an Ar atmosphere, a solution of 5 ml of benzene, 70 ml of nitrobenzene, a saturated amount of LiAsF ₆ and further a saturated amount of cadmium sulfate is prepared in a glass reaction vessel. Using aluminum 50 µm thick (ratio of the integrated intensity of the diffraction lines through the (200) surface / integrated intensity of the total diffraction lines = 0.65) as the anode and nickel as the cathode and using a constant voltage of 15 V. an electrolytic oxidative polymerization is carried out between the two electrodes. In this case, black polyphenylene is deposited uniformly on the aluminum electrode.

Comparative Example 8

The polymerization is carried out in the same way as in Bei game 7 performed, except that the used Aluminum (a thickness of 50 µm) a ratio of inte intensity of the diffraction lines by the (200) - Area / integrated intensity of the total diffraction lines Owns 0.28. The deposition of the polymer on aluminum is not even.

The cell test of the composite electrode in and after Example 8 is carried out after the composite The electrode is subjected to a suitable reduction treatment has been.  

Example 8

An acetonitrile solution containing 0.1 mol / l pyrrole and 0.1 mol / l tetrabutylammonium perchlorate is prepared in an glass atmosphere under an Ar atmosphere. Using aluminum which has been subjected to electrolytic etching, with a thickness of 50 µm (integrated intensity of the diffraction lines through the (200) surface / integrated intensity of the total diffraction lines = 0.94, and the immersion area is 16 × 32 mm) as the anode and nickel as the cathode, and applying a constant voltage of 5 V between the two electrodes to produce an electrical charge flow of 1.0 C / cm ² in the solution, an electrolytic oxidative polymerization is carried out. In this case, black polypyrrole is evenly deposited on the aluminum. After removing the resulting composite electrode and washing, as shown in Fig. 5, 4 mm × 4 mm grid-shaped lines are scored on one side of the composite electrode. A pressure sensitive adhesive tape is applied to the surface, which is peeled off at a speed of 60 mm / second in the direction parallel to the surface of the composite electrode to test the firm bond between the aluminum (1) and the polymer (2) depending on the number of 4 × 4 mm grid units that are peeled off. As a result, no peeled portions are observed.

Comparative Example 9

The same procedure as in Example 8 is followed leads, with the exception that the aluminum used (50 µm thickness) a ratio of the integrated intensity the diffraction lines through the (200) surface / integrated inten total diffraction lines = 0.35. With two Share peeling.  

Example 9

Under an Ar atmosphere, a solution is prepared in a glass reaction vessel, which contains 5 ml of benzene, 10 ml of nitrobenzene, a saturated amount of LiAsF ₆ and also a saturated amount of cadmium sulfate. Using aluminum that was subjected to electrolytic etching, 50 µm thick (ratio of the integrated intensity of the diffraction lines through the (200) surface / integrated intensity of the total diffraction lines = 0.65) as the anode and nickel as the cathode and under Applying a constant voltage of 15 V between these two electrodes to generate an electric charge flow of 1.0 C / cm ² , an electrolytic oxidative polymerization is carried out. In this case, black polyphenylene is deposited on the aluminum. When the same peeling test as in Example 8 was carried out, no peeled off portions were observed.

Comparative Example 10

The same procedure as in Example 9 is followed leads, with the exception that the aluminum used (50 µm thickness) a ratio of the integrated intensity of the diffraction lines through the (200) surface / integrated Intensity of the total diffraction lines = 0.28. Peeling occurs in three parts.

Example 10

An acetonitrile solution containing 4.5 mol / l N, N'-diphenylbenzidine, 0.1 mol / l tetrabutylammonium perchlorate and 0.05 mol / l 2,6-lutidine is prepared in a glass reaction vessel. Using the 3-electrode method using aluminum, which was used as the anode in Example 8, as the working electrode, platinum as the counter electrode and a saturated calomel electrode (SCE) as the reference electrode and applying a voltage of 1.2 V vs SCE for Generation of an electric charge flow in the solution of 1.0 C / cm ² , the polymerization is carried out. In this case, black oxidized polymer is deposited uniformly on the aluminum. When the same peeling test as in Example 1 is carried out, peeling occurs in one part.

Comparative Example 11

The same procedure as in Example 10 is followed leads, with the exception that the aluminum used a ratio of integrated intensity of diffraction lines through the (200) area / integrated intensity of the Total diffraction lines = 0.05. Peeling occurs six shares.

Reference Example 1

Aluminum with a thickness of 50 µm (ratio of integr th intensity of the diffraction lines through the (200) surface / integrated intensity of the total diffraction lines = 0.82) is in an aqueous solution containing 1.5 N hydrogen chloride acid, 0.3 mol / l oxalic acid and 0.3 mol / l aluminum chloride contains, subjected to an electrolytic etching. With the etched aluminum is made using a test piece of 10 × 100 mm measured area a tensile test carried out (with a tester according to JIS 7721). As a result 1.4 kg / cm are not found.

Reference example 2

The same procedure as in Reference Example 1 is repeated with the exception that the aluminum used (with a thickness of 50 µm) a ratio of integrated Intensity of the diffraction lines through the (200) surface / integrated intensity of the total diffraction lines = 0.2 owns. As a result, 1.1 kg / cm are found.  

Example 11

Using an aluminum polypyrrole electrode produced as in Example 8 as the reaction electrode and a voltage of 0.7 V vs SCE, an electrolytic polymerization in an electrolyte in which 0.5 M aniline and 1.0 M HBF _{4 are} dissolved, performed by electrolysis at constant potential. By repeated charging and discharging at 0.2 mA / cm ² in an electrolyte containing 3 M LiBF ₄ dissolved in a mixed solvent of propylene carbonate and dimethoxyethane (7: 3), cell performance is achieved using the resulting composite electrode determined as positive electrode and Li as negative electrode.

Result

Comparative Example 12

The same procedure as in Example 11 is followed leads, with the exception that the in Comparative Example 9 manufactured aluminum polypyrrole electrode is used.

Result

Example 12

Aluminum with a thickness of 60 µm (ratio of integr th intensity of the diffraction lines through the (200) surface / integrated intensity of the total diffraction lines = 0.94) is in an aqueous solution of 5.5 N sulfuric acid, the Contains 0.15 M aluminum sulfate, an electrolytic etch subject.

To get the aluminum polyaniline electrode, an electrolytic polymerization in a 5.5 N aqueous Solution of sulfuric acid containing 0.5 M aniline dissolved therein holds, using the aluminum obtained as an electric lysis electrode and carried out at 0.8 V vs SCE. In this Trap the polyaniline becomes uniform on the aluminum polymerized and the tight bond is also satisfied presenting. The aluminum polyaniline electrode is in the Electrolytes of the electrical used in Example 11 Cell electrochemically active. Then the same Auswer tion as in Example 11.

Result

Comparative Example 13

In the same way as in Example 12, an aluminum minium polyaniline electrode obtained, with the exception that the aluminum used has a ratio of integrated Intensity of the diffraction lines through the (200) surface / inte intensity of the total diffraction lines = 0.05. The film thickness of the polyaniline is not even that  tight bond is bad and it becomes partial Absence of the film observed.

Then the same evaluation as in Example 11 is carried out guided.

Result

Example 13

The same cell test as in Example 3 is carried out, with the exception that as a negative electrode in the cell test a Li-Al alloy is used.

Result

Example 14

The same cell test as in Example 12 is carried out, except that a Li-Al alloy is used as the negative electrode in the cell test and LiSbF ₆ as the electrolyte.

Result

Claims (13)

1. Composite body made of aluminum and an electrically conductive polymer, characterized in that the aluminum surface to which the polymer is bound has a (HOO) surface (H = 1, 2, 4) as the main crystal surface. 2. Composite body according to claim 1, characterized in that the aluminum surface has been etched. 3. Composite body according to claim 1 or 2, characterized characterized in that the polymer by chemical Polymerization on the aluminum surface has been deposited. 4. Composite body according to claim 1 or 2, characterized characterized in that the polymer by electrolytic Polymerization on the aluminum surface has been deposited. 5. Composite body according to claim 3, characterized in that on the polymer through a second polymer electrolytic polymerization has been deposited is. 6. Composite body according to claim 4, characterized in that on the polymer through a second polymer chemical polymerization has been deposited. 7. Composite body according to any one of claims 1 to 6, characterized in that the polymer polyaniline or a derivative thereof. 8. The method for producing the composite body according to Claim 1, characterized in that one on the Surface of aluminum that has a (HOO) surface  (H = 1, 2, 4) as the main crystal surface has an electrically conductive polymer chemical polymerization. 9. The method according to claim 8, characterized in that the aluminum surface before applying the Polymers is etched. 10. The method according to claim 8 or 9, characterized characterized in that the polymer by chemical Polymerization and subsequent electrolytic Application of polymerization. 11. The method according to claim 8 or 9, characterized characterized in that the polymer by electrolytic polymerization and subsequent chemical polymerization. 12. The method according to any one of claims 8 to 11, characterized characterized in that polyaniline or a applies substituted polyaniline. 13. The method according to claim 12, characterized in that that the electrolytic polymerization in a aqueous solution of an acid with a pKa value of Performs -2.5 to +2.5.