JPH11213999A - Positive active material for lithium battery, lithium battery provided with the same, and method for producing positive active material for lithium battery - Google Patents

Abstract

(57) [Problem] To provide an active material having a continuous change in voltage during charging and discharging and having a large capacity. SOLUTION: The chemical composition formula is Li _x Ni _{1- y My} 0 ₂ (however,
0.25 <X ≦ 2, M is one or more elements selected from Co, Mn, Al, P, B or S, and an amorphous lithium-containing nickel oxide represented by 0 ≦ y <1). Active material. In order to produce an amorphous lithium-containing nickel oxide, phosphate, borate or silicate after mixing a lithium salt and a lithium salt, nickel hydroxide or nickel oxyhydroxide, This is heat-treated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a positive electrode active material for a lithium battery, a lithium battery provided with the same, and a positive electrode active material for a lithium battery.

[0002]

2. Description of the Related Art In recent years, lithium-ion batteries using a carbon material for the negative electrode and lithium cobalt oxide, which is a composite oxide having a layered structure, for the positive electrode have rapidly spread due to their high operating voltage and high energy density. Have begun to do. On the other hand, lithium cobaltate is scarce in resources,
In addition, due to its high cost, lithium nickel oxide is actively being studied as a substitute substance.

[0003] Lithium nickelate (LiNiO ₂ )
It is a layered compound having the same crystal structure as lithium cobalt oxide that is put into practical use, and has a crystal structure in which lithium is inserted between layers of edge shear of a NiO ₆ octahedron. The manufacturing method is such that Ni (NO ₃ ) ₂ , N
i (OH) ₂ , NiCO ₃ , NiO, NiOOH and the like, and LiOH, LiNO ₃ , Li ₂ CO
₃ and Li ₂ O ₂ etc., and after mixing both,
Generally, a heat treatment at about 600 ° C. to 900 ° C. is performed in an oxygen stream.

[0004] However, lithium nickelate includes:
Solid State Ionics, 44, 87,
1990 and Chem. Express, 7,689,1
992 or 33rd Battery Symposium 21
As reported in (1992), its structure resembles a rock-salt structure, and nickel and lithium ions are easily replaced in the manufacturing process, resulting in an unreliable structure,
There is a problem that the capacity is reduced.

Attempts have been made to use nickel oxyhydroxide as a nickel raw material. For example, the present inventors have disclosed in Japanese Patent Application Laid-Open No. 8-306360.
A method for synthesizing lithium nickelate exhibiting a uniform charge / discharge reaction by reacting lithium nitrate with nickel oxyhydroxide containing cobalt is disclosed in JP-A-63-19 / 1988.
No. 761 describes a method of applying electrochemically produced lithium nickel oxide to a lithium battery by charging nickel hydroxide in a lithium hydroxide solution.

Further, the present inventors have proposed that nickel oxyhydroxide itself is used as an active material.
No. 9760 discloses a lithium battery active material comprising nickel oxyhydroxide containing 20 to 75% cobalt.

[0007]

Regarding lithium nickelate, despite various studies as described above, it is still difficult to obtain a sufficient capacity. Is multi-stage, for example, 4
However, there is a problem that the high-rate discharge performance deteriorates.

[0008]

Means for Solving the Problems The present invention was made in the course of continuing research on lithium nickel oxide by the present inventor,
This is achieved by finding that lithium nickel oxide having an amorphous structure has excellent characteristics which have not been seen before.

That is, in the first invention of the present application, the chemical composition formula is Li _x Ni _{1 -y My} 0 ₂ (where 0.25 <X ≦ 2, M is Co, Mn, Al, P, B or S And a lithium-containing amorphous nickel oxide represented by at least one element selected from the group consisting of 0 ≦ y <1).

In the second invention of the present application, the chemical composition formula is L
_{i x Ni 1-y M y} 0 2 ( where, 1 <X ≦ 2, M is Co, M
A positive electrode active material for a lithium battery, which is an amorphous nickel oxide containing lithium represented by at least one element selected from n, Al, P, B or S, and 0 ≦ y <1).

In the third invention of the present application, the chemical composition formula is L
_{i x Ni 1-y M y} 0 2 ( where, 1.4 <X ≦ 2, M is Co,
A positive electrode active material for a lithium battery, which is a lithium-containing amorphous nickel oxide synthesized to have at least one element selected from Mn, Al, P, B or S, 0 ≦ y <1). .

In the fourth invention of the present application, the chemical composition formula at the time of discharge is Li _x Ni _{1 -y My} 0 ₂ (where 1.4 <X ≦ 2, M
Is selected from Co, Mn, Al, P, B or S
A positive electrode active material for a lithium battery, which is a lithium-containing amorphous nickel oxide represented by at least one element, 0 ≦ y <1).

Further, the fifth invention of the present application is directed to a method of formula
_{i x Ni 1-y M y} 0 2 ( where, 1 <X ≦ 2, M is Co, M
At least one element selected from n, Al, P, B or S, which is a lithium-containing amorphous nickel oxide represented by 0 ≦ y <1), and having a cobalt content of 2 to 60 mol%
(Co / Ni + Co) is a positive electrode active material for a lithium battery.

In the sixth invention of the present application, the chemical composition formula is L
_{i x Ni 1-yz Co y} M z 0 2 (0.25 <X ≦ 2,0.0
2 ≦ y ≦ 0.6, M is one or more elements selected from Mn, Al, P, B or S, 0 ≦ z <1 and y + z <
A positive electrode active material for a lithium battery, which is the lithium-containing amorphous nickel cobalt oxide shown in 1).

In the seventh invention of the present application, the chemical composition formula is L
_{i x Ni 1-yz Co y} M z 0 2 (1.4 <X ≦ 2,0.02
≦ y ≦ 0.6, M is one or more elements selected from Mn, Al, P, B or S, 0 ≦ z <1 and y + z <1)
Is a lithium-containing amorphous nickel cobalt oxide synthesized to have a positive electrode active material for a lithium battery.

In the eighth invention of the present application, the chemical composition at the time of discharge is Li _x Ni _{1 -yz} Co _y M _z O ₂ (1.4 <X ≦ 2,
0.02 ≦ y ≦ 0.6, M is one or more elements selected from Mn, Al, P, B or S, 0 ≦ z <1 and y +
This is a positive electrode active material for a lithium battery, which is a lithium-containing amorphous nickel cobalt oxide represented by z <1).

According to a ninth aspect of the present invention, there is provided a positive electrode active material for a lithium battery according to any one of the first to eighth aspects of the present invention, wherein the positive electrode active material contains phosphorus, boron or silicon. is there.

Further, a tenth invention of the present application is a lithium battery provided with the positive electrode active material for a lithium battery according to any one of the above inventions.

Further, the eleventh invention of the present application relates to a phosphate,
A lithium battery according to the ninth aspect of the present invention, comprising mixing a lithium salt with at least one of borate or silicate, nickel hydroxide or nickel oxyhydroxide, and subjecting the mixture to heat treatment. This is a method for producing a positive electrode active material.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The positive electrode active material for a lithium battery according to the present invention is, for example, a method of mixing nickel hydroxide, a predetermined amount of a lithium salt and a phosphate, borate or silicate and then heat-treating the mixture. It is preferable to mix nickel oxyhydroxide, a predetermined amount of lithium salt and phosphate, borate or silicate, and then heat-treat the mixture.

In this case, a lithium salt and a phosphate, borate or silicate can be made into a solution state, and a solution containing lithium ion and phosphate ion, borate ion or silicon ion can be produced. As the state of nickel oxyhydroxide, β-form, γ-form, or a mixture of β-form and γ-form can be used. The state of nickel hydroxide may be β-form or α-form.

Further, Li _x Ni _1-y to which cobalt is added
In the case of manufacturing Co _y O ₂ , for example, it is preferable to use nickel hydroxide containing cobalt in the above method.

According to the above method, the amorphous oxide represented by the chemical composition formula Li _x Ni0 ₂ or _{Li x Ni 1-y Co y} 0 2 during synthesis is obtained, the structure of the chemical formula It is preferable that the synthesis is performed so that X representing the ratio of the elements satisfies 1 <X ≦ 2, and more preferably the synthesis is performed such that 1.4 <X ≦ 2. Li _x Ni _1-y Co _y O ₂ has the effect of further improving the charge / discharge life performance as a positive electrode active material. In this case, y represents the ratio of the constituent elements in the chemical composition formula.
Is more preferably synthesized so as to satisfy 0.02 ≦ y ≦ 0.6. By including cobalt in this way, the charge / discharge life performance as a positive electrode active material is further improved.

According to the method using the above-mentioned phosphate, borate or silicate, the above-mentioned amorphous oxide containing phosphorus, boron or silicon depending on the salt used can be obtained. In the above method, phosphate, borate or silicate is added to promote the formation of an amorphous phase, but apart from this effect, an amorphous phase containing phosphorus, boron or silicon is not included. L
i _x Ni0 ₂ or _{Li x Ni 1-y Co y} 0 2 is also a characteristic great positive electrode active material. Furthermore, the lithium-containing amorphous nickel oxide of the present invention may contain other elements other than the above, if necessary, for example, Co, Mn, Al, and the like. Is incorporated as one of the elements constituting the oxide, and the chemical composition formula is L
_{i x Ni 1-y M y} 0 2 ( where, 0.25 <X ≦ 2, M is C
At least one element selected from the group consisting of o, Mn, Al, P, B and S, and a lithium-containing amorphous nickel oxide represented by 0 ≦ y <1) are preferable. In this case, more preferably, y is 0 ≦ except when M selects Co.
It is preferable that y <0.5. When M selects Co, Li _x Ni _{1 -yz} Co _y M _z 0 ₂ (1.4 <X ≦
2,0.02 ≦ y ≦ 0.6, M is Mn, Al, P, B
Alternatively, a lithium-containing amorphous nickel-cobalt oxide represented by at least one element selected from S and 0 ≦ z <1 and y + z <1) is preferable. In this case, z is more preferably 0 ≦ z <0.5.

To prepare a positive electrode for a lithium secondary battery using this active material, for example, a lithium-containing amorphous nickel oxide powder and a graphite, carbon black, etc. A paste made of a conductive material and a binder such as polyethylene or polyvinylidene fluoride is applied and dried to produce a paste. The positive electrode may be mixed with other active materials such as crystalline lithium nickel oxide and lithium cobalt oxide in addition to the active material of the present invention in order to adjust the positive electrode characteristics.

In order to produce a non-aqueous electrolyte lithium secondary battery using the above-mentioned positive electrode, for example, lithium perchlorate and hexafluoride are mixed in a non-aqueous solvent comprising a mixed solvent of ethylene carbonate and diethyl carbonate. As an electrolyte and a negative electrode active material in which lithium salts such as phosphorus phosphorus lithium are dissolved,
An assembly is made by combining a lithium metal, a lithium alloy, a carbon material, and a negative electrode containing a substance capable of occluding and releasing lithium ions such as graphite and metal oxide.

For example, it is manufactured by the above method.
Amorphous Li _x NiO ₂ or Li _x Ni _y C according to the present invention
A lithium secondary battery including o _1-y O ₂ as a positive electrode active material has uniform charge / discharge characteristics and a large capacity exceeding a theoretical capacity of 200 mAh / g conventionally considered in Li _x NiO ₂ . Battery.

It is believed that this is because the active material of the present invention has the following reaction. The conventional reaction of crystalline lithium nickelate is represented by the following formulas (1) and (2).
It is an electron reaction, and the theoretical capacity density based on this is 275 m
Ah / g, which is an electrochemical reaction in which the valence of nickel is between trivalent and tetravalent. In this case, in the chemical composition formula Li _x NiO ₂ of the positive electrode active material in the battery, X is in the range of 0 ≦ X ≦ 1 depending on the charge / discharge state.

[0029] ^{_{Charging: LiNiO 2 → Li + + NiO}} 2 + e - (1) ^{_{discharge: LiNiO 2 ← Li + + NiO}} 2 + e - (2) On the other hand, amorphous of the present invention Li _x Ni0 ₂ Then, the 1.75 electron reaction of the following formulas (3) and (4) proceeds, and in the chemical composition formula Li _x NiO ₂ of the positive electrode active material in the battery, X is 0.25 according to the charge / discharge state. It changes reversibly in the range of <X ≦ 2. At this time, the theoretical capacity density was 448 mAh /
g, and the potential changes continuously.

Charge: Li ₂ NiO ₂ → 1.75 Li ⁺ + Li _0.25 NiO ₂ +1.75 e ⁻ (3) Discharge: Li ₂ NiO ₂ ← 1.75 Li ⁺ + Li _0.25 NiO ₂ +1.75 e ⁻ (4) where X Can be charged up to 0.25 or less, but it is not preferable to charge more than this in order to improve the repetition characteristics. Therefore, the chemical composition formula Li _x NiO ₂ of the positive electrode active material is: 0.25 <X ≦ 2 is preferable, and in order to sufficiently bring out the advantages of the present invention, the chemical composition formula at the time of discharge is Li _x NiO ₂ (1.4 <
X ≦ 2). Li _x Ni
_The same applies to _1-y Co _y O ₂ , preferably 0.25 <X ≦ 2, and the chemical composition formula at the time of discharge is Li _x Ni _1-y C
o _y 0 ₂ (1.4 <X ≦ _2, 0.02 ≦ y ≦ 0.6) is preferable.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to preferred embodiments.

Example 1 Nickel hydroxide powder of 2 mol% {(Co / (Ni + Co)} having a cobalt content of 5 to 50 μm {Ni _0.98 Co _0.02 (0H) ₂ } 3 mol
And lithium hydroxide (LiOH) 6 mol and 0.1 m
ol of phosphoric acid H ₃ PO ₄ was heat-treated at a temperature of 700 ° C. for 7 hours in an oxygen atmosphere to obtain a lithium-containing amorphous nickel oxide A as a positive electrode active material according to the present invention. Composition by chemical analysis was mainly composed of _{Li 1.8 Ni 0.98 Co 0.02 0 2} .

Example 2 β-nickel oxyhydroxide powder having a cobalt content of 5 mol% {(Co / (Ni + Co)} of 5 to 50 μm (β-Ni _0.95 Co _0.05 OO)
And H) 2 mol, of lithium hydroxide of 3 mol, hypophosphite lithium (LiH ₂ P0 ₂₎ 0.2mol and were mixed, and under an argon gas atmosphere containing 20% oxygen 450
Heat treatment was performed at 10 ° C. for 10 hours to obtain a lithium-containing amorphous nickel oxide B as a positive electrode active material according to the present invention. Composition by chemical analysis was mainly composed of _{Li 1.4 Ni 0.95 Co 0.05 0 2} .

Example 3 The content of cobalt was 10 mol
1% {(Co / (Ni + Co)} mixed aqueous solution of cobalt nitrate and nickel nitrate {pH = 1.0, specific gravity 1.65
(20 ° C.) of boric acid H ₃ B0 ₃ was added 30 g / l to 4.5
M sodium hydroxide aqueous solution was added. The resulting precipitate was washed with hot water, dried at 120 ° C., and then pulverized with a ball mill to synthesize amorphous nickel hydroxide powder containing 50 to 100 μm of boron. 3 mol of this powder and 6 mol of lithium nitrate (LiNO ₃ ) are mixed and pulverized, and then mixed under an argon gas atmosphere containing 20% oxygen.
Heat treatment was performed at 00 ° C. for 10 hours to obtain a lithium-containing amorphous nickel oxide C according to the present invention. Composition by chemical analysis was mainly composed of _{Li 1.8 Ni 0.9 Co 0.1 0 2} .

Example 4 The content of cobalt was 5 mol
% {(Co / (Ni + Co)} aqueous solution of cobalt nitrate and nickel nitrate {pH = 1.0, specific gravity 1.65.
(20 ° C.), a 4.5 M aqueous sodium hydroxide solution containing 35 g / l of silicate H ₄ SiO ₄ was added. The resulting precipitate was washed with hot water, dried at 120 ° C., and then pulverized with a ball mill to synthesize 50 to 100 μm nickel hydroxide powder. 3 mol of this powder and lithium hydroxide (L
After mixing with 7 mol of iOH) and pulverizing, oxygen 2
Heat treatment was performed at 700 ° C. for 10 hours in an argon gas atmosphere containing 0% to obtain a lithium-containing amorphous nickel oxide D according to the present invention. The composition by chemical analysis is Li _2.2 Ni _O.95
The Co _0.05 0 ₂ was mainly composed. in this case,
The composition formula for the chemical analysis of the formed lithium-containing amorphous nickel oxide is Li _x NiO ₂ , and the value of X exceeds 2 and
2, but it is presumed that lithium salt as an impurity was mixed. [Example 5] The cobalt content was 8 mol% ｛(Co /
(Ni + Co)｝ mixed aqueous solution of cobalt nitrate and nickel nitrate pH = 1.0, specific gravity 1.65 (20 ° C.), 35 g / l of phosphoric acid H ₃ PO ₄ added thereto, and a 4.5 M sodium hydroxide aqueous solution Was added. After washing the resulting precipitate with hot water,
After drying at 120 ° C., pulverizing with a ball mill
１００100 μm nickel hydroxide powder was synthesized. After mixing 3 mol of this powder and 6 mol of potassium peroxodisulfate in a 2 M aqueous sodium hydroxide solution, wash with hot water and dry at 110 ° C. to obtain β-Ni _0.92 Co _0.08 OO
H) was synthesized. After mixing 3 mol of this β-Ni _0.92 Co _0.08 OOH powder with 6 mol of LiOH,
Heat treatment was performed at 50 ° C. to obtain a lithium-containing amorphous nickel oxide E according to the present invention. The composition by chemical analysis is Li _1.9
The main component was Ni _0.92 Co _{0.080 2} .

As a result of X-ray diffraction analysis of these lithium nickelates, an acute angle diffraction peak was observed in each case as in the case of the conventional X-ray diffraction pattern of lithium nickelate (LiNiO ₂ ). However, since it was diffused, it is considered that the material became amorphous. As a result of emission analysis, A, B, C, and E contained phosphorus and D contained silicon. Therefore, these substances are considered to be effective in amorphization.

Conventional lithium nickelate (LiNiO ₂ )
FIG. 1 shows an X-ray diffraction pattern obtained with F and the lithium-containing amorphous nickel oxide A of Example 1. In the active material A according to the present invention, unlike the conventional active material F, almost no peak is observed. In addition, X-ray diffraction patterns almost similar to those of A were obtained for B, C, D and E.

Next, a mixed powder of 100 parts of these substances and 8 parts of acetylene black was mixed with 1 part of polyvinylidene fluoride.
% N-methyl-2-pyrrolidol solution in a paste form, filled in foamed aluminum having a porosity of 90%, dried at 120 ° C., and sized 30 mm × 4
A positive electrode plate having a size of 0 mm × 0.8 mm and a nominal capacity of 300 mAh was manufactured. Test batteries (A, B, and B) were prepared using two lithium metal plates having the same size as one of these positive electrode plates and 300 ml of a mixed solution of ethylene carbonate and diethyl carbonate containing 1 M lithium perchlorate as an electrolyte. C, D
And E: provided that the symbols correspond to the symbols of the positive electrode active material). For comparison, a similar battery F using a conventional lithium nickel oxide (LiNiO ₂ ) active material was also manufactured.

This positive electrode plate was charged to 4.2 V (to lithium metal) at 15 mA, and then discharged to 2.0 V at 30 mA.
Shown in

[0040]

[Table 1] As can be seen from the table, the capacity of the battery using the positive electrode active material according to the present invention is 260 to 320 mAh / g, which is much larger than that of the battery using the conventional positive electrode plate, which is 150 mAh / g. It can be seen that it has increased.

Further, an active material was manufactured in the same manner as in Example 1 except that the cobalt content was changed, and a battery similar to the test battery A was manufactured. The same charge / discharge test as in Table 1 was performed. Was done. FIG. 2 shows the relationship between the discharge capacity and the cobalt content at that time. From FIG. 2, the content of cobalt is 2-6.
In the case of 0 mol% (Co / Ni + Co), the content is 0
It can be seen that the discharge capacity is larger than in the case of the above, and that the content in this range is preferable.

The discharge characteristics of the batteries A, B, C, D and E according to the present invention are a continuous curve as compared with the conventional battery F, and the diffusion of lithium ions occurs uniformly. I knew it was there. As typical examples, FIG. 3 shows the discharge characteristics of the battery A according to the present invention and the conventional battery F having the maximum discharge capacity. The discharge capacity of the battery A using the positive electrode active material according to the present invention is larger than that of the battery using the conventional active material, and the discharge characteristic is a continuous curve. In the conventional battery discharge, the capacity rapidly decreases when the terminal voltage becomes 3.5 V or lower, but in the case of the battery of the present invention, the discharge is possible while gradually lowering even at 3.5 V or lower. there were.

In general, the discharge characteristics of the lithium-containing amorphous nickel oxide according to the present invention can be discharged even at 3.5 V or less. This feature was found to appear in the case where the positive electrode active material was amorphous. Particularly, when the content of cobalt is 2 to
The range of 60 mol% (Co / Ni + Co) was good.
It was also found that the addition of cobalt improves the charge / discharge cycle life performance as compared with the case of no addition.

More importantly, in the positive electrode active material of the present invention, a capacity of 275 mAh / g or more, which has been conventionally considered, is obtained. In general, the electrode reaction of a lithium nickelate positive electrode active material can be expressed by the formulas (1) and (2) as described above. However, when the oxidation state of nickel of the lithium nickelate exceeds 3.75, the crystal structure is changed. In order to be unstable, the maximum charging voltage is set to around 4.2 V with respect to lithium metal. In that case, the theoretical capacity that can be practically used is 2 due to the 0.75 electron reaction in the charging reaction of the formula (3) and the discharging reaction of the formula (4).
06 mAh / g.

[0045] ^{_{LiNiO 2 → 0.75Li + + Li 0.25}} NiO 2 + 0.75e - (3) LiNiO 2 ← 0.75Li + + Li 0.25 NiO 2 + 0.75e - (4) , however, using a positive electrode active material according to the present invention In the case of a battery, a discharge capacity greater than the theoretical capacity is obtained even when the charging condition is set such that the oxidation state of nickel is 3.75. This fact and the fact that discharge is possible even at a discharge voltage of 3.5 V or less means that discharge is possible even in a region where the depth of discharge is lower than the trivalence of nickel.

As mentioned above, lithium nickelate is
Although it is possible to discharge even at a valence of three or less, it has been reported that a change in the crystal structure occurs and the discharge potential becomes discontinuous. In the case of the present invention, however, the discharge potential becomes continuous. Therefore, in the case of an amorphous state as in the present invention, lithium ions easily diffuse from the surface to the inside of the crystal structure, and while the crystal structure is maintained, 3 It is presumed that it means that discharge is possible to a charge of less than or equal to the value.

In this case, the theoretical capacity is such that the discharge state is Li ₂
For NiO ₂ , the charge state is 448 mAh / g of the 1.75 electron reaction represented by the equation (5) for Li _0.25 NiO ₂ . When the state of charge changes to NiO ₂ , it is expected to reach 512 mAh / g. Equation (5) represents the charging reaction,
Equation (6) represents a discharge reaction.

[0048] ^{_{Li 2 NiO 2 → 1.75Li + +}} Li 0.25 NiO 2 + 1.75e - (5) Li 2 NiO 2 ← 0.75Li + + Li 0.25 NiO 2 + 1.75e - (6) Therefore, active according to the present invention The composition of the substance can be expressed as 1 <X ≦ 2 in Li _x NiO ₂ . As shown in Example 4, when lithium is contained as an impurity, it is natural that X exceeds 2 such as X = 2.2.

As described above, the case of the lithium battery using metal lithium for the negative electrode has been described as an example. However, it is needless to say that the same effect is exhibited when the carbon material is used for the negative electrode.

The use of the lithium-containing amorphous nickel oxide or lithium-containing amorphous nickel cobalt oxide positive electrode active material for a lithium battery according to the present invention increases the discharge capacity of the battery and reduces the change in discharge voltage. Being continuous, the battery of the present invention has a high energy density. Further, according to the production method of the present invention, the lithium-containing amorphous nickel oxide or lithium-containing amorphous nickel-cobalt oxide of the present invention can be easily produced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an X-ray diffraction pattern.

FIG. 2 is a diagram showing a relationship between a discharge capacity and a cobalt content.

FIG. 3 is a diagram comparing the discharge characteristics of a battery A of the present invention and a conventional battery F.

Claims (11)

[Claims] (1) a chemical composition formula of Li _x Ni _{1- y My} 0 ₂ (provided that
0.25 <X ≦ 2, M is at least one element selected from Co, Mn, Al, P, B or S, and is a lithium-containing amorphous nickel oxide represented by 0 ≦ y <1). Cathode active material for lithium batteries. 2. The method according to claim 1, wherein the chemical composition is Li _x Ni _{1 -y My} 0 ₂ (wherein
1 <X ≦ 2, M is at least one element selected from Co, Mn, Al, P, B or S, and a lithium-containing amorphous nickel oxide represented by 0 ≦ y <1). For positive electrode active material. 3. The chemical composition formula is Li _x Ni _{1 -y My} 0 ₂ (provided that:
1.4 <X ≦ 2, M is one or more elements selected from Co, Mn, Al, P, B or S, and lithium-containing amorphous nickel synthesized to have 0 ≦ y <1) A positive electrode active material for a lithium battery that is an oxide. 4. The chemical composition formula at the time of discharge is Li _x Ni _{1 -y My} 0 ₂
(However, 1.4 <X ≦ 2, M is Co, Mn, Al, P,
One or more elements selected from B or S, 0 ≦ y <
A positive electrode active material for a lithium battery, which is the lithium-containing amorphous nickel oxide shown in 1). 5. The method according to claim 1, wherein the content of cobalt is 2 to 60 mol% (C
3. The positive electrode active material for a lithium battery according to claim 2, wherein the positive electrode active material is o / Ni + Co). 6. The chemical composition represented by Li _x Ni _{1 -yz} Co _y M _z O _2.
(0.25 <X ≦ 2, 0.02 ≦ y ≦ 0.6, M is M
A positive electrode active material for a lithium battery, which is a lithium-containing amorphous nickel cobalt oxide represented by at least one element selected from n, Al, P, B or S, and 0 ≦ z <1 and y + z <1). 7. The chemical composition represented by Li _x Ni _{1 -yz} Co _y M _z O _2.
(1.4 <X ≦ 2, 0.02 ≦ y ≦ 0.6, M is Mn,
One or more elements selected from Al, P, B or S;
A positive electrode active material for a lithium battery, which is a lithium-containing amorphous nickel cobalt oxide synthesized so as to have 0 ≦ z <1 and y + z <1). 8. The chemical composition at the time of discharge is Li _x Ni _{1 -yz} Co
_y M _z 0 ₂ (1.4 <X ≦ _2, 0.02 ≦ y ≦ 0.6, M
Is a lithium-containing amorphous nickel cobalt oxide represented by at least one element selected from Mn, Al, P, B or S, and 0 ≦ z <1 and y + z <1). . 9. The positive electrode active material for a lithium battery according to claim 1, wherein the positive electrode active material contains phosphorus, boron or silicon. 10. The method of claim 1, 2, 3, 4, 5, 6, 7, or 8.
Or a lithium battery comprising the positive electrode active material for a lithium battery according to 9. 11. A method comprising mixing at least one of a phosphate, a borate and a silicate, a lithium salt, and nickel hydroxide or nickel oxyhydroxide, followed by heat treatment. Item 10. The method for producing a positive electrode active material for a lithium battery according to Item 9.