JP2003142088A - Electrode material for secondary battery by plating method and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode material for a secondary battery by a plating method. SOLUTION: This electrode material for a secondary battery is made by forming tin-or a tin alloy-plated film deposited from a tin or tin alloy plating bath on one or both surfaces of a collector. The electrode material for a secondary battery is characterized in that plated particles having the average diameter of 0.5 μm or less form a substantially continuous film in the plated film, and the plated film is formed of a material deposited from tin or tin alloy plating bath and contains at least the following as essential constituents (i)-(v): (i) 5-200 g/L of bivalent tin ions, (ii) one or more kinds of acids or complexing agents forming water-soluble salt or complex with tin ions stoichiometrically equivalent to or more than the bivalent tin ions in total, (iii) one or more kinds of antioxidants having concentration of at least 1 ppm in total, (iv) 0.5-200 g/L of one or more kinds of 6C or less aliphatic ketone, or 6C or less aliphatic branch or non-branch alcohol, and (v) one or more kinds of organic additives.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrode material and a manufacturing technique thereof, and more particularly to an electrode material for a secondary battery, an electrode, a secondary battery and a manufacturing technique thereof.

[0002]

2. Description of the Related Art In recent years, mobile devices such as mobile phones and laptop computers have rapidly become mobile, and along with this, secondary batteries that can be used for a long time and can be recharged. Battery production is increasing rapidly. Under such circumstances, the lithium secondary battery, which is highly lightweight, has made a great progress, but further improvement in performance is required. Current,
As a lithium battery electrode, various carbonaceous materials are used for the negative electrode,
The most widely used combination is a composite oxide of lithium and another metal for the positive electrode, but it is almost reached the limit to improve characteristics such as energy density and cycle life with the combination of these materials. It is considered. Instead of carbonaceous materials, various metals and alloys or their oxides, sulfides, nitrides, etc. have been studied and disclosed in patents and academic papers.

Utilization of lithium metal or a metal or alloy capable of inserting and desorbing lithium ions was carried out before the carbonaceous electrode was generally used, but a new study was conducted. It is being appreciated. Regarding the use of a metal for the electrode, tin or a tin alloy is considered to be a promising metal. For example, in JP-A-8-7884 (Fujitsu Limited), tin, lead, and
A negative electrode in which indium, bismuth and the like are laminated is disclosed. Japanese Unexamined Patent Publication No. 10-162823 (Hitachi Maxell Co., Ltd.) discloses Sn—Fe and Sn—Ni alloys as well as Si alloys. Japanese Patent Laid-Open No. 10-144351 (Matsushita Electric Industrial Co., Ltd.) describes In, Al, Pb, Bi, S.
An alloy of b, Ga, Sn, Si, Zn, Cd, As, Ti or an alloy thereof with lithium is disclosed.
Japanese Patent Laid-Open No. 11-343109 (Osaka Gas Co., Ltd.)
Carbonaceous materials and Ca, Sr, Ba, Ir, Ag, Cd, H
g, B, Al, Ga, In, Tl, Si, Sn, Pb,
Mixtures with Sb, Bi, Te, etc. are disclosed. Japanese Unexamined Patent Publication No. 2000-173670 (Matsushita Electric Industrial Co., Ltd.) discloses that tin, a Group 2 element, a transition element, and a Group 12 element of the periodic table,
A material that is a solid solution or an intermetallic compound with a Group 13 element and a Group 14 element other than carbon is disclosed.

Generally, those metal or alloy electrodes are
Although it is often produced by a metallurgical method, it is also disclosed that it is obtained by a plating method. That is,
Sonoda and Sakai et al. Disclose a tin negative electrode obtained by an electroplating method, and report that the negative electrode exhibits a larger charge / discharge capacity than a graphite negative electrode and can be a good electrode for a lithium secondary battery. The presenters disclose that an electrode is prepared using a nearly neutral sulfate bath containing gluconate as a complexing agent. [Sonoda, Sakai, Surface Technology Association 99th Lecture Meeting, 114 pages] and [Sonoda, Fujieda, Sakai, 2nd Kansai Surface Technology Forum, 11 pages]. Tamura, Oshita, Fujimoto, Fujitani, Jinno, Yonezu et al. Also reported about a negative electrode using a plated tin metal, but did not disclose detailed conditions for plating. [Tamura, Oshita, Fujimoto, Fujitani, Jinno, Yonezu, Proceedings of the 41st Battery Symposium, 540 pages]. Also, for example, Japanese Patent Laid-Open No. 11-24295.
4 (Canon Co., Ltd.) discloses a method for manufacturing an electrode structure in which the step of forming an electrode material such as metal tin or tin alloy is performed by plating. However, there is no report or disclosure that has been clarified as to what kind of characteristics the tin or tin alloy plating film has has good electrode characteristics. JP-A-11-24295
The conditions for tin or tin alloy plating disclosed in Japanese Patent Laid-Open No. 4 (Canon Co., Ltd.) are also very general conditions known in the related art, and are not necessarily suitable for forming electrodes of secondary batteries. .

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present application have proposed that, in place of an electrode using a current carbon material as described above, tin or a tin-based alloy using a plating method is used for the capacitance,
The research subject of the present invention was to develop an electrode material for a lithium secondary battery excellent in charge and discharge characteristics, and therefore to develop an electrode and a battery using the same and to establish a manufacturing method thereof.

[0006]

Means for Solving the Problems The inventors of the present application have conducted extensive studies to solve the above-mentioned problems, and as a result, found that a plating film having extremely fine crystals showed good electrode characteristics, and The inventors have found the conditions for stably producing such a plating film, and completed the present invention.
That is, for example, Japanese Patent Application Laid-Open No. 11-242954 mentioned above discloses an electrode material composed of metallic tin or a tin alloy, but it is composed of particles having an average particle size of 0.5 to 60 μm. However, the study by the inventors of the present application has revealed that finer metal particles have good electrode characteristics. The details of the mechanism are not clear at this time, but by making the crystals finer, the contact area between the crystals is significantly increased, the migration of lithium inside the electrode material is facilitated, and the utilization rate of the film is increased. It is supposed to be because. The refinement of the plating film crystal is usually achieved by an organic additive added to the plating bath, but a method of further refinement by adding a metal component other than tin can also be used.

Therefore, the subject matter of the present invention is an electrode material for a secondary battery comprising a collector or a tin or tin alloy plating film deposited from a tin or tin alloy plating bath on one surface or both surfaces of the current collector. The plating film has a substantially continuous film of plating particles having an average particle size of less than 0.5 μm, and the plating film has at least the following components (i) to
(V): (i) 5 g / L or more and 200 g / L or less of divalent tin ions, and (ii) divalent tin ions in a stoichiometrically equivalent amount or more with respect to divalent tin ions. One or more of an acid or a complexing agent that forms a water-soluble salt or complex with an ion, and (iii) a total of at least 1 ppm or more of an antioxidant
Or 2 or more, (iv) 0.5 g / L or more, 200 g /
L or less aliphatic ketone having 6 or less carbon atoms or 6 carbon atoms
Precipitated from a tin or tin alloy plating bath containing one or more of the following aliphatic branched or unbranched alcohols, and (v) one or more of organic additives as essential components The secondary battery electrode material is characterized by Here, that the plating particles form a substantially continuous film means that the plating particles do not form a crystal form such as dendrite, but are in contact with each other to form a film. It does not matter even if there are some cracks in the area.

The particles having an average particle size of less than 0.5 μm are further magnified by a scanning electron microscope at a magnification of 30.
It is a more preferable condition that the boundaries of the particles are substantially invisible when observed from the surface direction at a magnification of 00 to 5000.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION It is essential that the electrode material for a secondary battery of the present invention is a plating film obtained from a plating bath as described above. (V) is included as an essential component.

The tin or tin alloy plating bath for depositing the plating film of the secondary battery electrode material of the present invention is basically 2
It is deposited from valent tin ions. Generally, tin or tin alloy plating baths include a bath for depositing divalent tin ions and a bath for depositing tetravalent tin ions, but deposits from tetravalent tin ions have good visual appearance. However, since the particle size is large, it is unsuitable as a plating film for electrodes, which is the object of the present application. Therefore, as the tin or tin alloy plating bath used in the method of manufacturing the secondary battery electrode of the present application, a bath for depositing divalent tin ions is used. The plating bath has a first
Of divalent tin ion as an essential component of 5 g / L or more,
Used at a concentration of 200 g / L or less. More preferably, the range of 10 g / L to 100 g / L is used.

In the tin or tin alloy plating bath for depositing the plating film of the secondary battery electrode material of the present application, the second essential component is the stoichiometry of divalent tin ions in total. It is used by containing one or more kinds of acids or complexing agents that form a water-soluble salt or complex with divalent tin ions in an equal amount or more. The preferred concentration is 1.05 times or more and 30 times or less with respect to the divalent tin ion in terms of gram equivalent. More preferably, it is 1.3 times or more and 10 times or less.

As an acid or complexing agent which forms a water-soluble salt with a divalent tin ion contained as an essential component in the plating bath, the acid or (and) shown in the following (I) to (See) Complexing agents are preferably used alone or in combination. The acids and complexing agents may be added in the form of their alkali metal or ammonium salts. That is, (I): 1 of acids selected from sulfuric acid, hydrochloric acid, hydrofluoric acid, hydrofluoric acid, sulfamic acid, acetic acid, 1-hydroxyethane-1,1-diphosphonic acid, phosphoric acid and / or condensed phosphoric acid Species or two or more, (2): one kind of sulfonic acid selected from aliphatic sulfonic acids represented by the following general formula (I) or (II) or aromatic sulfonic acids represented by the general formula (III) Or two or more kinds, general formula (I)

[Chemical 8] [Wherein R ₁ represents a C _{1 to} C ₅ alkyl group, X ₁ represents hydrogen, a hydroxyl group, an alkyl group, an aryl group, an alkylaryl group, a carboxyl group, or a sulfonic acid group, and an arbitrary alkyl group. Position n, where n is an integer from 0 to 3. ] General formula (II)

[Chemical 9] [Here, R ₂ represents a C _{1 to} C ₅ alkyl group or a C _{1 to} C ₃ alkylene group, and a hydroxyl group may be present at any position of the alkylene group, and X ₂ is chlorine or (and) fluorine. Representing a halogen, the number of substitutions of chlorine or (and) fluorine substituted with hydrogen of an alkyl group or alkylene group is from 1 to a saturated substitution of all hydrogens coordinated to the alkyl group or alkylene group, There are one or two halogen species, and the chlorine or fluorine substituent may be present at any position. Y represents hydrogen or a sulfonic acid group, and the substitution number of the sulfonic acid group represented by Y is in the range of 0 to 2. ] General formula (III)

[Chemical 10] [Wherein X ₃ is a hydroxyl group, an alkyl group, an aryl group,
Alkylaryl group, aldehyde group, carboxyl group,
It represents a nitro group, a mercapto group, a sulfonic acid group or an ammono group, or two X3 can form a naphthalene ring together with a benzene ring, and m is an integer of 0 to 3. ] (Reference): An ion of an aliphatic carboxylic acid having at least one carboxyl group and further having at least one kind selected from the group consisting of a carboxyl group, a hydroxyl group, a sulfonic acid group, an amino group and a thiol group. 1 type or 2 types or more of are used.

As the condensed phosphoric acid, either linear polyphosphoric acid or cyclic metaphosphoric acid is used, but diphosphoric acid (pyrophosphoric acid) is particularly preferably used. As the sulfonic acid, methanesulfonic acid, methanedisulfonic acid,
Methanetrisulfonic acid, trifluoromethanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, 2-propanesulfonic acid, butanesulfonic acid, 2-butanesulfonic acid, pentanesulfonic acid, hexanesulfonic acid, decanesulfonic acid, dodecanesulfonic acid, 2-hydroxyethane-1-sulfonic acid, 1-hydroxypropane-2-
Sulfonic acid, 3-hydroxypropane-1-sulfonic acid, 2-hydroxypropane-1-sulfonic acid, 2-hydroxybutanesulfonic acid, 2-hydroxypentanesulfonic acid, 2-hydroxyhexane-1-sulfonic acid,
2-hydroxydecanesulfonic acid, 2-hydroxydodecanesulfonic acid, 1-carboxyethanesulfonic acid, 2
-Carboxyethanesulfonic acid, 1,3-propanedisulfonic acid, allylsulfonic acid, 2-sulfoacetic acid, 2- or 3-sulfopropionic acid, sulfosuccinic acid, sulfomaleic acid, sulfofumaric acid, monochloromethanesulfonic acid, perchloroethanesulfone Acid, trichlorodifluoropropanesulfonic acid, perfluoroethanesulfonic acid, monochlorodifluoromethanesulfonic acid, trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, tetrachloropropanesulfonic acid, trichlorodifluoroethanesulfonic acid, monochloroethanolsulfonic acid, dichloropropanolsulfonic acid , Monochlorodifluorohydroxypropanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, xylenesulfonic acid, nitrobenzenesulfone , Sulfobenzoic acid, sulfosalicylic acid, benzaldehyde sulfonic acid, p- phenolsulfonic acid, phenol-2,4-disulfonic acid, 2-
Sulfoacetic acid, 2-sulfopropionic acid, 3-sulfopropionic acid, sulfosuccinic acid, sulfomethylsuccinic acid, sulfofumaric acid, sulfomaleic acid, 2-sulfobenzoic acid, 3-sulfobenzoic acid, 4-sulfobenzoic acid, 5- Sulfosalicylic acid, 4-sulfophthalic acid, 5-sulfoisophthalic acid, 2-sulfoterephthalic acid and the like are preferably used. Especially, methanesulfonic acid, 2-hydroxyethane-1-sulfonic acid, 2-hydroxypropane-
1-sulfonic acid, phenolsulfonic acid, cresolsulfonic acid, trifluoromethanesulfonic acid and the like are particularly preferably used.

As the above-mentioned aliphatic carboxylic acid, oxalic acid,
Malonic acid, succinic acid, glycolic acid, lactic acid, tartaric acid, citric acid, tartronic acid, malic acid, ascorbic acid, glycine, alanine, valine, leucine, isoleucine,
Lysine, serine, threonine, phenylalanine, aspartic acid, glutamic acid, methionine, mercaptosuccinic acid, cystine, sulfosuccinic acid, ethylenediaminetetraacetic acid, iminodiacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, ethylenedioxybis (ethylamine ) −
N, N, N ', N'-tetraacetic acid, glycol ethylenediaminetetraacetic acid, N-hydroxyethylethylenediaminetetraacetic acid and the like are preferably used. Among them, sulfosuccinic acid, glycolic acid, lactic acid, tartaric acid, citric acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid and the like are more preferably used.

As will be described later, the tin or tin alloy plating bath for preparing the electrode material of the present invention preferably contains some tetravalent tin, though it is not an essential component.
On the other hand, the tetravalent tin has an adverse effect when it is present in excess of the limit, so that the concentration of the tetravalent tin compound or ion does not increase beyond the limit, and the concentration of the divalent tin ion does not increase. In order to maintain a constant value, as a third essential component, one of the antioxidants having a total concentration of at least 1 ppm or more is used.
It is necessary to include one or more antioxidants. Although there is no strict upper limit, it is usually used at a concentration of 50 g / L or less. More preferably, it is used in an amount of 5 mg / L or more and 2 g / L or less, and most preferably 10 mg / L.
Used in an amount of / L or more and 1 g / L or less.

The antioxidant is specifically selected from a substituted or unsubstituted aromatic mono-, di- or triphenol or (ro) aliphatic polyhydroxy compound selected from the following general formula (I). One or two or more of these are used alone or in combination. General formula (I)

[Chemical 11] [However, X represents hydrogen or a hydroxyl group, which may be the same or different, and n represents an integer of 1 to 3. At least one of X is a hydroxyl group. Y is one or more selected from hydrogen, a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carboxyl group, a sulfonic acid group or an amino group, which may be the same or different, and m is 6- It is an integer of n. The bonding position on the benzene ring of X and Y does not matter.
However, it includes compounds that can have the structure due to tautomerism. ] A substituted or unsubstituted aromatic mono-, di- or triphenol represented by the following formula. (RO) Aliphatic polyhydroxy compound.

More specific examples of the phenols of the above general formula (I) are hydroquinone, catechol, resorcin, pyrogallol, oxyhydroquinone, phloroglysin, gallic acid, catechol sulfonic acid, guaiacol, hydroquinone sulfonic acid, 3, 4-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid, p
One or more selected from phenol sulfonic acid, cresol sulfonic acid, hydroquinone sulfonic acid, β-naphthol and the like are particularly preferably used. As the aliphatic polyhydroxy compound of (ro), sorbic acid, sorbitol, sugar of budo, ascorbic acid, isoascorbic acid and the like are preferably used.

The above-mentioned plating bath contains a fourth essential component having a carbon number of 0.5 g / L or more and 200 g / L or less as a fourth essential component in order to refine the plating particles and improve the stability of the plating bath. 1 or 2 or more of an aliphatic ketone having 6 or less or an aliphatic branched or unbranched alcohol having 6 or less carbon atoms is used. More preferably, 1 g / L or more and 200 g /
Concentrations below L are used. Since it depends on the concentration of other additives, the absolute concentration cannot be limited, but if the alcohol concentration becomes too high, it will adversely affect the stabilizing effect of the bath, and especially if it exceeds 300 g / L, this effect will occur. large. Therefore, the upper limit concentration of the aliphatic alcohol or ketone is strictly regulated to 200 g / L or less. Further, when the concentration is high, odor becomes remarkable, which is not preferable from the working environment.

As the aliphatic branched or unbranched alcohol having 6 or less carbon atoms, alcohols represented by the following general formulas (a) to (c) are used. General formula (a)

[Chemical 12] [However, n is an integer larger than m and 6 or less, and m represents an integer of 1 or 2. X is hydrogen or a hydroxyl group,
They may be the same or different, and at least one of X is a hydroxyl group. The carbon chain may be linear or branched, regardless of the position of the carbon to which X is bonded. ] A chain-like saturated aliphatic mono- or dialcohol represented by the following formula. General formula (b)

[Chemical 13] [However, n is an integer larger than m and 6 or less, and m represents an integer of 1 or 2. X is hydrogen or a hydroxyl group,
They may be the same or different, and at least one of X is a hydroxyl group. The carbon chain may be branched regardless of the position of the carbon to which X is bonded. ] The cyclic | annular saturated aliphatic mono- or dialcohol represented by these. General formula (C)

[Chemical 14] [However, n is an integer larger than m and 6 or less, and m represents an integer of 1 or 2. l represents an integer of n-2 or less.
X is hydrogen or a hydroxyl group, which may be the same or different, and at least one of X is a hydroxyl group. The carbon chain may be branched regardless of the position of the carbon to which X is bonded.
O represents etheric oxygen, and is between two carbons, but its position does not matter. ] A chain-like saturated aliphatic mono- or dialcohol having an ether bond represented by the following formula.

More specific examples of the aliphatic ketone having 6 or less carbon atoms or the aliphatic branched or unbranched alcohol having 6 or less carbon atoms include methanol, ethanol,
(N- and i-) propanol, (n-, i- and t
-) Butanol, 1,2,6-hexanetriol, thiodiglycol, pentanediol, hexanediol, 1,3-propanediol, 1,4-butanediol, ethylene glycol, propylene glycol, acetone, methyl ethyl ketone, etc. One kind or two or more kinds are preferably used, more preferably i-propanol and acetone are used, and most preferably i-propanol is used.

In the tin or tin alloy plating bath for depositing the plating film of the secondary battery electrode material of the present application, as a fifth essential component, an organic solvent is used to obtain a plating film of fine crystal particles. One kind or two or more kinds of additives are contained. Organic additives include surfactants, leveling additives, semi-brightening agents, brightening agents, and the like. Generally 0.001 g /
It is preferably used in the range of L to 50 g / L, but the concentration used depends on the type and combination of compounds.

As the surface active agent, known surface active agents can be used, including nonionic type, anionic type, amphoteric type,
Any cationic surfactant is preferably used, and is used alone or in combination as appropriate, and nonionic, anionic and amphoteric surfactants are more preferably used.

Examples of nonionic surfactants that are preferably used include polyoxyalkylene alkyl ethers (or esters), polyoxyalkylene phenyl (or alkyl phenyl) ethers, polyoxy alkylene naphthyl (or alkyl naphthyl) ethers, Polyoxyalkylene styrenated phenyl ether (or polyoxyalkylene chain added to the phenyl group), polyoxyalkylene bisphenol ether type, polyoxyethylene polyoxypropylene block polymer, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene sorbit Fatty acid ester, polyethylene glycol fatty acid ester, polyoxyalkylene glycerin fatty acid ester, polyoxyalkylene alkylamine, Polyoxyalkylene condensate adduct of diamine, polyoxyalkylene fatty acid amide, polyoxyalkylene castor (or / and hydrogenated castor oil) oil, polyoxyalkylene alkylphenyl formalin condensate, glycerin (or polyglycerin) fatty acid ester-based interface Examples thereof include activators, pentaerythritol fatty acid esters, sorbitan mono (sesqui, tri) fatty acid ester surfactants, higher fatty acid mono (di) ethanolamides, alkyl alkylodamides, and oxyethylene alkylamines.

An example of a suitable anionic surfactant is alkyl (or formalin condensate) -β-
Naphthalene sulfonic acid (or salt thereof), fatty acid soap, alkyl sulfonate, α-olefin sulfonate, alkylbenzene sulfonate, alkyl (or alkoxy) naphthalene sulfonate, alkyl diphenyl ether disulfonate, alkyl ether sulfonate Salt, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, polyoxyethylene alkylphenol ether sulfate ester salt, higher alcohol phosphate monoester salt, polyoxyalkylene alkyl ether phosphate (salt), polyoxyalkylene alkylphenyl Ether phosphate, polyoxyalkylene phenyl ether phosphate, polyoxyethylene alkyl ether acetate, alkyloyl sarcosine, alkyloyl sarcosine Alkyloylmethylalanine salt, N-acylsulfocarboxylate salt, alkylsulfoacetate salt, sodium acylmethyltaurate, alkyl fatty acid glycerin sulfate ester salt, hydrogenated coconut oil fatty acid glyceryl sulfate sodium salt, alkylsulfocarboxylate ester salt system, alkyl Examples thereof include sulfosuccinate, dialkylsulfosuccinate, alkylpolyoxyethylene sulfosuccinic acid, sulfosuccinic acid monooleylamide sodium salt (or ammonium salt and TEA salt).

Examples of suitable amphoteric surfactants are 2-alkyl-N-carboxymethyl (or ethyl) -N-hydroxyethyl (or methyl) imidazolinium betaine and 2-alkyl-N-carboxy. Methyl (or ethyl) -N-carboxymethyloxyethyl imidazolinium betaine, dimethylalkyl betaine, N-alkyl-β-aminopropionic acid (or its sodium salt), alkyl (poly) aminoethylglycine, N-alkyl-N -Methyl-β-alanine (or its sodium salt), fatty acid amide propyl dimethylamino acetic acid betaine and the like can be mentioned.

Suitable surfactants include tetra-lower alkyl ammonium halides, alkyl trimethyl ammonium halides, hydroxyethyl alkyl imidazolines, polyoxyethylene alkyl methyl ammonium halides, alkyl benzalkonium halides, dialkyls. Dimethyl ammonium halide, alkyl dimethyl benzyl ammonium halide, alkyl amine hydrochloride, alkyl amine acetate,
Examples include alkylamine oleate, alkylaminoethylglycine, alkylpyridinium halides, and the like.

As the smoothing additive, semi-brightening agent or brightening agent, known ones can be used. As specific examples, the following compounds are used alone or in combination. Further, additives such as a leveling agent, a semi-brightening agent, and a brightening agent that can be used in the tin or tin alloy plating bath used for preparing the electrode material for a secondary battery of the present invention are tin or tin alloy plating. Known substances used can be used, and examples of particularly effective ones include polymer compounds, sulfanilic acid and its derivatives and salts thereof,
Quinolines, triazole and its derivatives, benzothiazole and its derivatives, imines, triazines, guanamines, aromatic oxycarboxylic acid esters, C =
Compounds having a double bond at the conjugated position with O, aldehydes, diketones, aniline and its derivatives, nitro compounds or their sodium, potassium or ammonium salts, mercaptocarboxylic acids, heterocyclic compounds, acetophenones, amines Examples thereof include alcohols, condensation products of aliphatic primary or secondary amines with aldehydes, and the like. These compounds can be used alone or in admixture as appropriate. When the following polymeric substances are used, 0.5 to 50 g / L is suitable, and preferably 1 to 2
It is 0 g / L. 0.00 for other additives
1 to 50 g / L is suitable, and more preferably 0.02
~ 20 g / L is added.

As an example of the polymer substance, gelatin, peptone, polyethylene glycol, polyacrylamide,
Examples thereof include polyethyleneimine and polyvinylpyrrolidone. Examples of sulfanilic acid derivatives and salts thereof include N-butylidene sulfanilic acid, N- (3-hydroxybutylidene) -p-sulfanilic acid, and aldol. Examples of quinolines include products obtained by adding 5 mol of propylene oxide to 8-hydroxyquinoline. Examples of triazole and its derivatives include benzotriazole, 4-methylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxybenzotriazole and the like. As an example of benzothiazole and its derivative, benzothiazole,
2-methylbenzothiazole, 2-mercaptobenzothiazole, 2-amino-4-chlorobenzothiazole,
2-amino-6-methoxybenzothiazole, 2-hydroxybenzothiazole, 2-chlorobenzothiazole, 2-methyl-5-chlorobenzothiazole, 2,5
-Dimethylbenzothiazole, 5-hydroxy-2-methylbenzothiazole, 6-chloro-2-methyl-4-
Methoxybenzothiazole, 2- (n-butyl) mercapto-6-aminobenzothiazole, 2-benzothiazolethioacetic acid, 2-benzothiazoleoxyacetic acid, 6-
Examples include ethoxy-2-mercaptobenzothiazole and the like. Examples of imines include N, N ′ diiso-butylidene-o-phenylenediamine. As an example of triazines, 2,4-diamino-6- [2'-
Methylimidazolyl (1 ′) ethyl-1,3,5-triazine, 2,4-diamino-6- [2′-ethylimidazolyl (1 ′) ethyl-1,3,5-triazine, 2,
4-diamino-6- [2′-undecylimidazolyl (1 ′) ethyl-1,3,5-triazine and the like can be mentioned. Examples of guanamines include β-N-dodecylaminopropioguanamine, β-N-hexylaminopropioguanamine, piperidine propioguanamine, cyclohexylaminopropioguanamine, morpholine propioguanamine, β-N- (2-ethyl). Hexyloxypropylamino) propioguanamine, β-N- (lauryloxypropylamino) propioguanamine and the like can be mentioned. Examples of aromatic oxycarboxylic acid esters include methyl o- (or m- or p-) benzoate, phenyl salicylate, and the like. Examples of the compound having a double bond at the conjugated position with C═O include itaconic acid, propylene-1,3-dicarboxylic acid, acrylic acid, crotonic acid, cinnamic acid, methyl acrylate, ethyl acrylate, methacrylic acid, Methyl methacrylate, butyl methacrylate, ethacrylic acid, acrylamide, diacetone acrylamide, t-butyl acrylamide, N-methoxydimethyl acrylamide, curcumin (1,7-bis (4
-Hydroxy-3-methoxyferral) -1,6-heptadiene-3,5-dione), isophorone (3,5,5
-Trimethyl-2-cyclohexenone), mesityl oxide, vinyl phenyl ketone, phenyl propenyl ketone, phenyl isobutenyl ketone, phenyl-1-methyl propenyl ketone, benzylidene acetophenone (c
Halcone), 2- (ω-benzoyl) vinylfuran, p-fluorophenylpropenyl ketone, p-chlorophenylpropenyl ketone, p-hydroxyphenylpropenyl ketone, m-nitrophenylpropenyl ketone, p-methylphenylpropenyl ketone, 2,4 , 6
-Trimethylphenylpropenyl ketone, p-methoxyphenylpropenyl ketone, p-methoxyphenylbutenyl ketone, p-methylthiophenylpropenyl ketone, p-isobutylphenylpropenyl ketone, α-naphthyl-1-methylpropenyl ketone, 4-methoxynaphthylpropenyl Ketone, 2-thienylpropenyl ketone, 2-furylpropenyl ketone, 1-methylpyrrole propenyl ketone, benzylidene methyl ethyl ketone,
Benzylideneacetone alcohol, p-toluideneacetone, anisalacetone (anisylideneacetone), p
-Hydroxybenzylideneacetone, benzylidenemethylisobutylketone, 3-chlorobenzylideneacetone, benzalacetone (benzylideneacetone), benzylideneacetylacetone, 4- (1-naphthyl) -3
-Buten-2-one, pyrideneacetone, furfuridine acetone, 4- (2-thiophenyl) -3-butene-
2-one, 4- (2-furyl) -3-buten-2-one, acrolein (acrylaldehyde, propenal), allylaldehyde, crotonaldehyde, cinnamaldehyde, benzylcrotonaldehyde, tenylideneacetone and the like can be mentioned. Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde (valeral, pentanal), isovaleraldehyde, n-capronaldehyde (hexanal, hexylaldehyde), succinaldehyde ( Succindialdehyde), glutaraldehyde (1,5-pentanedial, glutardialdehyde), aldol (3-hydroxybutyraldehyde,
Acetoaldol), crotonaldehyde, cinnamic aldehyde, propargyl aldehyde, benzaldehyde, o-
Phthalaldehyde, salicylaldehyde (o-hydroxybenzaldehyde), p-hydroxybenzaldehyde, p-nitrobenzaldehyde, o- (or p-) methoxybenzaldehyde (anisaldehyde), 3-methoxybenzaldehyde, vanillin, o-vanillin, veratraldehyde (3,4-dimethoxybenzaldehyde), 2,5-dimethoxybenzaldehyde, (2,4
-, 2,6-Dichlorobenzaldehyde, 1- (or 2-) naphthaldehyde, 2- (or 4-) chloro-1
-Naphthaldehyde, 2- (or 4-) hydroxy-1
-Naphthaldehyde, 5 (or 2) -methoxynaphthaldehyde, 2-furaldehyde (2-furaldehyde =
Furfural), 3-furaldehyde, 2 (3) -thiophenecarboxaldehyde, picolinaldehyde, 3
-Acenaphthaldehyde, 3-indolecarboxaldehyde and the like. Examples of diketones include glyoxal (ethanedial, oxalaldehyde,
Diformyl, biformyl), diacetyl (biacetyl,
Dimethylglyoxal, butanedione), hexanedione-3,4, acetylacetone (2,4-pentanedione), hexanedione-3,4-acetylacetone and the like can be mentioned. Examples of the aniline derivative include aniline, o- (or m- or p-) toluidine, o- (or p-) aminoaniline, o- (or p-) chloroaniline, 2,5- (or 3,4-). ) Chlormethylaniline,
Examples thereof include N-monomethylaniline, 4,4′diaminodiphenylmethane, N-phenyl- (α- or β-) naphthylamine and dithizone. Examples of nitro compounds or their sodium, potassium or ammonium salts include p-nitrophenol, nitrobenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, m-nitrobenzoic acid and the like. Examples of mercaptocarboxylic acids include mercaptoacetic acid (thioglycolic acid) and mercaptosuccinic acid. Examples of the heterocyclic compounds include 1,10-phenanthroline, 2-vinylpyridine, quinoline, indole, imidazole, 2-mercaptobenzimidazole, 1,2,3- (or 1,
2,4- or 1,3,5-) triazine, 1,2,3-
Examples thereof include benzotriazine, 2-mercaptobenzoxazole, 2-cinnamylthiophene and the like. Acetophenone and halogenated acetophenone. Examples of amine alcohols include triethanolamine, diethanolamine, monoethanolamine, N-methylethanolamine condensate and the like. As an example of a condensate of an aliphatic primary or secondary amine with an aldehyde, an amine-aldehyde condensate, for example, piperazine, biperidine, morpholine, cyclopropylamine, cyclohexylamine, cyclooctylamine, ethylenediamine, monoethanolamine, diethanolamine, etc. And the condensation products of the above-mentioned aldehydes with the aliphatic primary or secondary amines or aromatic amines.

The tin or tin alloy plating bath for depositing the plating film of the secondary battery electrode material of the present application further contains 0.1 g / L or more and 20 g / L or less of tetravalent tin ions or compounds. It is preferable. More preferably, a concentration of 0.1 g / L or more and 10 g / L or less is contained. In the plating of tin or tin alloy from divalent tin ions, tetravalent tin ions should not be directly involved in the precipitation of tin. However, according to the study by the inventors of the present application, the concentration range depends on the type of bath. 20 not necessarily strictly constant
If the concentration exceeds g / L, it will hinder the uniformity of the plating film and adversely affect it, but 0.1 g
It has been found that in the concentration range of / L to 10 g / L, it contributes to the miniaturization of crystals and gives a plating film having good cycle characteristics rather as an electrode of a lithium battery. The tetravalent tin compound or ion can be contained in the bath by oxidizing the divalent tin ion in the bath by a forced method such as air stirring or pre-electrolysis. It can be contained in the bath by adding a compound such as tin tetrachloride. The concentration of tetravalent tin is
The concentration of total tin can be measured by ICP analysis or atomic absorption spectrometry, and the analytical value of divalent tin obtained by the redox titration method can be subtracted for analysis and control. When instrumental analysis cannot be used, the total tin concentration can also be analyzed by redox titration after dissolving metallic aluminum under acidic conditions to reduce tetravalent tin to divalent.

The tin or tin alloy plating bath for depositing the plating film of the secondary battery electrode material of the present invention further has an atomic number of 26 to 33 in order to further improve the discharge capacity and / or the cycle characteristics. , And alloying metals selected from the group consisting of 44 to 51 excluding tin or 75 to 82 excluding mercury can be contained. At present, the mechanism for improving the electrode characteristics has not been fully clarified, but it is known that when electroplating contains dissimilar metals, the crystals become finer. It is envisioned that this will further improve the charge / discharge characteristics. The alloying metal represented by the above atomic number, iron, cobalt, nickel,
Zinc, gallium, germanium, arsenic, ruthenium, rhodium, palladium, silver, cadmium, indium, antimony, osmium, iridium, platinum, gold, mercury,
Thallium, lead and bismuth. Of these, iron, cobalt, nickel, copper, zinc, gallium, germanium, arsenic, silver, cadmium, indium, antimony, thallium, lead and bismuth are more preferably used. These alloying metals have an effect of refining crystal grains when the content in the plating bath is 20 ppm or more in total with respect to tin.
More preferably, 0.5% or more of tin is used. There is no clear definition of what percentage the metal component other than tin in the plating film is tin alloy plating, and what percentage it is tin (single) plating. In the present application, for convenience, either a non-destructive method such as EPMA or X-ray diffraction, or a destructive method such as ICP or atomic absorption may be used. All the cases including are defined as a tin alloy plating film, and those below are defined as a tin (single) plating film. Of the above metals, IIB, IIIB, IVB excluding mercury,
The VB group metal has a particular effect, and the tin alloy plating film containing 20 ppm or more of tin in total of one or more of these metals shows good charge and discharge characteristics. Where II
The expressions B, IIIB, IVB and VB are based on the IUPAC periodic table, and specifically, zinc, gallium, germanium, arsenic, cadmium, indium, antimony, thallium, lead and bismuth. Among these, lead, antimony, arsenic and cadmium are more preferably used.

The electrode material, which is a fine-crystal tin or tin alloy plating film of the present invention, has an extremely high energy density per unit weight and unit volume as compared with the currently predominantly used negative electrode of carbon material. Can be made thinner than when using current carbon materials. Especially for very small batteries such as micro batteries, 0.0
It is preferably used in a thickness of 1 μm or more and less than 5 μm. 5 μm thicker for batteries larger than normal button batteries
A plating film having a thickness of not less than 500 μm can also be suitably used.

When tin or a tin alloy is used as the negative electrode,
It has been conventionally considered that tin or a tin alloy should not have a high density and should have a certain amount of voids because expansion and contraction occur due to charge and discharge. However, the inventors of the present invention have found from the study of the present invention that rather good charge / discharge cycle characteristics can be obtained by using a tin or tin alloy plating film having a density close to that of tin prepared by usual melting.
That is, the tin or tin alloy plating film as the secondary battery electrode having a density of more than 6.6 g / cm ³ and 8.5 g / cm ³ or less is preferably used.

For the reasons described above, tin or tin alloy plating does not need to have a much lower density, and therefore the amount of stored organic matter in the coating should not exceed approximately 10%. That is, the electrode material for a battery can be preferably manufactured by maintaining the amount of carbon in the range of 0.0001% to 10%. As a result, the density of the tin or tin alloy plating film can be maintained at a value exceeding the above-mentioned 6.6 g / cm ³ .

In the step of depositing the plating film from the tin or tin alloy plating bath, (a) an insoluble anode and (b) are used as the anode so that unintended metal components do not accumulate in the plating bath and deposit in the plating film. 1) A tin anode having a purity of 3N or more, or (c) a tin alloy anode prepared by melting tin having a purity of 3N or more and the alloying metal having a purity of 3N or more
A plating method of performing plating by using one kind or two or more kinds is preferably used. An insoluble anode is preferable from the viewpoint of preventing impurities from mixing in, but (b) or (c) is more preferably used because the oxidation reaction on the surface of the anode may cause deterioration of the bath. In order to obtain a tin or tin alloy plating film having stable electrode characteristics over a long period of time, it is particularly preferable to use one or more tin anodes or alloying metals having a purity of 4N or more and a purity of 4N or more. The method of performing tin or tin alloy plating by using one or more tin alloy anodes prepared by melting the above tin and tin.

In producing a secondary battery electrode material by depositing a plating film from the tin or tin alloy plating bath of the present invention, a cathode current density of 0.1 A / dm ² or more and 100 A / dm ² or less is suitable. Used. More preferably 5A
A cathode current density of more than / dm ² and 100 A / dm ² or less is used. In particular, when plating is carried out in the continuous plating method, a current density exceeding 5 A / dm ² is preferably used.

In performing such plating, one or two or more treatments selected from electrolytic degreasing, pickling and activation prior to plating are preferably used. Furthermore, after the tin or tin alloy plating is performed on them, a temporal change preventing treatment can be used. Phosphate treatment is preferably used as the aging prevention treatment.

In the step of depositing the plating film from the tin or tin alloy plating bath, one or more of an acid, a complexing agent, a tin salt, an antioxidant or a salt of an alloying metal is dissolved in advance. A method for constructing a plating bath or (and) a method for controlling the concentration of an aqueous solution for replenishing components is preferably used.

The tin or tin alloy plating film used for the secondary battery electrode is required to have extremely strict control of the characteristics, and is required to be controlled much more strictly than general plating. To facilitate concentration control, it is easier to replenish each component to the plating bath by adjusting the concentration to a presumed concentration and then replenishing it with a solution Can be carried out. Therefore, in order to prepare an electrode using the plating film of the present invention, a method in which an acid, a complexing agent, a tin salt, an antioxidant, a salt of an alloying metal, or the like is dissolved in advance is prepared and supplied. Is used. In particular, in controlling the concentration of the alloying metal, it is possible to use a method in which an anode for the metal is placed in a plating bath and the metal is dissolved with the progress of electrolysis, but in order to keep the concentration constant strictly. A more preferable method is to use a method other than the anode, that is, a method of appropriately adding a solution in which a soluble salt or soluble complex of the metal element is previously dissolved to the plating bath.

Further, an antioxidant or (and) fifth which is the third essential component of the plating bath in the step of depositing a plating film from the tin or (and) tin alloy plating bath of the present invention.
As for the organic additive which is an essential component of, the fourth essential component, an aliphatic ketone having 6 or less carbon atoms or 6 carbon atoms is also included.
The following control method is preferably used by adding a solution prepared by dissolving a branched or unbranched aliphatic alcohol to a predetermined concentration.

For plating the above-mentioned tin or tin alloy or the underlying copper, copper alloy, nickel or nickel alloy on the plate-like body, there are known methods such as barrel plating, rack plating and continuous plating. However, the continuous plating method is more preferably used. The continuous plating method refers to a plating method in which the plate-shaped body wound in a roll is continuously unwound and supplied to a plating line including pre-treatment and winding.

For the current collector of the secondary battery electrode of the present invention, copper, nickel or iron is preferably used as the type of metal. Copper, nickel or iron includes those known alloys defined in JIS or the like which are usually used industrially and those coated with those metals by plating.

The current collector may be plated with copper or nickel undercoat according to a conventional plating technique. Depending on the components of the plating solution, substitutional precipitation may occur on the current collector when the current collector is immersed in the plating solution. To prevent this, it is recommended to perform copper or nickel undercoating. To be done.

As the current collector for the secondary battery electrode of the present invention, all current collectors having a shape usually used in a secondary battery are used, but a plate-shaped current collector is generally used.
The term plate-like material includes macroscopic materials such as sheet-like porous materials, foams, screens, nets, expanded materials, punching materials, non-woven fabrics, and sintered materials, in addition to simple planar materials. Those showing a plate shape are included.

The electrode material for a secondary battery composed of the tin or (and) tin alloy plating film of the present invention is preferably used as an electrode for a lithium battery, especially as a negative electrode material.

[0045]

EXAMPLES The present invention will be described in detail below based on examples, but the present invention is not limited to these examples and can be appropriately modified within the scope of the claims.

Example 1 Using a copper foil as a negative electrode current collector, electrolytic degreasing was performed in an alkaline electrolytic degreasing solution at 1 A / dm ² for 1 minute, and after washing with water, 5%
It was immersed in an aqueous solution of methanesulfonic acid for 30 seconds for activation.
After washing it with water, the following plating solution (a): Plating solution (a) 2-hydroxypropane-1-sulfonic acid tin (as divalent tin) 25 g / L 2-hydroxypropane-1-sulfonic acid 100 g / L o- Condensation product of toluidine and formalin 20 g / L sorbitol 0.5 g / L acetone 30 g / L Surfactant (polyethylene glycol nonyl phenyl ether) 10 g / L Acetaldehyde 15 g / L Immersed in 4N purity tin anode, current Density 8A / d
Plating was performed at m ² to obtain a plating film having a thickness of 2 μm.
5,000 magnification after scanning by scanning electron microscope
As a result of observing with double magnification, the boundaries of the plated particles could not be identified. Separately, the thickness of the plating film applied to a 10 cm square sample under the same conditions was calculated from the volume of the plating film calculated using the average film thickness obtained from microscopic observation of the cross section and the weight difference before and after plating. When the density was calculated from the weight, it was 7.3.

Comparative Example 1 The plating solution was changed to the following (b): Plating solution (b) Stannous sulfate 40 g / L Sulfuric acid 60 g / L Gelatin 2 g / L, and the cathode current density during plating was 1 A / dm ² . Except for this, the same operation as in Example 1 was performed to obtain a plating film having a thickness of 2 μm. After plating, observation with a scanning electron microscope at a magnification of 3000 times revealed that the boundaries of the plated particles were clearly identifiable and the average particle size was about 25 μm.

Example 2 The following plating solution (c) was used: Plating solution (c) Tin 2-hydroxypropane-1-sulfonate (as divalent tin) 25 g / L Antimony trichloride (as antimony) 5 mg / L 2- Lead hydroxypropane-1-sulfonate (as lead) 15 mg / L 2-Hydroxypropane-1-sulfonic acid 100 g / L Sorbitol 0.5 g / L Acetone 30 g / L Surfactant (polyethylene glycol nonylphenyl ether) 10 g / L The same operation as in Example 1 was carried out except that the condensation product of o-toluidine and formalin was changed to 20 g / L acetaldehyde 15 g / L to obtain a plating film having a thickness of 2 μm. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the boundaries of the plated particles could not be identified. Separately, the thickness of the plating film applied to a 10 cm square sample under the same conditions was calculated from the volume of the plating film calculated using the average film thickness obtained from microscopic observation of the cross section and the weight difference before and after plating. When the density was calculated from the weight, it was 7.3.

Example 3 The following plating solution (d) was used: Plating solution (d) Tin 2-hydroxypropane-1-sulfonate (as divalent tin) 25 g / L Lead sulfosuccinate (as lead) 5 mg / L, sulfuric acid Cadmium (as cadmium) 10 mg / L Arsenous acid (as arsenic) 5 mg / L 2-Hydroxypropane-1-sulfonic acid 100 g / L Sorbitol 0.5 g / L Acetone 30 g / L Surfactant (polyethylene glycol nonyl phenyl ether) 10 g / Condensation product of L o -toluidine and formalin 20 g / L Acetaldehyde 15 g / L, except that the procedure was the same as in Examples 1 and 2, and 2
A plating film having a thickness of μm was obtained. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the boundaries of the plated particles could not be identified. Separately, the thickness of the plating film applied to a 10 cm square sample under the same conditions was calculated from the volume of the plating film calculated using the average film thickness obtained from microscopic observation of the cross section and the weight difference before and after plating. When the density was calculated from the weight, it was 7.3.

Example 4 The following plating solution was used (e): Plating solution (e) Tin 2-hydroxypropane-1-sulfonate (as divalent tin) 25 g / L Antimony trichloride (as antimony) 5 mg / L Thallium nitrate (As thallium 50 mg / L 2-hydroxypropane-1-sulfonic acid 100 g / L sorbitol 0.5 g / L acetone 30 g / L surfactant (polyethylene glycol nonyl phenyl ether) 10 g / L condensation product of o-toluidine and formalin A plating film having a thickness of 2 μm was obtained by performing the same operations as in Examples 1, 2 and 3 except that the amount of acetaldehyde was changed to 20 g / L and acetaldehyde was changed to 15 g / L. As a result, the boundaries of the plated particles could not be identified.

Example 5 Using a copper foil as a negative electrode current collector, electrolytic degreasing was performed in an alkaline electrolytic degreasing solution at 1 A / dm ² for 1 minute, and after washing with water, 5%
It was immersed in an aqueous solution of methanesulfonic acid for 30 seconds for activation.
After washing with water, the following plating solution (f): Plating solution (f) tin methanesulfonate (as divalent tin) 24 g / L silver methanesulfonate (as silver), 0.5 g / L potassium pyrophosphate 260 g / l Potassium iodide 250 g / l Catechol 1 g / L Isopropyl alcohol 50 g / L Surfactant (polyoxyalkylene naphthyl ether) 0.5 g / L Reaction product of salicylaldehyde and hydroxylamine 5 g / l pH (adjusted with methanesulfonic acid) 5 And was plated at a current density of 6 A / dm ² using a platinum-plated titanium insoluble anode to obtain a plating film having a thickness of 2 μm. After plating, observation with a scanning electron microscope at a magnification of 3000 times revealed that the boundaries of the plated particles could not be identified. Separately, the thickness of the plating film thickly applied to a 10 cm square sample under the same conditions, and the volume of the plating film calculated using the average film thickness obtained from microscopic observation of the cross section,
It was 7.3 when the density was calculated from the weight of the film calculated from the weight difference before and after plating.

Comparative Example 2 The following plating solution (g) was used: Plating solution (g) Potassium pyrophosphate 178 g / l Potassium iodide 332 g / l Stannous chloride (as divalent tin) 23 g / L Silver iodide ( (As silver) 0.5 g / L pH (adjusted with KOH) 8.9, except that the cathode current density during plating was set to 1 A / dm ² , the same operation as in Example 1 was performed and a plating film having a thickness of 2 μm. Got As a result of observing with a scanning electron microscope at a magnification of 3000 times after plating, the boundaries of the plated particles can be clearly identified, and particles with a diameter of about 2 μm and particles with a diameter of about 1 μm connected in a volcanic mountain range coexist. Was.

Example 6 Using a copper foil as a negative electrode current collector, electrolytic degreasing was performed at 1 A / dm ² for 1 minute in an alkaline electrolytic degreasing solution, and after washing with water, 5%
It was immersed in an aqueous solution of methanesulfonic acid for 30 seconds for activation.
After washing it with water, it was plated with 3 μm of nickel undercoat from a Watt bath according to a conventional method, and then washed with water. (As zinc) 10 g / L lead sulfosuccinate (as lead) 5 mg / L cadmium sulfate (as cadmium) 10 mg / L arsenous acid (as arsenic) 5 mg / L sulfosuccinic acid 100 g / L sodium gluconate 20 g / L hydroquinone 8 g / L ethanol 10 g / L Surfactant (Alkyloyl sarcosinate) Immersed in 1 g / L and plated with a current density of 20 A / dm ² using an anode obtained by melting and alloying 4N-purity tin and zinc.
A plating film having a thickness of μm was obtained. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the boundaries of the plated particles could not be identified.

Example 7 Using a copper net as a negative electrode current collector, electrolytic degreasing was performed in an alkaline electrolytic degreasing solution at 1 A / dm ² for 1 minute, and after washing with water,
It was immersed in a 5% methanesulfonic acid aqueous solution for 30 seconds for activation. After washing it with water, the following plating solution (i): plating solution (i) tin methanesulfonate (as divalent tin) 30 g / l indium sulfamate (as indium) 2 g / L methanesulfonate 80 g / L gallic acid 5 mg / L ethanol 5 g / L Surfactant (polyoxyethylene alkylamine) 10 g / L, and an anode made by melting and alloying 4N-purity tin and indium was used and the current density was 50 A / dm ² and the thickness was 2 μm. A plating film was obtained. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the boundaries of the plated particles could not be identified.

Example 8 Using a nickel porous body as the negative electrode current collector, alkaline electrolysis
1 A / dm in degreasing liquid ²Electrolytic degreasing for 1 minute, water
After washing, immerse in 5% methanesulfonic acid aqueous solution for 30 seconds to activate
Sexualized. After washing it with water, the following plating solution (j):   Plating solution (j)     Tin phenolsulfonate (as divalent tin) 20g / L     Lead phenolsulfonate (as lead) 10g / L     Phenolsulfonic acid 100g / L     3,4,5-Trihydroxybenzoic acid 0.1 g / L     Ethanol 5g / L     Surfactant (2-alkyl-N-carboxymethyl-N-hydroxyethyl     Imidazolinium betaine) 5g / L     2-mercaptobenzothiazole 0.01 g / L     Formalin 3g / L Anode made by melting and alloying 3N-purity tin and lead
Current density of 8 A / dm²Plating at 2 μm
A plating film having a thickness was obtained. Scanning electron microscope after plating
As a result of observation at a magnification of 5000 times, the plated particles
The boundary of was not discernible. Separately for a 10 cm square sample
The thickness of the plating film applied under the same conditions can be
Plating skin calculated using average film thickness obtained from mirror observation
Film weight calculated from the film volume and the weight difference before and after plating
The density was determined to be 8.1.

Example 9 Using copper punching metal as a negative electrode current collector, electrolytic degreasing was performed for 1 minute at 1 A / dm ² in an alkaline electrolytic degreasing solution, followed by washing with water and immersion in a 5% methanesulfonic acid aqueous solution for 30 seconds. Activated. After washing it with water, the following plating solution (k): plating solution (k) tin methanesulfonate (as divalent tin) 20 g / L bismuth methanesulfonate (as bismuth) 1 g / L methanesulfonate 100 g / L ascorbic acid 0 0.5 g / L ethanol 5 g / L Surfactant (polyoxyethylene alkylmethyl ammonium chloride) 5 g / L Methyl methacrylate 3 g / L Immersed in platinum-plated titanium insoluble anode and plated at current density of 10 A / dm ² . Then, a plating film having a thickness of 2 μm was obtained. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the average particle size of the plated particles was about 0.3 μm.

Example 10 Using a copper non-woven fabric as a negative electrode current collector, electrolytic degreasing was performed in an alkaline electrolytic degreasing solution at 1 A / dm ² for 1 minute, and after washing with water,
It was immersed in a 5% methanesulfonic acid aqueous solution for 30 seconds for activation. After washing with water, the following plating solution (l): plating solution (l) stannous chloride (as divalent tin) 20 g / L ferrous chloride (as divalent iron) 1 g / L thallium nitrate (as thallium) 50 mg / L Methanesulfonic acid 100 g / L Catechol 1 g / L Ethanol 3 mh / L Surfactant (polyoxyethylene lauryl ether) 5 g / L Surfactant (polyoxyethylene phenyl ether phosphate) 0.5 g / L benzylideneacetone alcohol Immersion in 0.01 g / L formalin 3 g / L, plating was performed at a current density of 6 A / dm ² using a platinum-plated titanium insoluble anode, and a plating film having a thickness of 2 μm was obtained. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the boundaries of the plated particles could not be identified.

Example 11 Using a copper foil as a negative electrode current collector, electrolytic degreasing was performed at 1 A / dm ² for 1 minute in an alkaline electrolytic degreasing solution, and after washing with water, 5%
It was immersed in an aqueous solution of methanesulfonic acid for 30 seconds for activation.
After washing with water, the following plating solution (m): plating solution (m) stannous sulfate (as divalent tin) 20 g / L cobalt sulfate (as cobalt) 1 g / L sulfuric acid 100 g / L 3,4,5-tri Hydroxybenzoic acid 0.8 g / L Ethanol 50 g / L Surfactant (polyoxyethylene lauryl ether) 5 g / L 1-Naphthaldehyde 0.02 g / L Immersed in platinum-plated titanium insoluble anode, current density 15A Plating was performed at / dm ² to obtain a plating film having a thickness of 2 μm. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the boundaries of the plated particles could not be identified.

Example 12 Using a copper foil as a negative electrode current collector, electrolytic degreasing was performed in an alkaline electrolytic degreasing solution at 1 A / dm ² for 1 minute, and after washing with water, 5%
It was immersed in an aqueous solution of methanesulfonic acid for 30 seconds for activation.
After washing it with water, the following plating solution (n): plating solution (n) stannous chloride (as divalent tin) 20 g / L tin dioxide (as tetravalent tin) 0.5 g / L nickel chloride (as nickel) 100 mg / L Methanesulfonic acid 100 g / L Catechol 5 g / L Ethanol 5 g / L Surfactant (polyoxyethylene lauryl ether) 5 g / L 1,4-butynediol 0.01 g / L Formalin 3 g / L Platinum plating Using a titanium insoluble anode, plating was performed at a current density of 12 A / dm ² to obtain a plated film having a thickness of 2 μm. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the average particle size of the plated particles was about 0.3 μm. Separately, the thickness of the plating film applied to a 10 cm square sample under the same conditions was calculated from the volume of the plating film calculated using the average film thickness obtained from microscopic observation of the cross section and the weight difference before and after plating. When the density was calculated from the weight, it was 7.3.

Example 13 Using a copper foil as a negative electrode current collector, electrolytic degreasing was performed in an alkaline electrolytic degreasing solution at 1 A / dm ² for 1 minute, followed by washing with water and 5%.
It was immersed in sulfuric acid for 30 seconds for activation. After washing it with water, the following plating solution (o): plating solution (o) tin sulfate (as divalent tin) 33 g / L copper sulfate (pentahydrate) 15 g / L sulfuric acid 98 g / L cresol sulfonic acid 10 g / L catechol 3 g / L Ethylene glycol 50g / L Surfactant (Emulgen B66 (Kao Soap)) 2g / L Benzalacetone 0.3g / L Immersed in platinum-plated titanium insoluble anode, current density 6A / dm ² Then, a plating film having a thickness of 2 μm was obtained. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the average particle size of the plated particles was about 0.3 μm.

Example 14 Using an iron foil as a negative electrode current collector, electrolytic degreasing was performed in an alkaline electrolytic degreasing solution at 1 A / dm ² for 1 minute, and after washing with water, 5%
It was immersed in an aqueous solution of methanesulfonic acid for 30 seconds for activation.
After washing it with water, according to a conventional method, a copper undercoat of 3 μm was plated from a copper sulfate bath, followed by washing with water, and the following plating solution (p): plating solution (p) 1-hydroxyethane-1,1-diphosphonic acid 180 g / L stannous oxide (as divalent tin) 20 g / L antimony trioxide (as antimony) 20 g / L catechol sulfonic acid 50 mg / L isopropyl alcohol 20 g / L surfactant (polyoxyalkylene naphthyl ether) 3 g / L pH 2 And was plated at a current density of 6 A / dm ² using a platinum-plated titanium insoluble anode to obtain a plating film having a thickness of 2 μm. After plating, observation with a scanning electron microscope at a magnification of 5000 times revealed that the boundaries of the plated particles could not be identified.

Battery Evaluation In order to see the performance of the negative electrodes of the above Examples and Comparative Examples as a single electrode, coin type cells having a lithium foil as a counter electrode were prepared and evaluated. 1: 1 of propylene carbonate and dimethyl carbonate in which 1 mol / L of LiPF ₆ was dissolved.
1 A polypropylene separator impregnated with a mixed electrolyte was sandwiched between the negative electrode and a lithium foil, and this was set in a coin cell. Charge and discharge test is in the voltage range of 0 to 1V, 1
The current density was mA / cm ² . At that time, the discharge capacity at the 1st cycle (here, the reaction in which the inserted lithium is desorbed is called discharge) and 1 at the 100th cycle
The maintenance rate of the discharge capacity at the cycle is shown in the table. Example 1
14 is an example in which an electrode was prepared using a plating film composed of particles having a particle size of 0.5 μm or less. On the other hand, Comparative Example 1 is an example of a plating film containing only tin but having a particle diameter of about 25 μm, as in Example 1,
Comparative Example 2 is a tin-silver alloy plating film as in Example 5, but is an example of a plating film in which particles of about 1 μm and 2 μm coexist. In any of the examples and comparative examples, the discharge capacity at the first cycle showed a higher value than that of the current carbonaceous materials, and it was shown that tin and tin alloy plating are high capacity negative electrodes. However, the crystal grain size of the plating film has a great influence on the discharge capacity and the cycle characteristics. In the case of a tin single plating film, the particle size is so small that the boundaries of the particles cannot be identified by observation with a scanning electron microscope at a magnification of 5000 times. In Example 1, the discharge capacity in the first cycle and the capacity retention ratio both showed good values.
On the other hand, in Comparative Example 1 in which the average particle size of the plating film was 25 μm, both the discharge capacity in the first cycle and the capacity retention ratio were lower than those in Example 1, and the capacity retention ratio was particularly low.
It can be seen that the charge and discharge characteristics do not depend only on the kind of element called tin, but largely depend on the particle size. lead,
In Examples 2, 3 and 4 in which a trace amount of antimony, cadmium, arsenic and thallium was added to the plating bath, the discharge capacity at the first cycle was higher than that in Example 1 prepared under the same conditions except for the presence or absence of these trace addition metals, Both of the capacity retention ratios show good values, and even if a small amount of these metals is added to the plating bath, they contribute to the miniaturization of crystals and improve the charge / discharge characteristics.
As an example of using the alloy plating film, Example 5 shows an example of the tin-silver alloy plating film. In Example 5, which is a film having a small particle size, although the discharge capacity at the first cycle and the capacity retention rate showed good values,
In Comparative Example 2 in which particles of about 1 and 2 μm coexisted, the discharge capacity at the first cycle was low, and the capacity retention rate was remarkably low.

Plating Bath Life Test In order to industrially produce tin and tin alloys as a negative electrode for a battery by a plating method, it is essential that the plating bath has a long life in view of cost and workability. Continuous plating with a current density of 1 A / dm ² and 50 Ahr / L was performed using a newly constructed plating bath, and the appearance of the plating bath after electrolysis with 10 Ahr / L was evaluated. Example 1 containing all of an acid or complexing agent, an antioxidant, an alcohol or a ketone, which is stoichiometrically equivalent to the divalent tin ion, as an essential component contributing to stabilization of the plating bath. In ~ 14, 50 Ahr /
The plating bath was stable even after the electrolysis of L, and a plating film equivalent to that at the beginning of the construction bath was obtained, but in Comparative Examples 1 and 2 in which the components were lacking, precipitation and turbidity occurred after electrolysis of 10 Ahr / L, and plating The appearance also generated dendrites, and the particles became coarse.

[0064]

[Table 1] Table

[0065]

As described above, according to the present invention,
An electrode for a secondary battery having excellent charge / discharge characteristics by using a fine crystalline tin or tin alloy plating film deposited from a tin or tin alloy plating bath having a limited bath composition as an electrode material for a secondary battery And a secondary battery having excellent charge / discharge characteristics can be manufactured and provided.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C25D 7/00 C25D 7/00 GR Y H01M 4/02 H01M 4/02 D 4/04 4/04 A 4/66 4/66 A 4/70 4/70 A 10/40 10/40 Z (72) Inventor Masakazu Yoshimoto 21-8 Minami Futami, Futami Town, Akashi City, Hyogo Prefecture Daiwa Chemical Research Institute (72) Invention 21-8 Minami Futami, Futami-machi, Akashi-shi, Hyogo Prefecture, Inc. 21-8 Yamato Kasei Research Institute, Inc. (72) Shingo Kitamura 21-8, Minami-futami, Futami-cho, Akashi City, Hyogo Prefecture (72) Inventor Hidemi Nawafune 38-34 F-term 5-chome, Makamicho, Takatsuki-shi, Osaka (Reference) 4K023 AA17 AB34 BA06 BA08 BA09 BA13 BA15 BA19 CB03 CB04 CB05 CB09 4K024 AA07 AA16 AA21 AB09 AB19 BA01 CA02 BA06 CA16 DA02 CA06 CA02 CA06 GA16 5H017 AA03 AS1 0 BB16 CC03 CC05 CC27 CC28 EE01 EE04 HH06 5H029 AJ02 AJ03 AK03 AL11 AM03 AM05 AM07 BJ03 CJ12 CJ24 CJ28 DJ07 DJ08 DJ11 DJ17 EJ01 HJ00 HJ01 HJ02 FAJ EA07 EA07 DA05 EA07 DA05 EA07 A07 EA07 A07 EA07 A02 EA07 A07 EA07 A07 EA07 A02 GA12 GA24 GA27 HA00 HA01 HA02 HA04 HA05 HA08 HA10 HA11 HA17

Claims (28)

[Claims] 1. A secondary battery electrode material comprising a tin or tin alloy plating film deposited from a tin or tin alloy plating bath on one surface or both surfaces of a current collector, the plating film having a thickness of 0. The plating particles having an average particle size of less than 5 μm form a substantially continuous film, and the plating film has at least the following components (i) to (v): (i) 5 g / L or more, 200 g / L The following divalent tin ions, (ii) an acid or complex which forms a water-soluble salt or complex with the divalent tin ions in a stoichiometrically equivalent amount or more with respect to the divalent tin ions. 1 or 2 or more of the agents, and (iii) 1 of the antioxidants having a total concentration of at least 1 ppm or more.
Or 2 or more, (iv) 0.5 g / L or more, 200 g /
L or less aliphatic ketone having 6 or less carbon atoms or 6 carbon atoms
Precipitated from a tin or tin alloy plating bath containing one or more of the following aliphatic branched or unbranched alcohols, and (v) one or more of organic additives as essential components An electrode material for a secondary battery, characterized in that 2. When the plated particles having an average particle size of less than 0.5 μm are further observed from the surface direction at a magnification of 3000 to 5000 with a scanning electron microscope, the boundaries of the particles are substantially identified. The electrode material for a secondary battery according to claim 1, which has an unpredictable size. 3. The acid or complexing agent which forms a water-soluble salt or complex with divalent tin ions in the tin or tin alloy plating bath is as follows: (1) to (see): (1): sulfuric acid, Hydrochloric acid, borofluoric acid, hydrosilicofluoric acid, sulfamic acid, acetic acid, 1-hydroxyethane-
One or more sulfonic acids selected from 1,1-diphosphonic acid, phosphoric acid and condensed phosphoric acid, (II): an aliphatic sulfonic acid represented by general formula (I) or (II) or general formula (III) One or more sulfonic acids selected from aromatic sulfonic acids represented by the following general formula (I): [Wherein R ₁ represents a C ₁ -C ₅ alkyl group, X ₁ represents hydrogen, a hydroxyl group, an alkyl group, an aryl group, an alkylaryl group, a carboxyl group or a sulfonic acid group, and any of the alkyl groups It may be in position and n is an integer from 0-3. ] General formula (II) [Here, R ₂ represents a C _{1 to} C ₅ alkyl group or a C _{1 to} C ₃ alkylene group, and a hydroxyl group may be present at any position of the alkylene group, and X ₂ is chlorine or (and) fluorine. Representing a halogen, the number of substitutions of chlorine or (and) fluorine substituted with hydrogen of an alkyl group or alkylene group is from 1 to a saturated substitution of all hydrogens coordinated to the alkyl group or alkylene group, There are one or two halogen species, and the chlorine or fluorine substituent may be present at any position. Y represents hydrogen or a sulfonic acid group, and the substitution number of the sulfonic acid group represented by Y is in the range of 0 to 2. ] General formula (III) [Wherein X ₃ is a hydroxyl group, an alkyl group, an aryl group,
Alkylaryl group, aldehyde group, carboxyl group,
It represents a nitro group, a mercapto group, a sulfonic acid group or an amino group, or two X ₃ can form a naphthalene ring together with a benzene ring, and m is an integer of 0 to 3. ] (Reference): 1 of an acid or a complexing agent having at least one carboxyl group and further selected from one or two or more groups selected from a carboxyl group, a hydroxyl group, a sulfonic acid group, an amino group and a thiol group. The electrode material for a secondary battery according to claim 1 or 2, which is one kind or two or more kinds. 4. The aliphatic or aromatic sulfonic acid in the tin or tin alloy plating bath is selected from methanesulfonic acid, 2-propanolsulfonic acid, phenolsulfonic acid, trifluoromethanesulfonic acid or cresolsulfonic acid. The electrode material for a secondary battery according to any one of claims 1 to 3, which is one kind or two or more kinds. 5. The substituted or unsubstituted aromatic mono-, di- or triphenol or (ro) aliphatic polyhydroxy compound selected from the following general formula (I) is used as the antioxidant in the tin or tin alloy plating bath. The electrode material for a secondary battery according to any one of claims 1 to 4, which is one kind or two or more kinds selected from: [However, X represents hydrogen or a hydroxyl group, which may be the same or different, and n represents an integer of 1 to 3. At least one of X is a hydroxyl group. Y is one or more selected from hydrogen, a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carboxyl group, a sulfonic acid group or an amino group, which may be the same or different, and m is 6- It is an integer of n. The bonding position on the benzene ring of X and Y does not matter.
However, it includes compounds that can have the structure due to tautomerism. ] A substituted or unsubstituted aromatic mono-, di- or triphenol, (ro) aliphatic polyhydroxy compound represented by 6. The aliphatic branched or unbranched alcohol having 6 or less carbon atoms in the tin or tin alloy plating bath,
The following general formulas (a) to (c): General formula (a) [However, n is an integer larger than m and 6 or less, and m represents an integer of 1 or 2. X is hydrogen or a hydroxyl group,
They may be the same or different, and at least one of X is a hydroxyl group. The carbon chain may be linear or branched, regardless of the position of the carbon to which X is bonded. ] A chain-like saturated aliphatic mono- or dialcohol represented by the following general formula (II): [However, n is an integer larger than m and 6 or less, and m represents an integer of 1 or 2. X is hydrogen or a hydroxyl group,
They may be the same or different, and at least one of X is a hydroxyl group. The carbon chain may be branched regardless of the position of the carbon to which X is bonded. ] A cyclic saturated aliphatic mono- or dialcohol represented by the following general formula (C): [However, n is an integer larger than m and 6 or less, and m represents an integer of 1 or 2. l represents an integer of n-2 or less.
X is hydrogen or a hydroxyl group, which may be the same or different, and at least one of X is a hydroxyl group. The carbon chain may be branched regardless of the position of the carbon to which X is bonded.
O represents etheric oxygen, and is between two carbons, but its position does not matter. ] The electrode material for secondary batteries according to any one of claims 1 to 5, which is an alcohol represented by a chain-like saturated aliphatic mono- or dialcohol having an ether bond represented by: 7. The aliphatic ketone having 6 or less carbon atoms or the aliphatic alcohol having 6 or less carbon atoms in the tin or tin alloy plating bath is acetone, methyl ethyl ketone, methanol, ethanol, n-propanol, i-propanol, 1 selected from n-butanol and t-butanol
The electrode material for a secondary battery according to any one of claims 1 to 6, which is one kind or two or more kinds. 8. The organic additive in the tin or tin alloy plating bath is one or more selected from a surfactant, a smoothing additive, a semi-brightening agent and a brightening agent.
The electrode material for a secondary battery according to any one of 1. 9. The surface active agent in the tin or tin alloy plating bath is one or more selected from nonionic, anionic, amphoteric and cationic systems.
The electrode material for a secondary battery according to any one of 1. 10. The tin or tin alloy plating bath further contains 0.1 g / L or more and 20 g / L or less of a tetravalent tin ion or a tetravalent tin compound. Of secondary battery electrode materials. 11. The tin alloy plating bath has an atomic number of 2.
6 to 33, 44 to 51 excluding tin or 75 to 8 excluding mercury
The electrode material for a secondary battery according to any one of claims 1 to 10, which is an alloy plating bath of one type or two or more types of alloying metals selected from 2 and tin. 12. The electrode material for a secondary battery according to claim 1, wherein the total content of the alloying metal in the plating bath is 20 ppm or more based on tin. 13. The alloyed metal according to claim 11, wherein the tin or tin alloy plating film is IIB or III excluding mercury.
One or two of metals selected from B, IVB and VB metals
The electrode material for a secondary battery according to any one of claims 1 to 12, containing 20 ppm or more of tin in total of at least one kind. 14. The thickness of the tin or tin alloy plating film is 0.01 μm or more and less than 5 μm.
The electrode material for a secondary battery according to any one of 1. 15. The electrode material for a secondary battery according to claim 1, wherein the tin or tin alloy plating film has a thickness of 5 μm or more and 500 μm or less. 16. The secondary battery electrode according to claim 1, wherein the tin or tin alloy plating film has a density of more than 6.6 g / cm ³ and 8.5 g / cm ³ or less. material. 17. When depositing a plating film from the tin or tin alloy plating bath, the following (a) to (c): (a) insoluble anode, (b) tin anode having a purity of 3N or more,
(C) An anode selected from any one of tin alloy anodes prepared by melting tin having a purity of 3N or more and the alloying metal having a purity of 3N or more is used.
The electrode material for a secondary battery according to any one of 1. 18. The electrode material for a secondary battery according to claim 17, wherein the tin having a purity of 3N or more is tin having a purity of 4N or more. 19. When depositing a plating film from the tin or tin alloy plating bath, the cathode current density is 0.1 A / d.
The electrode material for a secondary battery according to any one of claims 1 to 18, wherein the electrode material has a range of m ² or more and 100 A / dm ² or less. 20. When depositing a plating film from the tin or tin alloy plating bath, the cathode current density is 5 A / dm ²
It is the range of more than 100 A / dm < ² > and less, The electrode material for secondary batteries in any one of Claims 1-18 characterized by the above-mentioned. 21. When depositing a plating film from the tin or tin alloy plating bath, a step of performing one or more treatments selected from electrolytic degreasing, pickling and activation as a pretreatment is included. The electrode material for a secondary battery according to any one of claims 1 to 20, which is characterized. 22. When depositing a plating film from the tin or tin alloy plating bath, one or more of an acid, a complexing agent, a tin salt, an antioxidant or a salt of an alloying metal is dissolved in advance. 22. A secondary battery for a secondary battery according to any one of claims 1 to 21, characterized by including a method of constructing a plating bath and / or a method of controlling a concentration of an aqueous solution used for replenishing components. Electrode material. 23. When depositing a plating film from the tin or tin alloy plating bath, one or more of the antioxidant or the organic additive is preliminarily used as an aliphatic ketone having 6 or less carbon atoms or A method of constructing a plating bath or (and) controlling the concentration of a solution prepared by dissolving a solution of an aliphatic branched or unbranched alcohol having 6 or less carbon atoms or a solvent containing them in a plating bath or (and) component replenishment The electrode material for a secondary battery according to any one of claims 1 to 22, comprising a method. 24. An electrode for a secondary battery manufactured using the electrode material according to claim 1. 25. The secondary battery electrode according to claim 24, wherein the current collector is copper, nickel or iron. 26. The electrode for a secondary battery according to claim 25, wherein the current collector is a plate, a porous body, a foam, a screen, a net, an expanded body, a punched body, a nonwoven fabric or a sintered body. 27. A secondary battery comprising at least a negative electrode, a positive electrode and an electrolyte, wherein the electrode is one of claims 24 to 2
7. The secondary battery according to any one of 6 above, which is an electrode for a secondary battery. 28. The secondary battery according to claim 27, wherein the secondary battery electrode is a negative electrode of a lithium secondary battery.