JP5598134B2 - Electric storage device and method for manufacturing electrode active material - Google Patents

Description

  The present invention relates to an electricity storage device and a method for producing an electrode active material.

Conventionally, as an electricity storage device, a high-capacity battery is expected to use sulfur having an extremely high theoretical capacity density of 1672 Ah / kg as an electrode active material. The basic structure of an electricity storage device using sulfur is relatively simple, using a mixture of sulfur, a conductive additive carbon and a binder for the positive electrode, using metallic Li or a material containing it for the negative electrode, and LiPF for the electrolyte. An ether-based organic electrolyte in which a supporting salt such as ₆ is dissolved is used. In the electricity storage device, the solubility of the positive electrode active material sulfur and the reaction product polysulfide ions in the electrolytic solution is high, so the capacity reduction and the reaction with the elution and reaction with the negative electrode (hereinafter also referred to as the shuttle effect) A decrease in charge / discharge efficiency is a problem. As a prevention method for this, for example, in Patent Document 1, carbon and sulfur are the main constituent elements, disulfide is bonded to the carbon chain, and the weight ratio of sulfur is increased as much as possible to increase the capacity and capacity retention rate in the charge / discharge cycle. Improvements have been proposed. Patent Document 2 proposes a polysulfurized carbon having a sulfur ratio of 67% by weight or more and a total of carbon and sulfur of 95% by weight or more as an active material and further improved cycle characteristics. Non-Patent Document 1 proposes a ladder polymer in which the main chain of conductive polyaniline is connected by disulfide. Non-Patent Document 2 proposes a method for immobilizing sulfur by reacting polyacrylonitrile, which is a linear polymer not containing aromatics, with sulfur, and then cyclizing the carbon chain. Yes.

JP 2002-154815 A JP 2003-123758 A

Journal of Electrochemical Society 144, L173, 1997 Journal of Electroanalytical Chemistry 572, 121-128, 2004

  However, when single sulfur is used, two electrons are exchanged during redox, whereas in the electric storage devices described in Patent Documents 1 and 2 and Non-Patent Documents 1 and 2, sulfur is combined with carbon. For this reason, only one electron is transferred during oxidation-reduction, and the capacity may be reduced. In addition, there is a problem that the capacity per unit weight is reduced because a portion not directly related to the redox reaction, that is, energy storage, such as a carbon chain increases. For example, in Patent Documents 1 and 2, an attempt is made to further increase the sulfur component, to form a sulfide bond between sulfurs, and to increase the sulfur component that is not bonded to carbon. As in the case of using simple sulfur, it was considered that a problem of dissolution of the active material occurred, causing a decrease in charge / discharge efficiency and a decrease in capacity during cycling. Further, in Non-Patent Document 1, in poly (2,2′-dithiodianiline), the theoretical capacity is 330 Ah / kg even when the redox of the polyaniline part is used, and the experimental capacity is 270 Ah / kg per active material. The theoretical capacity of sulfur alone is 1672 Ah / kg, which is significantly lower than 670 Ah / kg in the case of a 50 wt% sulfur positive electrode. Non-Patent Document 2 states that a high-capacity material can be produced. However, the sulfur concentration is the best with only 35% by weight. This is because 15% by weight of nitrogen which cannot be combined with sulfur is contained, and therefore the capacity is not sufficient.

  The present invention has been made in view of such a problem, and a main object of the present invention is to provide a power storage device and a method for producing an electrode active material that can further improve charge / discharge cycle characteristics and capacity in the case of containing sulfur. And

  As a result of diligent research to achieve the above-described object, the present inventor has found that a structure in which three or more aromatic rings are connected, and the two or more structures are combined in a plane to fix sulfur. It has been found that the charge and discharge cycle characteristics and capacity can be further improved by using a ring compound, and the present invention has been completed.

  That is, the electricity storage device of the present invention is a polycyclic compound having a structure in which three or more aromatic rings are connected, and a carbon-based aromatic ring in which at least one hydrogen in the connected aromatic rings is substituted with sulfur. The polycyclic compound having a basic structure including one or more and having two or more basic structures bonded together by a heterocyclic structure is used as an electrode active material.

  Alternatively, the electricity storage device of the present invention comprises at least one of an aromatic compound having a structure in which three or more aromatic rings are connected and an aromatic vinylene polymer having a structure in which one or more aromatic rings are connected, and sulfur. A polycyclic compound obtained by mixing and heating is used as an electrode active material.

  The method for producing an electrode active material according to the present invention is a method for producing an electrode active material used for an electrode of an electricity storage device, and has an aromatic structure in which three or more aromatic rings including carbon-based aromatic rings are connected. A synthesis step of synthesizing a polycyclic compound by mixing and heating at least one of the compound and an aromatic vinylene polymer having a structure in which one or more aromatic rings are linked to each other and sulfur.

  The manufacturing method of the electricity storage device and the electrode active material of the present invention can further improve charge / discharge cycle characteristics and capacity. The reason why such an effect is obtained is not clear, but is presumed as follows. For example, since elemental sulfur is bonded to polycyclic aromatics, the shuttle effect, which is a problem when using sulfur alone, can be prevented, and repeated charging / discharging in a state where capacity reduction and charge / discharge efficiency decrease are further suppressed. It can be carried out. This sulfur-bonded polycyclic compound has electronic conductivity and contributes to the oxidation-reduction electron transport of sulfur element. Polycyclic compounds are presumed to have a structure in which molecules are stacked due to intermolecular interactions such as van der Waals force and π-π interaction. When the distance is increased, it is presumed that a large capacitance like an electric double layer capacitor or Li intercalation is expressed. When sulfur is immobilized, only one-electron redox can occur, and lowering the capacity becomes a problem. However, in the present invention, three or more aromatic rings are connected, and the electrostatic capacity of the polycyclic compound is reduced. Capacitance can be superimposed. For this reason, in addition to the capacity associated with the redox of sulfur bonded to the polycyclic compound, the capacity of the polycyclic compound due to the oxidation / reduction of sulfur is superposed, and a new mechanism that has not been used so far greatly increases the capacity. It is presumed that the charge / discharge cycle characteristics could be further improved. Note that the three or more linked aromatic rings may be carbon-based aromatics, or at least one or more aromatic rings may include a heterocyclic ring containing sulfur, nitrogen, oxygen, and the like.

Explanatory drawing of the evaluation cell 10. FIG. The Raman spectrum of the polycyclic compound of Examples 1-6 and Comparative Example 1. Cyclic voltammetry of Example 1. Cyclic voltammetry of Comparative Example 3.

  The electricity storage device of the present invention uses a polycyclic compound as an electrode active material. This polycyclic compound has a structure in which three or more aromatic rings are linked. In addition, the polycyclic compound has a basic structure including one or more carbon-based aromatic rings in which at least one hydrogen is replaced with sulfur among the connected aromatic rings. In the polycyclic compound, two or more basic structures are bonded to each other by forming a heterocyclic structure. In this electricity storage device, for example, a polycyclic compound as an electrode active material may be used as a positive electrode active material or a negative electrode active material. That is, an electricity storage device of the present invention includes a positive electrode having the polycyclic compound as a positive electrode active material, a negative electrode having a negative electrode active material, and an ion conductive medium that is interposed between the positive electrode and the negative electrode to conduct ions. It may be a thing. In addition, an electricity storage device of the present invention includes a positive electrode having a positive electrode active material, a negative electrode having the polycyclic compound as a negative electrode active material, and an ion conductive medium that is interposed between the positive electrode and the negative electrode and conducts ions. It is also good. The conducting ions may be, for example, ions of Group 1 elements such as lithium, sodium and potassium, and ions of Group 2 elements such as magnesium and calcium. Among these, lithium ion is preferable from the viewpoint of energy density. Here, the case where the above polycyclic compound is used as the positive electrode active material and the ion conductive medium conducts lithium ions will be mainly described.

  In the electricity storage device of the present invention, the polycyclic compound has a structure in which three or more aromatic rings are connected. In this polycyclic compound, the connected aromatic ring may have a structure in which 10 or less aromatic rings are connected, and preferably has a structure in which 6 or less aromatic rings are connected. It is more preferable to have a structure in which 4 or less are connected. A smaller number of linked aromatic rings is preferable because it is easier to obtain and handle. Here, it is inferred that the polycyclic compound is planar and has a structure in which molecules are stacked by intermolecular interactions such as van der Waals force and π-π interaction. And when the distance between polycyclic compounds spreads by the production | generation of an anion etc., it is guessed that a large electrostatic capacitance like an electric double layer capacitor or Li intercalation is expressed. For this reason, battery capacity can be raised more. This aromatic ring may include a five-membered ring or a six-membered ring. The aromatic ring may include a carbon-based aromatic ring (for example, a benzene ring), or a heterocyclic ring (for example, a thiophene ring) containing one or more of sulfur, nitrogen, and oxygen in the ring structure. May be included. Examples of the aromatic ring include six-membered rings having anthracene structure and phenanthrene structure, tetracene structure, pyrene structure, triphenylene structure, tetraphen structure and chrysene structure, pentacene structure, picene structure and perylene structure. The thing etc. which have are mentioned. For example, “having an anthracene structure” includes anthracene, anthracene derivatives having a substituent bonded to anthracene, and those having a five-membered ring compound bonded to anthracene. Examples of the substituent include an alkyl group, a hydroxyl group, and halogen. Of these, the aromatic ring preferably includes any one of a structure in which naphthalene and thiophene are linked, an anthracene structure, a tetracene structure, and a pentacene structure, in consideration of handling and availability. That is, the basic structure of the polycyclic compound preferably includes a polyacene-like aromatic ring structure in which three or more aromatic rings are continuously connected. The polyacene-like aromatic ring has a structure in which three or more aromatic rings are linked in a one-dimensional manner, which may be composed of only carbon or elements other than carbon (for example, sulfur, nitrogen and oxygen). May be included. When the polyacene-like aromatic ring is composed of only carbon, if it is longer than anthracene, it is expected that the sulfur bonded to the carbon will be unstable. Therefore, the structural unit is shorter than five pentacene rings, more preferably It is preferable to make it shorter than anthracene. At this time, it is preferable that an aromatic heterocyclic ring such as thiophene, pyrrole, or pyridine is present at the end. That is, when the polyacene-like aromatic ring is composed of carbon, the aromatic structural unit composed of carbon is shorter than five rings of pentacene, more preferably shorter than anthracene, and the end thereof is an aromatic heterocyclic ring such as thiophene or pyrrole. It is preferable to have a structure connected by. In this case, since the planarity can be further ensured, the change in capacitance can be increased and the conductivity can be further increased. Further, when a five-membered ring such as thiophene or pyrrole is present, it is more preferable to have a dimer structure in which sulfur or nitrogen is alternately bonded in order to improve the linearity of the structure. In the sense of improving the stability of sulfur bonded to the aromatic ring, a compound in which aromatic rings made of carbon are connected in two rows, for example, a naphthopyrene structure is also preferable. In the case where the basic structure includes a naphthalene structure, a five-membered ring (for example, a thiophene ring) may be bonded to the end portion so that the aromatic ring has three or more rings.

  In the electricity storage device of the present invention, the polycyclic compound has a basic structure including one or more carbon-based aromatic rings in which at least one hydrogen is replaced with sulfur among the connected aromatic rings. For example, it is more preferable that hydrogen on the outer periphery of the aromatic ring is replaced with more sulfur. By doing so, the content of immobilized sulfur is increased, and therefore, progress of the oxidation-reduction reaction by sulfur and improvement of conductivity can be achieved, which is preferable. The sulfur bonded to the carbon-based aromatic ring may be bonded to sulfur bonded to the adjacent aromatic ring (adjacent sulfur).

  In the electricity storage device of the present invention, the polycyclic compound has a basic structure including one or more carbon-based aromatic rings, and the two or more basic structures form a heterocyclic structure and are bonded to each other. Examples of the heterocyclic structure include a structure containing one or more of sulfur, oxygen and nitrogen in the ring structure, and among them, the ring structure preferably contains sulfur. The heterocyclic structure may be, for example, a five-membered heterocyclic structure such as a thiophene structure or a thiazole structure, or a six-membered heterocyclic ring such as a dithiane structure that is a saturated heterocyclic six-membered ring containing two sulfur. It is good also as a structure. As described above, since the basic structures are bonded by the heterocyclic structure, the adjacent basic structures are less likely to be twisted, and planarity can be further ensured, and the capacitance can be increased and the conductivity can be further increased.

  In the electricity storage device of the present invention, the polycyclic compound preferably has a sulfur concentration, which is a weight ratio of sulfur with respect to the whole, in the range of 45 wt% to 62 wt%, and is 50 wt% to 60 wt%. Is more preferable. A sulfur concentration of 45% by weight or more is preferable because the amount of sulfur is more sufficient and the capacity can be further increased. Further, when the sulfur concentration is in the range of 62% by weight or less, it is possible to more reliably combine sulfur with the polycyclic compound, and the battery performance can be made more stable. In the electricity storage device of the present invention, the polycyclic compound preferably has an element ratio C / S of carbon to sulfur in the range of 1.5 to 4.0, and is 1.6 to 2.1. It is more preferable. When the element ratio C / S is 1.5 or more, sulfur and the polycyclic compound can be more reliably combined, and the battery performance can be made more stable. In addition, when the element ratio C / S is 4.0 or less, the amount of sulfur is more sufficient, and the capacity can be further increased. In addition, the polycyclic compound preferably has a total content of carbon and sulfur of 85% by weight or more, and more preferably 90% by weight or more. That is, it can be said that it is desirable that the content of nitrogen and oxygen is small in addition to the elements of carbon and sulfur. By doing so, the sulfur content becomes relatively large, so that the capacity can be further increased.

  In the electricity storage device of the present invention, sulfur is mixed with at least one of an aromatic compound having a structure in which three or more aromatic rings are connected and an aromatic vinylene polymer having a structure in which one or more aromatic rings are connected. A polycyclic compound obtained by heating may be used as an electrode active material. If it carries out like this, charging / discharging cycling characteristics and a capacity | capacitance can be improved more similarly to the electrical storage device mentioned above. At this time, examples of the aromatic compound include one or more of a structure in which naphthalene and thiophene are linked, an anthracene structure, a tetracene structure, and a pentacene structure. By doing so, an aromatic compound containing any one or more of a naphthalene structure, an anthracene structure and a pentacene structure becomes a basic structure, and the above-described polycyclic compound can be obtained. Examples of the aromatic vinylene polymer include a polymer containing a polyphenylene vinylene structure and a polymer containing a polynaphthalene vinylene structure. By doing so, a polymer containing a polyphenylene vinylene structure or a polynaphthalene vinylene structure becomes a basic structure, and the above-described polycyclic compound can be obtained. The “polyphenylene vinylene structure” means, like the above-described “anthracene structure”, polyphenylene vinylene, a polyphenylene vinylene derivative having a substituent bonded to polyphenylene vinylene, and the like. Examples of the substituent include those described above.

  Here, specific examples of the polycyclic compound of the electricity storage device will be described. Examples of the polycyclic compound of the present invention include those represented by the following formula (1) having an anthracene structure having sulfur bonded to the outer periphery and a dithian structure as a heterocyclic structure for bonding the basic structures to each other. Examples of the polycyclic compound include those represented by the following formula (2) having an anthracene structure having sulfur bonded to the outer periphery and a thiophene structure as a heterocyclic structure for bonding the basic structures to each other. Moreover, what is shown to following formula (3) which has a dithian structure as a heterocyclic structure which makes the basic structure the tetracene structure which sulfur couple | bonded with the outer periphery as a polycyclic compound and couple | bonds basic structures is mentioned. Examples of the polycyclic compound include those represented by the following formula (4) having a pentacene structure with sulfur bonded to the outer periphery and a dithian structure as a heterocyclic structure for bonding the basic structures to each other. Moreover, what is shown to following formula (5) which has a thiophene structure as a heterocyclic structure which makes a basic structure the naphthopylene structure which sulfur couple | bonded with the outer periphery as a polycyclic compound and couple | bonds basic structures. Moreover, what is shown to following formula (6) which has a thiophene structure as a heterocyclic structure which makes a basic structure the naphthalene structure and thiophene structure which sulfur couple | bonded with the outer periphery as a polycyclic compound and couple | bonds basic structures. Examples of the polycyclic compound include those represented by the following formula (7) having a basic structure including a benzene structure and a thiophene structure in which sulfur is bonded to the outer periphery, and a thiophene structure as a heterocyclic structure that bonds the basic structures to each other. In addition, n of Formula (1)-(4), Formula (6), (7) is arbitrary integers.

  In the electricity storage device of the present invention, the positive electrode is prepared by, for example, mixing a positive electrode active material, a conductive material, and a binder, and adding a suitable solvent to form a paste-like positive electrode material on the surface of the current collector. However, it may be compressed to increase the electrode density as necessary. The positive electrode active material is the above-described polycyclic compound bonded with sulfur.

  In the electricity storage device of the present invention, the negative electrode is prepared by, for example, mixing a negative electrode active material, a conductive material, and a binder, and adding a suitable solvent to form a paste-like negative electrode material on the surface of the current collector. However, it may be compressed to increase the electrode density as necessary. The negative electrode active material preferably contains a metal or metal ion. The negative electrode active material may include a material that absorbs and releases lithium. Here, examples of the material that occludes and releases lithium include metal oxides, metal sulfides, metal nitrides, and carbonaceous substances that occlude and release lithium, in addition to metal lithium and lithium alloys. Examples of the lithium alloy include alloys of lithium with aluminum, silicon, tin, magnesium, indium, calcium, and the like. Examples of the metal oxide include tin oxide, silicon oxide, lithium titanium oxide, niobium oxide, and tungsten oxide. Examples of the metal sulfide include tin sulfide and titanium sulfide. Examples of the metal nitride include lithium nitride. Examples of the carbonaceous material that occludes and releases lithium include graphite, coke, mesophase pitch-based carbon fiber, spherical carbon, and resin-fired carbon. For this negative electrode, a current collector, a conductive material, and a binder can be used as appropriate as in the case of the positive electrode.

  In the electricity storage device of the present invention, the conductive material used for the positive electrode and the negative electrode is not particularly limited as long as it is an electron conductive material that does not adversely affect the battery performance. For example, natural graphite (scale graphite, flake graphite) or artificial Graphite such as graphite, acetylene black, carbon black, ketjen black, carbon whisker, needle coke, carbon fiber, or a mixture of one or more of metals (copper, nickel, aluminum, silver, gold, etc.) Can be used. Among these, carbon black, ketjen black, and acetylene black are preferable as the conductive material from the viewpoints of electron conductivity and coatability. The binder serves to bind the active material particles and the conductive material particles. For example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), fluorine-containing resin such as fluorine rubber, or polypropylene, Thermoplastic resins such as polyethylene, ethylene-propylene-dienemer (EPDM), sulfonated EPDM, natural butyl rubber (NBR) and the like can be used alone or as a mixture of two or more. In addition, an aqueous dispersion of cellulose or styrene butadiene rubber (SBR), which is an aqueous binder, can also be used. Examples of the solvent for dispersing the active material, the conductive material, and the binder include ethanol, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, and N, N-dimethylamino. Organic solvents such as propylamine, ethylene oxide, and tetrahydrofuran can be used. Moreover, a dispersing agent, a thickener, etc. may be added to water, and an active material may be slurried with latex, such as SBR. As the thickener, for example, polysaccharides such as carboxymethyl cellulose and methyl cellulose can be used alone or as a mixture of two or more. Examples of the application method include roller coating such as applicator roll, screen coating, doctor blade method, spin coating, bar coater, and the like, and any of these can be used to obtain an arbitrary thickness and shape. Current collectors include copper, aluminum, titanium, stainless steel, nickel, iron, calcined carbon, conductive polymer, conductive glass, etc., as well as aluminum and aluminum for the purpose of improving adhesion, conductivity, and oxidation resistance. What processed the surface of copper etc. with carbon, nickel, titanium, silver, etc. can be used. For these, the surface can be oxidized. Examples of the shape of the current collector include foil, film, sheet, net, punched or expanded, lath, porous, foam, and formed fiber group. The thickness of the current collector is, for example, 1 to 500 μm.

In the electricity storage device of the present invention, the ion conductive medium may be a solution in which a supporting salt is dissolved in a solvent. The supporting salt is not particularly limited as long as it is a lithium salt used for a normal lithium secondary battery. For example, lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), Li (C ₂ F ₅ SO ₂ ) Known supporting salts such as ₂ N, LiPF ₆ , LiClO ₄ , and LiBF ₄ can be used. These may be used alone or in combination. The solvent of the ion conductive medium is not particularly limited, but carbonates such as ethylene carbonate (EC), diethyl carbonate (DEC) and propylene carbonate (PC), ethers such as dimethoxyethane (DME), triglyme and tetraglyme, Cyclic ethers such as dioxolane (DOL) and tetrahydrofuran and mixtures thereof are preferred. Alternatively, ionic liquids such as 1-methyl-3-propylimidazolium bis (trifluorosulfonyl) imide and 1-ethyl-3-butylimidazolium tetrafluoroborate can be used. The ion conductive medium may be gelled by adding an electrolyte containing a supporting salt to a polymer such as polyvinylidene fluoride, polyethylene oxide, polyethylene glycol, polyacrylonitrile, or a saccharide such as an amino acid derivative or a sorbitol derivative. .

  The electricity storage device of the present invention may include a separator between the negative electrode and the positive electrode. The separator is not particularly limited as long as it is a composition that can withstand the usage range of the electricity storage device. For example, a polymer nonwoven fabric such as a polypropylene nonwoven fabric or a polyphenylene sulfide nonwoven fabric, or a microporous film of an olefin resin such as polyethylene or polypropylene is used. Can be mentioned. These may be used alone or in combination.

  The shape of the electricity storage device of the present invention is not particularly limited, and examples thereof include a coin cell type, a wound battery type, a laminate type, a button type, a sheet type, a laminated type, a cylindrical type, a flat type, and a square type. Moreover, you may apply to the large sized thing etc. which are used for an electric vehicle etc.

  The electricity storage device of the present invention is preferably subjected to aging treatment in the range of 0.5 V or less on the basis of the Li potential in the initial charge and discharge on the electrode provided with the electrode active material. In this way, the capacity can be further increased.

  Next, the manufacturing method of the electrode active material containing the polycyclic compound to which sulfur mentioned above was combined is explained. The method for producing an electrode active material according to the present invention includes an aromatic compound having a structure in which three or more aromatic rings including carbon-based aromatic rings are connected, and an aromatic vinylene polymer having a structure in which one or more aromatic rings are connected. A synthesis step of synthesizing a polycyclic compound by mixing and heating at least one of them and sulfur is included. By so doing, a basic structure in which at least one hydrogen in the carbon-based aromatic ring contained in the aromatic ring is substituted with sulfur is combined, and two or more basic structures are bonded together by a heterocyclic structure, so that Ring compounds can be made. As a raw material for this synthesis step, as an aromatic compound, a compound containing any one of an anthracene structure, a tetracene structure and a pentacene structure, or as an aromatic vinylene polymer, any of a polyphenylene vinylene structure and a polynaphthalene vinylene structure Polymers containing one can be used. Specifically, examples of the aromatic compound include tricyclic compounds such as anthracene and phenanthrene, tetracyclic compounds such as tetracene, pyrene, triphenylene, tetraphen, and chrysene, and pentacyclic compounds such as pentacene, picene, and perylene. It is done. Among these, it is preferable to use an aromatic compound containing any one of anthracene, tetracene, and pentacene. By doing so, a polycyclic compound containing a polyacene-like aromatic ring structure can be produced. In addition, naphthopyrene can be used as a raw material. As the aromatic vinylene polymer, for example, a polymer having one or more aromatic rings and a vinylene structure such as polynaphthalene vinylene and polyphenylene vinylene can be used as a raw material. In this synthesis step, a substance having a basic structure in which three or more aromatic rings are linked and an excess amount of sulfur are reacted in an inert atmosphere at a temperature not lower than the melting point of sulfur, for example, at a high temperature of 300 ° C. It is good also as what forms a carbon sulfur bond, removing the. The treatment temperature is preferably in the range of 200 ° C. or higher and 450 ° C. or lower, for example. When the processing temperature is 200 ° C. or higher, carbon-sulfur bonds are easily formed, and when the processing temperature is 450 ° C. or lower, sulfur volatilization can be suppressed. Examples of the inert atmosphere include a nitrogen atmosphere, a helium atmosphere, and an argon atmosphere.

  In the method for producing an electrode active material of the present invention, a sulfur content optimization step for removing excess sulfur may be performed after this synthesis step. In this step, the polycyclic compound and sulfur are mixed and heated to 450 ° C. near the boiling point of sulfur to volatilize excess sulfur so that the sulfur content and element ratio C / S are in the above-described range. It is good also as what removes it. This heat treatment is preferably performed in an inert atmosphere. Here, in at least one of the synthesis step and the sulfur content optimization step, sulfur mixing conditions such that the sulfur content is 45 wt% or more and 62 wt% or less, more preferably 50 wt% or more and 60 wt% or less, It is preferable to set heating conditions such as processing temperature and processing time. In addition, at least one of the synthesis step and the sulfur content optimization step, sulfur is set so that the element ratio C / S of carbon to sulfur is 1.5 or more and 4.0 or less, more preferably 1.6 or more and 2.1 or less. It is preferable to set the mixing conditions and the heating conditions. Alternatively, in this step, the combined body is mixed with a sulfur good solvent such as carbon disulfide so that the sulfur content and the element ratio C / S are within the above ranges, and the sulfur is eluted to remove excess sulfur. It may be removed. Thus, a sulfur-bonded polycyclic compound as an electrode active material can be obtained. In addition, as another production method, for example, by reacting a compound in which a halogen such as chlorine is bonded to three or more aromatic rings with sodium sulfide or lithium sulfide, and substituting the halogen and sulfur, the present invention The polycyclic compound can be prepared.

  Here, the capacity development mechanism of the electrode active material of the electricity storage device of the present invention will be considered. The polycyclic compound that is the electrode active material of the present invention is presumed to have a structure in which molecules are stacked by intermolecular interactions such as van der Waals force and π-π interaction. Therefore, in this state, the specific surface area is small, and the capacity as a so-called electric double layer capacitor is small. Here, when the electrode active material of the present invention is used for the positive electrode, sulfur becomes a sulfide anion due to reduction of the sulfur substituent during discharge. At this time, the anion is delocalized in the bonded polycyclic compound, the intermolecular distance of the polycyclic compound is expanded by electrostatic repulsion, and the solvent and Li ions can enter the interlayer, and the specific surface area increases at a stretch. Conceivable. Therefore, the reduction of sulfur atoms significantly increases the capacitance as a capacitor, which is superposed on the sulfur-derived discharge capacity, and it is assumed that a large capacity is developed. Further, the oxidation-reduction potential of sulfur is around 2V with respect to the Li electrode, whereas it is slightly over 3V for carbon. Therefore, when the capacitance increases at a stretch in the vicinity of 2V, a capacity corresponding to the voltage difference between the open circuit voltage of 3V or more and the reduction potential of sulfur of about 2V is immediately developed in the vicinity of 2V. A constant-voltage discharge similar to a battery (charge that is negatively charged as a capacitor) occurs. The reverse phenomenon occurs reversibly during charging. Therefore, the electricity storage device of the present invention can express much larger capacity than the capacity expected from the sulfur content, and is considered to be an epoch-making electricity storage device with an unprecedented mechanism.

  We will also consider other structures here. For example, when a naphthalene structure is connected by a dithian structure, that is, a polycyclic compound in which two or less aromatic rings are connected, the conductivity is not sufficient and the capacity is low. Reference 1 (Proceedings of the 47th Battery Discussion Meeting, p. 558 (2006)) shows an example in which naphthalene skeletons are connected by a dithiane structure, but the capacity is 120 mAh / It is presumed that the increase in capacity due to the combined use of the capacitor function of the present invention has not occurred. Therefore, it can be seen that a structure in which three or more aromatic rings are connected is necessary so that the conductivity can be improved. In addition, when a polymer in which anthracene with sulfur bonded to the outer periphery is further bonded with a single chain is used as an electrode active material, that is, when a basic structure is not bonded with a heterocyclic structure, the polyacene-like aromatic ring is twisted. Therefore, it is difficult to develop the capacitance, and the capacitance is low. Reference 2 (Electrochem. Communications, 5,903 (2003)) shows an example in which a polymer in which six anthracenes bonded with sulfur are further bonded in a single chain and used as a positive electrode active material is shown. ing. However, the capacity is at most 300 mAh / g, which is less than the theoretical capacity 447 mAh / g when monovalent oxidation-reduction of sulfur occurs. Therefore, it is clear that the structure of the present invention in which the polyacene-like aromatic ring is connected by a heterocyclic ring so as to prevent twisting and the planarity is ensured is effective in greatly increasing the capacity. In addition, when there are three or more polyacene-like aromatic rings and a relatively short ring (such as six or less rings), a structure in which aromatic rings are connected by a heterocyclic ring such as a dithiane structure is desirable so that the aromatic rings do not greatly twist.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  Below, the example which produced the electrical storage device of this invention concretely is demonstrated as an Example.

[Example 1]
To 1 g of anthracene (manufactured by Aldrich), 5 g of sulfur powder (75 μm or less, 99.99%, manufactured by High Purity Chemical) was added and mixed well. The test tube was placed in a tubular furnace in a nitrogen stream and heated to 300 ° C. over 1 hour. After heating for 3 hours, the temperature was raised to 450 ° C. over 30 minutes and allowed to stand for 3 hours. After cooling to room temperature, a black solid (polycyclic compound) was obtained. This is hereinafter referred to as ANS450. 70% by weight of ANS450, 20% by weight of carbon (ECP600JD, manufactured by Lion), and 10% by weight of polytetrafluoroethylene (PTFE) as a binder are mixed together and kneaded well in a mortar until it becomes bowl-shaped. And molded into a sheet. This sheet was cut into a circular shape with a diameter of 12 mm and vacuum dried to obtain a positive electrode material. Using this positive electrode material, Li metal as a negative electrode, porous polyethylene as a separator, and electrolytic solution (ethylene carbonate EC + diethyl carbonate DEC (volume ratio 3: 7) containing 1M-LiPF ₆ ) of FIG. An evaluation cell was produced. This obtained evaluation cell was defined as Example 1. Note that the Li metal was a Li plate having a thickness of 0.4 mm and a diameter of 18 mm, and the weight of the positive electrode material was 3 mg and the electrode area was 1.3 cm ² .

  1A and 1B are explanatory views of the evaluation cell 10, FIG. 1A is a cross-sectional view before the evaluation cell 10 is assembled, and FIG. 1B is a cross-sectional view after the evaluation cell 10 is assembled. An evaluation cell 10 was produced in a glove box under an argon atmosphere. In assembling the evaluation cell 10, first, a negative electrode 16 and a polyethylene separator 18 (a microporous polyethylene film, a microporous polyethylene film, a cavity 14 provided in the center of the upper surface of a stainless steel cylindrical substrate 12 with a thread groove engraved on the outer peripheral surface thereof. Tonen Chemical Co., Ltd.) and the positive electrode 20 were laminated in this order while injecting an appropriate amount of a non-aqueous electrolyte into the cavity 14. Further, an insulating ring 29 made of polypropylene is inserted, and then a conductive column 24 fixed in a liquid-tight manner in the hole of the insulating ring 22 is disposed on the positive electrode 20, and a conductive cup-shaped lid 26 is formed on the cylinder. Screwed into the substrate 12. Further, an insulating resin ring 27 is disposed on the cylinder 24, and a pressure bolt 25 having a through hole 25a is screwed into a screw groove carved in an inner peripheral surface of an opening 26a provided at the center of the upper surface of the lid 26, The negative electrode 16, the separator 18, the solid electrolyte membrane 18, and the positive electrode 20 were pressed and adhered. Thus, the evaluation cell 10 was produced. Since the cylinder 24 is positioned below the upper surface of the ring 22 and is in contact with the lid 26 via the insulating resin ring 27, the lid 26 and the cylinder 24 are in an electrically non-contact state. In addition, since the packing 28 is disposed around the cavity 14, the electrolyte injected into the cavity 14 does not leak to the outside. In this evaluation cell 10, the lid 26, the pressure bolt 25, and the cylindrical base 12 are integrated with the negative electrode 16, so that the whole becomes the negative electrode side, and the column 24 is integrated with the positive electrode 20 and insulated from the negative electrode 16. Therefore, it becomes the positive electrode side. Thus, an evaluation cell was created.

(Elemental analysis)
Elemental analysis was performed on the obtained sample (polycyclic compound). The elemental analysis of CHN was performed by a combustion method using a fully automatic elemental analyzer (manufactured by Elemental, VarioEL). The sulfur was analyzed by flask combustion-ion chromatography. The system for sulfur analysis was DX320 manufactured by Dionex, the column was IonPacAS12A, and the mobile phase was Na ₂ CO ₃ (2.7 mmol / L) / NaHCO ₃ (0.3 mmol / L). The element ratio C / S of carbon with respect to sulfur was calculated | required from the obtained sulfur amount (weight%) and carbon amount (weight%).

(Raman spectrum analysis)
The obtained sample (polycyclic compound) was subjected to Raman spectroscopic measurement. The Raman spectrum analysis was measured using a laser Raman spectroscopy system (manufactured by JASCO Corporation, NRS-3300). Perform Raman spectroscopy with an excitation light having a wavelength of 532 nm, a complex containing a sulfur seen from 1200 cm ^-1 vicinity derived from an aromatic ring skeleton vibration peaks up 1600 cm ^-1 vicinity, and of 1020 cm ^-1 vicinity near 1050 cm ^-1 A peak derived from the ring was observed.

(Evaluation of electrochemical properties)
The electrochemical characteristics of the obtained evaluation cell were evaluated. In the evaluation of electrochemical characteristics, the capacity per unit weight (mAh / g), the charge / discharge efficiency (%) of the polycyclic compound as the electrode active material, the capacity retention rate (%) in 5-100 cycles, the unit of sulfur The capacity per weight (mAh / g-S) was examined. First, the evaluation cell was installed in a constant temperature bath at 25 ° C., and constant current charging / discharging at 0.5 mA was performed twice in the region from 3.0 V to 0.5 V as initial aging at this temperature. Thereafter, as a charge / discharge test, a constant current charge / discharge of 0.5 mA was performed in a region of 1.0 V to 3.0 V. A cycle test in which this constant current charging / discharging was repeated 100 cycles was performed, and the discharge capacity (mAh / g) per unit weight of the active material at the first, fifth and 100th cycles was determined. Each voltage value (V) shown here is a value based on the Li potential. Further, using the charge capacity and discharge capacity at the fifth cycle, the discharge capacity was divided by the charge capacity and multiplied by 100 to obtain the charge / discharge efficiency, and the discharge capacity per unit weight of sulfur was calculated. Further, the capacity retention rate (%) was obtained by multiplying 100 by the value obtained by dividing the discharge capacity (mAh / g) at the 100th cycle by the discharge capacity at the 5th cycle.

[Example 2]
A solid (polycyclic compound) was obtained through the same steps as in Example 1 except that 1 g of sulfur powder was added to 0.25 g of benzo [b] anthracene (manufactured by Aldrich) instead of anthracene. This is hereinafter referred to as TENS450. Using the obtained TENS450, an evaluation cell obtained through the same steps as in Example 1 was defined as Example 2.

[Example 3]
A solid (polycyclic compound) was obtained through the same steps as in Example 1 except that 2 g of sulfur powder was added to 0.5 g of pentacene (manufactured by Aldrich) instead of anthracene. This is hereinafter referred to as PENS450. Using the obtained PENS450, an evaluation cell obtained through the same steps as in Example 1 was defined as Example 3.

[Example 4]
A solid (polycyclic compound) was obtained through the same steps as in Example 1 except that 2 g of sulfur powder was added to 0.5 g of naphtho [2,3-a] pyrene (manufactured by Aldrich) instead of anthracene. This is hereinafter referred to as NPYS450. Using the obtained NPYS450, an evaluation cell obtained through the same steps as in Example 1 was defined as Example 4.

[Example 5]
A solid (polycyclic compound) was obtained through the same steps as in Example 1 except that 1 g of sulfur powder was added to 0.25 g of polynaphthalene vinylene (manufactured by Aldrich) instead of anthracene. This is hereinafter referred to as PNVS450. Using the obtained PNVS450, an evaluation cell obtained through the same steps as in Example 1 was defined as Example 5.

[Example 6]
To 100 ml of an aqueous solution containing 0.25% by weight of poly (p-xylenetetrahydrothiophenium-chloride) (manufactured by Aldrich), 2 g of sulfur powder suspended in ethanol was added, stirred well, and then concentrated on a rotary evaporator. A sulfur dispersed polymer was obtained. This was heat-treated at 315 ° C. for 3 hours under a nitrogen stream, and then heated to 450 ° C. and held for 2 hours to obtain a black solid. This is hereinafter referred to as PPVS450. Using the obtained PPVS450, an evaluation cell obtained through the same steps as in Example 1 was defined as Example 6.

[Comparative Example 1]
A solid (polycyclic compound) was obtained through the same steps as in Example 1 except that 2 g of sulfur powder was added to 0.5 g of 2-naphthalenethiol (manufactured by Aldrich) instead of anthracene. This is hereinafter referred to as NAS450. A similar treatment was performed using naphthalene instead of anthracene, but no heat-treated product was obtained. An evaluation cell obtained through the same steps as in Example 1 using the obtained NAS450 was defined as Comparative Example 1.

[Comparative Example 2]
Pentacene hexasulfide was prepared instead of anthracene. This is hereinafter referred to as PENS6. An evaluation cell obtained through the same steps as in Example 1 using this PENS6 was defined as Comparative Example 2.

[Comparative Example 3]
50% by weight of sulfur was mixed with 10% by weight of PTFE and 40% by weight of carbon (ECP600JD, manufactured by Lion Corporation). An evaluation cell obtained through the same steps as in Example 1 using each of these mixtures as a positive electrode material was used as Comparative Example 3. Regarding the evaluation, since the electrolyte solution (EC + DEC) does not operate when sulfur alone is contained, the electrolyte solution of Comparative Example 11 is 1M-LiTFSI so that the evaluation cell operates even if sulfur alone is contained. A solution of (lithium bistrifluoromethanesulfonic imide) in dimethoxyethane + dioxolane (volume ratio 9/1) was used.

Table 1 shows the structures of the raw materials used and the structures of the polycyclic compounds estimated from the results of elemental analysis and Raman spectroscopic analysis of the polycyclic compounds of Examples 1 to 6 and Comparative Examples 1 and 2. FIG. 2 is a Raman spectrum of the polycyclic compounds of Examples 1 to 6 and Comparative Example 1. In consideration of the results of Raman measurement, in any polycyclic compound, a plurality of peaks derived from the aromatic ring skeleton are observed between 1200 cm ^{−1 and} 1600 cm ⁻¹ . In addition, in the polycyclic compounds of Examples 1 to 3 and Comparative Example 1, a peak derived from a heterocycle containing sulfur was observed in the range of 1020 cm ⁻¹ or more and 1050 cm ⁻¹ or less (enclosed by a one-dot chain line in the figure). It was done. That is, it was speculated that the polycyclic compounds of Examples 1 to 3 and Comparative Example 1 had a heterocyclic ring containing sulfur. In the polycyclic compound of Example 4-6, a peak in the range of of 1020 cm ^-1 or 1050 cm ^-1 or less was observed. Further, in the polycyclic compounds of Examples 5 and 6, a peak derived from the thiophene skeleton was observed around 1450 cm ⁻¹ (enclosed by a broken line in the figure). Also in the polycyclic compound of Example 1, a slight shoulder peak was observed in this range. For this reason, it was speculated that some of the polycyclic compounds of Examples 5 and 6 and Example 1 contained a thiophene structure. On the other hand, in Example 4, the above characteristic peak was not observed. This is probably due to the fact that the number of repetitions of the basic structure is small (for example, 2 or less) and that a small aromatic ring is connected to a large aromatic skeleton. .

  The structure of each polycyclic compound estimated from the results of Raman spectroscopic analysis and elemental analysis will be described below. ANS450 had an element ratio C / S, which is a molar ratio of carbon atoms to sulfur atoms, of 14 / 8.4, and a sulfur concentration of 58.5% by weight. When the raw material structure and the above results are combined, the ANS450 has a basic structure shown in Table 1 in which the element ratio C / S of the structure is assumed to be mainly 14/8, and aromatic rings are connected by a dithian skeleton. It was inferred that In addition, ANS450 is presumed to include those having an element ratio C / S of 14/7, and the basic structure shown in Table 1 in which aromatic rings made of carbon are linked in a thiophene structure is one of them. It was inferred to be included in the department. TENS450 had an element ratio C / S of 18 / 9.3 and a sulfur concentration of 54.0% by weight. By summing up the raw material structure and the above results, TENS450 has a basic structure shown in Table 1 in which the elemental ratio C / S of the structure is presumed to be 18/10, and aromatic rings are connected by a dithian skeleton. It was guessed. PENS450 had an element ratio C / S of 22/12 and a sulfur concentration of 57.2% by weight. In summary of the raw material structure and the above results, PENS450 has a basic structure shown in Table 1 in which the element ratio C / S of the structure is presumed to be 22/12, and aromatic rings are connected by a dithian skeleton. It was guessed. NPYS450 had an element ratio C / S of 24 / 11.5 and a sulfur concentration of 49.8% by weight. In summary of the raw material structure and the above results, NPYS450 has a basic structure shown in Table 1 in which the element ratio C / S of the structure is presumed to be 24/12, and aromatic rings are connected by a dithian skeleton. It was guessed. PNVS450 had an element ratio C / S of 12 / 5.8 and a sulfur concentration of 52.6% by weight. In summary of the raw material structure and the above results, PNVS450 is assumed to have an element ratio C / S of 12/6, and has a basic structure shown in Table 1 in which aromatic rings made of carbon are linked in a thiophene structure. It was inferred that PPVS450 had an element ratio C / S of 8 / 4.1 and a sulfur concentration of 54.5% by weight. When the raw material structure and the above results were combined, PPVS450 was presumed to have an element ratio C / S of 8/4, and the basic structure shown in Table 1. NAS450 had an element ratio C / S of 10 / 6.9 and a sulfur concentration of 63.2% by weight. In summary of the raw material structure and the above results, NAS450 has a basic structure shown in Table 1 in which the elemental ratio C / S of the structure is assumed to be 10/6, and aromatic rings are connected by a dithian skeleton. It was guessed. PENS6 had an element ratio C / S of 22 / 5.4 and a sulfur concentration of 41.0% by weight. When the raw material structure and the above results were combined, PENS6 was presumed to have a structure element ratio C / S of 22/6, and was assumed to have the basic structure shown in Table 1. In Table 1, in Examples 1 to 3 and Comparative Example 2, the combined state in which sulfur is connected is drawn for convenience. However, in fact, a disulfide bond that is a dimer is formed or both are aromatic. It is presumed that it has a thiocarbonyl (thioquinone) structure bonded to. Moreover, it is guessed that the sulfur couple | bonded with carbon turns into an anion in a reduction | restoration state (refer to Reference Document 2: Electrochem.Communications, 5,903 (2003)).

  Next, Table 2 shows the results of the charge / discharge test for the evaluation cells of Examples 1 to 6 and Comparative Examples 1 and 2. Table 2 shows the discharge capacity (mAh / g) of the first, fifth and 100th active materials in the charge / discharge cycle, the charge / discharge efficiency (%) of the fifth charge / discharge cycle, the fifth and 100th charge / discharge cycles. The capacity retention rate (%), sulfur concentration (% by weight), and discharge capacity per unit weight of sulfur (mAh / g-S) determined from the discharge capacity at the second time are shown. As shown in Table 2, Comparative Example 1 had a capacity per sulfur of 831 mAh / g-S for the first time and 836 mAh / g-S, which is a monovalent redox capacity of sulfur. Further, Comparative Example 2 has a structure in which five aromatic rings are connected, but is not connected by a heterocyclic ring, the charge / discharge efficiency is poor, and the capacity reduction is remarkable. Moreover, also in the comparative example 3 using a sulfur simple substance, the charge / discharge efficiency was as low as 83% and the capacity maintenance rate was 37%. On the other hand, in the evaluation cell of Examples 1-6, it turned out that all of charging / discharging efficiency, a capacity | capacitance maintenance factor, and the discharge capacity per unit weight of sulfur are higher, and the battery performance is improving. In consideration of the sulfur concentration, in Comparative Example 2 in which the sulfur concentration was 41% by weight, the charge / discharge efficiency was low and the capacity was also small. On the other hand, in Comparative Example 1 where the sulfur concentration was 63.2% by weight, the capacity was small and the capacity retention rate was low. From these facts, it became clear that the sulfur concentration is preferably 45% by weight or more and 62% by weight or less, and more preferably 50% by weight or more and 60% by weight or less.

  FIG. 3 shows the measurement result of cyclic voltammetry of Example 1, and FIG. 4 shows the measurement result of cyclic voltammetry of Comparative Example 3 using simple sulfur. This cyclic voltammetry is the result of measurement in the region of 2.2V to 3V after charging up to 3V, or in the region of 2.5-3V, and in the region of 1V to 2V after discharging up to 1V. When these are compared, it can be seen that the capacitance changes as a capacitor after charging and discharging. In Comparative Example 3 using simple sulfur, the capacitor components in both regions have almost no difference and are small, whereas in Example 1, the capacitor components in the 1V to 2V region after discharge are very large, and after charging. It was found that the capacitance was about 9 times the 2.2 V to 3 V range. This is a new phenomenon that has not been reported so far, and as a result, an extremely high performance active material has been realized. In the polycyclic compounds of Examples 1 to 6 in Table 1, three or more aromatic rings are connected, and at least one carbon-based aromatic ring in which at least one hydrogen is replaced with sulfur among the connected aromatic rings is basic. It has a structure in which two or more basic structures are bonded by forming a heterocyclic structure containing sulfur. It has been inferred that such a structure has higher charge / discharge efficiency and capacity retention rate, and can further increase the discharge capacity per unit weight of sulfur. In particular, Example 1 produced using anthracene was found to be more preferable because of higher initial capacity, discharge capacity at 100 cycles, and capacity retention rate.

10 Evaluation Cell, 12 Cylindrical Base, 14 Cavity, 16 Negative Electrode, 18 Separator, 20 Positive Electrode, 22 Ring, 24 Column, 25 Pressure Bolt, 25a Through Hole, 26 Lid, 26a Opening, 27 Insulating Resin Ring, 28 Packing, 29 Insulation ring.

Claims (7)

A polycyclic compound having a structure in which three or more aromatic rings are connected, and the three or more connected aromatic rings are any one of a structure in which naphthalene and thiophene are connected, an anthracene structure, a tetracene structure, and a pentacene structure. And having at least one carbon-based aromatic ring in which at least one hydrogen atom is substituted with sulfur among the linked aromatic rings, the two or more basic structures are bonded by a heterocyclic structure. And at least one of the three or more linked aromatic rings and the heterocyclic structure in which the basic structures are bonded to each other contains sulfur in the ring structure, and is a weight ratio of sulfur to the whole polycyclic compound. An electricity storage device using the polycyclic compound having a sulfur concentration in the range of 45 wt% or more and 62 wt% or less as an electrode active material. The power storage device according to claim 1, wherein the polycyclic compound is one or more of the following formulas (1) to (7) (where n is an arbitrary integer).

  It is a polycyclic compound having a structure in which three or more aromatic rings are connected, and has a basic structure including one or more carbon-based aromatic rings in which at least one hydrogen is substituted with sulfur among the connected aromatic rings, Including at least the polycyclic compound in which two or more of the basic structures are bonded together by a heterocyclic structure as an electrode active material;
  The polycyclic compound is one or more of the following formulas (1) to (7) (where n is an arbitrary integer), an electricity storage device.

  A mixture obtained by mixing and heating at least one of an aromatic compound having a structure in which three or more aromatic rings are connected and an aromatic vinylene polymer having a structure in which one or more aromatic rings are connected, and sulfur. The electrical storage device of any one of Claims 1-3 which uses a ring compound as an electrode active material. A manufacturing method for manufacturing an electrode active material used for an electrode of an electricity storage device,
Sulfur is mixed with at least one of an aromatic compound having a structure in which three or more aromatic rings including a carbon-based aromatic ring are connected and an aromatic vinylene polymer having a structure in which one or more aromatic rings are connected. Is a polycyclic compound having a structure in which three or more aromatic rings are connected by heating, and the aromatic ring in which three or more aromatic rings are connected has a structure in which naphthalene and thiophene are connected, anthracene structure, tetracene structure, and pentacene structure And having a basic structure including one or more carbon-based aromatic rings in which at least one hydrogen in the linked aromatic rings is substituted with sulfur, the two or more basic structures are is linked by a heterocyclic ring, wherein the three or more linked at least one or more of the aromatic ring and the heterocyclic structure basic structure are bonded to each other includes sulfur in the ring structure, before Production method of the synthetic steps electrode active material containing, sulfur concentration by weight ratio of sulfur to the total to synthesize the polycyclic compound in the range of 62 wt% 45 wt% or more of the following polycyclic compound. A manufacturing method for manufacturing an electrode active material used for an electrode of an electricity storage device,
Sulfur is mixed with at least one of an aromatic compound having a structure in which three or more aromatic rings including a carbon-based aromatic ring are connected and an aromatic vinylene polymer having a structure in which one or more aromatic rings are connected. And having a basic structure including one or more carbon-based aromatic rings in which at least one hydrogen is replaced with sulfur among the linked aromatic rings, and the two or more basic structures are formed by a heterocyclic structure. synthesis step of synthesizing a polycyclic compounds bind to, only including,
The said polycyclic compound is 1 or more among following formula (1)-(7) (however, n is arbitrary integers), The manufacturing method of an electrode active material.

In the synthesis step, a compound containing any one of an anthracene structure, a tetracene structure, and a pentacene structure is used as the aromatic compound, and the aromatic vinylene polymer is a polyphenylene vinylene structure or a polynaphthalene vinylene structure. The manufacturing method of the electrode active material of Claim 6 using the polymer containing any one.

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