JP3707438B2 - battery - Google Patents

Description

【０１００】
（耐透水性の評価）
試料１〜７の評価として透水性を測定した。なお、ダイヤモンドライクカーボン被膜の耐透水性を確認するために、被膜が形成されていないポリエチレンテレフタレートフィルムのみの試料を比較例とした。
【０１０１】
（透水性）
透水性は、ＪＩＳ Ｋ ５４００ ８．１７に記載の水蒸気透過度測定法に準拠した手段により透過水分量を測定することでなされた。なお、透過水分量の測定は、温度が６０℃、湿度が９５ＲＨ％の状態で行われた。測定結果を表１にあわせて示した。
【０１０２】
表１より、比較例の透過水分量は、２１．３ｇ／ｍ²・２４ｈであった。これに対し、ダイヤモンドライクカーボン被膜を有する試料１〜７は、いずれも透過水分量が小さくなっている。
【０１０３】
詳しくは、試料１の透過水分量は、５．２０ｇ／ｍ²・２４ｈと比較例と比較して低い値となった。すなわち、ダイヤモンドライクカーボン被膜を形成することで、耐透水性が向上したことがわかる。
【０１０４】
試料２の透過水分量は、１０．９３ｇ／ｍ²・２４ｈと比較例と比較して低い値となった。すなわち、メタンガスを反応ガスに用いて形成されたダイヤモンドライクカーボン被膜であっても、高い耐透水性を発揮できる。
【０１０５】
試料３の透過水分量は、８．７１ｇ／ｍ²・２４ｈと比較例と比較して低い値となった。さらに、反応ガスにメタンガスを用いた被膜のスピン密度を低下させることで、耐透水性が向上することがわかる。
【０１０６】
試料４の透過水分量は、０．４６ｇ／ｍ²・２４ｈと比較例と比較してかなり低い値となった。さらに、反応ガスにトルエンガスを用いた被膜のピーク強度比およびスピン密度を低下させることで、耐透水性が大幅に向上することがわかる。
【０１０７】
試料５の透過水分量は０．６７ｇ／ｍ²・２４ｈと比較例と比較してかなり低い値となった。さらに、反応ガスにトルエンガスを用いた被膜のピーク強度比を低下させることで、耐透水性が向上することがわかる。
【０１０８】
試料６の透過水分量は０．５３ｇ／ｍ²・２４ｈと比較例と比較してかなり低い値となった。さらに、反応ガスにトルエンガスを用いた被膜のピーク強度比をかなり低下させることで、スピン密度が若干大きくなっても耐透水性がかなり向上することがわかる。
【０１０９】
試料７の透過水分量は０．２６ｇ／ｍ²・２４ｈと比較例と比較してかなり低い値となった。さらに、反応ガスにトルエンガスを用いた被膜のピーク強度比およびスピン密度を大幅に低下させることで、耐透水性がかなり向上することがわかる。
【０１１０】
以上のことから明らかなように、ダイヤモンドライクカーボン被膜を形成することで、透過水分量を減少させることができる。すなわち、耐透水性を向上させることができる。
【０１１１】
【発明の効果】
本発明の電池は、耐透水層が樹脂製電池容器を水分が透過することを抑えている。この結果、本発明の電池は、樹脂製電池容器を水分が透過することにより生じる電池性能の低下が抑えられた電池となっている。
【図面の簡単な説明】
【図１】 実施例１のモノブロック型電池を示した図である。
【図２】 実施例１のモノブロック型電池の断面を示した図である。
【図３】 実施例１のモノブロック型電池の電極体を示した図である。
【図４】 実施例２のモノブロック型電池の断面を示した図である。
【符号の説明】
１…モノブロック型電池 ２…電極体 ３…電池容器
３１…電槽部 ３２…蓋体 ３３…電池セル室
４、４’…ダイヤモンドライクカーボン膜
５…正極端子 ６…負極端子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery, and more particularly to a battery having a resin battery container.
[0002]
[Prior art]
In recent years, environmental pollution has become a major problem on a global scale, and in particular, exhaust gas from gasoline automobiles has become one of the sources of air pollution. For this reason, as one of clean vehicles that do not emit exhaust gas, development of electric vehicles that drive electricity as power is being promoted.
[0003]
Electric vehicles are driven by electric power, and in addition to battery performance such as high energy density and high output density, long life, high reliability, maintenance-free, and low cost for electric vehicle drive power supplies Etc. are requested. Secondary batteries using aqueous electrolytes such as lead batteries, Ni-Cd batteries, Ni-hydrogen batteries have been developed as power sources for driving electric vehicles.
[0004]
Furthermore, a high voltage is required for a power source for driving an electric vehicle. As a battery that satisfies this requirement, there is an assembled battery in which a plurality of single 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 housed in respective battery cell chambers of a battery container having a plurality of battery cell chambers. In a monoblock type battery, a plurality of battery cell chambers are arranged 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 electrolyte solution in the adjacent battery cell chamber. It is electrically isolated by a partition formed in the battery container.
[0005]
A resin battery container is widely used as a battery container that accommodates an electrode body and an electrolytic solution in not only a monoblock type battery but also a normal single battery.
[0006]
A battery using a resin battery container has a problem that the life characteristics of the battery deteriorate due to the moisture of the electrolyte passing through the resin battery container and dissipating into the atmosphere. That is, the electrolyte concentration increases due to a decrease in moisture.
[0007]
On the other hand, recently, non-aqueous electrolyte secondary batteries having high battery voltage and high energy density have attracted attention.
[0008]
However, in the non-aqueous electrolyte secondary battery, if a small amount of water is present inside the battery, the water and the electrolyte solution react to generate hydrofluoric acid. Hydrofluoric acid corrodes the electrode. Corrosion of the electrode causes a decrease in the capacity of the nonaqueous electrolyte secondary battery.
[0009]
In non-aqueous electrolyte secondary batteries, it is important not only to manufacture the battery container so that moisture does not enter the interior of the battery container, but also to ensure the airtightness of the battery container in order to suppress the ingress of moisture such as atmospheric moisture. It was. For this reason, Ni-plated steel plates and metals such as Al that do not allow moisture to permeate are used for the battery containers.
[0010]
However, when a metal material is used for the battery container, there is a drawback that the battery weight increases. When an assembled battery is configured by arranging a plurality of batteries, the weight of the battery container alone is considerable. Furthermore, the processing cost for processing a metal material and obtaining a battery container was high.
[0011]
For this reason, use of a resin container has been studied for non-aqueous electrolyte batteries because of further demands for weight reduction and cost reduction. However, it is known that the resin is slightly permeable to moisture.
[0012]
For this reason, a battery having a resin container that does not allow moisture to permeate has been developed.
[0013]
As a battery having a resin container that does not allow moisture to pass therethrough, for example, Japanese Utility Model Laid-Open No. 6-70152 includes a monoblock battery case made of plastic, and a thin metal layer is formed at least on the inner surface of the battery case. In addition, a monoblock battery case organic electrolyte battery characterized in that the partition wall of the battery case has a partition wall through conductive portion electrically insulated from the partition wall is disclosed. This thin metal layer is formed by applying a plating method or a sputtering method to the inner surface of the battery case.
[0014]
However, in the method of forming a thin metal layer on the inner surface of the battery case, the inner wall of the battery case and each electrode need to 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 it becomes complicated and resin and metal are difficult to adhere, and there is a possibility that moisture may permeate the battery case, There were problems such as high cost of forming the thin metal layer.
[0015]
Japanese Patent Application Laid-Open No. 6-124692 proposes the use of a film on which silicon oxide is deposited in order to ensure insulation.
[0016]
However, when a film deposited with silicon oxide is used, hydrogen fluoride contained in the electrolyte reacts with silicon oxide, and the film dissolves, making it difficult to suppress moisture permeation over a long period of time. .
[0017]
[Problems to be solved by the invention]
This invention is made | formed in view of the said actual condition, and makes it a subject to provide the battery which has a resin container lightweight and low cost.
[0018]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors have found that the above problems can be solved by using a battery container having a water-resistant layer made of diamond-like carbon.
[0019]
  That is, 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 enclosed together with an electrolyte solution. It has a water-resistant layer made of diamond-like carbon and formed integrally with the battery case.1560 cm in Raman spectroscopic analysis of diamond-like carbon ^-1 Near peak intensity I _G And 1370cm ^-1 Near peak intensity I _D Ratio I _D / I _G Is in the range of 1.0 to 1.5It is characterized by that.
[0020]
In the battery of the present invention, a water-permeable layer made of diamond carbon having light weight and electrical insulation prevents moisture from permeating through the resin battery container. As a result, it is a battery in which a decrease in battery performance caused by moisture permeating through the resin battery container is suppressed.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
  A battery according to 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 electrolyte solution. It has a water-permeable layer made of carbon and formed integrally with the battery case.1560 cm in Raman spectroscopic analysis of diamond-like carbon ^-1 Near peak intensity I _G And 1370cm ^-1 Near peak intensity I _D Ratio I _D / I _G Is in the range of 1.0 to 1.5The
[0022]
Since the battery of the present invention has a water-resistant layer to prevent moisture from permeating through the resin battery container, a decrease in battery performance caused by moisture permeation is suppressed.
[0023]
That is, in the nonaqueous electrolyte battery, the reaction between the water and the electrolytic solution generated by the water entering through the resin battery container is suppressed. Further, in a battery in which an aqueous solution is used as the electrolytic solution, an increase in the concentration of the electrolytic solution caused by leakage of moisture of the electrolytic solution through the resin battery container to the outside of the battery container can be suppressed.
[0024]
It is preferable that the water permeable layer is formed on a wall portion that forms the outer peripheral surface of the battery cell chamber and forms the battery cell chamber. That is, the moisture permeation between the battery cell chamber and the outside of the battery is suppressed by forming the water-permeable layer on the outer peripheral surface of the battery and the wall portion forming the battery cell chamber.
[0025]
Moreover, when the battery container has a plurality of battery cell chambers, the water permeable layer is formed on the wall portion that forms the outer peripheral surface of the battery and the battery cell chamber, thereby isolating each battery cell chamber. A water-resistant layer may not be formed on the partition wall. In addition, in the battery of this invention, when it has a some battery cell chamber, it does not exclude that a water-permeable layer is formed in a partition.
[0026]
The water-permeable layer is preferably a coating formed on the surface forming the battery cell chamber. Here, the surface that forms the battery cell chamber refers to a surface that partitions the battery cell chamber of the wall and faces the battery cell chamber. That is, by forming the water-permeable layer on the surface forming the battery cell chamber, the battery cell chamber is partitioned by the water-permeable layer, and the movement of moisture in the battery cell chamber is suppressed. As a result, a decrease in battery performance due to moisture movement can be suppressed. In addition, the electrochemically and chemically stable insulating diamond-like carbon film defines the battery cell chamber, and the battery container is stable in the oxidation-reduction reaction during charging and discharging of the battery. Furthermore, the resin battery container can be prevented from being attacked by the electrolytic solution.
[0027]
The water-resistant layer is preferably a coating formed on the surface forming the outer peripheral surface of the battery. That is, since the water-resistant layer is a film formed on the outer peripheral surface of the battery, the battery does not move moisture between the battery and the outside. For this reason, a decrease in battery performance is suppressed. In addition, since a water-permeable layer is formed on the outer peripheral surface, diamond-like carbon has a high hardness and a low coefficient of friction even when it comes into contact with an adjacent battery container, so that it does not break down due to friction. Can be used.
[0028]
Diamond-like carbon is SP^ThreeIt is preferred to have bonded amorphous carbon. Since diamond-like carbon has high hardness, insulation, and water permeability, the battery container can be provided with water permeability by being used in a resin battery container. The diamond-like carbon may contain i carbon.
[0029]
The diamond-like carbon preferably has at least one element selected from Si, B, N, Ti, Zr, Hf, W, F, H, O, V, Cr, Nb, Mo, and Ta. When diamond-like carbon has these elements, the characteristics of diamond carbon such as high hardness are improved.
[0030]
The water-resistant layer is 1.5 g / cm^ThreeIt is preferable to have the above density. The density of the water-resistant layer is 1.5 g / cm^ThreeIf it is less than this, moisture will permeate through the water-resistant layer, and sufficient water resistance cannot be imparted to the resin battery container.
[0031]
The water-permeable layer has a Vickers hardness of 650 kg / mm.²The above is preferable. That is, the Vickers hardness is 650 kg / mm.²By becoming the above, sufficient abrasion resistance can be exhibited when a water-permeable layer is formed in the outer peripheral surface of a battery container.
[0032]
The water-resistant layer preferably has a thickness of 10 nm or more. When the thickness of the water-resistant layer is less than 10 nm, it becomes difficult to form a uniform water-resistant layer, and the water-resistant layer has insufficient water resistance.
[0033]
The resin forming the battery container is preferably 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 viewpoints of having solvent resistance to the non-aqueous electrolyte, moldability, cost, and the like.
[0034]
Examples of the resin forming the battery container include polyethylene terephthalate (PET), which is a polyester resin, polybutylene terephthalate (PBT), and polypropylene (PP), polyethylene (PE), and polymethylpentene (PMP), which are polyolefin resins. , Cycloolefin copolymer (COC), polyether resin such as polyphenylene ether (PPE), polyphenylene sulfone (PPS), or a polymer alloy thereof. Moreover, the modified resin which gave the functional group to the above-mentioned resin material may be sufficient. Of these resin materials, polyolefin resin is particularly preferred because it is inexpensive.
[0037]
In the battery of the present invention, the number of battery cell chambers is not limited. That is, there may be one battery cell chamber or a plurality of battery cell chambers.
[0038]
The battery container is preferably a monoblock structure in which a plurality of battery cell chambers are partitioned. If it is a monoblock structure, since a plurality of electrode bodies can be enclosed in a battery container, while having high battery performance, a battery that is lighter and less expensive than a conventional metal battery case can be obtained.
[0039]
In a battery having a resin battery container having a monoblock structure, if a water-resistant layer made of diamond-like carbon is formed only at least inside the wall part that contacts the outside of the battery container among the wall parts that form the battery cell chamber. Good. That is, the water permeability of the battery container can be sufficiently ensured without forming a water-permeable layer on the surface of the partition wall that separates adjacent battery cell chambers. Furthermore, with such a configuration, the diamond-like carbon formation area can be minimized and the cost can be reduced.
[0040]
The battery of the present invention is preferably a nonaqueous electrolyte battery. That is, the nonaqueous electrolyte battery is a battery having high battery performance such as a high battery voltage and high energy density, and the battery of the present invention can have high battery characteristics by being a nonaqueous electrolyte battery. . Furthermore, the battery of the present invention is a battery having high battery performance of a non-aqueous electrolyte battery because the water permeation-resistant layer suppresses moisture permeation through the battery container.
[0041]
Diamond-like carbon is 1560cm in Raman spectroscopic analysis^-1Near peak intensity I_GAnd 1370cm^-1Near peak intensity I_DRatio I_D/ I_GIs preferably in the range of 0.6 to 2.0.
[0042]
Conventionally, Raman spectroscopic analysis has been used to quantify diamond-like carbon. When diamond-like carbon is analyzed by Raman spectroscopy, sp²D peak and sp caused by bonding^ThreeIt is known that a G peak due to bonding appears in the spectrum. By determining the ratio of the intensity of these two peaks, the carbon binding property of diamond-like carbon can be determined. By knowing the bondability, the water permeability of diamond-like carbon can be understood. Specifically, the binding property is increased (I_D/ I_GIs small) and the carbon constituting the diamond-like carbon becomes dense, and the water permeability is increased. In addition, the connectivity is reduced (I_D/ I_GThe diamond-like carbon is difficult to break.
[0043]
That is, I_D/ I_GIs in the range of 0.6 to 2.0, diamond-like carbon can form a water-resistant layer that is excellent in water permeability and is resistant to cracking. Peak intensity ratio (I_D/ I_G) Is more preferably in the range of 1.0 to 1.5. Peak intensity ratio (I_D/ I_G) Is within this range, a water-resistant layer that is resistant to cracking and excellent in water permeability can be obtained.
[0044]
Diamond-like carbon has a dangling bond number of 1 × 10 in ESR analysis.^{twenty one}spin / cm^ThreeThe following is preferable. The number of dangling bonds in ESR analysis is 1 × 10^{twenty one}spin / cm^ThreeBy being below, the water-permeable resistance as a water-permeable layer can be ensured.
[0045]
A dangling bond is a chemical bond related to an atom on the surface of the solid, and does not connect the atom and the second atom, and is a bond that is directed toward the outside of the solid. In the present invention, a dangling bond indicates an unbonded carbon atom. When the number of dangling bonds increases (the number of dangling bonds increases), the gap between the dangling bonds increases. Water molecules permeate through this gap. For this reason, when the number of dangling bonds increases, the water permeability of diamond-like carbon decreases.
[0046]
The dangling bond can be measured by ESR analysis (Electron Spin Resonance). 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 the absorption peak. Specifically, when unpaired electrons that exist in a substance are placed in a strong magnetic field, the magnetic field and its magnetic moment interact, and the unpaired electrons are split by releasing the degeneracy of the electronic state with spin angular motion. . Resonance absorption occurs when a microwave having a frequency corresponding to the energy difference between the electronic states is irradiated. From the frequency at which the absorption peak occurs, the existence of an atom having an unpaired electron (dangling bond) existing on the surface can be found, and from the presence of the side peak, knowledge about the environment near the atom having the unpaired electron can be obtained.
[0047]
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 in which a battery cell chamber in which the electrode body is sealed together with an electrolytic solution is formed.
[0048]
The electrode body having a positive electrode and a negative electrode is not particularly limited, and a material used for a normal battery can be used. As such an electrode body, the electrode body of a lithium secondary battery can be mention | raise | lifted, for example.
[0049]
Further, 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-shaped separator interposed therebetween. Furthermore, since it is excellent in volume efficiency, it is more preferable that it is a flat-shaped wound electrode body.
[0050]
The battery container is formed of a resin and has a battery cell chamber in which an electrode body is enclosed together with an electrolytic solution. By sealing the electrode body in the battery cell chamber, a substance such as an electrolytic solution constituting the electrode body does not leak to the outside. In addition, the battery can be easily handled by enclosing the electrode body in the battery container.
[0051]
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.
[0052]
In the battery of the present invention, the method for forming a water-permeable layer made of diamond-like carbon is not particularly limited, and can be formed using a normal method for forming diamond-like carbon.
[0053]
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 to a battery container and hit with energy.
[0054]
The battery of the present invention has a water-resistant layer made of diamond-like carbon, so that moisture can be prevented from passing through the battery container. For this reason, it is a battery in which deterioration of performance due to moisture permeation is suppressed.
[0055]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not limited only to an Example.
[0056]
Example 1
As Example 1, the monoblock type battery 1 shown in FIGS. Here, FIG. 1 is a perspective view of the monoblock type battery 1, FIG. 2 is a cross-sectional view taken along the line AA of the monoblock type battery 1 shown in FIG. 1, and FIG. FIG.
[0057]
The monoblock type battery 1 is a battery in which four electrode bodies 2 are enclosed in a monoblock type battery container 3 composed of a battery case 31 and a lid body 32 in a state where each electrode body 2 is isolated. At this time, the electrode body 2 is joined to the positive electrode terminal 5 and the negative electrode terminal 6. Further, in the battery case 3, a diamond-like carbon film 4 is integrally formed on the entire outer peripheral surface.
[0058]
The electrode body 2 is a flat type formed into a flat shape by winding a positive electrode sheet and a negative electrode sheet so as to have a substantially circular cross section through a separator, and then performing compression molding. This is a spirally wound electrode body.
[0059]
The positive electrode sheet is a sheet in which a positive electrode active material layer made of lithium manganese oxide or the like is formed on both surfaces of a strip-shaped aluminum foil. The positive electrode sheet is a positive electrode active material Li_1.12Mn_1.88O_FourWas mixed with N-methyl-2-pyrrolidone as a solvent in a composition of 86 wt%, 10 wt% of conductive graphite and 4 wt% of binder PVDF, and this paste was applied to both sides of the Al foil current collector. Then, after the drying, it was rolled, cut so as to leave a marginal portion where no positive electrode active material layer was formed in the length direction, and dried by vacuum heating.
[0060]
A negative electrode sheet consists of a sheet | seat in which the negative electrode active material layer which consists of graphite etc. was formed on both surfaces of the strip | belt-shaped copper foil. The negative electrode sheet was prepared by mixing 92.5 wt% of the negative electrode active material graphite and 2.5 wt% of the binder PVDF into N-methyl-2pyrrolidone and preparing a paste in the same manner as the positive electrode sheet. The paste was applied to both sides of the Cu foil current collector, dried and then rolled, cut so as to leave a marginal portion in which the negative electrode active material layer was not formed in the length direction, and dried by vacuum heating. .
[0061]
The separator was a polyethylene microporous film formed wider than the portion where the electrode active material layer of the positive electrode sheet and the negative electrode sheet was formed.
[0062]
The electrode body 2 was wound in an opal shape with each edge portion of the positive electrode sheet and the negative electrode sheet projecting in directions opposite to each other in the axial direction of the winding shaft, and the positive electrode sheet and the negative electrode sheet were interposed via a separator. Thereafter, it was formed into a flat shape. The electrode body 2 was compression-molded at the edge portions protruding in the opposite directions in the axial length direction of the winding shaft, and a protruding end portion was formed.
[0063]
In the electrode body 2, a positive electrode terminal 5 and a negative electrode terminal 6 are joined to protruding end portions that protrude in opposite directions in the axial direction. The positive electrode terminal 5 is made of an aluminum rod-shaped member, and the negative electrode terminal 6 is made of a copper rod-shaped member. The positive electrode terminal 5 and the negative electrode terminal 6 are joined by ultrasonic welding that imparts ultrasonic vibration in a state where the abutting portions with the protruding end portions are formed smoothly and the abutting portions are in contact with the protruding end portions. .
[0064]
The battery container 3 includes a battery case 31 and 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 with an opening of a concave internal space formed on the upper surface. The lid body 32 is a member having a plate shape formed in the same shape as the shape of the upper surface of the battery case 31 and hermetically sealing the internal space of the battery case 31. A space defined by the battery case 31 and the lid 32 is a battery cell chamber 33.
[0065]
The battery case 31 is made of polypropylene and has a tank shape in which a concave space of 120 mm in length, 85 mm in width, and 82 mm in height is divided into four by a partition wall having a thickness of 2 mm in the vertical direction. Moreover, the wall part which formed the side wall surface and bottom face of the battery case part 31 was formed in thickness of 2 mm. The lid 32 was made of polypropylene having a thickness of 2 mm. Both the battery case 31 and the lid 32 were manufactured by an injection molding method.
[0066]
In the battery case 31 and the lid 32, the diamond-like carbon film 4 is integrally formed on the surface that becomes the outer peripheral surface of the battery 1. The diamond-like carbon film 4 was formed using a high-frequency plasma CVD apparatus having an electrode body having a shape corresponding to the shape of the surface of the battery case 31 and the lid 32. The diamond-like carbon film 4 is formed by a high-frequency plasma CVD apparatus using a 13.56 MHz high-frequency power source as a plasma generation power source and a C gas as a reactive gas.₂H₂Gas was used.
[0067]
The diamond-like carbon film 4 formed on the battery case 31 and the lid 32 has a Vickers hardness of 2500 kg / mm.²The film density is 2.5 g / cm^ThreeThe film thickness was approximately 1 μm.
[0068]
The positive electrode terminal 5 and the negative electrode terminal 6 joined to the electrode body 2 pass through the lid body 32 and are fixed to the lid body 32 in a state where the terminal portions 41 and 51 protrude. Here, the fixing portions of the lid 32, the positive electrode terminal 5, and the negative electrode terminal 6 are fixed in an airtight manner. At this time, the plurality of electrode bodies 2 are arranged so that the winding axes of the electrode bodies 2 are parallel and the positive and negative electrodes are alternately adjacent to each other so as to be easily connected in series electrically. .
[0069]
The battery container 3 is in a state in which the electrode body 2 is fixed to the lid body 32 via the electrode terminals 5 and 6, and the electrode body 2 is accommodated in the battery cell chamber 33 of the battery case 31 together with the electrolytic solution. In this state, the battery case 31 and the lid 32 were formed by performing heat fusion at 270 ° C.
[0070]
In the electrolyte solution, LiPF was added to a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 3: 7.₆Was used at a rate of 1 mol / liter.
[0071]
In the monoblock type battery 1 of Example 1, since the diamond-like carbon film 4 having water resistance is formed on the entire outer peripheral surface of the battery container 3, the intrusion of moisture into the battery container 3 is 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 battery that can maintain high battery performance for a long period of time as a non-aqueous electrolyte battery.
[0072]
(Example 2)
Example 2 is a monoblock battery whose cross section is shown in FIG. The battery of Example 2 is the same battery as Example 1 except that the diamond-like carbon film 4 ′ is formed on the surface of the wall portion facing the outer peripheral surface of the battery container 3 and facing the battery cell chamber. .
[0073]
In the battery of Example 2, the diamond-like carbon film 4 ′ was formed on the surface of the wall facing the outer peripheral surface of the battery container 3, facing the battery cell chamber, so that the battery container 3 was removed from the outside of the battery container 3. The amount of moisture that permeates and enters the battery cell chamber is suppressed to 1/30. For this reason, in the monoblock type battery of Example 2, the reaction between moisture and the nonaqueous electrolyte is suppressed. As a result, the monoblock type battery of Example 2 is a battery that can maintain high battery performance for a long time as a nonaqueous electrolyte battery.
[0074]
(Evaluation of diamond-like carbon coating)
As an evaluation of 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 this sample was measured.
[0075]
In addition, the measurement of the peak intensity ratio and the measurement of the number of dangling bonds by Raman spectroscopic analysis of the manufactured sample were performed by the following means.
[0076]
(Measurement of peak intensity ratio)
The Raman spectroscopic analysis was performed by using a laser probe having a wavelength of 532 nm using a Horobe Probe micro laser Raman spectroscope manufactured by Kaiser as an analyzer, and a spectrum was obtained. Thereafter, from the obtained spectrum, the intensity I of the D peak and the G peak I_DAnd I_GAnd the intensity ratio (I_D/ I_G)
[0077]
(Measurement of dangling bond spin density)
The spin density was measured under the conditions of FIELD: 323 mT / G ± 10 mT / G, SWEEP TIME: 4 min, MOD: 100 kHz × 0.79 mT, and RESPONSE: 0.03 sec. .
[0078]
(Sample 1)
A diamond-like carbon film was formed on a polyethylene terephthalate film having a thickness of 100 μm. The diamond-like carbon film was formed using a plasma CVD apparatus. A high frequency power supply of 13.56 MHz was used as a power source for generating plasma, and a film having a thickness of 1 μm was formed with an output voltage of 4 kV. Moreover, toluene gas was used as the reaction gas.
[0079]
The film formed on Sample 1 has a peak intensity ratio I_D/ I_G2.144, dangling bond spin density 6.8 × 10²⁰Piece / cm^ThreeMet.
[0080]
(Sample 2)
Sample 2 is a sample having a diamond-like carbon coating produced in the same manner as Sample 1 except that the reaction gas was methane gas.
[0081]
The film formed on Sample 2 has a peak intensity ratio I_D/ I_GIs 0.641 and the spin density of dangling bonds is 9.3 × 10²⁰Piece / cm^ThreeMet.
[0082]
In sample 2, many cracks were confirmed in the coating. This crack is the sp of carbon bonds that make up the coating.^ThreeThis is considered to be caused by the property becoming too strong and the coating becoming brittle. In the sample 2, the methane gas as the reaction gas is easily turned into a carbon atom during the film formation. For this reason, the number of carbon atoms not bonded increases, and the number of dangling bonds increases.
[0083]
(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.
[0084]
The film formed on Sample 3 has a peak intensity ratio I_D/ I_GIs 0.653 and the spin density of dangling bonds is 8.80 × 10²⁰Piece / cm^ThreeMet.
[0085]
Sample 3 has a high collision probability of carbonized atoms by increasing the output voltage during film formation. That is, an increase in the collision probability of carbon atoms during film formation leads to an increase in the bonding probability of carbonized carbon atoms and causes a decrease in the number of dangling bonds. In Sample 3, as in Sample 2, cracks were confirmed on the surface of the coating. This is presumed to be due to the fact that the reaction gas is methane gas that is easily converted into plasma. Specifically, the sp of carbon bonds constituting the coating^ThreeThis is considered to be caused by the property becoming too strong and the coating becoming brittle.
[0086]
(Sample 4)
Sample 4 was 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.
[0087]
The film formed on Sample 4 has a peak intensity ratio I_D/ I_G1.101, dangling bond spin density 3.90 × 10²⁰Piece / cm^ThreeMet.
[0088]
In Sample 4, the film formation rate is reduced by reducing the output voltage. As the deposition rate decreases, the sp^ThreeIncreases nature. As a result, the peak intensity ratio of the coating is increased.
[0089]
(Sample 5)
Sample 5 was 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.
[0090]
The film formed on Sample 5 has a peak intensity ratio I_D/ I_GIs 1.097 and the spin density of dangling bonds is 5.40 × 10²⁰Piece / cm^ThreeMet.
[0091]
In the sample 5, the film formation speed is reduced by considerably reducing the output voltage. As a result, the sp of the film after film formation^ThreeSex is increasing. That is, the peak intensity ratio of the coating is increased. In Sample 5, the spin density of the danbling bond is increased. This increase is thought to be due to the binding energy of carbon atoms being too low.
[0092]
(Sample 6)
Sample 6 was manufactured in the same manner as Sample 1 except that the output voltage when the diamond-like carbon film was formed was 3 kV and the gas pressure was 2 Pa.
[0093]
The film formed on Sample 6 has a peak intensity ratio I_D/ I_GIs 1.455 and the spin density of dangling bonds is 6.10 × 10²⁰Piece / cm^ThreeMet.
[0094]
In Sample 6, the output voltage during film formation is reduced and the gas pressure is increased. The sp of the film after film formation due to the decrease in output voltage^ThreeSex is increasing. That is, the peak intensity ratio of the coating is increased. In addition, the crack formed in the film formed in the sample 6 was not seen.
[0095]
(Sample 7)
Sample 7 was 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.
[0096]
The film formed on Sample 7 has a peak intensity ratio I_D/ I_GIs 1.432 and the spin density of dangling bonds is 4.20 × 10¹⁹Piece / cm^ThreeMet.
[0097]
Sample 7 has a film formed under conditions where the output voltage and gas pressure are reduced. By adjusting the film formation conditions at the time of film formation, film formation after the plasma-ized carbon atoms are combined in a cluster shape is suppressed. As a result, the film of the sample 7 is a film having an appropriate peak intensity ratio and a small spin density. Note that no cracks were found in the sample 7 coating.
[0098]
Table 1 shows the characteristics of the diamond-like carbon coating formed on Samples 1-7.
[0099]
[Table 1]

[0100]
(Evaluation of water permeability)
Water permeability was measured as an evaluation of samples 1-7. In addition, in order to confirm the water permeability resistance of the diamond-like carbon coating, a sample of only a polyethylene terephthalate film without a coating was used as a comparative example.
[0101]
(Water permeability)
Water permeability was made by measuring the amount of permeated water by means based on the method for measuring water vapor permeability described in JIS K 5400 8.17. In addition, the measurement of the permeation | transmission water content was performed in the state whose temperature is 60 degreeC and humidity is 95 RH%. The measurement results are shown in Table 1.
[0102]
From Table 1, the permeated water amount of the comparative example is 21.3 g / m.²・ It was 24 hours. On the other hand, all of the samples 1 to 7 having the diamond-like carbon film have a small amount of permeated water.
[0103]
Specifically, the permeated water amount of Sample 1 is 5.20 g / m.²-It became a low value compared with 24h and a comparative example. That is, it can be seen that the water permeation resistance was improved by forming the diamond-like carbon film.
[0104]
The permeated water amount of Sample 2 is 10.93 g / m²-It became a low value compared with 24h and a comparative example. That is, even a diamond-like carbon film formed using methane gas as a reaction gas can exhibit high water permeability resistance.
[0105]
The permeated water amount of Sample 3 was 8.71 g / m.²-It became a low value compared with 24h and a comparative example. Furthermore, it can be seen that the water permeation resistance is improved by reducing the spin density of the film using methane gas as the reaction gas.
[0106]
The permeated water amount of Sample 4 is 0.46 g / m.²-It was a considerably low value compared with 24h and a comparative example. Furthermore, it can be seen that the water permeation resistance is greatly improved by reducing the peak intensity ratio and spin density of the coating film using toluene gas as the reaction gas.
[0107]
Sample 5 has a permeated water content of 0.67 g / m.²-It was a considerably low value compared with 24h and a comparative example. Furthermore, it is understood that the water permeation resistance is improved by reducing the peak intensity ratio of the coating film using toluene gas as the reaction gas.
[0108]
The permeated water amount of Sample 6 is 0.53 g / m.²-It was a considerably low value compared with 24h and a comparative example. Furthermore, it can be seen that by significantly reducing the peak intensity ratio of the film using toluene gas as the reaction gas, the water permeation resistance is significantly improved even when the spin density is slightly increased.
[0109]
Sample 7 has a permeated water content of 0.26 g / m.²-It was a considerably low value compared with 24h and a comparative example. Furthermore, it can be seen that the water permeation resistance is considerably improved by greatly reducing the peak intensity ratio and spin density of the coating film using toluene gas as the reaction gas.
[0110]
As is apparent from the above, the amount of permeated water can be reduced by forming a diamond-like carbon film. That is, water permeability resistance can be improved.
[0111]
【The invention's effect】
In the battery according to the present invention, the water-permeable layer prevents moisture from passing through the resin battery container. As a result, the battery of the present invention is a battery in which deterioration of battery performance caused by moisture permeating through the resin battery container is suppressed.
[Brief description of the drawings]
1 is a diagram showing a monoblock battery of Example 1. FIG.
2 is a view showing a cross section of the monoblock battery of Example 1. FIG.
3 is a view showing an electrode body of a monoblock type battery of Example 1. FIG.
4 is a view showing a cross section of a monoblock type battery of Example 2. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Monoblock type battery 2 ... Electrode body 3 ... Battery container
31 ... Battery case 32 ... Lid 33 ... Battery cell room
4, 4 '... Diamond-like carbon film
5 ... Positive terminal 6 ... Negative terminal

Claims (12)

In 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 enclosed together with an electrolyte solution,
The battery container, have a penetration resistance water layer formed on the battery container and integrally made of diamond-like carbon, 1560 cm peak intensity in the vicinity of ^-1 I _G and 1370cm around ^-1 in Raman spectroscopic analysis of the diamond-like carbon cell ratio I _D / I _G of the peak intensity I _D of characterized a near Rukoto the range of 1.0 to 1.5.   The battery according to claim 1, wherein the water-resistant layer is formed on a wall portion of the battery container that forms an outer peripheral surface of the battery and forms the battery cell chamber.   The battery according to claim 2, wherein the water-permeable layer is a film formed on a surface forming the battery cell chamber.   The battery according to claim 2, wherein the water-permeable layer is a film formed on a surface forming an outer peripheral surface of the battery. The battery according to claim 1, wherein the diamond-like carbon has SP ³ -bonded amorphous carbon.   The diamond-like carbon has at least one element selected from Si, B, N, Ti, Zr, Hf, W, F, H, O, V, Cr, Nb, Mo, and Ta. battery. The battery according to claim 1, wherein the water-permeable layer has a density of 1.5 g / cm ³ or more. The battery according to claim 1, wherein the water-permeable layer has a Vickers hardness of 650 kg / mm ² or more.   The battery according to claim 1, wherein the water-permeable layer has a thickness of 10 nm or more.   The battery according to claim 1, wherein the resin forming the battery container is polyolefin, polyester, polyether, or a polymer alloy thereof. 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. The battery according to claim 1, which is a nonaqueous electrolyte battery.

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