JP2008282632A - Secondary battery for energy regeneration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery for the energy regeneration of a high capacity capable of charging and discharging by a large current. <P>SOLUTION: The secondary battery for energy regeneration contains an organic radical polymer as an electrode active material, and the organic radical polymer contains a disubstituted polynorbornene structure with two substituents including a TEMPO radical three-dimensionally arranged in endo-exo to a main-chain 5-membered ring skeleton expressed in a formula (1). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic radical polymer, which is a disubstituted polynorbornene, in which two substituents containing a TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) radical are arranged endo-exo with respect to the main chain skeleton. The present invention relates to a secondary battery for energy regeneration as an electrode active material.

  Lithium ion secondary batteries that appeared in the 1990s have expanded their use to mobile phones, notebook computers, various portable information terminals, etc. as state-of-the-art batteries with high energy density. At present, applications for automobile use, power storage, and the like are also being considered.

However, the main positive electrode active materials used in this lithium-ion secondary battery are mainly affected by the international situation and political instability because ore production is biased in some countries. This is lithium cobalt oxide (LiCoO ₂ ) containing cobalt as a constituent element. Therefore, in order to stably develop and maintain the IT society, secondary battery active materials consisting of organic elements and elements such as iron that are abundant in resources and harmless to the environment, replacing cobalt. The challenge is to develop

  On the other hand, it is necessary to promote energy efficiency in order to combat global warming and resource depletion of fossil fuels. As one of them, solar cells and wind power generation are actively promoted to obtain energy from the sun and wind power, which are said to be inexhaustible in terms of resources. Also, in transportation equipment such as automobiles and trains that consume a large amount of valuable oil, a regenerative energy system that converts and recycles the inertial energy that was discarded in the form of thermal energy such as frictional heat during deceleration is converted to electrical energy. It has begun to introduce.

  However, none of the energy is constantly generated constantly, and the fluctuations in the load and generated current are very large. As long as a well-known secondary battery is used for power storage, the safety and durability of the battery In order to prioritize battery characteristics such as compatibility, it is not possible to store all energy.

For example, taking a gasoline car as an example, the energy used for work is 10 to 13% of the input energy, and even if it sees from the 10.15 mode of the fuel consumption domestic evaluation standard, deceleration energy must be recovered efficiently. I understand that it doesn't become. If all of this deceleration energy can be recovered, the running energy can be reduced by 50%, which greatly contributes to energy saving and CO ₂ reduction.

  By the way, even with hybrid vehicles that are currently attracting a lot of attention, depending on the calculation method, in order to ensure the safety and durability of the installed secondary battery, it is possible to recover deceleration energy from about 20 km / hour to stop It stays. Deceleration energy from higher speeds is too burdensome for the battery because the energy per hour is too large. For this reason, it is the present condition that it is thrown away into the atmosphere as thermal energy.

  Secondary batteries are always charged and discharged through a charge / discharge control circuit and a protection circuit to ensure their safety and durability. These circuits operate with self-extinguishing charge / discharge energy. Yes. Therefore, with a small energy that is lower than the operating voltage and operating current of the semiconductor in the circuit, the circuit does not operate and cannot be charged. In general, the time zone in which the electromotive force generated by the solar cell can be used is said to be around 10:00 to 15:00, because the electromotive force of the solar cell does not reach the operating voltage / current of the semiconductor in other time zones. It is.

  In order to store electricity more efficiently, in a lithium ion secondary battery, the Co atoms of lithium cobaltate as an active material are partially or entirely replaced with Ni atoms or Mn atoms, and damage to the active material due to lithium ions generated during charging and discharging Attempts have been made to suppress dendrite. However, in the lithium ion secondary battery, the movement speed of lithium ions in the transition metal crystal becomes the rate-determining charge / discharge speed, and it cannot handle instantaneous charging. From the viewpoint of charging, the lithium ion secondary battery is basically unsuitable as a secondary battery for energy regeneration.

  On the other hand, recently, electric double layer capacitors have been attracting attention as power storage devices for regenerative energy systems. This device uses the polarization at the interface to store electricity, discharges a large current at once, and has excellent characteristics such as no charge / discharge deterioration, but it essentially has a capacity energy higher than that of a lithium ion secondary battery. It has the disadvantage of low density.

  Recently, as a battery using an organic compound as an active material, a new type of secondary battery using a conductive polymer or an organic sulfur compound as an electrode active material has been proposed. (For example, refer to Patent Document 1).

  In this battery, the principle of battery operation is a doping reaction and a dedoping reaction of electrolyte ions with respect to a conductive polymer.

  The dope reaction described here is defined as a reaction that stabilizes excitons such as charged solitons, polarons, and bipolarons generated by electrochemical oxidation or reduction reactions of conductive polymers with counter ions. The de-doping reaction is defined as a reaction in which exciton stabilized by a counter ion is electrochemically oxidized or reduced.

  However, the exciton produced by the electrochemical redox reaction is delocalized over a wide area of the π-electron conjugated electron cloud spreading in the conductive polymer, so there is a limit to increasing the exciton concentration. there were. For example, polyaniline has a doping rate of 50% or less, and polyacetylene is around 7%. For this reason, although a certain effect is exhibited in reducing the weight of the battery, it is still insufficient in increasing the capacity.

  In addition, a battery has been proposed in which an organic compound having a disulfide bond is used as a positive electrode active material and dissociation / recombination of disulfide bonds is the battery operation principle (see, for example, Patent Document 2).

  However, in this battery, the dissociation product having a reduced molecular weight diffuses into the electrolytic solution, and the recombination efficiency is poor. For this reason, this battery has a problem that the capacity is significantly reduced during the charge / discharge cycle.

Further, as the newest battery using an organic compound as an electrode active material, a secondary battery using the oxidation / reduction of a radical of an organic radical compound as a battery operating principle has been proposed. Specifically, secondary batteries using an active material such as a nitrogen radical compound, a nitroxide radical compound, and an oxy radical compound have been proposed (see, for example, Patent Documents 3 and 4 and Non-Patent Document 1).
US Pat. No. 4,442,187 (published on April 10, 1984) US Pat. No. 4,833,048 (published May 23, 1989) JP 2004-207249 A (published July 22, 2004) Japanese Patent No. 2004-193004 (published July 8, 2004)

  However, the configurations disclosed in Patent Documents 3 and 4 and Non-Patent Document 1 have a problem that the capacity is smaller than that of the lithium ion secondary battery.

  Specifically, the batteries disclosed in Patent Documents 3 and 4 and Non-Patent Document 1 are superior to conventional existing secondary batteries in high-power and high-current rapid charging. Although it is effective and has the most powerful configuration as a secondary battery for energy regeneration, it has a great disadvantage that its capacity is smaller than that of a lithium ion secondary battery.

  As described above, various secondary batteries have been proposed to realize a secondary battery for energy regeneration that can be charged / discharged by a large current, but a secondary battery that sufficiently satisfies the requirements has been obtained. The situation is not being done.

  The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide an electrode capable of providing a secondary battery for energy regeneration that can be charged / discharged by a large current and has a high capacity, and includes the same. It is to realize a secondary battery for energy regeneration.

  In order to solve the above-mentioned problem, the secondary battery for energy regeneration according to the present invention is a secondary battery for energy regeneration containing an organic radical polymer as an electrode active material, and the organic radical polymer is represented by the following formula (1). )

The two substituents containing the TEMPO radical represented by the formula (1) are characterized in that they contain a disubstituted polynorbornene structure in which the steric configuration is endo-exo with respect to the main chain five-membered ring skeleton.

  According to the said structure, since the organic radical polymer which has a disubstituted polynorbornene structure represented by Formula (1) is included, the secondary battery for energy regeneration which can be charged / discharged by a large current and is high capacity | capacitance is provided. There is an effect that can be.

  In the secondary battery for energy regeneration according to the present invention, the number average molecular weight of the organic radical polymer is preferably 100,000 or more.

  According to the said structure, there exists the further effect that an active material does not melt | dissolve or swell in electrolyte solution. In particular, when the molecular weight is low, the active material moves between the electrodes during the charge / discharge cycle test, which affects the battery life.

  In the secondary battery for energy regeneration which concerns on this invention, it is preferable that a carbon material is further included as an electrode active material.

  According to the said structure, there exists the further effect that charging / discharging by a heavy current is attained, suppressing a voltage drop.

  In the secondary battery for energy regeneration according to the present invention, the carbon material is preferably pyrolytic vapor grown carbon fiber.

  According to the said structure, there exists the further effect that the secondary battery for energy regeneration which can be used even if it is a large electric current of 1A or more and 10-100A or less can be provided.

  Vapor-grown carbon fibers have extremely poor dispersibility compared to carbon black and have not been used for a long time even in lithium ion secondary batteries. However, in organic radical batteries, the superiority or inferiority of the dispersibility affects battery characteristics. Can be used.

  According to the said structure, since the said electrode which concerns on this invention is included, there exists an effect that the secondary battery for energy regeneration which can be charged / discharged by a large current and is high capacity | capacitance can be provided.

  In the secondary battery for energy regeneration according to the present invention, it is preferable that the battery further includes an electrolytic solution, and the organic radical polymer is insoluble in the electrolytic solution during charging and discharging.

  According to the said structure, since it can suppress that an organic radical polymer moves, there exists a further effect that a capacity | capacitance fall is not caused in a charging / discharging cycle test, and the swelling of an electrode does not arise easily.

  The secondary battery for energy regeneration according to the present invention is a secondary battery for energy regeneration containing an organic radical polymer as an electrode active material as described above, and the organic radical polymer is represented by the formula (1). The two substituents containing the TEMPO radical include a disubstituted polynorbornene structure in which the configuration is endo-exo with respect to the main chain skeleton.

  For this reason, there exists an effect that the secondary battery for energy regeneration which can be charged / discharged by a large current and is high capacity | capacitance can be provided.

  The present invention will be described in detail below.

  The secondary battery for energy regeneration according to the present embodiment has the following formula (1):

And an electrode containing an organic radical polymer having a disubstituted polynorbornene structure in which two substituents containing a TEMPO radical are arranged endo-exo with respect to the main chain skeleton.

  The secondary battery for energy regeneration according to the present embodiment is the same as a conventionally known configuration except that it includes an electrode including an organic radical polymer having a disubstituted polynorbornene structure represented by the formula (1). The battery structure is not particularly limited. For example, as shown in FIG. 1, a positive electrode layer (electrode) 2 and a negative electrode layer 4 are superposed via a separator 6 containing an electrolyte, and the positive electrode current collector is disposed outside the positive electrode layer 2 and the negative electrode layer 4. The body 8 and the negative electrode current collector 10 are disposed, and the current collectors have a structure in which a positive electrode terminal 12 and a negative electrode terminal 14 are attached, respectively, and the entire structure is covered with an exterior film 16. Is mentioned.

(1) Positive electrode layer 2
The positive electrode layer 2 according to the present embodiment is an electrode including an organic radical polymer, and the organic radical polymer is represented by the formula (1), and two substituents including a TEMPO radical are main chain five-membered rings. It contains a disubstituted polynorbornene structure that is configured endo-exo with respect to the skeleton.

  The organic radical polymer preferably has a number average molecular weight of 100,000 or more.

  The number average molecular weight can be measured by, for example, GPC (polystyrene standard, THF solvent).

  Further, it is more preferable that the organic radical polymer is insoluble in the electrolyte during charging / discharging. For example, the organic radical polymer is described in Non-Patent Document 3 (T. Katsumata., Et. Al., “Polyacetylene and polynorbornene”). Derivatives carrying TEMPO. Synthesis and properties as rechargeable batteries. ”, Macromolecular Rapid Communications, 27, 1206-1211, (2006)). Specifically, for example, it can be synthesized by polymerization at 30 ° C. in dichloromethane using a norbornene monomer and a Grubbs second generation complex as a catalyst.

  In the secondary battery for energy regeneration according to the present embodiment, it is more preferable that an organic radical polymer is included in the positive electrode layer 2 as an electrode active material, and the organic radical polymer is mixed with a carbon material. .

  The “electrode active material” is a substance that directly contributes to electrode reactions such as charging reaction and discharging reaction, and plays a central role in the battery system. In this embodiment, the organic radical polymer is used as the electrode active material.

  In the present embodiment, the carbon material is used as a conductivity-imparting material, and is also used in a conventional lithium ion secondary battery. However, in the case of the present embodiment, since the operation as a battery is not recognized with fine particles of metal powder or conductive polymer, the theoretical clarification has not yet been made, but the carbon material is a simple current collector. It is thought that the above-mentioned effects are exerted.

  In forming the positive electrode layer 2, the coating method used is not particularly limited. In that case, the type of solvent, the blending ratio of the organic radical polymer and the solvent, the type of additive and the amount added, etc. take into account the required characteristics of the secondary battery, etc., and ease of manufacture in the manufacturing process. Etc. are arbitrarily set.

  The positive electrode layer 2 according to the present embodiment is formed by, for example, mixing the organic radical polymer with a carbon material and molding the organic radical polymer and the carbon material as they are, or dissolving them in an appropriate solvent. It can be prepared by a method of dispersing and mixing, coating in the form of a solution or slurry, and drying. The carbon material is more preferably pyrolytic vapor grown carbon fiber.

  The solvent is not particularly limited as long as it is a general organic solvent. For example, dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, propylene carbonate, diethyl carbonate, dimethyl carbonate, γ-butyl lactone, acetonitrile, tetrahydrofuran, Nonaqueous solvents such as nitrobenzene and acetone; and protic solvents such as methyl alcohol and ethyl alcohol.

  Moreover, the positive electrode layer 2 according to the present embodiment can be manufactured in combination with various additives. Examples of the additives include polyethylene, polyvinylidene fluoride, polyhexafluoropropylene, polytetrafluoroethylene, polyacrylate, alkylnaphthalenesulfonic acid, formaldehyde condensate of naphthalenesulfonic acid, polyethylene oxide, carboxy, which act as a binder and a viscosity modifier. Examples thereof include resins such as methylcellulose.

  In the positive electrode layer 2 according to the present embodiment, a binder can be used as necessary in order to strengthen the connection between the constituent materials in the positive electrode layer 2. As the binder, polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene-butadiene copolymer rubber, polypropylene, polyethylene, polyimide, Resin binders such as various polyurethanes can be mentioned. These resin binders may be used alone or in combination of two or more. In addition, although the ratio of the binder in the positive electrode layer 2 is not specifically limited, For example, it can be 5-30 mass%.

  The mixing ratio of the organic radical polymer in the positive electrode layer 2 can be appropriately selected according to the required characteristics of the battery and is not uniquely limited. Usually, it is selected so that the mixing ratio is 10% by mass or more and 98% by mass or less. If the mixing ratio is 10% by mass or more, the energy density required for the secondary battery can be stably obtained, and if it is 98% by mass or less, the internal resistance can be lowered. It can be operated stably. This is thought to be because the contact between the carbon materials acting as current collectors is not hindered.

(2) Negative electrode layer 4
The negative electrode layer 4 serving as the counter electrode of the positive electrode layer 2 is not particularly limited as long as it is made of a conductive material, and conventionally known ones can be adopted according to battery specifications. Examples of such conductive materials include natural graphite, petroleum coke, coal coke, pitch coke, carbon black, activated carbon, resin-fired carbon, organic polymer fired body, pyrolytic vapor-grown carbon fiber, and mesocarbon microbeads. , Carbon materials such as mesophase pitch-based carbon fiber, polyacrylonitrile-based carbon fiber, low-temperature calcined carbon, fullerene, carbon nanotube, metal lithium, lithium alloy, lithium nitride, Li _(3-X) M _X N (0 <X <1 , M = Co, Ni, Cu) and mixtures thereof. More specifically, a copper foil obtained by coating graphite with a binder, a lithium-laminated copper foil, a platinum plate, and the like can be given. The negative electrode layer 4 serving as a counter electrode is provided to face the positive electrode layer 2 with a separator 6 described later.

(3) Current collector (positive electrode current collector 8, negative electrode current collector 10)
In the secondary battery for energy regeneration according to the present embodiment, as the negative electrode current collector 10 and the positive electrode current collector 8, a foil made of nickel, aluminum, copper, gold, silver, an aluminum alloy, stainless steel, carbon, or the like, A metal flat plate or a material having a mesh shape can be used.

(4) Separator 6
In the secondary battery for energy regeneration according to the present embodiment, the separator 6 can be used for the purpose of separating the positive electrode 2 and the negative electrode 4 as in the conventional lithium ion secondary battery. Examples of the separator 6 include polyolefin films such as porous polyethylene and polypropylene, and composite films of these with other resins.

(5) Electrolyte The electrolyte performs charge carrier transport between the positive electrode layer 2 and the negative electrode 4. Generally, those having ion conductivity of 10 ⁻⁵ to 10 ⁻¹ S / cm at room temperature are used. As such an electrolyte, for example, an electrolytic solution in which an electrolyte salt is dissolved in a solvent or a solid electrolyte made of a polymer compound containing the electrolyte salt can be used.

Examples of the electrolyte salt constituting the electrolytic solution include LiPF ₆ , LiClO ₄ , LiBF ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₃ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li Conventionally known materials such as (CF ₃ SO ₂ ) ₃ C and Li (C ₂ F ₅ SO ₂ ) ₃ N can be used.

  Examples of the solvent for dissolving the electrolyte include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyl lactone, tetrahydrofuran, dioxolane, sulfolane, dimethylformamide, dimethylacetamide, and N-methyl. An organic solvent such as -2-pyrrolidone can be used. These may be used singly or as a mixed solvent of two or more.

  As the polymer compound constituting the solid electrolyte, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride-monofluoroethylene copolymer, vinylidene fluoride- Vinylidene fluoride polymers such as trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, and acrylonitrile-methyl methacrylate copolymer Polymer, acrylonitrile-methyl acrylate copolymer, acrylonitrile-ethyl methacrylate copolymer, acrylonitrile-ethyl acrylate copolymer, acrylonitrile-methacrylic acid copolymer, acrylonitrile-acrylic acid copolymer Coalescence, acrylonitrile - acrylonitrile polymers such as vinyl acetate copolymer, further polyethylene oxide, ethylene oxide - propylene oxide copolymer, the polymerization products of these acrylates body or methacrylate products thereof. The solid electrolyte may be a gel obtained by adding an electrolytic solution to these polymer compounds, or only the polymer compound may be used as it is.

(6) Battery As described above, the secondary battery for energy regeneration according to the present embodiment constitutes the positive electrode layer 2 by mixing an organic radical polymer, preferably with a carbon material, with the transfer of electrons. It is configured so that the oxidation-reduction reaction proceeds smoothly. In addition, the general configuration of the secondary battery is such that an electrode layer containing an active material is formed on a current collector plate, both are opposed to each other with a separator 6, impregnated with an electrolytic solution, and sealed. It becomes. Furthermore, in such a configuration, the active material contained in the positive electrode layer 2 is an organic radical polymer, and is preferably configured as the positive electrode layer 2 by being mixed with a carbon material.

  In the secondary battery for energy regeneration according to the present embodiment, the shape of the battery is not particularly limited, and may be a cylindrical shape, a square shape, a coin shape, a sheet shape, or the like that is employed in a conventional battery. it can. Also, the exterior method is not particularly limited, and it can be performed with a metal case, a mold resin, an aluminum laminate film, or the like. Also, conventionally known methods can be used for taking out the leads from the electrodes.

  Further, in the secondary battery for energy regeneration according to the present embodiment, the method for laminating the positive electrode layer 2 and the negative electrode layer 4 is not particularly limited, and is alternately laminated in multiple layers or wound opposite to each other via the separator 6. It is possible to apply known techniques.

  Non-patent documents 1 to 3 (non-patent document 1: K. Nakahara, et. Al., “Rechargeable battery with organic radical cathodes”, Chem. Phys. Lett., 359, 351, which are papers by the present inventors. -354, (2002), Non-Patent Document 2: Katsumata et al., "Synthesis and Properties of Polymers Containing TEMPO in Side Chain", Abstract of the Society of Polymer Science, Non-Patent Document 3: T. Katsumata., Et. Al., " Polyacetylene and polynorbornene derivatives carrying TEMPO. Synthesis and properties as rechargeable batteries. ”, Macromolecular Rapid Communications, 27, 1206-1211, (2006)) discloses organic radical polymers.

  Conventionally, NO radicals such as TEMPO radicals were thought to cause only one-electron redox. Therefore, in order to increase the capacity, studies have been made so far in the direction of introducing as many TEMPO groups as possible.

  However, in organic radical polymers and compounds that have been reported so far, the theoretical capacity calculated from the molecular weight per radical has never exceeded the disclosed actual capacity. You can see that it has not happened. The same result was obtained with polynorbornene published by Professor Waseda Nishide.

  The present inventors paid attention to the configuration of two substituents containing a TEMPO radical, synthesized and measured three types of polynorbornene having a structural isomerism relationship, and as a result, only the endo-exo isomer was twice the theoretical capacity. Found to show capacity.

  In general, most inorganic substances have a density of 2 or higher, whereas organic substances containing polymers have essentially no specific gravity (density) of more than 1.5 and are usually 0.9 to 1.2. . The same applies to organic radical polymers or organic radical compounds. This is the biggest reason why organic semiconductors and organic magnetic materials are not actually used in each assumed application, not limited to battery active materials. That is, in the case of a battery, the battery capacity depends on the amount of active material filled per certain volume of the battery, that is, the number of molecules. Accordingly, the inorganic substance having a higher density has a larger number of molecules filled than the organic substance.

  Non-patent documents 1 to 3 are all one-electron oxidation-reduction, and disclose only the measured capacity corresponding to the theoretical capacity, and the mechanism is oxidation-reduction between NO radical (neutral) and cation (P-type semiconductor). It is. If this also causes oxidation / reduction (N-type semiconductor) between NO radicals (neutral) and anions that are expected on paper, the capacity naturally increases accordingly. However, it is rare that an N-type semiconductor including an organic semiconductor is used.

  Another possibility that the capacity is increased is that an empty orbit is generated by the interaction between radical spins, and the capacity is doubled. The development of substances with radical spin interaction has been attempted all over the world even with organic magnetic substances that are the same radical substances, but only a few examples have been found.

  Under such circumstances, in the endo-exo polynorbornene described in the present application, the measured measurement curve of the magnetic susceptibility change rate by SQUID (superconducting quantum interferometer) matched the simulation curve at the time of interaction. It was indirectly suggested that there was radical spin interaction in the endo-exo form. The remaining exo-exo and endo-endo bodies matched the simulation curves when there was no interaction.

  It is unclear at this time which of the above-mentioned mechanisms caused the remarkable multi-stage charge / discharge of the endo-exo body. In the study by the present inventors, a proxyl radical having the same NO radical instead of the TEMPO radical was also examined, but the capacity corresponding to the two-electron redox was clearly shown because the TEMPO radical described in the present application was used. The two substituents contained were only disubstituted polynorbornenes having an endo-exo configuration with respect to the main chain five-membered ring skeleton.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to a following example.

[Synthesis Example 1]
Polynorbornene, which is an organic radical polymer having a structure represented by the formula (1), in the presence of a base, 5-norbornene-endo-exo-2,3-dicarboxylic acid and 4-hydroxy-2,2,6, A norbornene di TEMPO ester obtained by esterifying 6-tetramethylpiperidinoxy radical with a carbodiimide-based condensing agent according to a conventional method, and then using this compound as a monomer and an inert gas using a second generation Grubbs catalyst Ring-opening metathesis polymerization could be carried out under atmosphere.

[Example 1]
300 mg of the organic radical polymer obtained in Synthesis Example 1, 600 mg of vapor grown carbon fiber, and 100 mg of polytetrafluoroethylene resin binder (manufactured by Kureha Chemical) were weighed and mixed uniformly. Next, the mixture was pressure-molded to obtain a pellet having a thickness of about 150 μm, dried under vacuum at 80 ° C. for 1 hour, punched into a circle having a diameter of 12 mm, and used as an electrode layer.

Next, the electrode layer was immersed in an electrolytic solution, and the electrolytic solution was soaked in the electrode. As the electrolytic solution, an ethylene carbonate / diethylene carbonate mixed solution (mixing volume ratio 3: 7) containing 1.0 mol / L LiPF ₆ electrolytic salt was used. This electrode is placed as a positive electrode layer 2 on a positive electrode current collector 8 constituting a coin-type battery, and a separator 6 made of a polypropylene porous film impregnated with an electrolytic solution is laminated thereon, and further, a negative electrode layer A lithium-laminated copper foil 4 was laminated. After that, with an insulating packing disposed around, an aluminum exterior (made by Hohsen) 16 of a coin-type battery is overlaid and pressurized by a caulking machine, thereby using an organic radical polymer as a positive electrode active material as a negative electrode active material. A sealed coin-type battery using metallic lithium was produced.

  The produced coin-type battery was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged with a constant current of 0.1 mA to a predetermined voltage (1.5 V in this example). As a result, it was confirmed that this battery was a secondary battery having a capacity of 220 Ah / kg.

  Then, charging / discharging was repeated 100 times in the range of 4.0-1.5V. As a result, even after 100 cycles, the capacity was 90% or more of the initial value, and it was confirmed that the secondary battery had a long cycle life with little reduction in capacity even after repeated charge and discharge.

  On the other hand, using a coin-type battery produced in the same manner, the battery was charged at a constant current of 0.1 mA until reaching 4.0 V, then discharged at a constant current of 5.0 mA, and the capacity was measured. As a result, although the capacity at 5.0 mA shows a tendency to decrease in capacity compared with the capacity at 0.1 mA, it has a maintenance rate of 80 to 90%, so that the output is small even at a large current. It was found to be a secondary battery of density.

  In charge and discharge measurement with a large current, a film pack type battery is usually used because a terminal having a thickness and width that can withstand the large current is used. However, since the current is small in the initial evaluation of electrical characteristics, convenience and ease of battery fabrication are improved. In consideration of this, in this example, a coin-type battery was produced and used.

[Example 2]
To a small homogenizer, 10 g of N-methylpyrrolidone and 400 mg of polyvinylidene fluoride were added and stirred for 30 minutes to completely dissolve.

  Thereto was added 0.5 g of the organic radical polymer obtained in Synthesis Example 1, and the mixture was further stirred until it became uniform. Next, 0.5 g of vapor grown carbon fiber was added and stirred to obtain a black slurry. This slurry was applied onto a high-purity aluminum foil and dried at 120 ° C. to obtain a positive electrode having a thickness of 90 μm. This was punched into a circle having a diameter of 12 mm, and a coin-type cell was produced in the same manner as in Example 1.

  As a result of evaluating the produced coin-type battery under the same conditions as in Example 1, it was confirmed that it was a secondary battery for energy regeneration having a charge / discharge voltage of 3.6 V and a discharge capacity of 215 Ah / kg. The capacity retention rate after 100 cycles was 90% or more, and it was confirmed that the secondary battery had a long cycle life.

[Comparative Example 1]
A coin-type battery was produced in the same manner as in Example 1 except that silver powder having an average particle size of 10 μm was used in place of the vapor growth carbon fiber of Example 1.

  When this battery was charged and discharged under the same conditions as in Example 1, no voltage flat portion was observed during discharge, the voltage dropped rapidly, and battery operation could not be confirmed.

  A secondary battery for energy regeneration according to the present invention includes a disubstituted polynorbornene structure represented by the formula (1), and in the disubstituted polynorbornene structure, two substituents including a TEMPO radical are a main chain five-membered ring skeleton. In contrast, it is arranged in endo-exo. Therefore, the secondary battery for energy regeneration which can be charged / discharged by a large current and has a high capacity can be provided.

It is sectional drawing which shows schematic structure of the secondary battery for energy regeneration which concerns on embodiment of this invention.

Explanation of symbols

2 Positive electrode layer (electrode)
4 Negative electrode layer 6 Separator 8 Positive electrode current collector 10 Negative electrode current collector 12 Positive electrode terminal 14 Negative electrode terminal 16 Exterior film

Claims (5)

It is a secondary battery for energy regeneration containing an organic radical polymer as an electrode active material,
The organic radical polymer has the following formula (1)

A secondary battery for energy regeneration, characterized in that it comprises a disubstituted polynorbornene structure in which two substituents containing a TEMPO radical are arranged in an endo-exo configuration with respect to the main chain five-membered ring skeleton.   The secondary battery for energy regeneration according to claim 1, wherein the number average molecular weight of the organic radical polymer is 100,000 or more.   The secondary battery for energy regeneration according to claim 1 or 2, further comprising a carbon material as an electrode active material.   The secondary battery for energy regeneration according to claim 3, wherein the carbon material is pyrolytic vapor grown carbon fiber. Further comprising an electrolyte,
The secondary battery for energy regeneration according to any one of claims 1 to 4, wherein the organic radical polymer is insoluble in the electrolyte during charging and discharging.

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