Battery cell comprising insulator assembly for preventing short circuit caused by nail

Abstract

Disclosed herein is a battery cell including an insulator assembly, wherein, when a needle-shaped conductor passes through the insulator assembly, a part of the insulator assembly into which a needle-shaped end part of the needle-shaped conductor is inserted is fallen and pass through the electrode assembly together with the needle-shaped conductor, and a planar shape of a through-hole of the electrode assembly is determined by the fell-off part of the insulator assembly.

Claims

1. A battery cell including an electrode assembly, an electrolyte solution and a cell case, comprising: an insulator assembly with electrical insulation attached to an outer side of at least one of both surfaces of the electrode assembly in a lamination direction of electrodes, the insulator assembly having a single insulator or a structure in which two or more insulators are laminated, the insulator having a structure including an insulating main body and a plurality of fall-off patterns formed on the insulating main body, and wherein when a needle-shaped conductor passes through the insulator assembly, a part of the insulator assembly into which a needle-shaped end part of the needle-shaped conductor is inserted falls and passes through the electrode assembly together with the needle-shaped conductor, and a planar shape of a through-hole of the electrode assembly is determined by a fall-off part of the insulator assembly.

2. The battery cell according to claim 1, wherein, in the insulator assembly, the two or more insulators have a structure in which the plurality of fall-off patterns formed in each insulator are laminated so as not to overlap each other.

3. The battery cell according to claim 1, wherein when the needle-shaped conductor passes through a fall-off pattern, the fall-off pattern falls from the insulating main body and passes through the electrode assembly together with the needle-shaped conductor by the needle-shaped end part of the needle-shaped conductor inserted into the insulator assembly.

4. The battery cell according to claim 3, wherein the fall-off pattern includes: the fall-off part made of metal, high-strength plastic or ceramic so as to have a tensile strength not to break when the electrode assembly passes through; and a needle-shaped conductor guiding part having a planar size of 50 to 80% of a planar size of the fall-off part in the vicinity of a center of the fall-off part, and wherein when the needle-shaped conductor guiding part is fixed to the needle-shaped end part of the needle-shaped conductor, the fall-off part passes through the electrode assembly in a penetrating direction along the needle-shaped conductor in a state of being fallen from the insulating main body.

5. The battery cell according to claim 4, wherein a total planar area of the fall-off pattern is in a range of about 7 to 200 mm2 so that the fall-off pattern determines a planar shape and area of the through-hole formed in the electrode assembly.

6. The battery cell according to claim 4, wherein a total planar area of the fall-off pattern is in a range of about 20 to 95 mm2.

7. The battery cell according to claim 4, wherein the tensile strength of the fall-off part is in a range of about 1 to 10 kg/cm.

8. The battery cell according to claim 4, wherein the high-strength plastic is one kind selected: from the group consisting of polyamide, polyacetyl, polycarbonate, polyester resin, polyphenylene oxide, polyolefin, polyimide, silicone, Teflon, aramid fiber, glass fiber, ultra-high molecular-weight polyethylene (UHMWPE) fiber and polybenzoxazole (PBO) fiber.

9. The battery cell according to claim 4, wherein the metal is one, or two or more kinds of alloys selected from the group consisting of aluminum, copper, SUS, duranium, palladium, platinum, nickel and molybdenum.

10. The battery cell according to claim 9, wherein a surface of the metal is subjected to an organic insulating coating process, or an anodizing treatment process.

11. The battery cell according to claim 4, wherein the needle-shaped conductor guiding part further includes an insulating film which is stretched along the needle-shaped end part of the needle-shaped conductor.

12. The battery cell according to claim 4, wherein the insulating main body has an opening corresponding to the planar shape of the fall-off part, and the insulating main body and the fall-off pattern are combined with each other in a manner that an adhesive is added to an interface between the insulating main body and the fall-off pattern in a state where the fell-off part is inserted into the opening.

13. The battery cell according to claim 4, wherein the insulating main body has an opening corresponding to the planar shape of the fall-off part, and the insulating main body and the fall-off pattern are combined with each other in a manner that interfaces thereof are fused with each other in a state where the fall-off part is inserted into the opening.

14. The battery cell according to claim 4, wherein the insulating main body and the fall-off pattern are integrated with each other in a manner that the insulating main body and the fall-off part are partitioned by a notch or perforation line.

15. The battery cell according to claim 4, wherein the planar shape of the fall-off pattern has a circular shape, an elliptical shape or a polygonal shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 and FIG. 2 are schematic views of a battery cell according to an exemplary embodiment of the present disclosure.

(2) FIG. 3 is a partial schematic view of an insulator constituting an insulator assembly according to an exemplary embodiment of the present disclosure.

(3) FIG. 4 is a schematic view showing a process in which a fell-off pattern acts in an insulator assembly due to penetration of a needle-shaped conductor.

(4) FIG. 5 is a schematic view of an insulator assembly according to another exemplary embodiment of the present disclosure.

(5) FIG. 6 is a schematic view of a battery cell according to another exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the description provided herein is for a better understanding of the present disclosure, and the scope of the present disclosure is not limited thereto.

(7) FIG. 1 is a schematic view of a battery cell 100 according to an exemplary embodiment of the present disclosure, FIG. 2 is a vertical sectional view of a side surface of the battery cell 100, and FIG. 3 is a schematic view of an insulator assembly 200.

(8) Referring to FIG. 1, the battery cell 100 has a structure in which an electrode assembly 30 including a positive electrode, a negative electrode, and a separator disposed therebetween is embedded in a pouch-shaped cell case 20 together with an electrolyte solution, and an outer periphery thereof which is an outer end part of the cell case 20, is sealed in a state in which electrode leads 60 and 70 coupled to electrode tabs 40 and 50 of the electrode assembly 30 protrude outside the cell case 20.

(9) In addition, the insulator assembly 200 with electrical insulation is provided on an outer side of an upper surface of the electrode assembly 30 in a lamination direction of the electrodes.

(10) The insulator assembly 200 shown in FIG. 3 includes one insulator 201 including an insulating main body 210, and a plurality of fell-off pattern 220 formed on the insulating main body 210.

(11) The fell-off pattern 220 includes a fell-off part 222 made of metal, high-strength plastic, or ceramic to have a hardness not to break when the electrode assembly 30 passes therethrough, and a needle-shaped conductor guiding part 224 having a planar size of 70% of a planar size of the fell-off part 222 in the vicinity of a center of the fell-off part 222.

(12) In particular, the insulating main body 210 have an opening corresponding to a planar shape of the fell-off part 222, and the insulating main body 210 and the fell-off pattern 220 are combined in a manner in which an adhesive is added to an interface between the insulating main body and the fell-off pattern in a state in which the fell-off part 222 is inserted into the opening of the insulating main body 210.

(13) Therefore, when an external force greater than an adhesive force of the adhesive is applied to the fell-off part 222, the fell-off part 222 may be fallen from the insulating main body 210.

(14) While not shown in the drawings, alternatively, the insulating main body 210 and the fell-off pattern 220 may be combined in a manner in which the interface is fused instead of the adhesive in a state in which the fell-off part 222 is inserted into the opening.

(15) The fusing may be fusing by heat, fusing by welding, fusing by soldering, and the like, but is not limited thereto.

(16) A total planar area of the fell-off pattern, that is, the sum of the areas of the fell-off part 222 and the needle-shaped conductor guiding part 224 on a plane may be about 30 mm.sup.2, and the area of the needle-shaped conductor guiding part 224 on the plane may be configured to be about 200 mm.sup.2. In this structure, when a needle-shaped conductor 1 having a diameter of about 5 mm passes through the needle-shaped conductor guiding part 224 and penetrates the battery cell 100, the needle-shaped conductor guiding part 224 is fixed to a needle-shaped end part of the needle-shaped conductor 1, and then the fell-off part 222, which is in a state of being fallen from the insulating main body 210, passes through the electrode assembly 30 in a penetrating direction along the needle-shaped conductor 1.

(17) For reference, the total area of the fell-off pattern 220 and the planar area of the needle-shaped conductor guiding part 224 are set under the assumption that the diameter is 5 mm, which is a general diameter of a nail. The scope of the present disclosure is not limited to the above numerical values, and a size and shape of the fell-off pattern 220 can be variously configured to prepare for various needle-shaped conductors 1.

(18) Therefore, the fell-off part 222 fixed to the needle-shaped conductor 1, not the needle-shaped conductor 1, penetrates the battery cell 100, and accordingly, the fell-off part 222 having a larger planar area than that of the needle-shaped conductor 1 determines a shape of a through-hole 2 of the electrode assembly 30, and the through-hole 2 has a larger planar area than that of the needle-shaped conductor 1. Accordingly, a space is formed between the needle-shaped conductor 1 and an inner surface of the through-hole 2, that is, between the electrodes, so that a possibility of the needle-shaped conductor 1 coming into contact with the electrode can be remarkably reduced.

(19) This is illustrated in more detail in FIG. 4. FIG. 4 schematically shows a process in which the fell-off pattern 220 acts in the insulator assembly 200 due to penetration of the needle-shaped conductor 1.

(20) Referring to FIG. 4, after the needle-shaped conductor 1 first passes through the battery case of the battery cell 100, the needle-shaped end part of the needle-shaped conductor 1 is inserted into the needle-shaped conductor guiding part 224. However, the diameter of the needle-shaped conductor 1 is larger than that of the needle-shaped conductor guiding part 224, and thus the needle-shaped conductor 1 is fixed in the needle-shaped conductor guiding part 224.

(21) When the needle-shaped conductor 1 continues to move in this state, the fell-off part 222 is fallen from the insulating main body 210.

(22) Since the fell-off part 222 has a larger planar area than that of the needle-shaped conductor 1, the fell-off part 222 fixed to the needle-shaped end part of the needle-shaped conductor 1 sequentially passes through the electrodes of the electrode assembly 30.

(23) Therefore, the needle-shaped conductor 1, which has a small size relative to the size of the through-hole 2, does not come into direct contact with the electrodes.

(24) As described above, in the present disclosure, since the insulating assembly for preparing for penetration of the needle-shaped conductor 1 is provided on an outer surface of the electrode assembly 30, stability of the battery cell 100 relative to the needle-shaped conductor 1 can be greatly improved.

(25) Meanwhile, while not shown in the drawings, the needle-shaped conductor guiding part 224 may have a structure in which the fell-off part 222 is simply perforated, or a structure in which an insulating film having high elongation is provided in the perforated state.

(26) Referring to FIG. 5, an insulator assembly 300 has a structure in which a first insulator 310 and a second insulator 320 are laminated.

(27) In the first insulator 310, hexagonal fell-off patterns 311 in a plane are formed on an insulating main body in a state of being spaced apart at regular intervals.

(28) In the second insulator 320, hexagonal fell-off patterns 321 are formed on an insulating main body at a position that does not overlap with the fell-off patterns 311 of the first insulator 310 in a plane.

(29) Therefore, in the insulator assembly 300, two or more insulators are laminated in a manner in which the fell-off patterns 311 and 321 respectively formed in the insulators 310 and 320 do not overlap.

(30) In this structure, the fell-off patterns 311 and 321 are arranged relatively closely in a plane so that formation of a blind spot during penetration of a needle-shaped conductor can be minimized.

(31) FIG. 6 is a schematic view of a battery cell according to another exemplary embodiment of the present disclosure.

(32) A basic structure of a battery cell 400 shown in FIG. 6, that is, an electrode assembly, a battery case, and the like, is identical to that of the battery cell 100 shown in FIGS. 1 to 4, but insulator assemblies 410 and 412 are attached to upper and lower surfaces of a battery case 420 and not an outer surface of an electrode assembly thereof.

(33) However, the specific structure and working structure of each of the insulator assemblies 410 and 412 are identical to those of the insulator assembly 200 shown in FIGS. 1 to 4 or the insulator assembly 300 shown in FIG. 5.

(34) Those skilled in the art should appreciate that various modifications, additions, and substitutions of the above-described embodiments are possible without departing from the scope and spirit of the present disclosure as disclosed in the accompanying claims.