JP2002313353A - Battery leakage sensing sheet and battery with leakage sensing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sense battery leakage simply and certainly. SOLUTION: A sheet 30 according to the invention is to sense the battery leakage upon being affixed to the surface of any battery in which a battery material likely to leak is encapsulated, and is equipped with a base material 36 consisting of a solution absorptive material and a solution absorption sensing part 34 attached to the surface of the base material and changing in its appearance with absorption of the solution. The solution having leaked eventually is absorbed by the base material 36, and the appearance of the sensing part 34 changes to allow knowing the battery leakage simply and certainly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery leakage detection sheet and a battery with a liquid leakage detection function, and more particularly, to a battery material provided in various batteries and the battery material sealed in the battery has leaked out of the container. It is intended for a liquid leakage detection sheet that sometimes detects such a case and a battery provided with such a liquid leakage detection sheet and provided with a liquid leakage detection function.

[0002]

2. Description of the Related Art In a general structure of a battery, a metal container is sealed with an electrode material and an electrolytic solution contained in the metal container. The outer surface of the metal container functions as one electrode, and the metal terminal serving as the other electrode is insulated from the metal container, with one end exposed to the outside and the other end connected to the internal electrode material. Be placed. There is a difference in the type or name of the battery depending on the difference in the materials and arrangement of the electrodes and the electrolyte. Batteries are broadly divided into secondary batteries for charging and primary batteries that are not charged. recent years,
A lithium-ion battery is a secondary battery that is widely used as a power source for portable devices and the like.

[0003] The electrolytic solution is contained in a container in a liquid state having a high fluidity, is in a jelly state, or is impregnated in paper or the like. In either case, the electrolyte may leak out of the container. The leakage of the electrolyte has a bad influence on the device containing the battery, and has a bad influence on the environment and the user. Even with a battery designed to have a strictly sealed structure, a small number of defective products that cause liquid leakage occur in the manufacturing process. Even if there is no problem immediately after production, liquid leakage may occur due to subsequent handling conditions or changes over time. Conventionally, in the battery manufacturing process,
An operator visually observes the surface of the battery and the seam of the container member,
It was inspected for the occurrence of liquid leakage. In some cases, a dedicated inspection device is used, such as capturing an image of the surface of a battery and detecting liquid leakage by image processing. JP 2000-26888
Patent Document 4 discloses a technique in which a whole or a part of a battery container is formed of a laminate having a sensor function of changing the conductivity when a liquid leak occurs. By connecting a detection circuit to the laminate, a warning lamp or warning buzzer notifies the operator of liquid leakage.

[0004]

Among the above-mentioned conventional techniques for detecting a liquid leak, it is difficult to visually detect a small amount of a liquid leak generated at a joint of a container material by visual observation. If a very skilled worker does not perform the inspection over time, there is a concern that the leak may be overlooked. If the above-described special inspection device is used, it may be possible to detect liquid leakage with sufficient accuracy. However, this requires a large amount of equipment and work steps, and is economically burdensome. Further, for example, it is not practical to completely inspect a large number of battery products flowing through a production line because productivity is greatly impaired.

Therefore, an object of the present invention is to simply and reliably detect the above-mentioned battery leakage.

[0006]

A battery leakage detection sheet according to the present invention is a sheet that is disposed on a surface of a battery in which a leaky battery material is sealed and detects battery leakage. A liquid-absorbing base material made of a liquid-absorbing material, and a liquid-absorbing detecting unit that is arranged on the surface of the liquid-absorbing substrate and changes its appearance by liquid absorption. [Battery] Applicable to various batteries that may leak. As a general classification of batteries, there are secondary batteries that can be repeatedly charged and discharged, and primary batteries that are not normally charged, and can be applied to any of the batteries.

There are various types of batteries depending on the materials of the electrodes and the electrolyte constituting the battery, and specific examples of the secondary battery include a lithium ion battery, a nickel hydride battery, a nickel cadmium battery, and a polymer battery.
Examples of the primary battery include a manganese dry battery, an alkaline battery, a lithium battery, and a mercury battery. The basic structure of a battery includes positive and negative electrode materials, electrolyte materials, and a container. One of the electrodes can also be used as the metal part of the container. The electrolyte material is usually a liquid and is called an electrolyte. The electrolyte may be used as a normal liquid, or may be prepared in a jelly state or impregnated with a fibrous material such as paper or nonwoven fabric or a porous material. The electrolyte may contain additives such as a solvent, a viscosity modifier, and a stabilizer in addition to the electrolyte material. In the present invention, leaky materials sealed in a battery, such as an electrolytic solution containing an electrolyte material, are collectively referred to as a leaky battery material or a leaky battery material.

[0008] The leaky battery material may include a volatile material. Some materials are corrosive. There are colored and transparent materials. [Container] The container material and structure of a normal battery are employed. Materials for the container include corrosion-resistant metals such as aluminum and iron, synthetic resins, glass, ceramics, and paper. It may be a composite of a plurality of materials. The container has a container body provided with an opening for accommodating an electrolytic solution and an electrode material, and a lid member closing the opening of the container body. The container body and the lid member may constitute a part of the electrode structure. A container is usually assembled from two members, a container body and a lid member,
In some cases, the container body or the lid member may be further composed of a plurality of members.

The electrode terminals are partially exposed outside the battery and are connected to an external circuit. The electrode terminal can be used also as a container body or a lid member, or an electrode terminal formed of a separate component may be incorporated in the container body or the lid member. In some cases, an insulating material that electrically insulates the electrode terminal from surrounding members may be provided. The joints between the members constituting the battery, such as the container and the electrode terminals, are sealed with a gasket, packing, adhesive, welding, or other means. [Liquid Absorbing Substrate] This is the basic structure of the liquid leakage detection sheet. It is composed of a liquid absorbing material. The liquid absorbing property means the absorbing property to the above-mentioned leaky battery material. When the leaky battery material is an aqueous liquid, it means water absorption.

[0010] Examples of the liquid absorbing material include paper, cloth, nonwoven fabric, porous resin sheet, and coating film. A composite of these multiple materials may be used. A material having excellent absorption and diffusion properties in which the absorbed leaky battery material spreads quickly is preferable. For example, a blotter material can be used. When the liquid-absorbing detection section is formed of a liquid-absorbing soluble printing pattern, a material having good printability of the liquid-absorbing printing ink is preferable. As long as the mechanical strength and durability of the liquid-absorbing base material are sufficient, the thinner the liquid-absorbing base material, the faster the leaked substance reaches the liquid-absorbing detecting portion, and the outer shape of the battery is hardly increased. Normal,
It can be set in the range of 0.1 to 1.0 mm.

The liquid-absorbing base material has a liquid-absorbing property in a portion other than the liquid-absorbing substrate, as long as the path from the portion in contact with the leaked substance from the battery to the liquid-absorbing detecting portion has the liquid-absorbing property. There may be some parts. It is preferable that the color of the liquid-absorbent substrate is set so that the appearance change at the time of liquid absorption in the liquid-absorbing detection section becomes clear. If the color is clearly different from the color of the substance that leaks from the battery and is absorbed by the liquid-absorbent substrate, liquid leakage can be detected quickly and clearly. In this case, the liquid-absorbing substrate itself also functions as a liquid-absorbing detection unit. A transparent liquid-absorbing substrate can also be used.

As long as the material of the liquid-absorbing base material can absorb and hold the leaked substance from the battery, even if a large amount of the leaked substance is generated, the material is held inside the liquid-absorbing base material and the battery can be used. It can be prevented from spreading to peripheral devices or soiling the hands of workers. For this purpose, for example, a highly absorbent paper can be used, or a highly absorbent substance such as a water absorbent polymer can be supported on a liquid absorbent substrate. [Liquid-absorbing detection unit] If it is disposed on the surface of the liquid-absorbing substrate and has a function of changing its appearance by liquid absorption of the liquid-absorbing substrate, various chemical or physical actions, Those that cause a change in appearance due to a mechanical action are used.

The change in appearance includes a change in color, a change in shape, the occurrence of swelling and unevenness, and the like. Needless to say, a plurality of elements such as both color and shape can be changed. It is preferable that the change in appearance is large enough to be visually observed, but the change in appearance may be such that it can be detected by a measuring device such as an image inspection or a sensor. For example, if the leaking battery material is a clear colored material and the liquid-absorbing base material is colorless, that is, a white material, the liquid-absorbing base material that has absorbed the leaking battery material is clearly different from the surrounding parts. Since a difference in color occurs, the liquid-absorbing substrate itself can be used as a liquid-absorbing detecting section.

The liquid absorption detecting section may be disposed uniformly over the entire surface of the liquid leakage detecting sheet, or may be disposed only at a portion necessary for detecting liquid leakage. For example, since the leaked substance permeates into the liquid-absorbent substrate from the peripheral portion of the liquid-leakage detection sheet, it is effective to arrange the liquid-absorbing detection portion near the peripheral edge of the liquid-absorbent substrate. If the appearance change of the liquid absorption detector is irreversible, the change in appearance does not return to its original state even after the leaked liquid evaporates or solidifies, the occurrence of liquid leakage can be reliably recorded. it can. <Liquid Absorbing Ink> A printing pattern using a liquid absorbing ink can be used as the liquid absorbing detecting section. The liquid-absorbing soluble ink can be printed on a liquid-absorbing substrate in the same manner as ordinary ink, and dissolves when it absorbs liquid after printing, causing bleeding or collapse of the external shape, The printed pattern changes in appearance due to penetration and diffusion. It may cause a change in color. Specifically, various printing inks can be used.

The printing pattern of the liquid-soluble ink can cause a large change in appearance that can be clearly confirmed visually when the liquid is absorbed. A liquid leak can be detected even by an unskilled person or a consumer of the inspection work. As a printing pattern of the ink having a liquid absorption solubility, a relatively simple set of lines and points, as well as symbols, characters, abstract figures, shapes of concrete objects, and the like can be adopted. The print pattern can also serve as display of product information such as product type and product number. The thickness of the print pattern only needs to be able to hold ink enough to cause a sufficient change in appearance when liquid is absorbed. If the print pattern is too thick, the thickness of the entire liquid leakage detection sheet increases.

By using a plurality of colors of the liquid-absorbing soluble ink, a change in appearance is produced by combining a plurality of colors and shapes.
Liquid leak determination can also be facilitated. The liquid-absorbing soluble ink may be applied uniformly over the entire surface of the base material so that the liquid absorption causes a change in appearance such as discoloration. [Transparent insulating material layer] The surface of the liquid absorption detecting portion can be covered with a transparent insulating material layer. The transparent insulating material layer can fulfill the mechanical protection of the liquid absorption detecting section and the insulating function in the battery structure. By increasing the electrical insulation of the surface of the liquid leakage detection sheet, the surface insulation of the battery structure on which the liquid leakage detection sheet is disposed is increased. If a liquid leakage detection sheet is arranged between the container that becomes one electrode of the battery and the electrode terminal that becomes the other electrode, the insulation between the two electrodes can be improved.

As the transparent insulating material layer, various kinds of transparent insulating materials used in the ordinary electric technology field can be used as long as the visibility of the change in the appearance of the liquid absorption detecting portion at the time of liquid absorption is not impaired. If the above function is not impaired, it may be translucent or partially opaque. PET, PPE, PP as the material of the transparent insulating material layer
Synthetic resin films such as S, PMMA, PVC, PE, PP, etc., sheets or coating agents can be used. The thickness of the transparent insulating material layer is set so that desired functions such as insulating properties and protective properties can be sufficiently exhibited.

The transparent insulating material layer can be laminated and integrated on the surface of the liquid-absorbing substrate or the liquid-absorbing detecting portion by means such as an adhesive or thermal bonding. [Adhesive layer] It can be used when attaching a liquid leakage detection sheet to a battery. The liquid leakage detection sheet having the pressure-sensitive adhesive layer on the back surface of the liquid-absorbent substrate can be fixed by sticking to the surface of the battery. As the material of the pressure-sensitive adhesive layer, the same material as that of a normal pressure-sensitive adhesive sheet material or an adhesive sheet can be used. An electrically insulating material can be used. If the material has a liquid absorbing property, the leaked substance can be promptly transferred from the surface of the battery to the liquid absorbing substrate and the liquid absorbing detection part through the adhesive layer. A double-sided pressure-sensitive adhesive sheet coated with a pressure-sensitive adhesive can also be used as the pressure-sensitive adhesive layer.

The thickness of the pressure-sensitive adhesive layer only needs to be able to exert a sufficient bonding force. The pressure-sensitive adhesive layer may be provided on the entire back surface of the liquid-absorbent substrate, or may be provided partially. If the pressure-sensitive adhesive layer is partially provided, in the portion without the pressure-sensitive adhesive layer, the back surface of the liquid-absorptive base material will be disposed directly adjacent to the battery surface, absorbing the leaked substance, Can quickly detect a liquid leak in the liquid absorption detecting section. As the arrangement of the pressure-sensitive adhesive layer, a large number of dot-like or linear patterns can be arranged at intervals. A lattice shape or a spiral shape can also be adopted. The pressure-sensitive adhesive layer may be disposed inside the periphery of the liquid-absorbent substrate, and an exposed portion of the back surface may be provided on the periphery of the liquid-absorbent substrate. If the back surface is exposed at the periphery of the liquid-absorbent base material, the leaked substance leaking from the joint of the battery member or the like is efficiently discharged from the periphery of the liquid-absorbent base material arranged adjacent to the joint. Liquid is absorbed.

If a release sheet is temporarily attached to the exposed surface of the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer can be protected until use. When used, the release sheet may be peeled off. [Liquid Leak Detection Sheet] It can be constructed by laminating the above-mentioned layers. The overall thickness of the liquid leakage detection sheet should be as thin as possible, as long as the intended function can be achieved, so that the liquid leakage detection sheet does not protrude or protrude from the outer shape of the battery. Usually 0.1 ~
It can be set to a range of 1.0 mm. The shape of the liquid leakage detection sheet is set in accordance with the arrangement structure of the location where liquid leakage is to be detected in the outer shape of the battery. Usually, it is preferable that the peripheral edge of the liquid leakage detection sheet is disposed adjacent to a joint between a plurality of members constituting the outer shape of the battery. Even if the seam is covered with the liquid leakage detection sheet, it is only necessary that the material leaking from the seam can be transferred from the liquid-absorbing base material to the liquid-absorbing detection section.

Further, the liquid leakage detection sheet is arranged at a position where workers and consumers can visually recognize the battery when inspecting and using the battery. The places where the liquid leakage easily occurs and the inspection is easily performed include the periphery of the electrode terminal protruding from the outer shape of the battery and the surface of the lid. The liquid leakage detection sheet can be disposed on the entire surface of the lid member, and the peripheral edge of the liquid leakage detection sheet can be disposed at the joint between the container body and the lid member and the joint between the lid member and the electrode terminal. The liquid leakage detection sheet may be arranged at a plurality of locations on the battery. If the liquid leak detection sheet is stuck on the outer surface of the battery,
Liquid leakage from the battery can be detected quickly. The liquid leak detection sheet can be attached using not only various adhesives and pressure-sensitive adhesives but also a fastener such as a stapler or a pin. Mechanical fixing such as fitting or engagement can also be employed. The liquid leakage detection sheet may be covered with a transparent glass or resin plate, and the covered transparent plate may be fixed to the battery. If the pressure-sensitive adhesive layer is provided on the liquid leakage detection sheet, the mounting operation is easy.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in FIG. 1 is a case where a rectangular lithium ion secondary battery is provided with a liquid leakage detecting function. [Basic Structure of Battery] Battery B has a battery case 10 having a thin rectangular parallelepiped shape. The outer structure of the battery container 10 is composed of a box-shaped container body 12 formed by press-molding an aluminum plate or the like, and a metal lid plate 14 that closes an upper surface opening of the container body 12. An electrode terminal 16 is arranged at the center of the cover plate 14. Between the electrode terminal 16 and the cover plate 14, there is provided an insulating separator 18 made of an insulating resin or the like.

The lower end of the electrode terminal 16 is electrically connected to the battery function section 20 inside the battery container 10. The battery function unit 20 is made of a laminate of a sheet-like electrode material, a separator, and an insulating material, and is impregnated with an electrolytic solution,
The battery function unit 20 may be immersed in the electrolyte stored in the container body 12. The electrolyte is usually an aqueous solution or dispersion, but may contain an organic solvent. The electrolytic solution is in a state of being colored with the color of the compounding component. One end of the battery function unit 20 is connected to the electrode terminal 16, and the other end is connected to the container body 12. As a result, by connecting the electrode terminal 16 and the container body 12 to an external circuit on the outer surface of the battery B, electricity can be taken out or charged.

[Liquid Leak Detection Sheet] A liquid leak detection sheet 30 is attached to the outer surface of the cover 14 of the battery B. As shown in FIG. 1 (b), the liquid leakage detection sheet 30
It has a rectangular ring shape that fills the space between the inner periphery of the upper edge of the container body 12 and the outer periphery of the electrode terminal 16. Liquid leak detection sheet 30
Is disposed adjacent to a joint between the container body 12 and the lid 14, and an inner peripheral edge of the liquid leakage detection sheet 30 is disposed at a joint between the electrode terminal 16 and the insulating separator 18. The joint between 18 and the lid 14 is covered with a liquid leakage detection sheet 30. As shown in FIGS. 1A and 2, the liquid leakage detection sheet 30 includes a pressure-sensitive adhesive layer 38, a liquid-absorptive base material 36, and a liquid-absorptive print pattern 34 from the side adjacent to the surface of the lid 14. , An adhesive layer 33 and a transparent insulating material layer 32.

The liquid-absorbing substrate 36 is made of water-absorbing paper. The liquid-absorptive printing pattern 34 is printed with a normal liquid-absorptive printing ink. The transparent insulating material layer 32 is made of PE
It consists of a T film. Adhesive layer 33 and pressure-sensitive adhesive layer 38
Is made of a usual adhesive and pressure-sensitive adhesive for paper and resin materials. As shown in FIG. 1 (b), the pattern shape of the liquid-absorbing soluble print pattern 34 is a vertical and horizontal grid line. In the figure, the hatched portions are the locations where the printing ink is present. As shown in FIG. 2, in the liquid leakage detection sheet 30, the pressure-sensitive adhesive layer 38 is applied to the entire back surface of the liquid-absorbent substrate 36, but the inner and outer peripheral edges are 3
6 are directly exposed to the outside. In the use state of FIG. 1A, the exposed portions of the inner and outer peripheral edges of the liquid-absorbent substrate 36 are arranged adjacent to the joints between the members 12 to 18 constituting the battery container 10.

[Liquid Leak Detection Function] In the battery B having the above-described structure, in the manufacturing process, the filling of the battery functional portion 20 and the electrolytic solution into the container main body 12 is completed, and the opening of the container main body 12 is connected to the electrode terminal. After completing the basic structure of the battery B by closing with the lid 14 having the
A liquid leak detection sheet 30 is attached to the surface of the liquid. Thereafter, before the battery B is shipped, various functional tests such as a charge / discharge test and an environmental test are performed, and a pre-shipment inspection is performed. During the handling during this time, the electrolyte or the like may leak from the inside of the battery B. In particular, in the charge / discharge test, since the internal pressure of the battery B greatly fluctuates, when the sealing property of the battery container 10 is lowered or there is a local defect, the liquid leaks from the joint between the members. Easy to occur.

The substance leaked from the battery container 10 is absorbed by the liquid-absorbent substrate 36 of the liquid-leakage detection sheet 30 and spreads inside the liquid-absorbent substrate 36. When the leaked substance spread inside the liquid-absorbent base material 36 comes into contact with the liquid-absorbable print pattern 34, the liquid-absorbable print pattern 34 is dissolved, and the contour of the pattern shape is broken or the liquid-absorbable solubility is reduced. The printing ink dissolves in the liquid-absorbent substrate 36 and spreads. By visually observing such a change in the appearance of the liquid-absorbing soluble printed pattern 34, it is possible to quickly and reliably detect the occurrence of liquid leakage of the battery B. The change in the appearance of the liquid-absorbent printed pattern 34 can be varied over a wide range due to the amount and spread of the leaked substance absorbed by the liquid-absorbent substrate 36 and the diffusion of the liquid-absorbable printed pattern 34 itself. Since it clearly appears due to collapse or bleeding, it is possible to easily determine the presence or absence of liquid leakage without requiring much skill.

Before the shipment, the battery B in which the liquid leakage was found,
They are discarded or sent for regeneration. The battery B confirmed to have no liquid leakage is shipped. Even if a liquid leak occurs during distribution and storage after shipment, the liquid leak can be quickly and surely found only by observing the liquid leak detection sheet 30. Even if the worker in the distribution process is not skilled in the liquid leakage inspection, the appearance change of the liquid-absorbing soluble printed pattern 34 can be easily confirmed. Furthermore, liquid leaks that occur while the battery B is being sold to consumers and used can be easily performed by general consumers with little technical knowledge by opening the battery compartment of the equipment used regularly. Leaks can be found.

[Specific Example of Liquid Leak Detection Sheet] Specific specifications of the liquid leakage detection sheet will be described. Outline: rectangular shape of 29 mm x 4 mm. 8.2mm x in the center
3 mm rectangular hole. The total thickness when used is 0.308 mm. Transparent insulating material layer: PET resin sheet (Toray). The thickness is 0.188 mm. Liquid-absorbing soluble printing pattern: Printing with printing ink (manufactured by Toyo Ink Co., Ltd., paint ink "Red").

FIG. 1B shows a lattice pattern. Liquid-absorbing substrate: An acrylic solvent-based pressure-sensitive adhesive layer was formed on a hygroscopic polyacrylic resin sheet (commercially available). The liquid leakage detection sheet manufactured according to the above specification was stuck on the upper surface of a battery (square lithium ion battery) in which the battery container was completely sealed in the manufacturing process. It was verified whether liquid leakage could be detected in the subsequent manufacturing and testing processes. A defective product that causes liquid leakage was prepared in advance and subjected to a test together with a non-defective product. In the case of a defective product, the liquid-absorbent printing pattern of the liquid leakage detection sheet bleeds and a wide area was colored with printing ink. In this state, the liquid leak was clearly visible.

[Exposed part of liquid-absorbent base material back surface] The liquid leakage detection sheet 30 shown in FIG. Part is provided. As shown in FIG. 3 (b), the adhesive layer 38 is not provided for a certain width of the outer peripheral edge and the inner peripheral edge of the back surface of the liquid-absorbent substrate 36, and the back surface of the liquid-absorbent substrate 36 is directly contacted. It is exposed 37. As shown in FIG.
A rectangular frame-shaped exposed portion 37 is provided on each of the inner and outer peripheries of 6. As shown in FIG. 3 (b), the liquid-absorptive soluble print pattern 34 includes a plurality of dotted line patterns arranged in parallel.

The liquid leakage detection sheet 30 having such a structure
Is attached to the battery B in FIG. Liquid-absorbent substrate 3
6 is covered with the adhesive layer 38, so that the operation of attaching the liquid leakage detection sheet 30 to the lid 14 can be performed without any trouble. There is no fear that the liquid leakage detection sheet 30 will be peeled off during the handling of the battery B. When a liquid leak occurs in the battery container 10, the leaked substance spreads along the surface of the battery container 10 and contacts the back surface exposed portion 37 of the liquid-absorbent substrate 36,
Immediately absorbed. The absorbed leaked substance comes into contact with the liquid-absorbing soluble printing pattern 34 and the liquid-absorbing soluble printing pattern 3
As described above, the appearance change of 4 is caused and the liquid leakage is detected.

In the above embodiment, the liquid is quickly absorbed not only from the end face of the liquid-absorbent base material 36 but also from the back surface exposed portion 37, so that even if a relatively small amount of liquid leakage occurs, quick and reliable liquid leakage occurs. Liquid leaks can be found.

[0034]

According to the battery leakage detecting sheet of the present invention, if the battery leakage detecting sheet is disposed adjacent to the joint of the members constituting the battery container, the battery material leaking to the outside from the joint of the container member will not leak. It is absorbed by the liquid-absorbent substrate of the detection sheet and rapidly spreads inside the liquid-absorbent substrate. The leaked substance that has been absorbed and spread by the liquid-absorbing substrate acts on the liquid-absorbing detection section, and causes a visible change in appearance over a wide range. As a result, the leakage of the battery material can be easily and reliably detected without using a high-precision detection device or requiring a skilled operator to take a long time to perform the inspection.

Since only the thin liquid leakage detection sheet is provided on the outer surface of the battery, the outer shape and weight of the battery do not increase, and the function of the battery itself is not affected at all. There is no significant increase in battery manufacturing costs. The battery provided with the liquid leakage detection sheet can detect the occurrence of the liquid leakage in the distribution sales and the use environment of the purchaser, in addition to the detection of the liquid leakage in the battery manufacturing process or the inspection after completion.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a battery representing an embodiment of the present invention.
(a) and top view (b)

FIG. 2 is a partially enlarged sectional view of a liquid leakage detection sheet.

FIG. 3 is a plan view (a) and a partially enlarged cross-sectional view (b) of a liquid leakage detection sheet showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Battery container 12 Container main body 14 Lid 16 Electrode terminal 18 Insulation separating material 20 Battery functional part 30 Liquid leak detection sheet 32 Transparent insulating material layer 33 Adhesive layer 34 Liquid-absorbing soluble printing pattern 36 Liquid-absorbing base material 38 Adhesive Layer B Battery

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H025 AA00 BB12 MM03 5H030 AA06 FF51 FF66 FF67 FF69

Claims (10)

[Claims] Claims: 1. A sheet for detecting liquid leakage of a battery disposed on a surface of a battery in which a leaky battery material is sealed, comprising: a base made of a liquid absorbing material; and a sheet disposed on the surface of the base. A liquid leakage detection sheet for a battery, comprising: a liquid absorption detection section whose appearance changes due to liquid absorption. 2. The liquid-absorbent substrate is selected from the group consisting of paper, cloth, nonwoven fabric, porous resin sheet, and coating film.
The battery leakage detection sheet according to claim 2, comprising a seed layer. 3. The battery leakage detection sheet according to claim 1, wherein the liquid absorption detection section has a print pattern made of a liquid absorption soluble ink. 4. The battery leakage detection sheet according to claim 1, further comprising a transparent insulating material layer covering a surface of the liquid absorption detection section. 5. The transparent insulating material layer is made of PET, PPE, P
The liquid leakage detection sheet for a battery according to any one of claims 1 to 4, comprising a resin layer selected from the group consisting of PS, PMMA, PVC, PE, and PP. 6. The liquid leakage detecting sheet for a battery according to claim 1, further comprising an adhesive layer on the back surface of the liquid absorbing substrate. 7. The liquid for a battery according to claim 6, wherein the pressure-sensitive adhesive layer is disposed inside the periphery of the liquid-absorbent substrate, and has an exposed portion on the back surface at the periphery of the liquid-absorbent substrate. Leak detection sheet. 8. A battery in which a leaky battery material is sealed in a container assembled from a plurality of members, wherein the surface of the container is adjacent to a joint between the plurality of members constituting the container. A battery with a liquid leakage detection function, wherein the liquid leakage detection sheet according to any one of claims 1 to 7 is arranged so that the liquid absorption detection unit can be visually recognized. 9. The container according to claim 1, wherein the container contains the battery material and has an opening on one side, and a lid member for closing the opening of the container body.
An electrode terminal disposed so as to penetrate the lid member, wherein the liquid leakage detection sheet is disposed on a surface of the lid member, and a peripheral edge of the liquid leakage detection sheet has a joint between the container body and the lid member and a lid. 9. The battery according to claim 8, wherein the battery is provided at a joint between the material and the electrode terminal. 10. The leaking battery material enclosed in the container is colored, the liquid-absorbing base material is colorless, and the liquid-absorbing detection unit absorbs the colored battery material. The battery with a liquid leakage detection function according to claim 9, wherein the colorless liquid-absorbing substrate is colored.