JP3969205B2 - Safety structure of prismatic nonaqueous electrolyte battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in the safety structure of a prismatic nonaqueous electrolyte battery.
[0002]
[Prior art]
When a rectangular non-aqueous electrolyte battery such as a prismatic lithium ion battery is exposed to overcharging, heating, etc., the electrolyte may be electrolyzed or thermally decomposed to generate flammable gas, which may increase the internal pressure of the battery case. is there.
[0003]
For this reason, the battery case is conventionally provided with a safety valve for releasing the internal gas to the outside.
[0004]
[Problems to be solved by the invention]
However, in the above conventional battery case, the separator of the electrode body is melted due to overcharging or heating of the battery, the positive electrode and the negative electrode are short-circuited, spark is generated, and the active material of the electrode body or the current collector foil is burned from the safety valve There is a possibility that high-temperature objects such as objects will blow out with combustible gas. In this case, there is a problem that the combustible gas may be ignited outside the battery case and burned explosively.
[0005]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a safety structure for a prismatic nonaqueous electrolyte battery that can prevent ignition of combustible gas blown out from the safety valve even when the safety valve is operated. There is to do.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a safety structure for a prismatic nonaqueous electrolyte battery in which a positive electrode, a negative electrode, and a separator impregnated with a nonaqueous electrolyte are accommodated in a rectangular battery case. A shut-off structure is provided to prevent a high-temperature object from being discharged from the opening of the safety valve to the outside of the battery case during abnormal battery operation.
[0007]
Further, in the safety structure of the rectangular non-aqueous electrolyte battery, the blocking structure is a cylindrical structure that constitutes a gas passage having inlets at both ends, and the gas that has entered the interior is discharged into the safety valve opening. It has a discharge port, and a partition plate is provided between the two discharge ports in the gas passage.
[0008]
According to each said structure, even when a safety valve is actuated, it is possible to avoid discharge of a high-temperature object from the opening of the safety valve to the outside of the battery case, and to prevent ignition of the combustible gas blown out from the safety valve.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.
[0010]
FIG. 1 shows a perspective view of an embodiment of a safety structure of a prismatic nonaqueous electrolyte battery according to the present invention. In FIG. 1, an electrode body 12 in which a positive electrode, a negative electrode, and a separator are stacked and an electrode terminal 14 connected to the electrode body 12 are accommodated in a rectangular battery case 10 of a rectangular nonaqueous electrolyte battery. . In addition, the battery case 10 is exposed to overcharge, heating, etc. of the rectangular non-aqueous electrolyte battery, and discharges flammable gas generated by electrolysis or thermal decomposition of the electrolyte solution. Two safety valves 16 are provided to prevent the internal pressure from rising.
[0011]
In the present embodiment, a characteristic point is that a blocking structure 18 for preventing a high temperature object from being released from the opening of the safety valve 16 to the outside of the battery case 10 during abnormal operation of the battery is provided inside the battery case 10. It is a point provided. FIG. 2 shows this blocking structure 18. In FIG. 2, the blocking structure 18 is a cylindrical structure having inlets at both ends, and the inside thereof constitutes a gas passage. This blocking structure 18 includes
Two discharge ports 20 are formed through which the gas that has entered is discharged to the opening of the safety valve 16. Further, a partition plate 22 is provided between the two discharge ports 20 in the gas passage inside the blocking structure 18. In addition, the material of the interruption | blocking structure 18 should just be able to endure the environment inside the battery case 10, for example, the same material as the battery case 10 can be used.
[0012]
As shown in FIG. 1, the blocking structure 18 having the above-described structure is disposed inside the battery case 10 so as to block between the electrode body 12 and the opening of the safety valve 16. For this reason, the battery is exposed to overcharge, heating, etc., the separator of the electrode body 12 is melted, the positive electrode and the negative electrode are short-circuited, sparks are generated, and the active material of the electrode body 12 and the burned material of the current collector foil Even when a hot object is ejected, the high temperature object is blocked from the opening of the safety valve 16 by the blocking structure 18, and the hot object can be prevented from being blown out together with the combustible gas outside the battery case 10. Therefore, it is possible to avoid that the combustible gas is ignited outside the battery case 10 and burns explosively.
[0013]
On the other hand, when the battery is exposed to overcharging, heating, etc., as described above, the electrolyte may be electrolyzed or thermally decomposed to generate flammable gas. The gas can be discharged from the safety valve 16 to the outside of the battery case via the discharge port 20. In this case, since the partition plate 22 is provided between the two discharge ports 20 in the gas passage, gas entering from one inlet can be prevented from escaping from the other inlet, and exhaust efficiency is improved. it can. Further, by making the cross-sectional area of the gas passage and the cross-sectional area of the discharge port 20 equal to or larger than the cross-sectional area of the opening of the safety valve 16, the exhaust efficiency can be further improved. The cross-sectional shape of the blocking structure 18 is not particularly limited as long as it does not reduce the exhaust efficiency. However, as shown in FIG. 2, a rectangular pipe having a rectangular cross section is also suitable.
[0014]
With the blocking structure 18 as described above, the high-temperature object is blocked and only the gas can be exhausted to the outside of the battery case 10.
[0015]
【The invention's effect】
As described above, according to the present invention, even when the battery is exposed to overcharge, heating, etc., only the combustible gas is exhausted to the outside of the battery case, and the high temperature object is ejected to the outside. Since this can be prevented, ignition of the combustible gas blown out from the safety valve can be prevented when the safety valve is operated.
[Brief description of the drawings]
FIG. 1 is a perspective view of an embodiment of a safety structure of a prismatic nonaqueous electrolyte battery according to the present invention.
FIG. 2 is a perspective view showing a configuration of the blocking structure shown in FIG.
[Explanation of symbols]
10 battery case, 12 electrode body, 14 electrode terminal, 16 safety valve, 18 shut-off structure, 20 discharge port, 22 partition plate.

Claims (5)

A safety structure of a prismatic nonaqueous electrolyte battery in which a positive electrode, a negative electrode, a separator laminated with a nonaqueous electrolyte, and an electrode terminal connected to the electrode body are accommodated in a rectangular battery case. There,
Inside the battery case, a blocking structure is provided to prevent high temperature objects from being released from the safety valve opening to the outside of the battery case during abnormal battery operation,
The safety valve opening is arranged to be sandwiched between the electrode terminals;
The shut-off structure is a cylindrical structure that constitutes a gas passage having inlets at both ends, and has two discharge ports for discharging the gas that has entered inside into the safety valve opening, and the gas passage includes A safety structure for a prismatic nonaqueous electrolyte battery, characterized in that a partition plate is provided between two discharge ports. A safety structure of a prismatic nonaqueous electrolyte battery in which a positive electrode, a negative electrode, a separator laminated with a nonaqueous electrolyte, and an electrode terminal connected to the electrode body are accommodated in a rectangular battery case. There,
Inside the battery case, a blocking structure for preventing a high temperature object from being released from the safety valve opening to the outside of the battery case at the time of abnormal battery operation is provided along the winding axis of the electrode body,
The shut-off structure is a cylindrical structure that constitutes a gas passage having inlets at both ends, and has two discharge ports for discharging the gas that has entered inside into the safety valve opening, and the gas passage includes A safety structure for a prismatic nonaqueous electrolyte battery, characterized in that a partition plate is provided between two discharge ports. 3. The safety structure of the rectangular nonaqueous electrolyte battery according to claim 1, wherein a cross-sectional area of the gas passage and a cross-sectional area of the discharge port are equal to a cross-sectional area of the safety valve opening, or of the safety valve opening. A safety structure for a prismatic non-aqueous electrolyte battery characterized by being larger than the cross-sectional area. A safety structure for a prismatic nonaqueous electrolyte battery in which a positive electrode, a negative electrode, and a separator impregnated with a nonaqueous electrolyte are housed in a rectangular battery case,
Inside the battery case, a blocking structure is provided to prevent high temperature objects from being released from the safety valve opening to the outside of the battery case during abnormal battery operation,
The shut-off structure is a cylindrical structure that constitutes a gas passage having inlets at both ends, and has two discharge ports for discharging the gas that has entered the interior to the safety valve opening, and the gas passage includes A safety structure for a prismatic nonaqueous electrolyte battery, characterized in that a partition plate is provided between two discharge ports. The safety structure of the rectangular nonaqueous electrolyte battery according to claim 4 , wherein a cross-sectional area of the gas passage and a cross-sectional area of the discharge port are equal to a cross-sectional area of the safety valve opening or a cross-sectional area of the safety valve opening. A safety structure for a rectangular non-aqueous electrolyte battery characterized by being larger.

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