JP2003272703A - Electrolyte and nonaqueous electrolyte secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new electrolyte practically nonvolatile and with a high electric charge transport performance and to provide a nonaqueous electrolyte secondary battery of a large capacity. <P>SOLUTION: This electrolyte contains a compound represented by general formula (1) and this nonaqueous electrolyte secondary battery contains this electrolyte. [R is an alkyl or an aryl which may have a substitutuent group; V is -COO-, -SOO-, or -SO<SB>2</SB>O-; X is a halogen atom]. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrolyte and a battery, and more particularly to an electrolyte suitable as an antistatic agent, a battery and a material for other electrochemical devices, and a large-capacity non-aqueous electrolyte secondary battery using the same. Is.

[0002]

2. Description of the Related Art Used in electrochemical cells such as non-aqueous secondary batteries
The electrolyte that contains the ions depending on the purpose.
Has the function of transporting ON between electrodes (called ion conduction)
Is a medium. For example, Lithium which is a representative of non-aqueous secondary batteries
In the secondary battery, the function of transporting lithium ions (I
It is a medium with on-conduction). Smell these batteries
In general, a solution system with high ionic conductivity is used as the electrolyte.
Are often used. As the electrolyte, for example, carbonic acid
Propylene, ethylene carbonate, diethyl carbonate, dimethy carbonate
As an electrolyte salt in an organic solvent such as γ-butyrolactone
LiPF₆, LiBF_Four, LiCF₃SO₂, LiClO_Four, LiN (CF₃SO₂)₂,
A solution of throat is widely used. But the electric
The organic solvent contained in the lysate is volatile and easily flammable
Therefore, there was a problem in safety. On the other hand, including organic solvent
First, it shows a liquid state at room temperature as an electrolyte with excellent safety.
The counter anion is BF_Four ^-, (CF₃SO₂) ₂N^-And so on
Imidazolium salts and pyridinium salts have been proposed.
It Although such room temperature molten salts are liquid, they are volatile.
Almost none, flame retardant or non-flammable and excellent in safety
Has been. Also, the ionic conductivity is high. Therefore, this
Una room temperature molten salt and LiBF_FourElectrolyte mixed with Li salt such as
It has been proposed as an electrolyte for lithium secondary batteries. Only
And this is contained in the room temperature molten salt compared to the required Li ions
Since the amount of cations used is overwhelmingly large, the capacity decreases
There was such a problem.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel electrolyte excellent in charge transport ability and safety, and to provide a high capacity non-aqueous secondary battery.

[0004]

In view of the above object, the present inventor has found as a result of earnest research that an electrolyte containing a compound represented by the following general formula (1) exhibits excellent charge transporting ability. The present invention was conceived. That is, the present invention provides an electrolyte containing a compound represented by the following general formula (1).

[0005]

[Chemical 2]

[In the general formula (1), R represents an alkyl or aryl group which may have a substituent. V is −COO
-, - SOO- or an -SO ₂ O-. X represents a halogen atom. ]

The present invention also provides a non-aqueous electrolyte secondary battery having a positive electrode and a negative electrode, the non-aqueous electrolyte secondary battery containing the electrolyte.

In the electrolyte and non-aqueous secondary battery of the present invention, more excellent charge transporting ability and battery performance can be obtained by satisfying the following conditions. (1) X is preferably a fluorine atom. (2) V is preferably -COO-. (3) R is preferably an alkyl group.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION [1] Electrolyte The electrolyte of the present invention comprises a chemical reaction, a reaction solvent for metal plating,
It can be used for CCD (charge-coupled device) cameras, various batteries, photoelectric conversion devices, optical sensors, image sensors (for example, electronic cameras), and among these, non-aqueous secondary batteries, especially lithium-ion secondary batteries. It is preferably used in batteries.

Hereinafter, each component of the electrolyte composition of the present invention will be described in detail.

Compound of General Formula (1) The electrolyte of the present invention contains a compound represented by the following general formula (1).

[0012]

[Chemical 3]

[In the general formula (1), R represents an alkyl or aryl group which may have a substituent. V is −COO
-, - SOO- or an -SO ₂ O-. X represents a halogen atom. ]

In the general formula (1), the alkyl group represented by R may be linear, branched or cyclic, and preferably has 1 to 24 carbon atoms. Examples of such an alkyl group include a methyl group, an ethyl group,
n-propyl group, isopropyl group, n-butyl group, sec-
Butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, n-octyl group, 2-ethylhexyl group, t
-Octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, n-hexadecyl group, 2-hexyldecyl group, heptadecyl group,
Octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group, tricosyl group, tetracosyl group, 2
—Ethylhexyl group, cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group and the like, which may be substituted or unsubstituted.

In the general formula (1), the aryl group represented by R preferably has 6 to 30 carbon atoms, and examples thereof include a phenyl group and a naphthyl group, which may be substituted or unsubstituted. .

In the general formula (1), examples of the substituent which the alkyl group or aryl group represented by R may have include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclo group). Propyl group, butyl group, octyl group, 2-carboxyethyl group, benzyl group, trifluoromethyl group etc.), alkenyl group (eg vinyl group, allyl group, propenyl group etc.), aryl group (eg phenyl group, methoxyphenyl) Group), a silyl group (preferably having 3 to 30 carbon atoms, which may be substituted or unsubstituted, for example, trimethylsilyl group, t-butyldimethylsilyl group, phenyldimethylsilyl group,-(Si (CH ₃ ) ₂ O) n
Si (CH ₃ ) ₃ etc.),

Silyloxy group (preferably having 3 carbon atoms
~ 20, for example trimethylsilyloxy group, t-butyloxy group
Ryloxy group etc.), alkoxy group (eg methoxy group,
Ethoxy group,-(OCH₂CH₂) n-OCH₃,-(OCH ₂CH₂) n-OCH₂
CH₃Etc.), amino groups (eg dimethylamino group, diet
Luamino group, etc., amide group (eg, acetylamino group,
Benzoylamino group, etc.), guanidino group, carbamoyl
Groups (eg N, N-dimethylcarbamoyl group, N-phenyl
Carbamoyl group, etc.), cyano group, alkylthio group (eg.
For example, methylthio group, ethylthio group etc.), heterocyclic group (eg
Pyridyl group, imidazolyl group, etc.), halogen atom (eg,
For example, chlorine atom, bromine atom, iodine atom, etc.)
It Among them, silyl group, silyloxy group, alkoxy
Groups and halogen atoms are preferred. These substituents are
May have a substituent. V is -COO-, -SOO-,
Or −SO₂Indicates O-. Preferred is -COO-.

In the general formula (1), the halogen atom represented by X is preferably a fluorine, chlorine, bromine or iodine atom. More preferably, it is a fluorine or chlorine atom. Particularly preferred is a fluorine atom.

Specific examples of the compound represented by the general formula (1) of the present invention are shown below, but the present invention is not limited thereto.

[0020]

[Chemical 4]

[0021]

[Chemical 5]

[0022]

[Chemical 6]

The compound of the general formula (1) can be easily obtained by reacting a simple substance of a boron halide or an adduct of a boron halide with a donor compound and Li ⁺ VR ⁻ . As the donor compound, an ether compound (for example, diethyl ether, t-butylmethyl ether, tetrahydrofuran, etc.), an amine compound (for example, ethylamine), an alcohol compound (for example,
Preferred are methanol, phenol, etc., thioether compounds (eg, dimethyl sulfide, etc.), water, carboxylic acids (eg, acetic acid, etc.), phosphoric acid, etc. The compound of the general formula (1) can be produced, for example, according to the following reaction formula.

[Chemical 7]

[Wherein R represents an alkyl or aryl group which may have a substituent. V is -COO-, -SOO
- or an -SO ₂ O-. X represents a halogen atom. That is, the compound of the general formula (1) can be obtained by reacting a lithium compound LiVR with a boron trihalide diethyl ether complex under a stream of an inert gas such as nitrogen.

The compound of the general formula (1) is preferably a salt having a low melting point, that is, a so-called molten salt, and more preferably a compound that is liquid at room temperature (around 25 ° C.), that is, a so-called room temperature molten salt. That is, the melting point of the compound represented by the general formula (1) is preferably 100 ° C or lower, more preferably 80 ° C or lower, particularly preferably 60 ° C or lower, and 30 ° C or lower. Is most preferred.

The compound of the general formula (1) can be used as an electrolyte in many cases without using a solvent, and it is preferably used alone as an electrolyte. Further, even if it is a solid at room temperature (around 25 ° C.), it can be used as an electrolyte in a liquid state by adding a small amount of a solvent, other additives and the like. Also, without adding anything, a method of dissolving by heating and permeating onto the electrode, a method of permeating onto the electrode using a low boiling point solvent (methanol, acetonitrile, methylene chloride, etc.), and then removing the solvent by heating. It can be incorporated into a battery by the above method.

The electrolyte composition of the present invention contains at least one compound represented by the general formula (1), but two or more compounds may be used in combination, and further another electrolyte salt such as WO
95/18456 or a low melting point compound (so-called room temperature molten salt) described in J. Phys. Chem. B, 103, 4164 (1999) and the like may be added. Furthermore, the electrolyte composition of the present invention may be used in combination with a salt of a metal ion belonging to Group Ia or Group IIa of the periodic table. As the metal ions belonging to Group Ia or Group IIa of the periodic table, lithium, sodium and potassium ions are preferable. As the anion of the metal ion salt,
Halide ions ^{(I -, Cl -, Br} - , _{^{etc.), SCN -, BF 4 -}} ,
_{^{PF 6 -, ClO 4 -,}} SbF 6 -, (CF 3 SO 2) 2 N -, (CF 3 CF 2 SO 2) 2 N
_{^{-, Ph 4 B -, (}} C 2 H 4 O 2) 2 B -, (CF 3 SO 2) 3 C -, CF 3 COO -, C
_{^{F 3 SO 3 -, C 6}} F 5 SO 3 - , and the like. As anions,
_{^{SCN -, BF 4 -, PF}} 6 -, ClO 4 -, SbF 6 -, (CF 3 SO 2) 2 N -, (C
_{F 3 CF 2 SO 2) 2} N -, (CF 3 SO 2) 3C-, CF3SO3 - is more preferable.

LiCF ₃ S is a typical metal ion salt.
O ₃ , LiPF ₆ , LiClO ₄ , LiI, LiBF ₄ , LiCF ₃ CO ₂ , LiSCN, Li
N (SO ₂ CF ₃ ) ₂ , NaI, NaCF ₃ SO ₃ , NaClO ₄ , NaBF ₄ , NaAsF ₆ ,
_{KCF 3 SO 3, KSCN, KPF} 6, KClO 4, etc. KAsF ₆ and the like. The Li salt is more preferable. These may be used alone or in combination of two or more.

(B) Solvent In the present invention, a solvent can be used together with the compound of the formula (1), preferably up to the same mass as this compound. However, from the viewpoint of storage stability, it is more preferable not to use a solvent.

The solvent used in the electrolyte of the present invention is a compound which can exhibit excellent ionic conductivity by having low viscosity and improving ionic mobility, or high dielectric constant and improving effective carrier concentration. Is desirable. Examples of such a solvent include carbonate compounds such as ethylene carbonate and propylene carbonate, 3-methyl-
Heterocyclic compounds such as 2-oxazolidinone, dioxane, ether compounds such as diethyl ether, chain ethers such as ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, methanol, ethanol,
Alcohols such as ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether and polypropylene glycol monoalkyl ether, polyhydric alcohols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol and glycerin, acetonitrile, Glutadinitrile, methoxyacetonitrile, propionitrile, benzonitrile and other nitrile compounds, carboxylic acid ester, phosphoric acid ester, phosphonic acid ester and other esters, dimethyl sulfoxide, sulfolane and other aprotic polar substances, etc. You can Among these, carbonate compounds such as ethylene carbonate and propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazolidinone, nitrile compounds such as acetonitrile, glutalodinitrile, methoxyacetonitrile, propionitrile and benzonitrile, and esters are particularly preferable. preferable. These may be used alone or in combination of two or more.

The solvent preferably has a boiling point of 200 ° C. or higher at normal pressure (1 atm), more preferably 250 ° C. or higher, and more preferably 270 ° C. or higher, from the viewpoint of improving durability due to volatility. More preferable.

(C) Others From the viewpoint of preventing liquid leakage and volatilization, it is preferable to solidify and use the electrolyte composition. The electrolyte composition of the present invention comprises a polymer addition, an oil gelling agent addition, a polymerization including polyfunctional monomers, a polymer crosslinking reaction, and the like.
It can also be used by gelling (solidifying). When gelling by adding the polymer, use Polymer
Electrolyte Reviews-1 and 2
(J.R. MacCallum and CA Vinece
Co-edited by nt, ELSEVIER APPLIED SC
IENCE) can be used, but polyacrylonitrile, polyvinylidene fluoride, polyethylene oxide, polysiloxane and the like are particularly preferably used. When gelation is performed by adding an oil gelling agent, an industrial science journal (J. ChemSoc.
an, Ind. Chem. Sec. ), 46, 779
(1943), J. Am. Chem. Soc. , 11
1, 5542 (1989), J. Chem. Soc. ，
Chem. Com mun. , 1993, 390, An
gew. Chem. Int. Ed. Engl. , 35,
1949 (1996), Chem. Lett. , 199
6,885, J. Chm. Soc. Chem. Com
mun. , 1997, 545 can be preferably used, but a compound having an amide structure in the molecular structure is more preferable.

[2] Non-Aqueous Secondary Battery Next, a secondary battery in which the electrolyte of the present invention is preferably used will be described. The secondary battery of the present invention is one in which a positive electrode sheet and a negative electrode sheet are laminated with a gap provided and the gap is filled with the electrolyte composition of the present invention.

The positive electrode sheet is a current collector coated with an electrode mixture containing a positive electrode active material, and the negative electrode sheet is a current collector coated with an electrode mixture containing a negative electrode active material. . Hereinafter, the materials of the positive electrode sheet and the negative electrode sheet will be described in detail.

(A) Current Collector As the current collector of the positive electrode sheet / negative electrode sheet, an electron conductor which does not cause a chemical change in the constructed battery is used.

As the current collector of the positive electrode sheet, in addition to aluminum, stainless steel, nickel, titanium, etc., aluminum or stainless steel whose surface is treated with carbon, nickel, titanium or silver is preferable, and particularly preferable. Aluminum and aluminum alloy.

As the current collector of the negative electrode sheet, copper, stainless steel, nickel and titanium are preferable, and copper or copper alloy is particularly preferable.

The shape of the current collector is usually a film sheet, but a net, a punched material, a lath body, a porous body, a foamed body, a molded body of fibers, etc. can also be used. . The thickness is not particularly limited, but 1 to 500 μ
m is preferred. It is also desirable that the surface of the current collector be roughened by surface treatment.

(B) Electrode mixture The electrode mixture (positive electrode mixture and negative electrode mixture) used in the present invention is
In addition to containing a positive electrode active material (negative electrode active material) as an essential component, a conductive agent, a binder, a filler, and an aprotic organic solvent are added. The electrode mixture is used after being coated (coated), dried and compressed on the current collector. The components of the electrode mixture will be described in detail below.

(1) Positive Electrode Active Material The electrode mixture for the positive electrode sheet contains a positive electrode active material as an essential component. A transition metal oxide capable of reversibly inserting and releasing lithium ions can be used as the positive electrode active material, and a lithium-containing transition metal oxide is particularly preferable. Preferred lithium-containing transition metal oxide positive electrode active material used in the present invention, lithium-containing Ti, V, Cr, M
Examples thereof include oxides containing n, Fe, Co, Ni, Cu, Mo and W.
Alkali metals other than lithium (1 (Ia) in the periodic table)
Group, Group 2 (IIa) elements) and / or Al, Ga, In,
Ge, Sn, Pb, Sb, Bi, Si, P, B and the like may be mixed. The mixing amount of these elements is preferably 0 to 30 mol% with respect to the transition metal.

A more preferable lithium-containing transition metal oxide positive electrode active material is a lithium compound / transition metal compound.
(Here, transition metals are Ti, V, Cr, Mn, Fe, Co, Ni, M.
The total molar ratio of at least one selected from o and W is 0.3.
It is preferable to use a mixture prepared by mixing so as to be about 2.2.

Further preferred lithium-containing transition metal oxide positive electrode active materials include lithium compounds / transition metal compounds.
(Transition metal here is preferably at least one selected from V, Cr, Mn, Fe, Co, and Ni), and is preferably synthesized by mixing so that the total molar ratio is 0.3 to 2.2.

A particularly preferable lithium-containing transition metal oxide positive electrode active material is a material containing Li _g M ³ O ₂ (M ³ is at least one selected from Co, Ni, Fe and Mn, g = 0 to 1.2), Or Li _h M ⁴ ₂ O ₄
(M ⁴ is Mn, h = 0 to 2) is a material having a spinel structure. As M ³ and M ⁴ , in addition to transition metals, Al, Ga,
In, Ge, Sn, Pb, Sb, Bi, Si, P, B and the like may be mixed. The mixing amount of these elements is 0 to 30 mol with respect to the transition metal.
% Is preferable.

The most preferable lithium-containing transition metal oxide positive electrode active materials include Li _g CoO ₂ , Li _g NiO ₂ , Li _g MnO ₂ , and Li _g
Co _j Ni _1-j O ₂ , Li _h Mn ₂ O ₄ (where g = 0.02 to 1.2, j = 0.
1 to 0.9, h = 0 to 2). Where g above
The value and h value are values before the start of charging / discharging and increase / decrease due to charging / discharging.

The positive electrode active material can be synthesized by a known method such as a method of mixing and firing a lithium compound and a transition metal compound or a solution reaction, and the firing method is particularly preferable.

The average particle size of the positive electrode active material is not particularly limited, but is preferably 0.1 to 50 μm. The specific surface area is not particularly limited, but is preferably 0.01 to 50 m ² / g according to the BET method. The pH of the supernatant when 5 g of the positive electrode active material is dissolved in 100 ml of distilled water is preferably 7 or more and 12 or less.

A well-known crusher or classifier is used to make the positive electrode active material have a predetermined particle size. For example, a mortar, a ball mill, a vibrating ball mill, a vibrating mill, a satellite ball mill, a planetary ball mill, a swirling airflow type jet mill, a sieve and the like are used.

The positive electrode active material obtained by firing may be used after washing with water, an acidic aqueous solution, an alkaline aqueous solution or an organic solvent.

(2) Negative Electrode Active Material The electrode mixture for the negative electrode sheet contains a negative electrode active material as an essential component. Examples of the negative electrode active material used in the secondary battery of the present invention include (i) a carbonaceous material capable of inserting and extracting lithium, (ii) an oxide and / or chalcogenide, and the like.

(I) Carbonaceous Material The carbonaceous material is a material which is substantially composed of carbon. Examples thereof include petroleum pitch, natural graphite, artificial graphite such as vapor-grown graphite, and carbonaceous materials obtained by firing various synthetic resins such as PAN resin and furfuryl alcohol resin. Furthermore, various carbon fibers such as PAN-based carbon fibers, cellulose-based carbon fibers, pitch-based carbon fibers, vapor-grown carbon fibers, dehydrated PVA-based carbon fibers, lignin carbon fibers, glassy carbon fibers, activated carbon fibers, and mesophase microfibers. sphere,
Graphite whiskers, flat graphite, etc. can also be mentioned.

These carbonaceous materials can be classified into non-graphitizable carbon materials and graphite-based carbon materials depending on the degree of graphitization. Further, the carbonaceous material is preferably one having the interplanar spacing, density and crystallite size described in JP-A-62-22066, JP-A-2-6856 and JP-A-3-45473.

The carbonaceous material does not have to be a single material, but a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, etc. Can also be used.

(Ii) Oxide, chalcogenide As the negative electrode active material of the secondary battery of the present invention, an oxide and / or chalcogenide can be used, but an amorphous oxide and / or chalcogenide is particularly preferable. Amorphous here refers to those having a broad scattering band having an apex in the 20 ° to 40 ° region in the 2θ value in the X-ray diffraction method using CuKα rays, and having a crystalline diffraction line. May be. Preferably, the strongest intensity of the crystalline diffraction lines observed at 2θ value of 40 ° or more and 70 ° or less is 2θ value.
It is not more than 100 times, more preferably not more than 5 times, the diffraction line intensity at the apex of the broad scattering band seen from 20 ° to 40 °, and particularly preferably not having a crystalline diffraction line. is there.

In the present invention, amorphous oxides and / or chalcogenides of semi-metal elements are preferable, and elements of Group 13 (IIIb) to 15 (Vb) of the periodic table, Al, Ga, Si, Sn and Ge are preferred. ,
An oxide or chalcogenide composed of Pb, Sb, or Bi alone or a combination of two or more thereof is selected.

For example, Ga₂O₃, SiO, GeO, SnO, SnO₂, Pb
O, PbO₂, Pb₂O₃, Pb₂O_Four, Pb₃O_Four, Sb ₂O₃, Sb₂O_Four, Sb
₂O_Five, Bi₂O₃, Bi₂O_Four, SnSiO₃, GeS, SnS, SnS₂, PbS, Pb
S₂, Sb₂S ₃, Sb₂S_Five, SnSiS₃Are preferred. Also this
Et al., A complex oxide with lithium oxide, for example, Li₂SnO₂so
It may be.

More preferably an amorphous oxide centered Sn, Si, and Ge in the negative electrode material of the [0056] present invention, among others the general formula _{^{(6) SnM 1 d M 2}} e O f ··· (6) ( General In the formula (6), M ¹ is at least one element selected from Al, B, P, Si and Ge, M ² is an element of Group 1 (Ia), Group 2 (IIa) of the periodic table, Represents at least one element selected from Group 3 (IIIa) elements and halogen elements, and d is
Number from 0.2 to 2 and e is a number from 0.01 to 1 and 0.2 <
d + e <2, f is a number of 1 or more and 6 or less) is preferable.

Examples of the amorphous oxide containing Sn as a main component include the following compounds, but the present invention is not limited thereto. C-1 SnSiO ₃ C-2 SnAl _0.2 B _0.4 P _0.2 Si _0.6 O _3.6 C-3 SnAl _0.4 B _0.5 Cs _0.1 P _0.5 O _3.65 C-4 SnAl _0.4 B _0.5 Mg _0.1 P _0.5 O _3.7 C-5 SnAl _0.4 B _0.4 Ba _0.08 P _0.4 O _3.28 C-6 SnAl _0.4 B _0.5 Ba _0.08 Mg _0.08 P _0.3 O _3.26 C-7 SnAl _0.1 B _0.2 Ca _0.1 P _0.1 Si _0.5 O _3.1 C-8 SnAl _0.2 B _0.4 Si _0.4 O _2.7 C- 9 SnAl _0.2 B _0.1 Mg _0.1 P _0.1 Si _0.5 O _2.6 C-10 SnAl _0.3 B _0.4 P _0.2 Si _0.5 O _3.55 C-11 SnAl _0.3 B _0.4 P _0.5 Si _0.5 O _4.3 C-12 SnAl _0.1 B _0.1 P _0.3 Si _0.6 O _3.25 C-13 SnAl _0.1 B _0.1 Ba _0.2 P _0.1 Si _0.6 O _2.95 C-14 SnAl _0.1 B _0.1 Ca _0.2 P _0.1 Si _0.6 O _2.95 C-15 SnAl _0.4 B _0.2 Mg _0.1 Si _0.6 O _3.2 C-16 SnAl _0.1 B _0.3 P _0.1 Si _0.5 O _3.05 C-17 SnB _0.1 K _0.5 P _0.1 SiO _3.65 C-18 SnB _0.5 F _0.1 Mg _0.1 P _0.5 O _3.05

For the amorphous oxide and / or chalcogenite of the present invention, either a firing method or a solution method can be adopted, but the firing method is more preferable. In the firing method, it is preferable that the oxide, chalcogenite or compound of the corresponding element is well mixed and then fired to obtain an amorphous oxide and / or chalcogenite. These can be produced by a known method.

The average particle size of the negative electrode material used in the present invention is preferably 0.1 to 60 μm. A well-known crusher or classifier is used to obtain a predetermined particle size. For example, mortar, ball mill, sand mill, vibrating ball mill,
A satellite ball mill, a planetary ball mill, a swirling airflow type jet mill, a sieve, etc. are used. At the time of pulverization, wet pulverization in which water or an organic solvent such as methanol is allowed to coexist can be performed as necessary. In order to obtain the desired particle size, it is preferable to carry out classification. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be carried out both dry and wet.

Examples of the negative electrode material that can be used in combination with the amorphous oxide negative electrode material centered on Sn, Si, and Ge of the present invention include carbon materials capable of inserting and extracting lithium ions or lithium metal, lithium, Examples include lithium alloys and metals that can be alloyed with lithium.

(3) Conductive agent The conductive agent used for the electrode mixture is
Any electron conductive material that does not chemically change may be used. Usually, natural graphite (scaly graphite, flake graphite, earthy graphite, etc.), artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber and metal powder (copper, nickel, aluminum, silver (JP-A-63- 148554) etc.),
Metal fiber or polyphenylene derivative (JP-A-59-2097)
Conductive materials such as No. 1) may be included alone or as a mixture thereof. The combined use of graphite and acetylene black is particularly preferred. The addition amount is preferably 1 to 50% by mass, and particularly preferably 2 to 30% by mass. For carbon and graphite, 2 to 15 mass% is particularly preferable.

(4) Binder In the present invention, a binder for holding the electrode mixture is used.
Examples of the binder include polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Preferred binders include starch, carboxymethyl cellulose,
Cellulose, diacetylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium alginate, polyacrylic acid, sodium polyacrylate, polyvinylphenol, polyvinylmethylether, polyvinylalcohol, polyvinylpyrrolidone, polyacrylonitrile, polyacrylamide, polyhydroxy (meth) Acrylate, water-soluble polymer such as styrene-maleic acid copolymer, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer Polymer, polyethylene, polypropylene, ethylene-propylene-diene terpolymer
(EPDM), sulfonated EPDM, polyvinyl acetal resin,
(Meth) acrylic acid ester copolymer containing (meth) acrylic acid ester such as methyl methacrylate and 2-ethylhexyl acrylate, (meth) acrylic acid ester-
Acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polybutadiene, neoprene rubber, fluororubber, polyethylene oxide, polyester polyurethane resin, poly Emulsion (latex) of ether polyurethane resin, polycarbonate polyurethane resin, polyester resin, phenol resin, epoxy resin, etc.
Another example is suspension. In particular, polyacrylic ester latex, carboxymethyl cellulose, polytetrafluoroethylene, and polyvinylidene fluoride are preferable.

These binders can be used alone or as a mixture. When the amount of the binder added is small, the holding power / cohesion of the electrode mixture is weak. If it is too large, the electrode volume increases and the capacity per unit volume or unit mass of the electrode decreases.
For this reason, the addition amount of the binder is preferably 1 to 30% by mass, and particularly preferably 2 to 10% by mass.

(5) Filler As the filler, any fibrous material which does not cause a chemical change in the constructed battery can be used.
Generally, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. The amount of the filler added is not particularly limited, but is preferably 0 to 30% by mass.

(C) Method for Producing Positive / Negative Electrode Sheet A positive electrode sheet and a negative electrode sheet can be produced by coating (coating) the above-mentioned electrode mixture on a current collector, drying and compressing.

Examples of the coating method include reverse roll method, direct roll method, blade method, knife method, extrusion method, curtain method, gravure method, bar method, dip method and squeeze method. Among them, the blade method, the knife method and the extrusion method are preferable. The coating is preferably carried out at a speed of 0.1 to 100 m / min. At this time, the solution physical properties of the mixture,
By selecting the coating method according to the drying property, a good surface condition of the coating layer can be obtained. The coating may be performed one by one or simultaneously on both sides.

The coating may be continuous, intermittent or striped. The thickness, length and width of the coating layer are determined by the shape and size of the battery, but the thickness of the coating layer on one side is
In the compressed state after drying, 1 to 2000 μm is preferable.

Examples of the method for drying and dehydrating the electrode sheet coating material include hot air, vacuum, infrared ray, far infrared ray, electron beam and low humidity air, alone or in combination. The drying temperature is preferably in the range of 80 to 350 ° C, particularly preferably in the range of 100 to 250 ° C. The water content is preferably 2000 ppm or less in the whole battery, and the positive electrode mixture, the negative electrode mixture and the electrolyte each contain 50% or less.
It is preferably 0 ppm or less. The sheet pressing method is
Although a generally adopted method can be used, a calendar press method is particularly preferable. The pressing pressure is not particularly limited, but 0.2 to 3 t / cm ² is preferable. The press speed of the calendar press method is preferably 0.1 to 50 m / min, and the press temperature is preferably room temperature to 200 ° C. The ratio of the negative electrode sheet width to the positive electrode sheet is preferably 0.9 to 1.1, 0.95 to 1.0
Is particularly preferable. The content ratio of the positive electrode active material and the negative electrode active material varies depending on the compound type and the mixture formulation.

(D) Method for Assembling Secondary Battery The secondary battery of the present invention is one in which a positive electrode sheet and a negative electrode sheet are laminated with a gap provided and the gap is filled with the electrolyte composition of the present invention. Preferably, a cylinder type battery as shown in FIG. 1 or a sheet type battery as shown in FIG. 2 is formed. In the cylinder type battery of FIG. 1, the electrolyte composition of the present invention is injected into a wound electrode group 2 in which a non-woven fabric or a separator is sandwiched between a positive electrode sheet and a negative electrode sheet and wound. Figure 2
In the sheet type battery of, the positive electrode sheet 11 and the negative electrode sheet 13
The non-woven fabric 12 is sandwiched between the
The electrolyte composition of the present invention is injected into.

As the separator, an insulating thin film having a large ion permeability and a predetermined mechanical strength is used. In order to ensure safety, it is necessary to have a function of blocking the pores of the separator at 80 ° C. or higher to increase resistance and interrupt current, and the blocking temperature is preferably 90 ° C. or higher and 180 ° C. or lower.

The shape of the holes of the separator is usually circular or elliptical, and the size is 0.05 to 30 μm, preferably 0.1 to 20 μm. Furthermore, as in the case of making by stretching method, phase separation method,
It may be a rod-shaped or amorphous hole. The ratio of these gaps, that is, the porosity is 20 to 90%, preferably 35 to 80%.

These separators are polyethylene,
It may be a single material such as polypropylene or a composite material of two or more kinds. Particularly preferred is a laminate of two or more kinds of microporous films having different pore diameters, porosities, pore blocking temperatures, and the like.

After stacking the positive and negative electrode sheets with a separator interposed therebetween, they are directly processed into a sheet-type battery or folded and then inserted into a square can to electrically connect the can and the sheet and then The electrolyte composition of the invention is injected and the sealing plate is used to form a prismatic battery. In addition, after stacking positive and negative electrode sheets with a separator interposed between them and inserting them into a cylindrical can and electrically connecting the can and the sheet,
The electrolyte composition of the present invention is injected, and a cylinder battery is formed using a sealing plate. At this time, the safety valve can be used as a sealing plate. In addition to the safety valve, various conventionally known safety elements may be provided. For example, a fuse, a bimetal, a PTC element or the like is used as the overcurrent prevention element.

In addition to the safety valve, as a measure for increasing the internal pressure of the battery can, a method of making a cut in the battery can, a method of cracking a gasket, a method of cracking a sealing plate, or a method of cutting with a lead plate can be used. Further, the charger may be provided with a protection circuit incorporating measures against overcharge or overdischarge, or may be connected independently.

As a measure against overcharge, it is possible to provide a method of interrupting the current by increasing the internal pressure of the battery. At this time, a compound that increases the internal pressure can be included in the mixture or the electrolyte. Examples of compounds used to increase the internal pressure include Li ₂ CO ₃ , LiHCO ₃ , Na ₂ CO ₃ , NaHCO ₃ , and Ca.
Carbonates such as C ₃ and MgCO ₃ can be mentioned.

For the can and the lead plate, a metal or alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper and aluminum or alloys thereof are used.

As the method of welding the cap, can, sheet and lead plate, known methods (eg, DC or AC electric welding, laser welding, ultrasonic welding) can be used. As the sealing agent for sealing, a conventionally known compound or mixture such as asphalt can be used.

(E) Specific Example of Internal Structure of Secondary Battery According to a preferred embodiment, as shown in FIG. 1, the secondary battery of the present invention comprises a positive electrode sheet and a negative electrode sheet wound with a nonwoven fabric or a separator. Winding electrode group 2 in battery can 1
The battery can 1 and the negative electrode sheet are electrically connected, and the electrolyte composition of the present invention is injected and sealed. The battery lid 6 also serves as a positive electrode terminal and is fitted into the upper opening of the battery can 1 via the gasket 5. The positive electrode sheet is electrically connected to the battery lid 6 via the positive electrode lead 4.

The sealing body is composed of a battery lid 6, a ring-shaped PTC element 63, a current interruption element 62, and a pressure sensitive valve body 6 in this order from the top.
1 is superposed and fitted in and supported by the gasket 5. The battery lid 6 is an exposed surface portion of the battery, and the pressure sensitive valve body 61 is inside the battery. The insulating cover 61a is used for the pressure sensitive valve body 6
Cover the upper surface of 1.

The wound electrode group 2 is, for example, a laminate in which a positive electrode sheet / separator / negative electrode sheet / separator is laminated in this order and is wound. The upper insulating plate 3 is arranged between the wound electrode group 2 and the pressure sensitive valve body 61.
The upper insulating plate 3 insulates the electrode group 2 from the sealing body, and
The electrode group 2 and the battery can 1 are insulated. Also, electrode group and battery can 1
A lower insulating plate 7 is disposed between the electrodes to insulate the electrode group and the battery can 1.

The PTC element 63 has the function of increasing the resistance and shutting off the current when the temperature inside the battery rises. The current interruption element 62 is a laminated structure of a first conductor 62a, an insulating ring 62c, and a second conductor 62b. The first conductor 62a is arranged on the pressure sensitive valve body 61 side and has a through hole. The two conductors 62b are arranged on the PTC element 63 side, that is, on the battery lid 6 side and have a through hole. The first conducting body 62a and the second conducting body 62b are electrically connected at the central portion, and have a thin portion around the connecting portion of the first conducting body 62a.
The pressure sensitive valve body 61 may be one that can be deformed to the side opposite to the electrode group side when the internal pressure rises, and can push up the central connecting portion of the first conducting body 62a. When the internal pressure rises due to an abnormal reaction in the battery, the pressure sensitive valve body 61 deforms to break the connection part of the first conducting body 62a and the second conducting body 62b of the current interrupting element 62 to interrupt the current,
When the pressure is further increased, the thin portion of the pressure sensitive valve body 61 is broken and the pressure is released. At this time, since the current cutoff element 62 is arranged on the side opposite to the electrode group side of the pressure sensitive valve body 61, even if a spark is generated at the cutoff portion, the battery is not ruptured due to the ignition of the electrolyte vapor. To be prevented.

Although FIG. 1 shows an example of a cylinder type battery, the shape of the battery can be applied to either a cylinder or a corner. If the winding core has a cylindrical shape, a cylinder type battery can be manufactured, and if the winding core has a rectangular shape, a rectangular battery can be manufactured.

The application of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when it is mounted on an electronic device, it is a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone handset. ,
Pager, handy terminal, mobile fax,
Mobile copy, mobile printer, headphone stereo,
Video movie, LCD TV, handy cleaner,
Examples include portable CDs, mini disks, electric shavers, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, and memory cards. Other consumer products such as automobiles, electric vehicles, motors, lighting equipment, toys, game machines, road conditioners, clocks, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.)
And so on. Furthermore, it can be used for various military purposes and for space. It can also be combined with a solar cell.

[0084]

EXAMPLES The present invention will be specifically described below with reference to examples. (1) Synthesis of Compounds Synthesis examples of the compound 1-1 of the present invention represented by the general formula (1) are shown. It should be noted that compounds other than these can also be synthesized according to the synthesis example shown in the following general formula (2).

[0085]

[Chemical 8]

[Wherein, R represents an alkyl or aryl group which may have a substituent. V is -COO-, -SOO
-, or an -SO ₂ O-. F represents a fluorine atom. ]

(Synthesis of Compound 1-1) Under a nitrogen stream, 6.5 g of anhydrous lithium acetate was gradually added to 14.2 g of boron trifluoride-diethyl ether complex cooled with ice while paying attention to heat generation. After the addition, the temperature was raised to room temperature and the mixture was stirred for 1 hour. Then, the volatile components are distilled off under reduced pressure, and the highly viscous liquid compound 1-
1 and 13.3 g were obtained.

(Synthesis of Compound 1-2) 8.0 g of anhydrous lithium propionate was gradually added to 14.2 g of boron trifluoride-diethyl ether complex cooled with ice under a nitrogen stream while paying attention to heat generation. After the addition, the temperature was raised to room temperature and the mixture was stirred for 1 hour. Then, the volatile components were distilled off under reduced pressure to give compound 1-2,
14.7g was obtained.

(Synthesis of Compound 1-7) To 14.2 g of boron trifluoride-diethyl ether complex cooled with ice in a nitrogen stream, 2-
14.0 g of lithium (2-methoxyethoxy) acetate was gradually added while paying attention to heat generation. After addition, warm to room temperature and
Stir for hours. Then, the volatile components were distilled off under reduced pressure to obtain 20.6 g of compound 1-7.

(Synthesis of Compound 1-11) To 14.2 g of boron trifluoride-diethyl ether complex cooled with ice in a nitrogen stream,
10.2 g of lithium methanesulfonate was gradually added while paying attention to heat generation. After the addition, the temperature was raised to room temperature and the mixture was stirred for 1 hour. Then, the volatile components were distilled off under reduced pressure to give compound 1-1
1, 16.9g was obtained.

(Synthesis of Compound 1-13) To 14.2 g of boron trifluoride diethyl ether complex cooled with ice under a nitrogen stream,
15.6 g of lithium trifluoromethanesulfonate was gradually added while paying attention to heat generation. After the addition, the temperature was raised to room temperature and the mixture was stirred for 1 hour. Then, the volatile components were distilled off under reduced pressure to obtain 22.3 g of compound 1-13.

(Synthesis of Compound 1-16) To 14.2 g of boron trifluoride-diethyl ether complex cooled with ice in a nitrogen stream,
8.6 g of lithium methanesulfinate was gradually added while paying attention to heat generation. After the addition, the temperature was raised to room temperature and the mixture was stirred for 1 hour. Then, the volatile components were distilled off under reduced pressure to give compound 1-1
6, 15.3 g were obtained.

(Synthesis of Compound 1-17) 14.2 g of boron trifluoride-diethyl ether complex was cooled with ice under a nitrogen stream.
14.8 g of lithium benzenesulfinate was gradually added while paying attention to heat generation. After the addition, the temperature was raised to room temperature and the mixture was stirred for 1 hour. Then, the volatile components were distilled off under reduced pressure to give compound 1
-17, 21.5 g were obtained.

(2) Preparation of Secondary Battery-1 (Preparation of Positive Electrode Sheet 1) LiCoO ₂ was used as a positive electrode active material.
3 parts by weight, flake graphite 2 parts by weight, acetylene black 2
3 parts by weight of polyacrylonitrile as a binder, and 100 parts by weight of acrylonitrile as a medium are kneaded to obtain a slurry, which is applied to an aluminum foil having a thickness of 20 μm by using an extrusion type coating machine,
After drying and compression molding with a calender press, an aluminum lead plate is welded to the ends to a thickness of 95 μm,
A positive electrode sheet having a width of 54 mm and a length of 49 mm was prepared.

(Preparation of Negative Electrode Sheet) 43 parts by weight of a mesophase pitch-based carbon material (Petka) as a negative electrode active material and 2 parts by weight of acetylene black and 2 parts by weight of graphite as a conductive agent were mixed and further bound. 3 parts by weight of polyacrylonitrile as an agent was added, and 100 parts by weight of N-methylpyrrolidone was kneaded as a medium to obtain a negative electrode mixture slurry. The negative electrode mixture slurry was applied to a copper foil having a thickness of 10 μm using an extrusion type coating machine, dried and compression-molded with a calender press to form a negative electrode sheet having a thickness of 46 μm, a width of 55 mm and a length of 50 mm. . After welding the nickel lead plate to the end of the negative electrode sheet, dew point
It heat-processed at 230 degreeC for 1 hour in dry air below 40 degreeC. The heat treatment was performed using a far infrared heater.

(Preparation of Sheet Battery) The negative electrode sheet and the positive electrode sheet were each dried in dry air with a dew point of −40 ° C.
It was dehydrated and dried at 30 ° C. for 30 minutes. 54mm width in a dry atmosphere
× A dehydrated and dried positive electrode sheet having a length of 49 mm, a separator (polyethylene porous film) cut into a width of 60 mm and a length of 60 mm, and a non-woven fabric are laminated, and the electrolyte (1-1) of the present invention is placed on the non-woven fabric in the same amount as acetonitrile. The solution dissolved in was applied, and acetonitrile was distilled off under reduced pressure at 70 ° C. A dehydrated and dried negative electrode sheet having a width of 55 mm and a length of 50 mm was laminated on it, and four edges were heat-sealed under a vacuum using an exterior material made of a laminated film of polyethylene (50 μm) -polyethylene terephthalate (50 μm). It was sealed and a sheet type battery (B-1) was prepared. Similarly, sheet type batteries B-2 to B having the same constitution using the electrolyte as shown in Table 1
-7, Comparative Example B-8 were prepared.

[0097]

[Table 1]

(Evaluation of Battery Performance) With respect to the sheet type battery prepared by the above method, charging / discharging was repeated 10 times under the conditions of 0.2 C, end-of-charge voltage 4.2 V and end-of-discharge voltage 2.6 V.
The discharge capacity in the cycle was calculated. This was examined for 10 batteries of the same formulation, and the average was taken as the capacity of the battery. In this way, the capacity of each battery is obtained and E-
The relative capacity was determined by dividing the values for 2 to E-8 by the value of E-1. The respective values are shown in Table 2.

[0099]

[Table 2]

From the above results, it was confirmed that when the compound of the present invention was used as the electrolyte, the battery capacity was larger than that of the comparative example using the conventional electrolyte.

[0101]

According to the present invention, it is possible to provide a novel electrolyte which is substantially non-volatile and has an excellent charge transporting ability, and further to provide a non-aqueous secondary battery containing the electrolyte and having a large battery capacity. it can.

[Brief description of drawings]

FIG. 1 shows a conceptual diagram of a sheet type battery used in Examples.

FIG. 2 shows a conceptual diagram of a sheet type battery used in Examples.

[Explanation of symbols]

1 Positive electrode sheet 2 winding electrode group 11 Positive electrode sheet 12 non-woven 13 Negative electrode sheet 14 Positive terminal 15 Negative electrode terminal

Claims (2)

[Claims] 1. An electrolyte containing a compound represented by the following general formula (1). [Chemical 1] [In the general formula (1), R represents an alkyl or aryl group which may have a substituent. V is, -COO -, - SOO- or an -SO ₂ O-. X represents a halogen atom. ] 2. A non-aqueous electrolyte secondary battery having a positive electrode and a negative electrode, which contains the electrolyte according to claim 1.