Battery cell tray including volatile corrosion inhibitor

Abstract

The present disclosure relates to a battery cell tray, which is a tray configured to accommodate a plurality of cylinder type battery cells in a storage of a first packaging member, including a first tray member having a plate type structure in which a plurality of first recessed portions surrounding one side end portions of the battery cells are formed; and a second tray member having a plate type structure in which a plurality of second recessed portions surrounding the other side end portions facing the one side end portions of the battery cells are formed, and the first and second tray members includes a volatile rust inhibitor which is vaporized at room temperature to form a rust-proofing film on surfaces of the battery cells.

Claims

1. A battery cell package, comprising: a plurality of cylinder type battery cells; a first tray member formed of resin having a plate type structure in which a plurality of first recessed portions surrounding one side end portions of the plurality of cylinder type battery cells are formed; a second tray member formed of resin having a plate type structure in which a plurality of second recessed portions surrounding the other side end portions facing the one side end portions of the plurality of cylinder type battery cells are formed; and a layer comprising a volatile rust inhibitor and binder coated on the first tray and the second tray, wherein the volatile rust inhibitor is vaporized at room temperature to form a rust-proofing film on surfaces of the battery cells.

2. The battery cell package of claim 1, wherein the cylinder type battery cell comprises a battery case configured to accommodate an electrode assembly, a cap assembly coupled to the battery case to seal the battery case and materials of the battery case and the cap assembly comprise an iron (Fe) element.

3. The battery cell package of claim 2, wherein at least a part of surfaces of the battery case and the cap assembly are nickel plated.

4. The battery cell package of claim 1, wherein the volatile rust inhibitor acts to prevent an inside of the battery case from being further oxidized by forming the rust-proofing film on the surface of the battery case or inducing surface oxidation of the materials of the battery case.

5. The battery cell package of claim 1, wherein the volatile rust inhibitor is NaNO.sub.2.

6. The battery cell package of claim 1, wherein the rust-proofing film comprises gamma-iron trioxide (-Fe.sub.2O.sub.3).

7. The battery cell package of claim 1, wherein the materials constituting the tray members comprise polypropylene, polyethylene, or a mixture thereof.

8. The battery cell package of claim 1, wherein the sum of lengths of both side end portions of the battery cell which are inserted into a first recessed groove of the first tray member and a second recessed groove of the second tray member corresponding to the first recessed groove is 30% to 70% of a length between both side end portions of the battery cell.

9. The battery cell package of claim 1, wherein the first tray member and the second tray member have a planar width of 90% to 100% of a planar width of a storage of a first package member.

10. The battery cell package of claim 1, wherein the plurality of cylinder type battery cells are arranged in a state of being spaced apart from adjacent battery cells at regular intervals.

11. A battery cell package, comprising: a plurality of cylinder type battery cells; a first packaging member comprising: a first tray member having a plate type structure in which a plurality of first recessed portions surrounding one side end portions of the plurality of cylinder type battery cells are formed; and a second tray member having a plate type structure in which a plurality of second recessed portions surrounding the other side end portions facing the one side end portions of the plurality of cylinder type battery cells are formed, wherein the first and second tray members comprise a volatile rust inhibitor which is vaporized at room temperature to form a rust-proofing film on surfaces of the battery cells; and a second package member configured to accommodate the first package member in which the battery cell package is accommodated in a sealed state to prevent the vaporized rust inhibitor from leaking out of the battery cell package.

12. The battery cell package of claim 11, wherein the first package member is made of paper having a predetermined thickness, and the second package member is made of a polymer resin.

13. The battery cell package of claim 12, wherein a sectional shape of the first package member is a corrugated cardboard structure.

14. The battery cell package of claim 12, wherein the material of the polymer resin is polypropylene, oriented polypropylene, or polyethylene terephthalate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view showing a structure of a battery cell tray according to one embodiment of the present disclosure.

(2) FIG. 2 is a schematic view showing a vertical sectional structure of the battery cell tray taken along line A-A of FIG. 1.

(3) FIG. 3 is a schematic view showing a structure in which the battery cell tray of FIG. 1 is accommodated in a battery cell package member according to another embodiment of the present disclosure.

(4) FIG. 4 is a schematic view showing a process of coating a volatile rust inhibitor on one side of a tray member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings, and the scope of the present disclosure is not limited thereto.

(6) FIG. 1 is a schematic view showing a structure of a battery cell tray according to one embodiment of the present disclosure.

(7) Referring to FIG. 1, a battery cell tray 100 includes a first tray member 110 and a second tray member 120, which are respectively disposed at one side end portion 131 and the other side end portion 132 of a cylinder type battery cell 130.

(8) The first tray member 110 and the second tray member 120, which have a plate type structure, are formed with a plurality of first recessed portion 111 and second recessed portions 121, which surround the one side end portion 131 and the other side end portion 132 of the battery cell 130 facing each other.

(9) Here, the one side end portion 131 and the other side end portion 132 of each of the plurality of cylinder type battery cells 130 facing each other are respectively inserted into the first recessed portion 111 of the first tray member 110 and the second recessed portion 121 of the second tray member 120. Accordingly, the plurality of cylinder type battery cells 130 are fixedly held and spaced apart from each other by a predetermined interval to be safely transported and stored while preventing damage due to interference or contact with each other.

(10) FIG. 2 is a schematic view showing a vertical sectional structure of the battery cell tray taken along line A-A of FIG. 1.

(11) Referring to FIG. 2, the one side end portion 131 and the other side end portion 132 of the cylinder type battery cell 130 facing each other are respectively inserted into the first recessed portion 111 of the first tray member 110 and the second recessed portion 121 of the second tray member 120.

(12) Accordingly, the cylinder type battery cell 130 is positioned between the first tray member 110 and the second tray member 120, and a volatile rust inhibitor included in the first tray member 110 and the second tray member 120 positioned at both side end portions 131 and 132 of the cylinder type battery cell 130 is vaporized at room temperature to form a rust-proofing film on a surface of the cylinder type battery cell 130.

(13) The sum of a length H1 of the one side end portion 131 of the cylinder type battery cell 130 inserted into the first recessed portion 111 and a length H2 of the other side end portion 132 of the cylinder type battery cell 130 inserted into the second recessed portion 121 is about 40% of a length between the both side end portions 131 and 132 of the cylinder type battery cell 130.

(14) FIG. 3 is a schematic view showing a structure in which the battery cell tray of FIG. 1 is accommodated in a battery cell package member according to another embodiment of the present disclosure.

(15) Referring to FIG. 3, a battery cell package member 300 includes a battery cell tray 100, a first package member 310, and a second package member 320.

(16) The first package member 310 is made of a paper box having a sectional shape of a corrugated structure and includes a storage 311 configured to accommodate the battery cell tray 100 in which a plurality of cylinder type battery cells 130 are accommodated between a first tray member 110 and a second tray member 120.

(17) The battery cell tray 100 is accommodated in the storage 311 of the first package member 310, and then the first package member 310 is accommodated in a storage 321 of the second package member 320.

(18) The second package member 320 is made of a polymer resin and may be easily deformed into a shape corresponding to a shape of an outer surface of the first package member 310 due to flexible physical properties thereof.

(19) Further, since the second package member 320 completely seal the storage 321 in a state of accommodating the first package member 310, a rust inhibitor vaporized in the first tray member 110 and the second tray member 120 may be prevented from flowing out to the outside of the second package member 320 so that a rust-proofing effect with a volatile rust inhibitor may be maintained for a longer period of time.

(20) Hereinafter, the present disclosure will be described in detail with reference to examples of the present disclosure, but the scope of the present disclosure is not limited thereto.

Example 1

(21) 5 parts by weight of NaNO.sub.2 powder was mixed with 100 parts by weight of a polypropylene resin, followed by an extrusion process to manufacture a polypropylene sheet having a thickness of 400 m. Thereafter, a battery cell tray having the shape shown in FIG. 1 was manufactured by a vacuum forming method at a temperature of about 100 C.

Example 2

(22) The polypropylene sheet having a thickness of 400 m was manufactured as shown in FIG. 4, 5 parts by weight of polyacryl as a binder and 5 parts by weight of NaNO.sub.2 powder as a volatile rust inhibitor were added to 100 parts by weight of a toluene solvent and stirred to prepare a rust inhibitor solution. Then, the rust inhibitor solution was applied on the polypropylene sheet to a thickness of 20 m and dried. Thereafter, a battery cell tray having the shape shown in FIG. 1 was manufactured by a vacuum forming method at a temperature of about 100 C.

Comparative Example

(23) The same battery cell tray as in Example 1 was manufactured, except that the volatile rust inhibitor was not mixed.

(24) Manufacturing of Battery Cell

(25) A cap assembly including an iron (Fe) element was coupled to a battery case including an iron (Fe) element and sealed to manufacture a cylinder type battery cell in a state in which a wound type electrode assembly was impregnated with an electrolyte in the battery case.

<Experimental Example 1> Corrosion Prevention Effect

(26) 120 cylinder type battery cells were respectively accommodated in the battery cell trays manufactured in Examples 1 and 2 and Comparative Example, and the battery cell tray accommodating the cylinder type battery cells was sealed in a state of being accommodated in a storage of a first package member made of a paper box. The first package members, each thereof accommodate the battery cell trays manufactured in Examples 1 and 2 and Comparative Example 1, were stored in a chamber maintained at a temperature of 60 C. and a humidity of 95% for 7 days, and then the number of the cylinder type battery cells in which corrosion occurred was confirmed, and the results are shown in Table 1 below.

(27) TABLE-US-00001 TABLE 1 Battery Cell with Corrosion Example 1 3 Example 2 0 Comparative Example 1 10

(28) As shown in Table 1, in the case of Example 1 in which the battery cell tray included the volatile rust inhibitor, corrosion occurred in three cylinder type battery cells, and in the case of Example 2, no corrosion occurred on a surface of the cylinder type battery cell. On the other hand, in the case of Comparative Example in which the battery cell tray did not include the volatile rust inhibitor, it was confirmed that corrosion occurred on surfaces of the 10 cylinder type battery cells.

(29) Therefore, it is confirmed that the volatile rust inhibitor included in the battery cell tray is vaporized at room temperature and reacted with the iron (Fe) element included in the battery case and cap assembly to finely oxidize the surface of the battery cell to form gamma-iron trioxide (-Fe.sub.2O.sub.3), and the gamma-iron trioxide (-Fe.sub.2O.sub.3) formed on the surface of the battery case or cap assembly acts as a rust-proofing film to prevent corrosion in the battery cell. It is also confirmed that the battery cell tray of Example 2 manufactured by applying a volatile rust inhibitor on the tray member has a more excellent rust-proofing effect than the battery cell tray of Example 1.

<Experimental Example 2> Tray Strength Evaluation

(30) Specimens were manufactured by cutting the trays of Examples 1 and 2 and Comparative Example to a width of 12.7 mm and a length of 12.7 mm. A tensile strength of the specimens was measured by the method according to ASTM D638, and the results are shown in Table 2.

(31) TABLE-US-00002 TABLE 2 Tensile Strength (MPa) Example 1 22.5 Example 2 32.7 Comparative Example 1 32.8

(32) As shown in Table 2, it is confirmed that the tensile strength of Example 1 including the volatile rust inhibitor was lower than that of Comparative Example 1 which did not include the volatile rust inhibitor, and the tensile strength of Example 2 manufactured by a coating method is equivalent to that of Comparative Example 1.

(33) Although the present disclosure has been described with reference to the accompanying drawings and embodiments thereof, it should be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the present disclosure.