JP2003157896A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of being high in initial discharge capacity, and being low in a service life characteristic in an alloy negative electrode material capable of storing and releasing lithium ions in a nonaqueous electrolyte secondary battery. SOLUTION: This nonaqueous electrolyte secondary battery has a negative electrode having an intermetallic compound having Ti or Si or an intermetallic compound having Ti and Sn, a positive electrode storing and releasing the lithium ions, and a nonaqueous electrolyte, and is characterized in that the nonaqueous electrolyte has a nonaqueous solvent and lithium salt indicated in (the formula 1). (The formula 1) R1-SO2+R2-SO2=N-Li [R1, R2: CnX (an integer of 8 from 2n+1, or 2n-1; n; 1) X: an element of hydrogen or a halogen group].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative electrode containing the above negative electrode material and a non-aqueous electrolyte secondary battery equipped with the negative electrode and having a high capacity and a long life.

[0002]

2. Description of the Related Art As a negative electrode for a non-aqueous electrolyte secondary battery, metallic lithium or a lithium compound has been extensively studied because it can realize a high energy density at a high voltage. On the other hand, as the positive electrode, LiMn ₂ O ₄ , LiCoO ₂ ,
LiNiO ₂ , V ₂ O ₅ , Cr ₂ O ₅ , MnO ₂ , TiS ₂ ,
Transition metal oxides such as MoS ₂ and chalcogen compounds have been investigated. It is known that these have a layered structure or a tunnel structure through which lithium ions can enter and exit.

When metallic lithium or the like is used for the negative electrode, dendritic lithium is deposited on the surface of the metallic lithium of the negative electrode during charging, the charge / discharge efficiency of the battery is lowered, and the dendritic lithium contacts the positive electrode to cause an internal short circuit. There is a problem that occurs. Therefore, in recent years, a lithium ion battery using a graphite-based carbon material, which has a smaller capacity than metallic lithium but can reversibly store and release lithium, and has excellent cycle life and safety, has been put into practical use.

However, when a carbon material is used for the negative electrode, its practical capacity is as small as 350 mAh / g, and
The fact that the theoretical density is as low as 2.2 g / cc hinders the demand for higher capacity batteries. Therefore, it is desired to use a metal-based material having a higher practical capacity as the negative electrode material.

On the other hand, when a metal-based material is used as the negative electrode active material, there is a problem that the active material repeatedly expands and contracts with the occlusion and release of lithium, and becomes fine powder.
The finely divided active material loses contact with other active materials in the negative electrode or the conductive agent, and becomes an apparently inactive active material.
The electron conductivity of the negative electrode is reduced and the capacity is also reduced.

As means for solving this problem, Si, S
A structure has been proposed in which an active phase capable of occluding and releasing Li such as n and an inactive phase that does not electrochemically react with Li coexist in one particle (Japanese Patent Laid-Open No. 11-86854). In this case, it is considered that the stress generated in the active material particles by occlusion of lithium is relaxed by the phase that does not occlusion of lithium, and expansion and pulverization of the active material are suppressed.

However, the negative electrode material as described above is used, and LiCoO 2, LiNiO 2, or Li is used for the positive electrode.
When a non-aqueous electrolyte secondary battery using a metal oxide such as Mn2O4 is used as a supporting electrolyte, a fluorine-containing inorganic anion lithium salt typified by LiPF6 and LiBF4, which is generally used in lithium-ion batteries, is used, and the life is rapidly increased. Deterioration was confirmed.

When the deterioration factor was analyzed for this deteriorated battery, a large amount of lithium-containing metal fluoride salt was formed on the surface of the negative electrode (for example, when Si-containing alloy was used for the negative electrode, LiSi
It was found that F6) was generated. As a cause for this, a small amount of water contained in the electrolytic solution reacts with the fluorine-containing inorganic anion lithium salt that is the supporting electrolyte to generate hydrofluoric acid (HF), and as a result, HF reacts with the alloy in the negative electrode. It is presumed that the above lithium-containing metal fluoride salt is produced.

[0009]

DISCLOSURE OF THE INVENTION The present invention finds a significant improvement in the life characteristics, which is a problem, while using a high capacity metal-based negative electrode material, and is a non-aqueous electrolyte secondary that achieves both high capacity and long life. A battery is provided.

[0010]

In order to solve the above conventional problems, the present invention provides an intermetallic compound containing Ti and Si,
Alternatively, a non-aqueous electrolyte secondary battery including a negative electrode including an intermetallic compound containing Ti and Sn, a positive electrode that absorbs and releases lithium ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is It is characterized by having a non-aqueous solvent and the lithium salt shown in Chemical formula 1.

At this time, when the concentration of the lithium salt shown in (Chemical Formula 1) in the non-aqueous electrolyte is 0.05 mol / L or more, 1.0
It is effective that it is not more than mol / L. Further, it is effective that the non-aqueous solvent contains at least one kind of cyclic carbonic acid ester, cyclic carboxylic acid ester, and non-cyclic carbonic acid ester.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a non-aqueous electrolyte secondary battery using a negative electrode active material containing a metal element capable of alloying with lithium, wherein the non-aqueous electrolyte is a non-aqueous solvent and the lithium shown in (Chemical Formula 1). A secondary battery comprising at least one electrolyte salt selected from salts. Also (Chemical formula 1)
In the formula, R1 and R2 are each independent,
CnX2n + 1 or CnX2n−1, wherein n
Is an integer of 1 to 8, and X is a hydrogen atom or a halogen atom. Lithium salt, LiPF6 or LiB as an electrolyte salt constituting the non-aqueous electrolyte
It is a mixed electrolyte salt with at least one selected from the group of fluorine-containing inorganic anion lithium salts consisting of F4. Examples of the lithium imide salt used in the present invention include LiN (CF3SO2) 2 and LiN (C
2F5SO2) 2, LiN (CF3SO2) (C4F9
SO2) and the like.

The amount of water contained in the non-aqueous electrolyte is at most 5
It is preferably 0 ppm or less.

The present invention is characterized in that the solvent constituting the non-aqueous electrolyte contains at least either a cyclic carbonic acid ester, a cyclic carboxylic acid ester or a non-cyclic carbonic acid ester. At that time, the total electrolyte salt concentration in the non-aqueous electrolyte is 0.5 mol / L or more and 2 mol / L or less, and ethylene carbonate is contained in the non-aqueous electrolyte.
Alternatively, it is desirable to contain any of vinylene carbonate, or γ-butyrolactone, or propylene carbonate, and the nonaqueous electrolyte may contain any of diethyl carbonate, ethyl methyl carbonate, or dimethyl carbonate. desirable.

Further, a solvent in which a cyclic carbonic acid ester or cyclic carboxylic acid ester and an acyclic carbonic acid ester are mixed is particularly preferable.

In the present invention, by utilizing a lithium salt, a lithium imide salt or the like as an additive to the non-aqueous electrolyte, it is possible to prevent generation of an excessive mask, which is a factor of deterioration of the alloy negative electrode in principle, and a good charge and discharge cycle is obtained. Characteristics (life characteristics).

Further, the electrolyte to which the lithium salt is added is characterized in that the generation of gas with the progress of charge / discharge cycles is suppressed.

Further, lithium salt and LiPF6 or LiBF
Fluorine-containing inorganic anion lithium salt such as No. 4 is mixed at an optimum mixing ratio to control the amount of water in the electrolytic solution to improve the rate performance while taking advantage of the above cycle characteristics and gas generation advantages. Became possible.

The metallic element which forms an alloy with lithium contained in the negative electrode active material is characterized by containing Si or Sn. Further, it is desirable that the negative electrode active material contains an intermetallic compound composed of Ti and Si or Ti and Sn.
As the intermetallic compound, TiSi2, TiSi, Ti2Sn, Ti6Sn5, or Ti5 is used.
It is particularly desirable that the intermetallic compound have a low crystallinity or an amorphous property.

It is considered that the lithium salt-added electrolyte is based on the following principle for improving the charge-discharge cycle characteristics.

Lithium salt has a typical composition, L
iN (CF3SO2) 2, LiN (C2F5SO2)
2. LiN (CF3SO2) (C4F9SO2) and the like contain elemental fluorine, but unlike fluorine-containing inorganic anion lithium salt, it has a carbon-fluorine bond having a strong binding force, and thus releases fluorine in principle. Hateful. Therefore, HF is not generated even if water is present in the electrolytic solution, and the deterioration mechanism such as the above-described lithium-containing metal fluoride salt is unlikely to occur.

Further, when a lithium salt is used, the film formed on the surface of the negative electrode by the side reaction with the supporting electrolyte and the solvent is formed at a higher potential (ratio of lithium to 0.8 V) than LiPF6, and the mask thickness is increased. Is thin, and the film thickness does not increase with the progress of cycles.
Although this factor is under diligent analysis, it is probable that the above-mentioned surface film, which uses a lithium salt as a starting material, is rich in electron conductivity and Li ion conductivity unlike that of LiPF6, and also expands and contracts due to charge and discharge of the alloy negative electrode. It is speculated that it may be a film that is rich in elasticity and can follow.

In addition, it is presumed that the electrolyte generated by adding a lithium salt suppresses the generation of gas with the progress of charge / discharge cycles according to the following principle.

Lithium salt is oxidatively decomposed at a lower potential than LiPF6 which is generally used in the past (it has been confirmed that the decomposition product at this time also does not contain HF). When a cyclic voltammogram was measured at room temperature using a platinum electrode as a working electrode, a lithium metal as a counter electrode, and a reference electrode, an oxidation current indicating decomposition of the supporting salt started to flow near 4.2 V on the Li standard. This battery system (L to the positive electrode
Since any one of iCoO2, LiNiO2, and LiMn2O4, or the alloy containing Si or Sn in the negative electrode) has a positive electrode potential of 4.2 V or more when fully charged, part of the lithium imide salt in the electrolytic solution is decomposed. At that time, decomposition products form a film not only on the surface of the positive electrode but also on the surface of the negative electrode, thereby protecting the active sites of both the positive electrode and the negative electrode, thereby suppressing excessive decomposition of the electrolytic solution, and as a result, suppressing gas generation. It is expected that

As described above, the lithium salt is a very excellent supporting electrolyte, but when an Al foil is used for the positive electrode current collector,
It is well known that adverse effects such as corrosion of the current collector are caused. Therefore, the present inventors have used LiP, which is a conventional salt.
The mixed salt with F6 and LiBF4 was examined,
As a result, the water content in the electrolytic solution was at most 50 ppm or less, and the concentration of the lithium salt was 0.05 mol / L.
It was found that the above range of 1.0 mol / L or less is suitable. By using such a mixed salt and a water content, it is possible to suppress the corrosion of the Al foil, which is the positive electrode current collector, and by mixing at an optimum mixing ratio, the rate of the battery can be maintained while maintaining the above good characteristics. It was found to improve the characteristics.

When the water content in the electrolytic solution exceeds 50 ppm, the mixed LiPF6 or LiBF4 reacts with water to easily generate HF, which tends to deteriorate the charge / discharge cycle characteristics.

When 1.0 mol / L or more of lithium salt was added, the viscosity of the electrolytic solution increased and the rate characteristics of the battery tended to deteriorate. Further, when the addition amount is 0.05 mol / L or less, it is difficult to suppress the gas generation because the decomposition product of the lithium salt is not sufficient. It is preferably 0.05 mol / L or more and 0.5 mol / L or less,
More preferably 0.1 mol / L or more and 0.3 mol / L
It is preferable to add the lithium salt in the range of L or less. In this range, the battery rate characteristics were the best, and the life characteristics and gas generation inhibition were excellent.

It is desirable that the total concentration of all electrolyte salts in the mixed salt is 0.5 mol / L or more and 2 mol / L or less. When it was 0.5 mol / L or less, the lithium ion conductivity of the electrolytic solution itself was lowered, and the rate property of the battery tended to be extremely lowered. On the other hand, when the salt concentration is 2 mol / L or more, the viscosity of the electrolytic solution becomes very high, and the rate characteristic also tends to deteriorate. Preferably 0.8
It was not less than mol / L and not more than 1.5 mol / L. In this range, the battery rate characteristics were good, and the life characteristics and the gas suppressing effect could be sufficiently exhibited.

A technique of using a mixed system of a fluorine-containing inorganic anion lithium salt such as LiPF6 and a lithium salt in a battery has already been disclosed in JP-A-10-189045, JP-A-2001-223025 and the like. .
On the other hand, in the present invention, Si or S is used as the negative electrode material.
This is an improvement by mentioning a problem peculiar to a battery using an alloy material containing a metal capable of inserting and extracting Li such as n.

The negative electrode material used in the present invention is limited to a material containing a metal element that can be alloyed with lithium, and examples thereof include Si, Sn, Al, Pb, Bi, Ge and Ga. Preferred elements are selected from Si, Sn, and Al, and particularly desirable elements are Si and Sn.

It has been experimentally proved that Si and Sn have a high capacity and a long life compared with the above-mentioned other elements theoretically and experimentally.

An element that does not electrochemically react with Li than the above-mentioned elements alone, such as Fe,
Transition metal elements represented by Mn, Co, etc., Mg, Ca
Alkaline earth metal elements represented by, Ti, group IVA elements represented by Zr, lanthanoids, V represented by V
Examples include Group A elements. A transition metal element and a group IVA element are preferable, and a group IVA element is particularly preferable. Among them, an alloy negative electrode material containing Ti is preferable, and it is desirable that a part of the alloy is formed of an intermetallic compound composed of Ti and Si or Ti and Sn. Furthermore, it is particularly desirable that the intermetallic compound has low crystallinity or amorphousness.

Sn alloy material alloyed with Ti and Si
The alloy material has improved life characteristics as compared with the Sn alloy material and Si alloy material alloyed with other various elements. It is expected that this is due to a marked improvement in corrosion resistance by alloying with Ti.

Further, the above alloy negative electrode material has an average particle size of 45.
It is preferable that the thickness is less than or equal to μm, and particularly preferably 10 μm.
m or less. If the particle size is 45 μm or more, it becomes impossible to produce a negative electrode plate effective for battery design. When the average particle size is 10 μm or less, an effective negative electrode plate can be easily formed, and the reaction surface area is increased due to the increase in the specific surface area of the material, so that a good rate property can be obtained.

The alloy negative electrode material has an average crystallite size of at least 10 μm or less, preferably 1 μm or less,
Particularly preferably, the thickness is 0.3 μm or less.
By reducing the crystallite size, particle cracking can be prevented, and as a result, cycle deterioration can be suppressed.

Further, in order to improve the electron conductivity of the entire negative electrode plate, it is desirable to add a conductive agent in addition to the alloy. Examples of the conductive agent include graphite, carbon black, acetylene black and the like. Particularly desirable are acetylene black and carbon black.

As the positive electrode material used in the present invention, a lithium-containing composite transition metal oxide or a lithium-containing composite transition metal oxide in which a metal element other than the transition metal constituting the lithium-containing composite transition metal oxide is solid-dissolved is used. . Examples of these are LiCoO2, LiNiO2, LiMn
2O4, LiMnO2, LiFeO2 or a part of their transition metals (Co, Ni, Mn, Fe), other transition metals,
Examples thereof include those substituted with Sn, Al, Mg and the like.

[0038]

EXAMPLES The present invention will be specifically described below based on examples. First, in the following examples, the test cell and rate characteristics used for measuring the discharge capacity, the cylindrical battery used for measuring the cycle life, the discharge capacity and rate characteristics, and the method for measuring the cycle life will be described.

(Test Cell) The test cell shown in FIG. 1 was prepared. First, as a negative electrode material, Ti-Si alloy and Ti-
Sn alloys and graphite were chosen as comparative examples. Ti-
For the Si alloy, a Ti ingot and a Si ingot were mixed at a molar ratio of 1: 2.5, and the mixed ingot was melted and pulverized by a gas atomizing method. This raw material alloy together with stainless steel balls (alloy: ball ratio
Milling was performed in an attritor ball mill for 24 hours. The powder was taken out in an Ar atmosphere to obtain a Ti-Si alloy active material. Similarly, for the Ti-Sn alloy, a raw material alloy was obtained by melting and pulverizing the individual ingots by the gas atomizing method (the alloy ratio is Ti: Sn =
2: 1 (molar ratio)). This raw material alloy was put into a ball mill with stainless steel balls (alloy: ball ratio).
Milling was performed under a nitrogen atmosphere for 3 days (1: 5 (weight ratio)). The powder was taken out under a nitrogen atmosphere and Ti-
The Sn alloy active material was used. Each of the alloy powders was amorphous according to the crystal structure analysis by X-ray diffraction, and the average particle size of both was about 2 μm. The crystallite size is 0.05μ
It was observed by a transmission electron microscope in the range of m to 0.2 μm. The graphite powder of the comparative example is made of natural graphite with a particle size of 50 μm.
It was obtained by classifying to m or less. A mixture was obtained by mixing 7.5 g of each active material, 2 g of acetylene black powder as a conductive agent, and 0.5 g of polyethylene powder as a binder. 0.1 g of this mixture was pressure-molded to a diameter of 17.5 mm to form an electrode 1, which was placed in a case 2. Next, the separator 3 made of microporous polypropylene was put on the electrode 1. Then, 2 ml of the predetermined electrolytic solution was injected into the test cell. In the preparation of the electrolytic solution, three points were selected as the lithium imide salt. LiN (CF3SO2) 2 as imide A, LiF (C2F5SO2) 2 as imide B, and LiF (CF3SO2) (C4F9SO2) as imide C
Were selected and mixed at the concentrations shown in Table 1. As for the water content in the electrolyte, basically, a solvent / supporting salt from which water is removed to the limit is used, and in the case of a high water content, the water content is controlled by appropriately mixing a trace amount of water. .
Next, metallic lithium 4 having a diameter of 17.5 mm was attached to the inside, and the case 2 was sealed with a sealing plate 6 having a polypropylene gasket 5 attached to the outer peripheral portion to form a test cell.

(Cylindrical Battery) A cylindrical battery shown in FIG. 2 was produced. First, the positive electrode active material LiCoO2 is
₂ CO ₃ and CoCO ₃ are mixed at a predetermined molar ratio to obtain 950
It was synthesized by heating at ℃. In addition, 1
The one classified into a size of 00 mesh or less was used. To 100 g of the positive electrode active material, 10 g of acetylene black as a conductive agent, 8 g of an aqueous dispersion of polytetrafluoroethylene as a binder (resin component) and pure water were added and mixed sufficiently to form a positive electrode mixture paste. Obtained. This paste was applied to an aluminum core material, dried, and rolled to obtain a positive electrode 11.

The negative electrode mixture paste contains a predetermined negative electrode active material, acetylene black powder as a conductive agent, and styrene-butadiene rubber as a binder in a weight ratio of 8.
It was obtained by mixing at a ratio of 0:10:10 and adding water. Then, this paste was applied to a copper core material and dried at 140 ° C. to obtain a negative electrode 12.

Next, the positive electrode lead 14 made of aluminum was attached to the core material of the positive electrode by ultrasonic welding. Similarly, a copper negative electrode lead 15 was attached to the negative electrode core material. And
A strip-shaped porous polypropylene separator 13 having a width wider than that of the positive electrode, the negative electrode, and the bipolar plates was laminated. At this time, a separator was interposed between the bipolar plates. Then, the laminate was rolled into a cylindrical shape to form an electrode group. Insulating plates 16 and 17 made of polypropylene were placed on the upper and lower sides of the electrode group, respectively, and inserted into a battery case 18. Then, after forming a step on the upper part of the battery case 18, an arbitrary electrolytic solution was injected and sealed with a sealing plate 19 having a positive electrode terminal 20 to obtain a cylindrical battery.

(Measurement Method of Discharge Capacity) The test cell is set to 0.5.
It is charged at a constant current of mA / cm ² until the terminal voltage becomes 0 V (storage of lithium in the negative electrode material), and then discharged at a current of 0.5 mA / cm ² until the terminal voltage becomes 1.5 V ( Lithium was released from the negative electrode material), and the discharge capacity (mAh / g) was measured.

(Method of measuring cycle life and rate characteristics)
The charge / discharge cycle test of the cylindrical battery was conducted at 20 ° C. as follows. First, constant-current charging of a cylindrical battery was performed with a charging current of 0.2 C (1 C is 1 hour rate current) and a battery voltage of 4.2 V.
Then, constant voltage charging was carried out until 4.2V and a current value became 0.01C. Then, the cylindrical battery was discharged at a current of 0.2 C until the battery voltage became 2.0 V. This charging / discharging cycle was repeated, the ratio of the discharge capacity at the 100th cycle to the discharge capacity at the first cycle was determined, and the value was multiplied by 100 to obtain the capacity retention rate (%). The closer the capacity retention rate is to 100, the better the cycle life.

During the cycle life characteristic evaluation, rate characteristic evaluation was performed under the following settings. The measurement was performed up to the 10th cycle, and after it was confirmed that the charge and discharge capacity was sufficiently stable during that period, the rate characteristics were evaluated in the following order. Here, the following charging rate describes the value in the area of constant current charging. Number of cycles Charge rate Discharge rate 10 0.2C 0.2C 11 0.2C 1.0C 12 0.2C 2.0C 13 0.2C 0.2C (capacity confirmation) 14 1.0C 0.2C 15 0.2C 0 .2 C (capacity confirmation) After that, the cycle characteristics were evaluated again.

Example 1 As shown in Table 1, batteries were prepared by changing the components of the electrolytic solution and the materials of the negative electrodes, and these were named batteries A1 to A24. In Table 1, EC is ethylene carbonate, EMC is ethyl methyl carbonate, and GBL is γ.
-Butyl lactone, PC is propyl carbonate.

The amount of gas generated after 100 cycles was measured using batteries A1 to A24. The results are shown in Table 1.
As a method for measuring the gas generation amount, a part of the test battery was put in a Teflon (registered trademark) bag, filled with a known amount of argon gas and sealed, and a hole was opened in the bag at the upper part of the battery. The gas inside the battery was released. The amount of gas was determined from the peak area ratio of gas chromatography. Battery A1
3, A23 is PC instead of EC in the non-aqueous electrolyte solution,
The batteries A14 and A24 similarly adopted GBL as the electrolyte solution.

Imide A is (LiN (CF3SO2) 2) Imide B is (LiF (C2F5SO2) 2) Imide C is (LiF (CF3SO2) (C4F9SO)
2)).

[0049]

[Table 1]

In the batteries A1 to A4, when graphite was used as the negative electrode material, the one obtained by adding a lithium salt to the non-aqueous electrolyte solution (Batteries A2 to A4) was improved in both the capacity retention rate and the amount of gas after cycling as compared with the battery A1. It was In batteries A5 to A14, an alloy compound containing Ti and Si was used as the negative electrode material, and only LiPF6 was added as an electrolyte or a lithium salt was added to LiPF6. The battery using the alloy negative electrode shows a high capacity (Batteries A1 to
A4 and batteries A5 to A14), and LiP in the non-aqueous electrolyte solution.
Compared to the battery using only F6 (battery A5), the battery using a non-aqueous electrolyte solution containing a lithium salt (batteries A6, A
8, A10, A13, A14), the life characteristics were improved and the amount of gas generated after the cycle was also reduced. However, in the batteries A7 and A11 having a water content (water content in Table 1) of more than 50 ppm, the capacity retention rate, the amount of gas after cycling, etc. decreased. Also from the viewpoint of rate characteristics, the discharge rate property decreased when the concentration of the entire electrolyte salt was 2 mol / L or more (Battery A9).

Further, in batteries A15 to 24, when an alloy compound containing Ti and Sn was used as the negative electrode material, Ti and S were obtained.
Results similar to the alloy compounds with i were obtained. However, the batteries A17 and A21 had a water content of more than 50 ppm, and the battery A19 had a molar concentration of the electrolyte salt of 2 mol / L or more, which corresponds to the comparative example.

[0052]

According to the present invention, a negative electrode comprising an intermetallic compound containing Ti and Si or an intermetallic compound containing Ti and Sn, a positive electrode capable of absorbing and releasing lithium ions, a non-aqueous solvent and lithium. The non-aqueous electrolyte secondary battery provided with the non-aqueous electrolyte solution containing a salt has a low water content, can maintain a high capacity, can easily generate gas after the cycle, and can achieve a longer life.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a test cell having a negative electrode containing the negative electrode material of the present invention.

FIG. 2 is a sectional view of a cylindrical battery used for measuring the cycle life of the present invention.

[Explanation of symbols]

1 test electrode 2 cases 3 separator 4 metallic lithium 5 gasket 6 sealing plate 11 Positive electrode 12 Negative electrode 13 separator 14 Positive electrode lead 15 Negative electrode lead 16 Upper insulating plate 17 Lower insulation plate 18 battery case 19 sealing plate 20 Positive terminal

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Osamu Shimamura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yasuhiko Mito             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yoshiaki Nitta             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5H029 AJ03 AJ05 AK03 AL11 AL12                       AM02 AM03 AM05 AM07 BJ02                       BJ03 BJ14 DJ09 EJ04 EJ11                       EJ12 HJ02 HJ10                 5H050 AA07 AA08 BA17 CA07 CA08                       CA09 CB12 DA13 EA10 EA23                       FA05 HA02

Claims (3)

[Claims] 1. A non-electrode comprising a negative electrode comprising an intermetallic compound containing Ti and Si or an intermetallic compound containing Ti and Sn, a positive electrode absorbing and releasing lithium ions, and a non-aqueous electrolyte. A non-aqueous electrolyte secondary battery, wherein the non-aqueous electrolyte solution contains a non-aqueous solvent and the lithium salt shown in Chemical formula 1. [Chemical 1] 2. The concentration of the lithium salt represented by (Chemical formula 1) in the non-aqueous electrolyte is 1.0 mol / L when the concentration is 0.05 mol / L or more.
It is L or less, The nonaqueous electrolyte secondary battery of Claim 1 characterized by the above-mentioned. 3. The non-aqueous electrolyte secondary battery according to claim 1, wherein the non-aqueous solvent contains at least one kind of cyclic carbonic acid ester, cyclic carboxylic acid ester, and non-cyclic carbonic acid ester.