JP3001823U - Outer container for secondary battery - Google Patents

Abstract

(57) [Summary] [Object] To provide an outer container for a secondary battery in which even a thin outer container having a rectangular parallelepiped shape is unlikely to undergo bulging deformation due to an increase in internal pressure due to charging. A stepped portion 3a that is substantially parallel to two diagonal lines connecting non-adjacent vertices of the maximum surface 2 to the maximum surface 2 having the maximum area of the outer container 1 having a rectangular shape for accommodating the power generation element. The concave portion 3 having is formed by pressing or the like.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a rechargeable battery that can be repeatedly charged and used. Even if the outer container has a rectangular shape, it does not easily bulge and deform due to an increase in internal pressure due to charging. Regarding the container.

[0002]

[Prior art]

 In recent years, compact electronic devices such as mobile phones, video movies, and portable notebook computers that are used without cord have become remarkably popular. Further, due to further improvement in performance and reduction in size and weight, there is an increasing demand for higher capacity and higher energy of the secondary battery as a power source of these electronic devices.

As the secondary battery, a lead secondary battery and a nickel-cadmium secondary battery have been conventionally used, but recently, a non-aqueous electrolyte solution such as a lithium ion secondary battery capable of achieving higher energy density has been used. Secondary battery development is in progress. Even in that shape, there are various types of shapes such as a rectangular shape and a strip shape in addition to the cylindrical shape corresponding to the shape of various devices.

[0004]

[Problems to be solved by the device]

 This secondary battery generates a small amount of gas when it is charged, and this causes the internal pressure to rise slightly above atmospheric pressure. If the outer container has a shape, it can be sufficiently absorbed. However, in the case of a rectangular outer container such as a rectangular parallelepiped shape or a strip shape, an increase in internal pressure may cause the side surface of the maximum area of the outer container to bulge.

This bulging deformation of the outer container is not only a problem that it does not fall within the product specifications of the secondary battery, but also the storage area of the equipment in which the secondary battery is loaded. There was also a risk that it could not be removed. In order to prevent such a situation, it was also considered to make the outer container thicker and to use a material with excellent mechanical strength.However, making the outer container thicker narrows the storage area of the power generation element and increases capacity. Contrary to the trend of higher energy, the use of a material with a particularly high mechanical strength as the outer container causes problems in processing and production cost, and the outer container serves as an electrode. It was impossible because it was limited.

Therefore, it is an object of the present invention to provide an outer container for a secondary battery in which even a thin outer container having a rectangular parallelepiped shape is unlikely to undergo bulging deformation due to an increase in internal pressure due to charging. To do.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the outer container for a secondary battery of the present invention has a concave portion formed in two diagonal directions that connect the diagonals on the surface of the rectangular outer container that houses the power generating element. It is a feature.

Alternatively, a concave portion having a step portion substantially parallel to two diagonal lines connecting the diagonals of the rectangular shape is formed on the surface of the rectangular outer container that houses the power generating element. Is.

Further, the surfaces forming the recesses may be a pair of surfaces facing each other having at least the maximum area in the outer container having a rectangular parallelepiped shape.

Further, the recess may be formed by pressing.

[0011]

[Action]

 By forming recesses in two diagonal directions that connect diagonally on the surface of the rectangular outer container that houses the power generation element, the center of the outer container where the recess is most likely to swell and deform Is difficult to be deformed by the rib reinforcement which is concentrated in two directions by the concave portions formed in the two diagonal directions of this surface so as to be trapped.

By forming a concave portion having a step portion substantially parallel to two diagonal lines connecting the diagonals of the rectangular shape on the surface of the rectangular outer container that houses the power generation element, the concave portion of the outer container can be formed. The center portion of the formed surface, which is most likely to be bulged and deformed, is difficult to be deformed due to the rib reinforcement in a trapezoidal shape concentrated in two directions by the step portion substantially parallel to the two diagonal lines of the surface.

When the surfaces forming the recesses are a pair of opposing surfaces having at least the maximum surface area in an outer container having a rectangular parallelepiped shape, the largest surface of the outer container which is most likely to be bulged and deformed is The ribs are efficiently reinforced and the outer container is less likely to be deformed.

When the recess is formed by pressing, the pressing force of the press causes the composition of the material of the exterior container to become dense and the mechanical strength to increase.

[0015]

【Example】

 1 and 2 show a first embodiment of an outer container for a secondary battery of the present invention, 1 is an outer container made of a stainless steel plate having a thickness of about 0.2 mm, 2 is about 34 mm in length in the outer container 1, A pair of maximum faces 3 facing each other having a maximum area of about 45 mm in width are concave portions formed on the maximum face 2 by an urging force such as press working in an X shape with a width diameter of about 5 mm. Moreover, the material of the outer container 1 is an example, and various materials such as aluminum and titanium are appropriately selected depending on the type of the secondary battery, the electrode terminal structure, and the like.

The concave portion 3 has two apexes which are not adjacent to each other on the maximum surface 2, that is, two diagonal directions connecting the corners 4 and 6 and the corners 5 and 7, or substantially parallel to the two diagonals. It is formed so as to be surrounded by the step portion 3a having a depth of 02 to 0.20 mm. The depth of the step portion 3a is appropriately set depending on the material and plate thickness of the outer container 1, the width diameter of the maximum surface 2 of the outer container 1, the increase amount of the internal pressure, and the like.

FIG. 3 shows a second embodiment of an outer container for a secondary battery of the present invention. In this outer container 1, the outer circumference of the X-shaped recess 3 of the first embodiment described above is shown. Substantially triangular recesses 8, 9, 10, 11 are formed in four directions.

The substantially triangular recesses 8, 9, 10 and 11 are formed by being surrounded by the step portions 8a, 9a, 10a and 11a having a depth of 0.02 to 0.20 mm, respectively. Of the three sides, the two sides on the concave portion 3 side are substantially parallel to the stepped portion 3a of the concave portion 3 in the first embodiment described above, that is, two diagonal lines connecting the corners 4 and 6 and the corners 5 and 7. It is located approximately parallel to the direction or two diagonals.

FIG. 4 shows a third embodiment of an outer container for a secondary battery according to the present invention. In this outer container 1, the recesses 12 and 13 are formed by combining the V-shapes symmetrically with each other. It has a shape that does not communicate. The concave portions 12 and 13 are surrounded by step portions 12a and 13a having a depth of 0.02 to 0.20 mm, and corner portions 4 and 6 and corner portions 5 and 5 are formed on both sides of the concave portions 12a and 13a except the central portion thereof. It is formed in two diagonal directions connecting the corners 7 or substantially parallel to the two diagonal lines.

FIG. 5 shows a fourth embodiment of an outer container for a secondary battery according to the present invention. In this outer container 1, the recesses 14, 15, 16, 17 are the same as the first embodiment. Except for the central portion of the X-shaped recess 3a in FIG. The recesses 14, 15, 16 and 17 are formed in the directions of two diagonal lines connecting the corners 4 and 6 and the corners 5 and 7, respectively, or approximately parallel to the two diagonal lines, and each of them is 0.02 to 0.2. It is formed by being surrounded by step portions 14a, 15a, 16a and 17a having a depth of 0 mm.

The shape and size of the recess in the secondary battery outer container of the present invention are not limited to the above-mentioned four embodiments, but may be, for example, one diagonal direction or diagonal line. A variety of arranging may be performed, such as forming one strip-shaped recess substantially parallel to the above, combining a plurality of steps substantially parallel to two diagonal lines connecting diagonals, dividing, joining, and the like. It is a thing.

Further, in the present embodiment, the concave portions are formed only on the pair of maximum surfaces 2 of the outer container 1 which face each other, but depending on the shape of the outer container, not only the maximum surface 2 but also all the surfaces. It may be formed on one side or only on one side.

Further, the outer container for a secondary battery of the present invention is extremely suitable for use in a lithium ion secondary battery capable of achieving high energy density, but of course, other secondary batteries may be used. Is.

[0024]

[Effect of device]

 As described above in detail, according to the secondary battery outer container of the present invention, two rectangular concave portions are formed to connect the diagonals on the surface of the rectangular outer container that houses the power generation element. As a result, the center of the surface of the outer container where the recess is formed is most likely to be bulged and deformed, and the two diagonally formed recesses of this surface are concentrated in two directions to provide rib-like reinforcement. It becomes difficult to be deformed, so that there is no fear that the secondary battery will be out of the product standard, and it is possible to prevent the occurrence of troubles such that the secondary battery cannot be attached to and detached from the storage area of the device.

Alternatively, by forming a concave portion having a step portion that is substantially parallel to two diagonal lines connecting the diagonals of the rectangular shape on the surface of the rectangular outer container that houses the power generating element, the outer container The central portion of the surface where the recess is formed is most likely to be bulged and deformed, and it is difficult for the surface to be deformed by the rib reinforcement that is concentrated in two directions due to the step portion that is substantially parallel to the two diagonal lines of this surface, and This eliminates the risk of the secondary battery deviating from the product standard, and prevents the occurrence of troubles such as the secondary battery being unable to be attached to and detached from the storage area of the device.

Further, when the surfaces forming the recesses are a pair of opposing surfaces having at least the maximum area in a rectangular parallelepiped outer container, the largest surface of the outer container that is most likely to be bulged and deformed. The ribs are efficiently reinforced and the outer container is less likely to be deformed.

Further, when the recess is formed by pressing, the pressing force of the press causes the composition of the material of the outer container to become dense and the mechanical strength to increase, so that the outer container can be further bulged and deformed. It can be suppressed.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of an outer container for a secondary battery according to the present invention.

FIG. 2 is a plan view of a first embodiment of an outer container for a secondary battery according to the present invention.

FIG. 3 is a plan view of a second embodiment of an outer container for a secondary battery according to the present invention.

FIG. 4 is a plan view of a third embodiment of an outer container for a secondary battery according to the present invention.

FIG. 5 is a plan view of a fourth embodiment of an outer container for a secondary battery according to the present invention.

[Explanation of symbols]

 1 Outer Container 2 Maximum Surface 3 Recessed Section 3a Stepped Section 4, 5, 6, 7 Square 8, 9, 10, 11 Recessed Section 8a, 9a, 10a, 11a Stepped Section 12, 13 Recessed Section 12a, 13a Stepped Section 14, 15, 16 , 17 Recesses 14a, 15a, 16a, 17a Steps

Claims (4)

[Scope of utility model registration request] 1. An outer container for a secondary battery, characterized in that recesses are formed in two diagonal directions connecting diagonally on a surface of an outer container having a rectangular shape for accommodating a power generation element. 2. A concave portion having a step portion substantially parallel to two diagonal lines connecting the diagonals of the rectangular shape is formed on the surface of an outer container having a rectangular shape for housing the power generating element. Outer case for secondary battery. 3. The secondary battery according to claim 1 or 2, wherein the surfaces forming the recesses are a pair of surfaces facing each other having at least the maximum area in the rectangular outer package. Exterior container for. 4. The outer container for a secondary battery according to claim 1, wherein the recess is formed by pressing.