JP2011146346A - Active material for secondary battery, and secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active material for a secondary battery capable of achieving the secondary battery superior in large current charge and discharge characteristics and high in energy density, and the secondary battery using it. <P>SOLUTION: The active material for the secondary battery has a polymer compound having a radical site in the side chain and having a polyphenylene vinylene structure and/or polyphenylene thiophene structure in the main chain. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an active material for a secondary battery that can realize a secondary battery that is excellent in large current charge / discharge characteristics and has a high energy density, and a secondary battery using the same.

  With the widespread use of electronic devices such as notebook computers, mobile phones, and digital cameras, the demand for secondary batteries for driving these electronic devices is increasing. In recent years, the power consumption of these electronic devices has increased with the progress of higher functionality, and the reduction in size is expected. Therefore, an increase in capacity is required for secondary batteries. Among secondary batteries, lithium ion secondary batteries are used in various electronic devices because of their high capacity.

  However, since a general lithium ion secondary battery uses a lithium-containing transition metal oxide having a large specific gravity for the positive electrode, it cannot be said that the secondary battery capacity per unit mass is sufficient, and a lighter electrode material can be used. Attempts to develop high-capacity secondary batteries using the same have been studied.

  For example, Patent Document 1 discloses a secondary battery using a conductive polymer as a positive electrode or negative electrode material. This is a secondary battery based on the principle of doping and dedoping of electrolyte ions accompanying redox of a conductive polymer.

  Since the conductive polymer is composed only of elements having a small specific gravity such as carbon and nitrogen, it is expected to increase the capacity of the secondary battery per unit mass. However, the doping of the electrolyte ions caused by the oxidation or reduction reaction of the conductive polymer is delocalized over a wide range of π-electron conjugated systems and has the property of interacting with them. Limit battery capacity. Therefore, a secondary battery using a conductive polymer as an electrode material has a certain effect in terms of weight reduction, but is insufficient in terms of a large capacity.

  On the other hand, Patent Document 2 discloses a secondary battery using a radical compound as a substance involved in the electrode reaction. This is a battery based on the principle of doping and dedoping reactions of electrolyte ions accompanying redox of stable radicals.

  Radical compounds are also composed only of elements with a low specific gravity such as carbon and nitrogen. Furthermore, in radical compounds, unpaired electrons that react are localized in radical atoms, increasing the concentration of reactive sites. Therefore, a high capacity secondary battery can be expected. Moreover, in this oxidation-reduction process, the oxidation-reduction reaction rate is large because there is no change in the chemical bonding state in the molecule and no ion diffusion process in the solid like the lithium-containing transition metal oxide that is the positive electrode material of the lithium battery, Charging / discharging with a large current is possible.

U.S. Pat. No. 4,442,187 Japanese Patent No. 3687736

  The present invention has been made in view of the above circumstances, and provides an active material for a secondary battery capable of realizing a secondary battery having excellent large current charge / discharge characteristics and high energy density, and a secondary battery using the same. Is a problem to be solved.

  As a result of intensive studies aimed at solving the above-mentioned problems, the present inventors have made the present invention.

  That is, the active material for a secondary battery of the present invention according to claim 1 is an active material for a positive electrode and / or a negative electrode of a secondary battery, and includes at least one of the polymer compounds represented by chemical formulas 43 to 45. It is characterized by having.

(Note that R1 to R4 are independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any one of structures represented by Chemical formulas 46 to 48. (N is a positive integer, and the values of n can be selected independently.)

(Chemical 46-48 is the part of *, and is bonded to the carbon atom of the benzene ring of Chemical Formula 43-45. In Chemical Formula 46-48, R is H, OH, CH3 or NH2. , Y is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH = N-, -S-, -CO-, may be substituted with any of Chemical Formulas 49 to 53.)

  The active material for a secondary battery according to a third aspect of the present invention is an active material for a positive electrode and / or a negative electrode of a secondary battery, and has a polymer compound represented by Chemical formula 55.

(Note that R1 to R4 are each independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any of the structures represented by Chemical formulas 56 to 58.) N is a positive integer.)

(Chemical 56-58 is the portion of * and is bonded to the carbon atom of the benzene ring of Chemical Formula 55. In Chemical Formula 56-58, R is H, OH, CH 3 or NH 2. Is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH═N -, -S-, -CO-, may be substituted with chemical formulas 59-63.)

  The active material for a secondary battery of the present invention according to claim 5 is an active material for a positive electrode and / or a negative electrode of a secondary battery, and has at least one unit compound represented by Chemical Formulas 65 to 67 as a main component. The monomer mixture is characterized by having a polymer compound polymerized by elimination of hydrogen bonded to units other than R1 to R4 of the unit compound.

(Note that R1 to R4 are each independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any one of structures represented by Chemical formulas 68 to 70. N is a positive integer.)

(Chemical 68-70 is the part of *, and it couple | bonds with the carbon atom of the benzene ring of the said chemical | chemical formula 65-67. In Chemical formula 68-70, R is H, OH, CH3, or NH2. , Y is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH ═N—, —S—, —CO—, may be substituted with Chemical Formulas 71 to 75.)

  The active material for a secondary battery of the present invention according to claim 6 is an active material for a positive electrode and / or a negative electrode of a secondary battery, and is a monomer mixture mainly composed of a unit compound represented by Chemical formula 76 Is characterized by having a polymer compound polymerized by elimination of hydrogen bonded to units other than R1 to R4 of the unit compound.

(Note that R1 to R4 are each independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any one of structures represented by Chemical Formulas 77 to 79. N is a positive integer.)

(Chemical 77-79 is the portion of * and is bonded to the carbon atom of the benzene ring of Chemical Formula 76. In Chemical Formula 77-79, R is H, OH, CH3 or NH2. In Chemical Formula 77-79, Y Is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH═N -, -S-, -CO-, may be substituted with chemical formulas 80 to 84.)

  A secondary battery according to a tenth aspect of the present invention includes an electrode using the active material for a secondary battery according to any one of the first to ninth aspects, and an electrolyte.

  The active material for a secondary battery of the present invention has a polymer compound having a radical site in the side chain and a polyphenylene vinylene structure and / or a polyphenylene thiophene structure in the main chain. This polymer compound is composed only of elements with a low specific gravity, such as carbon and nitrogen, and since unreacted unpaired electrons are localized in radical atoms, the concentration of the reaction site can be increased. As a result, high capacity can be achieved when used in a secondary battery.

  Furthermore, in this oxidation-reduction process, the oxidation-reduction reaction rate is large because there is no change in the chemical bonding state in the molecule and the ion diffusion process in the solid like the lithium-containing transition metal oxide that is the positive electrode material of the lithium battery, Since charging / discharging with a large current can be realized, a secondary battery having excellent large current charging / discharging characteristics and high energy density can be realized by employing this active material for a secondary battery.

1 is a cross-sectional view showing a configuration of a coin-type battery of Example 1. FIG.

(First invention)
The active material for a secondary battery of the present invention is an active material for a positive electrode and / or a negative electrode of a secondary battery, and has at least one of the polymer compounds represented by the above chemical formulas 43 to 45.

  The polymer compound contained in the active material for a secondary battery according to the present invention has a stable radical site in the side chain and a polyphenylene vinylene structure in the main chain as shown in the above chemical formulas 43 to 45 (43 to 53). It has.

  Since the polymer compounds shown in the above chemical formulas 43 to 45 (43 to 53) are composed only of elements having a small specific gravity such as carbon and nitrogen, the secondary battery capacity per unit mass is increased. The effect that the secondary battery which can be obtained is obtained is exhibited.

  In addition, the polymer compound contained in the active material for a secondary battery of the present invention has unreacted unreacted electrons localized in radical atoms, so that the concentration of reactive sites can be increased, The effect which can expect the increase in capacity | capacitance of the secondary battery in which a substance is used is exhibited.

  In addition, the oxidation-reduction process has a large oxidation-reduction reaction rate because it does not involve a change in the chemical bonding state in the molecule or an ion diffusion process in the solid like the lithium-containing transition metal oxide that is the cathode material of a lithium battery. Charging / discharging with current can be realized. For this reason, the secondary battery which employ | adopted the active material for secondary batteries of this invention as an active material can exhibit the effect that it is excellent in a large current charge / discharge characteristic, and an energy density is high.

  As described above, the polymer compound represented by Chemical Formulas 43 to 45 (43 to 53) has a stable radical site (radical structure) represented by Chemical Formulas 46 to 48 in the side chain. A stable radical structure of the side chain is required to ensure a space (a distance between adjacent main chains is about 10 mm) that allows counter-counter ions to enter and exit the polymer compound. Furthermore, it is required that the stable radical structure be separated to such an extent that it does not inhibit the polymerization reaction that creates the main chain having a polyphenylene vinylene structure. In Formulas 46 to 48, Y is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O This requirement is satisfied by replacement with —, —NH—, —CH═N—, —S—, —CO—, or any one of Chemical Formulas 49 to 53.

  Examples of the polymer compound represented by the above chemical formulas 43 to 45 include a polymer compound represented by the following chemical formula 54. That is, in the active material for a secondary battery of the present invention, the polymer compound is preferably represented by Formula 54.

(Note that m and p are each independently selected from integers of 0 to 10. n is a positive integer.)

(Second invention)
The active material for a secondary battery according to the present invention is an active material for a positive electrode and / or a negative electrode of a secondary battery, and includes the polymer compound represented by the chemical formula 55.

  The polymer compound contained in the active material for a secondary battery of the present invention is a polymer compound having a radical site in the side chain as shown in Chemical Formula 55, and has a polyphenylenethiophene structure in the main chain. Yes. Since these polymer compounds are composed only of elements having a small specific gravity such as carbon and nitrogen, they exhibit an effect of obtaining a secondary battery capable of increasing the capacity of the secondary battery per unit mass.

  In addition, the polymer compound contained in the active material for a secondary battery of the present invention has unreacted unreacted electrons localized in radical atoms, so that the concentration of reactive sites can be increased, The effect which can expect the increase in capacity | capacitance of the secondary battery in which a substance is used is exhibited.

  In addition, the oxidation-reduction process has a large oxidation-reduction reaction rate because it does not involve a change in the chemical bonding state in the molecule or an ion diffusion process in the solid like the lithium-containing transition metal oxide that is the cathode material of a lithium battery. Charging / discharging with current can be realized. For this reason, the secondary battery which employ | adopted the active material for secondary batteries of this invention as an active material can exhibit the effect that it is excellent in a large current charge / discharge characteristic, and an energy density is high.

  As described above, the polymer compound represented by Chemical formula 55 (55 to 63) has a stable radical site (radical structure) represented by Chemical formulas 56 to 58 in the side chain. A stable radical structure of the side chain is required to ensure a space (a distance between adjacent main chains is about 10 mm) that allows counter-counter ions to enter and exit the polymer compound. Furthermore, it is also required that the stable radical structure be separated to such an extent that it does not inhibit the polymerization reaction that creates the main chain having a polyphenylenethiophene structure. In Formulas 56 to 58, Y is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O This requirement is satisfied by substitution with —, —NH—, —CH═N—, —S—, —CO—, or any of Chemical Formulas 59 to 63.

  Examples of the polymer compound represented by the chemical formula 55 include a polymer compound represented by the following chemical formula 64. That is, in the active material for a secondary battery of the present invention, the polymer compound is preferably represented by Chemical Formula 64.

(Note that m and p are each independently selected from integers of 0 to 10. n is a positive integer.)

(Third invention)
The active material for a secondary battery of the present invention is an active material for a positive electrode and / or a negative electrode of a secondary battery, and contains as a main component at least one of the unit compounds represented by the above chemical formulas 65 to 67 (65 to 75). The monomer mixture is a polymer compound polymerized by elimination of hydrogen bonded to units other than R1 to R4 of the unit compound. The polymer compound contained in the active material for a secondary battery of the present invention is a polymer compound obtained by polymerizing the unit compounds shown in the above chemical formulas 65 to 67 (65 to 75) and having a polyphenylene vinylene structure in the main chain. It has become. Moreover, this polymer compound is a polymer compound having a radical site in the side chain. That is, since this polymer compound is composed of only elements having a small specific gravity such as carbon and nitrogen, it exhibits the effect of obtaining a secondary battery capable of increasing the capacity of the secondary battery per unit mass. .

  In addition, the polymer compound contained in the active material for a secondary battery of the present invention has unreacted unreacted electrons localized in radical atoms, so that the concentration of reactive sites can be increased, The effect which can expect the increase in capacity | capacitance of the secondary battery in which a substance is used is exhibited.

  In addition, the oxidation-reduction process has a large oxidation-reduction reaction rate because it does not involve a change in the chemical bonding state in the molecule or an ion diffusion process in the solid like the lithium-containing transition metal oxide that is the cathode material of a lithium battery. Charging / discharging with current can be realized. For this reason, the secondary battery which employ | adopted the active material for secondary batteries of this invention as an active material can exhibit the effect that it is excellent in a large current charge / discharge characteristic, and an energy density is high.

  As described above, the polymer compound represented by Chemical Formulas 65 to 67 (65 to 75) has a stable radical site (radical structure) represented by Chemical Formulas 68 to 70 in the side chain. A stable radical structure of the side chain is required to ensure a space (a distance between adjacent main chains is about 10 mm) that allows counter-counter ions to enter and exit the polymer compound. Furthermore, it is required that the stable radical structure be separated to such an extent that it does not inhibit the polymerization reaction that creates the main chain having a polyphenylene vinylene structure. In Formula 68 to 70, Y is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O This requirement is satisfied by substituting any one of-, -NH-, -CH = N-, -S-, -CO-, and Chemical Formulas 71-75.

(Fourth invention)
The active material for a secondary battery of the present invention is an active material for a positive electrode and / or a negative electrode of a secondary battery, and a monomer mixture mainly composed of a unit compound represented by the chemical formula 76 is used as a unit compound. In addition to R 1 to R 4, hydrogen bonded to the polymer compound is eliminated and polymerized. The polymer compound contained in the active material for a secondary battery of the present invention is a polymer compound obtained by polymerizing the unit compound shown in Chemical Formula 76 (76 to 84) and having a polyphenylenethiophene structure in the main chain. ing. Moreover, this polymer compound is a polymer compound having a radical site in the side chain. That is, since this polymer compound is composed of only elements having a small specific gravity such as carbon and nitrogen, it exhibits the effect of obtaining a secondary battery capable of increasing the capacity of the secondary battery per unit mass. .

  In addition, the polymer compound contained in the active material for a secondary battery of the present invention has unreacted unreacted electrons localized in radical atoms, so that the concentration of reactive sites can be increased, The effect which can expect the increase in capacity | capacitance of the secondary battery in which a substance is used is exhibited.

  In addition, the oxidation-reduction process has a large oxidation-reduction reaction rate because it does not involve a change in the chemical bonding state in the molecule or an ion diffusion process in the solid like the lithium-containing transition metal oxide that is the cathode material of a lithium battery. Charging / discharging with current can be realized. For this reason, the secondary battery which employ | adopted the active material for secondary batteries of this invention as an active material can exhibit the effect that it is excellent in a large current charge / discharge characteristic, and an energy density is high.

  As described above, the polymer compound represented by Chemical Formula 76 (76 to 84) has a stable radical site (radical structure) represented by Chemical Formulas 77 to 79 in the side chain. A stable radical structure of the side chain is required to ensure a space (a distance between adjacent main chains is about 10 mm) that allows counter-counter ions to enter and exit the polymer compound. Furthermore, it is also required that the stable radical structure be separated to such an extent that it does not inhibit the polymerization reaction that creates the main chain having a polyphenylenethiophene structure. Y in Chemical Formulas 77 to 79 is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O This requirement is satisfied by substituting any one of-, -NH-, -CH = N-, -S-, -CO-, and 80-84.

(Third and fourth inventions)
In the active material for secondary batteries of the third and fourth inventions described above, the polymerization reaction for producing the polymer compound is not particularly limited. A polymer compound that is soluble in any organic solvent may be produced by general chemical polymerization. If a polymer compound soluble in an organic solvent is produced, an electrode can be formed by applying and drying the solution. Further, even if the polymer compound is insoluble in a solvent, the polymerized polymer compound can be attached to the surface of the current collector. For example, electrolytic polymerization can be exemplified.

  Furthermore, in the active material for secondary batteries of the third and fourth inventions, in addition to the unit compounds shown in Chemical formulas 65 to 67 (65 to 75) and Chemical formula 76 (76 to 84), other monomers may be added. It may be copolymerized. Although it does not specifically limit as another monomer which can be copolymerized, It has a structure which can fully exhibit electroconductivity (For example, pyrrole, one or more hydrogen atoms are C1-C10 alkyl groups. Substituted pyrrole, thiophene, and thiophene in which one or more hydrogen atoms are substituted with an alkyl group having 1 to 10 carbon atoms can be employed. By copolymerizing other monomers, it is possible to control the affinity and stability to the electrolytic solution.

  That is, in the active material for a secondary battery according to the third and fourth inventions described above, the monomer mixture includes pyrrole, pyrrole in which one or more hydrogen atoms are substituted with an alkyl group having 1 to 10 carbon atoms, thiophene, It is preferable that one or more hydrogen atoms include at least one thiophene substituted with an alkyl group having 1 to 10 carbon atoms.

  These heterocyclic aromatic compounds are copolymerized with the above-described unit compounds of the third to fourth inventions (Chemical Formulas 65 to 67 (65 to 75), Chemical Formula 76 (76 to 84)) to form conductive polymer compounds. Can be formed. And when the battery of these heterocyclic aromatic compounds is comprised, it contributes to an electrode reaction. That is, the performance of the electrode active material, the electrode having the electrode active material, and the secondary battery can be adjusted by adjusting the type and addition amount of these heterocyclic aromatic compounds.

  As the heterocyclic aromatic compound, those capable of copolymerizing with the above unit compound by elimination of hydrogen and those capable of forming a conjugated system by copolymerizing with the above unit compound can be used.

  In the case where a heterocyclic aromatic compound having a structure that can sufficiently exhibit conductivity as described above is used as a monomer, the compounds are shown in Chemical formulas 65 to 67 (65 to 75) and Chemical formulas 76 (76 to 84). A mixture in which the unit compound and other monomers are combined may be present as a main component in the monomer mixture. The mixing ratio of the unit compounds shown in Chemical formulas 65 to 67 (65 to 75) and Chemical formula 76 (76 to 84) and other monomers is not particularly limited, but ranges from about 1:10 to 10: 1. Can be adopted. In particular, it is desirable to contain ½ or more of the unit compounds shown in Chemical formulas 65 to 67 (65 to 75) and Chemical formulas 76 (76 to 84).

(Other configurations of each invention)
The active material for a secondary battery of the present invention is a polymer compound having a radical site in the side chain and a polyphenylene vinylene structure and / or a polyphenylene thiophene structure in the main chain as described in the first to fourth inventions. Have The molecular weight of the polymer compound is not particularly limited. For example, when a secondary battery is formed, a molecular weight that does not dissolve and dissipate in the electrolyte used in the secondary battery can be employed, or a molecular weight that becomes a solid can be employed. Specifically, a value having a molecular weight of about 1000 to 100,000 can be adopted. Therefore, the value of n in each formula can be determined according to the molecular weight. Specifically, it is preferably in the range of 1000 to 50000. More specifically, when the polymer compound is the chemical formula 54 and is used for a lithium battery (lithium ion battery), it is preferably in the range of 1000 to 50000. When the polymer compound is the above-mentioned chemical formula 64 and used in a lithium battery (lithium ion battery), it is preferably in the range of 1000 to 50000.

  As described in the first to fourth inventions above, the active material for a secondary battery of the present invention is not limited in configuration other than having a polymer compound having a radical site in the side chain, It can be set as the structure similar to the conventionally well-known active material for secondary batteries.

  That is, the active material for a secondary battery according to the first to fourth inventions is not only a polymer compound described in Chemical Formulas 43 to 45, 55, 65 to 67, 76, but also as an active material in a conventional secondary battery. It can be used by mixing with the compound used.

An example of such a compound is a lithium-containing transition metal oxide that is a positive electrode active material of a lithium ion secondary battery. The lithium-containing transition metal oxide is a material that can insert and remove Li ions (Li ⁺ ), and includes a lithium-metal composite oxide having a layered structure or a spinel structure. Specific examples include metal oxide materials such as Li _1-Z NiO ₂ , Li _1-Z MnO ₂ , Li _1-Z Mn ₂ O ₄ , and Li _1-Z CoO ₂ . Furthermore, examples of Li _1-Z βPO ₄ include LiFePO _4, and examples thereof include compounds containing one or more of them. Z represents a number from 0 to less than 1. In addition, each metal oxide-based material may be Li, Mg, Al, or a material in which a transition metal such as Co, Ti, Nb, or Cr is added or substituted. Furthermore, these lithium-metal composite oxides may be used alone or in combination.

  That is, the active material for a secondary battery according to the first to fourth inventions is preferably a positive electrode active material, and the positive electrode active material preferably contains a lithium-containing transition metal oxide.

(Secondary battery)
The secondary battery of this invention has an electrode using the active material for secondary batteries of any one of Claims 1-9, and an electrolyte. That is, the secondary battery of this invention is a secondary battery using the electrode provided with the active material for secondary batteries as described in said 1st-4th invention. The electrode provided with the active material for a secondary battery according to the first to fourth inventions may be a positive electrode, a negative electrode, or both of a positive electrode and a negative electrode. .

  The configuration of the secondary battery of the present invention is not limited except that it is a secondary battery using an electrode including the active material for a secondary battery described in the first to fourth inventions, It can be set as the structure similar to a conventionally well-known secondary battery.

  That is, the secondary battery of the present invention may be a secondary battery having a positive electrode and a negative electrode including the active material for a secondary battery described in the first to fourth inventions, and an electrolyte solution. A water electrolyte battery is preferable, and a lithium battery and a lithium ion secondary battery are more preferable. The positive electrode and the negative electrode are formed by forming on the surface of the current collector an electrode mixture layer in which an additive selected from electrode active materials, binders, conductive materials and other materials as necessary is mixed. Is preferred.

  The binder is desirably formed of a polymer material, and is desirably a material that is chemically and physically stable in the atmosphere in the secondary battery. Examples of the binder include polyvinylidene fluoride, polytetrafluoroethylene (PTFE), and carboxymethyl cellulose (CMC).

  Examples of the conductive material include ketjen black, acetylene black, carbon black, graphite, carbon nanotube, and amorphous carbon. Further, conductive polymer polyaniline, polypyrrole, polythiophene, polyacetylene, polyacene and the like can be mentioned.

  As a method of forming an electrode mixture layer on the surface of the current collector, an electrode mixture having an active material, a binder, and a conductive material is dispersed or dissolved in an appropriate dispersion medium, and then the surface of the current collector The method of applying and drying can be mentioned.

  When the secondary battery of the present invention is a lithium battery or a lithium ion secondary battery, it is preferable to use the secondary battery active material described in the first to fourth inventions as the positive electrode active material. In this case, as the negative electrode active material, lithium, a lithium alloy, or a material capable of occluding and releasing lithium can be used. Examples of the material capable of occluding and releasing lithium include carbon materials such as graphite, coke, and fired organic polymer compound. The positive electrode active material can be further mixed with a metal oxide such as a lithium-containing transition metal oxide as described above.

The secondary battery of the present invention has an electrolyte. The electrolyte is preferably held in the secondary battery in the state of an electrolytic solution dispersed in a solvent such as an organic solvent. The electrolyte is a medium that transports charge carriers such as ions between the positive electrode and the negative electrode, and its type is not particularly limited, but is physically, chemically, and electrically stable in the atmosphere in which the secondary battery is used. Is desirable. Non-aqueous electrolytes include LiBF ₄ , LiPF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ An electrolytic solution in which one or more selected from SO ₂ ) is used as a supporting electrolyte and dissolved in an organic solvent is preferable. Examples of the organic solvent include propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran and the like and mixtures thereof. Among them, an electrolytic solution containing a carbonate solvent is preferable because of its high stability at high temperatures.

  The electrolyte may be a solid polymer electrolyte in which the above electrolyte is contained in a solid polymer such as polyethylene oxide.

  In the secondary battery of the present invention, it is preferable to interpose a separator, which is a member that achieves both electrical insulation and ion conduction, between the positive electrode and the negative electrode. When the supporting electrolyte is liquid, the separator also serves to hold the liquid supporting electrolyte. Examples of the separator include a porous synthetic resin film, particularly a porous film of polyolefin polymer (polyethylene, polypropylene). Furthermore, it is preferable that the separator has a larger size than the positive electrode and the negative electrode for the purpose of ensuring the insulation between the positive electrode and the negative electrode.

  The secondary battery according to the present invention includes elements other than the above elements as required. The shape of the secondary battery of the present invention is not particularly limited, and batteries of various shapes such as a coin shape, a cylindrical shape, and a square shape can be used.

  Hereinafter, the present invention will be specifically described with reference to examples.

  As an example of the present invention, a positive electrode active material and a lithium secondary battery were manufactured.

(Manufacture of positive electrode active material)
As the positive electrode active material of this example, polymer compounds represented by the following chemical formulas 85 and 86 were produced. The polymer compound represented by Chemical formula 85 is a polymer compound in which m and p are each 0 in Chemical formula 54 above. Further, the polymer compound represented by Chemical formula 86 is a polymer compound in which m and p are each 0 in Chemical formula 64 above.

  The polymer compound shown in Chemical formula 85 was produced by the following method.

  First, by reacting 2,5-diiodo-1,4-benzenedicarboxylic acid with 4-hydroxy-2,2-6,6-tetramethylpiperidine-1-oxyl in the presence of triethylamine, the chemical formula 87 is shown. The resulting compound was produced.

  Specifically, 2,2,6,6-tetramethylpiperidine-4-hydroxy-N-oxyl (1.74 g), triethylamine (10 mL), toluene (100 mL) were added to a 300 mL Schlenk tube under a nitrogen atmosphere. added. A toluene (50 mL) solution of 2,5-diiodo-1,4-benzenedicarboxylic acid chloride (2.30 g) was added dropwise thereto over 1 hour, and the reaction solution was stirred at room temperature for 21 hours. The reaction solution was added to water and extracted with chloroform. The organic layer was washed with saturated brine, and then dried using sodium sulfate. Subsequently, filtration was performed and the filtrate was concentrated, and then purified by alumina column chromatography (developing solution: chloroform) to obtain 2.82 g of a product represented by Chemical formula 87.

The spin concentration of the product represented by Chemical Formula 87 was measured using an electron spin resonance apparatus. JEOL-JES-FE2XG was used as a measuring device, and measurement was performed under conditions of a microwave output of 8 mW, a modulation frequency of 100 kHz, and a measurement range of 335.0 mT ± 10 mT. As a result of comparison with the absorption area intensity of a known sample measured under the same conditions as the absorption area intensity obtained in the above measurement, the spin concentration of the product represented by Chemical formula 87 is 1.0 × 10 ²¹ spin / g or more, It was confirmed that radicals were formed.

UV-visible absorption spectrum (nm): 323 (chloroform solution)
Infrared spectrum (cm ⁻¹ ): 3437, 3082, 2974, 2934, 2867, 1715, 1462, 1366, 1331, 1279, 1261, 1224, 1179, 1140, 1125, 1046, 962, 938, 908, 838, 777 688, 563, 481
Thus obtained 726 mg (1.0 mmol) of the diester represented by Chemical Formula 87 and 606 mg (1.0 mmol) of 1,2-bis (tributylstannyl) ethylene represented by Chemical Formula 88 were added to 25 mL of anhydrous N, N-dimethyl ester. In addition to formamide, 58 mg of tetrakis (triphenylphosphine) palladium (0) and 10 mg of copper (I) iodide were added and reacted at 80 ° C. for 2 days to synthesize a polymer compound according to the following chemical formula 89.

Regarding the reaction formula shown in Chemical Formula 89, an aromatic halogenated organic compound, a heterocyclic halogenated organic compound, and an organotin compound cause a CC coupling reaction in the presence of a palladium complex catalyst, and this coupling reaction is converted to a dihalogen. There are many reported examples of obtaining a polymer when polycondensation is caused by applying it to an organic compound having a fluorinated organic compound and two tin substituents (SnR ₃ (R is an alkyl group or the like)) (for example, J. Am. Chem. Soc., 117, 12426 (1995) and Synlett, 425 (2003)).

  After completion of the reaction, the reaction solution was added to a 5% aqueous solution of potassium fluoride, stirred and then filtered to separate the resulting polymer compound. The solid polymer compound thus obtained was washed with water, methanol, and acetone and vacuum dried to obtain 350 mg of the polymer compound (yield based on the above polycondensation reaction formula was 83%). . This polymer compound showed an ultraviolet / visible absorption peak at 385 nm in chloroform and was found to be a polymer compound in which a pi-conjugated system was developed.

Further, the spin concentration of the obtained polymer was measured with an electron spin resonance apparatus. JEOL-JES-FE2XG was used as a measuring device, and measurement was performed under conditions of a microwave output of 8 mW, a modulation frequency of 100 kHz, and a measurement range of 335.0 mT ± 10 mT. As a result of measuring the spin concentration in comparison with the absorption area intensity of the known sample measured under the same conditions as the absorption area intensity obtained in the above measurement, the polymer spin concentration was 2.1 × 10 ²¹ spin / g or more. It was confirmed that a radical was formed.

  Further, the polymer compound shown in Chemical formula 86 was produced by the following method.

  First, 166 mg (0.23 mmol) of the diester represented by Chemical Formula 87 and 94 mg (0.23 mmol) of 2,5-bis (trimethylstannyl) thiophene represented by Chemical Formula 90 were added to anhydrous N, N-dimethylformamide. Further, 13 mg of tetrakis (triphenylphosphine) palladium (0) was added, and a polymer compound was synthesized according to the reaction formula shown in the following chemical formula 91 in the same manner as in Example 1.

  After completion of the reaction, the reaction solution was added to a 5% aqueous solution of potassium fluoride, stirred and then filtered to separate the resulting polymer compound. The solid polymer compound thus obtained was washed with water, methanol, and acetone and vacuum dried to obtain 98 mg of the polymer compound (yield based on the above polycondensation reaction formula was 77%). . This polymer compound shows an ultraviolet / visible absorption peak at about 365 nm in chloroform, indicating that the pi-conjugated system has been developed. Compared with the polymer compound shown in Chemical formula 85, one of the causes that the ultraviolet and visible absorption peaks were observed on the short wavelength side is that the polymer compound has two substituents at the ortho position. This is considered to be because there is a steric hindrance between the phenylene unit and the thiophene unit, and the main chain of the polymer compound is twisted, so that a large pi-conjugated system does not develop.

Further, the spin concentration of the obtained polymer was measured with an electron spin resonance apparatus. The measurement apparatus was JEOL-JES-FE2XG, and measurement was performed under conditions of a microwave output of 8 mW, a modulation frequency of 100 kHz, and a measurement range of 335.0 mT ± 10 mT. As a result of measuring the spin concentration in comparison with the absorption area intensity of the known sample measured under the same conditions as the absorption area intensity obtained by the above measurement, the spin concentration of the polymer was 1.8 × 10 ²¹ spin / g or more. It was confirmed that a radical was formed.

Example 1
(Preparation of positive electrode)
N-methylpyrrolidone (NMP) is added to 30 parts by mass of the polymer compound shown in Chemical Formula 85, 60 parts by mass of carbon black, and 10 parts by mass of polyvinylidene fluoride (PVDF), and mixed and dispersed to obtain a homogeneous coating liquid. Was prepared.

  The prepared homogeneous coating liquid was applied to one surface of an aluminum current collector (film thickness 50 μm), dried, pressed, and cut into a predetermined size.

  Thereby, the positive electrode was produced.

  The produced positive electrode was provided with a positive electrode active material made of the polymer compound shown in Chemical Formula 85, a conductive material made of carbon black, and a binder made of PVDF on the surface of an aluminum current collector. The positive electrode mixture layer is formed. The produced positive electrode had a thickness of 100 μm including the aluminum current collector.

(Preparation of negative electrode)
A lithium metal foil (300 μm) was cut into a predetermined size.

(Preparation of electrolyte)
Ethylene carbonate and ethyl methyl carbonate were mixed at a volume ratio of 3: 7, and LiPF ₆ was dissolved in the mixed organic solvent as a supporting electrolyte to a concentration of 1 mol / L.

(Production of battery)
A coin-type battery (lithium secondary battery) was manufactured using the manufactured positive electrode. A coin-type battery 1 of this example is shown in FIG. The coin-type battery of this example includes a positive electrode 2, a negative electrode 3, an electrolytic solution 4, and a separator 7. The positive electrode 2 includes a positive electrode current collector 20 and a positive electrode mixture layer 21 formed on the surface of the positive electrode current collector 20. For the separator 7, a porous film made of porous polypropylene was used.

  These power generation elements were housed in a stainless steel case (consisting of a positive electrode case 50 and a negative electrode case 51). The positive electrode case 50 and the negative electrode case 51 serve as a positive electrode terminal and a negative electrode terminal. A gasket 6 made of polypropylene is interposed between the positive electrode case 50 and the negative electrode case 51 to ensure sealing and insulation between the positive electrode case 50 and the negative electrode case 51.

  The coin-type battery 1 was manufactured by placing the positive electrode 2 on the positive electrode case 50 in a state where the positive electrode current collector 20 was in contact with the positive electrode case 50 and placing the separator 7 thereon. And the electrolyte solution 4 was inject | poured in the case.

  Then, a negative electrode case 51 in which the negative electrode 3 was accommodated inside and a gasket 6 was attached to the peripheral portion was covered, and the outer periphery was crimped to manufacture the lithium ion secondary battery (coin battery) of this example.

  By the above procedure, a coin-type lithium battery having a diameter of 19 mm and a thickness of 3 mm was produced.

(Evaluation)
The charge / discharge capacity was measured as an evaluation of the produced lithium battery.

  First, after charging the manufactured lithium battery from 2.5 V to 4.1 V at a current value of 0.1 mA, the discharge state was observed when discharging from 4.1 V to 2.5 V at a current value of 0.1 mA. did. According to the observation result, a flat discharge curve was exhibited at around 3.5 V, and the capacity per battery active material was 99 mAh / g.

  Next, after charging from 2.5 V to 4.1 V again at a current value of 0.1 mA, discharging from 4.1 V to 2.5 V at a current value of 1.0 mA, the capacity per electrode active material is The discharge capacity was 88 mAh / g, and a discharge capacity of about 89% during discharge at 0.1 mA was obtained.

(Example 2)
A positive electrode active material and a lithium battery were produced in the same manner as in Example 1 except that the polymer compound shown in the chemical formula 86 was used instead of the polymer compound shown in the chemical formula 85.

  The lithium battery of this example was evaluated in the same manner as in Example 1.

  According to the observation result, a flat discharge curve was shown around 3.5 V, and the battery capacity at the time of 0.1 mA discharge was 88 mAh / g. Moreover, the battery capacity at the time of 1.0 mA discharge was 80 mAh / g, and about 91% of the discharge capacity at the time of discharge was obtained at 0.1 mA.

(Comparative Example 1)
A positive electrode active material and a lithium battery were produced in the same manner as in Example 1 except that LiNiO 2 was used instead of the polymer compound shown in Chemical Formula 85 above.

  The lithium battery of this comparative example was evaluated in the same manner as in Example 1.

  According to the observation result, the battery capacity at the time of 0.1 mA discharge was 138 mAh / g. Moreover, the battery capacity at the time of 1.0 mA discharge was 78 mAh / g, and about 56% of the discharge capacity at the time of discharge was obtained at 0.1 mA.

(Comparative Example 2)
A positive electrode active material and a lithium battery were produced in the same manner as in Example 1 except that carbon black was used instead of the polymer compound shown in Chemical Formula 85 above.

  The lithium battery of this comparative example was evaluated in the same manner as in Example 1.

  According to the observation results, a flat discharge curve was not seen and almost no battery capacity was obtained.

(Evaluation results)
From the above evaluation, it was confirmed that the lithium secondary battery of each example had higher battery capacity and discharge capacity than the secondary battery of each comparative example. That is, it was confirmed that the lithium secondary battery of each example had excellent battery performance.

1: Coin battery 2: Positive electrode 20: Positive electrode current collector 21: Positive electrode mixture layer 3: Negative electrode 4: Electrolytic solution 50: Positive electrode case 51: Negative electrode case 6: Gasket 7: Separator

Claims (10)

An active material for a positive electrode and / or a negative electrode of a secondary battery,
An active material for a secondary battery comprising at least one polymer compound represented by Chemical Formulas 1 to 3.



(Note that R1 to R4 are independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any one of structures represented by Chemical Formulas 4 to 6. (N is a positive integer, and the values of n can be selected independently.)



(Chemical 4-6 is the part of *, and it couple | bonds with the carbon atom of the benzene ring of the said chemical | chemical formulas 1-3. , Y is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH = N-, -S-, -CO-, or any one of Chemical Formulas 7 to 11 may be substituted.)




The active material for a secondary battery according to claim 1, wherein the polymer compound is represented by Chemical Formula 12.

(Note that m and p are each independently selected from integers of 0 to 10. n is a positive integer.) An active material for a positive electrode and / or a negative electrode of a secondary battery,
An active material for a secondary battery comprising a polymer compound represented by Chemical formula 13:

(Note that R1 to R4 are independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any one of structures represented by Chemical formulas 14 to 16. N is a positive integer.)



(Chemical 14-16 is a part of *, and is bonded to the carbon atom of the benzene ring of Chemical Formula 13. In Chemical Formula 14-16, R is H, OH, CH3 or NH2. In Chemical Formula 14-16, Y Is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH═N -, -S-, -CO-, and may be substituted with chemical formulas 17 to 21.)




The active material for a secondary battery according to claim 3, wherein the polymer compound is represented by Chemical Formula 22.

(Note that m and p are each independently selected from integers of 0 to 10. n is a positive integer.) An active material for a positive electrode and / or a negative electrode of a secondary battery,
A monomer mixture containing at least one of the unit compounds represented by Chemical Formulas 23 to 25 as a main component has a polymer compound obtained by polymerizing hydrogen bonded to other than R1 to R4 of the unit compound. An active material for a secondary battery.



(Note that R1 to R4 are independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any one of structures represented by Chemical Formulas 26 to 28. N is a positive integer.)



(Chemical 26-28 is the portion of * and is bonded to the carbon atom of the benzene ring of Chemical Formula 23. In Chemical Formula 26-28, R is H, OH, CH3 or NH2. In Chemical Formula 26-28, Y Is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH═N -, -S-, -CO-, and may be substituted with chemical formulas 29 to 33.)




An active material for a positive electrode and / or a negative electrode of a secondary battery,
A secondary battery comprising a polymer compound obtained by polymerizing a monomer mixture containing a unit compound represented by Chemical Formula 34 as a main component by eliminating hydrogen bonded to units other than R1 to R4. Active material.

(Note that R1 to R4 are each independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms. At least one of R1 to R4 is any of structures represented by Chemical formulas 35 to 37. N is a positive integer.)



(Chemical 35-37 is the part of *, and it couple | bonds with the carbon atom of the benzene ring of the said chemical | chemical formula 34. In Chemical 35-37, R is H, OH, CH3, or NH2. Is — (CH 2) m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, —NH—, —CH═N -, -S-, -CO-, may be substituted with chemical formulas 38 to 42.)




  In the monomer mixture, pyrrole, pyrrole in which one or more hydrogen atoms are substituted with an alkyl group having 1 to 10 carbon atoms, thiophene, and one or more hydrogen atoms are substituted with an alkyl group having 1 to 10 carbon atoms. The active material for a secondary battery according to claim 5, comprising at least one kind of thiophene.   It is a positive electrode active material, The active material for secondary batteries of any one of Claims 1-7.   The secondary battery active material according to claim 8, wherein the positive electrode active material has a lithium-containing transition metal oxide.   A secondary battery comprising: an electrode using the active material for a secondary battery according to claim 1; and an electrolyte.