JP3456561B2 - Ion conductor for non-aqueous battery and non-aqueous battery using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ionic conductor for a non-aqueous battery and a non-aqueous battery using the same, and more particularly to an ionic conductor for a non-aqueous battery excellent in high voltage stability and a non-aqueous battery. Regarding

[0002]

2. Description of the Related Art Non-aqueous batteries typified by manganese dioxide-lithium batteries have a high voltage of about 3 V and a high energy density, so that the demand thereof is increasing more and more. In addition, recently, a lithium ion secondary battery using LiCoO ₂ and carbon has been developed, and a high voltage of about 3.6 V can be obtained for this battery, so that demand is rapidly increasing.

Conventionally, perchlorate-based LiClO ₄ has been used as the electrolyte of this type of battery, but recently it has become less preferred because of its lack of safety. Further, it has been proposed to improve safety and reliability by dispersing various lithium salts including LiClO ₄ in a polymer such as polyethylene oxide (PEO) to form a solid ionic conductor. However, due to the solidification, the ionic conductivity is considerably reduced.

In addition to the above LiClO ₄ , LiB (C ₆ H ₅ ) ₄ and Li are used as electrolytes for this type of battery.
CF ₃ SO ₃ , LiCF ₃ CO ₂ , LiN (CF ₃ SO
It has been proposed to use organic lithium salts such as ₂ ) ₂ and LiC (CF ₃ SO ₂ ) ₃ (Japanese Patent Laid-Open No. 7-6584).
3 gazette, US Pat. No. 5,260,143, etc.).

[0005]

However, the above LiB (C ₆ H ₅ ) ₄ has a problem that the high voltage stability is insufficient and the storage stability is poor depending on the solvent used. In addition, the liquid ionic conductor (electrolyte solution) obtained by dissolving the above LiB (C ₆ H ₅ ) ₄ in an organic solvent causes discoloration when stored, and part of the solvent is polymerized.

As a result, the battery using the liquid ionic conductor (electrolytic solution) has a problem that the battery performance is deteriorated by storage.

Further, LiCF ₃ SO ₃ and LiCF ₃ CO
₂ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO
₂ ) Organolithium salts such as ₃ are safer than LiClO ₄ , but have insufficient oxidation resistance, and thus have poor stability under high voltage, low ionic conductivity, and electrode There is a problem in that some materials cannot be used for the current collector of or it is expensive.

Therefore, the present invention solves the problems of the conventional ion conductor for non-aqueous battery and the non-aqueous battery using the same as described above, and particularly the ion for non-aqueous battery excellent in high voltage stability. It is intended to provide a conductor and a non-aqueous battery.

[0009]

According to the present invention, a metal ion or hydrogen ion is used as a counter ion to form Vb which serves as an anion part.
By using a compound in which a resonance structure containing a group atom is bound to an electron-withdrawing substituent via a group VIb atom as an ionic conductor for a non-aqueous battery, the ionic conductor itself and a non-aqueous compound using the same The high voltage stability of the battery is improved to achieve the above object.

In the present invention, the above-mentioned compound used in the ionic conductor for a non-aqueous battery is not only a mere metal salt as a solute when it is dissolved in an organic solvent to form a liquid ionic conductor (electrolytic solution). If it becomes larger, it will also be an ion conductive structure, so it can also be a solid ion conductor for a non-aqueous battery. In this case, the compound has a moiety capable of pairing with several metal ions in one molecule. In the present invention, the portion is referred to as an anion portion including a case of a simple metal salt and a case of forming a polymer. Then, it is preferable that the anion portion be a resonance structure.

Further, the non-aqueous battery of the present invention is particularly suitable for a non-aqueous battery which is required to withstand a voltage. When the maximum voltage of the battery is 4.0 V or more on the Li standard, the effect of the ionic conductor for a non-aqueous battery of the present invention (hereinafter, may be simply referred to as “the ionic conductor of the present invention”) becomes clear. When the maximum voltage of the battery becomes 4.1 V or more, the effect of the ionic conductor of the present invention is more clearly expressed, and more preferable results are obtained by using the ionic conductor of the present invention. When the voltage is 4.2 V or higher, the effect of the ionic conductor of the present invention is more remarkably exhibited, and more preferable results are obtained by using the ionic conductor of the present invention.

In the present invention, the reason why the high voltage stability of the ionic conductor and the non-aqueous battery can be improved by using the above-mentioned specific compound in the ionic conductor for the non-aqueous battery is that It will be clarified in a concrete explanation.

First, the first point of the present invention is to investigate the degree to which an electrically negatively charged anion emits an electron to easily oxidize the anion. It has been found that it can be used as a guideline for stability against oxidation.

That is, the HOMO energies of various anions can be calculated by using the semi-empirical molecular orbital method. The HOMO energies are the energy levels of unstable electron orbits most easily released in the vacuum of anions. Therefore, it can be considered that the smaller this value is, the stronger the oxidation is.

Tables 1 and 2 show MOPAC (CAch
The HOMO energies of the representative examples of the conventional ionic conductor and the ionic conductor of the present invention are calculated by using the MNDO method, which is one of the semi-empirical molecular orbital methods.

[0016]

[Table 1]

[0017]

[Table 2]

As shown in Table 1, (CF ₃ OSO ₂ ) ₂ N ⁻ , (C ₄ F ₉ OSO) rather than RfSO ₂ groups such as (CF ₃ SO ₂ ) ₂ N ⁻ which conventional ion conductors have. ₂ )
^{_{(CF 3 OSO 2) N -}} , (C 8 F 17 OSO 2) (CF
It is considered that the ionic conductor of the present invention having an RfOSO ₂ group such as ₃ OSO ₂ N ⁻ has lower HOMO energy and is excellent in oxidation resistance. Further, as shown in Table 2, the ionic conductor of the present invention, that is, (CF ₃ OSO
^{_{2) 2 N -, (CF}} 3 CH 2 OSO 2) 2 N -, (CF
_{3 CF 2 CH 2 OSO 2)} 2 N -, [(CF _{3) 2} CH
The ionic conductor of the present invention having an anion such as OSO ₂ ] ₂ N ⁻ exhibits lower HOMO energy and oxidation resistance than an ionic conductor having a conventional (CF ₃ SO ₂ ) ₂ N ⁻ type anion. It turns out to be excellent.

The second important point of the present invention is that the Vb group atom which becomes the center of the anion part of the above compound in the present invention (hereinafter, simply referred to as anion center), such as N (nitrogen) or P (phosphorus). Has a relatively low electronegativity, and when these atoms become the anion centers, the battery voltage is 3 V
It has been found that excellent oxidation resistance can be expected because it is difficult to emit electrons even with the above.

In the above, the Vb group atom is an atom of an element belonging to the Vb group of the periodic table. This Vb group atom is
Two or more resonance structure groups (SO ₂ groups, CO groups, etc.) for stabilizing the same can be bonded, whereby the oxidation resistance is further improved. Among the Vb group atoms, atoms belonging to the second or third period are preferable, and atoms belonging to the second period such as N atom are particularly preferable. And, as a resonance structure group, SO ₂ group or CO
Group, PO _x group, NO _x group, etc., but especially SO
₂ groups and CO groups are preferred, especially SO ₂ groups. Thus, the most preferred resonance structure unit, (- SO _2)
2 N ^- it is.

The most characteristic part of the compound used in the present invention (hereinafter, simply referred to as the compound of the present invention) is that a VIb group atom is added to the anion part as a measure for preventing the oxidation of the anion part. It is said that an electron-withdrawing organic substituent is bonded to the compound via this to stabilize the compound.

The electron-withdrawing organic substituent attracts the electron of the central atom of the anion to reduce the electron density of the central atom of the anion and makes it difficult to take out the electron from the central anion, whereby the anion is oxidized. However, the VIb group atom interposed between the electron-withdrawing organic substituent and the anion moiety has the highest electronegativity as an atom capable of forming two bonds, and thus has an electron withdrawing property. It has the effect of further improving the action of the organic substituent. Further, the substituents are lengthened by the presence of the VIb group atom, and steric hindrance is increased, and particularly high voltage stability is improved when combined with the positive electrode current collector metal. In particular, it is highly effective for current collectors that become trivalent or more when eluted, such as aluminum.

For example, conventional (RfSO ₂ ) ₂ NLi
[Mitchel Arman (Michel Arman
(d) US Pat. No. 5,260,145], the (RfOSO ₂ ) ₂ NLi belonging to the compound of the present invention exhibits superior oxidation resistance. Examples of the VIb group atom include O (oxygen) and S (sulfur). Especially, it is difficult for the O (oxygen) atom to have two or more bonds, and electron-withdrawing organic substitution in a state where steric hindrance is small. Since the group can be bonded to the anion portion, high voltage stability can be further enhanced, which is particularly preferable.

Examples of the electron-withdrawing organic substituent bonded via a VIb group atom include a halogenated alkyl group and a cyano group. Among them, a halogenated alkyl group is particularly preferable, and a fluoroalkyl group is particularly preferable. preferable. The number of carbon atoms in the alkyl group is not particularly limited, but the effect of electron withdrawing increases as the number of carbon atoms in the halogenated alkyl group increases, but it is 20 when the solubility in an organic solvent is taken into consideration. The following are preferred.

Further, the halogenated alkyl group may contain a nitrogen atom or an oxygen atom. When the halogenated alkyl group is bonded to the VIb group atom through a non-halogenated carbon atom, steric hindrance is increased, and the high voltage stability of the positive electrode current collector is increased, which is particularly preferable. Specific examples of the halogenated alkyl group bonded to the VIb group atoms through the unhalogenated carbon atoms, for example, the following formula (I) _{[(Rf-O-Y) 2} -X ] _n M ( I) [In the formula, M is a metal atom, n is a valence of the metal atom, and X is Vb.
A group atom, Y represents a SO ₂ group or a CO group, Rf is an electron-attracting group containing a fluorine atom, and a halogen atom is not bonded to the atom at the bonding portion with the oxygen atom, or at least 1 Represents a group in which one hydrogen atom is bonded. However, Rf may be bonded to the O—Y—X group at at least two positions], and specific examples thereof include (RfCH ₂ OSO ₂ ) ₂ NLi.

Further, it is preferable that the halogenated alkyl group be branched in the middle because the stability at high voltage is further enhanced. Specific examples of the branched halogenated alkyl group include, for example, [(CF ₃ ) ₂ CFCH ₂ OSO ₂ ] ₂ N.
Examples thereof include Li.

In the compound of the present invention, as counter ions, in addition to hydrogen ions, metal ions such as alkali metal ions such as lithium ion, sodium ion and potassium ion, and alkaline earth ions such as magnesium ion and calcium ion can be used. Examples of the metal ions include alkali metal ions, and lithium ion is particularly preferable.

In preparing a liquid ionic conductor (electrolytic solution) using the compound of the present invention, it is preferable to dissolve the above compound in an organic solvent. Examples of the organic solvent at that time include propylene carbonate, Ethylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, dimethyl carbonate,
Esters such as methyl propionate and butyl acetate,
1,2-dimethoxyethane, 1,2-dimethoxymethane, dimethoxypropane, 1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 4-
Examples thereof include ethers such as methyl-1,3-dioxolane, and further sulfolane, but esters are preferable in order to enhance high voltage stability of the liquid ionic conductor,
Of these, carbonic acid esters are particularly preferable.

If further high voltage stability is desired, the compound of the present invention is a polymer or oligomer,
It is preferable that the compound functions as a solid ionic conductor (solid electrolyte). A specific example of this is, for example, [-R
_{f'-CH 2 OSO 2 N (} Li) SO 2 OCH 2 - ] _m
(In the formula, Rf ′ is a fluoroalkyl group having 1 to 20 carbon atoms, m represents the degree of polymerization, and is usually 2 to 100) and the like. This compound is a novel compound.

The ionic conductor of the present invention comprises a porous polymer, an insulating inorganic compound [alumina (Al ₂ O ₃ ),
Zeolite and the like], polyethylene oxide, polypropylene oxide, polymethylmethacrylate or their derivatives are used as a support material, and it is more preferable to use them together with the compound of the present invention.

In the case of metal salts, these compounds can be synthesized by reacting XSO ₂ NHSO ₂ X (where X is a halogen atom, particularly Cl) with Rf-CH ₂ OH, for example (Rf- CH ₂ OSO ₂ ) ₂ NH is obtained, which is neutralized with Li ₂ CO ₃ to give
(RfCH ₂ OSO ₂ ) ₂ NLi is obtained. These are compounds that are stable up to around 200 ° C.

In the case of a polymer or oligomer, the alcohol to be reacted is a secondary alcohol (HOCH).
₂ Rf ″ CH ₂ OH) etc. [-Rf ″ -CH
_{2 OSO 2 N (H) SO} 2 OCH 2 - ] Since _m is obtained as a product which may be neutralized with a Li salt. To give a specific example, HOCH ₂ (CF ₂ ) ₄ CH
_{Using 2} OH [N (Li) SO ₂ OCH ₂ (CF ₂ )
₄ CH ₂ OSO _{2] m} (m is 9-10), and may be synthesized.

[N (Li) SO ₂ OCH ₂
A polymer liquid ionic conductor (electrolytic solution) (80% by weight of acetonitrile, 20% by weight of the above polymer) obtained by dissolving (CF ₂ ) ₄ CH ₂ OSO ₂ ] _m (m is 9 to 10) in acetonitrile is at 25 ° C. It shows a high ionic conductivity of 8.9 ms / cm.

When a liquid ionic conductor (electrolytic solution) is prepared by dissolving the compound of the present invention in an organic solvent, the concentration of the above compound is not particularly limited, but usually 0.0
It is preferably 1 to 2 mol / l, particularly preferably about 0.05 to 1 mol / l.

In producing an electrochemical device using the ionic conductor of the present invention, particularly in the case of a non-aqueous battery, an alkali metal or a compound containing an alkali metal is used for the negative electrode, such as copper, nickel or stainless steel net. The one integrated with the current collector material is used.

Examples of the alkali metal at that time include lithium, sodium and potassium, and examples of the compound containing the alkali metal include alkali metal and aluminum, lead, indium, gallium, cadmium, tin and magnesium. Examples thereof include alloys, compounds of alkali metals and carbon materials, compounds of low-potential alkali metals and metal oxides, compounds of metal sulfides, and the like.

For the positive electrode, for example, lithium cobalt oxide, lithium nickel oxide, LiMn ₂ O ₄ , metal oxides such as manganese dioxide, vanadium pentoxide and chromium oxide, metal sulfides such as molybdenum disulfide, or those If necessary, a mixture of conductive materials such as graphite and a binder such as polytetrafluoroethylene is added to the positive electrode active material, and a current collector such as aluminum, tungsten or stainless steel net is used as a core material. A molded product is used as the product.

As the positive electrode active material, since the compound of the present invention is stable at high voltage, for example, lithium cobalt oxide, lithium nickel oxide, LiMn ₂ O ₄ or the like is charged with 4 V or more, especially 4. A high voltage of 2 V or higher is preferable because of its high utility value. The positive electrode current collector material is preferably a metal having a valence of 3 or more when dissolved in a liquid ionic conductor, such as aluminum or tungsten.

Further, when the surface area of the positive electrode active material is small, the high voltage stability is further improved. The positive electrode active material used in the present invention preferably has a surface area of 50 m ² / g or less, particularly 30 m ² / g or less, and particularly preferably 20 m ² / g.

Further, the active surface of the metal oxide of the positive electrode active material is treated with an alkali metal or alkaline earth metal compound, especially a carbonate thereof, so that the metal oxide contains an alkali metal or an alkaline earth metal. It is preferable that the high voltage stability is further improved.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described more specifically with reference to Examples. However, the present invention is not limited to only those examples. Prior to the examples, the synthesis of compounds used as electrolytes in the examples will be shown as synthesis examples.

Synthesis Example 1 50 ml of 2.55 g of bis (chlorosulfonyl) amine
Hexafluoro-2-propanol 20 was placed in a two-necked flask equipped with a bubble counter and a calcium chloride drying tube, and stirred with a magnetic stirrer.
ml was added and the reaction mixture was reacted for 43 hours under reflux conditions. Generation of hydrogen chloride gas was observed during the above reaction. Excess alcohol was removed on the evaporator, thereby giving 5.67 g of a highly hygroscopic white solid.

This white solid was placed at 80 ° C. and 0.25 mmHg.
Sublimation purification was carried out using ICE-TRAP (ice-trap) under the conditions of, and colorless crystals [(CF ₃ ) ₂ CHO were obtained.
SO _2] a ₂ N-H to obtain 5.36 g.

1.25 g of this crystal was dissolved in 15 ml of acetonitrile in a 50 ml two-necked flask, and 0.0968 g of lithium carbonate (purity 99.999%) was gradually added while stirring with a magnetic stirrer at room temperature. ,
Ultrasonic irradiation was performed for 1 hour.
During that time, generation of carbon dioxide was observed.

After the reaction solution was filtered, the solvent acetonitrile was removed by an evaporator to obtain a colorless liquid.
This was dried at 0.05 mmHg and 100 ° C. for 2 hours, and the residual acid was removed by sublimation. As a result, [(CF ₃ ) ₃ CHOSO in the form of a white powder having a very high hygroscopicity is obtained.
₂ ] ₂ N-Li 1g was obtained. The analysis results of this compound are shown below.

Melting point: 194-197 ° C. (decomposition) ¹ H-NMR (CD ₃ CN / TMS): δ; 3.76
_{(B, H 2 O),} 5.50 (m, CH, 2 J (F-H)
= 6 Hz) ¹⁹ F-NMR (CD ₃ CN / C ₆ F ₅ ): δ; 90.8
4 (d, CF ₃ , ² J (F-H) = 7 Hz)

Synthesis Example 2 2.75 g of bis (chlorosulfonyl) amine and 20 ml of anhydrous benzene were placed in a two-necked flask equipped with a 50 ml bubble counter and a calcium chloride drying tube, and distilled while stirring with a magnetic stirrer 2. 2, 3,
3.85 g of 3,3-pentafluoropropanol was added, and the reaction mixture was reacted for 1 hour under reflux conditions. Generation of hydrogen chloride gas was observed during the above reaction. The reaction solvent benzene and unreacted alcohol were removed by an evaporator to obtain 5.67 g of a highly hygroscopic colored solid.

This colored solid was dried at 90 ° C. and 0.15 mmHg.
Sublimation purification using ICE-TRAP under the conditions of
The colorless crystals [CF ₃ CF ₂ CH ₂ OSO _{2] 2} N-H to obtain 5.11 g.

4.42 g of this crystal was dissolved in 20 ml of water in a 50 ml two-necked flask, and lithium carbonate (purity 99.
0.3699 g (999%) was gradually added, and the mixture was reacted at 100 ° C. for 1 hour. Generation of carbon dioxide was observed during the above reaction. The pH of the resulting reaction mixture was about 7.

After filtering the reaction solution, the solvent water was removed by an evaporator to obtain a colorless solid. The colorless solid was dried at 100 ° C. for 1.5 hours under a pressure of 0.05 mmHg. This highly hygroscopic high white powder of [CF ₃ CF ₂ CH ₂ OSO _2] 4.10 ₂ N-Li
g was obtained. The analysis results of this compound are shown below.

Melting point: 210 ° C. (decomposition) ¹ H-NMR (CD ₃ CN / TMS): δ; 3.05
(S, H ₂ O), 4.67 (t, q, CH2, ² J (F
−H) = 13 Hz, ³ J (F−H) = 0.98 Hz) ¹⁹ F-NMR (CD ₃ CN / C ₆ F ₆ ): δ; 40.3
_{2 (CF 2), 80.19 (} CF 3)

Synthesis Example 3 2.88 g of bis (chlorosulfonyl) amine and 20 ml of anhydrous benzene were placed in a two-necked flask equipped with a 50 ml bubble counter and a calcium chloride drying tube, and distilled while stirring with a magnetic stirrer 2. 2, 3, 3
3.56 g of tetrafluoropropanol was added and the reaction mixture was heated under reflux conditions for 1 hour. During that time, generation of hydrogen chloride gas was observed. Benzene as a reaction solvent was removed by an evaporator, and a brown solid having high hygroscopicity was removed.
99 g were obtained.

This brown solid was heated at 120 ° C. and 0.05 mmH
Sublimation purification was carried out using a cold-finger trap at -90 ° C under the condition of g. Thus, 5.2 colorless crystals [HCF ₂ CF ₂ CH ₂ OSO ₂ ] ₂ NH were obtained.
6 g were obtained.

4.19 g of this crystal was dissolved in 20 ml of water in a 50 ml two-necked flask, and lithium carbonate (purity 99.
(999%) was gradually added, the temperature was raised to 100 ° C., and the reaction was carried out at the same temperature for 1 hour. Generation of carbon dioxide was observed during the above reaction. The pH of the reaction mixture was about 7.

After filtering the reaction solution, the solvent water was removed by an evaporator to obtain a colorless solid. The solid was dried at 100 ° C. for 2 hours under a pressure of 0.05 mmHg. As a result, the white powdery [HC
F ₂ CF ₂ CH ₂ OSO _2] to give 3.86g of the ₂ N-Li. The analysis results of this compound are shown below.

Melting point: 200 ° C. (decomposition) ¹ H-NMR (CD ₃ CN / TMS): δ; 2.91
(S, H ₂ O), 4.42 (t, t, CH ₂ , ² J (F
-H) = 13 Hz, ³ J (F-H) = 1.7 Hz),
_{6.19 (t, t, CF 2} H, 1 J (F-H) = 52H
z, ² J (F−H) = 5 Hz) ¹⁹ F-NMR (CD ₃ CN / C ₆ F ₆ ): δ; 23.8
2 (d, t, CF ₂ , ¹ J (F−H) = 52 Hz, ² J
(F-H) = 5Hz) , 37.88 (m, CF 2)

Synthesis Example 4 2.24 g of bis (chlorosulfonyl) amine and anhydrous benzene were placed in a two-necked flask equipped with a 50 ml bubble counter and a calcium chloride drying tube, and distilled under stirring with a magnetic stirrer 2,2 , 2-trifluoroethanol (2.25 g) was added, and the reaction mixture was reacted under reflux conditions for 1 hour after the generation of hydrogen chloride gas was completed. Benzene as a reaction solvent and unreacted alcohol were removed by an evaporator to obtain a highly hygroscopic colored solid at 3.7.
0 g was obtained.

This colored solid was purified by sublimation using ICE-TRAP under the conditions of 80 ° C. and 0.2 mmHg to give colorless crystals [CF ₃ CH ₂ OSO ₂ ] ₂ N-H 3.48.
g was obtained.

After carrying out this reaction twice, this compound 6.
10 g was dissolved in 20 ml of water in a 50 ml two-necked flask and stirred at room temperature with a magnetic stirrer.
0.6610 g of lithium carbonate (purity 99.999%)
The mixture was gradually added and reacted at 100 ° C. for 1 hour. Generation of carbon dioxide was observed during the above reaction. PH of reaction mixture
Was about 7.

After filtering the reaction solution, the solvent water was removed by an evaporator to obtain a colorless solid. This solid was dried at 100 ° C. for 3 hours under a pressure of 0.4 mmHg.
As a result, [CF ₃
CH ₂ OSO _2] the ₂ N-Li to give 6.03 g. The analysis results of this compound are shown below.

Melting point: 210 ° C. (decomposition) ¹ H-NMR (CD ₃ CN / TMS): δ; 2.93
(S, H ₂ O), 4.46 (q, CH ₂ , ² J (H-
F) = 8 Hz) ¹⁹ F-NMR (CD ₃ CN / C ₆ F ₆ ): δ; 89.7.
_{8 (t, 6F, CF 3} , 2 J (H-F) = 8Hz)

Synthesis Example 5 2,2,3,3,4,4,5,5 in a two-necked flask equipped with a 50 ml bubble counter and a calcium chloride drying tube.
-Octafluoro-1,6-hexanediol 2.57
g and 20 ml of anhydrous benzene were added, and a benzene solution in which 2.10 g of bis (chlorosulfonyl) amine was dissolved was added with stirring with a magnetic stirrer, and the mixture was reacted under reflux conditions for 5 hours. Generation of hydrogen chloride gas was observed during the above reaction. After the reaction was completed, a polymer precipitation product was obtained in the reaction vessel.

The precipitate is filtered off and dried to give a solid [H
_{-NSO 2 OCH 2 (CF 2)} 4 CH 2 OSO 2 ]
3.26 g of _m (m is 9 to 10) was obtained.

In a 50 ml two-necked flask, 1.30 g of this solid was dissolved in 15 ml of water, and 0.080 of lithium hydroxide was added while stirring with a magnetic stirrer at room temperature.
g was added slowly. After filtering the reaction solution, the solvent water was removed by an evaporator, and the residue was purified with acetonitrile. The solvent was removed on the evaporator to give a very viscous liquid. This liquid under a pressure of 0.05 mmHg,
It was dried at 100 ° C. for 3 hours and crushed. Thus, highly hygroscopic pale brown powdery [Li-NSO ₂ OCH
₂ (CF _{2) 4} CH ₂ OSO _{2] m} (m is 9-10) was obtained 1.30 g. When the molecular weight of this compound was measured by gel permeation chromatography, the number average molecular weight was 3,400 and the weight average molecular weight was 4,300. The analysis results of this compound are shown below.

Melting point: 150 ° C. or lower ¹ H-NMR (CD ₃ CN / TMS): δ; 3.00
(B, H ₂ O), 4.56 (t, CH ₂ ), 4.00
^{_{(T, CH 2) 19 F}} -NMR (CD 3 CN / C 6 F 6): δ; 40.6
3 (m), 44.08 (m), 41.80 (m)

In the above Synthesis Examples 1 to 5, the melting point was measured by using an MP-S3 melting point measuring instrument manufactured by Yanaco Co., Ltd., and the NMR spectrum was JEOL FX-100.
It is measured using FTNMR.

Example 1 [(CF ₃ ) ₂ C obtained in Synthesis Example 1 above was used as an electrolyte.
HOSO ₂ ] ₂ NLi was used to prepare a liquid ionic conductor (electrolytic solution) as shown below. In the above [(CF _{3) 2} CHOSO _{2] 2} NLi, its the anion (-SO ₂₎ organic electron-attracting substituent via ₂ N- to O (oxygen) atom [(CF ₃ ) ₂ CH-] is bonded.

Preparation of the liquid ionic conductor (electrolytic solution)
Note [(CF₃ )₂ CHOSO₂ ] ₂ NLi Propile
Carbonate and add, [(CF₃ )₂ CH
OSO₂ ]₂ Dissolve NLi in propylene carbonate
I went by. In liquid ionic conductor (electrolyte)
In [(CF₃ )₂ CHOSO₂ ]₂ NLi concentration
Is 0.1 mol / l, and this liquid ionic conductor (electric
The composition of the solution is 0.1 mol / l [(CF₃ )₂ CHO
SO₂ ]₂ Shown as NLi / PC. Liquid ionic conductor
PC in (electrolytic solution) is an abbreviation for propylene carbonate
It is a name.

Therefore, 0.1 mol / l [(CF ₃ ) ₂ CHOSO showing the above liquid ionic conductor (electrolytic solution) is used.
₂ ] ₂ NLi / PC is a liquid ionic conductor (electrolyte solution) of propylene carbonate [(CF ₃ ) ₂ CHOSO
₂ ] ₂ NLi was dissolved in 0.1 mol / l.

Next, 4 parts by weight of polyvinylidene fluoride was dissolved in N-methylpyrrolidone, and 90 parts by weight of LiCoO _{2 as a} positive electrode active material and 6 parts by weight of graphite as a conduction aid were added and mixed to form a slurry. I chose This positive electrode mixture slurry is uniformly applied to both surfaces of a positive electrode current collector made of an aluminum foil having a thickness of 20 μm and dried, and then compression molded by a roller press machine, and then cut into predetermined dimensions,
The lead body was welded to produce a positive electrode.

The positive electrode was attached to the lithium foil of the negative electrode through a separator made of a microporous polyethylene film having a thickness of 34 μm so as to surround the positive electrode, and then the whole was inserted into a polyethylene bag. did. After injecting the above liquid ionic conductor (electrolytic solution) into this, the upper part was heat-sealed to produce a thin non-aqueous secondary battery.

Example 2 The same as Example 1 except that (CF ₃ CF ₂ CH ₂ OSO ₂ ) ₂ NLi obtained in Synthesis Example 2 was used in place of [(CF ₃ ) ₂ CHOSO ₂ ] ₂ NLi. A non-aqueous secondary battery was produced in the same manner as in Example 1 except that a liquid ionic conductor (electrolytic solution) was prepared in Example 1 and the liquid ionic conductor (electrolytic solution) was used.

Example 3 [(CF ₃ ) ₂ CHOSO ₂ ] ₂ NLi was replaced with (HCF ₂ CF ₂ CH ₂ OSO ₂ ) ₂ NLi obtained in Synthesis Example 3.
A liquid ionic conductor (electrolytic solution) was prepared in the same manner as in Example 1 except that the liquid ionic conductor (electrolytic solution) was used.
A non-aqueous secondary battery was produced in the same manner as in Example 1 except that was used.

Example 4 Liquid crystal was prepared in the same manner as in Example 1 except that (CF ₃ CH ₂ OSO ₂ ) ₂ NLi obtained in Synthesis Example 4 was used in place of [(CF ₃ ) ₂ CHOSO ₂ ] ₂ NLi. Ion conductor (electrolyte)
Was prepared, and a non-aqueous secondary battery was produced in the same manner as in Example 1 except that the liquid ionic conductor (electrolytic solution) was used.

Example 5 [Li-NSO ₂ OCH ₂ (CF ₂ ) ₄ CH obtained in Synthesis Example 5 was used in place of [(CF ₃ ) ₂ CHOSO ₂ ] ₂ NLi.
₂ OSO ₂ ] _m (m is 9 to 10), and a mixture of propylene carbonate and 1,2-dimethoxyethane in a volume ratio of 1: 2 so that the concentration of the liquid ionic conductor is 0.01 mol / l. It was dissolved in a solvent to prepare a liquid ionic conductor (electrolytic solution). It was A non-aqueous secondary battery was produced in the same manner as in Example 1 except that this liquid ionic conductor (electrolytic solution) was used.

Comparative Example 1 Instead of [(CF ₃ ) ₂ CHOSO ₂ ] ₂ NLi, (C
A liquid ionic conductor (electrolytic solution) was prepared in the same manner as in Example 1 except that F ₃ SO ₂ ) ₂ NLi was used, and the liquid ionic conductor (electrolytic solution) was used. Similarly, a non-aqueous secondary battery was produced.

The oxidation resistance of the liquid ionic conductors (electrolyte solutions) of Examples 1 to 4 and Comparative Example 1 prepared as described above was measured as follows.

A platinum wire with a diameter of 0.3 mm manufactured by Niraco was used as the working electrode of the cell for measuring oxidation resistance, and a lithium film manufactured by Asahi Tohkin Co., Ltd. with a width of 21 mm was used as the counter electrode. The facing area of this counter electrode is 0.2 cm ² . A polyethylene microporous membrane was placed as a separator between the working electrode and the counter electrode. The cell thus prepared was 50 m using a Hokuto Denko potentiostat (HA-501) and a function generator (HB-104).
The potential is scanned at a scanning speed of V / s, and the current density is 0.5 m.
The oxidation resistance of the liquid ionic conductor (electrolytic solution) was evaluated by setting the potential reaching A / cm ² as the oxidation potential.

The above oxidation potential is a measure for showing the high voltage stability of the liquid ionic conductor (electrolyte), and the higher the oxidation potential is, the better the high voltage stability is. Completely liquid ionic conductor up to voltage (electrolyte)
Does not indicate that it will not decompose.

Table 3 shows the oxidation potentials of the liquid ionic conductors (electrolyte solutions) of Examples 1 to 4 and Comparative Example 1 measured as described above.

[0081]

[Table 3]

As shown in Table 3, the liquid ionic conductors (electrolytic solutions) of Examples 1 to 4 have a higher oxidation potential than the liquid ionic conductors (electrolytic solution) of Comparative Example 1.

Next, the above Examples 1 to 5 and Comparative Example 1
The battery was charged at 0.5 mA / cm ² for 3 hours in a dry atmosphere, and the charging was completed at an upper limit voltage of 4.2V. afterwards,
The batteries were discharged at 0.5 mA / cm ² to 2.75 V, and the discharge capacity was examined. The results are shown in Table 4 as a ratio (capacity ratio) with the discharge capacity of Example 1 as 100.

[0084]

[Table 4]

As shown in the results shown in Table 4, the capacity ratios of the batteries of Examples 1 to 5 were larger than the capacity ratio of the battery of Comparative Example 1, and by using the ion conductor of the present invention, high voltage The discharge capacity increased when charged at.

In order to investigate the cause, the battery was disassembled, and in the battery of Comparative Example 1, the aluminum of the positive electrode current collector was eluted in the liquid ionic conductor (electrolytic solution) or adhered to the negative electrode. The batteries of Examples 1 to 5 showed almost no such trace.

[0087]

As described above, according to the present invention, a resonance structure containing a metal ion such as [(CF ₃ ) ₂ CHOSO ₂ ] ₂ NLi as a counter ion and containing a Vb group atom as an anion part is provided. By using a compound bonded to an electron-withdrawing organic substituent through a VIb group atom as an ionic conductor, it is possible to provide an ionic conductor for a non-aqueous battery and a non-aqueous battery having excellent high voltage stability. did it.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Nie ▼ ▲ Jin ▼ 3-64 Kasugahara Higashimachi, Kasuga City, Fukuoka Prefecture (72) Inventor Hiroshi Kobayashi 695-18 Hara, Chikushino, Fukuoka Prefecture (72) Inventor Takaaki Sonoda Fukuoka Prefecture 2-1-23 Mitsuoka-cho, Hakata-ku, Fukuoka (56) References JP-A-7-6786 (JP, A) JP-A-7-65843 (JP, A) JP-A-8-45544 (JP, A) ( 58) Fields surveyed (Int.Cl. ⁷ , DB name) H01M 10/40 H01M 6/16 H01B 1/06 C07C 309/06 C07F 1/02

Claims (8)

(57) [Claims] 1. A resonance structure comprising a metal ion or hydrogen ion as a counter ion and containing a Vb group atom as an anion part,
An ionic conductor for a non-aqueous battery , which uses a compound bonded to an electron-withdrawing organic substituent through a VIb group atom. 2. A resonance structure comprising a group Vb atom containing an SO ₂ group.
Or a CO group bonded thereto.
Ion conductor for non-aqueous batteries. 3. The compound has a metal ion as a counter ion,
A resonance structure containing a nitrogen atom, which serves as the anion part, is bound to an electron-withdrawing organic substituent through an oxygen atom, and a halogen atom is bound to the atom at the part of the organic substituent that binds to the oxygen atom. The ionic conductor for a non-aqueous battery according to claim 1 , wherein the ionic conductor has no structure or has a structure in which at least one hydrogen atom is bonded. 4. The compound has a metal ion as a counter ion,
SO ₂ group or CO group is attached to the nitrogen atom in the anion portion, bonded to organic electron-attracting substituent resonant structure including the SO ₂ group or CO group through an oxygen atom,
The ionic conductor for a non-aqueous battery according to claim 1, which is represented by the following formula (I). _{[(Rf-O-Y) 2} -X ] _n M (I) wherein, M: a metal atom, n represents the valence of the metal atoms X: Vb group atoms Y: SO ₂ group or CO group O: Oxygen Atom Rf: an electron-withdrawing group containing a fluorine atom, in which a halogen atom is not bonded to the atom at the bonding portion with the oxygen atom, or at least one hydrogen atom is bonded.
Further, this Rf may be bonded to OYX at two or more positions. 5. A resonance structure comprising a metal ion or hydrogen ion as a counter ion and containing a Vb group atom as an anion part.
A non-aqueous battery comprising an ionic conductor using a compound bonded to an electron-withdrawing organic substituent through a VIb group atom. 6. A resonance structure comprising an SO ₂ group at a Vb group atom.
Or a CO group is bonded thereto.
Non-aqueous battery mounted . 7. The compound has a metal ion as a counter ion,
A resonance structure containing a nitrogen atom, which serves as an anion part, is bound to an electron-withdrawing organic substituent through an oxygen atom, and a halogen atom is bound to the atom at the part of the organic substituent that is bonded to the oxygen atom. A structure having no or at least one hydrogen atom bonded thereto.
5. The non-aqueous battery according to item 5 . 8. The compound has a metal ion as a counter ion,
SO ₂ group or CO group is attached to the nitrogen atom in the anion portion, bonded to organic electron-attracting substituent resonant structure including the SO ₂ group or CO group through an oxygen atom,
The non-aqueous battery according to claim 5, which is represented by the following formula (I). _{[(Rf-O-Y) 2} -X ] _n M (I) wherein, M: a metal atom, n valence of the metal atom X: Vb atom Y: SO ₂ group or CO group O: an oxygen atom Rf : An electron-withdrawing group containing a fluorine atom, in which a halogen atom is not bonded to the atom at the bonding portion with the oxygen atom, or at least one hydrogen atom is bonded.
Further, this Rf may be bonded to OYX at two or more positions.