JPH117981A - Secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the contact resistance between electrodes and the solid electrolyte, and provide a secondary battery having high density, in which electrode reaction is evenly performed, by dispersing the active material of at least one of a positive electrode and a negative electrode in the polymer gel. SOLUTION: A positive electrode active material layer 3, which is formed on one surface of a positive electrode collector 4, and a negative electrode active material layer 1, which is formed on one surface of a negative electrode collector 2, are laminated through a polymer solid electrolyte layer 5. As a matrix polymer of the polymer gel, the polymer having a dielectric constant at 4 or more is desirably, for example, a nitrocellulose resin, chlorosulfonated polyethylene, polymethyl methacrylate, a phenol resin, polyvinylidene fluoride, polyacrylonitrile are cited. Especially, polyvinylidene fluoride, polyacrylonitrile or the derivative thereof is desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid secondary battery having a high output density, and more particularly to a small and large-capacity lithium or lithium ion secondary battery.

[0002]

2. Description of the Related Art Multimedia technology has rapidly progressed in response to the information age, and the performance of electronic products has been improved.
There is a strong demand for portability. Regarding secondary batteries as an energy source, research and development of new secondary batteries aiming at miniaturization, high capacity and high energy density are actively conducted. In the early 1990s, so-called lithium ion secondary batteries were commercialized. Was A lithium ion secondary battery has a structure in which a negative electrode and a positive electrode are arranged using a carbon material having a property of absorbing lithium ions as a negative electrode and a metal oxide as a positive electrode, with a separator and an electrolyte interposed therebetween. It is a secondary battery having an energy density. However, since a lithium ion secondary battery uses an electrolytic solution, a metal can has to be used to prevent liquid leakage.

[0003] Armand (USP 4,303,748, 1
981) et al. Have proposed from an early stage the use of a solid electrolyte in which an alkali metal salt or an alkaline earth metal salt is dissolved in a polyalkylene oxide in place of an electrolytic solution. However, ordinary polyalkylene oxides such as polyethylene oxide and polypropylene oxide not only have insufficient ionic conductivity but also have extremely high contact resistance with the positive electrode and the negative electrode, and have not yet been adopted (K.
Murata, ElectrochimicaAct
a. Vol. 40, no. 13-14, p2177-
2184, 1995).

[0004] Various proposals have been made to solve these problems. For example, Lee et al. Have proposed application of a polymer gel in which a solution of an organic solvent having a high boiling point and a high polarity and an alkali metal salt is dispersed in a crosslinked product of a low molecular weight alkylene oxide having an acrylate end group or an acrylate side chain. (USP 4,830,939, 1
989). Further, for example, Gozdz et al. Have proposed application of a polymer gel in which a polyvinylidene fluoride derivative is impregnated with an electrolyte solution in which a lithium salt is dissolved (US Pat. No. 5,429,891, 1995).

On the other hand, various organic compound active materials have been developed in place of the metal oxide used for the positive electrode of the lithium ion secondary battery from the viewpoint of improving the energy density per unit weight and protecting the environment. . Among them, the sulfur-sulfur bond is cleaved by electrolytic reduction to generate a sulfur-metal ion or sulfur-proton bond, and the sulfur-metal ion or sulfur-proton bond is converted to the original sulfur-metal ion by electrolytic oxidation.
Organic disulfide compounds that regenerate into sulfur bonds (Dejo
nghe et al., US Pat. No. 4,833,048, 1989) and a quinone compound in which a quinone group is reduced to a dihydroxy group by electrolytic reduction and a dihydroxy group is oxidized to a quinone group by electrolytic oxidation (H. Krohn et al., NATO AS).
I Ser. 3, 1996) and the like.

Further, in a secondary battery using the above-mentioned organic disulfide compound as an active material, a composite electrode with a conductive polymer such as a polyaniline derivative has been proposed in order to improve the charge / discharge characteristics of the battery (Japanese Patent Application Laid-Open No. Hei 8 (1996)). -11572
No. 4, JP-A-8-222207).

[0007]

The use of a polymer gel electrolyte not only improves the ionic conductivity of the electrolyte, but also greatly reduces the contact resistance between the electrolyte and the electrodes. However, a polymer gel comprising a crosslinked product of an alkylene oxide and an electrolytic solution is not always mechanically sufficient, and various problems arise in practice because electron beams and ultraviolet rays are used for polymer crosslinking. Is left. In addition, if a large amount of the electrolytic solution is contained in the polymer gel electrolyte, the solution may leak at high temperatures, and the merit of using the polymer gel electrolyte is diminished.

Further, in a secondary battery using a disulfide compound or a quinone compound as an active material, when a liquid phase electrolyte or a polymer gel electrolyte is used as an electrolyte, reduction of capacity due to dissipation of the active material becomes a major problem. On the other hand, complete solid-state secondary batteries have the disadvantage that the charge / discharge efficiency of the battery is low and the charge / discharge cycle life is short due to the non-uniformity of the electrode reaction derived from the solid-phase reaction and the slow reaction rate. I have. For example, in the case of a disulfide compound, the polydisulfide compound is electrically insulative and has poor ionic conductivity, so it was formed again as a polymer at a location away from the vicinity of a conductive auxiliary such as carbon which was originally located in the electrode. At that time, the polymer is isolated from the electron-ion conduction network in the electrode, and cannot participate in the electrode reaction, and the cycle characteristics of the battery are greatly reduced.

The present invention has been made in order to solve the above-mentioned problems and the like. In a secondary battery using a solid electrolyte,
It is an object of the present invention to provide a high-density secondary battery in which the contact resistance between an electrode and a solid electrolyte is reduced and the electrode reaction is performed uniformly.

[0010]

Means for Solving the Problems As a result of repeated studies to achieve the above object, the present inventors have found that it is very difficult to use an electrode in which an active material is dispersed in a polymer gel and a solid electrolyte containing no organic solvent. And found that the present invention is effective.

That is, the present invention provides a secondary battery comprising a positive electrode, a solid electrolyte, and a negative electrode, wherein at least one of the positive electrode and the negative electrode has an active material dispersed in a polymer gel. It is a secondary battery.

The secondary battery of the present invention, particularly a lithium or lithium ion secondary battery, has a much lower organic solvent content than the case where a polymer gel electrolyte is used, and has a solid electrolyte and an electrode. Since the contact resistance between them can be greatly reduced, the safety of the secondary battery is greatly improved. Further, since the contact resistance between the solid electrolyte and the electrode is small, a practical secondary battery using a so-called completely solid electrolyte is provided for the first time.

In the present invention, in a secondary battery in which a disulfide compound or a quinone compound is used as an active material, since a polymer gel matrix is used for an electrode, the electrode reaction is uniform and a solid phase is used. It progresses faster than the above, and is extremely effective in improving the charge and discharge efficiency of the secondary battery and the charge and discharge cycle life.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

In the secondary battery of the present invention, when a metal oxide is used as the positive electrode active material, the metal oxide is not particularly limited. For example, amorphous-V ₂ O ₅ , Mn ₂ O ₄ ,
MnO ₂ , V ₃ O ₈ , V ₆ O ₁₃ , CoO ₂ , NiO ₂ , MoS
₂ , TiS ₂ or the like can be used. Among them, amorphous-V ₂ O ₅ , Mn ₂ O ₄ , CoO ₂ , Ni
O ₂ is also preferred in the present invention.

When an organic compound is used as the positive electrode active material,
For example, organic disulfide compounds and organic quinone compounds are preferred. The organic disulfide compound is not particularly limited, but a compound represented by the general formula (R (S) m) n can be used. Where R is an aliphatic group or an aromatic group,
S is sulfur, m is a positive number of 1 or more, and n is a positive number of 2 or more. For example, dithioglycol, 2,5-dimercapto-1,3,4-thiadiazole, S-triazine-2,
4,6-trithiol, 7-methyl-2,6,8-trimercaptopurine and the like are used. Further, the organic quinone compound is not particularly limited, but, for example, benzoquinone, anthraquinone, chloranil, a derivative thereof, and the like are used.

As the negative electrode active material, it is preferable to use lithium metal or a carbonaceous material capable of storing lithium ions. The carbonaceous material capable of occluding the lithium ions is not particularly limited. For example, natural graphite, crystalline carbon such as graphitized carbon obtained by heat-treating coal and petroleum pitch at a high temperature, or petroleum pitch coke and coal pitch Amorphous carbon obtained by heat-treating coke and acenaphthylene pitch coke can be exemplified.

In the present invention, at least one of the positive electrode and the negative electrode has a structure in which an active material is dispersed in a polymer gel. The matrix polymer of the polymer gel is preferably a polymer having a relative dielectric constant of 4 or more. For example, nitrocellulose resin, chlorosulfonated polyethylene, polymethyl methacrylate, phenol resin, polyvinylidene fluoride, polyacrylonitrile and the like can be exemplified. Among them, polyvinylidene fluoride, polyacrylonitrile, or derivatives thereof are particularly preferred. The reason why these polymers are preferably used is the same as the reason described in JP-B-61-23947.

The solvent contained in the polymer gel (solvent as a component of the electrolytic solution) is preferably a solvent having a relative dielectric constant of 5 or more. For example, carbonate solvents (propylene carbonate, ethylene carbonate,
Butyl solvent, etc.), amide solvent (N-methylformamide, N-ethylformamide, N, N-dimethylformamide, N-methylacetamide, N-ethylacetamide, N-methylpyrrolidone, etc.), lactone solvent (γ-butyllactone, γ-valerolactone, δ-valerolactone, etc.), ether solvents, nitrile solvents and the like. Among them, propylene carbonate, ethylene carbonate, γ-butyl lactone, γ-valerolactone, and tetrahydrofuran are particularly preferred. In order to use these solvents effectively, mixed solvents with other low-viscosity solvents are often used.

The polymer solid electrolyte includes polyether, polyester, polyamine, polyimide, polyurethane,
It is preferably a polysulfide, polyphosphazene, polysiloxane, a derivative thereof, a copolymer thereof, or a cross-linked product thereof. Among them, polyethylene oxide, polypropylene oxide, derivatives thereof, copolymers thereof, and cross-linked products thereof are particularly preferable.

The electrolyte solution dispersed in the polymer gel is prepared by dissolving various electrolyte salts in the solvent.

The electrolyte salt of the electrolyte solution is not particularly limited as long as it is used as a normal electrolyte. For example, LiBR ₄ (R is a phenyl group or an alkyl group),
_{LiPF 6, LiSbF 6, LiAsF 6} , LiBF 4, L
Examples thereof include iClO ₄ , CF ₃ SO ₃ Li, and (CF ₃ SO ₂ ) ₂ NLi.

The positive electrode active material layer is composed of a positive electrode active material, an electrolytic solution in which an electrolyte salt is dissolved, and a polymer matrix holding the electrolytic solution. In order to secure the electron conductivity of the positive electrode active material layer, a conductive auxiliary such as appropriate carbonaceous fine particles such as acetylene black may be added. Also,
A conductive polymer such as a polyaniline derivative, a polypyrrole derivative, or a polythiophene derivative may be added.

For the positive electrode, for example, a positive electrode active material, an electrolyte, a conductive auxiliary agent, a polymer serving as a matrix, and a polymer cross-linking agent are dissolved in an appropriate solvent, sufficiently dispersed, coated on a positive electrode current collector, and then heat-treated. Or gelation by light or radiation treatment. By using a partially crystalline polymer such as polyvinylidene fluoride and a polyacrylonitonyl derivative for the polymer serving as the matrix, the solvent is evaporated without adding the cross-linking agent or performing light or radiation treatment. Alone, a gel structure can be formed by physical cross-linking of the crystalline portion of the matrix polymer (AS Gozdz et al., The.
Electrochemical Society P
rosedings Volume94-28,19
1995, p400-407). In this case, it is preferable to use these matrix polymers because addition of a crosslinking agent and occurrence of side reactions due to light or radiation treatment are avoided.

As the positive electrode current collector, a conventionally known thin film such as stainless steel, copper, nickel, or aluminum, a mesh, or a sheet having another shape can be used.

The negative electrode active material layer and the negative electrode can be formed in the same manner as the positive electrode active material layer and the positive electrode.

The solid electrolyte is synthesized by a usual method, and the solid electrolyte layer is formed by a conventionally known method. After the solid electrolyte layer is formed in advance, it can be disposed between the positive and negative electrodes. Further, if desired, after coating on the positive electrode active material layer or the negative electrode active material layer to a predetermined thickness, the positive and negative electrodes can be arranged so as to sandwich the coating.

The form of the lithium secondary battery of the present invention is not particularly limited. For example, the lithium secondary battery can be mounted on a cylindrical, coin, gum, or flat secondary battery.

[0029]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Embodiment 1 FIG. 1 shows the present invention in a thin polymer lithium ion secondary battery using a metal oxide as a positive electrode active material, a polymer solid electrolyte as an electrolyte, and a lithium ion storage carbonaceous material as a negative electrode active material. It is a schematic sectional drawing of the Example of the applied secondary battery.

The battery of this embodiment includes a positive electrode active material layer 3 formed on one surface of a positive electrode current collector 4 and a negative electrode active material layer 1 formed on one surface of a negative electrode current collector 2. Have a structure in which they are laminated with a polymer solid electrolyte layer 5 interposed therebetween. This polymer lithium ion secondary battery was manufactured as follows.

88:12 with an average molecular weight of about 380 × 10 ³
Of vinylidene fluoride: hexafluoropropylene (P (V
dF / HFP)) copolymer and the P (VdF / HF)
P) with 0.2 mol / kg of LiPF _{6 in} a mixed solution of acetone, propylene carbonate, and ethylene carbonate in a weight ratio of 20: 3: 3 (hereinafter referred to as A).
C / PC / EC). Then, this P (VdF / HFP) / (AC / PC / EC)
Was mixed with a kneaded product of LiMn ₂ O ₄ and acetylene black (weight ratio: 80:20), and the mixture was stirred to form a mixture. Here, LiMn ₂
A mixture of O ₄ and acetylene black and P (VdF / H
The ratio of the (FP) / (AC / PC / EC) solution was adjusted so that the weight ratio of the kneaded material to P (VdF / HFP) was 90:10.

Next, after removing only acetone from the mixture by volatilization, the mixture is formed into a sheet by a roll press, cut into an appropriate size, and has a capacity of about 25 mAh, and has a thickness of 180 μm and a positive electrode active material. Layer 3 was made. Next, the positive electrode current collector 4 made of a stainless steel foil having a thickness of 20 μm was attached to a central portion on one surface. In addition, since the positive electrode active material layer 3 formed in this manner had adhesiveness, it could be attached to the positive electrode current collector without using a binder.

Next, the method of Motogami et al. (KM)
otogami et al., Electrochimica A
cta. Vol. 37, no. 9, 1992, p19
25-1727) to synthesize a poly (2-methoxyethyl glycidyl ether) (PMEGE), and a PGEGE crosslinked solid electrolyte film having a thickness of 0.1 mm containing LiPF ₆ at 1.5 mol% based on ethylene oxide units was prepared.

On the other hand, the electrolyte solution of P (VdF / HFP) / (AC / PC / EC) used in forming the positive electrode active material layer 3 was mixed with a 20: 1 weight ratio of petroleum coke powder and acetylene black. After mixing the kneaded material, it was stirred to form a mixture. Here, the kneaded product of powdered petroleum coke and acetylene black and P (VdF / HF
The ratio of the (P) / (AC / PC / EC) solution was set so that the weight ratio of the kneaded material to P (VdF / HFP) became 95: 5. Next, only acetone is volatilized and removed from the mixture, and then the mixture is formed into a sheet by a roll press.
The negative electrode active material layer was cut into the same size as the positive electrode active material layer 3 to form a negative electrode active material layer having a capacity of about 25 mAh and a thickness of 200 μm. Next, the negative electrode active material layer was attached to the stainless steel foil of the negative electrode current collector in the same manner as in the positive electrode.

Next, a hot-press type hot melt is placed on the outer periphery of the positive electrode current collector 4, and then the negative electrode current collector 2 having the negative electrode active material layer formed so as to sandwich the polymer solid electrolyte layer is provided.
Was combined. Then, by heating, the hot melt 6 was completely connected to the outer peripheral end of the current collector to complete a polymer lithium ion secondary battery.

In the charge / discharge test, the battery was charged at a current of 0.2 C from the charging direction until the battery voltage reached 4.5 V, and after a 30-minute pause, the battery voltage became 2.0 V at the same current density. Until discharge. Hereinafter, charge and discharge were repeated, and the battery characteristics were evaluated. HJ-201 manufactured by Hokuto Denko Co., Ltd. was used for repeated charge / discharge characteristic measurement of the battery.
FIG. 2 shows the discharge characteristics, and FIG. 3 shows the charge / discharge characteristics.

<Comparative Example 1> In Example 1, instead of poly (2-methoxyethyl glycidyl ether) which is a polyalkylene oxide-based solid electrolyte, P (VdF /
A (HFP) copolymer gel electrolyte was used. The polymer gel electrolyte was prepared as follows.

First, the average molecular weight of Example 1 was about 380 × 1
0 ³ and P (VdF / HFP) copolymer 88:12 of, 0.2 mol / k with respect to the P (VdF / HFP)
g of LiPF _{6 in} a mixed solution of acetone, propylene carbonate, and ethylene carbonate (hereinafter referred to as AC / PC / EC) at a weight ratio of 20: 5: 5.
0 wt% was dissolved. After the obtained electrolyte solution was flowed on a Teflon petri dish, acetone was evaporated to a thickness of 0.1 μm.
A 1 mm polymer gel electrolyte film was obtained. This polymer gel electrolyte film contains about 50 wt% of a mixed solvent of PC / EC.

Next, a polymer lithium ion secondary battery was completed in the same manner as in Example 1. As a result of evaluating the charge / discharge characteristics, almost the same results as in Example 1 were obtained.

<Example 2> First, a positive electrode and a negative electrode were produced in the same manner as in Example 1. Next, a polymer solid electrolyte was prepared as follows.

The structural formula is CH ₂ ＣＨCH—CH ₂ —O—CH ₂
1.58 g of a compound of —O—CH ₃ , 0.98 g of monomethylsiloxane having a trimethylsilyl terminal group and an average molecular weight of 200,000 and 0.02 g of hydroquinone were dissolved in 50 ml of toluene, and 3.8 × 10 ⁻³ M was added thereto. After adding 0.5 ml of a solution of chloroplatinic acid in isopropyl alcohol, the mixture was reacted at 50 ° C. for 24 hours. The polymer containing the obtained reaction product was dried under reduced pressure to recover the polymer. The obtained polymer and 0.3 mol / kg of L
After 20 wt% of iPF ₆ was dissolved in tetrahydrofuran, the solution was cast on a Teflon dish and dried. On the other hand, an electron beam of 3 MeV is applied to 10 Mra.
Irradiation to obtain a film having a thickness of 80 μm.

Next, in substantially the same manner as in Example 1, the solid electrolyte film thus obtained was disposed between the positive and negative electrodes to assemble a lithium ion secondary battery. As a result of evaluating the charge / discharge characteristics, substantially the same discharge characteristics and charge / discharge characteristics as in Example 1 were obtained.

Example 3 First, a positive electrode and a negative electrode were manufactured in the same manner as in Example 1. Next, a polymer solid electrolyte was prepared as follows.

First, a methoxy oligoethyleneoxy polyphosphazene having an average molecular weight of 1.5 million (hereinafter referred to as MEP) and 0.2 mol / kg of LiP
F ₆ was dissolved in a 1,2-dimethoxyethane (hereinafter, referred to as DME) solution at 20 wt%. Next, this MEP /
The DME solution was cast on a Teflon plate and the DME was evaporated to produce a 100 μm thick solid electrolyte film.

Next, in substantially the same manner as in Example 1, the solid electrolyte film thus obtained was disposed between the positive and negative electrodes to assemble a lithium ion secondary battery. As a result of evaluating the charge / discharge characteristics, substantially the same discharge characteristics and charge / discharge characteristics as in Example 1 were obtained.

<Embodiment 4> The P (VdF / HF) of Embodiment 1
Instead of P), polyacrylonitrile was used. That is, polyacrylonitonyl (PAN) having an average molecular weight of about 50 × 10 ³ and 0.15 mol / k
g of LiPF ₆ was added to a mixed solution of ethylene carbonate and propylene carbonate (hereinafter referred to as EC / PC) at a weight ratio of 70:30 so as to be 20 wt%, and heated to 120 ° C. When the solution is sufficiently heated, polyacrylonitrile as a gelling agent is gradually added to the solution, and after the addition is completed, stirring is performed while heating for further 10 minutes to obtain a transparent viscous liquid. Was.
Then, the solution is gradually cooled. When the temperature of the solution reaches about 60 ° C., LiMn ₂ O ₄ and acetylene black (weight ratio of 8
0:20) was quickly mixed. Here, the ratio of the kneaded product of LiMn ₂ O ₄ and acetylene black to the electrolyte solution of PAN / (EC / PC) is as follows:
The weight ratio between the kneaded material and PAN was set to be 90:10. Next, the mixture was cooled to room temperature, formed into a sheet by a roll press, and cut into an appropriate size to form a cathode active material layer 3 having a capacity of about 25 mAh and a thickness of 180 μm. Next, a positive electrode of the battery was manufactured in the same manner as in Example 1.

Next, the above-mentioned positive electrode was prepared by using PAN instead of P (VdF / HFP) and using a kneaded product of powdered petroleum coke and acetylene black instead of a kneaded product of LiMn ₂ O ₄ and acetylene black. Negative electrode 1 was produced in the same manner as the method. The composition ratio of the kneaded product of the petroleum petroleum coke and acetylene black and PAN was the same as in Example 1.

Using the positive electrode and the negative electrode thus prepared and the solid electrolyte film of Example 1, a solid electrolyte film is disposed between the positive and negative electrodes in the same manner as in Example 1 to form a lithium ion secondary battery. Assembled. As a result of evaluating the charge / discharge characteristics, substantially the same discharge characteristics and charge / discharge characteristics as in Example 1 were obtained.

Example 5 In Example 1, LiCoO ₂ was used instead of LiMn ₂ O _{4 as} the positive electrode active material.
Otherwise, a lithium secondary battery was assembled in the same manner as in Example 1. As a result of evaluating the charge / discharge characteristics, substantially the same discharge characteristics and charge / discharge characteristics as in Example 1 were obtained.

Example 6 FIG. 4 is a schematic sectional view of a coin-type lithium ion secondary battery of the present invention using an organic disulfide compound as a positive electrode active material. This coin-type lithium ion secondary battery was manufactured as follows.

As the organic disulfide compound, 2,5-
Dimercapto-1,3,4-thiadiazole (hereinafter referred to as D
McT) was used. In Example 1, LiMn
DMcT was used instead of ₂ O ₄ . Here, DMc
The ratio was such that the weight ratio between T and P (VdF / HFP) was 80:20. Otherwise, a positive electrode active material layer and a positive electrode were produced in the same manner as in Example 1. Further, a solid electrolyte was produced in exactly the same manner as in Example 1.

First, the positive electrode active material film was placed on the positive electrode current collector 4 made of a stainless steel net spot-welded in the positive electrode can 7. Then, an annular gasket made of polypropylene was placed on the outer peripheral end of the positive electrode can 7. Next, 0.2 mm thick metallic lithium cut into a disk shape having the same diameter as the positive electrode was placed on the negative electrode current collector 2 made of a stainless steel mesh spot-welded in the negative electrode can 8, and attached by crimping. .

Next, the solid electrolyte film was placed on the positive electrode active material layer 3, and the negative electrode can 8 was placed on the electrolyte layer 5 so as to sandwich the solid electrolyte film. Then, the positive electrode can 7 and the negative electrode can 8 were overlapped via the annular gasket, and the outer peripheral portions of both cans were caulked to complete a coin-type lithium ion secondary battery.

In the charge / discharge test, first, 0.2 C from the charging direction
And charge until the battery voltage reaches 4.1 V,
After a minimum pause time, the battery voltage is 2.2 V at the same current density.
Discharged until. Hereinafter, charge and discharge are repeated,
The battery characteristics were evaluated. The charge / discharge characteristics are shown in FIGS.

Comparative Example 2 In Example 6, a positive electrode containing an organic disulfide compound from which EC / PC as an organic solvent was almost completely removed was used in place of the gel positive electrode. Otherwise, a coin-type lithium ion secondary battery was completed in the same manner as in Example 6. Charge and discharge characteristics are shown in comparison with FIGS. 5 and 6.

<Embodiment 7> In Embodiment 6, Embodiment 2
A coin-type lithium ion secondary battery was completed in the same manner as in Example 6 except for using the same solid electrolyte as in Example 1. As a result of evaluating the charge / discharge characteristics, substantially the same discharge characteristics and charge / discharge characteristics as in Example 6 were obtained.

<Embodiment 8> In Embodiment 6, the DMcT
Was replaced by 4,5-diamino-2,6-dimercaptopyrimidine. Otherwise, a coin-type lithium secondary battery was completed in the same manner as in Example 6. As a result of evaluating the charge / discharge characteristics, substantially the same discharge characteristics and charge / discharge characteristics as in Example 6 were obtained.

As is clear from the above results, Example 1
Comparative Examples 1 to 5 using a polymer gel electrolyte despite the use of the polymer solid electrolytes
Almost the same performance as that of the secondary battery is realized. Also,
It was found that the secondary batteries of Examples 6 to 8 exhibited better performance than the conventional secondary batteries of Comparative Example 2.

[0060]

As described above, the present invention has the effect of significantly reducing the contact resistance between the electrode and the solid electrolyte by using a polymer gel as the dispersion medium of the electrode. Also,
This is extremely effective in making the electrode reaction uniform, and the effect is great.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a lithium ion secondary battery according to Embodiment 1 of the present invention.

FIG. 2 is a graph showing the discharge characteristics of the lithium ion secondary batteries of Example 1 and Comparative Example 1.

FIG. 3 is a graph showing charge / discharge repetition characteristics of the lithium ion secondary batteries of Example 1 and Comparative Example 1.

FIG. 4 is a sectional view of a coin-type lithium secondary battery according to Example 6 of the present invention.

FIG. 5 is a graph showing discharge characteristics of lithium secondary batteries of Example 6 and Comparative Example 2.

FIG. 6 is a graph showing charge / discharge repetition characteristics of the lithium secondary batteries of Example 6 and Comparative Example 2.

[Explanation of symbols]

 Reference Signs List 1 negative electrode active material layer 2 negative electrode current collector 3 positive electrode active material layer 4 positive electrode current collector 5 electrolyte layer 6 hot melt 7 positive electrode can 8 negative electrode can 9 annular gasket

Claims (13)

[Claims] 1. A secondary battery comprising a positive electrode, a solid electrolyte, and a negative electrode, wherein at least one of the positive electrode and the negative electrode has an active material dispersed in a polymer gel. . 2. The positive electrode active material is a metal oxide.
The secondary battery according to any one of the preceding claims. 3. The secondary battery according to claim 2, wherein the negative electrode active material is lithium metal or a carbonaceous material capable of storing lithium ions. 4. The method according to claim 1, wherein the metal oxide of the positive electrode active material is aV
_TwoO_Five, Mn_TwoO_Four, CoO _TwoOr NiO_TwoClaims that are
4. The secondary battery according to 2 or 3. 5. The positive electrode active material is an organic compound.
The secondary battery according to any one of the preceding claims. 6. The secondary battery according to claim 5, wherein the negative electrode active material is a lithium metal or a carbonaceous material capable of storing lithium ions. 7. The secondary battery according to claim 5, wherein the organic compound of the positive electrode active material is an organic disulfide compound or an organic quinone compound. 8. The secondary battery according to claim 1, wherein the matrix polymer of the polymer gel in which the active material is dispersed is a polymer having a relative dielectric constant of 4 or more. 9. The secondary battery according to claim 8, wherein the matrix polymer is polyvinylidene fluoride, polyacrylonitrile, or a derivative thereof. 10. The secondary battery according to claim 1, wherein the solvent contained in the polymer gel in which the active material is dispersed is a solvent having a relative dielectric constant of 5 or more. 11. The secondary battery according to claim 10, wherein the solvent contained in the polymer gel in which the active material is dispersed is propylene carbonate, ethylene carbonate, γ-butyl lactone, γ-valerolactone, or tetrahydrofuran. 12. A polymer solid electrolyte comprising a polyether, a polyester, a polyamine, a polyimide, a polyurethane, a polysulfide, a polyphosphazene, a polysiloxane, a derivative thereof, a copolymer thereof, or a cross-linked product thereof. Certain claims 1 to 1
The secondary battery according to claim 1. 13. The secondary battery according to claim 12, wherein the solid electrolyte is a polymer solid electrolyte composed of polyethylene oxide, polypropylene oxide, a derivative thereof, a copolymer thereof, or a cross-linked product thereof.