Battery pack

• US 6,225,778 B1
• Filed: 07/18/2000
• Issued: 05/01/2001
• Est. Priority Date: 07/19/1999
• Status: Expired due to Term

• Current Assignee: Toshiba Battery Co., Ltd. (Toshiba Corporation)
• Original Assignee: Toshiba Battery Co., Ltd. (Toshiba Corporation)
• Inventors: Hayama, Hideki, Takeishi, Ryuta, Kurihara, Yu, Tanaka, Haruhiko
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/618,287
• Time in Patent Office: 287 Days
• Field of Search: 320/107, 320/110, 320/112, D13/103, D13/107, D13/108, 307/150, 429/96, 429/97, 429/98, 429/99, 429/100
• US Class Current: 320/112
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 2200/106 PTC
• CPC Class Codes: H01M 50/296 characterised by terminals of battery packs terminals of batteries H01M50/543
• CPC Class Codes: H01M 50/55 on the same side of the cell
• CPC Class Codes: H01M 50/553 Terminals adapted for prismatic, pouch or rectangular cells
• CPC Class Codes: H01M 50/562 characterised by the material
• CPC Class Codes: H01M 50/566 by welding, soldering or brazing
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack has a flat battery cell, which includes a flat electric power generating element, at least one armor material for sealing the electric power generating element, and positive and negative tabs (1a, 2a) extending from the electric power generating element to the outside of the armor material through a sealing of the armor material; a circuit board (6) connected to the positive and negative tabs; and a container (16) having two main walls extending along two main surfaces of the flat battery cell. At least a portion of the circuit board is positioned in a space (8) defined by a sealing of the armor material beside the circuit board and the inner surface of the container. At least one of the two main walls of the container is at least partially formed of a metal plate (12a, 14a).

Claims

1. A battery pack (10, 10′

, 20, 30, 40, 50) comprising;

a flat battery cell (B1, B2) including a flat electric power generating element (A), at least one armor material (4) for sealing said flat battery cell, and a positive tab (1a) and a negative tab(2a) extending from said electric power generating element to the outside of the armor material through sealings (4A₁, 4A₂, 4A₃, 4A₄) of said armor material;

a circuit board (6) connected to said positive tab and said negative tab; and

a container (16, 26, 36, 46, 56) having two main walls (12a, 14a;

12′

, 14a;

22a, 24a;

32a, 34a;

42a, 44a;

52a, 54a) extending along two main surfaces of said flat battery cell,

wherein at least a portion of said circuit board is positioned in a space (8, 8′

) defined by the sealing (4A₄) of said armor material beside said circuit board and an inner surface of said container, and at least one of the two main walls of said container is at least partially formed of a metal plate.

2. The battery pack (10, 30, 40, 50) according to claim 1, wherein said container (16, 36, 46, 56) comprises two case halves (12, 14;

32, 34;

42, 44;

52, 54); and

each of said case halves includes a main wall (12a, 14a;

32a, 34a;

42a, 44a;

52a, 54a) at least partially made of a metal plate.

3. The battery pack (10, 30, 40, 50) according to claim 2, wherein each of said case halves includes a metal plate (12a, 14a;

32a, 34a;

42a, 44a;

52a, 54a) constituting the main wall, and a frame (12b, 14b;

32b, 34b;

42b, 44b;

52b, 54b) made of resin and attached to the metal plate, both said case halves being integrated with each other through said frames.

4. The battery pack according to claim 3, wherein said metal plate (12a, 14a) constituting the main wall of each said case half is insert molded into said frame (12b, 14b) of the case half associated therewith.

5. The battery pack (30, 40) according to claim 2, wherein one of said case halves (34) includes a metal plate (34a, 44a) constituting the main wall and a frame (34b, 44b) made of resin attached to said metal plate, and another case half only includes a metal plate (32, 42) having a side wall (32b, 42b) thereof fitted into the frame (34b, 42b) of said one of the case halves.

6. The battery pack (40) according to claim 5, wherein said side wall (42b) of the metal plate is formed with a stopper (42s), and said frame (44b) is formed with a recess (44c ) into which the stopper can be inserted, the stopper being extendable in the recess of the frame to prevent the metal plate from coming off from the frame.

7. The battery pack (10′

, 20) according to claim 1, wherein said container (26) comprises two case halves (12′

, 14;

22, 24);

one case half (12′

, 22) comprises a frame made of resin; and

another case half (14, 24) has a main wall thereof at least partially made of a metal plate (14a, 24a).

8. The battery pack (10′

, 20) according to claim 7, wherein said another case half (14, 24) includes a metal plate (14a, 24a) constituting the main wall and a frame (14b, 24b) made of resin and attached to the metal plate; and

said one case half (12′

, 22) is attached to the frame of said another case half.

9. The battery pack (10′

) according to claim 8, wherein said metal plate (14a) constituting the main wall of said another case half (14) is insert molded into the frame (14b) of said another case half.

10. The battery pack (10′

) according to claim 7, wherein said one case half (12′

) is provided at its surface with a label (37′

) made of metal.

11. The battery pack (10, 10′

, 20, 30, 40, 50) according to claim 3, 4 or 7, wherein said frame (12b, 14b;

12′

, 22;

32b, 34b;

42b, 44b;

52b, 54b) is made of a resin composition composed of a thermoplastic resin and a glass component.

12. The battery pack (10, 10′

, 20, 30, 40, 50) according to claim 11, wherein the thermoplastic resin is polycarbonate or liquid crystal polymer or a compound of polycarbonate and acrylic butadiene styrene resin, and the glass component is chopped glass fiber or glass beads.

13. The battery pack (10, 10′

, 20, 30, 40, 50) according to claim 12, wherein a percentage of the glass component is in a range of 10 to 25 volume %.

14. The battery pack (10) according to claim 3, wherein said frame (14b) of said one case half (14) forms an insulating region (14i) extending over an inner surface of the metal plate (14a) constituting the main wall of said one case half (14).

15. The battery pack (20) according to claim 8, wherein said frame (24b) of said another case half (24) forms an insulating region (24i) extending over an inner surface of the metal plate (24a) constituting the main wall of said another case half.

16. The battery pack (10, 30, 40) according to claim 3, wherein either one (14, 34, 44) of said two case halves is provided with connection terminals (6c) for connection of said circuit board (6) to an electronic device, said connection terminals being exposed on an outer surface of the case half.

17. The battery pack (10, 30, 40) according to claim 16, wherein said connection terminals (6c) are exposed on the outer surface of the frame (14b, 34b, 44b) of the case half (14, 34, 44) provided with these connection terminals, through openings (14d, 34d, 44d) formed in the frame of this case half.

18. The battery pack (10′

, 20) according to claim 8, wherein said another case half (14, 24) is provided with connection terminals (6c) for connection of said circuit board (6) to an electronic device, said connection terminal being exposed on an outer surface of said another case half.

19. The battery pack (10′

, 20) according to claim 18, wherein said connection terminals (6c) are exposed on the outer surface of the frame (14b, 24b) of the case half (14, 24) provided with these connection terminals, through openings (14d, 24d) formed through the frame of this case half.

20. The battery pack (10) according to claim 1, wherein connections of said positive and negative tabs (1a, 2a) to the terminals (6f) of said circuit board (6) are positioned within said space (8′

).

21. The battery pack according to claim 1, wherein a pair of lands (6m, 6n) are formed on said circuit board (6), said pair of lands being connected directly with said positive and negative tabs (1a, 2a).

22. The battery pack according to claim 21, wherein:

said circuit board (6) are mounted with protection circuit parts (61);

said positive tab (1a) is made of Al, and said negative tab (2b) is made of Ni;

said positive and negative tabs are welded to the pair of lands formed on said circuit board; and

said pair of lands are comprised of a positive land (6m) to which a Ni surface of an Al/Ni clad piece is soldered and a negative land (6n) to which a Ni piece is soldered.

23. The battery pack according to claim 22, wherein the soldering is performed simultaneously with reflow processing upon surface mounting the protection circuit parts (61) on said circuit board.

24. The battery pack (40) according to claim 3, wherein said metal plate (44a) constituting said main wall of at least one (44) of said two case halves is formed with a plurality of ribs (44r) or openings.

25. The battery pack (20) according to claim 7, wherein said one case half (22) forms part of an outer wall of an electronic device (80) to which said battery pack is mounted.

26. The battery pack according to claim 1, 2 or 7, wherein said battery pack is arranged to be mounted to an electronic device (202) having a terminal set (B11, B12, B13);

said battery pack includes a terminal set (A11, A12, A13) mounted on said container (201) oppose to and connectable to the terminal set of the electronic device; and

said terminal set (A11, A12, A13) of said battery pack includes a resin molding (203) mounted to said container (201), and terminals (203b) exposed in the resin molding and connected to said circuit board (6), said terminal set being firmly engaged with the terminal set (B11, B12, B13) of the electronic device when said battery pack is mounted to the electronic device.

27. The battery pack according to claim 26, wherein said terminal set (A11) of said battery pack includes a plurality of insertion holes (203a) formed in the resin molding (203) and a plurality of terminals (203b) accommodated in the insertion holes;

and

said terminal set (B11) of the electronic device includes a plurality of terminals (204) press fitted into the insertion holes (203a) formed in the resin molding of the terminal set of said battery pack.

28. The battery pack according to claim 26, wherein said terminal set (A13) of said battery pack includes a plurality of slits (203c) formed in the resin molding (203) and a plurality of terminals (203b) accommodated in the slits;

each of the terminals (203b) of the terminal set of said battery pack includes a leading end piece (203d) connected to said circuit board and two terminal pieces (203b₁, 203b₂) integral with said leading end piece, said two terminal pieces being in pressure contact with two mutually opposing slit-defining surfaces (203e) of the resin molding with a spring force of the two terminal pieces;

said terminal set (B13) of the electronic device includes a plurality of terminals (204) each of which is press fitted in between the two terminal pieces (203b₁, 203b₂) of a corresponding one of the plurality of terminals of said terminal set of said battery pack.

29. The battery pack according to claim 1, 2 or 7, wherein said electric power generating element (A) of said flat battery cell is sealed by at least one armor material (4);

said armor material is sealed along at least three peripheral sides including first and second peripheral sides (4A₁, 4A₃) respectively extending along two side edges of said electric power generating element and a third peripheral side (4A₄) extending along an end edge of said electric power generating element beside said circuit board;

the first and second peripheral sides of the armor material are bent along the side edges of said electric power generating element in a thickness direction of said flat battery cell; and

a width dimension of a portion of the first and second peripheral sides beside said circuit board is smaller than a width dimension of the remaining portion of the first and second peripheral sides, such that a height dimension of said portion of the two peripheral sides beside said circuit board becomes small when the first and second peripheral sides are bent.

30. The battery pack according to claim 29, wherein said electric power generating element (A) of said flat battery cell is sealed by a single armor material (4) folded in two;

and

said armor material is sealed on said first, second and third peripheral sides (4A₁, 4A₃, 4A₄).

31. The battery pack according to claim 1, 2 or 7, wherein said circuit board (313) is flexible, and includes an extension (313b) extending outwardly from said container (315), said extension serving as an external connection terminal for use in electric connection of said battery pack to an electronic device to which said battery pack is mounted.

32. The battery pack according to claim 31, wherein circuit parts (314) constituting a protection circuit for said flat battery cell are mounted on said circuit board (313);

and

said circuit board includes tabs (313a) connected to said positive and negative tabs (311a) of said flat battery cell.

33. The battery pack according to claim 31, wherein said container (315) is formed in the shape of flat box;

and

said extension (313b) of said circuit board extends from said container (315) in parallel with the main wall of said container.

34. The battery pack according to claim 33, wherein said extension (313b) of said circuit board is sandwiched by a connector (316) of the electronic device to which said battery pack is mounted.

35. The battery pack according to claim 1, 2 or 7, further including:

a resistive element (90) having a positive temperature coefficient and arranged on a sealing (4A₄), on a side of said circuit board, of said armor material through a thermally insulating material (91), said resistive element having one end portion thereof connected to one of said positive tab (1a) and said negative tab (2a).

36. The battery pack according to claim 35, wherein said resistive element (90) includes a pair of metal foils (90a, and 90b ) and an electrically conductive polymer sheet (90c) interposed between said metal foils and having a positive temperature coefficient, said resistive element being formed in L-shape as seen in a plan view.

37. The battery pack according to claim 8, wherein said metal plate constituting said main wall of said another case half is formed with a plurality of ribs or openings.

38. The battery pack according to claim 1, wherein said battery pack is mounted to an electronic device that is a portable telephone or a personal digital assistant.