JP2003151623A - Nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous secondary battery with high shelf life characteristics when left at a high temperature, high charging and discharging cycle life and characteristics. SOLUTION: This nonaqueous secondary battery is composed of a positive electrode capable of storing/releasing lithium, a negative electrode capable of storing/releasing lithium, and an electrolyte prepared by dissolving a lithium salt in a nonaqueous solvent, and the nonaqueous solvent contains vinyl ethylene carbonate represented by general formula (1), and moreover contains at least one selected from the group comprising vinylene carbonate, cyclic sulfonic acid or cyclic sulfate, and a cyclic acid unhydride. (In the formula, R1 , R2 , R3 , R4 , R5 and R6 independently represent a hydrogen atom, or a 1-4C Alkyl).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a non-aqueous secondary battery.

[0002]

2. Description of the Related Art In recent years, due to advances in electronic technology, mobile phones,
As electronic devices such as laptop computers and video cameras have become higher in performance, smaller in size and lighter in weight, there has been a strong demand for batteries with high energy density that can be used in these electronic devices. A typical battery that satisfies such requirements is a non-aqueous secondary battery that uses lithium as a negative electrode active material.

A non-aqueous secondary battery is, for example, a negative electrode plate in which a carbon material that absorbs and releases lithium ions is held by a current collector, and a lithium complex oxide that absorbs and releases lithium ions such as a lithium cobalt complex oxide. Positive electrode plate in which is held by a current collector, LiCl in an aprotic organic solvent
It is composed of a separator that holds an electrolyte solution in which a lithium salt such as O ₄ or LiPF ₆ is dissolved and that is interposed between the negative electrode plate and the positive electrode plate to prevent a short circuit between both electrodes.

The positive electrode plate and the negative electrode plate are formed into thin sheets or foils, which are sequentially laminated or spirally wound via a separator to form a power generating element. The power generating element is made of stainless steel. After being housed in a metal can made of nickel-plated iron or a lighter weight aluminum such as aluminum or a battery container made of a laminated film, an electrolytic solution is injected and sealed to be assembled into a battery.

By the way, generally, a battery is required to have various performances according to its use conditions, and one of them is a high temperature storage property. This is a very important performance especially in the non-aqueous secondary battery as described above. Normally, a battery in a charged state is left in an environment of 80 ° C. or higher for a predetermined time, and the swelling and discharge capacity of the battery after being left are It is evaluated by measuring.

There are various methods for improving the high temperature storage property, but in the above non-aqueous secondary battery,
There are a method of using a solvent having a high boiling point and a low vapor pressure, and a method of suppressing decomposition of the nonaqueous electrolyte on the positive and negative electrode surfaces. However, when a solvent having a high boiling point and a low vapor pressure like the former is used, the viscosity of the solvent is generally low, and there is a problem that the conductivity of the non-aqueous electrolyte is lowered and the discharge characteristics are lowered. It has been proposed to use gamma-butyrolactone or the like having a high dielectric constant and a high boiling point so as not to reduce the conductivity of the water electrolyte (JP 2000-235A).
868).

However, gamma butyrolactone is
There was a problem that the reductive decomposition reaction of gamma-butyrolactone occurs at the negative electrode during charging, the separator is clogged with degrading organisms, the surface resistance of the negative electrode increases, and the capacity decreases repetitively when repeatedly charged and discharged.

In order to suppress the reductive decomposition of the solvent on the negative electrode, so-called SEI (Solid-Ele) is formed on the negative electrode as a means for suppressing the reductive decomposition of lithium on the negative electrode.
A number of means for adding a compound forming a ctrolyte-Interface (solid electrolyte membrane) to an electrolytic solution have been proposed (JP 2001-6729A).

However, when these film-forming additives are used, a high resistance S having a low lithium ion conductivity is formed on the negative electrode.
When the EI is formed, the charge / discharge performance of the battery is significantly deteriorated, and when it is excessively added to the electrolyte, the excess is oxidized and decomposed in the positive electrode when left at a high temperature to generate a gas, and the internal pressure rises. There was a problem that the swelling of the product became remarkable.

[0010]

However, although the electrolytic solution described in the above publication has some excellent effects, it is not completely satisfactory in terms of compatibility between high temperature storage performance and charge / discharge performance. It was The present invention has been made to solve the above problems, and an object of the present invention is to provide a non-aqueous secondary battery having excellent storage characteristics and charge / discharge cycle life performance when left at high temperature, and having excellent charge / discharge performance. And

[0011]

According to the invention of claim 1, an electrolyte comprising a positive electrode capable of absorbing and releasing lithium, a negative electrode capable of absorbing and releasing lithium, and a lithium salt dissolved in a non-aqueous solvent. In a non-aqueous secondary battery including, the non-aqueous solvent contains a vinyl ethylene carbonate compound represented by the general formula (1), and further vinylene carbonate, cyclic sulfonic acid or cyclic sulfuric acid ester, cyclic acid anhydride It is characterized by containing at least one selected from the group consisting of

[0012]

[Chemical 2]

(In the formula, R1, R2, R3, R4, R5 and R6 are each independently a hydrogen atom or a carbon number of 1
According to the invention of claim 1, a stable negative electrode film is formed on the surface of the negative electrode active material, and as a result, swelling when left at high temperature is small, excellent charge / discharge cycle life performance, and A non-aqueous secondary battery having excellent charge / discharge performance can be obtained.

According to a second aspect of the present invention, in the non-aqueous secondary battery, the non-aqueous solvent contains gamma-butyrolactone.

According to a third aspect of the present invention, in the non-aqueous secondary battery, the cyclic sulfonic acid is 1,3-propane sultone,
1,4-butane sultone, 1,3-butane sultone,
The cyclic sulfate is at least one selected from the group consisting of 1,3-propene sultone, and the cyclic sulfate is glycol sulfate.

According to a fourth aspect of the present invention, in the non-aqueous secondary battery, the cyclic acid anhydride is succinic anhydride, grunonic anhydride,
Maleic anhydride, citraconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6
-Tetrahydrophthalic anhydride, 5-norbrunene-2,3-dicarboxylic acid anhydride, phenyl succinic anhydride,
It is characterized by being at least one selected from the group consisting of 2-phenyl glucuronic anhydride.

According to the invention of claim 2, 3 or 4, it is possible to obtain a non-aqueous secondary battery which is further excellent in charge / discharge cycle life performance and charge / discharge performance.

According to a fifth aspect of the present invention, in the above non-aqueous secondary battery, the electrolyte salt contains LiBF ₄ and LiPF ₆ .

According to the invention of claim 5, a stable negative electrode film is formed by adding an appropriate amount of LiPF ₆ to the electrolyte salt mainly composed of LiBF ₄ , and the charge-discharge performance and the charge-discharge cycle life performance are improved. An aqueous secondary battery can be obtained.

According to a sixth aspect of the invention, the total weight of the vinylethylene carbonate compound represented by the general formula (1), vinylene carbonate, cyclic sulfonic acid or cyclic sulfuric acid ester, vinylene carbonate and cyclic acid anhydride is equal to that of the electrolytic solution. It is characterized by being 0.05% by weight or more and 5% by weight or less based on the total weight.

According to the invention of claim 6, it is possible to obtain a non-aqueous secondary battery which is excellent in charge-discharge cycle life performance and high temperature storage performance.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

In the non-aqueous secondary battery of the present invention, the non-aqueous solvent contains the vinyl ethylene carbonate compound represented by the general formula (1), and further, vinylene carbonate, cyclic sulfonic acid or cyclic sulfuric acid ester, cyclic acid anhydride. It is characterized by containing at least one selected from the group consisting of things.

[0024]

[Chemical 3]

(In the formula, R1, R2, R3, R4, R5 and R6 are each independently a hydrogen atom or a carbon number of 1
~ 4 alkyl groups) As in the present invention, at least one selected from the group consisting of vinylene carbonate, cyclic sulfonic acid or cyclic sulfuric acid ester, cyclic acid anhydride in the organic electrolyte containing a vinyl ethylene carbonate compound. Addition of 2 improves the charge / discharge cycle life performance of the non-aqueous secondary battery,
It is presumed that the reason is that a stable negative electrode film is formed on the surface of the negative electrode active material, and that it functions as a protective film that suppresses the reductive decomposition of the electrolytic solution solvent such as gamma butyrolactone.

The reason why the charging / discharging performance is improved is that the vinyl ethylene carbonate compound represented by the general formula (1) forms a stable negative electrode film, but has low lithium ion conductivity. Conceivable. Also,
The effect of suppressing swelling when left at high temperature is because these films are stable even at high temperatures, so that decomposition of the electrolyte solvent is suppressed, gas generated by decomposition is suppressed, and the internal pressure of the battery does not increase. it is conceivable that.

Further, in the present invention, the non-aqueous solvent is
By containing gamma-butyrolactone having a high dielectric constant and a high boiling point, it is possible to prevent a decrease in conductivity of the non-aqueous electrolyte and obtain a non-aqueous electrolyte secondary battery excellent in high-rate discharge characteristics.

Further, as the cyclic sulfonic acid, at least one selected from the group consisting of 1,3-propane sultone, 1,4-butane sultone, 1,3-butane sultone and 1,3-propene sultone is used. Using glycol sulfate as a sulfuric acid ester, the cyclic acid anhydride is succinic anhydride, grunonic anhydride, maleic anhydride, citraconic anhydride, diglycolic acid anhydride, cyclohexanedicarboxylic acid anhydride, 4-cyclohexene-1,2-dicarboxylic acid. Selected from the group consisting of acid anhydrides, 3,4,5,6-tetrahydrophthalic acid anhydride, 5-norbrunene-2,3-dicarboxylic acid anhydride, phenylsuccinic acid anhydride, 2-phenylgrunulic acid anhydride. However, these compounds are easily available and easy to handle.

Further, the present invention is characterized by containing LiBF ₄ and LiPF ₆ as the electrolyte salt of the non-aqueous electrolyte. By adding an appropriate amount of LiPF ₆ to the electrolyte salt mainly composed of LiBF ₄ , a stable negative electrode film is formed, and a non-aqueous secondary battery having improved charge / discharge performance and charge / discharge cycle life performance can be obtained.

In the present invention, the total weight of the vinylethylene carbonate compound represented by the general formula (1), vinylene carbonate, cyclic sulfonic acid or cyclic sulfate, vinylene carbonate and cyclic acid anhydride is the total amount of the electrolytic solution. It is characterized by being 0.05% by weight or more and 5% by weight or less with respect to the weight.

When the total weight of the vinyl ethylene carbonate compound represented by the general formula (1), vinylene carbonate, cyclic sulfonic acid or cyclic sulfuric acid ester, vinylene carbonate and cyclic acid anhydride is less than 0.05% by weight. , A sufficient protective film for the negative electrode was not formed, sufficient charge / discharge cycle life performance was not obtained, and 5% by weight
When it is contained in a larger amount, the swelling of the battery becomes large because the excessive amount generates an oxidative decomposition gas in the positive electrode when left at a high temperature.

As the non-aqueous electrolyte, either an electrolytic solution or a solid electrolyte can be used. When using an electrolytic solution, the electrolytic solution solvent, ethylene carbonate, propylene carbonate, dimethyl carbonate,
Ethyl methyl carbonate, diethyl carbonate, gamma butyrolactone, sulfolane, dimethyl sulfoxide, acetonitrile, dimethylformamide, dimethylacetamide, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolane, methyl acetate, etc. You may use the polar solvent of these, or these mixtures.

Further, as a lithium salt which is soluble in an organic solvent,
For LiPF₆, LiClO_Four, LiBF_Four, LiA
sF₆, LiCF_ThreeCO_Two, LiCF_Three(C
F_Three)_Three, LiCF_Three(C_TwoF₅)_Three, LiCF_ThreeSO
_Three, LiN (SO_TwoCF_Three)_Two, LiN (SO_TwoCF_Two
CF_Three)_Two, LiN (COCF_Three)_TwoAnd LiN (C
OCF _TwoCF_Three)_Two, LiPF_Three(CF_TwoCF_Three)_ThreeNa
Any salt or mixture of these may be used.

As the positive electrode active material, as the inorganic compound
Composition formula Li_xMO_Two, Li_yM_TwoO _Four, Composition Na_xM
O_Two(However, M is one or more kinds of transition metals, 0 ≦ x ≦ 1,
0 ≦ y ≦ 2) compound oxide, tunnel structure or
Is a layered metal chalcogenide or metal oxide
Can be

As a specific example, LiCoO 2_Two, Li
NiO_Two, LiCo_xNi_1-xO _Two, LiMn
_TwoO_Four, Li_TwoMn_TwoO_Four, MnO_Two, FeO_Two, V_Two
O₅, V₆O_Thirteen, TiO_TwoOr TiS_TwoEtc.
Be done. Further, as the organic compound, for example, polyaniline
And the like conductive polymers. Furthermore, inorganic compounds
Mixed with any of the above active materials, regardless of substance or organic compound
You may stay.

Further, as a compound as a negative electrode material, A
Alloys of lithium with 1, 1, Si, Pb, Sn, Zn, Cd, etc., LiFe ₂ O ₃ , WO ₂ , MoO ₂ , SiO, Cu
A metal oxide such as O, graphite, a carbonaceous material such as carbon, lithium nitride such as Li ₅ (Li ₃ N), metal lithium, or a mixture thereof may be used.

As the separator of the non-aqueous electrolyte battery according to the present invention, woven cloth, non-woven cloth, synthetic resin microporous membrane or the like can be used, and particularly synthetic resin microporous membrane can be preferably used. . Among them, a polyolefin-based microporous film such as a polyethylene and polypropylene microporous film or a composite microporous film thereof is preferably used in terms of thickness, film strength, film resistance and the like.

Further, by using a solid electrolyte such as a polymer solid electrolyte, it can also serve as a separator.
In this case, the solid polymer electrolyte may further contain an electrolytic solution, for example, by using a porous solid polymer electrolyte membrane as the solid polymer electrolyte. In this case, when a gel-like polymer solid electrolyte is used, the electrolytic solution forming the gel may be different from the electrolytic solution contained in the pores or the like. Further, a synthetic resin microporous membrane and a polymer solid electrolyte may be used in combination.

The shape of the battery is not particularly limited, and the present invention can be applied to various shapes of non-aqueous electrolyte secondary batteries such as prismatic, elliptical, coin-shaped, button-shaped and sheet-shaped batteries. Is. The present invention suppresses the swelling of the battery when the battery is left in a high temperature environment. Therefore, when the mechanical strength of the battery case is weak, particularly when an aluminum case or an aluminum laminated case is used, Great effect can be obtained.

[0040]

EXAMPLES Hereinafter, specific examples to which the present invention is applied will be described. However, the present invention is not limited to the examples, and various modifications may be made without departing from the scope of the invention. Is possible.

[Example] A total of 15 kinds of non-aqueous secondary batteries A to O according to the present invention were manufactured by changing the kind and content of the additive to the electrolytic solution. The common parts of these non-aqueous secondary batteries are as follows.

A schematic cross section of the prismatic non-aqueous secondary battery of this example is shown in FIG. In FIG. 1, 1 is a non-aqueous secondary battery, 2
Is an electrode group, 3 is a positive electrode, 4 is a negative electrode, 5 is a separator, 6 is a battery case, 7 is a lid, 8 is a safety valve, 9 is a negative electrode terminal, 10
Is a positive electrode lead, and 11 is a negative electrode lead.

In this prismatic non-aqueous secondary battery 1, a separator 5 comprises a positive electrode 3 formed by applying a positive electrode mixture to an aluminum current collector and a negative electrode 4 formed by applying a negative electrode mixture to a copper current collector. The flat-wound electrode group 2 wound via the electrode and the non-aqueous electrolyte are housed in the battery case 6, and the size is 30 m in width.
m, height 48 mm, and thickness 5 mm.

A battery lid 7 provided with a safety valve 8 is attached to the battery case 6 by laser welding, and a negative electrode terminal 9 is attached.
Is connected to the negative electrode 4 via the negative electrode lead 11, and the positive electrode 3 is connected to the battery lid via the positive electrode lead 10.

The positive electrode plate was composed of 8% by weight of polyvinylidene fluoride as a binder, 5% by weight of acetylene black as a conductive agent, and a positive electrode active material 87 as a lithium cobalt composite oxide.
N-methylpyrrolidone was added to a positive electrode mixture made by mixing with 20 wt.
It was manufactured by coating both sides of a μm aluminum foil current collector and drying.

The negative electrode plate was prepared by adding 95% by weight of graphite (graphite), 2% by weight of carboxymethylcellulose and 3% by weight of styrene-butadiene rubber into a paste form by adding a suitable amount of water, and collecting the copper foil with a thickness of 15 μm. It was manufactured by coating both sides of the electric body and drying.

A polyethylene microporous membrane is used for the separator, and ethylene carbonate (E
C: gamma-butyrolactone (GBL) = 3: 7 (volume ratio) in a mixed solvent, di-normal butyl carbonate (D
3% by weight of NBC) and 1.5% of LiBF ₄
A mol / l dissolved non-aqueous electrolyte was used. Configuration above
The non-aqueous secondary battery of the example was manufactured by the procedure.

Next, the additive to the electrolytic solution will be described. The amount of ethylene carbonate (E
C: gamma-butyrolactone (GBL) = 3: 7 (volume ratio) in a mixed solvent, di-normal butyl carbonate (D
3% by weight of NBC) and 1.5% of LiBF ₄
The weight ratio (wt%) of the additive to the total weight of the dissolved non-aqueous electrolyte was expressed as mol / l.

First, seven types of non-aqueous secondary batteries were produced by using vinyl ethylene carbonate (VEC) and vinylene carbonate (VC) as additives and changing the addition amounts of each. A battery A was obtained by adding 1% by weight of VEC and 1% by weight of VC. VEC 0.04% by weight and VC 0.0
1% by weight was added to form a battery B. A battery C was obtained by adding 0.5% by weight of VEC and 0.5% by weight of VC. VE
A battery D was obtained by adding C1 wt% and VC2 wt%.
Battery E was prepared by adding 1% by weight of VEC and 3% by weight of VC. Battery F by adding 1% by weight of VEC and 4% by weight of VC
And Battery G was prepared by adding 1% by weight of VEC and 5% by weight of VC.

Next, vinyl ethylene carbonate (V
EC) addition amount to 1% by weight, and 1% by weight of another additive
Seven types of non-aqueous secondary batteries with the addition of wt% were produced.
Battery H was prepared by adding 1,3-propane sultone.
Battery I was prepared by adding 1,3-butane sultone. 1,
Battery J was prepared by adding 4-butane sultone. 1,3-
Battery K was prepared by adding propene sultone. A battery L was prepared by adding glycol sulfate. A battery M was obtained by adding succinic anhydride. Maleic anhydride was added to make a battery N.

Further, 0.1 mol of electrolyte salt LiPF ₆ was added.
A battery O was made in the same manner as the battery A except that 1 / l was added.

[Comparative Example] Three kinds of non-aqueous secondary batteries of Comparative Example were prepared in the same manner as in Example except for the additives. VE
A battery P was made in the same manner as the battery A, except that C and VC were not included at all. A battery Q was made in the same manner as the battery A, except that 1% by weight of VEC was added. A battery R was made in the same manner as the battery A except that 1% by weight of VC was added.

With respect to the 18 types of the prismatic nonaqueous electrolyte secondary batteries A to R produced as described above, the initial capacity, the battery thickness after being left at high temperature, and the capacity retention rate after 500 cycles were measured.

The initial capacity is room temperature and the charging current is 600 m.
A, constant current constant voltage charge of 4.20V charging voltage for 2.5 hours, then discharge current 600mA, end voltage 2.75
The discharge capacity when discharged under the condition of V was used.

The discharge capacity at 0 ° C. is room temperature and the charging current is 6
After charging for 2.5 hours with constant current constant voltage charging of 00mA, charging voltage 4.20V, leave it at 0 ° C for 10 hours, then 0 ° C
Shows the discharge capacity when discharged under the conditions of a discharge current of 600 mA and a final voltage of 2.75V.

The battery thickness after being left at a high temperature was measured by measuring the initial capacity of the battery at room temperature and charging current of 600 m.
A, after charging for 2.5 hours by constant-current constant-voltage charging with a charging voltage of 4.20 V, it was left for 200 hours in an environment of 80 ° C., cooled to room temperature, and then the thickness of the battery was measured.

The charging / discharging life performance was measured by measuring the battery whose initial capacity was finished with a charging current of 600 mA and a charging voltage of 4.
After 2.5 hours of constant-current constant-voltage charging of 20 V, discharge was repeated under the conditions of a discharge current of 600 mA and an end voltage of 2.75 V, and 500 cycles of discharge capacity for one cycle when 500 cycles were performed. The capacity ratio (%) was defined as the capacity retention rate.

Table 1 shows the measurement results of the batteries A to O of the example and the batteries P, Q and R of the comparative example.

[0059]

[Table 1]

The battery P to which no additive was added had a small initial capacity, a large increase in thickness when left at high temperature, and poor charge / discharge cycle life performance. In addition, the battery Q to which VEC simple substance, which is a vinylethylene carbonate compound represented by the general formula (1) is added as the non-aqueous solvent, has improved charge / discharge cycle life performance, but has a very small discharge capacity at 0 ° C. The charge / discharge performance was poor. Further, the non-aqueous solvent does not include VEC which is a vinyl ethylene carbonate compound represented by the general formula (1), but a battery R to which VC is added is used.
Had excellent charge / discharge performance, but had poor charge / discharge cycle life performance.

The batteries A to G to which VEC and VC were added were:
The discharge capacity at 0 ° C was large, and the charge / discharge performance was improved. Further, it was found that the effect was obtained when the addition amounts of VEC and VC were 0.05% by weight. Further, in the battery G in which the total amount of VEC and VC added was 5% by weight or more, the increase in battery thickness after high temperature storage was large. It is considered that this is because excess VC existing in the electrolytic solution reacted with the positive electrode to generate decomposed gas. Therefore, it was found that the total amount of VEC and VC added is more preferably 0.05% by weight or more and 5% by weight or less.

In the batteries H to K, instead of VC, cyclic sulfonic acid 1,3-propane sultone, 1,3-
Although butanesultone, 1,4-butanesultone and 1,3-propenesultone were added, the same effect as when VC was added could be obtained.

Further, as in batteries L to N, even if glycol sulfate, which is a cyclic sulfate, or succinic anhydride or maleic anhydride, which is a cyclic acid anhydride, is added, V
The same effect as when C was added could be obtained.

This time, LiBF ₄ alone was added to the electrolyte salt, but it was found that adding 0.1 mol / l of LiPF ₆ improves the low temperature discharge characteristics and life performance. This is L
It is considered that this is because iPF ₆ forms a stable film with low resistance on the surface of the negative electrode. Therefore, the electrolyte salt should be Li
It is desirable that PF ₆ is included.

In the above embodiment, VEC and VC, or cyclic sulfonic acid, cyclic sulfuric acid ester, and cyclic acid anhydride were added alone instead of VC, but they may be used in a mixture. Further, in the above examples, as the main solvent,
Although a mixed solvent of ethylene carbonate and gamma-butyrolactone, which has a low vapor pressure but is susceptible to reductive decomposition, was used, the same applies when ethylene carbonate and chain carbonate are used as the solvent or when the type and concentration of salt are changed. The effect of was obtained.

[0066]

INDUSTRIAL APPLICABILITY The present invention provides a non-aqueous secondary battery in which the non-aqueous solvent contains a vinyl ethylene carbonate compound represented by the general formula (1), and further vinylene carbonate, a cyclic sulfonic acid or a cyclic sulfate, By containing at least one selected from the group consisting of cyclic acid anhydrides, a non-aqueous electrolyte secondary battery having excellent storage performance under high temperature environment and charge / discharge cycle life performance, and further excellent charge / discharge performance is obtained. Is something that can be done.

When gamma-butyrolactone, which has a low vapor pressure and a high reactivity with the negative electrode, is used as the solvent, it is possible to further reduce the change in thickness when left at high temperature, and to obtain a greater effect. Furthermore, LiBF is added to the electrolyte salt.
By including ₄ and LiPF ₆ , more excellent charge / discharge performance and life performance can be obtained.

The total weight of the vinylethylene carbonate compound represented by the general formula (1), vinylene carbonate, cyclic sulfonic acid or cyclic sulfate, vinylene carbonate and cyclic acid anhydride is 0 with respect to the total weight of the electrolytic solution. By controlling the content to be 0.05% by weight or more and 5.0% by weight or less, it is possible to obtain a non-aqueous secondary battery that has a small swelling when left at high temperature and is excellent in charge / discharge cycle life performance and charge / discharge performance.

The present invention is a very effective means for a non-aqueous secondary battery using a laminated case having a low pressure resistance and aluminum as an outer casing, and therefore the effect of the present invention is great.

[Brief description of drawings]

FIG. 1 is a view showing a vertical cross section of a prismatic non-aqueous secondary battery of the present invention.

[Explanation of symbols]

1 Prismatic non-aqueous secondary battery 2 electrode group 3 positive electrode 4 Negative electrode 5 separator 6 battery case

Claims (6)

[Claims] 1. A non-aqueous secondary battery comprising a positive electrode capable of sucking / releasing lithium, a negative electrode capable of sucking / releasing lithium, and an electrolyte prepared by dissolving a lithium salt in a non-aqueous solvent, The non-aqueous solvent contains a vinyl ethylene carbonate compound represented by the general formula (1), and further contains at least one selected from the group consisting of vinylene carbonate, cyclic sulfonic acid or cyclic sulfate, and cyclic acid anhydride. A non-aqueous secondary battery characterized by containing. [Chemical 1] (In the formula, R1, R2, R3, R4, R5 and R6 are
Each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) 2. The non-aqueous secondary battery according to claim 1, wherein the non-aqueous solvent contains gamma-butyrolactone. 3. The cyclic sulfonic acid is at least one selected from the group consisting of 1,3-propane sultone, 1,4-butane sultone, 1,3-butane sultone and 1,3-propene sultone, and a cyclic sulfuric acid ester. Is a glycol sulfate, The non-aqueous secondary battery according to claim 1, wherein 4. The cyclic acid anhydride is succinic anhydride, glunuric acid anhydride, maleic acid anhydride, citraconic acid anhydride, diglycolic acid anhydride, cyclohexanedicarboxylic acid anhydride, 4-cyclohexene-1,2-dicarboxylic acid anhydride, 3, 4,
It is at least one selected from the group consisting of 5,6-tetrahydrophthalic anhydride, 5-norbrunene-2,3-dicarboxylic anhydride, phenylsuccinic anhydride, and 2-phenylglunuric anhydride. The non-aqueous secondary battery according to claim 1, 2, or 3. 5. The non-aqueous secondary battery according to claim 1, 2, 3 or 4, wherein the electrolyte salt contains LiBF ₄ and LiPF ₆ . 6. The total weight of the vinyl ethylene carbonate compound represented by the general formula (1), vinylene carbonate, cyclic sulfonic acid or cyclic sulfate, vinylene carbonate and cyclic acid anhydride is 0 relative to the total weight of the electrolytic solution. 6. The non-aqueous secondary battery according to claim 1, wherein the content is 0.05% by weight or more and 5% by weight or less.