JPH10172605A - Nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent charging/discharging capacity, excellent charging/ discharging cyclic property, and high energy density by containing at least one kind of chain hydrocarbon in the nonaqueous electrolyte containing lithium salt. SOLUTION: In a non-aqueous secondary battery comprising a negative electrode sheet having a layer mainly consisting of metallic oxide containing lithium, a negative electrode sheet having a synthetic layer mainly consisting of the negative electrode material, the non-aqueous electrolyte containing lithium salt, and a separator, the non-aqueous electrolyte consists of the solvent in which one or two or more kinds of chain hydrocarbon and non-proton organic solvent is mixed and lithium salt in the solvent. The content of chain hydrocarbon in the non-aqueous electrolyte is preferably 3wt.%, and more preferably, 0.02-1.5wt.%. Chain hydrocarbon is preferably the carbon number of 7-25, and more preferably, chain hydrocarbon of 8-16 in carbon number. Excellent discharging capacity and excellent cyclic characteristic can be obtained thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a non-aqueous secondary battery having improved charge / discharge capacity and cycle characteristics.

[0002]

2. Description of the Related Art As a negative electrode material for a non-aqueous secondary battery, lithium metal and lithium alloy are typical. However, when they are used, so-called dendrites in which lithium metal grows in dendrites during charge and discharge are generated. Due to the cause of the internal short circuit or the high activity of the dendrite itself, there was a danger such as ignition.

On the other hand, fired carbonaceous materials capable of reversibly inserting and releasing lithium have come into practical use. Since this carbonaceous material has a relatively small density, it has a drawback of low capacity per volume. For this reason, although the use of a lithium foil pressed or laminated on a carbon material is described in JP-A-5-151995, it has not essentially solved the above problem.

Further, Sn, V, Si, B, Z
A method using an oxide such as r or a composite oxide thereof has been proposed (JP-A-5-174818, JP-A-5-174818,
60867, 6-275267, 6-3257
No. 65, No. 6-338324, EP-615296
issue). By combining these oxides or composite oxide negative electrodes with a positive electrode of a transition metal compound containing a certain kind of lithium, a non-aqueous secondary battery having a large charge capacity of 3 to 3.6 V class can be provided. It is said that there is almost no dendrite generation and the safety is extremely high. However, batteries using these materials have a large problem that charging / discharging cyclability is not sufficient, and particularly, charging / discharging efficiency in an initial cycle is low.

[0005] In order to solve these problems, the anode material is made of S
A method of using a composite oxide containing n and adhering lithium metal on a negative electrode sheet has been proposed (PCT / JP
96/00527), however, the cycle characteristics in the middle and late stages are inadequate and have not yet reached the product level.

[0006]

The problems to be solved by the present invention are as follows: 1)
Has high charge / discharge capacity, good charge / discharge cycle characteristics,
2) To provide a non-aqueous secondary battery having a high energy density.

[0007]

An object of the present invention is to provide a positive electrode sheet having a layer mainly composed of a lithium-containing metal oxide,
In a non-aqueous secondary battery having a negative electrode sheet having a mixture layer mainly composed of a negative electrode material, a non-aqueous electrolyte containing a lithium salt and a separator, at least one type of chain hydrocarbon is contained in the non-aqueous electrolyte. Solved by

[0008]

FIG. 1 is a sectional view showing an example of a cylinder type non-aqueous secondary battery. The shape of the battery may be a button, a coin, a sheet, a corner, or the like. The positive electrode sheet 1 and the negative electrode sheet 2 are wound with a separator 3 interposed therebetween, and inserted into the battery can 4. An electrolyte is injected into the battery can 4,
Battery cover 5 is caulked to battery can 4 via gasket 6. The battery cover 5 is electrically connected to the positive electrode sheet 1 and serves as a positive electrode terminal. The battery can 4 is electrically connected to the negative electrode sheet 2 and serves as a negative electrode terminal. The safety valve 7 can be used as a sealing plate. Further, it is preferable to use a PTC (positive temperature coefficient) element in order to guarantee the safety of the battery.

The preferred composition of the electrolyte is one or two or more of a chain hydrocarbon and another aprotic organic solvent.
It is composed of a solvent in which more than one species are mixed and a lithium salt in the solvent.

[0010] The content of the chain hydrocarbon in the electrolyte is 0.1%.
It is preferably from 01 to 3% by weight, more preferably from 0.02 to 2% by weight, and particularly preferably from 0.02 to 1.5% by weight. The chain hydrocarbon preferably has 7 to 25 carbon atoms, more preferably has 7 to 20 carbon atoms, and particularly preferably has 8 to 16 carbon atoms.

Specifically, it is preferably selected from heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, and eicosane. Octane, nonane, decane, undecane, More preferably, it is selected from dodecane, tridecane, tetradecane, pentadecane, and hexadecane. These hydrocarbons may be linear or branched. Particularly preferred are straight-chain or branched octane, decane, dodecane and tetradecane.

Further, these hydrocarbons may be one kind or an arbitrary mixture of two or more kinds, but preferably one kind.

The aprotic organic solvent other than the chain hydrocarbon includes propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate,
Diethyl carbonate, γ-butyrolactone, 1,2-
Dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-
Dioxolane, formamide, dimethylformamide,
Dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, methyl propionate, ethyl propionate, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, 3-methyl-2-oxazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, diethyl Ether and 1,3-propane sultone can be exemplified. Of these, carbonates are preferred, and propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, and diethyl carbonate are more preferred.

Examples of lithium salts dissolved in these aprotic organic solvents include LiClO ₄ , LiBF
₄ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ C
_{O 2, LiAsF 6, LiSbF 6} , LiB 10 Cl 10,
Lithium lower aliphatic carboxylate, LiAlCl ₄ , Li
Examples thereof include Cl, LiBr, LiI, lithium chloroborane, and lithium tetraphenylborate. Among them, LiClO ₄ , LiBF ₄ , LiPF ₆ , LiCF
₃ SO ₃ is particularly preferred.

Among them, a mixture of propylene carbonate or ethylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate is added to LiC
An electrolyte containing F ₃ SO ₃ , LiClO ₄ , LiBF ₄ and / or LiPF ₆ is preferred. An electrolytic solution containing LiBF ₄ and / or LiPF ₆ in a mixture of ethylene carbonate and diethyl carbonate is particularly preferred.

The amount of these electrolytes to be added to the battery is not particularly limited, but can be used in a required amount depending on the amounts of the positive electrode active material and the negative electrode material and the size of the battery. The concentration of the supporting electrolyte is preferably 0.2 to 3 mol per liter of the electrolytic solution. The temperature at the time of pouring the electrolyte is -20 to + 50 ° C
Is more preferable, and more preferably −20 to + 40 ° C.
And particularly preferably -10 to + 30 ° C. It is preferable to cool both the electrolyte and the battery can during the injection.

In addition to the electrolytic solution, the following solid electrolyte can be used. Solid electrolytes are classified into inorganic solid electrolytes and organic solid electrolytes. Well-known inorganic solid electrolytes include nitrides, halides, and oxyacid salts of Li. Among them, Li ₃ N, LiI, Li ₅ N
_{I 2, Li 3 N-LiI} -LiOH, LiSiO 4, L
iSiO ₄ —LiI—LiOH, xLi ₃ PO ₄ — (1
-X) Li ₄ SiO ₄ , Li ₂ SiS ₃ , phosphorus sulfide compounds and the like are effective.

As the organic solid electrolyte, a polyethylene oxide derivative or a polymer containing the derivative, a polypropylene oxide derivative or a polymer containing the derivative, a polymer containing an ion dissociating group, a mixture of the polymer containing an ion dissociating group and the above aprotic electrolyte And phosphoric acid ester polymers are effective.

Further, there is a method of adding polyacrylonitrile to the electrolyte. In addition, a method of using an inorganic and an organic solid electrolyte in combination is also known.

It is known that the following compounds are added to an electrolyte for the purpose of improving discharge and charge / discharge characteristics. For example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphoric triamide, nitrobenzene derivative, sulfur, quinonimine dye, N-substituted oxazolidinone and N, N'-substituted imidazolidinone,
Ethylene glycol dialkyl ether, quaternary ammonium salt, polyethylene glycol, pyrrole, 2-methoxyethanol, AlCl ₃ , monomer of conductive polymer electrode active material, triethylene phosphoramide, trialkylphosphine, morpholine, aryl having carbonyl group Compounds, hexamethylphosphoric triamide and 4-alkylmorpholine, bicyclic tertiary amines, oils (JP-A-62-287580), quaternary phosphonium salts, tertiary sulfonium salts and the like.

Further, in order to make the electrolytic solution nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolytic solution. In addition, carbon dioxide gas can be included in the electrolytic solution in order to provide suitability for high-temperature storage. Further, the mixture of the positive electrode and the negative electrode can contain an electrolytic solution or an electrolyte. For example, a method of including the ionic conductive polymer, nitromethane, and an electrolytic solution is known.

The negative electrode sheet 2 shown in FIG. 1 has a negative electrode mixture layer formed on both surfaces of a sheet-shaped negative electrode current collector. On the negative electrode mixture layer, a metal foil mainly composed of lithium can be provided via an auxiliary layer.

As the metal mainly composed of lithium, it is preferable to use lithium metal, but a metal having a purity of 90% by weight or more is preferable, and a metal having a purity of 98% by weight or more is particularly preferable. It is preferable that the lithium superimposed pattern on the negative electrode sheet is superimposed on the entire surface of the sheet. However, since lithium preliminarily inserted into the negative electrode material gradually diffuses into the negative electrode material due to aging, it is not in the entire surface of the sheet but in a stripe or frame shape. Also, any of the disk-shaped partial overlaps is preferable. The term “overlap” as used herein means that a metal foil mainly composed of lithium is pressure-bonded directly onto a sheet having a negative electrode mixture and an auxiliary layer. The auxiliary layer will be described later.

The amount of lithium inserted can be arbitrarily controlled by the amount of lithium superimposed on the negative electrode sheet. The preliminarily inserted amount of lithium is preferably 0.5 to 4.0 equivalents to the negative electrode material, and more preferably 1 to 4.0 equivalents.
It is 3.5 equivalents, particularly preferably 1.2 to 3.2 equivalents. When less than 1.2 equivalents of lithium are preliminarily inserted into the negative electrode material, the battery capacity is low, and when more than 3.2 equivalents of lithium are preliminarily inserted, the cyclability deteriorates, which is not preferable.

The coverage of the metal foils on the negative electrode sheet is preferably 10 to 100%, more preferably 15 to 100%, and particularly preferably 20 to 100%. If it is less than 20%, the preliminary insertion of lithium may be non-uniform, which is not preferable. Further, from the viewpoint of uniformity, the thickness of the metal foil mainly composed of lithium is preferably 5 to 150 μm, more preferably 5 to 100 μm,
75 μm is particularly preferred.

The atmosphere for handling such as cutting and affixing of a metal foil mainly composed of lithium has a dew point of −30 ° C. or less and −80 ° C.
It is preferable to use a dry air or an argon gas atmosphere at a temperature of at least ℃. In the case of dry air, the temperature is more preferably -40 ° C or lower and -80 ° C or higher. In handling, carbon dioxide may be used in combination. Particularly, in the case of an argon gas atmosphere, it is preferable to use a carbon dioxide gas in combination.

The non-aqueous secondary battery can be uniformly inserted with lithium in the negative electrode material (negative electrode mixture) by aging after injecting the electrolyte and caulking the battery lid. The aging temperature is preferably from 0 to 80 ° C, more preferably from 10 to 70 ° C, and particularly preferably from 20 to 60 ° C. The aging time is preferably 1 to 60 days, and more preferably 5 to 5 days.
0 days is preferable, and especially 8 to 30 days is preferable.

It is more preferable to charge or charge / discharge before and / or during aging in order to uniformly insert lithium. In that case, it is preferable to perform partial charge or charge / discharge rather than full charge or charge / discharge.

Next, the auxiliary layer and the protective layer provided on the surfaces of the electrodes (the positive electrode sheet and the negative electrode sheet) will be described.

Providing a layer different from the active material, for example, a protective layer, on the electrode surface has been studied in the past. When a lithium metal or alloy is used as a negative electrode, a carbon material or a carbon powder containing a metal powder is used. JP-A-4-229562, U.S. Pat. No. 5,387,479
And JP-A-3-297072. However, the purpose of these patents is to protect the active parts of the lithium metal surface and to prevent the decomposition of the electrolyte upon contact with the electrolyte and the formation of passive films due to decomposition products and the like. The structure differs from that of the negative electrode.

Further, Japanese Patent Application Laid-Open No. 61-263069 describes that a transition metal oxide is used as a negative electrode material and its surface is coated with an ion-conductive solid electrolyte. It is described that a solid electrolyte membrane is provided by sputtering. The purpose of this patent is to prevent dendritic precipitation of lithium and to prevent decomposition of the electrolytic solution, as in the above-mentioned patents, and is not necessarily applicable to metal oxide negative electrodes. Further, an ion-conductive solid electrolyte has solubility in water and hygroscopicity, which is not preferable.

Further, Japanese Patent Application Laid-Open No. Sho 61-7577 describes a protective layer made of a material having both electron conductivity and ionic conductivity on the surface of the positive electrode. Tungsten, molybdenum and vanadium oxides are described as being preferred. However, these oxides are compounds capable of occluding and releasing lithium, and are not always preferable in a metal oxide negative electrode.

The auxiliary layer provided on the negative electrode sheet is composed of at least one layer, and may be composed of a plurality of layers of the same type or different types. These auxiliary layers are composed of water-insoluble conductive particles and a binder. As the binder, a binder used when forming an electrode mixture described later can be used. 2.5% by weight of conductive particles contained in the auxiliary layer
Not less than 96% by weight, preferably not less than 5% by weight and 95% by weight.
% By weight or less, more preferably 10% by weight or more and 93% by weight or less.

Examples of the water-insoluble conductive particles include metals, metal oxides, metal fibers, carbon fibers, and carbon particles such as carbon black and graphite. The solubility of the conductive particles in water is preferably 100 ppm or less, and more preferably insoluble. Among these water-insoluble conductive particles, those having low reactivity with alkali metals, particularly lithium, are preferable, and metal powder and carbon particles are more preferable. The electric resistivity at 20 ° C. of the elements constituting the particles is 5 × 10
^It is preferably ⁹ Ω · m or less.

As the metal powder, a metal having low reactivity with lithium, that is, a metal which is unlikely to form a lithium alloy is preferable, and specifically, copper, nickel, iron, chromium, molybdenum, titanium, tungsten, and tantalum are preferable. The shape of these metal powders may be any of a needle shape, a column shape, a plate shape, and a lump shape, and the maximum diameter is preferably 0.02 μm or more and 20 μm or less, more preferably 0.1 μm or more and 10 μm or less. It is preferable that the surface of these metal powders is not excessively oxidized. When the surfaces are oxidized, it is preferable to perform heat treatment in a reducing atmosphere.

As the carbon particles, there can be used a known carbon material which is conventionally used as a conductive material when the electrode active material is not conductive. Examples of these materials include carbon black such as thermal black, furnace black, channel black and lamp black, natural graphite such as flaky graphite, flaky graphite and earthy graphite, artificial graphite, and carbon fiber. In order to mix and disperse these carbon particles with a binder, it is preferable to use carbon black and graphite in combination. As carbon black, acetylene black and Ketjen black are preferable. The carbon particles are preferably 0.01 μm or more and 20 μm or less, more preferably 0.02 μm or more and 10 μm or less.

The auxiliary layer may be mixed with substantially non-conductive particles for the purpose of improving the strength of the coating film. Fine particles of Teflon, SiC,
Examples include aluminum nitride, alumina, zirconia, magnesia, mullite, forsterite, and steatite. These particles contain 0.0% of the conductive particles.
It is preferable to use at least 1 and at most 10 times.

When the negative electrode is formed by coating a mixture on both sides of the current collector, these auxiliary layers may be formed on both sides of the current collector or on only one side. You may.
The auxiliary layer is applied by applying a mixture mainly composed of a metal or a metalloid metal oxide, which is a material capable of reversibly absorbing and releasing lithium, on the current collector, and then sequentially applying the auxiliary layer. Or a simultaneous application method in which the mixture layer and the auxiliary layer are simultaneously applied.

Further, the positive electrode sheet to be combined may have a protective layer. In this case, the protective layer has at least one
It may be composed of layers and may be composed of a plurality of layers of the same type or different types. These protective layers may have substantially no electron conductivity, that is, may be insulating layers, or may be conductive layers like the negative electrode sheet. Further, a form in which an insulating layer and a conductive layer are stacked may be employed. The thickness of the protective layer is preferably 1 μm or more and 40 μm or less, more preferably 2 μm or more and 30 μm or less. Further, it is desirable that the protective layer containing these particles does not melt at 300 ° C. or lower and does not form a new film.

When the protective layer comprises water-insoluble conductive particles and a binder, the conductive particles used for the auxiliary layer of the negative electrode sheet can be used. The type and size of the conductive particles preferably used are the same as those of the negative electrode sheet.

When the protective layers are insulating, these layers preferably contain organic or inorganic particles. These particles preferably have a size of 0.1 μm or more and 20 μm or less,
More preferably, it is not less than μm and not more than 15 μm. The preferred organic particles are a crosslinked latex or a powdery fluororesin, and those which do not decompose or form a film at 300 ° C. or lower are preferable. More preferred is a fine powder of Teflon.

Examples of the inorganic particles include carbides, silicides, nitrides, sulfides, and oxides of metals and nonmetallic elements.

Among carbides, silicides and nitrides, Si
C, aluminum nitride (AlN), BN, and BP are preferable because they have high insulation properties and are chemically stable.
e, SiC using BN as a sintering aid is particularly preferred.

Among chalcogenides, oxides are preferable, and oxides that are hardly oxidized or reduced are preferable. These oxides include Al ₂ O ₃ , As ₄ O ₆ , B ₂ O
_{3, BaO, BeO, CaO,} Li 2 O, K 2 O, Na
₂ O, In ₂ O ₃ , MgO, Sb ₂ O ₅ , SiO ₂ , S
rO and ZrO ₄ . Among them, Al ₂ O
_{3, BaO, BeO, CaO,} K 2 O, Na 2 O, Mg
O, SiO ₂ , SrO, and ZrO ₄ are particularly preferred. These oxides may be used alone or as a composite oxide. Preferred compounds as the composite oxide include mullite (3Al ₂ O ₃ .2SiO ₂ ) and steatite (M
gO.SiO ₂ ), forsterite (2MgO.Si)
O ₂ ), cordierite (2MgO.2Al ₂ O ₃ .5)
SiO ₂ ) and the like.

These insulative inorganic compound particles may be formed to a size of 0.1 μm or more by controlling the production conditions or grinding.
0 μm or less, particularly preferably 0.2 μm or more, 15 μm
The following particles are used.

The protective layer comprises these conductive particles and / or
Alternatively, it is formed using particles having substantially no conductivity and a binder. As the binder, a binder used when forming an electrode mixture described later can be used. The ratio of the particles and the binder is 40% by weight or more based on the total weight of both,
It is preferably 96% by weight or less, more preferably 50% by weight or more and 94% by weight or less.

Hereinafter, other materials for producing a non-aqueous secondary battery and a manufacturing method thereof will be described in detail. The positive / negative electrode used in the non-aqueous secondary battery can be produced by applying a positive electrode mixture or a negative electrode mixture on a current collector. The positive electrode or negative electrode mixture can contain a conductive agent, a binder, a dispersant, a filler, an ionic conductive agent, a pressure enhancer, and various additives, respectively, in addition to the positive electrode active material or the negative electrode material.

As the negative electrode material, a carbonaceous compound, a transition metal or a metal belonging to Group 13 to Group 15 of the periodic table, an oxide of a metalloid element, and / or a chalcogenide can be used. The carbonaceous compound is selected from natural graphite, artificial graphite, vapor grown carbon, calcined organic material, and the like, and preferably contains a graphite structure. In addition, carbonaceous compounds include, besides carbon, heterogeneous compounds such as B, P, N,
S, SiC and B ₄ C may be contained in an amount of 0 to 10% by weight.

In particular, as the negative electrode material, it is preferable to mainly use a transition metal, a metal belonging to Group 13 to Group 15 of the periodic table, an oxide of a metalloid element, and / or a chalcogenide.

As the negative electrode material, a carbonaceous compound may be used in addition to a transition metal or a metal belonging to Group 13 to Group 15 of the periodic table, an oxide of a metalloid element and / or a chalcogenide.

As the transition metal compound, in particular, V, Ti,
A single or composite oxide and / or chalcogenide of Fe, Mn, Co, Ni, Zn, W and Mo is preferred. Further preferred compounds of JP-A 6-44972 Patent according _{Li p Co q V 1-q} O z ( where p = 0.1 to 2.
5, q = 0 to 1, z = 1.3 to 4.5).

Compounds of metals and semimetals other than transition metals include elements belonging to Groups 13 to 15 of the periodic table, Ga, Si,
A compound consisting of Sn, Ge, Pb, Sb, Bi alone or a combination of two or more thereof is selected.

For example, Ga ₂ O ₃ , SiO, GeO, G
eO ₂ , SnO, SnO ₂ , SnS, SnSiO ₃ , P
bO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb
₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , Bi ₂
O ₃ , Bi ₂ O ₄ , Bi ₂ O ₅ , SnSiO _{3 and the} like are preferable. These may be a composite oxide with lithium oxide, for example, Li ₂ GeO ₃ or Li ₂ SnO ₂ .

It is preferable that the above-mentioned composite oxide and / or chalcogenide be mainly amorphous when incorporated into a battery. The term “amorphous” as used herein refers to a substance having a broad scattering band having a peak at 20 ° to 40 ° in 2θ value by X-ray diffraction using CuKα ray, and having a crystalline diffraction line. Is also good. Preferably 40 ° or more and 70 ° in 2θ value
Among the crystalline diffraction lines shown below, the strongest intensity is 2
It is preferably 500 times or less, more preferably 100 times or less, particularly preferably 5 times or less, the diffraction line intensity of the peak of the broad scattering band seen at 20 ° or more and 40 ° or less in θ value, Most preferably, it has no crystalline diffraction lines.

The above-mentioned composite oxide and / or chalcogenide is B, Al, Ga, In, Tl, Si, Ge, Sn,
It is a composite compound of three or more elements among Pb, P, As, Sb, and Bi.

Particularly preferably, B, Al, Si, Ge, S
It is a composite compound composed of three or more elements of n and P. These composite compounds may contain an element of group 1 to group 3 of the periodic table or a halogen element mainly for modifying the amorphous structure.

Among the above-mentioned negative electrode materials, an amorphous composite compound mainly composed of tin is particularly preferable and is represented by the following general formula (1). SnM ¹ _a O _t S _u in the general formula (1), M ¹ is Al, B, P, Si, Ge, Periodic Table 1
Represents two or more elements selected from Group III elements, Group II elements, Group III elements, and halogen elements, a is a number of 0.2 or more, 2 or less, t is a number of 1 or more and 6 or less, and u is Represents a number of 0.5 or less.

Of the general formula (1), the following compounds of the general formula (2) are more preferred. SnM in ² _b O _t S _u general formula (2), 2 M ² are the Al, B, P, Ge, periodic table Group 1 element, group 2 element, a Group 3 element, selected from halogen B represents a number of 0.2 or more, 2 or less, t represents a number of 1 or more and 6 or less, and u represents a number of 0.5 or less.

Of the general formula (1), the compounds of the following general formula (3) are more preferred. ^{_{SnM 3 c M 4 d O t}} S u general formula (3) wherein, M ³ is Al, B, P, Si, Ge of at least 2
And M ⁴ represents at least one of Group 1 element, Group 2 element, Group 3 element and halogen element of the periodic table, and c is 0.
A number of 2 or more and 2 or less, d is a number of 0.01 or more and 1 or less, 0.2 <c + d <2, t is a number of 1 or more and 6 or less, and u represents a number of 0.5 or less.

M ³ and M ⁴ are elements for making the compound of the general formula (3) amorphous as a whole, and M ³ is an element capable of being amorphized, such as Al, B, P, Si, It is preferable to use two or more of Ge in combination. M ⁴ is an amorphous modifiable element, which is a Group 1 element, a Group 2 element, a Group 3 element, or a halogen element of the periodic table;
s, Mg, Ca, Ba, Y and F are preferred.

As the amorphous composite compound, any of a firing method and a solution method can be employed, but the firing method is more preferable. In the baking method, it is preferable to mix well the oxides or compounds of the elements described in the general formula (1) and then bake to obtain an amorphous composite compound.

As the firing conditions, the heating rate is preferably 5 ° C. to 200 ° C. per minute, the firing temperature is preferably 500 ° C. to 1500 ° C., and the firing time is Is more than 1 hour 10
It is preferably 0 hours or less. And, it is preferable as the descending rate of temperature or less per minute 2 ℃ least 10 ⁷ ° C..

The heating rate is defined as “the firing temperature (expressed in ° C.) of 50.
% ”Is the average rate of temperature rise from“% of firing temperature (° C display) ”to“ 80% of firing temperature (° C display) ”. 50
% "Is the average rate of temperature drop to reach"% ".

The temperature may be cooled in a firing furnace, or may be taken out of the firing furnace and put into, for example, water to cool. Also ceramic processing (Gihodo Publishing 19
87) A super quenching method such as a gun method, a Hammer-Anvil method, a slap method, a gas atomizing method, a plasma spray method, a centrifugal quenching method, and a melt drag method described on page 217 can also be used.
Also New Glass Handbook (Maruzen 1991) 172
The cooling may be performed using a single roller method or a twin roller method described on the page. In the case of a material that melts during firing, a fired product may be continuously taken out while supplying raw materials during firing. In the case of a material that melts during firing, it is preferable to stir the melt.

The firing gas atmosphere is preferably an atmosphere having an oxygen content of 5% by volume or less, and more preferably an inert gas atmosphere. Examples of the inert gas include nitrogen, argon, helium, krypton, xenon, and the like. The most preferred inert gas is pure argon.

The average particle size of the compound of the negative electrode material is 0.1.
1 to 60 μm is preferred. In order to obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, mortar, ball mill, sand mill, vibrating ball mill,
A satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can also be performed as necessary. Classification is preferably performed to obtain a desired particle size. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be performed both in a dry type and a wet type.

Examples of the negative electrode material are shown below, but are not limited thereto.
It is not specified. SnAl_0.1B_0.3P_0.4K
_0.2O_2.7, SnAl_0.1B_0.3P_0.4Na
_0.2O _2.7, SnAl_0.1B_0.3P_0.4Rb
_0.2O_2.7, SnAl_0.1B_0.3P_0.4Cs
_0.2O_2.7, SnAl_0.1B_0.5P_0.5Mg_0.1F_0.2
O_3.15, SnAl_0.1B_0.5P_0.5Ba_0.08F_0.08O
_3.19, SnAl_0.2B_0.4P_0.4O_2.9, SnAl_0.3
B_0.5P_0.2O_2.7, SnAl_0.3B_0.7O_2.5, Sn
B_0.2P_0.6Ba _0.08F_0.08O_2.84, SnB_0.4P_0.4
Ba_0.1F_0.1O_2.65, SnB_0.5P_0.5O_Three, SnB
_0.5P_0.5Mg_0.1O_3.1,

[0068] SnB_0.5P_0.5Mg_0.1F_0.2O_Three, S
nB_0.5P_0.5Li_0.1Mg_0.1F_{0. Two}O_3.05, SnB
_0.5P_0.5K_0.1Mg_0.1F_0.2O_3.05, SnB_0.5P
_0.5K _0.05Mg_0.05F_0.1O_3.03, SnB_0.5P_0.5K
_0.05Mg_0.1F_0.2O_3.03, SnB_0.5P_0.5Cs_0.1
Mg_0.1F_0.2O_3.05, SnB_0.5P_0.5Cs_0.05Mg
_0.05F_0.1O_3.03, SnB_0.5P_0.5Mg_0.1F_0.1O
_3.05, SnB_0.5P_0.5Mg_0.1F_0.2O_Three, SnB
_0.5P_0.5Mg_0.1F_0.06O_3.07, SnB_0.5P_{0. Five}M
g_0.1F_0.14O_3.03, SnPBa_0.08O_3.58, SnPK
_0.1O_3.55, SnP _0.05Mg_0.05O_3.58, SnPCs
_0.1O_3.55, SnPBa_0.08F_0.08O_3.54, SnPK
_0.1Mg_0.1F_0.2O_3.55, SnPK_0.05Mg_0.05F
_0.1O_3.53, SnPCs_0.1Mg_0.1F_0.2O_3.55, S
nPCs_0.05Mg_0.05F_0.1O_3.53,

[0069] Sn_1.1B_0.2P_0.6Ba_0.08F_0.08O
_2.94, Sn_1.1B_0.2P_0.6Li_0.1K _0.1Ba_0.1F
_0.1O_3.05, Sn_1.1B_0.4P_0.4Ba_0.08O_2.74, S
n_1.1PCs_0.05O_3.63, Sn_1.1PK_0.05O_3.63, S
n_1.2Al_0.1B_0.3P_0.4Cs _0.2O_2.9, Sn_1.2
B_0.2P_0.6Ba_0.08O_3.08, Sn_1.2B_0.2P_0.6B
a _0.08F_0.08O_3.04, Sn_1.2B_0.2P_0.6Mg_0.04B
a_0.04O_3.08, Sn_1.2B _0.3P_0.5Ba_0.08O_2.98,
Sn_1.3Al_0.1B_0.3P_0.4Na_0.2O_Three, Sn _1.3
B_0.4P_0.4Ca_0.2O_3.1, Sn_1.3B_0.4P_0.4B
a_0.2O_3.1, Sn _1.4PK_0.2O_Four, Sn_1.4Ba
_0.1PK_0.2O_4.15, Sn_1.4Ba_0.2PK
_{0. Two}O_4.3, Sn_1.4Ba_0.2PK_0.2Ba_0.1F_0.2
O_4.3, Sn_1.4PK_0.3O_4.05, Sn_1.5PK_0.2O
_4.1, Sn_1.5PK_0.1O_4.05, Sn_1.5PCs_{0. 05}O
_4.03, Sn_1.5PCs_0.05Mg_0.1F_0.2O_4.03, Sn
_TwoP_TwoO₇,

[0070] SnSi_0.5Al_0.1B_0.2P_0.1Ca
_0.4O_3.1, SnSi_0.4Al_0.2B_{0. Four}O_2.7, Sn
Si_0.5Al_0.2B_0.1P_0.1Mg_0.1O_2.8, SnS
i_0.6Al_0.2B_0.2O_2.8, SnSi_0.5Al_0.3B
_0.4P_0.2O_3.55, SnSi_0.5Al_0.3B_0.4P_0.5
O_4.30, SnSi_0.6Al_0.1B_0.1P_0.3O_3.25, S
nSi_0.6Al_0.1B_0.1P_0.1Ba_0.2O_2.95, Sn
Si_0.6Al_0.1B_0.1P _0.1Ca_0.2O_2.95, SnS
i_0.6Al_0.1B_0.2Mg_0.2O_2.85, SnSi_{0. 6}A
l_0.1B_0.3P_0.1O_3.05, SnSi_0.6Al_0.2Mg
_0.2O_2.7, SnSi_0.6Al_0.2Ca_0.2O_2.7, S
nSi_0.6Al_0.2P_0.2O_Three, SnSi_0.acid₆B_0.2
P_0.2O_Three, SnSi_0.8Al_0.2O_2.9, SnSi
_0.8Al_0.3B _0.2P_0.2O_3.85, SnSi_0.8B_0.2
O_2.9, SnSi_0.8Ba_0.2O_2.8, SnSi_0.8M
g_0.2O_2.8, SnSi_0.8Ca_0.2O_2.8, SnSi
_0.8P_{0. Two}O_3.1,

[0071] Sn_0.9Mn_0.3B_0.4P_0.4Ca_0.1R
b_0.1O_2.95, Sn_0.9Fe_0.3B_{0. Four}P_0.4Ca_0.1
Rb_0.1O_2.95, Sn_0.8Pb_0.2Ca_0.1P_0.9O
_3.35, Sn_0.3Ge_0.7Ba_0.1P_0.9O_3.35, Sn
_0.9Mn_0.1Mg_0.1P_0.9O_3.35, Sn_0.2Mn_0.8
Mg_0.1P_0.9O_3.35, Sn_0.7Pb_0.3Ca_0.1P
_0.9O _3.35, Sn_0.2Ge_0.8Ba_0.1P_0.9O_3.35.
SnAl_0.3B_0.5P_0.2O_2.7S_0.01, SnAl_0.2
B_0.4P_0.4O_2.85S_{0. 05}, SnB_0.2P_0.5K_0.1M
g_0.1Ge_0.1O_2.7S_0.1

The chemical formula of the compound obtained by calcining can be calculated by inductively coupled plasma (ICP) emission spectroscopy as a measuring method, and can be calculated from the difference in weight of powder before and after calcining as a simple method.

The negative electrode material can contain various elements. For example, lanthanoid metals (Hf, Ta, W,
It may contain dopants of Re, Os, Ir, Pt, Au, Hg) and various compounds (for example, compounds of Sn, In, and Nb) that increase electron conductivity. The amount of the compound to be added is preferably 0 to 5 mol%.

The surface of the oxide positive electrode active material or the negative electrode material can be coated with an oxide having a chemical formula different from that of the positive electrode active material or the negative electrode material used. The surface oxide is preferably an oxide containing a compound that dissolves in both acidity and alkalinity. Further, a metal oxide having high electron conductivity is preferable. For example, PbO ₂ , Fe ₂ O ₃ , SnO ₂ , I
It is preferable that n ₂ O ₂ , ZnO, or the like or a dopant thereof (eg, a metal having a different valence, a halogen element, or the like in an oxide) be contained in the oxide. Particularly preferably, SiO ₂ , SnO ₂ , Fe ₂ O ₃ , ZnO, PbO
₂ The amount of the metal oxide used in these surface treatments is preferably 0.1 to 10% by weight, particularly preferably 0.2 to 5% by weight, based on the positive electrode active material / negative electrode material.
0.3 to 3% by weight is most preferred.

In addition, the surfaces of the positive electrode active material and the negative electrode material can be modified. For example, the surface of a metal oxide is treated with an esterifying agent, treated with a chelating agent,
Treatment with a conductive polymer, polyethylene oxide, or the like can be given.

The positive electrode active material may be a transition metal oxide capable of reversibly inserting and releasing lithium ions, but is particularly preferably a lithium-containing transition metal oxide. Preferred lithium-containing transition metal oxide cathode active materials include lithium-containing T
i, V, Cr, Mn, Fe, Co, Ni, Cu, Mo,
An oxide containing W is given. Alkali metals other than lithium (elements IA and IIA of the periodic table) and / or Al, Ga, In, Ge, Sn, Pb, Sb, and B
i, Si, P, B, etc. may be mixed. The mixing amount is preferably 0 to 30 mol% based on the transition metal.

More preferred lithium-containing transition metal oxide positive electrode active materials include lithium compounds / transition metal compounds (where transition metals are Ti, V, Cr, Mn, Fe,
It is preferable to synthesize them by mixing them so that the total molar ratio of at least one selected from Co, Ni, Mo, and W) is 0.3 to 2.2.

Particularly preferred lithium-containing transition metal oxide positive electrode active materials include lithium compounds / transition metal compounds (where transition metals are V, Cr, Mn, Fe, Co,
It is preferable to synthesize them by mixing them so that the total molar ratio of at least one selected from Ni) is 0.3 to 2.2.

Particularly preferred lithium-containing transition metal oxide cathode active materials are Li _x QO _y (where Q is mainly
At least one of them is a transition metal containing Co, Mn, Ni, V and Fe, x = 0.02 to 1.2, y = 1.4 to 3)
It is preferred that Q is A besides transition metal
1, Ga, In, Ge, Sn, Pb, Sb, Bi, S
i, P, B and the like may be mixed. The mixing amount is preferably 0 to 30 mol% based on the transition metal.

More preferred lithium-containing metal oxide
As the extremely active material, Li_xCoO_Two, Li_xNiO_Two,
Li_xMnO_Two, Li_xCo_aNi_1-aO_Two, Li_zC
o_bV_1-bO_z, Li_xCo_bFe_1-bO_Two, Li_xM
n_TwoO_Four, Li_xMn_cCo _2-cO_Four, Li_xMn_cN
i_2-cO_Four, Li_xMn_cV_2-cO_z, Li_xMn_cF
e_2-cO_Four, Li_xCo_bB_1-bO_Two, Li_xCo_bS
i_1-bO_Two, Li_xMn_TwoO_FourAnd MnO_TwoA mixture of L
i_2xMnO_ThreeAnd MnO_TwoMixture of Li_xMnO_Four, L
i_2xMnO_ThreeAnd MnO_Two(Where x = 0.02)
-1.2, a = 0.1-0.9, b = 0.8-0.9
8, c = 1.6 to 1.96, z = 2.01 to 5)
Can be

Further preferred is a lithium-containing metal oxide.
As the extremely active material, Li_xCoO_Two, Li_xNiO_Two,
Li_xMnO_Two, Li_xCo_aNi_1-aO_Two, Li_xC
o_bV_1-bO_z, Li_xCo_bFe_1-bO_Two, Li_xM
n_TwoO_Four, Li_xMn_cCo _2-cO_Four, Li_xMn_cN
i_2-cO_Four, Li_xMn_cV_2-cO_Four, Li_xMn_cF
e_2-cO_Four(Where x = 0.02 to 1.2, a = 0.1
~ 0.9, b = 0.8 ~ 0.98, c = 1.6 ~ 1.9
6, z = 2.01 to 2.3).

Most preferred lithium-containing transition metal oxide
As the positive electrode active material, Li_xCoO _Two, Li_xNi
O_Two, Li_xMnO_Two, Li_xCo_aNi_1-aO_Two, L
i_xMn _TwoO_Four, Li_xCo_bV_1-bO_z(Where x =
0.02-1.2, a = 0.1-0.9, b = 0.9-
0.98, z = 2.02 to 2.3). here
In the above, the value x is a value before the start of charge / discharge, and
More.

The positive electrode active material can be synthesized by a method in which a lithium compound and a transition metal compound are mixed and fired, or a solution reaction, but the firing method is particularly preferable. The firing temperature is
The temperature may be a temperature at which a part of the mixed compound is decomposed and melted.
0 to 1500 ° C. is preferred. 250-9 for firing
Calcination at 00 ° C. is preferred. The firing time is 1 to
The time is preferably 72 hours, more preferably 2 to 20 hours. The method of mixing the raw materials may be a dry method or a wet method. After the firing, annealing may be performed at 200 ° C. to 900 ° C.

The firing gas atmosphere is not particularly limited, and may be an oxidizing atmosphere or a reducing atmosphere. For example, in air, or gas with oxygen concentration adjusted to any ratio,
Alternatively, hydrogen, carbon monoxide, nitrogen, argon, helium, krypton, xenon, carbon dioxide and the like can be mentioned.

As a method of chemically inserting lithium ions into the transition metal oxide when synthesizing the positive electrode active material, a method of synthesizing lithium metal, a lithium alloy or butyllithium with the transition metal oxide is preferable. .

The average particle size of the positive electrode active material is not particularly limited, but is preferably 0.1 to 50 μm. The specific surface area is not particularly limited, but is 0.01 to 50 m ^{2 by} the BET method.
/ g is preferred. The pH of the supernatant when 5 g of the positive electrode active material is dissolved in 100 ml of distilled water is preferably 7 or more and 12 or less.

To obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a vibrating ball mill, a vibrating mill, a satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used.

The positive electrode active material obtained by firing may be used after washing with water, an aqueous acidic solution, an aqueous alkaline solution, or an organic solvent.

The combination of the negative electrode material and the positive electrode active material is as follows:
Preferably, the compound represented by the above general formula (1) and Li
_x CoO ₂ , Li _x NiO ₂ , Li _x Co _a Ni _1-a O
₂ , Li _x MnO ₂ , Li _x Mn ₂ O ₄ , or Li _x
Co _b V _1-b O ₂ (where x = 0.02 to 1.2, a =
0.1-0.9, b = 0.9-0.98, z = 2.02
To 2.3), whereby a non-aqueous secondary battery having a high discharge voltage, a high capacity, and excellent charge-discharge cycle characteristics can be obtained.

The equivalent of lithium insertion into the negative electrode material is 3 to 1
It is 0 equivalent, and the usage ratio with the positive electrode active material is determined according to this equivalent. It is preferable to use a ratio of 0.5 to 2 times the used amount ratio based on this equivalent. When the lithium supply source is other than the positive electrode active material (for example, lithium metal, alloy, butyl lithium, etc.), the amount of the positive electrode active material used is determined according to the lithium release equivalent of the negative electrode material. Also at this time, the usage ratio based on this equivalent,
It is preferable to use a coefficient multiplied by 0.5 to 2 times.

A conductive agent, a binder, a filler, and the like can be added to the electrode mixture. The conductive agent may be any electronic conductive material that does not cause a chemical change in the configured battery. Usually, natural graphite (flaky graphite, flaky graphite, earthy graphite, etc.), artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber or metal (copper, nickel, aluminum, silver, etc.) powder, metal fiber or Conductive materials such as polyphenylene derivatives
It can be included as a seed or a mixture thereof.
A combination of graphite and acetylene black is particularly preferred. The addition amount is preferably 1 to 50% by weight, particularly preferably 2 to 30% by weight. 2-15% by weight for carbon and graphite
Is preferred.

The binder is usually starch, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl chloride, polyvinyl pyrrolidone,
Tetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, polybutadiene, fluoro rubber,
Polysaccharides such as polyethylene oxide, thermoplastic resins, polymers having rubber elasticity, and the like are used alone or as a mixture thereof. When a compound containing a functional group that reacts with lithium, such as a polysaccharide, is used, it is preferable to add a compound such as an isocyanate group to deactivate the functional group. The addition amount of the binder is preferably 1 to 50% by weight, particularly preferably 2 to 30% by weight.

As the filler, any fibrous material that does not cause a chemical change in the constructed battery can be used. Usually, fibers such as olefin-based polymers such as polypropylene and polyethylene, glass, and carbon are used. Although the amount of the filler is not particularly limited,
~ 30% by weight is preferred.

In using the negative electrode material in a non-aqueous secondary battery system, a water-dispersed mixture paste containing a compound is applied on a current collector and dried. PH of the aqueous dispersion mixture paste
Is preferably 5 or more and less than 10, more preferably 6 or more and less than 9. Further, the temperature of the aqueous dispersion paste is 5 ° C. or more and 8 ° C.
It is preferred to keep the temperature below 0 ° C. and to apply the paste on the current collector within 7 days after preparation of the paste.

As the separator 3 shown in FIG. 1, a material having high ion permeability, predetermined mechanical strength, insulating microporous material or having a gap is used. In order to further improve safety, it is necessary to have a function of closing the above gap at 80 ° C. or higher to increase resistance and cut off current. The closing temperature of these gaps is from 90 ° C to 180 ° C, more preferably from 110 ° C to 170 ° C.

The method of forming the gap differs depending on the material, but may be any known method. In the case of a porous film, the shape of the pores is usually circular or elliptical, and the size is 0.1 mm.
05 μm to 30 μm, 0.1 μm to 20 μm
Is preferred. Further, as in the case of the drawing method or the phase separation method, the holes may be rod-shaped or amorphous. For cloth,
The gap is a space between fibers, and depends on how to make a woven or nonwoven fabric. The ratio of closing these gaps, that is, the porosity is 2
0% to 90%, preferably 35% to 80%.

The thickness of the separator is 5 μm or more and 100
It is a microporous film, woven fabric, nonwoven fabric, or other cloth having a size of 10 μm or less, more preferably 10 μm or more and 80 μm or less. The separator preferably contains at least 20% by weight of an ethylene component, and particularly preferably contains 30% or more. As components other than ethylene, propylene,
Examples include butene, hexene, fluorinated ethylene, vinyl chloride, vinyl acetate, and acetalized vinyl alcohol, with propylene and fluorinated ethylene being particularly preferred.

The microporous film is preferably made of polyethylene, an ethylene-propylene copolymer or an ethylene-butene copolymer. Further, those made by mixing and dissolving polyethylene and polypropylene, or polyethylene and polytetrafluoroethylene are also preferable.

Non-woven fabrics and woven fabrics have a yarn diameter of 0.1 μm to 5 μm and are made of polyethylene, ethylene-propylene copolymer, ethylene-butene 1 copolymer, ethylene-methylbutene copolymer, ethylene-methylpentene copolymer. Those composed of a polymer, polypropylene or polytetrafluoroethylene fiber are preferred.

These separators may be a single material or a composite material. In particular, two or more types of microporous films with different pore diameters, porosity and pore closing temperature are laminated, microporous film and nonwoven fabric, microporous film and woven fabric, nonwoven fabric and paper are combined in different forms. Particularly preferred are the following.

As the current collectors for the positive and negative electrodes, any electronic conductors that do not cause a chemical change in the constructed battery may be used. For example, for the positive electrode, stainless steel,
In addition to nickel, aluminum, titanium, carbon, etc., carbon, nickel,
What processed titanium or silver is used. Particularly, aluminum or an aluminum alloy is preferable.

The negative electrode may be made of a material obtained by treating the surface of copper or stainless steel with carbon, nickel, titanium or silver, in addition to stainless steel, nickel, copper, titanium, aluminum, carbon, etc., and an Al—Cd alloy. Are used. Particularly, copper or a copper alloy is preferable.

The surface of these materials may be oxidized. In addition, it is desirable to make the current collector surface uneven by surface treatment. Other than foil, film, sheet, net, punched, lath, porous, foam,
A molded article of a fiber group is used. The thickness is not particularly limited, but a thickness of 1 to 500 μm is used.

The shape of the battery can be applied to any of coins, buttons, sheets, cylinders, flats, corners and the like. When the shape of the battery is a coin or a button, the mixture of the positive electrode active material and the negative electrode material is mainly used after being compressed into a pellet shape.
The thickness and diameter of the pellet are determined by the size of the battery. When the shape of the battery is a sheet, a cylinder, or a corner, the mixture of the positive electrode active material and the negative electrode material is mainly used by being coated (coated) on a current collector, dried, and compressed. As a coating method, a general method can be used.

For example, there can be mentioned a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion method, a curtain method, a gravure method, a bar method, a dip method and a squeeze method. Among them, a blade method, a knife method and an extrusion method are preferred.
The coating is preferably performed at a speed of 0.1 to 100 m / min. At this time, by selecting the above coating method in accordance with the solution physical properties and drying properties of the mixture, a good surface state of the coated layer can be obtained. The coating may be performed on one side at a time or on both sides simultaneously. The application may be continuous, intermittent, or striped. The thickness, length and width of the coating layer,
Although determined by the size of the battery, the thickness of the coating layer on one side is particularly preferably 1 to 2000 μm in a compressed state after drying.

As a method for drying or dehydrating the pellets and sheets, a generally employed method can be used. In particular, it is preferable to use hot air, vacuum, infrared rays, far infrared rays, electron beams, and low-temperature air alone or in combination. The temperature is preferably in the range of 80 to 350 ° C, particularly 10 ° C.
A range from 0 to 250 ° C is preferred. The water content of the entire battery is preferably 2000 ppm or less, and the positive electrode mixture, the negative electrode mixture and the electrolyte are each preferably 500 ppm or less from the viewpoint of cycleability. As a method for pressing pellets and sheets, a method generally used can be used, but a die pressing method and a calendar pressing method are particularly preferable. The pressing pressure is not particularly limited, but is 0.2 to 3 t /
cm ² is preferred. The press speed of the calender press method is preferably from 0.1 to 50 m / min, and the press temperature is from room temperature to 2 m / min.
00 ° C is preferred. The width ratio of the negative electrode sheet to the positive electrode sheet is preferably 0.9 to 1.1, and more preferably 0.95 to 1.0.
Is particularly preferred. The content ratio between the positive electrode active material and the negative electrode material is
Although it cannot be limited because it differs depending on the compound type and the mixture formulation, it can be set to an optimal value from the viewpoint of capacity, cycleability and safety.

As shown in FIG. 1, after the mixture sheets 1 and 2 are overlapped with each other with the separator 3 interposed therebetween, the sheets 1 and 2 are wound or folded, inserted into the can 4, and After electrically connecting the sheet 4 and the sheet 2, an electrolyte is injected,
A battery can is formed using the sealing plate. At this time, the safety valve 7 can be used as a sealing plate. In addition to the safety valve 7, various conventionally known safety elements may be provided.
For example, a fuse, a bimetal, a PTC element, or the like is used as the overcurrent prevention element. In addition to the safety valve, as a countermeasure against an increase in the internal pressure of the battery can, a method of cutting the battery can, a method of cracking a gasket, a method of cracking a sealing plate, or a method of cutting with a lead plate can be used.
Further, the charger may be provided with a protection circuit incorporating measures for overcharging or overdischarging, or may be connected independently.

As a measure against overcharging, the internal pressure of the battery increases.
To interrupt the current. This
At the same time, the compound or electrolyte contains a compound that increases the internal pressure.
I can do it. Compound used to increase internal pressure
An example of a product is Li_TwoCO _Three, LiHCO_Three, Na_Two
CO_Three, NaHCO_Three, CaCO_Three, MgCO_ThreeSuch as
Carbonates and the like.

For the can or the lead plate, a metal or an alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper, and aluminum or alloys thereof are used. Caps, cans,
Known methods (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used for welding the sheet and the lead plate. A conventionally known compound or mixture such as asphalt can be used as the sealing agent for closing.

The application of the non-aqueous secondary battery is not particularly limited. For example, when the non-aqueous secondary battery is mounted on an electronic device, a color notebook computer, a black-and-white notebook computer, a pen-input personal computer, a pocket (palmtop) personal computer, a notebook word processor, a pocket computer Word processor, e-book player, mobile phone, cordless phone handset, pegger, handy terminal, mobile fax, mobile copy, mobile printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini disk,
Electric shaver, electronic translator, car phone, transceiver, power tool, electronic organizer, calculator, memory card, tape recorder, radio, backup power supply, memory card, etc. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game machines, road conditioners, irons, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.). Furthermore, it can be used for various military purposes and space applications. Further, it can be combined with a solar cell.

The preferable combination of the members constituting the non-aqueous secondary battery is preferably a combination of the above-mentioned chemical materials and the preferable components of the battery. Particularly, as the positive electrode active material, Li _x CoO ₂ , Li _x NiO ₂ , Li _x Mn
O ₂ , Li _x MnO ₄ (where x = 0.02 to 1.2)
At least one compound selected from the group consisting of acetylene black and a conductive agent.

The positive electrode current collector is made of stainless steel or aluminum, and has a shape such as a net, a sheet, a foil, and a lath. As a negative electrode material, lithium metal, lithium alloy (Li-Al), carbonaceous compound, oxide (LiC
oVO ₄ , SnO ₂ , SnO, SiO, GeO ₂ , Ge
_{O, SnSiO 3, SnSi 0.3 Al} 0.1 B 0.2 P 0. 3
O _3.2 ), sulfides (TiS ₂ , SnS ₂ , SnS, Ge
It is preferable to use at least one compound containing S ₂ , GeS) or the like. The negative electrode current collector is made of stainless steel or copper, and has a shape such as a net, a sheet, a foil, and a lath. The mixture used together with the positive electrode active material or the negative electrode material may be mixed with a carbon material such as acetylene black or graphite as an electron conductive agent. As the binder, a fluorine-containing thermoplastic compound such as polyvinylidene fluoride or polyfluoroethylene, a polymer containing acrylic acid, an elastomer such as styrene-butadiene rubber or ethylene propylene terpolymer can be used alone or in combination. Further, as an electrolytic solution, ethylene carbonate, a combination of cyclic compounds such as diethyl carbonate and dimethyl carbonate, an acyclic carbonate or an ester compound such as ethyl acetate, and a supporting electrolyte such as LiPF
Comprises _6, further, it is preferable to use a mixture of a lithium salt such as LiBF _4, LiCF ₃ SO _3. Further, as the separator, polypropylene or polyethylene alone or a combination thereof is preferable. The form of the battery may be any of a cylinder, a flat type, and a square type.
It is preferable that the battery is provided with means (for example, an internal pressure release type safety valve, a current cutoff type safety valve, and a separator that increases resistance at high temperatures) that can ensure safety against malfunction.

[0113]

EXAMPLES The present invention will be described in more detail with reference to specific examples below, but the present invention is not limited to the examples unless it exceeds the gist of the invention.

Example 1 SnB _0.2 P _0.5 K _0.1 Mg _0.1 Ge as a negative electrode material
86 parts by weight of _0.1 O _2.8 (average particle size of 7.5 μm), 3 parts by weight of acetylene black as a conductive agent and graphite 6
Parts by weight, further added 4 parts by weight of polyvinylidene fluoride as a binder and 1 part by weight of carboxymethylcellulose, and kneaded with water as a medium to obtain a negative electrode mixture slurry. The slurry was applied to both sides of a copper foil having a thickness of 10 μm using an extrusion coating machine and dried to obtain a negative electrode mixture sheet.

Next, water was added as a medium to 79 parts by weight of α-alumina, 18 parts by weight of graphite, and 3 parts by weight of carboxymethyl cellulose and kneaded to obtain an auxiliary layer slurry.
The slurry is applied on the negative electrode mixture sheet, dried and then compression-molded by a calender press to obtain a thickness of 98 μm and a width of 5 μm.
A strip-shaped negative electrode sheet precursor having a length of 5 mm and a length of 520 mm was prepared.

After the nickel lead plate was spot-welded to the negative electrode sheet precursor, the nickel lead plate was heated in air having a dew point of −40 ° C. or less.
It was dehydrated and dried at 30 ° C. for 30 minutes.

A 40 μm-thick lithium foil (purity 99.5%) cut into 20 mm × 55 mm on both sides of the sheet.
Were respectively pressed by 12 sheets. The pressure bonding was performed while the lithium foil was once transferred to a polyethylene roller having a diameter of 300 mm, and a pressure of 5 kg / cm ² was simultaneously applied to both sides of the sheet. At this time, the coverage of the negative electrode sheet with the lithium foil was 40%.

87 parts by weight of LiCoO ₂ as a positive electrode active material, 3 parts by weight of acetylene black and 6 parts by weight of graphite as a conductive agent were mixed, and N was used as a binder.
3 parts by weight of ipo1820B (manufactured by Nippon Zeon) and 1 part by weight of carboxymethylcellulose were added and kneaded with water as a medium to obtain a positive electrode mixture slurry.

The slurry was applied on both sides of an aluminum foil having a thickness of 20 μm using an extrusion coating machine, dried, and compression molded by a calender press to form a strip having a thickness of 260 μm, a width of 53 mm and a length of 445 mm. A positive electrode sheet (1) was prepared. After welding an aluminum lead plate to the end of the positive electrode sheet, the electrode sheet was dehydrated and dried at 230 ° C. for 30 minutes in dry air having a dew point of −40 ° C. or less.

As shown in FIG. 1, a heat-treated positive electrode sheet (1), a microporous polyethylene / polypropylene film separator (3), a negative electrode sheet (2) and a separator (3) were laminated in this order. It was wound in a spiral.

This wound body was housed in a nickel-plated iron bottomed cylindrical battery can (4) also serving as a negative electrode terminal.

Further, a mixture of ethylene carbonate and diethyl carbonate at a weight ratio of 2 to 8 was used as a solvent for the electrolytic solution. 1 mol / L LiPF in the above solvent
₆ was added as a supporting salt, and chain hydrocarbons were added in the types and amounts shown in [Table 1]. The electrolytic solution is used in a battery can (4)
While the temperature of the battery can was maintained at room temperature. A battery lid (5) having a positive electrode terminal was caulked via a gasket (6) to produce a cylindrical battery having a height of 65 mm and an outer diameter of 18 mm.
The positive electrode terminal (5) was connected to the positive electrode sheet (1), and the battery can (4) was connected to the negative electrode sheet by a lead terminal in advance.
(7) is a safety valve.

After caulking, the temperature was set at 0 ° C. for 2 hours at 25 ° C.
After aging for 15 hours at 25 ° C., the battery was charged at a constant voltage of 3.1 mA at 25 ° C. at 0.4 mA / cm ² , and then stored at 50 ° C. for 2 weeks. The open circuit voltage of the battery 3 days after aging was 2.58V.

[0124] On completion of storage, was charged at 1mA / cm ² to 4.1V, it was discharged at then 1mA / cm ² to 2.8V. After the discharge capacity was charged to 4.1 V at 1 mA / cm ² ,
It was determined by discharging to 2.8 V at 0.5 mA / cm ² . Further, a cycle test of 4.1 to 2.8 V was performed at 2.5 mA / cm ² , and the capacity retention at the 500th cycle was measured. The results are shown in Table 1.

[0125]

[Table 1]

The batteries 1 to 8 and 10 to 12 are obtained by adding a chain hydrocarbon to the electrolyte, and the battery 9 is obtained by adding no chain hydrocarbon to the electrolyte. The above batteries 1 to 6,
Reference numerals 8 and 10 to 12 each include any one of n-dodecane, n-decane, n-tetradecane, n-octane, and n-hexane in the electrolytic solution.
Is obtained by adding two kinds of n-dodecane and n-decane to the electrolyte at a weight ratio of 1: 1.

Batteries 1 to 8, 10 to which chain hydrocarbons were added
-12 have a higher capacity retention ratio than the battery 9 in which no chain hydrocarbon is added. When at least one type of chain hydrocarbon is contained in the electrolytic solution, the capacity retention of the battery is increased, and good results are obtained.

The battery 12 to which n-hexane is added has a lower capacity retention ratio than the batteries 1 to 8, 10 and 11 to which other chain hydrocarbons are added. The chain hydrocarbon to be added has 6 carbon atoms.
It is preferable that the hydrocarbon is a hydrocarbon having 7 or more carbon atoms (eg, n-dodecane, n-decane, n-tetradecane, n-octane) than the following hydrocarbons (eg, n-hexane). As in the battery 7, a mixture of two kinds of chain hydrocarbons may be added. Therefore, the chain hydrocarbon to be added is one or more arbitrary mixtures of carbon atoms having 7 to 25 carbon atoms. It is preferred that The above-mentioned chain hydrocarbon is, in particular, one selected from linear or branched heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane or It is preferable that the mixture is an arbitrary mixture of plural kinds. When a compound having a carbon number equal to or greater than eicosane is used, it is difficult to form a uniform electrolytic solution.

The batteries 1 to 4 and 9 to 11 differ in the amount of n-dodecane added to the electrolyte. FIG. 2 is a graph showing the relationship between the capacity retention ratio and the discharge capacity with respect to the content of n-dodecane. Batteries 9 and 10 having a content of n-dodecane of 0.008 [% by weight] or less have a lower capacity retention ratio than batteries 1 to 4 having a content of 0.05 [% by weight] or more, which is not preferable. Battery 11 having a content of n-dodecane of not less than 3.2% by weight has a smaller discharge capacity than batteries 1 to 4, 9 and 10 having a content of not more than 2.0% by weight. Absent. In order to increase the discharge capacity and improve the cycle characteristics, the content of the chain hydrocarbon in the electrolyte is preferably 0.01 to 3% by weight.

[0130]

According to the present invention, a non-aqueous secondary battery having a large discharge capacity and excellent cycle characteristics can be provided by incorporating a chain hydrocarbon into the electrolytic solution.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a general cylindrical battery.

FIG. 2 is a graph showing a relationship between a capacity retention ratio and a discharge capacity with respect to a content of a chain hydrocarbon in an electrolytic solution.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Separator 4 Battery can 5 Battery cover 6 Gasket 7 Safety valve

Claims (8)

[Claims] 1. A positive electrode sheet having a layer mainly composed of a lithium-containing metal oxide, a negative electrode sheet having a mixture layer mainly composed of a negative electrode material, a non-aqueous electrolyte containing a lithium salt and a non-aqueous secondary having a separator A non-aqueous secondary battery, comprising: a non-aqueous electrolytic solution containing at least one chain hydrocarbon. 2. The non-aqueous secondary battery according to claim 1, wherein the chain hydrocarbon is one or an arbitrary mixture of hydrocarbons having 7 to 25 carbon atoms. 3. The chain hydrocarbon is selected from linear or branched heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, and eicosane. The non-aqueous secondary battery according to claim 2, wherein the non-aqueous secondary battery is one or an arbitrary mixture of a plurality of types. 4. The content of the chain hydrocarbon in a non-aqueous electrolyte is 0.01 to 3% by weight.
4. The non-aqueous secondary battery according to any one of claims 1 to 3. 5. The negative electrode sheet comprises a layer mainly composed of a metal or metalloid element oxide or chalcogenide and at least one auxiliary layer containing water-insoluble conductive particles, on which a metallic material mainly composed of lithium is formed. The nonaqueous secondary battery according to claim 1, wherein the nonaqueous secondary battery is a stacked negative electrode sheet. 6. The non-aqueous secondary battery according to claim 1, wherein the negative electrode material is a tin-containing composite oxide or chalcogenide. 7. The nonaqueous secondary battery according to claim 6, wherein the tin-containing composite oxide or chalcogenide is a compound represented by the following general formula (1). SnM ¹ _a O _t S _u in the general formula (1), M ¹ is Al, B, P, Si, Ge, Periodic Table 1
Represents two or more elements selected from Group III elements, Group II elements, Group III elements, and halogen elements, a is a number of 0.2 or more, 2 or less, t is a number of 1 or more and 6 or less, and u is Represents a number of 0.5 or less. 8. The non-aqueous secondary battery according to claim 7, wherein the tin-containing composite oxide or chalcogenide is a compound represented by the following general formula (3). _{^{SnM 3 c M 4 d O t}} S u general formula (3) wherein, M ³ is Al, B, P, Si, Ge of at least 2
And M ⁴ represents at least one of Group 1 element, Group 2 element, Group 3 element and halogen element of the periodic table, and c is 0.
A number of 2 or more and 2 or less, d is a number of 0.01 or more and 1 or less, and represents a number of 0.2 <c + d <2.