KR100330284B1 - Battery - Google Patents

Abstract

In the conventional battery, a rigid outer cylinder must be used to maintain the electrical connection between the electrodes, and there is a problem that it cannot be miniaturized.

In the case where the electrodes and the separator are bonded together with the adhesive resin, the behaviors in which the adhesive strength and the battery characteristics are opposed are shown.

In order to solve this problem, an object of the present invention is to obtain a battery that is thin, lightweight, and excellent in both battery characteristics and adhesive strength without using an outer cylinder.

The positive electrode, the negative electrode, and the separator are bonded to each other by an adhesive resin layer including at least one adhesive resin layer containing a filler, thereby making the adhesive resin layer porous, and the voids in the porous adhesive resin layer It is filled with electrolyte and has sufficient ionic conductivity, thereby improving battery characteristics and maintaining adhesive strength.

Description

Battery {BATTERY}

Batteries have been used as a main power source and a backup power source for various devices, and in recent years, demand has been increasing due to the development of portable electronic devices such as mobile phones and laptop computers.

Primary batteries and secondary batteries are used according to the use of the batteries. In particular, secondary batteries having high convenience are attracting attention as high-performance batteries such as lithium ion secondary batteries and nickel-hydrogen batteries.

Hereinafter, the present invention will be described by taking a lithium ion secondary battery, which is rapidly increasing in demand for portable electronic devices.

In the conventional lithium ion secondary battery, a separator having a function of insulation and electrolyte preservation is disposed between the positive electrode and the negative electrode, and those that are wound in a cylindrical shape or sequentially stacked in a single phase are stored in a metal cylinder. The positive electrode, the separator, and the negative electrode were brought into close contact with each other by the pressure of the cylinder to maintain contact between the electrode and the separator.

However, the electrical contact is preserved by storing the electrode body in a metal cylinder, but since the cylinder is made of metal, there is a problem that the weight of the battery itself increases.

Moreover, there existed a problem that it was difficult to manufacture a thin barrel in manufacturing a metal barrel.

For this reason, for the purpose of mounting it in a small portable device, if it cannot be made thin, it has become an important subject because it cannot respond to the demand for a battery.

For this problem, US Pat. No. 5,437,692 discloses bonding a positive electrode and a negative electrode to an ion conductive layer by using an adhesive layer containing a lithium compound using a lithium ion conductive polymer in the ion conductive layer.

Moreover, the present inventors propose the structure and manufacturing method of a battery which does not require a metal rigid barrel by bonding a positive electrode, a negative electrode, and a separator previously using adhesive resin, and is Japanese Patent Application Laid-Open No. 8-338240. .

By bonding the positive electrode, the negative electrode, and the separator with an adhesive resin, it is possible to preserve electrical contact between the positive electrode, the separator, and the negative electrode without applying external pressure.

However, since the adhesive resin is inherently insulative, when the adhesive resin is present at the interface between the positive electrode, the separator, and the negative electrode, it tends to block the electrical flow, that is, the ion conductivity.

In the case where the positive electrode, the negative electrode, and the separator are bonded by the adhesive resin, the larger the amount of the adhesive resin at each interface, the more the adhesive strength tends to increase.

However, as the amount of the adhesive resin increased, the battery characteristics tended to be deteriorated, and the adhesive strength and the battery characteristics exhibited opposite behaviors.

As the amount of the adhesive resin increases, the adhesive surface tends to increase because the adhesive resin covers the interface with a film rather than a point.

For this reason, it is thought that the adhesive strength increases, but the conduction path of the ions traveling between the electrodes decreases by covering the electrodes between the electrodes, resulting in deterioration of the battery characteristics.

In addition, when the adhesive resin component concentration of the solution-type adhesive is reduced and bonded in order to improve battery characteristics, the viscosity of the adhesive resin solution decreases, so that the adhesive resin solution is absorbed on the porous electrode side and the adhesive strength is low. In addition, it has become a non-adhesive situation.

For this reason, improving battery characteristics has become an important subject while maintaining adhesive strength.

The electrode surface is smoothed by pressing.

However, unevenness on the order of several microns exists, and there is a part that is free at the interface between the separator and the electrode locally.

This part was connected to the electrolyte impregnation amount and the state of use of the battery to deplete the electrolyte originally to be impregnated, to increase the battery internal resistance and to decrease the battery characteristics.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is intended to obtain a lightweight, thin battery that can improve battery characteristics while maintaining adhesive strength.

[Initiation of invention]

The 1st battery which concerns on this invention is equipped with the battery body which has the positive electrode and negative electrode which have an electrode active material, and the separator which preserves electrolyte, and the adhesive resin layer which bonds the said positive electrode and negative electrode to this separator, and is said adhesive property The resin layer becomes at least one layer and contains a filler.

According to this, by adding a filler, it becomes possible to make the adhesive resin layer porous, and since an electrolyte and an adhesive resin solution are preserve | saved in this pore, favorable battery characteristics are acquired, maintaining adhesive strength.

In the second battery according to the present invention, in the first battery, the electrolyte is an organic electrolyte containing lithium ions.

According to this, in the lithium ion secondary battery which requires weight reduction and thickness reduction, a high performance and compact battery are obtained.

In the third battery according to the present invention, in the first battery, the average diameter of the filler is equal to or smaller than the particle diameter of the electrode active material of the positive electrode and the negative electrode.

According to this, the adhesive resin solution is stored in the adhesive resin layer, and the required adhesive strength is obtained.

In the fourth battery according to the present invention, in the first battery, the average diameter of the filler is in a range of 1 µm or less.

According to this, since it can give a moderate effect to an adhesive resin solution, and an adhesive resin layer can be made porous, favorable battery characteristic is acquired, maintaining adhesive strength.

In the fifth battery according to the present invention, the sum of the adhesive resin volume ratio and the filler volume ratio per unit volume of the adhesive resin layer in the first battery is less than one.

This makes it possible to maintain the porosity of the formed adhesive resin layer.

In a sixth battery according to the present invention, the sum of the adhesive resin volume ratio and the filler volume ratio per unit volume of the adhesive resin layer in the first battery is 0.2 or more and 0.8 or less.

According to this, the voids of the porous adhesive resin are filled with the electrolyte, and sufficient ion conductivity is obtained.

In the seventh battery according to the present invention, in the first battery, the filler includes at least one of a nonconductor or a semiconductor.

According to this, the adhesive resin layer can be made porous, and good battery characteristics can be obtained while maintaining the adhesive strength.

In the eighth battery according to the present invention, in the first battery, the adhesive resin layer has a layer containing a conductive filler, a nonconductor, or a layer containing at least one of a semiconductor.

According to this, the battery internal resistance can be reduced by the layer containing the conductive filler.

In a ninth battery according to the present invention, in the first battery, the adhesive resin layer fills a space formed on the opposing surface of the electrodes and the separator by the unevenness of the positive electrode, the negative electrode, and the separator. It is composed.

This increases the adhesive strength and at the same time has the effect of preventing degradation of battery characteristics due to electrolyte deficiency.

The tenth battery according to the present invention is a laminate in which the battery body is a laminate of a plurality of electrode bodies each having a single layer of a positive electrode, a separator, and a negative electrode in the first battery.

In the eleventh battery of the present invention, in the tenth battery, the laminate is formed by alternately disposing a positive electrode and a negative electrode between a plurality of separators.

A twelfth battery according to the present invention is formed by alternately disposing a laminate between separators in which a positive electrode and a negative electrode are wound up.

A thirteenth battery according to the present invention is formed by alternately disposing a laminate between separators in which a positive electrode and a negative electrode are folded in the tenth battery.

According to these tenth to thirteenth batteries, there is an effect that a multilayer electrode battery having high performance and large battery capacity can be obtained.

The present invention relates to a battery.

More particularly, the present invention relates to a battery that is light in weight and thin in shape, and has a high discharge current at high current density and good cycle characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the volume ratio of the adhesive resin layer in the battery of this invention, FIG. 2 is a cross-sectional block diagram which shows the space formed in the interface of the electrode and a separator in the battery of this invention, 3 is a view showing the change in discharge capacity before and after adding alumina filler to PVDF resin, FIG. 4 is a view showing the change in discharge capacity before and after adding alumina filler to PVA resin, and FIG. Fig. 6 shows the relationship between the discharge capacity and the peeling capacity when the average diameter of one alumina filler is changed, and FIG. 6 shows the relationship between the peeling strength and discharge capacity with respect to the volume% of the adhesive resin layer. It is a figure, and FIG. 7 is a figure which shows the relationship between peel strength and discharge capacity with respect to the thickness of an adhesive resin layer.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described according to drawing.

When adhesive resin is used to bond a positive electrode, a negative electrode, and a separator, as the amount of adhesive resin is increased to increase the adhesive strength, the conductivity of ions is impaired and the battery characteristics are deteriorated.

This is because the adhesive resin layer is formed into a film to block the path where ions travel.

For this reason, if this adhesive resin is not a film but exists in porous form, the problem is solved.

In the present invention, a filler (filler) is added to the adhesive resin to give porosity to the adhesive resin layer.

In other words, when an adhesive resin solution containing no filler is applied to an electrode or a separator, the adhesive resin solution is absorbed because the electrode is porous.

When the filler is mixed with the adhesive resin solution, the adhesive resin itself has a porous structure, the adhesive resin solution is preserved in the pores, and absorption of the adhesive resin solution into the electrode can be prevented. An adhesive resin solution can be preserve | saved at an interface.

Moreover, because of this effect, the viscosity of the adhesive resin solution also increases, and the preservation of the adhesive is further improved.

As an average diameter of the filler to add, below the particle diameter of an electrode active material, Preferably it is 1 micrometer or less.

When the average site diameter is 1 µm or more, the pore diameter produced by the filler of this size is almost close to the pore diameter of the electrode, thereby degrading the ability to preserve the electrolyte solution.

When the electrode active material particle size is larger than the diameter of the electrolyte, the electrolyte storage capacity is lost. Therefore, the battery characteristics are lowered and the effect of filler addition is lost.

The larger the average diameter is, the faster the settling speed of the filler is, so the handing property of the adhesive resin solution is particularly poor.

When the thickness is less than 1 μm, the adhesive resin solution can have an appropriate thickening effect, the adhesive resin layer can be made porous, and the adhesive resin solution and the electrolyte solution can be stored in the electrode and separator interface.

Moreover, the particle diameter of the said filler is corresponded with respect to the particle | grains which comprise the majority of fillers, and there is no problem even if the thing of particle | grains outside this range is contained.

In solvent-type adhesive resin, an adhesive resin solution consists of a filler, adhesive resin, and a solvent.

Since the solvent is removed by drying, the adhesive resin layer is constituted by voids formed by the drying of the filler, the adhesive resin and the solvent.

This shape is displayed as shown in FIG.

As can be seen from this figure, the void volume formed by the filler is composed of an adhesive resin volume and a process volume produced by drying of the solvent.

Therefore, if all the voids formed by the filler are filled with the adhesive resin, the porosity of the adhesive resin layer cannot be maintained, and the adhesive resin layer becomes the insulating layer.

Therefore, the sum of the adhesive resin volume ratio and the filler volume ratio per unit volume of the adhesive resin layer must be less than one.

In order to preserve the porosity of the adhesive resin layer, the sum of the adhesive resin volume ratio and the filler volume ratio with respect to the unit volume of the adhesive resin layer needs to be less than 1, but the pores of the porous adhesive resin are filled with the electrolyte solution. In order to have sufficient ion conductivity, it is preferable to have the same void volume as the separator in which the adhesive resin layer is used. Therefore, the sum of the adhesive resin volume ratio and the filler volume ratio with respect to the adhesive resin layer unit volume is 0.2 or more and 0.8 or less (in other words, In other words, the void volume fraction of the adhesive resin layer needs to be 20% to 80%).

The material of the filler is not particularly limited as long as the average diameter is possible, but oxides such as Al ₂ O ₃ , SiO ₂ , ZrO ₂ , LiALO ₂ , carbides such as SiC, B ₄ C, ZrC, SiN, BN, TiN, etc. Inorganic materials such as nitrides and the like are stable even in the electrolyte, and even if an adhesive resin containing a filler exists to connect the electrodes, the conductivity is low, and thus no short circuit occurs.

Since polymers, such as a polyolefin resin, have low electroconductivity and are smaller in specific gravity, weight increase can be reduced compared with an inorganic filler or a metal filler.

* Inorganic salts such as LiPF ₆ and LiCLO ₄ are not dissolved or dissolved in the electrolyte, which can make micropores as fillers, and even when dissolved in the electrolyte, pores are present in the adhesive resin layer after melting. It is possible to increase the porosity (spacing rate) of the strata.

In the case of using conductive fillers such as carbon and metal, conductivity can be imparted to the adhesive resin layer.

Therefore, even when adhesive resin enters the space | gap of an electrode, since an adhesive resin layer has electroconductivity, electron conduction is not impaired.

However, the use of conductive materials such as carbon requires research to prevent short circuits.

For example, by bonding the electrode and the separator as a two-layer adhesive resin layer provided with an adhesive resin layer containing a conductive material and an adhesive resin layer containing an inorganic substance on the electrode side and the separator side, respectively, a short circuit can be prevented. have.

By filling the space present on the electrode surface and the separator interface with the adhesive resin including the filler, the adhesive strength is increased and the degradation of the battery characteristics due to the electrolyte deficiency can be prevented.

As shown in Fig. 2, since there are not many unevennesses on the order of several micrometers, it is preferable to exist so as to fill this gap.

If the reduction of the discharge capacity by the resistance of the adhesive resin layer is allowed to 50%, the thickness of the adhesive resin layer is preferably 50 µm or less.

Preferably, the thickness of the adhesive resin layer is preferably 10 µm or less in order to minimize the decrease in discharge capacity.

Although it does not specifically limit about the shape of the filler added to adhesive resin, A spherical shape, an ellipse shape, a fiber shape, a flake shape, etc. are mentioned.

If the shape is spherical, the packing density is increased, so that the adhesive resin layer can be thinned.

If the shape is elliptical, fiber, or flake, the specific surface area can be taken large, so that the void volume of the adhesive resin layer can be taken.

Although it does not specifically limit as a kind of adhesive resin, Although it exists in a battery material, it is preferable that it is a material which does not corrode to electrolyte or an electrode component, and can maintain adhesiveness.

In particular, in the solvent-type adhesive resin, since the adhesive resin layer is easy to be porous, it is easier to obtain the effect.

In particular, in a lithium ion secondary battery, since it is an organic electrolyte, the fluorine resin represented by polyvinylidene fluoride (PVDF), the polymer containing polyvinyl alcohol in the molecular structure represented by polyvinyl alcohol, etc. are preferable.

Although it does not specifically limit as a coating method of adhesive resin, The method suited to the target thickness and application form is preferable.

Examples of the coating method include screen printing, barcoty, roll coater, gravure printing, and doctor braiding.

This invention is not specifically limited about the structure of a battery, but it applies to the battery provided with the battery body which has a positive electrode, a negative electrode, and a separator, and the adhesive resin layer which bonds the said positive electrode and a negative electrode to this separator.

Therefore, the battery body may be an electrode body in which a positive electrode, a separator, and a negative electrode are formed in a single layer, respectively, and is also applied to a battery body in which a plurality of the electrode bodies are laminated.

When applied to a battery having a battery body made of such a laminate, a high performance and a large battery capacity are obtained.

Moreover, in order to form the said laminated body, many positive electrode, separator, and negative electrode which are disadvantageous may be laminated | stacked, and one set or multiple sets of continuous positive electrode, separator, and negative electrode may be wound or folded.

In the present invention, the effect is particularly limited in lithium secondary batteries, but is not particularly limited. For example, primary batteries such as lithium primary batteries, manganese-zinc batteries, silver-zinc batteries, nickel-cadmium batteries, and nickel-zinc batteries And a rechargeable battery such as a nickel-hydrogen battery, a polymer battery, and a carbon secondary battery may be used.

Hereinafter, although an Example demonstrates the detail of this invention, of course, this invention is not limited by these.

Example 1

(Making of electrode body)

91 parts by weight of LiCoO ₂ (manufactured by Kagaku Kogyo Co., Ltd.) having an average particle diameter of 10 µm, 6 parts by weight of graphite powder (Roger), and 3 parts by weight of polyvinylidene fluoride (manufactured by Kurehaka Chemical) on an aluminum foil substrate A positive electrode was prepared by coating a positive electrode active material layer composed of negative parts with an average film thickness of 80 μm.

A negative electrode was prepared by applying a negative electrode active material layer composed of 90 parts by weight of mesocarbon microbeads (manufactured by Osaka Gas) having an average particle diameter of 8 µm and 10 parts by weight of polyinert vinylidene to an average thickness of 80 µm.

An adhesive resin for bonding these electrodes to polypropylene, polyethylene, and polypropylene three-layer separators (manufactured by Hoechst Ceranise), comprising 10% by weight of polyvinylidene fluoride (manufactured by Elpart Chem Japan) and an average diameter of 0.01 μm. 10 weight% of the powder (made by Degussa) was dissolved and dispersed in N-methylpyrrolidone.

The positive electrode was cut into 50 mm x 50 mm, the negative electrode into 55 mm x 55 mm, the separator 60 mm x 60 mm, the adhesive resin solvent was apply | coated to the both sides of the separator by the 300-mesh screen printing machine, and the positive electrode and the negative electrode were bonded to both sides of the separator.

This was dried for 80 hours at 80 degreeC with the dryer and it was set as the electrode body of single layer.

(Evaluation of electrode body)

(1) Measurement of adhesive strength (fill strength)

The adhesive strength between the negative electrode / separator of the electrode body was measured by the created 180 ⁰ Peel Test.

(2) Measurement of battery characteristics

Both the positive electrode and the negative electrode of the prepared electrode body were attached with current collector terminals by spot welding, and placed in a bag made of an aluminate laminate sheet, an electrolyte solution was added thereto, and the inlet was sealed to form a battery.

The battery was charged and discharged at 1 C, and the discharge capacity at this time was measured as the battery characteristic.

Comparative Example 1

The electrode and battery were assembled and evaluated in the same manner as in Example 1 except that 10 wt% of polyvinylidene fluoride (PVDF) was dissolved in N-methylpyrrolidone (NMP) as the adhesive resin solution.

Example 2

The electrode and battery were assembled in the same manner as in Example 1 except that 2% by weight of polyvinyl alcohol and 5% by weight of alumina powder having an average diameter of 0.01 μm were dissolved in N-methylpyrrolidone as the adhesive resin solution. Evaluation was carried out.

Comparative Example 2

In Example 2, electrodes and batteries were assembled and evaluated in the same manner except that 2 weight% of polyvinyl alcohol was dissolved in N-methylpyrrolidone as the adhesive resin solution.

Example 3

The electrode was prepared in the same manner as in Example 1 except that 10% by weight of polyvinylidene fluoride and 10% by weight of alumina powder having an average diameter of 0.1 μm were dissolved and dispersed in N-methyl pyrrolidone as the adhesive resin solution. The battery was assembled and evaluated.

Example 4

In the same manner as in Example 1 except that 10% by weight of polyvinylidene fluoride and 10% by weight of alumina powder having an average diameter of 1 μm were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. The battery was assembled and evaluated.

Example 5

In the same manner as in Example 1 except that 10% by weight of polyvinylidene fluoride and 10% by weight of silica powder having an average diameter of 0.007 µm were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. Assembled and evaluated.

Comparative Example 3

In the same manner as in Example 1 except that 10% by weight of polyvinylidene fluoride and 10% by weight of alumina powder having an average diameter of 10 μm were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. Assembled and evaluated.

Example 6

The electrode and battery were prepared in the same manner as in Example 1, except that 10% by weight of polyvinylidene fluoride and 5% by weight of alumina powder having an average diameter of 0.01 μm were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. Assembled and evaluated.

Example 7

The electrode and battery were prepared in the same manner as in Example 1 except that 5% by weight of polyvinylidene fluoride, 0.01% in average diameter, and 25% by weight of alumina powder were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. Assembled and evaluated.

Comparative Example 4

The electrode and battery were prepared in the same manner as in Example 1 except that 10% by weight of polyvinylidene fluoride and 1% by weight of alumina powder having an average diameter of 0.01 μm were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. Assembled and evaluated.

Comparative Example 5

The electrode and battery were prepared in the same manner as in Example 1 except that 3% by weight of polyvinylidene fluoride and 30% by weight of alumina powder having an average diameter of 0.01 μm were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. Assembled and evaluated.

Example 8

In Example 1, 10% by weight of polyvinylidene fluoride and 10% by weight of alumina powder having an average diameter of 0.01 μm were dissolved and dispersed in N-methylpyrrolidone as an adhesive resin solution. An electrode and a battery were assembled and evaluated in the same manner except that 250 mesh was used as the screen mesh.

Example 9

In Example 1, 10% by weight of polyvinylidene fluoride and 10% by weight of alumina powder having an average diameter of 0.01 μm were dissolved and dispersed in N-methylpyrrolidone as an adhesive resin solution. The electrode and the battery were assembled and evaluated in the same manner except that 100 mesh was used as the screen mesh.

Example 10

In Example 1, 10% by weight of polyvinylidene fluoride and 10% by weight of alumina powder having an average diameter of 0.01 μm were dissolved and dispersed in N-methylpyrrolidone as an adhesive resin solution. The electrode and the battery were assembled and evaluated in the same manner except that 100 mesh was used as the screen mesh.

Comparative Example 6

In Example 1, 10% by weight of polyvinylidene fluoride and 10% by weight of alumina powder having an average diameter of 0.01 μm were dissolved and dispersed in N-methylpyrrolidone as an adhesive resin solution. The electrode and the battery were assembled and evaluated in the same manner except that 50 meshes were used twice as the screen mesh.

Example 11

In Example 1, 10% by weight of polyvinylidene fluoride and 10% by weight of silica powder (manufactured by Aerosil Co., Ltd.) with an average diameter of 0.01 µm were dissolved and dispersed in N-methylpyrrolidone as an adhesive resin solution. In the same manner as above, electrodes and batteries were assembled and evaluated.

Example 12

In Example 1, except that 10% by weight of polyvinylidene fluoride and 30% by weight of silicon carbide powder (manufactured by Seimi) were dissolved and dispersed in N-methylpyrrolidone as an adhesive resin solution. In the same manner, the electrode and the battery were assembled and evaluated.

Example 13

In Example 1, except that 10 wt% of polyvinylidene fluoride and a boron carbide powder (Semi-made) having an average diameter of 0.5 µm were dissolved and dispersed in N-methylpyrrolidone as an adhesive resin solution. In the same manner, the electrode and battery were assembled and evaluated.

Example 14

In Example 1, except that 10 wt% of polyvinylidene fluoride and 30 wt% of silicon nitride powder having a mean diameter of 0.5 µm were dissolved and dispersed in N-methylpyrrolidone as the adhesive resin solution. As a method, an electrode and a battery were assembled and evaluated.

Example 15

In Example 1, the adhesive resin solution was used by dissolving and dissolving 5% by weight of polyvinylidene fluoride and 5% by weight of polymethyl methacrylate (PMMA) powder having an average diameter of 0.5 µm in N-methylpyrrolidone. In the same manner as above, the electrode and the battery were assembled and evaluated.

Example 16

In the same manner as in Example 1, except that 10 wt% of polyvinylidene fluoride and 20 wt% of iron powder having an average diameter of 0.5 µm were dissolved and dissolved in N-methylpyrrolidone as the adhesive resin solution, The battery was assembled and evaluated.

Example 17

In Example 1, the same adhesive resin solution was used, except that 10 wt% of polyvinylidene fluoride and 50 wt% of carbon powder (manufactured by Osaka Gas) having an average diameter of 1 μm were dissolved and dissolved in N-methylpyrrolidone. As a method, electrodes and batteries were assembled and evaluated.

Example 18

In Example 1, as the adhesive resin solution, 10% by weight of polyvinylidene fluoride, 9% by weight of alumina powder having an average diameter of 0.01 µm, and 1% by weight of alumina powder having an average diameter of 1 µm were dissolved in N-methylpyrrolidone. The electrode and battery were assembled and evaluated in the same manner except that the decomposed one was used.

Example 19

In Example 1, 10 wt% of polyvinylidene fluoride, 5 wt% of alumina powder having an average diameter of 0.01 mu m, and 5 wt% of silica powder having an average diameter of 0.01 mu m were dissolved in N-methylpyrrolidone as an adhesive resin solution. The electrode and battery were assembled and evaluated in the same manner except that the decomposed one was used.

Example 20

In Example 1, as the adhesive resin solution, 10 wt% of polyvinylidene fluoride, 9 wt% of alumina powder having an average diameter of 0,01 mu m, and 1 wt% of silica powder having an average diameter of 0.5 mu m N-methylpyrrolidone The electrode and the battery were assembled and evaluated in the same manner except that the solution was dissolved in and dissolved.

Example 21

In Example 1, as the adhesive resin solution, 10% by weight of polyvinylidene fluoride, 9% by weight of an alumina powder having an average diameter of 0.01 µm, and 1% by weight of a polymethyl methacrylate (PMMA) powder having an average diameter of 0.5 µm were used. Electrode and battery were assembled and evaluated in the same manner except that the solution was dissolved and decomposed in N-methylpyrrolidone.

Example 22

In Example 1, as the adhesive resin solution, 10 wt% of polyvinylidene fluoride, 9 wt% of alumina powder having an average diameter of 0.01 μm, and 1 wt% of iron powder having an average diameter of 0.5 μm were dissolved in N-methylpyrrolidone. The electrode and battery were assembled and evaluated in the same manner except that the decomposed one was used.

Example 23

In Example 1, as the adhesive resin solution, 10 wt% of polyvinylidene fluoride, 9 wt% of alumina powder having an average diameter of 0.01 μm, and 1 wt% of carbon powder having an average diameter of 1 μm were dissolved in N-methylpyrrolidone. The electrode and battery were assembled and evaluated in the same manner except that the decomposed one was used.

Example 24

In Example 1, as the adhesive resin solution, 10 wt% of polyvinylidene fluoride, 9 wt% of alumina powder having an average diameter of 0.01 μm, and 1 wt% of alumina powder having an average diameter of 0.5 μm were dissolved in N-methylpyrrolidone. The electrode and battery were assembled and evaluated in the same manner except that the decomposed one was used.

Example 25

In Example 1, 10 wt% of polyvinylidene fluoride, 5 wt% of silicon carbide powder having an average diameter of 0.5 μm, and 5 wt% of PMMA powder having an average diameter of 0.5 μm were added to N-methylpyrrolidone as an adhesive resin solution. The electrode and the battery were assembled and evaluated in the same manner except that the solution was dissolved and dissolved.

Example 26

In Example 1, N-methyl 5 wt% polyvinylidene fluoride, 5 wt% iron powder having an average diameter of 0.5 mu m, and 5 wt% polymethyl methacrylate powder having an average diameter of 0.5 mu m were used as the adhesive resin solution. The electrode and battery were assembled and evaluated in the same manner except that the solution was dissolved and decomposed in pyrrolidone.

Example 27

In Example 1, N-methyl 10 wt% polyvinylidene fluoride, 5 wt% carbon powder having an average diameter of 0.5 μm, and 5 wt% polymethyl methacrylate powder having an average diameter of 0.5 μm were used as the adhesive resin solution. The electrode and battery were assembled and evaluated in the same manner except that the solution was dissolved and decomposed in pyrrolidone.

Example 28

After preparing a positive electrode, a negative electrode, and the adhesive resin solvent like Example 1, 50 mm x 50 mm of positive electrodes, 55 mm x 55 mm of negative electrodes, and 120 mm x 60 mm of separators were cut out.

The adhesive resin solution was apply | coated to one side of this separator by the screen printing machine, it was folded in half, the negative electrode was inserted in the center, and the separator attachment negative electrode was created through the laminator of two rolls.

The adhesive resin solution was apply | coated to one separator surface of this separator attachment negative electrode, and the positive electrode was adhered on it.

Then, an adhesive resin solution was applied to one separator surface of the new separator-attached negative electrode and adhered to the other surface of the positive electrode to which the separator was first adhered.

After repeating this process 6 times and constructing a laminated battery body, the battery body was dried while being pressurized to obtain a flat laminated structured battery in which a positive electrode, a negative electrode, and a separator were bonded.

This battery body was evaluated for battery characteristics as in Example 1.

Example 29

After preparing a positive electrode, a negative electrode, and the adhesive resin solution like Example 1, 50 mm x 50 mm of positive electrodes, 55 mm x 55 mm of negative electrodes, and 120 mm x 60 mm of separators were cut out.

The adhesive resin solution was apply | coated to one side of this separator by the screen printing machine, it was folded in half, the positive electrode was inserted in the center, and the positive electrode with a separator was created through the laminator of two rolls.

An adhesive resin solution was applied to one separator surface of the separator with positive electrode, and the negative electrode was bonded thereon. Then, an adhesive resin solution was applied to one separator surface of the new separator with positive electrode, and the other side of the negative electrode bonded first Adhesion.

After repeating this process 6 times and constructing the laminated battery body, the battery body was dried while pressurizing to obtain a plate-shaped laminated structure battery in which a positive electrode, a negative electrode, and a separator were bonded.

This battery body was evaluated for battery characteristics as in Example 1.

Example 30

After the positive electrode, the negative electrode, and the adhesive resin solvent were prepared as in Example 1, the positive electrode was cut out at 300 mm x 50 mm, and the negative electrode was cut at 620 mm x 60 mm.

The adhesive resin solution was apply | coated to one side of this separator by the screen printing machine, it was folded in half, the negative electrode was inserted in the center, and the negative electrode with a strip | belt-shaped separator was created through the laminator of two rolls.

The adhesive resin solution was apply | coated to one separator surface of the strip | belt-shaped negative electrode with a separator, and one end of the negative electrode with a separator was folded by a fixed amount, and the positive electrode was pinched | folded.

Subsequently, the laminator was passed by stacking the jig and the negative electrode with a separator.

Then, the adhesive resin solution was apply | coated to the opposite surface of the negative electrode with a separator on which the adhesive resin solution was apply | coated first, and then it wound up in the long form.

It dried while pressurizing the wound-shaped battery body wound up, and obtained the flat wound structure battery which adhere | attached the positive electrode, the negative electrode, and the separator.

This battery body was evaluated for battery characteristics as in Example 1.

Example 31

After the positive electrode, the negative electrode, and the adhesive resin solvent were prepared as in Example 1, the positive electrode was cut out to 300 mm x 50 mm, the negative electrode was 305 mm x 55 mm, and the separator was cut into 620 mm x 60 mm.

The adhesive resin solution was apply | coated to one side of this separator by the screen printing machine, it was folded in half, the positive electrode was inserted in the center, and the separator attachment positive electrode was created through the laminator of two rolls.

The adhesive resin solution was apply | coated to one separator surface of this separator positive electrode, the one end of the separator positive electrode was folded in fixed amount, and the negative electrode was pinched | folded.

Subsequently, the laminator was passed through the negative electrode and the separator-attached positive electrode.

Then, the adhesive resin solution was apply | coated to the surface opposite to the surface where the adhesive resin solution was apply | coated first of the separator with a separator, and it winded up continuously in the manor shape.

The persimmon was dried while pressurizing the long-circular battery body to obtain a flat wound structured battery in which a positive electrode, a negative electrode, and a separator were adhered to each other.

This battery body was evaluated for battery characteristics as in Example 1.

Example 32

After the positive electrode, the negative electrode, and the adhesive resin solvent were prepared as in Example 1, the positive electrode was cut out to 300 mm x 50 mm, the negative electrode was 305 mm x 55 mm, and the separator was cut into 620 mm x 60 mm.

Two strip-shaped separators are arranged on both sides of the negative electrode, and a positive electrode is disposed outside one of the separators.

An adhesive resin solution is applied to both the front and back of the separator positioned between the negative electrode and the positive electrode, and an adhesive resin solution is applied only to the side facing the negative electrode to one separator, and the one end of the positive electrode is preceded by a laminator. Then, the positive electrode, the separator, and the negative electrode were laminated so as to pass through the laminator to obtain a strip-shaped laminate.

Then, the adhesive resin solution was apply | coated to the separator surface of a strip | belt-shaped laminated body, the protruding positive electrode was folded, and it wound up to the manor shape continuously.

The persimmon was dried while pressurizing the long-circular battery body to obtain a flat wound structured battery in which a positive electrode, a negative electrode, and a separator were adhered to each other.

This battery body was evaluated for battery characteristics as in Example 1.

Example 33

After preparing the positive electrode, the negative electrode, and the adhesive resin solvent as in Example 1, the positive electrode was cut out to 300 mm x 50 mm, the negative electrode to 305 mm x 55 mm, and the separator to 310 mm x 60 mm.

Two strip-shaped separators are arranged on both sides of the positive electrode, and the negative electrode is arranged on the outer side of either separator.

The separator located between the negative electrode and the positive electrode applies an adhesive resin solution to both front and back, and the other separator applies an adhesive resin solution only to the side facing the positive electrode, and passes one end of the negative electrode through a laminator in a predetermined amount. A lamination was obtained by passing the laminator while overlapping the positive electrode separator and the negative electrode.

Then, the adhesive resin solution was apply | coated to the separator surface of strip | belt-shaped laminated body, the protruding negative electrode was folded, and it wound up continuously to the manor shape.

It dried while pressurizing the wound-shaped battery body wound up, and obtained the flat wound structured battery which adhere | attached the positive electrode, the negative electrode, and the separator.

This battery body was evaluated for battery characteristics as in Example 1.

The adhesive strength measurement results of the electrodes and batteries prepared above and the discharge capacities at charge and discharge at 1C are shown in Tables 1 to 7.

The figure which showed the discharge capacity with respect to each discharge current at the time of changing the adhesive resin of Table 1 was put together in FIG.

By comparing Examples 1 and 2 with Comparative Examples 1 and 2, it can be seen that the discharge capacity, especially the value at high load, is improved by adding the filler to the adhesive resin solution.

Table 2 shows the results of changing the average diameter of the alumina filler and again the results of the silica filler having a small particle diameter.

These results are put together in FIG. 5, and the peel strength and discharge capacity at the time of changing the particle diameter of the alumina filler to add are shown.

Although the peel strength decreased slightly when the location diameter was 1 micrometer or less, there was no problem in practical use.

Conversely, when the average particle diameter was larger than 1 µm, it was found that the void volume of the adhesive resin layer decreased, so that the discharge capacity tended to decrease.

Table 3 shows the results when the ratio of the alumina filler to the adhesive resin is changed.

The results are summarized in peel strength and battery capacity for the volume fraction as shown in FIG. 6.

By changing the ratio of the filler to the resin, the adhesive resin ratio in the void volume formed by the filler changes, so that the void volume of the adhesive resin layer changes.

When the pore volume fraction is 20% or less, the ion path of the adhesive resin layer decreases, so that the discharge capacity is obviously lowered.

On the contrary, it was found that the adhesive strength tends to decrease as the volume fraction increases, and when it exceeds 80%, the amount of filler is too high, so the amount of adhesive resin decreases, and the adhesive strength decreases extremely.

Table 4 summarizes the results when the thickness of the formed adhesive resin layer is changed.

The values of peel strength and discharge capacity for this thickness are shown in FIG. 7.

When the coating thickness is 10 µm or less, the adhesive resin layer fills the gap between the electrodes and the separator due to the unevenness, so that the discharge capacity is large, but when the thickness exceeds 10 µm, the ion path becomes too long. It can be seen that the resistance becomes gradually lowered and the discharge capacity gradually decreases.

When the thickness of the adhesive resin layer is about 50 µm, it can be seen that the drop of the discharge capacity reaches about 50%.

Table 5 shows the results when the material of the filler was changed.

The use of these various materials has been shown to have the same effect.

In particular, it was shown that the effect is large in inorganic compounds and polymers.

In Table 6, the result when two types of fillers were mixed is shown.

In this way, even if the filler is mixed in various combinations, the same effect can be seen.

In particular, the effect was shown to be large in the material which does not contain a conductive material.

Table 7 shows the battery characteristic test results for various battery structures.

It is understood that even when the battery structure is changed in this way, good battery characteristics can be obtained.

In particular, it was found that a battery having high performance and a large battery capacity can be obtained by using the battery body as a laminate obtained by stacking several electrode bodies.

The battery according to the present invention is used for secondary batteries of portable electronic devices and the like, and can be miniaturized and reduced in weight with improved battery performance.

Claims (13)

A battery body having a positive electrode and a negative electrode having an electrode active material, a separator for storing an electrolyte, and an adhesive resin layer for bonding the positive electrode and the negative electrode to the separator, wherein the adhesive resin layer is at least one layer, A battery comprising a filler. The battery according to claim 1, wherein the electrolyte is an organic electrolyte containing lithium ions. The battery according to claim 1, wherein the average diameter of the filler is equal to or smaller than the particle diameter of the electrode active material constituting each electrode. The battery according to claim 3, wherein the filler has an average diameter of 1 µm or less. The battery according to claim 1, wherein the sum of the adhesive resin volume ratio and the filler volume ratio per unit volume of the adhesive resin layer is less than one. The battery according to claim 5, wherein the sum of the adhesive resin volume ratio and the filler volume ratio per unit volume of the adhesive resin layer is 0.2 or more and 0.8 or less. The battery according to claim 1, wherein the filler comprises at least one of an insulator or a semiconductor. The battery according to claim 1, wherein the adhesive resin layer has a layer containing a conductive filler, a layer containing at least one of a nonconductor, or a semiconductor. The battery according to claim 1, wherein the adhesive resin layer is configured to fill the space formed on the opposing surface of each of the electrodes and the separator by the unevenness of the positive electrode, the negative electrode, and the separator. . The battery body is a battery according to claim 1, wherein the battery body is a laminate in which a plurality of electrode bodies each having a single layer of a positive electrode, a separator, and a negative electrode are laminated. The laminated body was formed by alternately disposing a positive electrode and a negative electrode between many separators, The battery of Claim 10 characterized by the above-mentioned. The laminated body was formed by alternately arrange | positioning between the separator which wound up the positive electrode and the negative electrode, The battery of Claim 10 characterized by the above-mentioned. The laminated body was formed by alternately arrange | positioning between the separator which folded the positive electrode and the negative electrode, The battery of Claim 10 characterized by the above-mentioned.