JP5549516B2 - Secondary battery and electrolyte and membrane used therefor - Google Patents

Description

  The present invention relates to a secondary battery, an electrolytic solution used therefor, and a membrane.

  In recent years, portable electronic devices such as notebook computers and mobile phones are rapidly spreading with the development of communication systems, and their performance is also improving year by year. In particular, portable devices tend to increase power consumption as performance improves. Therefore, demands for high energy density, high output, etc. are increasing for the battery as the power source. Furthermore, as global warming and environmental problems become more serious, electric vehicles or hybrid electric vehicles are being actively developed as clean vehicles to replace gasoline vehicles. Power storage devices used for such applications are required to achieve both high energy density and high output characteristics, and at the same time, are required to have durability exceeding 10 years, high safety, and the like.

  As a high energy density battery, a lithium ion battery has been developed and widely used since the 1990s. This lithium ion battery uses, for example, lithium-containing transition metal oxides such as lithium manganate, lithium cobaltate, and olivine iron as a positive electrode and carbon as a negative electrode as an electrode active material. Charging / discharging is performed using insertion and desorption reactions. Such a lithium ion battery has high energy density and excellent cycle characteristics, and is used in various electronic devices such as mobile phones. However, since the reaction rate of the electrode reaction is small, the battery performance is significantly lowered when a large current is taken out. For this reason, it is difficult to produce a large output, and there is a disadvantage that it takes a long time for charging.

  An electric double layer capacitor is known as an electricity storage device capable of generating a large output. Since a large current can be discharged at one time, it is possible to generate a large output, and it has excellent cycle characteristics, and is being developed as a backup power supply. However, since the energy density is very small and it is difficult to reduce the size, it is not suitable as a power source for portable electronic devices.

  In order to obtain an electrode material that is lightweight and has a large energy density, a battery using a sulfur compound or an organic compound as an electrode active material has been developed. For example, Patent Literature 1 and Patent Literature 2 describe batteries using an organic compound having a disulfide bond as a positive electrode. This battery utilizes an electrochemical redox reaction involving generation and dissociation of disulfide bonds as the battery principle. Since this battery is composed of an electrode material mainly composed of an element having a small specific gravity such as sulfur or carbon, it has a certain effect in terms of a high-capacity battery having a high energy density. However, due to the low efficiency of the dissociated bond recombining and the diffusion of the electrode active material into the electrolyte, the capacity tends to decrease when the charge / discharge cycles are repeated.

  In addition, as a battery using an organic compound, a battery using a conductive polymer as an electrode material has been proposed. This is a battery based on the principle of doping and dedoping of electrolyte ions with respect to a conductive polymer. The dope reaction is a reaction in which a charged radical generated by oxidation or reduction of a conductive polymer is stabilized by a counter ion. For example, Patent Document 3 describes a battery using such a conductive polymer as a positive electrode or negative electrode material. This battery was composed only of elements having a small specific gravity such as carbon and nitrogen, and was expected as a high capacity battery. However, conductive polymers have the property that charged radicals generated by redox are delocalized over a wide range of π-electron conjugated systems and interact with each other, resulting in electrostatic repulsion and radical disappearance. . This limits the generated charged radicals, that is, the doping concentration, and limits the capacity of the battery. For example, it has been reported that the doping rate of a battery using polyaniline as a positive electrode is 50% or less, and 7% in the case of polyacetylene. A battery using a conductive polymer as an electrode material has a certain effect in terms of weight reduction, but a battery having a large energy density has not been obtained.

  As a battery using an organic compound as a battery electrode active material, a battery using a redox reaction of a radical compound has been proposed. For example, Patent Document 4 describes an organic radical compound such as a nitroxide radical compound, an aryloxy radical compound, and a polymer compound having a specific aminotriazine structure as an active material, and the organic radical compound is used as a positive electrode or a negative electrode. A battery used as a material is described. Further, Patent Document 5 discloses a power storage device using a compound having a cyclic nitroxide structure as an electrode active material among nitroxide compounds. Further, a radical compound used as an electrode active material therefor is prepared by reacting 2,2,6,6-tetramethylpiperidine methacrylate with azobisisobutyronitrile as a polymerization initiator, followed by polymerization, and then m-chloroperbenzoic acid. It is synthesized by oxidizing with an acid.

US Pat. No. 4,833,048 Japanese Patent No. 2715778 U.S. Pat. No. 4,442,187 JP 2002-151084 A JP 2002-304996 A

Suguro et al., Macromolecular Rapid Communications 28, 1929-1933 (2007) Suguro et al., Macromolecular Chemistry and Physics 210, 1402-1407 (2009)

  As described above, in a secondary battery using an organic radical compound as an electrode active material, there is a problem in that the capacity decreases when it is repeatedly used.

  This invention is made | formed in view of the said situation, The place made into the objective is to provide the secondary battery excellent in the charge cycle characteristic, the electrolyte solution used for it, and a film | membrane.

［一般式（１）において、Ｒ^１〜Ｒ^４は、それぞれ独立に置換または無置換のアルキル基である。Ｘにおいて環員を構成する原子は、炭素原子、酸素原子、窒素原子、または硫黄原子である。ただし、Ｘは、ポリマーの主鎖または側鎖の一部を構成してもよく、Ｘは同一でも異なっていてもよい。ｎは、２または３の整数である。］ According to the present invention,
A positive electrode;
A negative electrode,
An electrolyte solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
A secondary battery is provided in which the electrolytic solution has a cyclic ether compound having a cyclic ether structure that is less than the content of the cyclic carbonate compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3. ]

［一般式（１）において、Ｒ^１〜Ｒ^４は、それぞれ独立に置換または無置換のアルキル基である。Ｘにおいて環員を構成する原子は、炭素原子、酸素原子、窒素原子、または硫黄原子である。ただし、Ｘは、ポリマーの主鎖または側鎖の一部を構成してもよく、Ｘは同一でも異なっていてもよい。ｎは、２または３の整数である。］ According to the present invention,
An electrolyte solution for use in a secondary battery comprising a positive electrode, a negative electrode, and an electrolyte solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The electrolytic solution is provided with an electrolytic solution having a cyclic ether compound having a cyclic ether structure that is less than the content of the cyclic carbonate compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3. ]

［一般式（１）において、Ｒ^１〜Ｒ^４は、それぞれ独立に置換または無置換のアルキル基である。Ｘにおいて環員を構成する原子は、炭素原子、酸素原子、窒素原子、または硫黄原子である。ただし、Ｘは、ポリマーの主鎖または側鎖の一部を構成してもよく、Ｘは同一でも異なっていてもよい。ｎは、２または３の整数である。］ According to the present invention,
A membrane for use in a secondary battery comprising a positive electrode, a negative electrode, and an electrolytic solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The electrolytic solution has a cyclic ether compound having a cyclic ether structure, which is less than the content of the cyclic carbonate compound,
The film is provided on the positive electrode or the negative electrode, and a film composed of a polymer of the cyclic ether compound is provided.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3. ]

  ADVANTAGE OF THE INVENTION According to this invention, the secondary battery excellent in the charge cycle characteristic, the electrolyte solution used for it, and a film | membrane are provided.

It is sectional drawing which shows the structure of the laminated exterior type battery in embodiment of this invention. It is a perspective view which shows the structure of the coin exterior type electrical storage device in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

First, the background that led to the present invention will be described.
The secondary battery using the redox reaction of the organic radical compound described in Patent Document 5 usually uses a mixture of a cyclic carbonate compound and a chain carbonate compound as an electrolyte solution solvent. As a result of investigations by the present inventors, capacity deterioration and cycle deterioration of a secondary battery using a nitroxide radical compound as an active material are cyclic carbonate compounds and NO cations (oxoammonium cations) represented by the following general formula (3). It was found that this was due to the reaction of

In General Formula (3), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3.

  The NO cation is a compound in a charged state of a secondary battery using an NO radical compound as an active material. The following formula (4) shows the reaction between the assumed cyclic carbonate compound and the NO cation. The present inventor believes that the NO cation generated by the charge of the organic radical compound reacts with the cyclic carbonate and opens the ring, so that the chargeable / dischargeable functional group (NO radical) is modified, resulting in a decrease in capacity. I found. Here, TEMPO cation is used as an example of the NO cation species, and ethylene carbonate is used as an example of the cyclic carbonate compound. However, the reaction between the NO cation and the cyclic carbonate compound is not limited to this.

  Therefore, the present inventor has considered that if the contact between the NO cation (oxoammonium cation) and the cyclic carbonate compound can be suppressed, the deterioration of the battery capacity can be suppressed.

  On the other hand, this inventor discovered that superposition | polymerization of a cyclic ether compound advances by using NO cation as a polymerization initiator. The following general formula (5) shows a reaction formula of a polymerization reaction using NO cations as polymerization initiators and cyclic ethers as monomers. The present inventor has found that a compound having a polyether structure can be synthesized by this reaction.

In General formula (5), R < ¹ > -R < ⁴ > is a substituted or unsubstituted alkyl group each independently. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3. Y is a halogen atom, a phosphorus compound, a boron compound, a fluorine compound, a perchloric acid compound, a nitrogen acid compound or an imide compound. In the general formula (5), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group, and these are substituents. You may have. m is an integer of 1-4. o represents the number of repeating units, and is an arbitrary constant that is not particularly limited. Although the number average molecular weight of the compound represented by the general formula (5) is not particularly limited, for example, 1,000 to 10,000,000.

  Accordingly, the present inventor has found that a polyether film is formed on the electrode by applying the reaction of the general formula (5) to a battery using an organic radical compound as an active material. That is, by adding a cyclic ether compound to the electrolyte in advance, the NO cation (oxoammonium cation) generated by charging becomes a polymerization initiator, and the cyclic ether compound existing inside the battery is polymerized, so that It was found that a polymer having a polyether structure was formed, and this became a film on the electrode. The formed coating protects the positive electrode and suppresses the direct contact between the cyclic carbonate and the NO cation and the decomposition of the NO cation, thereby reducing the capacity deterioration of the battery. According to the present invention, by adding a cyclic ether compound inside the battery, it is possible to provide a battery having high energy density and high output, little deterioration at high temperatures, and high long-term reliability.

  The secondary battery of the present invention includes at least a positive electrode, a negative electrode, and an electrolytic solution containing a cyclic carbonate compound, and the positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1), The electrode solution has a cyclic ether compound having a cyclic ether structure that is less than the content of the cyclic carbonate compound. That is, the electrolytic solution contains a solvent containing a cyclic carbonate compound, and has a cyclic ether compound separately from this solvent. For this reason, NO cation (oxoammonium cation) generated by charging is used as a polymerization initiator, and the reaction between the nitroxide cation compound and the cyclic carbonate compound is suppressed by the film obtained by the polymerization reaction of the added cyclic ether compound. Can do. That is, a cyclic ether compound is added to the electrolytic solution for the purpose of suppressing the reaction between the nitroxide cation compound and the cyclic carbonate compound, which is different from the purpose of dissolving the electrolyte of the solvent. For this reason, it is preferable that the content of the cyclic ether in the electrolytic solution is smaller than that of the solvent. Thereby, the battery to which the cyclic ether compound is added can be stably charged and discharged at a high temperature or in a long-term use, and becomes a battery having excellent cycle characteristics. Therefore, according to the present invention, it is possible to improve the reliability of a battery composed of a light and safe element that does not contain heavy metal as an electrode active material at a high temperature and for a long-term charge / discharge cycle characteristic.

  Moreover, the film | membrane obtained by such a polymerization reaction is provided on the electrode, for example, is formed so that the electrode whole surface may be covered. The film | membrane which concerns on this invention is a film | membrane used for a secondary battery provided with a positive electrode, a negative electrode, and the electrolyte solution which has a solvent, Comprising: This film | membrane is provided on the positive electrode or the negative electrode, and is cyclic | annular Consists of a polymerized ether compound. For this reason, reaction with a nitroxide cation compound and a cyclic carbonate compound can be suppressed. Therefore, in the secondary battery using such a film, the same effect as the effect of the present invention can be obtained.

  Moreover, in this invention, the cyclic ether compound should just be contained in the inside of a battery, and is not limited in electrolyte solution. However, from the viewpoint of energy density, it is preferable that the amount of cyclic ether compound added is small. For example, the electrolytic solution according to the present invention preferably has 30 wt% or less of a cyclic ether compound with respect to the entire electrolytic solution.

  The battery in the present invention will be described. FIG. 1 is a cross-sectional view of a laminated exterior battery 10 which is an example of a battery according to the present invention. The basic configuration of the battery in the present invention shown in FIG. 1 includes a positive electrode 1 having a nitroxide radical compound, a positive electrode current collector 1A connected to the positive electrode 1, and a positive electrode current collector 1A connected to extract energy from the cell. And a positive electrode lead 1B. Also, a negative electrode 2 containing a carbon material capable of reversibly inserting and removing lithium ions, a negative electrode current collector 2A connected to the negative electrode 2, and a negative electrode connected to the negative electrode current collector 2A to extract energy from the cell And leads 2B. Further, a lithium supply source 3 for pre-doping the negative electrode 2, a lithium supply source current collector 3 </ b> A connected to the lithium supply source 3, between the positive electrode 1 and the negative electrode 2, and between the lithium supply source 3 and the positive electrode current collector 1 </ b> A The separator 4 is interposed between the separator 4 that does not conduct electrons but conducts only ions, and the exterior body 5 that seals them.

  Further, FIG. 2 shows a configuration of a coin-type battery 20 which is an example of a battery according to the present invention. In this battery, the positive electrode 6 having a nitroxide radical compound, the negative electrode 7 and a separator 8 containing an electrolyte are stacked so as to face each other, and the positive electrode 6 is stacked on the positive electrode 6. A negative electrode current collector / exterior 7A is provided under the electric / external body 6A and the negative electrode 7. These are packaged by a stainless steel exterior on the negative electrode side and a stainless steel exterior on the positive electrode side, and an insulating packing 9 made of an insulating material such as plastic resin is disposed between them for the purpose of preventing electrical contact therebetween. In addition, when using solid electrolyte and gel electrolyte as electrolyte, it can replace with the separator 4 and can also be made into the form which interposes these electrolytes between electrodes.

  In the present invention, in such a configuration, the negative electrode 2, 7 or the positive electrode 1, 6 or the electrode active material used for both electrodes contains a radical compound having a partial structure represented by the general formula (1) described later. It is an electrode active material.

  From the viewpoint of battery capacity, the battery of the present invention is preferably a lithium battery using the above electrode active material as a positive electrode active material, particularly a lithium secondary battery.

[1] Electrode active material The electrode active material of the electrode in the present invention is a material that directly contributes to electrode reactions such as charge reaction and discharge reaction, and plays a central role in the battery system.

  In the present invention, an electrode active material containing a nitroxide radical compound represented by the general formula (1) is used as the electrode active material.

In the general formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3.

In the general formula (1), R ^{1 to} R ⁴ are not particularly limited, but an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group is more preferable from the viewpoint of easy availability. Examples of the substituent for the alkyl group include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a phosphorus atom, a boron atom, and a halogen atom.

In the general formula (1), X constitutes a part of the polymer side chain, or constitutes the main chain of the polymer, whereby the cyclic oxoammonium cation salt according to the present invention can be a polymer.
Here,-(X) n- shown in the general formula (1) represents a divalent group such that the general formula (1) forms a 5-membered ring or a 6-membered ring. In the-(X) n- group, the atom constituting the ring member is preferably carbon, oxygen, nitrogen, or sulfur. - (X) n-it is, for _{example, -CH 2 CH 2 -, -} CH 2 CH 2 CH 2 -, - CH = CH -, - CH = CHCH 2 -, - CH = CHCH 2 CH 2 - and the like include It is done. In this, non-adjacent —CH ₂ — may be replaced by —O—, —NH— or —S—, and —CH═ may be replaced by —N═. In addition, a hydrogen atom bonded to an atom constituting the ring may be substituted with an alkyl group, a halogen atom, ═O, or the like.

  In the battery of the present invention, the electrode active material may be fixed to the electrode, or may be dissolved or dispersed in the electrolyte. However, when used in a state of being fixed to the electrode, in order to suppress a decrease in capacity due to dissolution in the electrolytic solution, it is preferably insoluble or low-soluble in the electrolytic solution in the solid state. At this time, it may swell as long as it is insoluble or has low solubility in the electrolytic solution. This is because when the solubility in the electrolytic solution is high, the electrode active material is eluted from the electrode into the electrolytic solution, so that the capacity may decrease with the charge / discharge cycle.

  Therefore, the radical compound having a partial structure represented by the general formula (1) preferably has a number average molecular weight of 500 or more, more preferably a number average molecular weight of 2000 or more, and a number average molecular weight of 5000. More preferably, it is the above. This is because when the number average molecular weight is 500 or more, it is difficult to dissolve in the battery electrolyte, and when the number average molecular weight is 2000 or more, it is almost insoluble. The shape may be any of a chain, a branch, and a mesh. In addition, the obtained polymer is difficult to dissolve in dimethylformamide, tetrahydrofuran, etc., and the molecular weight may not be measured. A structure in which a clear molecular weight cannot be measured may be used, or a structure in which the molecular weight is crosslinked with a crosslinking agent may be used. The number average molecular weight is a value calculated by measuring the DMF soluble part of the sample by GPC using dimethylformamide (DMF) as an eluent.

  As said radical compound, the homopolymer which has only the partial structure represented by General formula (1) can be used, and the copolymer which has another partial structure can also be used. For the convenience of synthesis, a homopolymer is preferred. In the case of a copolymer, the partial structure represented by the general formula (1) is preferably 60 mol% or more, more preferably 70 mol% or more, more preferably 80 mol% with respect to the entire polymer compound. More preferably, it is more preferably 90 mol% or more. This is because the battery capacity increases as the proportion of the partial structure represented by the general formula (1) in the radical compound increases.

  Examples of the radical compound having a partial structure represented by the general formula (1) include radical compounds having a partial structure represented by the following formulas (6) to (13).

  The radical compound represented by the above formula (6) can be synthesized by the method described in Patent Document 5 (Japanese Patent Laid-Open No. 2002-304996). Further, the radical compound represented by (7) can be synthesized by the method described in Non-Patent Document 1 (Sukuro et al., Macromolecular Rapid Communications, Vol. 28, pages 1929-1933 (2007)). it can. Furthermore, the radical compound represented by (9) and (10) is described in Non-Patent Document 2 (Suguro et al., Macromolecular Chemistry and Physics 210, 1402-1407 (2009)). It can be synthesized by the method. In the above formula, r represents the number of repeating units, and is an arbitrary constant that is not particularly limited.

  In the electrolytic solution of the present invention, a cyclic ether compound is used as an additive, and a cyclic ether compound represented by the following general formula (2) is particularly preferable. Examples of the cyclic ether compound according to the present invention include those having various structures. For example, an ethylene oxide derivative (3-membered ring), an oxetane derivative (4-membered ring), a tetrahydrofuran derivative (5-membered ring), a tetrahydropyran derivative (6 Commercially available products that are widely sold such as (membered rings) can be used. In particular, ethylene oxide derivatives can be easily synthesized by reacting chloromethyloxirane and oxetane derivatives with chloromethyloxetane as a raw material and corresponding sodium alkoxide.

一般式（２）において、Ｒ^５〜Ｒ^８は、それぞれ独立に水素原子、ハロゲン原子、シアノ基、カルボニル基、ニトロ基、アミノ基、スルホ基、アリール基、アルキル基であり、これらは置換基を有してもよい。ｍは、１〜４の整数である。

In the general formula (2), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group, and these are substituents. You may have. m is an integer of 1-4.

  In the general formula (2), the alkyl group preferably has 1 to 10 carbon atoms, and preferably has a substituted or unsubstituted aryl group, ether, ester or the like. The halogen atom preferably has a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or the like.

  In the general formula (2), the substituent is not particularly limited, and examples thereof include a halogen atom, an alkyl group, a carbonyl group, an amino group, an imino group, a cyano group, an azo group, an azide group, a thiol group, a sulfo group, and a nitro group. Group, hydroxy group, acyl group, aldehyde group, cycloalkyl group, aryl group and the like.

  Examples of the cyclic ether compound represented by the general formula (2) include compounds represented by the following formulas (14) to (51). Of course, the compound of this application is not limited to these examples, and it cannot be overemphasized that various aspects can be considered.

  Moreover, in the electrode active material of one electrode of the battery of the present invention, the radical compound having the partial structure represented by the general formula (1) can be used alone, but two or more kinds may be used in combination. good. Moreover, you may use in combination with another electrode active material. At this time, it is preferable that the radical compound which has the partial structure represented by General formula (1) is contained in the electrode active material 10 to 90 mass%, and it is more preferable that 50 to 90 mass% is contained. preferable.

When a radical compound having a partial structure represented by the general formula (1) is used for the positive electrode, a metal oxide, a disulfide compound, another stable radical compound, a conductive polymer, or the like is combined as another electrode active material. Can do. Here, as the metal oxide, for example, lithium manganate such as LiMnO ₂ , Li _x Mn ₂ O ₄ (0 <x <2) or lithium manganate having a spinel structure, MnO ₂ , LiCoO ₂ , LiNiO ₂ , Or olivine materials such as Li _y V ₂ O ₅ (0 <y <2), LiFePO ₄ , LiCoPO ₄ , LiMnPO ₄ , LiNi _0.5 Mn _1.5 O ₄ , LiCr _0.5 Mn _1.5 O ₄ LiCo _0.5 Mn _1.5 O ₄ , LiCoMnO ₄ , LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.33 Mn _0,33 Co _0.33 O ₂ , LiNi _0.8 Co _0.2 O ₂ , part of Mn in spinel structure such as LiN _0.5 Mn _1.5-z Ti _z O ₄ (0 <z <1.5), Li ₂ MnO ₃ and other transition gold And materials substituted with a genus. Examples of the disulfide compound include dithioglycol, 2,5-dimercapto-1,3,4-thiadiazole, S-triazine-2,4,6-trithiol and the like. Other stable radical compounds include poly (4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl), poly (4-acryloyloxy-2,2,6,6-tetramethylpiperidine -N-oxyl), poly (4-vinyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl) and the like. Examples of the conductive polymer include polyacetylene, polyphenylene, polyaniline, and polypyrrole. Among these, it is particularly preferable to combine with lithium manganate or LiCoO ₂ . In the present invention, these other electrode active materials can be used alone or in combination of two or more.

  When the radical compound having the partial structure represented by the general formula (1) is used for the negative electrode, as other electrode active materials, graphite, amorphous carbon, metallic lithium, lithium alloy, lithium ion occlusion carbon, metallic sodium, conductive Can be used. Moreover, you may use another stable radical compound. Other stable radical compounds include poly (4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl), poly (4-acryloyloxy-2,2,6,6-tetramethylpiperidine -N-oxyl), poly (4-vinyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl), and the like. These shapes are not particularly limited. For example, metallic lithium is not limited to a thin film shape, and may be a bulk shape, a powdered shape, a fiber shape, a flake shape, or the like. Among these, it is preferable to combine with metallic lithium or graphite. These other electrode active materials can be used alone or in combination of two or more.

  The battery of the present invention uses a radical compound having a partial structure represented by the general formula (1) as an electrode active material in one electrode reaction of the positive electrode or the negative electrode, or in both electrode reactions. When using as an electrode active material, conventionally well-known electrode active materials as exemplified above can be used as the electrode active material in the other electrode. These electrode active materials can be used alone or in combination of two or more kinds, and a combination of at least one of these electrode active materials and a radical compound having a partial structure represented by the general formula (1). It may be used. Moreover, the radical compound which has the partial structure represented by General formula (1) can also be used independently.

In the present invention, the radical compound having the partial structure represented by the general formula (1) may directly contribute to the electrode reaction at the positive electrode or the negative electrode, and the electrode used as the electrode active material is either a positive electrode or a negative electrode. It is not limited to crab. However, from the viewpoint of energy density, it is particularly preferable to use a radical compound having a partial structure represented by the general formula (1) as the electrode active material of the positive electrode. At this time, as the positive electrode active material, a radical compound having a partial structure represented by the general formula (1) is preferably used alone. However, it can also be used in combination with other positive electrode active materials, and as the other positive electrode active materials at that time, lithium manganate, LiCoO ₂ , LiFePO ₄ are preferable. Furthermore, when using said positive electrode active material, it is preferable to use metallic lithium or graphite as a negative electrode active material.

[2] Conductivity-imparting agent (auxiliary conductive material) and ion conduction auxiliary material When forming an electrode using the radical compound represented by the general formula (1), the impedance is lowered, and the energy density and output characteristics are improved. For the purpose, a conductivity-imparting agent (auxiliary conductive material) or an ion conduction auxiliary material may be mixed. Among these materials, auxiliary conductive materials include carbonaceous fine particles such as graphite, carbon black, and acetylene black, carbon fibers such as vapor grown carbon fiber (VGCF) and carbon nanotube, polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacetylene. Conductive polymers such as carbon nanotubes and carbon nanohorns, and examples of the ion conduction auxiliary material include polymer gel electrolytes and polymer solid electrolytes. Among these, it is preferable to mix carbon fibers. By mixing carbon fiber, the tensile strength of the electrode is increased, and the electrode is less likely to crack or peel off. More preferably, it is more preferable to mix vapor growth carbon fiber. These materials can be used alone or in admixture of two or more. As a ratio of these materials in an electrode, 10-80 mass% is preferable.

[3] Binder A binder can also be used to strengthen the connection between the constituent materials of the electrode. Examples of such binders include polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene / butadiene copolymer rubber, polypropylene, and polyethylene. , Resin binders such as polyamide, polyimide, polyamideimide, varnish, and various polyurethanes. These resin binders can be used alone or in admixture of two or more. As a ratio of the binder in an electrode, 1-30 mass% is preferable, and 1-15 mass% is more preferable.

[4] Catalyst In order to perform the electrode reaction more smoothly, a catalyst that assists the redox reaction can be used. Examples of such catalysts include conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacene, basic compounds such as pyridine derivatives, pyrrolidone derivatives, benzimidazole derivatives, benzothiazole derivatives, and acridine derivatives, and metal ion complexes. Can be mentioned. These catalysts can be used alone or in admixture of two or more. The ratio of the catalyst in the electrode is preferably 10% by mass or less.

[5] Current collector and separator As the negative electrode current collector and the positive electrode current collector, foils made of nickel, aluminum, copper, gold, silver, aluminum alloy, stainless steel, carbon, etc., metal flat plates, mesh shapes, etc. Things can be used. Further, the current collector may have a catalytic effect, or the electrode active material and the current collector may be chemically bonded.
On the other hand, a separator such as a porous film or non-woven fabric made of polyethylene, polypropylene, or the like can be used so that the positive electrode and the negative electrode are not in contact with each other.

[6] Electrolyte In the present invention, the electrolyte performs charge carrier transport between the negative electrode and the positive electrode, and generally has an ionic conductivity of 10 ⁻⁵ to 10 ⁻¹ S / cm at 20 ° C. Preferably it is. As the electrolyte, for example, an electrolytic solution in which an electrolyte salt is dissolved in a solvent can be used. Examples of the electrolyte salt include LiPF ₆ , LiClO ₄ , LiBF ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C Conventionally known materials such as Li (C ₂ F ₅ SO ₂ ) ₃ C can be used. These electrolyte salts can be used alone or in admixture of two or more.

  When a solvent is used for the electrolytic solution, examples of the solvent include acetonitrile, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, dioxolane, sulfolane, dimethylformamide, dimethylacetamide, N-methyl- An organic solvent such as 2-pyrrolidone can be used. These solvents can be used alone or in admixture of two or more.

  Furthermore, an ionic liquid can also be used as the electrolyte of the present invention. These ionic liquids include 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium bis (trifluoromethanesulfonyl) imide, 1-butyl-2,3-dimethyl. Imidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium tetrafluoroborate 1-ethyl-2,3-dimethylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium hexafluoro Imidazolium salts such as phosphate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-methyl-3-n-octylimidazolium hexafluorophosphate, 1-butyl-1-methylpyrrolidinium bis (trifluoro) Pyrrolidinium salts such as 1-methyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-butyl-4-methylpyridinium hexafluorophosphate, 1-butylpyridinium hexafluorophosphate, -Pyridinium salts such as ethyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, triethylpentylammonium bis (trifluoromethanesulfonyl) imide, cyclohexyltrimethylan Niumubisu (trifluoromethanesulfonyl) imide, can be used organic solvents such as ammonium salts, such as methyltri -n- octyl ammonium bis (trifluoromethanesulfonyl) imide, tributyl ammonium bis (trifluoromethanesulfonyl) imide. These solvents can be used alone or in admixture of two or more.

  Furthermore, in the present invention, a solid electrolyte can be used as the electrolyte. Polymer compounds used in these solid electrolytes include 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 Le acid copolymers, acrylonitrile - vinyl acetate copolymer, acrylonitrile-based polymer, further polyethylene oxide, ethylene oxide - propylene oxide copolymers, and polymers of these acrylates body or methacrylate body thereof. These polymer compounds may be used in the form of a gel containing an electrolytic solution, or only a polymer compound containing an electrolyte salt may be used as it is.

  Thus, the electrolytic solution according to the present invention includes a positive electrode, a negative electrode, and an electrolytic solution having a solvent, and the positive electrode or the negative electrode has a nitroxide radical represented by the general formula (1). In addition, the electrolytic solution can be used for a secondary battery having a cyclic ether compound having a cyclic ether structure separately from the solvent. Accordingly, it is possible to provide an electrode active material having a high capacity density and capable of taking out a large current, and a battery having a high energy density and a high output, and having a high temperature and a long-term reliability.

[7] Battery shape In the present invention, the shape of the battery is not particularly limited, and a conventionally known battery can be used. Examples of the battery shape include an electrode laminate or a wound body sealed with a metal case, a resin case, or a laminate film made of a metal foil such as an aluminum foil and a synthetic resin film, etc. A mold, a coin mold, and a sheet mold are used, but the present invention is not limited to these.

[8] Battery Manufacturing Method The battery manufacturing method is not particularly limited, and a method appropriately selected according to the material can be used. For example, a solvent is added to an electrode active material, a conductivity-imparting agent, etc. to form a slurry, which is applied to an electrode current collector, and the electrode is produced by heating or volatilizing the solvent at room temperature, and this electrode is sandwiched between a counter electrode and a separator. And then wrapped or wrapped in an outer package, and an electrolyte solution is injected and sealed. Solvents for slurrying include ether solvents such as tetrahydrofuran, diethyl ether and ethylene glycol dimethyl ether, amine solvents such as N, N-dimethylformamide and N-methylpyrrolidone, and aromatic carbonization such as benzene, toluene and xylene. Hydrogen solvents, aliphatic hydrocarbon solvents such as hexane and heptane, halogenated hydrocarbon solvents such as chloroform, dichloromethane, dichloroethane, trichloroethane and carbon tetrachloride, alkyl ketone solvents such as acetone and methyl ethyl ketone, methanol, ethanol, Examples include alcohol solvents such as isopropyl alcohol, dimethyl sulfoxide, and the like. In addition, as a method for manufacturing an electrode, there is a method in which an electrode active material, a conductivity-imparting agent, and the like are kneaded in a dry method and then thinned and laminated on an electrode current collector. In the production of electrodes, in particular, in the case of a method in which a solvent is added to an organic electrode active material, a conductivity imparting agent, etc. and applied to an electrode current collector, and the solvent is volatilized by heating or at room temperature, peeling of the electrode, cracking, etc. Is likely to occur. When a radical compound having a partial structure represented by the general formula (1) of the present invention is used, and an electrode having a thickness of preferably 80 μm or more and 500 μm or less is produced, the electrode is less likely to be peeled off or cracked, and the like. This makes it possible to produce a simple electrode.

When manufacturing a battery, a case where a battery is manufactured using the radical compound itself represented by the general formula (1) as an electrode active material, and a radical compound represented by the general formula (1) by an electrode reaction. In some cases, a battery is produced using a polymer that changes into a slab. Examples of the polymer that changes to the radical compound represented by the general formula (1) by such an electrode reaction include a lithium salt composed of an anion body obtained by reducing the radical compound and an electrolyte cation such as lithium ion or sodium ion. sodium salt or the general formula cation body obtained by oxidizing the compound represented by (3) and PF ₆ ^- or BF ₄ ^-, salts consisting of such electrolyte anions.

  The power storage device (secondary battery) according to the present invention can simultaneously achieve high energy density and high output characteristics, low environmental load, and high safety. It can be used as a power source for various portable electronic devices that require output, a power storage device for various types of energy such as solar energy and wind power generation, or a storage power source for household appliances.

  In the present invention, a conventionally known method can be used as a method for manufacturing a battery for other manufacturing conditions such as taking out leads from electrodes and packaging.

  Hereinafter, although the detail of this invention is concretely demonstrated by a synthesis example and an Example, this invention is not limited to these Examples. In addition, all the cell preparation processes in a present Example were performed in the dry room whose dew point is -60 degrees C or less.

Example 1
<Preparation of positive electrode>
200 mg of radical compound (6), 700 mg of graphite powder, and 100 mg of polytetrafluoroethylene (PTFE) resin binder were weighed and kneaded using an agate mortar. The mixture obtained by dry-mixing for about 10 minutes was subjected to roller stretching under pressure to obtain a thin film having a thickness of about 150 μm. This was dried overnight at 80 ° C. in a vacuum, and then punched into a circle with a diameter of 12 mm to form a coin battery electrode. The mass of this electrode was 15.0 mg.

<Cell fabrication>
Next, the obtained electrode was immersed in an electrolytic solution, and the electrolytic solution was infiltrated into voids in the electrode. As the electrolytic solution, an ethylene carbonate / diethyl carbonate mixed solution (mixing volume ratio 3: 7) containing both 1.0 mol / L LiPF ₆ electrolyte salt and 4 wt% of the cyclic ether compound (18) was used. The electrode impregnated with the electrolytic solution was placed on the positive electrode current collector, and a polypropylene porous film separator impregnated with the electrolytic solution was laminated thereon. Further, a lithium disk serving as a negative electrode was laminated, and further, the respective stainless steel sheaths were stacked from the positive electrode side and the negative electrode side with an insulating packing disposed around. By applying pressure with a caulking machine, a sealed coin-type battery using a radical compound (6) as a positive electrode active material and metallic lithium as a negative electrode active material was obtained.

<Evaluation of charge / discharge>
Conditioning charge / discharge is performed on the coin battery manufactured as described above, and further, charging is performed at a constant current of 0.1 mA until the voltage reaches 4.0 V, and then discharging is performed at a constant current of 0.1 mA to 3.0 V. It was. As a result, a voltage flat portion was observed in the vicinity of 3.5 V, and the discharge capacity per electrode active material was 110 mAh / g. Furthermore, charging / discharging was repeated 50 times in the voltage range 4.0-3.0V in the temperature of 50 degreeC. As a result, in all 50 charge / discharge cycles, the voltage was constant at around 3.5 V during discharge, and (50th discharge capacity) / (1st discharge capacity) was 95%.

(Example 2)
<Preparation of positive electrode>
In a small homogenizer container, 20 g of N-methylpyrrolidone was weighed, 300 mg of polyvinylidene fluoride (PVdF) was added, and stirred for 30 minutes to completely dissolve. Thereto, 200 mg of the radical compound (6) was added and stirred for 5 minutes until the whole became a uniform orange color. To this was added 500 mg of vapor grown carbon fiber (VGCF), and the mixture was further stirred for 15 minutes to obtain a slurry. The obtained slurry was applied on an aluminum foil and dried at 120 ° C. to produce a positive electrode. The thickness of the positive electrode layer was 120 μm. The produced electrode was not peeled off or cracked, and the surface was uniform. This was punched out into a circle with a diameter of 12 mm to mold a coin battery electrode. In addition, the mass of this electrode was 16.2 mg (of which aluminum foil was 6.0 mg).

<Production of negative electrode>
13.5 g of graphite powder (particle size 6 microns), 1.35 g of polyvinylidene fluoride, 0.15 g of carbon black, and 30 g of N-methyl-2-pyrrolidone solvent were mixed well to prepare a negative electrode slurry. A negative electrode slurry was applied to one side of an expanded metal copper foil having a thickness of 32 μm coated with a carbon-based conductive paint, and vacuum-dried to prepare a negative electrode. The total thickness of the negative electrode including the current collector was 90 microns.

<Cell fabrication>
Next, the obtained electrode was immersed in an electrolytic solution, and the electrolytic solution was infiltrated into voids in the electrode. As the electrolytic solution, an ethylene carbonate / diethyl carbonate mixed solution (mixing volume ratio 3: 7) containing both 1.0 mol / L LiPF ₆ electrolyte salt and 4 wt% of the cyclic ether compound (18) was used. The electrode impregnated with the electrolytic solution was placed on a positive electrode current collector (aluminum foil), and a polypropylene porous film separator impregnated with the electrolytic solution was laminated thereon. Furthermore, the copper foil which attached | coated the graphite layer used as a negative electrode on one side was laminated | stacked. Further, the respective stainless steel sheaths were overlapped from the positive electrode side and the negative electrode side with the insulating packing disposed around the periphery. By applying pressure with a caulking machine, a sealed coin type battery using radical compound (2) as a positive electrode active material and graphite as a negative electrode active material was obtained.

<Evaluation of charge / discharge>
Conditioning charge / discharge is performed on the coin battery manufactured as described above, and further, charging is performed at a constant current of 0.1 mA until the voltage reaches 4.0 V, and then discharging is performed at a constant current of 0.1 mA to 3.0 V. It was. As a result, a voltage flat portion was observed in the vicinity of 3.5 V, and the discharge capacity per electrode active material was 101 mAh / g. Furthermore, charging / discharging was repeated 50 times in the voltage range 4.0-3.0V in the temperature of 50 degreeC. As a result, in all 50 charge / discharge cycles, the voltage was constant at around 3.5 V during discharge, and (50th discharge capacity) / (1st discharge capacity) was 95%.
Next, the coin 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 5.0 mA. As a result, the voltage became constant around 3.4 V and then dropped rapidly. (Discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 92%.

(Example 3)
<Preparation of positive electrode>
Pure water (42 mL) and carboxymethylcellulose (CMC) 400 mg (4 wt%) were added to the homogenizer cup and completely dissolved by the homogenizer, and then 100 mg (1 wt%) of an aqueous dispersion of PTFE was added and stirred. Further, 2.5 g (15 wt%) of VGCF was added little by little and stirred until uniform. Radical compound (6), 7 g (70 wt%) was added to the resulting black slurry, and stirred until it became more uniform to prepare a slurry. Furthermore, after apply | coating the obtained slurry on aluminum foil (20 micrometers), the positive electrode was produced by making it dry at 50 degreeC. The produced electrode was not peeled off or cracked, and the surface was uniform. This was punched out into a circle with a diameter of 12 mm to mold a coin battery electrode. The mass of this electrode was 17.2 mg (including 6.0 mg for aluminum foil).

<Cell fabrication>
Next, the obtained electrode was immersed in an electrolytic solution, and the electrolytic solution was infiltrated into voids in the electrode. As the electrolytic solution, an ethylene carbonate / diethyl carbonate mixed solution (mixing volume ratio 3: 7) containing both 1.0 mol / L LiPF ₆ electrolyte salt and 4 wt% of the cyclic ether compound (18) was used. The electrode impregnated with the electrolytic solution was placed on the positive electrode current collector, and a polypropylene porous film separator impregnated with the electrolytic solution was laminated thereon. Further, a lithium disk serving as a negative electrode was laminated. The respective stainless steel sheaths were overlapped from the positive electrode side and the negative electrode side in a state where the insulating packing was arranged around the periphery. By applying pressure with a caulking machine, a sealed coin-type battery using a radical compound (6) as a positive electrode active material and metallic lithium as a negative electrode active material was obtained.

<Evaluation of charge / discharge>
Conditioning charge / discharge is performed on the coin battery manufactured as described above, and further, charging is performed at a constant current of 0.1 mA until the voltage reaches 4.0 V, and then discharging is performed at a constant current of 0.1 mA to 3.0 V. It was. As a result, a voltage flat portion was observed around 3.5 V, and the discharge capacity per electrode active material was 103 mAh / g. Furthermore, charging / discharging was repeated 50 times in the voltage range 4.0-3.0V in the temperature of 50 degreeC. As a result, in all 50 charge / discharge cycles, the voltage was constant at around 3.5 V during discharge, and (50th discharge capacity) / (1st discharge capacity) was 96%.

(Example 4)
<Cell fabrication>
A positive electrode was produced using the same method as in Example 3 except that the radical compound (7) was used instead of the radical compound (6), and a coin battery was produced using it. The produced electrode was not peeled off or cracked, and the surface was uniform. The weight of the positive electrode of this coin battery was 16.8 mg (of which aluminum foil was 6.0 mg).

<Evaluation of charge / discharge>
Conditioning charge / discharge is performed on the coin battery manufactured as described above, and further, charging is performed at a constant current of 0.1 mA until the voltage reaches 4.0 V, and then discharging is performed at a constant current of 0.1 mA to 3.0 V. It was. As a result, a voltage flat portion was observed around 3.5 V, and the discharge capacity per electrode active material was 120 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (1st discharge capacity) was 96%.
Next, the coin 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 5.0 mA. (Discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 94%.

(Example 5)
<Cell fabrication>
A positive electrode was produced in the same manner as in Example 3 except that the radical compound (9) was used instead of the radical compound (6), and a coin battery was produced using the positive electrode. The produced electrode was not peeled off or cracked, and the surface was uniform. The coin battery had a positive electrode weight of 17.3 mg (of which aluminum foil was 6.0 mg).

<Evaluation of charge / discharge>
Conditioning charging / discharging is performed on the coin battery manufactured as described above, and the coin battery is further charged at a constant current of 0.1 mA until the voltage reaches 4.0 V, and thereafter, the coin battery is charged with a constant current of 0.1 mA. Discharge was performed to 0V. As a result, a voltage flat portion was observed around 3.5 V, and the discharge capacity per electrode active material was 109 mAh / g. Furthermore, as a result of repeating charge and discharge 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (first discharge capacity) was 95%.

(Example 6)
<Cell fabrication>
The positive electrode containing the radical compound (6) prepared in Example 3 and the graphite negative electrode prepared in Example 2 were sequentially stacked via a separator to prepare an electrode laminate. A lithium metal-laminated copper foil serving as a lithium supply source was inserted into the uppermost part of the laminate. The positive electrode current collector aluminum foil and the positive electrode lead were ultrasonically welded, and the negative electrode current collector copper foil, the lithium supply source current collector copper foil, and the negative electrode lead were similarly welded. These were covered with an aluminum laminate film having a thickness of 115 microns, and the three sides including the lead portions were heat-sealed first. Next, a mixed electrolyte solution of EC / DEC = 3/7 containing 1 mol / L LiPF ₆ , 4 wt% of the cyclic ether compound (18) was inserted into the cell, and the electrode was well impregnated. Finally, the last four sides were thermally fused under reduced pressure to produce an electricity storage device.

<Evaluation of charge / discharge>
The aluminum laminate cell produced as described above was subjected to conditioning charge / discharge, and charged to 4 V with a current of 1 mA. Thereafter, discharge was similarly performed at a current of 1 mA, and the capacity up to 3.0 V was measured. As a result, a flat voltage portion was observed around 3.5 V, and the discharge capacity per electrode active material was 102 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (1st discharge capacity) was 94%.

(Example 7)
<Cell fabrication>
An aluminum laminate was prepared in the same manner as in Example 6 except that the positive electrode containing the radical compound (7) prepared in Example 4 was used instead of the positive electrode containing the radical compound (6) prepared in Example 3. A battery was produced.

<Evaluation of charge / discharge>
The aluminum laminate cell produced as described above was subjected to conditioning charge / discharge, and charged to 4.0 V with a current of 1 mA. Thereafter, discharge was similarly performed at a current of 1 mA, and the capacity up to 3.0 V was measured. As a result, a flat voltage portion was observed around 3.5 V, and the discharge capacity per electrode active material was 121 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (1st discharge capacity) was 96%.

(Example 8)
<Cell fabrication>
An aluminum laminate was prepared in the same manner as in Example 6 except that the positive electrode containing the radical compound (9) prepared in Example 5 was used instead of the positive electrode containing the radical compound (6) prepared in Example 3. A cell was produced.

<Evaluation of charge / discharge>
The aluminum laminate cell produced as described above was subjected to conditioning charge / discharge, and charged to 4.0 V with a current of 1 mA. Thereafter, discharge was similarly performed at a current of 1 mA, and the capacity up to 3.0 V was measured. As a result, a flat voltage portion was observed around 3.5 V, and the discharge capacity per electrode active material was 105 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (1st discharge capacity) was 96%.

(Examples 9 to 112)
Hereinafter, experimental operations in Examples 9 to 112 will be described.
<Cell fabrication>
Instead of the cyclic ether compound (18), the cyclic ether compound was added to the electrolytic solution, and an aluminum laminate cell was produced in the same manner as in Example 6.
<Evaluation of charge / discharge>
The aluminum laminate cell produced as described above was subjected to conditioning charge / discharge, and charged to 4.0 V with a current of 1 mA. Thereafter, discharge was similarly performed at a current of 1 mA, and the capacity up to 3.0 V was measured. Furthermore, charging / discharging was repeated 50 times in the voltage range 4.0-3.0V in the temperature of 50 degreeC. The results are summarized in Tables 1 to 3.

(Comparative Example 1)
A coin battery was produced in the same manner as in Example 1, but without adding the cyclic ether compound (18).
The produced battery was charged / discharged in the same manner as in Example 1, and the discharge capacity per electrode active material was calculated to be 109 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (1st discharge capacity) was 20%.

(Comparative Example 2)
A coin battery was produced in the same manner as in Example 2, except that the cyclic ether compound (18) was not added.
The produced battery was charged and discharged in the same manner as in Example 1, and the discharge capacity per electrode active material was calculated to be 102 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (1st discharge capacity) was 16%.

(Comparative Example 3)
A coin battery was produced in the same manner as in Example 3 except that the cyclic ether compound (18) was not added.
The produced battery was charged and discharged in the same manner as in Example 1, and the discharge capacity per electrode active material was calculated to be 102 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (first discharge capacity) was 15%.

(Comparative Example 4)
An aluminum laminate battery was produced in the same manner as in Example 6 except that the cyclic ether compound (18) was not added.
The produced battery was charged and discharged in the same manner as in Example 1, and the discharge capacity per electrode active material was calculated to be 108 mAh / g. Furthermore, as a result of repeating charge and discharge 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (first discharge capacity) was 11%.

(Comparative Example 5)
An aluminum laminate battery was produced in the same manner as in Example 7 except that the cyclic ether compound (18) was not added.
The produced battery was charged and discharged in the same manner as in Example 1, and the discharge capacity per electrode active material was calculated to be 122 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (first discharge capacity) was 10%.

(Comparative Example 6)
An aluminum laminate battery was produced in the same manner as in Example 8, except that the cyclic ether compound (18) was not added.
The produced battery was charged and discharged in the same manner as in Example 1, and the discharge capacity per electrode active material was calculated to be 108 mAh / g. Furthermore, as a result of repeating charging and discharging 50 times in a voltage range of 4.0 to 3.0 V at a temperature of 50 ° C., (50th discharge capacity) / (1st discharge capacity) was 12%.

  Table 4 summarizes comparative examples.

  By comparing and examining these examples and comparative examples, it was shown that the capacity retention rate at high temperature of the secondary battery using a nitroxide radical as the active material is improved by the addition of the cyclic ether compound.

［一般式（１）において、Ｒ ^１ 〜Ｒ ^４ は、それぞれ独立に置換または無置換のアルキル基である。Ｘにおいて環員を構成する原子は、炭素原子、酸素原子、窒素原子、または硫黄原子である。ただし、Ｘは、ポリマーの主鎖または側鎖の一部を構成してもよく、Ｘは同一でも異なっていてもよい。ｎは、２または３の整数である。］
（付記２）
前記電解液は、前記電解液の全体に対して３０ｗｔ％以下の前記環状エーテル化合物を有する、付記１に記載の二次電池。
（付記３）
前記環状エーテル化合物が下記一般式（２）で表される、付記１または２に記載の二次電池。

［一般式（２）において、Ｒ ^５ 〜Ｒ ^８ は、それぞれ独立に水素原子、ハロゲン原子、シアノ基、カルボニル基、ニトロ基、アミノ基、スルホ基、アリール基、アルキル基であり、これらは置換基を有してもよい。ｍは、１〜４の整数である。］
（付記４）
正極と、負極と、環状カーボネート化合物を含む電解液と、を備える、二次電池に用いる電解液であって、
前記正極または前記負極は、下記一般式（１）で示されるニトロキシドラジカル化合物を有しており、
前記電解液は、前記環状カーボネート化合物の含有量よりも少ない、環状エーテル構造を有する環状エーテル化合物を有する、電解液。

［一般式（１）において、Ｒ ^１ 〜Ｒ ^４ は、それぞれ独立に置換または無置換のアルキル基である。Ｘにおいて環員を構成する原子は、炭素原子、酸素原子、窒素原子、または硫黄原子である。ただし、Ｘは、ポリマーの主鎖または側鎖の一部を構成してもよく、Ｘは同一でも異なっていてもよい。ｎは、２または３の整数である。］
（付記５）
前記電解液の全体に対して３０ｗｔ％以下の前記環状エーテル化合物を有する、付記４に記載の電解液。
（付記６）
前記環状エーテル化合物が下記一般式（２）で表される、付記４または５に記載の電解液。

［一般式（２）において、Ｒ ^５ 〜Ｒ ^８ は、それぞれ独立に水素原子、ハロゲン原子、シアノ基、カルボニル基、ニトロ基、アミノ基、スルホ基、アリール基、アルキル基であり、これらは置換基を有してもよい。ｍは、１〜４の整数である。］
（付記７）
正極と、負極と、環状カーボネート化合物を含む電解液と、を備える、二次電池に用いる膜であって、
前記正極または前記負極は、下記一般式（１）で示されるニトロキシドラジカル化合物を有しており、
前記電解液は、前記環状カーボネート化合物の含有量よりも少ない、環状エーテル構造を有する環状エーテル化合物を有しており、
前記膜は、前記正極上または前記負極上に設けられており、かつ前記環状エーテル化合物の重合物で構成される、膜。

［一般式（１）において、Ｒ ^１ 〜Ｒ ^４ は、それぞれ独立に置換または無置換のアルキル基である。Ｘにおいて環員を構成する原子は、炭素原子、酸素原子、窒素原子、または硫黄原子である。ただし、Ｘは、ポリマーの主鎖または側鎖の一部を構成してもよく、Ｘは同一でも異なっていてもよい。ｎは、２または３の整数である。］
（付記８）
前記電解液は、前記電解液の全体に対して３０ｗｔ％以下の前記環状エーテル化合物を有する、付記７に記載の膜。
（付記９）
前記環状エーテル化合物が下記一般式（２）で表される、付記７または８に記載の膜。

［一般式（２）において、Ｒ ^５ 〜Ｒ ^８ は、それぞれ独立に水素原子、ハロゲン原子、シアノ基、カルボニル基、ニトロ基、アミノ基、スルホ基、アリール基、アルキル基であり、これらは置換基を有してもよい。ｍは、１〜４の整数である。］ Needless to say, the above-described embodiment and a plurality of modifications can be combined within a range in which the contents do not conflict with each other. Further, in the above-described embodiments and modifications, the structure of each part has been specifically described, but the structure and the like can be changed in various ways within a range that satisfies the present invention.
An example of a reference form of the present invention will be added.
<Appendix>
(Appendix 1)
A positive electrode;
A negative electrode,
An electrolyte solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The said electrolyte solution is a secondary battery which has a cyclic ether compound which has less cyclic carbonate structure than content of the said cyclic carbonate compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3. ]
(Appendix 2)
The secondary battery according to appendix 1, wherein the electrolytic solution has 30% by weight or less of the cyclic ether compound with respect to the entire electrolytic solution.
(Appendix 3)
The secondary battery according to appendix 1 or 2, wherein the cyclic ether compound is represented by the following general formula (2).

[In General Formula (2), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group. It may have a group. m is an integer of 1-4. ]
(Appendix 4)
An electrolyte solution for use in a secondary battery comprising a positive electrode, a negative electrode, and an electrolyte solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The electrolyte solution has a cyclic ether compound having a cyclic ether structure that is less than the content of the cyclic carbonate compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3. ]
(Appendix 5)
The electrolyte solution according to appendix 4, which has 30% by weight or less of the cyclic ether compound with respect to the whole electrolyte solution.
(Appendix 6)
The electrolyte solution according to appendix 4 or 5, wherein the cyclic ether compound is represented by the following general formula (2).

[In General Formula (2), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group. It may have a group. m is an integer of 1-4. ]
(Appendix 7)
A membrane for use in a secondary battery comprising a positive electrode, a negative electrode, and an electrolytic solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The electrolytic solution has a cyclic ether compound having a cyclic ether structure, which is less than the content of the cyclic carbonate compound,
The film is provided on the positive electrode or the negative electrode, and is composed of a polymer of the cyclic ether compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X may constitute a part of the main chain or side chain of the polymer, and X may be the same or different. n is an integer of 2 or 3. ]
(Appendix 8)
The membrane according to appendix 7, wherein the electrolytic solution has 30% by weight or less of the cyclic ether compound with respect to the entire electrolytic solution.
(Appendix 9)
The membrane according to appendix 7 or 8, wherein the cyclic ether compound is represented by the following general formula (2).

[In General Formula (2), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group. It may have a group. m is an integer of 1-4. ]

DESCRIPTION OF SYMBOLS 1 Positive electrode 1A Positive electrode collector 1B Positive electrode lead 2 Negative electrode 2A Negative electrode collector 2B Negative electrode lead 3 Lithium supply source 3A Lithium supply source current collector 4 Separator 5 Exterior body 6 Positive electrode 6A Positive electrode current collector and exterior body 7 Negative electrode 7A Negative electrode Current collector / exterior 8 Separator 9 Insulating packing 10 Laminated external battery 20 Coin-type battery

Claims (12)

A positive electrode;
A negative electrode,
An electrolyte solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The said electrolyte solution is a secondary battery which has a cyclic ether compound which has less cyclic carbonate structure than content of the said cyclic carbonate compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X constitutes a part of the main chain or side chain of the polymer . X may be the same or different. n is an integer of 2 or 3. ]   The secondary battery according to claim 1, wherein the electrolytic solution has 30 wt% or less of the cyclic ether compound with respect to the entire electrolytic solution. The secondary battery according to claim 1, wherein the cyclic ether compound is represented by the following general formula (2).

[In General Formula (2), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group. It may have a group. m is an integer of 1-4. ]   The nitroxide radical compound represented by the general formula (1) is a radical compound having a partial structure selected from partial structures represented by the following formulas (6) to (13). A secondary battery according to item.

An electrolyte solution for use in a secondary battery comprising a positive electrode, a negative electrode, and an electrolyte solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The electrolyte solution has a cyclic ether compound having a cyclic ether structure that is less than the content of the cyclic carbonate compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X constitutes a part of the main chain or side chain of the polymer . X may be the same or different. n is an integer of 2 or 3. ] The electrolytic solution according to claim 5 , comprising 30 wt% or less of the cyclic ether compound with respect to the entire electrolytic solution. The electrolytic solution according to claim 5 or 6 , wherein the cyclic ether compound is represented by the following general formula (2).

[In General Formula (2), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group. It may have a group. m is an integer of 1-4. ]   The nitroxide radical compound represented by the general formula (1) is a radical compound having a partial structure selected from partial structures represented by the following formulas (6) to (13). The electrolyte solution according to item.

A membrane for use in a secondary battery comprising a positive electrode, a negative electrode, and an electrolytic solution containing a cyclic carbonate compound,
The positive electrode or the negative electrode has a nitroxide radical compound represented by the following general formula (1),
The electrolytic solution has a cyclic ether compound having a cyclic ether structure, which is less than the content of the cyclic carbonate compound,
The film is provided on the positive electrode or the negative electrode, and is composed of a polymer of the cyclic ether compound.

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group. An atom constituting a ring member in X is a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. However, X constitutes a part of the main chain or side chain of the polymer . X may be the same or different. n is an integer of 2 or 3. ] The film according to claim 9 , wherein the electrolytic solution has 30 wt% or less of the cyclic ether compound with respect to the entire electrolytic solution. The film according to claim 9 or 10 , wherein the cyclic ether compound is represented by the following general formula (2).

[In General Formula (2), R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, a carbonyl group, a nitro group, an amino group, a sulfo group, an aryl group, or an alkyl group. It may have a group. m is an integer of 1-4. ]   The nitroxide radical compound represented by the general formula (1) is a radical compound having a partial structure selected from partial structures represented by the following formulas (6) to (13). The membrane according to item.

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