JP2016192401A - Electrolyte additive for nonaqueous power storage device, electrolyte for nonaqueous power storage device, and lithium ion secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery operating at high voltage, while suppressing degradation in cycle life and increase in the resistance during the cycle time, and to provide an electrolyte additive for nonaqueous power storage device capable of giving such a lithium ion secondary battery, and an electrolyte for nonaqueous power storage device.SOLUTION: An electrolyte additive for nonaqueous power storage device contains a compound (A) containing 2-4 P atoms in one molecule, and having a structural unit represented by a following formula (1). (In the above formula (1), R represents hydrocarbon groups of 1C-22C, each may be substituted independently).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrolyte solution additive for a non-aqueous electricity storage device, an electrolyte solution for a non-aqueous electricity storage device, and a lithium ion secondary battery.

  With the recent development of electronic technology and increasing interest in environmental technology, various electrochemical devices have been developed. In particular, since there are many requests for energy saving, expectations for electrochemical devices that can contribute to energy saving are increasing. Examples of such electrochemical devices include power storage devices such as non-aqueous electrolyte secondary batteries. Lithium ion secondary batteries, which are also representative examples of nonaqueous electrolyte secondary batteries, have been used mainly as rechargeable batteries for portable devices, but in recent years, they are also expected to be used as batteries for hybrid and electric vehicles. .

  In a conventional lithium ion secondary battery that operates at a voltage of about 4 V, a nonaqueous electrolytic solution in which a lithium salt is dissolved in a nonaqueous solvent mainly composed of a carbonate-based solvent is widely used (for example, Patent Document 1). reference). The feature of the electrolytic solution containing the carbonate-based solvent is that it has a good balance between oxidation resistance and reduction resistance at a voltage of about 4 V, and is excellent in lithium ion conductivity.

  Lithium ion secondary batteries are required to have higher energy density, and in order to achieve the higher energy density, higher voltage of the battery is being studied. In order to achieve high voltage of the battery, it is necessary to use a positive electrode that operates at a high potential.

In response to this, various positive electrode active materials that operate at 4.3 V (vsLi / Li ⁺ ) or higher have been proposed (see, for example, Patent Document 2).

However, in a lithium ion secondary battery including a positive electrode containing a positive electrode active material that operates at a high potential of 4.3 V (vs Li / Li ⁺ ) or higher, a conventional non-aqueous electrolyte mainly composed of a carbonate-based solvent is used. When used, a phenomenon occurs in which the carbonate-based solvent undergoes oxidative decomposition on the positive electrode surface. Such a phenomenon causes a problem that the cycle life of the battery is reduced, the resistance of the battery is increased, and further, gas is generated inside the battery.

  As a method for solving this problem, Patent Document 3 describes that by adding a silyl group-containing compound to a non-aqueous electrolyte, even if the lithium ion secondary battery is operated at a high voltage, the cycle life of the battery is deteriorated. It has been suggested that it can be reduced.

JP-A-7-006786 JP 2000-515672 A US Patent Application Publication No. 2012/0315536

However, even if the silyl group-containing compound described in Patent Document 3 is added to the non-aqueous electrolyte, an increase in battery resistance is not sufficiently suppressed. In power storage devices that require high output, such as for use in electric vehicles, it is required to achieve a high cycle life and further suppress the increase in resistance. The cycle life of the above-mentioned high-voltage lithium ion secondary battery is required. There is a demand for a lithium ion secondary battery that is capable of improving and suppressing an increase in resistance over time, and an electrolyte additive and electrolyte that can provide such a lithium ion secondary battery.

  The present invention has been made in view of such circumstances, and is a lithium ion secondary battery that operates at a high voltage and can suppress a decrease in cycle life and an increase in resistance at the time of the cycle. An object of the present invention is to provide an electrolyte solution additive for a non-aqueous electricity storage device and an electrolyte solution for a non-aqueous electricity storage device that can provide a simple lithium ion secondary battery.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above problem can be solved if a lithium ion battery is provided with an electrolytic solution containing a compound having a specific structure as an electrolytic solution additive. The invention has been completed.

（上記式（１）中、Ｒは、各々独立に、置換されていてもよい炭素数１〜２２の炭化水素基を示す。）
［２］前記化合物（Ａ）は、下記式（２）、（３）又は（４）で表される化合物である、前記［１］に記載の非水蓄電デバイス用電解液添加剤、

（上記式（２）、（３）及び（４）中、Ｒは、上記と同義とする。）
［３］前記化合物（Ａ）は、前記式（２）又は（３）で表される化合物である、前記［１］又は［２］に記載の非水蓄電デバイス用電解液添加剤、
［４］前記Ｒが下記式（５）で表される前記［１］〜［３］のいずれかに記載の非水蓄電デバイス用電解液添加剤、
ＳｉＲａ_３（５）
（上記式（５）中、Ｒａは、各々独立に、置換されていてもよい炭素数１〜２０の炭化水素基を示す。）
［５］前記電解液添加剤に含まれるリン化合物のモル数のうち、前記式（２）で表される化合物又は式（３）で表される化合物の含有率が５０モル％以上である、前記［１］〜［４］のいずれかに記載の非水蓄電デバイス用電解液添加剤、
［６］前記［１］〜［５］のいずれかに記載の非水蓄電デバイス用電解液添加剤と、非水溶媒と、リチウム塩（Ｂ）と、を含有することを特徴とする、非水蓄電デバイス用電解液、
［７］前記電解液添加剤の前記化合物（Ａ）の含有量が、前記電解液１００質量％に対して、０．１質量％以上１０質量％以下である、前記［６］に記載の非水蓄電デバイス用電解液、
［８］前記非水溶媒が、環状カーボネート及び鎖状カーボネートを含有する、前記［６］又は［７］に記載の非水蓄電デバイス用電解液、
［９］前記環状カーボネートが、エチレンカーボネート及びプロピレンカーボネートからなる群より選ばれる１種以上を含み、
前記鎖状カーボネートが、ジメチルカーボネート、ジエチルカーボネート、及びエチルメチルカーボネートからなる群より選ばれる１種以上を含む、前記［８］に記載の非水蓄電デバイス用電解液、
［１０］正極活物質を含有する正極と、
負極活物質を含有する負極と、
前記［６］〜［９］のいずれかに記載の電解液と、
を備えることを特徴とする、リチウムイオン二次電池、
［１１］前記正極活物質が、４．３Ｖ（ｖｓＬｉ／Ｌｉ^＋）以上の電位で１０ｍＡｈ／ｇ以上の放電容量を有する、請求項１０に記載のリチウムイオン二次電池、
［１２］前記正極活物質が、式（６）で表される酸化物、式（７）で表される酸化物、式（８）で表される複合酸化物、式（９）で表される化合物、及び式（１０）で表される化合物からなる群より選ばれる１種以上を含む、前記［１０］又は［１１］に記載のリチウムイオン二次電池、
ＬｉＭｎ_２−ｘＭａ_ｘＯ_４ （６）
（上記式（６）中、Ｍａは遷移金属からなる群より選ばれる１種以上を示し、ｘは０．２≦ｘ≦０．７である。）
ＬｉＭｅＯ_２ （７）
（上記式（７）中、Ｍｅは遷移金属からなる群より選ばれる１種以上を示す。）
ｚＬｉ_２ＭｃＯ_３−（１−ｚ）ＬｉＭｄＯ_２ （８）
（上記式（８）中、Ｍｃ及びＭｄは、各々独立に、遷移金属からなる群より選ばれる１種以上を示し、ｚは０．１≦ｚ≦０．９である。）
ＬｉＭｂ_１−ｙＦｅ_ｙＰＯ_４ （９）
（上記式（９）中、Ｍｂは、Ｍｎ及びＣｏからなる群より選ばれる１種以上を示し、ｙは０≦ｙ≦０．９である。）
Ｌｉ_２ＭｆＰＯ_４Ｆ （１０）
（上記式（１０）中、Ｍｆは遷移金属からなる群より選ばれる１種以上を示す。）
［１３］満充電時におけるリチウム基準の正極電位が、４．３Ｖ（ｖｓＬｉ／Ｌｉ^＋）以上である、前記［１０］〜［１２］のいずれか１項に記載のリチウムイオン二次電池、
である。 That is, the present invention is as follows.
[1] A non-aqueous electricity storage device comprising a compound (A) containing 2 or more and 4 or less P atoms in one molecule and containing a structural unit represented by the following formula (1) Electrolytic solution additive,

(In the above formula (1), each R independently represents an optionally substituted hydrocarbon group having 1 to 22 carbon atoms.)
[2] The compound (A) is a compound represented by the following formula (2), (3), or (4), the electrolyte solution additive for nonaqueous electricity storage devices according to the above [1],

(In the above formulas (2), (3) and (4), R is as defined above.)
[3] The electrolyte additive for a non-aqueous storage device according to [1] or [2], wherein the compound (A) is a compound represented by the formula (2) or (3),
[4] The electrolyte solution additive for a non-aqueous storage device according to any one of [1] to [3], wherein R is represented by the following formula (5):
SiRa ₃ (5)
(In the formula (5), each Ra independently represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms.)
[5] Of the number of moles of the phosphorus compound contained in the electrolytic solution additive, the content of the compound represented by the formula (2) or the compound represented by the formula (3) is 50 mol% or more. The electrolyte solution additive for non-aqueous electricity storage devices according to any one of [1] to [4],
[6] The non-aqueous storage device electrolytic solution additive according to any one of [1] to [5], a nonaqueous solvent, and a lithium salt (B). Electrolyte for water storage device,
[7] The content of the compound (A) in the electrolyte solution additive is 0.1% by mass or more and 10% by mass or less with respect to 100% by mass of the electrolyte solution. Electrolyte for water storage device,
[8] The electrolyte solution for a non-aqueous storage device according to [6] or [7], wherein the non-aqueous solvent contains a cyclic carbonate and a chain carbonate,
[9] The cyclic carbonate includes one or more selected from the group consisting of ethylene carbonate and propylene carbonate,
The electrolyte solution for a non-aqueous storage device according to [8], wherein the chain carbonate includes one or more selected from the group consisting of dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate,
[10] a positive electrode containing a positive electrode active material;
A negative electrode containing a negative electrode active material;
The electrolytic solution according to any one of [6] to [9];
A lithium ion secondary battery, comprising:
[11] The lithium ion secondary battery according to claim 10, wherein the positive electrode active material has a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more.
[12] The positive electrode active material is represented by the oxide represented by the formula (6), the oxide represented by the formula (7), the composite oxide represented by the formula (8), and the formula (9). And the lithium ion secondary battery according to [10] or [11], including at least one selected from the group consisting of a compound represented by formula (10):
_{LiMn 2-x Ma x O 4} (6)
(In the above formula (6), Ma represents one or more selected from the group consisting of transition metals, and x is 0.2 ≦ x ≦ 0.7.)
LiMeO ₂ (7)
(In the above formula (7), Me represents one or more selected from the group consisting of transition metals.)
_{zLi 2 McO 3 - (1-} z) LiMdO 2 (8)
(In the above formula (8), Mc and Md each independently represent one or more selected from the group consisting of transition metals, and z is 0.1 ≦ z ≦ 0.9.)
LiMb _1-y Fe _y PO ₄ (9)
(In the above formula (9), Mb represents one or more selected from the group consisting of Mn and Co, and y is 0 ≦ y ≦ 0.9.)
Li ₂ MfPO ₄ F (10)
(In the above formula (10), Mf represents one or more selected from the group consisting of transition metals.)
[13] The lithium ion secondary battery according to any one of [10] to [12], wherein a lithium-based positive electrode potential at full charge is 4.3 V (vsLi / Li ⁺ ) or more.
It is.

  According to the present invention, a lithium ion secondary battery that operates at a high voltage and can suppress a decrease in cycle life and an increase in resistance during the cycle, and such a lithium ion secondary battery are provided. The electrolyte solution additive for non-aqueous storage devices and the electrolyte solution for non-aqueous storage battery devices can be provided.

It is sectional drawing which shows roughly an example of the lithium ion secondary battery in this embodiment.

  Hereinafter, a form for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. The following embodiment is an exemplification for explaining the embodiment, and is not intended to limit the embodiment to the following contents. The present embodiment can be appropriately modified and implemented within the scope of the gist. It should be noted that the positional relationship such as up, down, left and right between the elements of the present embodiment is based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimension ratio of each element of this embodiment is not limited to the ratio shown in drawing.

（上記式（１）中、Ｒは、各々独立に、置換されていてもよい炭素数１〜２２の炭化水素基を示す。） (Compound (A))
The electrolyte solution additive for non-aqueous electricity storage devices of this embodiment contains a compound (A).
The compound (A) contains 2 or more and 4 or less P atoms in one molecule and contains a structural unit represented by the following formula (1).

(In the above formula (1), each R independently represents an optionally substituted hydrocarbon group having 1 to 22 carbon atoms.)

  The compound (A) is characterized by containing 2 or more and 4 or less P atoms in one molecule. By having two or more P atoms in one molecule, it is possible to effectively suppress an increase in resistance during a cycle test when the compound (A) is used as an electrolyte solution additive for non-aqueous electricity storage devices. It becomes. Further, from the viewpoint of synthesis of the additive, the number of P atoms in one molecule is preferably 2 or more and 3 or less, more preferably 3.

  The compound (A) has a structural unit represented by the formula (1). When the compound (A) has such a structural unit, a good protective film is formed on the positive electrode or the negative electrode, or both in the battery, and the capacity decrease during the cycle test is suppressed, and the resistance increase during the cycle test is increased. The details are not clear.

  The compound (A) is characterized by containing the structural unit represented by the formula (1), but the bonding mode between the structural units in one molecule is not particularly limited. For example, a P atom may be bonded by a P—O—P bond bonded through an oxygen atom, such as P—O—R—O—P via an arbitrary hydrocarbon group between structural units. The structure may be used. From the viewpoint of forming a good film in the battery and suppressing an increase in resistance, it is preferable to have a P—O—P bond in which P atoms are bonded through oxygen atoms.

（上記式（２）〜式（４）中、Ｒは、各々独立に、置換されていてもよい炭素数１〜２２の炭化水素基を示す。） In addition, the bonding mode between the structural units in one molecule of the compound (A) may be a bonding mode in which all the structural units are bonded in a chain or a bonding mode in which the structural units are bonded in a ring, or a bond that is branched in the middle. It may be a style. From the viewpoint of the stability of the compound in the electrolytic solution, preferably, the structural unit of the formula (1) is a structure in which all of the structural units are bonded in a chain, specifically, the following formulas (2), (3), Alternatively, a structure represented by the formula (4) is preferable, a structure represented by the formula (2) or (3) is particularly preferable, and a structure represented by the formula (3) is most preferable.

(In the formulas (2) to (4), each R independently represents an optionally substituted hydrocarbon group having 1 to 22 carbon atoms.)

In formulas (1) to (4), each R independently represents an optionally substituted hydrocarbon group having 1 to 22 carbon atoms. The “optionally substituted hydrocarbon group” for R is not particularly limited. For example, an aliphatic hydrocarbon group, an aromatic hydrocarbon group such as a phenyl group, and all the hydrogen atoms in the hydrocarbon group A fluorine-substituted hydrocarbon group such as a trifluoromethyl group substituted with a fluorine atom can be mentioned. In addition, the said hydrocarbon group may have a functional group and a heterogeneous element in the arbitrary positions in the said group (namely, as a side chain or in a main chain or in a side chain) as needed. Such functional groups and heterogeneous elements are not particularly limited. For example, halogen atoms such as fluorine atom, chlorine atom and bromine atom, boron atom, nitrogen atom, sodium atom, magnesium atom, aluminum atom, silicon atom, sulfur An atom, a potassium atom, a calcium atom, a titanium atom, etc. are mentioned. Moreover, as a functional group, a nitrile group (—CN), an ether group (—O—), a carbonate group (—OCO ₂ —), an ester group (—CO ₂ —), a carbonyl group (—CO—), a sulfide group ( -S-), sulfoxide group (-SO-), sulfone group _(-SO 2 -), urethane group (-NHCO ₂ -) and the like. Here, in the case where the hydrocarbon contains a divalent one of these different elements and functional groups, the different elements and functional groups are P atoms having a structure represented by the formulas (1) to (4). It may be directly bonded to the oxygen atom adjacent to R. A preferred example of the hydrocarbon group represented by R having a different element or functional group is a trialkylsilyl group.

  In formulas (1) to (4), R has 1 to 22 carbon atoms of each hydrocarbon group, more preferably 1 to 10, and particularly preferably 1 to 6. When the carbon number of R is within the above range, the miscibility with the nonaqueous solvent tends to be superior.

In formulas (1) to (4), preferred examples of R are not particularly limited. For example, methyl group, ethyl group, vinyl group, allyl group, 1-methylvinyl group, n-propyl group, iso-propyl Group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, fluoromethyl group and other aliphatic hydrocarbon groups; and benzyl group, phenyl group, nitrile-substituted phenyl group, fluorinated phenyl group And among the groups represented by the following formula (5), a trialkylsilyl group in which Ra is an alkyl group. Among these, a vinyl group, an allyl group, and a trialkylsilyl group represented by the formula (5) are more preferable from the viewpoint of effectively suppressing an increase in resistance during a cycle test. Preferable examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a dimethylbutylsilyl group, a dimethylpropylsilyl group, and a tripropylsilyl group.
SiRa ₃ (5)
(In the formula (5), each Ra independently represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms.)

(5) In the formula, each Ra independently represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms. Regarding Ra, the “optionally substituted hydrocarbon group” is not particularly limited, but for example, an aliphatic hydrocarbon group, an aromatic hydrocarbon group such as a phenyl group, and all the hydrogen atoms in the hydrocarbon group A fluorine-substituted hydrocarbon group such as a trifluoromethyl group substituted with a fluorine atom can be mentioned. In addition, the said hydrocarbon group may have a functional group in the arbitrary positions (namely, as a side chain or in a main chain or in a side chain) in the said group as needed. Such a functional group is not particularly limited. For example, halogen atoms such as fluorine atom, chlorine atom, bromine atom, nitrile group (—CN), ether group (—O—), carbonate group (—OCO ₂ ). -), ester group _(-CO 2 -), carbonyl group (-CO-), sulfide groups (-S-), sulfoxide group (-SO-), sulfone group _(-SO 2 -), urethane group (-NHCO _2- ) and the like.

  About Ra, carbon number of each hydrocarbon group is 1-20, 1-10 are more preferable, and 1-6 are especially preferable. When the number of carbon atoms of each Ra is within the above range, the miscibility with the non-aqueous solvent tends to be superior.

  Preferred examples of Ra include, but are not limited to, for example, methyl group, ethyl group, vinyl group, allyl group, 1-methylvinyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl. Group, sec-butyl group, tert-butyl group, fluoromethyl group and other aliphatic hydrocarbon groups; and benzyl group, phenyl group, nitrile-substituted phenyl group, fluorinated phenyl group and other aromatic hydrocarbon groups. . Among these, from the viewpoint of availability, handling, and chemical stability, a methyl group, an ethyl group, a vinyl group, an allyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a tert-butyl group, A phenyl group or a fluoromethyl group is more preferable, and a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, or a tert-butyl group is particularly preferable. Moreover, two of Ra may combine to form a ring. To form a ring, for example, two of Ra can be substituted with a substituted or unsubstituted, saturated or unsaturated alkylene group.

Although compound (A) contains the structural unit represented by Formula (1), the following can be mentioned as a preferable example of the structural unit represented by Formula (1).

Preferred structures of the compound (A) include structures represented by the following formulas (2a) to (4e). Among these, from the viewpoint of chemical stability in the electrolytic solution and battery resistance suppression, preferably, the formula (2a), the formula (2b), the formula (2c), the formula (2d), the formula (2e), the formula ( 3a), Formula (3b), Formula (3c), Formula (3d), and Formula (3e). More preferably, Formula (2a), Formula (2b), Formula (2c), Formula (3a), Formula (3b) and Formula (3c) are the most preferable, and Formula (3a), Formula (3b), and Formula (3c) are most preferable.

  In addition, the compound represented by the said Formula (1) can be used individually by 1 type or in combination of 2 or more types.

Although it does not specifically limit as a manufacturing method of the compound (A) of this embodiment, The following is mentioned as a preferable example.
Into a reaction vessel charged with dried pyrophosphate, triphosphate or tetraphosphate, formamide and an excess of trialkylsilyl halide represented by trialkylsilyl chloride are added respectively, and the reaction is performed at room temperature. Make it progress.
If the above mixture is heated too much, side reactions may proceed, and temperature control becomes important. After completion of the reaction, an extraction solvent such as petroleum ether is added at room temperature to extract the reaction product, and then the extraction solvent such as petroleum ether is distilled off under reduced pressure to obtain compound (A) with high purity. Become.

((Electrolyte additive for non-aqueous electricity storage devices))
Since the compound (A) of this embodiment can improve the cycle life of the battery and suppress an increase in resistance during the cycle, the compound (A) is suitably used as an electrolyte additive for non-aqueous energy storage devices. The electrolyte solution additive for non-aqueous electricity storage devices of this embodiment contains the compound (A) of this embodiment.
Here, the “non-aqueous electricity storage device” is an electricity storage device that does not use an aqueous solution for the electrolyte in the electricity storage device, and examples include a lithium ion secondary battery, a sodium ion secondary battery, a calcium ion secondary battery, and lithium. An ion capacitor is mentioned. Among these, from the viewpoints of practicality and durability, the non-aqueous storage device is preferably a lithium ion secondary battery and a lithium ion capacitor, and more preferably a lithium ion secondary battery.

Here, the electrolyte solution additive for non-aqueous electricity storage devices of this embodiment should just contain the compound (A) of this embodiment, and when adding to an electrolyte solution, it adds a compound (A) and a compound (A ) Or a phosphorus compound other than the compound (A) may be used as an additive before being added to the electrolytic solution.
Examples of phosphorus compounds other than the compound (A) include trimethyl phosphate, triethyl phosphate, tris phosphate (trimethylsilyl), tris phosphite (trimethylsilyl), and tris phosphate (2,2,2-trifluoroethyl). And tris phosphite (2,2,2-trifluoroethyl).

  From the viewpoint of improving the cycle performance of the battery and suppressing the increase in resistance during cycling, among the number of moles of the phosphorus compound contained in the electrolyte additive, the compound represented by the formula (2) and the formula (3) It is preferable that the content rate of the represented compound is 50 mol% or more. More preferably, the content is 70 mol% or more, and particularly preferably 80 mol% or more. In addition, "the content rate of the compound represented by Formula (2) and the compound represented by Formula (3)" means the content rate and the formula of the compound represented by Formula (2) in the electrolyte additive ( 3) means the total content of the compounds represented by 3), and when only one of the compounds is included in the electrolyte additive, it refers to the content of the one compound, and the content of the compound is It means the above range. In addition, a phosphorus compound other than the compound (A) represented by the formula (1) can be contained in the electrolyte additive. In such a case, “the number of moles of the phosphorus compound contained in the electrolyte additive” includes the compound. The number of moles of phosphorus compounds other than (A) is also included.

(((Electrolytic solution for non-aqueous electricity storage device))))
The electrolyte additive for a non-aqueous electricity storage device of the present embodiment containing the compound (A) of the present embodiment can improve the cycle life of the battery and suppress an increase in resistance during the cycle. It is suitably used as an electrolytic solution for an electricity storage device. The electrolyte solution for a non-aqueous electricity storage device of the present embodiment includes an electrolyte solution additive for the non-aqueous electricity storage device of this embodiment, a lithium salt (B), a non-aqueous solvent, and other additives as necessary. Containing.

Here, the content of the compound (A) in the electrolyte solution for a non-aqueous electricity storage device of the present embodiment is not particularly limited, but from the viewpoint of improving the cycle life of the battery and suppressing the increase in resistance, preferably the electrolyte solution It is 0.1 mass% or more with respect to 100 mass%, and 10 mass% or less is preferable from a viewpoint of the ionic conductivity of electrolyte solution. More preferably, the content is 0.2% by mass or more and 8% by mass or less, particularly preferably 0.3% by mass or more and 5% by mass or less, and most preferably 0.5% by mass or more and 3% by mass or less. The content of the compound (A) in the electrolyte solution in the lithium ion secondary battery can be calculated by NMR measurement such as ¹ H-NMR and ³¹ P-NMR.

-Lithium salt (B)-
The nonaqueous electricity storage device for electrolyte lithium salt used in the present embodiment (B), is not particularly limited, for _{example, LiPF 6, LiBF 4, LiB} (C 2 O 4) 2, LiBF 2 (C 2 O ₄ ), LiClO ₄ , LiAsF ₆ , Li ₂ SiF ₆ , LiOSO ₂ C _k F _{2k + 1} [k is an integer of 1 to 8], LiN (SO ₂ C _k F _{2k + 1} ) ₂ [k is an integer of 1 to 8], _{LiPF n (C k F 2k +} 1) 6-n [n is an integer of 1 to 5, k is an integer of 1 to _{8], LiPF 4 (C 2 O 4} ), LiPF 2 (C 2 O 4) 2 and the like can be mentioned Among them, from the viewpoint of ion conductivity and from the viewpoint of improving the cycle life of the battery, LiPF ₆ , LiBF ₄ , LiB (C ₂ O ₄ ) ₂ , LiBF ₂ (C ₂ O ₄ ), LiOSO ₂ C _k F _{2k + 1} [k is an integer of 1 to 8], LiN (SO ₂ C _k F _{2k + 1} ) ₂ [k is an integer of 1 to 8], LiPF _n (C _k F _{2k + 1} ) _6-n [n is an integer of 1 to 5 , K is an integer of 1 to 8], LiPF ₄ (C ₂ O ₄ ), and LiPF ₂ (C ₂ O ₄ ) ₂ are preferable, and LiPF ₆ , LiBF ₄ , LiB (C ₂ O ₄ ) ₂ , LiBF ₂ ( C ₂ O ₄ ) is particularly preferred.
These may be used alone or in combination of two or more.

  In order to improve the cycle characteristics of the lithium ion secondary battery, the electrolyte for a non-aqueous storage device of this embodiment includes any one of lithium difluorophosphate and lithium monofluorophosphate in addition to the lithium salt. The above may be included.

Here, the content of the lithium salt (B) in the electrolyte solution for a non-aqueous electricity storage device of the present embodiment is not particularly limited, but from the viewpoint of further improving the ion conductivity of the lithium ion secondary battery, 100 masses of the electrolyte solution. % Is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, particularly preferably 7.0% by mass or more, and lithium salt (B) From the viewpoint of further improving the solubility at a low temperature, it is preferably 40% by mass or less, more preferably 35% by mass or less, and further preferably 30% by mass or less with respect to 100% by mass of the electrolytic solution. Particularly preferred.
In addition, content of lithium salt (B) in electrolyte solution can be computed by NMR measurement, such as < ¹⁹ > F-NMR and < ³¹ > P-NMR.

-Non-aqueous solvent-
Although it does not specifically limit as a nonaqueous solvent used for the electrolyte solution for nonaqueous electrical storage devices of this embodiment, For example, an aprotic polar solvent etc. are mentioned.
Examples of the aprotic polar solvent include ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, and trifluoromethylethylene. Cyclic carbonates such as carbonate, fluoroethylene carbonate, 4,5-difluoroethylene carbonate, vinylene carbonate, vinylethylene carbonate; lactones such as γ-butyrolactone and γ-valerolactone; cyclic sulfones such as sulfolane; cyclic ethers such as tetrahydrofuran and dioxane Ethyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, dipropyl carbonate Chain carbonates such as methyl butyl carbonate, dibutyl carbonate, ethyl propyl carbonate, methyl trifluoroethyl carbonate; nitriles such as acetonitrile, propionitrile, adiponitrile, succinonitrile, malononitrile, glutaronitrile; chain ethers such as dimethyl ether Chain carboxylic acid esters such as methyl propionate and ethyl propionate; and chain diethers such as 1,2-dimethoxyethane, etc.
Among these, carbonate solvents such as cyclic carbonate and chain carbonate are preferable,
In particular, examples of the cyclic carbonate include those described above. In particular, from the viewpoint of further improving the ionic conductivity of the electrolytic solution, the cyclic carbonate is preferably at least one selected from the group consisting of ethylene carbonate and propylene carbonate. As the chain carbonate, the above-mentioned ones are mentioned, and in particular, from the viewpoint of further improving the ionic conductivity of the electrolytic solution, it is at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. It is preferable.
These may be used alone or in combination of two or more.
In particular, vinylene carbonate, fluoroethylene carbonate, succinonitrile, and adiponitrile have a function of further improving the cycle characteristics of the lithium ion secondary battery.

Moreover, as said carbonate type solvent, what combined and used the cyclic carbonate and the chain carbonate from a viewpoint which shall make ion conductivity more excellent is still more preferable.
In this case, the mixing ratio of the cyclic carbonate and the chain carbonate is preferably 1:10 to 5: 1 by volume from the viewpoint of further improving the ion conductivity of the obtained lithium ion secondary battery, It is more preferable that it is 1: 5 to 3: 1, and it is especially preferable that it is 1: 5 to 1: 1.

  When using a carbonate-based solvent as the non-aqueous solvent, in order to further improve the battery physical properties of the lithium ion secondary battery, in addition to the carbonate-based solvent, a nitrile-based solvent such as acetonitrile is used as the electrolyte solution. In addition, a non-aqueous solvent different from the carbonate solvent such as sulfolane solvent such as sulfolane may be used in combination.

-Additives-
From the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery, the electrolyte for a non-aqueous storage device of the present embodiment, the electrolyte additive for the non-aqueous storage device, the lithium salt (B), and the non In addition to the aqueous solvent, additives may be contained as necessary.
Although it does not specifically limit as an additive used for the electrolyte solution for nonaqueous electrical storage devices of this embodiment, For example, ethylene sulfite, 1, 3- propane sultone, 1-propene-1, 3- sultone, 1, 4 -Butane sultone, diphenylphosphazenes and the like.
These may be used alone or in combination of two or more.

  The electrolyte solution for a non-aqueous electricity storage device of the present embodiment may be prepared so as to have a predetermined composition by mixing each component by a known technique, and may have a predetermined composition by a reaction in the electrolyte solution. It may be prepared as follows. Here, “preparing by reaction in an electrolytic solution” specifically means that an electrolytic solution having a predetermined composition is prepared by a reaction between substances contained in the electrolytic solution in the initial state. That means.

((((Lithium ion secondary battery))))
The lithium ion secondary battery of this embodiment includes the electrolyte solution for a nonaqueous electricity storage device of this embodiment containing the electrolyte solution additive for the nonaqueous electricity storage device of this embodiment containing the compound (A) of this embodiment; And a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, a separator, and a battery exterior as needed. This battery may have the same configuration as that of a conventional lithium ion secondary battery except that the battery includes the electrolyte for a non-aqueous storage device of the present embodiment.

The positive electrode potential based on lithium at the time of full charge of the lithium ion secondary battery of the present embodiment is the viewpoint of efficiently utilizing the charge / discharge capacity of the positive electrode active material of the lithium ion secondary battery, and the lithium ion secondary battery from the viewpoint of improving the energy density, 4.3 V is preferably (vsLi / Li ⁺⁾ or higher, further preferably 4.35V (vsLi / Li ⁺⁾ or more, 4.4V (vsLi / Li ⁺ It is particularly preferable that the positive electrode potential based on lithium is 5.2 V (vsLi / Li ⁺ ) or less. Note that “(vsLi / Li ⁺ )” indicates that the potential is based on lithium. In addition, the positive electrode potential based on lithium at the time of full charge can be controlled by controlling the voltage of the battery at the time of full charge.

The lithium-based positive electrode potential during full charge is determined by disassembling a fully charged lithium ion secondary battery in an Ar glove box, taking out the positive electrode, reassembling the battery using metallic lithium as the counter electrode, It can be measured by measuring.
In particular, when the lithium-based negative electrode potential at full charge is known, the negative electrode potential is added to the voltage (Va) of the lithium ion secondary battery at full charge to obtain the lithium-based positive electrode potential at full charge. Can be calculated. For example, when a carbon negative electrode active material is used for the negative electrode, it is known that the lithium-based negative electrode potential at full charge is 0.05 V (vsLi / Li ⁺ ). When the voltage (Va) of the secondary battery is 4.3V, the positive electrode potential based on lithium at the time of full charge can be calculated as 4.3V + 0.05V = 4.35V.

The lithium-based positive electrode potential at the time of full charge of the lithium ion secondary battery of the present embodiment of 4.3 V (vsLi / Li ⁺ ) or higher is usually from 4.1 V (vsLi / Li ⁺ ) to 4.2 V (vsLi /). Li ⁺ ), which is higher than the lithium-based positive electrode potential at the time of full charge of the conventional lithium ion secondary battery set below.

-Positive electrode-
The lithium ion secondary battery of this embodiment preferably includes a positive electrode.
The positive electrode used for the lithium ion secondary battery of this embodiment will not be specifically limited if it acts as a positive electrode of a lithium ion secondary battery, and can be a well-known thing.
The positive electrode preferably includes a positive electrode active material containing a material capable of inserting and extracting lithium ions, and may include a positive electrode current collector, a conductive additive, and a binder as necessary.

--- Positive electrode active material-
The positive electrode active material preferably has a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more from the viewpoint of realizing a higher voltage in the lithium ion secondary battery. When such a positive electrode is provided, the cycle life can be improved while operating at a high voltage in the lithium ion secondary battery of the present embodiment.

Here, 4.3 V and a positive electrode active material having a 10 mAh / g or more discharge capacity (vsLi / Li ⁺⁾ or more potential, 4.3V (vsLi / Li ⁺⁾ of the lithium ion secondary battery or a potential It is a positive electrode active material capable of causing charge and discharge reactions as a positive electrode and having a discharge capacity of 10 mAh or more per gram of active material when discharged at a constant current of 0.1 C. In this respect, the positive electrode active material only needs to have a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more, and a potential of less than 4.3 V (vsLi / Li ⁺ ). The discharge capacity does not matter.

The lithium ion secondary battery of the present embodiment is a lithium ion secondary battery including a positive electrode containing a positive electrode active material having a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more, It is preferable that the positive electrode potential based on lithium at full charge is 4.3 V (vsLi / Li ⁺ ) or more.
In the application of this embodiment in which the lithium-based secondary battery is used with a lithium-based positive electrode potential of 4.3 V (vs Li / Li ⁺ ) or more when fully charged, a carbonate-based solvent contained in the electrolyte is present on the positive electrode surface. As a result, the battery may have a problem that the cycle life of the battery decreases and the resistance at the interface between the positive electrode and the electrolyte increases. Such a problem is unlikely to occur in a conventional application in which a lithium ion secondary battery is used at a positive electrode potential of less than 4.3 V (vsLi / Li ⁺ ) when fully charged.
Since the lithium ion secondary battery of this embodiment has a configuration of a positive electrode containing a positive electrode active material having a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more, It solves the problem in the application of the form, and can operate at a high voltage and has a high cycle life.

The discharge capacity of the positive electrode active material used in the lithium ion secondary battery of the present embodiment is 4.3 V (vsLi / V) from the viewpoint of enabling a high energy density to be achieved by driving the battery at a high voltage. Li ⁺ ) or higher is preferably 10 mAh / g or higher, more preferably 15 mAh / g or higher, and particularly preferably 20 mAh / g or higher. The discharge capacity of the positive electrode active material is preferably 400 mAh / g or less at a potential of 4.3 V (vsLi / Li ⁺ ) or more.
The discharge capacity of the positive electrode active material can be measured by the method described in the examples.

The positive electrode active materials having a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more may be used alone or in combination of two or more. Also, as the positive electrode active material, 4.3V (vsLi / Li ⁺⁾ and the positive electrode active material having a 10 mAh / g or more discharge capacity than the potential, 4.3V (vsLi / Li ⁺⁾ or more potential 10 mAh / g A positive electrode active material having no discharge capacity as described above can also be used in combination. Here, the positive electrode active material not having a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more is not particularly limited, and examples thereof include LiFePO ₄ .

Such a positive electrode active material is not particularly limited. For example, an oxide represented by the formula (6), an oxide represented by the formula (7), a composite oxide represented by the formula (8), It is preferable that it is 1 or more types chosen from the group which consists of a compound represented by Formula (9), and a compound represented by Formula (10). By using such a positive electrode active material, the structural stability of the positive electrode active material tends to be more excellent. Among these, an oxide represented by the formula (6), an oxide represented by the formula (7), and a composite oxide represented by the formula (8) are more preferable, and the formula (7) is most preferable. It is an oxide represented by.
_{LiMn 2-x Ma x O 4} (6)
(In the above formula (6), Ma represents one or more selected from the group consisting of transition metals, and x is 0.2 ≦ x ≦ 0.7.)
LiMeO ₂ (7)
(In the above formula (7), Me represents one or more selected from the group consisting of transition metals.)
_{zLi 2 McO 3 - (1-} z) LiMdO 2 (8)
(In the above formula (8), Mc and Md each independently represent one or more selected from the group consisting of transition metals, and z is 0.1 ≦ z ≦ 0.9.)
LiMb _1-y Fe _y PO ₄ (9)
(In the above formula (9), Mb represents one or more selected from the group consisting of Mn and Co, and y is 0 ≦ y ≦ 0.9.)
Li ₂ MfPO ₄ F (10)
(In the above formula (10), Mf represents one or more selected from the group consisting of transition metals.)
These may be used alone or in combination of two or more.

Although it does not specifically limit as an oxide represented by the said Formula (6), From a viewpoint of making the structural stability of a positive electrode active material more excellent, a spinel type oxide is preferable and represented by Formula (6a). More preferred is an oxide.
LiMn _2-x Ni _x O ₄ (6a)
(In the above formula (6a), x satisfies 0.2 ≦ x ≦ 0.7.)
The compounds represented by the above formula (6) are used singly or in combination of two or more.

The oxide represented by the formula (6a), is not particularly _limited, and examples thereof include LiMn _{1.5 Ni} 0.5 _{O 4.}

Although it does not specifically limit as an oxide represented by the said Formula (7), For example, it is preferable that it is a layered oxide from a viewpoint of making the structural stability of a positive electrode active material more excellent, and following formula ( The oxide represented by 7a) or (7b) or (7c) is more preferable.
LiMn _1- vw Co _v Ni _w O ₂ (7a)
(In the above formula (7a), 0.1 ≦ v ≦ 0.4 and 0.1 ≦ w ≦ 0.8.)
LiCoO ₂ (7b)
LiNi _1- ut Co _u Al _t O ₂ (7c)
(In the above formula (7c), 0.1 ≦ u ≦ 0.2 and 0.01 ≦ t ≦ 0.1.)
The compounds represented by the above formula (7) are used singly or in combination of two or more.

The layered oxide represented by the above formula (7a) is not particularly limited. For example, LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _0.6 Co _0.2 Mn _0.2 O ₂ , LiNi _0.7 Co _0.2 Mn _0.1 O ₂ , LiNi _0.8 Co _0.1 Mn _0.1 O ₂ , and the like. It is done. Examples of the layered oxide represented by the above formula (7c) include LiNi _0.8 Co _0.15 Al _0.05 O ₂ .

Although it does not specifically limit as complex oxide represented by the said Formula (8), For example, it is preferable that it is a composite layered oxide from a viewpoint of making the structural stability of a positive electrode active material more excellent, The composite oxide represented by the formula (8a) is more preferable.
_{zLi 2 MnO 3 - (1-} z) LiNi a Mn b Co c O 2 (8a)
(In the above formula (8a), z satisfies 0.3 ≦ z ≦ 0.7, and a, b, and c are a + b + c = 1, 0.2 ≦ a ≦ 0.6, 0.2 ≦ b ≦ 0.6, 0.05 ≦ c ≦ 0.4 is satisfied.)
The composite oxide represented by the above formula (8) is used singly or in combination of two or more.

  Among these, in the above formula (8a), 0.4 ≦ z ≦ 0.6, a + b + c = 1, 0.3 ≦ a ≦ 0.4, 0.3 ≦ b ≦ 0.4, 0.2 ≦ c A composite oxide satisfying ≦ 0.3 is more preferable.

Although it does not specifically limit as a compound represented by the said Formula (9), For example, an olivine type compound is preferable from a viewpoint of making the structural stability and electronic conductivity of a positive electrode active material more excellent, and following formula ( 9a) and a compound represented by the following formula (9b) are more preferable.
LiMn _1-y Fe _y PO ₄ (9a)
(In the above formula (9a), y satisfies 0.05 ≦ y ≦ 0.8.)
LiCo _1-y Fe _y PO ₄ (9b)
(In the above formula (9b), y satisfies 0.05 ≦ y ≦ 0.8.)
The compounds represented by the above formula (9) are used singly or in combination of two or more.

The fluoride olivine-type positive electrode active material is a compound represented by the above formula (10), is not particularly limited, for example, from the viewpoint of the excellent more structural stability of the positive electrode active material, Li ₂ FePO ₄ F, Li ₂ MnPO ₄ F and Li ₂ CoPO ₄ F are preferred. The compound represented by Formula (10) is used individually by 1 type or in combination of 2 or more types.

The positive electrode active material can be manufactured by a method similar to a general method for manufacturing an inorganic oxide.
Although it does not specifically limit as a manufacturing method of a positive electrode active material, For example, by baking the mixture which mixed metal salt (for example, sulfate and / or nitrate) in a predetermined ratio in the atmospheric environment containing oxygen, A method for obtaining a positive electrode active material containing an inorganic oxide, a carbonate salt and / or a hydroxide salt is allowed to act on a solution in which a metal salt is dissolved to precipitate a hardly soluble metal salt, which is then extracted and separated. A method of obtaining a positive electrode active material containing an inorganic oxide by mixing lithium carbonate and / or lithium hydroxide as a lithium source and then firing the mixture in an atmosphere containing oxygen can be used.

The positive electrode can be produced as follows, for example.
First, a paste containing a positive electrode mixture is prepared by dispersing, in a solvent, a positive electrode mixture obtained by adding a conductive additive or a binder to the positive electrode active material, if necessary. Next, this paste is applied to a positive electrode current collector and dried to form a positive electrode mixture layer, which is pressurized as necessary to adjust the thickness, whereby a positive electrode can be produced.
Although it does not specifically limit as a positive electrode electrical power collector, For example, what is comprised with metal foil, such as aluminum foil or stainless steel foil, is mentioned.

In the production of the positive electrode, the conductive aid used as necessary is not particularly limited, and examples thereof include carbon black such as graphite, acetylene black, and ketjen black, carbon fiber, and the like.
In the production of the positive electrode, the binder used as necessary is not particularly limited, and examples thereof include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyacrylic acid, styrene-butadiene rubber, and fluorine rubber. Can be mentioned.

-Negative electrode-
The lithium ion secondary battery of this embodiment preferably includes a negative electrode.
The negative electrode used for the lithium ion secondary battery of this embodiment will not be specifically limited if it acts as a negative electrode of a lithium ion secondary battery, and can be a well-known thing.
The negative electrode preferably includes a negative electrode active material containing a material capable of inserting and extracting lithium ions, and may include a negative electrode current collector, a conductive additive, and a binder as necessary.

--- Negative electrode active material-
Although it does not specifically limit as a negative electrode active material, For example, a carbon negative electrode active material; Negative electrode active material containing the element which can be alloyed with lithium represented by a silicon alloy negative electrode active material and a tin alloy negative electrode active material; Silicon oxide Examples thereof include a negative electrode active material; a tin oxide negative electrode active material; and a lithium-containing compound typified by a lithium titanate negative electrode active material. These negative electrode active materials are used singly or in combination of two or more.

The carbon negative electrode active material is not particularly limited. For example, hard carbon, soft carbon, artificial graphite, natural graphite, graphite, pyrolytic carbon, coke, glassy carbon, a fired body of an organic polymer compound, mesocarbon microbeads , Carbon fiber, activated carbon, graphite, carbon colloid, carbon black and the like.
Although it does not specifically limit as coke, For example, pitch coke, needle coke, petroleum coke, etc. are mentioned. The fired body of the organic polymer compound is not particularly limited, but is a carbonized material obtained by firing a polymer material such as a phenol resin or a furan resin at an appropriate temperature.

The negative electrode active material containing an element capable of forming an alloy with lithium is not particularly limited. For example, it may be a metal or a metalloid simple substance, an alloy or a compound, or a metal or metalloid. It may have at least a part of one or two or more phases.
Note that alloys include those containing one or more metal elements and one or more metalloid elements, in addition to those composed of two or more metal elements. Further, the alloy may have a nonmetallic element as long as it has metal properties as a whole.
Although it does not specifically limit as a metal element and a metalloid element, For example, titanium (Ti), tin (Sn), lead (Pb), aluminum (Al), indium (In), silicon (Si), zinc (Zn) , Antimony (Sb), bismuth (Bi), gallium (Ga), germanium (Ge), arsenic (As), silver (Ag), hafnium (Hf), zirconium (Zr), yttrium (Y), and the like. Among these, metal elements and metalloid elements of Group 4 or Group 14 in the long-period periodic table are preferable, and titanium (Ti), silicon (Si), and tin (Sn) are particularly preferable.
These may be used alone or in combination of two or more.

The negative electrode can be produced as follows, for example.
First, a negative electrode mixture containing a negative electrode mixture, which is mixed with the negative electrode active material, if necessary, added to the negative electrode as necessary is dispersed in a solvent to prepare a paste containing the negative electrode mixture. Next, the paste is applied to the negative electrode current collector and dried to form a negative electrode mixture layer on the negative electrode current collector. Subsequently, this is pressurized as necessary to adjust the thickness of the negative electrode mixture layer, thereby obtaining a negative electrode.
Although it does not specifically limit as a negative electrode electrical power collector, For example, what is comprised with metal foil, such as copper foil, nickel foil, or stainless steel foil, is mentioned.
The conductive auxiliary agent and the binder may be the same as those used in the production of the positive electrode.

-Separator-
The lithium ion secondary battery of the present embodiment preferably includes a separator between the positive electrode and the negative electrode from the viewpoint of preventing a short circuit between the positive and negative electrodes and providing safety such as shutdown.
Although it does not specifically limit as a separator, For example, it may be the same as what is equipped in a well-known lithium ion secondary battery, Especially, the insulating thin film which is large in ion permeability and excellent in mechanical strength is preferable. Specifically, examples of the separator include a woven fabric, a non-woven fabric, and a synthetic resin microporous membrane, and among them, a synthetic resin microporous membrane is preferable. Here, the nonwoven fabric is not particularly limited, and examples thereof include a porous film made of a heat resistant resin such as ceramic, polyolefin, polyester, polyamide, liquid crystal polyester, and aramid. The microporous membrane made of synthetic resin is not particularly limited, and examples thereof include a microporous membrane containing polyethylene or polypropylene as a main component, and a polyolefin microporous membrane such as a microporous membrane containing both of these polyolefins. .
The separator may be a single microporous film or a multilayer of two or more microporous films.

The lithium ion secondary battery of the present embodiment is the non-aqueous storage device electrolyte of the present embodiment, a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and, if necessary, It can be produced by a known method using a separator and a battery exterior.
For example, the positive electrode and the negative electrode are wound in a laminated state with a separator interposed therebetween and formed into a laminate having a wound structure, or the positive electrode and the negative electrode are alternately laminated by bending or laminating a plurality of layers. Then, it is molded into a laminate obtained by interposing a separator between the positive electrode and the negative electrode, and then the laminate is accommodated in a battery exterior (battery case), and then the non-aqueous electricity storage of this embodiment The lithium ion secondary battery of this embodiment can be produced by injecting a device electrolyte into the case, immersing the laminate in the electrolyte, and finally sealing the battery exterior. .

  The shape of the lithium ion secondary battery of the present embodiment is not particularly limited, and for example, a cylindrical shape, an elliptical shape, a rectangular tube shape, a button shape, a coin shape, a flat shape, and a laminate shape are suitably employed.

FIG. 1 is a schematic cross-sectional view showing an example of a lithium ion secondary battery in the present embodiment.
An example 100 of the lithium ion secondary battery of the present embodiment includes a separator 110, a positive electrode 200 obtained by applying a positive electrode active material-containing layer 120 containing a positive electrode active material or the like to a positive electrode current collector 140, a negative electrode active material, or the like. A negative electrode 300 formed by coating a negative electrode current collector 150 with a negative electrode active material-containing layer 130, and a battery casing 160 that houses a laminate composed of these. Here, the positive electrode 200 and the negative electrode 300 sandwich the separator 110 from both sides in such a manner that the positive electrode active material-containing layer 120 and the negative electrode active material-containing layer 130 face each other. In addition, a laminate in which the positive electrode 200, the separator 110, and the negative electrode 300 are laminated is impregnated with an electrolytic solution (not shown).
Note that the example shown in FIG. 1 includes one stacked body including the separator 110, the positive electrode 200, and the negative electrode 300, but the lithium ion secondary battery of the present invention is not limited to this, and includes a plurality of stacked bodies. It may be included.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to these Examples.

  Analytical methods and evaluation methods used in Examples and Comparative Examples are as follows.

(1) Nuclear magnetic resonance analysis (NMR): Molecular structure analysis by ¹ H-NMR, ¹³ C-NMR, ³¹ P-NMR Measuring apparatus: JNM-GSX400G type nuclear magnetic resonance apparatus (400 MHz) (manufactured by JEOL Ltd.)
Solvent: deuterated chloroform Reference material: ¹ H-NMR chloroform (7.26 ppm), ¹³ C-NMR chloroform (77.16 ppm), ³¹ P-NMR 85% phosphoric acid (0 ppm)
Internal standard: Trimethyl phosphate (for calculation of quantitative ratio between ³¹ P-NMR and ¹ H-NMR)

(2) Battery performance evaluation of lithium ion secondary battery (1)
The obtained sheet-like lithium ion secondary battery is housed in a thermostatic bath set at 25 ° C. (trade name: PLM-73S manufactured by Futaba Kagaku Co., Ltd.), and a charge / discharge device (manufactured by Asuka Electronics Co., Ltd., product name: ACD-01) and allowed to stand for 16 hours. The battery was then charged at a constant current of 0.05C, charged for 4. hours at a constant voltage of 4.35V after the voltage reached 4.35V, and then 3.0V at a constant current of 0.2C. The battery was initially charged / discharged by repeating the charge / discharge cycle of discharging until 3 times. In addition, 1C shows the electric current value in the case of discharging the full capacity of a battery in 1 hour.
After the initial charge / discharge, the battery is housed in a thermostat set at 50 ° C., and the battery is charged with a constant current of 1 C. After the voltage reaches 4.35 V, the battery is charged with a constant voltage of 4.35 V. After charging for 1 hour, the cycle test of the battery was performed by repeating a charge / discharge cycle of discharging to 3.0 V at a constant current of 1 C 150 times.
The discharge capacity (mAh) at the first cycle, the discharge capacity (mAh) at the 100th cycle, and the discharge capacity (mAh) at the 150th cycle were measured under the condition of discharging at a constant current of 1.0 C. Divided by weight (g) (mAh / g). Further, the capacity retention rate (%) of the battery in the cycle test (initial capacity at the first cycle: 100%) was calculated.
Further, the battery resistance (Ω) at each cycle was measured from the IR drop of the initial 10 seconds at the first cycle, 100th cycle and 150th cycle.

(3) Battery performance evaluation of lithium ion secondary battery (2)
The obtained coin-type lithium ion secondary battery is housed in a thermostatic chamber (manufactured by Futaba Kagaku Co., Ltd., trade name: PLM-73S) set at 25 ° C., and a charge / discharge device (manufactured by Asuka Electronics Co., Ltd., trade name: ACD-01) and allowed to stand for 16 hours. The battery was then charged at a constant current of 0.05C, charged for 2. hours at a constant voltage of 4.45V after the voltage reached 4.45V, and then 3.0V at a constant current of 0.2C. The battery was initially charged / discharged by repeating the charge / discharge cycle of discharging until 3 times.
After the initial charging / discharging, the battery is housed in a thermostat set at 25 ° C., and the battery is charged with a constant current of 1 C. After the voltage reaches 4.35 V, the battery is charged with a constant voltage of 4.35 V. A cycle test of the battery was performed by repeating a charge / discharge cycle of charging to 3.0 V at a constant current of 1 C after charging for 1 hour, 1200 times.
The discharge capacity (mAh) at the first cycle, the discharge capacity (mAh) at the 600th cycle, and the discharge capacity (mAh) at the 1200th cycle were measured under the condition of discharging at a constant current of 1.0 C. Divided by weight (g) (mAh / g). Further, the capacity retention rate (%) of the battery in the cycle test (initial capacity at the first cycle: 100%) was calculated.
In addition, the battery resistance (Ω) at each cycle was measured from the IR drop of the initial 10 seconds at the first cycle, 600th cycle and 1200th cycle.

(4) Discharge capacity evaluation of positive electrode active material The obtained sheet-like lithium ion secondary battery was accommodated in the thermostat set to 25 degreeC (the Futaba Kagaku company make, brand name: PLM-73S), and charging / discharging apparatus ( The product was connected to Asuka Electronics Co., Ltd. (trade name: ACD-01) and allowed to stand for 16 hours. The battery was then charged at a constant current of 0.05C, charged for 2. hours at a constant voltage of 4.45V after the voltage reached 4.45V, and then 3.0V at a constant current of 0.2C. The battery was initially charged / discharged by repeating the charge / discharge cycle of discharging until 3 times.
After the initial charge / discharge, the battery is charged with a constant current of 0.05C, charged for 2. hours at a constant voltage of 4.45V after the voltage reaches 4.45V, and then charged with a constant current of 0.1C to 3.0V. The discharge capacity from the start of discharge to a battery voltage of 4.25 V was confirmed. The obtained sheet-like lithium ion secondary battery uses a later-described carbon negative electrode active material for the negative electrode. When the voltage of the secondary battery is 4.25 V, the lithium-based positive electrode potential is 4.3 V ( vsLi / Li ⁺ ).

Example 1
<Synthesis of Compound (A1)>
4.44 g of sodium pyrophosphate (H ₂ Na ₂ O ₇ P ₂ , manufactured by Aldrich, trade name: P8135-500G) was vacuum-dried at 180 ° C., charged into a reaction vessel purged with nitrogen, and formamide (manufactured by Aldrich) , Trade name: 221198-1L) and 9.56 g of trimethylsilyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: C0306) were added, and the mixture was reacted at room temperature for 1 hour with stirring. The obtained reaction product was extracted with petroleum ether, and petroleum ether was removed under reduced pressure at 40 ° C. to obtain 7.83 g of a colorless and transparent liquid. The measurement results of ¹ H-NMR and ³¹ P-NMR of the obtained liquid are shown below.
¹ H-NMR: 0.56 ppm ppm (m, 36H)
³¹ P-NMR: -30.40 ppm (s, 2P),
From the NMR results, it was confirmed that the compound (A1) had a structure represented by the following formula (2a). From the NMR, it was found that 2% O = P (OSi (CH ₃ ) ₃ ) ₃ was contained in the liquid, and the purity of the compound (A1) was 98%.

<Preparation of electrolyte>
A solution (9.80 g) containing 1 mol / L of LiPF ₆ as a lithium salt in a mixture of ethylene carbonate and ethyl methyl carbonate as a nonaqueous solvent in a volume ratio of 1: 2 was obtained by the above synthesis. An electrolyte solution was prepared by containing 0.20 g of the compound (A1). The content of the compound (A1) in the electrolytic solution was 2.0% by mass, and the content of LiPF _{6 in} the electrolytic solution was 13% by mass.

<Preparation of positive electrode sheet 1>
Lithium / nickel / manganese / cobalt mixed oxide (LiNi _0.5 Co _0.2 Mn _0.3 O ₂ ) (formula (4a)) having a particle size of 7.9 μm (D50) as a positive electrode active material, Carbon black powder (manufactured by Timcal, trade name: SuperP Li) as an agent and PVDF as a binder were mixed at a mass ratio of mixed oxide: conductive auxiliary agent: binder = 100: 3.5: 3. N-methyl-2-pyrrolidone was added to the obtained mixture so that the total solid content concentration was 58% by mass, and the mixture was further mixed to prepare a slurry-like solution. This slurry solution was applied to both sides of an aluminum foil as a positive electrode current collector having a thickness of 15 μm, the solvent was removed by drying, and then the applied aluminum foil was pressed with a roll press to obtain a positive electrode sheet. .

<Preparation 1 of negative electrode sheet>
Graphite powder (product name: MAG, manufactured by Hitachi Chemical Co., Ltd., product name: MAG) having a particle size of 22 μm (D50) as a negative electrode active material, carboxymethyl cellulose (product of Daicel Corp., manufactured by Nippon Zeon Co., Ltd., product name: BM400B). , Trade name: # 2200) and graphite powder: binder: thickener = 100: 1.5: 1.1 in a mass ratio of 45% by mass of the total solid content, A slurry solution was prepared. The slurry solution is applied to one side and both sides of a copper foil as a negative electrode current collector having a thickness of 10 μm, the solvent is removed by drying, and then the applied copper foil is pressed with a roll press to form a negative electrode sheet Got.

<Preparation 1 of sheet-like lithium ion secondary battery>
The positive electrode sheet and the negative electrode sheet produced as described above were punched into a square shape to obtain a positive electrode and a negative electrode. The obtained positive electrode and negative electrode are sandwiched with a separator made of a polyethylene microporous film between the opposing surfaces of the respective active materials, with a single-side coated negative electrode / double-sided coated positive electrode / double-sided coated negative electrode / double-sided coated positive electrode / single-sided. The layers were laminated in the order of the coated negative electrode. Next, the obtained 4 facing laminate was inserted while projecting positive and negative terminals inside a bag (battery exterior) made of a laminate film in which both surfaces of an aluminum foil (thickness 40 μm) were coated with a resin layer. Thereafter, the electrolytic solution prepared as described above was poured into a 0.8 mL bag, and the bag was vacuum-sealed to prepare a sheet-like lithium ion secondary battery.

About the sheet-like lithium ion secondary battery of Example 1, when the cycle test was performed by the method as described in (2), the discharge capacity of the 1st cycle is 184 mAh / g, and the 100th cycle and the 150th cycle The discharge capacities are as high as 167 mAh / g and 156 mAh / g, respectively, and the battery resistance at the first cycle is 0.33Ω, and the battery resistances at the 100th and 150th cycles are 0.83Ω and 1.04Ω, respectively. And showed a low value. The results of battery performance evaluation are shown in Table 1.
Further, the discharge capacity of the positive electrode active material was evaluated for the sheet-like lithium ion secondary battery of Example 1 by the method described in (4), and the result was 16 mAh / g. Therefore, it was found that the positive electrode active material in the sheet-like lithium ion secondary battery of Example 1 had a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more. Table 1 shows the results of the evaluation of the discharge capacity of the positive electrode active material.

(Example 2)
<Synthesis of Compound (A2)>
7.36 g of sodium triphosphate (Na ₅ O ₁₀ P ₃ , manufactured by Aldrich, trade name: 72061-100G) was vacuum-dried at 130 ° C., charged into a reaction vessel purged with nitrogen, and formamide (produced by Aldrich, product) Name: 221981-1L) 10 mL and 12.0 g of trimethylsilyl chloride (trade name: C0306, manufactured by Tokyo Chemical Industry Co., Ltd.) were added, and the mixture was reacted at room temperature for 1 hour with stirring. The obtained reaction product was extracted with petroleum ether, and then the petroleum ether was removed under reduced pressure at 40 ° C. to obtain 12.1 g of a colorless transparent liquid (yield 98%). The measurement results of ¹ H-NMR and ³¹ P-NMR of the obtained liquid are shown below.
¹ H-NMR: 0.53 ppm (m, 45H)
³¹ P-NMR: −31.02 ppm (d, 2P), −36.02 ppm (m, 1P)
From the NMR results, it was confirmed that the compound (A2) had a structure represented by the following formula (3a). From the NMR, it was found that the purity of the compound (A2) in the liquid was 88%.

<Preparation of electrolyte>
A solution (9.80 g) containing 1 mol / L of LiPF ₆ as a lithium salt in a mixture of ethylene carbonate and ethyl methyl carbonate as a nonaqueous solvent in a volume ratio of 1: 2 was obtained by the above synthesis. An electrolyte solution was prepared by containing 0.20 g of the compound (A2). The content of the compound (A2) in the electrolytic solution was 2.0% by mass, and the content of LiPF _{6 in} the electrolytic solution was 13% by mass.

  Except for the above points, in the same manner as in Example 1, a positive electrode sheet, a negative electrode sheet, and a sheet-like lithium ion secondary battery were manufactured.

With respect to the sheet-like lithium ion secondary battery of Example 2, when the cycle test was performed by the method described in (2), the discharge capacity at the first cycle was 185 mAh / g, and at the 100th cycle and the 150th cycle. The discharge capacities are as high as 165 mAh / g and 154 mAh / g, respectively, the battery resistance at the first cycle is 0.3Ω, and the battery resistances at the 100th and 150th cycles are 0.72Ω and 0.82Ω, respectively. And showed a low value. The results of battery performance evaluation are shown in Table 1.
In addition, the discharge capacity of the positive electrode active material was evaluated for the sheet-like lithium ion secondary battery of Example 2 by the method described in (4), and the result was 16 mAh / g. Therefore, it was found that the positive electrode active material in the sheet-like lithium ion secondary battery of Example 2 had a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more. Table 1 shows the results of the evaluation of the discharge capacity of the positive electrode active material.

Example 3
Compound (A1) and compound (A2) were synthesized in the same manner as in Examples 1 and 2.

<Preparation of electrolyte>
A solution (9.60 g) containing 1 mol / L of LiPF ₆ as a lithium salt in a mixed solvent obtained by mixing ethylene carbonate and ethyl methyl carbonate as a nonaqueous solvent in a volume ratio of 1: 2 was obtained by the above synthesis. An electrolytic solution was prepared by containing 0.20 g of the compound (A1) and 0.20 g of the compound (A2) obtained by the above synthesis. The content of the compound (A1) and the content of the compound (A2) in the electrolytic solution were 2.0% by mass, respectively, and the content of LiPF _{6 in} the electrolytic solution was 13% by mass.

  Except for the above points, in the same manner as in Example 1, a positive electrode sheet, a negative electrode sheet, and a sheet-like lithium ion secondary battery were manufactured.

The sheet-like lithium ion secondary battery of Example 3 was subjected to a cycle test by the method described in (2). As a result, the first cycle discharge capacity was 184 mAh / g, and the 100th cycle and the 150th cycle The discharge capacities are as high as 166 mAh / g and 155 mAh / g, respectively, and the battery resistance at the first cycle is 0.31Ω, and the battery resistances at the 100th cycle and 150th cycle are 0.78Ω and 0.92Ω, respectively. And showed a low value. The results of battery performance evaluation are shown in Table 1.
Further, the discharge capacity of the positive electrode active material was evaluated for the sheet-like lithium ion secondary battery of Example 3 by the method described in (4), and the result was 16 mAh / g. Therefore, it was found that the positive electrode active material in the sheet-like lithium ion secondary battery of Example 3 had a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more. Table 1 shows the results of the evaluation of the discharge capacity of the positive electrode active material.

(Comparative Example 1)
<Preparation of electrolyte>
A solution (10.00 g) containing 1 mol / L of LiPF ₆ as a lithium salt in a mixture of ethylene carbonate and ethyl methyl carbonate as a non-aqueous solvent in a volume ratio of 1: 2 was used as an electrolytic solution. The content of LiPF ₆ in the electrolytic solution was 13% by mass. In Comparative Example 1, compound (A) was not used.

  Except for the above points, in the same manner as in Example 1, a positive electrode sheet, a negative electrode sheet, and a sheet-like lithium ion secondary battery were manufactured.

About the sheet-like lithium ion secondary battery of Comparative Example 1, when the cycle test was performed by the method described in (2), the discharge capacity at the first cycle was 184 mAh / g, and the 100th cycle and the 150th cycle The discharge capacities are 144 mAh / g and 67 mAh / g, respectively, the battery resistance at the first cycle is 0.32Ω, and the battery resistances at the 100th and 150th cycles are 2.01Ω and 3.34Ω, respectively. Met. The results of battery performance evaluation are shown in Table 1.
Moreover, when the discharge capacity evaluation of the positive electrode active material was performed by the method described in (4) for the sheet-like lithium ion secondary battery of Comparative Example 1, it was 16 mAh / g. Therefore, it turned out that the positive electrode active material in the sheet-like lithium ion secondary battery of Comparative Example 1 has a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more. Table 1 shows the results of the evaluation of the discharge capacity of the positive electrode active material.

(Comparative Example 2)
<Preparation of electrolyte>
To a solution (9.80 g) containing 1 mol / L of LiPF ₆ as a lithium salt in a mixture of ethylene carbonate and ethyl methyl carbonate as a non-aqueous solvent in a volume ratio of 1: 2, O═P (OSi ( An electrolyte solution was prepared by containing 0.20 g of CH ₃ ) ₃ ) ₃ (manufactured by Aldrich, trade name: 275794). The content of O═P (OSi (CH ₃ ) ₃ ) _{3 in} the electrolytic solution was 2.0% by mass, and the content of LiPF _{6 in} the electrolytic solution was 13% by mass.

  Except for the above points, in the same manner as in Example 1, a positive electrode sheet, a negative electrode sheet, and a sheet-like lithium ion secondary battery were manufactured.

The sheet-like lithium ion secondary battery of Comparative Example 2 was subjected to a cycle test by the method described in (2). As a result, the first cycle discharge capacity was 179 mAh / g, and the 100th cycle and the 150th cycle. The discharge capacities are 162 mAh / g and 152 mAh / g, respectively, the battery resistance at the first cycle is 0.40Ω, and the battery resistances at the 100th and 150th cycles are 1.51Ω and 1.65Ω, respectively. Met. The results of battery performance evaluation are shown in Table 1.
The discharge capacity of the positive electrode active material was evaluated by the method described in (4) for the sheet-like lithium ion secondary battery of Comparative Example 2, and the result was 16 mAh / g. Therefore, it turned out that the positive electrode active material in the sheet-like lithium ion secondary battery of Comparative Example 2 has a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more. Table 1 shows the results of the evaluation of the discharge capacity of the positive electrode active material.

  The obtained results are shown in Table 1. As can be seen from Table 1, it can be seen that the use of the compound (A) not only improves the capacity retention rate in the cycle test, but also significantly suppresses the increase in battery resistance in the cycle test.

Example 4
<Preparation of electrolyte>
Obtained by the above synthesis into a solution (9.95 g) containing 1 mol / L of LiPF ₆ as a lithium salt in a mixture of ethylene carbonate and ethyl methyl carbonate as a non-aqueous solvent in a volume ratio of 1: 2. An electrolyte solution was prepared by containing 0.05 g of the compound (A2). The content of the compound (A2) in the electrolytic solution was 0.5% by mass, and the content of LiPF _{6 in} the electrolytic solution was 13% by mass.

<Preparation 2 of positive electrode sheet>
90: 6: LiCoO ₂ (manufactured by Nippon Kagaku Kogyo Co., Ltd.) as the positive electrode active material, acetylene black powder (manufactured by Denki Kagaku Kogyo Co., Ltd.) as the conductive additive, and a polyvinylidene fluoride solution (manufactured by Kureha Co., Ltd.) as the binder. Mixed at a mass ratio of 4. A slurry was prepared by adding N-methyl-2-pyrrolidone as a dispersion solvent so that the solid concentration was 40% by mass and further mixing. The slurry was applied to one side of an aluminum foil having a thickness of 20 μm, and after removing the solvent by drying, the positive electrode sheet was obtained by rolling with a roll press.

<Preparation of negative electrode sheet 2>
Graphite powder (made by Osaka Gas Chemical Co., trade name “OMAC1.2H / SS”) and another graphite powder (made by TIMCAL, trade name “SFG6”) as a negative electrode active material, and styrene butadiene rubber (SBR) as a binder and The aqueous carboxymethyl cellulose solution was mixed at a mass ratio of 90: 10: 1.5: 1.8. The obtained mixture was added to water as a dispersion solvent so as to have a solid content concentration of 45% by mass to prepare a slurry. The slurry was applied to one side of a copper foil having a thickness of 18 μm, and after removing the solvent by drying, the negative electrode sheet was obtained by rolling with a roll press.

<Preparation of lithium ion secondary battery 2>
The positive electrode sheet and the negative electrode sheet prepared as described above were each punched into a disk shape having a diameter of 16 mm to obtain a positive electrode and a negative electrode. A laminated body in which the obtained positive electrode and negative electrode are superimposed on both sides of a separator (film thickness: 25 μm, porosity: 50%, pore diameter: 0.1 to 1 μm) made of a polypropylene microporous film is formed into a stainless steel disk type battery. Inserted into the case (exterior body). Next, 0.2 mL of the electrolytic solution described in each of the following Examples and Comparative Examples was injected therein, the laminate was immersed in the electrolytic solution, and then the battery case was sealed, thereby coin-type lithium ion secondary battery. Was made.

  With respect to the coin-type lithium ion secondary battery of Example 4, when the cycle test was performed by the method described in (3), the discharge capacity at the first cycle was 155 mAh / g, and the 600th cycle and the 1200th cycle The discharge capacities were as high as 111 mAh / g and 81 mAh / g, respectively, the battery resistance in the first cycle was 16Ω, and the battery resistances in the 600th cycle and 1200th cycle were as low as 27Ω and 47Ω, respectively. . Table 2 shows the results of battery performance evaluation.

(Comparative Example 3)
An electrolyte solution similar to that of Comparative Example 1 was prepared, and other than that, a positive electrode sheet, a negative electrode sheet, and a coin-type lithium ion secondary battery were manufactured in the same manner as in Example 4.

  With respect to the coin-type lithium ion secondary battery of Comparative Example 3, when the cycle test was performed by the method described in (3), the first cycle discharge capacity was 159 mAh / g, and the 600th cycle and the 1200th cycle The discharge capacities were 106 mAh / g and 45 mAh / g, respectively. The battery resistance at the first cycle was 13Ω, and the battery resistances at the 600th cycle and 1200th cycle were 31Ω and 71Ω, respectively. Table 2 shows the results of battery performance evaluation.

  The obtained results are shown in Table 2. As can be seen from Table 2, it can be seen that the use of the compound (A) not only improves the capacity retention rate in the cycle test, but also significantly suppresses the increase in battery resistance in the cycle test.

According to the present invention, a lithium ion secondary battery that operates at a high voltage and can suppress a decrease in cycle life and an increase in resistance during the cycle, and such a lithium ion secondary battery are provided. The compound, the electrolyte solution additive for non-aqueous electricity storage devices, and the electrolyte solution for non-aqueous electricity storage devices can be provided.
The electrolyte solution additive for non-aqueous electricity storage devices, the electrolyte solution for non-aqueous electricity storage devices, and the lithium ion secondary battery of the present invention have industrial applicability in the fields of various consumer equipment power supplies and automotive power supplies.

  100: lithium ion secondary battery, 110: separator, 120: positive electrode active material-containing layer, 130: negative electrode active material-containing layer, 140: positive electrode current collector, 150: negative electrode current collector, 160: battery exterior, 200: positive electrode , 300: negative electrode

Claims (13)

An electrolyte for a non-aqueous storage device, comprising a compound (A) containing 2 to 4 P atoms in one molecule and containing a structural unit represented by the following formula (1) Additive.

(In the above formula (1), each R independently represents an optionally substituted hydrocarbon group having 1 to 22 carbon atoms.) The said compound (A) is an electrolyte solution additive for nonaqueous electrical storage devices of Claim 1 which is a compound represented by following formula (2), (3) or (4).

(In the above formulas (2), (3) and (4), R is as defined above.)   The said compound (A) is an electrolyte solution additive for nonaqueous electrical storage devices of Claim 1 or 2 which is a compound represented by the said Formula (2) or (3). The electrolyte solution additive for nonaqueous energy storage devices according to any one of claims 1 to 3, wherein R is represented by the following formula (5).
SiRa ₃ (5)
(In the formula (5), each Ra independently represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms.)   The content rate of the compound represented by the said Formula (2) and the compound represented by Formula (3) among the mole number of the phosphorus compound contained in the said electrolyte solution additive is 50 mol% or more. The electrolyte solution additive for nonaqueous electrical storage devices in any one of -4.   An electrolyte solution for a non-aqueous electricity storage device, comprising: the electrolyte solution additive for a non-aqueous electricity storage device according to any one of claims 1 to 5; a non-aqueous solvent; and a lithium salt (B). .   The content of the compound (A) in the electrolyte solution additive is 0.1% by mass or more and 10% by mass or less with respect to 100% by mass of the electrolyte solution. Electrolytic solution.   The electrolyte solution for a nonaqueous electricity storage device according to claim 6 or 7, wherein the nonaqueous solvent contains a cyclic carbonate and a chain carbonate. The cyclic carbonate includes one or more selected from the group consisting of ethylene carbonate and propylene carbonate,
The electrolyte solution for a non-aqueous electricity storage device according to claim 8, wherein the chain carbonate includes one or more selected from the group consisting of dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. A positive electrode containing a positive electrode active material;
A negative electrode containing a negative electrode active material;
The electrolyte solution according to any one of claims 6 to 9,
A lithium ion secondary battery comprising: 11. The lithium ion secondary battery according to claim 10, wherein the positive electrode active material has a discharge capacity of 10 mAh / g or more at a potential of 4.3 V (vsLi / Li ⁺ ) or more. The positive electrode active material is an oxide represented by formula (6), an oxide represented by formula (7), a complex oxide represented by formula (8), a compound represented by formula (9), The lithium ion secondary battery of Claim 10 or 11 containing 1 or more types chosen from the group which consists of and the compound represented by Formula (10).
_{LiMn 2-x Ma x O 4} (6)
(In the above formula (6), Ma represents one or more selected from the group consisting of transition metals, and x is 0.2 ≦ x ≦ 0.7.)
LiMeO ₂ (7)
(In the above formula (7), Me represents one or more selected from the group consisting of transition metals.)
_{zLi 2 McO 3 - (1-} z) LiMdO 2 (8)
(In the above formula (8), Mc and Md each independently represent one or more selected from the group consisting of transition metals, and z is 0.1 ≦ z ≦ 0.9.)
LiMb _1-y Fe _y PO ₄ (9)
(In the above formula (9), Mb represents one or more selected from the group consisting of Mn and Co, and y is 0 ≦ y ≦ 0.9.)
Li ₂ MfPO ₄ F (10)
(In the above formula (10), Mf represents one or more selected from the group consisting of transition metals.) The lithium ion secondary battery according to any one of claims 10 to 12, wherein a positive electrode potential based on lithium at a full charge is 4.3 V (vsLi / Li ⁺ ) or more.

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