JPH11191431A - Nonaqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a nonaqueous solvent flame-resistant and to improve the cycle characteristic of a battery by providing a positive electrode, a negative electrode and a nonaqueous electrolyte with electrolyte disolved in a nonaqueous solvent, including a specific phosphate compound and a specific phosphagen compound as the nonaqueous solvent. SOLUTION: A nonaqueous solvent to be used contains a phosphate compound expressed by formula I and a phosphagen compound expressed by formula II. In the formula, R1 -R4 represent substituted or nonsubstituted cyclic aromatic groups, and A represents a nonsubstituted cyclic aromatic group or a heterocycle. In the formula, R5 , R6 represent a straight chain or branched alkyl group, a cyclic saturated alkyl group or an alkylene group, and (n) is an integer of 1-100. Flame resistance is displayed because of containing the phosphate compound in the nonaqueous solvent, and the cycle characteristic of a battery is improved since containing the phosphagen compound is contained. In this nonaqueous electrolyte battery, a wound layer body with a positive electrode, and a negative electrode wound through a separator is charged in a battery can.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-aqueous electrolyte battery using a non-aqueous solvent as a solvent for an electrolyte.

[0002]

2. Description of the Related Art In recent years, many portable electronic devices such as a camera-integrated video tape recorder, a mobile phone, and a portable computer have appeared and their size and weight have been reduced. Researches have been made to improve the energy density of batteries that are portable power sources for these electronic devices, particularly secondary batteries. Among secondary batteries, lithium-ion batteries are expected to have higher energy density than lead batteries and nickel-cadmium batteries, which are secondary batteries using conventional aqueous electrolytes. It is being advanced.

[0003] Non-aqueous electrolytes used for lithium batteries or lithium ion batteries include carbonate-based non-aqueous solvents such as propylene carbonate and diethyl carbonate, and Li
A solution in which PF ₆ is dissolved is widely used because it has relatively high conductivity and is stable in potential. Among batteries using these nonaqueous electrolytes, lithium ion secondary batteries are known to have higher safety than batteries using metallic lithium.

[0004]

[Problems to be solved by the invention] However,
When considering a significant increase in the energy density and an increase in the size of a battery, it is considered that a technology for further improving safety is important. The electrolyte used here is a non-aqueous type, that is, an organic solvent type, and is flammable. Therefore, it is almost impossible for the electrolyte to leak from the battery. However, considering the case where the electrolyte leaks for some reason, it is more preferable that the electrolyte is flame-retardant.

[0005] Therefore, it has been proposed to include a phosphate compound in a non-aqueous solvent in order to make the electrolyte solution nonflammable. However, despite the fact that phosphate ester compounds are relatively stable electrochemically, the oxidizing and reducing power of the material used for the positive electrode or negative electrode is very strong,
The phosphoric ester compound reacts with the material used for the positive electrode or the negative electrode. The reaction product of this reaction grows as a film on the electrode surface, and this film increases the impedance of the battery. As a result, there is a problem that the voltage drop becomes large particularly when the battery is discharged with a large current, and the cycle characteristics deteriorate. In particular, when the content of the phosphate compound in the non-aqueous solvent is 30% by weight or more, there is a problem that the deterioration of the cycle characteristics becomes large.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned conventional circumstances, and has been proposed in which a non-aqueous solvent used in an electrolyte is made nonflammable and the cycle characteristics of a battery are improved. It is intended to provide a liquid battery.

[0007]

A non-aqueous electrolyte battery according to the present invention comprises a positive electrode having a positive electrode active material, a negative electrode having a negative electrode active material, and a non-aqueous electrolyte having an electrolyte dissolved in a non-aqueous solvent. And containing, as the nonaqueous solvent, a phosphate compound represented by the general formula (1) and a phosphazene compound represented by the general formula (2).

[0008]

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(In the formula, R _{1 to} R ₄ represent a substituted or unsubstituted cyclic aromatic group, and A represents an unsubstituted cyclic aromatic group or a heterocyclic ring.)

[0010]

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(Wherein R ₅ and R ₆ are a linear or branched alkyl group, a cyclic saturated alkyl group, or an alkylene group, and n is an integer of 1 to 100). In the non-aqueous electrolyte battery according to the above, since the non-aqueous solvent of the non-aqueous electrolyte contains the phosphate compound represented by the general formula (1), the non-aqueous solvent is made flame-retardant. In addition, since the nonaqueous electrolyte battery contains the phosphazene compound represented by the general formula (2), the battery cycle characteristics are improved.

[0012]

Embodiments of the present invention will be described below.

FIG. 1 is a longitudinal sectional view showing one structural example of the nonaqueous electrolyte battery of the present invention. The non-aqueous electrolyte battery 1 is formed by loading a wound body in which a film-shaped positive electrode 2 and a film-shaped negative electrode 3 are wound in close contact with a separator 4 inside a battery can 5. .

The positive electrode 2 is manufactured by applying a positive electrode mixture containing a positive electrode active material and a binder on a current collector and drying the mixture. A metal foil such as an aluminum foil is used for the current collector.

As the positive electrode active material, a metal oxide, a metal sulfide, or a specific polymer can be used depending on the type of the intended battery.

For example, when a lithium primary battery is constructed, TiS ₂ , MnO ₂ , graphite, F
eS ₂ or the like can be used. When a lithium secondary battery is configured, TiS ₂ ,
Metal sulfides or oxides such as MoS ₂ , NbSe ₂ , and V ₂ O ₅ can be used. Further, a lithium composite oxide mainly composed of LiM _x O ₂ (where M represents one or more transition metals and x varies depending on the charge / discharge state of the battery and is usually 0.05 or more and 1.10 or less). Things and the like can be used. As the transition metal M constituting the lithium composite oxide, Co, Ni, Mn, or the like is preferable. A specific example of such a lithium composite oxide is LiCo.
O ₂ , LiNiO ₂ , LiNiyCo _1-y O ₂ (where 0 <
y <1. ), LiMn ₂ O _{4 and the} like. These lithium composite oxides can generate a high voltage and become positive electrode active materials excellent in energy density. The positive electrode 2 may use a plurality of these positive electrode active materials in combination.

As the binder for the above-mentioned positive electrode mixture, a known binder which is usually used for a positive electrode mixture for a battery can be used. Can be added.

The negative electrode 3 is manufactured by applying a negative electrode mixture containing a negative electrode active material and a binder on a current collector and drying the mixture. For the current collector, for example, a metal foil such as a copper foil is used.

In forming a lithium primary battery or a lithium secondary battery, it is preferable to use lithium, a lithium alloy, or a material capable of doping or undoping lithium as a negative electrode material. As a material that can be doped and de-doped with lithium, for example, a carbon material such as a non-graphitizable carbon-based material and a graphite-based material can be used. Specifically, carbon materials such as pyrolytic carbons, cokes, graphites, glassy carbon fibers, fired organic polymer compounds, carbon fibers, and activated carbon can be used. Examples of the coke include pitch coke, needle coke, and petroleum coke. The fired organic polymer compound is obtained by firing a phenol resin, a furan resin or the like at an appropriate temperature and carbonizing the same.

In addition to the above-mentioned carbon materials, polymers such as polyacetylene and polypyrrole and oxides such as SnO ₂ can also be used as materials capable of doping and undoping lithium. Further, as the lithium alloy, a lithium-aluminum alloy or the like can be used.

As the binder for the negative electrode mixture, a known binder that is usually used for a negative electrode mixture of a lithium ion battery can be used, and a known additive for the negative electrode mixture can be used. Etc. can be added.

The non-aqueous electrolyte is prepared by dissolving an electrolyte in a non-aqueous solvent.

As the electrolyte, a known electrolyte usually used in a battery electrolyte can be used. Specifically, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiC
10 ₄ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ , Li
Lithium salts such as C (SO ₂ CF ₃ ) ₃ , LiAlCl ₄ , and LiSiF ₆ can be given. Among them, especially Li
PF ₆ and LiBF ₄ are desirable from the viewpoint of oxidation stability.

Such an electrolyte is contained in a non-aqueous solvent at a concentration of 0.1%.
Preferably, it is dissolved at a concentration of from mol / l to 3.0 mol / l. More preferably, 0.5 mol / l
２．０2.0 mol / l.

As the non-aqueous solvent, various non-aqueous solvents conventionally used for non-aqueous electrolytes can be used. For example, propylene carbonate, cyclic carbonates such as ethylene carbonate, chain carbonates such as diethyl carbonate and dimethyl carbonate, carboxylate esters such as methyl propionate and methyl butyrate, γ-butyl lactone, sulfolane, 2-methyltetrahydrofuran Ethers such as dimethoxyethane can be used. These non-aqueous solvents may be used alone or in combination of two or more. Among them, especially from the viewpoint of oxidation stability,
It is preferable to use a carbonate ester.

Further, the non-aqueous solvent preferably contains a phosphate compound. By making the non-aqueous electrolyte contain a phosphate compound, the non-aqueous solvent can be made flame-retardant.

As such a phosphate compound,
It is preferable to use the compound represented by the general formula (1) from the viewpoint of electrochemical stability.

[0028]

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Wherein R _{1 to} R ₄ are a phenyl group, a benzyl group, a toluoyl group or an xylyl group at the ortho, meta or para position, and A is an ortho, meta or para substituted phenyl group or It is a substituted biphenyl group, an unsubstituted phenyl group, an unsubstituted biphenyl group, or bisphenol A.) As the phosphoric ester compound, an aromatic condensed phosphoric ester is preferable, and for example, R _{1 to} R ₄ are the same substituent. Examples include, but are not limited to, symmetric aromatic condensed phosphate esters, asymmetric aromatic condensed phosphate esters in which R _{1 to} R ₄ are different substituents, or halogen-substituted aromatic condensed phosphate esters. Not something.

These phosphoric ester compounds can be used alone or in combination of two or more. In addition, one of these phosphate compounds may be used alone, or a plurality of them may be used as a mixture.

The non-aqueous solvent preferably contains the phosphate compound represented by the general formula (1) at a ratio of 0.5% by weight to 20% by weight. If the amount of the phosphate ester compound is too small, the effect of enhancing the flame retardancy of the non-aqueous solvent is not sufficient. On the other hand, if the amount of the phosphate ester compound is too large, the battery characteristics of the non-aqueous electrolyte battery 1 will deteriorate. Therefore, by setting the content of the phosphate compound to 0.5% by weight to 20% by weight, the flame retardancy of the non-aqueous solvent can be increased without lowering the battery characteristics of the non-aqueous electrolyte battery 1. it can.

However, although the phosphoric ester compound is relatively stable electrochemically, the oxidizing power and the reducing power of the material used for the positive electrode 2 or the negative electrode 3 are very strong. The ester compound reacts with the material used for the positive electrode 2 or the negative electrode 3. The reaction product of this reaction grows as a film on the electrode surface, and this film increases the impedance of the battery, thereby deteriorating the cycle characteristics of the battery.

Therefore, in the non-aqueous electrolyte battery 1, the phosphazene compound represented by the general formula (2) is contained in the non-aqueous solvent. By adding the phosphazene compound represented by the general formula (1) to the non-aqueous electrolyte containing the phosphate ester compound, a stable film can be formed on the electrode surface and the film growth can be suppressed.

[0034]

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(Wherein, R ₅ and R ₆ are a linear or branched alkyl group, a cyclic saturated alkyl group, or an alkylene group, and n is an integer of 1 to 100). As the molecular weight increases, the viscosity of the electrolytic solution increases, and the conductivity decreases. Therefore, in the general formula (2), R ₅ and R ₆ may be the same or different, and —CH ₃ , —CH ₂ CH ₃ , -CH ₂ CH ₂ CH _3, -
The number of carbon atoms n = 1 to 1 such as CH (CH ₃ ) ₂ and cyclohexyl
It is preferably an alkyl group selected from the group of 10. Further, it is also possible to replace hydrogen in the above substituents or side chain groups with a halogen element such as fluorine or boron.

Specific examples of the phosphazene compound include, but are not limited to, polybispropyloxyphosphazene. In addition, one of these phosphazene compounds may be used alone, or a plurality thereof may be used as a mixture.

The non-aqueous solvent preferably contains the phosphazene compound represented by the general formula (2) at a ratio of 0.5% by weight to 20% by weight. If the amount of the phosphazene compound is too small, the effect of suppressing the film growth on the electrode surface and improving the cycle characteristics of the nonaqueous electrolyte battery 1 is not sufficient. On the other hand, if the amount of the phosphazene compound is too large, the viscosity of the non-aqueous electrolyte increases, and the conductivity decreases. Therefore, by setting the content of the phosphazene compound to 0.5% by weight to 20% by weight, the electric conductivity of the non-aqueous electrolytic solution is not reduced.
The cycle characteristics of the nonaqueous electrolyte battery 1 can be improved.

Such a non-aqueous electrolyte battery 1 is manufactured as follows.

The positive electrode 2 is uniformly coated with a positive electrode mixture containing a positive electrode active material and a binder on a metal foil such as an aluminum foil, which serves as a positive electrode current collector, and dried to form a positive electrode active material layer. It is produced by forming. Known binders can be used as the binder of the positive electrode mixture, and known additives and the like can be added to the positive electrode mixture.

The negative electrode 3 is formed by uniformly applying a negative electrode mixture containing a negative electrode active material and a binder on a metal foil such as a copper foil serving as a negative electrode current collector and drying the same to form a negative electrode active material layer. It is produced by forming. As the binder of the negative electrode mixture, a known binder can be used, and a known additive or the like can be added to the negative electrode mixture.

The positive electrode 2 and the negative electrode 3 obtained as described above are brought into close contact with each other via a separator 4 made of, for example, a microporous polypropylene film, and wound in a spiral form many times to form a wound layer body. Is done.

Next, an insulating plate 6 was inserted into the bottom of an iron battery can 5 having nickel plating on the inside thereof, and the wound body was further housed. Then, in order to collect the current of the negative electrode, one end of a negative electrode lead 7 made of, for example, nickel is pressed against the negative electrode 3 and the other end is welded to the battery can 5. Thereby, the battery can 5
Has conductivity with the negative electrode 3 and becomes an external negative electrode of the nonaqueous electrolyte battery 1. In order to collect the current of the positive electrode 2, one end of a positive electrode lead 8 made of, for example, aluminum is connected to the positive electrode 2.
To the battery cover 1 at the other end via a current interrupting thin plate 9.
0 is electrically connected. The current interrupting thin plate 9 interrupts the current in accordance with the internal pressure of the battery. This allows
The battery lid 10 has conductivity with the positive electrode 2, and serves as an external positive electrode of the nonaqueous electrolyte battery 1.

Next, a non-aqueous electrolyte is injected into the battery can 5. This non-aqueous electrolyte is prepared by dissolving an electrolyte in a non-aqueous solvent.

Next, the battery lid 5 is fixed by caulking the battery can 5 through the insulating sealing gasket 11 coated with asphalt, and the cylindrical nonaqueous electrolyte battery 1 is manufactured.

In this non-aqueous electrolyte battery 1,
As shown in FIG. 1, a center pin 12 connected to the negative electrode lead 7 and the positive electrode lead 8 is provided, and a safety valve device for bleeding gas when the pressure inside the battery becomes higher than a predetermined value. 13 and a PTC element 14 for preventing a rise in temperature inside the battery.

The shape of the non-aqueous electrolyte battery of the present invention is not particularly limited, such as a cylindrical type, a square type, a coin type, a button type and the like. can do.

[0047]

EXAMPLE A non-aqueous electrolyte battery as described above was manufactured.

Example 1 First, a negative electrode was manufactured as follows.

First, a petroleum pitch was used as a starting material and calcined at 1000 ° C. in an inert gas stream to obtain a non-graphitizable carbon material having properties similar to glassy carbon. When an X-ray diffraction measurement was performed on the non-graphitizable carbon material, the (002) plane spacing was 3.76 Å, and the true specific gravity was 1.58 g / cm ³ .

Next, the obtained non-graphitizable carbon material was pulverized to obtain a carbon material powder having an average particle diameter of 10 μm. 90 parts by weight of the carbon material powder and 10 parts by weight of the binder were mixed to prepare a negative electrode mixture. Here, polyvinylidene fluoride was used as the binder.

Finally, the negative electrode mixture was dispersed in N-methyl-2-pyrrolidone to form a slurry. Then, this slurry was uniformly applied to both surfaces of a 10 μm-thick strip-shaped copper foil as a negative electrode current collector, dried to form a negative electrode active material layer, and then compression-molded with a roll press to prepare a negative electrode. .

Next, a positive electrode was produced as follows.

First, lithium carbonate and cobalt carbonate were mixed at a ratio of 0.5 mol to 1 mol, and 900
Calcination was performed at 5 ° C. for 5 hours to obtain LiCoO _{2 serving} as a positive electrode active material.

Next, 91 parts by weight of the obtained LiCoO ₂ , 6 parts by weight of a conductive agent, and 10 parts by weight of a binder were mixed to prepare a positive electrode mixture. Here, graphite was used as the conductive agent, and a copolymer of vinylidene fluoride and hexafluoropropylene was used as the binder.

Finally, the positive electrode mixture was dispersed in N-methyl-2-pyrrolidone to form a slurry. Then, this slurry was uniformly applied on one surface of a 20-μm-thick aluminum foil serving as a positive electrode current collector, dried to form a positive electrode active material layer, and then compression-molded with a roll press to produce a positive electrode.

The positive electrode obtained as described above and the negative electrode are brought into close contact with each other via a separator made of a microporous polypropylene film having a thickness of 25 μm, and wound in a spiral form many times to produce a wound layer body. did.

Next, an insulating plate was inserted into the bottom of the nickel-plated iron battery can, and the wound body was further housed. Then, in order to collect the current of the negative electrode, one end of a nickel negative electrode lead was pressed against the negative electrode, and the other end was welded to the battery can. Further, in order to collect the current of the positive electrode, one end of an aluminum positive electrode lead was attached to the positive electrode, and the other end was electrically connected to the battery lid via a current interrupting thin plate. The current interrupting thin plate interrupts the current according to the internal pressure of the battery.

Then, a non-aqueous electrolyte was injected into the battery can. This non-aqueous electrolyte is made of propylene carbonate (hereinafter referred to as P
Called C. ) And 40% by weight of dimethyl carbonate (hereinafter, referred to as dimethyl carbonate).
Called DMC. ), 40 parts by weight of a phosphoric acid ester compound, and 10 parts by weight of a phosphazene compound.

Here, the phosphoric ester compound includes:
Compound 1 in which R _{1 to} R ₄ and A in the general formula (1) are substituents as shown in Table 1 was used.

[0060]

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In the phosphazene compound, R ₅ and R ₆ in the general formula (2) are each —CH ₂ CH ₂ CH ₃ ,
SPR1 manufactured by Otsuka Chemical Co., where n is an integer of 15 to 20
00 was used.

[0062]

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Finally, the battery lid is fixed by caulking the battery can through an insulating sealing gasket coated with asphalt, and a cylindrical non-aqueous electrolyte battery having a diameter of about 18 mm and a height of about 65 mm is obtained. Produced.

Example 2 The amount of the phosphazene compound was 5
A non-aqueous electrolyte battery was manufactured in the same manner as in Example 1 except that the amount of the phosphoric acid ester compound was changed to 15% by weight.

Example 3 When the amount of the phosphazene compound was 1
And weight%, the amount of phosphoric acid ester compound and 19% by weight, R ₁ as phosphoric acid ester compound of the general formula (1)
A non-aqueous electrolyte battery was produced in the same manner as in Example 1 except that Compound 2 in which R ₄ and A were substituents as shown in Table 1 was used.

Example 4 The amount of the phosphazene compound was adjusted to 5
% By weight, the amount of the phosphate compound was 15% by weight, and R ₁ of the general formula (1) was used as the phosphate compound.
A non-aqueous electrolyte battery was produced in the same manner as in Example 1 except that Compound 3 in which R ₄ and A were substituents as shown in Table 1 was used.

Example 5 The same procedure as in Example 5 was carried out except that compound 5 in which R _{1 to} R ₄ and A in the formula (1) were substituents as shown in Table 1 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 6 Example 6 was repeated except that compound 6 in which R _{1 to} R ₄ and A in the general formula (1) were substituents as shown in Table 1 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 7 Example 7 was repeated except that compound 7 in which R _{1 to} R ₄ and A in the general formula (1) were substituents as shown in Table 2 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 8 The same procedure as in Example 8 was carried out except that compound 8 in which R _{1 to} R ₄ and A in formula (1) were substituents as shown in Table 2 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 9 The same procedures as in Example 9 were carried out except that compound 9 in which R _{1 to} R ₄ and A in formula (1) were substituents as shown in Table 2 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 10 The same procedure as in Example 10 was carried out except that compound 10 in which R _{1 to} R ₄ and A in the formula (1) were substituents as shown in Table 2 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 11 The same procedures as in Example 11 were carried out except that compound 11 in which R _{1 to} R ₄ and A in formula (1) were substituents as shown in Table 2 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 12 Example 12 was repeated except that compound 12 in which R _{1 to} R ₄ and A in the general formula (1) were substituents as shown in Table 2 was used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 13 The procedure of Example 13 was repeated except that R _{1 to} R _{4 in} the general formula (1) and Compound 13 in which A was a substituent as shown in Table 3 were used as the phosphate compound. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 14 The same procedure as in Example 14 was carried out except that as the phosphoric ester compound, compound 14 in which R _{1 to} R ₄ and A in the general formula (1) were substituents as shown in Table 3 was used. In the same manner as in Example 1, a non-aqueous electrolyte battery was manufactured.

Example 15 The amount of the phosphazene compound was 15% by weight and the amount of the phosphate compound was 5% by weight.
And a phosphoric ester compound represented by R of the general formula (1)
₁ to R ₄ and A, except that the compound 1 is a substituted group, as indicated in Table 1, it was used to fabricate a non-aqueous electrolyte battery in the same manner as in Example 1.

Example 16 The amount of the phosphazene compound was 5% by weight, and the amount of the phosphate compound was 15% by weight.
And a phosphoric ester compound represented by R of the general formula (1)
₁ to R ₄ and A, except that the compound 3 is a substituted group, as indicated in Table 1, it was used to fabricate a non-aqueous electrolyte battery in the same manner as in Example 1.

Example 17 The amount of the phosphazene compound was 5% by weight, and as the phosphate compound, a compound in which R _{1 to} R ₄ and A in the general formula (1) are substituents as shown in Table 1. 1 and 5% by weight, and 10% by weight of compound 3 in which R _{1 to} R ₄ and A in the general formula (1) are substituents as shown in Table 1. Similarly, a non-aqueous electrolyte battery was manufactured.

Example 18 The amount of the phosphazene compound was 5% by weight, and as the phosphate compound, a compound in which R _{1 to} R ₄ and A in the general formula (1) are substituents as shown in Table 1. 1 and 10% by weight of R _{1 in the} general formula (1).
A non-aqueous electrolyte battery was manufactured in the same manner as in Example 1 except that 5 wt% of Compound 4 in which R ₄ and A were substituents as shown in Table 1.

EXAMPLE 19 The amount of the phosphazene compound was 5% by weight, and the phosphoric ester compound was a compound in which R _{1 to} R ₄ and A in the general formula (1) are substituents as shown in Table 1. 1 and 10% by weight of R _{1 in the} general formula (1).
A non-aqueous electrolyte battery was manufactured in the same manner as in Example 1 except that 5 wt% of Compound 5 in which R ₄ and A were substituents as shown in Table 1.

Example 20 The amount of the phosphazene compound was 5% by weight, and as the phosphate compound, a compound in which R _{1 to} R ₄ and A in the general formula (1) are substituents as shown in Table 1. 3 and 5% by weight, and 10% by weight of compound 5 in which R _{1 to} R ₄ and A of the general formula (1) are substituents as shown in Table 1. Similarly, a non-aqueous electrolyte battery was manufactured.

Comparative Example 1 The amount of the phosphazene compound was 2
A non-aqueous electrolyte battery was produced in the same manner as in Example 1 except that the content was 0% by weight and no phosphate compound was used.

Comparative Example 2 The procedure of Example 1 was repeated except that the amount of propylene carbonate was 50% by weight, the amount of dimethyl carbonate was 50% by weight, and the phosphazene compound and the phosphate compound were not used. A non-aqueous electrolyte battery was manufactured.

Here, in each of the above-described embodiments,
Tables 1 to 3 show specific examples of the substituents R _{1 to} R ₄ and A of the phosphate compound represented by the general formula (1).

[0086]

[Table 1]

[0087]

[Table 2]

[0088]

[Table 3]

For each of the non-aqueous electrolyte batteries prepared as described above, the initial discharge capacity, the discharge capacity retention rate after 100 cycles, and the temperature dependency were evaluated.

The initial discharge capacity was as follows: at 23 ° C., each non-aqueous electrolyte battery was charged at a constant current and a constant voltage of 1 A up to an upper limit of 4.2 V for 3 hours, and then terminated at a constant current of 1000 mA. It was determined by performing the voltage up to 2.5V.

The discharge capacity retention ratio was obtained by performing charge / discharge 100 cycles under the same charge / discharge conditions as described above, and calculating the ratio of the discharge capacity at the 100th cycle to the initial discharge capacity.

The temperature dependence was as follows. First, under the same charge / discharge conditions except that the temperature was set to −20 ° C., 1 A constant current / constant voltage charging was performed for 3 hours up to an upper limit of 4.2 V, and then 1000 mA.
Was performed to a final voltage of 2.5 V, and the initial discharge capacity at -20 ° C was determined. Next, the ratio of the initial discharge capacity at -20 ° C to the initial discharge capacity at 23 ° C was determined. The evaluation of the temperature dependence was evaluated by setting less than 50% as Δ and 5
0% or more was evaluated as ○.

Table 4 shows the evaluation results of the initial capacity, the discharge capacity retention rate, and the temperature dependency of each nonaqueous electrolyte battery.

[0094]

[Table 4]

As is clear from Table 2, the non-aqueous electrolyte batteries of Examples 1 to 20 in which the electrolyte solution contains a phosphate compound and a phosphazene compound of the general formula (1) are as follows:
Compared to the non-aqueous electrolyte batteries of Comparative Examples 1 and 2, 1
Even at a relatively large discharge current of 000 mA, the results showed that the initial discharge capacity was large and the discharge capacity retention rate after 100 cycles was high. It was also found that the temperature dependency was excellent.

[0096]

According to the non-aqueous electrolyte battery of the present invention, since the non-aqueous solvent of the non-aqueous electrolyte contains a phosphate compound, the non-aqueous solvent is made flame-retardant and the non-aqueous solvent is excellent in safety. A water electrolyte battery can be realized. Further, the nonaqueous electrolyte battery of the present invention can realize a nonaqueous electrolyte battery having excellent cycle characteristics since the nonaqueous solvent of the nonaqueous electrolyte contains a phosphazene compound.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration example of a nonaqueous electrolyte battery according to the present invention.

[Explanation of symbols]

1 Non-aqueous electrolyte battery, 2 Positive electrode, 3 Negative electrode, 4
Separator, 5 Battery can, 10 Battery lid

Claims (7)

[Claims] A non-aqueous electrolyte comprising a positive electrode having a positive electrode active material, a negative electrode having a negative electrode active material, and an electrolyte dissolved in a non-aqueous solvent. A non-aqueous electrolyte battery comprising a phosphate compound represented by formula (1) and a phosphazene compound represented by formula (2). Embedded image (Wherein, R _{1 to} R ₄ represent a substituted or unsubstituted cyclic aromatic group, and A represents an unsubstituted cyclic aromatic group or a heterocyclic ring.) (Wherein, R ₅ and R ₆ are a linear or branched alkyl group, a cyclic saturated alkyl group, or an alkylene group;
It is an integer of 00. ) 2. The phosphoric ester compound has a substituent R
_{1 to} R ₄ are a phenyl group, a benzyl group, a toluoyl group or an xylyl group at the ortho, meta or para position, and the substituent A is a substituted phenyl group or a substituted biphenyl group at the ortho, meta or para position, or an unsubstituted phenyl group; The non-aqueous electrolyte battery according to claim 1, wherein the non-aqueous electrolyte is a group, an unsubstituted biphenyl group, or bisphenol A. 3. The method according to claim 1, wherein the phosphazene compound has a substituent R ₅
And R _6, the non-aqueous electrolyte battery according to claim 1, wherein the linear or branched alkyl groups are selected from the group of carbon number n = 1 to 10. 4. The non-aqueous electrolyte battery according to claim 1, wherein the positive electrode contains lithium. 5. The non-aqueous electrolyte battery according to claim 1, wherein the positive electrode contains a composite oxide of lithium and a transition metal. 6. The non-aqueous electrolyte battery according to claim 1, wherein the negative electrode contains a material capable of doping and / or undoping lithium. 7. The non-aqueous electrolyte battery according to claim 6, wherein the material capable of doping and / or undoping lithium is a carbon material.