KR100428978B1 - Secondary battery unit - Google Patents

Abstract

Disclosed is a secondary battery unit. The present invention includes a battery unit having a positive electrode plate, a negative electrode plate, and a separator interposed therebetween; a case in which the battery unit is housed; and the battery unit are electrically connected to each other to forcibly cut off the flow of current when there is an abnormality of the battery. And a molding material formed in at least one of front and rear sides of the protection device to prevent the electrolyte from penetrating into the protection device, and an external terminal electrically connected to the protection device. It is electrically connected to the branch and forms a molding material on at least one side of the protection element that blocks the flow of current when there is an abnormality of the battery, thereby sealing it from the outside. It is possible to improve the stability of the battery.

Description

Secondary battery unit

The present invention relates to a secondary battery, and more particularly, to a secondary battery unit having an improved structure to prevent damage to a protection device due to leakage of an electrolyte.

Lithium secondary batteries, which are capable of charging and discharging, are rapidly expanding in terms of higher operating voltage and higher energy density per unit weight than nickel-cadmium batteries and nickel-metal hydride batteries. Lithium secondary batteries can be classified into liquid electrolyte batteries and polymer electrolyte batteries according to the type of electrolyte. Generally, a battery using a liquid electrolyte is called a lithium ion battery, and a battery using a polymer electrolyte is called a lithium polymer battery.

Such lithium secondary batteries are vulnerable to safety. That is, in lithium ion batteries, lithium-based oxide is used for the positive electrode, carbon-based material for the negative electrode, and an organic solvent electrolyte is used for the electrolyte. When the battery is overcharged, the electrolyte is decomposed at the positive electrode, and lithium metal is precipitated at the negative electrode. do. Since lithium polymer batteries are locally overheated during charging and discharging, the polymer electrolyte, which is weak to heat, is partially dissolved or softened.

Therefore, the characteristics of the battery are deteriorated, the current and potential are not uniform, which causes a short circuit, and poses a risk of fire and explosion. In general, the mechanism of a battery that causes ignition or heat generation can be classified into an internal short circuit and a thermal runaway. To eliminate this risk, the battery is equipped with various types of protective elements.

Referring to FIG. 1, the conventional secondary battery unit 10 includes a battery case 11 in which a battery part including a positive electrode and a negative electrode plate and a separator insulated therebetween is accommodated, and an electrode lead drawn from the battery case 11 ( 12), a protection element 13 electrically connected to the electrode lead 12 to protect the battery in the presence of abnormality, and a plurality of insulators 14 and 15 installed in front and rear of the protection element 13. And a terminal 17 connected by the protection element 13 and the connection lead 16 and exposed to the outside.

At this time, the protection element 31 is provided to prevent incomplete elements of the battery, and is attempted to insulate with an insulator 14, 15 such as insulating paper or tape in front and rear of the protection element 31.

By the way, the conventional battery unit 10 has the following problems.

When leakage of the electrolyte solution occurs from the battery case 11, which is one of the defects most frequently generated in the battery unit 10, the leaked electrolyte solution may come into contact with the protection element 31, and a short circuit may occur. have. Accordingly, there is a risk of ignition and explosion of the battery. Although a plurality of insulators 14 and 15 are installed in front and rear of the protection element 31 in preparation for such a phenomenon, the sealing is not guaranteed, and thus, a complete prevention of leaked electrolyte is not performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a secondary battery unit having an improved structure to prevent a short circuit of a protection device against leakage of an electrolyte.

1 is an exploded perspective view showing a conventional secondary battery unit,

2 is an exploded perspective view illustrating a conventional secondary battery;

Figure 3 is an exploded perspective view showing a secondary battery unit according to an embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

30 Secondary battery unit 31 Case

32 ... electrode lead 33 ... protective element

34.Front molding material 35 ... Rear molding material

36.Connection lead 37 ... External terminal

38.Electronic components

A secondary battery unit according to an aspect of the present invention to achieve the above object,

A battery unit having a positive electrode plate, a negative electrode plate, and a separator interposed therebetween;

A case accommodating the battery unit;

A protection device electrically connected to the battery unit to forcibly cut off the flow of current when the battery is abnormal;

A molding material formed in at least one of front and rear sides of the protection device to prevent electrolyte from penetrating into the protection device; And

And an external terminal electrically connected to the protection device.

In addition, the molding material is molded in the protective element so as to cover the portion in which the electronic component is mounted on the protective element, and the protective element is electrically connected to the battery unit or the external terminal.

In addition, the molding material is characterized in that it is formed integrally with the front and rear of the protective element.

Further, the molding material is characterized in that the insulating material.

Further, the molding material is characterized in that any one selected from silicon, epoxy, urethane.

Hereinafter, a secondary battery unit according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 illustrates a secondary battery 20 according to an embodiment of the present invention.

Referring to the drawings, the secondary battery 20 includes a battery unit 21 and a case 22 in which the battery unit 21 is accommodated.

The battery unit 21 includes a positive electrode plate 23, a negative electrode plate 24, and a separator 25 interposed between the positive electrode plate and the negative electrode plates 23 and 24 to insulate them from each other. The battery unit 21 is disposed in the order of the positive electrode plate 23, the separator 25, and the negative electrode plate 24. Positive and negative electrode tabs 26 and 27 are electrically connected to the positive and negative electrode plates 23 and 24, respectively.

The case 22 has a space portion 22a in which the battery portion 21 is accommodated, and has a pouch shape.

The secondary battery 20 having such a structure is assembled with the battery part 21 in a jelly-roll type or a stacked type, and mounted in the case 22, and then, a protective means is installed to improve safety.

3 illustrates a secondary battery unit 30 according to an embodiment of the present invention.

Referring to the drawings, the secondary battery unit 30 is provided with a case 31. The case 31 includes a battery unit disposed in the order of the positive plate, the separator, and the negative plate as described above, and the case ( Outside the 31), an electrode lead 32 electrically connected to the battery unit is drawn out.

The electrode lead 23 is provided with a protective means connected to the electrode lead 23 to block the flow of current when there is an abnormality of the battery such as a short circuit.

The protection means includes a protection element 33 electrically connected to the electrode lead 23 to protect the battery. The protection element 33 is provided with an electronic component 38 such as a FET or TR so as to forcibly block the flow of current in a circuit when the battery is overcharged.

The protection element 33 is connectable to the terminal 37 exposed to the outside by the connection lead 36. The terminal 37 is a portion directly connected to an external electric terminal during charging.

At least one of the front and rear surfaces of the protection element 33 may be used to prevent damage to or short circuit of the electronic component 38 on the protection element 33 due to leakage of the electrolyte injected into the case 31. A blank is installed.

That is, the front molding material 34 is formed in front of the protective element 33 to protect the electronic lead 38 and the part connected between the electrode lead 32 and the protective element 33. The front molding material 34 is preferably any one of an insulating material selected from silicon, epoxy, urethane. The front molding material 34 is formed to completely cover the electronic component 38 from the surface of the protective element 33. Accordingly, the front surface of the protection element 33 can be completely sealed from the outside by the front molding material 34.

In addition, a rear molding material 35 is formed at the rear of the protection element 33 to protect the electronic component 38 and the portion of the connection lead 33 and the protection element 33. The raw material of the rear molding material 35 can be said to be substantially the same as that of the front molding material 34. The rear molding material 34 seals the rear surface of the protective protector 33.

At this time, it will be advantageous to simplify the manufacturing process to form the front and rear molding material 34, 35 together. In addition, the front and rear molding materials 34 and 35 have electronic components 38 mounted on the protection element 33, and electrodes and connection leads 34 and 36 are connected to the protection element 33. After being connected, it can be placed in a predetermined molding die to inject a molding material material into a desired shape.

The secondary battery unit 30 having the above structure has a case 31, a protective means, and an external terminal 37 laid out to be mounted in a battery pack (not shown). If such a battery is leaked due to an abnormality of the electrolyte injected into the case 31 during operation, the electrolyte flows in the battery pack. At this time, since the molding materials 34 and 35 are applied to the front and rear of the protection element 33, the electrolyte penetrates into the protection element 33 and damages the electronic component 38, thereby losing the function of the protection circuit. It is prevented beforehand.

As described above, the secondary battery unit of the present invention is electrically connected to the battery unit to form a molding material on at least one side of the protection element to block the flow of current in the presence or absence of the battery is sealed from the outside, the electrolyte solution Due to leakage, damage to the protection device in which the electronic component is mounted may be prevented in advance, thereby improving battery stability.

In addition, since the outer surface of the protection device is wrapped by the molding material, even when the external impact or swelling phenomenon of the battery part to protect it safely to ensure the function as a protection device.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (5)

A battery unit having a positive electrode plate, a negative electrode plate, and a separator interposed therebetween; A case accommodating the battery unit; A protection device electrically connected to the battery unit to forcibly cut off the flow of current when the battery is abnormal; A molding material formed in at least one of front and rear sides of the protection device to prevent electrolyte from penetrating into the protection device; And And an external terminal electrically connected to the protection device. The method of claim 1, And the molding material is molded in the protection element to cover a portion in which an electronic component is mounted in the protection element and a portion in which the protection element is electrically connected to the battery unit or an external terminal. The method of claim 2, The molding material unit of the secondary battery, characterized in that formed integrally with the front and rear of the protective element. The method of claim 1, The molding material unit of the secondary battery, characterized in that the insulator. The method of claim 4, wherein The molding material unit of the secondary battery, characterized in that any one selected from silicon, epoxy, urethane.