Lithium ion rechargeable battery

• US 20070154789A1
• Filed: 12/28/2006
• Published: 07/05/2007
• Est. Priority Date: 12/29/2005
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Kim, Yong-Tae, Hyung, Yoo-Eup, Chang, Seok-Gyun, Nam, Sang-Bong, Kim, Jung-Seog
• Granted Patent: US 8,053,101 B2
• Time in Patent Office: Days
• US Class Current: 429/130
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 50/186 characterised by the disposition of the sealing members
• CPC Class Codes: H01M 50/325 comprising deformable valve members, e.g. elastic or flexible valve members
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A lithium ion secondary battery in which an electrode assembly is easily impregnated with an electrolyte is provided. The lithium ion secondary battery includes an electrode assembly wrapped by a sealing tape, an upper insulating plate positioned on the top of the electrode assembly, a lower insulating plate positioned at the bottom of the electrode assembly, a case for accommodating the electrode assembly, and a cap assembly for sealing the case. In one embodiment, the upper insulating plate has holes which may include a form of a mesh. In another embodiment, the lower insulating plate has various shapes of recesses on the surface. The surface of the lower insulating plate may be coated with a material that has an affinity for the electrolyte. An inner surface of the case may have various shapes of recesses or grooves. The sealing tape may be coated with a material that has an affinity for an electrolyte. Therefore, according to the principles of the present invention, the electrode assembly is easily impregnated with the electrolyte, and overall performance of the lithium ion secondary battery is improved.

Claims

1. A lithium ion secondary battery comprising:

a case having an open top end and a closed bottom end;

an electrode assembly disposed inside the case;

a cap assembly disposed on the top end of the case, the cap assembly sealing the open top end of the case; and

a lower insulating plate disposed between the electrode assembly and the bottom end of the case, a recess with a depth formed on a surface of the lower insulating plate.

2. The lithium ion secondary battery as claimed in claim 1, comprised of the recess including a check pattern.

3. The lithium ion secondary battery as claimed in claim 1, comprised of the recess including a radial pattern.

4. The lithium ion secondary battery as claimed in claim 1, wherein a material of the lower insulating plate is one selected from the group consisting of polyethylene (PE) and polypropylene (PP).

5. The lithium ion secondary battery as claimed in claim 1, comprised of the lower insulating plate being made of compressed felt.

6. The lithium ion secondary battery as claimed in claim 1, wherein a surface of the lower insulating plate is coated with polyvinyldifluride (PvdF) material.

7. The lithium ion secondary battery as claimed in claim 6, wherein the polyvinyldifluride (PVdF) material is one selected from the group consisting of PVdF 761, PVdF 2801, and a mixture of the PVdF 761 and the PVdF 2801.

8. The lithium ion secondary battery as claimed in claim 1, comprised of the lower insulating plate having a hollow on the center.

9. The lithium ion secondary battery as claimed in claim 8, comprised of the recess including a radial pattern.

10. The lithium ion secondary battery as claimed in claim 9, comprised of the recess including a circular recess encircling the hollow.

11. The lithium ion secondary battery as claimed in claim 1, comprised of the surface of the lower insulating plate being a surface of the lower insulating plate facing the electrode assembly.

12. A lithium ion secondary battery comprising:

a case having an open top end and a closed bottom end;

an electrode assembly disposed inside the case;

a cap assembly disposed on the top end of the case, the cap assembly sealing the open top end of the case; and

a lower insulating plate disposed between the electrode assembly and the bottom end of the case, a recess with a depth formed on a surface of the lower insulating plate; and

an upper insulating plate disposed between the electrode assembly and the cap assembly, the upper insulating plate having a plurality of holes.

13. The lithium ion secondary battery as claimed in claim 12, comprised of the holes of the upper insulating plate including a form of a mesh.

14. The lithium ion secondary battery as claimed in claim 12, wherein the upper insulating plate is made of polyethylene (PE) or polypropylene (PP), and the lower insulating plate is made of polyethylene (PE) or polypropylene (PP).

15. The lithium ion secondary battery as claimed in claim 12, wherein the upper insulating plate and the lower insulating plate are made of compressed felt.

16. The lithium ion secondary battery as claimed in 12, wherein the upper insulating plate and the lower insulating plate are coated with polyvinyldifluride (PvdF) material.

17. The lithium ion secondary battery as claimed in claim 16, comprised of the polyvinyldifluride (PVdF) material being one selected from the group consisting of PVdF 761, PVdF 2801, and a mixture of the PVdF 761 and the PVdF 2801.

18. A lithium ion secondary battery comprising:

a case having an open top end and a closed bottom end;

an electrode assembly disposed inside the case;

a cap assembly disposed on the top end of the case, the cap assembly sealing the open top end of the case; and

a sealing tape wrapping the outer circumference of the electrode assembly, a groove with a predetermined depth formed on an inner surface of the case where the inner surface of the case partially contacts the sealing tape.

19. The lithium ion secondary battery as claimed in claim 18, comprised of the groove of the inner surface of the case including a shape of a straight line stretched from the top end of the case to the bottom end of the case.

20. The lithium ion secondary battery as claimed in claim 18, wherein the cross-section of the groove is in a form of one selected from the group consisting of a triangle, a rectangle, and a semi-circle.

21. The lithium ion secondary battery as claimed in claim 18, wherein the depth of the groove is no more than about 15% of the thickness of the case.

22. The lithium ion secondary battery as claimed in claim 18, wherein the depth of the groove is no more than about 37.5 micro-meters.

23. The lithium ion secondary battery as claimed in claim 18, comprised of the cap assembly including a safety vent.

24. The lithium ion secondary battery as claimed in claim 23, comprised of the case withstanding pressure no less than about three times of operation pressure of the safety vent.

25. The lithium ion secondary battery as claimed in claim 23, comprised of the case withstanding internal pressure no less than about 15 kgf/m².

26. The lithium ion secondary battery as claimed in claim 18, comprised of the sealing tape being coated with polyvinyldifluride (PvdF) material.

27. The lithium ion secondary battery as claimed in claim 26, comprised of the polyvinyldifluride (PvdF) material being one selected from the group consisting of PVdF 761, PVdF 2801, and a mixture of the PVdF 761 and the PVdF 2801.

28. A lithium ion secondary battery comprising:

a case having an open top end and a closed bottom end;

an electrode assembly disposed inside the case;

a cap assembly disposed on the top end of the case, the cap assembly sealing the open top end of the case; and

a sealing tape wrapping the outer circumference of the electrode assembly, an inner surface of the case having a regular pattern where the inner surface of the case partially contacts the sealing tape.

29. The lithium ion secondary battery as claimed in claim 28, comprised of the regular pattern of the inner surface of the case including either a plurality of stripes or a plurality of protrusions.

30. The lithium ion secondary battery as claimed in claim 28, comprised of the sealing tape being coated with polyvinyldifluride (PVdF) material.

31. The lithium ion secondary battery as claimed in claim 30, comprised of the polyvinyldifluride (PVdF) material being one selected from the group consisting of PVdF 761, PVdF 2801, and a mixture of the PVdF 761 and the PVdF 2801.