JPH11204105A - Nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery with its improved energy quantity and cycle life by employing a compound oxide and a carbon material, mainly Sn (II) at a specific rate as a negative electrode material of a nonaqueous secondary battery consisting of a positive electrode active material, a negative electrode material, and a nonaqueous electrolyte. SOLUTION: A compound oxide and a carbon material are employed at a percent of 10/90 to 80/20 by weight. The compound oxide is a non-crystal oxide, including an oxygen atom and including at least three or more kinds of elements. The carbon material including a graphite structure, is obtained by burning a graphite retardant carbon at a temperature exceeding 2,400 deg.C using a sintered body of methophase pitch, phenol resin, and acrylonitrile resin, has an X-ray refraction peak equivalent to a plurality of 002 faces, and is suitably 0.1 to 15 microns in average particle size. Preferably, the positive electrode active material is a material, including Lix MO2 (M: Co, Ni, Fe, Mn, x: 0 to 1.2) or a spinel structure of Liy N2 O4 (N: Mn, y: 0 to 2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-aqueous secondary battery, and more particularly to a lithium secondary battery having a high capacity and a long cycle life.

[0002]

2. Description of the Related Art In a lithium secondary battery using a negative electrode material containing no lithium metal and a positive electrode active material containing lithium, first, lithium contained in the positive electrode active material is inserted into the negative electrode material to increase the activity of the negative electrode material. . This is the charging reaction, and the reverse reaction of inserting lithium ions from the negative electrode material into the positive electrode active material is the discharging reaction. When a composite oxide mainly composed of Sn (II) is used as the negative electrode material of this type of lithium battery, the capacity is large, but the discharge voltage is low.
On the other hand, carbon materials have a high discharge voltage but a small capacity. In order to solve the inconvenience of the carbon material, a material in which a graphite structure and a non-graphite structure are mixed has been proposed, but there is a limit in improving the capacity.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to increase the energy amount and the cycle life of a lithium secondary battery.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a nonaqueous secondary battery comprising a positive electrode active material, a negative electrode material and a nonaqueous electrolyte. And a carbon material in a weight ratio of 10/90 to 80/20.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. (1) In a non-aqueous secondary battery comprising a positive electrode active material, a negative electrode material, and a non-aqueous electrolyte, a composite oxide mainly composed of Sn (II) and a carbon material are used as the negative electrode material in a ratio of 10/90 to 80/20.
A non-aqueous secondary battery characterized by being used in a weight ratio of: (2) The non-aqueous oxide according to item 1, wherein the composite oxide centered on Sn (II) is an amorphous oxide containing at least three or more elements including oxygen atoms. Next battery. (3) The nonaqueous secondary battery according to item 1 or 2, wherein the carbon material has at least a graphite structure. (4) The carbon material is a granular material, a microsphere, a flat plate, a fiber, a whisker, or the like.
3. The non-aqueous secondary battery according to any one of 3. (5) The nonaqueous secondary battery according to any one of Items 1 to 4, wherein the carbon material is a fired body of mesophase pitch, phenol resin, and acrylonitrile resin. (6) The non-aqueous secondary battery according to any one of items 1 to 5, wherein the carbon material is a material obtained by firing non-graphitizable carbon at a temperature exceeding 2400 ° C. (7) The nonaqueous secondary battery according to any one of Items 1 to 6, wherein the carbon material is a material having an X-ray diffraction peak corresponding to a plurality of 002 planes. (8) The average particle size of the carbon material is 0.1 to 15 μm
Item 8. The non-aqueous secondary battery according to any one of Items 1 to 7, (9) The positive electrode active material is Li _x MO ₂ (M = Co, Ni,
Fe, a material containing Mnx = 0 to 1.2), or Li
_{y N 2 O 4 (N =} Mn y = 0~2) in the non-aqueous secondary battery according to any one of claim 1-8, characterized by using at least one material having a spinel structure represented by .

Hereinafter, the constitution and material of the present invention will be described in detail. First, a composite oxide centered on Sn (II) will be described. The composite oxide centered on divalent Sn (hereinafter referred to as Sn (II)) used in the present invention is mainly an amorphous oxide containing at least three or more elements including oxygen atoms. . The term “amorphous” as used herein means 20 ° in 2θ value by X-ray diffraction using CuKα ray.
It is a substance having a broad scattering band having a peak at 40 ° from, and may have a crystalline diffraction line. Preferably 2
Among the crystalline diffraction lines having a θ value of 40 ° or more and 70 ° or less, the strongest intensity is 500 of the diffraction line intensity at the top of a broad scattering band which is found at a 20 value of 20 ° or more and 40 ° or less.
It is preferably at most 100 times, more preferably 100 times or less.
It is at most 5 times, particularly preferably at most 5 times, and most preferably it has no crystalline diffraction line.

The above-mentioned composite oxide contains one or more atoms selected from Group 1, 2, 13, 14, and 15 atoms in addition to tin and oxygen atoms. These atoms are B, Al, G
a, In, Tl, Si, Ge, Sn, Pb, P, As,
Sb and Bi are preferred, and two or more are more preferred.

Among the above-mentioned negative electrode materials, a particularly preferred compound is a compound represented by the following general formula (1). Formula (1) Sn M ¹ _c M ² _{d Ot In the} formula, M ¹ is at least one of Al, B, P, Ge, and Si.
M ² represents at least one element of Group 1 and Group 2 elements of the periodic table, c is a number of 0.2 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
Represents a number of 1 or more and 6 or less.

For the amorphous composite oxide of the present invention, any of a firing method, a sol-gel method and a solution method such as a coprecipitation method can be employed. Hereinafter, the synthesis by the firing method will be described. 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 oxide.

The firing conditions are preferably a heating rate of 5 ° C. to 200 ° C. per minute, a firing temperature of 500 ° C. to 1500 ° C., and a firing time of Is more than 1 hour 10
It is preferably 0 hours or less. In addition, the rate of temperature decrease is preferably 2 ° C. or more and 107 ° C. or less per minute. In the present invention, the heating rate is defined as "the firing temperature (expressed in ° C).
Is the average rate of temperature rise from "50% of the firing temperature (expressed in ° C)" to "80% of the firing temperature (expressed in ° C)." It is the average rate of temperature drop until it reaches "50% (in ° C)". The temperature may be cooled in a firing furnace, or may be taken out of the firing furnace and put into, for example, water for cooling. Also ceramic processing (Gihodo Publishing 1)
987) Gun method described on page 217, Hammer-An
A super quenching method such as a vil method, a slap method, a gas atomizing method, a plasma spray method, a centrifugal quenching method, and a melt drag method can also be used. Also, the single roller method described in page 172 of the New Glass Handbook (Maruzen 1991),
Cooling may be performed using a twin roller method. 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, 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.

Examples of the negative electrode material of the present invention are shown below.
The invention is not limited to these. SnAl_0.4B_0.5P_0.5K_0.1O_3.65, SnAl_0.4
B_0.5P_0.5Na_0.2O_3.7, SnAl_0.4B_0.3P
_0.5Rb_0.2O_3.4, SnAl_0.4B_0.5P_0.5Cs
_0.1O_3.65, SnAl_0.4B_0.5P_0.5K_0.1Ge_0.05
O_3.85, SnAl_{0. Four}B_0.5P_0.5K_0.1Mg_0.1Ge
_0.02O_3.83, SnAl_0.4B_0.4P_0.4O_{3. Two}, SnA
l_0.3B_0.5P_0.2O_2.7, SnAl_0.3B_0.5P_0.2
O_2.7, SnAl_0.4B_0.5P_0.3Ba_0.08Mg_0.08O
_3.26, SnAl_0.4B_0.4P_0.4Ba _0.08O_3.28, Sn
Al_0.4B_0.5P_0.5O_3.6, SnAl_0.4B_0.5P
_0.5Mg _0.1O_3.7

SnAl_0.5B_0.4P_0.5Mg_0.1F_0.2
O_3.65, SnB_0.5P_0.5Li_0.1Mg_0.1F_0.2O
_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. Two}O_3.03, SnAl_0.4
B_0.5P_0.5Cs_0.1Mg_0.1F_0.2O_3.65, SnB_0.
FiveP_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_0.1
F_0.2O_Three, SnB_0.5P_0.5Mg_0.1F_0.06O _3.07,
SnB_0.5P_0.5Mg_0.1F_0.14O_3.03, SnPBa
_0.08O_3.58, SnPK_0.1O_3.55, SnPK_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, Sn
PK_0.05Mg_{0. 05}F_0.1O_3.53, SnPCs_0.1Mg
_0.1F_0.2O_3.55, SnPCs_0.05Mg_{0. 05}F_0.1O
_3.53,

Sn_1.1Al_0.4B_0.2P_0.6Ba_0.08F
_0.08O_3.54, Sn_1.1Al_0.4B_0.2P_0.6Li_0.1K
_0.1Ba_0.1F_0.1O_3.65, Sn_1.1Al_0.4B_0.4P
_0.4Ba_0.08O_3.34, Sn_1.1Al_0.4PCs_0.05O
_4.23, Sn_1.1Al_0.4PK_0.05O_4.23, Sn_1.2Al
_0.5B_0.3P_0.4Cs_0.2O_3.5, Sn_1.2Al_0.4B
_{0. Two}P_0.6Ba_0.08O_3.68, Sn_1.2Al_0.4B_0.2P
_0.6Ba_0.08F_0.08O_3.64, Sn_1.2Al_0.4B_0.2P
_0.6Mg_0.04Ba_0.04O_3.68, Sn_1.2Al_0.4B _0.3
P_0.5Ba_0.08O_3.58, Sn_1.3Al_0.3B_0.3P_0.4
Na_0.2O_3.3, Sn_1.3Al_0.2B_0.4P_0.4Ca
_0.2O_3.4, Sn_1.3Al_0.4B_0.4P_0.4Ba_0.2O
_3.6, Sn_1.4Al_0.4PK_0.2O_4.6, Sn_1.4Al
_0.2Ba_0.1PK_0.2O_4.45, Sn_1.4Al_0.2Ba
_0.2PK_0.2O_4.6, Sn_1.4Al_0.4Ba_0.2PK
_0.2Ba_0.1F_0.2O_4.9, Sn_1.4Al_0.4PK_0.3
O_4.65, Sn _1.5Al_0.2PK_0.2O_4.4, Sn_1.5A
l_0.4PK_0.1O_4.65, Sn_1.5Al _0.4PCs_0.05O
_4.63, Sn_1.5Al_0.4PCs_0.05Mg_0.1F_0.2O
_4.63

[0015] SnSi_0.5Al_0.1B_0.2P_0.1Ca
_0.4O_3.1, SnSi_0.4Al_0.2B _0.4O_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. Five}Al_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_0.4B_0.2Mg_0.1O_3.2, SnSi _0.6A
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 _0.6B_0.2P
_0.2O_Three, SnSi_0.8Al_0.2O_2.9, SnSi_0.8
Al_0.3B _0.2P_0.2O_3.85, SnSi_0.8B_0.2O
_2.9, SnSi_0.8Ba_0.2O_2.8, SnSi_0.8Mg
_0.2O_2.8, SnSi_0.8Ca_0.2O_2.8, SnSi
_0.8P_{0. Two}O_3.1

[0016] Sn_0.9Mn_0.3B_0.4P_0.4Ca_0.1R
b_0.1O_2.95, Sn_0.9Fe_0.3B _0.4P_0.4Ca_0.1
Rb_0.1O_2.95, Sn_0.8Pb₀._TwoCa_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.

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

Examples of the carbon material include a non-graphitizable carbon material and a graphite-based carbon material. Specifically, carbon materials having plane spacing, density and crystallite size described in JP-A-62-22066, JP-A-2-66856, JP-A-3-245473 and the like, -29084
4, a mixture of natural graphite and artificial graphite, disclosed in JP-A-63-24555, JP-A-63-13282 and JP-A-63-282.
No. 58763, a vapor-grown carbon material described in JP-A-6-212617, and a material obtained by heating and calcining the non-graphitizable carbon described in JP-A-5-182664 at a temperature exceeding 2400 ° C. A material having an X-ray diffraction peak corresponding to the 002 plane of JP-A-5-307957,
5-307958, 7-85862, 8-3
No. 15820, a mesophase carbon material synthesized by pitch firing, graphite having a coating layer described in JP-A-6-84516, and various types of granular materials.
Examples of the material include a carbon material in the form of a microsphere, a plate, a microfiber, and a whisker, a phenol resin, an acrylonitrile resin, a fired body of furfuryl alcohol resin, and a carbon material such as a polyacene material containing a hydrogen atom.

In particular, carbon materials described in JP-A-5-182664, various granular materials, microspheres, flat plates, fibers, whisker-shaped carbon materials, mesophase pitch, phenolic resin, acrylonitrile resin A fired body and a polyacene material containing a hydrogen atom are preferred.

As the negative electrode material, the mixed weight ratio of the composite oxide mainly composed of Sn (II) and the carbon material is 10%.
/ 90-80 / 20 (composite oxide / carbon material) is preferred. Particularly, 20/80 to 75/25 is preferable. It is more preferably in the range of 30/70 to 70/30, and particularly preferably in the range of 40/60 to 70/30. Further, a range of 50/50 to 70/30 is more preferable.

As the negative electrode material, an oxide containing lithium metal, a lithium alloy, or Si (II) can be used in addition to a composite oxide or carbon material centered on Sn (II). The amount to be added is preferably 10 mol% or less.

The average particle size of the negative electrode material is 0.01 μm.
m to 50 μm is preferred, and 0.1 to 20 μm is particularly preferred. Particularly, the range of the carbon material is preferably 0.1 to 20 μm. Further, the thickness is preferably 0.1 to 15 μm.

The first composite oxide mainly composed of Sn (II)
As a method of increasing the coulomb efficiency of the cycle, a method of contacting with lithium metal or a lithium alloy, a method of electrochemically inserting lithium, a method of reacting with lithium in an ammonia liquid, and a reduction method with active hydrogen such as NaBH ₄ are used. be able to.

The cathode material used in the present invention contains lithium.
It is a transition metal oxide. Preferably Ti, V, Cr,
Mn, Fe, Co, Ni, Mo, W
Contains mainly one transition metal element and lithium
Oxide having a molar ratio of lithium to the transition metal of 0.1.
3 to 2.2. More preferably, V, C
at least one selected from r, Mn, Fe, Co, and Ni
Oxidation mainly containing some transition metal elements and lithium
Wherein the molar ratio of lithium to the transition metal is from 0.3 to
2.2. Note that mainly transition metals
Al, Ga, I in a range of less than 30 mole percent
n, Ge, Sn, Pb, Sb, Bi, Si, P, B, etc.
May be contained. Among the above positive electrode active materials, general
Formula Li_xMO_Two(M = Co, Ni, Fe, Mnx = 0 to
1.2) or Li_yN_TwoO_Four(N = M n y = 0
At least the material having a spinel structure represented by 2)
It is preferable to use one kind. Specifically, Li_xC
oO_Two, Li_xNiO_Two, Li_xMnO_Two, Li_xCo
_aNi _1-aO_Two, Li_xCo_bV_1-bO_z, Li_xCo
_bFe_1-bO_Two, Li_xMn_TwoO_Four, Li_xMn_cCo
_2-cO_Four, Li_xMn_cNi_2-cO_Four, Li_xMn_cV
_2-cO_Four, Li_xMn_cFe_2-cO_Four(Where x = 0.
02-1.2, a = 0.1-0.9, b = 0.8-0.
98, c = 1.6-1.96, z = 2.01-2.3)
It is. Most preferred lithium-containing transition metal oxide
And Li_xCoO_Two, Li_xNiO_Two, Li_xMnO
_Two, Li_xCo_aNi_1-aO_Two, Li_xMn_TwoO_Four, L
i_xCo_bV_1-bO_z(X = 0.02 to 1.2, a =
0.1-0.9, b = 0.9-0.98, z = 2.01
To 2.3). Note that the value of x is
It is a value that increases or decreases with charge and discharge.

Hereinafter, a method for producing the nonaqueous electrolyte secondary battery of the present invention will be described. In the non-aqueous electrolyte secondary battery of the present invention, a battery in which positive and negative electrode sheets are wound together with a separator (wound group) is inserted into a battery can, the can is electrically connected to the electrode, and an electrolyte is injected. Create after sealing. Various members (sealing plate, lead plate, gasket, exterior material, etc.) are used as needed.

The positive (negative) electrode sheet can be prepared by applying a positive (negative) electrode mixture on a current collector, drying and compressing. To prepare the mixture, a positive electrode (or negative electrode) material and a conductive agent are mixed, a binder (a resin powder suspension or an emulsion) and a dispersion medium are added and kneaded and mixed. Homogenizer,
Dispersion can be carried out with a stirring mixer or disperser such as a dissolver, a planetary mixer, a paint shaker, or a sand mill. In addition, additives such as a dispersant, a filler, an ion conductive agent, and a pressure enhancer may be appropriately added.

Water or an organic solvent is used as a dispersion medium. When water is used as the dispersion medium, it is preferable to use a material in which a hydrophobic material such as a conductive agent is dispersed in advance.
When an organic solvent is used as the dispersion medium, the organic solvent may be N
In addition to -methyl 2-pyrrolidone, N, N-dimethylformamide, ketones such as acetone and methyl ethyl ketone, hydrocarbons such as toluene and xylene, esters such as ethyl acetate, ethers such as dimethyl carbonate, and electrolytes. Solvents can be used. Others are the same as the above-mentioned aqueous coating formulation.

The coating can be performed by various methods.
Examples of the method include 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. The blade method, the knife method and the extrusion method are preferred. Application is 0.1-100
It is preferably carried out at a rate of m / min. At this time, by selecting the above-mentioned coating method in accordance with the liquid physical properties and drying properties of the mixture paste, a good surface state of the coating layer can be obtained. The thickness, length and width of the coating layer are determined by the size of the battery. A typical thickness of the coating layer is 10 to 1000 μm in a compressed state after drying.

The electrode sheet after application is dried and dehydrated by the action of hot air, vacuum, infrared rays, far infrared rays, electron beams and low humidity air. These methods can be used alone or in combination. The drying temperature is preferably in the range of 80 to 350C, particularly preferably in the range of 100 to 250C. When an organic solvent is used as the dispersion medium, for example, N-methyl 2
Preferably, -pyrrolidone is dried at about 200 ° C or more, N, N-dimethylformamide is dried at about 150 ° C or more, and acetone is dried at about 60 ° C or more. Water content after drying is 2000
ppm or less is preferable, and 500 ppm or less is more preferable. The compression of the electrode sheet can be performed by a commonly used pressing method, but a die pressing method and a calendar pressing method are particularly preferable. The press pressure is not particularly limited, but is preferably 10 kg / cm ^{2 to 3} t / cm ² .
The press speed of the calender press method is 0.1 to 50 m /
Minutes are preferred. The pressing temperature is preferably from room temperature to 200 ° C.

The pressed electrode sheet is preferably subjected to a dehydration / desolvent treatment before assembling the battery. The dehydration / desolvent treatment is performed under a high-temperature air or a high vacuum. The temperature is 150 ° C
To 270 ° C.

The conductive agent used in the present invention may be any electronic conductive material which does not cause a chemical change in the constructed battery. Specific examples include flake graphite, flake graphite, natural graphite such as earthy graphite, petroleum coke, coal coke, celluloses, sugars, high-temperature fired bodies such as mesophase pitch, and graphite such as artificial graphite such as vapor-grown graphite. , Acetylene black, furnace black, ketjen black, channel black, lamp black,
Carbon blacks such as thermal black, asphalt pitch, coal tar, activated carbon, carbon materials such as meso fuse pitch, polyacene, conductive fibers such as metal fibers, metal powders such as copper, nickel, aluminum, silver, and zinc oxide And conductive whiskers such as potassium titanate, and conductive metal oxides such as titanium oxide.
Among these, graphite and carbon black are preferred. These may be used alone or as a mixture. The amount of the conductive agent added to the mixture layer is preferably 6 to 50% by weight, and more preferably 6 to 30% by weight, based on the negative electrode material or the positive electrode material. In the case of carbon black or graphite, the content is particularly preferably 6 to 20% by weight.

In the present invention, a binder is used to hold the electrode mixture. Examples of the binder include polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Preferred binders include starch, carboxymethyl cellulose, cellulose, diacetyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium alginate, polyacrylic acid,
Water-soluble polymers such as polyacrylic acid Na, polyvinylphenol, polyvinylmethylether, polyvinylalcohol, polyvinylpyrrolidone, polyacrylamide, polyhydroxy (meth) acrylate, styrene-maleic acid copolymer, polyvinyl chloride, polytetrafluoroethylene, Polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM),
(Meth) acrylate copolymer containing (meth) acrylate such as sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate, etc., (meth) acrylate-acrylonitrile copolymer, vinyl Polyvinyl ester copolymer containing vinyl ester such as acetate, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polybutadiene, neoprene rubber, fluorine rubber, polyethylene oxide, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane Resin, polyester resin,
An emulsion (latex) such as a phenol resin or an epoxy resin or a suspension can be used. In particular, polyacrylate latex, carboxymethylcellulose, polytetrafluoroethylene, and polyvinylidene fluoride are exemplified. These binders can be used alone or as a mixture. If the amount of the binder is small, the holding power and cohesive strength of the electrode mixture are weak. If it is too large, the electrode volume increases and the capacity per unit volume or unit weight of the electrode decreases. For these reasons, the amount of the binder added is preferably 1 to 30% by weight, particularly preferably 2 to 10% 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. As the ionic conductive agent, those known as inorganic and organic solid electrolytes can be used, and the details are described in the section of the electrolytic solution. The pressure booster is a compound for increasing the internal pressure described later, and a carbonate is a typical example.

In the current collector which can be used in the present invention, the positive electrode is aluminum, stainless steel, nickel, titanium or an alloy thereof, and the negative electrode is copper, stainless steel, nickel,
Titanium or their alloys. The form of the current collector is foil, expanded metal, punched metal, or wire mesh. In particular, an aluminum foil is preferable for the positive electrode, and a copper foil is preferable for the negative electrode.

The separator that can be used in the present invention may be any thin film having a high ion permeability, a predetermined mechanical strength, and an insulating thin film.
Fluorine polymer, cellulose polymer, polyimide, nylon, glass fiber, alumina fiber is used,
As the form, a nonwoven fabric, a woven fabric, or a microporous film is used. In particular, the material is preferably polypropylene, polyethylene, a mixture of polypropylene and polyethylene, a mixture of polypropylene and Teflon, a mixture of polyethylene and Teflon, and the form is preferably a microporous film. In particular, a microporous film having a pore size of 0.01 to 1 μm and a thickness of 5 to 50 μm is preferable.

The electrolyte generally comprises a supporting salt and a solvent.
You. Lithium salt is the main supporting salt in lithium secondary batteries.
Used as As a lithium salt that can be used in the present invention,
For example, LiClO_Four, LiBF_Four, LiP
F₆, LiCF_ThreeCO_Two, LiAsF₆, LiSb
F₆, LiB_TenCl _Ten, LiOSO_TwoC_nF_{1n + 1}Represented by
(N is a positive integer of 6 or less),
iN (SO_TwoC_nF_{2n + 1}) (SO_TwoC_mF_{2m + 1})
Imide salt (m and n are each a positive integer of 6 or less),
LiN (SO_TwoC_pF_{2p + 1}) (SO_TwoC_qF_{2q + 1}) (S
O_TwoC_rF_{2r + 1}) (P, q, r are
Each a positive integer of 6 or less), lower aliphatic carboxylic acid
Um, LiAlCl_Four, LiCl, LiBr, LiI,
Lithium chloroborane, lithium tetraphenylborate, etc.
One or two of these
These can be used in combination. Above all, LiB
F_FourAnd / or LiPF₆Dissolved is preferred
No. The concentration of the supporting salt is not particularly limited.
0.2 to 3 moles per title is preferred.

Solvents usable in the present invention include propylene
Lencarbonate, ethylene carbonate, butyleneca
-Carbonate, dimethyl carbonate, diethyl carbonate
, Methyl ethyl carbonate, γ-butyrolact
, Methyl formate, methyl acetate, 1,2-dimethoxyethane
, Tetrahydrofuran, 2-methyltetrahydrofuran
Dimethylsulfoxide, 1,3-dioxolane, e
Lumamide, dimethylformamide, dioxolan, di
Oxane, acetonitrile, nitromethane, ethyl mono
Grime, phosphoric acid triester, trimethoxymethane,
Dioxolane derivative, sulfolane, 3-methyl-2-o
Xazolidinone, propylene carbonate derivative, tet
Lahydrofuran derivative, ethyl ether, 1,3-pro
List aprotic organic solvents such as pansaltone
Can be used alone or in combination of two or more.
You. Of these, carbonate solvents are preferred.
And a mixture of cyclic carbonate and non-cyclic carbonate
It is particularly preferred to use them. As cyclic carbonates
Tylene carbonate and propylene carbonate are preferred
No. In addition, as the acyclic carbonate, diethyl carbonate
Carbonate, dimethyl carbonate, methyl ethyl carbonate
Nates are preferred. As an electrolyte that can be used in the present invention
Is ethylene carbonate, propylene carbonate,
1,2-dimethoxyethane, dimethyl carbonate
Or lithium electrolyte in an electrolyte
CF_ThreeSO_Three, LiClO_Four, LiBF_FourAnd / or
Is LiPF₆An electrolytic solution containing Especially propylene
At least carbonate or ethylene carbonate
Dimethyl carbonate or diethyl carbonate
LiCF in at least one mixed solvent of_ThreeSO
_Three, LiClO_FourOr LiBF_FourSelected from
LiPF with at least one salt₆Electrolyte containing
New The amount of these electrolytes added to the battery is not particularly limited.
Depending on the amount of cathode and anode materials and the size of the battery.
Can be used.

In addition to the electrolytic solution, the following solid electrolyte can be used in combination. 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
NI 2, Li 3 N-LiI} -LiOH, Li 4 Si
_{O 4, Li 4 SiO 4 -LiI} -LiOH, x Li 3 P
_{O 4 - (1-X)} Li 4 SiO 4, Li 2 SiS 3, it is effective and phosphorus sulfide compounds. In 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 aprotic electrolyte,
A polymer matrix material containing a phosphate ester polymer and an aprotic polar solvent is effective. further,
There is also 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.

Further, another compound may be added to the electrolyte for the purpose of improving the discharge and charge / discharge characteristics. For example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphoric triamide, nitrobenzene derivative,
Sulfur, quinone imine dye, N-substituted oxazolidinone and N, N'-substituted imidaridinone, ethylene glycol dialkyl ether, quaternary ammonium salt, polyethylene glycol, pyrrole, 2-methoxyethanol, A
1Cl ₃ , monomer of conductive polymer electrode active material, triethylene phosphoramide, trialkylphosphine, morpholine, aryl compound having a carbonyl group, 12-
Crown ethers such as crown-4, hexamethylphosphoric triamide and 4-alkylmorpholine,
Bicyclic tertiary amines, oils, quaternary phosphonium salts, tertiary sulfonium salts and the like can be mentioned.

Further, in order to make the electrolyte nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolyte. In addition, carbon dioxide gas can be included in the electrolytic solution in order to provide suitability for high-temperature storage.

The entire amount of the electrolyte may be injected once, but it is preferable to inject the electrolyte in two or more portions. In the case of injecting two or more times, even if each liquid has the same composition, different compositions (for example, after injecting a non-aqueous solvent or a solution in which a lithium salt is dissolved in a non-aqueous solvent, a non-aqueous solution having a higher viscosity than the solvent) A solution in which a lithium salt is dissolved in a solvent or a non-aqueous solvent is injected). Further, in order to shorten the injection time of the electrolyte solution, the pressure of the battery can may be reduced, or a centrifugal force or an ultrasonic wave may be applied to the battery can.

The battery can and the battery lid that can be used in the present invention are made of nickel-plated iron steel plate or stainless steel plate (SUS304, SUS304L, SUS304).
N, SUS316, SUS316L, SUS430, S
US444, etc.), nickel-plated stainless steel plate (same as above), aluminum or its alloy, nickel,
They are titanium and copper, and have a shape of a perfect circular cylinder, an elliptical cylinder, a square cylinder, or a rectangular cylinder. In particular, when the outer can also serves as the negative electrode terminal, a stainless steel plate or a nickel-plated iron steel plate is preferable, and when the outer can also serves as the positive electrode terminal, a stainless steel plate, aluminum or an alloy thereof is preferable. The shape of the battery can may be any of buttons, coins, sheets, cylinders, corners, and the like.

In order to prevent an internal pressure rise or a runaway reaction due to an abnormal reaction in the battery, it is preferable to incorporate a valve body and a current interrupting element. In particular, it is more preferable to incorporate a valve body that opens the internal pressure by breaking the valve due to an increase in the internal pressure and a current cutoff switch that operates in response to the displacement of the valve body in the sealing part. These pressure-sensitive valve bodies and current cutoff switches are disclosed in JP-A-2-112151,
JP-A-288063, JP-A-6-215760, and JP-A-9-92334 can be used. In addition, various conventionally known safety elements (for example, fuse, bimetal,
PTC element).

For the lead plate used in the present invention, a metal having electrical conductivity (for example, iron, nickel, titanium, chromium, molybdenum, copper, aluminum, etc.) or an alloy thereof can be used. Battery lid, battery can, electrode sheet,
As a method for welding the lead plate, a known method (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used. A conventionally known compound or mixture such as asphalt can be used as the sealing agent for sealing.

The gaskets usable in the present invention are olefin polymers, fluorine polymers, cellulose polymers, polyimides and polyamides, and olefin polymers are preferred from the viewpoint of organic solvent resistance and low moisture permeability. Propylene-based polymers are preferred. Further, it is preferably a block copolymer of propylene and ethylene.

The battery assembled as described above is
It is preferable to perform an aging treatment. The aging treatment includes a pretreatment, an activation treatment, and a post-treatment, whereby a battery having high charge / discharge capacity and excellent cycleability can be manufactured. The pre-treatment is a treatment for making the distribution of lithium in the electrode uniform, such as a control of dissolution of lithium, a temperature control for making the distribution of lithium uniform, a swing and / or rotation treatment, and an optional charge and discharge. Are performed. The activation process is a process for inserting lithium into the negative electrode of the battery body, and it is preferable to insert 50 to 120% of the amount of lithium inserted when the battery is actually used and charged.
The post-processing is a process for sufficiently activating the activation process,
There are a preservation process for making the battery reaction uniform and a charge / discharge process for determination, and these can be arbitrarily combined.

The battery of the present invention is covered with an exterior material if necessary. Examples of the exterior material include a heat-shrinkable tube, an adhesive tape, a metal film, paper, cloth, paint, a plastic case, and the like. Further, at least a part of the exterior may be provided with a portion that changes color by heat so that the heat history during use can be recognized.

The batteries of the present invention are assembled in series and / or in parallel as required, and stored in a battery pack. In addition to safety elements such as positive temperature coefficient resistors, thermal fuses, fuses and / or current interrupting elements, battery packs have safety circuits (voltage, temperature, current, etc. of each battery and / or assembled battery as a whole, Then, a circuit having a function of interrupting the current may be provided. In addition to the positive and negative terminals of the whole battery pack, the positive and negative terminals of each battery, the temperature detection terminals of the whole battery pack and each battery, the current detection terminals of the whole battery pack, etc. shall be provided as external terminals on the battery pack. Can also. The battery pack may have a built-in voltage conversion circuit (such as a DC-DC converter). In addition, connection of each battery
The lead plate may be fixed by welding, or may be fixed with a socket or the like so as to be easily detachable. Further, the battery pack may be provided with a display function of the remaining battery capacity, the presence or absence of charging, the number of times of use, and the like.

The battery of the present invention is used for various devices.
In particular, video movies, portable VCRs with built-in monitors, movie cameras with built-in monitors, compact cameras,
It is preferably used for a single-lens reflex camera, a film with a lens, a notebook computer, a notebook word processor, an electronic organizer, a mobile phone, a cordless phone, a razor, a power tool, a power mixer, a car, and the like.

[0050]

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

Example 1 Amorphous SnSi _0.6 B _0.4 P _0.2 Al as negative electrode material
_0.2 O _3.6 (compound 1) and amorphous SnSiO ₃ (Compound-2) and natural graphite as the carbon material (Compound -3), materials (compounds described in JP-A-5-182664 -
4) a microfibrous material (compound-5) obtained by firing a mesoface pitch described in JP-A-7-85862, and a vapor-grown carbon (compound-6) described in JP-A-63-58763 by weight. 190 g of powder mixed in the ratio shown in Table 1 and 10 g of polyvinylidene fluoride as a binder
Is dispersed in 500 ml of N-methyl 2-pyrrolidone,
A negative electrode paste was prepared. The average particle size of each of the negative electrode materials (compounds 1 to 6) used was in the range of 0.05 to 15 μm.

200 g of the positive electrode active material LiCoO ₂ and 10 g of acetylene black were mixed with a homogenizer, followed by mixing with 5 g of polyvinylidene fluoride as a binder.
Add 500 ml of methyl 2-pyrrolidone, knead and mix,
A positive electrode mixture paste was prepared.

The positive electrode mixture paste prepared above was coated on both sides of a 30 μm thick aluminum foil current collector with a blade coater, dried at 150 ° C., compression-molded with a roller press, cut into a predetermined size, and strip-shaped. A positive electrode sheet was prepared. Further, in a dry box (dew point; dry air having a temperature of -50 ° C. or lower), dehydration and drying were sufficiently performed with a far-infrared heater to prepare a positive electrode sheet. Similarly, paste the negative electrode mixture
m of the copper foil current collector, and a negative electrode sheet was prepared in the same manner as in the preparation of the positive electrode sheet. The length of the sheets of the negative electrode and the positive electrode was made constant, the coating amount was changed, and a cylindrical battery having a diameter of 18 mm and a maximum height of 65 mm was prepared. Each electrode sheet was prepared with a maximum coating amount at which the capacity did not decrease by 10% or more (a minute short circuit did not occur). At this time, the Sn (II) composite oxide is previously reduced with lithium metal as a negative electrode. The relative weight ratio between the positive electrode active material and the negative electrode material was determined from the charge amount in each first cycle.

Next, an electrolytic solution was prepared as follows. In an argon atmosphere, 65.3 g of diethyl carbonate was placed in a 200 cc narrow-neck polypropylene container, and the liquid temperature was 3
22.2 g of ethylene carbonate were dissolved in small portions, taking care not to exceed 0 ° C. Next, 0.4 g of LiB
F ₄ , 12.1 g of LiPF ₆ were dissolved in small portions in the above-mentioned polypropylene container in order, respectively, while taking care that the liquid temperature did not exceed 30 ° C. The obtained electrolyte was a colorless and transparent liquid having a specific gravity of 1.135. 18 pp water
m (measured with a Karl Fischer moisture meter, product name: MKC-210, manufactured by Kyoto Electronics Co., Ltd.), and the free acid content is 24 ppm (using bromthymol blue as an indicator, 0.1 N NaOH
Neutralization titration using an aqueous solution and measured).

The cylinder battery was prepared as follows. A method of manufacturing a battery will be described with reference to FIG. The positive electrode sheet, the microporous polyethylene film separator, the negative electrode sheet, and the separator prepared above were sequentially laminated, and the resultant was spirally wound. The wound electrode group (2) was housed in a nickel-plated iron bottomed cylindrical battery can (1) also serving as a negative electrode terminal, and an upper insulating plate (3) was further inserted. After injecting the electrolyte solution E-1 into the battery can, a gasket is formed by laminating a positive electrode terminal (6), an insulating ring, a PTC element (63), a current interrupter (62), and a pressure-sensitive valve (61). A cylindrical battery was prepared by caulking through (5).

The above cylindrical battery is charged at 1.2 A.
In this case, charging was performed at a constant current up to 4.2 V, and the charging current was controlled so as to keep the voltage constant at 4.2 V until 2.5 hours had elapsed from the start of charging. Discharge is 2.6V at 1.2A
Up to a constant current. The discharge capacity, average discharge voltage, energy amount (discharge capacity × average discharge voltage) of the first cycle at that time, and the capacity retention ratio at the 200th cycle of repeated charging and discharging are shown in Table 1 below.

Table 1 Battery Negative electrode Negative electrode Mixing weight ratio Discharge capacity Average discharge Energy cycle number Material Material (mAh) Voltage (V) Energy (1) (2) (1) / (2 (Wh) (%) D-1 13 30/70 1820 3.6 6.6 80 21 13 70/30 1850 3.5 6.5 79 79 14 30/70 1780 3.6 6.4 84 4 144 70/30 1830 3.5 6.4 81 5 15 30/70 1840 3.6 6.6 87 87 15 70/30 1890 3.5 6.6 83 71 16 30/70 1820 3.6 6.6 85 8 1 6 70/30 1860 3.5 6.5 82 9 23 30/70 1800 3.6 6.6 80 80 10 23 70/30 1840 3.5 6.5 79 11 24 4 30/70 1760 3 6.6 6.4 84 12 24 70/30 1810 3.5 6.4 81 13 2 30/70 1820 3.6 6.6 86 14 25 5 70/30 1870 3.5 6.6 83 15 26 30/70 1800 3.6 6.6 84 16 26 70/30 1840 3.5 6 .58 82

Comparative Example 1 A battery was prepared in the same manner as in Example 1 except that each of the negative electrode materials of Compounds 1 to 6 was used alone, and the same treatment as in Example 1 was carried out to obtain the results shown in Table 2 below. . Battery Negative Discharge Capacity Average Discharge Energy Cycle No. Material (mAh) Voltage (V)-Amount (Wh) Life (%) C-1 11 183.4 3.4 6.2 77 2 222 1800 3.4 6.1 75 3 3 1520 3.7 5.6 80 4 4 1400 3.7 5.2 87 5 5 1500 1500 3.7 5.6 88 6 6 1500 1500 3.7 5.6 85

A comparison between the battery of Example 1 using the compound of the present invention and the battery performance of Comparative Example 1 shows that the compound of the present invention has a discharge capacity, charge / discharge efficiency and average discharge voltage of 7 from the sum of the individual ratios.
Up to about 15%. The above results are shown in Example 2 below.
The same result was obtained in a battery using the negative electrode material having the above composition. The same effect was obtained even when the positive electrode active material LiCoO ₂ was changed to LiNiO ₂ or LiMn ₂ O ₄ .

Example 2 Amorphous SnSi _0.6 B _0.4 P _0.2 Al as negative electrode material
_0.2 O _3.6 (compound 1) and amorphous SnSiO ₃ (Compound-2) and natural graphite as the carbon material (Compound -3), materials (compounds described in JP-A-5-182664 -
4) a microfibrous material (compound-5) obtained by firing a mesoface pitch described in JP-A-7-85862, and a vapor-grown carbon (compound-6) described in JP-A-63-58763 by weight. 200 g of the powder mixed at a ratio of 30/70, 70/30, and 30 g of a conductive agent (artificial graphite) were mixed with a homogenizer, and 50 g of a 2% by weight aqueous solution of carboxymethylcellulose was used as a binder. 30 g of water mixed with 10 g of vinylidene and water
g was further added and kneaded and mixed to prepare a negative electrode mixture paste. The average particle size of each of the negative electrode materials (compounds 1 to 5) used was in the range of 0.05 to 15 μm.

200 g of the positive electrode active material LiCoO ₂ and 10 g of acetylene black were mixed with a homogenizer, and subsequently a water dispersion of a copolymer of 2-ethylhexyl acrylate, acrylic acid and acrylonitrile (solid content: 50% by weight) was used as a binder. ), 60 g of a 2% by weight carboxymethylcellulose aqueous solution was added, kneaded and mixed, and 50 g of water was further added, followed by stirring and mixing with a homogenizer to prepare a positive electrode mixture paste.

A cylindrical battery was prepared in the same manner as in Example 1 except that these electrode sheets were used, and the same results as in Example 1 were obtained.

[0063]

As described above, in a non-aqueous secondary battery comprising a positive electrode active material, a negative electrode material and a non-aqueous electrolyte, Sn (I
10/90 ~ composite oxide and carbon material centered on I)
When used in a weight ratio of 80/20, a non-aqueous secondary battery with improved energy amount and cycle life could be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylinder battery used in Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery can also serve as a negative electrode 2 Wound electrode group 3 Upper insulating plate 4 Positive electrode lead 5 Gasket 6 Battery lid also serving as a positive electrode terminal 61 Pressure sensitive valve element 62 Current cutoff element (switch) 63 PTC element

Claims (9)

[Claims] In a non-aqueous secondary battery comprising a positive electrode active material, a negative electrode material, and a non-aqueous electrolyte, Sn (I
10/90 ~ composite oxide and carbon material centered on I)
A non-aqueous secondary battery used in a weight ratio of 80/20. 2. The composite oxide according to claim 1, wherein the composite oxide centered on Sn (II) is an amorphous oxide containing at least three or more elements including oxygen atoms. Non-aqueous secondary battery. 3. The non-aqueous secondary battery according to claim 1, wherein the carbon material has at least a graphite structure. 4. The non-aqueous secondary battery according to claim 1, wherein the carbon material is a granular material, a microspherical material, a plate-like material, a fibrous material, or a whisker-like material. . 5. The non-aqueous secondary battery according to claim 1, wherein the carbon material is a fired body of mesophase pitch, phenol resin, and acrylonitrile resin. 6. The carbon material is made of non-graphitizable carbon at 2400 ° C.
The non-aqueous secondary battery according to any one of claims 1 to 5, wherein the non-aqueous secondary battery is a material obtained by firing at a temperature exceeding. 7. The non-aqueous secondary battery according to claim 1, wherein the carbon material is a material having an X-ray diffraction peak corresponding to a plurality of 002 planes. 8. The carbon material has an average particle size of 0.1 to
The non-aqueous secondary battery according to claim 1, wherein the thickness is 15 μm. 9. The cathode active material is Li _x MO ₂ (M = C
At least one of a material containing o, Ni, Fe, and Mnx = 0 to 1.2) or a material having a spinel structure represented by Li _y N ₂ O ₄ (N = M n y = 0 to 2) is used. The non-aqueous secondary battery according to claim 1, wherein: