JP2002216721A - Countermeasure structure for leakage of liquid from battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a countermeasure structure for the leakage of liquid in which an electrolyte leaked out is not diffused, contaminations are not generated and the influence is not imparted to an electric circuit when the liquid is leakage from the battery in a device using the battery. SOLUTION: A liquid reservoir structure 3 is formed at a position facing a sealing part 1a of a battery 1 in a pack case 2. The liquid reservoir structure 3 is preferably constituted by providing straight grooves in parallel in a direction crossing to a direction of an electric circuit part to which an influence of the electrolyte leaked out should by not be imparted. When the liquid is leaked from the battery 1, the electrolytic solution is retained such that the electrolytic solution leaked out is not diffused to other portions by a capillary phenomenon of the groove and a surface tension of a recessed part. Since the liquid flows to a direction of the groove even when the liquid leaked is much, it is prevented that the electrolytic solution flows into the electric circuit part or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing leakage of an electrolyte from a battery when the electrolyte leaks from the battery, and a structure for preventing the leakage of the electrolyte from the battery.

[0002]

2. Description of the Related Art Although the leakage resistance of batteries has been improved, leakage may occur due to reverse loading of batteries or malfunction of equipment. Leakage of the electrolyte may not only contaminate the device, but also cause skin damage and failure of the device circuit due to the strong alkaline solution. To prevent damage caused by this liquid leakage, a battery pack containing batteries in a pack case,
BACKGROUND ART In a battery device such as a device using a battery in which a battery is loaded in a battery storage chamber of a device using a battery as a power supply, a structure for preventing leakage of electrolyte from the battery is provided.

[0003] The structure for preventing leakage is configured as a liquid reservoir that stops at a predetermined location so that the leaked electrolyte does not diffuse, and an arrangement of a liquid absorbing material that absorbs the leaked electrolyte.
Since the liquid leakage occurs from the sealed portion of the battery, as shown in FIG. 6, a structure in which a liquid reservoir rib 13 is provided at a predetermined position on the sealed portion side of the battery 1 in a case 12 for housing the battery 1 to form a liquid reservoir. It has been known. Further, a structure in which a liquid absorbing sheet 14 for absorbing an electrolytic solution is arranged on the sealing portion side of the battery 1 is also widely adopted.

[0004]

However, the structure for preventing liquid leakage by the liquid reservoir is effective only when the concave portion serving as the liquid reservoir is directed downward, and when the direction changes like a portable device. The effect of preventing the effect of liquid leakage cannot be expected. In addition, there is a problem that the space of the battery housing part increases.

In addition, the structure for preventing liquid leakage by arranging the liquid absorbing material has a problem that the number of steps for arranging the liquid absorbing material at a predetermined position increases and the number of parts increases, which leads to an increase in cost. Further, in a battery pack which is required to be reduced in size and weight, there is a problem that the reduction in size is impaired because a space for disposing the liquid absorbing material is provided, which leads to an increase in weight.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure for preventing liquid leakage from a battery in which a liquid storage structure is formed in a case for accommodating the battery without increasing the space to prevent the influence of the liquid leakage. is there.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a battery for leaking liquid from a battery contained in a case to stop the leak at a predetermined position. A countermeasure structure, characterized in that a liquid reservoir structure in which minute width grooves are arranged in a predetermined portion in the case is formed, and when leakage occurs from the battery, the leaked electrolytic solution is formed. The liquid falls into the liquid reservoir structure in which the micro-width grooves are arranged, and the micro-width grooves are arranged, so that the liquid is stored without flowing out to other parts due to capillary action or surface tension of the grooves, The effect of the leak is prevented from affecting the others.

In the above structure, the groove having a very small width has a width of 0.1 mm.
It is suitable to store the leaked electrolyte solution to have a depth of 15 to 1.5 mm and a depth of 0.2 to 1.0 mm, preferably 0.3 to 0.5 mm in width and 0.4 to 0.4 in depth. By setting the thickness to 0.8 mm, a storage effect adapted to the viscosity of the electrolytic solution can be obtained.

The liquid reservoir structure is preferably formed in a groove having a width and a depth for storing the liquid in the groove by capillary action or surface tension. It can be held so that it does not flow out to an electric circuit portion or the like.

Further, if the micro-width groove is formed in a direction intersecting a predetermined direction in the case, even when the amount of the leaked electrolytic solution increases and flows in the groove, the flow is kept in the groove. In the forming direction, it does not flow in the direction of a predetermined component. The predetermined component is an electric circuit component, and prevents the liquid from affecting the electric circuit.

In addition, if a liquid reservoir structure is provided around the sealed portion of the battery, it is possible to prevent the effect of retaining the electrolytic solution from affecting the electric circuit and the like regardless of the direction of the liquid leakage. This is also effective when the installation angle of the device is not constant as in the case of, for example, FIG.

Further, by forming the grooves having a very small width so that grooves in different directions intersect with each other, the storage amount per unit area can be increased.

Further, the groove having a very small width can be formed by connecting a large number of liquid-recessed concave portions of any shape in the vertical and horizontal directions by the grooves. A liquid reservoir structure having a volume can be configured.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiment described below is an example embodying the present invention, and does not limit the technical scope of the present invention.

In this embodiment, a battery pack in which a secondary battery and a circuit board having a battery protection circuit for protecting the secondary battery from overcharge and overdischarge is housed in a pack case is provided with a structure for preventing liquid leakage. Although an example in which the battery is provided is shown, a portable device or the like using a battery as a power source can be similarly configured in the battery storage room.

FIG. 1 is a plan view showing components of a battery pack arranged in a pack case 2, in which a secondary battery 1, a circuit board 4 and a connector 5 are arranged, and are not shown. However, wiring is connected between each of the secondary batteries 1, the circuit board 4, and the connector 5. On the inner surface of the pack case 2, a liquid reservoir structure 3 is formed at a portion facing the sealing portion 1a of each secondary battery 1. In a specific example of the structure of the pack case 2, as shown in FIG. 2, the liquid storage structure 3 is formed in a required range on the bottom surface of the pack case 2 facing the sealing portion 1 a of the secondary battery 1.

As shown in FIG. 3, the liquid reservoir structure 3 has a straight groove 8 in a direction orthogonal to the direction of the circuit board 4 (see FIG. 1).
Are formed in a row. The linear grooves 8 are formed at a groove forming angle θ = 90 degrees and a depth h = 0.5 mm, and are formed in a row so as to be adjacent to each other. When the linear groove 8 is formed so as to correspond to the electrolytic solution, the depth h =
It is desirable to form it at a formation angle θ of 45 to 90 degrees at 0.4 mm or more. The cross-sectional shape of the straight groove 8 can be not only a triangle as described above but also an arbitrary shape having a width of 0.2 to 0.5 mm.

The direction in which the linear groove 8 is formed is
It is effective to form at least a direction that intersects with the direction of the component that is obstructed by the leaked electrolytic solution. That is, even when the amount of the leaked electrolytic solution is large, it flows in the direction in which the linear groove 8 is formed, so that the electrolytic solution is prevented from flowing to the circuit board 4 and the like.

Since the linear groove 8 having a small width holds the electrolytic solution in the groove by capillary action or surface tension, the electrolytic solution can be stopped in the linear groove 8 even when the liquid storage structure 3 is inclined from a horizontal state. . If the depth h of the straight groove 8 is sufficiently ensured, the electrolytic solution can be stopped in the groove even when the surface of the liquid reservoir structure 3 is in the vertical direction.

The liquid reservoir structure 3 has a structure in which the linear grooves 8 are arranged in a row. However, as shown in FIG. 4, a liquid reservoir structure 3a in which grooves are arranged vertically and horizontally may be formed. Since the grooves are connected vertically and horizontally, the electrolyte that cannot be accommodated in one groove flows into the vertical and horizontal grooves, and a sufficient storage amount can be obtained.
Also, as shown in FIG.
And a liquid reservoir structure 3b arranged in a row as shown in the figure.
Can also be configured. Since the liquid storage recesses 6 hold the electrolytic solution between the bottom surface and the peripheral wall by surface tension, a sufficient storage capacity can be obtained with a large number of liquid storage recesses 6.

The above-mentioned liquid reservoir structures 3, 3a, 3b are formed at required portions when the pack case 2 is formed, and do not contribute to space occupation in forming the battery pack. Has no effect.

In the state shown in FIG. 1, the liquid reservoir structure 3 is formed only on the inner bottom surface of the pack case 2.
Liquid storage structures 3, 3 around the inner surface of the case surrounding the sealing portion 1a.
By forming a and 3b, diffusion of liquid leakage can be prevented even when the position angle changes like a portable device.

[0023]

As described above, according to the structure for preventing liquid leakage according to the present invention, a liquid reservoir structure can be provided without occupying space in a case of a battery pack or the like, which hinders miniaturization. It is possible to take a countermeasure for liquid leakage without any problem. Further, since it is not necessary to separately prepare a member for liquid leakage countermeasures, cost reduction can be achieved including reduction in the number of manufacturing steps.

[Brief description of the drawings]

FIG. 1 is a plan layout view of a battery pack provided with a liquid reservoir structure according to an embodiment.

FIG. 2 is a perspective view showing a configuration example in a battery pack provided with a liquid reservoir structure.

FIG. 3 is a perspective view of a liquid storage structure.

FIG. 4 is a perspective view showing another embodiment of the liquid reservoir structure.

FIG. 5 is a perspective view showing another embodiment of the liquid reservoir structure.

FIG. 6 is a side view showing a conventional liquid leakage countermeasure structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Pack case 3, 3a, 3b Liquid reservoir structure 8 Straight groove

Claims (7)

[Claims] An anti-leakage structure for stopping a leak from a battery housed in a case at a predetermined location when the battery leaks from the battery, wherein a small-width groove is formed in the predetermined location in the case. A structure for preventing liquid leakage from a battery, wherein a liquid reservoir structure in which are arranged in a row is formed. 2. The micro-width groove has a width of 0.15 to 1.5 m.
m, depth 0.2-1.0 mm, preferably width 0.3-
The liquid leakage prevention structure according to claim 1, wherein the structure is formed to have a depth of 0.5 mm and a depth of 0.4 to 0.8 mm. 3. The liquid leakage prevention structure according to claim 1, wherein the liquid reservoir structure has a groove having a width and a depth for storing the liquid in the groove by capillary action or surface tension. 4. The liquid leakage prevention structure according to claim 1, wherein the minute width groove is formed in a direction intersecting a predetermined direction in the case. 5. The structure for preventing liquid leakage according to claim 1, wherein a liquid reservoir structure is provided so as to surround a sealed portion of the battery. 6. The liquid leakage prevention structure according to claim 1, wherein the minute width concave portions are formed in rows so that grooves in different directions intersect. 7. The liquid leakage prevention structure according to claim 1, wherein the concave portion having a minute width is formed by connecting a large number of liquid reservoir concave portions of any shape vertically and horizontally by grooves.