JPH0888023A - Nonaqueous electrolyte and nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE: To provide a nonaqueous electrolyte with self-fire extinguishing function and having conductivity of a practical-use level by using an organic solvent containing a specific compound as the solvent of an electrolyte. CONSTITUTION: By replacing at least one of substituent groups of a phosphoric ester with a halogen atom such as a fluorine atom, reactivity of the phosphoric ester with lithium metal is decreased, and by adding it to an electrolyte, self-fire extinguishing function is kept and performance of a battery is enhanced. A phosphoric ester compound has self-fire extinguishing function, and by adding to the electrolyte, the self-fire extinguishing function is given to the electrolyte, and by replacing at least one of R<1> , R<2> , and R<3> with a halogen atom, reactivity of the nonaqueous electrolyte with lithium metal can be decreased. The self-fire extinguishing function is increased with the increase in the content of phosphorus, that is, with the decrease in the molecular weight of R<1> , R<2> , and R<3> , and with the increase in the adding amount. By increasing the adding amount of phosphoric ester with high molecular weight, since viscosity of the electrolyte is increased and conductivity is decreased, the amount of carbon of R<1> , R<2> , and R<3> is required to decrease.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel non-aqueous electrolyte and a non-aqueous electrolyte battery using the same.

[0002]

2. Description of the Related Art Batteries using non-aqueous electrolytes are widely used as power sources for consumer electronic devices because they have high voltage, high energy density, and excellent reliability such as storability. . As the non-aqueous electrolytic solution, propylene carbonate, γ-butyrolactone, sulfolane, etc., which are generally high-dielectric constant solvents, and dimethoxyethane, tetrahydrofuran, 1,3-dioxolane, etc., which are low-viscosity solvents, are mixed in a solvent such as LiBF ₄ , LiPF ₆ , LiClO ₄ , LiAsF ₆ , L
_{iCF 3 SO 3, LiN (CF} 3 SO 2) 2, LiAlC
A mixture of electrolytes such as l ₄ and LiSiF ₆ is used.

However, many of the solvents of such non-aqueous electrolytes have a low withstand voltage, and when an electrolyte using a solvent with a low withstand voltage is used for a secondary battery, the solvent becomes an electric solvent when charging and discharging are repeated. As a result of the decomposition, the generated gas raises the internal pressure of the battery, and the product causes a polymerization reaction to adhere to the electrode. As a result, the charge / discharge efficiency of the battery is lowered, and the energy density of the battery is lowered, so that the life of the battery is shortened. As an attempt to improve the durability of the electrolytic solution, conventionally used esters such as γ-butyrolactone and ethyl acetate, and 1,3
-Using a carbonate with a high withstand voltage such as diethyl carbonate or the like instead of a solvent with a low withstand voltage such as ethers such as dioxolane, tetrahydrofuran, dimethoxyethane, etc., and suppressing the decrease in battery energy density after repeated charge and discharge. Has been proposed (for example, JP-A-2-10666).

On the other hand, metallic lithium or a lithium alloy is used for the negative electrode of a lithium secondary battery. When charging and discharging are repeated, lithium ions in the electrolytic solution are unevenly deposited on the negative electrode, which is called a dendrite. In some cases, highly reactive metals were produced. When the dendrite falls off the electrode, it is self-depleted and the cycle life of the battery is shortened, and there is a possibility that the dendrite may penetrate the separator separating the positive electrode and the negative electrode to cause a short circuit.

[0005]

By the way, since a battery having a high energy density is desired, research on a high-voltage battery is being promoted from various fields. For example, there is a secondary battery called a rocking chair type that uses a composite oxide of lithium and a transition metal such as LiCoO ₂ , LiNiO ₂ , and Li ₂ Mn ₂ O ₄ for the positive electrode of the battery and a carbon material for the negative electrode. Has been studied. In this case, the battery voltage can generate 4 V, and since there is no deposition of metallic lithium,
Safety has been confirmed by experiments such as overcharging, external short-circuiting, needle stick, and crushing, and it is now available for consumer use. However, in the future, when the energy density is increased significantly and the size is increased, further improvement in safety such as flame retardancy is required. The electrolyte solvents currently used do not necessarily have a satisfactory high flash point, nor are they self-extinguishing.

For this reason, it has been proposed to add phosphoric acid esters, which are known as self-extinguishing compounds, to the electrolytic solution (JP-A-4-184870).
However, although the electrolyte solution containing 15% by weight or more of this type of compound clears the flame retardancy, it has problems in terms of battery charge / discharge efficiency, battery energy density, and battery life. Furthermore, since phosphoric acid esters such as trimethyl phosphate and triethyl phosphate have reactivity with metallic lithium, they are not suitable for a lithium secondary battery using metallic lithium or a lithium alloy for the negative electrode. Even with the rocking chair type lithium ion secondary battery described above, under severe test conditions such as extreme overcharging due to misuse,
Lithium metal may precipitate.

The present invention has been made in view of the above problems and has self-extinguishing property without causing a decrease in charge / discharge efficiency or a decrease in battery energy density after repeated charge / discharge.
It is an object of the present invention to provide a non-aqueous electrolytic solution having a high flash point and a low reactivity with metallic lithium. Further, the present invention is
It is an object of the present invention to provide a non-aqueous electrolytic solution which is excellent in withstand voltage and electric conductivity, and is excellent in load characteristics and low temperature characteristics. Another object of the present invention is to provide a non-aqueous electrolyte battery that can generate a high voltage, has excellent battery performance, and has a long life.

[0008]

[Means for Solving the Problems] The inventors of the present invention have diligently studied phosphoric acid ester compounds having a high self-extinguishing action in order to produce an electrolytic solution for a non-aqueous battery which can generate a high voltage and has excellent battery characteristics. I went. As a result, it was found that the reactivity with lithium metal can be reduced by substituting at least one of the substituents of the phosphoric acid ester with a halogen atom such as a fluorine atom, and by adding this phosphoric acid ester, the self-extinguishing property can be improved. It was found that an electrolyte solution for non-aqueous batteries, which maintains the above-mentioned value and is excellent in battery performance, can be obtained.

That is, the non-aqueous electrolytic solution of the present invention contains the phosphoric acid ester compound represented by the general formula [1].

[0010]

[Chemical 3]

(R ¹ , R ² and R ³ may be the same or different and each represents an alkyl group or a halogen atom-substituted alkyl group, and at least one of R ¹ , R ² and R ³ is a halogen atom-substituted alkyl group. In addition, the non-aqueous electrolyte battery of the present invention uses an electrolyte solution containing the above phosphoric acid ester compound.

The phosphoric acid ester compound represented by the general formula [1] has self-extinguishing property, and when added to the electrolytic solution, imparts self-extinguishing property to the electrolytic solution, and at least ^one of R ¹ , R ² and R ³ By substituting one with a halogen atom, the reactivity of the non-aqueous electrolyte of the present invention with lithium metal can be reduced. At least 1 of R ¹ , R ² and R ³
If one is a halogen atom-substituted alkyl group, the rest may be an alkyl group or a halogen atom-substituted alkyl group.

Here, the self-extinguishing action of the phosphoric acid ester increases as the phosphorus content in the phosphoric acid ester increases, that is, as the molecular weight of the substituents R ¹ , R ² and R ³ decreases.
Also, the larger the amount added, the larger. However, increasing the addition amount of the phosphoric acid ester having a large molecular weight is not preferable because the addition of the phosphoric acid ester increases the viscosity of the electrolytic solution and decreases the conductivity. Therefore, it is desirable that the number of carbon atoms of R ¹ , R ² and R ³ is as small as possible, and when R ¹ , R ² and R ³ are alkyl groups, preferably 1 to 4 and when halogen atom-substituted alkyl groups are used. It is preferably 2 to 4.

Examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a sec-butyl group, a t-butyl group and an isobutyl group. Examples of the halogen atom-substituted alkyl group include a fluorine atom-substituted alkyl group, a chlorine atom atom-substituted alkyl group, and a bromine atom-substituted alkyl group, and one in which fluorine, chlorine, or bromine is mixed in one substituent. Good. Taking the case of a fluorine atom-substituted alkyl group as an example, a trifluoroethyl group, a difluoroethyl group, a monofluoroethyl group, a pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, 1,
1,1-trifluoroisopropyl group, 1,3-difluoro-2-propyl group, hexafluoroisopropyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 2,2,3 4,4,4-hexafluorobutyl group, hexafluoro-2-methylisopropyl group, 3,
3,4,4,4-pentafluoro-2-butyl group, 4,
Examples include 4,4-trifluorobutyl group and perfluoro-t-butyl group. In addition, those having the same structure as the above and substituting chlorine or bromine instead of fluorine are also exemplified.

The phosphoric acid ester compound of the present invention includes
Tri (trifluoroethyl) phosphate, methyl phosphate (ditrifluoroethyl), dimethyl phosphate (trifluoroethyl), ethyl phosphate (ditrifluoroethyl), diethyl phosphate (trifluoroethyl), propyl phosphate (ditrifluoroethyl) Fluoroethyl), dipropyl phosphate (trifluoroethyl), triphosphate (pentafluoropropyl), methyl phosphate (dipentafluoropropyl), dimethyl phosphate (pentafluoropropyl), ethyl phosphate (dipentafluoropropyl) , Diethyl phosphate (pentafluoropropyl), butyl phosphate (dipentafluoropropyl), dibutyl phosphate (pentafluoropropyl), and those having the above-mentioned halogen atom-substituted alkyl group and alkyl group.

The halogen atom-substituted phosphoric acid ester compound of the formula [1] has the action of making the solvent inflammable as described above, and has a greater reactivity with lithium metal than ordinary phosphoric acid ester compounds such as trimethyl phosphate. Although it is suppressed, when it is used alone as a solvent, it has the property of lowering the conductivity of the electrolytic solution and lowering the energy density of the battery. Therefore, in order to use the non-aqueous electrolytic solution of the present invention as a practical secondary battery electrolytic solution, a mixed solvent of the above halogen atom-substituted phosphate compound and another solvent is used as a solvent. In this case, the amount of the halogen atom-substituted phosphate compound added is preferably 1 with respect to the entire solvent.
-20% by volume, more preferably 5-15% by volume may be added. With such a range, sufficient self-extinguishing action can be obtained without affecting the battery performance such as a decrease in electric conductivity and a decrease in energy density of the battery.

As the solvent to which the above halogen atom-substituted phosphate compound is added, conventionally used chain ethers such as dimethoxyethane, cyclic ethers such as tetrahydrofuran, amides such as dimethylformamide, and methyl. Carbamates such as -N, N-dimethyl carbamate, chain esters such as diethyl carbonate, and cyclic esters such as propylene carbonate can be used alone or in combination of two or more. Especially when used as a high-voltage battery, the halogen atom-substituted phosphate ester can enhance the conductivity of the electrolytic solution by using a mixed solvent with a chain ester and / or a cyclic ester, thereby improving battery performance. Can be

The chain ester used here is one kind represented by the general formula [2] or a mixture thereof.

[0019]

[Chemical 4]

(In the formula, R ⁴ represents a methyl group, an ethyl group, a propyl group, a methoxy group or an ethoxy group, and R ⁵ represents a chain or branched alkyl group having 1 to 3 carbon atoms.) By mixing the chain ester represented by the formula [2] with the halogen atom-substituted phosphate ester and using it, the viscosity of the electrolytic solution can be lowered, and an electrolytic solution excellent in electric conductivity from normal temperature to low temperature can be obtained. can get. Examples of such chain ester include dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, methyl butyl carbonate, ethyl butyl carbonate,
Methyl formate, ethyl formate, propyl formate, methyl butyrate,
Ethyl butyrate, methyl acetate, ethyl acetate, propyl acetate,
Examples include methyl propionate and ethyl propionate. In particular, LiCoO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , LiN capable of generating 4 V as the positive electrode of the battery.
In the case of an electrolyte solution of a battery using iO ₂ or the like, dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate are preferable from the viewpoint of oxidation resistance stability.

The concentration of the chain ester in the solvent of the electrolytic solution can be usually used in the range of 20 to 90% by volume, preferably 40 to 80% by volume. As the cyclic ester, one selected from propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, γ-butyrolactone or sulfolane or a mixture thereof is used, and propylene carbonate and ethylene carbonate are preferably selected. These cyclic esters can be used in a concentration of 10 to 70% by volume, preferably 20 to 60% by volume, in the electrolyte solvent.
By mixing the cyclic ester with the halogen-substituted phosphate and using them, the dissociation property of the electrolyte can be enhanced and the electrical conductivity can be enhanced.

Further, it is more preferable to use both the above-mentioned chain ester and cyclic ester in a mixture with a halogen atom-substituted phosphate ester because the effect of lowering the viscosity and the effect of dissociating the electrolyte are synergistic. In the case of a battery using V ₂ O ₅ , polyaniline or the like capable of generating a voltage of about 3 V as the positive electrode of the battery, the chain ester or cyclic ester may be used in place of or in combination, and the withstand voltage is lower than that. Chain ethers such as dimethoxyethane, cyclic ethers such as tetrahydrofuran, amides such as dimethylformamide, carbamates such as methyl-N, N-dimethylcarbamate, carbamates and amides such as N-methyloxazolidone and N-methylpyrrolidone. Kinds can also be used.

As the electrolyte used in the electrolytic solution of the present invention,
LiPF₆, LiBF_Four, LiClO _Four, LiAsF₆, L
iCF₃SO₃, LiN (CF₃SO₂)₂, LiAlC
l_Four, LiSiF₆Can be used with lithium salts such as
But especially LiPF₆Is preferred. Li as electrolyte
PF₆Is used, the phosphoric acid ester compound of the present invention
High self-extinguishing property can be maintained even if the content is lowered. Follow
To prevent the battery charge / discharge efficiency and energy density from decreasing.
You can

The electrolyte concentration in the electrolytic solution is usually 0.1 to 3
It can be used in a concentration range of mol / liter, and preferably in a concentration range of 0.5 to 2 mol / liter. The nonaqueous electrolytic solution battery of the present invention uses the electrolytic solution having the above composition, and is a battery including at least a positive electrode, a negative electrode, and a separator.

As the negative electrode material, metallic lithium, a lithium alloy, or a carbon material capable of doping / dedoping with lithium ions can be used, and particularly a carbon material capable of doping / dedoping with lithium ions is preferably used.
Graphite or amorphous carbon may be used as such a carbon material, and any carbon material such as activated carbon, carbon fiber, carbon black, and mesocarbon microbeads can be used.

As the positive electrode material, MoS ₂ , TiS ₂ , M
nO ₂ , V ₂ O _{5 and} other transition metal oxides, transition metal sulfides,
Conductive polymers such as polyaniline and polypyrrole, compounds that reversibly undergo electrolytic polymerization and depolymerization such as disulfide compounds, or LiCoO ₂ , LiMnO ₂ , LiMn ₂
A composite oxide composed of lithium and a transition metal such as O ₄ or LiNiO ₂ can be used, and preferably a composite oxide composed of lithium and a transition metal is used.

Since the non-aqueous electrolyte battery of the present invention contains the above-mentioned non-aqueous electrolyte solution as an electrolyte solution, a high voltage can be generated, the battery charging / discharging efficiency is high, and the energy density of the battery can be maintained even after repeated charging / discharging. It is possible to obtain a non-aqueous secondary battery that is excellent in practicability and has no decrease in The shape, form, etc. of the non-aqueous electrolyte battery of the present invention are not particularly limited, and may be arbitrarily selected within the scope of the present invention such as a cylindrical type, a square type, a coin type, a card type, and a large size. it can.

[0028]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. 1. Evaluation of Reactivity of Phosphate Ester Compound with Metallic Lithium In an argon atmosphere with a dew point of −60 ° C., a length of 2 cm and a width of 0.
A 5 cm thick 0.5 mm thick metallic lithium foil and 10 ml of a dehydrated / distilled and purified phosphate ester compound are mixed in a glass container, and the lithium foil is ground in a phosphate ester so that a clean surface of the metal appears. It was This glass container was heated to various temperatures and the reaction between metallic lithium and the phosphate compound was observed. Examples of the phosphoric acid ester compound include a fluorine atom-substituted phosphoric acid ester compound tri (trifluoroethyl) phosphate (hereinafter abbreviated as TFEPA) and tris (2-chloroethyl) phosphate (hereinafter,
Abbreviated as TCEPA), and trimethyl phosphate and triethyl phosphate as comparative examples (hereinafter abbreviated as TEPA)
Was used.

As a result, triethyl phosphate was 165 ° C.
The reaction heat caused the lithium to melt, and trimethyl phosphate also foamed and reacted at 180 ° C, whereas TFEPA showed melting of metallic lithium at 180 ° C. However, only a gray film was formed on the surface, and the reaction did not continue. 2. Evaluation of self-extinguishing property of electrolytic solution Propylene carbonate (hereinafter PC
Abbreviated), methyl ethyl carbonate (hereinafter, ME
Abbreviated as C) and phosphoric acid ester (TFEPA, TC
(EPA) using a solvent in which the three components are mixed at a predetermined ratio, and lithium hexafluorophosphate (LiPF ₆ ) as an electrolyte is 1.
An electrolytic solution having 0 mol / liter dissolved therein was prepared. As a comparative example, a mixed solvent of PC and MEC was used as a solvent, and an electrolytic solution was prepared using the same amount of the same electrolyte as the electrolyte.

Width 1.5 cm, length 30 cm, thickness 0.0
A 4 mm strip of Manila paper for a separator was immersed in a beaker containing an electrolyte sample for 1 minute or more. After the excess sample dripping from the Manila paper was wiped with the beaker wall, the Manila paper was pierced at 2.5 cm intervals on the supporting needle of the sample table having the supporting needle and fixed horizontally. Manila paper and sample stand 25c
It was put in a metal box of mx 25 cm x 50 cm, ignited with a lighter at one end, and required for the Manila paper to burn within the burned length (burning length) and 30 cm from the first needle to the last needle. The time was measured 3 times each. Table 1 shows the burning length and the burning rate calculated from the time required for burning.

[0031]

[Table 1]

The burning velocity "0" in the table means that the burning did not occur. In addition, PC, MEC and T are used as electrolyte solvent.
Burning of separator paper (Manila paper) was carried out in the same manner as above when mixed solvents containing FEPA at a ratio of 40/50/10 (volume ratio) were used, the electrolyte concentration was 1.0 mol / liter, and the electrolyte was changed variously. The length was measured. The results are shown in Table 2.

[0033]

[Table 2]

As is clear from Table 2, particularly excellent self-extinguishing property was exhibited when LiPF ₆ was used as the electrolyte. 3. Measurement of withstand voltage and electric conductivity of electrolytic solution LiPF ₆ was used as an electrolyte using a mixed solvent in which the mixed composition of PC, MEC and TFEPA was changed as shown in Table 3.
Dissolve 3.8 g (25 mmol) in each mixed solvent,
An electrolytic solution of 1 (electrolyte concentration 1.0 mol / liter) was prepared. The electric conductivity and withstand voltage of these electrolytes were measured. Use an impedance meter for electrical conductivity of 10k
It was measured at Hz. The withstand voltage of the electrolytic solution was measured by putting the electrolytic solution in a three-electrode type withstand voltage measuring cell using glassy carbon for the working electrode, platinum for the counter electrode, and lithium metal for the reference electrode, and using a potentiogalvanostat for 10 mV / scc. The potential withstand voltage was set to the range in which the oxidative decomposition current did not flow by 0.1 mA or more based on the potential of the lithium metal. The results are shown in Table 3.

[0035]

[Table 3]

As is clear from Table 3, the electrolytic solution of the present invention exhibited a high withstand voltage and a practical level of electrical conductivity. 4. Evaluation of charging / discharging efficiency and cycle characteristics of the battery As shown in FIG. 1, the battery has an outer diameter of 20 mm and a height of 2.5.
A mm-shaped non-aqueous electrolyte battery was prepared. Lithium metal was used for the negative electrode 1, and for the positive electrode 2, a mixture of 85 parts by weight of LiCoO _2, 12 parts by weight of graphite as a conductive agent, and 3 parts by weight of fluororesin as a binder was pressure-molded. The substances forming the negative electrode 1 and the positive electrode 2 are pressure-bonded to the negative electrode can 4 and the positive electrode can 5, respectively, via the porous separator 3 made of polypropylene. As an electrolytic solution for such a battery, lithium hexafluorophosphate is dissolved in a solvent in which PC, MEC and TFEPA are mixed in a volume ratio of 45:45:10 at a ratio of 1.0 mol / l. Was sealed with a sealing gasket 6.

Regarding the battery thus prepared (Example 1), the current was 1.0 mA and the upper limit voltage was 4.2 V.
The charging / discharging efficiency was measured when the battery was charged for 0 hours and then discharged at a current of 1.0 mA to 3.0 V. Further, such charging / discharging was repeated for a predetermined cycle, and changes in charging / discharging efficiency were observed. FIG. 2 shows the result, which is a plot of charge / discharge efficiency against the number of cycles.

In Example 2, PC was used as the electrolyte solvent.
A mixed solvent of MEC and TCEPA in a volume ratio of 45:45:10 was used, and as a comparative example, PC and MEC were used as electrolyte solvent.
And TEPA mixed solvent (45:45:10 by volume)
The same charge-discharge efficiency was measured for the coin-shaped battery prepared in the same manner as described above. As is clear from FIG. 2, the battery using the electrolytic solution solvent of this example exhibited excellent cycle characteristics.

[0039]

As is apparent from the above examples, according to the present invention, the use of an organic solvent containing a specific halogen-substituted phosphate compound as the electrolyte solvent,
It is possible to provide a non-aqueous electrolytic solution which has a low reactivity with lithium metal, exhibits a self-extinguishing action, and has a practical level of electrical conductivity. In particular, by using a mixed solvent of a specific halogen-substituted phosphate ester compound and a specific ester compound as the electrolytic solution solvent, an electrolytic solution having low viscosity and excellent low temperature characteristics can be obtained. Further, according to the present invention, by using such a non-aqueous electrolytic solution as an electrolytic solution, it is possible to generate a high voltage, to provide a non-aqueous secondary battery excellent in battery performance such as charge and discharge performance. You can

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing one embodiment of a non-aqueous electrolyte battery of the present invention.

FIG. 2 is a diagram showing charge / discharge cycle characteristics of a battery using the non-aqueous electrolyte solution of the present invention.

[Explanation of symbols]

 1 ... Negative electrode 2 ... Positive electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigeru Fujita 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Yoshiaki Naruse 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Atsushi Komaru 2-32 Shibuya, Shibuya-ku, Tokyo Sony Energy Tech Co., Ltd.

Claims (9)

[Claims] 1. A non-aqueous electrolytic solution containing a lithium salt as an electrolyte, wherein the electrolytic solvent contains a phosphoric acid ester compound represented by the general formula [1]. Embedded image (R ¹ , R ² and R ³ may be the same or different,
Each represents an alkyl group or a halogen atom-substituted alkyl group, and at least one of R ¹ , R ² , and R ³ represents a halogen atom-substituted alkyl group. ) 2. In the general formula [1] according to claim 1,
The non-aqueous electrolyte according to claim 1, wherein the halogen atom-substituted alkyl group is a fluorine atom-substituted alkyl group. 3. In the general formula [1] according to claim 1,
The non-aqueous electrolyte according to claim 1 or 2, wherein the halogen atom-substituted alkyl group has 2 to 4 carbon atoms. 4. The non-electrolytic solvent according to claim 1, wherein the electrolyte solvent contains a chain ester compound and / or a cyclic ester compound represented by the general formula [2]. Water electrolyte. Embedded image (In the formula, R ⁴ represents a methyl group, an ethyl group, a propyl group, a methoxy group or an ethoxy group, and R ⁵ represents a chain or branched alkyl group having 1 to 3 carbon atoms.) 5. The non-aqueous electrolyte solution according to claim 1, wherein the content of the phosphoric acid ester compound is 1 to 20% by volume of the entire electrolyte solution solvent. 6. The non-aqueous electrolyte solution according to claim 1, which contains LiPF ₆ as the electrolyte. 7. The non-aqueous electrolyte solution according to claim 1, wherein the content of the electrolyte is in the range of 0.1 to 3.0 mol / liter. 8. A non-aqueous electrolyte battery containing the non-aqueous electrolyte according to claim 1 as an electrolyte. 9. A negative electrode containing a material selected from metallic lithium, a lithium alloy, and a carbon material capable of doping / dedoping lithium ions as a negative electrode active material, and a composite oxide of lithium and a transition metal as a positive electrode active material. The non-aqueous electrolyte battery according to claim 8, further comprising a positive electrode.