JPH09199168A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-capacity nonaqueous electrolyte secondary battery having a high capacity and good charge/discharge cycle characteristics by using an oxide negative electrode and an electrolyte containing organic acid and/or organic acid salt in combination. SOLUTION: The positive electrode of this nonaqueous electrolyte secondary battery contains a material capable of reversibly storing/discharging lithium, and the negative electrode contains three or more kinds of atoms selected from 1, 2, 13, 14, 15 group atoms in the periodic table and is mainly made of an amorphous chalcogen compound and/or an amorphous oxide. A nonaqueous electrolyte contains lithium salt, and it contains at least one kind of organic acid and/or organic acid salt. The nonaqueous electrolyte secondary battery having a large capacity, excellent charge/discharge characteristics, and little deterioration of the discharge capacity by repeated charges/discharges is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-capacity nonaqueous electrolyte secondary battery having excellent charge / discharge cycle characteristics, wherein the negative electrode material is mainly composed of an amorphous chalcogen compound and
Also, the present invention relates to improvement of charge / discharge characteristics such as charge / discharge cycle life of a nonaqueous electrolyte secondary battery having a large discharge capacity, which is an amorphous oxide.

[0002]

2. Description of the Related Art As a negative electrode material for a non-aqueous electrolyte secondary battery, lithium metal and lithium alloy are typical, but when they are used, so-called dendrite in which lithium metal grows in a dendritic manner during charge and discharge is generated. However, dangers such as fire were caused due to the internal short circuit or the high activity of the dendrite itself. On the other hand, fired carbonaceous materials capable of reversibly inserting and releasing lithium have come into practical use. The disadvantage of this carbonaceous material is that it has conductivity in itself, so lithium metal may be deposited on the carbonaceous material during overcharging or rapid charging, resulting in the precipitation of dendrites. . In order to avoid this, we have devised a charger or adopted a method of reducing the positive electrode active material to prevent overcharging, but the latter method limits the amount per active material. Therefore, the discharge capacity is also limited. In addition, since the density of the carbonaceous material is relatively small, the discharge capacity is limited in the double sense that the capacity per volume is low. It is disclosed in JP-A-61-54165 and JP-A-2-82447 that a carbon material is used by pressure bonding or laminating a lithium foil.
2-215062, 3-122974, 3-27
2571, the same 5-144471, the same 5-144472,
Although disclosed in JP-A-5-144473 and JP-A-5-151995, the carbon material is used as the negative electrode active material, and the above problems are not essentially solved.

On the other hand, as negative electrode materials other than lithium metal, lithium alloys, and carbonaceous materials, lithium of TiS ₂ , LiTiS ₂ (US Pat. No. 983476), WO ₂ , FeO ₃ capable of inserting and extracting lithium ions. Compound (JP-A-3-112070), Nb ₂ O ₅ (Japanese Patent Publication No.
2-59412, JP-A-2-82447), iron oxide, F
eO, Fe ₂ O ₃ , Fe ₃ O ₄ , cobalt oxide, Co
_{O, Co 2 O 3, Co} 3 O 4 ( JP-A-3-29186
2) is known. None of these compounds has a low redox potential, and it has not been possible to realize a non-aqueous electrolyte secondary battery having a high discharge potential of 3 V class. Moreover, the discharge capacity is not satisfactory.

For the purpose of improving the above-mentioned drawbacks, a non-aqueous electrolyte secondary battery having a high discharge potential with an average discharge voltage of 3 to 3.6 V is used as a negative electrode material containing Sn, V, Si,
It has been proposed to use oxides such as B and Zr, and composite oxides thereof (Japanese Patent Laid-Open No. 174818/1993).
6-60867, 6-275267, 6-325
765, 6-338324, EP-615296).
Oxides such as Sn, V, Si, B, and Zr, and
By combining these composite oxides with a positive electrode of a transition metal compound containing lithium of a certain kind, the average discharge voltage is 3 to 3.6 V class, the discharge capacity is large, and dendrite generation in the practical range is almost zero. Although a non-aqueous electrolyte secondary battery having extremely high safety is provided, there is a problem that the charge / discharge cycle characteristics are not sufficient.

[0005]

An object of the present invention is to improve the charge / discharge cycle characteristics of a non-aqueous electrolyte secondary battery having a large discharge capacity.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a positive electrode and a negative electrode containing a material capable of reversibly inserting and extracting lithium,
A non-aqueous electrolyte secondary battery comprising a non-aqueous electrolyte containing a lithium salt and a separator, the non-aqueous electrolyte secondary battery being characterized in that the electrolyte contains at least one organic acid.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the following modes are provided.
However, the present invention is not limited thereto.
Not. (1) Positive electrode containing a material capable of reversibly inserting and extracting lithium
Pole, selected from the periodic table 1, 2, 13, 14, 15 atoms
Predominantly amorphous chalcogen containing three or more atoms
Negative electrode composed of compound and / or amorphous oxide, lithium
Non-aqueous electrolyte including a non-aqueous electrolyte and separator
Secondary battery, at least one nonaqueous electrolyte is used.
Characterized by containing an organic acid and / or an organic acid salt
Non-aqueous electrolyte secondary battery. (2) Organic acid and / or organic contained in the non-aqueous electrolyte
The acid salt is at least one carboxylic acid and / or carbohydrate.
Item 2. The non-aqueous electrolyte secondary battery according to item 1, which is a phosphate. (3) Organic acid and / or organic contained in the non-aqueous electrolyte
The acid salt is at least one polycarboxylic acid and / or polycarboxylic acid.
Item 3. The non-aqueous electrolyte secondary battery which is a carboxylic acid salt
pond. (4) Organic acid and / or organic contained in the non-aqueous electrolyte
The content of the acid salt is 0.001 with respect to the supporting salt in the electrolyte.
Item characterized by being at least 10% by weight
The non-aqueous electrolyte secondary battery according to any one of 1 to 3. (5) The supporting salt of Item 4 is LiPF₆And / or LiBF
_FourA non-aqueous electrolyte secondary battery comprising: (6) At least one of the negative electrode materials has the general formula (1)
In any one of items 1 to 5, characterized in that
Non-aqueous electrolyte secondary battery listed. M₁M_2pM_4qM_6r General formula (1) (wherein M₁, M_TwoAre different Si, Ge, Sn, P
at least one selected from b, P, B, Al and Sb,
M_FourIs Li, Na, K, Rb, Cs, Mg, Ca, S
at least one selected from r and Ba, M₆Is O, S,
At least one selected from Te, p and q are each 0.0
01-10 and r represent the number of 1.00-50. (7) At least one of the negative electrode materials has the general formula (2)
Item 7. The non-aqueous electrolyte secondary according to Item 6, characterized in that
battery. SnM_3pM_5qM_7r General formula (2) (wherein M_ThreeIs selected from Si, Ge, Pb, P, B and Al.
At least one, M_FiveIs Li, Na, K, R
b, Cs, Mg, Ca, Sr, Ba
Both kinds, M₇Is at least one selected from O and S,
p and q are 0.001 to 10, and r is 1.00 to 50
Represents a number. (8) At least one of the positive electrode materials is Lix Co
O_Two, Lix NiO_Two, Lix MnO_Two, Li_xCo_a
Ni (_1-a) O_Two, Li_xCo_bV (_1-b) O_z, Li
_xCo_bFe (_1-b) O_Two, Li_xMn_TwoO_Four, Li_x
Mn_cCo (_2-c) O _Four, Li_xMn_cNi (_2-c) O
_Four, Li_xMn_cV (_2-c) O_Four, Li_xMn _cFe (
_2-c) O_Four(In the formula, x = 0.2 to 1.2, a = 0.1
~ 0.9, b = 0.8 ~ 0.98, c = 1.6 ~ 1.9
6, z = 2.01 to 2.3)
The non-aqueous electrolyte secondary battery according to any one of Items 1 to 7.
pond.

The structure of the present invention will be described in detail below. In the present invention, the charge and discharge cycle characteristics can be improved without impairing the high capacity of the non-aqueous electrolyte secondary battery by including at least one organic acid in the electrolyte. Examples of the organic acid that can be used in the present invention include at least one carboxylic acid, sulfonic acid, sulfinic acid, sulfenic acid, phosphoric acid mono (or di) ester, phosphonic acid, boric acid mono (or dicarboxylic acid) in the molecule. ) An organic compound containing an ester or a phenol can be mentioned, and an organic compound containing a plurality of the same or different acid functional groups in one molecule is also included. Preferred acid functional groups are carboxylic acid, sulfonic acid,
Phosphonic acids, particularly preferred are carboxylic acids, and more preferred are dicarboxylic acids, tricarboxylic acids and the like. The organic acid salts include the above-mentioned organic acids and L
Examples thereof include salts with alkali metals such as i, Na, K, Mg and Ca or alkaline earth metals and quaternary ammonium ions. Examples of the organic acid of the present invention are shown below, but the present invention is not limited thereto. Examples of organic acids include acetic acid, propionic acid, butyric acid, palmitic acid, monocarboxylic acids such as stearic acid, glyoxylic acid, pyruvic acid, acetoacetic acid, levulinic acid, phenylacetic acid, substituted carboxylic acids such as benzoylpropionic acid,
Aromatic carboxylic acids such as benzoic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, 1.4-cyclohexanedicarboxylic acid, maleic acid, aliphatic or aromatic dicarboxylic acids such as phthalic acid, trimellitic acid, Examples thereof include polymers containing aromatic polycarboxylic acid such as pyromellitic acid, polyacrylic acid, polymethacrylic acid and the like, and methanesulfonic acid, benzenesulfonic acid, phenylphosphonic acid and the like.

The content of organic acid or organic acid salt contained in the electrolyte is preferably 0.0001 to 0.1 mol / liter, and more preferably 0.001 to 0.1 mol / liter, based on the solvent of the electrolytic solution.
L is more preferred. The content of the organic acid and the organic acid salt with respect to the supporting salt contained in the electrolyte is 0.001.
% To 10% by weight is preferred, 0.01-5% by weight
Is more preferred.

The electrolyte is generally composed of a solvent and a supporting salt which is soluble in the solvent, and the supporting salt is preferably a lithium salt (anion and lithium cation). The electrolyte solvent that can be used in the present invention, propylene carbonate, ethylene carbonate, butylene carbonate,
Dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, methyl formate, methyl acetate, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide,
Dimethylformamide, dioxolane, dioxane, acetonitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, 3-methyl-2-oxazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, ethyl ether, 1,3 An aprotic organic solvent such as propane sultone can be mentioned, and one kind or a mixture of two or more kinds thereof is used. Of these, carbonate-based solvents are preferred, and those containing cyclic carbonate and / or non-cyclic carbonate are preferred. As the cyclic carbonate, ethylene carbonate and propylene carbonate are preferable. In addition, the non-cyclic carbonate preferably contains diethyl carbonate, dimethyl carbonate, and methyl ethyl carbonate. Examples of the supporting salt which can be used in the present invention and which is soluble in these solvents include LiClO ₄ and Li
BF ₄ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ C
O ₃ , LiAsF ₆ , LiSbF ₆ , lower aliphatic lithium carboxylate, LiAlCl ₄ , LiCl, LiBr,
Li salts such as LiI, lithium chloroborane and lithium tetraphenylborate can be used, and one or more of these can be used in combination. Among them, those in which LiBF ₄ and / or LiPF ₆ are dissolved are preferable. The concentration of the supporting salt is not particularly limited, but is preferably 0.2 to 3 mol per liter of the electrolyte solution.
The combination of electrolytes that can be used in the present invention includes LiCF ₃ S in an electrolytic solution in which ethylene carbonate, propylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate or diethyl carbonate is appropriately mixed.
O ₃ , LiClO ₄ , LiBF ₄ and / or Li
An electrolyte containing PF ₆ is preferred. In particular, LiCF ₃ SO ₃ , LiClO ₄ , LiBF _{4 in} a mixed solvent of propylene carbonate or ethylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate.
And / or an electrolyte containing LiPF ₆ is preferred,
Particularly, those containing at least ethylene carbonate and LiPF ₆ are preferable. The amount of these electrolytes added to the battery is not particularly limited, but a necessary amount can be used depending on the amount of the positive electrode active material or the negative electrode material and the size of the battery.

Hereinafter, other materials and manufacturing methods for making the non-aqueous electrolyte secondary battery of the present invention will be described in detail. The positive and negative electrodes used in the nonaqueous electrolyte secondary battery of the present invention can be prepared by applying a positive electrode mixture or a negative electrode mixture on a current collector. The positive electrode or negative electrode mixture can contain a conductive agent, a binder, a dispersant, a filler, an ionic conductive agent, a pressure enhancer, and various additives, respectively, in addition to the positive electrode active material or the negative electrode material.

The negative electrode material used in the present invention is preferably 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, the strongest intensity of the crystalline diffraction lines observed at 40 ° to 70 ° in 2θ value is 20 ° in 2θ value.
It is preferably 500 times or less, more preferably 100 times or less, particularly preferably 5 times or less, and most preferably the crystallinity of the diffraction line intensity at the peak of the broad scattering band observed at 40 ° or more. Has no diffraction line.

The negative electrode material used in the present invention is preferably represented by the following general formula (1). M ₁ M _2p M _4q M _6r General formula (1) In the formula, M ₁ and M ₂ are different from each other. Si, Ge, Sn, Pb,
It is at least one selected from P, B, Al, and Sb, preferably Si, Ge, Sn, P, B, and Al, and particularly preferably Si, Sn, P, B, and Al.
M ₄ is Li, Na, K, Rb, Cs, Mg, Ca, S
It is at least one selected from r and Ba, preferably K, Cs, Mg and Ca, and particularly preferably Cs and Mg.
It is. M ₆ is at least one selected from O, S and Te, preferably O and S, and particularly preferably O.
It is. p and q are each 0.001 to 10, preferably 0.01 to 5, and particularly preferably 0.01 to 2;
It is. r is 1.00 to 50, preferably 1.
00 to 26, particularly preferably 1.02 to 6. The valences of M ₁ and M ₂ are not particularly limited, and may be a single valence or a mixture of each valence. Further, the ratio of M ₁ , M ₂ and M ₄ can be continuously changed within the range of 0.001 to 10 molar equivalents of M ₂ and M ₄ with respect to M ₁ , and accordingly the amount of M ₆ (generally, In equation (1), the value of r) also changes continuously.

Of the compounds listed above, it is preferred in the present invention that M ₁ is Sn, and the compound represented by the general formula (2)
It is represented by SnM _3p M _5q M _7r General formula (2) In the formula, M ₃ is at least one selected from Si, Ge, Pb, P, B and Al, preferably Si, Ge,
P, B, Al, particularly preferably Si, P, B, A
l. M ₅ is Li, Na, K, Rb, Cs, Mg,
At least one selected from Ca, Sr, and Ba,
Preferably, it is Cs or Mg, particularly preferably Mg.
M ₇ is at least one selected from O and S, and is preferably O. p and q are each 0.001 to 10, preferably 0.01 to 5, more preferably 0.01 to 1.5, and particularly preferably 0.7 to 1.
5 r is 1.00 to 50, preferably 1.r
00 to 26, particularly preferably 1.02 to 6.

Examples of the negative electrode material of the present invention are shown below.
The invention is not limited to these. SnAl_0.4
B_0.5P_0.5K_0.1O_3.65, SnAl_0.4B_0.5P_0.5
Na _0.2O_3.7, SnAl_0.4B_0.3P_0.5Rb_0.2O
_3.4, SnAl_0.4B_0.5P _0.5Cs_0.4O_3.65, Sn
Al_0.4B_0.5P_0.5K_0.1Ge_0.05O_3.85, SnAl
_0.4B_0.5P_0.5K_0.1Mg_0.1Ge_0.02O_3.83, Sn
Al_0.4B_0.4P_0.4O_3.2, SnAl_0.3B_0.5P
_0.2O_2.7, SnAl_0.3B_0.5P_0.2O_2.7, SnA
l_0.4B_0.5P_0.3Ba_0.08Mg_0.08O_3.26, SnAl
_0.4B_0.4P_0.4Ba_0.08O_3.28, SnAl_0.4B_0.5
P_0.5O_3.6, SnAl_0.4B_0.5P_0.5Mg_0.1O
_3.7.

SnAl_0.5B_0.4P_0.5Mg_0.1F_0.2
O_3.65, SnB_0.5P_0.5Li_0.1Mg_0.1F_0.2O
_3.05, SnB_0.5P_0.5K_0.1Mg_0.1F_0.2O_3.05,
SnB_0.5P_0.5K_0.05Mg_0.05F_0.1O_3.03, SnB
_0.5P_0.5K_0.05Mg_0.1F_0.2O_3.03, SnAl_0.4
B_0.5P_0.5Cs_0.1Mg_0.1F_0.2O_3.65, SnB
_0.5P_0.5Cs_0.05Mg_0.05F_0.1O_3.03, SnB_0.5
P_0.5Mg_0.1F_0.1O_3.05, SnB_0.5P_0.5Mg
_0.1F_0.2O_Three, SnB_0.5P_0.5Mg_0.1F_0.06O
_3.07, SnB_0.5P_0.5Mg_0.1F_0.14O _3.03, SnP
Ba_0.08O_3.58, SnPK_0.1O_3.55, SnPK_0.05M
g_0.05O_{3. 58}, SnPCs_0.1O_3.55, SnPBa_0.08
F_0.08O_3.54, SnPK_0.1Mg_0.1F_0.2O_3.55, S
nPK_0.05Mg_0.05F_0.1O_3.53, SnPCs_0.1Mg
_0.1F_0.2O_3.55, SnPCs_0.05Mg_0.05F_0.1O
_3.53.

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

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. 4 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 _0.5 Al _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 A
_{l 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 ₃ , SnSi _0.6 B _0.2 P
_0.2 O ₃ , SnSi _0.8 Al _0.2 O _2.9 , SnSi _0.8
Al _0.3 B _0.2 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 _0.2 O _3.1 .

Sn_0.9Mn_0.3B_0.4P_0.4Ca_0.1R
b_0.1O_2.95, Sn_0.9Fe_0.3B_0.4P_0.4Ca_0.1
Rb_0.1O_2.95, Sn_0.8Pb_0.2Ca_0.1P_0.9O
_3.35, Sn_0.3Ge_0.7Ba_0.1P_0.9O_{3. 35}, Sn
_0.9Mn_0.1Mg_0.1P_0.9O_3.35, Sn_0.2Mn_0.8
Mg_0.1P_0.9O_3.35, Sn_0.7Pb_0.3Ca_0.1P
_0.9O_3.35, Sn_0.2Ge_0.8Ba_0.1P _0.9O_3.35.

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

The amount of the light metal to be inserted into the negative electrode material of the present invention may be close to the deposition potential of the light metal.
The amount is preferably from 50 to 700 mol%, more preferably from 100 to 600 mol%, per negative electrode material. It is preferable that the release amount be larger than the insertion amount. How to insert light metal
Electrochemical, chemical and thermal methods are preferred. As the electrochemical method, a method of electrochemically inserting a light metal contained in the positive electrode active material or a method of directly electrochemically inserting a light metal or an alloy thereof from a light metal is preferable. As a chemical method, there is a method of mixing or contacting with a light metal or a method of reacting with an organic metal such as butyllithium. Electrochemical and chemical methods are preferred. The light metal is particularly preferably lithium or lithium ion.

In the present invention, the compounds represented by the general formulas (1) and (2) as described above are mainly used as the negative electrode material, so that the charge and discharge cycle characteristics are more excellent, the high discharge voltage and the high discharge voltage are high. It is possible to obtain a non-aqueous electrolyte secondary battery with high capacity, high safety and excellent high current characteristics. In the present invention, a particularly excellent effect can be obtained by using a compound containing Sn and having a divalent Sn valence as the negative electrode material. The valence of Sn can be determined by a chemical titration operation. For example, Phys
ics and Chemistry of Glasses Vol.8 No.4 (1967)
It can be analyzed by the method described on page 65. Also, S
It can also be determined from the night shift by n solid state nuclear magnetic resonance (NMR) measurement. For example, in wide measurement, Sn (zero-valent Sn) has a peak in an extremely low magnetic field of around 7,000 ppm with respect to Sn (CH ₃ ) ₄ , whereas SnO (= 2 valence) has a peak of around 100 ppm.
In SnO ₂ (= tetravalent), it appears near −600 ppm. In the case of having the same ligand as described above, the knight shift greatly depends on the valence of Sn as the central metal.
The valence can be determined at the peak position determined by Sn-NMR measurement. Various compounds can be included in the negative electrode material of the present invention. For example, transition metals (Sc, Ti, V,
Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Z
r, Nb, Mo, Tc, Ru, Rh, Pd, Ag, C
d, lanthanoid metal, Hf, Ta, W, Re, O
s, Ir, Pt, Au, Hg) and Group 17 elements of the periodic table (F, Cl). Further, it may contain dopants of various compounds (for example, compounds of Sb, In, and Nb) that increase electron conductivity. The amount of the compound added is preferably 0 to 20 mol%.

The method for synthesizing the composite oxide mainly composed of the oxides represented by the general formulas (1) and (2) in the present invention is a firing method,
Any of the solution methods can be employed. For example, the firing method will be described in detail. M ₁ compound, M ₂ compound and M ₄ compound (M ₁ and M ₂ are different from Si, Ge, S
n, Pb, P, B, Al, Sb, M ₄ are Mg, Ca, S
r, Ba) may be mixed and fired. Examples of the Sn compound include SnO, SnO ₂ , Sn ₂ O ₃ , and Sn.
₃ O ₄ , Sn ₇ O ₁₃ .H ₂ O, Sn ₈ O ₁₅ , stannous hydroxide, stannic oxyhydroxide, stannic acid, stannous oxalate, stannous phosphate, orthostannic acid, meta Stannic acid, parastannic acid, stannous fluoride,
Examples thereof include stannic fluoride, stannous chloride, stannic chloride, stannous pyrophosphate, tin phosphide, stannous sulfide, and stannic sulfide. Examples of the Si compound include SiO ₂ , S
Organic silicon compounds such as iO, tetramethylsilane and tetraethylsilane, alkoxysilane compounds such as tetramethoxysilane and tetraethoxysilane, and hydrosilane compounds such as trichlorohydrosilane can be exemplified. Examples of the Ge compound include GeO ₂ , GeO, and alkoxy germanium compounds such as germanium tetramethoxide and germanium tetraethoxide. Examples of the Pb compound include PbO ₂ and P
bO, Pb ₂ O ₃ , Pb ₃ O ₄ , lead nitrate, lead carbonate, lead formate, lead acetate, lead tetraacetate, lead tartrate, lead diethoxide, lead di (isopropoxide) and the like can be mentioned. Examples of the P compound include phosphorus pentoxide, phosphorus oxychloride, phosphorus pentachloride, phosphorus trichloride, phosphorus tribromide, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, stannous pyrophosphate, boron phosphate and the like. Can be mentioned. As the B compound, for example, boron trioxide, boron trichloride,
Examples thereof include boron tribromide, boron carbide, boric acid, trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, boron phosphide, and boron phosphate. Examples of the Al compound include aluminum oxide (α-alumina, β-alumina), aluminum silicate, aluminum tri-iso-propoxide, aluminum tellurite, aluminum chloride, aluminum boride, aluminum phosphide, aluminum phosphate, and lactic acid. Examples include aluminum, aluminum borate, aluminum sulfide, aluminum sulfate, and aluminum boride. Examples of the Sb compound include diantimony trioxide and triphenylantimony.

As the Mg, Ca, Sr, and Ba compounds,
Each oxide, hydroxide, carbonate, phosphate, sulfate,
Nitrate, aluminum compound and the like can be mentioned.

The firing conditions are preferably a temperature raising rate of 4 ° C. or more and 2000 ° C. or less per minute,
More preferably, it is 6 ° C. or higher and 2000 ° C. or lower. It is particularly preferably 10 ° C or more and 2000 ° C or less, and the firing temperature is preferably 250 ° C or more and 1500 ° C or less, more preferably 350 ° C or more and 1500 ° C or less.
Or less, particularly preferably 500 ° C. or more and 1500 ° C.
And the firing time is 0.01 hours or more 1
It is preferably 00 hours or less, more preferably 0.5 hours or more and 70 hours or less, particularly preferably 1 hour or more and 20 hours or less, and the temperature decreasing rate is 2 ° C or more and 107 ° C or less per minute. It is more preferably 4 ° C. or higher and 10 7 ° C. or lower, particularly preferably 6 ° C. or higher and 10 7 ° C. or lower, and particularly preferably 1
It is above 0 ° C and below 10 7 ° C. The rate of temperature rise in the present invention is an average rate of temperature rise from “50% of firing temperature (displayed in ° C)” to “80% of firing temperature (displayed in ° C)”. "Firing temperature (℃
80% of the display) to “50% of the firing temperature (° C)”
Is the average rate of temperature drop to reach. The temperature may be cooled in a firing furnace, or may be taken out of the firing furnace and put into, for example, water for cooling. In addition, the gun method, Hammer-Anvil method, slap method, and the like described in page 217 of ceramics processing (Gihodo Shuppan 1987).
Gas atomizing method, plasma spray method, centrifugal quenching method,
An ultra-quenching method such as a melt drag method can also be used. See also New Glass Handbook (Maruzen 199
1) Cooling may be performed using a single roller method or a twin roller method described on page 172. 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 average particle size of the compounds represented by the general formulas (1) and (2) used in the present invention is preferably 0.1 to 60 μm, particularly preferably 1.0 to 30 μm, and 2.0 to
20 μm is more preferable. In order to obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, mortar, ball mill, sand mill, vibrating ball mill,
A satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can also be performed as necessary. Classification is preferably performed to obtain a desired particle size. The classification method is not particularly limited, and a sieve, an air classifier, a drainage, and the like can be used as necessary. Classification can be performed both in a dry type and a wet type.

A more preferable lithium-containing transition metal oxide positive electrode material used in the present invention is a lithium compound / transition metal compound (wherein the transition metal means Ti, V, C).
It is preferable to mix and synthesize so that the total molar ratio of r, Mn, Fe, Co, Ni, Mo, and W) is 0.3 to 2.2. As a particularly preferable lithium-containing transition metal oxide positive electrode material used in the present invention, a lithium compound / transition metal compound (wherein the transition metal is at least one selected from V, Cr, Mn, Fe, Co and Ni) The total molar ratio of
It is preferable to synthesize them by mixing them to 2.2.
Particularly preferable lithium-containing transition metal oxide positive electrode material used in the present invention is Lix QOy (wherein Q is mainly at least one of Co, Mn, Ni, V, and F).
e), x = 0.2-1.2, y = 1.4
To 3). As Q, besides transition metals, Al, Ga, In, Ge, Sn, Pb, Sb, Bi,
Si, P, B, etc. may be mixed. The mixing amount is preferably 0 to 30 mol% with respect to the transition metal.

More preferred lithium used in the present invention
Examples of the metal-containing metal oxide positive electrode material include Li_xCoO_Two,
Li_xNiO_Two, Li_xMnO_Two, Li_xCo_aNi
_1-aO _Two, Li_xCo_bV_1-bOz, Li_xCo_bFe
_1-bO_Two, Li_xMn_TwoO_Four, Li_xMn_cCo_2-cO
_Four, Li_xMn_cNi_2-cO_Four, Li_xMn_cV_2-cO
_Four, Li_xMn_cFe_2-cO_Four(Where x = 0.7-
1.2, a = 0.1-0.9, b = 0.8-0.98,
c = 1.6 to 1.96, z = 2.01 to 2.3).
Can be Most preferred lithium containing used in the present invention
As the transition metal oxide cathode material, Li_xCoO_Two, L
i_xNiO_Two, Li_xMnO_Two, Li_xCo_aNi_1-a
O2, Li_xMn_TwoO_Four, Li_xCo_bV_1-bO_z(This
Where x = 0.7-1.2, a = 0.1-0.9, b =
0.9 to 0.98, z = 2.01 to 2.3).
You. Most Preferred Lithium-Containing Transitions Used in the Present Invention
As a metal oxide positive electrode material, Li_xCoO_Two, Li_x
NiO_Two, Li_xMnO_Two, Li_xCo_aNi
_1-aO_Two, Li_xMn_TwoO_Four, Li_xCo_bV_1-bO
_z(Where x = 0.7-1.2, a = 0.1-0.9,
b = 0.9-0.98, z = 2.02-2.3)
Can be Here, the above x value is a value before the start of charging / discharging.
Change with charging and discharging.

The conductive carbon compound that can be used in the present invention may be any electron-conductive material that does not undergo a chemical change in the constructed battery. Specific examples include flake graphite, flake graphite, natural graphite such as earthy graphite, petroleum coke, coal coke, celluloses, sugars, high-temperature fired bodies such as mesophase pitch, and graphite such as artificial graphite such as vapor-grown graphite. Carbon blacks such as acetylene black, furnace black, ketjen black, channel black, lamp black and thermal black, asphalt pitch, coal tar, activated carbon, meso fuse pitch, polyacene and the like. Of these, graphite and carbon black are preferable. As non-carbon conductive agents, conductive fibers such as metal fibers, metal powders such as copper, nickel, aluminum and silver, conductive whiskers such as zinc oxide and potassium titanate, conductive metals such as titanium oxide. Oxides and the like can be included alone or as a mixture thereof as required.

The amount of the conductive agent added to the mixture layer is preferably 6 to 50% by weight, more preferably 6 to 30% by weight, based on the negative electrode material or the positive electrode material. In the case of carbon or graphite, the content is particularly preferably 6 to 20% by weight.

As the binder for holding the electrode mixture used in the present invention, polysaccharides, thermoplastic resins, and polymers having rubber elasticity can be used alone or as a mixture thereof. Preferred binders include starch, carboxymethyl cellulose, cellulose, diacetyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium alginate,
Water-soluble polymers such as polyacrylic acid, sodium polyacrylate, polyvinylphenol, polyvinylmethylether, polyvinylalcohol, polyvinylpyrrolidone, polyacrylamide, polyhydroxy (meth) acrylate, styrene-maleic acid copolymer, polyvinyl chloride, polytetra Fluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfone (Meth) acrylates containing (meth) acrylic acid esters such as activated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate, etc. Acrylic acid ester copolymer, (meth) acrylic acid ester - acrylonitrile copolymer,
Polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene butadiene copolymer, acrylonitrile butadiene copolymer, polybutadiene, neoprene rubber, fluoro rubber, polyethylene oxide, polyester polyurethane resin, polyether polyurethane resin, polycarbonate Emulsions (latex) or suspensions of polyurethane resins, polyester resins, phenol resins, epoxy resins and the like can be given. In particular, polyacrylic ester latex, carboxymethyl cellulose, polytetrafluoroethylene, and polyvinylidene fluoride are preferable. These binders can be used alone or as a mixture. If the amount of the binder added is small, the holding power and cohesive force of the electrode mixture is weak and the cycleability is poor, and if too large, the electrode volume increases and the volume per electrode unit volume or unit weight decreases, and further, The conductivity decreases and the capacity decreases. The amount of the binder added is not particularly limited, but is 1 to 30.
% By weight, and particularly preferably 2 to 10% by weight.

The negative electrode mixture or the positive electrode mixture paste of the present invention is preferably prepared in an aqueous system. The mixture paste is prepared by first mixing the active material and the conductive agent, adding the binder (suspension of resin powder or emulsion (latex)) and water, kneading and mixing, and then mixing, It can be carried out by dispersing using a homogenizer, a dissolver, a planetary mixer, a paint shaker, a stirring mixer such as a sand mill, or a disperser. The prepared mixture paste of the positive electrode active material and the negative electrode active material is mainly used after being coated (coated) on a current collector, dried, and compressed. Coating can be performed by various methods, for example, 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. I can do it. The blade method, the knife method and the 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-mentioned coating method in accordance with the liquid physical properties and drying properties of the mixture paste, a good surface state of the coating layer can be obtained. The thickness, length and width of the coating layer are determined depending on the size of the battery. The thickness of the coating layer is particularly preferably 1 to 2000 μm in a compressed state after drying.

As a drying or dehydrating method for removing water from the pellets or sheets, a generally adopted method can be used. Hot air, vacuum, infrared rays, far infrared rays, electron beams and low humidity air can be used alone or in combination. Can be used. The temperature is preferably in the range of 80 to 350C, particularly preferably in the range of 100 to 250C. The water content is preferably 2000 ppm or less in the whole battery, and is preferably 500 ppm or less in each of the positive electrode mixture, the negative electrode mixture and the electrolyte from the viewpoint of charge / discharge cycleability.

The sheet-like electrode mixture can be compressed by a generally used pressing method, but a die pressing method and a calendar pressing method are particularly preferable. The pressing pressure is not particularly limited, but is 10 kg / cm ^{2 to 3} t / c.
m ² is preferred. The press speed of the calendar press method is
0.1 to 50 m / min is preferred. Press temperature is room temperature ~
200 ° C. is preferred.

The positive electrode and negative electrode supports, ie, current collectors, which can be used in the present invention, are made of aluminum, stainless steel, nickel, titanium or an alloy thereof for the positive electrode and copper, stainless steel for the negative electrode. Nickel, titanium,
Or, these are alloys, and are in the form of foil, expanded metal, punching metal, or wire mesh. Especially,
Aluminum foil is preferable for the positive electrode, and copper foil is preferable for the negative electrode.

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

The shape of the battery can be applied to any of buttons, coins, sheets, cylinders, corners and the like. A battery is formed by inserting an electrode wound with a pellet, a sheet, or a separator into a battery can, electrically connecting the can and the electrode, injecting an electrolyte, and sealing the battery. At this time, a safety valve can be used as a sealing plate. Further, it is preferable to use a PTC element in order to guarantee the safety of the battery.

The bottomed battery outer can which can be used in the present invention is made of nickel-plated steel plate, stainless steel plate (SUS304, SUS304L, SUS304N, S).
US316, SUS316L, SUS430, SUS4
44, etc.), a nickel-plated stainless steel plate (same as above), aluminum or its alloy, nickel, titanium, and copper.
It has a square tubular shape and a rectangular tubular shape. In particular, when the outer can also serves as the negative electrode terminal, a stainless steel plate or a nickel-plated iron steel plate is preferable, and when the outer can also serves as the positive electrode terminal, a stainless steel plate, aluminum or an alloy thereof is preferable.

The sheet-shaped mixture electrode is rolled or folded and inserted into a can, the can and the sheet are electrically connected, an electrolyte is injected, and a sealing plate is used to form a battery can. At this time, a safety valve can be used as a sealing plate. In addition to the safety valve, various conventionally known safety elements may be provided. For example, a fuse, a bimetal, a PTC element, or the like is used as the overcurrent prevention element. In addition to the safety valve, as a countermeasure against an increase in the internal pressure of the battery can, a method of making a cut in the battery can, a gasket cracking method or a sealing plate cracking method can be used. Further, the charger may be provided with a circuit incorporating measures for overcharging and overdischarging.

The total amount of electrolyte may be injected once, but it is preferable to perform the injection in two or more stages. In the case of injecting in two or more stages, even if each solution has the same composition, different compositions (for example, after injecting a non-aqueous solvent or a solution of a lithium salt dissolved in a non-aqueous solvent, a non-aqueous solvent having a higher viscosity than the solvent) are used. A solution of a lithium salt dissolved in a solvent or a non-aqueous solvent may be injected). Also, in order to shorten the electrolyte injection time, the pressure of the battery can is reduced (preferably 500 to 1).
torr, more preferably 400 to 10 torr) or
Centrifugal force or ultrasonic waves may be applied to the battery can.

For the can and 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. As a method for welding the cap, the can, the sheet, and the lead plate, a known method (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used. A conventionally known compound or mixture such as asphalt can be used as the sealing agent for sealing.

The gasket which can be used in the present invention is made of an olefin polymer, a fluorine polymer, a cellulosic polymer, a polyimide or a polyamide as a material, and the olefin polymer is preferable from the viewpoint of organic solvent resistance and low water permeability, and particularly, Polymers based on propylene are preferred. Further, it is preferably a block copolymer of propylene and ethylene.

The battery of the present invention is optionally covered with an exterior material. Examples of the exterior material include a heat-shrinkable tube, an adhesive tape, a metal film, paper, cloth, paint, a plastic case, and the like. Further, at least a part of the exterior may be provided with a portion that changes color by heat so that the heat history during use can be recognized. A plurality of batteries of the present invention are assembled in series and / or in parallel and stored in a battery pack as needed. In addition to safety elements such as positive temperature coefficient resistors, thermal fuses, fuses and / or current interrupting elements, battery packs have safety circuits (voltage, temperature, current, etc. of each battery and / or assembled battery as a whole, Then, a circuit having a function of interrupting the current may be provided. In addition to the positive and negative terminals of the whole battery pack, the positive and negative terminals of each battery, the temperature detection terminals of the whole battery pack and each battery, the current detection terminals of the whole battery pack, etc. shall be provided as external terminals on the battery pack. Can also. The battery pack may have a built-in voltage conversion circuit (such as a DC-DC converter). The connection of each battery may be fixed by welding a lead plate, or may be fixed by a socket or the like so that it can be easily detached. Further, the battery pack may be provided with a display function of the remaining battery capacity, the presence / absence of charging, the number of times of use, and the like.

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

[0046]

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.

[Preparation Example of Positive Electrode Mixture Paste; Examples and Comparative Examples] Positive electrode active material; LiCoO ₂ (a mixture of lithium carbonate and tricobalt tetroxide in a molar ratio of 3: 2 was placed in an alumina crucible and aired. Medium, heated to 750 ° C. at 2 ° C./min for 4 hours, calcined for 4 hours, further heated to 900 ° C. at a rate of 2 ° C./minute and fired at that temperature for 8 hours to be crushed. When 50 g of the washed product is dispersed in 100 ml of water, the dispersion has an electric conductivity of 0.6 mS / m and a pH of 10.
1. 200 g of a specific surface area of 0.42 m ² / g) by a nitrogen adsorption method and 10 g of acetylene black were mixed with a homogenizer, and subsequently a copolymer of 2-ethylhexyl acrylate, acrylic acid and acrylonitrile was used as a binder. 8 g of water dispersion (solid content 50% by weight), concentration 2
A 60% by weight carboxymethylcellulose aqueous solution was added and kneaded and mixed, 50 g of water was further added, and the mixture was stirred and mixed by a homogenizer to prepare a positive electrode mixture paste. [Example of preparing negative electrode mixture paste] Negative electrode active material: SnGe
_0.1 B _0.5 P _0.58 Mg _0.1 K _0.1 O _3.35 (tin monoxide 6.
7 g, tin pyrophosphate 10.3 g, diboron trioxide 1.7
g, potassium carbonate 0.7 g, magnesium oxide 0.4
g and 1.0 g of germanium dioxide were dry-mixed, placed in an alumina crucible, and heated at 10 ° C./min in an argon atmosphere at 10 ° C./min.
After heating to 00 ° C and firing at 1100 ° C for 12 hours,
3. What was taken out from the firing furnace after being cooled to room temperature at 10 ° C / min, and which was crushed by a jet mill and had an average particle size of 4.
It has a broad peak with an apex near 28 ° at 2θ value of 5 μm and an X-ray diffraction method using CuKα ray, and crystalline diffraction lines are observed at 40 ° to 70 ° at 2θ value. There wasn't. ) Is mixed with 30 g of a conductive agent (artificial graphite) with a homogenizer, 50 g of a carboxymethylcellulose aqueous solution having a concentration of 2% by weight as a binder and 10 g of polyvinylidene fluoride are added and mixed, and 30 g of water is further mixed and kneaded and mixed. Then, a negative electrode mixture paste was prepared. [Preparation of Positive Electrode and Negative Electrode Sheet] The positive electrode mixture paste prepared above was applied by a blade coater on both sides of an aluminum foil current collector having a thickness of 30 μm to give an application amount of 400 g / m ² ,
The sheet was compressed so as to have a thickness of 280 μm, dried, and then compression-molded by a roller press and cut into a predetermined size to prepare a belt-shaped positive electrode sheet. Further, it was thoroughly dehydrated and dried with a far infrared heater in a dry box (dew point; dry air at -50 ° C or lower) to prepare a positive electrode sheet. Similarly, the negative electrode mixture paste is applied to a copper foil current collector having a thickness of 20 μm, and the same method for producing the positive electrode sheet is used.
Application amount 70 g / m ² , compressed sheet thickness 90 μm
Was prepared. [Electrolyte Preparation Example (Examples 1 to 13)] 65.3 in a 200 cc narrow-mouth polypropylene container in an argon atmosphere.
2 g of ethylene carbonate was dissolved little by little, taking care that the liquid temperature did not exceed 30 ° C. Next, 0.4 g of LiBF ₄ , 12.
1 g of LiPF ₆ was dissolved little by little in the above polypropylene container, taking care so that the liquid temperature did not exceed 30 ° C. The obtained electrolyte was a colorless and transparent liquid having a specific gravity of 1.135. Moisture is 18 ppm (measured with a Karl Fischer moisture meter, Model MKC-210, manufactured by Kyoto Electronics Co., Ltd.), and free acid content is 24 ppm (measured by neutralization titration with a 0.1 N NaOH aqueous solution using bromthymol blue as an indicator). )Met. Further, the compounds shown in Table 1 were each dissolved in this electrolytic solution to a predetermined concentration to prepare an electrolyte. [Cylinder Battery Preparation Example] A positive electrode sheet, a microporous polypropylene film separator, a negative electrode sheet and a separator were laminated in this order and spirally wound.
The wound body was housed in a nickel-plated iron bottomed cylindrical battery can also serving as a negative electrode terminal. Further, an electrolyte to which the additives shown in Table 1 were added was injected into the battery can as the electrolyte. A battery cover having a positive electrode terminal was caulked via a gasket to produce a cylindrical battery.

(Comparative Example 1) A cylindrical battery was prepared in the same manner as in Example 1 except that the electrolyte containing no additive was used. (Comparative Examples 2 to 3) A negative electrode sheet was prepared by using a carbon active material (graphite powder) in the same manner as the negative electrode sheet instead of the oxide negative electrode active material, and each of the electrolytes shown in Table 1 was used. To make a cylindrical battery.

The battery prepared by the above method was charged and discharged under the conditions of a current density of 5 mA / cm ² , a charge end voltage of 4.1 V and a discharge end voltage of 2.8 V, and the discharge capacity and cycle life were determined. The ratio of the capacity (Wh) of each battery,
Table 1 shows the cyclability (the ratio of the 300th capacity to the first charge / discharge).

Table 1 Experiment Additives Additive concentration Initial capacity Cycle No Type (mol / l) Relative value Example 1 Propionic acid 0.001 1.0 80 Example 2 Propionic acid 0.01 0.98 81 Example 3 Propionic acid 0.05 0.97 82 Example 4 Oxalic acid 0.001 1.0 85 Example 5 Oxalic acid 0.01 1.01 85 Example 6 Oxalic acid 0.05 1.0 87 Example 7 Succinic acid 0.01 0.9984 Example 8 Maleic acid 0.01 0.98 83 Example 9 Phthalic acid 0.01 1.01 86 Example 10 Trimellitic acid 0.01 0.9984 Example 11 Pyromellitic acid 0.01 1. 02 88 Example 12 Benzenesulfonic acid 0.01 0.96 82 Example 13 Phenylphosphonic acid 0.01 0.98 86 Example 14 Lithium oxalate 0.0 1.0 82 Example 15 succinic lithium 0.01 1.0 82 Comparative Example 1 None 0 1.0 70 Comparative Example 2 None 0 0.80 75 Comparative Example 3 oxalate 0.01 0.81 80

As shown in Examples 1 to 15 of the present invention, the battery using the oxide-based negative electrode active material in combination with the electrolyte containing the organic acid or the organic acid salt is the organic acid of Comparative Example 1 or It is clear that the cycle property is improved as compared with the battery using the electrolyte without adding the organic acid salt. In addition, the battery of this example has a larger capacity than the batteries using the carbon-based negative electrode active materials of Comparative Examples 2 and 3,
Further, it is apparent that the improvement rate of the cycle property by adding the organic acid or the organic acid salt is larger than that using the carbon-based negative electrode active material.

[0052]

As in the present invention, by using the oxide type negative electrode and the electrolyte containing the organic acid and / or the organic acid salt in combination, the capacity is large and the charge and discharge characteristics are excellent. It is possible to obtain a non-aqueous electrolyte secondary battery with little deterioration in discharge capacity due to repeated discharge.

[Brief description of drawings]

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

[Explanation of symbols]

 Reference Signs List 1 gasket made of polypropylene 2 negative electrode can (battery can) also serving as negative electrode terminal 3 separator 4 negative electrode sheet 5 positive electrode sheet 6 nonaqueous electrolyte solution 7 explosion-proof valve 8 positive electrode cap also serving as positive electrode terminal 10 internal lid 11 ring

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yukio Maekawa 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Fuji Photo Film Co., Ltd.

Claims (6)

[Claims] 1. A positive electrode containing a material capable of reversibly occluding and releasing lithium, a predominantly amorphous chalcogen compound containing three or more kinds of atoms selected from the atoms of groups 1, 2, 13, 14, and 15 of the periodic table, and / or Or a negative electrode made of an amorphous oxide,
A non-aqueous electrolyte secondary battery comprising a non-aqueous electrolyte containing a lithium salt and a separator, wherein the non-aqueous electrolyte contains at least one organic acid and / or organic acid salt. battery. 2. The non-aqueous electrolyte secondary battery according to claim 1, wherein the organic acid and / or organic acid salt contained in the non-aqueous electrolyte is at least one carboxylic acid and / or carboxylic acid salt. 3. The organic acid and / or organic acid salt contained in the non-aqueous electrolyte is at least one polyvalent carboxylic acid and / or
Alternatively, the non-aqueous electrolyte secondary battery according to claim 2, which is a polycarboxylic acid salt. 4. The content of the organic acid and / or organic acid salt contained in the non-aqueous electrolyte is 0.001% by weight or more and 10% by weight or less with respect to the supporting salt in the electrolyte. The non-aqueous electrolyte secondary battery according to claim 1. 5. A non-aqueous electrolyte secondary battery, wherein the supporting salt of claim 4 contains LiPF ₆ and / or LiBF ₄ . 6. The non-aqueous electrolyte secondary battery according to claim 1, wherein at least one of the negative electrode materials is represented by the general formula (1). M ₁ M _2p M _4q M _6r General formula (1) (where M ₁ and M ₂ are different from each other, Si, Ge, Sn, P
at least one selected from b, P, B, Al, and Sb;
M ₄ is Li, Na, K, Rb, Cs, Mg, Ca, S
at least one selected from r and Ba, M ₆ is O, S,
At least one selected from Te, p and q are each 0.0
01 to 10, r represents a number of 1.00 to 50. )