JP2001223010A - Nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable nonaqueous secondary battery with a high capacity and a little capacity reduction accompanied with the charge- discharge cycle. SOLUTION: A benzenoid aromatic compound which has the dichalcogenide bond with at least S, or with either element of S, Se or Te is used as a positive electrode active substance, and then a nonaqueous secondary battery is constituted. As the benzenoid aromatic compound, either of the derivative of naphthalene, anthracene, 1,2-benzanthracence, tetracene or pyrene is preferable, and as the electrolyte for battery, gel polyelectrolyte is preferable, and as the electrolyte salt which is made to be contained in the gel polyelectrolyte, fluorine-containing organolithium salt is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-aqueous secondary battery using a benzenoid aromatic compound having a dichalcogenide bond with a specific element as a positive electrode active material.

[0002]

2. Description of the Related Art With the rapid expansion of portable electronic devices in the market, there is an increasing demand for higher performance of batteries used as power sources, and on the other hand, the development of more environmentally friendly batteries. Is required. Under such circumstances, expectations are growing for sulfur (sulfur) and its derivatives that are low-cost, have low environmental impact, and have high capacity as positive electrode active materials for non-aqueous secondary batteries.

If the two-electron reaction of sulfur can be used in a battery, theoretically elemental sulfur becomes an active material having a large energy density of 1675 Ah / kg. However, since sulfur is a highly insulating insulator, an alkali metal-sulfur battery utilizing a reduction reaction to an alkali metal sulfide requires the coexistence of a conductive auxiliary having no reactivity with sulfur. However, in reality, only a low utilization rate can be obtained. In addition, sulfur is poor in reversibility, and there is a problem that sulfur and its derivatives at high temperatures are highly active, so that the battery case and the like are eroded.
It is said that application to small consumer batteries is difficult.

Also, organic sulfur compounds such as polycarbon sulfide (CS _x ) _n (x is 2.3 to about 50, n is 2 or more) having a high energy density of 1000 to 1600 Ah / kg are used in non-aqueous secondary batteries. Skotheim et al. Have announced that they have developed a sulfur-based non-aqueous secondary battery exhibiting high capacity even at room temperature (Japanese Patent Application Laid-Open No. 11-514128, US Pat. 441,831). This polycarbon sulfide can be prepared by reacting sodium sulfide with elemental sulfur and further reacting with an organic chloride compound, or by reacting acetylene with elemental sulfur in an ammonia solution of metallic sodium, or by disulfide using metallic sodium as a catalyst. It can be synthesized by a method of reacting carbon and dithimelsulfone. The molecular structure of the polycarbon sulfide is characterized in that it has a conjugated structure having mainly carbon as a skeleton and polysulfide as a side chain.

[0005]

However, the sulfur-based nonaqueous secondary battery has various problems as described below. That is, when elemental sulfur is used, in addition to the above-mentioned problems, there is almost no solvent capable of dispersing it, and it is difficult to form a positive electrode.In addition, a polysulfide metal salt is formed during the charge / discharge process, and the polysulfide metal salt is used. There is a problem that the cycle life is shortened due to elution into the electrolytic solution.

In a battery using an organic sulfur compound such as polycarbon sulfide, the organic sulfur compound actually used is in a liquid state, and even a solid one has a low melting point in many cases. It has essentially high solubility in the electrolytic solution, and has -S _x- (x
Has 3 or more) polysulfide segments, so that a polysulfide metal salt is formed during the charge / discharge process, as in the case of elemental sulfur, and the polysulfide metal salt dissolves in the electrolyte and inhibits the reversibility of the positive electrode. There is a problem that the cycle life is shortened by the formation of metal sulfide.

Therefore, the present invention solves the above-mentioned problems of the conventional sulfur-based nonaqueous secondary battery, and has a high capacity and a highly reliable nonaqueous secondary battery with little reduction in capacity due to charge / discharge cycles. It is intended to provide a battery.

[0008]

[Means for Solving the Problems]

The present invention provides at least S, S, Se, Te
By using a benzenoid aromatic compound having a dichalcogenide bond with any of the elements as a positive electrode active material, dissolution of the positive electrode active material in the electrolytic solution is suppressed, and a reduction in capacity due to a charge / discharge cycle is reduced. It is an object of the present invention to improve the reliability of a sulfur-based nonaqueous secondary battery capable of achieving a high capacity and to solve the above-mentioned problems.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The non-aqueous secondary battery of the present invention is characterized in that the positive electrode active material is a benzenoid aromatic compound having a dichalcogenide bond between at least S and any of S, Se and Te. And In the benzenoid aromatic compound, two atoms forming a dichalcogenide bond (any one of a combination of S and S, S and Se, and S and Te) are used to secure stability during charge and discharge. It preferably has a bond with a C atom, and more preferably has a bond with a C atom of a benzene ring adjacent to each other. In the present invention, the reason why at least one of the two atoms forming the dichalcogenide bond is limited to the S atom is to impart electrochemical reversibility to the benzenoid aromatic compound, From the viewpoint of capacity per weight, disulfide bonds between S atoms are preferred.

Examples of the benzenoid aromatic ring constituting the benzenoid aromatic compound include aromatic rings such as naphthalene, anthracene, 1,2-benzanthracene, tetracene and pyrene. Further, a derivative in which a hydrogen atom of the benzenoid aromatic compound is substituted with an atom such as C, N, O, S or a functional group containing any of those atoms, or an aromatic ring of the benzenoid aromatic compound has N, Compounds having a hetero atom such as O and S are also included in the category of the benzenoid aromatic compound in the present invention, and can be used as the positive electrode active material.

The atoms in the molecule of the benzenoid aromatic compound are preferably present on the same plane as much as possible, and more preferably all the atoms are present on the same plane. That is, by adopting such a special molecular structure, the compound is stabilized, the dissolution in the electrolytic solution is reduced, and the electrochemical reversibility is improved.

In the present invention, at least S and S, Se,
Examples of the benzenoid aromatic compound having a dichalcogenide bond with any element of Te include naphthalene disulfide (NDS), naphthaleneselenosulfide (NSeS), and tetrathiolnaphthalene (T
TN), tetrathiolanthracene (TTA), tetrathioltetracene (TTT), octathiolpyrene (OTP) and the like. The symbols added in parentheses after the names of the above benzenoid aromatic compounds are abbreviations of those benzenoid aromatic compounds. And, the chemical structural formula of the above benzenoid aromatic compound is as follows. Abbreviations of the above benzenoid aromatic compound names are added in parentheses (parentheses) below the chemical structural formulas.

Embedded image

In each of the above benzenoid aromatic compounds, all atoms in the molecule are present on the same plane. In addition, these compounds can of course be used as monomolecular compounds, but may be polymers formed based on them. The theoretical capacities of tetrathiolnaphthalene and octathiopyrene are 425 Ah / kg and 476 Ah / kg, respectively, and LiCoO ₂ (theoretical capacity: 137), which is the most common cathode active material in a conventional lithium ion secondary battery, is used.
(Ah / kg).

The positive electrode is composed of a positive electrode active material comprising a benzenoid aromatic compound having a dichalcogenide bond, as well as a conductive auxiliary and a binder which are added as necessary. For example, graphite,
A carbonaceous material such as carbon black, a conductive polymer, or the like is preferably used. As the conductive polymer, for example, polymers having a conjugated structure such as polyacene, polyacetylene, polyaniline, and polypyrrole, and derivatives thereof having side chains such as methyl, butyl, and benzyl are preferably used.

Examples of the binder include polyvinylidene fluoride, amorphous polyether, polyacrylamide, polyaniline and polypyrrole having solubility in a solvent, a copolymer of these compounds and a compound formed by crosslinking, and the like. It is preferable that the polymer compound is chemically stable and has a strong adhesive force to the positive electrode active material.

The positive electrode is prepared, for example, by adding the above-mentioned conductive auxiliary agent, binder and the like to the positive electrode active material comprising the above-mentioned benzenoid aromatic compound, if necessary, and mixing to prepare a positive electrode mixture. Disperse into a paste (the binder may be dissolved in a solvent in advance and then mixed with the positive electrode active material, etc.), and the positive electrode mixture-containing paste is applied to a positive electrode current collector made of metal foil or the like, and dried. The positive electrode current collector is formed through a step of forming a positive electrode mixture layer on at least a part of the positive electrode current collector. However, the manufacturing method of the positive electrode
The present invention is not limited to the method described above, but may be another method.

Examples of the active material for the negative electrode include alkali metals such as lithium and sodium, alkaline earth metals such as calcium and magnesium, alloys thereof with aluminum and the like, carbonaceous materials such as graphite, tin (tin) and silicon. (Silicon) -containing oxides, nitrogen compounds of lithium cobalt, polymers having a conjugated structure such as polyacene, polyacetylene, polyaniline, polythiofin, polypyrrole, and derivatives thereof having side chains such as methyl, butyl, and benzyl. Examples include a conductive polymer.

The method for manufacturing the negative electrode is roughly classified into two methods depending on the type of the negative electrode active material used. One is to use a metal or alloy as the negative electrode active material, and press the metal or alloy of the negative electrode active material onto the negative electrode current collector made of a porous metal such as wire mesh, expanded methyl, or punched metal to produce a negative electrode. The method is adopted. When a carbonaceous material or the like is used as the negative electrode active material, the same conductive auxiliary agent or binder as in the case of the positive electrode is added to the negative electrode active material composed of the carbonaceous material, if necessary, and mixed. Prepare a negative electrode mixture, disperse it in a solvent to form a paste (the binder may be dissolved in the solvent before mixing with the negative electrode active material, etc.), and paste the negative electrode mixture-containing paste into a copper foil or the like. The negative electrode current collector is formed by applying to a negative electrode current collector, drying and forming a negative electrode mixture layer on at least a part of the negative electrode current collector. However, the method for producing the negative electrode is not limited to the method exemplified above, and may be another method.

As the electrolyte, any of a liquid electrolyte (hereinafter, referred to as "electrolyte"), a gel polymer electrolyte, and a solid electrolyte can be used.

First, the electrolyte will be described from an electrolyte. The electrolyte is formed by dissolving an electrolyte salt in a solvent component.

As the solvent component of the electrolytic solution, ethers, esters, carbonates and the like are preferably used. In particular, it is preferable to use a mixture of an ester having a high dielectric constant (dielectric constant of 30 or more). Examples of such high dielectric constant esters include, for example, ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, sulfur-based esters such as ethylene glycol sulfite, and the like, and particularly preferred are cyclic esters, particularly ethylene carbonate. And the like are preferred.

As the solvent component, in addition to the above-mentioned solvents, for example, an organic solvent having a chain COO-bond such as dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propionate, or a chain such as trimethyl phosphate is used. Phosphoric acid triester and the like, and in addition, 1,2-dimethoxyethane, 1,1,
3-dioxolan, tetrahydrofuran, 2-methyl-
Tetrahydrofuran, diethyl ether and the like can also be used. Further, an amine-based or imide-based organic solvent, a sulfur-based organic solvent such as sulfolane, or the like can also be used.

Further, when a compound having a C ＝ C unsaturated bond is added to the electrolyte as an additive, a decrease in cycle characteristics can be suppressed even when the negative electrode mixture layer is formed at a high density to increase the capacity. It is preferred. As such a compound having a C ＝ C unsaturated bond, a fluorinated compound is particularly preferable, and a compound having an ester bond is more preferable.
(CF ₂ ) ₄ CH ₂ OOCCH = CH ₂ , F (CF ₂ )
Esters having a C ＝ C unsaturated bond such as ₈ CH ₂ CH ₂ OOCCH ＝ CH ₂ are mentioned.

As an electrolyte salt dissolved in the above solvent component
Are alkali metals such as lithium and sodium,
Halogen salts or persalts of alkaline earth metals such as calcium
Including citrate and trifluoromethanesulfonate
A salt of a fluorine compound or the like is preferably used. like this
Specific examples of the electrolyte salt include, for example, LiF, LiC
1, LiClO_Four, Mg (ClO_Four)_Two, LiPF₆,
LiBF_Four, LiAsF ₆, LiSbF₆, LiCF_Three
SO_Three, LiC_FourF₉SO_Three, LiCF_ThreeCO_Two, Li
_TwoC_TwoF_Four(SO_Three)_Two, LiN (RfSO_Two) (R
f'SO_Two), LiN (RfOSO)_Two) (Rf'OSO
_Two), LiC (RfSO_Two)_Three, LiC_nF _{2n + 1}SO_Three
(N ≧ 2), LiN (RfOSO_Two)_Two[Where Rf
Rf 'is a fluoroalkyl group] and the like.
May be used alone or in combination of two or more.
it can. And, as this electrolyte salt, particularly, a carbon number 2
The above fluorinated organic lithium salts are preferred. In other words, above
The fluorine-containing organic lithium salt has a large anionic property, and
Is it easy to dissolve in the above solvent components because of easy ion separation?
It is. The concentration of electrolyte salt in the electrolyte is particularly limited.
Although not specified, it is preferably 1 mol / l or more,
1.2 mol / l or more is more preferable, and 1.7 m / l
ol / l or less is preferable, and 1.5 mol / l or less is more preferable.
preferable.

The gel polymer electrolyte corresponds to one obtained by gelling the above electrolytic solution with a gelling agent. In the gelation, for example, a linear polymer such as polyethylene oxide or polyacrylonitrile or a copolymer thereof, a monomer that is polymerized by irradiation with ultraviolet light, or a reaction between active hydrogen of an amine compound and an isocyanate group of urethane. Monomers that are polymerized by utilizing are used. However, in the case of a monomer, a polymer obtained by polymerizing the above-mentioned monomer acts as a gelling agent, instead of the monomer itself gelling the electrolytic solution. Solid electrolytes include inorganic and organic ones. Examples of inorganic solid electrolytes include sodium β-alumina, 60LiI-40Al ₂ O ₃ , L
_{i 3 N, 5LiI-4Li 2} S-2P 2 S 6, Li 3 N
-LiI, etc. _{Li 1.26 Si 0.365 O 0. 04 P} 0.01 S 1.36 , and the like, Examples of the organic solid based electrolyte, for example, polyethers amorphous or low phase transition temperature (Tg), amorphous vinylidene fluoride Copolymers, blends of different polymers, and the like are included.

[0027]

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples. Also, in the following examples,
The percentages indicating the concentration of the solution or the dispersion or the percentages indicating the composition, the yield, etc. are by weight unless otherwise specified.

Example 1 A positive electrode was prepared as shown below using tetrathiol naphthalene (molecular weight: 252) as a positive electrode active material. That is, 10 g of tetrathiol naphthalene, 7.2 g of graphite (KS-6 (trade name, manufactured by Lonza)) and 0.8 g of acetylene black as a conductive auxiliary agent are put in a mixing vessel, and mixed for 10 minutes in a dry system. 50 g of N-methyl-2-pyrrolidone was added and mixed for 30 minutes. Next, N containing 12% of polyvinylidene fluoride
16.7 g of -methyl-2-pyrrolidone solution was added, and the mixture was further mixed for 1 hour to prepare a positive electrode mixture-containing paste.

The obtained paste containing the positive electrode mixture was coated to a thickness of 20
μm aluminum foil (size: 250 mm x 220 m
m) and dried on a hot plate at 50 ° C. for 10 minutes, and then dried and removed at 120 ° C. for 10 hours in vacuum to form a positive electrode mixture layer. The electrode body after drying was heated to 100 ° C. and pressed, and the thickness of the positive electrode mixture layer was 2 mm.
A positive electrode of 0 μm was used.

The negative electrode has a thickness of 20 in an argon gas atmosphere.
0 μm metallic lithium foil is coated on a nickel mesh (size: 250
mm × 220 mm) and pressed with a roller to press the metallic lithium foil against a nickel net.

As an electrolyte used in combination with these positive and negative electrodes, a gel polymer electrolyte prepared as described below was used.

Jeffamine X which is an amine compound
TJ-502 [AHEW (active hydrogen equivalent) = 525, trade name, Huntsman corporation, U
SA] 100 g to 130 g PC / EC (1/1 wt)
And 25.2 g of epoxy resin SR-8E
G (trade name, manufactured by Sakaki Yakuhin, epoxy equivalent = 290) was added, and the mixture was reacted at room temperature with stirring for 7 days. The PC / EC (1/1 wt) indicates that it is a mixed solvent of propylene carbonate (PC) and ethylene carbonate (EC) at a weight ratio of 1: 1.

The above Jeffamine XTJ-502 is represented by the following equation:

Embedded image (Where b = 39.5 and a + c = 5.0)

The epoxy resin SR-8EG is represented by the following formula.

Embedded image (Where d = 8)

Then, the above-mentioned Jeffamine XTJ-
The reaction between 502 and the epoxy resin SR-8EG proceeds according to the following reaction formula.

[0036]

Embedded image

LiCF ₃ SO ₃ was added to the pale yellow transparent solution obtained by the reaction of the above Jeffamine XTJ-502 with the epoxy resin SR-8EG to a concentration of 1.0 M, and the mixture was stirred until it was uniformly dissolved. On the other hand, urethane [AX-1043 (trade name) manufactured by Mitsui Chemicals, Inc .;
8.60%] of MEC / EC (2/1 wt)
It was dissolved in a 1.0 M solution of ICF ₃ SO ₃ . MEC above
/ EC (2/1 wt) is methyl ethyl carbonate (M
EC) and ethylene carbonate (EC) in a weight ratio of 2:
1 is a mixed solvent.

The product obtained by the reaction between the above-mentioned Jeffamine XTJ-502 and the epoxy resin SR-8EG, and
An amine compound solution in which iCF ₃ SO ₃ is dissolved and a urethane solution are mixed with active hydrogen of an amine compound and -N of urethane.
The mixture was mixed so that the molar ratio of CO was 1.1: 1.0, and the polybutylene terephthalate nonwoven fabric having a thickness of 80 μm was immersed in the above-mentioned mixed solution. Was prepared. About the obtained gel polymer electrolyte, the polymer content was 12.5%, and the electrolyte salt LiCF was used.
The concentration of ₃ SO ₃ was adjusted to 1M, and the ionic conductivity at room temperature was measured to be 1.0 × 10 ⁻³ S · cm ⁻¹ .

The above-mentioned positive electrode and negative electrode were laminated in an argon gas atmosphere via the gel polymer electrolyte to produce a laminated electrode body. This laminated electrode body is shown in FIG.

Referring to the laminated electrode assembly shown in FIG. 1, the positive electrode 1 is formed by forming a positive electrode mixture layer 1b on one surface of a positive electrode current collector 1a made of aluminum foil, and the negative electrode 2 is made of nickel mesh. The positive electrode 1 and the negative electrode 2 are formed by pressing a metallic lithium foil 2b on one surface of a negative electrode current collector 2a
b and the metallic lithium foil 2b are laminated so as to face each other with the gel polymer electrolyte 3 interposed therebetween.

This laminated electrode assembly was placed in a package consisting of a three-layer laminate film of a nylon film-aluminum foil-modified polyolefin resin film, and sealed to produce a non-aqueous secondary battery. The battery was charged and discharged at a current value corresponding to 40 mA per 1 g of the positive electrode active material (the end voltage of the discharge was 1.5 V), and this was repeated for 20 cycles.
The change in the discharge capacity per 1 g of the positive electrode active material accompanying the charge / discharge cycle was examined. The results are shown in Table 1 below.

Example 2 In the same manner as in Example 1, a positive electrode using tetrathiolnaphthalene as a positive electrode active material and a negative electrode using lithium metal as a negative electrode active material were produced. As an electrolyte, a mixed solvent of propylene carbonate and ethylene carbonate having a weight ratio of 1: 1 and a concentration of LiPF ₆ of 1.4 mol was used.
/ L was used.

Then, the positive electrode and the negative electrode were formed to a thickness of 80 μm.
Laminated in an argon gas atmosphere via a separator made of polypropylene non-woven fabric of the above, the laminated electrode body is placed in a package made of the same laminated film as in Example 1,
After injecting the above electrolyte, a non-aqueous secondary battery was sealed and a change in discharge capacity with a charge / discharge cycle was examined in the same manner as in Example 1. The results are shown in Table 1 below.

Example 3 Tetrathiol naphthalene was used as a positive electrode active material, and 10 g of the tetrathiol naphthalene was added to graphite (KS-6 (trade name, manufactured by Lonza)) as a conductive additive.
5.8 g and 0.6 g of acetylene black are put in a mixing container, mixed for 10 minutes in a dry system, and then mixed with N-methyl-2.
-50 g of pyrrolidone were added and mixed for 30 minutes. Next, 51.6 g of an N-methyl-2-pyrrolidone solution containing 1.6 g of polyaniline and 12 mL of polyvinylidene fluoride were added.
% -Containing N-methyl-2-pyrrolidone solution 16.8 g
Were successively added and mixed for another hour to prepare a positive electrode mixture-containing paste. A non-aqueous secondary battery was prepared in the same manner as in Example 2 except that this paste containing the positive electrode mixture was used, and a change in discharge capacity accompanying a charge / discharge cycle was examined in the same manner as in Example 1. The results are shown in Table 1 below.

Example 4 A non-aqueous secondary battery was fabricated in the same manner as in Example 2 except that octathiolpyrene (molecular weight: 450) was used as the positive electrode active material. The change in discharge capacity was examined. The results are shown in Table 1 below.

Comparative Example 1 A non-aqueous secondary battery was prepared in the same manner as in Example 2 except that 2,5-dimethylcapto-1,3,4-thiadiazole (molecular weight: 150) was used as a positive electrode active material. In the same manner as in Example 1, a change in discharge capacity due to a charge / discharge cycle was examined.
The results are shown in Table 1 below.

Comparative Example 2 A non-aqueous secondary battery was produced in the same manner as in Example 1 except that elemental sulfur was used as the positive electrode active material, and the change in discharge capacity accompanying the charge / discharge cycle was examined in the same manner as in Example 2. Was. Table 1 shows the results.

Table 1 shows the discharge capacity per 1 g of the positive electrode active material and the 1 g of the positive electrode active material at the 20th charge / discharge cycle during the initial discharge of the batteries of Examples 1 to 4 and the batteries of Comparative Examples 1 and 2.
Per discharge capacity, and the discharge capacity of the initial discharge and 2
The change in the discharge capacity due to the charge / discharge cycle is evaluated based on the difference from the discharge capacity at the 0th cycle.

[0049]

[Table 1]

As shown in Table 1, the discharge capacities of the batteries of Examples 1-4 were 418-482 mAh / g (that is, 418 mAh / g).
482 Ah / kg), and the positive electrode active material used in the batteries of Examples 1 to 4 is LiCoO ₂ (theoretical capacity: 137 Ah / kg) which is widely used as the positive electrode active material of non-aqueous secondary batteries. ). Also,
As shown in Table 1, in the batteries of Examples 1 to 4, the difference between the initial discharge capacity and the discharge capacity at the 20th cycle is small, and the discharge capacity at the 20th cycle is larger than the initial discharge capacity. In some of the batteries of Examples 1 to 4, there was little decrease in capacity due to charge / discharge cycles.

That is, the batteries of Examples 1 to 4 had a high capacity, and had less capacity reduction due to charge / discharge cycles than the battery of Comparative Example 2 corresponding to a conventional sulfur-based nonaqueous secondary battery, and exhibited a high reliability. Was high. In particular, in the battery of Example 1 using the gel polymer electrolyte, since the electrolyte is in a gel state,
The elution of the positive electrode active material into the electrolyte is further suppressed as compared with the battery of Example 2 using the electrolytic solution, the stability in the battery is further improved, and a decrease in capacity due to charge / discharge cycles is observed. Did not. In addition, the battery of Example 3 using polyaniline, which is a conductive polymer, as the conductive auxiliary agent for the positive electrode improved the conductivity in the positive electrode and enabled a uniform reaction of the active material in the positive electrode. And the capacity was not reduced by the charge / discharge cycle.

On the other hand, in the battery of Comparative Example 1, since the organic sulfur compound different from that of the present invention was used as the positive electrode active material, the discharge capacity was smaller than that of the batteries of Examples 1 to 4, and the charge / discharge cycle was increased. , The capacity was reduced, and the reliability was poor. Further, the battery of Comparative Example 2 using elemental sulfur had a large initial discharge capacity, but could not be discharged in a short cycle due to elution of the positive electrode active material into the electrolytic solution, and was lacking in reliability.

[0053]

As described above, according to the present invention, the stability of a positive electrode active material in a battery is improved, and a non-aqueous secondary battery having a high capacity, a small capacity reduction due to charge / discharge cycles, and a high reliability is obtained. Battery could be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a main part of a laminated electrode body in which a positive electrode and a negative electrode in a non-aqueous secondary battery of Example 1 are laminated with a gel polymer electrolyte interposed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 1a Positive electrode current collector 1b Positive electrode mixture layer 2 Negative electrode 2a Negative electrode current collector 2b Metal lithium foil 3 Gel polymer electrolyte

 ──────────────────────────────────────────────────の Continuation of the front page (72) Inventor Hideki Nishihama 1-88 Ushitora, Ibaraki-shi, Osaka Inside Hitachi Maxell Co., Ltd. (72) Shoko Takabayashi 1-188 Ushitora, Ibaraki-shi, Osaka F term in Hitachi Maxell, Ltd. (reference) 5H029 AJ05 AK15 AL02 AL12 AL16 AM03 AM04 AM05 AM07 AM16 BJ04 EJ12 5H050 AA07 BA18 CA22 CB07 CB12 CB20 EA24 HA02

Claims (5)

[Claims] 1. A non-aqueous secondary battery characterized in that a benzenoid aromatic compound having a dichalcogenide bond between at least S and any one of S, Se and Te is used as a positive electrode active material. 2. The non-aqueous secondary battery according to claim 1, wherein the benzenoid aromatic compound is any one of naphthalene, anthracene, 1,2-benzanthracene, tetracene and pyrene or a derivative thereof. . 3. A positive electrode comprising a conductive polymer having a conjugated structure or a derivative thereof in a positive electrode.
3. The non-aqueous secondary battery according to 2. 4. The non-aqueous secondary battery according to claim 1, wherein a gel polymer electrolyte is used as an electrolyte of the battery. 5. The non-aqueous secondary battery according to claim 4, wherein the electrolyte salt contained in the gel polymer electrolyte is a fluorine-containing organic lithium salt.