JP2004349268A - Non-aqueous electrolytic solution for lithium secondary battery and non-aqueous electrolytic solution secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high capacity non-aqueous electrolytic solution secondary battery which has a high capacity and an excellent charge and discharge cycle characteristics. <P>SOLUTION: This is a non-aqueous electrolytic solution which has a non-aqueous solvent and lithium salt and at least one kind of compound as expressed by a general formula (1) ( wherein, R<SP>1</SP>and R<SP>2</SP>may be mutually same or different and each expresses alkyl group, cycloalkyl group, alkoxy group, alkenyl group, or alkynil group) is contained in the electrolytic solution. A non-aqueous electrolytic solution secondary battery using this electrolytic solution is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a non-aqueous electrolyte for a lithium secondary battery and a non-aqueous electrolyte secondary battery, which has excellent charge / discharge characteristics, and further, has less deterioration in discharge capacity due to repeated charge / discharge. The present invention relates to a non-aqueous electrolyte for a lithium secondary battery from which a liquid secondary battery can be obtained, and a non-aqueous electrolyte secondary battery using the same.

  As a negative electrode material for a non-aqueous electrolyte secondary battery, lithium metal and lithium alloy are typical.However, when they are used, a so-called dendrite in which lithium metal grows in a dendritic manner during charge and discharge occurs, and an internal short circuit occurs. Due to the cause or the high activity of the dendrite itself, there was a danger such as ignition. On the other hand, fired carbonaceous materials capable of reversibly inserting and releasing lithium have come into practical use. Disadvantages of this carbonaceous material are its relatively low density, low capacity per volume, and its own conductivity, so lithium metal can be deposited on the carbonaceous material during overcharging or rapid charging. Is that it may precipitate

  As a non-aqueous electrolyte secondary battery having a high discharge potential with an average discharge voltage of 3 to 3.6 V class for the purpose of remedying the above drawbacks, Sn, V, Si, B, Zr, etc. It has been proposed to use oxides of these and composite oxides thereof (Patent Documents 1 to 6). By combining these oxides such as Sn, V, Si, B, and Zr, and their composite oxides with a positive electrode of a transition metal compound containing a certain kind of lithium, the average discharge voltage is 3 to 3.6 V class. Thus, a non-aqueous electrolyte secondary battery which has a large discharge capacity, has very little dendrite generation in a practical area, and has extremely high safety is provided. However, further improvement in charge / discharge cycle characteristics has been desired.

  On the other hand, attempts have been made to improve the charge / discharge cycle characteristics of non-aqueous secondary batteries by changing the composition of the electrolyte. For example, Patent Document 7 discloses the use of an unsaturated cyclic carbonate as an electrolyte solvent. Has been proposed. However, even when these techniques are used, when a lithium metal, a lithium alloy, or a carbon material is used as a negative electrode material, the level has not yet reached a level where both high discharge capacity and excellent cycle characteristics can be achieved.

JP-A-5-174818 JP-A-6-60867 JP-A-6-275267 JP-A-6-325765 JP-A-6-338324 EP-A-615296 JP-A-4-169075

  An object of the present invention is to provide a non-aqueous electrolyte and a non-aqueous electrolyte secondary battery for a lithium secondary battery, which can provide a non-aqueous electrolyte secondary battery having a large discharge capacity and excellent charge / discharge cycle characteristics. Is to do.

（式中、Ｒ¹及びＲ²は互いに同一でも異なってもよく、各々アルキル基、シクロアルキル基、アルコキシ基、アルケニル基、アルキニル基を表す。）
で表される化合物を少なくとも１種含有することを特徴とするリチウム二次電池用非水電解液、及びそれを用いた非水電解液二次電池によって達成された。 An object of the present invention is a non-aqueous electrolyte containing a non-aqueous solvent and a lithium salt, wherein the electrolyte contains a compound represented by the general formula (1):

(In the formula, R ¹ and R ² may be the same or different and each represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkenyl group, or an alkynyl group.)
The non-aqueous electrolyte solution for a lithium secondary battery comprising at least one compound represented by the formula: and a non-aqueous electrolyte secondary battery using the same.

  By using the non-aqueous electrolyte for a lithium secondary battery of the present invention, it is possible to obtain a non-aqueous electrolyte secondary battery having excellent charge / discharge characteristics and further having little deterioration in discharge capacity even after repeated charge / discharge. Can be.

（式中、Ｒ¹及びＲ²は互いに同一でも異なってもよく、各々アルキル基、シクロアルキル基、アルコキシ基、アルケニル基、アルキニル基を表す。）
で表される化合物を少なくとも１種含有することを特徴とするリチウム二次電池用非水電解液。
（２）一般式（１）で表される化合物が、ジメチルビニレンカーボネート、ジエチルビニレンカーボネート又はメチルエチルビニレンカーボネートである前記（１）に記載のリチウム二次電池用非水電解液。
（３）一般式（１）で表される化合物の含有量が、電解液溶媒に対して０．００１モル／ｌから０．１モル／ｌである前記（１）又は（２）に記載のリチウム二次電池用非水電解液。
（４）一般式（１）で表される化合物の含有量が、電解液に含有される支持塩に対して０．００１重量％から１０重量％である前記（１）〜（３）のいずれかに記載のリチウム二次電池用非水電解液。
（５）リチウムを可逆的に吸蔵放出可能な材料を含む正極と負極、非水溶媒とリチウム塩とを含む非水電解液、セパレーターからなる非水電解液二次電池において、電池内に一般式（１）

（式中、Ｒ¹及びＲ²は互いに同一でも異なってもよく、各々アルキル基、シクロアルキル基、アルコキシ基、アルケニル基、アルキニル基を表す。）
で表される化合物を少なくとも１種含有することを特徴とする非水電解液二次電池。 Preferred embodiments of the present invention will be described below, but the present invention is not limited thereto.
(1) A non-aqueous electrolytic solution containing a non-aqueous solvent and a lithium salt, wherein the electrolytic solution contains a general formula (1)

(In the formula, R ¹ and R ² may be the same or different and each represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkenyl group, or an alkynyl group.)
A non-aqueous electrolyte for a lithium secondary battery comprising at least one compound represented by the formula:
(2) The non-aqueous electrolyte for a lithium secondary battery according to the above (1), wherein the compound represented by the general formula (1) is dimethylvinylene carbonate, diethylvinylene carbonate or methylethylvinylene carbonate.
(3) The method according to the above (1) or (2), wherein the content of the compound represented by the general formula (1) is 0.001 mol / l to 0.1 mol / l with respect to the electrolyte solvent. Non-aqueous electrolyte for lithium secondary batteries.
(4) Any of the above (1) to (3), wherein the content of the compound represented by the general formula (1) is 0.001% by weight to 10% by weight based on the supporting salt contained in the electrolytic solution. A non-aqueous electrolyte for a lithium secondary battery according to any of the above items
(5) In a non-aqueous electrolyte secondary battery including a positive electrode and a negative electrode containing a material capable of reversibly inserting and extracting lithium, a non-aqueous electrolyte containing a non-aqueous solvent and a lithium salt, and a separator, a general formula (1)

(In the formula, R ¹ and R ² may be the same or different and each represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkenyl group, or an alkynyl group.)
A non-aqueous electrolyte secondary battery comprising at least one compound represented by the formula:

In the present invention, the charge / discharge cycle characteristics can be improved without impairing the high capacity of the nonaqueous electrolyte secondary battery by including at least one compound represented by the general formula (1) in the battery. Can be.
In the general formula (1), R ¹ and R ² may be the same or different from each other, and each is an alkyl group (eg, methyl, ethyl, propyl, dodecyl), a cycloalkyl group (eg, cyclopropyl, cyclohexyl), an alkoxy group (For example, methoxy, ethoxy, 2-methoxyethoxy), an alkenyl group (for example, vinyl, allyl, cyclohexenyl) and an alkynyl group (for example, ethynyl, 2-propenyl, hexadecynyl).

As the compound represented by the general formula (1), specifically, dimethylvinylene carbonate (A-30), diethylvinylene carbonate (A-31) or methylethylvinylene carbonate (A-32) represented by the following formula: And the like. Vinylene carbonate derivatives having a substituent such as

  The compound of the general formula (1) of the present invention may be contained in any part of the battery. Preferably, it is in the electrode active material or in the electrolytic solution. When contained in the electrode, the content of the compound of the general formula (1) is preferably from 0.01% by weight to 5% by weight, more preferably from 0.1% by weight to 2% by weight, based on the active material of the electrode. . When contained in the electrolytic solution, the content of the compound of the general formula (1) is preferably 0.0001 to 0.1 mol / l, more preferably 0.001 to 0.1 mol / l, based on the electrolytic solution solvent. More preferred. The content of the compound of the general formula (1) with respect to the supporting salt contained in the electrolytic solution is preferably from 0.001% by weight to 10% by weight, more preferably from 0.01% by weight to 5% by weight.

The electrolyte is generally composed of a solvent and a supporting salt dissolved in the solvent, and is preferably a lithium salt (anion and lithium cation). Examples of the solvent of the electrolytic solution that can be used in the present invention include propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, methyl formate, methyl acetate, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolan, formamide, dimethylformamide, dioxolan, dioxane, acetonitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, 3-methyl-2 -Non-produced products such as oxazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ethyl ether, 1,3-propane sultone, etc. Can be exemplified ton organic solvent, mixed and used alone or in combination.
Among them, a carbonate-based solvent is preferable, and a solvent containing a cyclic carbonate and / or a non-cyclic carbonate is preferable. As the cyclic carbonate, ethylene carbonate and propylene carbonate are preferable. Further, as the acyclic carbonate, it is preferable to include diethyl carbonate, dimethyl carbonate, and methylethyl carbonate.

Examples of the lithium salt dissolved in those solvents which can be used in the present invention, for _{example, LiClO 4, LiBF 4, LiPF} 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiB 10 Cl 10, lower aliphatic Li salts such as lithium group carboxylate, LiAlCl ₄ , LiCl, LiBr, LiI, lithium chloroborane, lithium tetraphenylborate, and the like, and one or more of these can be used in combination. Among them, those in which LiBF ₄ and / or LiPF ₆ are dissolved are preferred. The concentration of the supporting salt is not particularly limited, but is preferably 0.2 to 3 mol per liter of the electrolytic solution.

Examples of the electrolytic solution that can be used in the present invention include an electrolytic solution obtained by appropriately mixing ethylene carbonate, propylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate, or diethyl carbonate with LiCF ₃ SO ₃ , LiClO ₄ , LiBF _4, and / or LiPF _6. An electrolytic solution containing Particularly, an electrolytic solution in which LiBF ₄ and / or LiPF ₆ is added to a mixed solvent of ethylene carbonate, diethyl carbonate and / or dimethyl carbonate is preferable. The amount of these electrolytes to be added to the battery is not particularly limited, but the required amount can be used depending on the amounts of the positive electrode active material and the negative electrode material and the size of the battery.

Hereinafter, other materials and a manufacturing method for manufacturing the nonaqueous electrolyte secondary battery of the present invention will be described in detail.
The positive and negative electrodes used in the non-aqueous electrolyte secondary battery of the present invention can be produced by applying a positive electrode mixture or a negative electrode mixture on a current collector. The positive electrode or negative electrode mixture can contain a conductive agent, a binder, a dispersant, a filler, an ionic conductive agent, a pressure enhancer, and various additives, respectively, in addition to the positive electrode active material or the negative electrode material, respectively.

  It is preferable that the negative electrode material used in the present invention is mainly amorphous when the battery is incorporated. The term “mainly amorphous” as used herein means a substance having a broad scattering band having a peak at 20 ° to 40 ° in 2θ value by X-ray diffraction using CuKα ray, May have. Preferably, the strongest intensity of the crystalline diffraction lines observed at a 2θ value of 40 ° or more and 70 ° or less has a diffraction line intensity of 500 at the vertex of a broad scattering band observed at a 20 value of 20 ° or more and 40 ° or less. It is preferably not more than 100 times, more preferably not more than 100 times, particularly preferably not more than 5 times, and most preferably not having a crystalline diffraction line.

The negative electrode material used in the present invention is preferably represented by the following general formula (2).
M ¹ M ² pM ⁴ qM ⁶ r (2)
In the formula (2), M ¹ and M ² are different from each other and are at least one selected from Si, Ge, Sn, Pb, P, B, Al, and Sb, preferably, Si, Ge, Sn, P, B, and Al. And particularly preferably Si, Sn, P, B and Al. M ⁴ is at least one of Li, Na, K, Rb, Cs, Mg, Ca, Sr, selected from Ba, preferably K, Cs, Mg, with Ca, particularly preferably Cs, Mg. M ⁶ is at least one selected from O, S, and Te, preferably O and S, and particularly preferably O.
p and q are each 0.001 to 10, preferably 0.01 to 5, and particularly preferably 0.01 to 2. r is 1.00 to 50, preferably 1.00 to 26, and particularly preferably 1.02 to 6.
The valences of M ¹ and M ² are not particularly limited, and may be a single valence or a mixture of each valence. The M ^1, M ^2, the ratio of M ⁴ can be continuously changed in a range M ² and M ⁴ are from 0.001 to 10 molar equivalents relative to M ^1, the amount of M ⁶ accordingly (typically In the equation (2), the value of r) also changes continuously.

Among the compounds mentioned above, in the present invention, the case where M ¹ is Sn is preferable, and represented by the general formula (3).
SnM ³ pM ⁵ qM ⁷ r (3)
In the formula (3), M ³ is at least one selected from Si, Ge, Pb, P, B and Al, preferably Si, Ge, P, B and Al, and particularly preferably Si, P and B. , Al. M ⁵ is at least one of Li, Na, K, Rb, Cs, Mg, Ca, Sr, selected from Ba, preferably Cs, with Mg, particularly preferably Mg. M ⁷ is at least one selected from O and S, and is preferably O.
p and q are each 0.001 to 10, preferably 0.01 to 5, more preferably 0.01 to 1.5, and particularly preferably 0.7 to 1.5. r is 1.00 to 50, preferably 1.00 to 26, and particularly preferably 1.02 to 6.

Examples of the negative electrode material of the present invention are shown below, but the present invention is not limited thereto.
_{SnAl 0.4 B 0.5 P 0.5 K 0.1} O 3.65, SnAl 0.4 B 0.5 P 0.5 Na 0.2 O 3.7, SnAl 0.4 B 0.3 P 0.5 Rb 0.2 O 3.4, SnAl 0.4 B 0.5 P 0.5 Cs 0.1 O 3.65, SnAl 0.4 B 0.5 P 0.5 _{K 0.1 Ge 0.05 O 3.85, SnAl} 0.4 B 0.5 P 0.5 K 0.1 Mg 0.1 Ge 0.02 O 3.83, SnAl 0.4 B 0.4 P 0.4 O 3.2, SnAl 0.3 B 0.5 P 0.2 O 2.7, SnAl 0.3 B 0.5 P 0.2 O 2.7, SnAl _0.4 B _0.5 P _0.3 Ba _0.08 Mg _0.08 O _3.26 , SnAl _0.4 B _0.4 P _0.4 Ba _0.08 O _3.28 , SnAl _0.4 B _0.5 P _0.5 O _3.6 , SnAl _0.4 B _0.5 P _0.5 Mg _0.1 O _3.7 .

_{SnAl 0.5 B 0.4 P 0.5 Mg 0.1} F 0.2 O 3.65, SnB 0.5 P 0.5 Li 0.1 Mg 0.1 F 0.2 O 3.05, SnB 0.5 P 0.5 K 0.1 Mg 0.1 F 0.2 O 3.05, SnB 0.5 P 0.5 K 0.05 Mg 0.05 F 0.1 O _{3.03, SnB 0.5 P 0.5 K 0.05} Mg 0.1 F 0.2 O 3.03, SnAl 0.4 B 0.5 P 0.5 Cs 0.1 Mg 0.1 F 0.2 O 3.65, SnB 0.5 P 0.5 Cs 0.05 Mg 0.05 F 0.1 O 3.03, SnB 0.5 P 0.5 Mg 0.1 F _0.1 O _3.05 , SnB _0.5 P _0.5 Mg _0.1 F _0.2 O ₃ , SnB _0.5 P _0.5 Mg _0.1 F _0.06 O _3.07 , SnB _0.5 P _0.5 Mg _0.1 F _0.14 O _3.03 , SnPBa _0.08 O _3.58 , SnPK _0.1 O _3.55 , SnPK _0.05 Mg _{0.05 O 3.58, SnPCs 0.1 O 3.55} , SnPBa 0.08 F 0.08 O 3.54, SnPK 0.1 Mg 0.1 F 0.2 O 3.55, SnPK 0.05 Mg 0.05 F 0.1 O 3.53, SnPCs 0.1 Mg 0.1 F 0.2 O 3.55, Sn _{Cs 0.05 Mg 0.05 F 0.1 O 3.53} .

_{Sn 1.1 Al 0.4 B 0.2 P 0.6} Ba 0.08 F 0.08 O 3.54, Sn 1.1 Al 0.4 B 0.2 P 0.6 Li 0.1 K 0.1 Ba 0.1 F 0.1 O 3.65, Sn 1.1 Al 0.4 B 0.4 P 0.4 Ba 0.08 O 3.34, Sn 1.1 Al _0.4 PCs _0.05 O _4.23 , Sn _1.1 Al _0.4 PK _0.05 O _4.23 , Sn _1.2 Al _0.5 B _0.3 P _0.4 Cs _0.2 O _3.5 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Ba _0.08 O _3.68 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Ba _0.08 F _0.08 O _3.64 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Mg _0.04 Ba _0.04 O _3.68 , Sn _1.2 Al _0.4 B _0.3 P _0.5 Ba _0.08 O _3.58 , Sn _1.3 Al _0.3 B _0.3 P _0.4 Na _0.2 O _3.3 , Sn _1.3 Al _0.2 B _0.4 P _0.4 Ca _0.2 O _3.4 , Sn _1.3 Al _0.4 B _0.4 P _0.4 Ba _0.2 O _3.6 , Sn _1.4 Al _0.4 PK _0.2 O _4.6 , Sn _1.4 Al _0.2 Ba _0.1 PK _0.2 O _4.45 , Sn _1.4 Al _0.2 Ba _0.2 PK _0.2 O _4.6 , Sn _1.4 Al _{0. 4} Ba _0.2 PK _0.2 Ba _0.1 F _0.2 O _4.9 , Sn _1.4 Al _0.4 PK _0.3 O _4.65 , Sn _1.5 Al _0.2 PK _0.2 O _4.4 , Sn _1.5 Al _0.4 PK _0.1 O _4.65 , Sn _1.5 Al _0.4 PCs _0.05 O _4.63 , Sn _1.5 Al _0.4 PCs _0.05 Mg _0.1 F _0.2 O _4.63 .

SnSi _0.5 Al _0.1 B _0.2 P _0.1 Ca _0.4 O _3.1 , SnSi _0.4 Al _0.2 B _0.4 O _2.7 , SnSi _0.5 Al _0.2 B _0.1 P _0.1 Mg _0.1 O _2.8 , SnSi _0.6 Al _0.2 B _0.2 O _2.8 , SnSi _0.5 Al _0.3 B _{0.4 P 0.2 O 3.55, SnSi 0.5 Al} 0.3 B 0.4 P 0.5 O 4.30, SnSi 0.6 Al 0.1 B 0.1 P 0.3 O 3.25, SnSi 0.6 Al 0.1 B 0.1 P 0.1 Ba 0.2 O 2.95, SnSi 0.6 Al 0.1 B 0.1 P 0.1 Ca 0.2 O _2.95 , SnSi _0.6 Al _0.4 B _0.2 Mg _0.1 O _3.2 , SnSi _0.6 Al _0.1 B _0.3 P _0.1 O _3.05 , SnSi _0.6 Al _0.2 Mg _0.2 O _2.7 , SnSi _0.6 Al _0.2 Ca _0.2 O _2.7 , SnSi _0.6 Al _0.2 P _0.2 O _{3, SnSi 0.6 B 0.2 P 0.2} O 3, SnSi 0.8 Al 0.2 O 2.9, SnSi 0.8 Al 0.3 B 0.2 P 0.2 O 3.85, SnSi 0.8 B 0.2 O 2.9, SnSi 0.8 Ba 0.2 O 2.8, _{nSi 0.8 Mg 0.2 O 2.8, SnSi} 0.8 Ca 0.2 O 2.8, SnSi 0.8 P 0.2 O 3.1.

_{Sn 0.9 Mn 0.3 B 0.4 P 0.4} Ca 0.1 Rb 0.1 O 2.95, Sn 0.9 Fe 0.3 B 0.4 P 0.4 Ca 0.1 Rb 0.1 O 2.95, Sn 0.8 Pb 0.2 Ca 0.1 P 0.9 O 3.35, Sn 0.3 Ge 0.7 Ba 0.1 P 0.9 O _{3.35, Sn 0.9 Mn 0.1 Mg 0.1} P 0.9 O 3.35, Sn 0.2 Mn 0.8 Mg 0.1 P 0.9 O 3.35, Sn 0.7 Pb 0.3 Ca 0.1 P 0.9 O 3.35, Sn 0.2 Ge 0.8 Ba 0.1 P 0.9 O 3.35.

  The chemical formula of the compound obtained by calcination can be calculated by inductively coupled plasma (ICP) emission spectroscopy as a measuring method, and can be calculated from the weight difference between powder before and after calcination as a simple method.

  Lithium ions can be inserted into the negative electrode material of the present invention in the battery before and / or after the battery is assembled. The amount of insertion may be up to approximation of the deposition potential of lithium. For example, the amount is preferably 50 to 700 mol% per negative electrode material, and particularly preferably 100 to 600 mol%. It is preferable that the release amount is larger than the insertion amount. The method of inserting the light metal is preferably an electrochemical, chemical or thermal method. As the electrochemical method, a method of electrochemically inserting a light metal contained in the positive electrode active material or a method of directly electrochemically inserting a light metal or an alloy thereof from a light metal is preferable. As a chemical method, there is a method of mixing or contacting with a light metal or a method of reacting with an organic metal such as butyllithium. Electrochemical and chemical methods are preferred.

In the present invention, the compounds represented by the general formulas (2) and (3) as described above are mainly used as the negative electrode material, whereby the charge / discharge cycle characteristics are more excellent, the discharge voltage is higher, and the capacity is higher. It is possible to obtain a non-aqueous electrolyte secondary battery having high performance and high current characteristics. In the present invention, a particularly excellent effect can be obtained by using a compound containing Sn and having a Sn valence of 2 as the negative electrode material. The valence of Sn can be determined by a chemical titration operation. For example, it can be analyzed by the method described on page 165 of Physics and Chemistry of Glasses Vol. 8 No. 4 (1967).
It can also be determined from the night shift of Sn by solid state nuclear magnetic resonance (NMR) measurement. For example, in the wide measurement, the metal Sn (zero-valent Sn) has a peak in an extremely low magnetic field of about 7000 ppm relative to Sn (CH ₃ ) ₄ , whereas the SnO (= bivalent) has a peak of about 100 ppm and SnO (= bivalent). _{At 2} (= tetravalent), it appears near -600 ppm. As described above, when the same ligand is used, the night shift greatly depends on the valence of Sn as the central metal, so that the valence can be determined based on the peak position obtained by ¹¹⁹ Sn-NMR measurement.

  Various compounds can be included in the negative electrode material of the present invention. For example, transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, lanthanoid metals, Hf , Ta, W, Re, Os, Ir, Pt, Au, Hg) and Group 17 elements of the periodic table (F, Cl). Further, it may contain dopants of various compounds (for example, compounds of Sb, In, and Nb) that increase electron conductivity. The amount of the compound to be added is preferably 0 to 20 mol%.

As a method for synthesizing the composite oxide mainly containing the oxides represented by the general formulas (2) and (3) in the present invention, any of a firing method and a solution method can be adopted. For example, when the firing method is described in detail, the M ¹ compound, the M ² compound and the M ⁴ compound (M ¹ and M ² are different from each other, Si, Ge, Sn, Pb, P, B, Al, Sb, and M ⁴ are Mg, Ca, Sr, and Ba) may be mixed and fired.
Examples of the Sn compound include SnO, SnO ₂ , Sn ₂ O ₃ , Sn ₃ O ₄ , Sn ₇ O ₁₃ .H ₂ O, Sn ₈ O ₁₅ , stannous hydroxide, stannic oxyhydroxide, and tin tin. Acid, stannous oxalate, stannous phosphate, orthostannic acid, metastannic acid, parastannic acid, stannous fluoride, stannic fluoride, stannous chloride, stannic chloride, stannous pyrophosphate Tin, tin phosphide, stannous sulfide, stannic sulfide, and the like.
Examples of the Si compound include organic silicon compounds such as SiO ₂ , SiO, tetramethylsilane and tetraethylsilane, alkoxysilane compounds such as tetramethoxysilane and tetraethoxysilane, and hydrosilane compounds such as trichlorohydrosilane.
Examples of the Ge compound include GeO ₂ , GeO, and alkoxy germanium compounds such as germanium tetramethoxide and germanium tetraethoxide. Examples of the Pb compound include PbO ₂ , PbO, Pb ₂ O ₃ , Pb ₃ O ₄ , lead nitrate, lead carbonate, lead formate, lead acetate, lead tetraacetate, lead tartrate, lead diethoxide, lead di (isopropoxide) and the like. Can be mentioned.
Examples of the P compound include phosphorus pentoxide, phosphorus oxychloride, phosphorus pentachloride, phosphorus trichloride, phosphorus tribromide, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, stannous pyrophosphate, boron phosphate and the like. Can be mentioned.
Examples of the B compound include diboron trioxide, boron trichloride, boron tribromide, boron carbide, boric acid, trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, boron phosphide, boron phosphate and the like. it can.
Examples of the Al compound include aluminum oxide (α-alumina, β-alumina), aluminum silicate, aluminum tri-iso-propoxide, aluminum tellurite, aluminum chloride, aluminum boride, aluminum phosphide, aluminum phosphate, aluminum phosphate, Examples include aluminum lactate, aluminum borate, aluminum sulfide, aluminum sulfate, and aluminum boride.
Examples of the Sb compound include diantimony trioxide and triphenylantimony.

  Examples of the Mg, Ca, Sr, and Ba compounds include respective oxides, hydroxides, carbonates, phosphates, sulfates, nitrates, and aluminum compounds.

As the firing conditions, the heating rate is preferably 4 ° C. or more and 2000 ° C. or less per minute, and more preferably 6 ° C. or more and 2000 ° C. or less. It is particularly preferably at least 10 ° C and no more than 2000 ° C.
The firing temperature is preferably from 250 ° C to 1500 ° C, more preferably from 350 ° C to 1500 ° C, and particularly preferably from 500 ° C to 1500 ° C.
The firing time is preferably from 0.01 hours to 100 hours, more preferably from 0.5 hours to 70 hours, and particularly preferably from 1 hour to 20 hours.
The temperature decreasing rate is preferably 2 ° C to 107 ° C per minute, more preferably 4 ° C to 107 ° C, particularly preferably 6 ° C to 107 ° C, particularly preferably 10 ° C to 107 ° C. It is as follows.

The rate of temperature rise in the present invention is an average rate of temperature rise from “50% of firing temperature (displayed in ° C.)” to “80% of firing temperature (displayed in ° C.)”. This is the average rate of temperature decrease from "80% of firing temperature (expressed in ° C)" to "50% of firing temperature (expressed in ° C)". The temperature may be cooled in a baking furnace, or may be taken out of the baking furnace and put into, for example, water to cool. Further, a super-quenching method such as a gun method, a Hammer-Anvil method, a slap method, a gas atomizing method, a plasma spray method, a centrifugal quenching method, and a melt drag method described on page 217 of Ceramics Processing (Gihodo Publishing Co., Ltd., 1987) can also be used. Alternatively, cooling may be performed using a single-roller method or a twin-roller method described in page 172 of the New Glass Handbook (Maruzen 1991). In the case of a material that melts during firing, a fired product may be continuously taken out while supplying raw materials during firing. In the case of a material that melts during firing, it is preferable to stir the melt.
The firing gas atmosphere is preferably an atmosphere having an oxygen content of 5% by volume or less, and more preferably an inert gas atmosphere. Examples of the inert gas include nitrogen, argon, helium, krypton, xenon, and the like.

  The average particle size of the compounds represented by the general formulas (2) and (3) used in the present invention is preferably 0.1 to 60 μm, particularly preferably 1.0 to 30 μm, and further preferably 2.0 to 20 μm. In order to obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can also be performed if necessary. Classification is preferably performed to obtain a desired particle size. The classification method is not particularly limited, and a sieve, an air classifier, a drainage or the like can be used as necessary. Classification can be performed both in a dry type and a wet type.

More preferred lithium-containing transition metal oxide cathode materials used in the present invention include lithium compounds / transition metal compounds (where transition metals are Ti, V, Cr, Mn, Fe, Co, Ni, Mo, W It is preferable to mix and synthesize so that the total molar ratio of at least one selected) is 0.3 to 2.2. Particularly preferred lithium-containing transition metal oxide cathode materials used in the present invention include lithium compounds / transition metal compounds (where the transition metal is at least one selected from V, Cr, Mn, Fe, Co, and Ni). It is preferable to synthesize them by mixing them so that the total molar ratio becomes 0.3 to 2.2.
Particularly preferred lithium-containing transition metal oxide cathode materials used in the present invention are Li _x QO _y (where Q is a transition metal mainly containing at least one of Co, Mn, Ni, V and Fe), and x = 0.2 to 1.2, y = 1.4 to 3). As Q, other than transition metals, Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P, B, etc. may be mixed. The mixing amount is preferably 0 to 30 mol% based on the transition metal.

More preferred lithium-containing metal oxide cathode materials used in the present invention include Li _x CoO ₂ , Li _x NiO ₂ , Li _x MnO ₂ , Li _x Co _a Ni _1-a O ₂ , and Li _x Co _b V _{1- b O z, Li x Co b} Fe 1-b O 2, Li x Mn 2 O 4, Li x Mn c Co 2-c O 4, Li x Mn c Ni 2-c O 4, Li x Mn c V 2 _{-c O 4, Li x Mn c} Fe 2-c O 4 ( wherein x = 0.02~1.2, a = 0.1~0.9, b = 0.8~0.98, c = 1.6 to 1.96, z = 2.01 to 2.3).
The most preferred lithium-containing transition metal oxide cathode materials used in the present invention include Li _x CoO ₂ , Li _x NiO ₂ , Li _x MnO ₂ , Li _x Co _a Ni _1-a O ₂ , and Li _x Mn ₂ O ₄ , Li _x Co _b V _1-b O _z (where x = 0.02 to 1.2, a = 0.1 to 0.9, b = 0.9 to 0.98, z = 2.01 to 2.3). Here, the above-mentioned x value is a value before the start of charge / discharge, and increases / decreases due to charge / discharge.

As the conductive carbon compound that can be used in the present invention, any electronic conductive material that does not cause a chemical change in the configured battery may be used. Specific examples include flake graphite, flaky graphite, natural graphite such as earthy graphite, petroleum coke, coal coke, celluloses, sugars, high-temperature fired bodies such as mesophase pitch, and graphite such as artificial graphite such as vapor-grown graphite. And carbon blacks such as acetylene black, furnace black, Ketjen black, channel black, lamp black and thermal black, asphalt pitch, coal tar, activated carbon, meso fuse pitch, polyacene and the like.
Among these, graphite and carbon black are preferred. Non-carbon conductive agents include conductive fibers such as metal fibers, metal powders such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide and potassium titanate; and conductive metals such as titanium oxide. An oxide or the like may be included alone or a mixture thereof as necessary.

  The amount of the conductive agent added to the mixture layer is preferably 6 to 50% by weight, particularly preferably 6 to 30% by weight, based on the negative electrode material or the positive electrode material. In the case of carbon or graphite, the content is particularly preferably 6 to 20% by weight.

As the binder for holding the electrode mixture used in the present invention, a polysaccharide, a thermoplastic resin and a polymer having rubber elasticity or a mixture thereof can be used. Preferred binders include starch, carboxymethylcellulose, cellulose, diacetylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium alginate, polyacrylic acid, sodium polyacrylate, polyvinylphenol, polyvinylmethylether, polyvinyl alcohol, polyvinylpyrrolidone , Polyacrylamide, polyhydroxy (meth) acrylate, water-soluble polymers such as styrene-maleic acid copolymer, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene flow Ride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene (Meth) acrylic ester copolymers containing (meth) acrylic esters such as styrene-diene terpolymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate, and (meth) acryl Acid ester-acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene butadiene copolymer, acrylonitrile butadiene copolymer, polybutadiene, neoprene rubber, fluorine rubber, polyethylene oxide, polyester polyurethane Emulsion (latex) or suspension of resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, phenol resin, epoxy resin, etc. It can be mentioned. In particular, polyacrylate latex, carboxymethyl cellulose, polytetrafluoroethylene, and polyvinylidene fluoride are preferred. The particle size of these particles is preferably 0.05 μm to 5 μm.
These binders can be used alone or as a mixture. If the amount of the binder added is small, the holding power and cohesion of the electrode mixture is weak and the cyclability is poor, and if too large, the electrode volume increases and the volume per electrode unit volume or unit weight decreases, and further, The conductivity decreases and the capacity decreases. The amount of the binder added is not particularly limited, but is preferably 1 to 30% by weight, and particularly preferably 2 to 10% by weight.

The preparation of the negative electrode mixture or the positive electrode mixture paste of the present invention is preferably performed in an aqueous system. The mixture paste is prepared by first mixing the active material and the conductive agent, adding a binder (a suspension of resin powder or an emulsion (latex)) and water, and kneading and mixing. The dispersion can be carried out by a homogenizer, a dissolver, a planetary mixer, a paint shaker, a stirring mixer such as a sand mill, or a disperser. The prepared mixture paste of the positive electrode active material and the negative electrode active material is mainly used after being applied (coated) on a current collector, dried, and compressed.
Coating can be performed by various methods, for example, a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion method, a curtain method, a gravure method, a bar method, a dip method, and a squeeze method. it can. The blade method, the knife method and the extrusion method are preferred.
The application is preferably performed at a speed of 0.1 to 100 m / min. At this time, by selecting the above-mentioned coating method in accordance with the liquid physical properties and drying properties of the mixture paste, a good surface state of the coated layer can be obtained. The thickness, length and width of the coating layer are determined according to the size of the battery, and the thickness of the coating layer is particularly preferably 1 to 2000 μm in a compressed state after drying.

  As a drying or dehydrating method for removing moisture from the pellets and sheets, a generally employed method can be used, and hot air, vacuum, infrared rays, far infrared rays, electron beams, and low-humidity air can be used alone or in combination. Can be done. The temperature is preferably in the range of 80 to 350C, particularly preferably in the range of 100 to 250C. The water content is preferably 2000 ppm or less in the whole battery, and is preferably 500 ppm or less in each of the positive electrode mixture, the negative electrode mixture and the electrolytic solution from the viewpoint of charge / discharge cycleability.

The compression of the sheet-like electrode mixture can be performed by a commonly used pressing method, but a die pressing method and a calendar pressing method are particularly preferable. The pressing pressure is not particularly limited, but is preferably from 10 kg / cm ^{2 to 3} t / cm ² . The press speed of the calender press method is preferably 0.1 to 50 m / min. The pressing temperature is preferably from room temperature to 200 ° C.

  The support or current collector for the positive electrode and the negative electrode that can be used in the present invention is, as a material, the positive electrode is aluminum, stainless steel, nickel, titanium, or an alloy thereof, and the negative electrode is copper, stainless steel, nickel, titanium. Or alloys thereof, in the form of foil, expanded metal, punched metal, or wire mesh. In particular, an aluminum foil is preferable for the positive electrode, and a copper foil is preferable for the negative electrode.

  The separator that can be used in the present invention has a high ion permeability, a predetermined mechanical strength, and may be any insulating thin film. As the material, olefin-based polymers, fluorine-based polymers, cellulose-based polymers, polyimides, nylons, Glass fiber and alumina fiber are used, and as a form, a nonwoven fabric, a woven fabric, or a microporous film is used. In particular, the material is preferably polypropylene, polyethylene, a mixture of polypropylene and polyethylene, a mixture of polypropylene and Teflon (registered trademark of DUPONT, USA), and a mixture of polyethylene and Teflon, and the form is a microporous film. preferable. In particular, a microporous film having a pore size of 0.01 to 1 μm and a thickness of 5 to 50 μm is preferable.

  The shape of the battery can be applied to any of buttons, coins, sheets, cylinders, corners, and the like. A battery is formed by inserting an electrode wound with a pellet, a sheet, or a separator into a battery can, electrically connecting the can and the electrode, injecting an electrolyte, and sealing the battery. At this time, a safety valve can be used as a sealing plate. Further, it is preferable to use a PTC element in order to guarantee the safety of the battery.

  Nickel-plated iron steel sheet, stainless steel sheet (SUS304, SUS304L, SUS304N, SUS316, SUS316L, SUS430, SUS444, etc.), and nickel-plated stainless steel sheet (same as above) can be used for the bottomed battery outer can that can be used in the present invention. , Aluminum or its alloys, nickel, titanium, and copper, and have a shape of a perfect circular cylinder, an elliptical cylinder, a square cylinder, or a rectangular cylinder. In particular, when the outer can also serves as the negative electrode terminal, a stainless steel sheet or a nickel-plated iron steel sheet is preferable, and when the outer can also serves as the positive electrode terminal, a stainless steel sheet, aluminum, or an alloy thereof is preferable.

  The sheet-shaped mixture electrode is wound or folded and inserted into a can, the can and the sheet are electrically connected, an electrolyte is injected, and a battery can is formed using a sealing plate. At this time, a safety valve can be used as a sealing plate. In addition to the safety valve, various conventionally known safety elements may be provided. For example, a fuse, a bimetal, a PTC element, or the like is used as the overcurrent prevention element. In addition to the safety valve, as a countermeasure against the rise in the internal pressure of the battery can, a method of making a cut in the battery can, a gasket cracking method or a sealing plate cracking method can be used. Further, the charger may be provided with a circuit incorporating measures for overcharging and overdischarging.

  The entire amount of the electrolyte may be injected at one time, but it is preferable to perform the injection in two or more steps. When the injection is performed in two or more steps, each liquid may have the same composition but different compositions (for example, after injecting a non-aqueous solvent or a solution in which a lithium salt is dissolved in a non-aqueous solvent, a non-aqueous solution having a higher viscosity than the solvent). A solution in which a lithium salt is dissolved in a solvent or a non-aqueous solvent is injected). Further, in order to shorten the injection time of the electrolyte solution, the battery can is depressurized (preferably 500 to 1 torr, more preferably 400 to 10 torr), or a centrifugal force or ultrasonic wave is applied to the battery can. Good.

  For the can or the lead plate, a metal or an alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper, and aluminum or alloys thereof are used. Known methods (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used for welding the cap, can, sheet, and lead plate. A conventionally known compound or mixture such as asphalt can be used as the sealing agent for closing.

  The gasket that can be used in the present invention is, as a material, an olefin-based polymer, a fluorine-based polymer, a cellulose-based polymer, a polyimide, or a polyamide.From the viewpoint of organic solvent resistance and low moisture permeability, an olefin-based polymer is preferable. Polymers are preferred. Further, it is preferably a block copolymer of propylene and ethylene.

The battery of the present invention is covered with an exterior material as necessary. Examples of the exterior material include a heat-shrinkable tube, an adhesive tape, a metal film, paper, cloth, paint, a plastic case, and the like. Further, at least a part of the exterior may be provided with a portion that changes color by heat so that the heat history during use can be recognized. The battery of the present invention is assembled in a battery pack in a plural number in series and / or parallel as required.
In addition to safety elements such as positive temperature coefficient resistors, temperature fuses, fuses and / or current interrupting elements, battery packs have safety circuits (monitoring the voltage, temperature, current, etc. of each battery and / or assembled battery as a whole, Then, a circuit having a function of interrupting the current may be provided. In addition to the positive and negative terminals of each battery, the battery pack should have external terminals such as the positive and negative terminals of each battery, the temperature detection terminals of the entire battery and each battery, and the current detection terminals of the entire battery. You can also. The battery pack may include a voltage conversion circuit (such as a DC-DC converter). The connection of each battery may be fixed by welding a lead plate, or may be fixed by a socket or the like so that it can be easily detached. Further, the battery pack may be provided with a display function such as a remaining battery capacity, whether or not charging is performed, and the number of times of use.

  The battery of the present invention is used for various devices. In particular, video movies, portable VCRs with built-in monitors, movie cameras with built-in monitors, compact cameras, single-lens reflex cameras, film with lenses, notebook computers, notebook word processors, electronic notebooks, mobile phones, cordless phones, hairdressers, electric tools, It is preferably used for electric mixers, automobiles and the like.

  Hereinafter, the present invention will be described in more detail by way of specific examples. However, the present invention is not limited to the examples unless it exceeds the gist of the invention.

Example-1
[Example of making positive electrode mixture paste]
Positive electrode active material: LiCoO ₂ (a mixture of lithium carbonate and tricobalt tetroxide at a molar ratio of 3: 2 was placed in an alumina crucible, heated to 750 ° C. at 2 ° C./min in air, and calcined for 4 hours. Thereafter, the temperature is further raised to 900 ° C. at a rate of 2 ° C. per minute, and baked at that temperature for 8 hours to be crushed, and the conductivity of the dispersion when 50 g of the washed product is dispersed in 100 ml of water with a central particle size of 5 μm. Is 0.6 mS / m, pH is 10.1, specific surface area by nitrogen adsorption method is 0.42 m ² / g), 200 g of acetylene black is mixed with a homogenizer, and then 2-ethylhexyl is used as a binder. 8 g of an aqueous dispersion of a copolymer of acrylate, acrylic acid and acrylonitrile (solid content concentration: 50% by weight) and 60 g of a 2% by weight aqueous solution of carboxymethylcellulose were added, kneaded and mixed. The addition of 50 g, were agitated and mixed by a homogenizer to prepare a positive electrode mixture paste.
(Example of preparing negative electrode mixture paste)
Negative electrode active material: SnGe _0.1 B _0.5 P _0.58 Mg _0.1 K _0.1 O _3.35 (6.7 g of tin monoxide, 10.3 g of tin pyrophosphate, 1.7 g of diboron trioxide, 0.7 g of potassium carbonate, 0.4 g of magnesium oxide And 1.0 g of germanium dioxide were dry-mixed, placed in an alumina crucible, heated to 1000 ° C. at 15 ° C./min in an argon atmosphere, baked at 1100 ° C. for 12 hours, and then cooled to room temperature at 10 ° C./min. What was taken out of the firing furnace was collected and pulverized by a jet mill, and had an average particle size of 4.5 μm and a broad peak having a peak at around 28 ° in 2θ value by X-ray diffraction using CuKα ray. 200 g and a conductive agent (artificial graphite) 30 g were mixed with a homogenizer, and concentrated as a binder. A mixture of 50 g of a 2% by weight aqueous carboxymethylcellulose solution and 10 g of polyvinylidene fluoride and 30 g of water were further added and kneaded and mixed to prepare a negative electrode mixture paste.
[Preparation of positive and negative electrode sheets]
The above-prepared positive electrode mixture paste was applied on both surfaces of a 30 μm-thick aluminum foil current collector using a blade coater so that the coating amount was 400 g / m ² and the thickness of the compressed sheet was 280 μm, and then dried. Then, it was compression-molded by a roller press machine and cut into a predetermined size to prepare a belt-shaped positive electrode sheet. Further, in a dry box (dew point; dry air having a temperature of -50 ° C. or lower), dehydration and drying were sufficiently performed with a far-infrared heater to prepare a positive electrode sheet. Similarly, the negative electrode mixture paste is applied to a 20 μm copper foil current collector, and a negative electrode sheet having a coating amount of 70 g / m ² and a compressed sheet thickness of 90 μm is prepared in the same manner as in the preparation of the positive electrode sheet. did.
(Example of electrolyte solution adjustment)
In an argon atmosphere, 65.3 g of diethyl carbonate was placed in a 200 cc narrow-neck polypropylene container, and 22.2 g of ethylene carbonate was dissolved therein little by little while taking care that the liquid temperature did not exceed 30 ° C. Next, 0.4 g of LiBF ₄ and 12.1 g of LiPF ₆ were dissolved little by little in the above polypropylene container in order, respectively, while being careful not to exceed a liquid temperature of 30 ° C. The obtained electrolyte was a colorless and transparent liquid having a specific gravity of 1.135. The water content is 18 ppm (measured by a Karl Fischer moisture meter, Model MKC-210, manufactured by Kyoto Electronics Co., Ltd.), and the free acid content is 24 ppm (measured by neutralization titration with a 0.1 N aqueous NaOH solution using bromthymol blue as an indicator). )Met. Further, the compounds shown in Table 1 were dissolved in this electrolyte solution so as to have a predetermined concentration to prepare electrolyte solutions.
[Example of creating a cylinder battery]
A positive electrode sheet, a separator made of a microporous polypropylene film, a negative electrode sheet, and a separator were laminated in this order, and this was spirally wound. This wound body was housed in a nickel-plated iron bottomed cylindrical battery can also serving as a negative electrode terminal. Further, an electrolytic solution to which an additive described in Table 1 was added as an electrolytic solution was injected into the battery can. A battery lid having a positive electrode terminal was caulked via a gasket to produce a cylindrical battery.

  Thus, sample batteries 108 to 110 (Example) and sample batteries 101 to 107 and 111 to 115, 117 and 118 (Reference Examples) were prepared.

Comparative Example 1
In the same manner as in Example 1, a cylindrical battery was prepared using an electrolyte solution to which no additive was added.
Reference Example (Sample Battery 116), Reference Example (Sample Battery 119), and Comparative Example 2
Instead of the oxide-based negative electrode active material, a negative electrode sheet was prepared in the same manner as the negative electrode sheet using a carbon-based active material (graphite powder), and a cylindrical battery was prepared using each of the electrolytes in Table 1. did.
The battery characteristics of the sample battery 116 and the sample battery 119 were larger in capacity and more excellent in cyclability as compared with Comparative Example 2 without the additive.
Reference Comparative Examples 1 and 2
In the same manner as in Example 1, a cylindrical battery was prepared using an electrolytic solution that was added while changing the amount of the additive significantly.

The battery prepared by the above method was charged and discharged under the conditions of a current density of 5 mA / cm ² , a charge end voltage of 4.1 V, and a discharge end voltage of 2.8 V, and the discharge capacity and cycle life were determined. Tables 1 and 2 show the ratio of the capacity (Wh) of each battery and the cyclability (the ratio of the 300th capacity to the first charge / discharge).

The additives in Tables 1 and 2 are as follows.

Table 1 Experimental results 1 (Examples and Comparative examples)
Sample Additive Additive concentration Initial volume Cycle properties
(Mol / liter) (%)
108 A-30 0.01 0.97 81
109 A-31 0.01 0.99 82
110 A-32 0.01 0.98 81
Comparative Example 1 None 0 1.0 70
Comparative Example 2 None 0 0.80 76

Table 2 Experimental results No. 2 (Reference example and Reference comparative example)
Sample Additive Additive concentration Initial volume Cycle properties
(Mol / liter) (%)
101 A-8 0.01 0.99 83
102 A-15 0.001 1.00 82
103 A-15 0.01 0.98 83
104 A-15 0.05 0.97 82
105 A-29 0.01 0.98 83
106 A-29 0.001 1.0 83
Reference Comparative Example 1 A-29 0.0001 1.071
Reference Comparative Example 2 A-29 1.0 0.78 69
107 A-29 0.01 0.98 82
111 A-45 0.01 0.97 83
112 B-10 0.01 0.98 82
113 B-18 0.01 0.98 84
114 B-20 0.01 0.97 83
115 C-2 0.01 0.98 82
117 C-6 0.01 0.98 84
118 C-19 0.01 0.97 83
Comparative Example 1 None 0 1.0 70
116 A-29 0.01 0.82 82
119 A-15 0.01 0.82 82
Comparative Example 2 None 0 0.80 76

Example-2
Example 1 was repeated and the same result was obtained except that the addition of the additive was changed from the electrolytic solution to the positive electrode active material.

Example-3
Example ¹ was repeated except that a lithium metal foil of 120 mg per 1 g of the negative electrode material was stuck on the negative electrode mixture to make electrical contact, and the coating amount of the positive electrode mixture was 240 g / m ² on one side. Example 1 and Example 2 were repeated to obtain similar results.

  The battery using the oxide-based negative electrode active material of the present invention has a larger capacity than the battery using the carbon-based negative electrode active material, and the battery containing the compound of the present invention has improved cycleability. The ratio is higher than that using the carbon-based negative electrode active material.

FIG. 1 shows a cross-sectional view of a cylinder type battery used in Examples.

Explanation of reference numerals

1 Gasket made of polypropylene 2 Negative electrode can (battery can) also serving as negative electrode terminal
DESCRIPTION OF SYMBOLS 3 Separator 4 Negative electrode sheet 5 Positive electrode sheet 6 Nonaqueous electrolyte 7 Explosion-proof valve body 8 Positive electrode cap which also serves as a positive electrode terminal 9 PTC element 10 Inner lid body 11 Ring

Claims (5)

A non-aqueous electrolytic solution containing a non-aqueous solvent and a lithium salt, wherein the electrolytic solution has a general formula (1)

(In the formula, R ¹ and R ² may be the same or different and each represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkenyl group, or an alkynyl group.)
A non-aqueous electrolyte for a lithium secondary battery comprising at least one compound represented by the formula:   The non-aqueous electrolyte for a lithium secondary battery according to claim 1, wherein the compound represented by the general formula (1) is dimethylvinylene carbonate, diethylvinylene carbonate, or methylethylvinylene carbonate.   3. The non-rechargeable lithium battery according to claim 1, wherein the content of the compound represented by the general formula (1) is 0.001 mol / l to 0.1 mol / l with respect to the electrolyte solvent. 4. Water electrolyte.   The lithium secondary battery according to any one of claims 1 to 3, wherein the content of the compound represented by the general formula (1) is 0.001% by weight to 10% by weight based on the supporting salt contained in the electrolytic solution. Non-aqueous electrolyte for secondary batteries. In a non-aqueous electrolyte secondary battery including a positive electrode and a negative electrode containing a material capable of reversibly storing and releasing lithium, a non-aqueous electrolyte containing a non-aqueous solvent and a lithium salt, and a separator, a general formula (1)

(In the formula, R ¹ and R ² may be the same or different and each represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkenyl group, or an alkynyl group.)
A non-aqueous electrolyte secondary battery comprising at least one compound represented by the formula:

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