JPH07235293A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

PURPOSE:To provide a nonaqueous electrolyte lithium-ion secondary battery with high discharge working voltage, high discharge capacity, high charge/ discharge performance, and high safety. CONSTITUTION:In a nonaqueous electrolyte secondary battery comprising a positive active material, a negative active material, a nonaqueous electrolyte containing a lithium salt, at least one kind of the negative active materials is a semimetal in the IV-B and V-B groups of the periodic table, capable of inserting/releasing lithium or an oxide of In, Zn, or Mg. The positive active material is a composite oxide whose main component is cobalt and containing at lest one metal selected from the IV-A and IV-B groups of the periodic table or a lithium-containing manganese oxide having spinel structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention improves charge / discharge characteristics,
The present invention also relates to a secondary battery with improved safety.

[0002]

2. Description of the Related Art In order to develop a high-capacity secondary battery having excellent safety and a higher voltage of 3-4 V class, a negative electrode active material having a larger capacity and a lower potential and a higher potential are used. A technique of combining with a positive electrode active material is required.

As an example of using SnO 2 or a Sn compound as an active material of a lithium battery, Li of a positive electrode active material of a secondary battery is used.
1.03Co0.95Sn0.04O2 (EP86-106,30
1), addition of SnO2 to V2 O5 of the secondary battery positive electrode active material (JP-A-2-158,056), addition of SnO2 to α-Fe2 O3 of the secondary battery negative electrode active material (preferred addition range of SnO2 is 0.5). (About 10 mol%) (Japanese Patent Laid-Open No. 62-219,
465), SnO2 as a positive electrode active material for primary batteries (electrochemistry and industrial physical chemistry, Vol. 46, No. 7, page 407, 197).
8 years) is known. In the field of electrochromism, SnO2 can reversibly insert Li ions (Journal of Electrochemical Society 140 Vol. 5, L81 1993), In.
A film (ITO) in which O2 is doped with 8 mol% Sn can reversibly insert Li ions (Solid State Ionics 28-30, page 1733 1
Issued in 988) is known. However, unlike the practical range of the battery, it is common to operate the Li ion insertion at a considerably low current.
In State Ionics, 1 μA to 30 μA / cm
Two experimental examples are shown.

As an example of using an element of IV-B group and V-B group other than Sn in a lithium battery, GeO2 is added to V2 O5 of the positive electrode active material of a secondary battery (Japanese Patent Laid-Open No. 2-15).
8,056), as the positive electrode active material of the primary battery, GeO,
The use of GeO2 (JP-A-55-96,567) is known. An example of using Pb oxide as an active material of a lithium battery is to use PbOx as a positive electrode active material of a primary battery.
(X = 1.4 to 1.8) (UK Patent 78-6,
271), PbO, Pb as the positive electrode active material of the primary battery
Use of O2, Pb2 O3, Pb3 O4 (Materials
Chemistry and Physics Volume 25 No. 2 2
07 page 1990) is known. Also, Sb
As an example of using an oxide as an active material of a lithium battery,
The use of Sb oxide as a positive electrode active material for primary batteries (German Patent 2,516,703) is known. further,
An example of using Bi oxide as the active material of a lithium battery is
The use of Bi2 O3 as the positive electrode active material of the primary battery (JP-A-52-12425) and the composite oxide of Bi and Pb as the cathode active material of the primary battery (JP-A-59-151,7).
61) is known. All of the above techniques using Sn and its homologous elements are examples of application to a positive electrode active material, and do not indicate a method of using these to a low-potential negative electrode active material.

On the other hand, as a high-potential positive electrode active material, Li
Mn2 O4, γ-β MnO2 and LiMn2 O4 composite oxide, LiCoO2, LiCo0.5 Ni0.5 O2, Li
NiO2, V2 O5, amorphous V2 O5, V6 O13, Li
V3 O8, VO2 (B), Ti compounds TiS2, Mo
The compounds MoS2, MoO3, LiMo2 O4, etc. are known. Among these, complex oxides containing cobalt are particularly effective for high-potential secondary batteries in that they have a high potential, but to combine them with a negative electrode to make a 3-4V class secondary battery, another potential is used. Improvement and improvement of capacity stability are required. For example, as a combination of a positive electrode active material and a negative electrode active material, both of which are metal chalcogenides, TiS2 and Li
TiS2 (US Pat. No. 983,476), chemically synthesized Li0.1 V2 O5 and LiMn1-s Mes O2.
(0.1 <s <1 Me = transition metal JP-A-63-21
0,028), Li0.1 V2 O5 and LiCo1-s Fe
s O2 (s = 0.05 to 0.3, 63-211, 56
4), Li0.1V2O5 and LiCo1-sNisO2
(S = 0.5 to 0.9 JP-A-1-294,364),
V2 O5, Nb2 O5 and lithium metal (JP-A-2-82)
447), Lix Fe2 O3 electrochemically synthesized with V2 O5 or TiS2 (US Pat. No. 4,464,447).
Journal of Power Sources, Vol. 8, p. 289, 1982), LiNix for positive electrode active material and negative electrode active material.
Co1-x O2 (0≤x <1 JP-A-1-120,765
In the specification, the positive electrode active material and the negative electrode active material are described as the same compound from Examples. ), LiCoO2 or LiMn2 O4 and iron oxide, FeO, Fe2 O3, Fe
3 O4, cobalt oxide, CoO, Co2 O3 or C
O3 O4 (JP-A-3-291,862) and the like are known. However, any combination of these is a non-aqueous secondary battery having a discharge potential lower than 3 V class and a low capacity.

[0006]

An object of the present invention is to obtain a non-aqueous secondary battery having high discharge potential, high capacity, good charge / discharge cycle characteristics, and improved safety.

[0007]

An object of the present invention 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, and at least one of the negative electrode active materials.
The species is a periodic table IV-B, V that inserts and releases lithium.
-Group B semimetal or an oxide selected from In, Zn, and Mg, wherein the positive electrode active material is mainly cobalt, and at least one metal selected from Group IV-A and Group IV-B of the periodic table. Can be achieved by using a non-aqueous electrolyte secondary battery characterized by being a lithium-containing manganese oxide having a stoichiometric or non-stoichiometric composition with a complex oxide containing or a spinel structure. It was

In the present invention, the periodic table IV-B and / or
Alternatively, the V-B group semimetal means Ge, Sn, Pb, Sb,
It is Bi.

The precursor of the negative electrode active material according to the present invention will be described. For example, α-PbO structure SnO and rutile structure S
It was discovered that nO2 itself does not work as a negative electrode active material for a secondary battery, but if lithium is continuously inserted into them, the crystal structure changes and it can work reversibly as a negative electrode active material for a secondary battery. That is, the charging / discharging efficiency in the first cycle is as low as about 80% or about 60%. Therefore, in the present invention,
A compound such as a α-PbO structure SnO or a rutile structure SnO2 as a starting material, that is, a compound before lithium is inserted will be referred to as a "negative electrode active material precursor". The negative electrode active material of the present invention is obtained by electrochemically intercalating lithium ions into an oxide that is a precursor of an active material. At that time, the lithium ion is inserted until the basic structure of the oxide is changed (for example, the X-ray diffraction pattern is changed), and the basic structure of the lithium ion-containing oxide after the insertion is charged and discharged. The process is carried out until the state is substantially unchanged (until the X-ray diffraction pattern is substantially unchanged). This change in the basic structure means a change from one crystal structure to a different crystal structure, or a change from a crystal structure to an amorphous structure.

Specific examples of the negative electrode active material or the precursor thereof referred to in the present invention include GeO, GeO2, SnO, SnO2,
PbO, PbO2, Pb2 O3, Pb3 O4, Sb2 O
3, Sb2 O4, Sb2 O5, Bi2 O3, Bi2 O4
, Bi2 O5 or non-stoichiometric compounds of their oxides. Among them, SnO, SnO2, G
eO and GeO2 are preferable, and SnO and SnO2 are particularly preferable. α-PbO structure SnO, rutile structure SnO2,
GeO and GeO2 having a rutile structure are preferred, and especially .alpha.-Pb.
O structure SnO and rutile structure SnO2 are preferable.

Various compounds can be included in the negative electrode active material precursor of the present invention. For example, transition metals (elements of the 4th, 5th, and 6th periods of the periodic table belonging to groups III-A to II-B), elements of the group IV-B of the periodic table, alkali metals (Elements I-A and II-A of the periodic table) or P, Cl, Br, I, F can be included. For example, SnO2 may contain Si as a homologous element as a dopant of various compounds (for example, compounds of Sb, In, and Nb) that enhance electron conductivity. The amount of the compound added is preferably 0 to 20 mol%.

As a method of synthesizing the precursor of the negative electrode active material, Sn is used.
In O2, an aqueous solution of a Sn compound such as stannic chloride, stannic bromide, stannic sulfate, and stannic nitrate and an alkali hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, water. Calcium oxide, magnesium hydroxide,
An aqueous solution such as ammonium hydroxide is mixed to precipitate stannic hydroxide, which is washed and separated. After the stannic hydroxide is almost dried, the gas containing much oxygen in the air
250 to 2000 in medium or low oxygen gas
Bake at ℃. Or burn with stannic hydroxide as it is,
It can then be washed. The average size of the primary particles is 0.01 μm to 1 μm as measured by a scanning electron microscope.
m is preferred. Particularly, 0.02 μm to 0.2 μm is preferable. The average size of the secondary particles is preferably 0.1 to 60 μm. Similarly, with SnO, an aqueous solution of stannous chloride, stannous bromide, stannous sulfate, and stannous nitrate and an alkali hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide are used. , Magnesium hydroxide,
Mix an aqueous solution such as ammonium hydroxide and boil. Also, stannous oxalate was added to
Bake at 0 to 1000 ° C. The average particle size is preferably 0.1 to 60 μm. Other oxides are Sn
Like O2 and SnO, it can be synthesized by well-known methods. Its preferable physical properties are the same as those of SnO described above.

One preferred form of the positive electrode active material used in the present invention is a lithium-containing metal oxide containing cobalt as a main component, and one or more selected from the group IV-A and the group IV-B of the periodic table. A metal is added to the crystal structure. By using the compound having such a structure as the active material, higher capacity and voltage can be obtained with respect to the cobalt oxide to which the above metal is not added, and therefore, the object of the present invention when combined with the above negative electrode active material. Is 3-4
A secondary battery of V class (average discharge voltage of 3.5 V or more) and high energy density can be designed.

The preferred structure of the positive electrode active material is LiCoxM
yOz (M is at least one metal selected from Group IVA and Group IVB of the periodic table, 0.9 ≦ x ≦ 1.0, 0 <y ≦ 0.
1, 1.9 ≦ z ≦ 2.1). Here, Li is released as a cation during the charging process, and the number of elements in the structural formula decreases to nearly 0.2 during a large charge. Preferred elements for M are Ti, Zr, Ge, and Sn. Of these, Ge and Zr are particularly preferred for their ability to maintain charge / discharge stability (cycle performance) of capacity. From the viewpoint of enhancing charge / discharge performance, a particularly preferable structural formula is LiCoxMyO.
z (M is at least one metal selected from Group IVA and Group IVB of the periodic table, 0.95 ≦ x ≦ 1.0, 0 <y ≦ 0.0
5, 1.9 ≦ z ≦ 2.1).

Another preferred form of the positive electrode active material used in the present invention is spinel-type manganese-containing oxide. The spinel-type oxide has a structure represented by the general formula A (B2) O4, in which oxygen anions are arranged in a cubic close-packed form, and occupy part of the faces and vertices of tetrahedra and octahedra. ing. The unit cell is composed of 8 molecules, and oxygen occupies position 32e in the Fd3m space. The unit cell occupies 64 octahedral lattice gaps in three non-crystallographically equivalent positions 8a, 8b, 48f. In this spinel, the B cation is located at the site of the 16d octahedral lattice gap (empty octahedral site is 16c), and the A cation is located at the 8a tetrahedral lattice gap. Each 8a octahedron shares a surface with four adjacent empty 16c octahedra, thereby providing a pathway for A cation diffusion (eg, 8a → 16c → 8a → 16c).
On the other hand, the 8b tetrahedron shares a face with the 16d octahedron formed by the B cation, which causes the cation occupation with energy.
Is disadvantageous. 48f tetrahedron is 16d, 16c
Share faces with both octahedra. Depending on the distribution state of cation A, A (B2) O4 is normal spinel, B
(A, B) O4 is called reverse spinel. The structure of Ax By (A1-x B1-y) O4, which is an intermediate state between them, also exists as a spinel.

A typical example of manganese oxide having a normal spinel structure is LiMn2 O4 which is a positive electrode active material. In this structure, half the Mn cations are trivalent and half are tetravalent. Λ-also known as active material
MnO2 is a defective spinel structure in which lithium is removed from the structure of LiMn2 O4, as shown in U.S. Pat. No. 4,246,253, in which all Mn cations are tetravalent. The manganese oxide positive electrode active material used in the present invention includes normal spinel type, reverse spinel type, and defect-free spinel structure or defective non-stoichiometric spinel structure.

A preferred example of the lithium-containing manganese oxide having a spinel structure contained in the positive electrode active material of the present invention is represented by the general formula Li1 + x [Mn2-y] O4 (0 <x <1.7,0≤
y <0.7). An example of this is Li4 Mn
5 O12 or Li [Li1 / 3 Mn in spinel structure display
5/3] O4 is mentioned. In addition, the following compounds are also included in the range of the above general formula (the structural formula includes those represented by the integer multiple or the decimal multiple of the general formula). Li4 Mn4 O9 LiMnO2 or Li2 Mn2 O4 Li2 MnO3 Li5 Mn4 O9 Li4 Mn5 O12 Another preferable example of the spinel-type lithium-containing manganese oxide contained in the positive electrode active material of the present invention is the general formula Li1-x.
[Mn2-y] O4 (0 <x <1.0, 0≤y <0.5)
Indicated by. Among these, the preferred structure is the general formula Li1-
x [Mn2-y] O4 (0.20 <x <1.0, 0 <y <
0.2). As an example of this, for example, Li2Mn5O11 which is a non-stoichiometric spinel compound disclosed in JP-A-4-240117 or Li1-x [Mn2-x] O4 (x = 0.273, y =
0.182). Another preferred structure is the general formula Li1-x [Mn2-y] O4 (0 <x≤0.2
0,0 <y <0.4). An example of this compound is Li2 Mn4 O9. In addition to these, the following compounds also have the above-mentioned various general formulas Li1-x [Mn2-y] O.
Included in the range of 4 (Structural formulas include those shown in integer multiples or decimal multiples of the general formula). Li4 Mn16.5 O35 Li2 Mn7.5 O16 Li0.7 MnO4

The manganese oxide which is the positive electrode active material of the present invention can be obtained by reacting a lithium salt with a manganese salt or manganese oxide in a solid phase at a high temperature according to a conventional method. When using lithium carbonate and manganese dioxide as raw materials, the firing temperature is 350 ° C to 900 ° C, preferably 35 ° C.
The temperature is 0 ° C to 500 ° C, and the firing time is 8 hours to 48 hours. When low-melting lithium nitrate (melting point 261 ° C) is used as the lithium salt, the firing temperature is 300 ° C.
To 900 ° C, preferably 300 ° C to 500 ° C
Is. As the manganese oxide, .lambda.-MnO2, electrolytically prepared MnO2 (EMD), chemically prepared MnO2 (CMD), and mixtures thereof can be used. Besides, as the lithium raw material, a lithium-manganese composite oxide (for example, Li2 Mn4 O9) can be used. In this case, the lithium-manganese composite oxide is mixed with a manganese raw material such as manganese dioxide and fired in the range of 350 ° C to 500 ° C.

The spinel type manganese oxide which is the positive electrode active material of the present invention contains at least one transition metal element, a typical element, and a rare earth element as a metal dopant other than manganese.
Complex metal oxides may be formed. Particularly preferred dopants are Co, Ni, Ti, V, Zr, Nb, Mo, W, F.
e, etc. are transition metal elements. In addition, in the positive electrode active material of the present invention, in the above general formula, Li is H, K, Na,
And a cation such as ammonium ion partially or mostly (eg, 95% or more) substituted.
-270125 etc. shall include the manganese oxide compound having a holland ore skeleton structure. The Holland ore type compound in which hydrogen is substituted as a cation can be easily obtained, for example, by an operation of subjecting the lithium-manganese composite oxide of the above general formula to an acid delithiation treatment at high temperature.

The positive electrode active material can be synthesized by a method of mixing and firing a lithium compound and a transition metal compound or a solution reaction, but a firing method is particularly preferable. The firing temperature used in the present invention may be a temperature at which a part of the compound used as the raw material for the positive electrode active material is decomposed and melted, and for example, 3
50 to 1500 ° C is preferable, and particularly 600 to 1000 ° C.
Is preferred. The firing gas atmosphere used in the present invention is
Although not particularly limited, the positive electrode active material is in the air or a gas having a high oxygen content (for example, about 30% or more), and the negative electrode active material is in the air or a gas having a low oxygen content (for example, about 10% or less), or It is preferably in an inert gas (nitrogen gas, argon gas).

The average particle size of the positive electrode active material used in the present invention is preferably 0.1 to 50 μm, and particularly 1 to 9.5.
μm is preferred. A well-known crusher or classifier is used to obtain a predetermined particle size. For example, a mortar, a ball mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling airflow type jet mill, a sieve and the like are used. The morphology of the active material is such that the average particle size is 0.1 micron or more.2.
It is preferable to be composed of primary particle aggregates having an average particle size of 1 micron or more and 9.5 micron or less formed by aggregating primary particles of 5 micron or less, and particularly preferably, an average particle size of 0.1 micron or more and 2.5 micron or less. It is preferable that the primary particles have an average particle diameter of 3.5 μm or more and 9.5 μm or less formed by aggregating primary particles. Further, in the above-mentioned primary particle aggregate, 80% or more of the total volume preferably has a particle size of 1 micron or more and 15 microns or less, more preferably 85% or more of the total volume, and further preferably 90% or more of the total volume. is there. The average particle size here is a mode diameter showing the most frequent point, and in the primary particles is an average value of values visually observed from an electron micrograph,
It is a value measured by a particle size distribution measuring device in the primary particle aggregate. The preferred specific surface area of the positive electrode active material is 0.
It is more than 1 m2 / g and not more than 5 m2 / g, particularly preferably more than 0.1 m2 / g and not more than 3 m2 / g.

The negative electrode active material used in the present invention can be obtained by chemically inserting lithium into its precursor. For example, a method of reacting with lithium metal, a lithium alloy, butyl lithium, or the like, or electrochemically inserting lithium is preferable. In the present invention, it is particularly preferable to electrochemically insert lithium into the oxide that is the precursor. As a method of electrochemically inserting lithium ions, a target oxide (a negative electrode active material precursor referred to in the present invention) as a positive electrode active material and a nonaqueous electrolyte containing lithium metal and a lithium salt as a negative electrode active material are used. It can be obtained by discharging a redox system (for example, an open system (electrolysis) or a closed system (battery)). In addition, as another embodiment example, a lithium-containing transition metal oxide as a positive electrode active material, a negative electrode active material precursor as a negative electrode active material, and a redox system comprising a non-aqueous electrolyte containing a lithium salt (for example, an open system (electrolysis)) Alternatively, the method obtained by charging a closed system (battery) is most preferable.

When inserting lithium electrochemically, it is preferable to apply a current of 0.04 A to 1 A per 1 g of the precursor oxide. Attempts to insert lithium at lower currents have surprisingly found to result in less reversible compounds. It is preferable that this current be supplied especially at the beginning of the first cycle, particularly within about 30% from the beginning of the required capacity of the first cycle. For example, L
It is preferable to continue to flow the current or more until it becomes about 0.6 V or less with respect to i-Al (80-20% by weight). After that, high current or low current may be used. Furthermore,
It is preferable to apply a current of 0.06 A to 0.8 A per 1 g of the oxide of the precursor.

The amount of lithium to be inserted into the negative electrode is not particularly limited, but it is preferable to insert lithium up to 0.05 V with respect to Li-Al (80-20% by weight), for example. Furthermore, it is preferable to insert up to 0.1 V, and in particular,
It is preferable to insert up to 0.15V. At this time,
The equivalent of lithium insertion is 3 to 10 equivalents, and the ratio of the amount used with the positive electrode active material of the present invention is determined according to this equivalent. It is preferable to multiply the usage ratio based on this equivalent by a coefficient of 0.5 to 2 to use. If the lithium source is other than the positive electrode active material (for example, lithium metal or alloy,
(Butyl lithium, etc.) Determine the amount of positive electrode active material used according to the lithium release equivalent of the negative electrode active material. Also at this time, it is preferable to multiply the usage ratio based on this equivalent by a coefficient of 0.5 to 2 times.

It was discovered that, when the negative electrode active material of the present invention was used as a precursor, "each metal (alloy with lithium) was not reduced even when lithium was inserted".
It is (1) there is no metal deposition (particularly dendrite deposition) observed by transmission electron microscopy, (2) the potential of lithium insertion / release via metal is different from that of oxide, and (3) In SnO, the loss of release due to insertion of lithium was about 1 equivalent, so it can be inferred from the fact that it does not match the 2 equivalent loss when metallic tin is generated. The potential of the oxide is similar to that of currently used calcined carbonaceous compounds, and it is presumed that, like calcined carbonaceous compounds, it is in a state where it is neither a simple ionic bond nor a simple metal bond. It Therefore, the negative electrode active material of the present invention is basically different from the lithium alloy.

The negative electrode oxide (precursor) of the present invention may be crystalline or amorphous, but even if it has a crystalline structure, the crystallinity decreases as lithium is inserted, and the amorphous It will change to qualitative. Therefore, the structure in which reversible redox is performed as the negative electrode active material is presumed to be a compound having high amorphousness. Therefore, the oxide (precursor) of the present invention may have a crystalline structure, an amorphous structure, or a mixed structure thereof.

As the negative electrode active material that can be used in combination with the present invention, lithium metal, lithium alloy (Al, A
1-Mn (U.S. Pat. No. 4,820,599), Al-
It absorbs Mg (JP-A-57-98977), Al-Sn (JP-A-63-6,742), Al-In, Al-Cd (JP-A-1-144,573), lithium ion or lithium metal. A calcined carbonaceous compound that can be released (for example, JP-A-58-209,864 and 61-214,
417, the same 62-88, 269, the same 62-216,
170, same 63-13, 282, same 63-24, 5
55, the same 63-121, 247, the same 63-121,
257, 63-155, 568, 63-276,
873, 63-314, 821, JP-A-1-20.
4,361, 1-221,859, 1-27
4,360). The purpose of using the lithium metal or lithium alloy together is to insert lithium in the battery, and does not utilize the dissolution / precipitation reaction of lithium metal or the like as the battery reaction.

The positive electrode active material and the negative electrode active material of the present invention are preferably synthesized by firing a mixture of a lithium compound and a transition metal compound described below. Examples of the lithium compound include oxygen compounds, oxyacid salts and halides. As the transition metal compound,
A monovalent to hexavalent transition metal oxide, the same transition metal salt, or the same transition metal complex salt is used.

Preferred lithium compounds used in the synthesis of the active material include lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium sulfite, lithium phosphate, lithium tetraborate, lithium chlorate and lithium perchlorate. , Lithium thiocyanate, lithium formate, lithium acetate, lithium oxalate, lithium citrate, lithium lactate, lithium tartrate, lithium pyruvate, lithium trifluoromethanesulfonate, lithium tetraborate, lithium hexafluorophosphate, lithium fluoride, Examples thereof include lithium chloride, lithium bromide and lithium iodide.
Preferred manganese compounds used for the synthesis of the positive electrode active material in the present invention include MnO2, Mn2O3, manganese hydroxide, manganese carbonate, manganese nitrate, ammonium manganese sulfate, manganese acetate, manganese oxalate, and manganese citrate.

Further, as a preferable transition metal compound, T
iO2 (rutile or anatase type), lithium titanate, acetylacetonato titanyl, titanium tetrachloride, titanium tetraiodide, titanyl ammonium oxalate, VOd (d = 2)
~ 2.5 d = 2.5 compound is vanadium pentoxide),
VOd lithium compound, vanadium hydroxide, ammonium metavanadate, ammonium orthovanadate,
Ammonium pyrovanadate, vanadium oxosulfate,
Vanadium oxytrichloride, vanadium tetrachloride, MnO2
, Mn2 O3, manganese hydroxide, manganese carbonate, manganese nitrate, manganese sulfate, ammonium 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 stearate, manganese fluoride, chloride Manganese manganese bromide, manganese iodide, manganese acetylacetonate, iron oxide (2,3 valent), ferric tetroxide, iron hydroxide (2,
Trivalent), iron chloride (2,3 valent), iron bromide (2,3 valent), iron iodide (2,3 valent), iron sulfate (2,3 valent), ammonium iron sulfate (2,3 valent) ), Iron nitrate (2,3 valent) iron phosphate (2,
Trivalent), iron perchlorate, iron chlorate, iron acetate (2,3 valent),
Iron citrate (2,3 valent), ammonium iron citrate (2,3 valent, iron oxalate (2,3 valent), ammonium iron oxalate (2,3 valent), CoO, Co2 O3 Co3 O4, LiC
oO2, 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, hexaamminecobalt complex salt (as salts, sulfuric acid, nitric acid, perchloric acid, thiocyanic acid, oxalic acid, acetic acid, fluorine, chlorine, bromine, iodine) 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, nickel acetylacetonate, niobium oxychloride, niobium pentachloride, niobium pentaiodide, Niobium oxide, niobium dioxide, niobium trioxide, niobium pentoxide,
Niobium oxalate, niobium methoxide, niobium ethoxide, niobium propoxide, niobium butoxide, lithium niobate, MoO3, MoO2, LiMo2 O4, molybdenum pentachloride, ammonium molybdate, lithium molybdate, ammonium molybdophosphate, molybdenum acetylacetonate oxide. Can be given.

A conductive agent, a binder, a filler and 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 fibers and metals (copper, nickel, aluminum, silver (JP-A-63) -1
48, 554), powders, metal fibers, or polyphenylene derivatives (Japanese Patent Laid-Open No. 59-20971) can be included as one kind 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. For carbon and graphite, 2 to 15% by weight is particularly preferable. Further, when the precursor of the active material is made to have electronic conductivity as in the case of SnO2 being doped with Sb, the amount of the conductive agent can be reduced. For example, addition of 0 to 10% by weight is preferable.

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, and particularly preferably 2 to 30% by weight. As the filler, any fibrous material that does not cause a chemical change in the constructed battery can be used. 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 the electrolyte, organic solvents such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran are used. , Dimethyl sulfoxide, 1,3-dioxolane,
Formamide, dimethylformamide, dioxolane,
Acetonitrile, nitromethane, methyl formate, methyl acetate, methyl propionate, ethyl propionate, phosphoric acid triester (JP-A-60-23,973), trimethoxymethane (JP-A-61-4,170), dioxolane derivative ( JP-A-62-15,771 and JP-A-62-22,3
72, 62-108,474), sulfolane (JP 62-31959), 3-methyl-2-oxazolidinone (JP 62-44,961), propylene carbonate derivative (JP 62-290,069, 62-2
290, 71), a tetrahydrofuran derivative (Japanese Patent Laid-Open Publication No.
3-32,872), diethyl ether (JP-A-63-
62,166), 1,3-propane sultone (Japanese Patent Application Laid-Open No. 6-242242).
3-102, 173) and a mixture of at least one aprotic organic solvent and a lithium salt soluble in the solvent, such as LiClO4, LiBF6, LiP.
F6, LiCF3 SO3, LiCF3 CO2, LiAs
F6, LiSbF6, LiB10Cl10 (JP-A-57-7)
4,974), lower aliphatic lithium carboxylate (JP-A-60-41,773), LiAlCl4, LiCl, L
iBr, LiI (JP-A-60-247,265), lithium chloroborane (JP-A-61-165,957), lithium tetraphenylborate (JP-A-61-214,37).
6) and the like. Above all, a mixture of propylene carbonate or ethylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate is mixed with LiCF3 SO3 and LiClO.
Electrolytes containing 4, LiBF4 and / or LiPF6 are preferred. Particularly, it is preferable to contain at least ethylene carbonate and LiPF6.

In addition to 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, Li3 N, LiI, Li5 N
I2, Li3 N-LiI-LiOH, LiSiO4, L
iSiO4 -LiI-LiOH (JP-A-49-81,8
99), xLi3 PO4-(1-x) Li4 SiO4
(JP 59-60,866), Li2 SiS3 (JP 60-501,731), phosphorus sulfide compound (JP 6
2-82,665) is 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 above aprotic electrolytic solution (US Pat. Nos. 4,792,504, 4,30,939, JP-A-62-22,375 and 62).
-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). Also,
Method using both inorganic and organic solid electrolytes (JP-A-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 μm
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-
(JP-A-60-89,075), AlCl3 (JP-A-61-88,466), conductive polymer-monomer of electrode active material (JP-A-61-161,673), triethylenephosphoramide. (JP 61-208,758), trialkylphosphine (JP 62-80,976), morpholine (JP 62-80,977), aryl compound having a carbonyl group (JP 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, carbon dioxide gas can be included in the electrolytic solution in order to have suitability for high temperature storage. (JP-A-59-
134,567)

The mixture of the positive electrode and the negative electrode may contain an electrolytic solution or an electrolyte. For example, the ion conductive polymer or nitromethane (Japanese Patent Laid-Open No. 48-36,6).
33), a method of adding an electrolytic solution (JP-A-57-124,870) is known.

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.

As the current collector of the electrode active material, for example, for the positive electrode, in addition to stainless steel, nickel, aluminum, titanium, calcined carbon, etc. as the material, carbon, nickel, titanium or aluminum on the surface of aluminum or stainless steel or Those treated with silver, the negative electrode, in addition to stainless steel, nickel, copper, titanium, aluminum, calcined carbon, etc. as the material, the surface of copper or stainless steel treated with carbon, nickel, titanium or silver. ), Al-C
d alloy or the like is used. It is also used to oxidize the surface of these materials. As the shape, 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 one having a thickness of 1 to 500 μm is 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 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 after being coated, dried, and compressed on the current collector. The coat thickness, length and width are determined by the size of the battery,
The thickness of the coat is 1-2 in the compressed state after drying.
000 μm is particularly preferable.

The application of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when it is installed in an electronic device, a color notebook computer, a black and white notebook computer, a pen input computer, a pocket (palmtop) computer, a notebook. Type word processor, pocket word processor, e-book player, mobile phone, cordless phone handset, pager, handy terminal, mobile fax, mobile copy, mobile printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini disk, Electric shaver, electronic translator, car phone,
There are transceivers, power tools, electronic organizers, calculators, memory cards, tape recorders, radios, backup power supplies, memory cards, etc. Other consumer products such as automobiles, electric vehicles, motors, lighting equipment, toys,
Game equipment, road conditioners, irons, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.), etc. Furthermore, it can be used for various military purposes and for space. It can also be combined with a solar cell.

[0043]

EXAMPLES The present invention will be described in more detail with reference to specific examples below, but the present invention is not limited to the examples as long as the gist of the invention is not exceeded. Example 1 Synthesis of active material SnO, GeO, GeO2, SiO2, PbO, PbO
2, Pb2 O3, Pb3 O4, Sb2 O3, Sb2 O4
, Bi2 O3, WO2 (comparative active material for negative electrode), Fe2
As O3 (comparative active material for negative electrode), a commercially available product was used as a raw material or the active material itself. Synthesis Example-1 Synthesis of SnO2 for negative electrode: Sn (OH) 4 was precipitated by reacting tin chloride with sodium hydroxide in an aqueous solution. The precipitate was calcined in air at 400 ° C. for 4 hours to synthesize SnO 2 having a rutile structure and ground in a mortar. 1
The average size of the secondary particles is about 0.05 μm. Synthesis Example-2 Synthesis of Li2SnO3 for Negative Electrode: 7.3 g of lithium carbonate and 15.1 g of tin dioxide are dry-mixed,
Firing was performed in an alumina crucible at 1000 ° C. for 12 hours in air. After firing, it was cooled to room temperature to obtain Li2 SiO3. In the same manner, the stoichiometric amounts of the raw materials are mixed and fired to form Li2 GeO3 and Li2 PbO.
3, Li3 BiO4, Li3 SbO4, Li2 ZnO2
, Li3 InO3, Li2 ZnSn2 O6, Li2 M
gSn2 O6, Li0.1 SnO2.05, Li4 SnO4,
Li6SnO5 and Li8SnO6 were synthesized as the negative electrode active material.

Synthesis Example-3 Synthesis of Li2SnO2 for negative electrode: 10.2 g of lithium acetate dihydrate, tin monoxide 1
3.5 g was dry-mixed, put in a porcelain crucible, and baked in an argon atmosphere at 350 ° C. for 24 hours. After firing, it was cooled to room temperature to synthesize Li2 SnO2. The composite was ground with a jet mill to an average particle size of 2.5 μm. In the same manner, the stoichiometric amounts of the raw materials are mixed and fired,
Li0.1 SnO1.05, Li6 SnO4, Li8 SnO5
Was synthesized. Synthesis Example-4 Synthesis of SiSnO3 for Negative Electrode: 2.60 g of silicon dioxide and 1.16 g of tin monoxide were dry-mixed and baked in an alumina crucible at 1000 ° C for 12 hours in the air. After firing, it is rapidly cooled to room temperature to obtain amorphous glassy Si.
SnO3 was synthesized. Synthesis Example-5 Synthesis of LiCoGe0.03O2 for positive electrode:
2.26 g of lithium carbonate, 5.0 g of tricobalt tetroxide and 0.19 g of germanium dioxide are dry-mixed and then mixed in air 9
The crystalline active material LiCoGe was calcined at 00 ° C. for 18 hours.
0.03 O2 was synthesized. The average particle size is 4 μm. Synthesis Example-6 Synthesis of LiCoZr0.02O2 for positive electrode:
2.26 g of lithium carbonate, 5.0 g of tricobalt tetroxide and 0.16 g of zirconium dioxide are dry mixed to obtain 9 in air.
The crystalline active material LiCoZr was calcined at 00 ° C. for 18 hours.
0.02 O2 was synthesized. Average particle size 5 μm.

Synthesis Example-7 LiCoGe0.02Zr for positive electrode
Synthesis of 0.02O2: 2.26 g of lithium carbonate, 5.0 g of tricobalt tetroxide, 0.13 g of germanium dioxide and 0.16 g of zirconium dioxide are dry-mixed, and 90% in air
After firing at 0 ° C. for 18 hours, the crystalline active material LiCoZr 0.
02O2 was synthesized. The average particle size is 4 μm. Further, similarly, the respective stoichiometric amounts of the raw materials are mixed and fired to obtain LiC.
oGe0.08O2, LiCoGe0.06O2, LiCoZr
0.06O2, LiCoZr0.08O2, LiCoTi0.08O2
, LiCoTi0.03O2 was synthesized for the positive electrode. Synthesis of active material for positive electrode comparison, LiCoO2: 2.26 g of lithium carbonate and 5.0 g of tricobalt tetroxide were dry-mixed and fired in air at 900 ° C for 18 hours to synthesize a crystalline active material LiCoO2. Average particle size 5 μm. Synthesis of active material for positive electrode comparison, LiMn2O4: 1.20 g of lithium carbonate and 5.92 g of manganese dioxide were dry-mixed and baked in air at 800 ° C for 12 hours to synthesize a crystalline active material LiMn2O4. Average particle size 3 μm. Synthesis of active material for positive electrode comparison, LiNi0.5 Co0.5 O2: 2.26 g of lithium carbonate, tricobalt tetroxide 2.
50 g of nickel oxide and 2.29 g of nickel oxide were dry-mixed and fired in air at 800 ° C. for 20 hours to obtain a crystalline active material LiNi0.
5 Co0.5 O2 was synthesized. Average particle size 7 μm.

In the following manner, coin-type secondary batteries were produced by various combinations of the negative electrode active material precursor of the present invention and the positive electrode active material. Regarding the negative electrode, the negative electrode active material precursor was mixed in a mixing ratio of 82% by weight, scaly graphite as a conductive agent 8% by weight, acetylene black 4% by weight, and polyvinylidene fluoride as a binder 6% by weight. The above mixture was compression molded to prepare pellets (13 mmΦ, 22 mg).
On the other hand, for the positive electrode, 82% by weight of the positive electrode active material, 8% by weight of scaly graphite as a conductive agent, 4% by weight of acetylene black, and 6% of tetrafluoroethylene as a binder.
The mixture mixed at a mixing ratio of wt% was compression molded into pellets (13 mmΦ, 110 mg). Dry these pellets in a dry box (dew point -40 to -70 ° C, dry air)
It was dried in a far infrared heater (150 ° C.) for about 3 hours. For the collector of the coin battery, both positive and negative cans are 80μ
A m-thick SUS316 net was welded to a coin can for use. As the electrolyte, 200 μl of a solution prepared by dissolving 1 mol / L of LiPF6 in a 2: 2: 6 volume mixture of ethylene carbonate, butylene carbonate and dimethyl carbonate was used, and a microporous polypropylene sheet was used as a separator between both electrodes. Using a polypropylene non-woven fabric, the non-woven fabric was impregnated with the electrolytic solution. Positive and negative electrode cans were stacked and the electrolytic solution was sealed to prepare a coin-type lithium ion secondary battery.

This battery was subjected to a charge / discharge test at a constant current density of 0.75 mA / cm 2 in the range of 2.7 to 4.3V. All the tests were started with a reaction of inserting lithium into the negative electrode active material precursor of the present invention. As described above, 100 kinds or more of coin batteries were manufactured by combining these for various negative electrode active materials and positive electrode active materials synthesized from various raw materials,
The charge / discharge performances were compared and evaluated, and Table 1 shows the typical results. The types of the negative electrode and the positive electrode active material forming the battery of the present invention are not limited to the types described in this table. In Table 1, the cycle property means (discharge capacity of 10th charge / discharge-discharge capacity of 1st charge / discharge) / first
The discharge capacity of the second charging / discharging means the capacity decrease rate, and the smaller the value, the better the performance stability.

Table 1 Charge / Discharge Performance of Coin Battery Positive Electrode Active Material Negative Electrode Active Material Average Discharge Voltage Second Cycle Discharge Capacity Cycleability (V) (mAh / g) (Capacity Reduction Rate) (Comparison) LiCoO2 WO2 3.20 160 0.15 LiMn2 O4 WO2 3.15 145 0.16 LiNi0.5Co0.5 O2 WO2 3.15 140 0.16 LiCoO2 SnO 3.52 480 0.08 LiCoO2 SnO2 3.52 470 0.07 LiMn2 O4 SnO 3.50 390 0.09 LiNi0.5Co0.5O2 SnO 3.48 360 0.09 LiCoO2 SnSiO3 3.50 460 0.04 LiCoO2 Li2Sn O3 3.50 440 0.06 LiCoO2 GeO2 3.46 229-0.10

(Invention) LiCoGe0.03O2 SnO 3.55 490 0.05 LiCoGe0.06O2 SnO 3.55 482 0.06 LiCoGe0.08O2 SnO 3.53 482 0.06 LiCoZr0.02O2 SnO 3.55 515 0.5. 05 LiCoZr0.06O2 SnO 3.55 505 0.06 LiCoZr0.08 O2 SnO 3.53 500 0.06 LiCoGe0.03O2 SnSiO3 3.55 482 0.03 LiCoGe0.03O2 Li2Sn O3 3.55 450 0.05 LiCoGe0.03O2 GeO2 3.48 255 -0.10 LiCoZr0.02O2 SnSiO3 3.55 490 0.03 LiCoZr0.02O2 Li2Sn O3 3.55 460 0.05 LiCoZr0.02O2 GeO2 3.50 265 -0.10 LiCoGe0.02Zr0.02O2 SnSiO3 3 .55 485 0.03 LiCoGe0.02Zr0.02O2 Li2SnO3 3.55 455 0.04 LiCoTi0.03O2 SnO 3.55 482 0.06 LiCoTi0.08O2 SnO 3.54 480 0.05 LiCoGe0.0 3O2 SnO2 3.54 475 0.05 LiCoGe0.03O2 Li2Sn O2 3.55 490 0.05 LiCoGe0.03O2 Li2MgSn2O6 3.54 485 0.06

Example 2 Synthesis of Positive Electrode Active Material Synthesis Example 8. Li2 Mn4 O9 (or Li0.89 Mn
1.78O4) Synthesis Li2 CO3 and MnO2 were mixed at a molar ratio of about 1: 4, and the mixture was heated in air at 400 ° C. for 12 hours to obtain Li2 Mn4 O9 (or Li0.89 Mn1.78).
The spinel type lithium manganese oxide of the present invention having a composition of O4) was synthesized. Alternatively, oxides of similar composition can also be synthesized by mixing Li2 CO3 and MnCO3 in a similar molar ratio of 1: 4 and calcining the mixture in air at 430 ° C. for 5 hours. It was Synthesis example 9. Synthesis of Li0.7 Mn2 O4 Li2 CO3 and MnO2 have a molar ratio of about 0.35: 2.
And mix the mixture in air at 450 ° C for 12
After heating for a period of time, the spinel type lithium manganese oxide of the present invention having a composition of Li0.7 Mn2 O4 was synthesized. Synthesis example 10. Li2 Mn5 O11 (or Li0.73 Mn
1.82O4) Synthesis of the above compound Li2Mn4O9 and .lambda.-MnO2 into L
Mixing so that the atomic ratio of i: Mn is approximately 2: 5,
The spinel type lithium manganese oxide Li2 Mn5 O11 of the present invention was synthesized by heating in air at 250 ° C. for 24 hours. Synthesis example 11. Li4 Mn5 O12 (or Li1.33 Mn
1.67O4) synthesis

Li2 CO3 and λ-MnO2 are replaced with Li: Mn
To give a molar ratio of about 4: 5, and the mixture is heated in air at 430 ° C. for 12 hours to obtain Li4 Mn5 O
The lithium manganese oxide of the present invention having a composition of 12 (or Li1.33Mn1.67O4) was synthesized. Synthesis example 12. Li0.5 Mn1.88O4 (or Li2 M
n7.5 O16) The above Li4 Mn5 O12 and EMD were mixed at a molar ratio of about 1:10 and heated in air at 400 ° C. for 40 hours to obtain a composition of Li0.5 Mn1.88 O4. The lithium manganese oxide of the present invention was synthesized. Alternatively, the compound Li0.5 Mn1.88 O4 was obtained by mixing CMD instead of EMD so that the molar ratio of Li4 Mn5 O12 and EMD was 1:10 and calcining at 400 ° C. for 24 hours. . Synthesis example 13. Li0.46Mn1.89O4 (or Li4
Synthesis of Mn16.5O35) The above-mentioned Li4 Mn5 O12 and λ-MnO2 were mixed at a molar ratio of about 1:12, and the mixture was mixed in air at 400 ° C. for 12 hours.
After heating for a period of time, the lithium manganese oxide of the present invention having a composition of Li0.46Mn1.89O4 was synthesized. Incidentally, the Mn oxide synthesized as described above has a structure of Li2O (MnO
2) When displayed by x, the value of x corresponds to the range of 2-9.

Preparation of Electrode Mixture and Coin Battery and Charge / Discharge Test According to Example 1, positive electrode pellets (active material weight: 16.4 mg) and i negative electrode pellets (active material weight: 85 mg) were prepared. 80μm thick SUS for current collector
The net of 316 was used, and this was welded to the positive and negative electrode cans for coin batteries. 1 mol / l Li as electrolyte
250 .mu.l of an equal volume mixture of ethylene carbonate containing PF6 and diethylene carbonate was used, and this was impregnated into a separator made of a microporous polypropylene sheet and polypropylene nonwoven fabric. Set the positive electrode pellets, negative electrode active material precursor pellets on the current collector, insert a separator between the positive electrode and the negative electrode, and combine the positive electrode and the negative electrode can with a caulking machine in the dry box, A coin type lithium ion battery was produced. Using this lithium ion battery, a charge / discharge test was conducted at a constant current density of 0.75 mA / cm 2. All tests started with charging. The charge / discharge cycle performance was evaluated by setting the charge cutoff voltage to 4.3V and the discharge cutoff voltage to 2.7V.

A positive electrode active material and a negative electrode active material precursor shown in the above synthesis examples, various active materials synthesized according to these synthesis examples, and a comparative active material were combined as follows to form a lithium ion secondary battery. It was made. Negative electrode active material precursor Positive electrode active material Cell 1 (comparative example) WO2 LiMn2 O4 cell 2 (comparative example) WO2 Li0.46M1.89O4 cell 3 (comparative example) SnO2 LiMn2 O4 cell 4 (comparative example) SnO LiMn2 O4 cell 5 (comparative example) Comparative Example) Li2 SnO3 LiMn2 O4 Cell 6 (Comparative Example) SnSiO3 LiMn2 O4 Cell 7 (Invention) SnO2 Li2 Mn5 O11

Cell 8 (Invention) SnO Li2 Mn5 O11 Cell 9 (Invention) Li2 SnO3 Li2 Mn5 O11 Cell 10 (Invention) SnSiO3 Li2 Mn5 O11 Cell 11 (Invention) SnO Li2 Mn4 O9 Cell 12 (Invention) SnO Li0.46 M1.89 O4 cell 13 (invention) SnO Li0.5 Mn1.88 O4 cell 14 (invention) SnO Li0.38 Mn1.9 O4 cell 15 (invention) SnSiO3 Li2 Mn4 O9 cell 16 (invention) SnSiO3 Li0 .46 M1.89O4 cell 17 (invention) SnSiO3 Li0.5 Mn1.88O4 cell 18 (invention) SnSiO3 Li0.38Mn1.9 O4 cell 19 (invention) Li2 SnO3 Li0.46 M1.89O4 cell 20 (invention) Li2 SnO3 Li0.43 M1.89 O4 cell 21 (invention) Li2 SnO2 Li0.5 Mn1.88 O4 cell 22 (invention) GeO2 Li2 Mn5 O11 Le 23 (present invention) GeO2 Li0.46Mn1.89O4

Table 2 summarizes the results of evaluation of the charge / discharge performance of the lithium ion secondary battery with each combination of positive electrode / negative electrode in terms of electric capacity and charge / discharge cycle performance. The discharge capacity is 1.8 V and indicates the capacity per weight of the negative electrode active material until the time when the discharge is terminated. The capacity cycle property means the number of times of charge and discharge required until the initial capacity decreases to 60%.

Table 2 Second Cycle Discharge Average Voltage Capacity Cycle Performance Discharge Capacity (mAh / g) (V) (times) Cell 1 170 3.15 40 Cell 2 180 3.20 50 Cell 3 410 3.45 130 Cell 4 430 3.45 120 Cell 5 420 3.45 125 Cell 6 425 3.46 135 Cell 7 430 3.50 130 Cell 8 450 3.50 122 Cell 9 440 3.50 130 Cell 10 445 3.52 135 Cell 11 445 3.50 120

Cell 12 455 3.50 120 Cell 13 450 3.50 120 Cell 14 460 3.50 120 Cell 15 440 3.52 150 Cell 16 450 3.52 155 Cell 17 445 3.53 150 Cell 18 455 3. 52 155 cell 19 435 3.50 145 cell 20 440 3.50 145 cell 21 450 3.50 140 cell 22 250 3.40 200 cell 23 270 3.40 210

From the results of Table 2, the lithium ion non-aqueous secondary battery prepared by the combination of the negative electrode active material disclosed in the present invention and the positive electrode active material of the spinel type lithium manganese composite oxide was used as a conventional metal oxide type negative electrode active material. It was found that the comparative battery using the substance and the manganese oxide has excellent performance in terms of electric capacity and cycleability. The negative electrode active material of the present invention is obtained by electrochemically intercalating lithium ions into an oxide that is a precursor of an active material. At that time, the insertion of lithium ions changes the basic structure of the oxide (for example, X-ray diffraction pattern).
Until the basic structure of the lithium ion-containing oxide after insertion is substantially unchanged during charging / discharging (until the X-ray diffraction pattern does not substantially change). Be implemented. This change in the basic structure means a change from one crystal structure to a different crystal structure, or a change from a crystal structure to an amorphous structure.

[0059]

EFFECTS OF THE INVENTION An oxide selected from the IV-B and V-B groups is used as a negative electrode active material, and a complex oxide containing cobalt and IV-B and V-B group elements or a spinel type lithium manganese complex oxide is prepared. By using a lithium ion secondary battery with a positive electrode active material and a non-aqueous solution as an electrolyte,
High discharge capacity and high charging / discharging efficiency are obtained, and high safety and good cycle performance brought about by the properties of the negative electrode active material are shown. In addition, cost advantages can be obtained when inexpensive manganese is used. it can.

Claims (16)

[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 at least one of the negative electrode active materials inserts and releases lithium. B, V-B group semi-metal or In, Zn,
An oxide selected from Mg, wherein the positive electrode active material is a composite oxide mainly composed of cobalt and containing one or more metals selected from groups IV-A and IV-B of the periodic table. Non-aqueous electrolyte secondary battery 2. In a secondary battery comprising a positive electrode active material, a negative electrode active material and a non-aqueous electrolyte containing a lithium salt, the basic structure of the negative electrode active material is changed by inserting lithium ions into the negative electrode active material precursor. Periodic table I formed by
Lithium-containing manganese whose main component is an oxide composed of one or more elements selected from VB and VB groups, and whose positive electrode active material has a spinel structure and has a stoichiometric or non-stoichiometric composition A non-aqueous electrolyte secondary battery comprising an oxide. 3. The positive electrode active material is LiCoxMyOz (M is at least one metal selected from Group IVA and Group IVB of the periodic table, 0.9 ≦ x ≦ 1.0, 0 <y ≦ 0.1, 1. 9 ≦ z
≦ 2.1), The non-aqueous electrolyte secondary battery according to claim 1, wherein 4. The positive electrode active material is LiCoxMyOz (M =
Ge, Zr, 0.9 ≦ x ≦ 1.0, 0 <y ≦ 0.1,
1.9 ≦ z ≦ 2.1), The non-aqueous electrolyte secondary battery according to claim 1. 5. The positive electrode active material has the general formula Li1 + x [Mn2-
y] O4 (0 <x <1.7, 0≤y <0.7), which contains a lithium-containing manganese oxide having a spinel structure, and the non-aqueous electrolyte secondary according to claim 2. battery 6. The positive electrode active material has the general formula Li1-x [Mn2-
The non-aqueous electrolyte secondary according to claim 2, further comprising a lithium-containing manganese oxide having a spinel structure represented by y] O4 (0 <x <1.0, 0≤y <0.5). battery 7. The positive electrode active material has the general formula Li1-x [Mn2-
The non-aqueous electrolyte according to claim 2, further comprising a lithium-containing manganese oxide having a spinel structure represented by y] O4 (0.2 <x <1.0, 0 <y <0.2). Secondary battery 8. The non-aqueous electrolyte secondary battery according to claim 2, wherein the positive electrode active material has an essentially single-layer spinel structure. 9. A cathode active material is synthesized by calcining a manganese oxide selected from λ-MnO2, electrolytically prepared MnO2, chemically prepared MnO2, and mixtures thereof. Claim 2 characterized by the above-mentioned.
Non-aqueous electrolyte secondary battery described in 10. At least one of the negative electrode active materials is Ge, Sn, Pb, Sb, B that inserts and releases lithium.
The non-aqueous electrolyte secondary battery according to claim 1, which is an oxide mainly containing i, Si, In, Zn, and Mg. 11. The non-aqueous electrolyte secondary battery according to claim 1, wherein at least one of the negative electrode active materials is an oxide mainly composed of Sn that inserts and releases lithium. 12. The negative electrode active material precursor, wherein at least one of Sn-based oxides before insertion of lithium is α-PbO structure SnO or rutile structure SnO2. The non-aqueous secondary battery according to claim 1 or 2. 13. The non-aqueous secondary battery according to claim 1, wherein at least one of the negative electrode active materials is an amorphous chalcogen compound that inserts and releases lithium. 14. The method of inserting lithium into the precursor of the negative electrode active material is a method of passing an electric current of 0.04 A or more per 1 g of the precursor, wherein Non-aqueous secondary battery 15. The non-aqueous secondary battery according to claim 1, wherein at least one kind of the electrolytic solution is ethylene carbonate. 16. The non-aqueous secondary battery according to claim 1, wherein at least one kind of lithium salt contained in the electrolytic solution is a compound containing fluorine.