JP6754535B2 - Method for manufacturing polymer for lithium battery, lithium battery electrolyte and lithium battery - Google Patents

Description

The present invention relates to a method for producing a polymer for a lithium battery, a lithium battery electrolyte, and a lithium battery. In particular, the lithium battery is being charged and discharged by dissolving a polymer for a lithium battery having a specific structure in the lithium battery electrolyte. The present invention relates to a technique capable of forming a polymer film on the surface of an electrode.

In recent years, due to changes in the environment, the global focus has been on reducing carbon emissions and promoting the rapid development of electric vehicles, and the demand for the electrical characteristics of batteries has become more stringent. Due to the demand for energy density of electronic consumption and power batteries, in lithium batteries, the positive electrode material is moving toward high capacitance and high voltage materials, and the negative electrode material is also moving toward high energy silicon materials, lithium metal or stone ink materials. There is.

The lithium battery has a lithium transition metal oxide as a positive electrode and a graphite electrode as a negative electrode. During charging and discharging, a solid electrolyte interface (SEI) is formed on the surfaces of the positive electrode and the negative electrode by the electrolytic solution of the lithium battery.

Alkoxy lithium carbonate SEI membranes formed by organic solvents of carbonic acid esters in the electrolytic solution currently used are not stable and may be dissolved or burst during the charge / discharge cycle. Therefore, the SEI membranes are used. Need to be played again. Therefore, the lithium ions are continuously worn as the usage time (or the number of charge / discharge cycles) increases, and the capacitance of the lithium battery decreases. At the same time, the increase in the SEI film also increases the internal resistance of the lithium battery, which accelerates the decline in the performance of the lithium battery. If the SEI film is incomplete, a good protective effect cannot be provided to the electrode, the metal of the positive electrode material is precipitated, the material structure is burst, and the cycle life of the lithium battery is deteriorated.

In response to the above-mentioned drawbacks of the lithium alkoxycarbonate SEI film, it is currently proposed to add an additive to the electrolytic solution and use this additive to form a protective film of a different material on the surface of the electrode during charging and discharging of the lithium battery. There is.

One of the additives is a silicon-containing maleimide and / or a silicon-containing bismaleimide monomer molecule. With the above additives, the electrochemical window of the lithium battery can be made wider than 5V to improve the cycle life and the capacitance. However, with the above additives, the conductivity of lithium ions is deteriorated, and the cycle life and capacitance are also slightly improved.

Another additive is a polymer formed by polymerizing maleimide and / or bismaleimide monomer and diamine compound in N-methylpyrrolidone. However, the maleimide used in the method for producing such an additive has an excessively large content and a high polymerization reaction temperature, so that the produced additive has a poor film-forming property. A lithium battery to which such an additive is added has a poor capacitance.

Therefore, at present, in order to effectively improve the high temperature capacitance of a lithium battery and improve the cycle life of the lithium battery at high temperature and high voltage, a method for producing a polymer for a lithium battery, the above-mentioned polymer for a lithium battery, is used. It is desired to provide the used lithium battery electrolyte and the lithium battery.

Therefore, one aspect of the present invention provides a method for producing a polymer for a lithium battery obtained by reacting with a maleimide compound and a diamine compound having a specific structure.

Another aspect of the present invention provides a lithium battery electrolytic solution containing the above polymer for a lithium battery.

Another aspect of the present invention provides a lithium battery in which the above-mentioned lithium battery electrolytic solution is used to form a polymer film on the electrodes of the lithium battery by the polymer for the lithium battery in the electrolytic solution.

According to the above aspect of the present invention, there is provided a method for producing a polymer for a lithium battery. In a certain embodiment, the production method comprises polymerizing a mixture of a maleimide compound and at least one diamine compound for 96 hours to 144 hours in the presence of an organic acid to produce the polymer for a lithium battery. including. The structure of the maleimide compound contains at least two maleimide units, and the molar ratio of the maleimide compound to at least one diamine compound in the mixture is 1: 1-3: 1.

According to one embodiment of the present invention, the reaction temperature of the polymerization reaction is 100 ° C. to 130 ° C., and the organic acid contains acetic acid.

According to one embodiment of the present invention, the weight average molecular weight of the polymer for lithium batteries is 20,000 to 1,000,000.

According to one embodiment of the present invention, the maleimide compound has a structure represented by the following formula (I-1) or formula (I-2).
In formula (I-1), R ₁ is -RCH ₂ R-, -C (O) CH _2- , -CH ₂ OCH _2- , -C (O)-, -O-, -O-O-, -S -, - S-S - , - S (O) -, - CH 2 S (O) CH 2 -, - (O) S (O) -, - C 6 H 4 -, - CH 2 (C ₆ H ₄ ) CH _2- , -CH ₂ (C ₆ H ₄ ) O-, biphenylene, substituted phenylene or substituted biphenylene, R is an alkylene group having 1 to 6 carbon atoms.
In formula (I-2), R ₂ is -RCH _2- , -C (O)-, -C (CH ₃ ) _2- , -O-, -O-O-, -S-, -SS. -,-(O) S (O)-or-S (O)-,
Represents, and n is an integer of 1 to 3.

According to one embodiment of the present invention, at least one diamine compound contains a structure represented by the following formula (II).
In formula (II), the R ₃ represents -CH _2- , -O-, -S- or -SO _2- .

According to the above aspect of the present invention, a lithium battery electrolytic solution is provided. In one embodiment, the lithium battery electrolyte contains an electrolyte, a polymer for a lithium battery produced by the production method, and a solvent. Assuming that the amount of the lithium battery electrolytic solution used is 100 parts by weight, the amount of the polymer for lithium battery used is 0.2 parts by weight to 2 parts by weight.

According to one embodiment of the present invention, the amount of the lithium battery electrolyte used is 100 parts by weight, the amount of the electrolyte used is 10 to 20 parts by weight, and the electrolyte contains an electrolyte of alkali metal salts.

According to one embodiment of the present invention, the solvent contains a hydrocarbyl ester carbonate having 3 to 5 carbon atoms.

According to one embodiment of the present invention, the lithium battery polymer is dissolved in the solvent.

According to the above aspect of the present invention, a lithium battery is provided. In one embodiment, the lithium battery comprises a lithium transition metal oxide electrode, a graphite electrode, a separator, a polymer film, and the lithium battery electrolyte. The separator is provided between the lithium transition metal oxide electrode and the graphite electrode. The polymer film covers the surfaces of the lithium transition metal oxide electrode and the graphite electrode. The polymer film is formed during charging / discharging of a lithium battery by a polymer for a lithium battery in a lithium battery electrolytic solution.

In the method for producing a polymer for a lithium battery of the present invention, a polymer is produced in the presence of a catalyst (for example, an organic acid) using a maleimide compound having a specific structure and proportion to use and at least one diamine compound. To do. The produced polymer can be applied to a lithium battery electrolytic solution as an additive. In the case of a lithium battery using the above lithium battery electrolytic solution, a polymer film is formed on the surface of the positive and negative electrodes during charging and discharging to protect the active substance of the positive and negative electrodes, and later on the surface of the electrode of the electrolytic solution. Deterioration of the active substance due to the reaction can be prevented.

Further, by applying the polymer film, the high-temperature capacitance of the lithium battery and the cycle life of the lithium battery at a high temperature and high voltage can be effectively improved.

The detailed description of the following accompanying drawings is for facilitating the above and other purposes, features, merits and embodiments of the present invention.
The results of the cycle test of the lithium batteries of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention at room temperature are shown. The results of the cycle test performed at high temperature and high voltage of Examples 1 to 4 and Comparative Example 1 of the present invention are shown.

An object of the present invention is to improve the performance of currently known solid electrolyte interface membranes for lithium batteries. This solid electrolyte interface film is formed on the surface of the electrode by the substance in the electrolytic solution so as to protect the active substance in the electrode during charging and discharging of the battery. The present invention provides a method for producing a polymer for a lithium battery for forming the solid electrolyte interface film (later referred to as a polymer film), a lithium battery electrolytic solution to which the polymer for a lithium battery is applied, and a lithium battery. ..

The method for producing a polymer for a lithium battery of the present invention can be obtained by selecting and reacting a maleimide compound having a specific structure and a specific proportion of use and at least one diamine compound. Such a polymer for a lithium battery can be dissolved in a solvent of a lithium battery electrolytic solution to improve the conductivity of lithium ions. If the polymer film of the lithium battery electrode is formed by the electrolytic solution, the electrode of the lithium battery can be protected, and the high temperature capacitance of the lithium battery and the cycle life at high temperature and high voltage can be improved. Hereinafter, a method for producing a polymer for a lithium battery, a lithium battery electrolytic solution, and a lithium battery of the present invention will be described.
Method for manufacturing polymer for lithium battery

The production method includes producing the lithium battery polymer by polymerizing a mixture of a maleimide compound and at least one diamine compound for 96 hours to 144 hours in the presence of an organic acid.

The structure of the maleimide compound contains at least two maleimide units. Specifically, when the molecular structure of the maleimide compound contains two or more maleimide units, it contributes to the formation of a polymer for a lithium battery. Therefore, the present invention eliminates polymerization reactions with maleimides containing only a single maleimide unit.

The molar ratio of the maleimide compound to at least one diamine compound in the above mixture is 1: 1-3: 1. Too little maleimide compound in the mixture results in an incomplete structure of the lithium battery polymer and cannot effectively protect the lithium battery electrodes when later applied to the lithium battery electrolyte. On the other hand, if the amount of the diamine compound in the mixture is too small, the conductivity of lithium ions in the produced polymer film is poor, the performance of the lithium battery deteriorates, and the film forming property of the polymer for the lithium battery is also deteriorated due to the excessive amount of maleimide. It becomes defective, is disadvantageous in forming the following polymer film, and affects the properties of the lithium battery.

Since the reaction time controls the molecular weight of the polymerized polymer for lithium batteries, if the time is insufficient, a polymer for lithium batteries having an appropriate structure cannot be produced. If the time is too long, the polymerization reaction will be saturated and will not continue. In one embodiment, the weight average molecular weight of the lithium battery polymer is 20,000 to 1,000,000. Preferably, the weight average molecular weight of the lithium battery polymer is 45,000 to 740,000.

In certain examples, the reaction temperature of the polymerization reaction is 100 ° C. to 130 ° C. Specifically, the production method of the present invention can obtain a polymer for a lithium battery having a suitable film-forming property by controlling the type, proportion, reaction time and reaction temperature of the maleimide compound and the diamine compound. It can be formed, which is advantageous for forming a polymer film on an electrode.

In certain examples, the maleimide compound may have a structure represented by the following formula (I-1) or formula (I-2).
In formula (I-1), R ₁ is -RCH ₂ R-, -C (O) CH _2- , -CH ₂ OCH _2- , -C (O)-, -O-, -O-O-, -S -, - S-S - , - S (O) -, - CH 2 S (O) CH 2 -, - (O) S (O) -, - C 6 H 4 -, - CH 2 (C ₆ H ₄ ) CH _2- , -CH ₂ (C ₆ H ₄ ) O-, biphenylene, substituted phenylene or substituted biphenylene, R is an alkylene group having 1 to 6 carbon atoms.
In formula (I-2), R ₂ is -RCH _2- , -C (O)-, -C (CH ₃ ) _2- , -O-, -O-O-, -S-, -SS. -,-(O) S (O)-or-S (O)-,
Represents, and n is an integer of 1 to 3.

Specifically, the maleimide compound is N, N'-bismaleimide-4,4'-diphenylmethane (N, N'-bismaleimide-4,4'-diphenylmethane; formula (I-3)) 1,1 '-(Methylenedi-4,1-phenylene) Bismaleimide [1,1'-(methylenedi-4,1-phenylene) bismaleimide], N, N'-(1,1'-biphenyl-4,4'-dimethylene ) Bismaleimide [N, N'-(1,1'-biphenyl-4,4'-diyl) bismaleimide], N, N'-(4-methyl-1,3-phenylene) Bismaleimide [N, N' -(4-methyl-1,3-phenylene) bismaleimide], 1,1'-(3,3'-dimethyl-1,1'-biphenyl-4,4'-dimethylene) bismaleimide [1,1'- (3,3'dimethyl-1,1'-biphenyl-4,4'-diyl) bismaleimide], N, N'-ethylenedimaleimide (N, N'-ethyllenedimaleimide), N, N'-(1,2) -Phenylene) dimaleimide [N, N'-(1,2-phenylene) dimaleimide], N, N'-(1,3-phenylene) dimaleimide [N, N'-(1,3-phenylene) dimaleimide], N , N'-thiodimaleimide (N, N'-thiodimaleimide), N, N'-dithiodimaleimide, N, N'-ketonedimaleimide, N, N'-ketonedimaleimide, N, N'-methylenebismaleimide (N, N'-methylene-bis-maleinimid), bis-maleimidemethyl-ether, 1,2-bismaleimide-1,2-ethanediol [1, 2-bis- (maleimide) -1,2-ethandil], N, N'-4,4'-diphenylether-bismaleimide (N, N'-4,4'-diphenylether-bis-maleimide), and 4, 4'-bismaleimide-diphenylsulfone [4,4'-bis (maleimide) -diphenylsulfone], phenylmethanemaleimide oligomer (formula (I-4)), bi Sphenol A diphenyl ether bismaleimide (Bisphenol A diphenyl ether bismaleimide; formula (I-5)) or a compound represented by the formula (I-6) may be included, and the compound of the formula (I-6) may contain Taiwan Patent Publication No. I335917. Is synthesized with reference to.

In one preferred example, the compounds represented by the formulas (I-3) to (I-6) may be selected as the maleimide compound of the present invention.

In certain examples, at least one diamine compound comprises the structure represented by the following formula (II).
In formula (II), R ₃ represents -CH _2- , -O-, -S-, or -SO _2- .

Preferably, as the diamine compound, Bis (4-aminophenyl) Sulfone; DDS) or 4,4'-methylenedianiline (4,4'-Methylenedianiline; MDA) may be selected. ..

Preferably, the lithium battery polymer contains a sulfone group (eg, synthesized with a maleimide compound and / or a diamine compound containing a sulfone group). When the above-mentioned polymer for a lithium battery is applied to the formation of a polymer film, the conductivity with respect to lithium ions is suitable, so that the performance of the lithium battery can be improved.

In a certain embodiment, the maleimide compound and the diamine compound are dissolved in a solvent and then mixed with each other to carry out the polymerization reaction. The solvent may be, for example, metacresol (m-cresol).

Of particular note is that the silicon-containing polymer has the drawback of poor lithium ion conductivity, so the lithium battery polymer of the present invention does not contain silicon (or a silicon-containing maleimide compound for polymerization. do not use).
Lithium battery electrolyte

The lithium battery electrolyte of the present invention contains an electrolyte, the above-mentioned polymer for a lithium battery, and a solvent. Assuming that the amount of the lithium battery electrolytic solution used is 100 parts by weight, the amount of the polymer for lithium battery used is 0.2 parts by weight to 2 parts by weight. In one embodiment, the polymer is dissolved in the solvent of the lithium battery electrolyte. If the amount of the polymer for a lithium battery used is too small, the protective effect of the formed polymer film on the lithium battery electrode is poor, and the lithium battery electrode is damaged during charging and discharging. On the other hand, if the lithium battery electrolytic solution contains an excessive amount of a polymer for a lithium battery, the solubility of this polymer decreases, which is disadvantageous to the electrochemical reaction of the lithium battery.

Here, the electrolyte of the present invention may include an alkali metal salt electrolyte that is often applied to lithium batteries, and is not particularly limited. Examples, as the electrolyte of the alkali metal _{salts, LiPF 6, LiBF 4, LiAsF} 6, LiSbF 6, LiClO 4, LiAlCl 4, LiGaCl 4, LiNO 3, LiC (SO 2 CF 3) 3, LiN (SO 2 CF ₃ ) ₂ , LiSCN, LiO ₃ SCF ₂ CF ₃ , LiC ₆ F ₅ SO ₃ , LiO ₂ CCF ₃ , LiSO ₃ F, Li (C ₆ H ₅ ) ₄ or LiCF ₃ SO ₃ may be included. In one embodiment, the amount of the lithium battery electrolyte used is 100 parts by weight, and the amount of the electrolyte used is 10 to 20 parts by weight.

Here, the solvent of the present invention may contain a hydrocarbyl ester carbonate having 3 to 5 carbon atoms. Specifically, the solvent is ethylene carbonate (Ethylene carbonate; EC), propylene carbonate (Propylene carbonate; PC), butylene carbonate (Butylene carbonate), dimethyl carbonate (DIMyl carbonate; DMC), diethyl carbonate (Diethyl carbonate; , Ethyl methyl carbonate (EMC), or any combination of the above, but is not limited thereto.

In one embodiment, the amount of solvent used in the lithium battery electrolyte is the total amount of electrolyte minus the electrolyte and the lithium battery polymer.
Lithium battery

The lithium battery of the present invention includes a lithium transition metal oxide electrode, a graphite electrode, a separator, a polymer film, and the above-mentioned lithium battery electrolytic solution. The separator is provided between the lithium transition metal oxide electrode and the graphite electrode. The polymer film covers the surfaces of the lithium transition metal oxide electrode and the graphite electrode. The polymer film is formed during charging / discharging of a lithium battery by a polymer for a lithium battery in a lithium battery electrolytic solution.

In one embodiment, the lithium transition metal oxide electrode is formed of lithium and a composite oxide of one or more transition metal elements. The transition metal element may include, but is not limited to, cobalt, aluminum, manganese, chromium, iron, vanadium, titanium, zirconium, niobium, molybdenum, tungsten, copper, zinc, indium, lanthanum, cerium and the like.

In one embodiment, the separator may be a polymeric membrane. In general, the separator may be formed of, for example, a polyolefin such as polyethylene or polypropylene. The present invention is not particularly limited here.

Hereinafter, the effects of the method for producing a polymer for a lithium battery of the present invention and the application of the polymer for a lithium battery to a lithium battery electrolyte (used for a lithium battery) will be described by a plurality of production examples, examples and comparative examples. explain.
Production Example 1: Production of polymer for lithium battery

1.861 g (0.0075 mol) of bis (4-aminophenyl) sulfone (DDS) and 0.496 g (0.0025 mol) of 4,4'-methylenedianiline (MDA) dissolved in 13 g of metacresol. It was. Next, 5.375 g (0.015 mol) of maleimide (n is 1) of the above formula (I-4) is dissolved in 20 g of metacresol and mixed with a solution of the above diamine compound to obtain a catalytic amount. Glacial acetic acid was added. The reaction was carried out at 103 ° C. for 96 hours. After precipitation, washing and drying with alcohol, a polymer for a lithium battery of Production Example 1 was obtained.
Production Example 2 to Production Example 8

In Production Examples 2 to 8, the same method as in Production Example 1 was carried out except that the type, molar ratio, reaction temperature and / or reaction time of the maleimide compound and / or diamine compound used were changed. The specific conditions of Production Examples 2 to 8 are shown in Table 1, and will not be described in detail here.

Example 1: Lithium battery

In the lithium battery of Example 1, an electrolytic solution is added to the lithium battery with the NMC (111) electrode as the positive electrode and the graphite electrode as the negative electrode. The composition of the electrolytic solution contains about 12.5 parts by weight of LiPF ₆ electrolyte, about 0.5 parts by weight of the polymer for lithium battery of Production Example 1, and 87 parts by weight of a solvent. The solvent is a mixed solution composed of ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) in a volume ratio of 1: 1: 1.
(1) Room temperature cycle test

When the lithium battery of Example 1 is cycle-tested at room temperature (25 ° C.) at a voltage of 3.0 V to 4.2 V and the number of room temperature cycles increases, the change in capacitance of the lithium battery of Example 1 Was detected. The results of the room temperature cycle test are shown in FIG. In general, it is preferable that the larger the number of cycles, the smaller the change in capacitance.
(2) High temperature and high voltage cycle test

The lithium battery of Example 1 was subjected to a cycle test at 60 ° C. and 3.0 V to 4.3 V to detect a change in the capacitance of the lithium battery of Example 1 when the number of high-temperature and high-voltage cycles increased. .. The results of the high temperature and high voltage cycle test are shown in FIG. In general, it is preferable that the larger the number of cycles, the smaller the change in capacitance.
Example 2 to Example 8

In Examples 2 to 8, the same method as in Example 1 was carried out except that the polymer for lithium batteries used was changed. Regarding the polymers for lithium batteries of Examples 2 to 8, Production Examples 2 to 8 will be referred to in sequence, but will not be described separately here. The evaluation results of Examples 1 to 4 are shown in FIGS. 1 and / or FIG. In the present invention, the evaluation results of Examples 5 to 8 are not shown, but when tested, the evaluation results of Examples 5 to 8 were similar to those of Examples 1 to 4.
Comparative Example 1

Comparative Example 1 was carried out in the same manner as in Example 1 except that the polymer for a lithium battery was not added to the electrolytic solution. The evaluation results of Comparative Example 1 are shown in FIGS. 1 and 2.
Comparative Example 2

Comparative Example 2 was carried out in the same manner as in Example 1 except that a bismaleimide monomer was used instead of the polymer for a lithium battery in Example 1. The evaluation results of Comparative Example 1 are shown in FIG.

First, a cycle test was performed at room temperature of the lithium batteries of Example 1 (line segment 110), Example 2 (line segment 120), Comparative Example 1 (line segment 130) and Comparative Example 2 (line segment 140) of the present invention. See FIG. 1, which shows the results obtained. As shown in Example 1 and Example 2 of the line segment 110 and the line segment 120 of FIG. 1, when the lithium battery polymer synthesized by the method for producing the lithium battery polymer of the present invention is used, the lithium battery The capacitance at room temperature is about 475 mAh to about 480 mAh, and the capacitance does not substantially decline in 50 charge / discharge cycles. On the other hand, as shown in Comparative Example 1 of the line segment 130 of FIG. 1, the lithium battery to which the polymer for the lithium battery of the present invention is not added has a capacitance equivalent to that of the embodiment of the present invention, but later. The expression is bad in the high temperature and high voltage test of (Fig. 2). Further, in Comparative Example 2 (line segment 140) in which a bismaleimide monomer was used instead of the polymer for a lithium battery of the present invention, the capacitance was low (lower than 470 mAh) and the charge / discharge cycle was 5 to 10. When repeated, the capacitance decreased significantly.

Next, a cycle test was performed at high temperatures and high voltages of Examples 1 to 4 of the present invention (line segment 110, line segment 120, line segment 150 and line segment 160, respectively) and Comparative Example 1 (line segment 130). See FIG. 2, showing the results performed. As shown in line segment 110, line segment 120, line segment 150, and line segment 160 in FIG. 2, a lithium battery using the polymer for a lithium battery of the present invention is cycled at a high temperature and a high voltage about 75 to 90 times. , Capacitance slowly decreased by only about 10%. However, as shown by line segment 130 in FIG. 2, in Comparative Example 1 in which the polymer for lithium batteries was not added, the capacitance had already rapidly decreased by 10% after about 55 cycle tests. The lithium battery of Comparative Example 1 has poor properties at high temperature and high voltage.

The polymer for lithium batteries produced by the method for producing a polymer for lithium batteries of the present invention can be dissolved in a solvent of an electrolytic solution to form a good polymer film on an electrode of a lithium battery. This polymer for lithium batteries not only has good film-forming properties, but also improves the conductivity of lithium ions, improving the capacitance of lithium batteries (especially at high temperatures) and the cycle life at high temperatures and high voltages. be able to.

Although the present invention has been clarified in a plurality of examples as described above, this is not intended to limit the present invention, and those skilled in the art can make various changes and make various modifications as long as the spirit and scope of the present invention are not deviated. Modifications can be made, and therefore the scope of protection of the present invention is based on what is specified in the appended claims below.

110, 120, 130, 140, 150, 160: Line segment

Claims (9)

In the presence of an organic acid, a mixture of a maleimide compound and at least one diamine compound is polymerized at 100 ° C. to 130 ° C. for 96 hours to 144 hours to produce a polymer for a lithium battery.
The polymer for a lithium battery is dissolved in an electrolytic solution of a lithium battery.
The structure of the maleimide compound contains at least two maleimide units, and the molar ratio of the maleimide compound to the at least one diamine compound in the mixture is 1: 1-3: 1, and at least one of the above. Is a method for producing a polymer for a lithium battery containing a bis (4-aminophenyl) sulfone. The method for producing a polymer for a lithium battery according to claim 1, wherein the weight average molecular weight of the polymer for a lithium battery is 20,000 to 1,000,000. The maleimide compound has a structure represented by the following formula (I-1) or formula (I-2).
In formula (I-1), R ₁ is -RCH ₂ R-, -C (O) CH _2- , -CH ₂ OCH _2- , -C (O)-, -O-, -O-O-, -S -, - S-S - , - S (O) -, - CH 2 S (O) CH 2 -, - (O) S (O) -, - C 6 H 4 -, - CH 2 (C ₆ H ₄ ) CH _2- , -CH ₂ (C ₆ H ₄ ) O-, biphenylene, substituted phenylene or substituted biphenylene, R is an alkylene group having 1 to 6 carbon atoms.
In formula (I-2), R ₂ is -RCH _2- , -C (O)-, -C (CH ₃ ) _2- , -O-, -O-O-, -S-, -SS. -,-(O) S (O)-or-S (O)-,
The method for producing a polymer for a lithium battery according to claim 1, wherein n is an integer of 1 to 3. The at least one diamine compound contains a structure represented by the following formula (II).
The method for producing a polymer for a lithium battery according to claim 1, wherein R ₃ represents -CH _2- , -O- or -S- in the formula (II). With electrolytes
A polymer for a lithium battery obtained from a mixture of a maleimide compound and at least one diamine compound,
With solvent
Lithium battery electrolyte containing
The at least one diamine compound contains bis (4-aminophenyl) sulfone, and the amount of the lithium battery electrolytic solution used is 100 parts by weight, and the amount of the lithium battery polymer used is 0.2 parts by weight. ~ 2 parts by weight lithium battery electrolyte. The lithium battery electrolyte according to claim 5, wherein the amount of the lithium battery electrolyte used is 100 parts by weight, the amount of the electrolyte used is 10 to 20 parts by weight, and the electrolyte contains an electrolyte of alkali metal salts. liquid. The lithium battery electrolytic solution according to claim 5, wherein the solvent contains a hydrocarbyl ester carbonate having 3 to 5 carbon atoms. The lithium battery electrolytic solution according to claim 5, wherein the polymer for a lithium battery is dissolved in the solvent. Lithium transition metal oxide electrode and
Graphite electrode and
A separator provided between the lithium transition metal oxide electrode and the graphite electrode,
A polymer film that covers the surfaces of the lithium transition metal oxide electrode and the graphite electrode,
The lithium battery electrolytic solution according to any one of claims 5 to 8.
Including
The polymer film is a lithium battery formed during charging / discharging of a lithium battery by a polymer for a lithium battery in the lithium battery electrolytic solution.