JP5200523B2 - Lithium ion secondary battery - Google Patents

Description

  The present invention relates to a lithium ion secondary battery.

  In recent years, with the downsizing of electronic devices, further increase in capacity of secondary batteries is desired. Therefore, lithium ion secondary batteries with higher energy density are attracting attention as compared to nickel cadmium batteries and nickel metal hydride batteries. Initially, metallic lithium was used as the negative electrode active material of the lithium ion secondary battery. This is because metallic lithium exhibits the most basic potential, but as the charge and discharge are repeated, dendrites, which are resinous crystals of metallic lithium, deposit on the negative electrode, reach the positive electrode through the separator, and are short-circuited. There was a case. Therefore, at present, carbon materials capable of inserting / extracting lithium ions, such as graphite and coke, and a mixture of graphite and coke, are mainly used as the negative electrode active material.

Since graphite can insert and desorb one lithium ion with respect to six carbon atoms, a theoretical capacity of 372 mAh / g can be obtained. However, in actuality, since the SEI film (SEI is an abbreviation of Solid-Electrolyte Interface) is formed when lithium ions are inserted for the first time, the charge / discharge capacity is less than 372 mAh / g, and only a capacity of 300 mAh / g is obtained at most. I can't. For these reasons, recently, crystalline and amorphous silicon (see Patent Document 1) and metallic tin (see Non-Patent Document 1) have attracted attention as high-capacity negative electrode active materials that replace graphite. These materials exhibit a charge / discharge capacity of 700 mAh / g or more.
Japanese Patent No. 3733065 Sanyo Electric Technical Report, Vol. 34, no. 1, JUN. 2002, p87-p92, issued by Sanyo Electric Co., Ltd.

  However, while alloy materials such as silicon and tin exhibit a charge / discharge capacity of 700 mAh / g or more, the volume expansion during charge / discharge is extremely large as compared with the carbon material. For example, the volume expansion during charging / discharging is about 10% for graphite and about 300% for tin-based material. Therefore, a material having a large volume expansion during charging / discharging is not suitable for a lithium ion secondary battery that is always used in a sealed container. In addition, these materials have a redox potential of about 0.5 V to about 2 V with respect to metallic lithium. On the other hand, graphite shows an oxidation-reduction potential almost similar to metallic lithium. For this reason, the fact is that an alloy material such as silicon or tin is inferior to graphite in terms of volumetric energy density or power energy density even if the charge / discharge capacity that can be taken out is larger than that of graphite.

  The present invention has been made in view of the above-described problems, and provides a lithium ion secondary battery having a high energy density and having the same or improved cycle characteristics as compared with the case of using graphite as a negative electrode active material. Main purpose.

  In order to achieve the above-described object, the present inventors produced a lithium ion secondary battery using a graphene compound having a hexabenzocoronene derivative as a basic skeleton as a negative electrode active material. It was found that the initial discharge capacity was higher than that of the ion secondary battery, and the capacity retention rate and resistance increase rate after the charge / discharge cycle test were equal or improved, and the present invention was completed.

  That is, the lithium ion secondary battery of the present invention is characterized in that a graphene compound having 42 to 144 carbon atoms having hexabenzocoronene as a basic skeleton is used as a negative electrode active material.

  According to the lithium ion secondary battery of the present invention, the energy density is high and the cycle characteristics are equal or improved as compared with the case where graphite is used as the negative electrode active material. The reason why such an effect can be obtained is not clear, but graphene compounds based on hexabenzocoronene derivatives are considered to be a single layer or a small number of layers of graphite. In addition to exhibiting a near potential, that is, a potential close to metallic lithium, structurally, electrostatic repulsion between lithium ions when lithium ions are inserted can be reduced. As a result, it is considered that a larger amount of lithium ions can be inserted than when graphite is used as the negative electrode active material. In addition, since such graphene compounds are known to have mechanical strength equivalent to that of carbon nanotubes, expansion and contraction associated with charge / discharge cycle tests can be reduced, and it is considered to have excellent reversible characteristics.

The lithium ion secondary battery of the present invention uses a graphene compound having 42 to 144 carbon atoms (preferably 42 to 96 carbon atoms) having hexabenzocoronene as a basic skeleton as a negative electrode active material. A graphene compound having less than 42 carbon atoms is not preferable because the number of sites into which lithium ions can be inserted decreases, and a graphene compound having more than 144 carbon atoms is not preferable because electrostatic repulsion between lithium ions becomes significant. Is not preferable because it decreases. Such a graphene compound is preferably any of the graphene compounds represented by the general formulas (1) to (7) described above. Note that the graphene compound having hexabenzocoronene as a basic skeleton refers to a compound containing a hexabenzocoronene moiety in the structural formula. Also, carbon number of a portion excluding the R ¹ to R ¹⁷⁴ of the graphene compounds of general formula (1) to (7), respectively 42 pieces, 72, 60, 78, 54 pieces, 78 pieces, 114 It is a piece.

In the formula, R ^{1 to} R ¹⁷⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group. Selected from the group consisting of a group, a cyano group, an amide group, an acyl group, a perfluoroaryl group, and a perfluoroalkyl group. Note that in this specification, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, and an arylthio group have at least one hydrogen atom as a halogen atom (particularly Fluorine atoms) and those substituted with a substituent such as a cyano group are also included.

  Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkyl group preferably has 1 to 6 carbon atoms. For example, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert- A butyl group, an n-pentyl group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group and the like can be mentioned. Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a styryl group, a cyclopropenyl group, a cyclopentenyl group, and a cyclohexenyl group. Examples of the alkynyl group include an ethynyl group, a propargyl group, and a phenylacetinyl group. Examples of the aryl group include phenyl group, 2,6-xylyl group, mesityl group, duryl group, biphenyl group, terphenyl group, naphthyl group, anthryl group, pyrenyl group, toluyl group, anisyl group, fluorophenyl group, diphenylamino. Examples thereof include a phenyl group, a dimethylaminophenyl group, a diethylaminophenyl group, and a phenanthrenyl group. Examples of the aralkyl group include an ethynyl group, a propargyl group, and a phenylacetinyl group. Examples of the heterocyclic group include a furyl group, a thienyl group, a pyrrolyl group, a pyridyl group, a benzothienyl group, and a quinolyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, and a tert-butoxy group. Examples of the aryloxy group include those in which the aryl group exemplified above is bonded to an oxygen atom. Examples of the alkylthio group include those in which the already exemplified alkyl group is bonded to a sulfur atom. Examples of the arylthio group include those in which the already exemplified aryl group is bonded to a sulfur atom. Examples of the amide group include a methylamide group, an ethylamide group, a dimethylamide group, a diethylamide group, and a dicyclohexylamide group. Examples of the acyl group include formyl group, acetyl group, propionyl group, isopropionyl group, butyryl group, and pivaloyl group. Examples of the perfluoroaryl group include a pentafluorophenyl group, a nonafluorobiphenyl group, and a heptafluoronaphthyl group. Examples of the perfluoroalkyl group include a trifluoromethyl group and a pentafluoroethyl group.

In the graphene compound of the general formula (1), at least one of R ^{1 to} R ¹⁸ is a fluorine atom, or a substituent having a fluorine atom (an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a heterocyclic group) , An alkoxy group, an aryloxy group, an alkylthio group, and an arylthio group). This is because the decomposition reaction of the electrolytic solution can be suppressed as much as possible by replacing the edge portion of the graphene compound with an inert fluorine atom. For example, all of R ^{1 to} R ¹⁸ may be fluorine atoms, some may be fluorine atoms, and the remaining may be hydrogen atoms. For the same reason, it is preferable that at least one of R ^{19 to} R ⁴⁴ in the graphene compound of the general formula (2) is a fluorine atom or a substituent having a fluorine atom. In the graphene compound of the general formula (3), R ^{19 45 to} R ⁶⁶ are preferably at least one fluorine atom or a substituent having a fluorine atom. In the graphene compound of the general formula (4), R ^{67 to} R ⁹² are at least one fluorine atom or a fluorine atom. In the graphene compound of the general formula (5), at least one of R ^{93 to} R ¹¹⁴ is preferably a fluorine atom or a substituent having a fluorine atom, and the general formula (6) it is preferable that R ¹¹⁵ to R ¹⁴⁴ is a substituent having at least one or a fluorine atom is a fluorine atom in graphene compound It is preferred in the graphene compounds of the general formula (7) R ¹⁴⁵ ~R ¹⁷⁴ is a substituent having at least one or a fluorine atom is a fluorine atom.

Of the graphene compounds represented by the general formula (1), those in which R ^{1 to} R ¹⁸ are all hydrogen atoms can be synthesized by, for example, the route represented by the following formula. That is, the compound (11) and the compound (12) are heated at a molar ratio of 1: 1 using diphenyl ether or the like as a solvent to obtain the compound (13), and then dichloromethane or the like as a solvent to the compound (13) in a nitromethane solution of iron chloride. Can be added to obtain the graphene compound represented by the general formula (1). Here, although the exemplified for the case of all R ¹ to R ¹⁸ hydrogen atoms, when part or all of R ¹ to R ¹⁸ are such as an alkyl group, the compound according to R ¹ ~R ¹⁸ (11 ) And (12) may be appropriately set.

Of the graphene compounds represented by the general formula (2), those in which R ^{19 to} R ⁴⁴ are all hydrogen atoms can be synthesized, for example, by the route represented by the following formula. That is, the compound (21) and the compound (22) are heated at a molar ratio of 1: 2 using diphenyl ether or the like as a solvent to obtain the compound (23), and then dichloromethane or the like as a solvent to the compound (23) in a nitromethane solution of iron chloride. Is added, the graphene compound represented by the general formula (2) can be obtained. Here, although the exemplified for the case of all R ¹⁹ to R ⁴⁴ hydrogen atoms, when part or all of R ¹⁹ to R ⁴⁴ are such as an alkyl group, the compound according to R ¹⁹ ~R ⁴⁴ (21 ) And (22) may be appropriately set.

Of the graphene compounds represented by the general formula (3), those in which R ^{45 to} R ⁶⁶ are all hydrogen atoms can be synthesized, for example, by the route represented by the following formula. That is, first, compound (31) and compound (32) are heated at a molar ratio of 1: 1 using diphenyl ether or the like as a solvent to obtain compound (33). Thereafter, the compound (33) is reacted with tetrabutylammonium fluoride using THF or the like as a solvent to obtain the compound (34). Then, the compound (34) and the compound (32) are heated at a molar ratio of 1: 1 using diphenyl ether or the like as a solvent to obtain a compound (35), and then dichloromethane or the like as a solvent to the compound (35) in a nitromethane solution of iron chloride. Can be added to obtain the graphene compound represented by the general formula (3). Here, although the exemplified case R ⁴⁵ to R ⁶⁶ are all hydrogen atoms, when part or all of R ⁴⁵ to R ⁶⁶ are such as an alkyl group, the compound according to R ⁴⁵ ~R ⁶⁶ (31 ) And (32) may be appropriately set.

  Note that the graphene compounds represented by the general formulas (4) to (7) can also be synthesized according to these routes.

In the lithium ion secondary battery of the present invention, a negative electrode and a positive electrode are spaced apart from each other in an ion conductive medium. The ion conductive medium is not particularly limited. For example, an electrolytic solution containing a supporting salt, a gel electrolyte, a solid electrolyte, or the like can be used. Examples of the supporting salt include known supports such as LiPF ₆ , LiClO ₄ , LiBF ₄ , Li (CF ₃ SO ₃ ), LiAsF ₆ , LiN (CF ₃ SO ₂ ) ₂ , and LiN (C ₂ F ₅ SO ₂ ). A salt can be used. As a solvent for the electrolytic solution, for example, an aprotic organic solvent can be used. Examples of such an organic solvent include cyclic carbonates, chain carbonates, cyclic esters, cyclic ethers, chain ethers, and the like. Examples of the cyclic carbonate include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, and vinyl carbonate. Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate. Examples of the cyclic ester carbonate include gamma butyrolactone and gamma valerolactone. Examples of the cyclic ether include tetrahydrofuran and 2-methyltetrahydrofuran. Examples of the chain ether include dimethoxyethane and ethylene glycol dimethyl ether. These may be used alone or in combination. The gel electrolyte is not particularly limited. For example, a polymer such as polyvinylidene fluoride, polyethylene glycol, or polyacrylonitrile, or a saccharide such as an amino acid derivative or sorbitol derivative is added with an electrolyte containing a supporting salt. And a gel electrolyte. Examples of the solid electrolyte include inorganic solid electrolytes and organic solid electrolytes. Well-known inorganic solid electrolytes include, for example, Li nitrides, halides, oxyacid salts, and the like. Among _{them, Li 4 SiO 4, Li 4} SiO 4 -LiI-LiOH, xLi 3 PO 4 - (1-x) Li 4 SiO 4, Li 2 SiS 3, Li 3 PO 4 -Li 2 S-SiS 2, sulfide Examples thereof include phosphorus compounds. These may be used alone or in combination. Examples of the organic solid electrolyte include polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyvinylidene fluoride, polyphosphazene, polyethylene sulfide, polyhexafluoropropylene, and derivatives thereof. These may be used alone or in combination.

  In the lithium ion secondary battery of the present invention, the negative electrode is, for example, a negative electrode active material mixed with a binder, added with a suitable solvent into a paste, and applied to the surface of the current collector and dried. If necessary, it can be compressed to increase the electrode density. Here, the binder is not particularly limited, and examples thereof include a thermoplastic resin and a thermosetting resin. For example, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene butadiene rubber, tetrafluoroethylene-hexafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer (ETFE resin) , Polychlorotrifluoroethylene (PCTFE), vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-chlorotrif Examples include olefin copolymer (ECTFE), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, and ethylene-acrylic acid copolymer. . These materials may be used alone or in combination. Although it does not specifically limit as a collector, For example, metal plates or metal meshes, such as stainless steel, aluminum, copper, and nickel, are mentioned. Although it does not specifically limit as a solvent for making a paste, For example, N-methyl- 2-pyrrolidone etc. are mentioned.

  In the lithium ion secondary battery of the present invention, the positive electrode is obtained by mixing a positive electrode active material with a conductive material and a binder, and adding a suitable solvent to form a paste-like positive electrode mixture. It can be applied and dried, and compressed to increase the electrode density as necessary. Here, as the positive electrode active material, a lithium-containing composite oxide capable of reversibly inserting and extracting lithium can be used. Specifically, for example, lithium cobalt composite oxide, lithium nickel composite oxide, lithium manganese composite oxide, lithium iron composite phosphorus oxide, and the like can be given. The conductive material is not particularly limited as long as it is a conductive material. For example, carbon blacks such as ketjen black, acetylene black, channel black, furnace black, lamp black, and thermal black may be used. Such as natural graphite, artificial graphite, graphite such as expanded graphite, conductive fibers such as carbon fiber and metal fiber, or metal powder such as copper, silver, nickel, aluminum, Organic conductive materials such as polyphenylene derivatives may be used. These may be used alone or in combination. Note that the same material as the negative electrode can be used for the binder, the solvent, and the current collector.

  The lithium ion secondary battery 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 the composition can withstand the use range of the lithium ion secondary battery. For example, a polymer nonwoven fabric such as a polypropylene nonwoven fabric or a polyphenylene sulfide nonwoven fabric, or a thin olefin resin such as polyethylene or polypropylene is used. A microporous membrane is mentioned. These may be used alone or in combination.

  The shape of the water based lithium ion secondary battery of the present invention is not particularly limited, and examples thereof include a coin type, a button type, a sheet type, a laminated type, a cylindrical type, a flat type, and a rectangular type. A plurality of such water-based lithium ion secondary batteries may be connected in series to serve as a power source for an electric vehicle. Examples of the electric vehicle include a battery electric vehicle driven only by a battery, a hybrid electric vehicle combining an internal combustion engine and a motor drive, a fuel cell vehicle generating power by a fuel cell, and the like.

  Hereinafter, specific examples of the present invention will be described using examples.

[Example 1]
(1) Synthesis of hexabenzocoronene (see formula below)
1.10 g of hexaphenylbenzene was dissolved in 500 mL of dichloromethane, and nitrogen was blown for 5 minutes. To this solution, a solution prepared by dissolving 6.30 g of anhydrous iron chloride (FeCl ₃ ) in 72 mL of nitromethane was added dropwise under a nitrogen atmosphere and stirred at room temperature for 30 minutes. 500 mL of methanol was added, and the generated precipitate was filtered. The precipitate was stirred in 50 mL of 10 wt% aqueous ammonia and filtered. Further, it was washed with 50 mL of water and 50 mL of dichloromethane, and vacuum-dried to obtain 470 mg of hexabenzocoronene as an orange powder. This structure was confirmed as follows. That is, molecular ions were confirmed by MALDI-MS measurement combining a matrix-assisted laser desorption ionization method (MALDI) and a mass spectrometer (MS) (M ⁺ = 522), and the structure was determined. .

(2) Production of Coin Battery Here, a coin battery was produced using hexabenzocoronene as the negative electrode active material. That is, 95% by weight of the negative electrode active material, 5% by weight of polyvinylidene fluoride (manufactured by Kureha Chemical Co., Ltd.) as a binder, and an appropriate amount of N-methyl-2-pyrrolidone (NMP) as a dispersant is added and dispersed. A slurry-like negative electrode mixture was obtained. The negative electrode mixture was applied to an aluminum foil current collector with a thickness of 20 μm, vacuum-dried at 120 ° C. for about 12 hours, then densified with a roll press and cut into a 15 mmφ shape to obtain a negative electrode sheet. In addition, the adhesion amount of the negative electrode active material was about 30 mg. As the counter electrode, metallic lithium having a diameter of 19 mm and a thickness of about 0.2 mm was used. The negative electrode sheet and metallic lithium described above were sandwiched between polyethylene separators to produce a 2016 type coin battery. As the electrolytic solution, 1M LiPF6 dissolved in a solution in which ethylene carbonate (EC) and diethylene carbonate (DEC) were mixed at a volume ratio of 1: 1 was used. All steps for producing the coin battery were performed in a glove box under an argon atmosphere.

(3) Coin Battery Evaluation / Charge / Discharge Cycle Test At a test temperature of 25 ° C. and a current value of 0.5 mA (corresponding to a current density of about 0.28 mA / cm ² ), the lithium metal is charged to 5 V and then up to 3 V Charging / discharging to discharge was made into 1 cycle, and this cycle was performed 100 times in total.
• The capacity retention rate capacity retention rate in charge-discharge cycle test, the discharging capacity at the first cycle test as an initial capacitance SC _0, following from this initial capacity SC ₀ and the discharge capacity at SC test of each cycle It was calculated by the formula (a). The results are shown in Table 1.
Capacity maintenance ratio (%) = SC / SC ₀ × 100 (a)
Resistance increase rate The resistance increase rate is calculated by the following formula (b) from the initial resistance R ₀ and the resistance R after the charge / discharge test, where the resistance before the charge / discharge test is the initial resistance R ₀ in the charge / discharge cycle test. did. The initial resistance R ₀ is obtained by charging the coin battery up to 3 V, passing a current of 0.5 mA, 1.0 mA, 2.0 mA, 4.0 mA, 8.0 mA and measuring the battery voltage after 10 seconds. The applied current and voltage were approximated by a straight line and obtained from the slope. The results are shown in Table 1.
Resistance increase rate (%) = (R−R ₀ ) / R ₀ × 100 (b)

[Example 2]
(1) Synthesis of hexabenzocoronene analog (B) (see Chemical Formula 6)
1.0 g of 1,4-bis (phenylethynyl) benzene and 2.9 g of 2,3,4,5-tetraphenylcyclopentadienone were added to 5 mL of diphenyl ether and reacted at 220 ° C. for 2 days in a nitrogen atmosphere. 100 mL of methanol was added, and the generated precipitate was filtered. By recrystallizing the precipitate from nitrobenzene, 3.2739 g of hexaphenylbenzene analog (A) was obtained as milky white crystals (yield 91.9%). This structure was confirmed as follows. That is, the molecular ion was confirmed by MALDI-MS measurement (M ⁺ = 990), and the structure was confirmed.

Further, 12.6 g of copper trifluoromethanesulfonate and 4.90 g of aluminum chloride were added to 250 mL of carbon disulfide (CS2) and dissolved by stirring under a nitrogen atmosphere. To this solution, 370 mg of hexaphenylbenzene analog was added and stirred at room temperature for 2 days. After adding 200 mL of 10 wt% hydrochloric acid and stirring, the carbon disulfide layer was separated and concentrated under reduced pressure. The residue was stirred in 100 mL of 10 wt% aqueous ammonia and filtered. Further, it was washed with 100 mL of water, 100 mL of carbon disulfide and 100 mL of dichloromethane, and vacuum-dried to obtain 311.4 mg of hexabenzocoronene analog (B) as a brown powder. This structure was confirmed as follows. That is, the molecular ion was confirmed by MALDI-MS measurement (M ⁺ = 962), and the structure was confirmed.

(2) Production of Coin Battery A coin battery was produced in the same manner as in Example 1 except that the hexabenzocoronene analog (B) was used as the negative electrode active material.

(3) Evaluation of coin battery A coin battery was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
(1) Synthesis of hexabenzocoronene analog (C) (see Chemical Formula 7)
Hexabenzocoronene analog (C) (2,5,8,11,14,17-hexafluoro-hexa-peri-hexabenzocoronene) was synthesized according to Example 1 of Japanese Patent Application Laid-Open No. 2007-19086.

(2) Production of Coin Battery A coin battery was produced in the same manner as in Example 1 except that the hexabenzocorene analogue (C) was used as the negative electrode active material.

(3) Evaluation of coin battery A coin battery was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
A coin battery was prepared and evaluated in the same manner as in Example 1 except that artificial graphite (manufactured by Petka) was used as the negative electrode active material. The results are shown in Table 1.

[Evaluation results]
As apparent from Table 1, the coin batteries of Examples 1 to 3 have an initial capacity (mAh / g) of 1.5 to 3.7 times that of the coin battery of Comparative Example 1, and have a high energy density. I understand that. In addition, the capacity maintenance rate and the resistance increase rate were substantially the same in the coin batteries of Examples 1 and 2 as compared with the coin battery of Comparative Example 1, but were improved in the coin battery of Example 3. Recognize. Here, the discharge curves of the coin batteries of Examples 1 and 3 and Comparative Example 1 are shown in FIG. As is clear from FIG. 1, the negative electrode active material of Example 1 shows almost the same reduction potential (about 0.2 V) as that of the graphite of Comparative Example 1. In addition, the negative electrode active material of Example 3 shows a relatively flat reduction potential in the vicinity of about 0.5V.

2 is a discharge curve of each coin battery of Examples 1 and 3 and Comparative Example 1;

Claims (1)

A lithium ion secondary battery using, as a negative electrode active material, a graphene compound having 42 to 144 carbon atoms having hexabenzocoronene as a basic skeleton ,
A lithium ion secondary battery using any graphene compound represented by the general formulas (1) to (7) as a negative electrode active material.

Wherein R ^{1 to} R ¹⁷⁴ are each independently a hydrogen atom, halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, heterocyclic group, alkoxy group, aryloxy group, alkylthio group, An arylthio group, a cyano group, an amide group, an acyl group, a perfluoroaryl group and a perfluoroalkyl group,
R ^{1 to} R ¹⁸ are at least one fluorine atom, R ^{19 to} R ⁴⁴ are at least one fluorine atom, R ^{45 to} R ⁶⁶ are at least one fluorine atom, and R ^{67 to} R ⁹² are at least 1 One is a fluorine atom, at least one of R ^{93 to} R ¹¹⁴ is a fluorine atom, at least one of R ^{115 to} R ¹⁴⁴ is a fluorine atom, and at least one of R ^{145 to} R ¹⁷⁴ is a fluorine atom)

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