JP2002158034A - Non-aqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-aqueous secondary battery that suppresses generation of gas and has little deterioration of the battery property. SOLUTION: In a non-aqueous secondary battery that has a positive electrode, a negative electrode, and an electrolyte, the non-aqueous secondary battery is constructed by containing 0.1-2 wt.% of an acrylic system monomer or acrylic system oligomer containing at least one double bond capable of polymerization in the liquid electrolyte. As a content of the above acrylic system monomer or acrylic system oligomer containing at least one double bond capable of polymerization, 0.5-1.5 wt.% is desirable, and as the acrylic system monomer containing at least one double bond capable of polymerization, dipentaerythritolhexaacrylate is desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous secondary battery, and more particularly, to a non-aqueous secondary battery particularly suitable for packaging with a laminate film.

[0002]

2. Description of the Related Art Non-aqueous rechargeable batteries such as lithium ion rechargeable batteries are small and have high energy densities and are suitable as power sources for portable equipment. Although used as a power source for mobile phones and the like, recently, batteries using a laminate film as an exterior material have attracted attention for further reduction in weight and thickness.

The battery packaged with the laminate film includes a battery using a gel polymer electrolyte obtained by gelling an electrolyte solution as a liquid electrolyte with a polymer, and a battery in which the electrolyte solution is sealed without gelation. In each case, a laminated film using an aluminum foil as a core material is used as an exterior material, and a sheet-like electrode is laminated or wound into an electrode group, which is exteriorly covered with the laminated film to form a battery. Since it is possible and the area can be increased, new applications are expected.

[0004]

However, the battery packaged with this laminated film is advantageous in reducing the weight because the package material is made of a material having a small strength called a laminate film. When a battery occurs, unlike a battery packaged with a metal can, the battery swells even with a small amount of gas generated, the battery thickness deviates from the standard, the electrode loosens due to gas, and the internal resistance increases. was there.

[0005] In the case of a lithium ion secondary battery, when the battery is assembled and formed (initial charge), lithium ions enter between layers of the negative electrode carbon. Ethylene carbonate and propylene carbonate are decomposed by reacting with carbon to form a stable solid electrolyte layer on the carbon surface,
It is generally said that subsequent lithium ions can easily enter the interlayer.

However, when ethylene carbonate or propylene carbonate reacts and decomposes as described above, it is said that decomposition products such as ethylene, propylene, carbon monoxide (CO), and carbon dioxide (CO ₂ ) are generated. And these are accumulated as gas inside the battery.

[0007] When such gas is generated, the battery swells and bubbles accumulate between the electrodes to inhibit the reaction, or the swelling itself impairs the product value.

[0008] Gas generation occurs in a large amount in the formation step, which is the first charge (first charge), by the above-mentioned mechanism, and it is almost negligible thereafter. Therefore, in the process of assembling the battery, the generated gas is discharged out of the battery. It becomes necessary.

[0009] From the viewpoint of the process, a method of forming a battery without sealing the battery and sealing the battery after the formation is completed, or forming a sealed battery once, opening the package, removing gas, and resealing the battery. For example, there is a problem that very complicated steps must be taken.

The present invention solves the above-mentioned problems in the prior art, suppresses the generation of gas, eliminates complicated steps for degassing, increases productivity, and suppresses deterioration of battery characteristics. It is an object of the present invention to provide a non-aqueous secondary battery.

[0011]

According to the present invention, an acrylic monomer or an acrylic oligomer containing at least one polymerizable double bond is added to a liquid electrolyte as an additive for suppressing the generation of gas in a battery. By assembling the battery containing 0.1 to 2% by weight, gas generation during chemical formation is suppressed, degassing is not substantially performed, and deterioration of battery characteristics is suppressed. The present invention has solved the above problem.

That is, by adopting the above configuration,
It is considered that the acrylic monomer or acrylic oligomer attacks the active site during charging of the negative electrode carbon and suppresses the reaction with ethylene carbonate or propylene carbonate, thereby reducing gas generation.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a positive electrode active material is used.
Various types can be used without particular limitation.
However, transition metal oxides containing lithium have an energy density
Highly used because of its high reversibility,
Physically, for example, LiCoO_TwoSuch as lithium koval
Oxide, LiMn_TwoO_FourSuch as lithium manganese oxidation
Material, LiNiO_TwoSuch as lithium nickel oxide, it
Mixtures thereof, and also LiNiO _TwoPart of Ni in Co
Alternatively, those substituted with Mn are preferably used.

As the negative electrode active material, a carbon-based material capable of doping / dedoping lithium ions is used. Specifically, for example, graphite-based materials such as natural graphite and artificial graphite, pyrolytic carbons, coke , Glassy carbons, fired bodies of organic polymer compounds, mesocarbon microbeads,
Carbon fiber, activated carbon, graphite and the like are preferably used. Among them, when a graphite-based material is used as the negative electrode active material, the effects of the present invention are more remarkably exhibited.

The electrolyte constituting the power generating element together with the positive electrode active material and the negative electrode active material is usually a non-aqueous liquid electrolyte obtained by dissolving an electrolyte salt such as a lithium salt in an organic solvent (hereinafter referred to as “electrolyte solution”). Alternatively, a gel polymer electrolyte obtained by gelling the above-mentioned electrolytic solution with a polymer is used. First,
To explain the electrolytic solution, as a solvent of the electrolytic solution, for example, diethyl carbonate, dimethyl carbonate, chain carbonate such as ethyl methyl carbonate, ethylene carbonate, propylene carbonate,
Cyclic carbonates such as butylene carbonate, ethyl acetate, methyl propionate, γ-butyrolactone, ethylene glycol sulfite, 1,2-dimethoxyethane, 1,3-dioxolan, tetrahydrofuran,
Methyl-tetrahydrofuran, diethyl ether and the like can be used. In addition, an amine-based or imide-based organic solvent, a sulfur-containing or fluorine-containing organic solvent, and the like can also be used. These solvents can be used alone or in combination of two or more. Among them, when a mixed solvent of a chain carbonate and a cyclic carbonate is used as a constituent solvent of the electrolytic solution,
The effects of the present invention are more remarkably exhibited.

When preparing the electrolytic solution, the
As an electrolyte salt to be used, for example, LiClO_Four, LiP
F₆, LiBF_Four, LiAsF₆, LiSbF₆, Li
CF _ThreeSO_Three, LiC_FourF₉SO_Three, LiCF_ThreeC
O_Two, Li_TwoC_TwoF_Four(SO_Three) _Two, LiN (CF_ThreeS
O_Two)_Two, LiC (CF_ThreeSO_Two)_Three, LiC_nF_{2n + 1}
SO_Three(N ≧ 2) alone or as a mixture of two or more
Used. Especially LiPF ₆And LiC_FourF₉SO_ThreeSuch
Is preferable because of good charge / discharge characteristics. In the electrolyte
Is not particularly limited.
Is at least 0.3 mol / l, especially at least 0.4 mol / l
And preferably 1.7 mol / l or less, particularly 1.5 mol / l.
mol / l or less is preferred.

The gel polymer electrolyte corresponds to a gel obtained by gelling the above-mentioned electrolytic solution with a gelling agent. For the gelation, for example, a linear polymer such as polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile or the like is used. These copolymers, polyfunctional monomers polymerized by irradiation with actinic rays such as ultraviolet rays, electron beams, visible rays, and far infrared rays (for example, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentane) Tetrafunctional or more acrylates such as erythritol hydroxypentaacrylate, dipentaerythritol hexaacrylate, and the like, and the like. . 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.

When the electrolytic solution is gelled using a polyfunctional monomer as described above, if necessary, a polymerization initiator such as benzoyls, benzoin alkyl ethers, benzophenones, and benzoylphenylphosphine oxides may be used. , Acetophenones, thioxanthones, anthraquinones, and the like, and further, alkylamines, aminoesters, and the like as sensitizers for the polymerization initiator.

In the present invention, at least one polymerizable double bond contained in the electrolyte as a gas generation inhibitor is used.
The acrylic monomer or acrylic oligomer may be any one that can be polymerized by actinic rays such as ultraviolet rays, electron beams, visible rays, and far-infrared rays or heat, and specific examples thereof include a polymerizable double bond. As one containing, for example, methyl acrylate, methyl methacrylate,
Examples include ethyl acrylate and ethyl methacrylate.

Examples of acrylic monomers containing two double bonds (bifunctional crosslinkable acrylic monomers) include, for example, 1,3-butanediol acrylate, 1,4-butanediol acrylate, 1,6-butanediol Acrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, ethoxylated bisphenol A diacrylate, novolak diacrylate, propoxylated neopentyl Examples include bifunctional acrylates such as glycol diacrylate and bifunctional methacrylates similar to the above acrylates.

Examples of acrylic monomers containing three polymerizable double bonds (trifunctional crosslinkable acrylic monomers) include, for example, tris (2-hydroxyethyl) isocyanurate triacrylate, trimethylolpropane triacrylate, Ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate,
Examples include trifunctional acrylates such as caprolactone-modified trimethylolpropane acrylate, and trifunctional methacrylates similar to the above acrylates.

Examples of acrylic monomers containing four or more polymerizable double bonds (tetrafunctional or more crosslinkable acrylic monomers) include, for example, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol Examples thereof include tetrafunctional or higher acrylates such as tetraacrylate, dipentaerythritol hydroxypentaacrylate, and dipentaerythritol hexaacrylate, and tetrafunctional or higher methacrylate similar to the above acrylate.

In the acrylic monomer or acrylic oligomer containing at least one polymerizable double bond, it is considered that the greater the number of polymerizable double bonds, the greater the effect. Those containing four or more heavy bonds (ie, those having four or more functional groups) are preferably used, and particularly, hexafunctional acrylates and methacrylates such as dipentaerythritol hexaacrylate and dipentaerythritol hexamethacrylate are preferably used. In consideration of solubility in an electrolytic solution and the like, those having a molecular weight of 2000 or less are preferable, and 1
000 or less is more preferable. As is clear from the above examples, in the present invention, the acrylic monomer or acrylic oligomer includes not only acrylate and the like but also methacrylate and the like.

The acrylic monomer or acrylic oligomer containing at least one polymerizable double bond is contained in an amount of 0.1 to 2% by weight based on the weight of the electrolyte (liquid electrolyte).
(I.e., 0.1 to 2 parts by weight of an acrylic monomer or an acrylic oligomer containing at least one polymerizable double bond with respect to 100 parts by weight of the electrolytic solution). Preferably, it is contained in an amount of from 1.5 to 1.5% by weight, more preferably from 0.7 to 1.5% by weight.

When the content of the acrylic monomer or the acrylic oligomer containing at least one polymerizable double bond is in the above range, a film can be formed on the surface of the negative electrode without gelling the electrolytic solution. It is considered that the reaction between the carbon-based material of the negative electrode active material and ethylene carbonate or propylene carbonate, which are constituent solvents of the electrolytic solution, during formation (initial charge) is thereby suppressed.

When the content of the acrylic monomer or acrylic oligomer containing at least one polymerizable double bond is less than 0.1% by weight with respect to the electrolytic solution, the above-mentioned effects are sufficiently obtained. When the content does not appear and the content of the acrylic monomer or acrylic oligomer containing at least one polymerizable double bond is more than 2% by weight with respect to the electrolytic solution, the load characteristics of the battery are reduced. There is a risk. Also, when a gel polymer electrolyte is used in the construction of the battery, 0.1 to 2% by weight of an acrylic monomer or acrylic oligomer containing at least one polymerizable double bond with respect to an electrolyte serving as a base thereof. What is necessary is just to make it contain.

Many of the above acrylic monomers or acrylic oligomers are known as a material for gelling an electrolytic solution, and dipentaerythritol hexaacrylate is also used as a gelling agent to gel an electrolytic solution by an ultraviolet curing method. Used in polymer batteries.

However, in order to gel the electrolyte,
The gelling agent is required in a certain amount or more, and in the case of a monofunctional or bifunctional one, at least about 10% by weight with respect to the electrolytic solution,
The amount can be reduced by making it polyfunctional, but even with dipentaerythritol hexaacrylate, 3
If it is not used in an amount of not less than% by weight, gelation is difficult.

According to the present invention, it has been found that these materials have a function of suppressing the generation of gas by adding a very small amount of a concentration not more than the concentration that causes the electrolyte to gel. The reaction,
It is considered that when gelation occurs, the active site of the negative electrode active material cannot be attacked inside the battery, and generation of gas cannot be suppressed. Therefore, it is preferable to incorporate the battery into the battery system without irradiating with an actinic ray such as ultraviolet light or adding an initiator for thermal polymerization even when assembling the battery.

In the present invention, as the separator, for example, a microporous resin film, a nonwoven fabric and the like are suitably used. Examples of the microporous resin film include a microporous polyethylene film, a microporous polypropylene film, and a microporous ethylene-propylene copolymer film. Further, as the nonwoven fabric, for example,
Examples include a polypropylene nonwoven fabric, a polyethylene nonwoven fabric, a polyethylene terephthalate nonwoven fabric, and a polybutylene terephthalate nonwoven fabric.

As the exterior material, for example, a three-layer laminated film composed of a nylon film-aluminum foil-modified polyolefin film or a three-layer laminated film composed of a polyester film-aluminum foil-modified polyolefin film is used. Can be

[0032]

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.

Example 1 First, the preparation of the positive electrode and the negative electrode used in Example 1 and the preparation of the electrolytic solution will be described.

Preparation of positive electrode: LiCoO as positive electrode active material
And ₂ 90 parts by weight, and 5 parts by weight of carbon black as a conductive auxiliary agent were uniformly mixed and polyvinylidene fluoride 5 parts by weight of the binder, added to and mixed with further N- methyl-2-pyrrolidone as a diluent Then, a positive electrode mixture-containing paste was prepared. The obtained positive electrode mixture-containing paste is applied to both surfaces of a positive electrode current collector made of aluminum foil, dried to form a positive electrode mixture layer, and then calendered and compressed, so that both surfaces of the positive electrode current collector are compressed. In this example, four positive electrodes having a positive electrode mixture layer were produced. However, during the production of the positive electrode, the positive electrode mixture-containing paste was not applied to a part of the positive electrode current collector, and an exposed part was left, and the exposed part was used as a lead part. The lead portion of the positive electrode was made longer than that of the others, and was used as a connection portion with the positive terminal as an external terminal.

Preparation of negative electrode: natural graphite 9 as negative electrode active material
4 parts by weight, 6 parts by weight of polyvinylidene fluoride, and N-methyl-2-pyrrolidone were mixed to prepare a negative electrode mixture paste. The obtained negative electrode mixture-containing paste was applied to a negative electrode current collector made of copper foil, dried to form a negative electrode mixture layer, calendered, and compressed to produce a negative electrode. However, when producing the negative electrode, the paste containing the negative electrode mixture was not applied to a part of the negative electrode current collector, an exposed part was left in part, and the exposed part was used as a lead part. In the production of this negative electrode, three negative electrode mixture layers were formed on both sides of the negative electrode current collector, so-called double-sided negative electrodes, and a negative electrode mixture layer was formed on one surface of the negative electrode current collector, a so-called single-sided negative electrode. Were produced. Further, at the time of producing the above-mentioned negative electrode, the lead portion of one negative electrode was made longer than the others, and was used as a connection portion with the negative electrode terminal as an external terminal.

Preparation of electrolytic solution: LiPF ₆ was added to a mixed solvent of ethylene carbonate, propylene carbonate and diethyl carbonate at a volume ratio of 1: 1: 1 at a concentration of 1.2 mol / L.
1 prepared by dissolution. Then, 0.7% by weight of dipentaerythritol hexaacrylate (0.7 parts by weight of dipentaerythritol hexaacrylate with respect to 100 parts by weight of the electrolytic solution) is added to the electrolytic solution to add dipentaerythritol hexaacrylate to the electrolytic solution. Acrylate was included.

As a separator, a microporous polyethylene film was used. In assembling the battery, four positive electrode-coated positive electrodes each having the positive electrode mixture layer formed on both surfaces of a positive electrode current collector and three double-coated negative electrodes described above were used. And two single-sided coated negative electrodes,
Using the above eight separators, these positive electrodes, negative electrodes, and separators are referred to as negative electrodes (the negative electrodes are single-side coated negative electrodes), separators, positive electrodes,. There is a middle 3
Each of the negative electrodes was a double-sided coated negative electrode), in which order, four positive electrodes, five negative electrodes, and eight separators were laminated to form a laminated electrode group.

Then, the lead portions of the four positive electrodes were welded, and the free end side of the longest lead portion was used for connection to the positive terminal as an external terminal. Further, the lead portions of the five negative electrodes were welded, and one of them was welded.
The free end side of the longest lead portion is used for connection to a negative terminal as an external terminal.

Two sheets of a three-layer laminated film composed of a nylon film, an aluminum foil, and a modified polyolefin film were prepared as an exterior material for exteriorly covering the above-mentioned laminated electrode group. The sheet is kept in the shape of a container with a flange), a nickel ribbon is used as the positive electrode terminal, and the aluminum foil of the positive electrode is removed from the aluminum foil of the positive electrode at a position where the laminated electrode group is sealed with the outer material. The longest of the lead portions and the positive electrode terminal made of the nickel ribbon were ultrasonically welded. Further, when a nickel ribbon is used as a negative electrode terminal and the above-mentioned laminated electrode group is packaged with a package, the longest one of the lead portions made of copper foil of the negative electrode and the nickel The negative electrode terminal made of a ribbon was ultrasonically welded, and then, the laminated electrode group was packaged with a package and sealed. The exterior by this exterior material, by arranging the laminated electrode group between two exterior materials, heating the overlapping portion of the peripheral portion, melting the innermost modified polyolefin film and heat-sealing the same. In this heat fusion, the peripheral parts of three sides of the four sides are thermally fused in advance, and a predetermined amount of the above-mentioned electrolyte is injected from the peripheral part of the remaining one side. After the inside was reduced in pressure, the periphery of the remaining one side was heat-sealed. For the above-mentioned reason, the two exterior materials were arranged so that their modified polyolefin films faced each other.

The welding width between the lead portion of the positive electrode and the positive electrode terminal was 2 mm, and the width of the sealing portion of the exterior material was 4 mm. The welding width between the negative electrode lead and the negative electrode terminal is 2 mm.
mm, and the width of the sealing portion of the exterior material is 4 m as described above.
m. And the thickness of the whole battery was 3.0 mm.

FIG. 1 is a cross-sectional view schematically showing the laminated non-aqueous secondary battery of Example 1. The laminated electrode is formed by using four positive electrodes 1, five negative electrodes 2, and eight separators 3. A stacked battery is formed by forming a group, and enclosing and sealing the stacked electrode group with an exterior material 4 composed of a three-layer laminated film of a nylon film-aluminum foil-modified polyolefin film. Reference numeral 1a denotes a lead portion of the positive electrode 1. The free end side of the longest one of these lead portions 1a is connected to one end of the positive electrode terminal 5 by welding. It is arranged in the part 4a. Reference numeral 2a denotes a lead portion of the negative electrode 2, and the free end side of the longest one of these lead portions 2a is connected to one end of the negative electrode terminal 6 by welding,
The connection part is arranged in the sealing part 4 a of the exterior material 4. Here, the stacked electrode group will be described in more detail.
First, a negative electrode 2 (this negative electrode 2 is a single-sided coated negative electrode) is disposed on the lowermost layer, and a separator 3, a positive electrode 1, a separator 3, a negative electrode 2, a separator 3, a positive electrode 1, a separator 3, a negative electrode 2, a separator 3, 3, positive electrode 1, separator 3, negative electrode 2, separator 3, positive electrode 1, separator 3 are arranged,
Further, a negative electrode 2 (the negative electrode 2 is a single-sided coated negative electrode) is disposed thereon. Each of the three intermediate negative electrodes 2 is a double-sided coated negative electrode, and the single-sided coated negative electrodes on both sides are arranged such that their negative electrode mixture layers face the separator 3.

Example 2 A laminated nonaqueous secondary battery was produced in the same manner as in Example 1 except that dipentaerythritol hexaacrylate was contained in an amount of 1.0% by weight based on the weight of the electrolyte.

Example 3 A laminated non-aqueous secondary battery was produced in the same manner as in Example 1, except that dipentaerythritol hexaacrylate was contained in an amount of 1.5% by weight based on the weight of the electrolyte.

Example 4 A laminated nonaqueous secondary battery was produced in the same manner as in Example 1 except that dipentaerythritol hexaacrylate was contained in an amount of 2.0% by weight based on the weight of the electrolyte.

Example 5 A laminated nonaqueous secondary battery was produced in the same manner as in Example 1 except that 0.5% by weight of dipentaerythritol hexaacrylate was contained in the electrolytic solution.

Example 6 A laminated non-aqueous secondary battery was produced in the same manner as in Example 1, except that 0.3% by weight of dipentaerythritol hexaacrylate was contained in the electrolytic solution.

Comparative Example 1 A laminated non-aqueous secondary battery was manufactured in the same manner as in Example 1 except that dipentaerythritol hexaacrylate was not contained in the electrolytic solution.

Comparative Example 2 A laminated battery was manufactured in the same manner as in Example 1, except that 3.0% by weight of dipentaerythritol hexaacrylate was contained in the electrolytic solution.

The amounts of gas generated and the load characteristics of the batteries of Examples 1 to 6 and Comparative Examples 1 and 2 after formation (initial charge) were measured. Table 1 shows the results.

The above-mentioned formation is performed at 25 ° C. for 1 hour at 0.05 ° C., then at 0.2 ° C. for 8 hours under the conditions of 4.2 V constant current-constant voltage. The swelling was evaluated. In other words, the evaluation was made based on the thickness (3.0 mm) of the battery before formation and the thickness of the battery after formation.

The load characteristic is a ratio of a discharge capacity when discharging to 3.0 V at a current density of 2 C to a discharging capacity when discharging to 3.0 V at a current density of 0.2 C at 25 ° C. %) [(Discharge capacity at 2 C ÷ discharge capacity at 0.2 C) × 100].

Table 1 shows the content of dipentaerythritol hexaacrylate in the electrolytic solution together with their load characteristics and battery swelling. The dipentaerythritol hexaacrylate is abbreviated as "DPHA". indicate.

[0053]

[Table 1]

As shown in Table 1, the content of dipentaerythritol hexaacrylate in the electrolyte was 0.7%.
In Examples 1 to 4 at 〜2% by weight, there was no swelling of the battery, and it was clear that generation of gas due to chemical formation was suppressed. In Example 5 and Example 6 in which the content of dipentaerythritol hexaacrylate in the electrolyte was 0.5% by weight or 0.3% by weight, the battery was slightly swollen. Comparative Example 1 in which no hexaacrylate was contained in the electrolytic solution
As compared with, the swelling of the battery was small, and gas generation was suppressed. With respect to the load characteristics, since the content of dipentaerythritol hexaacrylate decreases as the content increases, the content of dipentaerythritol hexaacrylate in the electrolytic solution is considered as long as the decrease in the load characteristics is not too large. It is believed that the upper limit is preferably 2% by weight.

In the above embodiments, the case where a laminated film is used as the exterior material has been described. However, the present invention is not limited to this case, and a material other than the laminated film such as a metal can is used as the exterior material. You may.

[0056]

As described above, according to the present invention, it is possible to provide a non-aqueous secondary battery in which generation of gas is suppressed and battery characteristics such as load characteristics are hardly deteriorated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a stacked nonaqueous secondary battery of Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 1a Lead part 2 Negative electrode 2a Lead part 3 Separator 4 Exterior material 4a Seal part 5 Positive terminal 6 Negative terminal

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Eri Yokoyama 1-88 Ushitora, Ibaraki-shi, Osaka F-term in Hitachi Maxell Co., Ltd. 5H029 AJ14 AK03 AL06 AL07 AL08 AM03 AM04 AM05 AM07 AM16 BJ03 DJ08 EJ11 HJ01

Claims (4)

[Claims] 1. A non-aqueous secondary battery having a positive electrode, a negative electrode and an electrolyte, wherein an acrylic monomer or an acrylic oligomer containing at least one polymerizable double bond is contained in an amount of 0.1 to 2% by weight based on the liquid electrolyte. Non-aqueous secondary battery characterized by containing. 2. The non-aqueous secondary battery according to claim 1, wherein an acrylic monomer or an acrylic oligomer containing at least one polymerizable double bond is contained in an amount of 0.5 to 1.5% by weight based on the liquid electrolyte. . 3. An acrylic monomer or acrylic oligomer containing at least one polymerizable double bond,
The non-aqueous secondary battery according to claim 1, wherein the non-aqueous secondary battery is an acrylic monomer or an acrylic oligomer containing four or more polymerizable double bonds. 4. The non-aqueous secondary battery according to claim 1, wherein the acrylic monomer containing at least one polymerizable double bond is dipentaerythritol hexaacrylate.