WO2002009210A2

WO2002009210A2 - Battery case for thin metal film cells

Info

Publication number: WO2002009210A2
Application number: PCT/US2001/018277
Authority: WO
Inventors: Michael G. Andrew
Original assignee: Johnson Controls Technology Co
Current assignee: Johnson Controls Technology Co
Priority date: 2000-07-21
Filing date: 2001-06-26
Publication date: 2002-01-31
Anticipated expiration: 2003-01-21
Also published as: AU2001268202A1; WO2002009210A3

Abstract

The present invention includes a battery case (1) and battery (8) wherein the battery case includes a housing (12) having a top (14) and a bottom (16) and wherein the housing defines a plurality of cavities (40) that are generally octagonal in cross-section. The battery includes a housing defining octagonal shaped cavities, a terminal (88) coupled to the housing, and a plurality of battery cells (18) disposed in the cavities and electrically interconnected in series with the terminal. In another embodiment, the present invention includes a battery case and battery wherein the battery case includes a housing having a top and a bottom and wherein the housing defines a plurality of cavities having an upper portion, a central portion and a lower portion. The upper and lower portions of each cell cavity are generally circular in cross-section. The battery includes a housing defining a plurality of cavities, the cavities having an upper portion being generally octagonal in cross section, a central portion being generally circular in cross section, and a lower portion being generally octagonal in cross section; that are generally octagonal in cross-section, a terminal coupled to the housing, a top and bottom sealingly coupled to the housing, and a plurality of battery cells disposed win the cavities and electrically interconnected in series with the terminal.

Description

BATTERY CASE FOR THIN METAL FILM CELLS

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electric storage batteries, and more particularly, to a container for thin metal film battery cells.

2. Description of the Related Art

Thin metal film (TMF) battery technology provides a compact high power battery cell. Cells of this type are well known and their construction and manufacture have been described in, for example, U.S. Pat. Nos. 3,494,800; 5,045,086; 5,047,300; 5,198,313 and 5,368,961 the disclosures of which are hereby incorporated by reference. A thin metal film battery cell includes thin metal film plates sealed within a sealed cell container which is valve regulated. The cells include absorptive glass-mat (AGM) separator technology in an electrolyte starved system. The thin metal film plates are made from very thin lead foil approximately about 0.005 inches thick, pasted with an active material forming a pasted plate approximately about 0.012 inches thick. The plates are spiral wound with separator material, and terminations are cast-on or soldered to the ends of the spiral roll. The roll is encapsulated in a container which is filled with electrolyte and then sealed except for the vent. The performance characteristics of thin metal film cells include a high power/weight ratio and rapid recharge capability.

In the present state of the art, TMF cells are individually packaged and sealed in plastic containers. These cells are then electrically joined in series to make the TMF battery. While the individual packaging of TMF cells is acceptable for single celled batteries or multiple celled batteries used in environments where the structural integrity of the cells is not of great concern, it is desirable to provide greater structural integrity for serially connected TMF cells. The prior art has failed to adequately address this need. SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a battery case for thin metal film battery cells. The case includes a modified honeycomb design that defines a plurality of generally octagonal shaped cell cavities. The modified honeycomb design provides a container with a structural strength that is improved over prior art containers for multiple TMF cells. The modified honeycomb design also allows for uniform cell wall thickness throughout the case thereby increasing the uniform expansion or shrinkage during operation of the battery and reducing distortion following the molding process. Additionally, the case configuration provides a flat surface within each cavity to facilitate alignment of the cells within the cavity and the electrical interconnection of the cells. The modified honeycomb also improves the moldability of the case by eliminating knife edges within the mold core.

In another form, the present invention is directed to a battery case for thin metal film battery cells. The battery case includes a housing having a top and a bottom, wherein the housing defines a plurality of cavities having an upper portion, a central portion and a lower portion. The upper and lower portions of each cell cavity are generally octagonal in cross-section and the central portion of each cell cavity is generally circular in cross-section.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description, appended claims and accompanying drawings where:

Figure 1 is a perspective view of the thin metal film cell battery according to the present invention;

Figure 2 is an exploded perspective view of the thin metal film cell battery illustrated in Figure 1 ;

Figure 3 is a bottom plan view of the battery case illustrated in Figure 1 with the bottom of the case removed for clarity;

Figure 4 is a top plan view of the battery shown in Figure 1 with the top of the case removed for clarity; Figure 5 is a cross-sectional view of the battery taken along the plane 5-5-5 shown in Figure 1 ;

Figure 6 is a cross-sectional view of the top of the battery case taken along the line 6-6 illustrated in Figure 2;

Figure 7 is a cross-sectional view of the bottom of the battery case taken along the line 7-7 shown in Figure 2;

Figure 8 is an exploded perspective view of another embodiment of a thin metal film cell battery;

Figure 9 is a top plan view of the battery shown in Figure 8 with the top of the case removed for clarity;

Figure 10 is a cross-sectional view of the battery of Figure 8 taken along plane 10-10-10 of Figure 8 with the battery cells removed for clarity; and

Figure 11 is a bottom plan view of the battery case illustrated in Figure 8 with the bottom of the case removed for clarity.

It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

Like reference numerals will be used to refer to like or similar parts from Figure to Figure in the following description of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated in Figure 1 the battery 8 includes a case 10 having a body 12 with a top 14 and a bottom 16 each coupled to the body in a manner known in the art such as by heat sealing. Case 10 is configured to accommodate a plurality of thin metal film cells 18 (Figure 2) that include a thin metal film 20 coiled in a manner generally known in the art. The film 20 defines an outer cylindrical surface area generally indicated by reference numeral 21 , a first end 22, and second end 24. First and second conducting leads 26 and 28 are coupled to the respective first and second ends 22 and 24 of the coiled thin metal film 20 such as by welding or an equivalent technique known in the art. As thin metal film (TMF) battery cells are generally known in the art, recognized techniques for manufacturing TMF cells and the manner in which they generate electricity will not be described herein. For a general description of such cells, reference may be had to U.S. Patent Application Serial. No. 08/870,803, filed Jun. 6, 1997, entitled "Modular Electric Storage Battery", and assigned to the assignee of the present invention, the disclosure of which is incorporated herein by reference.

With reference to Figures 2 and 3, body 12 includes exterior side walls 30 and 32 and exterior end walls 34 and 36 as well as a plurality of partition walls generally indicated by reference numeral 38. Partition walls 38 interconnect exterior side walls 30 and 32 and exterior end walls 34 and 36 in a modified honeycomb configuration that includes a plurality of generally octagonal shaped cell cavities 40. This honeycomb configuration provides a structurally robust battery case capable of withstanding the internal pressures generated during operation, generally on the order of about twenty pounds per square inch gage (20 psig), without distortion.

In the illustrated embodiment, exterior walls 30, 32, 34, and 36, as well as each of the plurality of partition walls 38, have the same wall thickness 41 (Figure 3) thereby simplifying the manufacture of case 10. Additionally, the modified honeycomb configuration and the uniform wall thicknesses of the various external and partition walls increases the uniformity of expansion or shrinkage during operation of the battery and reduces distortion following the molding process. Accordingly, case 10 more consistently maintains structural integrity throughout its operational life. Moreover, the honeycomb configuration includes a flat surface within each cavity to facilitate alignment of the cells within the cavity and the electrical interconnection of the cells such as by welding. A still further advantage of the present invention is that the honeycomb configuration improves the moldability of the case by eliminating knife edges within the mold core.

The modified honeycomb configuration will now be described in detail. Partition walls 38 include a plurality of first planar segments 46 and second planar segments 48 oriented orthogonal to first planar segments 46. Second planar segments 48 are further orthogonal to first and second exterior end walls 36 and parallel to first and second exterior side walls 30 and 32. In a similar manner, each of first planar segments 46 are parallel to first and second exterior end walls 34 and 36 and perpendicular to side walls 30 and 32. A plurality of arcuate connector segments 50 interconnect first and second planar segments 46 and 48 as well as couple the planar segments to the respective exterior side and end walls 30, 32, 34, and 36. Each of the arcuate connector segments 50 are integral with one or three other arcuate connector segments to define a plurality of roughly diamond shaped passages 52 or half diamond shaped passages 53, each with rounded corners as shown.

The planar segments 46 and 48, the exterior side and end walls, and the arcuate connector segments cooperate to define the octagonal cell cavities 40 for accommodating cells 18. As best illustrated in Figure 3, cells 18a-18f are each disposed in a cavity 40 (Figure 2) of body 12. The arcuate configuration of segments 50 is predetermined to securely retain the cells 18 within each cavity 40. More particularly, in the preferred embodiment, the overall size of each cavity as well as the shape of arcuate segments 50 are predetermined so that during the insertion of each cell 18 within each cavity 40, the arcuate segments 50 matingly engage the cell 18 along in excess of fifty percent (50%) of the exterior surface area 21 of film 20. The uniform thickness of the exterior case walls 30, 32, 34, and 36 and each partition wall 38 uniformly compresses the cell during insertion such as by compressing the glass fiber separators normally included therewithin. Accordingly, cells 18 are securely nested and retained within cavities 40. Finally, as illustrated in Figure 5, top 14 and stops 62 longitudinally retain the cells within the cavities as shown.

As illustrated, the exterior end walls, exterior side walls, and partition walls of body 12 are integral with one thereby further increasing the robustness of body 12. It is preferred that the walls are formed of a thermally resistant plastic material such as polypropylene through processes known in the art such as stamping, casting, or injection molding. In order to further define generally octagonal cell cavities 40, exterior side walls 30 and 32 are connected to exterior end walls 34 and 36 via truncated planar corner segments 54. As best illustrated in Figure 2, the exterior walls 30, 32, 34, and 36 of body 12 are of a uniform length 56 defining an upper end 58 and a lower end 60. Top 14 is coupled to the case 12 proximate to upper end 58 and bottom 16 is coupled proximate to lower end 60 thereof (Figure 1 ).

In addition to the robustness, retention features, and moldability of the modified honeycomb configuration of the present invention, the flat surfaces provided by planar segments 46 and 48 facilitate the proper alignment of each cell within its respective cavity and provides a flat surface for complete electrical interconnection of the cells by welding as hereinafter described. More particularly, as best illustrated in Figures 3 and 4, the upstanding tabs 27a-27f of the cells 18a-18f are disposed within the cells 40 adjacent one of the planar surfaces 46 and 48. The welding interconnection between adjacent tabs within the battery case occurs through an orifice 71 formed in the planar segments 46 and 48 as hereinafter described and as illustrated in Figure 5. Those skilled in the art will appreciate that a complete weld connection between adjacent tabs is facilitated by the planar configuration of surfaces 46 and 48.

As shown in Figures 3 and 5, body 12 further includes a plurality of semicircular stops 62 integral with and extending inwardly from arcuate connector segments 50 and truncated planar corner segments 54. Stops 62 are recessed from lower end 60 (Figure 5) of these respective segments to properly position TMF cells 18 within cell cavities 40 thereby facilitating the electrical interconnection of TMF cells 18 as hereinafter described.

The configuration of top 14 will now be described with reference to Figures 1 , 5 and 6. Top 14 is preferably formed of the same plastic material as body 12 through stamping, casting, injection molding, or other method known in the art. Top 14 includes an upper planar member 64, a connecting flange 66 extending downwardly from the periphery of upper member 64, and a plurality of vents 68 (Figure 6) disposable within cell cavities 40 when top 14 is connected to body 12 (Figure 5). Vents 68 are configured in a manner generally known in the art and allow dissipation of gases generated within case 10 during the charging and discharging cycles of the TMF cells. Vents 68 also include venting passages 70 that selectively provide access to cell cavities 40 for placement of an electrolyte within each of the cell cavities.

Vents 68 are partially defined by a cylindrical connecting wall 72 interconnecting upper planar member 64 and a lower member 73. Cylindrical connecting walls 72 of adjacent vents 68 are separated from one another to define a recessed cavity 74 that accommodates the upstanding tab 27 on conducting leads 26 of 28 for electrically interconnecting the TMF cells 18 as hereinafter described.

As illustrated in Figure 7, bottom 16 is configured in a manner substantially similar to top 14 and includes a lower planar member 78, a connecting flange 80, and upper members 82 recessed from lower planar member 78 and connected thereto via tapered cylindrical connecting walls 84. Bottom 16 does not include the vent arrangement formed in top 14.

Top and bottom 14 and 16, respectively, are connected to body 12 such as by heat sealing or other method known in the art. More particularly, connecting flanges 66 and 80 of top 14 and bottom 16, respectively, are configured to operatively engage exterior side and end walls 30, 32, 34, and 36 whereupon the top 14 and bottom 16 are heat sealed to body 12 to provide a sealed case that is vented through vents 68 in top 14.

The electrical interconnection of TMF cells 18 within the case 10 will now be described with reference to Figures 3 and 4. As illustrated, adjacent TMF cells are oppositely oriented in a manner generally known in the art for serial connection. Thus, cell 18a is electrically connected to exterior terminal 86 by second conducting lead 28a (Figure 3) and is electrically connected to cell 18b via the connection of the respective first conducting leads 26a and 26b. The serial electrical connection of the remaining cells 18b-18f is accomplished in a substantially similar manner and is illustrated in the drawings.

As illustrated in Figure 5, planar segment 46 separating cells 18c and 18d is provided with an orifice 71 for electrically connecting upstanding tabs 27c and 27d in a manner generally known in the art such as welding. Those skilled in the art will appreciate that the electrical interconnection of each of the plurality of cells 18a-18f occurring through second planar segments 48 are made in a manner substantially the same as that illustrated in Figure 5 for connection to first planar segment 46. As shown in Figure 3, the serial electrical connection of cells 18a-18f is completed by electrically connecting the second lead of cell 18f in a manner generally known in the art to terminal 88 which is coupled to the exterior of battery case 12 and, more particularly, to end wall 34.

As indicated above, the position of each TMF cell 18a-18f within its respective cavity 40 is dictated by the positioning of stops 62 as best illustrated in Figures 3 and 5. More particularly, each of the TMF cells are disposed within the respective cavity 40 until one of the first and second leads 26 and 28 connected thereto engage the stops 62 projecting inwardly into the cavity. The stops facilitate the proper positioning of the TMF cells relative to one another to allow precise electrical interconnection, as described above, with relative ease and simplicity.

Turning to Figures 8, 9, 10 and 11 , another embodiment of a battery case 10a is shown. In the embodiment of the battery case 10a, partition walls 38a interconnect exterior side walls 30a and 32a and exterior ends walls 34a and 36a in a second modified honeycomb configuration. In this battery case 10a, the partition walls 38a include an upper section, a central section and a lower section that define an upper portion, a central portion and a lower portion of the cell cavities 40a. Preferably, exterior walls 30a, 32a, 34a, and 36a, as well as each of the plurality of partition walls 38a, have the same wall thickness 41a (Figures 9 and 10) thereby simplifying the manufacture of case 10a. Additionally, the second modified honeycomb configuration and the uniform wall thicknesses of the various external and partition walls increases the uniformity of expansion or shrinkage during operation of the battery and reduces distortion following the molding process. Accordingly, case 10a more consistently maintains structural integrity throughout its operational life. Moreover, the second honeycomb configuration includes a flat surface within each cavity to facilitate alignment of the cells within the cavity and the electrical interconnection of the cells such as by welding. A still further advantage of the present invention is that the honeycomb configuration improves the moldability of the case by eliminating knife edges within the mold core.

Looking first at Figures 8 and 9, the upper section of the partition walls 38a include a plurality of first planar segments 46a and second planar segments 48a oriented orthogonal to first planar segments 46a. Second planar segments 48a are further orthogonal to first and second exterior end walls 34a and 36a and parallel to first and second exterior side walls 30a and 32a. In a similar manner, each of first planar segments 46a are parallel to first and second exterior end walls 34a and 36a and perpendicular to side walls 30a and 32a. A plurality of arcuate connector segments 50a interconnect first and second planar segments 46a and 48a as well as couple the planar segments to the respective exterior side and end walls 30a, 32a, 34a, and 36a. Each of the arcuate connector segments 50a are integral with one or three other arcuate connector segments to define a plurality of roughly diamond shaped passages 52a or half diamond shaped passages 53a, each with rounded corners as shown.

The planar segments 46a and 48a, the exterior side and end walls, and the arcuate connector segments cooperate to define a generally octagonal upper portion of cell cavities 40a for accommodating cells 18. As best illustrated in Figure 9, cells 18a-18f are each disposed in a cavity 40a (Figure 8) of body 12a. The arcuate configuration of segments 50a is predetermined to securely retain the upper portion of the cells 18 within each cavity 40a. More particularly, in the preferred embodiment, the overall size of each cavity as well as the shape of arcuate segments 50a are predetermined so that during the insertion of each cell 18 within each cavity 40a, the arcuate segments 50a matingly engage the upper portion of cell 18 along in excess of fifty percent (50%) of the exterior surface area 21 of film 20. The uniform thickness of the exterior case walls 30a, 32a, 34a, and 36a and the upper section of each partition wall 38a uniformly compresses the cell during insertion such as by compressing the glass fiber separators normally included therewithin. Accordingly, the upper portion of the cells 18 are securely nested and retained within the upper portion of cavities 40a. Finally, as illustrated in Figures 5 and 11 , top 14 and stops 62a longitudinally retain the cells within the cavities as shown.

As illustrated, the exterior end walls, exterior side walls, and partition walls of body 12a are integral with one another thereby further increasing the robustness of body 12a. It is preferred that the walls are formed of a thermally resistant plastic material such as polypropylene through processes known in the art such as stamping, casting, or injection molding.

In order to further define the generally octagonal upper portion of cell cavities 40a, exterior side walls 30a and 32a are connected to exterior end walls 34a and 36a via truncated planar corner segments 54a. As best illustrated in Figure 8, the exterior walls 30a, 32a, 34a, and 36a of body 12a are of a uniform length 56a defining an upper end 58a and a lower end 60a. Top 14 is coupled to the case 12a proximate to upper end 58a and bottom 16 is coupled proximate to lower end 60a thereof.

In addition to the robustness, retention features, and moldability of the second modified honeycomb configuration of the present invention, the flat surfaces provided by planar segments 46a and 48a facilitate the proper alignment of each cell within its respective cavity and provides a flat surface for complete electrical interconnection of the cells by welding. More particularly, as best illustrated in Figures. 8 and 9, the upstanding tabs 27a-27f of the cells 18a-18f are disposed within the cells 40a adjacent one of the planar surfaces 46a and 48a. The welding interconnection between adjacent tabs within the battery case occurs through an orifice 71 formed in the planar segments 46a and 48a as illustrated in Figure 5. Those skilled in the art will appreciate that a complete weld connection between adjacent tabs is facilitated by the planar configuration of surfaces 46a and 48a.

Looking now at Figure 10, the central section of the partition walls 38a include a generally circular wall 99 that defines a generally circular central portion of cell cavities 40a for accommodating cells 18. The circular configuration of the circular wall 99 is predetermined to securely retain the cells 18 within each cavity 40a. More particularly, in the preferred embodiment, the overall size of each cavity as well as the shape of the circular wall 99 is predetermined so that during the insertion of each cell 18 within each cavity 40a, the circular wall 99 matingly engages the cell 18 along all or nearly all of the exterior surface area 21 of the film 20. The central section of each partition wall 38a uniformly compresses the cell during insertion such as by compressing the glass fiber separators normally included therewithin. Accordingly, the central portion of the cells 18 are securely nested and retained within the central portion of cavities 40a.

Looking now at Figure 11 , the lower section of the partition walls 38a include a plurality of first planar segments 46b and second planar segments 48b oriented orthogonal to first planar segments 46b. Second planar segments 48b are further orthogonal to first and second exterior end walls 34 and 36a and parallel to first and second exterior side walls 30a and 32a. In a similar manner, each of first planar segments 46b are parallel to first and second exterior end walls 34a and 36a and perpendicular to side walls 30a and 32a. A plurality of arcuate connector segments 50b interconnect first and second planar segments 46b and 48b as well as couple the planar segments to the respective exterior side and end walls 30a, 32a, 34a, and 36a. Each of the arcuate connector segments 50b are integral with one or three other arcuate connector segments to define a plurality of roughly diamond shaped passages 52b or half diamond shaped passages 53b, each with rounded corners as shown.

The planar segments 46b and 48b, the exterior side and end walls, and the arcuate connector segments cooperate to define a generally octagonal lower portion of cell cavities 40a for accommodating cells 18. As best illustrated in Figure 11 , cells 18a-18f are each disposed in a cavity 40a (Figure 8) of body 12a. The arcuate configuration of segments 50b is predetermined to securely retain the lower portion of the cells 18 within each cavity 40a. More particularly, in the preferred embodiment, the overall size of each cavity as well as the shape of arcuate segments 50b are predetermined so that during the insertion of each cell 18 within each cavity 40a, the arcuate segments 50b matingly engage the lower portion of cell 18 along in excess of fifty percent (50%) of the exterior surface area 21 of film 20. The uniform thickness of the exterior case walls 30a, 32a, 34a, and 36a and the lower section of each partition wall 38a uniformly compresses the cell during insertion such as by compressing the glass fiber separators normally included therewithin. Accordingly, the lower portion of the cells 18 are securely nested and retained within the lower portion of cavities 40a. Finally, as illustrated in Figures 5 and 11 , top 14 and stops 62a longitudinally retain the cells within the cavities as shown.

As illustrated, the exterior end walls, exterior side walls, and partition walls of body 12a are integral with one another thereby further increasing the robustness of body 12. It is preferred that the walls are formed of a thermally resistant plastic material such as polypropylene through processes known in the art such as stamping, casting, or injection molding.

In order to further define the generally octagonal lower portion of cell cavities 40a, exterior side walls 30a and 32a are connected to exterior end walls 34a and 36a via truncated planar corner segments 54a. As best illustrated in Figure 8, the exterior walls 30a, 32a, 34a, and 36a of body 12a are of a uniform length 56a defining an upper end 58a and a lower end 60a. Top 14 is coupled to the case 12a proximate to upper end 58a and bottom 16 is coupled proximate to lower end 60a thereof.

In addition to the robustness, retention features, and moldability of the second modified honeycomb configuration of the present invention, the flat surfaces provided by planar segments 46b and 48b facilitate the proper alignment of each cell within its respective cavity and provides a flat surface for complete electrical interconnection of the cells by welding. More particularly, as best illustrated in Figure 11 , the upstanding tabs 27a-27f of the cells 18a-18f are disposed within the cells 40a adjacent one of the planar surfaces 46b and 48b. The welding interconnection between adjacent tabs within the battery case occurs through an orifice 71 formed in the planar segments 46b and 48b as illustrated in Figure 5. Those skilled in the art will appreciate that a complete weld connection between adjacent tabs is facilitated by the planar configuration of surfaces 46b and 48b. The use of cell cavities 40a with a generally octagonal upper portion above a generally circular central portion and a generally octagonal lower portion below the generally circular central portion, as in the embodiment of the battery case 10a shown in Figures 8, 9, 10 and 11 , provides significant advantages. For example, the upper portion of each cell cavity matingly engages the upper portion of cell 18 along in excess of fifty percent (50%) of the exterior surface area 21 of the film 20. Likewise, the lower portion of each cell cavity matingly engages the lower portion of cell 18 along in excess of fifty percent (50%) of the exterior surface area 21 of the film 20. At the same time, the upper and lower portion of the cell cavity are configured such that flat surfaces 46a, 48a, 46b and 48b are available for complete electrical interconnection of the cells by welding as described above. In addition, the circular central portion of each cell cavity matingly engages the cell 18 along all or nearly all of the central exterior surface area 21 of the film 20. This provides an even tighter fit for compressing the glass fiber separators normally included within each cell 18. Accordingly, the central portion of the cells 18 are securely nested and retained within the cell cavities 40a. It can be appreciated that the vertical length of the upper portion, the vertical length of the central portion and the vertical length of the lower portion of each cell cavity 40a can vary as long as the upper portion and the lower portion of each cell cavity 40a includes flat vertical sections 46a, 48a, 46b and 48b of a sufficient surface area for complete electrical interconnection of the cells by welding as described above.

When a TMF battery is constructed in accordance with the present invention as described herein and illustrated in the appended drawings, the battery is contained within the structurally robust case 10 or 10a so as to securely retain the TMF cells therewithin. While the battery case 10 and 10a are illustrated and described herein as a six cell configuration, those skilled in the art will appreciate that the body 12 or 12a, top 14, and bottom 16 of case 10 or 10a may be modified to provide a battery with virtually any number of TMF cells in order to meet capacity and space restrictions for a specific application. Moreover, while the electrical interconnection of the cells through connecting leads 26 and 28 is contemplated for the present invention, other techniques generally known in the art may be used without departing from the scope of the invention as defined by the appended claims.

Claims

CLAIMSWhat Is Claimed Is:

1. A battery case comprising: a housing having a top and a bottom, the housing defining a plurality of cavities, the cavities having an upper portion being generally octagonal in cross section and a second portion below the upper portion, the second portion being generally circular in cross section.

2. The case of claim 1 wherein the housing includes first and second side walls, first and second end walls, and a plurality of partition walls defining the plurality of cavities, the partition walls having an upper section defining the upper portion of the cavities, and a second section defining the second portion of the cavities.

3. The case of claim 2 wherein the first and second side walls, the first and second end walls, and the upper section of each of the partition walls each have the same thickness.

4. The case of claim 2 wherein the upper section of the partition walls include planar walls and arcuate walls.

5. The case of claim 4 wherein each of the arcuate walls have a first end integral with one of the planar walls and a second end integral with one of the planar walls, the first and second end walls, or the first and second side walls.

6. The case of claim 2 further including a plurality of stops coupled to the housing, one of the plurality of stops extending into each of the plurality of cavities.

7. The battery case of claim 6 wherein each of the plurality of stops are formed integral with one of the first and second side walls, the first and second end walls, or the plurality of partition walls.

8. The battery case of claim 7 further including connecting walls interconnecting the first and second walls and the first and second end walls.

9. The battery case of claim 8 wherein the connecting walls partially define at least one of the plurality of cavities.

10. The battery case of claim 8 wherein the first and second side walls, the first and second end walls, the plurality of partition walls, and the connecting walls are integral with one another.

11. The battery case of claim 1 wherein the top includes a plurality of vents.

12. A battery comprising: a housing defining cavities, the cavities having an upper portion being generally octagonal in cross section and a second portion below the upper portion, the second portion being generally circular in cross section. a terminal coupled to the housing; a top sealingly coupled to the housing; a bottom sealingly coupled to the housing; and battery cells disposed in the cavities, the battery cells being electrically interconnected in series with the terminal.

13. The battery of claim 12 wherein the housing includes side walls, end walls and partition walls, wherein the end, side, and partition walls define the cavities, the partition walls having an upper section defining the upper portion of the cavities, and a second section defining the second portion of the cavities.

14. The battery of claim 13 wherein the end walls, the side walls, and the upper section of the partition walls each have the same thickness.

15. The battery of claim 13 wherein the upper section of the partition walls include planar walls and arcuate walls.

16. The battery of claim 15 wherein each of the arcuate walls have a first end integral with one of the planar walls and a second end integral with one of another of the planar walls, the end walls, or the side wall.

17. The battery of claim 12 wherein the battery cells each include a coiled thin metal film body defining a first end and a second end, and wherein the battery further includes a first conducting lead coupled to the first ends of the bodies and a second conducting lead coupled to the second ends of the bodies.

18. The battery of claim 17 wherein the first and second conducting leads are adjacent one of the planar walls, end walls, and side walls.

19. The battery of claim 12 further including a plurality of stops coupled to the housing, one of the plurality of stops extending into each of the cavities.

20. A battery case comprising: a body and a top and a bottom joined to the body, the body having exterior walls and interior partitions which together define a pattern of separate cavities extending between the top and the bottom, the partitions including an upper section having alternating planar and arcuate sections and a second circular section below the upper section.

21. The battery case of claim 20 wherein the partitions and exterior walls are integral with each other.

22. The battery case of claim 20 wherein the body includes terminal extensions projecting outwardly from an exterior wall.

23. A battery comprising: a case including a body and a top and bottom joined to the body, the body having exterior walls and interior partitions which together define a pattern of separate cavities extending between the top and bottom, the interior partitions including an upper section having alternating planar and arcuate sections and a second circular section below the upper section; a terminal extending from the case; and a battery cell disposed in each cavity, the cells being electrically connected to each other and to the terminal.

24. A battery case comprising: a housing having a top and a bottom, the housing defining a plurality of cavities, the cavities having an upper portion being generally octagonal in cross section, a central portion being generally circular in cross section, and a lower portion being generally octagonal in cross section.

25. The case of claim 24 wherein the housing includes first and second side walls, first and second end walls, and a plurality of partition walls defining the plurality of cavities, the partition walls having an upper section defining the upper portion of the cavities, a central section defining the central portion of the cavities, and a lower section defining the lower portion of the cavities.

26. The case of claim 25 wherein the first and second side walls, the first and second end walls, and the upper section and the lower section of each of the partition walls each have the same thickness.

27. The case of claim 25 wherein the upper section and the lower section partition walls include planar walls and arcuate walls.

28. The case of claim 27 wherein each of the arcuate walls have a first end integral with one of the planar walls and a second end integral with one of the planar walls, the first and second end walls, or the first and second side walls.

29. The case of claim 25 further including a plurality of stops coupled to the housing, one of the plurality of stops extending into each of the plurality of cavities.

30. The battery case of claim 29 wherein each of the plurality of stops are formed integral with one of the first and second side walls, the first and second end walls, or the plurality of partition walls.

31. The battery case of claim 30 further including connecting walls interconnecting the first and second walls and the first and second end walls.

32. The battery case of claim 31 wherein the connecting walls partially define at least one of the plurality of cavities.

33. The battery case of claim 31 wherein the first and second side walls, the first and second end walls, the plurality of partition walls, and the connecting walls are integral with one another.

34. The battery case of claim 24 wherein the top includes a plurality of vents.

35. A battery comprising: a housing defining cavities, the cavities having an upper portion being generally octagonal in cross section, a central portion being generally circular in cross section, and a lower portion being generally octagonal in cross section; a terminal coupled to the housing; a top sealingly coupled to the housing; a bottom sealingly coupled to the housing; and battery cells disposed in the cavities, the battery cells being electrically interconnected in series with the terminal.

36. The battery of claim 35 wherein the housing includes side walls, end walls and partition walls, wherein the end, side, and partition walls define the cavities, the partition walls having an upper section defining the upper portion of the cavities, a central section defining the central portion of the cavities, and a lower section defining the lower portion of the cavities.

37. The battery of claim 36 wherein the end, side, and each of the lower section and the upper section of the partition walls each have the same thickness.

38. The battery of claim 36 wherein the lower section and the upper section of the partition walls include planar walls and arcuate walls.

39. The battery of claim 38 wherein each of the arcuate walls have a first end integral with one of the planar walls and a second end integral with one of another of the planar walls, the end walls, or the side wall.

40. The battery of claim 35 wherein the battery cells each include a coiled thin metal film body defining a first end and a second end, and wherein the battery further includes a first conducting lead coupled to the first ends of the bodies and a second conducting lead coupled to the second ends of the bodies.

41. The battery of claim 40 wherein the first and second conducting leads are adjacent one of the planar walls, end walls, and side walls.

42. The battery of claim 35 further including a plurality of stops coupled to the housing, one of the plurality of stops extending into each of the cavities.

43. A battery case comprising: a body and a top and a bottom joined to the body, the body having exterior walls and interior partitions which together define a pattern of separate cavities extending between the top and the bottom, the partitions including an upper section and a lower section having alternating planar and arcuate sections and a central circular section between the upper section and the lower section.

44. The battery case of claim 43 wherein the partitions and exterior walls are integral with each other.

45. The battery case of claim 43 wherein the body includes terminal extensions projecting outwardly from an exterior wall.

46. A battery comprising: a case including a body and a top and bottom joined to the body, the body having exterior walls and interior partitions which together define a pattern of separate cavities extending between the top and bottom, the interior partitions including an upper section and a lower section having alternating planar and arcuate sections and a central circular section between the upper section and the lower section; a terminal extending from the case; and a battery cell disposed in each cavity, the cells being electrically connected to each other and to the terminal.