JP2002313289A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery that has a light weight and low cost resin container. SOLUTION: In the battery, which comprises electrode bodies 2 having a positive electrode and a negative electrode and a battery container 3, made of resin that has a battery cell chamber in which the electrode bodies 2 are enclosed together with an electrolyte solution, the battery container 3 has a water-permeability resistant layer 4 that is made of diamond-like carbon and formed into a single body together with the battery container. Since the water- permeability resistant layer restrains water from permeating through the resin battery container, the degradation of the battery performance, that is brought about by water passing through the resin battery container, is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery, and more particularly, to a battery having a resin battery case.

[0002]

2. Description of the Related Art In recent years, environmental pollution has become a major problem on a global scale, and in particular, exhaust gas from gasoline vehicles has become one of the sources of air pollution. For this reason, as one of the clean vehicles which do not emit exhaust gas, the development of an electric vehicle driven by electric power has been advanced.

[0003] Electric vehicles are driven by electric power. In addition to battery performance such as high energy density and high output density, they also have long life, high reliability, and are maintenance-free. , Low cost, etc. are demanded. Lead batteries, Ni
Secondary batteries using aqueous electrolytes such as -Cd batteries and Ni-hydrogen batteries have been developed.

Further, it is required that a power supply for driving an electric vehicle has a high voltage. A battery that satisfies this requirement is an assembled battery in which a plurality of cells are connected in series. The assembled battery is usually integrally formed as a so-called monoblock type battery in which a plurality of electrode bodies are accommodated in each battery cell chamber of a battery container having a plurality of battery cell chambers. In a monoblock type battery,
The plurality of battery cell chambers are formed in the battery container so that the electrode body accommodated in the battery cell chamber and the electrolyte impregnated in the electrode body do not contact the electrode body and the electrolyte in the adjacent battery cell chamber. Is electrically isolated by

[0005] Not only a monoblock type battery but also a normal unit cell, a resin battery container is widely used as a battery container for accommodating an electrode body and an electrolytic solution therein.

A battery using a battery case made of resin has a problem that the life of the battery is deteriorated due to moisture of the electrolytic solution permeating through the battery case made of resin and dissipating into the atmosphere.
That is, the concentration of the electrolyte increases due to the decrease in the water content.

On the other hand, recently, a non-aqueous electrolyte secondary battery having a high battery voltage and a high energy density has attracted attention.

However, in a non-aqueous electrolyte secondary battery, even if a small amount of water exists inside the battery, the water reacts with the electrolytic solution to generate hydrofluoric acid. Hydrofluoric acid corrodes the electrodes. The corrosion of the electrode causes a reduction in the capacity of the non-aqueous electrolyte secondary battery.

In a non-aqueous electrolyte secondary battery, not only is it manufactured so that water does not enter the inside of the battery case, but also the airtightness of the battery case is ensured in order to suppress intrusion of moisture such as atmospheric moisture. Was important. For this reason, metals such as Ni-plated steel sheets and Al, which do not allow moisture to permeate, are used for battery containers.

However, when a metal material is used for the battery container, there is a disadvantage that the battery weight is increased. When a battery pack is constructed by arranging a plurality of batteries, the weight of the battery container alone becomes considerable. Further, the processing cost for processing a metal material to obtain a battery container has been increased.

[0011] Therefore, in view of the demand for further weight reduction and cost reduction, the use of a resin container in a non-aqueous electrolyte battery has been studied. However, resins are known to transmit moisture, albeit slightly.

For this reason, batteries having a resin container that does not allow moisture to permeate have been developed.

As a battery having a resin container that does not allow moisture to permeate, for example, Japanese Utility Model Laid-Open No. 6-70152 discloses a monoblock battery case made of plastic, and a thin metal layer is formed on at least the inner surface of the battery case. A monoblock battery case type organic electrolyte battery is disclosed in which a partition wall of the battery case has a partition penetrating conductive portion electrically insulated from the partition wall. This thin metal layer is formed by applying a plating method or a sputtering method to the inner surface of the battery case.

However, in the method of forming a thin metal layer on the inner surface of the container, the inner wall of the container and each electrode must be electrically insulated so that the positive electrode and the negative electrode are not short-circuited. It is difficult to form a thin metal layer so that there is no pinhole on the resin surface because the structure of the resin becomes complicated and it is difficult for the resin and metal to adhere to each other, and moisture may permeate the battery case. And the cost of forming the thin metal layer is high.

Further, Japanese Patent Application Laid-Open No. 6-124692 proposes to use a film on which silicon oxide is deposited in order to ensure insulation.

However, when a film on which silicon oxide is deposited is used, hydrogen fluoride contained in the electrolytic solution reacts with silicon oxide, and the film dissolves, which makes it difficult to suppress water permeation for a long time. Had become.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and has as its object to provide a battery having a lightweight and low-cost resin container.

[0018]

Means for Solving the Problems In order to solve the above problems, the present inventors have found that a battery container having a water-resistant layer made of diamond-like carbon can solve the above problems.

That is, the battery of the present invention comprises: an electrode body having a positive electrode and a negative electrode; a battery container made of a resin having a battery cell chamber in which the electrode body is sealed together with an electrolyte;
Wherein the battery case has a water-resistant layer made of diamond-like carbon and formed integrally with the battery case.

In the battery of the present invention, the water-permeable layer made of diamond carbon, which is lightweight and has electrical insulation, suppresses the permeation of moisture through the resin battery container. As a result,
This is a battery in which a decrease in battery performance caused by permeation of moisture through a resin battery container is suppressed.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A battery according to the present invention is a battery comprising: an electrode body having a positive electrode and a negative electrode; and a battery container made of a resin having therein a battery cell chamber in which the electrode body is sealed together with an electrolyte. The battery case has a water-permeable layer made of diamond-like carbon and formed integrally with the battery case.

Since the battery of the present invention has a water-permeable layer to prevent moisture from permeating through the resin-made battery container, a decrease in battery performance caused by moisture permeation is suppressed.

That is, in the non-aqueous electrolyte battery, the reaction between the water and the electrolyte caused by the intrusion of the water through the resin battery container is suppressed. Further, in a battery using an aqueous solution as the electrolyte, an increase in the concentration of the electrolyte caused by leakage of the water of the electrolyte through the resin battery container to the outside of the battery container is suppressed.

It is preferable that the water-permeable layer forms the outer peripheral surface of the battery cell chamber and is formed on a wall forming the battery cell chamber. That is, since the water-permeable layer is formed on the outer peripheral surface of the battery and the wall forming the battery cell chamber, the movement of moisture between the battery cell chamber and the outside of the battery is suppressed.

Further, since the water-permeable layer is formed on the wall which forms the outer peripheral surface of the battery and forms the battery cell chamber, when the battery container has a plurality of battery cell chambers, each battery cell chamber has a plurality of battery cell chambers. It is not necessary that the water-permeable layer be formed on the partition wall that separates the water. In the battery of the present invention,
This does not exclude the formation of the water-permeable layer on the partition wall when a plurality of battery cell chambers are provided.

The water-resistant layer is preferably a film formed on the surface forming the battery cell chamber. Here, the surface forming the battery cell chamber refers to the surface that partitions the battery cell chamber on the wall and faces the battery cell chamber. That is, since the water-permeable layer is formed on the surface forming the battery cell chamber, the battery cell chamber is partitioned by the water-resistant layer, and the movement of moisture in the battery cell chamber is suppressed. As a result, a decrease in battery performance due to the movement of moisture is suppressed. In addition, an electrochemically and chemically stable insulating diamond-like carbon film partitions the battery cell chamber, and has an effect of stabilizing the battery container even in an oxidation-reduction reaction during charging and discharging of the battery. Further, it is possible to prevent the battery case made of resin from being attacked by the electrolytic solution.

The water-resistant layer is preferably a film formed on the surface forming the outer peripheral surface of the battery. That is, since the water-permeable layer is a coating formed on the outer peripheral surface of the battery,
The battery does not transfer moisture to and from the outside. For this reason, a decrease in battery performance is suppressed. Also, by forming a water-permeable layer on the outer peripheral surface, even in the case of contact with an adjacent battery container, diamond-like carbon has a high hardness and a small friction coefficient, so that it does not break down due to friction, and is not used for a long time. Can be used.

The diamond-like carbon preferably has SP ³ -bonded amorphous carbon. Since diamond-like carbon has high hardness, insulation properties, and water resistance, water resistance can be imparted to a battery container by using the resin in a resin battery container. In addition, diamond-like carbon may include i-carbon.

The diamond-like carbon is Si,
B, N, Ti, Zr, Hf, W, F, H, O, V, C
It is preferable to have at least one element selected from r, Nb, Mo, and Ta. When the diamond-like carbon has these elements, the diamond-carbon has improved properties such as high hardness.

The water-permeable layer preferably has a density of 1.5 g / cm ³ or more. The density of the water-permeable layer is 1.5 g /
If it is less than ³ cm ³ , moisture will pass through the water-permeable layer, and it will not be possible to impart sufficient water resistance to the resin battery container.

The water-permeable layer has a Vickers hardness of 650 kg.
/ Mm ² or more. That is, when the Vickers hardness is 650 kg / mm ² or more, sufficient abrasion resistance can be exhibited when the water-permeable layer is formed on the outer peripheral surface of the battery container.

The water-permeable layer preferably has a thickness of 10 nm or more. When the thickness of the water permeable layer is less than 10 nm, it is difficult to form a uniform water permeable layer, and the water permeable layer has insufficient water permeability.

The resin forming the battery container is preferably a polyolefin, polyester, polyether or a polymer alloy thereof. That is, the resin forming the battery container is not particularly limited, but these resins are particularly preferable from the viewpoint of having solvent resistance to the non-aqueous electrolyte, moldability, cost, and the like.

The resin forming the battery container is, for example, polyethylene terephthalate (PET) or polybutylene terephthalate (PB) which is a polyester resin.
T) or polyolefin resins such as polypropylene (PP), polyethylene (PE), polymethylpentene (PMP), and cycloolefin copolymer (CO
C) or polyphenylene ether (PPE) or polyphenylene sulfone (P
PS) or these polymer alloys. Further, a modified resin obtained by adding a functional group to the above resin material may be used. Of these resin materials,
In particular, polyolefin resin is inexpensive and more preferable.

Preferably, the water-resistant layer is integrally joined to the battery container via an adhesive layer. That is, since the water-permeable layer exerts the water resistance required for the battery container, the water-permeable layer may be joined to the battery container via an adhesive layer.

The adhesive layer may include an adhesive resin or an adhesive. The adhesive resin is not particularly limited, and examples thereof include an unsaturated carboxylic anhydride-modified polyolefin such as maleic anhydride-modified polyolefin and phthalic anhydride-modified polyolefin. The adhesive is not particularly limited, and examples thereof include a polyester resin and a curing agent for the polyester resin.

In the battery of the present invention, the number of battery cell chambers is not limited. That is, the number of battery cell chambers may be one or more.

The battery container is preferably a monoblock structure in which a plurality of battery cell chambers are partitioned. With a monoblock structure, a plurality of electrode bodies can be sealed in a battery container, so that a battery having high battery performance and lighter and lower cost than a conventional metal battery case can be obtained.

In a battery having a resin battery container having a monoblock structure, a water-resistant layer made of diamond-like carbon is provided only at least on the inner side of the wall portion of the wall forming the battery cell chamber, which is in contact with the outside of the battery container. It may be formed. That is, the water resistance of the battery container can be sufficiently secured without forming a water-permeable layer on the surface of the partition wall that separates the adjacent battery cell chambers. Further, by adopting such a configuration, the formation area of the diamond-like carbon can be minimized, and the cost can be reduced.

The battery of the present invention is preferably a non-aqueous electrolyte battery. That is, the nonaqueous electrolyte battery is a battery having high battery performance such as a high battery voltage and a high energy density, and the nonaqueous electrolyte battery allows the battery of the present invention to have high battery characteristics. . Further, the battery of the present invention is a battery having high battery performance as a non-aqueous electrolyte battery because the permeation of moisture in the battery container is suppressed by the water-permeable layer.

The diamond-like carbon, the peak intensity I _G of around 1560 cm ^-1 in the Raman spectroscopic analysis 13
The ratio I _D / I _G to the peak intensity I _D near 70 cm ⁻¹ is 0.
It is preferably in the range of 6 to 2.0.

Conventionally, Raman spectroscopy has been used for quantifying diamond-like carbon. When diamond-like carbon is analyzed by Raman spectroscopy, sp
It is known that a D peak due to ^two bonds and a G peak due to sp ³ bonds appear in the spectrum. By calculating the ratio of the intensities of these two peaks, the carbon bonding property of diamond-like carbon can be determined. By knowing the binding property, the water resistance of the diamond-like carbon can be understood. Specifically, the binding is higher (I _D /
Carbon becomes dense where I _G is small) and constituting the diamond-like carbon, water penetration resistance is increased. Further, when the bonding property is reduced (I _D / I _G is increased), the diamond-like carbon is less likely to be broken.

That is, when I _D / I _G is in the range of 0.6 to 2.0, it becomes possible for diamond-like carbon to form a water-resistant layer that is excellent in water resistance and is resistant to cracking. It is more preferable that the peak intensity ratio (I _D / I _G) is within the range of 1.0 to 1.5. Peak intensity ratio ( _ID /
I _G) is that in this range, penetration resistance water layer excellent in hard to break and water penetration resistance can be obtained.

Diamond-like carbon has a dangling bond number of 1 × 10 ²¹ spin in ESR analysis.
/ Cm ³ or less. The number of dangling bonds in ESR analysis is 1 × 10 ²¹ spin / cm ³
When the water content is below, water resistance as a water-permeable layer can be secured.

A dangling bond is a chemical bond related to an atom on the surface of a solid, which is not connected between the atom and a second atom and is directed toward the outside of the solid.
In the present invention, dangling bonds indicate carbon atoms that are not bonded. When the number of dangling bonds increases (the number of dangling bonds increases), the gap between the dangling bonds increases. Water molecules pass through this gap. For this reason, when the number of dangling bonds increases,
The water resistance of diamond-like carbon decreases.

The dangling bond is subjected to ESR analysis (electron spin resonance: Electron Spin Resonance).
ance). ESR analysis is an analysis method in which a sample in a strong magnetic field is irradiated with microwaves, and the surface of the sample is observed from this absorption peak. Specifically, when an unpaired electron present in a substance is placed in a strong magnetic field, the magnetic field and its magnetic moment interact, and the degeneracy of the electronic state with spin angular motion is resolved, causing the unpaired electron to split . Irradiation with a microwave having a frequency corresponding to the energy difference between the electronic states causes resonance absorption. The frequency at which the absorption peak occurs indicates the presence of an atom having an unpaired electron (dangling bond) present on the surface, and the presence of the side peak provides knowledge about the environment near the atom having the unpaired electron.

The battery of the present invention is a battery having an electrode body having a positive electrode and a negative electrode, and a battery container made of a resin having a battery cell chamber in which the electrode body is sealed together with an electrolytic solution.

The electrode body having a positive electrode and a negative electrode is not particularly limited, and materials used for ordinary batteries can be used. Examples of such an electrode body include an electrode body of a lithium secondary battery.

The form of the electrode body is not particularly limited. The electrode body is preferably a wound electrode body in which a positive electrode and a negative electrode are formed in a sheet shape and wound with a sheet-like separator interposed therebetween. Further, a flat wound electrode body is more preferable because of its excellent volume efficiency.

The battery container has a battery cell chamber formed therein, in which an electrode body is sealed together with an electrolytic solution. Since the electrode body is sealed in the battery cell chamber, substances such as an electrolyte solution constituting the electrode body do not leak to the outside. In addition, the battery container encloses the electrode body, which facilitates the handling of the battery.

For this reason, the type of the battery of the present invention is not particularly limited, and may be a primary battery or a secondary battery.

In the battery of the present invention, the method for forming the water-permeable layer made of diamond-like carbon is not particularly limited, and the battery can be formed using a usual method for forming diamond-like carbon.

For example, there is a method in which a hydrocarbon gas is decomposed by arc discharge plasma in a high vacuum, and ions and excited molecules in the plasma are electrically accelerated against a battery container and are formed by hitting with energy.

Since the battery of the present invention has a water-resistant layer made of diamond-like carbon, permeation of moisture through the battery container was suppressed. For this reason, it is a battery in which a decrease in performance due to permeation of moisture is suppressed.

[0055]

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited only to the embodiments.

(Example 1) As Example 1, the monoblock type battery 1 shown in FIGS. Here, FIG. 1 is a perspective view of a monoblock battery 1, and FIG.
FIG. 3 is a cross-sectional view taken along line AA of the monoblock battery 1 shown in FIG. 1, and FIG. 3 is a diagram showing an electrode body 2.

The monoblock type battery 1 has four electrode bodies 2
Are sealed in a monoblock type battery container 3 composed of a battery case section 31 and a lid 32 in a state where the respective electrode bodies 2 are separated from each other. At this time, the electrode body 2 is joined to the positive terminal 5 and the negative terminal 6. The battery case 3 has a diamond-like carbon film 4 on the entire outer peripheral surface.
Are formed integrally.

The electrode body 2 is formed in a flat shape by winding a positive electrode sheet and a negative electrode sheet through a separator so that the cross section thereof becomes substantially elliptical, and then performing compression molding. It is a flat-shaped wound electrode body.

The positive electrode sheet is made of both aluminum foil strips.
A positive electrode active material layer made of lithium manganese oxide etc.
It is a formed sheet. The positive electrode sheet is made of a positive electrode active material.
Li _1.12Mn_1.88O_Four86% by weight, conductive agent grapher
10 wt% of PVDF and 4 wt% of PVDF binder
Mix in solvent N-methyl-2-pyrrolidone
And paste this paste on both sides of the Al foil current collector.
Cloth, dried and rolled to form a positive electrode active material layer in the length direction.
Cut to leave unformed edges, and heat under vacuum
It was created by drying.

The negative electrode sheet is a sheet in which a negative electrode active material layer made of graphite or the like is formed on both sides of a strip-shaped copper foil. The negative electrode sheet is made of graphite as a negative electrode active material.
A paste was prepared by mixing 2.5 wt% of PVDF as a binder in N-methyl-2-pyrrolidone in a proportion of 2.5 wt% to prepare a paste in the same manner as in the case of the positive electrode sheet.
It was applied to both sides of the foil current collector, dried and rolled, cut so as to leave an edge portion where the negative electrode active material layer was not formed in the length direction, and dried by vacuum heating.

The separator was a polyethylene microporous membrane formed wider than the portion of the positive electrode sheet and the negative electrode sheet where the electrode active material layer was formed.

The electrode body 2 is formed in an opal shape with the respective edges of the positive electrode sheet and the negative electrode sheet protruding in directions opposite to each other in the axial direction of the winding shaft, and the positive electrode sheet and the negative electrode sheet are interposed therebetween. After being wound, it was formed into a flat shape. The electrode body 2 was formed by compression-molding the edges protruding in directions opposite to each other in the axial length direction of the winding shaft to form a protruding end.

The positive electrode terminal 5 and the negative electrode terminal 6 are joined to the protruding ends of the electrode body 2 protruding in the axially opposite directions. The positive electrode terminal 5 is made of a rod-shaped member made of aluminum, and the negative electrode terminal 6 is made of a rod-shaped member made of copper. The positive electrode terminal 5 and the negative electrode terminal 6 are joined by ultrasonic welding in which a contact portion with each protruding end is formed smoothly, and ultrasonic vibration is applied while the contact portion is in contact with each protruding end. .

The battery container 3 includes a battery case 31, a lid 32,
And has a battery cell chamber 33 in which the electrode body 2 is accommodated. The battery case 31 has a substantially rectangular parallelepiped shape in which an opening of a concave internal space is formed on the upper surface. Lid 32
Is a member that has a plate shape formed in the same shape as the shape of the upper surface of the battery case section 31 and hermetically seals the internal space of the battery case section 31. A space defined by the battery case 31 and the lid 32 is a battery cell chamber 33.

The battery case 31 is made of polypropylene.
A concave space having a length of 120 mm, a width of 85 mm and a height of 82 mm has a tank shape divided into four by a partition wall having a thickness of 2 mm in the vertical direction. Further, the wall portion forming the side wall surface and the bottom surface of the battery case portion 31 was formed with a thickness of 2 mm. Lid 32
Was made of polypropylene having a thickness of 2 mm. The battery case 31 and the lid 32 were both manufactured by an injection molding method.

In the battery case 31 and the lid 32, a diamond-like carbon film 4 is integrally formed on the outer peripheral surface of the battery 1. The diamond-like carbon film 4 is formed by high-frequency plasma CVD having an electrode body having a shape corresponding to the surface shape of the battery case 31 and the lid 32.
This was done with the equipment. The diamond-like carbon film 4 was formed using a high-frequency plasma CVD apparatus using a 13.56 MHz high-frequency power supply as a plasma generation power supply and a C ₂ H ₂ gas as a reaction gas.

The diamond-like carbon film 4 formed on the battery case 31 and the lid 32 has a Vickers hardness of 2
500 kg / mm ² , the film density was 2.5 g / cm ³ , and the film thickness was about 1 μm.

The positive electrode terminal 5 and the negative electrode terminal 6 joined to the electrode body 2 are fixed to the cover 32 with the terminal parts 41 and 51 projecting through the cover 32 and projecting. Here, the fixing portions of the lid 32 and the positive electrode terminal 5 and the negative electrode terminal 6 are air-tightly fixed. At this time, the plurality of electrode bodies 2 were arranged such that the winding axes of the electrode bodies 2 were parallel and the positive electrode and the negative electrode were alternately adjacent to each other so as to facilitate electrical serial connection. .

The battery container 3 has electrode terminals 5 and 6
In a state where the electrode body 2 is fixed via the electrode body 2 and the electrode body 2 is accommodated in the battery cell chamber 33 of the battery case part 31 together with the electrolytic solution, the battery case part 31 and the lid body 32 are connected to each other by 270. It was formed by performing a thermal fusion at a temperature of ° C.

As the electrolytic solution, an electrolytic solution in which LiPF ₆ was dissolved at a ratio of 1 mol / liter in a mixed solvent of ethylene carbonate and diethyl carbonate mixed at a volume ratio of 3: 7 was used.

In the monoblock battery 1 of the first embodiment, since the diamond-like carbon film 4 having water resistance is formed on the entire outer peripheral surface of the battery case 3, the battery case 3
Of water was suppressed to 1/30. For this reason, in the monoblock battery 1 of Example 1, the reaction between moisture and the non-aqueous electrolyte is suppressed. As a result, the monoblock battery 1 of Example 1 is a nonaqueous electrolyte battery that can maintain high battery performance for a long time.

Example 2 Example 2 is a monoblock type battery whose cross section is shown in FIG. The battery of the second embodiment is the same as the battery of the first embodiment except that the diamond-like carbon film 4 ′ is formed on the surface of the wall facing the outer peripheral surface of the battery container 3 facing the battery cell chamber. .

In the battery of the second embodiment, the diamond-like carbon film 4 ′ is formed on the surface of the wall facing the outer peripheral surface of the battery container 3, which faces the battery cell chamber. The amount of water that permeates through the container 3 and enters the battery cell chamber is suppressed to 1/30. For this reason,
In the monoblock battery of Example 2, the reaction between water and the non-aqueous electrolyte was suppressed. As a result, the monoblock battery of Example 2 is a nonaqueous electrolyte battery that can maintain high battery performance for a long period of time.

(Evaluation of Diamond-Like Carbon Coating) In order to evaluate the diamond-like carbon coating, a sample in which a diamond-like carbon coating was formed on a polyethylene terephthalate film was manufactured, and the water permeability of the sample was measured.

The measurement of the peak intensity ratio and the number of dangling bonds of the manufactured sample by Raman spectroscopy were performed by the following means.

(Measurement of Peak Intensity Ratio) Raman spectroscopy was carried out using a Holo Probe microlaser Raman spectrometer manufactured by Kaiser as an analyzer with a wavelength of 532 nm.
The analysis was performed using a laser beam, and a spectrum was obtained. Then, the D peak and G
The peak intensities _ID and _IG were determined, and the intensity ratio ( _ID / _ID) was obtained.
_IG ) was determined.

(Measurement of Spin Density of Dangling Bond) The spin density was measured by using RE-2X manufactured by JEOL as a analyzer and measuring FIELD: 323 mT / G ± 10 mT / G, S
WEEP TIME: 4 min, MOD: 100 kHz
× 0.79 mT, RESPONSE: Measurement was performed under the conditions of 0.03 sec.

(Sample 1) A diamond-like carbon film was formed on a 100 μm-thick polyethylene terephthalate film. The diamond-like carbon film was formed using a plasma CVD apparatus. A 13.56 MHz high frequency power source was used as a power source for plasma generation, and an output voltage of 4 kV was used to form a film having a thickness of 1 μm. Further, toluene gas was used as a reaction gas.

The coating formed on Sample 1 had a peak intensity ratio I _D / I _G of 2.144 and a spin density of dangling bonds of 6.8 × 10 ²⁰ / cm ³ .

(Sample 2) Sample 2 is a sample having a diamond-like carbon coating produced in the same manner as in Sample 1 except that the reaction gas was methane gas.

The coating formed on Sample 2 had a peak intensity ratio I _D / I _G of 0.641 and a spin density of dangling bonds of 9.3 × 10 ²⁰ / cm ³ .

In sample 2, many cracks were observed in the coating. This crack is too strong sp ³ property of binding of the carbon constituting the coating is believed to be caused by the coating becomes brittle. In the sample 2, when the film is formed, the methane gas of the reaction gas is easily turned into plasma to carbon atoms. Therefore, the number of unbonded carbon atoms increases, and the number of dangling bonds increases.

(Sample 3) Sample 3 is a sample manufactured in the same manner as Sample 2 except that the output voltage at the time of forming the diamond-like carbon film was 6 kV.

The coating formed on Sample 3 had a peak intensity ratio I _D / I _G of 0.653 and a dangling bond spin density of 8.80 × 10 ²⁰ / cm ³ .

In sample 3, the probability of collision of plasmated carbon atoms is increased by increasing the output voltage during film formation. That is, an increase in the probability of collision of carbon atoms at the time of film formation leads to an increase in the probability of bonding of carbon atoms converted into plasma, and causes a decrease in the number of dangling bonds. In addition,
In sample 3, cracks were observed on the surface of the coating as in sample 2. This is presumed to be due to the fact that the reaction gas is methane gas which is easily converted into plasma. For details, too strong sp ³ property of binding of the carbon constituting the coating is believed to be caused by the coating becomes brittle.

(Sample 4) Sample 4 is a sample manufactured in the same manner as Sample 1 except that the output voltage at the time of forming the diamond-like carbon film was 2 kV.

The coating formed on Sample 4 had a peak intensity ratio I _D / I _G of 1.101 and a spin density of dangling bonds of 3.90 × 10 ²⁰ / cm ³ .

Sample 4 has a low output voltage,
The film forming speed is reduced. As the film formation rate decreases, the sp ³ property of the produced film increases. As a result, the peak intensity ratio of the coating increases.

(Sample 5) Sample 5 is a sample manufactured in the same manner as Sample 1 except that the output voltage at the time of forming the diamond-like carbon film was 1 kV.

The coating formed on Sample 5 had a peak intensity ratio I _D / I _G of 1.097 and a spin density of dangling bonds of 5.40 × 10 ²⁰ / cm ³ .

[0091] In Sample 5, the film formation rate was reduced by considerably reducing the output voltage. As a result, the sp ³ property of the film after film formation is increased. That is, the peak intensity ratio of the coating is large. In sample 5, the spin density of the dumbling bond is increased. This increase may be due to the binding energy of the carbon atoms being too low.

(Sample 6) Sample 6 is a sample manufactured in the same manner as Sample 1 except that the output voltage at the time of forming the diamond-like carbon film was 3 kV and the gas pressure was 2 Pa.

The coating formed on Sample 6 had a peak intensity ratio I _D / I _G of 1.455 and a spin density of dangling bonds of 6.10 × 10 ²⁰ / cm ³ .

[0094] For Sample 6, the output voltage during film formation was reduced and the gas pressure was increased. As the output voltage decreases, the sp ³ property of the film after film formation increases. That is, the peak intensity ratio of the coating is large. In addition,
No crack was observed in the coating formed on Sample 6.

(Sample 7) Sample 7 is a sample manufactured in the same manner as Sample 1 except that the output voltage at the time of forming the diamond-like carbon film was 3 kV and the gas pressure was 0.5 Pa.

The coating formed on Sample 7 had a peak intensity ratio I _D / I _G of 1.432 and a spin density of dangling bonds of 4.20 × 10 ¹⁹ / cm ³ .

[0097] Sample 7 has a coating film formed under the conditions of reduced output voltage and gas pressure. By adjusting the film-forming conditions at the time of film-forming, it is possible to suppress the film formation after the carbon atoms converted into plasma are combined in a cluster. As a result, the film of Sample 7 is a film having an appropriate peak intensity ratio and a small spin density. No crack was found in the coating of Sample 7.

Table 1 shows the characteristics of the diamond-like carbon coatings formed on Samples 1 to 7.

[0099]

[Table 1]

(Evaluation of Water Permeability) As an evaluation of Samples 1 to 7, water permeability was measured. In addition, in order to confirm the water resistance of the diamond-like carbon coating, a sample of only the polyethylene terephthalate film having no coating was used as a comparative example.

(Water permeability) Water permeability is measured in accordance with JIS K540.
The measurement was carried out by measuring the amount of permeated water by a means based on the water vapor permeability measurement method described in Section 8.17. In addition,
The measurement of the amount of permeated water was conducted at a temperature of 60 ° C and a humidity of 95 RH%.
Made in the state. The measurement results are shown in Table 1.

As shown in Table 1, the permeated water content of the comparative example was 21.
It was 3 g / m ² · 24 h. On the other hand, all of the samples 1 to 7 having the diamond-like carbon coating have a small amount of permeated moisture.

More specifically, the amount of permeated water of the sample 1 was 5.2.
0 g / m ² · 24 h, which was lower than that of the comparative example. That is, it can be seen that the formation of the diamond-like carbon coating improved the water resistance.

The amount of permeated water of Sample 2 was 10.93 g / m
^The value was 2.24 h, which was lower than that of the comparative example. That is, even a diamond-like carbon coating formed using methane gas as a reaction gas can exhibit high water resistance.

The amount of permeated water of Sample 3 was 8.71 g / m ^2.
・ 24h was a lower value than the comparative example. further,
It can be seen that lowering the spin density of the coating using methane gas as the reaction gas improves the water resistance.

The amount of permeated water of Sample 4 was 0.46 g / m ^2.
・ 24h was considerably lower than that of the comparative example. Further, it can be seen that by lowering the peak intensity ratio and the spin density of the film using toluene gas as the reaction gas, the water resistance is significantly improved.

Sample 5 had a permeated water content of 0.67 g / m ² ···
24h was considerably lower than that of the comparative example. Further, it can be seen that the water permeability resistance is improved by reducing the peak intensity ratio of the film using toluene gas as the reaction gas.

The amount of permeated water of Sample 6 was 0.53 g / m ² ·
24h was considerably lower than that of the comparative example. Further, it can be seen that by considerably lowering the peak intensity ratio of the film using toluene gas as the reaction gas, the water resistance is considerably improved even when the spin density is slightly increased.

The amount of permeated water of sample 7 was 0.26 g / m ² ·
24h was considerably lower than that of the comparative example. Further, it can be seen that the water permeability resistance is considerably improved by greatly reducing the peak intensity ratio and the spin density of the film using toluene gas as the reaction gas.

As is clear from the above, the formation of the diamond-like carbon film can reduce the amount of permeated water. That is, the water resistance can be improved.

[0111]

According to the battery of the present invention, the water-permeable layer suppresses the permeation of moisture through the resin battery container. As a result, the battery of the present invention is a battery in which a decrease in battery performance caused by permeation of moisture through the resin battery container is suppressed.

[Brief description of the drawings]

FIG. 1 is a view showing a monoblock type battery of Example 1.

FIG. 2 is a diagram showing a cross section of the monoblock battery of Example 1.

FIG. 3 is a diagram showing an electrode body of the monoblock battery of Example 1.

FIG. 4 is a diagram showing a cross section of the monoblock battery of Example 2.

[Explanation of symbols]

1. Monoblock battery 2. Electrode body 3.
Battery container 31 ... Battery case 32 ... Lid 33
... Battery cell chamber 4,4 '... Diamond-like carbon film 5 ... Positive electrode terminal 6 ... Negative electrode terminal

Continued on the front page (72) Inventor Satoru Suzuki 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture, Denso Corporation (72) Inventor Manabu Yamada 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture F-term, Denso Corporation (Reference) 4K030 AA09 BA06 BA10 BA13 BA18 BA19 BA20 BA22 BA26 BA28 BA29 CA07 FA01 JA20 5H011 AA10 CC02 DD14 DD23 KK00 KK01 5H029 AJ07 AJ14 AK03 AL07 AM03 AM05 AM07 BJ02 BJ06 BJ14 DJ02 DJ18 EJ04 HJ00 HJ04

Claims (16)

[Claims] 1. A battery comprising: an electrode body having a positive electrode and a negative electrode; and a battery container made of a resin having a battery cell chamber in which the electrode body is sealed together with an electrolytic solution. A battery comprising a water-permeable layer made of like carbon and integrally formed with the battery container. 2. The battery according to claim 1, wherein the water-permeable layer is formed on a wall of the battery container forming an outer peripheral surface of the battery and forming the battery cell chamber. 3. The battery according to claim 2, wherein the water-resistant layer is a coating formed on a surface forming the battery cell chamber. 4. The battery according to claim 2, wherein the water-permeable layer is a coating formed on a surface forming an outer peripheral surface of the battery. 5. The method according to claim 1, wherein the diamond-like carbon is S
The battery according to claim 1, comprising a P ³ -bonded amorphous carbon. 6. The diamond-like carbon is S
i, B, N, Ti, Zr, Hf, W, F, H, O, V,
The battery according to claim 5, wherein the battery has at least one element selected from Cr, Nb, Mo, and Ta. 7. The battery according to claim 1, wherein the water-resistant layer has a density of 1.5 g / cm ³ or more. 8. The water-permeable layer has a Vickers hardness of 65.
2. The battery according to claim 1, wherein the battery weight is 0 kg / mm ² or more. 9. The battery according to claim 1, wherein the water-permeable layer has a thickness of 10 nm or more. 10. The resin forming the battery container,
The battery according to claim 1, which is a polyolefin, polyester, polyether or a polymer alloy thereof. 11. The battery according to claim 1, wherein the water-permeable layer is integrally joined to the battery container via an adhesive layer. 12. The battery according to claim 1, wherein the battery container is a monoblock structure in which a plurality of the battery cell chambers are partitioned. 13. The battery according to claim 1, which is a non-aqueous electrolyte battery. 14. The diamond-like carbon,
Peak intensity I near 1560 cm ^{-1 in} Raman spectroscopy
The ratio I _D / I _G between _G and the peak intensity I _D near 1370 cm ⁻¹
The battery according to claim 1, wherein is in the range of 0.6 to 2.0. 15. The method according to claim 15, wherein the peak intensity ratio ( _ID / _IG ) is
16. The battery according to claim 15, which is in the range of 1.0 to 1.5. 16. The diamond-like carbon,
The number of dangling bonds in ESR analysis is 1 × 10 ²¹
The battery according to claim 1, which has a spin / cm ³ or less.