JP2009295397A - Organic radical secondary battery, charge/discharge control method of the organic radical secondary battery, and charge/discharge control device of the organic radical secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery which is easy to detect the battery charging state. <P>SOLUTION: In the secondary battery equipped with a positive electrode capable of adsorbing and discharging anions, a negative electrode capable of adsorbing and discharging cations, and an electrolytic solution in which the cations and the anions are dissolved between the positive electrode and the negative electrode, at least one electrode active material of the positive electrode and the negative electrode contains two or more of radical compounds which differ in oxidation-reduction potential. According to this constitution, since it becomes possible to multi-stage the battery potential at the time of charge/discharge, it is possible to carry out detection of the battery charging state easily. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an organic radical secondary battery, a charge / discharge control method for an organic radical secondary battery, and a charge / discharge control device for an organic radical secondary battery. The present invention relates to a charge / discharge control method for a secondary battery and a charge / discharge control device for an organic radical secondary battery.

  With the widespread use of electronic devices such as notebook computers, mobile phones, and digital cameras, the demand for secondary batteries for driving these electronic devices is increasing. In recent years, the power consumption of these electronic devices has increased with the progress of higher functionality, and the reduction in size is expected. Therefore, an increase in capacity is required for secondary batteries. Among secondary batteries, an organic radical battery using a radical compound having a light weight and a high electromotive force as a positive electrode active material has attracted attention because it may have a high energy density and a high output density.

Incidentally, there is a method of performing charge / discharge control for the secondary battery based on a change in terminal voltage. Specifically, charging / discharging is controlled based on the magnitude of the terminal voltage that changes in accordance with the charging capacity of the secondary battery.
JP 2002-304966 A

  However, as shown in the examples of Patent Document 1, when a battery is configured using a radical compound as an active material, the battery voltage during charging / discharging is flat. There is a problem that it is difficult to detect easily.

  The present invention has been completed in view of the above circumstances, and by charging the battery potential at the time of charging and discharging in multiple stages, the charging state of the organic radical secondary battery and the organic radical secondary battery in which the charged state of the secondary battery can be easily detected. An object to be solved is to provide a discharge control method and a charge / discharge control device for an organic radical secondary battery.

The feature of the organic radical secondary battery according to claim 1 for solving the above-mentioned problems is that a positive electrode capable of adsorbing and releasing anions, a negative electrode capable of adsorbing and releasing cations, and the positive and negative electrodes between a positive electrode and a negative electrode. In an organic radical secondary battery comprising an electrolytic solution in which ions are dissolved,
At least one of the positive electrode and the negative electrode has an active material containing two or more radical compounds having different oxidation-reduction potentials.

  The feature of the organic radical secondary battery according to claim 2 that solves the above-mentioned problem is that, in claim 1, the oxidation-reduction potential difference of the radical compound is 0.1 V or more.

  The feature of the organic radical secondary battery according to claim 3 that solves the above problem is that, in claim 1 or 2, the difference in the highest occupied molecular orbital energy (HOMO, calculated by a semi-empirical molecular orbital method) of the radical compound is Each is 0.2 eV or more.

The feature of the organic radical secondary battery according to claim 4 for solving the above problem is that a positive electrode capable of adsorbing and releasing anions, a negative electrode capable of adsorbing and releasing cations, and the positive and negative ions between the positive electrode and the negative electrode. In an organic radical secondary battery comprising an electrolyte solution in which
At least one of the positive electrode and the negative electrode has an electrode active material containing a radical compound and a tetrathiafulvalene derivative.

  A feature of the organic radical secondary battery according to claim 5 that solves the above problem is that in claim 4, the tetrathiafulvalene derivative is a compound represented by any one of the following general formulas (A1) to (A3): It is to be.

（式（Ａ１）〜（Ａ３）中、Ｒ^１〜Ｒ^７は水素、炭素数１〜４のアルキル基、フェニル基、Ｈ、ＯＨ、Ｆ、Ｃｌ、Ｂｒ、ＣＮ、及びＮＨ_２からそれぞれ独立して選択される。Ｙは−（ＣＨ_２）ｍ−（ｍは０〜１０の整数）であり、ｍが１以上のときはＹを構成するメチレン基の１つ以上が、−Ｏ−、−ＣＨ＝Ｎ−、−Ｓ−、及び−ＣＯ−の何れかで置換されても良い。ｎは自然数。）

(In the formulas (A1) to (A3), R ^{1 to} R ⁷ are independent of hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, H, OH, F, Cl, Br, CN, and NH _2. is the .Y is selected Te - _(CH 2) m-a (m is an integer of 0), one or more methylene groups constituting the Y when m is 1 or more is, -O -, - (It may be substituted with any one of CH = N-, -S-, and -CO-, where n is a natural number.)

The feature of the organic radical secondary battery according to claim 6 for solving the above problem is that a positive electrode capable of adsorbing and releasing anions, a negative electrode capable of adsorbing and releasing cations, and the positive and negative ions between the positive electrode and the negative electrode. In an organic radical secondary battery comprising an electrolyte solution in which
At least one of the positive electrode and the negative electrode has an electrode active material containing a radical compound and a quinone derivative.

  The feature of the organic radical secondary battery according to claim 7 for solving the above problem is that in claim 6, the quinone derivative is a compound represented by any one of the following general formulas (B1) to (B3). There is.

（式（Ｂ１）〜（Ｂ３）中、Ｒ^８〜Ｒ^１５は水素、炭素数１〜４のアルキル基、フェニル基、Ｈ、ＯＨ、Ｆ、Ｃｌ、Ｂｒ、ＣＮ、及びＮＨ_２からそれぞれ独立して選択される。
式（Ｂ１）中、Ｙは−（ＣＨ_２）_ｍ−（ｍは０〜１０の整数）であり、ｍが１以上のときはＹを構成するメチレン基の１つ以上が、−Ｏ−、−ＣＨ＝Ｎ−、−Ｓ−、及び−ＣＯ−の何れかで置換されても良い。ｎは自然数。）

(In the formulas (B1) to (B3), R ^{8 to} R ¹⁵ are independently of hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, H, OH, F, Cl, Br, CN, and NH _2. Selected.
In formula (B1), Y is — (CH ₂ ) _m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, It may be substituted with any of -CH = N-, -S-, and -CO-. n is a natural number. )

  The feature of the organic radical secondary battery according to claim 8 that solves the above problem is that, in any one of claims 1 to 7, the radical compound is a nitroxy radical compound or an oxy radical compound.

  The feature of the organic radical secondary battery according to claim 9 for solving the above-mentioned problem is that, in claim 8, the radical compound contains 2,2,6,6-tetramethylpiperidinoxymethacrylate as a unit compound. is there.

  A feature of the organic radical secondary battery according to claim 10 that solves the above problem is that, in claim 8 or 9, the radical compound is a compound represented by the following general formula (D1) or (D2). .

（式（Ｄ１）及び（Ｄ２）中、Ｒ^１６〜Ｒ^２０は水素、炭素数１〜４のアルキル基からそれぞれ独立して選択され、式（Ｄ１）中におけるＲ^１６及びＲ^１７の少なくとも１つは下記一般式（１）〜（４）で表される構造のうちの何れかである。式（Ｄ２）中におけるＲ^１８及びＲ^２０の少なくとも１つは下記一般式（１）〜（４）で表される構造のうちの何れかである。）

(In the formulas (D1) and (D2), R ^{16 to} R ²⁰ are independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, and at least one of R ¹⁶ and R ¹⁷ in the formula (D1). Is any one of the structures represented by the following general formulas (1) to (4), wherein at least one of R ¹⁸ and R ²⁰ in the formula (D2) is represented by the following general formulas (1) to (4). Any of the structures represented by

（式（１）〜（４）は＊の部分にて、前記式（Ｄ１）におけるピロール環の炭素原子又は窒素原子に結合する。式（１）〜（４）は＊の部分にて、前記式（Ｄ２）におけるチオフェン環の炭素原子に結合する。式（１）〜（４）中、ＲはＨ、ＯＨ、ＣＨ_３又はＮＨ_２である。式（１）〜（４）中、Ｙは−（ＣＨ_２）_ｍ−（ｍは０〜１０の整数）であり、ｍが１以上のときはＹを構成するメチレン基の１つ以上が、−Ｏ−、−ＣＨ＝Ｎ−、−Ｓ−、−ＣＯ−、

で置換されてもよい。）

(Formulas (1) to (4) are bonded to the carbon atom or nitrogen atom of the pyrrole ring in the formula (D1) at the part *. Formulas (1) to (4) are the part *. It binds to the carbon atom of the thiophene ring in formula (D2), wherein R is H, OH, CH ₃ or NH ₂ in formulas (1) to (4), where Y is formula (1) to (4). - _{(CH 2)} m - is (m is an integer of 0), m is at least one methylene group constituting the Y when one or more, -O -, - CH = N -, - S -, -CO-,

May be substituted. )

  The characteristic of the organic radical secondary battery according to claim 11 that solves the above problem is that, in any one of claims 8 to 10, the radical compound is a compound represented by the following general formula (E): is there.

（式（Ｅ）中、Ｒは水素、炭素数１〜４のアルキル基、フェニル基、Ｈ、ＯＨ、Ｆ、Ｃｌ、Ｂｒ、ＣＮ、及びＮＨ_２の何れかから選択される。式（Ｅ）中、Ｙは−（ＣＨ_２）_ｍ−（ｍは０〜１０の整数）であり、ｍが１以上のときはＹを構成するメチレン基の１つ以上が、−Ｏ−、−ＣＨ＝Ｎ−、−Ｓ−、−ＣＯ−で置換されても良い。）

(In the formula (E), R is selected from any of hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, H, OH, F, Cl, Br, CN, and NH _2. Formula (E) In the formula, Y is — (CH ₂ ) _m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O— or —CH═N. (It may be substituted with-, -S-, or -CO-.)

  A feature of the organic radical secondary battery according to claim 12 for solving the above-described problem is that, in claim 9, the radical compound is poly (2,2,6,6-tetramethylpiperidinoxymethacrylate). is there.

The charging / discharging control method of the organic radical secondary battery according to claim 13 for solving the above-described problem is characterized in that the organic radical secondary battery according to any one of claims 1 to 12 has a predetermined upper limit value. Charge and discharge control method of an organic radical secondary battery that performs charging and discharging so as to maintain the charging capacity between and a predetermined lower limit value,
The oxidation-reduction potential of the radical compound, the tetrathiafulvalene derivative, and / or the quinone derivative is equal to or less than a value corresponding to the predetermined upper limit value in the charge capacity, and a value corresponding to the predetermined lower limit value in the charge capacity. There are two or more in the working voltage range which is the above range,
The charge / discharge state is calculated from the terminal voltage of the organic radical secondary battery.

  A feature of the charge / discharge control method for an organic radical secondary battery according to claim 14 for solving the above-mentioned problem is that, in claim 13, when the charge capacity approaches the predetermined upper limit value from the predetermined lower limit value side. The terminal voltage of the organic radical secondary battery exceeds one of the two or more redox potentials.

  The charge / discharge control method for an organic radical secondary battery according to claim 15 that solves the above problem is characterized in that, in claim 13 or 14, the charge capacity approaches the predetermined lower limit value from the predetermined upper limit value side. In some cases, the terminal voltage of the organic radical secondary battery is lower than one of the two or more redox potentials.

The feature of the charge / discharge control device for an organic radical secondary battery according to claim 16 for solving the above-described problem is that the organic radical secondary battery according to any one of claims 1 to 12 has a predetermined upper limit value. And a charge / discharge control device for an organic radical secondary battery that performs charge / discharge so as to maintain a charge capacity between a predetermined lower limit value and
It exists in having a control means which controls charging / discharging by the charging / discharging control method of the organic radical secondary battery of any one of Claims 13-15.

  In the invention according to claim 1, since the battery voltage at the time of charging / discharging is multi-staged by having a plurality of types of radical compounds having different oxidation-reduction potentials as active materials, it is easy to detect the state of charge based on the battery voltage. Can be performed with high accuracy.

  In particular, as in the invention according to claim 2, it is effective to set the difference in oxidation-reduction potential of each radical compound to 0.1 V or more. Moreover, as in the invention according to claim 3, it is effective that the difference in the maximum occupied orbital energy of each radical compound is 0.2 eV or more. The difference in the maximum occupied orbital energy is a value calculated by the semi-empirical molecular orbital method. Although it does not specifically limit as a semi-empirical molecular orbital method, PPP method, CNDO method, INDO method, MNDO method can be illustrated.

  In the invention which concerns on Claim 4, since the battery voltage at the time of charging / discharging is multistaged by containing the mixture of a radical compound and a tetrathiafulvalene derivative in an electrode active material, the detection of the charge condition by a battery voltage is detected. This can be performed easily or with high accuracy.

  In particular, by employing a tetrathiafulvalene derivative as in the invention according to claim 5, the magnitude of voltage fluctuation during charging and discharging can be increased.

  In the invention which concerns on Claim 6, since the battery voltage at the time of charging / discharging is multistaged by containing the mixture of a radical compound and a quinone derivative in an electrode active material, the detection of the charge condition by a battery voltage is easy. Or it can be performed with high accuracy.

  In particular, by employing a quinone derivative as in the invention according to claim 7, the magnitude of voltage fluctuation during charging and discharging can be increased.

  In the invention which concerns on Claim 8, the voltage fluctuation at the time of charging / discharging can be made favorable by employ | adopting a nitroxy radical compound or an oxy radical compound as a specific radical compound.

  In particular, as in the invention according to claim 9, by adopting a compound containing 2,2,6,6-tetramethylpiperidinoxymethacrylate as a unit compound as a specific radical compound, at the time of charge and discharge The voltage fluctuation can be made more preferable. Further, as in the invention according to claim 12, by adopting poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), it is possible to make voltage fluctuation during charge / discharge more preferable. it can.

  Further, in the invention according to claim 10, by adopting a compound represented by the general formula (D1) or (D2) as a specific radical compound, voltage fluctuation during charge / discharge is made more preferable. Can do.

  Furthermore, in the invention which concerns on Claim 12, the voltage fluctuation at the time of charging / discharging can be made more preferable by employ | adopting the compound represented by General formula (E) as a specific radical compound.

  In the invention which concerns on Claim 13, the radical compound, tetrathiafulvalene derivative, and / or quinone derivative which are contained in the electrode active material which the organic radical secondary battery has as mentioned above are used. Voltage when using an organic radical secondary battery by having an oxidation-reduction potential within a working voltage range corresponding to a predetermined upper limit value and a predetermined lower limit value that are assumed to be charged / discharged for the organic radical secondary battery It becomes possible to increase the fluctuation.

  In particular, as in the invention according to claim 14, the battery voltage corresponding to the oxidation-reduction potential was exceeded by positioning the oxidation-reduction potential in the vicinity of the upper limit value of the charge / discharge range using the organic radical secondary battery. Thus, it is possible to easily detect that the charge capacity is near the upper limit of the charge / discharge range.

  Further, as in the invention according to claim 15, by placing the oxidation-reduction potential in the vicinity of the lower limit value of the charge / discharge range using the organic radical secondary battery, the battery voltage corresponding to the oxidation-reduction potential is reduced. It becomes possible to easily detect that the charge capacity is near the lower limit of the charge / discharge range.

  In the invention which concerns on Claim 16, by setting it as the charging / discharging control apparatus of the organic radical secondary battery which employ | adopted the charging / discharging control method of the organic radical secondary battery which concerns on any of Claims 13-15, It becomes possible to detect the charge / discharge state of the secondary battery with high accuracy.

[Organic radical secondary battery]
The organic radical secondary battery of the present invention will be described below based on the embodiments. The organic radical secondary battery of this embodiment is characterized by containing a radical compound in the electrode active material. A radical compound is a compound that contributes to the battery reaction. The organic radical secondary battery includes a positive electrode capable of adsorbing and releasing anions, a negative electrode capable of adsorbing and releasing cations, and an electrolytic solution in which cations and anions are dissolved between the positive electrode and the negative electrode.

  The electrode active material (the active material possessed by the positive electrode and / or the negative electrode) has two or more redox potentials. The oxidation-reduction potential exists in a battery voltage range that passes within a range where charge and discharge are performed on the organic radical secondary battery. Thus, when there are two or more oxidation-reduction potentials, voltage fluctuation when charging / discharging the organic radical secondary battery becomes large, and it becomes easy to detect the charge / discharge state from the voltage fluctuation. . The difference in redox potential is preferably 0.1 V, and more preferably 0.2 V or more. Further, the difference in the HOMO values calculated by the semi-empirical molecular orbital method is desirably 0.2 eV or more, and more desirably 0.4 eV or more.

  In order to make the electrode active material have a plurality of redox potentials, three methods are generally adopted. As a first method, radical compounds having different redox potentials are employed. As a second method, a configuration in which a tetrathiafulvalene derivative is contained in addition to the radical compound is adopted. As a third method, a configuration in which a quinone derivative is contained in addition to the radical compound is adopted. These first to third methods can be combined. Specifically, a radical compound having a different redox potential and a tetrathiafulvalene derivative are combined, a radical compound having a different redox potential and a quinone derivative are combined, or a radical compound, a tetrathiafulvalene derivative and a quinone derivative are combined. A radical compound having a different oxidation-reduction potential, a tetrathiafulvalene derivative, and a quinone derivative can be combined. Hereinafter, description will be made separately for the positive electrode and the negative electrode.

(Positive electrode)
The positive electrode is formed by mixing a binder conductive assistant in addition to the above-described active material in a solvent such as water or NMP, and then applying the mixture on a current collector made of a metal such as aluminum. The binder is preferably formed of a polymer material, and is preferably a material that is chemically and physically stable in the atmosphere in the secondary battery. For example, polyvinylidene fluoride, polytetrafluoroethylene, EPDM, SBR, NBR, fluorine rubber and the like can be mentioned. Examples of the conductive assistant include ketjen black, acetylene black, carbon black, graphite, carbon nanotube, and amorphous carbon. Further, conductive polymer polyaniline, polypyrrole, polythiophene, polyacetylene, polyacene and the like can be exemplified.

  Examples of radical compounds include copolymers or homopolymers partially containing 2,2,6,6-tetramethylpiperidinoxymethacrylate, the above general formulas (D1), (D2), and (E) The thing represented by is mentioned. The compounds represented by 2,2,6,6-tetramethylpiperidinoxymethacrylate, general formulas (D1), (D2), and (E) can be made into a copolymer that is arbitrarily combined.

In formulas (D1) and (D2), R ^{16 to} R ²⁰ are independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms (preferably a methyl group). At least one of R ¹⁶ and R ¹⁷ in the formula (D1) is any one of the structures represented by the general formulas (1) to (4). At least one of R ¹⁸ and R ²⁰ in the formula (D2) is any one of the structures represented by the general formulas (1) to (4). Of the general formulas (1) to (4), substituents represented by the general formulas (1) and (2) are preferable.

(Negative electrode)
As the negative electrode active material, the combination of the radical compound, tetrathiafulvalene derivative, and quinone derivative described in the positive electrode can be employed. The description of these combinations will be omitted. In addition to these compounds, compounds capable of occluding and releasing lithium ions can be used alone or in combination. Examples of compounds that can occlude and release lithium ions include metal materials such as lithium, alloy materials containing silicon, tin, etc., graphite, coke, organic polymer compound fired bodies, or carbon materials such as amorphous carbon. . These active materials can be used not only alone but also as a mixture of two or more thereof. For example, when a lithium metal foil is used as the negative electrode active material, it can be formed by pressure bonding the lithium foil to the surface of a current collector made of a metal such as copper. On the other hand, when an alloy material or a carbon material is used as the negative electrode active material, the negative electrode active material, a binder, a conductive additive, etc. are mixed in a solvent such as water or NMP, and then on a current collector made of a metal such as copper. It can be applied and formed. The binder is preferably formed of a polymer material, and is preferably a material that is chemically and physically stable in the atmosphere in the secondary battery. For example, polyvinylidene fluoride, polytetrafluoroethylene, EPDM, SBR, NBR, fluorine rubber and the like can be mentioned. Examples of the conductive assistant include ketjen black, acetylene black, carbon black, graphite, carbon nanotube, and amorphous carbon. Further, conductive polymer polyaniline, polypyrrole, polythiophene, polyacetylene, polyacene and the like can be exemplified.

(Electrolyte)
Although it does not specifically limit as electrolyte, What melt | dissolved supporting salt in solvents, such as an organic solvent, the ionic liquid which is liquid itself, and what further melt | dissolved supporting salt with respect to the ionic liquid can be illustrated. As an organic solvent, the organic solvent normally used for the electrolyte solution of a lithium secondary battery can be illustrated. For example, carbonates, halogenated hydrocarbons, ethers, ketones, nitriles, lactones, oxolane compounds and the like can be used. In particular, propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and the like, and mixed solvents thereof are suitable.

  Among these organic solvents mentioned in the examples, in particular, by using one or more non-aqueous solvents selected from the group consisting of carbonates and ethers, in terms of solubility, dielectric constant and viscosity, and stability of the supporting salt. It is preferable because it is excellent and the charge / discharge efficiency of the battery is also high.

An ionic liquid will not be specifically limited if it is an ionic liquid normally used for the electrolyte solution of a lithium secondary battery. For example, examples of the cation component of the ionic liquid include N-methyl-N-propylpiperidinium and dimethylethylmethoxyammonium cation. Examples of the anion component include BF ₄ ⁻ , N (SO ₂ CF ₃ ) ₂ ^—. Etc.

The supporting salt used in the electrolyte of the present embodiment is not particularly limited. For example, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiSbF ₆ , LiSCN, LiClO ₄ , LiAlCl ₄ , NaClO ₄ , BClO ₄ , NaI, and salt compounds such as derivatives thereof. Among these, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiN (FSO ₂ ) ₂ , LiN (CF ₃ One or more selected from the group consisting of a derivative of SO ₂ ) (C ₄ F ₉ SO ₂ ), a derivative of LiCF ₃ SO _3, a derivative of LiN (CF ₃ SO ₂ ) _{2 and} a derivative of LiC (CF ₃ SO ₂ ) ₃ It is preferable to use a salt from the viewpoint of electrical characteristics.

  It is desirable to interpose a separator that is a member that achieves both electrical insulation and ion conduction between the positive electrode and the negative electrode. When the electrolyte is liquid, the separator also serves to hold the liquid electrolyte. Examples of the separator include porous synthetic resin films, particularly porous films made of polyolefin polymers (polyethylene, polypropylene) and glass fibers, and nonwoven fabrics. Furthermore, it is preferable that the separator has a larger size than the positive electrode and the negative electrode for the purpose of ensuring the insulation between the positive electrode and the negative electrode.

  In general, the positive electrode, the negative electrode, the electrolyte, the separator, and the like are housed in some case. The case is not particularly limited and can be made of a known material and form.

[Charging / Discharging Control Method and Charge / Discharge Control Device for Organic Radical Secondary Battery]
Hereinafter, the charge / discharge control method and apparatus for an organic radical secondary battery of the present invention will be described based on embodiments. The organic radical secondary battery in which the charge / discharge control method and apparatus of this embodiment controls charge / discharge is the organic radical secondary battery of this embodiment described above. Since the charge / discharge control apparatus of this embodiment is an apparatus which implement | achieves the charge / discharge control method of this embodiment, it replaces with description of a charge / discharge control apparatus by description about a charge / discharge control method.

  This charge / discharge control method is a control method for performing charge / discharge so as to maintain the charge capacity between a predetermined upper limit value and a predetermined lower limit value. The predetermined upper limit value and lower limit value can be arbitrarily set. This control method maintains the voltage of the organic radical secondary battery within the operating voltage range defined by the upper limit voltage and the lower limit voltage corresponding to these predetermined upper limit value and lower limit value, thereby reducing the charge capacity to the predetermined upper limit value and lower limit value. It is a method to control to the range.

  The radical compound, tetrathiafulvalene derivative, and / or quinone derivative contained in the electrode active material of the organic radical secondary battery to be controlled have two or more redox potentials within this operating voltage range. That is, two or more types of electrode active materials having different redox potentials are contained. The electrode active material is a compound that contributes to the battery reaction by oxidation-reduction, and by changing the content ratio, a large fluctuation can be generated in the voltage of the organic radical secondary battery at an arbitrary charge capacity value.

  For example, description will be made based on an organic radical secondary battery in which an electrode active material is configured by combining only two kinds of radical compounds (a radical compound (i) having a low redox potential and a radical compound (ii) having a high redox potential). Needless to say, any combination of a radical compound and a tetrathiafulvalene derivative, a combination of a radical compound and a quinone derivative, or a combination of a radical compound, a tetrathiafulvalene derivative and a quinone derivative may be used.

  With regard to this organic radical secondary battery, considering a case where charging is performed from 0% SOC (state of charge) to 100% SOC, a radical compound having a low redox potential among two types of radical compounds From (i), it will be used for battery reaction. As charging progresses, radical compound (i) reacts preferentially.

  When the reaction of the radical compound (i) is completed, the reaction of the radical compound (ii) proceeds. By performing charging, the battery reaction proceeds as described above, and the radical compound contributing to the battery reaction shifts from the radical compound (i) having a low redox potential to the radical compound (ii) having a high redox potential. . As a result, the voltage of the battery increases as the redox potential changes.

  Here, by changing the mixing ratio of the radical compound (i) and the radical compound (ii), the SOC value at which the compound involved in the battery reaction switches from the radical compound (i) to the radical compound (ii) is changed. be able to.

  For example, when the radical compound (i) is in an amount corresponding to 80% of the SOC and the radical compound (ii) is in an amount corresponding to 20% of the SOC, when the SOC becomes 80%, the change in voltage increases. You can adjust as you like. By changing the amount of this mixture, the magnitude of the SOC in which the voltage changes can be changed arbitrarily, and by including the third and fourth components having different oxidation-reduction potentials, a plurality of SOC values can be obtained. The voltage can be changed greatly.

  The voltage fluctuation at the time of charging has been described above, but the same voltage fluctuation also occurs at the time of discharging. That is, when the discharge is performed from 100% to 0%, since the reaction of the radical compound (i) is completed after the reaction of the radical compound (ii) is completed, when reaching the SOC where the transition occurs, A large change (decrease) in voltage occurs. The SOC at which the voltage changes can be controlled by the mixing ratio of the radical compounds (i) and (ii).

  When detecting the SOC of an organic radical secondary battery by measuring the voltage of the organic radical secondary battery, if the voltage change in a specific SOC increases, the detection accuracy of the SOC change in the vicinity of the SOC increases, and the more precise charging is performed. The discharge amount can be controlled.

  In particular, when the charge capacity approaches the predetermined upper limit value (SOC 100%) from the predetermined lower limit value (SOC 0%) side, two or more redox potentials so that the terminal voltage of the organic radical secondary battery changes. By controlling the mixing ratio of the components so as to exceed one of the above, the controllability near the upper limit of the SOC can be improved.

  On the contrary, two or more redox reductions so that the terminal voltage of the organic radical secondary battery changes when the charge capacity approaches the predetermined lower limit (SOC 0%) from the predetermined upper limit (SOC 100%) side. By controlling the mixing ratio of the components so as to be lower than one of the potentials, the controllability near the lower limit of the SOC can be improved.

  Specifically, in the example of the radical compound (i) and (ii) described above, the radical compound at a mixing ratio corresponding to the target SOC causing the voltage change (for example, in the case of SOC 90%). (I): The radical compound (ii) (charge / discharge amount ratio) is mixed (in the case of SOC 90%, 10:90).

  Examples are shown below, and the details of the organic radical secondary battery of the present invention are described.

[Example 1]
(Synthesis of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate))
In a 2 L four-necked flask equipped with a stirrer under a nitrogen atmosphere, 135 g (0.563 mol) of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl and ethylene glycol dimethacrylate were added. 6.75 g (0.034 mol), 1.35 g (0.008 mol) of n-hexyl methacrylate, and 780 ml of dry toluene were charged and dissolved, and then cooled to −10 ° C.

  14.0 ml (0.028 mol) of a 2M ether solution of cyclopentylmagnesium chloride was slowly added dropwise so that the temperature of the solution for the reaction did not exceed -5 ° C. After completion of dropping, the mixture was stirred as it was at −10 ° C. for 5 hours, and further stirred at room temperature for 5 hours. After adding 34 g of acetic acid and 34 g of methanol to the reaction solution to deactivate the catalyst, it was dropped into 10 liters of a mixed solvent of water / methanol (volume ratio 1/9), filtered and dried to obtain poly (2,2 2,6,6-tetramethylpiperidinoxymethacrylate) was obtained.

(Synthesis of Compound of Formula (E) (Y is — (CH ₂ ) _m — (m is 0), R is Hydrogen))
To a tetrahydrofuran solution (15 ml) added with (4-bromo-2,6-di-tert-butylphenoxy) trimethylsilane (15.0 g, 41.9 mmol) cooled at −78 ° C. was added 5 mol / L butyllithium (28 A hexane solution containing 4 mL, 42.6 mmol) was added. This solution was stirred at −78 ° C. for 30 minutes, after which N, N, N ′, N′-tetramethylethylenediamine (6.9 mL), methyl-4-bromobenzene (4.1 g, 19.1 mmol) and tetrahydrofuran were added. (19.1 mL) was added and held at room temperature for 12 hours. Thereafter, water (19.1 mL) to which potassium hydroxide (6.9 g) was added was added, stirred for 24 hours, washed with an aqueous ammonium chloride solution and water, and then extracted with chloroform. The extract was purified by column chromatography (developing solvent: hexane-chloroform 1: 2). As a result, 4-bromo-[(3,5-di-tert-butyl-4-hydroxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-diene-1-ylidine) Methyl] -benzene was obtained.

  4.5 g (7.79 mmol) of 4-bromo-[(3,5-di-tert-butyl-4-hydroxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5 -Diene-1-ylidine) methyl] -benzene was dissolved in 191 mL of acetic anhydride and 1 drop of perchloric acid was added. The solution was stirred at room temperature for 15 h and excess water was further added. This mixed solution was extracted with ether and water. The ether layer was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by chromatography (silica gel, developing solvent hexane: chloroform (1: 2)). As a result, 4-bromo-[(3,5-di-tert-butyl-4-acetoxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-diene-1-ylidine) Methyl] -benzene was obtained.

  3-thiopheneboronic acid (0.68 g, 5.33 mmol) and 4-bromo-[(3,5-di-tert-butyl-4-acetoxyphenyl) (3,5-di-tert-butyl-4- Oxo-cyclohexa-2,5-diene-1-ylidine) methyl] -benzene (3.0 g, 4.84 mmol) was dissolved in 1,2-dimethoxyethane (10.2 mL) and tetrakis (triphenylphosphine). ) -Palladium (0.352 g, 0.305 mmol) and 2N sodium carbonate (10.2 mL) were added, and the mixture was stirred at 95 ° C. for 24 hours under a nitrogen atmosphere. Then, it cooled to room temperature and extracted with ether and water. The ether layer was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by chromatography (silica gel, developing solvent hexane: chloroform (1: 2)). As a result, 3- {4-[(3,5-di-tert-butyl-4-acetoxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-diene-1-ylidine ) Methyl] -phenyl} thiophene was obtained.

  3- {4-[(3,5-di-tert-butyl-4-acetoxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-diene-1-ylidine) methyl ] -Phenyl} thiophene (0.30 g, 0.482 mmol) dissolved in chloroform solution (96.3 ml) was added with iron chloride (0.31 g, 1.91 mmol) and stirred at room temperature for 200 hours under a nitrogen atmosphere. A red-purple reaction mixture was obtained. The reaction mixture was added to methanol and washed several times with a mixed solution of water and methanol. As a result, poly (3- {4-[(3,5-di-tert-butyl-4-acetoxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-diene-1 -Iridine) methyl] -phenyl} thiophene).

  Poly (3- {4-[(3,5-di-tert-butyl-4-acetoxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-diene-1-ylidine ) Methyl] -phenyl} thiophene) (199 mg) was dissolved in a small amount of tetrahydrofuran, and dimethyl sulfoxide (31 ml) and 2.5 N potassium hydroxide (1.5 mL) were added. The solution was stirred at 45 ° C. for 12 hours under a nitrogen atmosphere, neutralized with 1N hydrochloric acid, and extracted with ether and water. The organic layer was dried over sodium sulfate and evaporated under reduced pressure. This distilled solution was added to methanol, and poly (3- {4-[(3,5-di-tert-butyl-4-hydroxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa) was added. -2,5-diene-1-ylidine) methyl] -phenyl} thiophene).

Poly (3- {4-[(3,5-di-tert-butyl-4-hydroxyphenyl) (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-diene-1-ylidine ) Methyl] -phenyl} thiophene) (23.5 mg, 20 units mmol / L) in toluene solution (2 mL) was added aqueous sodium hydroxide (1 mL), and the mixture was stirred for 30 minutes under a nitrogen atmosphere. To this solution was added 1 mL of an aqueous solution of potassium ferricyanide (13.1 mg, 12 equivalents per galvinoxyl unit), and the mixture was further stirred for 30 minutes. The toluene layer is washed with water, dried over sodium sulfate, and then distilled off under reduced pressure. The radical compound represented by the above formula (E) (Y is — (CH ₂ ) _m — (m is 0), and R is hydrogen. (Hereinafter simply referred to as the compound of formula (E)).

(Preparation of positive electrode)
6 parts by weight of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), 54 parts by weight of the compound of formula (E), 30 parts by weight of acetylene black, and 10 parts of polyvinylidene fluoride (PVDF) Normal methylpyrrolidone (NMP) was added to the parts by mass, mixed and dispersed to prepare a homogeneous coating liquid. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector.

(Preparation of negative electrode)
A negative electrode was produced by cutting lithium metal foil (thickness 300 μm) into a predetermined size.

(Preparation of electrolyte)
Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed at a volume ratio of 3: 7, and LiPF ₆ as a supporting electrolyte was dissolved in the mixed organic solvent at a concentration of 1 mol / L to obtain an electrolytic solution. .

(Production of battery)
A plate-shaped electrode body was formed by sandwiching a polypropylene separator between the positive electrode and the negative electrode obtained above. The obtained flat electrode body was inserted into the case and held in the case. Then, after inject | pouring the said electrolyte solution in the case holding the flat electrode body, the case was sealed and sealed (FIG. 2).

  Specifically, the positive electrode was used for the positive electrode 1 and lithium metal was used for the negative electrode 2. As the electrolytic solution 3, the prepared electrolytic solution was used. Separator 7 manufactured a coin type battery using a 25-micrometer-thick polyethylene porous membrane, respectively. The positive electrode 1 has a positive electrode current collector 1a, and the negative electrode 2 has a negative electrode current collector 2a.

  These power generation elements were housed in a stainless steel case (consisting of a positive electrode case 4 and a negative electrode case 5). The positive electrode case 4 and the negative electrode case 5 serve as a positive electrode terminal and a negative electrode terminal. A gasket 6 made of polypropylene is interposed between the positive electrode case 4 and the negative electrode case 5, thereby ensuring sealing and insulating properties between the positive electrode case 4 and the negative electrode case 5. Through the above procedure, a coin-type battery having a diameter of 19 mm and a thickness of 3 mm was manufactured and used as a test battery of this example.

(Evaluation of battery voltage during discharge)
Evaluation of charge and discharge voltage characteristics of the produced non-aqueous electrolyte secondary battery was charged from 2.5V to 4.1V at a current value of 0.01 mA / cm ^2, the current value of 0.01 mA / cm ² FIG. 1 shows the result of measuring the battery voltage with respect to the SOC when discharging from 4.1 V to 2.5 V. As a result, there are flat portions around 3.6V (corresponding to poly (2,2,6,6-tetramethylpiperidinoxymethacrylate)) and around 3.1V (corresponding to the compound of formula (E)). It was confirmed that a discharge potential curve causing a large voltage change in a charged state of about 80% was shown.

[Example 2]
NMP is added to 18 parts by mass of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), 42 parts by mass of the compound of formula (E), 30 parts by mass of acetylene black, and 10 parts by mass of PVDF. , Mixed and dispersed to prepare a homogeneous coating liquid. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector.

  A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it was confirmed that there were flat portions in the vicinity of about 3.6 V and 3.1 V, and a discharge potential curve that caused a large voltage change in a charged state of about 50% was shown (FIG. 1).

[Example 3]
NMP is added to 29 parts by mass of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), 31 parts by mass of the compound of the formula (E), 30 parts by mass of acetylene black, and 10 parts by mass of PVDF. , Mixed and dispersed to prepare a homogeneous coating liquid. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector. A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it was confirmed that there were flat portions in the vicinity of about 3.6 V and 3.1 V, and a discharge potential curve that caused a large voltage change in a charged state of about 30% was shown (FIG. 1).

[Example 4]
(Compound of Formula (F) (R ¹ in General Formula (D2) is General Formula (1), R ² and R ³ are Hydrogen; In General Formula (1), R is Hydrogen, Y is —O (CH ₂ ) Synthesis of _3- (bonded to nitrogen atom of pyrrole ring at carbon atom)))
While cooling in an ice bath, 18 mL (0.24 mol) of 3-amino-1-propanol was added to 33 mL of acetic acid, and 9 mL (0.07 mol) of 2,5-dimethoxytetrahydrofuran was added all at once and refluxed for 2 hours. did. After cooling to room temperature, 120 mL of water was added, and extraction operation was performed 3 times with 50 mL of dichloromethane.

The obtained organic layer was dried over Na ₂ SO ₄ and the solvent was removed under reduced pressure. Methanol (60 mL) and 20% by mass NaOH aqueous solution (60 mL) were added to the residue, and the mixture was stirred at room temperature for 2.5 hours. Then, 100 mL of saturated NaCl aqueous solution was added, and extraction operation was performed 3 times with 50 mL of dichloromethane.

The obtained organic layer was dried over Na ₂ SO ₄ , the solvent was removed under reduced pressure, and the residue was purified by column chromatography (developing solvent: ethyl acetate-hexane 1: 1) to give 1- (3-hydroxypropyl) -1H. -Pyrrole was obtained.

While cooling with an ice bath in a nitrogen atmosphere, 3.5 g (0.28 mol) of 1- (3-hydroxypropyl) -1H-pyrrole and 4.16 mL (0.30 mol) of triethylamine were added to 25 mL of dichloromethane. Then, 2.45 mL (0.30 mol) of methanesulfonic acid chloride was added dropwise, and the mixture was stirred at room temperature for 3 hours. 60 mL of water was added, and extraction operation was performed with 60 mL of dichloromethane. The obtained organic layer was washed with 60 mL of a 5% by mass aqueous NaHCO ₃ solution and then dried over Na ₂ SO ₄ , and the solvent was removed under reduced pressure. Thereafter, purification was performed by column chromatography (developing solvent: chloroform) to obtain 1- (3′-MsO-propyl) -1H-pyrrole.

Under nitrogen atmosphere, NaH (60% in Oil, 0.81 g, 0.203 mol) washed with hexane and 3.5 g (0.203 mol) of 4-hydroxy-TEMPO were added to 30 mL of DMF, and the mixture was stirred at 0 ° C. for 1 hour. . Thereafter, 5 g (0.246 mol) of 1- (3′-MsO-propyl) -1H-pyrrole was added dropwise and stirred at room temperature for 15 hours. 60 mL of water was added, and extraction operation was performed with 150 mL of hexane. The obtained organic layer was washed 6 times with 25 mL of water, dried over Na ₂ SO ₄ , and the solvent was removed under reduced pressure. Thereafter, purification was performed by column chromatography (developing solvent: ethyl acetate-hexane 1: 3) to obtain a radical compound represented by the following formula (F).

  NMP is added to 39 parts by mass of the compound represented by the formula (E), 21 parts by mass of the compound represented by the formula (F), 30 parts by mass of acetylene black, and 10 parts by mass of PVDF. A coating liquid was prepared. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector. A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it can be confirmed that a discharge potential curve having a flat portion near 3.6 V (corresponding to the compound of formula (F)) and 3.1 V and causing a large voltage change in a charged state of about 50% can be confirmed. It was.

[Example 5]
(Synthesis of compound of formula (G) (tetrathiafulvalene derivative: R ^{1 to} R ³ in formula (A1) are hydrogen and m in Y is 0))
While cooling in an ice bath under a nitrogen atmosphere, 2.71M n-butyllithium / hexane (2.5 mL, 6.7 mmol) was added to a solution of 3 mL of tetrahydrofuran and diisopropylamine (0.94 mL, 6.7 mmol) for 15 minutes. A lithium diisopropylamide solution was prepared by stirring. Under a nitrogen atmosphere, a lithium diisopropylamide solution was added dropwise to a solution of tetrathiafulvalene (compound a, 1.23 g, 6 mmol) and tetrahydrofuran 20 mL at −78 ° C. and stirred for 1 hour. Tridecafluorohexyl iodine (2.6 mL, 6.7 mmol) was added all at once, and the mixture was further stirred for 1 hour. After returning to room temperature over about 1 hour, a small amount of water was added to stop the reaction. The solvent was distilled off under reduced pressure and extracted with chloroform and water. The organic layer was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by column chromatography (silica gel, developing solvent hexane: CHCl ₃ (2: 1)) to obtain compound b.

Triethylamine was added to compound b (1.0 g, 3 mmol), tetrakistriphenylphosphine palladium (0.46 g, 0.4 mmol) and copper (I) iodide (0.15 g, 0.79 mmol) at room temperature under a nitrogen atmosphere. 10 mL and 20 mL of tetrahydrofuran were added. Next, trimethylsilylacetylene (1.0 mL, 7.2 mmol) was added and stirred for 5 hours. Thereafter, the solvent was distilled off under reduced pressure, and extraction was performed with hexane: CHCl ₃ (1: 1) and water. The organic layer was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by column chromatography (silica gel, developing solvent hexane: CHCl ₃ (2: 1)) to obtain compound c.

To a solution of compound c (0.4 g, 1.3 mmol) and tetrahydrofuran 5 ml at room temperature, 1.0 M tetrabutylammonium fluoride / tetrahydrofuran (0.75 mL, 2.6 mmol) was added and stirred for 5 minutes. Thereafter, calcium chloride (0.33 g, 3 mmol) / 5 ml of water was added to stop the reaction. Extraction was performed with chloroform and water, the organic layer was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and purification was performed by column chromatography (silica gel, developing solvent hexane: CHCl ₃ (1: 1)) to obtain compound d. It was.

Compound d (228 mg, 1 mmol), norbornadiene rhodium (I) chloride dimer (11 mg, 2.4 × 10 ⁻⁵ mol), triethylamine (1.59 mL, 11.4 mmol) and tetrahydrofuran 4 at room temperature under a nitrogen atmosphere. .5 ml was added and stirred for 3 hours. Chloroform was added and filtered to obtain a tetrathiafulvalene derivative represented by the following formula (G).

  Add NMP to 15 parts by mass of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), 45 parts by mass of formula (G), 30 parts by mass of acetylene black, 10 parts by mass of PVDF, and mix Then, a homogeneous coating liquid was prepared by dispersing. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector. A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it was confirmed that a discharge potential curve having a flat portion was observed in the vicinity of 3.6V and 3.3V (corresponding to compound G).

[Example 6]
(Synthesis of Compound of Formula (H) (Quinone Derivative: R ⁸ and R ⁹ in General Formula (B) are OH Groups, and m in Y is 0))
By adding an aqueous formaldehyde solution in glacial acetic acid that was heated to 60 ° C. with 2,5 dihydroxybenzoquinone, 2,5 dihydroxybenzoquinone was polymerized to obtain a compound of the following formula (H).

  NMP is added to 15 parts by mass of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), 45 parts by mass of the compound of formula (H), 30 parts by mass of acetylene black, and 10 parts by mass of PVDF. , Mixed and dispersed to prepare a homogeneous coating liquid. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector. A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it was confirmed that a discharge potential curve having a flat portion near 3.6 V and near 2.9 V (corresponding to the compound portion of formula (H)) was shown.

[Example 7]
(Synthesis 2 of the compound of formula (J) (quinone derivative: R ¹⁰ and R ¹¹ in formula (B2) are hydrogen) 2)
1,4-Naphthoquinone was added to concentrated sulfuric acid to which sodium nitrate was added, and the mixture was kept at 5 ° C. and recrystallized with methanol to obtain 5-nitro-1,4-naphthoquinone. 5-Nitro-1,4-dihydroxynaphthalene is obtained by dissolving 5-nitro-1,4-naphthoquinone in acetic acid, adding concentrated hydrochloric acid in which tin chloride is dissolved to this acetic acid solution, and maintaining the temperature at 100 ° C. It was.

  Further, an iron (III) chloride aqueous solution was added to the above solution, and purified by column chromatography and recrystallized to obtain 5-amino-1,4 naphthoquinone.

  5-Amino-1,4 naphthoquinone (0.01 mol / L) is added to an acetonitrile solution in which 0.1 mol / L lithium perchlorate is dissolved, and 0.5 to 1.45 V with respect to the saturated calomel electrode. Electrolytic polymerization was performed by repeating potential scanning at 50 mV / sec to obtain a quinone derivative represented by the following formula (J). A Pt electrode was used as the electrode for electrolytic polymerization.

  NMP is added to 15 parts by mass of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), 45 parts by mass of the compound of formula (J), 30 parts by mass of acetylene black, and 10 parts by mass of PVDF. , Mixed and dispersed to prepare a homogeneous coating liquid. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector. A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it was confirmed that a discharge potential curve having a flat portion was exhibited around 3.6 V and around 2.5 V (corresponding to the compound of formula (J)).

[Comparative Example 1]
NMP was added to 60 parts by mass of poly (2,2,6,6-tetramethylpiperidinoxymethacrylate), 30 parts by mass of acetylene black, and 10 parts by mass of PVDF, and mixed and dispersed to prepare a homogeneous coating liquid. . This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector. A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it was confirmed that a discharge potential curve having a flat portion in the vicinity of about 3.6 V was shown (FIG. 1).

[Comparative Example 2]
Normal methyl pyrrolidone (NMP) was added to 60 parts by mass of the compound of formula (F), 30 parts by mass of acetylene black, and 10 parts by mass of polyvinylidene fluoride (PVDF), mixed and dispersed to prepare a homogeneous coating liquid. This homogeneous coating liquid was applied to one side of an aluminum current collector (50 μm), dried, pressed, and then cut into a predetermined size to produce a positive electrode. The thickness of the produced positive electrode was 100 μm including the aluminum current collector. A battery was produced in the same manner as in Example 1 except that the positive electrode was used, and the battery voltage during discharge was evaluated. As a result, it was confirmed that a discharge potential curve having a flat portion in the vicinity of about 3.6 V was shown (FIG. 1).

(result)
As shown in Comparative Examples 1 and 2, when the electrode is configured using only one radical compound as the active material, the battery voltage during discharge is flat. However, it is difficult to detect these compounds by using a plurality of radical compounds having different oxidation-reduction potentials (Examples 1 and 4), or by combining radical compounds tetrathiafulvalene derivatives and quinone derivatives. Since it becomes possible to make the discharge potential multistage, it has been confirmed that it is possible to provide a nonaqueous electrolyte secondary battery in which the battery charge state can be easily detected.

  Further, as shown in FIG. 1 (Examples 1, 2, and 3), it is possible to change the SOC value at which the voltage changes by adjusting the blending amount of the radical compound added in the electrode. It was confirmed that it is possible to provide an organic radical secondary battery in which the state of charge can be easily detected.

The discharge potential curve of each battery measured in the Example is shown. It is a longitudinal cross-sectional view which shows roughly an example of the structure of the coin-type battery of the nonaqueous electrolyte secondary battery of this invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Positive electrode 1a ... Positive electrode collector 2 ... Negative electrode 2a ... Negative electrode collector 3 ... Electrolyte solution 4 ... Positive electrode case 5 ... Negative electrode case 6 ... Gasket 7 ... Separator 10 ... Coin type nonaqueous electrolyte secondary battery

Claims (16)

In an organic radical secondary battery comprising a positive electrode capable of adsorbing and releasing anions, a negative electrode capable of adsorbing and releasing cations, and an electrolyte solution in which the positive and negative ions are dissolved between the positive electrode and the negative electrode,
An organic radical secondary battery, wherein at least one electrode active material of the positive electrode and the negative electrode contains two or more radical compounds having different oxidation-reduction potentials.   The organic radical secondary battery according to claim 1, wherein each of the radical compounds has a redox potential difference of 0.1 V or more.   The organic radical secondary battery according to claim 1 or 2, wherein the difference in the maximum occupied orbital energy of the radical compound is 0.2 eV or more. In an organic radical secondary battery comprising a positive electrode capable of adsorbing and releasing anions, a negative electrode capable of adsorbing and releasing cations, and an electrolyte solution in which the positive and negative ions are dissolved between the positive electrode and the negative electrode,
An organic radical secondary battery, wherein at least one of the positive electrode and the negative electrode active material contains a radical compound and a tetrathiafulvalene derivative. The organic radical secondary battery according to claim 4, wherein the tetrathiafulvalene derivative is a compound represented by any one of the following general formulas (A1) to (A3).

(In the formulas (A1) to (A3), R ^{1 to} R ⁷ are independent of hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, H, OH, F, Cl, Br, CN, and NH _2. Y is — (CH ₂ ) _m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, — (It may be substituted with any one of CH = N-, -S-, and -CO-, where n is a natural number.) In an organic radical secondary battery comprising a positive electrode capable of adsorbing and releasing anions, a negative electrode capable of adsorbing and releasing cations, and an electrolyte solution in which the positive and negative ions are dissolved between the positive electrode and the negative electrode,
At least one electrode active material of the positive electrode and the negative electrode contains a radical compound and a quinone derivative. The organic radical secondary battery according to claim 6, wherein the quinone derivative is a compound represented by any one of the following general formulas (B1) to (B3).

(In the formulas (B1) to (B3), R ^{8 to} R ¹⁵ are independently of hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, H, OH, F, Cl, Br, CN, and NH _2. Selected.
In formula (B1), Y is — (CH ₂ ) _m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O—, It may be substituted with any of -CH = N-, -S-, and -CO-. n is a natural number. )   The organic radical secondary battery according to claim 1, wherein the radical compound is a nitroxy radical compound or an oxy radical compound.   The organic radical secondary battery according to claim 8, wherein the radical compound includes 2,2,6,6-tetramethylpiperidinoxymethacrylate as a unit compound. The organic radical secondary battery according to claim 8 or 9, wherein the radical compound is a compound represented by the following general formula (D1) or (D2).

(In the formulas (D1) and (D2), R ^{16 to} R ²⁰ are independently selected from hydrogen and an alkyl group having 1 to 4 carbon atoms, and at least one of R ¹⁶ and R ¹⁷ in the formula (D1). Is any one of the structures represented by the following general formulas (1) to (4), wherein at least one of R ¹⁸ and R ²⁰ in the formula (D2) is represented by the following general formulas (1) to (4). Any of the structures represented by

(Formulas (1) to (4) are bonded to the carbon atom or nitrogen atom of the pyrrole ring in the formula (D1) at the part *. Formulas (1) to (4) are the part *. It binds to the carbon atom of the thiophene ring in formula (D2), wherein R is H, OH, CH ₃ or NH ₂ in formulas (1) to (4), where Y is formula (1) to (4). - _{(CH 2)} m - is (m is an integer of 0), m is at least one methylene group constituting the Y when one or more, -O -, - CH = N -, - S -, -CO-,

May be substituted. ) The organic radical secondary battery according to any one of claims 8 to 10, wherein the radical compound is a compound represented by the following general formula (E):

(In the formula (E), R is selected from any of hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, H, OH, F, Cl, Br, CN, and NH _2. Formula (E) In the formula, Y is — (CH ₂ ) _m — (m is an integer of 0 to 10), and when m is 1 or more, one or more methylene groups constituting Y are —O— or —CH═N. (It may be substituted with-, -S-, or -CO-.)   The organic radical secondary battery according to claim 9, wherein the radical compound is poly (2,2,6,6-tetramethylpiperidinoxymethacrylate). The organic radical secondary battery which charges / discharges the organic radical secondary battery according to any one of claims 1 to 12 so as to maintain a charge capacity between a predetermined upper limit value and a predetermined lower limit value. Charge / discharge control method,
The oxidation-reduction potential of the radical compound, the tetrathiafulvalene derivative, and / or the quinone derivative is equal to or less than a value corresponding to the predetermined upper limit value in the charge capacity, and a value corresponding to the predetermined lower limit value in the charge capacity. There are two or more in the working voltage range which is the above range,
A charge / discharge control method for an organic radical secondary battery, wherein a charge / discharge state is calculated from a terminal voltage of the organic radical secondary battery.   When the charge capacity approaches the predetermined upper limit value from the predetermined lower limit value side, the terminal voltage of the organic radical secondary battery exceeds one of the two or more redox potentials. The charge / discharge control method of the organic radical secondary battery according to claim 13.   When the charge capacity approaches the predetermined lower limit value from the predetermined upper limit side, the terminal voltage of the organic radical secondary battery is lower than one of the two or more redox potentials. The charge / discharge control method of the organic radical secondary battery according to claim 13 or 14. The organic radical secondary battery which charges / discharges the organic radical secondary battery according to any one of claims 1 to 12 so as to maintain a charge capacity between a predetermined upper limit value and a predetermined lower limit value. Charge / discharge control device,
16. A charge / discharge control device for an organic radical secondary battery, comprising a control means for controlling charge / discharge in the charge / discharge control method for an organic radical secondary battery according to any one of claims 13 to 15. .

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