JP2000133308A - Non-aqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-aqueous secondary battery free of oil leakage, capable of operating in ordinary temperature, having a high energy density, and suppressing resinoid generation of lithium metal during charging and discharging. SOLUTION: A non-aqueous secondary battery includes a sheet containing negative electrode material (negative electrode sheet) 13 capable of occluding or emitting lithium, a sheet containing positive electrode active material (positive electrode sheet) 11, and a non-aqueous electrolytic solution, wherein the non- aqueous electrolytic solution consists of a gel-form substance containing, (a) organic polymer, (b) non-protonic solvent, and (c) ammonium salt or alkali metal or alkali earth metal salt, and a metal foil chiefly containing lithium is affixed to the negative electrode sheet 13 in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel non-aqueous secondary battery having a high energy density without liquid leakage, and in particular, contains at least one gel polymer electrolyte as a component of the non-aqueous electrolyte. It relates to a non-aqueous secondary battery.

[0002]

2. Description of the Related Art In recent years, with the spread of portable personal computers and mobile phones, demands for higher energy density of secondary batteries have increased, and the development of lithium ion non-aqueous secondary batteries capable of high energy density has been widespread. Although it has been performed and has occupied the leading role of small secondary batteries, batteries that mainly use low molecular solvents such as ethylene carbonate, propylene carbonate, diethyl carbonate as the solvent for the electrolyte,
The problem of liquid leakage is inevitable.

As a technique for fundamentally solving the problem of liquid leakage, use of a gel polymer electrolyte has been proposed, and a positive electrode active material: LiCoO ₂ / acrylate gel, a lithium salt, a plasticizer composite / anode active material: carbon Of the porous material (US Pat. Nos. 5,609,974 and 5,603,985)
No. 2), positive electrode active material: lithium manganese oxide / vinylidene fluoride-hexafluoropropylene copolymer, lithium salt, plasticizer composite / negative electrode active material: constitution of carbonaceous material (JP-A-9-22,736) 9-35, 7
Non-aqueous secondary batteries such as No. 49 have been proposed, but lithium-ion non-aqueous secondary batteries in practical use (the solvent of the electrolyte is mainly a low molecular solvent such as ethylene carbonate, propylene carbonate, diethyl carbonate, etc.). The energy density is lower than that of a positive electrode material used as a cobalt or manganese-based lithium-containing metal oxide, and a negative electrode material is a calcined carbonaceous material capable of inserting and releasing lithium.

[0004] As a non-aqueous secondary battery that can fundamentally overcome the problem of liquid leakage using a gel polymer electrolyte and ensure a high energy density, a positive electrode active material: metal oxide material / gel polymer electrolyte / anode material: Structure of lithium metal and lithium alloy (JP-A-8-287,949, 8-30)
6,389, 9-97,618, 9-45,3
No. 40, No. 9-147, 863).
As a next-generation non-aqueous secondary battery with the potential to secure a higher energy density, a sulfur-containing compound is used instead of the conventional metal oxide for the cathode material, and the cathode material: sulfur-containing compound / gel polymer electrolyte / negative electrode active Material: Non-aqueous secondary battery configuration of lithium metal or lithium alloy (U.S. Pat. Nos. 5,460,905 and 5,462)
No. 566, No. 5,529,860, No. 5,60
Nos. 1,947 and 5,648,187).

However, the Li metal used as a negative electrode material in these materials has a specific capacity per unit volume or a specific capacity per unit weight that is significantly larger than that of a carbonaceous material currently in practical use, and ensures a high energy density. On the other hand, the material has a risk of internal short circuit due to dendritic growth of lithium metal during charging and discharging, and is a material that requires sufficient compensation for safety. The history so far is "Selecting a carbonaceous material negative electrode to compensate for the safety of Li metal negative electrode"
In a non-aqueous secondary battery having a Li metal negative electrode, it is necessary to suppress dendritic growth of lithium metal due to charge and discharge.

[0006] A non-aqueous secondary battery that suppresses dendritic growth of lithium metal during charging and discharging by combining a negative electrode material made of lithium metal or a lithium alloy with an intrinsic polymer electrolyte (a polymer electrolyte containing no low molecular solvent). Journal of Electrochemical Society 132, 6,133
3 (1985), Journal of Power Sources, 54, 163 (1995), 43, 89 (199)
3), European Patent Nos. 213,985 and 357,85
No. 9) has been proposed. However, since the non-aqueous secondary battery uses an intrinsic polymer electrolyte that does not contain a low-molecular solvent, good battery characteristics cannot be obtained due to poor ionic conductivity at low to normal temperatures, resulting in good battery characteristics. It is necessary to operate in a temperature range of about 60 ° C. or higher in order to secure the ion conductivity in order to obtain the ion conductivity.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel non-volatile semiconductor device which has no liquid leakage, can operate at room temperature, has a high energy density, and suppresses the dendritic growth of lithium metal during charging and discharging. That is, to obtain a water secondary battery.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-aqueous secondary battery having a negative electrode material-containing sheet (negative electrode sheet), a positive electrode active material-containing sheet (positive electrode sheet) and a non-aqueous electrolyte capable of inserting and extracting lithium. In batteries, non-aqueous electrolytes
(a) an organic polymer, (b) a gel electrolyte containing an aprotic solvent and (c) an ammonium salt or an alkali metal or alkaline earth metal salt, and a metal foil mainly composed of lithium is previously attached to a negative electrode sheet. This has been achieved by a non-aqueous secondary battery characterized by the above.

Hereinafter, the non-aqueous secondary battery of the present invention will be described in detail. A non-aqueous secondary battery having a high energy density, which is the object of the present invention, and in which the dendritic growth of lithium metal during charge and discharge is suppressed, is a current collector sheet coated with a negative electrode material capable of inserting and extracting lithium. By attaching a metal foil mainly composed of lithium to the (negative electrode sheet), the lithium is finally absorbed in the negative electrode material, which is substantially achieved.

The amount of lithium occlusion can be arbitrarily controlled by the amount of lithium to be superposed, and the preferable amount of occlusion is selected depending on the types of the negative electrode material and the positive electrode material.

In order to occlude lithium in the negative electrode material, a method of forming a local battery in a state where the negative electrode sheet and the metal foil mainly composed of lithium are electrically conducted is used. After stacking the metal foils together, assembling a non-aqueous secondary battery together with a separator and a positive electrode sheet, a method of injecting an electrolyte and aging for a certain period of time is common. Aging is preferably performed for 1 hour to 60 days at 0 to 80 ° C, and particularly preferably for 10 hours to 30 days at 20 to 80 ° C.

Although the battery of the present invention may be fully charged immediately after assembly, it is preferable to charge the battery after aging so that lithium diffuses more uniformly in the negative electrode material.

The portion where the metal foil mainly composed of lithium is pressure-bonded may be at any position as long as it is on the negative electrode sheet, but is preferably on the negative electrode mixture layer on which the negative electrode material is applied or on the negative electrode material layer. On the current collector metal, more preferably on the negative electrode mixture layer. The overlapping pattern is preferably such that a metal foil having a constant thickness is overlapped on the entire surface of the negative electrode sheet. However, since lithium preliminarily inserted into the negative electrode material gradually diffuses in the negative electrode material due to aging, in principle, the entire surface of the negative electrode sheet is in principle. Instead of stripes (vertical / horizontal),
Partial superposition such as a frame shape and a disc shape can also be used.
In the case of these partial superpositions, uniform insertion of lithium into the negative electrode material can be achieved by controlling the size of the metal foil. The interval of the overlapping of the stripes is preferably constant, but need not be constant. It is also preferable to use a lattice-like pattern combining the vertical direction and the horizontal direction for uniform insertion of lithium into the negative electrode material. A roll transfer method or a board transfer method is used as a method of laminating a metal foil mainly composed of lithium on a negative electrode material.

The roll transfer method is a method in which a metal foil cut to an arbitrary size is once adhered to a roll and then continuously adhered to a negative electrode sheet while performing a calendar press. It is preferable to use a twin roller for improving the sticking property. The roll may have any size, but preferably has a diameter of 0.5 to 100 cm, more preferably 1 to 50 cm. The roll material is preferably a material that does not easily react with lithium, and is preferably a polymer such as polyolefin (polyethylene, polypropylene, etc.), polyimide, polycarbonate, or the like, or a metal, such as stainless steel or molybdenum. The board transfer method is a method in which a metal foil cut to an arbitrary size is once stuck on a flat surface, and then stuck on a negative electrode sheet while pressing. The material of the board is preferably the same as the material of the roll.

Preferred examples of the metal foil mainly composed of lithium include, for example, Li-Al, Li-Al-Mn, and L-Al.
i-Al-Mg, Li-Al-Sn, Li-Al-I
n, Li-Al-Cd and the like, and preferable metals that can be alloyed with lithium include, for example, Al, Al-M
n, Al-Mg, Al-Sn, Al-In and the like.
The lithium content of the metal foil is preferably at least 90%, most preferably at least 98%. The thickness of the lithium foil is important from the viewpoint of uniformity, and is 1 to 100 μm.
Is preferably 5 to 50 μm or less, more preferably about 10 to 40 μm. The coverage of the metal foil mainly composed of lithium on the negative electrode sheet is preferably 20% or more by area, more preferably 30% or more.

The lithium-based metal foil may be directly pressed on the mixture layer containing the negative electrode material. However, the mixture layer further contains at least another layer of water-insoluble particles, and the negative electrode material is substantially removed. It is more preferable to provide an auxiliary layer that does not contain and press-bond it thereon for uniform insertion of lithium.

Providing a layer different from the active material, for example, a protective layer, on the surface of the negative electrode is performed by using a negative electrode: lithium metal or alloy / protective layer: carbon containing carbon material or metal powder (Japanese Patent Laid-Open No. 3-297,072). No. 4,229,563, U.S. Pat. No. 5,387,479), negative electrode: transition metal oxide / protective layer: ion-conductive solid oxide set by sputtering (JP-A-61-263). No. 069), but the configuration is different from the present invention.

In the present invention, 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 may be insulating layers having substantially no electron conductivity or conductive layers. Further, a form in which a conductive layer and an insulating layer are stacked may be employed. The thickness of the auxiliary layer is preferably from 0.2 μm to 40 μm,
More preferably, it is in the range of μm to 20 μm.

The auxiliary layer is preferably composed of water-insoluble insulating particles, water-insoluble conductive particles and an organic polymer material.

The water-insoluble insulating particles of the present invention include:
Examples thereof include inorganic particles and organic particles.

Examples of the inorganic particles include metal and nonmetal chalcogenites (for example, sulfides and oxides), carbides, silicides, and nitrides. For chalcogenite, an oxide is preferable, and an oxide that is hardly reduced is preferable. These oxides include, for example, 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, S
b ₂ O ₅ , SiO ₂ , SrO, ZrO ₄ .
Among them, Al ₂ O ₃ , BaO, BeO, CaO,
K ₂ O, Na ₂ O, MgO, SiO ₂ , SrO, ZrO
₄ is 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 .2Si
O ₂ ), steatite (MgO.SiO ₂ ), forsterite (2MgO.SiO ₂ ), cordierite (2
MgO.2Al ₂ O ₃ .5SiO ₂ ). Among carbides, silicides and nitrides, SiC,
Aluminum nitride (AlN), BN, and BP are preferable because they have high insulating properties and are chemically stable, and in particular, BeO, Be, and B
SiC using N as a sintering aid is particularly preferred. These insulating inorganic compound particles are used in the form of particles having a size of 0.1 μm or more and 20 μm or less, particularly preferably 0.2 μm or more and 15 μm or less, by a method such as control of production conditions or pulverization.

The organic particles are preferably a crosslinked latex or a powder of a 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 water-insoluble conductive particles include carbon particles such as carbon black and graphite, carbon fibers, metals, metal oxides and metal fibers, and carbon particles having low reactivity with lithium. Metal particles are preferred.

As the carbon particles, known carbon materials which are conventionally used as a conductive material when the electrode active material is not conductive can be used. 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 the organic polymer material, 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 metal powder is preferably copper, nickel, iron, molybdenum, titanium, tungsten, or tantalum, which has low reactivity with lithium and hardly forms an alloy. 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.

The ratio of the conductive particles contained in the auxiliary layer is as follows:
5 wt% or more and 96 wt% or less, preferably 5 wt% or more and 95 wt% or less, more preferably 10 wt% or more,
Particularly preferred is 93% by weight or less.

Examples of the organic polymer material used in the auxiliary layer of the present invention together with particles having substantially no conductivity and / or with conductive particles include an organic polymer and an electrode mixture constituting a gel electrolyte described later. Binders used when forming them can be given. The ratio of the particles to the organic polymer is preferably from 40% by weight to 96% by weight, more preferably from 50% by weight to 94% by weight, based on the total weight of both.

The auxiliary layer is applied by applying a mixture mainly composed of a metal or a semi-metal oxide, which is a material capable of reversibly storing and releasing lithium, on the current collector. A sequential coating method in which the layers are sequentially coated or a simultaneous coating method in which the mixture layer and the auxiliary layer are simultaneously coated may be used.

The negative electrode material used in the present invention may be any compound capable of inserting and extracting lithium. In particular, silicon
Preferred are non-oxide materials such as germanium, tin, and lead, which can form an intermetallic compound in which lithium and lithium are ionized, inorganic oxides, inorganic chalcogenides, and carbonaceous compounds.

Materials containing silicon, germanium, tin, and lead atoms are preferable because of their high capacity. The theoretical capacity of the carbon material as a negative electrode material for a lithium ion secondary battery is 372 m.
Ah / g (C ₆ Li), the theoretical capacity of silicon forming an intermetallic compound with lithium exceeds 4000 mAh / g, which is much larger than that of carbon, and single crystal silicon (Japanese Patent Laid-Open No. 5-74, No. 463), amorphous silicon (JP-A-7-29,602), and an alloy containing silicon (JP-A-63-66369: 19% by weight of silicon;
174,275: 0.05 to 1.0% by weight of silicon;
No. 63-285,865: 1 to 5% by weight of silicon) is disclosed. Germanium, tin, lead and the like also form an intermetallic compound in which lithium is ionized with lithium.

The 13th (IIIB) group of the periodic table to 15 (V
Group B elements, Al, Ga, Si, Sn, Ge, Pb,
It is known that oxides and chalcogenides composed of Sb and Bi alone or in combination of two or more thereof also have high capacities and are very safe as a negative electrode material with little generation of dendrites in a practical area ( JP 5
-174,818, 6-60,867, 6-2
Nos. 75,267, 6-325,765, 6-33
8,324, EP-615,295).

For example, Ga ₂ O ₃ , SiO, GeO, S
nO, SnO ₂ , PbO, 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 , SnSiO ₃ , Ge
S, SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S
₃ , Sb ₂ S ₅ , SnSiS _{3 and the} like are preferable. Also,
These are complex oxides with lithium oxide, for example, Li
₂ SnO ₂ may be used.

The inorganic oxide and the chalcogenide are preferably amorphous. The term “amorphous” as used herein refers to a substance having a broad scattering band having an apex in a region of 20 ° to 40 ° in 2θ value by X-ray diffraction using CuKα ray, and having a crystalline diffraction line. You may. Preferably 40 ° or more in 2θ value 7
The strongest intensity of the crystalline diffraction lines observed at 0 ° or less is 100 times or less the diffraction line intensity at the apex of a broad scattering band seen at 20 ° or more and 40 ° or less in 2θ value, and more preferably. It is 5 times or less, and particularly preferably does not have a crystalline diffraction line.

Furthermore Sn, Si, amorphous oxide is more preferable that the center of Ge, among them the general formula _{^{(1) SnM 1 d M 2}} e O f ( wherein, M ¹ is, Al, B, P, At least one or more elements selected from Ge, and M ² is at least one or more elements selected from Group 1 (IA), Group 2 (IIA), Group 3 (IIIA), and halogen elements of the periodic table. Represents an element, d is a number from 0.2 to 2 and e is 0.01 to 1
(0.2 <d + e <2, f represents a number of 1 or more and 6 or less).

Examples of the amorphous oxide mainly composed of Sn include the following compounds, but the present invention is not limited to these compounds. C- 1 SnSiO ₃ C- 2 Sn _0.8 Al _0.2 B _0.3 P _0.2 Si _0.5 O _3.6 C- 3 SnAl _0.4 B _0.5 Cs _0.1 P _0.5 O _3.65 C- 4 SnAl _0.4 B _0.5 Mg _0.1 P _0.5 O _3.7 C- 5 SnAl _0.4 B _0.4 Ba _0.08 P _0.4 O _3.28 C-6 SnAl _0.4 B _0.5 Ba _0.08 Mg _0.08 P _0.3 O
_3.26 C-7 SnAl _0.1 B _0.2 Ca _0.1 P _0.1 Si _0.5 O
_3.1 C-8 SnAl _0.2 B _0.4 Si _0.4 O _2.7 C-9 SnAl _0.2 B _0.1 Mg _0.1 P _0.1 Si _0.5 O
_2.6 C-10 SnAl _0.3 B _0.4 P _0.2 Si _0.5 O _3.55 C-11 SnAl _0.3 B _0.4 P _0.5 Si _0.5 O _4.3 C-12 SnAl _0.1 B _0.1 P _0.3 Si _0.6 O _3.25 C-13 SnAl _0.1 B _0.1 Ba _0.2 P _0.1 Si _0.6 O
_2.95 C-14 SnAl _0.1 B _0.1 Ca _0.2 P _0.1 Si _0.6 O
_2.95 C-15 SnAl _0.4 B _0.2 Mg _0.1 Si _0.6 O _3.2 C-16 SnAl _0.1 B _0.3 P _0.1 Si _0.5 O _3.05 C-17 SnB _0.1 K _0.5 P _0.1 SiO _3.65 C-18 SnB _0.5 F _0.1 Mg _0.1 P _0.5 O _3.05

For the amorphous oxide and chalcogenite of the present invention, any of a firing method and a solution method can be adopted, but the firing method is more preferable. In the firing method, it is preferable to mix well the oxides, chalcogenites, or compounds of the corresponding elements, and then fire to obtain an amorphous oxide or chalcogenite.

The firing temperature is 500 ° C. or more and 1500 ° C.
The firing time is preferably 1 hour or more and 100 hours or less.

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 19
87) Gun method described on page 217, Hammer-Anv
An ultra-quenching method such as an il 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. Alternatively, cooling may be performed using a single roller method or a twin roller method described in page 172 of the New Glass Handbook (Maruzen 1991). 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 oxide and chalcogenide of the present invention is preferably 0.1 to 60 μm. In order to obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibration ball mill, a satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used. Water when crushing,
Alternatively, wet pulverization in the presence of an organic solvent such as methanol can also be performed if 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.

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

Preferred as the carbon material are a non-graphitizable carbon material and a graphite-based carbon material.
2,066, JP-A-2-66,856, and 3-24
5,473), a mixture of natural graphite and artificial graphite (JP-A-5-290,844), a vapor-grown carbon material (JP-A-6
Nos. 3-24,555, 63-13,282, 63
-58,763, JP-A-6-212,617), mesophase carbon materials synthesized by pitch firing (JP-A-5-307,957, JP-A-5-307,958, JP-A-7-85,862) No. 8-315,820), graphite having a coating layer (Japanese Patent Application Laid-Open No. 6-84,516), and further, a carbon material such as a fired body of a phenol resin or a furfuryl alcohol resin, and a polyacene material having hydrogen atoms remaining. Can be mentioned. As the form of the carbon material, a granular material, a microsphere, a flat plate, a fiber, or a whisker is preferably used.

A compound containing atoms of silicon, germanium, tin, and lead, an amorphous composite oxide mainly composed of Sn, Si, and Ge, and a carbon material can be used in combination of two or more.

The positive electrode active material used in the present invention is a material capable of reversibly inserting and releasing lithium ions, such as a lithium-containing transition metal oxide, a lithium-free organic material, a metal oxide material, and a metal sulfide. Materials and the like can be mentioned.

Preferred positive electrode active materials as the lithium-containing transition metal oxide include lithium-containing Ti, V, Cr, Mn,
Oxides containing Fe, Co, Ni, Cu, Mo and W (Japanese Patent Application Laid-Open Nos. 55-138, 131 and 58-220, 362).
No. 62-256, 371, No. 62-90, 863
Nos. 62-264,560 and 63-114,06
No. 5, 63-121, 258, 63-211,5
No. 65 and No. 62-176,054). Alkali metals other than lithium (first in the periodic table)
(IA) element, Group (IIA) element), and / or Al, 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.

The most preferred lithium-containing transition metal oxide cathode active material used in the present invention is Li _g C
oO ₂ , Li _g NiO ₂ , Li _g MnO ₂ , Li _g Co
_j Ni _1-j O ₂ , Li _h Mn ₂ O ₄ (where g = 0.0
2 to 1.2, j = 0.1 to 0.9). Here, the above-mentioned g value is a value before the start of charging and discharging, and increases or decreases due to charging and discharging.

A cathode active material which is preferable as a lithium-free organic material is an organic sulfur material which is electrochemically active and contains an SS bond during charging and forms an S-Li bond in a discharged state (US Patent No. 4,833,048,
Nos. 5,460,905 and 5,462,566
No. 5,516,598 and 5,529,86
No. 0, JP-A-4-264363, JP-A-4-272,6
No. 59, 5-135,767, 5-135, 79
No. 8, No. 5-135,799, No. 6-231,725
No., 6-283, 175, 7-282, 801
Nos. 7-312,220 and 8-138,742
No., 8-222,207, 9-82,327,
Nos. 9-139,213, 9-153,362, 9-259,864, and 9-293,513), oxidation-reduction polymers (US Pat. No. 4,833,048,
JP-A-6-56,989), metal complex compounds (JP-A-58-223,265, JP-A-59-46760, JP-A-59-66,059, JP-A-59-163,763),
Ion exchange resin (JP-A-1-279,567;
279,568) and the like.

A positive electrode active material which is preferable as a lithium-free metal oxide material or a metal sulfide material is a Mn-containing oxide (Japanese Patent Application Laid-Open Nos. 54-56,137 and 54-118,53).
No. 8), a Co-containing oxide (JP-A-54-163,324).
, V-containing oxides (JP-A-48-54,443 and JP-A-57-212,778).
No. 59-134,561, No. 62-290,075
No.), Cu-containing oxides (JP-A-58-1,971, 59-151,761, 60-10,558, 62-47,973, 62-200,661) ,
Fe-containing sulfides (JP-A-57-1748663, 5
Nos. 7-194,459, 58-150,269, 59-91,670, and 61-66,363).

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

For obtaining 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 being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

The gel polymer electrolyte of the present invention comprises a polymer network, at least one aprotic organic solvent, and a lithium salt.

The organic polymer contained in the electrolyte includes:
The following (A) to (G) are preferred. (A) A crosslinked organic polymer having a side chain containing a polar group containing no active hydrogen. Specific examples include a polyalkylene oxide having a vinyl group as a cross-linking group, and a copolymer of a vinyl monomer having a polyalkylene oxide group in a side chain and a monomer having two or more vinyl groups. Examples include the following:

[0053]

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(B) a first monomer containing a vinyl group and an oligo (oxyalkylene) group, a second monomer containing a vinyl group and a polar group selected from a carbonate group and a cyano group, and a plurality of vinyl groups Preferably, the vinyl group of the first and second monomers is derived from at least one functional group selected from an acryloyl group and a methacryloyl group. More preferably, a polymer containing the structure represented by the general formula (2). General formula (2)

[0055]

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In the formula, R1 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group having 1 to 10 carbon atoms, and R2 represents a group having a structure represented by the general formula (3). . General formula (3)

[0057]

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In the formula, R4 is an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group having 1 to 10 carbon atoms,
An aryl group or an aralkyl group having 1 to 10 carbon atoms,
Represents a fluorinated aryl group having 1 to 10 carbon atoms. R
5 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R6 has the same meaning as R5.

R3 represents -CN or a group containing a structure represented by the general formula (4). General formula (4)

[0060]

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X, y, and z are the same or different;
It is an integer of 0 or less, a, b, and c are the mole fraction (percentage) of the first, second, and third monomers, respectively, and n represents the degree of polymerization.

Hereinafter, a copolymer mainly composed of the polyacrylic ester derivative and the polymethacrylic ester derivative represented by the general formula (1) contained in the polymer network preferred for the constitution of the gel polymer electrolyte of the present invention will be described. Specific examples of the first, second, and third monomer structures are shown below, but are not limited thereto. First monomer

[0063]

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Second monomer

[0065]

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Third monomer

[0067]

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Table 1 shows specific examples of the copolymer mainly composed of the structural unit represented by the general formula (2) of the present invention formed by polymerization by heating and / or irradiation of radiation.
Of course, it is not limited to these.

Table 1 Compound No. First monomer Second monomer Third monomer (A) / (B) / (C) (A) (B) (C) Molar ratio P-21 1-1 2-4 3- 5 4/3/1 P-22 1-2 2-2 3-3 4/2/1 P-23 1-3 2-6 3-4 2/5/1

(C) An acrylonitrile or methacrylonitrile homopolymer or a copolymer with another polymerizable monomer. Specific examples include the following polymers.

[0071]

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(D) Either a homopolymer or a copolymer of ethylene oxide or propylene oxide, or -CH ₂ O (CH ₂ CH ₂ O) ₂ CH ₃ as a side chain in the homopolymer or the copolymer. Having polymers. Specific examples include the following polymers.

[0073]

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(E) A homopolymer of vinylidene fluoride or a copolymer with another polymerizable monomer, and a homopolymer or a copolymer with another polymerizable monomer. Specific examples include the following polymers.

[0075]

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(F) Polysiloxane or a derivative thereof.
Specific examples include the following polymers.

[0077]

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(G) Polyphosphazene or a derivative thereof. Specific examples include the following polymers.

[0079]

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The aprotic organic solvent usable in the present invention includes, for example, ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone,
2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, methyl acetate, methyl propionate, acetonitrile, 1,3-dioxolane, dimethyl sulfoxide, phosphoric acid triester (JP-A-60-2)
No. 3,973), dioxolane derivatives (JP-A-62-1)
Nos. 5,771 and 62-22,372, 62-10
No. 8,474), propylene carbonate derivatives (Japanese Patent Application Laid-Open Nos. 62-290,069 and 62-290,071).
No.), tetrahydrofuran derivatives (Japanese Unexamined Patent Publication No. 63-32,
872) and the like.

The lithium salts usable in the present invention include, for example, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiCF
₃ SO ₃ , LiC ₄ F ₉ SO ₃ , Li (CF ₃ SO ₂ ) ₂
N, Li (C ₂ F ₅ SO ₂ ) ₂ N, LiCF ₃ CO ₂ , L
One or more kinds of salts such as iAsF ₆ and LiSbF ₆ can be mentioned.

The gel polymer electrolyte of the present invention comprises: 1. When used in combination of a polymer network, a lithium salt, and an aprotic organic solvent In some cases, a combination of a polymer network, a lithium salt, an aprotic organic solvent, and a porous membrane is used.

As the porous membrane used in the present invention, a material having high ion permeability, predetermined mechanical strength, insulating microporous material or having a gap is used.

The thickness of the porous film of the present invention is 5 μm or more and 1
It is a microporous film, woven fabric, nonwoven fabric, or the like having a size of 00 μm or less, more preferably 10 μm or more and 80 μm or less.

The porous membrane of the present invention includes polyethylene, polypropylene, polybutene, polyfluorinated ethylene, polyvinyl chloride, and polyacrylonitrile, and preferably contains at least 20% by weight of an ethylene component, and more preferably 30% or more. Including. Further, those made by mixing and dissolving polyethylene, polypropylene 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 copolymer, ethylene-methylbutene copolymer, ethylene-methylpentene copolymer. , Polypropylene and polytetrafluoroethylene fibers are preferred.

The porous membrane of the present invention may contain inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as silicon dioxide, zeolite, alumina and talc.

The electrode mixture of the present invention includes, in addition to an active material and a gel electrolyte (an organic polymer containing a structural unit of the general formula (1), an aprotic organic solvent, and a lithium salt), a conductive agent and a binder. An adhesive and a filler are added.

The conductive agent may be any electronic conductive material that does not cause a chemical change in the constructed battery.
Usually, natural graphite (scale graphite, flaky graphite, earthy graphite, etc.), artificial graphite, carbon black, acetylene black, ketjen black, carbon fibers and metal powders (copper, nickel, aluminum, silver (Japanese Unexamined Patent Publication No. 148,554
), A metal fiber or a polyphenylene derivative (JP-A-59-20,971).
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 2 to 30% by weight.
% By weight is preferred. For carbon and graphite, 2 to 15% by weight is particularly preferred.

In the present invention, an organic polymer containing a structural unit of the general formula (1), an aprotic organic solvent, and a lithium salt are used as a binder for holding the electrode mixture. Fluoro rubber, ethylene-propylene-diene terpolymer (EPDM), polyvinylpyrrolidone, ethylene-propylene-diene terpolymer (EPDM), styrene-butadiene rubber, polybutadiene, and other polymers having an affinity of 1 or a mixture thereof. Can be used. The amount of the binder added is 1
It is preferably from 30 to 30% by weight, particularly preferably from 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.

The gel polymer electrolyte of the present invention can be used in combination with a separator to ensure safety. 80 separators are used to ensure safety
It is necessary to have a function of closing the above gap at a temperature of not less than 0 ° C. to increase the resistance and cut off the current, and the closing temperature is preferably 90 ° C. or more and 180 ° C. or less.

The shape of the holes in the separator is usually circular or elliptical, and the size is 0.05 μm to 30 μm.
1 μm to 20 μm is preferred. Further, as in the case of making by a stretching method or a phase separation method, the holes may be rod-shaped or amorphous. The ratio occupied by these gaps, that is, the porosity is 20
% To 90%, preferably 35% to 80%.

These separators are made of polyethylene,
It may be a single material such as polypropylene or a composite material of two or more. In particular, those obtained by laminating two or more kinds of microporous films having different pore diameters, porosity, and pore closing temperatures are particularly preferable.

As the positive / negative current collector, an electron conductor which does not cause a chemical change in the constructed battery is used.

As the current collector of the positive electrode, in addition to aluminum, stainless steel, nickel, and titanium, those obtained by treating the surface of aluminum or stainless steel with carbon, nickel, titanium, or silver are preferable, and aluminum is particularly preferable. , Aluminum alloy.

The current collector of the negative electrode is preferably copper, stainless steel, nickel, or titanium, and particularly preferably copper or a copper alloy.

The current collector is usually in the form of a film sheet, but may be a net, a punched one, a lath, a porous body, a foam, a fiber group molded body, or the like. . The thickness is not particularly limited, but is 1 to 500
μm. It is also desirable that the surface of the current collector be made uneven by surface treatment.

Examples of the coating 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. 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 coating may be continuous, intermittent, or striped. The thickness, length and width of the coating layer are determined by the shape and size of the battery, but the thickness of the coating layer on one side is
In a compressed state after drying, the thickness is preferably 1 to 2000 μm.

The method for drying and dehydrating the electrode sheet coating material is as follows.
Hot air, vacuum, infrared rays, far-infrared rays, electron beams and low-humidity air can be used alone or in combination. The drying temperature is preferably in the range of 80 to 350 ° C, particularly 100 to 350 ° C.
A range of 250 ° C. is preferred. The water content is 20
It is preferably at most 00 ppm, and more preferably at most 500 ppm for each of the positive electrode mixture, the negative electrode mixture and the electrolyte. As a method for pressing the sheet, a method generally used can be used, but a calendar press method is 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 0.1 to 50 m / min, and the press temperature is room temperature to
200 ° C. is preferred. The ratio of the negative electrode sheet width 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
It depends on the compound type and the mixture formulation.

After the positive and negative electrode sheets are overlapped with a separator interposed therebetween, a sheet-like battery is formed. However, the battery may be wound or otherwise processed into a cylinder battery, a prismatic battery, or the like. These batteries may be provided with various safety elements known in addition to safety valves. For example,
Fuse, bimetal, PTC as overcurrent prevention element
The safety can be further improved by using an element or the like.

As a measure against overcharging, a method of interrupting the current by increasing the internal pressure of the battery can be provided. At this time, Li ₂ CO ₃ , LiHCO ₃ , Na ₂ CO ₃ ,
The NaHCO _3, CaCO _3, MgCO ₃ increase the internal pressure, such as carbonates, such compounds can be included in a fixed combination or an electrolyte.

For the can or the lead plate, a metal or 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.

The use of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when the non-aqueous secondary battery is mounted on an electronic device, a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone handset ,
Pager, handy terminal, mobile fax,
Portable copy, portable printer, headphone stereo,
Video movies, LCD TVs, handy cleaners,
Portable CD, mini disk, electric shaver, transceiver, electronic organizer, calculator, memory card, portable tape recorder, radio, backup power supply, memory card, and the like. Other consumer products include motors, lighting equipment, toys, game machines, road conditioners, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.). Furthermore, it can be combined with a solar cell.

[0106]

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.

[Synthesis Example of Oxide Anode Material] Tin Monoxide
78 g and silicon dioxide 3.01 g were dry-mixed and placed in an alumina crucible, and placed at 15 ° C./min in an argon atmosphere at 11 ° C.
The temperature was raised to 00 ° C. After baking at 1100 ° C. for 12 hours, the temperature was lowered to room temperature at 10 ° C./min, taken out of the baking furnace, and SnSiO ₃ was obtained. The compound was coarsely pulverized and further pulverized with a jet mill to obtain a powder having an average particle size of 7.0 μm (MO-1). This is a substance having a broad peak having an apex in the vicinity of 28 ° in 2θ value in the X-ray diffraction method using CuKα ray, and 40 ° or more and 70 ° in 2θ value.
No crystalline diffraction lines were observed below.

In the same manner, stoichiometric amounts of raw materials were mixed, fired and pulverized to synthesize the following compounds. Sn _0.8 Al _0.2 B _0.3 P _0.2 Si _0.5 O _3.6 (MO-2) SnAl _0.4 B _0.5 Cs _0.1 P _0.5 O _3.65 (MO-3)

[Negative electrode sheet preparation example-1] 20 parts by weight of polycrystalline silicon alone as a negative electrode active material, flaky natural graphite 20
Parts by weight, and 3 parts by weight of polyacrylonitrile as a binder were added.
The mixture was kneaded with 00 parts by weight as a medium to obtain a negative electrode mixture slurry. Next, 45 parts by weight of α-alumina, 7 parts by weight of graphite, 3 parts by weight of polyacrylonitrile, and 100 parts by weight of N-methylpyrrolidone were mixed to obtain an auxiliary layer slurry. The negative electrode mixture slurry is applied as a lower layer and the auxiliary layer slurry as an upper layer on a 10 μm-thick copper foil using an extrusion coating machine. Created a sheet. This was cut to a length of 50 mm, and a nickel lead plate was welded to the end, and then heat-treated at 230 ° C. for 1 hour in dry air having a dew point of −40 ° C. or less. The heat treatment was performed using a far infrared heater. 4mm × over the entire negative electrode sheet after heat treatment
35 μm thick lithium foil cut to 55 mm (purity 9
9.8%) at a 10 mm interval perpendicular to the sheet length direction (AN-1).

[Example of Preparation of Negative Electrode Sheet-2] 43 parts by weight of SnSiO ₃ (MO-1) as a negative electrode active material, 2 parts by weight of acetylene black and 2 parts by weight of graphite as conductive agents, and a binder were further added. Then, 3 parts by weight of polyacrylonitrile was added, and the mixture was kneaded using 100 parts by weight of N-methylpyrrolidone as a medium to obtain a negative electrode mixture slurry. After the preparation of the auxiliary layer slurry, coating, compression molding, preparation of a negative electrode sheet, lead plate welding, heat treatment, and lithium foil sticking were performed in the same manner as in the negative electrode sheet preparation example-1, to prepare a negative electrode sheet (AN-2).

[0111] [negative electrode sheet creation example -3] negative electrode active material SnSiO ₃ in the negative electrode sheet creation example -2 (MO-1) a _{Sn 0. 8 Al 0.2 B 0.3 P} 0.2 Si 0.5 O 3.6 (MO-
2) and SnAl _0.4 B _0.5 Cs _0.1 P _0.5 O
_{3.65 In place of} (MO-3), the negative electrode sheet AN-3
And AN-4.

[Example of Preparation of Negative Electrode Sheet-4] 43 parts by weight of a mesoface pitch-based carbon material (Petoka) as a negative electrode active material and 2 parts by weight of acetylene black and 2 parts by weight of graphite as conductive agents were mixed. 3 parts by weight of polyacrylonitrile was added as a binder and kneaded with 100 parts by weight of N-methylpyrrolidone as a medium to obtain a negative electrode mixture slurry. Example of negative electrode sheet preparation, except that the interval of attaching lithium foil to negative electrode sheet after heat treatment was set to 50 mm
A negative electrode sheet was prepared in the same manner as in No. 1 (AN-5).

[Positive electrode sheet preparation example-1] As a positive electrode material, 43 parts by weight of LiCoO ₂ , ₂ parts by weight of flake graphite,
2 parts by weight of acetylene black and 3 parts by weight of polyacrylonitrile as a binder were added, and acrylonitrile 1 was added.
The slurry obtained by kneading the mixture by using 00 parts by weight as a medium was applied to an aluminum foil having a thickness of 20 μm using an extrusion coating machine, dried, compression-molded by a calender press, and an aluminum The lead plate was welded to produce a positive electrode sheet having a thickness of 95 μm, a width of 54 mm and a length of 49 mm (CA-1).

[Positive Electrode Sheet Preparation Example-2] LiMn ₂ O ₄ was used as a positive electrode material, and the same operation as in the positive electrode preparation example-1 except for the coating thickness was performed, and a 114 μm thick, 54 mm wide × 49 mm long positive electrode was prepared. A sheet was prepared (CA-2).

[Example of Preparation of Gel Polymer Electrolyte-1] 4/3
/ 1 (molar ratio) mixture of the above first monomer 1-1, second monomer 2-4 and third monomer 3-5 (composition equivalent to P-21) 1
6.5 parts by weight, 11 parts by weight of LiPF ₆ , 1.1 parts by weight of 2,2′-azobis (methylisobutyrate), ethylene carbonate: diethyl carbonate = 2: 8 (weight)
71.4 parts by weight were mixed to obtain a uniform solution. This solution is 30 μm thick non-woven fabric TAPYRUS P22F manufactured by Tonen Tapils Co., Ltd.
After coating via W-0CS, the mixture was heated at 70 ° C. for 5 minutes to obtain a gel polymer electrolyte membrane having a thickness of 50 μm (PE-1).

[Gel Polymer Electrolyte Preparation Example-2] 4/2
16.5 parts by weight of a mixture of the above-mentioned first monomer 1-2, second monomer 2-2, and third monomer 3-3 (composition equivalent to P-22) at a ratio of 1/1 (molar ratio) by gel polymer electrolyte In the same manner as in Example 1, a gel polymer electrolyte membrane having a thickness of 50 μm was obtained (PE
-2).

[Example of Preparation of Gel Polymer Electrolyte-3] 2/5
16.5 parts by weight of a mixture of the above first monomer 1-3, second monomer 2-6, and third monomer 3-4 (composition equivalent to P-23) at a ratio of 1/1 (molar ratio) by gel polymer electrolyte In the same manner as in Example 1, a gel polymer electrolyte membrane having a thickness of 50 μm was obtained (PE
-3).

[Gel Polymer Electrolyte Preparation Example-4] 16.5 parts by weight of polyacrylonitrile, 11 parts by weight of LiPF ₆ , ethylene carbonate: diethyl carbonate =
2: 8 (weight) 71.4 parts by weight were mixed to obtain a uniform solution. This solution was applied through a nonwoven fabric TAPYRUS P22FW-0CS manufactured by Tonen Tapils Co., Ltd. having a thickness of 30 μm, and then cooled to a thickness of 50 μm.
A μm gel polymer electrolyte membrane was obtained. This is 60mm wide
It was cut to a length of 540 mm (PE-4).

[Example of Preparation of Gel Polymer Electrolyte-5] Vinylidene fluoride / hexafluoropropylene copolymer (88
Preparation Example-4 using 16.5 parts by weight)
Similarly, a gel polymer electrolyte membrane having a width of 60 mm, a length of 540 mm and a thickness of 50 μm was obtained. (PE-5).

FIG. 1 is a conceptual diagram of a sheet battery.

Example-1 Each of the negative electrode sheet and the positive electrode sheet was heated at 230 ° C. in dry air having a dew point of −40 ° C. or less.
It was dehydrated and dried for 0 minutes. In a dry atmosphere, a dehydrated and dried positive electrode sheet (CA-1) having a width of 54 mm and a length of 49 mm (1)
1), a gel polymer electrolyte membrane (PE-1) (12) cut to a width of 60 mm x a length of 60 mm, and a dehydrated and dried negative electrode sheet (AN-1) (AN-1) of a width of 55 mm x a length of 50 mm (13) are laminated in this order. A sheet type battery (B-1) was prepared by using an exterior material made of a laminated film of polyethylene (50 μm) -polyethylene terephthalate (50 μm) and heat-sealing the four edges under vacuum to seal.

The sheet-type battery (B-1) thus prepared was heated at 40 ° C.
, And then return to room temperature and charge at 60 mA. In this case, the charging was performed at a constant current up to 4.2 V, and the constant 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 2.6 at 60 mA
The test was performed at a constant current up to V. Discharge capacity, average discharge voltage, energy amount (discharge capacity × average discharge voltage) at that time, 1
Table 3 shows the results of visual observation of dendrite generation on the negative electrode surface after 50 cycles.

[Example 2] In the same manner as in Example 1, sheet batteries B-2 to 5 were prepared by combining a positive electrode sheet, a negative electrode sheet, and a gel polymer electrolyte membrane as shown in Table 2. After aging at 40 ° C. for 7 days in the same manner as in 1, the battery was returned to normal temperature and charged and discharged.
Table 3 shows the average discharge voltage, the amount of energy (discharge capacity x average discharge voltage), and the results of visual observation of dendrite generation on the negative electrode surface after 150 cycles.

[Comparative Example-1] 43 parts by weight of a mesophase pitch-based carbon material (Petoka) as a negative electrode active material, 2 parts by weight of acetylene black as a conductive agent and graphite 2
Parts by weight, and 3 parts by weight of polyacrylonitrile as a binder were added.
The mixture was kneaded with 00 parts by weight as a medium to obtain a negative electrode mixture slurry, applied to a copper foil having a thickness of 10 μm using an extrusion coating machine, dried, and compression-molded with a calender press to obtain a thickness of 46 μm × width. A negative electrode sheet was prepared by welding a nickel lead plate to the end at 55 mm × length 50 mm (AN-6).

As in Example-1, a thickness of 95 μm and a width of 5
4 mm x 49 mm long dehydrated and dried positive electrode sheet (CA-
1) A sheet battery BR-1 was prepared by combining the negative electrode sheet (AN-6) and the gel polymer electrolyte membrane (PE-1), and under the same charge / discharge conditions as in Example-1, the discharge capacity and average discharge. Voltage, energy amount (discharge capacity x average discharge voltage),
Table 3 shows the results of visual observation of dendrite generation on the negative electrode surface after 150 cycles.

[Comparative Example-2] A 100-μm-thick lithium foil was placed in a dry air having a dew point of −40 ° C. or less by 55 mm in width × 5 in length.
It was cut to 0 mm, and a nickel lead plate was welded to the end to form a negative electrode sheet (AN-7).

Comparative Example 1 Using Negative Electrode Sheet AN-7
After preparing a sheet battery BR-2 in the same manner as above, the battery performance was evaluated, and the discharge capacity, average discharge voltage, energy amount (discharge capacity x average discharge voltage), and visual observation results of dendrite generation on the negative electrode surface after 150 cycles Are shown in Table 3.

Table 2 Negative electrode Positive electrode sheet Sheet Negative electrode material Li foil stuck sheet Positive electrode material Gel polymer Battery No. No. Electrolyte membrane Present invention B-1 AN-1 Polycrystalline Si With CA-1 LiCoO ₂ PE-1-2-2 Sn system Oxide 〃 〃 〃 ３ -3-3 〃 〃 〃 〃 ４ -4 -4 〃 〃 〃 〃 -5 -5 Carbon material 〃 〃 〃 例 Comparative example BR-1 AN-6 Carbon material None CA-1 LiCoO ₂ PE-1-2-7 Lithium foil 〃 〃 〃 〃

Table 3 Negative Seed Discharge Average Release Energy Dendrite Sheet Battery Capacity Observation of Electric Voltage Visual Energy Attaching Li Foil (mAh) (V) (mWh) (150cy) Example-1 B-1 Yes 78 3.7 289 No occurrence (the present invention) Example-2 B-2 Yes 72 3.4 245 No occurrence (The present invention) -3 〃 78 3.4 265 〃 -4 〃 73 3.4 248 ５ -5 〃 59 3.7 218 比較 Comparative example -1 BR -1 None 51 3.7 189 No occurrence Comparative Example-2 BR-2 None 80 3.7 296

As is clear from Examples 1 and 2, the nonaqueous secondary battery of the present invention comprising a combination of a negative electrode sheet to which a lithium foil was previously adhered and a polymer gel electrolyte exhibited lithium dendrite growth during charge and discharge. Suppressed and the discharge energy amount at normal temperature operation is higher than that of the non-aqueous secondary battery (Comparative Example-1) composed of the combination of the carbon material negative electrode and the polymer gel electrolyte to which the lithium foil is not attached in advance. Although the lithium foil negative electrode of Comparative Example-2 can obtain a high discharge energy amount, even in combination with the polymer gel electrolyte, the generation of lithium dendrite during charging and discharging could not be suppressed.

[Example-3] In the same manner as in Example-1, sheet batteries B-6 to 10 were prepared by combining the positive electrode sheet, the negative electrode sheet, and the gel polymer electrolyte membrane as shown in Table 4. After aging at 40 ° C. for 7 days in the same manner as in 1, the battery was returned to normal temperature and charged and discharged.
Table 5 shows the average discharge voltage, the amount of energy (discharge capacity x average discharge voltage), and the results of visual observation of dendrite generation on the negative electrode surface after 150 cycles.

[Comparative Example-3] Sheet batteries BR-3 to BR-6 were prepared by combining the gel polymer electrolyte membranes as shown in Table 4 using the negative electrode sheet AN-7. The performance was evaluated, and the discharge capacity, average discharge voltage, energy amount (discharge capacity × average discharge voltage), and the results of visual observation of dendrite generation on the negative electrode surface after 150 cycles are shown in Table 5.

Table 4 Negative electrode Positive electrode sheet Sheet Negative electrode material Li foil stuck sheet Positive electrode material Gel polymer Battery No. No. Electrolyte membrane B-6 AN-1 Polycrystalline Si With CA-2 LiMn ₂ O ₄ PE-2 -7 -2 Sn-based oxide 〃 〃 〃 PE-3-8-3 〃 〃 〃 〃 PE-4 -9 -4 〃 〃 〃 〃 10 -10 -5 Carbon material 〃 〃 〃 PE-5 Comparative example BR-3 AN-7 Lithium foil None CA-2 LiMn ₂ O ₄ PE-2-4 〃 〃 〃 〃 〃 PE-3-5 〃 〃 〃 〃 〃 PE-4-6 〃 〃 〃 〃 − PE-5

Table 5 Negative Seed Discharge Average Release Energy Dendrite Sheet Battery Capacity Electric Voltage Visual Observation of Energy Attaching Li Foil (mAh) (V) (mWh) (150cy) Example-3 B-6 Yes 76 3.7 281 No occurrence (invention) -7 〃 73 3.4 248 〃 -8 〃 75 3.4 255 ９ -9 〃 74 3.4 252 〃 -10 〃 62 3.7 229 比較 Comparative example-3 BR-3 None 80 3.7 296 Occurred -4 〃 76 3.7 281 〃 -5 〃 75 3.7 278 〃 -6 〃 77 3.7 285 〃

As is clear from Example-3, the nonaqueous secondary battery of the present invention comprising a combination of a negative electrode sheet to which a lithium foil has been previously adhered and a polymer gel electrolyte has suppressed lithium dendrite growth during charge and discharge. The discharge energy amount at normal temperature operation is higher than that of the non-aqueous secondary battery (Comparative Example-1) which is composed of a combination of a carbon material negative electrode to which a lithium foil is not previously attached and a polymer gel electrolyte. Although the lithium foil negative electrode of Comparative Example-3 can obtain a high discharge energy amount, even in combination with the polymer gel electrolyte, the generation of lithium dendrite during charging and discharging could not be suppressed.

[Brief description of the drawings]

FIG. 1 shows a conceptual diagram of a sheet-type battery used in Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Positive electrode sheet 12 Polymer solid electrolyte 13 Negative electrode sheet 14 Positive electrode terminal 15 Negative electrode terminal

 ────────────────────────────────────────────────── ─── Continued on the front page F-term (reference)

Claims (29)

[Claims] 1. A non-aqueous secondary battery comprising a negative electrode material-containing sheet (negative electrode sheet) capable of inserting and extracting lithium, a positive electrode active material-containing sheet (positive electrode sheet), and a non-aqueous electrolyte, wherein the non-aqueous electrolyte comprises (a) A gel electrolyte containing an organic polymer, (b) an aprotic solvent and (c) an ammonium salt or an alkali metal or alkaline earth metal salt, and a metal foil mainly composed of lithium is previously attached to the negative electrode sheet. Non-aqueous secondary battery characterized by the following. 2. The non-aqueous secondary battery according to claim 1, wherein the portion of the negative electrode sheet to which the metal foil mainly composed of lithium is attached is on the mixture layer on which the negative electrode material is applied. 3. The non-aqueous material according to claim 1, wherein the portion of the negative electrode sheet to which the metal foil mainly composed of lithium is attached is on the negative electrode current collector metal on the surface not facing the positive electrode sheet. Rechargeable battery. 4. The negative electrode sheet has a multilayer structure having a layer mainly composed of a negative electrode material capable of inserting and extracting lithium and an auxiliary layer containing at least one layer of water-insoluble particles. 4. The non-aqueous secondary battery according to any one of claims 1 to 3. 5. The non-aqueous secondary battery according to claim 4, wherein the water-insoluble particles contained in the auxiliary layer are mixed with conductive particles and particles having substantially no conductivity. . 6. The non-aqueous secondary battery according to claim 4, wherein a portion of the negative electrode sheet to which a metal foil mainly composed of lithium is attached is on the auxiliary layer according to claim 4. 7. The method according to claim 1, wherein at least one kind of the negative electrode material is silicon,
At least one selected from germanium, tin, and lead
The non-aqueous secondary battery according to claim 1, which is a compound containing a kind of element. At least one 8. negative electrode material, the general formula (1) SNM to ¹ _d M ² _e claim 1, wherein the O is an amorphous oxide represented by _f The non-aqueous secondary battery according to the above. [Where M ¹
Is at least one or more elements selected from Al, B, P, Si, and Ge; and M ² is at least one or more elements selected from Group 1 elements, Group 2 elements, Group 3 elements, and halogen elements of the periodic table. And d is a number from 0.2 to 2,
e is a number from 0.01 to 1 and 0.2 <d + e <2,
f represents a number from 1 to 6. 9. The non-aqueous secondary battery according to claim 1, wherein at least one kind of the negative electrode material is a carbon material. 10. The non-aqueous secondary battery according to claim 9, wherein the carbon material has a graphite structure. 11. The non-aqueous secondary battery according to claim 9, wherein the carbon material is a granular material, a microsphere, a flat plate, a fiber, or a whisker. 12. A compound containing at least one element selected from silicon, germanium, tin and lead according to claim 7 as a negative electrode material, and an amorphous material represented by the general formula (1) according to claim 8 Composite oxide and claims 9 and 1
The material selected from the carbon materials described in 0 or 11 is 2
The non-aqueous secondary battery according to claim 1, wherein the non-aqueous secondary battery is used in combination of two or more kinds. 13. A negative electrode sheet is laminated with a metal foil mainly composed of lithium, and a non-aqueous secondary battery is assembled using the positive electrode sheet and a gel electrolyte. The non-aqueous secondary battery according to claim 1, wherein the secondary battery is inserted. 14. The non-aqueous secondary battery according to claim 1, wherein the organic polymer has a side chain containing a polar group containing no active hydrogen and is crosslinked. 15. An organic polymer comprising a first monomer containing a vinyl group and an oligo (oxyalkylene) group, a second monomer containing a vinyl group and a polar group of either a carbonate group or a cyano group, a plurality of vinyl monomers. The non-aqueous secondary battery according to any one of claims 1 to 14, wherein the non-aqueous secondary battery is a copolymer of a third monomer containing a group. 16. The copolymer according to claim 15, wherein the vinyl group of the first and second monomers is derived from at least one functional group selected from an acryloyl group and a methacryloyl group. Claim 15
The non-aqueous secondary battery according to 1. 17. The non-aqueous secondary battery according to claim 15, wherein the copolymer according to claim 15 has a structure represented by the general formula (2). General formula (2) In the formula, R1 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group having 1 to 10 carbon atoms, R2
Represents a group having a structure represented by the general formula (3). General formula (3) In the formula, R4 represents an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group having 1 to 10 carbon atoms, an aryl group or an aralkyl group having 1 to 10 carbon atoms, or a fluorinated aryl having 1 to 10 carbon atoms. Represents a group. R5 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R6 has the same meaning as R5. R3 represents -CN or a group containing a structure represented by the general formula (4). General formula (4) x, y, and z are the same or different integers from 1 to 20, a, b, and c are the mole fractions (percentages) of the first, second, and third monomers, respectively, and n is the degree of polymerization. Represent. 18. The copolymer of claim 17 wherein the first monomer: 2-ethoxyethyl acrylate, the second monomer: ethylene glycol ethyl carbonate methacrylate, and the third monomer: tri (ethylene glycol) dimethacrylate. The non-aqueous secondary battery according to claim 17, wherein the non-aqueous secondary battery is formed by uniting. 19. The copolymer of claim 17, wherein the copolymer comprises a first monomer: 2-ethoxyethyl acrylate, a second monomer: acrylonitrile, and a third monomer: tri (ethylene glycol) dimethacrylate. 18. The non-aqueous secondary battery according to claim 17, which is a crosslinked polymer network. 20. The non-aqueous secondary battery according to claim 1, wherein the organic polymer is a homopolymer of acrylonitrile or methacrylonitrile or a copolymer with another polymerizable monomer. 21. The non-aqueous secondary battery according to claim 1, wherein the organic polymer is a homopolymer of ethylene oxide or propylene oxide or a copolymer thereof. 22. The homopolymer or copolymer according to claim 21, wherein —CH ₂ (CH ₂ CH ₂ O) ₂ CH ₃ is used as a side chain.
22. The non-aqueous secondary battery according to claim 21, which is a polymer having: 23. The non-aqueous secondary battery according to claim 1, wherein the organic polymer is a homopolymer of vinylidene fluoride or a copolymer with another polymerizable monomer. 24. The non-aqueous secondary battery according to claim 1, wherein the organic polymer is polysiloxane or a derivative thereof. 25. The non-aqueous secondary battery according to claim 1, wherein the organic polymer is polyphosphazene or a derivative thereof. 26. The non-aqueous secondary battery according to claim 1, further comprising a separator. 27. A metal foil mainly composed of lithium is stuck on a negative electrode sheet including a layer mainly composed of a negative electrode material capable of occluding and releasing lithium and at least one auxiliary layer containing water-insoluble particles. Non-aqueous sheet having a gel electrolyte containing (a) an organic polymer, (b) an aprotic solvent, and (c) an ammonium salt or an alkali metal or alkaline earth metal salt. This is a method of manufacturing a non-aqueous secondary battery in which lithium is preliminarily inserted into a negative electrode material by assembling and then aging a secondary battery. A method for manufacturing a non-aqueous secondary battery, which is performed by overlapping at least one type of pattern from among a frame shape and a disk shape. 28. The production of a non-aqueous secondary battery according to claim 27, wherein the portion where the metal foil mainly composed of lithium is overlapped is on the auxiliary layer containing the water-insoluble conductive particles of the negative electrode sheet. Method. 29. The coverage of the metal foil mainly composed of lithium on the negative electrode sheet is 20 to 100%.
29. The method for producing a non-aqueous secondary battery according to 7 or 28.