JP2012221574A - Radical compound and manufacturing method thereof, electrode active material, and secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode active material having excellent capacity maintenance rate and output characteristics at a high temperature and an excellent energy density.SOLUTION: The electrode active material including a radical compound containing a cyclic siloxane structure a part of which is a structure represented by a predetermined formula is provided in an embodiment. The electrode active material according to the embodiment has excellent cycle characteristics and output characteristics at high temperature and an excellent energy density. According to the embodiment, a battery including the electrode active material composed of light and safety elements without heavy metals can be obtained.

Description

  The present invention relates to a radical compound. The present invention also relates to a method for producing the radical compound. The present invention also relates to an electrode active material containing the radical compound. Further, the present invention relates to a secondary battery having the electrode active material.

  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, the battery as the power source is required to have a high energy density and a high output.

  Examples of the battery having a high energy density include a lithium ion battery. Lithium ion batteries have been widely used since they were developed in the 1990s. As the electrode active material, for example, a lithium ion battery is known in which a lithium-containing transition metal oxide such as lithium manganate or lithium cobaltate is used for the positive electrode and carbon is used for the negative electrode. Lithium ion batteries are charged and discharged by utilizing insertion and desorption reactions of lithium ions into these electrode active materials. Lithium ion batteries have high energy density and excellent cycle characteristics, and are used in various electronic devices such as mobile phones. However, since the reaction rate of the electrode reaction is small, the battery performance may be significantly lowered when a large current is taken out. Therefore, the lithium ion battery has a problem that it is difficult to obtain a large output, and it takes a long time for charging.

  An electric double layer capacitor is known as an electricity storage device capable of producing a large output. Since a large current can be discharged at one time, a large output can be produced and the cycle characteristics are excellent. Therefore, electric double layer capacitors are being developed as backup power sources. However, since energy density is small and downsizing is difficult, it may not be suitable for the power source of 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 Document 1 (US Pat. No. 4,833,048) and Patent Document 2 (Japanese Patent No. 2715778) disclose batteries using an organic compound having a disulfide bond as a positive electrode. This is an electrochemical redox reaction involving generation and dissociation of disulfide bonds, which is used as a 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.

  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. Patent Document 3 (US Pat. No. 4,442,187) discloses 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.

  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 (Japanese Patent Laid-Open No. 2002-151084) discloses organic radical compounds such as nitroxide radical compounds, aryloxy radical compounds, and polymer compounds having a specific aminotriazine structure as active materials. Patent Document 4 discloses a battery using these organic radical compounds as a positive electrode or negative electrode material. Further, Patent Document 5 (Japanese Patent Application Laid-Open No. 2002-304996) discloses an electricity storage device using a compound having a cyclic nitroxide structure as an electrode active material among nitroxide compounds. Further, the radical compound used as an electrode active material therefor is 2, m-chloroperbenzoic acid after polymerization by reacting 2,2,6,6-tetramethylpiperidine methacrylate with azobisisobutyronitrile as a polymerization initiator. It is synthesized by oxidizing with an acid.

  Furthermore, a battery using an organosilicon compound (silicone) as an organic radical compound has also been proposed. For example, Patent Document 6 (Japanese Patent Laid-Open No. 2009-298873) discloses a compound in which a radical is substituted via an alkyl chain by a hydrosilylation reaction, and Patent Document 7 (Japanese Patent Laid-Open No. 2010-163551). Discloses a compound in which a radical compound is substituted without an alkyl chain.

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 JP 2009-298873 A JP 2010-163551 A

  However, when the organic compound having a disulfide bond described in Patent Documents 1 and 2 is used, the charge / discharge cycle is reduced due to the low efficiency of the dissociated bond recombining and the diffusion of the electrode active material into the electrolyte. If they are stacked, the capacity may be easily reduced.

  In addition, in the conductive polymer described in Patent Document 3, charged radicals generated by redox are delocalized over a wide range of π-electron conjugated systems, which cause electrostatic repulsion and radical disappearance. There is a characteristic of interacting. This characteristic brings a limit to the generated charged radical, 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 it is difficult to obtain a battery having a high energy density.

  Moreover, in the battery using the oxidation-reduction reaction of the organic radical compound as described in Patent Documents 4 to 7, although the output characteristics are excellent, there is a case where the capacity is reduced by charging / discharging cycle at a high temperature. is there.

  Moreover, the organosilicon compounds as described in Patent Documents 6 and 7 have certain effects in terms of the high stability of silicone. However, since it is difficult to introduce a radical functional group into the side chain of the silicone skeleton with high efficiency, a battery having a high energy density may not be obtained. This is presumed to be due to the presence of many trimethylsilyl groups that do not contribute to charge / discharge at the terminal of the silicone.

  As described above, in a lithium ion battery using a transition metal oxide for the positive electrode, it has been difficult to achieve high energy density and high output. Moreover, although the electric double layer capacitor has a large output, the energy density per weight is low and it is difficult to increase the capacity. A battery using a sulfur compound or a conductive polymer as an electrode active material has a problem in terms of energy density. Further, in a battery using an organic radical compound, cycle deterioration at a high temperature has been a problem.

  Therefore, an object of the present embodiment is to provide an electrode active material that is excellent in energy density, capacity retention at high temperatures, and output characteristics. Another object of the present embodiment is to provide a battery that has a high energy density and can provide a large output. Moreover, it aims at providing the manufacturing method of the radical compound used as an electrode active material.

  One of the embodiments is an electrode active material containing a radical compound containing a cyclic siloxane structure having a partial structure represented by the following formula (1).

(In formula (1), Z is represented by the following formula (2). R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

(In the formula (2), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group. X represents a single bond or a substituted or unsubstituted alkylene group.)
One of the embodiments is a method for producing a compound characterized by reacting a radical compound represented by the following formula (7) with a cyclic siloxane compound represented by the following formula (8).

(In the formula (7), A is, .Y showing a linking group heterocyclic ring containing nitrogen to form a 5- to 7-membered ring, .R ¹ to R represents a hydrogen atom, or a substituted or unsubstituted alkenyl group ⁴ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group.)

(In Formula (8), R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)
One of the embodiments is a radical compound having a cyclic siloxane structure represented by the following formula (13).

(In the formula (13), A represents a substituent in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ are each independently a hydrogen atom or a group having 1 to 3 carbon atoms. R ⁵ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms, X represents a single bond or an alkylene group having 3 to 12 carbon atoms, n represents , Represents an integer of 2 to 6.)

  The electrode active material according to this embodiment is excellent in energy density, high-temperature cycle characteristics, and output characteristics. According to the present embodiment, it is possible to obtain a battery composed of light and safe elements that do not contain heavy metals as the electrode active material.

  As a result of intensive studies, the present inventors have determined that a specific organic compound that has not been used as an electrode active material until now, that is, a radical containing a cyclic siloxane structure having a partial structure represented by the following formula (1) in the molecule It has been found that the above problem can be solved by using a compound (hereinafter also referred to as a cyclic siloxane radical compound) as an electrode active material. Since the cyclic structure does not have a terminal structure, a substituent that does not contribute to charge / discharge existing in a general polymer can be omitted. That is, by using the electrode active material of the present embodiment, a battery having a high energy density and capable of discharging a large current can be provided.

(Embodiment 1)
This embodiment is an electrode active material containing a radical compound containing a cyclic siloxane structure having a partial structure represented by the following formula (1).

(In formula (1), Z is represented by the following formula (2). R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

(In the formula (2), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group. X represents a single bond or a substituted or unsubstituted alkylene group.

  The cyclic siloxane radical compound is preferably represented by the following formula (3).

(In the formula (3), Q is a group represented by hydrogen or the formula (2), .R ⁵ at least one of Q is a group represented by the above formula (2) has the formula ( It has the same meaning as R ⁵ in 1), and n represents an integer of 2 to 6.)

  Furthermore, the cyclic siloxane radical compound is more preferably represented by the following formula (4) or formula (5).

In (Equation ^{(4), A, R 1} ~R 4, R 5, and X, A in the formula (1) and ^{(2), R 1 ~R 4} , R 5, and X and the same meaning, respectively N represents an integer of 2 to 6.)

(In Formula (5), R < ¹ > -R < ⁴ >, R < ⁵ > and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ > and X in Formula (1) and Formula (2), respectively. Represents an integer of 2 to 6).

(In Formula (6), R < ¹ > -R < ⁴ >, R < ⁵ >, and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ >, and X in Formula (1) and Formula (2), respectively. Represents an integer of 2 to 6).

  In the present specification, the alkyl group includes a linear, branched or cyclic group.

Moreover, it is preferable that R < ¹ > -R < ⁴ > shows a C1-C3 alkyl group each independently. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

R ⁵ preferably represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the aryl group include a phenyl group and a naphthyl group.

  X preferably represents a single bond or an alkylene group having 1 to 12 carbon atoms. X is more preferably an alkylene group having 3 to 12 carbon atoms, more preferably an alkylene group having 3 to 9 carbon atoms, and particularly preferably an alkylene group having 3 to 6 carbon atoms. Examples of the alkylene group include a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, and a dodecylene group.

  Examples of the substituent include a halogen atom and an alkyl group having 1 to 3 carbon atoms.

  The cyclic siloxane radical compound undergoes an oxidation-reduction reaction represented by, for example, the following scheme (I) or (II) during the charge / discharge process. In the oxidation-reduction reaction of Scheme (I), when a cyclic siloxane radical compound is used for the positive electrode, the state changes from (A) to (B) by charging, and electrons are released. The state changes from (B) to (A) by discharging, and receives electrons. In addition, in the oxidation-reduction reaction of Scheme (II), when a cyclic siloxane radical compound is used for the positive electrode, the state changes from (C) to (D) by charging, and electrons are released. The state changes from (D) to (C) by discharging, and receives electrons. In view of the stability of the redox reaction of the cyclic siloxane radical compound, it is preferable to perform charge / discharge by redox of scheme (I).

  In the battery, the electrode active material is oxidized or reduced by charge / discharge, and therefore the electrode active material takes two states, a starting state and a reduced state. In this embodiment, the electrode active material has a structure represented by any one of the above formulas in either a charged or discharged state.

  The cyclic siloxane radical compound in this embodiment has excellent properties as an electrode active material. The cyclic siloxane radical compound in this embodiment can reversibly and stably cause a redox reaction. Therefore, the battery using the cyclic siloxane radical compound in the present embodiment as an electrode active material can be stably charged and discharged, and has excellent cycle characteristics even at high temperatures.

  In addition, the battery using the radical compound as an electrode active material in the present embodiment has excellent high output characteristics as compared with a conventional lithium ion battery or the like. This is because the radical structure ring of the cyclic siloxane radical compound in the present embodiment has a large electrode reaction rate, so that a large current can be discharged at a time. Further, since the radical structure ring can be composed of elements having a small mass such as carbon, nitrogen, hydrogen, and oxygen, the mass of the electrode active material can be reduced. Therefore, the capacity density per unit mass of the electrode manufactured using the cyclic siloxane radical compound of this embodiment becomes large. As a result, by using the electrode active material of this embodiment, a battery having a large energy density per mass can be produced. In particular, when a siloxane structure is used, a battery having excellent high-temperature cycle characteristics can be obtained. This is thought to be because the bond energy of the Si—O bond, which is the main chain skeleton of the siloxane structure, is larger than that of the C—C bond and the C—O bond, and is chemically and thermally stable. Furthermore, it is considered that when a cyclic siloxane structure is used among siloxane structures, a larger energy density can be obtained as compared with a case where a chain siloxane is used. This is presumably because the chain siloxane has trimethylsilyl groups that do not contribute to charge / discharge at both ends of the molecule, whereas the cyclic siloxane has no terminal structure.

  In the present embodiment, the cyclic siloxane radical compound only needs to contribute to the electrode reaction at the positive electrode or the negative electrode, and is not limited to being used as either the positive electrode active material or the negative electrode active material as the electrode active material. Absent. However, the cyclic siloxane radical compound in the present embodiment is preferably used as a positive electrode active material from the viewpoint of energy density. In addition, in the secondary battery of the present embodiment, it is preferable to use metallic lithium or carbon into which lithium ions can be inserted / desorbed as the negative electrode active material from the viewpoint of obtaining a high voltage and a large capacity.

  In addition, the cyclic siloxane radical compound in this embodiment can be manufactured by the following method, for example. That is, this embodiment is a method for producing a radical compound, characterized by reacting a radical compound represented by the following formula (7) with a cyclic siloxane compound represented by the following formula (8).

(In the formula (7), A is, .Y showing a linking group heterocyclic ring containing nitrogen to form a 5- to 7-membered ring, .R ¹ to R represents a hydrogen atom, or a substituted or unsubstituted alkenyl group ⁴ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group.

(In Formula (8), R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

  Moreover, in the manufacturing method of this embodiment, it is preferable that the radical compound used as a raw material is represented by following formula (11).

(In the formula (11), Y, and R ¹ to R ⁴ denotes as in equation (7) Y, and R ¹ to R ⁴ the same meaning.).

  Moreover, in the manufacturing method of this embodiment, it is preferable that the radical compound used as a raw material is represented by following formula (12).

(In Formula (12), Y and R < ¹ > -R < ⁴ > show the group similar to Formula (7).).

Further, as described above, R ¹ to R ⁴ are each independently, it is preferable that an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and an isopropyl group. R ⁵ also preferably represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms, as described above.

  Y is preferably a hydrogen atom or an alkenyl group having 2 to 12 carbon atoms. Y is more preferably an alkenyl group having 3 to 12 carbon atoms, more preferably an alkenyl group having 3 to 9 carbon atoms, and particularly preferably an alkenyl group having 3 to 6 carbon atoms. Examples of the alkenyl group include a vinyl group, 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-methyl-1-propenyl group, 2-methyl-1- A propenyl group, 1-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 1-hexenyl group, 1-decenyl group and the like can be mentioned. The alkenyl group preferably has a double bond at the terminal, and more preferably has a double bond at the terminal having 3 to 12 carbon atoms.

  Specific examples of the radical compound used as a raw material include radical compounds represented by the following formulas (34) and (35).

  Examples of the substituent include a halogen atom and an alkyl group having 1 to 3 carbon atoms.

(Embodiment 2)
FIG. 1 shows a configuration example of the battery of this embodiment. The battery shown in FIG. 1 has a configuration in which a positive electrode 5, a negative electrode 3, and a separator 4 containing an electrolyte are stacked so as to face each other, and a positive electrode current collector 6 is stacked on the positive electrode 5. . These are externally covered with a stainless steel exterior 1 on the negative electrode side and a stainless steel exterior 1 on the positive electrode side, and an insulating packing 2 made of an insulating material such as a 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, the present invention is characterized in that the electrode active material used for the negative electrode 3 or the positive electrode 5 or both electrodes is an electrode active material containing a cyclic siloxane radical compound.

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

[1] Electrode active material An electrode active material is a substance that contributes to electrode reactions such as charge reaction and discharge reaction.

  The electrode active material of this embodiment contains the cyclic siloxane radical compound of this embodiment.

  In the battery of the present embodiment, the electrode active material is preferably fixed to the electrode current collector.

  In the radical compound including the cyclic siloxane structure having the partial structure represented by the formula (1), the partial structure represented by the formula (1) is preferably 60 mol% or more, and 70 or more based on the radical compound. It is more preferably mol%, more preferably 80 mol%, and particularly preferably 90 mol%. This is because the battery capacity increases as the proportion of the partial structure represented by the formula (1) in the radical compound increases.

  Examples of the cyclic siloxane radical compound of the present embodiment include compounds represented by the following formulas (16) to (31).

  The cyclic siloxane radical compound represented by the above formula (16) can be synthesized, for example, by the route shown in the following synthesis scheme (32). That is, it can be synthesized by a method of reacting a cyclic siloxane with a radical compound in the presence of a transition metal catalyst.

Examples of the transition metal catalyst that can be used include iridium compounds, ruthenium compounds, rhodium compounds, platinum compounds, palladium compounds, and nickel compounds. Examples of the nickel catalyst include Ni (cod) ₂ , NiCl ₂ (PPh ₃ ) ₂ , NiCl ₂ , Ni (OAc) ₂ , and Ni (PPh ₃ ) ₄ . Examples of the palladium catalyst include Pd ₂ (dba) ₃ , Pd (PPh ₃ ) ₄ , Pd (OAc) ₂ , PdCl ₂ , PdCl ₂ (PPh ₃ ) ₂ , PdCl ₂ (dppf), PdCl ₂ (dppb), and the like. Is mentioned. Examples of the platinum catalyst include H ₂ PtCl ₆ , K ₂ PtCl ₆ , Na ₂ PtCl ₆ , (Bu ₄ N) PtCl ₆ , [Pt (CH ₂ = CHSiMe ₂ ) ₂ O] (Karstedt's catalyst), and the like. Can be mentioned. Examples of the rhodium catalyst include RhCl ₃ , Rh ₂ (OAc) ₄ , [RhCl (cod)] ₂ , RhCl (PPh ₃ ) ₃ , [RhCl (nbd)] ₂ , [Rh (nbd) ₂ ] BF ₄ , [Rh (cod) ₂ ] BF _{4 and the} like. Examples of the ruthenium catalyst include RuCl ₂ (PPh3) _{3 and the} like.

Examples of the cyclic siloxane include trimethylcyclotrisiloxane (D ₃ ^H ), tetramethylcyclotetrasiloxane (D ₄ ^H ), pentamethylcyclopentasiloxane (D ₅ ^H ), hexamethylcyclohexasiloxane (D ₆ ^H ), and the like. A compound having a Si—H group in the molecule can be used. Since the hydrogen atoms in the Si—H group in the cyclic siloxane are highly reactive, they are usually all substituted, but a substitution reaction may be caused only in part.

  As the radical compound, a compound having a functional group such as a hydroxyl group or a vinyl group can be used.

  Moreover, the cyclic siloxane radical compound represented by the above formula (20) can be synthesized, for example, by the route shown in the following synthesis scheme (33). That is, for example, it can be synthesized by a method of reacting a cyclic siloxane with a radical compound (hydrosilylation reaction) in the presence of a group 8-10 transition metal catalyst.

  The compounds represented by the above formulas (16) and (20) can be synthesized by a similar method. In that case, the target radical compound can be synthesized by appropriately changing the synthesis scheme, raw materials to be used, reaction conditions and the like, and combining known synthesis techniques. This reaction is preferably performed in an organic solvent. As the organic solvent, a general organic solvent such as tetrahydrofuran, toluene, dimethylformamide, dichloromethane, chloroform, etc. can be used. Furthermore, from the viewpoint of solubility of the radical compound, cyclic siloxane, and catalyst, it should be carried out in a tetrahydrofuran solvent. Is preferred.

  Moreover, the electrode active material of this embodiment may contain 1 type, or 2 or more types of the cyclic siloxane radical compound of this embodiment.

  In addition to the cyclic siloxane radical compound, the electrode active material of the present embodiment may include other electrode active materials.

  The electrode active material of this embodiment preferably contains 10 to 90% by mass of the cyclic siloxane radical compound of this embodiment, and more preferably contains 20 to 80% by mass.

When a cyclic siloxane radical compound is used as the positive electrode active material, examples of other electrode active materials include metal oxides, disulfide compounds, other stable radical compounds, and conductive polymers. Here, examples of the metal oxide include lithium manganate such as LiMnO ₂ and Li _x Mn ₂ O ₄ (0 <x <2) or lithium manganate having a spinel structure, MnO ₂ , LiCoO ₂ , LiNiO ₂ , Alternatively, Li _y V ₂ O ₅ (0 <y <2), olivine-based material LiFePO ₄ , materials in which a part of Mn in the spinel structure is substituted with another transition metal, 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, LiN 0.5 Mn 1.5-z Ti z O 4 (0 < z <1.5), and the like. Examples of the disulfide compound include dithioglycol, 2,5-dimercapto-1,3,4-thiadiazole, S-triazine-2,4,6-trithiol and the like. Examples of other stable radical compounds include poly (4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl) and poly (4-acryloyloxy-2,2,6,6-tetra). Methyl piperidine-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, lithium manganate or LiCoO ₂ is preferable. These other electrode active materials can be used alone or in combination of two or more.

  When the cyclic siloxane radical compound is used as the negative electrode active material, examples of other electrode active materials include graphite, amorphous carbon, metallic lithium and lithium alloy, lithium ion storage carbon, metallic sodium, and conductive polymer. be able to. 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.

  In the battery of this embodiment, a cyclic siloxane radical compound can be used as an electrode active material in one electrode reaction of the positive electrode or the negative electrode, or in both electrode reactions. When a cyclic siloxane radical compound is used as one electrode active material, a conventionally known electrode active material can be used as the electrode active material in the other electrode.

  The electrode active material of the present embodiment is not limited to either a positive electrode active material or a negative electrode active material, but is preferably a positive electrode active material from the viewpoint of energy density.

  Furthermore, when the electrode active material of the present embodiment is a positive electrode active material, examples of the negative electrode active material include metallic lithium, silicon-based compounds such as silicon and silicon oxide, tin-based compounds such as tin and tin oxide, Examples thereof include graphite.

[2] Conductivity-imparting agent (auxiliary conductive material) and ion-conducting auxiliary material The electrode active material has a conductivity-imparting agent (auxiliary conductive material) and ionic conduction auxiliary for the purpose of reducing impedance and improving energy density and output characteristics It is also possible to mix the materials. Examples of 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, and conductive properties such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacene. Examples thereof include polymers. Examples of the ion conduction auxiliary material include a polymer gel electrolyte and a polymer solid electrolyte. Among these, it is preferable to mix carbon fiber with the electrode active material. By mixing the carbon fiber, the tensile strength of the electrode is further increased, and the occurrence of cracks and peeling in the electrode is suppressed. Moreover, it is more preferable to mix vapor growth carbon fiber with an electrode active material. These materials can be used alone or in admixture of two or more. As a ratio of these materials, it can be set as 1-80 mass%, for example, and 10-50 mass% is preferable.

[3] Binder In order to fix the electrode active material to the electrode current collector, a binder can also be used. The binder is not particularly limited. For example, polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene Examples of the resin binder include butadiene copolymer rubber, polypropylene, polyethylene, polyimide, and various polyurethanes. These resin binders can be used alone or in admixture of two or more. Content of a binder is 1-20 mass parts with respect to 100 mass parts of active materials, for example, and 2-10 mass parts is preferable.

[5] Current collector The material of the negative electrode current collector or the positive electrode current collector is not particularly limited, and for example, nickel, aluminum, copper, gold, silver, aluminum alloy, stainless steel, carbon, or the like is used. Can do. Moreover, shapes, such as foil, plate shape, and mesh shape, can be selected as a shape of a negative electrode collector or a positive electrode collector. Further, the current collector may have a catalytic effect, or the electrode active material and the current collector may be chemically bonded.

[6] Separator The separator is not particularly limited, and for example, a porous film or a nonwoven fabric made of polyethylene, polypropylene, or the like can be used.

[7] Electrolyte 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. .

  As the electrolyte, for example, an electrolytic solution in which an electrolyte salt is dissolved in a solvent can be used.

As an electrolyte salt, but are not particularly limited, for _{example, 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 Conventionally known materials such as Li (CF ₃ SO ₂ ) ₃ C and 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.

  Although it does not restrict | limit especially as a solvent, For example, cyclic carbonates, such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC); dimethyl carbonate (DMC), Chain carbonates such as diethyl carbonate (DEC), methyl ethyl carbonate, ethyl methyl carbonate (EMC), dipropyl carbonate (DPC); propylene carbonate derivatives; aliphatic carboxylic acids such as methyl formate, methyl acetate, ethyl propionate And aprotic organic solvents such as esters; Solvents are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (MEC), dipropyl carbonate ( Cyclic or chain carbonates such as DPC) are preferred. In addition, an organic solvent such as γ-butyrolactone, tetrahydrofuran, dioxolane, sulfolane, dimethylformamide, dimethylacetamide, or N-methyl-2-pyrrolidone can be used. These solvents may be used alone or in combination of two or more.

  Further, a solid electrolyte can be used as the electrolyte. The polymer compound used for the solid electrolyte is not particularly limited. For example, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride- Vinylidene fluoride such as monofluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer Polymer, acrylonitrile-methyl methacrylate copolymer, acrylonitrile-methyl acrylate copolymer, acrylonitrile-ethyl methacrylate copolymer, acrylonitrile-ethyl acrylate copolymer, acrylonitrile-methacrylic acid copolymer And acrylonitrile polymers such as acrylonitrile-acrylic acid copolymer, acrylonitrile-vinyl acetate copolymer, polyethylene oxide, ethylene oxide-propylene oxide copolymer, and polymers of these acrylates and methacrylates. It is done. As the solid electrolyte, those obtained by gelling an electrolytic solution with these polymer compounds may be used. Moreover, a polymer compound containing an electrolyte salt may be used as it is as the solid electrolyte.

[8] Battery shape The shape of the battery is not particularly limited, and for example, a conventionally known one 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 composed of a metal foil such as an aluminum foil and a synthetic resin film. Moreover, although a battery is produced with a cylindrical shape, a square shape, a coin shape, a sheet | seat shape etc., for example, this invention is not limited to these.

[9] Battery Manufacturing Method The battery manufacturing method is not particularly limited, and a method appropriately selected according to the material can be used.

  Examples of the battery manufacturing method include the following steps. First, a solvent is added to an electrode active material, a conductivity-imparting agent and the like to form a slurry, which is applied to an electrode current collector, and an electrode is produced by heating or volatilizing the solvent at room temperature. Next, the produced positive electrode and negative electrode are laminated or wound with a separator in between and wrapped with an outer package. Then, a battery is manufactured by injecting an electrolyte into the exterior body and sealing it.

  Examples of the solvent 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 aromatics such as benzene, toluene and xylene. Group hydrocarbon 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, Examples thereof include alcohol solvents such as ethanol and isopropyl alcohol, and dimethyl sulfoxide.

  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 room temperature, peeling of the electrode, cracking, etc. Is likely to occur. When a cyclic siloxane radical compound is used, the thickness of the electrode active material is preferably 80 to 500 μm. If it is the thickness of this range, there exists a tendency for it not to peel to an electrode and to generate | occur | produce a crack.

  Conventionally known methods can be used for other manufacturing conditions such as lead extraction from the electrode and exterior.

(Embodiment 3)
Further, the present embodiment is a radical compound having a cyclic siloxane structure represented by the following formula (13). The cyclic siloxane radical compound of this embodiment has excellent properties as an electrode active material.

(In Formula (13), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ are each independently a hydrogen atom or a group having 1 to 3 carbon atoms. R ⁵ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms, X represents a single bond or an alkylene group having 3 to 12 carbon atoms, n represents , Represents an integer of 2 to 6.)

  Moreover, it is preferable that the radical compound represented by Formula (13) is represented by following formula (14).

(In Formula (14), R < ¹ > -R < ⁴ >, R < ⁵ >, and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ >, and X in Formula (13), respectively, n is 2-6. Indicates an integer.)

  Moreover, it is preferable that the radical compound represented by Formula (13) is represented by following formula (15).

(In Formula (15), R < ¹ > -R < ⁴ >, R < ⁵ > and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ > and X in Formula (13), respectively, n is 2-6. Indicates an integer.)

  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.

(Synthesis Example 1)
According to the synthesis scheme (32) shown below, the cyclic siloxane radical compound (A) represented by the above formula (16) was synthesized.

First, 31.5 g (183 mmol) of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO-OH) was added to 300 mL of dehydrated tetrahydrofuran in an argon atmosphere in a 1 L three-necked flask. Dissolve. Next, 10 g (55.4 mmol) of trimethylcyclotrisiloxane (D ₃ ^H ) and 226 mg (0.25 mol%) of [RhCl (cod)] as a catalyst are added. Next, after stirring at room temperature for 6 hours, the solvent was distilled off by an evaporator, methanol (500 mL × 3) was added, and the compound was washed by stirring at room temperature. After washing, vacuum drying (40 ° C., 6 hours) is performed to obtain 2,4,6-trimethyl-2,4,6-tri (2,2,6,6-tetramethylpiperidine-70% in a yield of 70%. N-oxy) cyclotrisiloxane was obtained.

(Synthesis Example 2)
According to the following scheme (36), the cyclic siloxane radical compound (B) was synthesized using D ₄ H instead of D ₃ H.

First, 31.5 g (183 mmol) of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO-OH) was added to 300 mL of dehydrated tetrahydrofuran in an argon atmosphere in a 1 L three-necked flask. Dissolve. Next, 10 g (41.6 mmol) of trimethylcyclotrisiloxane (D ₄ ^H ) and 225 mg (0.25 mol%) of [RhCl (cod)] in a catalytic amount are added. Next, after stirring at room temperature for 6 hours, the solvent was distilled off by an evaporator, hexane (300 mL × 3) and diethyl ether (300 mL × 3) were added, and the compound was washed by stirring at room temperature. After washing, vacuum drying (40 ° C., 6 hours) is performed to obtain 2,4,6,8-tetramethyl-2,4,6,8-tetra (2,2,6,6) in a yield of 70%. 6-tetramethylpiperidine-N-oxy) cyclotetrasiloxane was obtained.

(Synthesis Example 3)
The cyclic siloxane radical compound (C) represented by the formula (20) was synthesized according to the following scheme (33).

First, 38.8 g (183 mmol) of 4-allyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl is added and dissolved in 100 mL of dehydrated tetrahydrofuran in a 500 mL three-necked flask under an argon atmosphere. Next, 10 g (55.4 mmol) of trimethylcyclotrisiloxane (D ₃ ^H ) and a xylene solution (0.2 mol%) of Karstedt's catalyst are added as a catalyst. Next, after stirring at 100 ° C. for 3 hours, the solvent was distilled off by an evaporator, hexane (500 mL × 3) was added, and the compound was washed by stirring at room temperature. After washing, vacuum drying (40 ° C., 6 hours) is performed to obtain 2,4,6-trimethyl-2,4,6-tri (2,2,6,6-tetramethylpiperidine-70% in a yield of 70%. N-oxy) propylcyclotrisiloxane was obtained.

(Synthesis Example 4)
The cyclic siloxane radical compound (D) was synthesized according to the following scheme (37).

First, 38.8 g (183 mmol) of 4-allyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl is added and dissolved in 100 mL of dehydrated tetrahydrofuran in a 500 mL three-necked flask under an argon atmosphere. Next, 10 g (41.6 mmol) of tetramethylcyclotetrasiloxane (D ₄ ^H ) and a xylene solution of Karstedt's catalyst (0.2 mol%) are added as a catalyst. Next, after stirring at 100 degreeC for 3 hours, the solvent was distilled off by the evaporator and the compound was wash | cleaned by adding hexane (500 mLx3) and stirring at room temperature. After washing, vacuum drying (40 ° C., 6 hours) is performed to obtain 2,4,6,8-tetramethyl-2,4,6,8-tetra (2,2,6,6) in a yield of 70%. -Tetramethylpiperidine-N-oxy) propylcyclotetrasiloxane was obtained.

Example 1
<Preparation of positive electrode>
200 mg of the cyclic siloxane radical compound (A) synthesized in Synthesis Example 1, 700 mg of graphite powder, and 100 mg of polytetrafluoroethylene (PTFE) resin binder were measured 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 1.0 mol / L LiPF ₆ electrolyte salt 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-laminated copper foil serving as a negative electrode was laminated, and the respective stainless steel exteriors were superposed from the positive electrode side and the negative electrode side in a state where an insulating packing was arranged around the lithium foil. By applying pressure with a caulking machine, a sealed coin-type battery using a cyclic siloxane radical compound (A) as a positive electrode active material and metallic lithium as a negative electrode active material was produced.

<Evaluation of charge / discharge>
The coin battery fabricated as described above was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged to 3.0 V with a constant current of 0.1 mA. As a result, the voltage became substantially constant for about 3 hours and 10 minutes around 3.5 V, and then dropped rapidly. The discharge capacity per electrode active material was 105 mAh / g. By the same operation, charging / discharging was repeated 50 times in the range of 4.0 to 3.0V. 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 97%.

  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 2)
<Preparation of positive electrode>
20 g of N-methylpyrrolidone was weighed into a small homogenizer container, 300 mg of polyvinylidene fluoride (PVdF) was added, and stirred for 30 minutes to completely dissolve. Thereto, 200 mg of the cyclic siloxane radical compound (A) 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 active material 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. The mass of this electrode was 16.0 mg (including 6.0 mg for aluminum foil).

<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 μm.

<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 1.0 mol / L LiPF ₆ electrolyte salt 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 a radical compound (A) 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 around 3.5 V, and the discharge capacity per electrode active material was 106 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%.

  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. The (discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 91%.

(Example 3)
<Preparation of positive electrode>
Pure water (42 mL) and carboxymethylcellulose (CMC) 400 mg (4 wt%) were added to a homogenizer cup, and completely dissolved with a 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 is added little by little and stirred until uniform. To the obtained black slurry, 7 g (70 wt%) of the cyclic siloxane radical compound (A) was added 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. In addition, the mass of this electrode was 17.0 mg (of which aluminum foil was 6.0 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 1.0 mol / L LiPF ₆ electrolyte salt 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 cyclic siloxane radical compound (A) as a positive electrode active material and metallic lithium as a negative electrode active material was produced.

<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 flat voltage portion was observed around 3.5 V, and the discharge capacity per electrode active material was 106 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. (Discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 94%.

Example 4
<Cell fabrication>
A coin battery was produced in the same manner as in Example 3 except that the cyclic siloxane radical compound (B) was used instead of the cyclic siloxane radical compound (A). 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 16.6 mg (of which, the 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 104 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%.

  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 coin battery was fabricated in the same manner as in Example 3 except that the cyclic siloxane radical compound (C) was used instead of the cyclic siloxane radical compound (A). The produced electrode was not peeled off or cracked, and the surface was uniform. The positive electrode weight of this coin battery was 17.1 mg (of which, the 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 90 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%.

  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 95%.

(Example 6)
<Cell fabrication>
The positive electrode containing the cyclic siloxane radical compound (A) prepared in Example 3 and the graphite negative electrode prepared in Example 2 were sequentially stacked through 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 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, the battery was also discharged 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 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%. 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 7)
<Cell fabrication>
Similar to Example 6 except that the positive electrode containing the cyclic siloxane radical compound (B) prepared in Example 4 was used instead of the positive electrode containing the cyclic siloxane radical compound (A) prepared in Example 3. An aluminum laminate battery was produced by the method described above.

<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, the battery was also discharged 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 106 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 8)
<Cell fabrication>
Similar to Example 6 except that the positive electrode containing the cyclic siloxane radical compound (C) prepared in Example 5 was used instead of the positive electrode containing the cyclic siloxane radical compound (A) prepared in Example 3. An aluminum laminate cell was prepared by the method described above.

<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, the battery was also discharged 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 91 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 95%.

(Comparative Example 1)
A coin battery was produced in the same manner as in the example except that the amount of graphite powder used was increased to 900 mg without using the cyclic siloxane radical compound (A).

  The produced battery was charged and discharged in the same manner as in Example 1. As a result, no flat voltage portion was observed during discharge, the voltage dropped rapidly, and the battery did not operate sufficiently.

(Comparative Example 2)
A coin battery was produced in the same manner as in Example 1 except that LiCoO ₂ was used instead of the cyclic siloxane radical compound (A).

  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 123 mAh / g. As a result of repeating charge and discharge 50 times in the range of 4.0 to 3.0 V, (50th discharge capacity) / (1st discharge capacity) was 96%. However, (Discharge capacity at 5.0 mA discharge) / (Discharge capacity at 0.1 mA discharge) was 27%, and the capacity decreased significantly when the discharge current value was increased.

(Comparative Example 3)
A coin battery is produced in the same manner as in Example 1 except that poly [vinyloxy (2,2,6,6-tetramethylpiperidinoxyl-N-oxyl)] is used instead of the cyclic siloxane radical compound (A). Was made.

  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. The initial discharge capacity was 123 mAh / g. However, as a result of repeating charge and discharge 50 times in the range of 4.0 to 3.0 V, (50th discharge capacity) / (first discharge capacity) was reduced to 50%. Further, (discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 90%.

(Comparative Example 4)
A coin battery was prepared in the same manner as in Example 1 except that poly [methacryloyloxy (2,2,6,6-tetramethylpiperidinoxyl-N-oxyl) was used instead of the cyclic siloxane radical compound (A). Produced.

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. The initial discharge capacity was 101 mAh / g. As a result of repeating charge and discharge 50 times in the range of 4.0 to 3.0 V, (50th discharge capacity) / (first discharge capacity) was 60%. Moreover, (discharge capacity in 5.0 mA discharge) / (discharge capacity in 0.1 mA discharge) was 85%.
(Comparative Example 5)
According to the same method as in Example 1 except that poly [methyl (2,2,6,6-tetramethylpiperidinoxyl-N-oxyloxy) siloxane] was used instead of the cyclic siloxane radical compound (A). A coin battery was produced.

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. The initial discharge capacity was 78 mAh / g. As a result of repeating charge and discharge 50 times in the range of 4.0 to 3.0 V, (50th discharge capacity) / (first discharge capacity) was 95%. Further, (discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 70%.

The following table summarizes the examples and comparative examples.

  The battery in this embodiment is a driving or auxiliary storage power source for an electric vehicle, a hybrid electric vehicle, etc., a power source for various portable electronic devices, a power storage device for various energies such as solar energy and wind power generation, or a household electric appliance. It can be used as a storage power source.

（式（１）において、Ｚは下記式（２）で表される。Ｒ^５は、置換若しくは無置換のアルキル基、又は置換若しくは無置換のアリール基を示す。）

（式（２）において、Ａは、窒素を含む複素環が５〜７員環を形成する連結基を示す。Ｒ^１〜Ｒ^４は、それぞれ独立に、水素原子、又は置換若しくは無置換のアルキル基を示す。Ｘは、単結合、又は置換若しくは無置換のアルキレン基を示す。）。
[付記２]
前記ラジカル化合物が下記式（３）で表される付記１に記載の電極活物質；

（式（３）において、Ｑは水素原子又は上記式（２）で表される基であり、Ｑの少なくとも１つは上記式（２）で表される基である。Ｒ^５は、式（１）におけるＲ^５と同じ意味を示す。ｎは、２〜６の整数を示す。）。
[付記３]
前記ラジカル化合物が下記式（４）で表される付記１に記載の電極活物質；

（式（４）において、Ａ、Ｒ^１〜Ｒ^４、Ｒ^５、及びＸは、式（１）及び式（２）におけるＡ、Ｒ^１〜Ｒ^４、Ｒ^５、及びＸとそれぞれ同じ意味を示す。ｎは２〜６の整数を示す。）。
[付記４]
前記ラジカル化合物が下記式（５）で表される付記３に記載の電極活物質；

（式（５）において、Ｒ^１〜Ｒ^４、Ｒ^５、及びＸは、式（１）及び式（２）におけるＲ^１〜Ｒ^４、Ｒ^５、及びＸとそれぞれ同じ意味を示す。ｎは２〜６の整数を示す。）。
[付記５]
前記ラジカル化合物が下記式（６）で表される付記３に記載の電極活物質；

（式（６）において、Ｒ^１〜Ｒ^４、Ｒ^５、及びＸは、式（１）及び式（２）におけるＲ^１〜Ｒ^４、Ｒ^５、及びＸとそれぞれ同じ意味を示す。ｎは２〜６の整数を示す。）。
[付記６]
前記Ｒ^１〜Ｒ^４は、それぞれ独立に、炭素数１〜３のアルキル基を示し、
前記Ｒ^５は、炭素数１〜３のアルキル基又は炭素数６〜１０のアリール基を示し、
前記Ｘは、単結合又は炭素数３〜１２のアルキレン基を示す付記１乃至５のいずれかに記載の電極活物質。
[付記７]
付記１乃至６のいずれかに記載の電極活物質を有する二次電池。
[付記８]
前記電極活物質が正極活物質である付記７に記載の二次電池。
[付記９]
リチウム電池である付記７又は８に記載の二次電池。
[付記１０]
下記式（７）で表されるラジカル化合物と下記式（８）で表される環状シロキサン化合物とを反応させることを特徴とする化合物の製造方法；

（式（７）において、Ａは、窒素を含む複素環が５〜７員環を形成する連結基を示す。Ｙは、水素原子、又は置換若しくは無置換のアルケニル基を示す。Ｒ^１〜Ｒ^４は、それぞれ独立に、水素原子、又は置換若しくは無置換のアルキル基を示す。）

（式（８）において、Ｒ^５は、置換若しくは無置換のアルキル基、又は置換若しくは無置換のアリール基を示す。）。
[付記１１]
前記ラジカル化合物と前記環状シロキサン化合物とを反応させて、下記式（９）で表される部分構造を有する環状シロキサン構造を含むラジカル化合物を得る付記１０に記載の化合物の製造方法；

（式（９）において、Ｚは下記式（１０）で表される。Ｒ^５は、式（８）におけるＲ^５と同じ意味を示す。）。

（式（１０）において、Ａ、及びＲ^１〜Ｒ^４は、式（７）におけるＡ、及びＲ^１〜Ｒ^４とそれぞれ同じ意味を示す。Ｘは、単結合、又は置換若しくは無置換のアルキレン基を示す。）。
[付記１２]
前記ラジカル化合物が下記式（１１）で表される付記１０又は１１に記載の化合物の製造方法。

（式（１１）において、Ｙ、及びＲ^１〜Ｒ^４は、式（７）におけるＹ、及びＲ^１〜Ｒ^４とそれぞれ同じ意味を示す。）。
[付記１３]
前記ラジカル化合物が下記式（１２）で表される付記１０又は１１に記載の化合物の製造方法。

（式（１２）において、Ｙ、及びＲ^１〜Ｒ^４は、式（７）におけるＹ、及びＲ^１〜Ｒ^４とそれぞれ同じ意味を示す。）。
[付記１４]
前記Ｒ^１〜Ｒ^４は、それぞれ独立に、炭素数１〜３のアルキル基を示し、
前記Ｒ^５は、炭素数１〜３のアルキル基又は炭素数６〜１０のアリール基を示し、
前記Ｙは、水素原子又は炭素数３〜１２のアルケニル基を示す付記１０乃至１３のいずれかに記載の化合物の製造方法。
[付記１５]
前記ラジカル化合物と前記環状シロキサン化合物とを遷移金属触媒下で反応させる付記１０乃至１４のいずれかに記載の化合物の製造方法。
[付記１６]
前記遷移金属触媒がイリジウム系化合物、ルテニウム系化合物、ロジウム系化合物、白金系化合物、パラジウム系化合物、又はニッケル系化合物である付記１５に記載のラジカル化合物の製造方法。
[付記１７]
下記式（１３）で表される環状シロキサン構造を有するラジカル化合物；

（式（１３）において、Ａは、窒素を含む複素環が５〜７員環を形成する連結基を示す。Ｒ^１〜Ｒ^４は、それぞれ独立に、水素原子、又は炭素数１〜３のアルキル基を示す。Ｒ^５は、炭素数１〜３のアルキル基、又は炭素数６〜１０のアリール基を示す。Ｘは、単結合、又は炭素数３〜１２のアルキレン基を示す。ｎは、２〜６の整数を示す。）。
[付記１８]
下記式（１４）で表される付記１７に記載のラジカル化合物；

（式（１４）において、Ｒ^１〜Ｒ^４、Ｒ^５、及びＸは、式（１３）におけるＲ^１〜Ｒ^４、Ｒ^５、及びＸとそれぞれ同じ意味を示す。ｎは、２〜６の整数を示す。）。
[付記１９]
下記式（１５）で表される付記１７に記載のラジカル化合物；

（式（１５）において、Ｒ^１〜Ｒ^４、Ｒ^５、及びＸは、式（１３）におけるＲ^１〜Ｒ^４、Ｒ^５、及びＸとそれぞれ同じ意味を示す。ｎは、２〜６の整数を示す。）。 (Appendix 1)
An electrode active material containing a radical compound containing a cyclic siloxane structure having a partial structure represented by the following formula (1);

(In Formula (1), Z is represented by the following Formula (2). R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

(In formula (2), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ each independently represents a hydrogen atom, or a substituted or unsubstituted alkyl group. X represents a single bond or a substituted or unsubstituted alkylene group.
[Appendix 2]
The electrode active material according to supplementary note 1, wherein the radical compound is represented by the following formula (3):

(In the formula (3), Q is a group represented by hydrogen or the formula (2), .R ⁵ at least one of Q is a group represented by the above formula (2) has the formula ( It has the same meaning as R ⁵ in 1), and n represents an integer of 2 to 6.)
[Appendix 3]
The electrode active material according to supplementary note 1, wherein the radical compound is represented by the following formula (4):

In (Equation ^{(4), A, R 1} ~R 4, R 5, and X, ^A in the formula (1) and ^{(2), R 1 ~R 4} , R 5, and X and the same meaning, respectively N represents an integer of 2 to 6.)
[Appendix 4]
The electrode active material according to supplementary note 3, wherein the radical compound is represented by the following formula (5):

(In Formula (5), R < ¹ > -R < ⁴ >, R < ⁵ > and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ > and X in Formula (1) and Formula (2), respectively. Represents an integer of 2 to 6).
[Appendix 5]
The electrode active material according to supplementary note 3, wherein the radical compound is represented by the following formula (6):

(In Formula (6), R < ¹ > -R < ⁴ >, R < ⁵ > and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ > and X in Formula (1) and Formula (2), respectively. Represents an integer of 2 to 6).
[Appendix 6]
R ^{1 to} R ⁴ each independently represents an alkyl group having 1 to 3 carbon atoms,
R ⁵ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms,
The electrode active material according to any one of appendices 1 to 5, wherein X represents a single bond or an alkylene group having 3 to 12 carbon atoms.
[Appendix 7]
A secondary battery comprising the electrode active material according to any one of appendices 1 to 6.
[Appendix 8]
The secondary battery according to appendix 7, wherein the electrode active material is a positive electrode active material.
[Appendix 9]
The secondary battery according to appendix 7 or 8, which is a lithium battery.
[Appendix 10]
A method for producing a compound comprising reacting a radical compound represented by the following formula (7) with a cyclic siloxane compound represented by the following formula (8);

(In the formula (7), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. Y represents a hydrogen atom or a substituted or unsubstituted alkenyl group. R ^{1 to} R ⁴ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group.)

(In Formula (8), R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)
[Appendix 11]
The method for producing a compound according to appendix 10, wherein the radical compound and the cyclic siloxane compound are reacted to obtain a radical compound having a cyclic siloxane structure having a partial structure represented by the following formula (9):

(In the formula (9), Z is .R ⁵ represented by the following formula (10), the same meaning as ^{R 5} in the formula (8).).

(In the formula (10), A, and ^R 1 to R ⁴ are .X indicating each the same meaning A, and the ^R 1 to R ⁴ in the formula (7) represents a single bond, or a substituted or unsubstituted alkylene Group.)
[Appendix 12]
The method for producing a compound according to appendix 10 or 11, wherein the radical compound is represented by the following formula (11).

(In the formula (11), Y, and ^R 1 to R ⁴ indicate respectively the same meaning Y, and the ^R 1 to R ⁴ in the formula (7).).
[Appendix 13]
The method for producing a compound according to appendix 10 or 11, wherein the radical compound is represented by the following formula (12).

(In the formula (12), Y, and ^R 1 to R ⁴ indicate respectively the same meaning Y, and the ^R 1 to R ⁴ in the formula (7).).
[Appendix 14]
R ^{1 to} R ⁴ each independently represents an alkyl group having 1 to 3 carbon atoms,
R ⁵ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms,
The method for producing a compound according to any one of appendices 10 to 13, wherein Y represents a hydrogen atom or an alkenyl group having 3 to 12 carbon atoms.
[Appendix 15]
15. The method for producing a compound according to any one of appendices 10 to 14, wherein the radical compound and the cyclic siloxane compound are reacted under a transition metal catalyst.
[Appendix 16]
The method for producing a radical compound according to appendix 15, wherein the transition metal catalyst is an iridium compound, a ruthenium compound, a rhodium compound, a platinum compound, a palladium compound, or a nickel compound.
[Appendix 17]
A radical compound having a cyclic siloxane structure represented by the following formula (13);

(In the formula (13), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ each independently represents a hydrogen atom or a carbon atom having 1 to 3 carbon atoms. R ⁵ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms, X represents a single bond or an alkylene group having 3 to 12 carbon atoms, and n represents , Represents an integer of 2 to 6.)
[Appendix 18]
The radical compound according to appendix 17, represented by the following formula (14):

(In Formula (14), R < ¹ > -R < ⁴ >, R < ⁵ > and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ > and X in Formula (13), respectively, n is 2-6. Indicates an integer.)
[Appendix 19]
The radical compound according to appendix 17, represented by the following formula (15):

(In Formula (15), R < ¹ > -R < ⁴ >, R < ⁵ >, and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ >, and X in Formula (13), respectively, n is 2-6. Indicates an integer.)

It is a general-view figure which shows the structure of a coin-type battery.

DESCRIPTION OF SYMBOLS 1 Stainless steel exterior 2 Insulation packing 3 Negative electrode 4 Separator 5 Positive electrode 6 Positive electrode collector

Claims (10)

An electrode active material containing a radical compound containing a cyclic siloxane structure having a partial structure represented by the following formula (1);

(In formula (1), Z is represented by the following formula (2). R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

(In the formula (2), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group. X represents a single bond or a substituted or unsubstituted alkylene group. The electrode active material according to claim 1, wherein the radical compound is represented by the following formula (3):

(In the formula (3), Q is a group represented by a hydrogen atom or the above formulas (2), .R ⁵ at least 1 of the Q is a group represented by the above expression (2), the formula ( It has the same meaning as R ⁵ in 1), and n represents an integer of 2 to 6.) The electrode active material according to claim 1, wherein the radical compound is represented by the following formula (4):

In (Equation ^{(4), A, R 1} ~R 4, R 5, and X, A in the formula (1) and ^{(2), R 1 ~R 4} , R 5, and X and the same meaning, respectively N represents an integer of 2 to 6.) The electrode active material according to claim 3, wherein the radical compound is represented by the following formula (5):

(In Formula (5), R < ¹ > -R < ⁴ >, R < ⁵ > and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ > and X in Formula (1) and Formula (2), respectively. Represents an integer of 2 to 6). The electrode active material according to claim 3, wherein the radical compound is represented by the following formula (6):

(In Formula (6), R < ¹ > -R < ⁴ >, R < ⁵ >, and X show the same meaning as R < ¹ > -R < ⁴ >, R < ⁵ >, and X in Formula (1) and Formula (2), respectively. Represents an integer of 2 to 6). R ^{1 to} R ⁴ each independently represents an alkyl group having 1 to 3 carbon atoms,
R ⁵ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms,
The electrode active material according to claim 1, wherein X represents a single bond or an alkylene group having 3 to 12 carbon atoms.   A secondary battery comprising the electrode active material according to claim 1.   The secondary battery according to claim 7, wherein the electrode active material is a positive electrode active material. A method for producing a compound comprising reacting a radical compound represented by the following formula (7) with a cyclic siloxane compound represented by the following formula (8);

(In the formula (7), A is, .Y showing a linking group heterocyclic ring containing nitrogen to form a 5- to 7-membered ring, .R ¹ to R represents a hydrogen atom, or a substituted or unsubstituted alkenyl group ⁴ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group.)

(In Formula (8), R ⁵ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.) A radical compound having a cyclic siloxane structure represented by the following formula (13);

(In Formula (13), A represents a linking group in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ^{1 to} R ⁴ are each independently a hydrogen atom or a group having 1 to 3 carbon atoms. R ⁵ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms, X represents a single bond or an alkylene group having 3 to 12 carbon atoms, n represents , Represents an integer of 2 to 6.)

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