JPH076761A - Nonaqueous secondary battery - Google Patents

Abstract

PURPOSE:To provide a nonaqueous secondary battery with high safety, high capacity, and long cycle life by using a baked material prepared by baking a mixture of a lithium compound, a transition metal oxide and others in a wet process for a negative active material. CONSTITUTION:A lithium secondary battery is fabricated with a negative active material precursor consisting of a lithium-containing metal oxide, a positive active material, and an organic electrolyte containing a lithium salt. For a negative active material a lithium-containing transition metal oxide is used, in which at least one kind of the lithium-containing transition metal oxides into which a lithium ion is not yet chemically inserted is a baked material of a mixture of each compound represented by a general formula mixed in a wet process, or a lithium-containing metal oxide is a baked material of a mixture of each compound represented by a specified general formula as a negative active material and a positive active material mixed in a wet process. A nonaqueous secondary battery with high safety, high capacity, and long cycle life can be provided.

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 charge / discharge characteristics.

[0002]

2. Description of the Related Art Lithium metal and lithium alloys are typically used as a negative electrode active material for non-aqueous secondary batteries. When they are used, lithium metal grows in a dendritic form during charge / discharge, causing internal short circuit. , The activity of the dendritic metal itself is high,
There is a risk of ignition. On the other hand, recently, a calcined carbonaceous material capable of inserting and extracting lithium has come into practical use. The disadvantage of this carbonaceous material is that it has conductivity so that lithium metal may be deposited on the carbonaceous material during overcharging or rapid charging, resulting in the deposition of dendritic metal. become. In order to avoid this, we have devised a charger or adopted a method to prevent overcharging by reducing the amount of positive electrode active material.
In the latter method, the discharge capacity is also limited because the amount of active material is limited. Further, since the carbonaceous material has a relatively low density, the discharge capacity is limited in the dual sense that the capacity per volume is low. On the other hand, as the negative electrode active material other than lithium metal, lithium alloy or carbonaceous material, TiS ₂ and LiTiS ₂ (US Pat. No. 3,9,9) capable of inserting and extracting lithium ions.
83,476), WO _{2 having} a rutile structure (US Pat.
198, 476), spinel compounds such as Li _x Fe (Fe ₂ ) O ₄ (JP-A-58-220,362), and electrochemically synthesized lithium compounds of Fe ₂ O ₃ (US Pat. No. 4,464). , 447), a lithium compound of Fe ₂ O ₃ (JP-A-3-112,070), Nb ₂ O ₅ (JP-B-62-59,412, JP-A-2-824,47), iron oxide, FeO, Fe ₂ O ₃ , Fe ₃ O ₄ , cobalt oxide,
CoO, Co ₂ O ₃ , Co ₃ O ₄ (JP-A-3-291,
862) is known. Since all of these compounds have a high redox potential, a non-aqueous secondary battery having a high discharge potential of 3 V class and a high capacity has not been realized. For the purpose of improving the above-mentioned drawbacks, it has been proposed to use a lithium-containing transition metal oxide as a negative electrode active material precursor in order to achieve a non-aqueous secondary battery having a high discharge potential of 3 V class (Japanese Patent Application No. Hei 10-135242). 4-106642). By combining this Li-containing transition metal oxide with a certain kind of positive electrode, a non-aqueous secondary battery having a large discharge capacity of 3 V class can be provided. In addition, it is extremely safe because it hardly causes dendrites of lithium. In addition, it has the advantage of having a higher specific gravity and a higher capacity per unit volume than carbonaceous materials. However,
When this Li-containing transition metal oxide is used as the negative electrode active material, the initial cycleability is good, but the discharge capacity is lower than the initial capacity after 40 to 50 cycles. It was strongly expected that this cycle property would be further improved.

[0003]

The first problem of the present invention
Relates to a non-aqueous secondary battery having excellent safety.
The second object of the present invention relates to a non-aqueous secondary battery having a high charge / discharge capacity. Further, the third object of the present invention relates to a non-aqueous secondary battery having excellent cycleability.

[0004]

The object of the present inventor is to provide a non-aqueous secondary battery comprising a positive electrode active material, a negative electrode active material, and a non-aqueous electrolyte containing a lithium salt. The lithium-containing transition metal oxide is a lithium-containing transition metal oxide in which the basic structure of the crystal changes when lithium ions are inserted into the lithium ion-exchange layer, and the new basic structure does not substantially change during subsequent charge and discharge. At least one of the lithium-containing transition metal oxides before insertion is a fired product obtained by mixing each of the compounds represented by the following general formula (1), general formula (2) and general formula (3) under wet conditions. Or a lithium-containing metal oxide comprising a calcined product of the negative electrode active material and the positive electrode active material obtained by mixing the compounds represented by the following general formulas (1) and (2) under wet conditions. Characterized by being a thing It was achieved by a non-aqueous secondary battery. General formula (1) LivL (In the formula, L represents a monovalent, divalent or trivalent group, and OH, CO
₃ , NO ₃ , SO ₃ , SO ₄ , PO ₄ , B ₄ O ₇ , Cl
O ₃ , ClO ₄ , SCN, HCO ₂ , CH ₃ CO ₂ , C
₂ O ₄ , C ₄ H ₄ O ₆ , CF ₃ SO ₃ , PF ₆ , F, C
It contains at least one of 1, 1, Br and I. v represents 1, 2, or 3. ) General formula (2) MwNx (In the formula, M is Co, Ni, Mn, Mo, Ti, Fe, M
at least one selected from o, N is O, OH, C
O ₃ , NO ₃ , SO ₃ , SO ₄ , PO ₄ , B ₄ O ₇ , C
10 ₃ , ClO ₄ , SCN, HCO ₂ , C ₂ O ₄ , C _{4
H 4 O 6, C 3 H} 5 O 3, C 6 H 6 O 7, F, Cl, B
It contains at least one of r, I and the like. w is 1, 2,
Represents 3 or 4. 0 <x ≦ 7) General formula (3) (NH ₄ ) aVbRc (in the formula, a = 0, 1, 2, 3, or 4, b = 1, 2, or 4, R is O, F, Cl, At least one of SO ₄ , c = 1 to 11)

Examples of the compound represented by the general formula (1) include lithium hydroxide, lithium carbonate, lithium nitrate, lithium tetraborate, lithium chlorate, lithium perchlorate, lithium formate, lithium acetate, lithium oxalate and citric acid. Examples include lithium, lithium lactate, lithium tartrate, lithium pyruvate, and lithium iodide. Particularly preferred are lithium carbonate, lithium hydroxide, and lithium acetate, and two or more of these may be used in combination.

An example of the compound of the general formula (2) is TiO 2.
₂ , titanium tetrachloride, titanium tetraiodide, MnO ₂ , Mn ₂ O
₃ , manganese hydroxide, manganese carbonate, manganese nitrate, manganese sulfate, manganese sulfite, manganese phosphate, manganese borate, manganese chlorate, manganese perchlorate, manganese thiocyanate, manganese formate, manganese acetate, manganese oxalate, manganese citrate , Manganese lactate, manganese tartrate, manganese fluoride, manganese chloride, manganese bromide, manganese iodide, iron oxide (2 or 3 valent), ferric oxide, iron hydroxide (2 or 3 valent), iron chloride (2 Trivalent), iron bromide (2, 3)
Valence), iron iodide (2,3 valence), iron sulfate (2,3 valence), iron nitrate (2,3 valence), iron phosphate (2,3 valence), iron perchlorate, iron chlorate, acetic acid Iron (2,3 values), iron citrate (2,3)
Valence), iron oxalate (2 and 3 valence), CoO, Co ₂ O ₃ , Co
₃ O ₄ , cobalt carbonate, basic cobalt carbonate, cobalt hydroxide, cobalt sulfate, cobalt nitrate, cobalt sulfite, cobalt perchlorate, cobalt thiocyanate, cobalt oxalate, cobalt acetate, cobalt fluoride, cobalt chloride,
Cobalt bromide, cobalt iodide, nickel oxide, nickel hydroxide, nickel carbonate, basic nickel carbonate, nickel sulfate, nickel nitrate, nickel fluoride, nickel chloride, nickel bromide, nickel iodide, nickel formate, nickel acetate, These are MoO ₃ , MoO ₂ and molybdenum pentachloride, and two or more of them may be used in combination.

Particularly preferred transition metal as the general formula (2)
As the compound, TiO₂, MnO ₂, Mn₂O₃,water
Manganese oxide, manganese carbonate, manganese nitrate, man acetate
Cancer, manganese oxalate, manganese citrate, iron oxide (2,
Trivalent), ferric oxide, iron hydroxide (2,3 valent), iron acetate
(2,3 values), iron citrate (2,3 values), iron oxalate (2,3 values)
Trivalent), CoO, Co₂O₃, Co₃O_Four, Carbon dioxide carbonate
G, basic cobalt carbonate, cobalt hydroxide, cobalt oxalate
G, cobalt acetate, nickel oxide, nickel hydroxide, charcoal
Nickel acid, basic nickel carbonate, nickel sulfate, nitric acid
Nickel, nickel acetate, MoO₃, MoO₂Give
Be done.

As an example of the compound of the general formula (3), VO
_d(D = 2-2.5), NH_FourVO₃, VOCl₃, V
OSO_Four, VCl ₃, VF₃, VI₃, VCl_Four, V
(OH)₃, V (OH)₂, (NH_Four)₃VO_Four, (N
H_Four)_FourV₂O₇Therefore, even if two or more of these are used in combination
I don't care. Particularly preferably, VO_d(D = 2-2.
5), NH_FourVO₃Is.

In the present invention, the mixing ratio of the compounds represented by the general formulas (1), (2) and (3) is Li and M.
As a molar ratio of Li and M: Li: M: V = X: Y: 1 (0 ≦ X <4, 0 <Y <
4) is preferable.

Prior to the preferred negative electrode active material used in the present invention
At least one of the precursors is Li_pMO_r(Where M is small
At least one kind is Ti, V, Mn, Co, Ni, Fe, N
b, transition metal containing Mo, p = 0 to 3.1, r = 1.6
~ 4.1). More preferable used in the present invention
Li as the negative electrode active material_pM_1q1M_2q2~ M_nqnO
_r(Where M₁~ Mn is at least one of Ti, V,
The transition metal containing Mn, Co, Ni, Mo and Fe.
, P = 0 to 3.1, q₁+ Q₂+ To + q _n= 1 and n =
1 to 10 and r = 1.6 to 4.1).
As a specific negative electrode active material precursor, Li_pCo_qV_1-qO
_r, Li_pNi_qV_{1- q}O_r, Li_pCo_qxTi_xV
_1-qO_r, Li_pCo_qxMn_xV_1-qO_r, Li_pC
o_qxFe_xV_1-qO_r, Li_pCo_qxNb_xV_1-q
O_r, Li_pCo_qxMo_xV_1-qO_r, Li_pCo
_qxNi_xV_1-qO_r, Li_pNi_qxTi_xV_1-qO
_r, Li_pNi_qxMn_xV_1-qO_r, Li_pNi_qx
Fe_xV_{1- q}O_r, Li_pNi_qxNb_xV_1-qO_r,
Li_pNi_qxMo_xV_1-qO_r(Where p = 0.3 ~
2.2, q = 0.02-0.7, r = 1.5-2.5,
x = 0.01-0.60). The present invention
As the most preferable negative electrode active material precursor used in
i_pCo_qV_{1- q}O_r, Li_pNi_qV_1-qO_r(here
At p = 0.3 to 2.2, q = 0.02 to 0.7, r =
1.5-2.5).

The mixing ratio of the compounds represented by the general formulas (1) and (2) used in the present invention is a molar ratio of Li and M: Li: M = Z: 1 (0≤X <3 ) Is preferable.

Preferred positive electrode active materials used in the present invention include Ti, V, Cr, Mn, Fe, Co, Ni and C.
Examples thereof include Li-containing transition metal oxides containing u, Mo and W. It is preferable that the positive electrode active material and the negative electrode active material have different composition formulas. Particularly preferable positive electrode active material used in the present invention is Li _x MO _z (where M = Co, Mn, N
A transition metal containing at least one selected from i, V and Fe, x = 0.3 to 1.2, and z = 1.4 to 3) are preferable.

More preferred positive electrode activity used in the present invention
As the substance, Li_xCoO₂, Li_xNiO₂, Li
_xCo_aNi_1-aO₂, Li_zCo_bV_1-bO_z, Li
_xCo_bFe_1-bO₂, Li_xMn₂O_Four, Li_xMn
_cCo_2-cO_Four, Li_xMn _cNi_2-cO_Four, Li_xM
n_cV_2-cO_z, Li_xMn_cFe_2-cO_Four, Li_xM
n₂O_FourAnd MnO₂Mixture of Li_2xMnO₃And MnO
₂Mixture of Li_xMn₂O_Four, Li_2xMnO₃And Mn
O₂Mixture (where x = 0.6 to 1.2, a = 0.1)
~ 0.9, b = 0.8 to 0.98, c = 1.6 to 1.9.
6, z = 2.01 to 5).

Most preferred positive electrode active material used in the present invention
As for quality, Li_xCoO₂, Li _xNiO₂, Li_x
Co_aNi_1-aO₂, Li_xMn₂O_Four, Li_xCo_b
V_{1- b}O_z(Where x = 0.7 to 1.1, a = 0.1
0.9, b = 0.9-0.98, z = 2.01-2.
3) can be given.

The active material precursor according to the present invention is obtained by mixing two or more kinds of powders and firing the mixture. The calcination temperature is usually below the melting point of the final product of the reaction. This is because in order to avoid an undesired reaction between the melt and the reaction vessel due to the melting of the final product of the reaction, and to prevent the vessel components from being mixed into the melt and adversely affecting the battery performance. This is to avoid reacting with the reaction container and significantly impairing the durability of the container. The reaction in which the firing temperature is equal to or lower than the melting point of the final product compound basically proceeds as a solid / solid phase reaction. Generally, a solid / solid phase reaction requires a long reaction time to complete the reaction (see Chemical Society of Japan, 1976, 10, pp 1539). In a solid / solid reaction where stirring during the reaction is difficult, the raw materials must be sufficiently mixed at the desired mixing ratio before firing, and if the mixing of the raw materials deviates from the desired composition, the product Produce different or undesired by-products. Therefore, when the active material precursor for a non-aqueous secondary battery is obtained by firing, sufficient mixing of the raw materials is extremely important.

The characteristics of carrying out the raw material of the lithium-containing metal oxide under wet conditions are that a plurality of powders can be mixed very uniformly, that mechanical heat can be easily dissipated during mixing, and it is industrially large-scale. It can be carried out in. The crushing and mixing apparatus under the wet condition according to the present invention,
Mortar, pot mill, circular vibration ball mill, rotary vibration mill,
Planetary ball mill, centrifugal mill, tower mill, sand mill,
An attritor, a sentrimill, a dyno mill, a roller mill, a kneader, a paint shaker, etc. can be used. Particularly preferably, a pot mill, a planetary ball mill,
Sand mill and mortar.

Various liquids can be selected as the liquid used for the pulverization and mixing under wet conditions depending on the material and the pulverization and mixing machine. As an example of the liquid for wet pulverization and mixing, those described in Solvent Handbook (edited by Kodansha, Asakura, Tokura et al., 1976) can be used. From the viewpoint of handling, the liquid used for the wet pulverization and mixing preferably has a boiling point of 50 to 150 ° C. and a vapor pressure at room temperature of 30 mmHg to 5 mm.
It is preferably in the range of about 00 mmHg. From the viewpoint of safety, those with low toxicity and less static electricity are preferable. Particularly preferred are water, toluene, xylene, methanol, ethanol, propanol, butanol, isobutyl alcohol, acetone, methyl ethyl ketone,
Such as butyl acetate, N, N-dimethylformamide and mixtures thereof. The amount ratio of the pulverized and mixed raw material and the liquid is appropriately selected depending on the material type, the amount of material, the pulverized and mixed apparatus type, and the processing speed, but is 1/10 of the raw material weight
It is preferably ˜20 times, and particularly preferably ⅕ to 10 times. The temperature at the time of pulverization and mixing depends on the material used and the type of liquid, but is preferably not lower than the melting point of the liquid and not higher than the boiling point, and is not higher than the melting point and decomposition temperature of the starting material used, and most preferably not lower than 5 ° C and not higher than 110. It is below ℃. The firing temperature of the active material precursor according to the present invention is 250 ° C.
It is preferably 2000 ° C. or higher and more preferably 350.
The temperature is from ℃ to 1000 ℃.

The firing atmosphere of the active material precursor according to the present invention is not particularly limited, but any of air, oxygen, hydrogen, carbon monoxide, carbon dioxide, water vapor, helium, argon, etc., which is suitable for the material, can be used. They can be used alone or in combination of two or more. The active material precursor according to the present invention is preferably washed and dried after firing. In particular, it is very preferable to wash the positive electrode active material. The washing method is not particularly limited, and the synthesized mass or the one crushed by a crusher may be washed. The cleaning method is not particularly limited, but examples of typical methods include a dipping method, a stirring method, and an ultrasonic cleaning method.
Moreover, you may heat if needed at the time of washing. The cleaning solution is neutral,
Either acidic or basic, but preferably pH = 4
8 to 8, more preferably pure water, ion-exchanged water or organic solvent having pH = 7. The amount of the cleaning liquid is not particularly limited, and is preferably an amount at which the lithium-containing transition metal oxide is immersed or more. The washing time and the number of washings are appropriately selected depending on the material, but it is often preferable to wash twice or more in 1 hour or more. The treatment method after washing is not particularly limited, and the washing solution is removed by a decantation method, a filtration method, a centrifugation method, or the like, and the washing solution is dried. In the case of an aqueous cleaning solution, acetone, methanol, ethanol,
Drying after washing with an organic solvent such as isopropyl alcohol is effective in accelerating the drying. The drying method is not particularly limited, and any method such as an air drying method, a heat drying method, a vacuum drying method and an infrared drying method can be used.

The active material precursor according to the present invention is preferably pulverized after firing. The pulverizing method is not particularly limited, and a vibration mill, a ball mill, a sand mill, a jet mill, a tube mill, a conical mill, a rod mill, a jaw crusher, a roll pulverizer, an edge runner, a ring roll mill or the like can be used. Particularly preferably a vibration mill,
It is pulverization by a jet mill, a ball mill and a sand mill. This is for inserting lithium ions in the battery, and does not utilize the dissolution and precipitation reaction of lithium metal or the like as the battery reaction. A conductive agent, a binder, a filler, or the like can be added to the electrode mixture. The conductive agent may be any electron-conductive material that does not cause a chemical change in the constructed battery. Usually, natural graphite (scaly graphite, flake graphite, earthy graphite, etc.), artificial graphite, carbon black, acetylene black, Ketjen black,
Carbon fiber, metal (copper, nickel, aluminum, silver (JP-A-63-148,554) powder), metal fiber or polyphenylene derivative (JP-A-59-20,971)
Conductive materials such as can be included as one type or a mixture thereof. The combined use of graphite and acetylene black is particularly preferred. The amount added is not particularly limited, but is preferably 1 to 50% by weight, and particularly preferably 2 to 30% by weight, based on the negative electrode active material. 2-1 for carbon and graphite
5% by weight is particularly preferred.

The binder is usually starch, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl chloride, polyvinyl pyrrolidone, tetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, ethylene-propylene- Diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, polybutadiene, fluororubber, polysaccharides such as polyethylene oxide, thermoplastic resins, polymers having rubber elasticity and the like are used alone or as a mixture thereof. When a compound containing a functional group that reacts with lithium, such as a polysaccharide, is used, it is preferable to add a compound such as an isocyanate group to deactivate the functional group. The amount of the binder added is not particularly limited, but is preferably 1 to 50% by weight, particularly preferably 2 to 30% by weight. As the filler, any fibrous material can be used as long as it does not cause a chemical change in the constructed battery. Generally, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. The amount of the filler added is not particularly limited, but is preferably 0 to 30% by weight.

As an electrolyte, an organic solvent such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran is used. , Dimethyl sulfoxide, 1,3-dioxolane,
Formamide, dimethylformamide, dioxolane,
Acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester (JP-A-60-23, 97)
3), trimethoxymethane (JP-A-61-4,17)
0), a dioxolane derivative (JP-A-62-15,77).
1, 62-222, 372, 62-108, 47
4), sulfolane (JP-A-62-31959), 3-
Methyl-2-oxazolidinone (JP-A-62-44,9
61), a propylene carbonate derivative (Japanese Patent Laid-Open No. 62-62-62).
290,069, 62-290,071), tetrahydrofuran derivative (JP-A-63-32,872), diethyl ether (JP-A-63-62,166), 1,3-
A solvent prepared by mixing at least one aprotic organic solvent such as propane sultone (JP-A-63-102,173) and a lithium salt soluble in the solvent, for example, LiC.
lO ₄ , LiBF ₆ , LiPF ₆ , LiCF ₃ SO ₃ ,
_{LiCF 3 CO 2, LiAsF 6,} LiSbF 6, Li
B ₁₀ Cl ₁₀ (JP-A-57-74,974), lower aliphatic lithium carboxylate (JP-A-60-41,773), L
iAlCl ₄ , LiCl, LiBr, LiI
0-247,265), lithium chloroborane (JP-A 61-165,957), lithium tetraphenylborate (JP-A 61-214,376), and the like. Above all, Li is added to a mixed solution of propylene carbonate or ethylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate.
_{CF 3 SO 3, LiClO 4,} LiBF 4 and / or an electrolyte containing LiPF ₆ is preferred. 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 active material and the size of the battery. The volume ratio of the solvent is not particularly limited, but in the case of a mixed solution of propylene carbonate or ethylene capote and 1,2-dimethoxyethane and / or diethyl carbonate, 0.4 / 0.6 to 0.
6 / 0.4 (mixing ratio when both 1,2-dimethoxyethane and diethyl carbonate are used is 0.4 / 0.6-
0.6 / 0.4) is preferable. The concentration of the supporting electrolyte is not particularly limited, but is 0.2 to 3 per liter of the electrolytic solution.
Molar is preferred.

Besides the electrolytic solution, the following solid electrolytes can be used. Solid electrolytes are classified into inorganic solid electrolytes and organic solid electrolytes. Li-nitrides, halides, oxyacid salts, and the like are well known as inorganic solid electrolytes. Among them, Li ₃ N, LiI, Li ₅ N
_{I 2, Li 3 N-LiI} -LiOH, LiSiO 4, L
iSiO ₄ -LiI-LiOH (JP-A-49-81,8)
_{99), xLi 3 PO 4 -} (1-x) Li 4 SiO
₄ (JP-A-59-60,866), Li ₂ SiS ₃ (JP-A-60-501,731), phosphorus sulfide compound (JP-A-62-82,665) and the like are effective. In the organic solid electrolyte, a polyethylene oxide derivative or a polymer containing the derivative (JP-A-63-135,447), a polypropylene oxide derivative or a polymer containing the derivative, a polymer containing an ion-dissociating group (JP-A-62-135). 254,30
2, ibid. 62-254, 303, ibid. 63-193, 95
4), a mixture of a polymer containing an ionic dissociative group and the aprotic electrolytic solution (U.S. Pat. Nos. 4,792,504, 4,830,939, JP-A-62-22,375, and JP-A-6-222,375.
2-22, 376, 63-2, 375, 63-2
2,776, JP-A-1-95,117) and phosphoric acid ester polymers (JP-A-61-256,573) are effective. Furthermore, there is also a method of adding polyacrylonitrile to the electrolytic solution (JP-A-62-278,774). Further, a method of using an inorganic and organic solid electrolyte in combination (Japanese Patent Laid-Open No. 60-1,
768) is also known.

As the separator, an insulating thin film having a large ion permeability and a predetermined mechanical strength is used. A sheet or non-woven fabric made of olefin polymer such as polypropylene or glass fiber or polyethylene is used because of its resistance to organic solvent and hydrophobicity. The pore size of the separator is in the range generally used for batteries. For example, 0.01 to 10 μ
m is used. The thickness of the separator is generally within the range for batteries. For example, 5 to 300 μm is used.

It is also known to add the following compounds to the electrolyte for the purpose of improving discharge and charge / discharge characteristics. For example, pyridine (JP-A-49-108,52)
5), triethylphosphite (JP-A-47-4,3)
76), triethanolamine (JP-A-52-72,4).
25), cyclic ether (JP-A-57-152,68)
4), ethylenediamine (JP-A-58-87,77)
7), n-glyme (JP-A-58-87,778), hexaphosphoric acid triamide (JP-A-58-87,779),
Nitrobenzene derivative (JP-A-58-214, 28)
1), sulfur (JP-A-59-8,280), quinoneimine dye (JP-A-59-68,184), N-substituted oxazolidinone and N, N'-substituted imidazolidinone (JP-A-5-280).
9-154,778), ethylene glycol dialkyl ether (JP-A-59-205,167), quaternary ammonium salt (JP-A-60-30,065), polyethylene glycol (JP-A-60-41). , 773), pyrrole (JP-A-60-79,677), 2-methoxyethanol-
Le (JP 60-89,075), AlCl ₃ (JP-61-88,466), conductive polymer - monomer of the electrode active material - (JP 61-161,673), triethylene phosphoramide Amide (JP-A-61-208,758), trialkylphosphine (JP-A-62-80,976), morpholine (JP-A-62-80,977), aryl compound having a carbonyl group 62-86, 67
3), hexamethylphosphoric triamide and 4-alkylmorpholine (JP 62-217,575), bicyclic tertiary amine (JP 62-217,578), oil (JP 62 -287,580), a quaternary phosphonium salt (JP-A-63-121268), a tertiary sulfonium salt (JP-A-63-121269), and the like.

Further, in order to make the electrolytic solution nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolytic solution. (JP-A-48-36,
632) Further, the electrolytic solution may contain carbon dioxide gas in order to have suitability for high temperature storage. (JP-A-59-1
34, 567) Further, the mixture of the positive electrode and the negative electrode may contain an electrolytic solution or an electrolyte. For example, a method is known in which the ion conductive polymer, nitromethane (JP-A-48-36,633) and an electrolytic solution (JP-A-57-124,870) are included. Further, the surface of the positive electrode active material can be modified. For example, the surface of the metal oxide may be treated with an esterifying agent (JP-A-55-163,779),
Treatment with a photocatalyst (JP-A-55-163,780), conductive polymers (JP-A-58-163,188, 59-14).
274), polyethylene oxide, etc. (JP-A-60-
97, 561). Also, the surface of the negative electrode active material can be modified. For example, an ion conductive polymer or polyacetylene layer is provided (JP-A-58-111276), or LiCl
(JP-A-58-142,771) and the like.

The collector of the electrode active material may be any electron conductor that does not undergo a chemical change in the constructed battery. For example, for the positive electrode, in addition to stainless steel, nickel, aluminum, titanium, calcined carbon, etc. as the material, carbon on the surface of aluminum or stainless steel,
Those treated with nickel, titanium or silver, and the negative electrode are made of stainless steel, nickel, copper, titanium,
In addition to aluminum and calcined carbon, copper, stainless steel whose surface is treated with carbon, nickel, titanium, or silver), an Al-Cd alloy, or the like is used. It is also used to oxidize the surface of these materials. The shape is
In addition to the foil, a film, a sheet, a net, a punched product, 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, but is 1 to 5
Those having a diameter of 00 μm are used.

The shape of the battery can be any of coins, buttons, sheets, cylinders, 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 active material precursor is used by being compressed into a pellet shape. The thickness and diameter of the pellet are determined by the size of the battery. Further, when the battery has a sheet, cylinder, or square shape, the mixture of the positive electrode active material and the negative electrode active material is mainly used by being coated, dried, and compressed on the current collector. The coat thickness, length and width are determined by the size of the battery,
The coat thickness is 1 to 20 when compressed after drying.
00 μm is particularly preferable. The mixture sheet may be rolled,
It is folded and inserted into a can, the can and the sheet are electrically connected, an electrolytic solution is injected, and a battery can is formed using a sealing plate. At this time, the safety valve can be used as a sealing plate. 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 the sealing agent for sealing, a conventionally known compound or mixture such as asphalt can be used. The use of the battery according to the present invention is not particularly limited, for example, a portable personal computer, a pen input personal computer, a portable word processor, an electronic book player, a mobile phone, a cordless phone, a pager, a handy terminal, a mobile facsimile, Portable copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, electric shaver, electronic translator, mobile phone, specified low power transceiver, electric tool, electronic notebook, calculator, memory card, electronic tape recorder , Clocks, cameras, hearing aids, etc.

Specific examples of synthesis of the active material precursor according to the present invention will be given below. Synthesis Example 1 (Synthesis of Compound A) CoO (Wako Pure Chemicals Reagent), 125
g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g, lithium carbonate (Wako Pure Chemicals Reagent), 45 g and 4500 cc of methanol were automatically mortar (Ntoka Kagaku Co., Ltd., ANM1).
000) in an open system for 20 minutes at room temperature. Then, the mixture was air-dried in a petri dish having a diameter of 30 cm for 24 hours in the air. Next, vacuum dryer (RV- manufactured by Hirano Seisakusho)
In F3), it was vacuum dried at 40 ° C. for 2 hours. The obtained mixture was fired at 750 ° C. for 18 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, it was crushed for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho), and the average particle size was 18 μm.
Compound I of was obtained. Powder X-ray diffraction pattern of the obtained substance (using a powder X-ray diffractometer manufactured by Rigaku Denki, Cu
(Using Kα ray), the obtained substance was in agreement with LiCoVO ₄ described in JCPDS card index 38-1396, and other peaks were not substantially found. The X-ray diffraction pattern is shown in FIG. With respect to the obtained substance, the content ratio of Li, Co, and V was determined by inductively coupled plasma (I
CP) Emission analysis. Li / Co / V =
It was 0.99 / 1.00 / 0.99.

Synthesis Example 2 (Synthesis of Compound B) CoO (Wako Pure Chemicals Reagent), 125
g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g, lithium carbonate (Wako Pure Chemicals Reagent), 45 g and ethanol 450 cc were automatically mortar (manufactured by Nitto Kagaku KK, ANM10).
00) was mixed in an open system for 20 minutes at room temperature, and then air-dried in air. Next, vacuum dryer (manufactured by Hirano Seisakusho)
RV-F3) was vacuum dried at 40 ° C. for 3 hours. The obtained mixture was fired at 750 ° C. for 18 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, it was crushed for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho Co., Ltd.) to obtain an average particle size of 1
8 μm of compound b was obtained.

Synthesis Example 3 (Synthesis of Compound C) CoO (reagent manufactured by Wako Pure Chemical Industries, Ltd.), 125
g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g, lithium carbonate (Wako Pure Chemicals Reagent), 45 g and toluene 400 cc were automatically mortar (NNM 100, ANM100).
In (0), the mixture was mixed in a closed system for 20 minutes at room temperature, and then naturally dried in the air. Next, vacuum dryer (Hirano Seisakusho R
It was vacuum dried at 40 ° C. for 2 hours under V-F3). An electric furnace (Yamato Scientific muffle furnace FP-3
1 used) and baked at 750 ° C. for 18 hours. After firing, it was naturally cooled in the furnace. Next, it was pulverized for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho) to obtain an average particle size of 18
μm of compound Ha was obtained.

Synthesis Example 4 (Synthesis of Compound D) CoO (Wako Pure Chemicals Reagent), 125
g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g and lithium carbonate (Wako Pure Chemicals Reagent), 45 g and ethanol 400cc were sand milled (AIMX Co., Ltd., TSG).
Glass beads (3 mm, 400
g) was crushed and mixed for 2 hours at a rotation speed of 1500 RPM and a blade diameter of 6 cm, and then naturally dried at room temperature. Next, it was vacuum dried at 40 ° C. for 2 hours with a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). 750 by using an electric furnace (using a Yamato Scientific muffle furnace FP-31)
Calcination was performed for 18 hours. After firing, it was naturally cooled in the furnace.
Next, a vibration mill (TI-100 manufactured by Hirako Seisakusho) was pulverized for 5 minutes to obtain a compound D having an average particle size of 15 μm.

Synthesis Example 5 (Synthesis of Compound E) CoO (Wako Pure Chemicals Reagent), 125
g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152g, lithium carbonate (Wako Pure Chemicals Reagent), 45g and ethanol 400cc are paint shaker (Asada Iron Works Co., Ltd.)
Then, the glass beads (3 mm, 400 g) were pulverized and mixed for 3 hours, and then naturally dried at room temperature. Next, it was vacuum dried at 40 ° C. for 2 hours with a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). The obtained mixture was heated at 750 ° C. for 1 using an electric furnace (using a Yamato Scientific muffle furnace FP-31).
It was baked for 8 hours. After firing, it was naturally cooled in the furnace. Next, it was pulverized for 5 minutes by a vibration mill (TI-100 manufactured by Hirako Seisakusho Co., Ltd.) to obtain a compound E having an average particle size of 19 μm.

Synthesis Example 6 (Synthesis to Compound) NiO (Wako Pure Chemicals Reagent), 125
g and and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g
And 45 g of lithium carbonate (Wako Pure Chemical Industries, Ltd. reagent) and 400 cc of ethanol were ground and mixed with a paint shaker (manufactured by Asada Iron Works Co., Ltd.) for 3 hours using glass beads (3 mm, 400 g), and then natural at room temperature. Dried. Next, using a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho), 40
It was vacuum dried at ℃ for 2 hours. The obtained mixture was used with an electric furnace (using a Yamato Scientific muffle furnace FP-31).
It was baked at 50 ° C. for 18 hours. After firing, it was naturally cooled in the furnace. Next, a vibration mill (TI-100 manufactured by Hirako Seisakusho)
And pulverized for 5 minutes to obtain a compound having an average particle size of 17 μm.

Synthesis Example 7 (Synthesis of Compound) CoO (reagent manufactured by Wako Pure Chemical Industries, Ltd.), 113
g and TiO ₂ (Wako Pure Chemicals Reagent), 16 g and V
₂ O ₅ (Wako Pure Chemicals Reagent), 152 g and lithium carbonate (Wako Pure Chemicals Reagent), 45 g and ethanol 400 cc
Was pulverized and mixed in a paint shaker (manufactured by Asada Iron Works Co., Ltd.) using glass beads (3 mm, 400 g) for 3 hours, and then naturally dried at room temperature. Next, it was vacuum dried at 40 ° C. for 2 hours with a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). The obtained mixture was fired at 750 ° C. for 18 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, it was ground for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho) to obtain a compound having an average particle size of 19 μm.

Synthesis Example 8 (Synthesis of Compound H) CoO (Wako Pure Chemicals Reagent), 113
g and Fe ₂ O ₃ (Wako Pure Chemicals Reagent), 16 g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g and lithium carbonate (Wako Pure Chemicals Reagent), 45 g and ethanol 400
The cc was ground and mixed with a paint shaker (manufactured by Asada Iron Works Co., Ltd.) for 3 hours using glass beads (3 mm, 400 g), and then naturally dried at room temperature. Next, it was vacuum dried for 2 hours at 40 ° C. in a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). The obtained mixture was fired at 750 ° C. for 18 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, it was pulverized for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho) to obtain a compound H having an average particle size of 17 μm.

Synthesis Example 9 (Synthesis of Compound Li) CoO (Wako Pure Chemicals Reagent), 113
g and Mn ₂ O ₃ (Wako Pure Chemical Reagent), 15.8 g and V ₂ O ₅ (Wako Pure Chemical Reagent), 152 g and lithium carbonate (Wako Pure Chemical Reagent), 45 g and ethanol 4
00 cc was ground and mixed for 3 hours with a glass shaker (3 mm, 400 g) using a paint shaker (manufactured by Asada Iron Works Co., Ltd.), and then naturally dried at room temperature. Next, it was vacuum dried at 40 ° C. for 2 hours with a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). The obtained mixture was fired at 750 ° C. for 18 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, it was pulverized for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho Co., Ltd.) to obtain a compound L having an average particle size of 19 μm.

Synthesis Example 10 (Synthesis of Compound N) CoO (Wako Pure Chemicals Reagent), 113
g and MoO ₃ (Wako Pure Chemicals Reagent), 29 g and V
₂ O ₅ (Wako Pure Chemicals Reagent), 152 g, lithium carbonate (Wako Pure Chemicals Reagent), 45 g and P ₂ O ₅ , 7 g and ethanol 400 cc were applied to glass beads (using Asa Tekko Co., Ltd.). 3 mm, 400 g) were pulverized and mixed for 3 hours, and then naturally dried at room temperature. Next, it was vacuum dried at 40 ° C. for 2 hours with a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). 750 by using an electric furnace (using a Yamato Scientific muffle furnace FP-31)
Calcination was performed for 18 hours. After firing, it was naturally cooled in the furnace.
Next, it was pulverized for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho Co., Ltd.) to obtain a compound g having an average particle size of 18 μm.

Synthesis Example 11 (Synthesis of Comparative Compound 1) CoO (Wako Pure Chemicals Reagent), 1
25 g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g and lithium carbonate (Wako Pure Chemicals Reagent), 45 g were mixed for 20 minutes at room temperature in an automatic mortar (NNM 1000, ANM1000). Then, the obtained mixture was baked in air at 750 ° C. for 18 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, the vibration mill (TI-
100) for 5 minutes to obtain Comparative Compound 1 having an average particle size of 15 μm. Powder X-ray diffraction pattern of the obtained substance (using a powder X-ray diffractometer manufactured by Rigaku Denki, CuKα
The use of a line) is significantly different from Synthesis Example 1 and a plurality of substances are mixed. The main substance obtained was LiCoVO ₄ described in JCPDS Card Index 38-1396.
In addition, JCPDS card index
39-378 Li ₃ VO ₄ and JCPDS
Co ₃ O ₄ described in Card Index No. 9-418
Was observed to be generated. According to the internal standard method, it was revealed that Li ₃ VO ₄ was mixed in ₃ % by weight and Co ₃ O ₄ was mixed in 1% by weight. (See FIG. 2) With respect to the obtained substance, the content ratio of Li, Co and V was examined by an inductively coupled plasma (ICP) emission spectrometry. L
It was i / Co / V = 1.00 / 1.00 / 0.99.

Synthesis Example 12 (Synthesis of Comparative Compound 2) CoO (Wako Pure Chemicals Reagent), 1
25 g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g and lithium carbonate (Wako Pure Chemicals Reagent), 45 g were mixed for 20 minutes at room temperature with a cross rotary powder mixer (Meiwa Kogyo Co., Ltd.). After that, the obtained mixture was fired at 750 ° C. for 18 hours in the air using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, the vibration mill (TI-
100) for 5 minutes to obtain Comparative Compound 2 having an average particle size of 16 μm.

Synthesis Example 13 (Synthesis of Comparative Compound 3) CoO (Wako Pure Chemicals Reagent), 1
25 g and V ₂ O ₅ (Wako Pure Chemicals Reagent), 152 g and lithium carbonate (Wako Pure Chemicals Reagent), 45 g were mixed with a glass shaker (3 mm, 400 g) using a paint shaker (Asada Iron Works Co., Ltd.). After pulverizing and mixing for an hour, it was naturally dried at room temperature. The obtained mixture was fired at 750 ° C. for 18 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.). After firing, it was naturally cooled in the furnace. Next, it was ground for 5 minutes with a vibration mill (TI-100 manufactured by Hirako Seisakusho) to obtain a comparative compound 3 having an average particle size of 18 μm.

Synthesis Example 14 (Synthesis of Compound) CoCO ₃ (Wako Pure Chemicals Reagent), 2
37.9 g and lithium carbonate (Wako Pure Chemicals Reagent), 8
1.2 g and 400 cc of methanol were mixed in an automatic mortar (manufactured by Nitto Kagaku Co., Ltd., ANM1000) in an open system for 20 minutes at room temperature. Then, the mixture was air-dried in a petri dish having a diameter of 30 cm for 24 hours in the air. Next, it was vacuum dried at 40 ° C. for 2 hours with a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). The obtained mixture was fired at 750 ° C. for 10 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.), and then naturally cooled in the furnace. Then, it was crushed with a ball mill. Next, it was washed by stirring in a beaker with 1000 cc of water (25 ° C.) for 2 hours. Next 12
The supernatant was decanted after standing for a time. 5 precipitates
After washing twice with 00 cc of acetone, it was vacuum dried for 2 hours at 40 ° C. in a vacuum dryer (RV-F3 manufactured by Hirano Seisakusho). A compound having an average particle size of 10 μm was obtained. The specific surface area was 0.1 m ² / g as determined by the BET 1-point method (Cantasorb, manufactured by Cantachrome). From the powder X-ray diffraction pattern (using a powder X-ray diffractometer manufactured by Rigaku Denki, using CuKα ray) of the obtained substance, the obtained substance is JCP.
Li described in DS Card Index 36-1004
It was CoO ₂ . No peaks due to other substances were found. The X-ray diffraction pattern is shown in FIG. The content ratio of Li, Co, and V in the obtained substance was examined by inductively coupled plasma (ICP) emission spectrometry. Li / C
It was o = 1.00 / 1.00.

Synthetic Example 15 (Synthesis of Comparative Compound 5) CoCO ₃ (Wako Pure Chemicals Reagent), 237.9 g and lithium carbonate (Wako Pure Chemicals Reagent), 81.2 g were put into an automatic mortar (Nichito Kagaku Co., Ltd.). Made, AN
M1000) in an open system for 20 minutes at room temperature. Then, the mixture is put in a petri dish with a diameter of 30 cm in air for 2 times.
It was naturally dried for 4 hours. Next, vacuum dryer (manufactured by Hirano Seisakusho)
RV-F3) was vacuum dried at 40 ° C. for 2 hours. The obtained mixture was fired at 750 ° C. for 10 hours using an electric furnace (using a muffle furnace FP-31 manufactured by Yamato Scientific Co., Ltd.), and then naturally cooled in the furnace. Then, it was crushed with a ball mill. Next, it was washed by stirring in a beaker with 1000 cc of water (25 ° C.) for 2 hours. Then, after standing for 12 hours, the supernatant was decanted. After washing the precipitate twice with 500 cc of acetone, vacuum dryer (Hirano Seisakusho R
It was vacuum dried at 40 ° C. for 2 hours under V-F3). Comparative compound 5 having an average particle size of 13 μm was obtained.

[0043]

The present invention will be described in more detail with reference to the following examples, but the invention is not limited to the examples as long as the gist of the invention is not exceeded. Example 1 (Preparation and Evaluation of Lithium Secondary Battery) Above Synthesis Examples 1 to 1
82% by weight of each of the compounds a to n obtained by
A mixture of 12% by weight of scaly graphite as a conductive agent and 6% by weight of polyvinylidene fluoride as a binder was dried and then compression-molded into a negative electrode pellet (13 mmφ, 3
0 mg) was used. The weight, thickness and diameter of this pellet were measured to obtain the pellet specific gravity. A positive electrode 106 composed of this negative electrode, a compound, polyvinylidene fluoride, and graphite
thoroughly dry mg in dry air with a far infrared heater,
A separator using a microporous polypropylene non-woven fabric, 1 mol / liter as an electrolyte, LiPF ₆ (equal volume mixture of ethylene carbonate and diethylene carbonate), a positive electrode and a negative electrode as a current collector, SUS316
Coin-type battery 1 using a net (80 microns thick)
-10 and charged at a current density of 0.75 mA / cm ² 4.1
Charge and discharge test was performed under the conditions of V and discharge 1.8V.
The discharge capacity at 0 cycle was determined. As a result of disassembling the battery after the charge / discharge cycle and observing the negative electrode pellet, deposition of Li metal was not observed. The results obtained are shown in Table 1.

[0044]

[Table 1]

Comparative Example 1 (Preparation and Evaluation of Lithium Secondary Battery) Synthesis Examples 11 to 1
Example 1 using Comparative Compounds 1-3 obtained according to Example 3
In the same manner as described above, coin type batteries 11 to 13 were prepared, and negative electrode pellet production, negative electrode pellet specific gravity measurement, battery production, and charge / discharge test were performed. As a result of disassembling the battery after the charge / discharge cycle and observing the negative electrode pellet, deposition of Li metal was not observed. The obtained results are shown in Table 2.

[0046]

[Table 2]

Comparative Example 2 (Preparation and Evaluation of Lithium Secondary Battery) Comparative Example 1 obtained in Synthesis Example 11 was used in the same manner as in Example 1 except that Comparative Compound 5 obtained in Synthesis Example 15 was used as a positive electrode active material. As a coin-type battery 14, a negative electrode pellet preparation, a negative electrode pellet specific gravity measurement, a battery preparation, and a charge / discharge test were performed. As a result of disassembling the battery after the charge / discharge cycle and observing the negative electrode pellet, deposition of Li metal was not observed. The obtained results are shown in Table 2.

Comparative Example 3 (Preparation and Evaluation of Lithium Secondary Battery) As a comparative compound, a commercially available coal-based coke (trade name LP manufactured by Nippon Steel Chemical Co., Ltd.) was used.
Cu, Lc (crystal thickness in the C-axis direction in X-ray diffraction)
= 41 angstrom, d002 (distance between 002 surfaces)
= 3.47 angstrom, ρ = 2.09 g / cm ³ )
84% by weight, commercially available acetylene black (manufactured by Denki Kagaku Kogyo, trade name Denka Black) 8% by weight, ethylene-propylene-diene copolymer EPDM as a binder
(Sumitomo Chemical Co., Ltd., trade name ESPRENE) 8% by weight
Negative electrode pellets (diameter: 13 m) coated with a mixture mixed in a mixing ratio of (toluene), dried, and compressed into a disk shape.
m) was prepared and used as the negative electrode material. The weight, thickness and diameter of this pellet were measured to obtain the pellet specific gravity. This negative electrode and L
A positive electrode composed of iCoO ₂ , polyvinylidene fluoride and graphite, a separator using a microporous polypropylene nonwoven fabric, and 1 mol / liter as an electrolyte, LiBF
Coin type battery 15 was prepared with ₄ (equal volume mixture of propylene carbonate and 1,2-dimethoxyethane),
Charge 3.95V discharge 3.2V with current density of 75mA / cm ^2.
A charge / discharge test was carried out under the conditions described above to determine the discharge capacities of the second and 40th cycles. The battery after the cycle was disassembled, and it was confirmed that deposition of Li metal did not occur even after the cycle at this charge potential. The obtained results are shown in Table 2.

Results A battery using the negative electrode active material precursor and the positive electrode active material synthesized by the method of the present invention 1 is highly safe since deposition of Li metal does not occur even after cycling 2 Carbonaceous material of Comparative Example 3 Clearly superior in charge / discharge capacity per volume 3. From comparison with Comparative Example 1, a high charge / discharge capacity can be obtained by the negative electrode active material precursor and the positive electrode active material according to the present invention,
And it is clear that the cycleability is greatly improved.

[0050]

As described above, the safety of the lithium secondary battery according to the present invention is characterized by comprising the negative electrode active material precursor composed of the Li-containing metal oxide, the positive electrode active material, and the organic electrolyte containing a lithium salt. It was possible to obtain a lithium secondary battery having excellent chargeability, high charge-discharge capacity and excellent cycleability.

[Brief description of drawings]

FIG. 1 shows a powder X-ray diffraction pattern of Compound A.

FIG. 2 shows a powder X-ray diffraction pattern of Comparative Compound 1.

FIG. 3 shows a powder X-ray diffraction pattern of compound Le.

FIG. 4 shows a sectional view of the coin battery used in the examples.

[Explanation of symbols]

 1 Negative Electrode Sealing Plate 2 Negative Electrode 3 Separator 4 Positive Electrode 5 Al Current Collector 6 Positive Electrode Case 7 Gasket

Claims (2)

[Claims] 1. A non-aqueous secondary battery comprising a positive electrode active material, a negative electrode active material and a non-aqueous electrolyte containing a lithium salt, wherein the negative electrode active material has a basic crystal structure when lithium ions are first chemically inserted. The new basic structure is a lithium-containing transition metal oxide that is changed and does not substantially change during subsequent charge and discharge, and is a lithium-containing transition metal oxide before lithium ions are chemically inserted. At least one of the following general formula (1), general formula (2) and general formula (3)
Non-aqueous secondary battery characterized by containing a lithium-containing transition metal oxide which is a calcined product obtained by mixing each of the compounds represented by the formula (1) LivL (where L is 1 Represents a divalent or trivalent group, OH, CO
₃ , NO ₃ , SO ₃ , SO ₄ , PO ₄ , B ₄ O ₇ , Cl
O ₃ , ClO ₄ , SCN, HCO ₂ , CH ₃ CO ₂ , C
₂ O ₄ , C ₄ H ₄ O ₆ , CF ₃ SO ₃ , PF ₆ , F, C
It contains at least one of 1, 1, Br and I. v represents 1, 2, or 3. ) General formula (2) MwNx (In the formula, M is Co, Ni, Mn, Mo, Ti, Fe, M
at least one selected from o, N is O, OH, C
O ₃ , NO ₃ , SO ₃ , SO ₄ , PO ₄ , B ₄ O ₇ , C
10 ₃ , ClO ₄ , SCN, HCO ₂ , C ₂ O ₄ , C _{4
H 4 O 6, C 3 H} 5 O 3, C 6 H 6 O 7, F, Cl, B
It contains at least one of r, I and the like. w is 1, 2,
Represents 3 or 4. 0 <x ≦ 7) General formula (3) (NH ₄ ) aVbRc (in the formula, a = 0, 1, 2, 3, or 4, b = 1, 2, or 4, R is O, F, Cl, At least one of SO ₄ , c = 1 to 11) 2. The positive electrode active material is a lithium-containing metal oxide which is a calcined product obtained by mixing compounds represented by the following general formulas (1) and (2) under wet conditions. The non-aqueous secondary battery according to claim 1, characterized by the general formula (1) LivL (wherein L represents a mono-, di-, or trivalent group, and OH, CO
₃ , NO ₃ , SO ₃ , SO ₄ , PO ₄ , B ₄ O ₇ , Cl
O ₃ , ClO ₄ , SCN, HCO ₂ , CH ₃ CO ₂ , C
₂ O ₄ , C ₄ H ₄ O ₆ , CF ₃ SO ₃ , PF ₆ , F, C
It contains at least one of 1, 1, Br and I. v represents 1, 2, or 3. ) General formula (2) MwNx (In the formula, M is Co, Ni, Mn, Mo, Ti, Fe, M
at least one selected from o, N is O, OH, C
O ₃ , NO ₃ , SO ₃ , SO ₄ , PO ₄ , B ₄ O ₇ , C
10 ₃ , ClO ₄ , SCN, HCO ₂ , C ₂ O ₄ , C _{4
H 4 O 6, C 3 H} 5 O 3, C 6 H 6 O 7, F, Cl, B
It contains at least one of r, I and the like. w is 1, 2,
Represents 3 or 4. 0 <x ≦ 7)