JPH1097874A - Nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve charge/discharge cycle properties and storage quality while a discharge voltage is heightened by a method wherein either a negative or positive electrode sheet is constituted of three or more layers, and the other two layers effectively contain insulative fine solid particles. SOLUTION: A negative electrode sheet includes three or more coating layers on a collector, and also includes two layers spaced away from the collector. These two layers contain insulative fine solid particles which do not substantially occlude or discharge lithium ions. In the case of a layered constitution, the coating layer is provided in the electrode material capable of occluding or discharging the lithium ions on the collector side, and the two layers are also provided containing the insulative fine solid particles which do not substantially occlude or discharge the lithium ions. The percentage content of insulative fine solid particles in the outermost layer is 5% or more smaller than that of insulative fine solid particles in the adjacent layer, and the two layers spaced away from the collector contain 1 to 40wt.% electrode material capable of occluding or discharging the lithium ions. Consequently, while maintaining large capacity, cycle properties and storage quality can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous secondary battery having improved productivity, high discharge potential, excellent life and safety.

[0002]

2. Description of the Related Art Non-aqueous secondary batteries using lithium have been widely developed because of their high capacity. These lithium secondary batteries are generally composed of a positive electrode and a negative electrode containing a material capable of reversibly storing and releasing lithium, a non-aqueous electrolyte containing a lithium salt, and a separator. However, these non-aqueous secondary batteries have a problem that storage stability is deteriorated in order to ensure long life and high capacity at a high discharge potential, which is the original purpose.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high discharge voltage, good charge / discharge cycle characteristics,
Another object of the present invention is to improve the productivity of a non-aqueous secondary battery having excellent storage properties.

[0004]

An object of the present invention is to provide a sheet-shaped positive electrode having at least one layer containing a positive electrode material which is a lithium-containing transition metal compound, and a layer containing a negative electrode material capable of inserting and extracting lithium ions. And a nonaqueous secondary battery comprising a nonaqueous electrolyte containing a lithium salt, wherein at least one of the negative electrode sheet and the positive electrode sheet is coated on a current collector.
This is achieved by a non-aqueous secondary battery comprising two or more layers and two layers far from the current collector containing insulating solid fine particles that do not substantially occlude or release lithium ions.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below, but the present invention is not limited to these. (1) A sheet-shaped positive electrode having at least one layer containing a positive electrode material which is a lithium-containing transition metal compound, a sheet-shaped negative electrode having at least one layer containing a negative electrode material capable of inserting and extracting lithium ions, and a lithium salt In a non-aqueous secondary battery comprising a non-aqueous electrolyte, at least one of the negative electrode sheet and the positive electrode sheet is composed of three or more layers coated on a current collector, and two layers far from the current collector are substantially formed. A non-aqueous secondary battery characterized by containing insulating solid fine particles that do not occlude or release lithium ions. (2) The two layers far from the current collector of item 1 are two layers having different contents of insulating solid fine particles that do not substantially occlude and release lithium ions, and the outermost layer of the insulating solid fine particles. A non-aqueous secondary battery having a content of 5% or more lower than that of an adjacent layer. (3) The two layers far from the current collector of item 1 contain insulating solid fine particles that do not substantially occlude or release lithium ions, and a hydrophilic polymer compound, and the outermost layer has a high hydrophilicity. Item 3. The non-aqueous secondary battery according to Item 1 or 2, wherein the weight content of the molecular compound is higher than that of the adjacent layer. (4) The two layers far from the current collector of item 1 contain insulating solid fine particles that do not substantially occlude or release lithium ions, and conductive particles, and the outermost layer has a weight content of the conductive particles. The non-aqueous secondary battery according to any one of Items 1 to 3, wherein is higher than an adjacent layer. (5) The two layers far from the current collector of item 1 contain insulating solid fine particles that do not substantially occlude or release lithium ions, and contain 1% by weight or more of an electrode material capable of storing and releasing lithium ions. The nonaqueous secondary battery according to any one of Items 1 to 4, wherein the content of the nonaqueous secondary battery is 40% by weight or less. (6) The non-aqueous secondary according to any one of (1) to (5), wherein each of the two layers remote from the current collector of item 1 has a thickness of 0.1 μm or more and 40 μm or less. battery. (7) The nonaqueous secondary battery according to any one of items 1 to 6, wherein the insulating solid fine particles are inorganic oxides.

(8) The non-aqueous secondary battery according to any one of items 1 to 7, wherein the electrode sheet composed of three or more layers applied on the current collector is a negative electrode sheet. . (9) The nonaqueous secondary battery according to any one of items 1 to 8, wherein lithium ions are electrochemically inserted into the negative electrode material before battery assembly and / or in the battery. (10) The lithium ion pre-insertion method has a thickness of 10 μm.
Item 10. The non-aqueous secondary battery according to any one of Items 1 to 9, wherein a lithium metal foil of 70 μm or less is attached to the negative electrode sheet. (11) The amount of the lithium metal foil is 1 per gram of the negative electrode material.
Item 11. The non-aqueous secondary battery according to any one of Items 1 to 10, wherein the amount is from 0 mg to 2 g. (12) The negative electrode material is composed of groups 13 and 14 of the periodic table, 15
12. The non-aqueous secondary battery according to any one of items 1 to 11, wherein the non-aqueous secondary battery is an oxide or a chalcogenide mainly containing at least one element selected from elements of group III. (13) The non-anode according to any one of items 1 to 12, wherein the negative electrode material is an oxide or a chalcogenide mainly containing at least one element selected from Pb, Sn, Ge or Si. Water secondary battery. (14) The nonaqueous secondary battery according to any one of items 1 to 13, wherein the negative electrode material is an amorphous oxide mainly composed of Sn. (15) The negative electrode material has a general formula (1) SnM ¹ _a M ² _b O _s (1) (wherein, M ¹ is at least one or more elements selected from Al, B, P, Ge, and Si; ² represents at least one or more elements selected from Group 1 elements, Group 2 elements, Group 3 elements, and halogen elements of the periodic table;
The following number, b is a number from 0.01 to 1 and 0.2 <
a + b <2, s represents a number from 1 to 6. 15. The non-aqueous secondary battery according to any one of Items 1 to 14, wherein the non-aqueous secondary battery is an amorphous oxide represented by the following formula:

Hereinafter, the present invention will be described in detail. The electrode sheet of the present invention has at least two or more layers containing insulating solid fine particles that do not substantially occlude or release lithium ions. One of the layer configurations of the present invention is, for example, a coating layer of an electrode material capable of occluding and releasing lithium ions, a layer containing insulating fine particles, and an outermost layer containing insulating fine particles from the current collector side. Hereinafter, a layer containing insulating solid fine particles that do not substantially occlude and release lithium ions (hereinafter, referred to as an auxiliary layer and expressed separately from a coating layer of an electrode material) will be described. The thickness of these auxiliary layers is preferably 0.1 to 40 μm, and 0.5 to 2 μm.
0 μm is more preferred. The content of the insulating solid fine particles that does not substantially absorb or release lithium ions is 10 to 90.
% By weight is preferred, and 20 to 80% by weight is more preferred.
It is preferable that the content of the layer far from the current collector is smaller than that of the layer on the near side. The difference is preferably 5% by weight or more,
% Or more is more preferable. The auxiliary layer of the present invention can contain an electrode material described later in a range that does not affect the electrode reaction. The addition amount of these electrode materials is 1% by weight or more and 40% by weight or less, more preferably 2% by weight or more and 20% by weight, based on the insulating solid fine particles that do not substantially occlude or release lithium ions. % Or less.

[0008] Examples of the insulating solid fine particles that do not substantially occlude or release lithium ions include metal, non-metallic carbide, silicide, nitride, sulfide and oxide particles. Among carbides, silicides and nitrides, S
iC, aluminum nitride (AlN), BN, and BP are preferable because they have high insulation properties and are chemically stable.
e, SiC using BN as a sintering aid is particularly preferred. Among chalcogenides, oxides are preferable, and oxides that are not easily oxidized or reduced are preferable. These oxides include Al ₂ O ₃ , As ₄ O ₆ , B ₂ O ₃ , Ba
O, BeO, CaO, Li ₂ O, K ₂ O, Na ₂ O, I
n ₂ O ₃ , MgO, Sb ₂ O ₅ , SiO ₂ , SrO, Z
rO ₄ . Among these, Al ₂ O ₃ , Ba
O, BeO, CaO, K ₂ O, Na ₂ O, MgO, Si
O ₂ , SrO and ZrO ₄ are particularly preferred. These oxides may be used alone or as a composite oxide. Preferred compounds as the composite oxide include mullite (3
Al ₂ O ₃ .2SiO ₂ ), steatite (MgO.S)
iO ₂ ), forsterite (2MgO.SiO ₂ ),
Cordierite (2MgO.2Al ₂ O ₃ .5Si
O ₂ ). These inorganic compound particles, 0.1μ by control of production conditions and methods such as pulverization
m to 20 μm, particularly preferably 0.2 μm to 1
Used as particles of 5 μm or less.

In the auxiliary layer of the present invention, in addition to the above-mentioned insulating solid fine particles, if necessary, a hydrophilic polymer compound,
Conductive particles and an electrode material capable of occluding and releasing lithium ions described below can be included. Examples of the hydrophilic polymer compound include polysaccharides such as starch, polyvinyl alcohols having different degrees of saponification, cellulose derivatives such as carboxymethylcellulose, polyvinylpyrrolidone, and polyethylene oxide. Particularly preferred is carboxymethylcellulose. The amount of the hydrophilic polymer compound added is 0.1% by weight or more and 20% by weight or less, 0.3% by weight or more,
0% by weight or less is more preferable. The content of the outermost layer is higher than that of the adjacent layer, 1.1 times or more, more preferably 1.times.
It is three times or more.

As the conductive particles, any electronic conductive material that does not cause a chemical change in the constructed battery may be used. Natural graphite (scale graphite, flake graphite, earthy graphite, etc.), artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber and metal (copper, nickel, aluminum, silver, etc.) powder, metal fiber or A conductive material such as a polyphenylene derivative can be included as one type or a mixture thereof. Among these, graphite and acetylene black are particularly preferred. The addition amount is preferably 1 to 50% by weight, more preferably 2 to 30% by weight, and particularly preferably 3 to 15% by weight. The addition amount of the outermost layer is preferably at least 1.2 times higher than that of the adjacent layer, more preferably at least 1.4 times higher.

The content of the electrode material, particularly the negative electrode material described later, is preferably 0 to 40% by weight, more preferably 0 to 20% by weight, and still more preferably 0 to 10% by weight. In addition to the above, a binder such as a fluororesin described below may be added to the auxiliary layer of the present invention.

The auxiliary layer of the present invention may be applied to either the positive electrode or the negative electrode, or may be applied to both the positive electrode and the negative electrode. When the positive electrode and the negative electrode are formed by applying a mixture on both sides of the current collector, the protective layer may be applied on both sides thereof, or may be applied on only one side. Is also good. However, it is necessary that one of the positive electrode and the negative electrode opposed via the separator is coated. Particularly preferred is a mode in which an auxiliary layer is formed on the negative electrode. The method of applying the auxiliary layer may be a sequential method in which a mixture containing a material capable of reversibly occluding and releasing lithium is applied on the current collector, and then a protective layer is sequentially applied. And a protective layer at the same time.

The negative electrode material used in the present invention is an oxide or a chalcogenide capable of inserting and extracting lithium.
Above all, it is preferable that the negative electrode material is an oxide or a chalcogenide mainly composed of at least one element selected from the elements of Groups 13, 14, and 15 of the periodic table. Further, it is preferable that the negative electrode material is an oxide or a chalcogenide mainly composed of at least one element selected from Pb, Sn, Ge or Si.

For example, Ga ₂ O ₃ , SiO, GeO, G
eO ₂ , SnO, 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 , Bi ₂ O ₅
, SnSiO ₃ , GeS, GeS ₂ , SnS, SnS ₂
, PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ , Sn
SiS _{3 and the} like. These are complex oxides with lithium oxide such as Li ₂ GeO ₃ and Li ₂ SnO.
_It may be ₂ .

Further, these compounds contain a transition metal.
For example, SnMnO_Two, SnMnO_Three , S
nTiO_Two , SnTiO_Three , SnWO_Three , SnWO_Four ,
SnVO_3.5 , SnVO_4.5 , SnFeO_2.5 , SnF
eO_3.5 , SnCoO_Two , SnCoO_Three , SnNiO
_Two , SnNiO_Three , SnCuO_Two , SnCuO_Three , Sn
MoO_Three , SnMoO_Four , SnMoO_Five , SnAgO
_1.5 , SnAg_2.5 , GeMnO_Two , GeMnO_Three , G
eTiO_Two , GeTiO_Three , GeWO_Three , GeWO _Four ,
GeVO_3.5 , GeVO_4.5 , GeFeO_2.5 , GeF
eO_3.5 , GeCoO_Two , GeCoO_Three , GeNiO
_Two , GeNiO_Three , GeCuO_Two , GeCuO _Three , Ge
MoO_Three , GeMoO_Four , GeMoO_Five , GeAgO
_1.5 , GeAg_{2. Five} , SiMnO_Two , SiMnO_Three , S
iTiO_Two , SiTiO_Three , SiWO_Three , SiWO_Four ,
SiVO_3.5 , SiVO_4.5 , SiFeO_2.5 , SiF
eO_3.5 , SiCoO_Two , SiCoO_Three , SiNiO
_Two , SiNiO_Three , SiCuO_Two , SiCuO_Three , Si
MoO_Three , SiMoO_Four , SiMoO_Five , SiAgO
_1.5 , SiAg_2.5 , PbnMnO_Two , PbMnO_Three ,
PbTiO_Two , PbTiO_Three , PbWO_Three , PbWO
_Four , PbVO_3.5 , PbVO_4.5 , PbFeO_2.5 , P
bFeO_3.5 , PbCoO_Two , PbCoO_Three , PbNi
O_Two , PbNiO_Three , PbCuO_Two , PbCuO_Three , P
bMoO_Three , PbMoO_Four , PbMoO_Five , PbAgO
_1.5 , PbAg_2.5 And the like. Also these
May be a composite oxide with lithium.

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

In the present invention, an amorphous oxide containing Sn as a main component is more preferable. Among them, a general formula (1) SnM ¹ _a M ² _b O _s (1) (where M ¹ is Al, B , P, Ge, at least one element selected from the group consisting of Si, and M ² represents at least one element selected from the group 1 element, group 2 element, group 3 element, and halogen element of the periodic table. Is 0.2 or more 2
The following number, b is a number from 0.01 to 1 and 0.2 <
a + b <2, s represents a number from 1 to 6. ) Is preferable.

An amorphous oxide mainly composed of Sn;
Examples of the amorphous oxide represented by the general formula (1) include
The present invention is not limited to these.
Not only. SnAl_0.4 B_0.5 P_0.5 K_0.1 O_3.65,
SnAl_0.4 B_0.5 P_0.5 Na_0.2O_3.7 , SnAl_0.4
 B_0.3 P_0.5 Rb_0.2 O_3.4 , SnAl_0.4 B_0.5 P
_0.5Cs_0.1 O_3.65, SnAl_0.4 B_0.5 P_0.5 K_0.1 
Ge_0.05O_3.85, SnAl_{0. Four} B_0.5 P_0.5 K_0.1 Mg
_0.1 Ge_0.02O_3.83, SnAl_0.4 B_0.4 P_0.4 O
_{3. Two} , SnAl_0.3 B_0.5 P_0.2 O_2.7 , SnAl_0.3 
B_0.5 P_0.2 O_2.7 , SnAl_0.4 B_0.5 P_0.3 Ba
_0.08Mg_0.0 O_3.26, SnAl_0.4 B_0.4 P_0.4 Ba
_0.08O_3.28, SnAl_0.4 B_0.5 P_0.5 O_3.6, SnA
l_0.4 B_0.5 P_0.5 Mg_{0 . 1}O_3.7

SnAl_0.5 B_0.4 P_0.5 Mg_0.1 F_0.2 
O_3.65, SnB_0.5 P_0.5 Li_0.1 Mg_0.1 F_0.2 O
_3.05, SnB_0.5 P_0.5 K_0.1 Mg_0.1 F_0.2 O_3.05,
SnB_{0. Five} P_0.5 K_0.05Mg_0.05F_0.1 O_3.03, SnB
_0.5 P_0.5 K_0.05Mg_0.1 F_0.2O_3.03, SnAl_0.4 
B_0.5 P_0.5 Cs_0.1 Mg_0.1 F_0.2 O_3.65, SnB
_0.5P_0.5 Cs_0.05Mg_0.05F_0.1 O_3.03, SnB_0.5 
P_0.5 Mg_0.1 F_0.1 O_3.05, SnB_0.5 P_0.5 Mg
_0.1 F_0.2 O_Three , SnB_0.5 P_0.5 Mg_0.1 F_0.06O_3.
07, SnB_0.5 P_0.5 Mg_0.1 F_0.14O_3.03, SnPB
a_0.08O_3.58, SnPK _0.1 O_3.55, SnPK_0.05Mg
_0.05O_3.58, SnPCs_0.1 O_3.55, SnPBa _0.08F
_0.08O_3.54, SnPK_0.1 Mg_0.1 F_0.2 O_3.55, Sn
PK_0.05Mg_0.05F_0.1 O_3.53, SnPCs_0.1 Mg
_0.1 F_0.2 O_3.55, SnPCs_0.05Mg_0.05F_0.1 O
_3.53,

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

SnSi_0.5 Al_0.1 B_0.2 P_0.1 Ca
_0.4 O_3.1 , SnSi_0.4 Al_0.2 B_{0. Four} O_2.7 , Sn
Si_0.5 Al_0.2 B_0.1 P_0.1 Mg_0.1 O_2.8 , SnS
i_0.6 Al_0.2 B_0.2 O_2.8 , SnSi_0.5 Al_0.3 B
_0.4 P_0.2 O_3.55, SnSi_0.5Al_0.3 B_0.4 P_0.5 
O_4.30, SnSi_0.6 Al_0.1 B_0.1 P_0.3 O_3.25, S
nSi_0.6 Al_0.1 B_0.1 P_0.1 Ba_0.2 O_2.95, Sn
Si_0.6 Al_0.1 B_0.1 P _0.1 Ca_0.2 O_2.95, SnS
i_0.6 Al_0.4 B_0.2 Mg_0.1 O_3.2, SnSi_0.6 Al
_0.1 B_0.3 P_0.1 O_3.05, SnSi_0.6 Al_0.2 Mg
_0.2 O_2.7 , SnSi_0.6 Al_0.2 Ca_0.2 O_2.7 , S
nSi_0.6 Al_0.2 P_0.2 O_Three , SnSi_{0. 6} B_0.2 P
_0.2 O_Three , SnSi_0.8 Al_0.2 O_2.9 , SnSi_0.8 
Al_0.3 B_{0. Two} P_0.2 O_3.85, SnSi_0.8 B_0.2 O
_2.9 , SnSi_0.8 Ba_0.2 O_2.8 , SnSi_0.8 Mg
_0.2 O_2.8 , SnSi_0.8 Ca_0.2 O_2.8 , SnSi
_0.8 P_0.2O_3.1

Sn _0.9 Mn _0.3 B _0.4 P _0.4 Ca _0.1 R
_{b 0.1 O 2.95, Sn 0.9 Fe} 0.3 B 0. 4 P 0.4 Ca 0.1
Rb _0.1 O _2.95 , Sn _0.8 Pb _0.2 Ca _0.1 P _0.9 O
_3.35 , Sn _0.9 Mn _0.1 Mg _0.1 P _0.9 O _3.35 , Sn
_0.2 Mn _0.8 Mg _0.1 P _0.9 O _3.35 , Sn _0.7 Pb _0.3
Ca _0.1 P _0.9 O _{3.35 and the} like.

For the oxide or chalcogenite of the present invention, any of a firing method and a solution method can be employed, but the firing method is more preferable. In the firing method, oxides, chalcogenites or compounds of the corresponding elements are mixed well and then fired to obtain an amorphous oxide and / or
Alternatively, it is preferable to obtain chalcogenite.

As the firing conditions, the heating rate is preferably 5 ° C. to 200 ° C. per minute, the firing temperature is preferably 500 ° C. to 1500 ° C., and the firing time is Is more than 1 hour 10
It is preferably 0 hours or less. And, it is preferable as the descending rate of temperature or less per minute 2 ℃ least 10 ⁷ ° C.. In the present invention, the heating rate is defined as “the firing temperature (° 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, 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 negative electrode material used in 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. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can also be performed as necessary. Classification is preferably performed to obtain a desired particle size. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be performed both in a dry type and a wet type. The chemical formula of the compound obtained by calcining can be calculated from 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.

The negative electrode material of the present invention can contain various elements. For example, lanthanoid metals (Hf, T
a, W, Re, Os, Ir, Pt, Au, Hg) and various compounds that increase electron conductivity (for example, Sb, In, N
b) may be included. The amount of the compound to be added is preferably 0 to 5 mol%.

The positive electrode active material used in the present invention may be a transition metal oxide capable of reversibly inserting and releasing lithium ions, but is particularly preferably a lithium-containing transition metal oxide. Preferred lithium-containing transition metal oxide positive electrode active materials used in the present invention include lithium-containing Ti, V, Cr, M
An oxide containing n, Fe, Co, Ni, Cu, Mo, and W can be used. Alkali metals other than lithium (elements IA and IIA of the periodic table), and / or Al, Ga,
In, Ge, Sn, Pb, Sb, Bi, Si, P, B, etc. may be mixed. The mixing amount is 0 to 3 with respect to the transition metal.
0 mol% is preferred. More preferred lithium-containing transition metal oxide cathode active materials used in the present invention include lithium compounds / transition metal compounds (where the transition metal is T
i, V, Cr, Mn, Fe, Co, Ni, Mo, W, at least one of them) in a total molar ratio of 0.3 to
It is preferable to synthesize them by mixing them to 2.2.
Particularly preferred lithium-containing transition metal oxide positive electrode active materials for use in the present invention include lithium compounds / transition metal compounds (where transition metals are V, Cr, Mn, F
It is preferable to synthesize them by mixing them so that the total molar ratio of at least one selected from e, Co, and Ni) is 0.3 to 2.2. Particularly preferred lithium-containing transition metal oxide cathode active materials used in the present invention are Lix QO
y (where Q is mainly at least one of Co,
Transition metal containing Mn, Ni, V, Fe), x = 0.2 to
1.2, y = 1.4-3). As Q, other than transition metals, Al, Ga, In, Ge, Sn,
Pb, Sb, Bi, Si, P, B and the like may be mixed. The mixing amount is preferably 0 to 30 mol% based on the transition metal.

More preferred lithium used in the present invention
Li-containing metal oxide positive electrode active materials include Li_xCoO
_Two , Li_xNiO_Two , Li_xMnO_Two , Li_xCo_aN
i_1-aO_Two , Li_zCo_bV_1-bO_z, Li_xCo_bF
e_1-bO_Two , Li_xMn_Two O_Four, Li_xMn_cCo_2-c
O_Four , Li_xMn_cNi_2-cO_Four , Li_xMn_cV_2-c
O_z, Li_xMn_cFe_2-cO_Four , Li_xCo_bB_1-b
O_Two , Li_xCo_bSi _1-bO_Two , Li_xMn_Two O_Four When
MnO_Two Mixture of Li_2xMnO_Three And MnO_Two Mixing
Object, Li_xMn_Two O_Four , Li_2xMnO_Three And MnO_Two Blend of
Compound (where x = 0.2-1.2, a = 0.1-0.
9, b = 0.8 to 0.98, c = 1.6 to 1.96, z
= 2.01-5). Used in the present invention
More preferred lithium-containing metal oxide positive electrode active material
Is Li_xCoO_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_Two O_Four, L
i_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 = 0.7-1.2, a = 0.1-0.9, b
= 0.8-0.98, c = 1.6-1.96, z = 2.
01 to 2.3). Most used in the present invention
Preferred lithium-containing transition metal oxide cathode active material
Is Li_xCoO_Two , Li_xNiO_Two , Li_xMnO
_Two , Li_xCo_aNi_{1- a}O_Two , Li_xMn_Two O_Four , L
i_xCo_bV_1-bO_z(Where x = 0.7-1.2, a
= 0.1-0.9, b = 0.9-0.98, z = 2.0
2 to 2.3). Here, the above x value is
This is a value before the start of discharge, and increases or decreases due to charging and discharging.

The positive electrode active material can be synthesized by a method in which a lithium compound and a transition metal compound are mixed and fired, or a solution reaction, but a firing method is particularly preferable. The firing temperature used in the present invention may be a temperature at which a part of the mixed compound used in the present invention decomposes and melts.
50-2000 ° C is preferred, and especially 350-1500 ° C
Is preferred. In firing, it is preferable to calcine at 250 to 900 ° C. The firing time is preferably from 1 to 72 hours, more preferably from 2 to 20 hours. The method of mixing the raw materials may be a dry method or a wet method. After firing, 20
Annealing may be performed at 0 ° C. to 900 ° C. The firing gas atmosphere is not particularly limited, and may be an oxidizing atmosphere or a reducing atmosphere. For example, in air, or a gas whose oxygen concentration is adjusted to an arbitrary ratio, or hydrogen, carbon monoxide,
Examples include nitrogen, argon, helium, krypton, xenon, and carbon dioxide.

In the synthesis of the positive electrode active material of the present invention, as a method of chemically inserting lithium ions into the transition metal oxide, the positive electrode active material is synthesized by reacting lithium metal, a lithium alloy or butyllithium with the transition metal oxide. The method is preferred. 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.
It is preferably from 01 to 50 m ² / g. Further, when 5 g of the positive electrode active material is dissolved in 100 ml of distilled water, the pH of the supernatant is preferably 7 or more and 12 or less. In order to obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a vibrating ball mill, a vibrating mill, a satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used. The positive electrode active material obtained by firing may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

Negative electrode material and positive electrode active material used in the present invention
Is preferably represented by the general formula (1)
Compound and Li_xCoO_Two , Li_xNiO_Two , Li_xCo
_aNi_1-aO_Two , Li_xMnO_Two , Li_xMn_Two O_Four ,
Or Li_xCo_bV_1-bO _z(Where x = 0.7-
1.2, a = 0.1 to 0.9, b = 0.9 to 0.98,
z = 2.02-2.3), and high discharge
Non-aqueous secondary battery with high voltage, high capacity and excellent charge / discharge cycle characteristics
You can get a pond.

The equivalent of inserting lithium into the negative electrode material of the present invention is 3 to 10 equivalents, and the usage ratio with the positive electrode active material is determined according to this equivalent. It is preferable to multiply the usage ratio based on this equivalent by a factor of 0.5 to 2 times. When the lithium supply source is other than the positive electrode active material (for example, lithium metal, alloy, butyl lithium, etc.), the amount of the positive electrode active material used is determined according to the lithium release equivalent of the negative electrode material. Also in this case, it is preferable to multiply the used amount ratio based on this equivalent by a factor of 0.5 to 2 times.

When lithium is previously inserted into the negative electrode from a lithium source other than the positive electrode, the lithium source may be lithium metal, lithium alloy (Al, Al--Mn,
It is preferable to use foil or metal powder of Al-Mg, Al-Sn, Al-In, or an alloy of Al-Cd and lithium.
These metal foils and the like may be located directly on the negative electrode mixture or via the protective layer of the present invention. Further, it may be located on a current collector without a negative electrode mixture. As the foil, a thin foil having a thickness of about 20 μm may be applied uniformly, or a thicker foil may be partially arranged. The thickness of the foil can be determined from the amount that is naturally inserted into the negative electrode after battery formation.

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

Examples of the binder include starch, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl chloride, polyvinyl pyrrolidone,
Tetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, polybutadiene, fluoro rubber,
Polysaccharides such as polyethylene oxide, thermoplastic resins, polymers having rubber elasticity, and the like are used alone or as a mixture thereof. When a compound containing a functional group that reacts with lithium, such as a polysaccharide, is used, for example, it is preferable to add a compound such as an isocyanate group to deactivate the functional group. The amount of the binder added is preferably 1 to 50% by weight, particularly 2 to 30% by weight.
Is preferred. As the filler, any fibrous material that does not cause a chemical change in the configured battery can be used. Usually, fibers such as olefin-based polymers such as polypropylene and polyethylene, glass, and carbon are used. Although the amount of the filler is not particularly limited,
~ 30% by weight is preferred.

In using the negative electrode material of the present invention in a non-aqueous secondary battery system, a water-dispersed mixture paste containing the compound of the present invention is applied and dried on a current collector, and the water-dispersed mixture paste is applied. Is preferably 5 or more and less than 10, more preferably 6 or more and less than 9. Further, it is preferable that the temperature of the aqueous dispersion paste is maintained at 5 ° C. or higher and lower than 80 ° C., and the application on the current collector is performed within 7 days after the preparation of the paste.

As the separator, a material having high ion permeability, predetermined mechanical strength, insulating microporous material or having a gap is used. In order to further improve safety, it is necessary to have a function of closing the above gap at 80 ° C. or higher to increase resistance and cut off current. The closing temperature of these gaps is from 90 ° C to 180 ° C, more preferably from 110 ° C to 170 ° C. The method of forming the gap differs depending on the material, but may be any known method. In the case of a porous film, the shape of the holes is usually circular or elliptical, and the size is 0.05 μm to 30 μm, preferably 0.1 μm to 20 μm. Further, as in the case of the drawing method or the phase separation method, the holes may be rod-shaped or amorphous. In the case of cloth, the gap is a space between fibers, and depends on how to make a woven or nonwoven fabric. The ratio of closing of these gaps, that is, the porosity is from 20% to 90%,
35% to 80% is preferred.

The separator of the present invention has a size of 5 μm to 10 μm.
It is a microporous film, woven fabric, nonwoven fabric or the like having a thickness of 0 μm or less, more preferably 10 μm or more and 80 μm or less.
Non-woven fabrics and woven fabrics have a yarn diameter of 0.1 μm to 5 μm and are made of polyethylene, ethylene-propylene copolymer, ethylene-butene 1 copolymer, ethylene-methylbutene copolymer, ethylene-methylpentene copolymer, polypropylene And those made of polyfluorinated ethylene fiber yarn. Among films, woven fabrics and nonwoven fabrics, a porous film made of polyolefin is particularly preferable, and examples thereof include a microporous separator made of polyethylene or polypropylene. The polyolefin microporous separator of the present invention preferably contains at least 20% by weight or more of an ethylene component, and particularly preferably contains 30% by weight or more. Components other than ethylene include propylene, butene, hexene, fluorinated ethylene, vinyl chloride, vinyl acetate, and acetalized vinyl alcohol, and propylene and fluorinated ethylene are particularly preferred. The microporous separator of the present invention may be a copolymer as long as it contains a polyolefin, such as an ethylene-propylene copolymer or an ethylene-propylene copolymer.
Those comprising a butene copolymer are preferred. Further, a mixture may be used, and a mixture prepared by mixing and dissolving polyethylene and polypropylene, or polyethylene and polytetrafluoroethylene is also preferable. These separators may be a single film or a composite film. In particular, those obtained by laminating two or more kinds of microporous films having different pore diameters, porosity, closing temperature, etc., particularly, a two-layer separator and a three-layer separator are preferable. Further, a composite of different materials such as a microporous film and a woven fabric may be used. The separator of the present invention may contain inorganic fibers such as glass fibers and carbon fibers, and inorganic particles such as silicon dioxide, zeolite, alumina and talc. Further, the voids and surfaces may be treated with a surfactant to make them hydrophilic.

As an electrolyte, propylene is used as an organic solvent.
Lencarbonate, ethylene carbonate, butyleneca
-Carbonate, dimethyl carbonate, diethyl carbonate
, Gamma-butyrolactone, 1,2-dimethoxy eta
, Tetrahydrofuran, 2-methyltetrahydrofuran
Dimethyl sulfoxide, 1,3-dioxolane,
Formamide, dimethylformamide, dioxolan,
Acetonitrile, nitromethane, methyl formate, methyl acetate
, Methyl propionate, ethyl propionate, phosphoric acid
Triester, trimethoxymethane, dioxolane derivatives
Body, sulfolane, 3-methyl-2-oxazolidinone,
Propylene carbonate derivative, tetrahydrofuran derivative
Conductor, diethyl ether, 1,3-propane sultone
Mix at least one of any aprotic organic solvents
Solvent and a lithium salt soluble in the solvent, for example, Li
ClO_Four , LiBF_Four , LiPF₆ , LiCF_Three SO
_Three , LiCF_Three CO_Two , LiAsF₆ , LiSbF₆ ,
LiB_TenCl_Ten, Lithium lower aliphatic carboxylate, Li
AlCl_Four , LiCl, LiBr, LiI, chlorobora
One or more of lithium, lithium tetraphenylborate, etc.
Consists of salt. Among them, propylene carbohydrate
Neat or ethylene carbonate and 1,2-dimethoxy
Mixture of ethane and / or diethyl carbonate
LiCF_Three SO _Three , LiClO_Four , LiBF_Four and
/ Or LiPF₆ An electrolytic solution containing Echile
LiBF in a mixture of carbohydrate and diethyl carbonate
_Four And / or LiPF₆ Is particularly preferred.
New The amount of these electrolytes added to the battery is not particularly limited
The amount of the positive electrode active material and negative electrode material and the size of the battery
Depending on the required amount. Supporting electrolyte concentration
Is preferably 0.2 to 3 mol per liter of electrolyte.
No.

In addition to the electrolytic solution, the following solid electrolyte can be used. Solid electrolytes are classified into inorganic solid electrolytes and organic solid electrolytes. Well-known inorganic solid electrolytes include nitrides, halides, and oxyacid salts of Li. Among them, Li ₃ N, LiI, Li ₅ N
_{I 2, Li 3 N-LiI} -LiOH, LiSiO 4, L
iSiO ₄ —LiI—LiOH, xLi ₃ PO ₄ — (1
-X) Li ₄ SiO ₄ , Li ₂ SiS ₃ , phosphorus sulfide compounds and the like are effective. 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 above-mentioned aprotic electrolyte, and a phosphate polymer are effective. Furthermore, there is a method of adding polyacrylonitrile to the electrolytic solution. In addition, a method of using an inorganic and an organic solid electrolyte in combination is also known.

As the separator, an insulating thin film having a high ion permeability, a predetermined mechanical strength, and the like is used. Sheets or nonwoven fabrics made of olefin polymers such as polypropylene or glass fibers or polyethylene are used because of their resistance to organic solvents and hydrophobicity. The pore size of the separator is in a range generally used for batteries. For example, 0.01-10 μ
m is used. The thickness of the separator is generally used in the range for batteries. For example, a thickness of 5 to 300 μm is used. It is known that the following compounds are added to an electrolyte for the purpose of improving discharge and charge / discharge characteristics. For example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-
Glyme, hexaphosphoric triamide, nitrobenzene derivative, sulfur, quinone imine dye, N-substituted oxazolidinone and N, N'-substituted imidazolidinone, ethylene glycol dialkyl ether, quaternary ammonium salt, polyethylene glycol, pyrrol, 2-methoxyethanol
, AlCl ₃ , monomer of conductive polymer electrode active material, triethylene phosphoramide, trialkylphosphine, morpholine, aryl compound having carbonyl group, hexamethylphosphoric triamide and 4-alkylmorpholine Tertiary amines, bicyclic tertiary amines, oils (JP-A-62-287580), quaternary phosphonium salts, tertiary sulfonium salts and the like.

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. Further, the mixture of the positive electrode and the negative electrode can contain an electrolytic solution or an electrolyte. For example, a method is known in which the ion-conductive polymer, nitromethane, and an electrolyte are included.

As the current collectors for the positive and negative electrodes, any electronic conductor that does not cause a chemical change in the constructed battery may be used. For example, for the positive electrode, stainless steel,
In addition to nickel, aluminum, titanium, carbon, etc., carbon, nickel,
What processed titanium or silver is used. Particularly, aluminum or an aluminum alloy is preferable. For the negative electrode, stainless steel, nickel,
In addition to copper, titanium, aluminum, carbon, and the like, copper, stainless steel, which is obtained by treating carbon, nickel, titanium, or silver on the surface, an Al—Cd alloy, or the like is used. Particularly, copper or a copper alloy is preferable. Oxidizing the surface of these materials is also used. In addition, it is desirable to make the current collector surface uneven by surface treatment. As the shape, in addition to a foil, a film, a sheet, a net, a punched material, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like are used. The thickness is not particularly limited.
〜500 μm is used.

The shape of the battery can be applied to any of coins, buttons, sheets, cylinders, flats, corners and the like. When the shape of the battery is a coin or a button, the mixture of the positive electrode active material and the negative electrode material is mainly used after being compressed into a pellet shape.
The thickness and diameter of the pellet are determined by the size of the battery. When the shape of the battery is a sheet, a cylinder, or a corner, the mixture of the positive electrode active material and the negative electrode material is mainly used by being coated (coated) on a current collector, dried, and compressed. As a coating method, a general method can be used. For example,
Reverse roll method, direct roll method, blade method,
Knife method, extrusion method, curtain method, gravure method, bar method, dip method and squeeze method can be mentioned. Among them, a blade method, a knife method and an extrusion method are preferred. Application is 0.1-10
It is preferably carried out at a speed of 0 m / min. On this occasion,
By selecting the above-mentioned coating method in accordance with the solution physical properties and drying property of the mixture, a good surface state of the coated layer can be obtained. The coating may be performed on one side at a time or on both sides simultaneously. The application may be continuous, intermittent, or striped. The thickness, length and width of the coating layer are determined according to the size of the battery, and the thickness of the coating layer on one side is particularly preferably 1 to 2000 μm in a compressed state after drying.

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

The mixture sheet and the separator are interposed
After fitting, the sheets are rolled or folded
After inserting the can and the sheet electrically,
The liquid is injected, and a battery can is formed using the sealing plate. this
Sometimes, a safety valve can be used as a sealing plate. safety valve
In addition, equipped with various conventionally known safety elements
May be. For example, fuses,
A bimetal, a PTC element, or the like is used. Also safe
In addition to the valve, cut off the battery
Method, gasket cracking method or sealing plate turtle
It is possible to use a splitting method or a cutting method with a lead plate.
it can. In addition, overcharge and overdischarge measures are incorporated in the charger.
With a protection circuit or connected independently
Is also good. In addition, as a measure against overcharging,
A method of interrupting the current. This and
The compound or electrolyte to increase the internal pressure
Can be Of compounds used to increase internal pressure
For example, Li_Two CO _Three , LiHCO_Three , Na_Two CO
_Three , NaHCO_Three , CaCO_Three , MgCO_Three Such as carbonic acid
Salts and the like can be mentioned.

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. Caps, cans,
Known methods (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used for welding the sheet and the lead plate. A conventionally known compound or mixture such as asphalt can be used as the sealing agent for closing.

The 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 color notebook computer, a black-and-white notebook personal computer, a pen-input personal computer, a pocket (palmtop) personal computer, a notebook computer Type word processor, pocket word processor, e-book player, mobile phone, cordless phone handset, pager, handy terminal, mobile fax, mobile copy, mobile printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini disk, Electric shaver, electronic translator, car phone,
Examples include a transceiver, a power tool, an electronic organizer, a calculator, a memory card, a tape recorder, a radio, a backup power supply, and a memory card. For other consumer use, automobiles, electric vehicles, motors, lighting equipment, toys,
Game devices, road conditioners, irons, watches, strobes, cameras, medical devices (pacemakers, hearing aids, shoulder massagers, etc.). Furthermore, it can be used for various military purposes and space applications. Further, it can be combined with a solar cell.

[0050]

The present invention will be described in more detail with reference to the following specific examples.
As will be described, the present invention may be practiced without departing from the gist of the invention.
It is not limited to the example. Synthesis Example-1 6.7 g of tin monoxide, 10.3 g of stannous pyrophosphate, α-
2.87 g of alumina, 1.7 g of boric anhydride, cesium carbonate
1.63 g and 0.73 g of secondary germanium oxide were dried.
Mixed in an alumina crucible and placed in a nitrogen atmosphere for 15 minutes.
The temperature is raised to 500 ° C at a rate of 500 ° C / min and calcined at 500 ° C for 3 hours.
did. Thereafter, it is further 1200 at 15 ° C./min in a nitrogen atmosphere.
After heating to 1200 ° C and firing at 1200 ° C for 12 hours, 10 ° C
/ Minute to room temperature. Take it out of the firing furnace
This is coarsely pulverized and further pulverized with a jet mill to obtain an average particle size.
7μm negative electrode material SnGe_0.07Al_0.4 B_0.5 P_0.5 C
s _0.1 O_3.79(Compound Example 1) was obtained. Use CuKα ray
Peak at around 28 ° in 2θ value in the X-ray diffraction method
Having a broad peak, and a 2θ value of 40
No crystalline diffraction line is observed in the range from 70 ° to 70 °
Was.

In the same manner, stoichiometric amounts of raw materials were mixed, fired, and pulverized to synthesize Compound Examples 23 and 4.
Further, those compounds had a broad scattering band having a peak at 20 ° to 40 ° in 2θ value in an X-ray diffraction method using CuKα ray. 20 ° in 2θ value
When the diffraction line intensity at the apex of the broad scattering band which is observed at the angle of 40 ° or more and A is 40 ° or more and 70 ° or less in terms of the 2θ value, the strongest intensity is B (crystallinity). (B = 0) when no diffraction line was obtained, the value of B / A was B / A = 0 for all of the above compounds. Compound Example-2 SnK _0.07 Al _0.4 B _0.3 P _0.5 Cs
_0.1 O _3.38 Compound Example-3 SnBa _0.07 Al _0.4 B _0.5 P _0.7 Cs
_0.1 K _0.1 O _4.27 Compound Example-4 SnMg _0.05 Al _0.4 B _0.6 P _0.5 Cs
_0.1 O _{3. 85}

Example 1 Compound-1 synthesized in Synthesis Example 1 was used as a negative electrode material, and it was mixed at a ratio of 86% by weight, flake graphite 6% by weight, and acetylene black 3% by weight. 4% by weight of an aqueous dispersion of polyvinylidene fluoride and 1% by weight of carboxymethylcellulose were added as a binder, and kneaded with water as a medium to obtain a mixture slurry A-1. Particle size 1μ
m-α-alumina 85% by weight, flaky graphite 10% by weight, aqueous dispersion of polyvinylidene fluoride 4% by weight, and carboxymethylcellulose 1% by weight, using water as a medium, adjust the pH to 10.3 with lithium hydroxide. Then, the mixture was kneaded to prepare a slurry B-1. 63% by weight of α-alumina having a particle size of 2 μm, 32% by weight of flake graphite, 2.5% by weight of an aqueous dispersion of polyvinylidene fluoride, 2% by weight of carboxymethylcellulose, and 0.5% by weight of sodium alkylbenzenesulfonate. Using water as a medium, the pH was adjusted to 10.7 with lithium hydroxide, followed by kneading to prepare a slurry B-2. B-1 was applied on the slurry A-1, and B-2 was further applied thereon by simultaneous extrusion coating on both sides of a copper foil having a thickness of 18 μm by an extrusion method, followed by drying and compression molding with a calender press machine. For 20 minutes, and cut into a predetermined width and length to produce a strip-shaped negative electrode sheet-1. The thickness of the negative electrode sheet is 128 μm
Met. The thickness of the A-1 layer was 51 μm on one side, the B-1 layer was 3.3 μm, and the B-2 layer was 0.9 μm. As a positive electrode material, 86.4% by weight of LiCoO ₂ , 4% by weight of flaky graphite, 3% by weight of acetylene black, 0.6% by weight of sodium hydrogen carbonate, and 2.5% aqueous dispersion of polytetrafluoroethylene as a binder % By weight, 2.5% by weight of an aqueous dispersion of polyvinylidene fluoride and 1% by weight of sodium polyacrylate were added, and kneaded using water as a medium to obtain a mixture slurry C-1. The obtained slurry was applied to both sides of a 15 μm-thick aluminum foil in the same manner as described above, dried, subjected to a heat treatment at 250 ° C. for 15 minutes, compression-molded with a calender press, and formed to a predetermined width and length. It cut | disconnected and produced the belt-shaped positive electrode sheet-1. Then, a 210 μm strip-shaped positive electrode sheet-1 was produced. The ratio of the applied amount of the negative electrode material on the negative electrode sheet-1 and the applied amount of the positive electrode material on the positive electrode sheet-1 per unit area was positive electrode material / negative electrode material = 5.7.

After nickel and aluminum lead plates were spot-welded to the ends of the negative electrode sheet and the positive electrode sheet, dehydration drying was performed at 250 ° C. for 1 hour in dry air having a dew point of −40 ° C. or less. Further, the dehydrated and dried positive electrode sheet (8), the microporous polyethylene film separator, the dehydrated and dried negative electrode sheet (9) and the separator (10) were laminated in this order, and this was spirally wound by a winding machine.

This wound body was housed in a nickel-plated iron bottomed cylindrical battery can (11) also serving as a negative electrode terminal. LiPF ₆ and LiBF ₄ are each added in an amount of 0.1 to 1 liter.
An electrolyte containing 9,0.1 mol and a solvent composed of a mixed solution of ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl propionate in a volume ratio of 2: 4: 3: 1 was injected into the battery can. The battery lid (12) having the positive electrode terminal was caulked via a gasket (13) to produce a cylindrical battery. The positive electrode terminal (12) was connected to the positive electrode sheet (8), and the battery can (11) was connected to the negative electrode sheet (9) by a lead terminal in advance. FIG. 1 shows a cross section of a cylindrical battery. (14) is a safety valve. This is designated as Sample-1.

As a comparative example, a negative electrode sheet-A was obtained in the same manner as the negative electrode sheet-1 except that only A-1 was applied without using the slurries B-1 and B-2. Negative electrode sheet-B was obtained in the same manner as negative electrode sheet-1, except that only A-1 and B-1 were applied without using slurry B-2. Anode sheet-2 was prepared in the same manner as Anode sheet-1 except that zirconia having a particle size of 2 μm and 3 μm was used for B-1 and B-2 instead of α-alumina.
C was produced in the same manner as described above. The charge and discharge conditions are 4.2 to
The voltage was set to 2.7 V and 1.4 mA / cm ² . The results are shown below. Charge / discharge cycle property; number of cycles at which the capacity becomes 80% of the first capacity High current suitability: ratio of first discharge capacity when charge / discharge current is 7 mA / first discharge capacity when charge / discharge current is 1.4 mA Table 1 Battery No. Cycling property High current suitability Negative electrode sheet Positive electrode sheet (times) (%) 1 11 520 92 Present invention 2 A 1 380 87 Comparative example 3 B 1 390 88 Comparative example 4 2 1 510 92 Present invention 5 C 1 390 88 Comparative example Batteries 1, 4 having two or more layers containing solid fine particles of the present invention
Are excellent in the charge / discharge cycle property and excellent in the charge / discharge characteristics using a high current, as compared with Comparative Examples 2, 3, and 5.

Example 2 A positive electrode sheet 2 was prepared in the same manner as the positive electrode sheet 1 of Example 1, except that the amount of the slurry C-1 described in Example 1 was reduced to 53%. A negative electrode sheet 1 described in Example 1 was prepared, and steps up to dehydration at 250 ° C. for 1 hour were performed. A 30 μm-thick lithium metal foil was cut into strips on the negative electrode sheet after dehydration, and 1.4 g per 1 m ² was attached to both sides. This is designated as Negative electrode sheet-3. The positive electrode sheet-1 was treated in the same manner as in Example-1, and this positive electrode sheet-1,
Battery 1 was prepared in the same manner as in Example 1 using negative electrode sheet-1.
1 was produced. The battery was charged to 3.3 V and left at 46 ° C. for 13 days. Thereafter, the battery was charged to 4.1 V under constant voltage control. Anode sheets-4, E, F, and G were prepared in the same manner as in Anode sheet-3 except that Anode sheet-2, A, B, and C of Example 1 were used instead of Anode sheet-1. Batteries 12 to 16 were produced in the same manner as battery 11 by combining the negative electrode sheet and the positive electrode sheet. The number of production is 100 each. The average capacities of these batteries (expressed as a relative value with the battery 11 being 100) and the percentage of batteries whose open-circuit voltage became 4.0 V or less after one month at 25 ° C. are shown. Table 2 4.0 V or less Battery No. Negative electrode sheet Positive electrode sheet Percentage of average capacity Remarks 11 32 100 0% The present invention 12 E 230 8% Comparative example 13 F 2 81 3% Comparative example 14 4 299 1% Present invention 15 G 278 3% Comparative example Book Battery 11, having two or more layers of the solid fine particle-containing layer of the invention,
The battery 14 has a higher average capacity than that of the batteries 12, 13 and 15 of the comparative examples, and preferably has a smaller ratio of batteries having a voltage of 4.0 V or less.

Example 3 As a negative electrode material, instead of compound-1, compound-2,
Example 2 was repeated using 3, 4 to obtain similar results.

Example 4 The negative electrode sheet-1 of Example 1 was cut to 57 mm, and the positive electrode sheet of Example 2 was cut to 55.5 mm. The positive and negative electrode sheets were dehydrated and dried in dry air having a dew point of −40 ° C. or less at 180 ° C. for 2 hours and the negative electrode at 210 ° C. for 2 hours. The negative electrode sheet was cut at a width of 55.5 mm and a width of 4 mm with a lithium foil having a thickness of 45 μm, and was adhered onto the mixture on both sides at a pitch of 9 mm. When cutting the lithium foil, dodecane was applied to the cutting blade to prevent lithium from adhering to the blade. About one day later, using the positive and negative electrodes prepared as described above, a positive electrode sheet, a microporous polyethylene film separator, a negative electrode sheet, and a separator were laminated in this order, and this was spirally wound by a winder. This winding machine has a portion for ultrasonically welding a lead plate made of aluminum or nickel to the ends of the positive and negative electrodes.

The wound body was housed in a nickel-plated iron bottomed cylindrical battery can also serving as a negative electrode terminal. next
Containing 0.95 and 0.05 mol of LiPF ₆ and LiBF ₄ respectively,
An electrolyte consisting of a mixed solution of ethylene carbonate and diethyl carbonate in a volume ratio of 2: 8 was injected into the battery can. The cylindrical battery 16 was formed by caulking the battery cover also serving as the positive electrode terminal via a gasket. When this battery was disassembled and the amount of todecane in the electrolytic solution was analyzed, it was 0.002% by weight based on diethyl carbonate. Battery 16 except that dodecane is not used when cutting lithium foil
A battery 17 was prepared in the same manner as described above. Also, by shortening the amount of dodecane used and the time until winding of the negative electrode sheet, the amount of dodecane in the electrolytic solution was 0.028% by weight with respect to diethyl carbonate, and the battery 18 was 0.2% by weight. A battery 19 of 1% by weight was prepared.

Using these batteries, cyclability and high current suitability were measured in the same manner as in Example 1. Batteries 16 and 17 did not differ in either cyclability or high current suitability. Battery 18 was slightly inferior to 17 in high current suitability. In particular, it was found that the capacity of the battery 18 decreased when stored at 60 ° C. Battery 19 was found to be significantly inferior in both cyclability and high current suitability, and was also unfavorable in terms of other battery performance.

[0061]

As described above, in a non-aqueous secondary battery comprising a positive electrode and a negative electrode containing a material capable of reversibly inserting and extracting lithium, a non-aqueous electrolyte containing a lithium salt, and a separator, the negative electrode material contains only 0 to 40% by weight. When a negative electrode sheet having two or more layers containing insulating solid fine particles is used, a nonaqueous secondary battery having high capacity, good cycleability, and good storage stability can be obtained.

[Brief description of the drawings]

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

[Explanation of symbols]

 8 Positive electrode sheet 9 Negative electrode sheet 10 Separator 11 Battery can 12 Battery lid 13 Gasket 14 Safety valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01M 4/62 H01M 4/62 Z

Claims (15)

[Claims] 1. A sheet-shaped positive electrode having at least one layer containing a positive electrode material which is a lithium-containing transition metal compound, a sheet-shaped negative electrode having at least one layer containing a negative electrode material capable of inserting and extracting lithium ions, made of polyolefin In a non-aqueous secondary battery comprising a porous separator and a non-aqueous electrolyte containing a lithium salt, at least one of the negative electrode sheet and the positive electrode sheet comprises three or more layers applied on a current collector, and 2 far from the current collector
A non-aqueous secondary battery characterized in that the layer contains insulating solid fine particles that do not substantially occlude or release lithium ions. 2. The two layers far from the current collector according to claim 1 are two layers having a different content of insulating solid fine particles that do not substantially occlude or release lithium ions, and the outermost layer has the insulating property. A non-aqueous secondary battery, wherein the content of solid fine particles is 5% or more lower than that of the adjacent layer. 3. The two layers far from the current collector according to claim 1 which contain insulating solid fine particles that do not substantially occlude and release lithium ions, and a hydrophilic polymer compound, and the outermost layer is a hydrophilic layer. The non-aqueous secondary battery according to claim 1, wherein the weight content of the hydrophilic polymer compound is higher than that of the adjacent layer. 4. A method according to claim 1, wherein the two layers far from the current collector include insulating solid fine particles that do not substantially occlude and release lithium ions, and conductive particles, and the outermost layer of the conductive particles. The non-aqueous secondary battery according to any one of claims 1 to 3, wherein a weight content is higher than that of the adjacent layer. 5. The two layers far from the current collector according to claim 1 contain insulating solid fine particles that do not substantially occlude or release lithium ions, and insulate the electrode material capable of storing and releasing lithium ions. 1% by weight based on the total amount of conductive solid fine particles
The content is at least 40% by weight.
5. The non-aqueous secondary battery according to any one of 4. 6. The method according to claim 1, wherein each of the two layers remote from the current collector has a thickness of 0.1 μm or more and 40 μm or less. Non-aqueous secondary battery. 7. The non-aqueous secondary battery according to claim 1, wherein the insulating solid fine particles are inorganic oxides. 8. The non-aqueous secondary battery according to claim 1, wherein the electrode sheet composed of three or more layers applied on the current collector is a negative electrode sheet. . 9. The non-aqueous secondary battery according to claim 1, wherein lithium ions are electrochemically inserted into the negative electrode material before the battery is assembled and / or in the battery. . 10. The non-aqueous solution according to claim 1, wherein a lithium metal foil having a thickness of 10 μm or more and 70 μm or less is attached to the negative electrode sheet by the lithium ion preliminary insertion method. Rechargeable battery. 11. The amount of the lithium metal foil is 1 g of the negative electrode material.
The non-aqueous secondary battery according to any one of claims 1 to 10, wherein the non-aqueous secondary battery has a weight of 10 mg or more and 2 g or less. 12. The negative electrode material is selected from the group 13 and 14 of the periodic table.
The non-aqueous secondary battery according to any one of claims 1 to 11, wherein the non-aqueous secondary battery is an oxide or a chalcogenide mainly containing at least one element selected from elements belonging to Group 15 and Group 15. 13. The method according to claim 1, wherein the negative electrode material is an oxide or a chalcogenide mainly containing at least one element selected from Pb, Sn, Ge or Si. The non-aqueous secondary battery according to the above. 14. The non-aqueous secondary battery according to claim 1, wherein the negative electrode material is an amorphous oxide mainly composed of Sn. 15. The negative electrode material according to the general formula (1), SnM ¹ _a M ² _b O _s (1), wherein M ¹ is at least one element selected from the group consisting of Al, B, P, Ge and Si. , M ² represents at least one element selected from Group 1 elements, Group 2 elements, Group 3 elements, and halogen elements of the periodic table;
The following number, b is a number from 0.01 to 1 and 0.2 <
a + b <2, s represents a number from 1 to 6. 2. An amorphous oxide represented by the formula (1):
5. The non-aqueous secondary battery according to any one of 4.