WO2004093224A1

WO2004093224A1 - Nonaqueous electrolyte solution and nonaqueous electrolyte battery using same

Info

Publication number: WO2004093224A1
Application number: PCT/JP2004/004961
Authority: WO
Inventors: Masashi Otsuki; Yasuo Horikawa
Original assignee: Bridgestone Corporation
Priority date: 2003-04-11
Filing date: 2004-04-06
Publication date: 2004-10-28
Also published as: JPWO2004093224A1

Abstract

A nonaqueous electrolyte solution is disclosed which has an excellent permeability through an electrode material and/or a separator and enables to reduce the internal resistance of a battery. A mode of such a nonaqueous electrolyte solution is characterized in that a contact angle (θ1) of a nonaqueous electrolyte solution (1) to an electrode (2) becomes 2° or less within less than 0.5 second after dropping the nonaqueous electrolyte solution (1) on the electrode (2). Another mode of such a nonaqueous electrolyte solution is characterized in that a contact angle (θ2) of the nonaqueous electrolyte solution (1) to a separator (3) becomes 25° or less within 2 seconds after dropping the nonaqueous electrolyte solution (1) on the separator (3).

Description

Description Non-aqueous electrolyte and non-aqueous electrolyte battery provided with the same

The present invention relates to a non-aqueous electrolyte and a non-aqueous electrolyte battery provided with the same, and more particularly to a non-aqueous electrolyte having excellent permeability to an electrode and / or a separator. Background art

Conventionally, in non-aqueous electrolyte batteries, the electrolyte material penetrates poorly into the battery material such as the separator and the battery electrode material, and particularly the electrolyte material penetrates poorly into the separator. After packing the members, the electrolytic solution was injected into the battery can while evacuating the battery can. Therefore, the conventional non-aqueous electrolyte battery had a complicated manufacturing process and low productivity. On the other hand, if the nonaqueous electrolyte is injected without evacuation of the battery can, it is necessary to leave the battery until the nonaqueous electrolyte penetrates into the battery electrode material, etc. Usually required a standing period of about two weeks. Further, the conventional non-aqueous electrolyte has a problem that the internal resistance is large because of poor permeability to the battery electrode material and the separator. Here, assuming that the internal resistance of the battery is R, the current value that can be taken out of the battery is I, and the value of the voltage drop is E, the voltage drops according to E = IR according to Ohm's law. In other words, by suppressing the internal resistance of the battery, the voltage drop of the battery can be suppressed, the capacity that can be taken out of the battery can be increased, and the battery life can be prolonged. be able to.

On the other hand, “Lithium-ion secondary batteries” published by Masayuki Yoshio and Akiya Ozawa, Nikkan Kogyo Shimbun Inc., have been devised in order to reduce the internal resistance of batteries by adding a conductive agent to the electrode material, Control is introduced. In addition, battery components such as separators However, since the wettability of the electrolyte is an important factor in achieving battery characteristics, various developments, such as control of separator pores, are introduced from the viewpoint of optimizing components. There is no mention of efforts to improve and improve wettability. Disclosure of the invention

On the other hand, in recent years, there has been a demand for a technology for reducing the internal resistance of a nonaqueous electrolyte battery in order to improve various characteristics thereof. In particular, for large rechargeable batteries that are required as a main power source or an auxiliary power source for electric vehicles and fuel cell vehicles, the following characteristics are extremely important. There is an urgent need for a technology to reduce the internal resistance of the battery in order to improve the characteristics of the battery.

In addition, primary batteries used in tire internal pressure warning devices are constantly exposed to pulse discharge, so they must have low internal resistance and excellent pulse discharge characteristics.

Therefore, an object of the present invention is to provide a non-aqueous electrolyte capable of solving the above-mentioned problems of the prior art, having excellent permeability to a battery electrode material and / or a separator, and capable of reducing the internal resistance of a battery. It is in. Another object of the present invention is to provide a non-aqueous electrolyte battery having a low internal resistance, comprising the non-aqueous electrolyte.

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the power of adding a specific compound to a conventional non-aqueous electrolyte mainly comprises a non-aqueous electrolyte formed from the compound. The present inventors have found that the internal resistance of a nonaqueous electrolyte battery can be reduced by improving the permeability of the electrolyte to the battery electrode material and / or the separator, and have completed the present invention.

That is, the first nonaqueous electrolytic solution of the present invention has a time of 0.5 seconds after the nonaqueous electrolytic solution is dropped on the electrode until the contact angle of the nonaqueous electrolytic solution to the electrode becomes 2 ° or less. Less than or equal to. In a preferred example of the first nonaqueous electrolyte according to the present invention, the electrode is a positive electrode, and an active material of the positive electrode is a lithium-containing composite oxide. Here, the active material of the positive electrode, that is L i C O_〇 _2, L i M n ₂ 〇 ₄ and L i N I_〇 least one lithium-containing composite oxide selected from the group consisting of ₂ More preferred. ·

In another preferable embodiment of the first non-aqueous electrolyte solution of the present invention, the electrode is a positive electrode, it is either the active material of the positive electrode is M n 0 ₂ and fluorinated graphite.

In another preferred embodiment of the first nonaqueous electrolyte of the present invention, the electrode is a negative electrode, and the active material of the negative electrode is graphite.

In another preferred example of the first non-aqueous electrolyte of the present invention, the non-aqueous electrolyte contains a compound having at least one of phosphorus and nitrogen in a molecule. Here, as the compound, a compound having phosphorus and nitrogen in the molecule is preferable, and a compound having phosphorus-nitrogen double bond is more preferable. It is preferable that the non-aqueous electrolyte further contains ester carbonate.

Further, a first non-aqueous electrolyte battery of the present invention includes the above-mentioned first non-aqueous electrolyte of the present invention, a positive electrode, and a negative electrode.

On the other hand, in the second non-aqueous electrolyte of the present invention, after the non-aqueous electrolyte is dropped on the separator, the time until the contact angle of the non-aqueous electrolyte with the separator becomes 25 ° or less is 2 seconds or less. It is characterized.

In a preferred example of the second non-aqueous electrolyte according to the present invention, the separator is a porous polymer membrane, and the separator is made of polypropylene (PP), polyethylene (PE), and polyethylene'polypropylene copolymer (P EZ PP). It consists of either.

In another preferred embodiment of the second non-aqueous electrolyte according to the present invention, the non-aqueous electrolyte contains a compound having at least one of phosphorus and nitrogen in a molecule. Here, as the compound, a compound having phosphorus and nitrogen in a molecule is preferable, and a compound having a phosphorus-nitrogen double bond is more preferable. It is preferable that the non-aqueous electrolyte further contains ester carbonate. Further, a second non-aqueous electrolyte battery of the present invention includes the second non-aqueous electrolyte of the present invention, a positive electrode, a negative electrode, and a separator.

ADVANTAGE OF THE INVENTION According to this invention, the non-aqueous electrolyte which is excellent in the permeability to a battery electrode material and / or a separator and which can reduce the internal resistance of a battery can be provided. In addition, since the non-aqueous electrolyte is provided and the internal resistance is low, a non-aqueous electrolyte battery having excellent pulse discharge characteristics ゃ large current discharge and charging characteristics can be provided. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram of a non-aqueous electrolyte dropped on an electrode.

FIG. 2 is a schematic diagram of the non-aqueous electrolyte dropped on the separator.

FIG. 3 is a graph showing the change over time of the contact angle of the electrolyte of Example 1 with respect to the positive electrode.

FIG. 4 is a graph showing the change over time of the contact angle of the electrolyte of Comparative Example 1 with respect to the positive electrode.

FIG. 5 is a graph showing the remaining discharge capacity of the batteries of Example 1 and Comparative Example 1. FIG. 6 is a graph showing the change over time of the contact angle of the electrolytic solution of Example 65 with the separator.

FIG. 7 is a graph showing the change over time of the contact angle of the electrolytic solution of Comparative Example 9 with the separator. BEST MODE FOR CARRYING OUT THE INVENTION

<Non-aqueous electrolyte>

Hereinafter, the first nonaqueous electrolytic solution of the present invention will be described in detail with reference to FIG. In the first nonaqueous electrolyte of the present invention, the time until the contact angle Θi of the nonaqueous electrolyte 1 with respect to the electrode 2 becomes 2 ° or less after dropping the nonaqueous electrolyte 1 on the electrode 2 is 0. It is characterized by being less than 5 seconds. The conventional non-aqueous electrolyte had a time of 0.5 seconds or more until the contact angle of the non-aqueous electrolyte with the electrode became ² ° or less after dropping on the electrode, so the permeability to the electrode was poor. Although the internal resistance has been increased, the first electrolytic solution of the present invention has extremely good permeability to the electrodes, so that the internal resistance of the battery can be kept low. Therefore, the non-aqueous electrolyte battery provided with the first non-aqueous electrolyte of the present invention has significantly improved pulse discharge characteristics ゃ large current discharge and charging characteristics as compared with the conventional non-aqueous electrolyte batteries. It is suitable as a large secondary battery for electric vehicles and fuel cell vehicles and a small primary battery for tire internal pressure alarm devices.

The first nonaqueous electrolyte of the present invention preferably has a viscosity at 25 ° C of 10 mPa's (10 cP) or less. The non-aqueous electrolyte whose viscosity at 25 ° C exceeds K) mPa's (lOcP) is dropped on the electrode and the time required for the contact angle of the non-aqueous electrolyte to the electrode to become 2 ° or less is 0. It tends to be 5 seconds or longer, and the effect of reducing the internal resistance of the battery is insufficient. From the viewpoint of further improving the permeability to the electrode, the first nonaqueous electrolyte of the present invention more preferably has a viscosity at 25 ° C. of 5 mPa's (5 cP) or less.

The first nonaqueous electrolytic solution of the present invention is not particularly limited as long as it satisfies the above-mentioned properties relating to the permeability to the electrode, but includes at least a supporting salt, and contains at least phosphorus and nitrogen in the molecule. It is preferable to include a compound containing one of them. Further, the non-aqueous electrolytic solution may contain a non-protonic organic solvent such as a carbonate ester as necessary.

Next, the second nonaqueous electrolyte of the present invention will be described in detail with reference to FIG. The second nonaqueous electrolytic solution of the present invention, was added dropwise nonaqueous electrolyte 1 separator 3 on the contact angle theta ₂ of the non-aqueous electrolyte 1 against separator one 3 the time until the 25 ° or less 2 Seconds or less.

The conventional non-aqueous electrolyte had a time of 5 seconds or longer until the contact angle of the non-aqueous electrolyte with the separator became 25 ° or less after dropping on the separator, so the permeability to the separator was poor and the internal Although the increase in resistance was caused, the second electrolytic solution of the present invention Since the permeability to the separator is extremely good, the internal resistance of the battery can be kept low. Therefore, the non-aqueous electrolyte battery provided with the second non-aqueous electrolyte of the present invention has significantly improved pulse discharge characteristics ゃ large current discharge and charging characteristics as compared with the conventional non-aqueous electrolyte battery, and in particular, It is suitable as a large secondary battery for electric vehicles and fuel cell vehicles.

The second non-aqueous electrolyte of the present invention preferably has a viscosity at 25 ° C. of 10 mPa ′ _S (10 cP) or less. The non-aqueous electrolyte whose viscosity at 25 ° C exceeds lOmPa's (lOcP) is dropped on the separator and the time until the contact angle of the non-aqueous electrolyte with the separator becomes 25 ° or less is 2 seconds. And the effect of reducing the internal resistance of the battery is insufficient. From the viewpoint of further improving the permeability to the separator, the second nonaqueous electrolytic solution of the present invention more preferably has a viscosity at 25 ° C of 5 mPa's (5 cP) or less.

The second nonaqueous electrolytic solution of the present invention is not particularly limited as long as it satisfies the above-mentioned properties relating to permeability to the separator, but includes at least a supporting salt, and contains at least phosphorus and nitrogen in the molecule. It is preferable to include a compound containing one of them. In addition, the non-aqueous electrolyte may contain an aprotic organic solvent such as a carbonate ester, if necessary.

Examples of the compound having phosphorus in the molecule that can be suitably used in the first and second nonaqueous electrolytes of the present invention include an esterinol phosphate compound, a polyphosphate ester compound, and a condensed phosphate ester compound. .

Compounds having nitrogen in the molecule that can be suitably used in the first and second nonaqueous electrolytes of the present invention include cyclic nitrogen-containing compounds such as triazine compounds, guanidine compounds, and pyrrolidine compounds. Is mentioned.

Further, as the compound having phosphorus and nitrogen in the molecule which can be suitably used in the first and second non-aqueous electrolytes of the present invention, phosphazene compounds, isomers of phosphazene compounds, phosphazene compounds, and A compound having phosphorus in the molecule And the compound exemplified as the compound having nitrogen in the molecule. Note that these compounds having phosphorus and nitrogen in the molecule are naturally examples of the compound having phosphorus in the molecule and the compound having nitrogen in the molecule. Among the compounds containing at least one of phosphorus and nitrogen in the molecule, compounds having phosphorus and nitrogen in the molecule are preferable from the viewpoint of cycle characteristics. Further, among the above compounds having phosphorus and nitrogen in the molecule, a compound having a phosphorus-nitrogen double bond such as a phosphazene compound is particularly preferable from the viewpoint of improving thermal stability and high-temperature storage characteristics. .

Specific examples of the phosphazene compound include a chain phosphazene compound represented by the following formula (I) and a cyclic phosphazene compound represented by the following formula (II).

R ² Y ² — Ρ = N— X ¹ … (I)

Y ³ R ³

(Wherein R ¹ R ² and R ³ each independently represent a monovalent substituent or a halogen element; X ¹ represents carbon, silicon, germanium, tin, nitrogen, phosphorus, arsenic, antimony, bismuth , oxygen, sulfur, selenium, tellurium and Polo - represents a substituent containing at least one element selected from the group consisting © beam; Upsilon Upsilon ² and Upsilon ³ are each independently a ^divalent linking group, 2 Represents a valence element or a single bond.

(NPR ₂ ) _n · ■ ■ (II)

(In the formula, R ⁴ represents a monovalent substituent or a halogen element. N represents 3 to 15.

)

Among the phosphazene compounds represented by the formula (I) or (II), those which are liquid at 25 ° C. (room temperature) are preferable. The occupancy of the liquid phosphazene compound at 25 ° C. is preferably 300 mPa's (300 cP) or less, more preferably 20 mPa's (20 cP) or less, and particularly preferably 5 mPa · s (5 cP) or less. In the present invention, the viscosity is measured using a viscometer (R type) Viscometer M odel RE 5 0 0 - using SL, Toki Sangyo Co., Ltd.), lrpm, 2rptn, 3rpm, 5rpra, 7rpm, 10rpra, 20rpm, and ⁵ to 120 seconds Dzu' measured at each rotational speed of Orpm, The rotational speed when the indicated value became 50 to 60% was used as the analysis condition, and the viscosity at that time was measured. If the viscosity at 25 ° C exceeds ¾00 mPa's (300 cP), the supporting salt becomes difficult to dissolve, the wettability to the positive electrode material, negative electrode material, separator, etc. decreases, and the ionic conductivity increases due to the increase in the viscous resistance of the electrolyte. The performance is remarkably reduced, and the performance becomes insufficient especially when used under low temperature conditions such as below the permanent point. In addition, since these phosphazene compounds are liquid, they have the same conductivity as ordinary liquid electrolytes, and exhibit excellent cycle characteristics when used in electrolytes of secondary batteries.

In the formula (I), RR ² and R ³ are not particularly limited as long as they are monovalent substituents or halogen elements. Examples of the monovalent substituent include an alkoxy group, an alkyl group, a hydroxyl group, an acyl group, an aryl group, and the like. Among them, an alkoxy group is preferable because the viscosity of the electrolytic solution can be reduced. On the other hand, preferred examples of the halogen element include fluorine, chlorine, and bromine. Ι ^ ~Ι ³ may be all the same kind of the substituent, may some of them in different kinds of substituents.

Here, examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like, and an alkoxy-substituted alkoxy group such as a methoxyethoxy group and a methoxyethoxyethoxy group. Among them, R ¹ ! ^ ³ is preferably a methoxy group, an ethoxy group, a methoxy ethoxy group, or a methoxy ethoxy ethoxy group, and all are methoxy groups from the viewpoint of low viscosity and high dielectric constant. Or an ethoxy group is particularly preferred. Examples of the alkynole group include a methynole group, an ethylenole group, a propyl group, a butyl group, a pentyl group and the like. Examples of the acyl group include a formyl group, an acetyl group, a propioyl group, a butyryl group, an isoptyryl group, and a valeryl group. Examples of the aryl group include a fuel group, a trinole group, and a naphthyl group. The hydrogen element in these monovalent substituents is preferably substituted with a halogen element. As the halogen element, fluorine, chlorine, and bromine are preferable. A certain force Of these, fluorine is particularly preferred, followed by chlorine. When the hydrogen element in the monovalent substituent is replaced by fluorine, the effect of improving the cycle characteristics of the secondary battery tends to be greater than that in the case where the hydrogen element is replaced by chlorine.

In the formula (I), the divalent linking group represented by Y Upsilon ² and Upsilon ^3, for example, addition of CH ₂ group, oxygen, sulfur, selenium, nitrogen, boron, Anoremi - © beam, scandium © beam , Gallium, ittrium, indium, lanthanum, talmium, carbon, silicon, titanium, tin, germanium, zirconium, lead, phosphorus, vanadium, arsenic, niobium, antimony, tantalle, bismuth, chromium, molybdenum, tungsten, tungsten, tungsten , iron, Kobanoreto, include a divalent linking group containing at least one element selected from the group consisting of nickel, among these, CH ₂ group,及beauty, oxygen, sulfur, selenium, from the group consisting of nitrogen A divalent linking group containing at least one of the selected elements is preferable, and a divalent linking group containing elements of sulfur and Z or selenium is preferred. Valent linking groups are particularly preferred. Y ² and ³ may be a divalent element such as oxygen, sulfur, selenium, or a single bond. Υ ^{1 to} Υ ³ may be all the same type, or some may be different types.

In the formula (I), X ¹ represents at least one element selected from the group consisting of carbon, silicon, nitrogen, phosphorus, oxygen, and sulfur from the viewpoint of harmfulness and environmental considerations. Substituents containing species are preferred. Among these substituents, a substituent having a structure represented by the following formula (ΠΙ), (IV) or (V) is more preferable.

Y ⁵ R ⁵

? D ... (! Π)

γθρο

— S— Y 7 'ηR7 (IV) Y ⁸ R ⁸

/

— N · · (V)

ヽ 9

In the formulas (111), (IV), and (V), R ^{5 to} R ⁹ independently represent a monovalent substituent or a halogen element. Y ^{5 to} Y ⁹ independently represent a divalent linking group, a divalent element, or a single bond; and Ζ represents a divalent group or a divalent element.

In the formulas (111) and (IV) ヽ (V), R ^{5 to} R ⁹ are the same monovalent substituents or halogen elements as described for R ^ R ³ in the formula (I). Preferred examples are given. Further, these may be of the same type within the same substituent, or may be of different types. R ⁵ and R ^{6 in} the formula (III), and R ⁸ and R ^{9 in} the formula (V) may be bonded to each other to form a ring.

Equation (111), (IV), in (V), Y ⁵ as the group represented by to Y ^9, similar divalent linking group as described in the Yi～Y ³ that put the formula (I) Or a divalent element. Similarly, a group containing sulfur, Z, or selenium is particularly preferable because the risk of ignition and ignition of the electrolytic solution is reduced. These may be of the same type within the same substituent, or some may be of different types.

In the formula (III), Z represents, for example, CH ₂ , CHR (R represents an alkyl group, an alkoxyl group, a fuel group, etc .; the same applies hereinafter), an NR group, oxygen, sulfur, selenium, Boron, aluminum, scandium, gallium, yttrium, indium, lanthanum, thallium, carbon, silicon, titanium, tin, germanium, zirconium, lead, phosphorus, vanadium, arsenic, jap, antimony, tantalum, bismuth, chromium, molybdenum, tenorenole , polonium, tungsten, iron, cobalt, and a divalent group containing at least one element selected from the group consisting of nickel. among them, CH ₂ group, CHR group, in addition to NR group, oxygen , A divalent group containing at least one element selected from the group consisting of sulfur and selenium is preferable . Particularly, in the case of a ^divalent group containing sulfur and / or selenium, the ignition of the electrolyte - It is preferable because the risk of ignition is reduced. Z may be a divalent element such as oxygen, sulfur, and selenium.

As these substituents, a phosphorus-containing substituent represented by the formula (III) is particularly preferable, since the risk of ignition and ignition can be particularly effectively reduced. Further, when the substituent is a substituent containing sulfur as represented by the formula (IV), it is particularly preferable in terms of reducing the interface resistance of the electrolytic solution.

In the formula (II), R ⁴ is not particularly limited as long as it is a monovalent substituent or a halogen element. Examples of the monovalent substituent include an alkoxy group, an alkyl group, a carboxyl group, an acyl group, an aryl group, and the like. Among them, an alkoxy group is preferable because the viscosity of the electrolytic solution can be reduced. On the other hand, as the halogen element, for example, fluorine, chlorine, bromine and the like are preferably mentioned. Examples of the alkoxy group include a methoxy group, an ethoxy group, a methoxetoxy group, a propoxy group, a phenoxy group and the like. Among them, when used in a nonaqueous electrolyte primary battery, a methoxy group, an ethoxy group Groups, n-propoxy groups and phenoxy groups are particularly preferred, and when used in non-aqueous electrolyte secondary batteries, methoxy groups, ethoxy groups, methoxyethoxy groups and phenoxy groups are particularly preferred. The hydrogen element in these monovalent substituents is preferably substituted with a halogen element. Examples of the halogen element include fluorine, chlorine, and bromine. Is, for example, a trifluoro mouth ethoxy group.

In equations (I) to (V)! By selecting ^ ¹ to! ^ ⁹ , Y ^{1 to} Y ³ , Υ ^{5 to} Υ ⁹ , 適宜 as appropriate, it is possible to prepare an electrolyte having more suitable viscosity, solubility suitable for addition and mixing, etc. It becomes. These phosphazene compounds may be used alone or in a combination of two or more.

Among the phosphazene compounds of the formula (II), from the viewpoint of improving the low-temperature characteristics of the battery by lowering the viscosity of the electrolyte and further improving the resistance to deterioration and safety of the electrolyte, the following formula (VI) is used. Phosphazene compounds are preferred. (NPF ₂ ) _n · · ■ (VI)

(In the formula, n represents 3 to 13.)

The phosphazene compound represented by the formula (VI) is a low-viscosity liquid at room temperature (25 ° C.) and has a freezing point depressing action. Therefore, by adding the phosphazene compound to the electrolytic solution, it is possible to impart excellent low-temperature characteristics to the electrolytic solution, and a low viscosity of the electrolytic solution is achieved, and a low internal resistance and high! / ヽ It is possible to provide a non-aqueous electrolyte battery having conductivity. Therefore, it is possible to provide a non-aqueous electrolyte battery that exhibits excellent discharge characteristics over a long period of time even when used under low-temperature conditions, particularly in regions and periods when the temperature is low.

In the formula (VI), n is preferably from 3 to 5, more preferably from 3 to 4, because it can impart excellent low-temperature properties to the electrolytic solution and can reduce the viscosity of the electrolytic solution. It is good. When the value of n is small, the boiling point is low, and the ignition prevention characteristics at the time of flame contact can be improved. On the other hand, as the value of n increases, the boiling point increases, so that it can be used stably even at high temperatures. It is also possible to select and use multiple phosphazenes in a timely manner to obtain the desired performance using the above properties.

By appropriately selecting the value of n in the formula (VI), it becomes possible to prepare an electrolyte having more favorable viscosity, solubility suitable for mixing, low-temperature characteristics, and the like. These phosphazene compounds may be used alone or in a combination of two or more.

The viscosity of the phosphazene compound represented by the formula (VI) is not particularly limited as long as it is 20 mPa's (20 cP) or less, but from the viewpoint of improving conductivity and improving low-temperature characteristics, it is 10 mPa's (10 cP). ) Or less, more preferably 5 mPa's (5 cP) or less.

Among the phosphazene compounds of the formula (II), a phosphazene compound represented by the following formula (VII) is preferable from the viewpoint of improving the deterioration resistance and safety of the electrolytic solution.

(NPR ¹⁰ ₂ ) _n '--(VII)

(Wherein, R ^1G each independently represents a monovalent substituent or fluorine, at least one of all R ^1D is a monovalent substituent containing fluorine or fluorine, and n is 3 to 8 Represents However, not all R ¹⁰ is fluorine. )

When the phosphazene compound of the formula (II) is contained, the electrolyte can be provided with excellent self-extinguishing properties or flame retardancy to improve the safety of the electrolyte. , All R ¹ . When at least one of them contains a phosphazene compound which is a monovalent substituent containing fluorine, it is possible to impart more excellent safety to the electrolytic solution. Further, when a phosphazene compound represented by the formula (VII) and at least one of all R ^1Q is fluorine is contained, more excellent safety can be provided. That is, compared to a phosphazene compound containing no fluorine, a phosphazene compound represented by the formula (VII) in which at least one of all R ¹⁰ is a monovalent substituent containing fluorine or fluorine is more difficult to burn the electrolytic solution. This can provide more excellent safety to the electrolytic solution.

In the formula (VII), all R ¹ . Is a non-flammable ring phosphazene compound in which n is 3 and has a great effect of preventing ignition when a flame approaches, but all of them have a very low boiling point because of their extremely low boiling point. If it evaporates, the remaining aprotic organic solvent will burn.

Examples of the monovalent substituent in the formula (VII) include an alkoxy group, an alkyl group, an acyl group, an aryl group, a carboxyl group, and the like.The alkoxy group is particularly excellent in improving the safety of the electrolytic solution. It is suitable. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, a butoxy group, and an alkoxy-substituted alkoxy group such as a methoxyethoxy group. A methoxy group, an ethoxy group, and an n-propoxy group are particularly preferable in terms of excellent improvement. Further, a methoxy group is preferable from the viewpoint of reducing the viscosity of the electrolytic solution.

In the formula (VII), n is preferably from 3 to 5, more preferably from 3 to 4, from the viewpoint that excellent safety can be imparted to the electrolytic solution.

The monovalent substituent is preferably substituted with fluorine. When R ^{1Q in} the formula (VII) is not fluorine, at least one monovalent substituent contains fluorine. The content of the fluorine in the phosphazene compound is preferably from 3 to 70% by weight, and more preferably from 7 to 45% by weight. When the content is within the above range, “excellent safety” can be particularly suitably imparted to the electrolytic solution.

The molecular structure of the phosphazene compound represented by the formula (VII) may contain a halogen element such as chlorine and bromine in addition to the above-mentioned fluorine. Most preferably, fluorine is followed by chlorine. Those containing fluorine tend to have a greater effect of improving the cycle characteristics of the secondary battery than those containing chlorine.

By appropriately selecting the values of R ^w and n in the formula (VII), it is possible to prepare an electrolyte having more suitable safety, viscosity, solubility suitable for mixing, and the like. These phosphazene compounds may be used alone or in a combination of two or more. The viscosity of the phosphazene compound represented by the formula (VII) is not particularly limited as long as it is 20 mPa's (20 cP) or less, but from the viewpoint of improving conductivity and improving low-temperature characteristics, the viscosity is preferably 10 raPa-s (lOcP ) Or less, and more preferably 5 raPa-s (5 cP) or less.

Among the phosphazene compounds of the formula (Π), from the viewpoint of improving the resistance to deterioration and safety of the electrolyte while suppressing the increase in the viscosity of the electrolyte, the phosphazene compound is a solid at 25 ° C. (room temperature), A phosphazene compound represented by the following formula (VI 11) is also preferable.

(NPR ⁿ ₂ ) _n · · ■ (VIII)

(Wherein, R ¹¹ each independently represents a monovalent substituent or a halogen element; n represents 3 to 6.)

Since the phosphazene compound represented by the formula (VIII) is solid at room temperature (25 ° C.), when it is added to an electroconductive solution, it is dissolved in the electrolytic solution and the viscosity of the electrolytic solution increases. However, if the addition amount is a predetermined amount, a nonaqueous electrolyte battery having a low rate of increase in the viscosity of the electrolyte, a low internal resistance, and a high conductivity is obtained. In addition, since the phosphazene compound represented by the formula (VIII) dissolves in the electrolyte, the electrolyte has excellent long-term stability.

In the formula (VIII), R ¹¹ is not particularly limited as long as it is a monovalent substituent or a halogen element. Examples of the monovalent substituent include an alkoxy group, an alkyl group and a carboxy group. And aryl groups, aryl groups and aryl groups. Further, as the halogen element, for example, a halogen element such as fluorine, chlorine, bromine, and iodine is preferably exemplified. Among these, an alkoxy group is particularly preferred, since it can suppress an increase in the viscosity of the electrolytic solution. The alkoxy group is preferably a methoxy group, an ethoxy group, a methoxetoxy group, a propoxy group (isopropoxy group, n-propoxy group), a phenoxy group, a trifluoroethoxy group or the like, which suppresses an increase in the viscosity of the electrolytic solution. From the viewpoint of obtaining, a methoxy group, an ethoxy group, a propoxy group (isopropoxy group, n-propoxy group), a phenoxy group, a trifluoroethoxy group, and the like are more preferable. The monovalent substituent preferably contains the halogen element described above.

In the formula (VIII), n is particularly preferably 3 or 4 from the viewpoint that the increase in the viscosity of the electrolytic solution can be suppressed.

Wherein the phosphazene compound represented by (VIII), for example, the formula (VI II) to your stomach structure a R ¹¹ turtles butoxy group and n is 3, R ¹¹ turtles preparative In formula (VIII) A structure wherein at least one of an xy group and a phenoxy group and n is 4, a structure wherein R ¹¹ is an ethoxy group and n is 4 in the formula (VIII), and a structure wherein R ¹¹ is isopropoxy in the formula (VII I) A structure in which n is 3 or 4; a structure in which R ¹¹ is an n-propoxy group in the formula (VI Π) and n is 4; and a compound in which R ¹¹ is a trifluoroethoxy group in the formula (VI II) And n is 3 or 4, and in the formula (VI 11), R ¹¹ is a phenoxy group and n is 3 or 4, particularly in that it can suppress an increase in the viscosity of the electrolyte. preferable.

By appropriately selecting each substituent and the value of n in the formula (VIII), it becomes possible to prepare an electrolyte having more suitable viscosity, solubility suitable for mixing, and the like. These phosphazene compounds may be used alone or in a combination of two or more.

Specific examples of the isomer of the phosphazene compound include a compound represented by the following formula (IX). The compound of the formula (IX) is an isomer of a phosphazene compound represented by the following formula (X). 0 R ¹⁴

II I

2 γ12. P— N— X

γ 13 ^ 13

0R, 14

"

R ¹² Y ¹² — — X ² (X)

(In the formulas (IX) and (X), R ¹² , R ¹³ and R ″ each independently represent a monovalent substituent or a halogen element; X ² represents carbon, silicon, germanium, tin, nitrogen, Li down represents arsenic, antimony, bismuth, oxygen, sulfur, selenium, a substituent containing at least one element selected from the group consisting of tellurium及Pi polonium; Y ¹² and Y ¹³ are each independently Represents a divalent linking group, a divalent element or a single bond.

R ¹² , R ¹³ and R ¹⁴ in the formula (IX) are not particularly limited as long as they are monovalent substituents or halogen elements, and are the same as those described for Ri R ³ in the above formula (I). Both a valent substituent and a halogen element are preferably exemplified. Moreover, Te formula (IX) smell, the divalent linking group or a bivalent element represented by Y ¹² and Y ^13, similar to that described in ^Υ Σ ~Υ ³ that put the formula (I) A divalent linking group, a divalent element, and the like are all preferably exemplified. Further, in the formula (IX), as the substituent represented by X ² , any of the same substituents as those described for X ¹ in the formula (I) are preferably exemplified.

The isomer of the phosphazene compound represented by the formula (IX) and the formula (X), when added to the electrolyte, allows the electrolyte to exhibit extremely excellent low-temperature characteristics. Can be improved in deterioration resistance and safety.

The isomer represented by the formula (IX) is an isomer of the phosphazene compound represented by the formula (X). For example, the degree of vacuum and / or It can be produced by adjusting the temperature, and the content (% by volume) of the isomer can be measured by the following measuring method.

[Measuring method] The peak area of the sample is determined by Geno Permeation Chromatography (GPC) or High Performance Liquid Chromatography, and the peak area is compared with the previously determined area per mole of the isomer. It can be measured by obtaining the molar ratio and converting the volume taking into account the specific gravity.

Specific examples of the phosphoric acid ester include alkynolephosphates such as trifuninolephosphate, tricrezi / rephosphate, tris (fluorenetinole) phosphate, tris (trifluoroneopentinole) phosphate, alkoxyphosphate and alkoxyphosphate. These derivatives may be mentioned.

As the supporting salt contained in the first and second non-aqueous electrolytes of the present invention, a supporting salt serving as a lithium ion ion source is preferable. As the supporting salt is not particularly limited, for _{example, L i C 10 4, L} i BF 4, L i PF 6, L i CF 3 S_〇 _3,及_{Pi, L i A s F 6,} L i Lithium salts such as C ₄ F ₉ S〇 ₃ , Li (CF ₃ S〇 ₂ ) ₂ N, and Li (C ₂ F ₅ S 0 ₂ ) ₂ N are preferred. These may be used alone or in combination of two or more.

The concentration of the supporting salt in the electrolyte is preferably from 0.2 to 1.5 mol / L (M), more preferably from 0.5 to 1 mol / L (M). If the concentration of the supporting salt is less than 0.2 mol / L (M), sufficient conductivity of the electrolyte cannot be secured, which may impair the charge / discharge characteristics of the battery. ), The viscosity of the electrolyte increases, and sufficient mobility of lithium ions cannot be secured.Therefore, sufficient conductivity of the electrolyte cannot be secured as described above, and the discharge and charge characteristics of the battery are hindered. May occur.

The first and second non-aqueous electrolytes of the present invention, in addition to the above-described compound containing at least one of phosphorus and nitrogen in the molecule and the supporting salt, also have a viscosity of the electrolyte without reacting with the negative electrode. From the viewpoint of keeping the content low, it is preferable to contain an aprotic organic solvent. As the aprotic organic solvent, specifically, dimethyl carbonate (DMC), ethynolecarbonate (DEC), dipheninolecarbonate, ethynolemethinolecarbonate (EMC), ethylene carbonate (EC), Propylene carbonate (PC), Preferable examples include carbonates such as y-butyrolactone (GBL) and γ-valerolatatotone, and ethers such as 1,2-dimethoxetane (DME) and tetrahydrofuran (THF). Of these, carbonate esters are preferred. Cyclic carbonates are preferred in that they have a high relative dielectric constant and are excellent in the solubility of the supporting salt, while chain-like carbonates have a low viscosity, so that the viscosity of the electrolytic solution is reduced. It is suitable. These may be used alone or in combination of two or more.

From the viewpoint of improving the permeability of the electrolyte to the electrode material, the content of the compound containing at least one of phosphorus and nitrogen in the molecule at night is preferably 0.1 vol% or more, More preferably, it is at least volume%. Further, from the viewpoint of improving the safety of the electrolyte, the content is preferably 3% by volume or more, more preferably 5% by volume or more. On the other hand, the content of the compound containing at least one of phosphorus and nitrogen in the molecule in the second nonaqueous electrolyte of the present invention is preferably 0.1% by volume or more from the viewpoint of improving the permeability of the electrolyte to the separator. It is preferably at least 0.5% by volume. Further, from the viewpoint of improving the safety of the electrolyte, the content is preferably 3% by volume or more, more preferably 5% by volume or more.

Non-aqueous electrolyte battery>

Next, the nonaqueous electrolyte battery of the present invention will be described in detail. A first non-aqueous electrolyte battery of the present invention includes the above-described first non-aqueous electrolyte of the present invention, a positive electrode, and a negative electrode. If necessary, a non-aqueous electrolyte battery such as a separator is provided. Equipped with components commonly used in the technical field. On the other hand, a second non-aqueous electrolyte battery of the present invention includes the above-described second non-aqueous electrolyte of the present invention, a positive electrode, a negative electrode, and a separator. It has members commonly used in the technical field.

The positive electrode active materials of the first and second nonaqueous electrolyte batteries of the present invention are partially different between the primary battery and the secondary battery. For example, as the positive electrode active material of the nonaqueous electrolyte primary battery, fluorinated graphite is used. _{_{((CF x) n),}} Mn0 2 ( even electrochemical synthesis may be chemical synthesis), V ₂ 0 _5, Mo_〇 _3, Ag. C R_〇 _{4, CuO, Cu S, F} e S 2, S_〇. ·, S〇 C 1 ₂ , Ti S ₂ Among these, MnO ₂ and fluorinated graphite are preferred among them because of their high capacity, high safety, and high discharge potential and excellent electrolyte wettability. These materials may be used alone or in combination of two or more.

On the other hand, as the positive electrode active material of the nonaqueous electrolyte secondary _{_{_{battery, V 2 0 5, V 6}}} 0 13, Mn0 2, Mn 0 metal oxides such as _3, L i C O_〇 _2, L i N i 0 _2, L i Mn ₂ 〇 _4, L i F e 0 ₂ and L i F e P0 ₄ such as a lithium-containing composite Sani匕物of, T i S _2, Mo S metal sulfides such as _2, Poria diphosphate etc. And the like. The lithium-containing composite oxide may be a composite oxide containing two or three transition metals selected from the group consisting of Fe, Mn, Co, and Ni. Object is L i F e _x C o _y N i ₍₁ - _x - _y) 0 ₂ (where 0≤χ <1, 0≤y <1 0 <x + y≤ l) or L iMn _x It is represented by F e _y 〇 ₂ _ _x _ _y or the like. Among these, high safety in high capacity, even from the viewpoint of excellent wettability of the electrolytic solution, L i C O_〇 _{_{2, L i N i 0 2}} , L i Mn 2 〇 ₄ is particularly preferred. These materials may be used alone or in combination of two or more.

The negative electrode active materials of the first and second nonaqueous electrolyte batteries of the present invention are partially different between the primary battery and the secondary battery. For example, the negative electrode active material of the nonaqueous electrolyte primary battery is lithium metal itself. And a lithium alloy. Examples of the metal that forms an alloy with lithium include Sn, Pb, Al, Au, Pt, In, Zn, Cd, Ag, and Mg. Among them, A1, Zn, and Mg are preferable from the viewpoint of large reserves and toxicity. These materials may be used alone or in combination of two or more.

On the other hand, negative electrode active materials for nonaqueous electrolyte secondary batteries include lithium metal itself, alloys of lithium with Al, In, Pb or Zn, and carbon materials such as black holes doped with lithium. Among these, carbon materials such as graphite are preferable, and graphite is particularly preferable, in view of higher safety and excellent wettability of the electrolytic solution. Here, examples of graphite include natural graphite, artificial graphite, mesophase carbon microbeads (MCM B), and the like, and broadly graphitizable carbon and non-graphitizable carbon. These materials The materials may be used alone or in combination of two or more.

The positive electrode and the negative electrode can be mixed with a conductive agent and a binder as needed. Examples of the conductive agent include acetylene black and the like. As the binder, polyvinylidene fluoride (PVDF) is used. , Polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), and the like. These additives can be used in the same mixing ratio as in the past. Specifically, in the case of a positive electrode of a primary battery, the mass ratio of the positive electrode active material: the binder: the conductive agent is 8: 1. : 0.2 to 8: 1: 1. In the case of a positive electrode and a negative electrode of a secondary battery, the mass ratio of active material: binder: conductive agent is preferably 94: 3: 3:

The shapes of the positive electrode and the negative electrode are not particularly limited, and may be appropriately selected from known shapes as electrodes. For example, a sheet shape, a column shape, a plate shape, a spiral shape and the like can be mentioned.

The separator used in the second nonaqueous electrolyte battery of the present invention is disposed between the positive and negative electrodes, and prevents a short circuit of current due to contact between both electrodes. As a material of the separator, a material capable of reliably preventing contact between the two electrodes and capable of passing or containing an electrolyte, for example, polypropylene (PP), polyethylene (PE), polyethylene-polypropylene copolymer Suitable examples include nonwoven fabrics made of synthetic resins such as (PE / PP), polytetrafluoroethylene, cellulosic, polybutylene terephthalate, and polyethylene terephthalate, and porous polymer films. Among these, porous polymer membranes made of polyolefin such as polypropylene, polyethylene and polyethylene-polypropylene copolymer having a thickness of about 20 to 50 zm are particularly preferred. The separator 1 can be used for the first nonaqueous electrolyte battery of the present invention.

For the first and second nonaqueous electrolyte batteries of the present invention, known members usually used for nonaqueous electrolyte batteries can be suitably used.

There are no particular restrictions on the form of the first and second nonaqueous electrolyte batteries of the present invention described above. A coin type, a button type, a paper type, a square type, or a spiral type Various known forms, such as a cylindrical battery having a monolithic structure, are preferably exemplified. Bo:

In this case, a nonaqueous electrolyte battery can be manufactured by preparing a sheet-shaped positive electrode and a negative electrode, and sandwiching a separator between the positive electrode and the negative electrode. In the case of a spiral structure, for example, a nonaqueous electrolyte battery is manufactured by forming a sheet-shaped positive electrode, sandwiching a current collector, and stacking and winding a sheet-shaped negative electrode. Can be made. Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

(Example 1)

Against L IMN ₂ 0 ₄ (positive electrode active material) ⁹⁴ parts by mass of acetylene black (conductive agent) and 3 parts by mass of polyvinylidene fluoride (binder) and 3 parts by mass of an organic solvent (acetic Echiru 50/50 mass% mixed solvent with ethanol), apply the kneaded material to a 25 μηι thick aluminum foil (current collector) with a doctor blade, and dry with hot air (100 to 120 ° C) Thus, a positive electrode sheet having a thickness of 80 im was produced.

In a mixed solution of ethylene carbonate (EC) and getyl carbonate (DEC) (aprotic organic solvent, volume ratio: ECZDEC = 1/1), 90% by volume of cyclic phosphazene A (in formula (II)) 3, a cyclic phosphazene compound in which one of six R ⁴ is a phenoxy group (PhO_) and five is fluorine, viscosity at 25 ° C .: 1.7 mPa's (L7cP)) ₆ (supporting salt) was dissolved at a concentration of 1 mol / L (M) to prepare an electrolytic solution.

At room temperature, 5 μL of the above electrolytic solution was dropped onto the above positive electrode sheet, and the state of penetration of the electrolytic solution into the positive electrode sheet was monitored using a CCD camera with a resolution of 360 frames / sec. The corner was measured. The contact angle was measured using an automatic contact angle measuring device OCA20 manufactured by dataphysics. Figure 3 shows the change over time in the contact angle of the electrolyte with the positive electrode. As a result, the time required for the contact angle of the electrolyte with the positive electrode sheet to be 2 ° or less was less than 0.1 second. In addition, the safety of the above electrolyte was evaluated based on the combustion behavior of a flame ignited in an atmospheric environment by a method arranging the UL (Underwriting Laboratory) standard UL 94 HB method. At that time, ignitability, flammability, carbide formation, and the phenomenon during secondary ignition were also observed. Specifically, based on UL test standards, a non-combustible quartz fiber was impregnated with 1.OmL of the above electrolytic solution to prepare a 127 mm x 12.7 mm test piece. Here, the case where the test flame does not ignite the test piece (combustion length: 0 瞧) is “non-flammable”, the case where the ignited flame does not reach the 25 hidden line and the ignition of the falling object is not recognized. If the flame is `` flame retardant '', the ignited flame extinguishes in the 25-100 mm line and no ignition is found on the falling object, `` self-extinguishing '', if the ignited flame exceeds the lOOnm line The combination was evaluated as “flammability”. Table 1 shows the results.

Next, a lithium metal foil with a thickness of 150 / zm is overlaid on the above-mentioned positive electrode sheet via a separator (microporous film: made of polypropylene) with a thickness of 25 ^ πι, and rolled up. Produced. The length of the positive electrode of the cylindrical electrode was about 260 mm. The electrolytic solution was injected into the cylindrical electrode and sealed to prepare an AA lithium battery (a non-aqueous electrolytic solution secondary battery).

For the above batteries, the discharge capacity (A) when discharging at 2 C rate (the condition where the whole capacity is discharged in 30 minutes) and the discharge when discharging at 0.2 C rate (the condition where the whole capacity is discharged in 5 hours) The capacity (B) was measured. The 2 C capacity (° / ₀ ) was calculated from these measured values and the following formula, and the results shown in Table 1 were obtained.

Formula: 2 C capacity = AZB X 100 (%)

(Examples 2 to 21 and Comparative Examples 1 to 6)

An electrolytic solution having the formulation shown in Table 1 was prepared, and the permeability and safety of the electrolytic solution to the positive electrode were evaluated in the same manner as in Example 1. FIG. 4 shows the change over time of the contact angle of the electrolyte of Comparative Example 1 with respect to the positive electrode. And伹In Example 3 and Comparative Example 2, using L i C o 0 ₂ instead of L i M n ₂ 〇 ₄ as a cathode active material, in Example 4 and Comparative Example 3, L i N i 0 ₂ Was used to prepare a positive electrode, and the permeability to the positive electrode was tested. The results are shown in Table 1. You. In Table 1, DMC indicates dimethyl carbonate, and Li BETI indicates Li (C ₂ F ₅ S〇 ₂ ) ₂ N.

The cyclic phosphazene B is a compound of the formula (II) in which n is 3, one of six R ⁴ is an ethoxy group, and five are fluorine (viscosity at 25 ° C .: 1.2 mPa-s (l .2cP)) is a compound of the formula (II) wherein n is 4, one of eight R ⁴ is an ethoxy group, and seven are fluorine (viscosity at 25 ° C .: 1 lmPa's (L IcP)); cyclic phosphazene D is represented by the formula (II), wherein n is 3 and one of the six R ^{4 is} a methoxyethoxyethoxyethoxy group (CH ₃ OC ₂ H ₄ OC in _₂ H _₄ OC ₂ H ₄ 〇 I), compound 5 is a fluorine: a (viscosity at 25 ° C .5mPa's (4.5cP) ).

In the chain phosphazene E, X ¹ is a substituent represented by the formula (III) in the formula (I) and ¹ , Y ² R ² , Y ³ R ³ , Y ⁵ R ⁵ and Y ⁶ R ⁶ Among them, three are an ethoxy group, two are fluorine, and Z is 0 (oxygen) (viscosity at 25 ° C: 4.7 mPa's (4.7 cP));

The chain phosphazene F is a compound represented by the following formula (XI) (viscosity at 25 ° C .: 4.9 mPa-s (4.9 cP));

The chain phosphazene G is a compound represented by the following formula (XII) (viscosity at 25 ° C: 2.8 mPa-s (2.8 cP));

F 0

F P N S CH, (ΧΠ)

F 0 The chain phosphazene H is a compound represented by the following formula (XIII) (viscosity at 25 ° C: 3.9 mPa-s (3.9 cP)).

F CH ₂ C00CH ₃ F— P = N —— P = 0 · · '(ΧΙΠ)

F F Further, the phosphate ester X is a compound represented by the following formula (XIV) (viscosity at 25 ° C .: 2.5 mPa's (2.5 cP)).

0

II

P― 0C ₂ H ₅ '''(XIV)

/ \

F F Further, phosphazane Y is a compound represented by the following formula (XV) (viscosity at 25 ° C .: 5.0 mPa-s (5.0 cP)).

0 C ₂ H ₅ 0

II I II

C ₂ H ₅ 0—— PNP— 0 C ₂ H ₅ · · · (XV)

0C ₂ H ₅ 0C ₂ H ₅ triazine Z is a compound represented by the following formula (XVI) (viscosity at 25 ° C .: 2. ImPa-s (2.lcP)).

(XVI)

N N

C

F A non-aqueous electrolyte secondary battery was prepared in the same manner as in Example 1 using the above-mentioned electrolyte, and the 2 C capacity was measured. Table 1 shows the results. In Example 3 and Comparative Example 2, the L IMN ₂ 〇 Yore ,, examples L i CO0 ₂ instead of ₄ 4 and Comparative Example 3 as the positive electrode active material, using L i N i 0 ₂ .

From Table 1, it can be seen that the batteries of Examples using the non-aqueous electrolyte in which the time until the contact angle of the non-aqueous electrolyte with the Since the voltage drop between the and positive electrode was small, the 2C capacity was large and the large current discharge characteristics were excellent. On the other hand, the battery of the comparative example using the conventional non-aqueous electrolyte had a large 2C capacity due to a large voltage drop between the electrolyte and the positive electrode, and was inferior in large-current discharge characteristics.

In addition, the residual capacity of the batteries produced in Example 1 and Comparative Example 1 was measured when the batteries were discharged at a rate of 0.125C, 0.2C, 0.5C, 1.0C, 2.0C, and 3.0C. Fig. 5 shows the results.

From FIG. 5, it can be seen that the battery of Example 1 has a higher remaining capacity at each discharge rate than the battery of Comparative Example 1. In particular, it can be seen that the battery of Example 1 has a higher capacity remaining ratio when subjected to a high rate discharge than the battery of Comparative Example 1, and is excellent in large current discharge characteristics. <Permeability of electrolyte to negative electrode of secondary battery>

(Example 22)

Graphite [GD A-K 2 manufactured by Mitsui Mining & Smelting Co., Ltd.] (carbon material) 94 parts by mass, 3 parts by mass of acetylene black (conductive agent) and 3 parts by mass of polyvinylidene fluoride (binder) The mixture is kneaded with an organic solvent (50/50 mass% mixed solvent of ethyl acetate and ethanol), and the kneaded product is coated on a 25 μηι thick aluminum foil (current collector) with a doctor blade. Then, hot-air drying (100 to 120 ° C) was performed to produce a 150-zm-thick negative electrode sheet. 5 μL of the same electrolytic solution as in Example 1 was dropped on the negative electrode sheet, and the contact angle between the droplet of the electrolytic solution and the negative electrode sheet was measured in the same manner as in Example 1. Table 2 shows the results.

A 25 im-thick separator (microporous film: made of polypropylene) was interposed on the same positive electrode sheet as in Example 1, and the negative electrode sheets prepared as described above were stacked and rolled up to produce a cylindrical electrode. . The length of the positive electrode of the cylindrical electrode was about 260 mm. The electrolytic solution was injected into the cylindrical electrode and sealed, and an AA lithium battery (non-aqueous electrolyte secondary battery) was prepared, and the 2C capacity was measured. Table 2 shows the results.

(Examples 23 to 49 and Comparative Examples 6 to 7) An electrolytic solution having the formulation shown in Table 2 was prepared, the permeability of the electrolytic solution to the negative electrode was evaluated in the same manner as in Example 22, and the safety of the electrolytic solution was evaluated in the same manner as in Example 1. In addition, a negative electrode was prepared using mesophase carbon microbeads (MCMB) [Nikki Carbon two-stroke beads] instead of graphite as the carbon material, and the permeability to the negative electrode was also tested. Further, a non-aqueous electrolyte secondary battery was prepared in the same manner as in Example 22 using the electrolyte, and the 2 C capacity was measured. Table 2 shows the results.

From Table 2, it can be seen that the battery of the example using the non-aqueous electrolyte in which the time required for the contact angle of the non-aqueous electrolyte to the Since the voltage drop between the negative electrode and the negative electrode was small, the 2C capacity was large and the large current discharge characteristics were excellent. On the other hand, the battery of the comparative example using the conventional non-aqueous electrolyte had a small 2C capacity and inferior high-current discharge characteristics due to a large voltage drop between the electrolyte and the negative electrode.

(Example 50)

After mixing and mixing Mn ₂ (positive electrode active material), acetylene black (conductive agent), and polyvinylidene fluoride (binder) in a ratio of 8: 1: 1 (mass ratio), The kneaded material was pressed and pelletized on a nickel foil (current collector) having a thickness of 25 μηι, and then heated and dried (100 to 120 ° C) to produce a positive electrode pellet having a thickness of 500 μπι.

Further, propylene carbonate (PC)及Pi 1, 2 - a mixed solution of dimethoxyethane E Tan (DME) (aprotic organic solvent, a volume ratio: PC / DME = 1/1) to 90 volume ^_0/0, the cyclic phosphazene A (In the formula (II), n is 3, a cyclic phosphazene compound in which one of six R ⁴ is a phenoxy group (PhO_), and five are fluorine, viscosity at 25 ° 0: 1.71111′′5 ( 1.70?)) 10% by volume was added, and Li BF ₄ (supporting salt) was dissolved at a concentration of 0.75 mol / L (M) to prepare an electrolytic solution.

5 μL of the electrolytic solution was dropped on the positive electrode pellet, and the contact angle between the droplet of the electrolytic solution and the positive electrode pellet was measured in the same manner as in Example 1. Further, the safety of the above electrolyte was evaluated in the same manner as in Example 1. Table 3 shows the results. '

Next, a positive electrode one punched out from the positive electrode pellet to phi 16瞧, one punched out lithium foil (thickness 0.5Mra) to (Micromax ⁶瞧a negative electrode, a cellulose separator (Japan advanced paper Industry Co. TF4030 ), The positive and negative electrodes were opposed to each other, the above-mentioned electrolyte was injected and sealed, to produce a CR 2016 type non-aqueous electrolyte primary battery (lithium primary battery). Was measured by the following method: The results are shown in Table 3. One pulse discharge

Using a battery with a discharge depth of 0%, (i) 3raA—discharge for 3 seconds and (ii) stop for 27 seconds were repeated until the battery voltage reached 1.8 V, and the number of possible discharges was counted. (Examples 51 to 64 and Comparative Example 8)

An electrolytic solution having the formulation shown in Table 3 was prepared, the permeability of the electrolytic solution to the positive electrode was evaluated in the same manner as in Example 51, and the safety of the electrolytic solution was evaluated in the same manner as in Example 1. Also, a non-aqueous electrolyte primary battery was prepared in the same manner as in Example 51 using the electrolyte, and the number of pulse discharges was measured. Table 3 shows the results.

Electrolyte permeability c. Luth positive electrode Electrolyte

Non-toning supporting salt Additive Discharge Active material Penetration time Evaluation Safety Organic solvent (M) (% by mass) Number of times

PC / DME LiBF ₄

Mn0 ₂ cyclic phosphasene A

Example 50 Less than 0.1 second

(1/1) (0.0% by volume) ◎ Non-flammable 1512

75M) (1

PC / DME UBF ₄ cyclic phosphasenes A

Example 51 Mn0 ₂ Less than 0.1 second

(1/1) Flame retardant 1573 (0.75M) (5% by volume) ◎

PC / DME LiBF ₄ cyclic phosphasene A

Example 52 Mn0 ₂ Less than 0.1 second

(1/1) self

(0.75M) (3% by volume) ◎ Fire extinguishing 1589

PC / DME LiBF ₄ cyclic phosphasen B

Example 53 Mn0 ₂ Less than 0.1 second

(1/1) (0.75M) (10% by volume) ◎ Non-flammable 1535

PC / DME LiBF ₄ cyclic phosphasen C

Example 54 Mn0 ₂ Less than 0.1 second

(1/1) ◎ Non-flammable 1568 (0.75M) (5% by volume)

PC / DME LiBF ₄ cyclic phosphasen C

Example 55 n0 ₂ Less than 0.1 second

(1/1) (3% by volume) 6 (0.75M) ◎ Flame retardant 158

PC / DME LiBF ₄ cyclic phosphasen D

Example 56 Mn0 ₂ Less than 0.1 second

(1/1) (0J5M) (10% by volume) ◎ Non-flammable 1635

PC / DME LiBF _4- chain phosphasene E

Example 57 n0 ₂ Less than 0.1 second

(1/1) (0.75M) (10% by volume) ◎ Non-flammable 1654

PC / DME LiBF _4- chain phosphasene E

Example 58 Mn0 ₂ Less than 0.1 second

(1/1) Nonflammable

(0J5M) (5 volumes ° /.) ◎ 1664

PC / DME LiBF _4- chain phosphasen F

Example 59 Mn0 ₂ Less than 0.1 second

(1/1) Nonflammable 1602 (075M) (10% by volume) ◎

PC / DME LiBF _4- chain phosphasene G

Example 60 Mn0 ₂ Less than 0.1 second

(1/1) (0J5M) (10% by volume) ◎ Non-flammable 1623

PC / DME LiBF _4- chain phosphasene H

Example 61 Mn0 ₂ Less than 0.1 second Nonflammable 1590

(1/1) (0.75M) (10 volumes ¾ ◎

PC / DME LiBF ₄ -phosphate :! : Tool X

Example 62 Mn0 ₂ Less than 0.1 second Non-flammable 1501

(1/1) (0.75M) (10% by volume) ◎

PC / DME LiBF ₄

Mn0 ₂ Phosphora Y

Example 63 Less than 0.1 second

(1/1) (0J5M) (10% by volume) ◎ Non-flammable 1542

PC / DME LiBF ₄ Triass Z

Example 64 MnO ₂ Less than 0.1 second Flammability 1527

0/1) (0.75M). 0 volume ⁰ /. ◎ ◎ not

PC / DME LiBF ₄

Comparative Example 8 Mn0 ₂ 0.5 seconds or more X Flammability 1374

(1/1) (0.75M) From Table 3, it can be seen that the battery of the example using the non-aqueous electrolyte in which the time until the contact angle of the non-aqueous electrolyte with the Since the voltage drop between the and positive electrodes was small, the number of pulse discharges was large and the pulse discharge characteristics were excellent. On the other hand, the battery of the comparative example using the conventional nonaqueous electrolyte had a large voltage drop between the electrolyte and the positive electrode, so the number of pulse discharges was small and the pulse discharge characteristics were poor. .

Electrolyte permeability to separator>

(Example 65)

In a mixed solution of ethylene carbonate (EC) and getyl carbonate (DEC) (carbonic acid ester, volume ratio: EC / D EC = 1/1), 90% by volume of cyclic phosphazene A (in the formula (II), n a 3, six one of phenoxy groups among R ⁴ (PhO-), 5 single although cyclic phosphazene compound is a fluorine, viscosity at ² 5 ° C of: (? 1.7) 1.7 ^ &'3) 10 volume ^_0/0 was added and the electrolyte solution was prepared by L i PF ₆ (the supporting salt) dissolved at a concentration of i mol / L (M).

At room temperature, 5 / L of the above electrolyte is dropped on a 25 m-thick separator made of polyethylene porous polymer membrane [SETELA manufactured by Tonen Chemical Co., Ltd.]. The contact angle between the electrolyte droplet and the separator was measured using a CCD camera. The contact angle was measured using an automatic contact angle measuring device OCA20 manufactured by dataphysics. Figure 6 shows the change over time in the contact angle of the electrolyte with the separator. As a result, it took less than 2 seconds for the contact angle of the electrolyte to the separator to become 25 ° or less. Further, the safety of the electrolytic solution was evaluated in the same manner as in Example 1. Table 4 shows the results.

Next, using the electrolyte solution and the separator, a non-aqueous secondary battery was manufactured as follows. First, L i CO0 ₂ against [Nippon Chemical Industrial Co., Ltd.] (positive electrode active material) 100 parts by weight of acetylene black (conductive agent) 10 parts by weight, Teflon (R) Vine After adding 10 parts by mass of a binder (binder) and kneading with an organic solvent (50/50% by mass mixed solvent of ethyl acetate and ethanol), roll-rolled to form a thin layer with a thickness of 100 μπι and a width of 40 mm. A positive electrode sheet was produced. On the other hand, a negative electrode sheet made of graphite with a thickness of 150 μηι was used as the negative electrode. The separator was sandwiched between one positive electrode sheet and one negative electrode sheet and rolled up to produce a cylindrical electrode. The length of the positive electrode of the cylindrical electrode was about 260. Next, the above-mentioned electrolytic solution was injected into the cylindrical electrode and sealed, to prepare an AA lithium battery (non-aqueous electrolyte secondary battery), and the internal resistance (DC resistance of the battery) was measured according to a conventional method. It was measured. As a result, the internal resistance of the battery was 0.10Ω.

(Examples 66 to 83 and Comparative Examples 9 to: L 1)

An electrolytic solution having the formulation shown in Table 4 was prepared, the permeability of the electrolytic solution into the separator was evaluated in the same manner as in Example 65, and the safety of the electrolytic solution was evaluated in the same manner as in Example 1. FIG. 7 shows the change over time of the contact angle of the electrolytic solution of Comparative Example 9 with the separator. In Examples 66, 68 to 70, 72, 74, 75, 77 to 82, and Comparative Example 10, a polypropylene separator (porous polymer membrane, thickness 25 / ra, Celgard) was used instead of a polyethylene separator. For Example 67, 73, 83 and Comparative Example 11 using polyethylene # polypropylene copolymer separator (porous polymer membrane, thickness 25 / zm, Celgard # 35 04) Was used. Table 4 shows the results.

Further, a non-aqueous electrolyte secondary battery was prepared in the same manner as in Example 65 using the electrolyte and the separator shown in Table 4, and the internal resistance was measured. Table 4 shows the results.

¾

Electrolyte permeable battery

¾J

Serra. Lator carbonate support salt additive, light internal resistance

51 14 Safety ester () (% by volume) (Ω)

EC / DEC LiPF ₆ cyclic phosphasen A

Example 65 PE C J, non-flammable

(1/1) (1M) (10% by volume) 0.10

EC / DEC LiPF ₆ cyclic phosphasen A

Example 66 PP Z

(1/1) (1M) (10% by volume) 0.09

EC / DEC LiPF ₆ cyclic phosphasen A

Example 67 PE / PP!

(1/1) (1M) (10% by volume) 0.09

EC / DEC LiPF ₆ cyclic phosphasen A

Example 68 PP Kaman (Q)

%) Flame retardance 0.07 (1/1) (1M) (5

EC / DEC LiPF ₆ cyclic phosphasen A

Example 69 PP 2 mushrooms (Q) Self-extinguishing 0.07

(1/1) (1M) (3% by volume)

EC / DEC LiPF ₆ cyclic phosphane A

Example 70 PP Kaman (Q) Self-extinguishing 0.07

(1/1) (1M) (1% by volume)

EC / DEC LiPF ₆ cyclic phosphasene B

Example 71 PE Kaman Incombustibility

(1/1) (1M) (10% by volume) 0.10

EC / DEC LiPF ₆ cyclic phosphasene B

Example 72 PP wood

(1/1) (1M) (10% by volume) 0.11

EC / DEC LiPF ₆ cyclic phosphasene B

Example 73 PE / PP

(1/1) (1M) (10% by volume) 0.10

EC / DEC LiPF ₆ cyclic phosphase C

Example 74 PP

(1/1) (1M) (10% by volume) 0.10

EC / DEC LiPF ₆ cyclic phosphase C

Example 75 PP ^ sec Kaman Flame Retardancy

(1/1) (1M) (3% by volume) 0.07

EC / DEC LiPF ₆ cyclic phosphasen D

Example 76 PE ^ sec.

(1/1) (1M) (10% by volume) 0.10

EC / DEC LiPF ₆ View:! Phosphaase D

Example 77 PP 2 sec.

(1/1) (1M) (10% by volume) 0.11

EC / DEC LiPF _6- chain phosphasene E

Example 78 PP

(1/1) (1M) (10% by volume) 0.09

EC / DEC LiPF _6- chain phosphasen F

Example 79 PP 2 sheets

(1/1) (1M) (10% by volume) 0.08

EC / DEC LiPF _6- chain phosphasene G

Example 80 PP

(1/1) (1M) (10% by volume) 0.08

EC / DEC LiPF _6- chain phosphasene H

Example 81 PP (Q) Nonflammable

(1/1) (1M) (10% by volume) 0.09

EC / DEC LiPF ₆ Phosphate I Steal X

Example 82 PP 术 / both nonflammable

(1/1) (1M) (10 volumes!) 0.08

EC / DEC LiPF ₆ Phosphora "Y

Example 83 PE / PP small, 'S non-flammable

(1/1) (1M) (10% by volume) 0.09

EC / DEC LiPF ₆

Comparative Example 9 PE 5 seconds or more X Flammability

(1/1) (1M) 0.18

EC / DEC LiPF ₆

Comparative Example 10 PP 5 seconds or more X Flammability

(1/1) (1M) 0.19

EC / DEC LiPF ₆

Comparative Example 11 PE / PP 5 seconds or more X Flammability

(1/1) (1M) 0.18 From Table 4, the time required for the contact angle of the non-aqueous electrolyte to the separator to drop to 25 ° or less after dropping on the separator The battery of the example using the non-aqueous electrolyte of ¾ seconds or less has the voltage at the separator. Due to the small drop, the internal resistance of the battery was small. On the other hand, the battery of the comparative example using the conventional non-aqueous electrolyte had a large internal resistance of the battery due to a large voltage drop at the separator.

Claims

Scope of the claim The non-aqueous electrolyte characterized in that the time required for the contact angle of the non-aqueous electrolyte to the electrode to become 2 ° or less after the non-aqueous electrolyte is dropped on the electrode is less than 0.5 seconds. Electrolyte. 2. The non-aqueous electrolyte according to claim 1, wherein the electrode is a positive electrode, and the active material of the positive electrode is a lithium-containing composite oxide.

The electrode is a positive electrode, at least one lithium-containing double case of the active material of the positive electrode is selected from _{L i C o 0 2, L} i M n 2 〇 ₄及beauty L i N i 0 ₂ consists of the group 3. The non-aqueous electrolyte according to claim 2, wherein the non-aqueous electrolyte is an oxide.

_2. The non-aqueous electrolyte according to claim 1, wherein the electrode is a positive electrode, and the active material of the positive electrode is one of Mn02 and fluorinated graphite.

2. The non-aqueous electrolyte according to claim 1, wherein the electrode is a negative electrode, and the active material of the negative electrode is graphite.

2. The non-aqueous electrolyte according to claim 1, wherein the non-aqueous electrolyte contains a compound having phosphorus in a molecule.

2. The non-aqueous electrolyte according to claim 1, wherein the non-aqueous electrolyte contains a compound having nitrogen in a molecule.

2. The non-aqueous electrolyte according to claim 1, wherein the non-aqueous electrolyte contains a compound having phosphorus and nitrogen in a molecule.

9. The non-aqueous electrolyte according to claim 8, wherein the compound having phosphorus and nitrogen in the molecule has a phosphorus-nitrogen double bond.

The non-aqueous electrolyte according to any one of claims 6 to 8, wherein the non-aqueous electrolyte further contains a carbonate ester.

A non-aqueous electrolyte characterized in that the time required for the contact angle of the non-aqueous electrolyte to the separator to become 25 ° or less after the non-aqueous electrolyte is dropped on the separator is 2 seconds or less.

21. The non-aqueous electrolyte according to claim 11, wherein the separator is a porous polymer membrane and is made of any of polypropylene, polyethylene, and a polyethylene-polypropylene copolymer.

The non-aqueous electrolyte according to claim 11, wherein the non-aqueous electrolyte contains a compound having phosphorus in a molecule.

The non-aqueous electrolyte according to claim 11, wherein the non-aqueous electrolyte contains a compound having nitrogen in a molecule.

12. The non-aqueous electrolyte according to claim 11, wherein the non-aqueous electrolyte contains a compound having phosphorus and nitrogen in a molecule.

16. The non-aqueous electrolyte according to claim 15, wherein the compound having phosphorus and nitrogen in the molecule has a phosphorus-nitrogen double bond.

The non-aqueous electrolyte according to any one of claims 13 to 15, wherein the non-aqueous electrolyte further contains a carbonate ester.

A non-aqueous electrolyte battery comprising the non-aqueous electrolyte according to claim 1, a positive electrode, and a negative electrode.

A non-aqueous electrolyte battery comprising the non-aqueous electrolyte according to any one of claims 11 to 17, a positive electrode, a negative electrode, and a separator.