JP2017171737A - Polymer having trioxotriangulene as side chain and secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode active material for secondary batteries having excellent charging/discharging capacities.SOLUTION: A polymer has a side chain of a structure represented by formula (1) and/or formula (2) (X is a C1-10 organic group, H, halogen, a hydroxyl group, a silyl group, an amino group or a nitro group ; Mis a cation).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a polymer having trioxotriangulene (TOT) as a side chain, and a secondary battery using this as an electrode active material.

Lithium ion secondary batteries have a relatively high operating voltage and are lightweight, and are widely used as power sources for mobile devices such as mobile phones and notebook computers. However, since lithium cobaltate often used as the positive electrode active material is a metal oxide, there is a problem in safety in use.
In order to solve such a problem, attempts to use an organic compound as a safe electrode active material have been actively promoted.

  For example, Patent Document 1 discloses a secondary battery using an organic compound having a disulfide bond as a positive electrode active material. Patent Document 2, Patent Document 3 and Non-Patent Document 1 disclose secondary batteries using a redox compound capable of transferring a plurality of electrons per molecule as a positive electrode active material. However, since the positive electrode active material is dissolved in the electrolytic solution, there is a problem that the cycle characteristics of the secondary battery are poor.

  On the other hand, Patent Document 4 discloses a pendant type radical polymer battery in which a compound having a charge / discharge action is bonded to a polymer main chain. However, since only two electrons per unit are involved in the redox reaction, there is a problem that the theoretical capacity as an electrode active material is small.

US Pat. No. 4,833,048 International Publication No. 2013/042706 Pamphlet JP 2007-227186 A JP 2012-74209 A

Y. Morita, et al. "Organic Tailored Batteries Materials Using Stable Open-shell Molecules with Degenerate Frontier Orbitals" Nature Materials 10, pp.947-951 (2011)

  The problem to be solved by the present invention is to achieve both large charge / discharge capacity and good cycle characteristics in a secondary battery using an organic compound as an electrode active material. It is to provide a suitable polymer and a secondary battery using the same.

In order to solve the above-mentioned problems, the present inventor has developed a polymer having a multi-stage redox ability TOT as a side chain and applied it to a secondary battery as an electrode active material. We succeeded in improving the cycle characteristics by suppressing the dissolution of the electrode active material in the electrolyte without greatly reducing the charge / discharge capacity.
The polymer according to the present invention has a structure represented by the formula (1) in which the TOT radical is bonded to the polymer main chain as a side chain.

(Wherein X is selected from the group consisting of an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, silyl group, amino group, and nitro group, and may be the same or different from each other. Polymer is a polymer. Represents the main chain.)
In addition, the polymer according to the present invention has a structure represented by the formula (2) in which the TOT anion is bonded to the polymer main chain as a side chain.

(Wherein X is an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, a silyl group, selected from the group consisting of amino groups and nitro groups, and may .M ⁺ be the same as or different from each other protons , A metal ion, or an organic cation. Polymer represents a polymer main chain.)
The TOT radical or TOT anion may be directly bonded to the main chain, or may be bonded to the main chain via some spacer.

The substituent X in the formula (1) and / or the formula (2) is preferably hydrogen.
The polymer main chain may have a structure selected from the group consisting of polyethylene, polypropylene, polyacetylene, polyacrylic acid ester, polymethacrylic acid ester, polystyrene, polyether, polyester, polycarbonate, polyamide, polyimide, and polysiloxane. preferable.

  The secondary battery of the present invention is a secondary battery containing the polymer as an electrode active material.

  According to the present invention, it is possible to provide a secondary battery having a large charge / discharge capacity and good cycle characteristics.

Each charging / discharging curve from the 1st cycle to the 10th cycle obtained as a result of repeating the charging / discharging of the secondary battery produced in Example 3 with a voltage range of 1.4-4.0V and a current amount equivalent to 1C is shown. Show. The secondary battery produced in Example 3 is a graph in which the horizontal axis represents the number of charge / discharge cycles and the charge / discharge capacity per TOT weight (unit: mAh / g) is plotted. Each charging / discharging curve from the 1st cycle to the 10th cycle obtained as a result of repeating the charging / discharging of the secondary battery produced in Example 4 with a voltage range of 1.4-4.0V and a current amount equivalent to 1C is shown. Show. Each charging / discharging curve from the 1st cycle to the 10th cycle obtained as a result of repeating the charging / discharging of the secondary battery produced in Example 5 with a voltage range of 1.4-4.0V and an amount of current equivalent to 1C is shown. Show. The secondary battery produced in Example 5 is a graph in which the horizontal axis represents the number of charge / discharge cycles and the charge / discharge capacity per TOT weight (unit: mAh / g) is plotted.

Embodiments of the present invention will be described below, but the present invention is not limited to the embodiments disclosed herein. The scope of the present invention is defined by the terms of the claims, and includes all modifications and similar structures that fall within the meaning and scope equivalent to the terms of the claims.
The polymer of the present invention is a polymer having a structure in which a TOT radical represented by the following formula (1) and / or a TOT anion represented by the following formula (2) is bonded to the polymer main chain as a side chain.

(Wherein X is selected from the group consisting of an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, silyl group, amino group, and nitro group, and may be the same or different from each other. Polymer is a polymer. Represents the main chain.)
The polymer of the present invention is a polymer represented by the following formula (2) and having a structure in which the TOT anion is bonded to the polymer main chain as a side chain.

(Wherein X is an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, a silyl group, selected from the group consisting of amino groups and nitro groups, and may .M ⁺ be the same as or different from each other protons , A metal ion, or an organic cation. Polymer represents a polymer main chain.)
In the polymer of the formula (1) and / or (2), the TOT radical as a side chain has a structure in which spins are delocalized in the entire molecule. TOT can perform a reversible oxidation-reduction reaction of four electrons from a radical body to a tetraanion body, and can achieve a large charge / discharge capacity when this is used as an electrode for a secondary battery.

  As the substituent X in the formula (1) and / or (2), the smaller the molecular weight, the larger the theoretical capacity (battery capacity per unit weight of the battery) as the battery active material, which is preferable. Halogen or an organic group having 1 to 4 carbon atoms is more preferable, and hydrogen is most preferable. When the substituent X is an organic group having 1 to 10 carbon atoms, the methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group are not particularly limited but are easy to synthesize. , A phenyl group, a cyano group, or a carboxyl group is preferable.

  The TOT radical or TOT anion may be directly bonded to the main chain, or may be bonded via some spacer. As the spacer, a divalent organic group can be used, but the smaller the molecular weight, the larger the theoretical capacity as the battery active material, which is preferable, and the structure represented by the following formula (3) and a combination thereof are more preferable. .

The polymer main chain represented by Polymer in the formula (1) and / or (2) is not particularly limited, and an addition polymer, a condensation polymer, a ring-opening polymer, a natural polymer, or the like can be used. .
The polymer main chain includes polyethylene, polypropylene, polyacetylene, polyacrylic acid ester, polymethacrylic acid ester, polystyrene, polyether, polyester, polycarbonate, polyamide, polyimide, polyaniline, and poly because it is easy to synthesize and has excellent physical properties. At least one selected from the group consisting of siloxane is preferred. These may be used alone, may be used by blending a plurality, or may be used as a copolymer.

A method for producing the polymer of the present invention will be described. As a production method, for example, a method in which a polymer is first synthesized and then TOT is bonded to the polymer, or a method in which a monomer having a polymerizable group linked to TOT is polymerized can be employed.
A structure in which TOT is closely connected to the polymer main chain is preferable in that the charge / discharge capacity can be increased. For this purpose, a method in which a monomer in which a polymerizable group is connected to TOT is polymerized is preferable.

  In the monomer in which a polymerizable group is linked to TOT, the structure of TOT is preferably an anion body or a closed shell structure capped with a protecting group because it is highly soluble in a solvent and facilitates the polymerization reaction. It is done. That is, the structure shown in Formula (4) or Formula (5) is preferable.

(In the formula, X is selected from an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, silyl group, amino group, and nitro group, and may be the same or different. M ⁺ represents a proton, a metal ion, Or an organic cation.)
In the formula (4), M ⁺ is preferably used as long as it is a proton, metal ion or organic cation, and is an ammonium ion such as proton, lithium ion, sodium ion or tetraalkylammonium ion, or oxatriquinane, More preferred are oxonium ions such as triquinacene, phosphonium ions such as triphenylmonoalkylphosphonium ions, or sulfonium ions such as trialkylsulfonium ions, protons, lithium ions, tetra n-butylammonium ions, or tetra-t-butylammonium ions. Ions are more preferred.

(Wherein X is selected from the group consisting of an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, silyl group, amino group, and nitro group, and may be the same or different from each other. R is the number of carbon atoms. 1 to 20 organic groups or silyl groups.)
In formula (5), R is not particularly limited, but is preferably an alkyl group having 1 to 10 carbon atoms, an aryl group, an alkylcarbonyl group, or an arylcarbonyl group from the viewpoint of easy synthesis.

  In the structures of the formulas (4) and (5), examples of the “polymerizable group” include vinyl group, ethynyl group, acryloyl group, methacryloyl group, vinylphenyl group, epoxy group, glycidyl group, dimethoxysilyl group, carboxyl group, ester A bond, a hydroxy group, an amino group, an amide group, or an imide group can be suitably used, and a vinyl group, an ethynyl group, an acryloyl group, a methacryloyl group, and a vinylphenyl group can be used because they can be easily synthesized and polymerized. , An epoxy group, a glycidyl group, or a dimethoxymethylsilyl group is preferred.

  In the structures of the formulas (4) and (5), the polymerizable group and TOT may be directly bonded, or may be bonded via some spacer. A divalent organic group can be used as the spacer, but the smaller the molecular weight, the larger the theoretical capacity as the battery active material, and the more preferable is the structure represented by the following formula (3) or a combination thereof. .

The polymer represented by the formula (2) can be obtained by polymerizing the TOT having a polymerizable group represented by the formula (4) or the formula (5). When polymerizing TOT having a polymerizable group, it may be polymerized alone, or a monomer not containing TOT may be copolymerized.
The kind of polymerization method is not specifically limited, The polymerization method according to the property of a polymeric group can be taken. For example, when the polymerizable group is a functional group having an unsaturated bond such as a vinyl group, an ethynyl group, an acryloyl group, a methacryloyl group, or a vinylphenyl group, addition polymerization such as radical polymerization, anionic polymerization, cationic polymerization, and coordination polymerization It can be performed. When the polymerizable group is a carboxyl group, an ester bond, a hydroxy group, an amino group, an amide group, an imide group, or a dimethoxymethyl group, condensation polymerization can be performed. When the polymerizable group is an epoxy group or the like, ring-opening polymerization can be performed.

  When the TOT represented by the formula (4) is used, the polymer represented by the formula (1) can be produced by oxidizing the obtained polymer having the TOT anion as a side chain. A method for oxidizing a polymer having a TOT anion as a side chain is not particularly limited, and a method of electrochemically oxidizing, a method of chemically oxidizing by acting an oxidizing agent, and the like can be employed.

In the case of using the polymer represented by the formula (5), after removing the protective group and converting TOT to an anion, the polymer represented by the formula (1) can be produced by oxidation by the above method. it can.
In the secondary battery according to the present invention, the polymer represented by the formula (1), the polymer represented by the formula (2), or a polymer including both structures is used as an electrode active material.

Although it does not specifically limit as a method of producing a secondary battery using the polymer of this invention as an electrode active material, The example is demonstrated below.
First, 10 parts by weight of the polymer having TOT as a side chain, 80 parts by weight of acetylene black, and 200 parts by weight of a 5% N-methylpyrrolidone (NMP) solution of polyvinylidene fluoride (PVDF) are mixed and stirred. For mixing and stirring, a mortar, a ball mill, a planetary stirring device, or the like can be used.

Next, the paste thus obtained is applied onto a rolled aluminum foil using a bar coater or the like to obtain a sheet.
Thereafter, the sheet is decompressed at 120 ° C. for 1 hour to remove NMP. Thereafter, the sheet is pressed by a roll press.
Thereafter, the electrode is cut out to a predetermined size from the sheet.

Next, a spacer, a metal lithium foil, a separator, the above-described polymer-containing positive electrode, a spacer, a spring, and a positive electrode side housing are combined in this order on the negative side housing.
Then, after filling with electrolyte solution, it seals. Although it does not specifically limit as electrolyte solution, For example, electrolytes, such as LiPF ₆ , were dissolved in ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), or these liquid mixture. Things can be used.

  In this way, a lithium ion secondary battery using the polymer having the TOT of the present invention as a side chain as an electrode active material is produced.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
<Synthesis Example 1> A TOT anion having a vinylphenyl group was synthesized by the method shown in the following formula (6).

Tetrabutylammonium salt of TOT anion having bromo group in 100 mL Schlenk tube (2.0 g), bis [1,2-bis (diphenylphosphino) ethane] palladium (0) (Pd (DIPHOS) ₂ ) (221 mg) and Tetrahydrofuran (THF) (38 mL) was added, and the mixture was stirred at room temperature for 1 hour in an argon atmosphere. In a separate 50 mL Schlenk tube, 4-vinylphenylboronic acid (520 mg), THF (10 mL), and methanol (10 mL) were added and purged with argon, and this solution was added to the solution in the 100 mL Schlenk tube with a syringe at room temperature. Stir for minutes. Further, an aqueous potassium carbonate (K ₂ CO ₃ ) solution (3.1 mL) was added. The reaction vessel was heated to reflux for 10 hours and then cooled, and extracted by adding chloroform (150 mL) and pure water (100 mL). The aqueous layer was further extracted with chloroform (300 mL), the organic layers were combined, and washed with water until the pH of the washing solution became 7. Crystals obtained by concentration under reduced pressure were filtered and washed with hexane to obtain 2.71 g of a crude product.

  The crude product (2.71 g), methanol (300 mL) and 6N hydrochloric acid (10 mL) were charged into a 500 mL eggplant flask and stirred at room temperature for 2 hours. The precipitated crystals were filtered and washed with pure water until the pH of the washing liquid became 7. The crystals were dried under reduced pressure (60 ° C./4 hours) to obtain 1.18 g of TOT having a vinylphenyl group and a hydroxy group (yield 96%).

To a 200 mL eggplant flask, TOT (924 mg) and THF (50 mL) having the vinylphenyl group and hydroxy group were added, and 11 mL of a methanol solution (1 M) of tetrabutylammonium hydroxide (Bu ₄ NOH) was added. Stir for 5 hours. Diluted with pure water (200 mL) and extracted with ethyl acetate. The organic layer was washed with water until the pH of the wash became 7, and concentrated under reduced pressure to obtain 1.02 g of tetrabutylammonium salt of TOT anion having a vinylphenyl group (yield 71%).

<Example 1>
A polymer having the TOT anion obtained in Synthesis Example 1 as a side chain was synthesized by the methods shown in the following formulas (7), (8) and (9).

  First, as shown in Formula (7), in a 100 mL Schlenk tube in an argon atmosphere, a tetrabutylammonium salt of a TOT anion having a vinylphenyl group synthesized in Synthesis Example 1 (1.17 g), THF (20 mL), and pivaloyl chloride (0.3 mL) was charged and stirred overnight at room temperature. The reaction solution was diluted with pure water (200 mL) and extracted with chloroform. The organic layer was washed with water until the pH of the washing liquid became 7, and insoluble matter was filtered off. The solution was concentrated under reduced pressure, and the obtained crystals were washed with hexane to obtain 840 mg of a crude product. This was purified by silica gel chromatography to obtain 666 mg of TOT having a vinylphenyl group and a t-butylcarbonyl group (yield 81%).

  Next, as shown in Formula (8), TOT (642 mg) having the vinylphenyl group and t-butylcarbonyl group in a 100 mL Schlenk tube under an argon atmosphere, 2,2′-azobis (N-butyl-) as a polymerization initiator 2-Methylpropionamide) (77 mg) and chlorobenzene (20 mL) were charged and heated to 150 ° C. (32 hours). After cooling, the reaction solution was poured into hexane (250 mL), and the precipitated powder was collected by filtration and purified by recrystallization to obtain 417 mg of a polymer having TOT having a t-butylcarbonyl group as a side chain (yield). Rate 68%).

  The gel was analyzed by gel permeation chromatography with the weight average molecular weight Mw = 4526 and Mw / Mn = 2.05.

Subsequently, as shown in Formula (9), in a 100 mL Schlenk tube, a polymer (400 mg) having TOT having a t-butylcarbonyl group as a side chain, THF (40 mL), a methanol solution of Bu ₄ NOH (1M) (4 mL) was added and stirred at room temperature for 3 hours. Diluted with pure water (400 mL) and extracted with chloroform and ethyl acetate. The organic layer was washed with water and then concentrated under reduced pressure to obtain 402 mg of a polymer having a tetrabutylammonium salt of TOT anion as a side chain (yield 77%).

<Example 2> (Synthesis of a polymer having a TOT radical as a side chain)
The polymer having the TOT anion synthesized in Example 1 as a side chain was converted to a radical by the method shown in Formula (10).

  A 500 mL four-necked flask is charged with a solution of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) (250 mg) in dichloromethane (80 mL) and has the TOT anion synthesized in Example 1 as a side chain. The polymer (357 mg) was added dropwise at 25 ° C. over 2.5 hours together with a mixed solvent of dichloromethane (200 mL) and THF (80 mL). After stirring at room temperature overnight, the precipitated powder was filtered and washed with dichloromethane and THF to obtain 221 mg of a polymer having a TOT radical as a side chain (yield 97%).

<Example 3> (Production of secondary battery using polymer having TOT radical as side chain as active material)
A planetary stirrer prepared by mixing 160 mg of acetylene black, 400 mg of an N-methylpyrrolidone solution of polyvinylidene fluoride (5 wt%), 2.4 mL of N-methylpyrrolidone, and 20 mg of a polymer having a TOT radical synthesized in Example 2 as a side chain. The mixture was stirred for 10 minutes and then cast on an aluminum foil using a bar coater having a clearance of 300 μm and dried under reduced pressure at 120 ° C. for 1 hour. This was pressed with a roll press at a pressure of 800 kg / cm ² to prepare a positive electrode sheet in which a polymer having TOT radicals as side chains was dispersed.

The film thickness of the positive electrode sheet combined with the aluminum foil (20 μm) was 45 μm. The TOT content in the positive electrode is 10 wt%. Before producing the battery, the positive electrode sheet was further dried under reduced pressure at 80 ° C./12 hours.
A lithium ion secondary battery was manufactured using this positive electrode sheet. The battery shape is CR2032. Negative electrode side exterior, stainless steel metal plate (negative electrode current collector), lithium foil (negative electrode active material), polypropylene porous membrane separator, positive electrode sheet, stainless steel metal plate (positive electrode current collector), spring, positive electrode side exterior It was produced by stacking in order and caulking the electrolyte inside. As the electrolytic solution, LiPF ₆ dissolved in ethylene carbonate / diethyl carbonate (volume ratio 3: 7) at a concentration of 1.0 M was used.

  This battery was set in a charge / discharge tester TOSCAT-3100 manufactured by Toyo Systems Co., Ltd., and charging / discharging was repeated with a voltage range of 1.4-4.0 V and a current amount of 1C. FIG. 1 shows charge / discharge curves from the first cycle to the tenth cycle. Charging was continued at a current value equivalent to 1 C. When the voltage reached 4 V, charging of the cycle was terminated. Next, discharging was started at a current value corresponding to 1 C, and the battery voltage was lowered according to the discharging curve of FIG.

The charge cycle and the discharge cycle are combined to form one charge / discharge cycle.
FIG. 2 shows a graph in which the charge / discharge capacity per TOT weight (unit: mAh / g) is plotted against the number of charge / discharge cycles. A large discharge capacity of about 230 mAh / g is shown up to about 100 cycles, and a discharge capacity of 143 mAh / g is shown even at the 300th cycle. It can be seen that this secondary battery is also excellent in cycle characteristics.

<Example 4> 8 mg of a polymer having the TOT anion synthesized in Example 1 as a side chain, 24 mg of polytetrafluoroethylene, and 48 mg of acetylene black were mixed and kneaded. A 1/4 amount of this mixture was pressure-bonded to a circular (diameter 15 mm) stainless steel mesh with a hydraulic press. This was dried under reduced pressure at 80 ° C. for 12 hours to obtain a positive electrode sheet.
A lithium ion secondary battery was manufactured using this positive electrode sheet. The battery shape is CR2032. Negative electrode side exterior, stainless steel metal plate (negative electrode current collector), lithium foil (negative electrode active material), polypropylene porous membrane separator, positive electrode sheet, stainless steel metal plate (positive electrode current collector), spring, positive electrode side exterior It was produced by stacking in order and caulking the electrolyte inside. As the electrolytic solution, LiPF ₆ dissolved in ethylene carbonate / diethyl carbonate (volume ratio 3: 7) at a concentration of 1.0 M was used.

This battery was set in a charge / discharge tester TOSCAT-3100 manufactured by Toyo Systems Co., Ltd., and charging / discharging was repeated at a voltage range of 1.4-4.0V and a current amount of 0.2C. FIG. 3 shows charge / discharge curves from the first cycle to the tenth cycle. According to FIG. 3, it can be seen that a large discharge capacity of 140 mAh / g is shown in the first cycle, and the cycle characteristics are also stable.
<Example 5> 160 mg of acetylene black, 400 mg of an N-methylpyrrolidone solution (5 wt%) of polyvinylidene fluoride, 2.4 mL of N-methylpyrrolidone, and 20 mg of a polymer having the TOT radical synthesized in Example 2 as a side chain After mixing and stirring with a planetary stirrer for 10 minutes, it was cast on an aluminum foil using a bar coater with a clearance of 300 μm and dried under reduced pressure at 120 ° C. for 1 hour. This was pressed with a roll press at a pressure of 800 kg / cm ² to prepare a positive electrode sheet in which a polymer having TOT radicals as side chains was dispersed.

The film thickness of the positive electrode sheet combined with the aluminum foil (thickness 20 μm) was 45 μm. The TOT content in the positive electrode is 10 wt%. Before producing the battery, the positive electrode sheet was further dried under reduced pressure at 80 ° C./12 hours.
A lithium ion secondary battery was manufactured using this positive electrode sheet. The battery shape is CR2032. Negative electrode side exterior, stainless steel metal plate (negative electrode current collector), lithium foil (negative electrode active material), polypropylene porous membrane separator, positive electrode sheet, stainless steel metal plate (positive electrode current collector), spring, positive electrode side exterior It was produced by stacking in order and caulking the electrolyte inside. As the electrolytic solution, LiPF ₆ dissolved in ethylene carbonate / diethyl carbonate (volume ratio 3: 7) at a concentration of 1.0 M was used.

  This battery was set in a charge / discharge tester TOSCAT-3100 manufactured by Toyo Systems Co., Ltd., and charging / discharging was repeated with a voltage range of 1.4-4.0 V and a current amount of 1C. FIG. 4 shows charge / discharge curves from the first cycle to the tenth cycle. FIG. 5 shows a graph in which the discharge capacity per TOT weight (unit: mAh / g) is plotted against the number of charge / discharge cycles. A large charge / discharge capacity exceeding 200 mAh / g is shown in the first cycle, and it can be seen that a discharge capacity of 170 mAh / g or more is maintained even after exceeding 600 cycles.

Claims (5)

A polymer having a structure in which a trioxotriangulene radical represented by formula (1) and / or a trioxotriangulene anion represented by formula (2) is bonded as a side chain to a polymer main chain.

(In the formula, the substituent X is selected from an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, silyl group, amino group, and nitro group, and may be the same or different from each other. Represents a chain.)

(In the formula, X is selected from an organic group having 1 to 10 carbon atoms, hydrogen, halogen, hydroxyl group, silyl group, amino group, and nitro group, and may be the same or different from each other. M ⁺ is a proton or metal ion. Or an organic cation. Polymer represents a polymer main chain.)   The polymer according to claim 1, wherein the substituent X is hydrogen.   The polymer main chain is at least one selected from the group consisting of polyethylene, polypropylene, polyacetylene, polyacrylic acid ester, polymethacrylic acid ester, polystyrene, polyether, polyester, polycarbonate, polyamide, polyimide, and polysiloxane. The polymer according to claim 1 or 2.   The polymer according to any one of claims 1 to 3, wherein the side chain is a trioxotriangulene radical represented by the formula (1).   A secondary battery containing the polymer according to claim 1 as an electrode active material.

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