HK1165100A - Modular cid assembly for a lithium ion battery - Google Patents

Description

Modular current interrupt device assembly for lithium ion batteries

This application claims benefit of united states provisional patent application No. 61/206,461, filed on 30/1/2009, and united states provisional patent application No. 61/166,580, filed on 3/4/2009. The entire teachings of the above-mentioned application and U.S. patent application No. 12/641,871 filed on 12/18/2009 are incorporated herein by reference.

Technical Field

The present invention relates to lithium ion batteries, and more particularly, to a Current Interrupt Device (CID) assembly for a lithium ion battery.

Background

Lithium ion batteries in portable electronic devices are generally subjected to different charging, discharging, and storing procedures depending on the manner in which they are used. Batteries that utilize lithium ion battery cell chemistry will generate gases when overcharged beyond their built-in safety limits. This gas can be used to trigger a pressure activated safety assembly to improve the reliability and safety of the battery. It generally uses a Current Interrupt Device (CID) to protect any excessive internal pressure increase in the battery by interrupting the current path of the battery when the internal pressure of the battery is greater than a certain value. The CID basically includes a rupture disc (rupture disc) and a pressure disc (pressure disc) electrically connected to each other. The rupture disk and the pressure disk are electrically connected to an electrode and a tab of the battery, respectively. When the internal pressure of the battery is greater than a certain value, the pressure disc of the CID is separated (e.g., separated by deformation or from each other) from the rupture disc, thereby interrupting the current flow between the electrode and the tab.

However, existing CIDs generally start at extremely high pressures, e.g., with a gauge pressure greater than about 15 kilograms per square centimeter (kg/cm) therein²) At the same time. Basically, when any excessive increase in internal pressure triggering such CID occurs, the internal temperature of the battery is also relatively high at the same time, causing additional safety problems. High temperatures are a particular concern in very large cells, such as cells larger than the "18650" cell (which has a diameter of about 18mm and a length of 65 mm).

Furthermore, the production of CID is usually performed simultaneously with the production of the rest of the battery and requires very low tolerances in ensuring the start-up variation at the right pressure. In some designs, the surface area available for welding tabs from the battery reel is often limited by the need for a vent tube that provides gas pressure. The gas pressure conduction channel in the disc typically contains at least one perforation which may not be blocked during welding of the tab from the cell reel to the rupture disc.

The surface area of the pressure disc is one of the factors that affects its pressure of activation or reversal, and the material thickness is the other factor. In a prismatic or non-circular cell, the shortest side of the cell generally represents the maximum size of the pressure plate that can be used. By utilizing a thin elongated (elliptical, oval, etc.) pressure disk within the housing of any particular prismatic cell design, it is possible to achieve lower activation or reversal pressures than a circular pressure disk of the same material thickness.

Therefore, there is a need to propose a CID for a battery that can reduce or minimize the aforementioned problems, particularly for a relatively large lithium ion battery.

Disclosure of Invention

The present invention is generally directed to a modular current interrupt device, a battery including the modular current interrupt device of the present invention, and a method of forming the modular current interrupt device of the present invention.

The modular current interrupt device described above includes a conductive rupture disc and a conductive pressure disc attached to the rupture disc to form an electrical pathway. An electrically insulating ring separates a perimeter of the rupture disk from a perimeter of the pressure disk. A mounting member of the current interrupt device secures the electrically insulating ring to the pressure plate. At least one of the rupture disc and the electrically insulating ring defines a conduit through which exposure to sufficient pressure through one side of the pressure disc will cause the pressure disc to separate from the rupture disc thereby severing the electrical path. The mounting member may be electrically conductive and electrically connected to the pressure plate. The rupture disc and the electrically insulating ring may together define the conduit. The rupture disk may include a plurality of clamping points (interference points) that form an interference fit with the electrically insulating ring. The perimeter of the rupture disc may be a polygon. The polygon may define the clamping points. The polygon may have 10 to 20 sides, for example 14 sides. In some embodiments, the communication conduit may be defined in part by the perimeter of the rupture disc. The perimeter of the rupture disc may be beveled. In some embodiments, the perimeter of the rupture disc may include a double chamfer. The angular extent of at least one of the aforementioned bevels may be between about 40 degrees and about 55 degrees, such as about 47 degrees. In some embodiments, the angles of the two inclined planes may be both about 47 degrees. In some embodiments, the electrically insulating ring may define a flange around the ring such that the flange overlaps the perimeter of the rupture disc. In these embodiments, the rupture disk may define a groove around the rupture disk such that the flange of the insulating ring overlaps the rupture disk at the groove, and a surface of the flange of the insulating ring may be substantially flush with a surface of the rupture disk. In some embodiments, the electrically insulating ring may define at least one channel that cooperates with the rupture disk to define at least a portion of the conduit. The channel may have a major axis that is substantially perpendicular to a tangent of a circle defined by the electrically insulating ring. In some embodiments, the rupture disc, pressure disc, and mounting member may be aluminum (aluminum). The electrically insulating ring may comprise a polymer.

In some embodiments, the rupture disk may define at least one communication channel. Alternatively, the electrically insulating ring defines at least one conduit around the ring such that fluid communication exists between a frustoconical (frustoconical) element of the pressure disc and an external surface of the current interrupt device. The pressure disk may further comprise an elevated surface and a peripheral base, the elevated surface being connected to the peripheral base by the frustoconical element, and wherein the rupture disk is electrically connected to the pressure disk at the elevated surface. The pressure disc may be electrically connected to the rupture disc at least one point. The point may comprise a solder point. In some embodiments, the mounting member may be electrically conductive. In such embodiments, the pressure plate may be electrically connected to the mounting member, and the mounting member may secure the electrically insulating ring to the pressure plate via a crimp on its periphery. In some embodiments, the mounting member may define a mounting member passage channel. In other embodiments, the rupture disc may define the conduit.

In another embodiment, the invention is a battery, such as a lithium ion battery, comprising a modular current interrupt device, wherein the current interrupt device comprises a conductive rupture disc and a conductive pressure disc attached to the rupture disc to form an electrical pathway. The battery also includes a first terminal in electrical communication with a first electrode of the battery, a second terminal in electrical communication with a second electrode of the battery, and a battery compartment (battery can) having a battery cartridge and a cover in electrical communication with each other, the battery compartment being electrically isolated from the first terminal, wherein at least a portion of the battery compartment is at least a component of the second terminal or is electrically connected to the second terminal. The battery cell cartridge may be a prismatic battery cell cartridge. An electrically insulating ring separates a perimeter of the rupture disk from a perimeter of the pressure disk. A mounting member of the current interrupt device secures the electrically insulating ring to the pressure plate. At least one of the rupture disc and the electrically insulating ring defines a conduit through which exposure to sufficient pressure through one side of the pressure disc will cause the pressure disc to separate from the rupture disc thereby severing the electrical path. In some embodiments, the modular current interrupt device is located in a recess in a cover of the battery that defines an opening in the cover. The modular current interrupt device may be a component of a positive terminal of the battery. In such embodiments, at least one lead of a positive terminal of the battery may be electrically connected to the rupture disk of the modular current interrupt device. In some embodiments, the current interrupt device may be electrically connected to the battery compartment. In such embodiments, the current interrupt device may be electrically connected to the battery compartment cover, and the cover may include a recess facing the pressure plate. The recess may be co-bounded (co-term) with the periphery of the first end of a deformed frustum (frustum variant).

In yet another embodiment, a method of forming a modular current interrupt device includes combining a pressure disc and a mounting member of the current interrupt device, and combining a rupture disc and an electrically insulating ring. The combined pressure disc and mounting member and combined rupture disc and electrically insulating ring are then assembled and the rupture disc is laser or resistance spot welded to the pressure disc to form an electrical path therebetween. The method may include welding the rupture disc to at least one point, and preferably two points, of a substantially planar housing (access panel) of the pressure disc, while the temperature of the pressure disc is controlled so as not to melt through the pressure disc to the other side of the weld. A batteryCan be formed by thereafter placing the modular current interrupt device within a recess of an outer cover of the battery, wherein the recess defines an opening of the outer cover, attaching a first electrode or a second electrode of the battery to the current interrupt device, attaching the current interrupt device to a cell compartment of the battery, the cell compartment comprising a cell cartridge and an outer cover that are electrically connected to each other, and forming a first connector electrically connected to the first electrode and a second connector electrically connected to the second electrode. The method may further comprise welding the current interrupt device to the outer cover of the battery compartment. Welding of the current interrupt device to the cover of the battery chamber may be performed by seam welding (welding) a peripheral interface between the cover and the current interrupt device, preferably by penetration welding (welding) at the base of the pressure plate. The method may further comprise the step of welding the outer cover of the battery compartment to the battery cartridge of the battery compartment. When the gauge pressure between the discs is in the range of, for example, about 4kg/cm²And about 10kg/cm²Or between about 4kg/cm²And about 9kg/cm²In between, the electrical connection may be interrupted. In some embodiments, the gage pressure between the outer cover and the battery cell cartridge is greater than or equal to about 20kg/cm²At this time, the welding for connecting the outer cap and the battery cell cartridge is broken. The method may further comprise the step of forming at least one exhaust device on the battery cell cartridge when an internal gauge pressure range is between about 10kg/cm²And about 20kg/cm²In between, the gas in the battery will be discharged through the exhaust device.

In yet another embodiment, the present invention is directed to a CID comprising a pressure disc comprising a deformed frustum having a first end and a second end, wherein at least one of the first or second ends is non-circular in cross-section. A base extends radially from a periphery of the first end of the deformed frustum, and a substantially planar housing encloses the second end of the deformed frustum. The first end is opposite to the second endThe ends have a relatively broad dimension. At least one of the first end and the second end may be elliptical in cross-section. The cross-section of both the first end and the second end may be non-circular. In some embodiments, the cross-section of both the first end and the second end may be elliptical. The rupture disc is preferably in electrical contact with the substantially planar housing via a weld. A gage pressure range between the disks of about 4kg/cm²And about 9kg/cm²Between, or preferably between, about 7kg/cm²And about 9kg/cm²The weld connecting the pressure disc and rupture disc will rupture. The rupture disc may define a depression and the weld may be located at the depression. The weld may be at least one spot weld, and preferably a two spot weld, at least one of which spot welds contains aluminum. The rupture disk may define at least one opening. At least one of the pressure disc and the rupture disc may comprise aluminum. In some embodiments, both the pressure disc and the rupture disc may comprise aluminum. In some embodiments, the thickness of the outer cover may range between about 0.05mm and about 0.5mm, such as about 0.127 mm. The diameter of the housing may range between about 2 millimeters and about 8 millimeters. The height of the cover from the base may range between about 0.5 millimeters and about 1 millimeter, such as about 0.762 millimeters. The frustum of the deformation may have an angle with a plane parallel to the base of the pressure disk ranging between about 15 degrees and about 25 degrees. In some embodiments, an electrically insulating ring may extend around the perimeter of the frustum of the deformation and between the base of the pressure disc and the rupture disc. In such embodiments, the base of the pressure disk may include at least one tab and the electrically insulating ring may define at least one opening, the tab and the opening being capable of aligning with one another when the insulating ring and the base are concentric (concentric), wherein the tab may be extensibly adjusted to secure the insulating ring to the pressure disk. The electrically insulating ring may define a trench about a periphery of the insulating ring. Such embodiments may further comprise a plurality of tabsA metal ring that can be positioned inside the groove and the plurality of tabs can be extensibly adjusted to be secured to a metal surface on which the pressure disk is located, thereby securing the insulating ring over the pressure disk. The thickness of the rupture disc proximate the weld with the pressure disc may be less than the thickness of the pressure disc proximate the weld, preferably equal to or less than half the thickness of the pressure disc proximate the weld.

The present invention has many advantages. For example, the modular current interrupt device described above can be produced separately from the lithium ion battery, thereby greatly reducing the cost of producing the battery and increasing the types of applications for which the modular CID can be used. In addition, the modular CID includes a significantly increased surface area for welding a tab on a cell roll as compared to typical conventional current interrupt devices, which significantly increases yield during battery production. Furthermore, in some embodiments, because both the pressure disk and the electrically insulating ring define a conduit, the pressure disk need not include perforations that allow gas to pass through, thereby eliminating the possibility of perforation blockage during welding of tabs on the cell roll. Also, the modular current interrupt device of the present invention may be versatile in at least one orientation, such as by having a circular shape, thereby eliminating the need for orientation of the current interrupt device during assembly. Which thereby significantly reduces the possibility of errors during production and being subsequently rejected during quality inspection. In one embodiment, a beveled edge on the rupture disk defines a channel and provides a mechanism to mechanically secure the rupture disk to an electrically insulating ring of a current interrupt device, thereby eliminating the need for the rupture disk to define perforations to deliver gas pressure to the pressure disk.

One advantage of an elongated, non-circular pressure disk is that it is possible to achieve lower activation or reversal pressures within the housing of any particular prismatic cell design by using a pressure disk that is elongated (elliptical, oval, etc.) compared to a circular pressure disk of the same material thickness.

Drawings

FIG. 1 is a cross-sectional view of one embodiment of a modular current interrupt device of the present invention;

FIGS. 2A and 2B are plan and cross-sectional views, respectively, of an electrically conductive rupture disc assembly of the modular current interrupt device of FIG. 1;

FIGS. 3A and 3B are plan and cross-sectional views, respectively, of an electrically conductive pressure disc assembly of the modular current interrupt device of FIG. 1;

4A, 4B and 4C are perspective, cross-sectional and plan views, respectively, of one embodiment of an electrically insulating ring assembly in the modular current interrupt device of FIG. 1;

FIG. 5 is a partial cross-sectional view of the modular current interrupt device of FIG. 1 taken along line V-V;

FIGS. 6A and 6B are plan and cross-sectional views, respectively, of a mounting member assembly in the modular current interrupt device of FIG. 1;

FIGS. 7A through 7D illustrate steps in a method of manufacturing a modular current interrupt device according to one embodiment of the present invention;

fig. 8A, 8B and 8C are external, cross-sectional and internal views, respectively, of an outer cover of an angular cell showing a modular current interrupt device of the present invention attached to the outer cover;

fig. 9 is a cross-sectional view of an angular cell of the present invention, also showing in cross-section that the modular current interrupt device of the present invention is installed in place in the cover;

FIG. 10 is a plan view of an elongated, or oval, pressure disc of the present invention having a deformed frustum shape shown alongside a circular pressure disc having a non-deformed frustum shape;

FIG. 11 is a cross-sectional view of one embodiment of a CID of the present invention;

FIG. 12 shows an embodiment of a pressure disk in the CID of FIG. 11.

Detailed Description

The foregoing features will be apparent from the following more particular description of exemplary embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the invention.

The present invention is generally directed to a modular current interrupt device for a battery, such as a lithium ion battery, particularly a prismatic lithium ion battery. In another embodiment, the invention is a battery that includes the modular current interrupt device. In yet another embodiment, the present invention is a method of manufacturing a modular current interrupt device.

The "tab" of the battery of the present invention used in the description means a portion or surface of the battery to which an external circuit is connected. In addition, "electrically connected" or "electrically contacted" as used in the specification means that some portions are connected to each other by the flow of electrons through a conductor, relative to the case where Li is involved, for example⁺Flows through the electrochemical connection of the electrolyte.

Fig. 1 is a cross-sectional view of an embodiment of a modular current interrupt device 10 including a conductive rupture disc 12, a conductive pressure disc 14, an electrically insulating ring 16, and a mounting member 18.

As shown in fig. 2A and 2B, conductive rupture disc 12 includes central recessed portions 11, 13 each independently having a depth ranging between about 0.16mm and about 0.26mm and a width ranging between about 2.95mm and about 3.05 mm. Alternatively, as shown in FIG. 11, conductive rupture disc 240 may include a single central recess 280. Conductive rupture disc 12, as shown in FIG. 2A, is a polygon. Although shown in fig. 2A as having fourteen sides, conductive rupture disc 12 may have a number of side edges 48 substantially between about 10 and 20. The sides 48 of the conductive rupture disc 12 intersect one another and thereby define a pinch point 50. Alternatively, or in the alternative, rupture disc 12 contains vent perforations, which are not shown in the figures. The beveled edges 20, 22 of the rupture disc 12 are at an angle to a major plane of the rupture disc 12 in a range substantially between about 40 and 55 degrees. In a preferred embodiment, the angular extent of the beveled edges 20, 22 is between about 45 ° and about 49 °, with a most preferred embodiment being about 47 °. Essentially, rupture disc 12 has a major diameter D in the range of between about 6mm and about 16mm and a thickness T in the range of between about 0.3mm and about 0.7 mm. In the preferred embodiment, rupture disc 12 has a diameter of about 11mm and a thickness of about 0.5 mm. The thickness of the rupture disc 12 in the recessed portions 11, 13 typically ranges between about 0.065mm and preferably about 0.085 mm. Rupture disc 12 is fabricated from a suitable material. Examples of suitable materials include aluminum, nickel (nickel), and copper (copper). Examples of suitable materials include the aluminum 3003 series, such as the aluminum 3003H-0 or H-14 series, and preferably the H-14 series.

Returning to fig. 1, conductive pressure disc 14 is attached to conductive rupture disc 12 at welds 24, 26. Alternatively, conductive pressure disc 14 may be connected to conductive rupture disc 12 without any welds, a single weld, or three or more welds. Generally, the welding points are spot welding. In the preferred embodiment, the spot welds are spaced apart from one another. In a particularly preferred embodiment, the spot welds comprise aluminum.

While other configurations of conductive pressure plates may be used in the modular current interrupt device of the present invention, as shown in fig. 3A and 3B, the preferred embodiment of the conductive pressure plate 14 includes a frustum (frustum) 28. The frustum or frustoconical member 28 has a first end 30 and a second end 32. The first end 30 has a wider diameter than the second end 32. The conductive pressure plate 14 also includes a base 34 extending radially from the periphery of the first end 30 of the frustum 28. A cover 36 encloses second end 32 of frustum 28. In the present specification, the term "frustum" means a base wall portion (excluding the base and the tip) of a solid right circular cone (i.e., a solid produced by rotating a right triangle centering on one strand of the right triangle) whose top is cut off. In one embodiment, the housing 36 is substantially planar. In another embodiment, not shown, frustum 28 may be a modified frustum, such as a cross-section of first end 30 or second end 32 that is independently non-circular. In one embodiment, the cross-section of each of the first end 30 and the second end 32 is elliptical, as shown by the pressure disc 120 in FIG. 10.

In this specification, the term "substantially planar or envelope" means a surface that is substantially similar to a plane, which may be brought into contact with another planar surface at any one or more points, and which may be welded to the one or more points in a suitable manner, such as spot welding. Returning to fig. 3A and 3B, in some embodiments, the outer cover 36 is considered to be substantially planar, although the manufacture of the pressure disc 14 or the assembly of the modular current interrupt device 10 shown in fig. 1 results in deformation (e.g., due to welding of the conductive rupture disc 12 to the conductive pressure disc 14).

A shaping pin simultaneously shapes the housing 36 on the pressure disc 14 and the die cast 11 on the rupture disc 12. Pressure disc 14 is then attached to rupture disc 12 to form an electrically conductive path. In a preferred embodiment, pressure disc 14 and rupture disc 12 are spot welded together with a number of weld locations ranging between 1 and about 6, such as 2 weld locations. In a preferred embodiment, laser welding is used. In a preferred embodiment, the laser welding apparatus is arranged to strike each weld point in succession and rapidly with multiple repetitive laser pulses. Which adjusts the energy of each repetitive laser pulse such that the total energy of all the repetitive laser pulses at a single weld spot is sufficient to locally melt the aluminum in pressure disc 14 and rupture disc 12, thereby metallically bonding them to the weld spot. An advantage of using multiple repeated laser pulses is that the variation in total laser energy applied to each weld spot is significantly reduced, thereby achieving less variation in weld spot weld strength relative to using a single laser pulse with higher energy.

In the preferred embodiment, the cover 36 and/or the base 34 each independently has a material thickness (denoted as reference character "d" in FIG. 3B) in a range between about 0.05mm and about 0.5mm, such as between about 0.05mm and about 0.3mm, between about 0.05mm and about 0.2mm, between about 0.05mm and about 0.15mm (e.g., about 0.127mm), or about 5 milli-inches.

In a preferred embodiment, the diameter of the outer cover 36 (shown as reference character "B" in FIGS. 3A and 3B) ranges between about 2mm and about 10mm, preferably between about 5mm and about 10mm, and more preferably between about 5mm and about 8mm (e.g., between about 0.20 inch and 0.25 inch), such as about 5.5mm (or about 0.215 inch).

In the preferred embodiment, the surface of the housing 36 is elevated from the peripheral base 34. The height of the cover 36 from the base 34 (indicated by reference character "c" in fig. 3B) ranges between about 0.5mm and about 1mm, more preferably between about 0.55mm and about 0.65 mm, such as about 0.596 mm (or about 0.024 inches).

In the preferred embodiment, frustum 28 has an angle with respect to a plane parallel to base 34 in a range between about 15 degrees and about 25 degrees, such as between about 18 degrees and about 23 degrees, or between about 19 degrees and about 21 degrees. More preferably, frustum 28 is angled at about 21 degrees relative to a plane parallel to base 34. In a preferred embodiment, the ratio of the diameter of the first end 30 to the second end 32 of the frustum 28 (i.e., the ratio of "B" to "a" in FIG. 3B) ranges between about 1: 1.20 and about 1: 1.35, such as between about 1: 1.23 and about 1: 1.28.

Returning to FIG. 1, conductingRupture disk 12 and conductive pressure disk 14 are separated when an internal gage pressure applied to a surface of conductive pressure disk 14 contacting conductive rupture disk 12 ranges from about 4kg/cm²And about 10kg/cm²In between, such as between about 4kg/cm²And about 9kg/cm²Between about 5kg/cm²And about 9kg/cm²Or between about 7kg/cm²And about 9kg/cm²In the meantime. The separation of conductive pressure disc 14 from conductive rupture disc 12 activates modular current interrupt device 10. In this description, "activation" of modular current interrupt device 10 means that the flow of current between conductive rupture disc 12 and conductive pressure disc 14 is interrupted. In the preferred embodiment, conductive pressure disc 14 maintains its integrity when conductive pressure disc 14 is separated from conductive rupture disc 12, i.e., conductive pressure disc 14 does not rupture or allow gas to flow from one side of pressure disc 14 to the other side of pressure disc 14. Typically, separation of pressure disc 14 from conductive rupture disc 12 results in rupture at any one of the spot welds that electrically connects pressure disc 14 to rupture disc 12.

The pressure disc 14 may be constructed of a suitable metal, such as aluminum, copper, and nickel. An example of a suitable material is the aluminum 3003 series, such as the aluminum 3003H-0 or H-14 series. In a preferred embodiment, the pressure disk 14 comprises aluminum, and more preferably consists essentially of aluminum.

An electrically insulating ring 16 separates a perimeter of rupture disc 12 from a perimeter of pressure disc 14. Referring to fig. 4A, 4B and 4C, electrically insulating ring 16 includes a base 38 and a rim 40. Basically, the rim 40 is spaced a distance "b" from the periphery of the base 38 in a range between about 0.40mm and about 0.55 mm. The rim 40 has a height "h" substantially ranging between about 0.80mm and about 0.90 mm. Flange 44 extends from rim 40 and overlaps conductive rupture disc 12. In one embodiment, flange 44 contacts rupture disc 12 to form an interference fit between seat 38 and rupture disc 12. As shown in fig. 4A, the electrically insulating ring 16 defines a channel 46 in the base 38. In one embodiment, as shown in FIG. 4C, at least one channel 46 has a major axis that is substantially perpendicular to a tangent on the circle defined by ring 16. Examples of suitable materials for the electrically insulating ring 16 include polypropylene (polypropylene), such as high density polypropylene (hdpe), and perfluoroalkoxy copolymer (perfluoroalkoxy copolymer) synthetic resin.

As can be seen in fig. 5, point 50 on rupture disc 12 is in substantially interference-fit relation with rim 40 of electrically-insulating ring 16. Side 48 of electrically conductive rupture disc 12 and rim 40 of electrically insulating ring 16 define a conduit 42 that provides gas pressure fluid communication from one side of rupture disc 12 to the other side of rupture disc 12. Channel 46 of ring 16 also provides fluid communication between the major surfaces of rupture disc 12.

A mounting member, or mounting cup, 18 overlies the pressure plate 14. The mounting member 18, which is also shown in fig. 6A and 6B, includes a base 52 and a raised portion 54 that defines a through-hole 56. Corrugations 58 at the periphery of mounting member 18 secure pressure disk 14 to electrically insulating ring 16. Alternatively, the mounting member 18 may be secured to the pressure plate 14 by a weld (not shown) where the mounting member 18 contacts the electrically conductive pressure plate 14. In a preferred embodiment, the diameter of the opening 56 ranges between about 2mm and about 4 mm. The mounting member 18 is made of a suitable material such as aluminum, nickel and copper. In the preferred embodiment, the mounting member 18 is made of metal and is electrically connected to the pressure plate 14. In the preferred embodiment, the mounting member 18 comprises aluminum, and more preferably consists essentially of aluminum.

Alternatively, where the pressure plate 14 is connected to an electrical terminal of a battery, such as a battery compartment, the mounting member 18 may be made of an electrically insulating material, such as polypropylene. Shown in fig. 6A is a plan view of the mounting member 18, which shows that the mounting member 18 is circular in configuration, and in one embodiment, the raised portion 54 substantially follows the base 34 of the pressure disc 14. The thickness of the material used to form the mounting member 18 is typically in the range of between about 0.3mm and about 0.5 mm.

A method of making a modular current interrupt device according to the present invention includes combining a conductive pressure disc 14 with a mounting member 18, and combining a conductive rupture disc 12 with an electrically insulating ring 16. The combined conductive pressure disc 14 and mounting member 18, and combined conductive rupture disc 12 and electrically insulating ring 16 are then secured to one another mechanically, or by a suitable method using other mechanisms to join conductive rupture disc 12 and conductive pressure disc 14, such as by laser or resistance spot welding. The edge of the mounting member 18 may be crimped around the edge of the pressure disc 14 and insulator ring 16. In another embodiment, shown in FIGS. 7A through 7D, the pressure disc 14 and mounting member 18 are combined, as shown in FIG. 7A, and then a single fold is formed by a suitable method, such as crimping, as shown in FIG. 7B. Optionally, a suitable lining filler material, such as an electrolyte-resistant sealing material (e.g., an asphalt-type sealing material), as is known in the relevant art, may be disposed between the bonding surfaces of the pressure plate 14 and the mounting member 18. As shown in fig. 7C, a double fold is then formed as a sealing mechanism. The insulating ring 16 is then placed at the pressure disc 14, and the pressure disc 14 and the mounting member 18 are then crimped again to clamp the insulating ring 16. As shown in FIG. 7D, rupture disc 12 is then placed in position, as shown in FIG. 1, and spot welded to pressure disc 14, as previously described.

In the preferred embodiment, conductive pressure disc 14 and conductive rupture disc 12 are made of substantially the same metal. In the present specification, the term "substantially the same metal" means a metal having substantially the same chemical and electrochemical stability at a particular voltage, such as the operating voltage of a battery. In a particular embodiment, at least one of the conductive rupture disc 12 and the conductive pressure disc 14 comprises aluminum, such as the aluminum 3003 series. In another specific embodiment, conductive pressure disc 14 comprises aluminum which is softer than the conductive rupture disc 12. In the preferred embodiment, both conductive pressure disc 14 and conductive rupture disc 12 comprise aluminum. More preferably, rupture disc 12 is constructed of aluminum 3003H-14 series and pressure disc 14 is constructed of aluminum 3003H-0 series. Pressure disc 12 and rupture disc 14 may be formed by any suitable method known in the relevant art, such as, for example, coining (stamping), casting (cladding), and/or milling (milling) techniques.

Fig. 8A, 8B and 8C show exterior plan, cross-sectional and interior plan views, respectively, of an outer cover assembly for a battery that includes the modular current interrupt device of the present invention. As can be seen in fig. 8A, 8B and 8C, the current interrupt device 10 is installed in a through hole 62 defined in the outer cover 60 of a battery. The modular current interrupt device 10 is located mostly inside the battery, while the raised portion 54 of the mounting member 18 is located within the aperture 62 of the outer cover 60. The mounting member 18 is secured to the cover 60 by a suitable method, such as by interference fit, welding, crimping, riveting, or the like. In the preferred embodiment, mounting member 18 and outer cover 60 are welded to one another. Which may use any suitable welding technique known in the relevant art. In the preferred embodiment, the mounting member 18 and the outer cover 60 are sealingly joined to one another. In the preferred embodiment, a laser welding technique is used in the invention. In a more preferred embodiment, a peripheral laser welding technique is used to sealingly join the mounting member 18 and the cover 60, for example, by using seam welding at the peripheral interface between the two components, or by using a penetration weld at the base 62 of the mounting member 18. In the preferred embodiment, the weld is made around the middle of the base 52 or around the edge of the base 52. In a preferred embodiment, the temperature of the mounting member 18 is controlled so that it does not exceed the melting point of the surface of the mounting member 18 on the other side of the weld during the welding process, such as a laser welding process. Such temperature control may be accomplished using any suitable cooling method known in the art. In the preferred embodiment, the cover 60 is made of substantially the same material as the mounting member 18, such as aluminum 3003H-0 or the H-14 series.

As can be seen from the exterior plan view of the battery outer cover 60 of fig. 8A, the raised portion 54 of the mounting member 18 is visible and is substantially circular in configuration. Typically, the mounting member 18 and the remaining portion of the cover 60 and the battery compartment to which the cover 60 is electrically connected serve as a positive terminal, and the feedthrough assembly 64 serves as a negative terminal as shown in fig. 8A-8C and is electrically isolated from the remaining portion of the cover 60, the modular current interrupt device 10, and the battery compartment to which the cover 60 is electrically connected by the assembly 66.

Fig. 9 shows a cross-sectional view of a battery 70 of the present invention including an outer cover 60 in which the modular current interrupt device 10 is installed. Tab 72 connects an electrode, preferably a positive electrode, to rupture disc 12. Which may be joined to rupture disc 12 by a suitable method, such as laser or resistance spot welding. The tabs 74 connect the other electrodes to the feedthrough assembly 64, again by a suitable method, such as laser or resistance spot welding.

Alternatively, the conductive components of the modular current interrupt device 10 may be constructed of materials other than aluminum, such as nickel-plated iron, particularly when the current interrupt device 10 is electrically connected to the anode of a battery rather than the cathode.

In another embodiment, a non-circular pressure disc provides a larger surface area than a circular pressure disc that fits in the same size (non-circular) housing. The larger available area allows for a lower activation pressure than a circular pressure disk that fits within the same rectangular housing base.

When the design of the battery cell is changed from a circular shape to a prismatic shape, the space available for the pressure disc is reduced. In particular, for prismatic cells with thin external dimensions, the maximum size of the circular pressure disk is so small that the force generated by the pressure is not sufficient to activate the pressure mechanism in the preferred pressure range. Making the pressure disk material very thin can bring the reversal pressure back to the preferred range. The use of extremely thin materials weakens the structural integrity of the pressure disc and increases the risk of puncture and cracking.

The elongated, or oval, shape of the present invention, disc 120 is shown in fig. 10, which is shown in contrast to a pressure disc 80 having a circular cross-section at both the first and second ends of its frustum. Table 1 below shows the test results for the elongated pressure disc of the present invention. The elongated, or oval shape of the disk increases the area over which pressure forces can be applied as compared to a circular pressure disk that can be contained within a particular prismatic cell, thereby increasing the sensitivity of the pressure disk and allowing operation with a slim profile prismatic cell.

Table 1: reverse pressure monitoring report of prototype sample of slender pressure disc

In some embodiments, the CID of the cells of the invention, which utilize a pressure disk and a rupture disk in electrical communication and pressure (i.e., fluid such as gas) communication with the pressure disk and cell compartment of the cell, is activated at an internal gauge pressure in the range, for example, of about 4kg/cm²And about 9kg/cm²Between, such as about 5kg/cm²And about 9kg/cm²Or between about 7kg/cm²And about 9kg/cm²In the meantime. In such embodiments, the pressure disc preferably comprises a conical or hemispherical member. More preferably, at least a portion of the top (or mantle) of the conical or hemispherical member is substantially planar. In a preferred embodiment, the pressure disc and rupture disc are in direct contact with each other at a portion of the substantially planar housing. More preferably, the pressure disc comprises a frustum having a substantially planar outer shell. In this specification, the "activation" of a CID means that the flow of current through the CID by an electronic device is interrupted. In a particular embodiment, the CID of the present invention comprises a pressure disc and a rupture disc in electrical communication with one another (e.g., by welding, crimping, riveting, etc.). In this CID, the "activation" of the CID means that the electrical communication between the pressure disc and the rupture disc is interrupted. In a preferred embodiment, the pressure disc does not rupture when the rupture disc is spaced apart from the pressure disc (e.g., deformed apart or separated from each other).

FIG. 11 shows a cross-sectional view of a specific embodiment of a CID of the present invention. CID100 shown in fig. 11 includes pressure disc 120 and rupture disc 240. The pressure disk 120 includes a deforming frustum 140 (also referred to as frustum 140) that includes a first end 160 and a second end 180. The deformed frustum has a non-circular cross-sectional shape (such as a cross-section taken along line I-I relative to the second end 180) at least one of its first end 160 or second end 180, such as the elongated or elliptical shape shown in fig. 10. The first end 160 has a relatively broad dimension relative to the second end 180. The pressure disk 120 also includes a base 200 that extends radially from the periphery of the first end 160 of the frustum 140. A substantially planar housing 220 encloses the second end 180 of the frustum 140. In this specification, the term "deformed frustum" refers to a portion of the base wall of a solid non-right circular cone lying between the parallel planes of two truncated cones (excluding the base and the tip). In other words, the frustum of the cone is essentially a right circular cone, but the base or cross-sectional portion of the truncated cone is not circular but rather elongated or elliptical, as shown in the left portion of FIG. 10, or other non-circular shape. The base of the elongate cone may have a ratio of length to width in the range of about 1: 1.3 to about 1: 2, preferably about 1: 1.5, as shown in fig. 10.

In a preferred embodiment, the planar cover 220 and/or the base 200 has a thickness (denoted as reference character "d" in fig. 12) in a range between about 0.05mm and about 0.5mm, such as between about 0.05mm and about 0.3mm, between about 0.05mm and about 0.2mm, between about 0.05mm and about 0.15mm (e.g., about 0.127mm (or about 5 mils)).

In a preferred embodiment, the narrowest dimension of the planar housing 220 (designated by reference character "b" in FIG. 12) ranges between about 1mm and about 10mm, more preferably between about 2mm and about 10mm, still more preferably between about 2mm and about 6mm, such as about 3 mm.

In a preferred embodiment, the height of the substantially planar housing 220 from the base 200 (shown as reference character "c" in FIG. 12) ranges between about 0.5 millimeters and about 1 millimeter, more preferably between about 0.6 millimeters and about 0.8 millimeters, such as about 0.762 millimeters (or about 0.315 inches).

In the preferred embodiment, the frustum 140 has an angle with respect to a plane parallel to the base 200 in a range between about 15 degrees and about 25 degrees, such as between about 18 degrees and about 23 degrees, or between about 19 degrees and about 21 degrees. More preferably, the frustum 140 has an angle of about 21 degrees with respect to a plane parallel to the base 200. In a preferred embodiment, the ratio of the diameter of the first end 160 to the second end 180 of the frustum 140 (i.e., the ratio of "b" to "a" in FIG. 12) ranges between about 1: 1.20 and about 1: 1.35, such as between about 1: 1.23 and about 1: 1.28.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (68)

1. A modular current interrupt device, comprising:

a) a pressure disk, comprising:

i) a modified frustum having a first end and a second end, the first end having a broader diameter than the second end, at least one of the first end and the second end being a modification of a frustum that varies in a cross-section of the end other than circular,

ii) a base extending radially from a periphery of the first end of the frustum, and

iii) a substantially planar housing enclosing the second end of the deformed frustum; and

b) a rupture disk in electrical contact with the substantially planar housing of the pressure disk.

2. The modular current interrupt device of claim 1, wherein the cross-section of at least one of the first end and the second end is oval.

3. The modular current interrupt device of claim 1, wherein the cross-section of both the first and second ends is non-circular.

4. The modular current interrupt device of claim 1, wherein the cross-section of both the first and second ends is elliptical.

5. The modular current interrupt device of claim 1, wherein the rupture disc is in electrical contact with the substantially planar enclosure of the pressure disc via a weld.

6. The modular current interrupt device of claim 5, wherein a gage pressure range between the two plates is between about 4kg/cm²And about 9kg/cm²The weld connecting the pressure disc and the rupture disc will rupture.

7. The modular current interrupt device of claim 5, wherein a gage pressure range between the two plates is between about 7kg/cm²And about 9kg/cm²In between, the weld will break.

8. The modular current interrupt device of claim 5, wherein the rupture disc defines a depression, and wherein the weld is located at the depression.

9. The modular current interrupt device of claim 8, wherein the weld is at least one spot weld.

10. The modular current interrupt device of claim 9, wherein at least one of the spot welds includes aluminum.

11. The modular current interrupt device of claim 9, wherein the weld is a two-spot weld.

12. The modular current interrupt device of claim 1, wherein the rupture disc defines at least one opening.

13. The modular current interrupt device of claim 5, wherein at least one of the pressure disc and the rupture disc comprises aluminum.

14. The modular current interrupt device of claim 13, wherein both the pressure disc and the rupture disc comprise aluminum.

15. The modular current interrupt device of claim 14, wherein the thickness of the housing ranges between about 0.05mm and about 0.5 mm.

16. The modular current interrupt device of claim 15, wherein the thickness of the housing is about 0.127 millimeters.

17. The modular current interrupt device of claim 15, wherein the diameter of the housing ranges between about 2 millimeters and about 8 millimeters.

18. The modular current interrupt device of claim 17, wherein a height of the cap from the base is in a range between about 0.5mm and about 1 mm.

19. The modular current interrupt device of claim 18, wherein the height of the cap from the base is about 0.762 millimeters.

20. The modular current interrupt device of claim 18, wherein the frustum deformation has an angle with a plane parallel to the base of the pressure disc ranging between about 15 degrees and about 25 degrees.

21. The modular current interrupt device of claim 1, further comprising an electrically insulating ring extending around the frustum of the deformation and between the base of the pressure disc and the rupture disc.

22. The modular current interrupt device of claim 21, wherein the base of the pressure disc includes at least one tab and wherein the electrically insulating ring defines at least one opening, the tab and the opening being capable of aligning with one another when the insulating ring and the base are concentric, and wherein the tab is telescopically adjustable to secure the insulating ring to the pressure disc.

23. The modular current interrupt device of claim 22, wherein the electrically insulating ring defines a groove around a perimeter of the insulating ring, and further comprising a metal ring having a plurality of tabs, the metal ring being positionable within the groove and the tabs being adjustably extendable to secure to a metal surface on which the pressure plate is located to secure the insulating ring to the pressure plate.

24. The modular current interrupt device of claim 21, wherein the thickness of the rupture disc proximate the weld with the pressure disc is less than the thickness of the pressure disc proximate the weld, preferably equal to or less than half the thickness of the pressure disc proximate the weld.

25. A battery, comprising:

a) a first connector in electrical communication with a first electrode of the battery;

b) a second terminal in electrical communication with a second electrode of the battery;

c) a battery compartment having a battery cartridge and a cover in electrical communication with each other, the battery compartment being electrically insulated from the first terminal, wherein at least a portion of the battery compartment is at least a component of the second terminal or is electrically connected to the second terminal; and

d) at least one current interrupt device in electrical communication with the first or second electrode, the current interrupt device comprising:

i) a pressure disk comprising a deformed frustum having a first end and a second end, the second end having a smaller diameter than the first end, at least one of the first and second ends being non-circular in cross-section, and a substantially planar housing enclosing the second end of the deformed frustum, wherein the base is located proximal to the battery compartment and the substantially planar housing is located distal to the battery compartment; and

ii) a rupture disk in electrical communication with the pressure disk and the first or second electrode.

26. The battery of claim 25, wherein the cross-section of at least one of the first and second ends is elliptical.

27. The battery of claim 25, wherein the cross-section of both the first and second ends is non-circular.

28. The battery of claim 25, wherein the cross-section of both the first and second ends is elliptical.

29. The battery of claim 25, wherein the pressure disc and the rupture disc are joined together by at least one weld, and wherein the rupture disc defines at least one opening.

30. The battery of claim 29, wherein the battery cell cartridge is an angular battery cell cartridge.

31. The battery of claim 30, wherein the rupture disc defines a depression, and wherein the weld is located at the depression.

32. The battery of claim 31, wherein the weld is at least one spot weld.

33. The battery of claim 32, wherein at least one of the spot welds includes aluminum.

34. The battery of claim 32, wherein the weld is a two-spot weld.

35. The cell of claim 25 wherein at least one of the pressure disk and the rupture disk comprises aluminum.

36. The battery of claim 35, wherein both the pressure disk and the rupture disk comprise aluminum.

37. The battery of claim 36, wherein the housing has a thickness in a range between about 0.05mm and about 0.5 mm.

38. The battery of claim 37, wherein the diameter of the housing ranges between about 2mm and about 8 mm.

39. The battery of claim 38, wherein the height of the cover from the base is in a range between about 0.5mm and about 1 mm.

40. The battery of claim 39, wherein the frustum deformation has an angle with a plane parallel to the base of the pressure disk in a range between about 15 degrees and about 25 degrees.

41. The battery of claim 25, further comprising an electrically insulating ring extending around the frustum of the deformation and between the base of the pressure disc and the rupture disc.

42. The battery of claim 41, wherein the base of the pressure disk comprises at least one tab and wherein the electrically insulating ring defines at least one opening, the tab and the opening being alignable when the insulating ring and the base are concentric, and wherein the tab is extendably adjustable to secure the insulating ring to the pressure disk.

43. The battery of claim 41, wherein the electrically insulating ring defines a groove around a perimeter of the insulating ring, and further comprising a metal ring having a plurality of tabs, the metal ring being positionable inside the groove and the plurality of tabs being adjustably extendable to secure to a metal surface on which the pressure plate is located to secure the insulating ring to the pressure plate.

44. The battery of claim 25, wherein the range of gauge pressure between the two plates is about 4kg/cm²And about 9kg/cm²The weld connecting the pressure disc and the rupture disc will rupture.

45. The battery of claim 44, wherein the pressure range is between about 5kg/cm²And about 9kg/cm²In between, the weld will break.

46. The battery of claim 45 wherein the pressure range is between about 7kg/cm²And about 9kg/cm²In between, the weld will break.

47. The cell of claim 25 wherein the thickness of the rupture disc proximate the weld with the pressure disc is less than the thickness of the pressure disc proximate the weld, preferably equal to or less than half the thickness of the pressure disc proximate the weld.

48. The battery of claim 25, wherein the current interrupt device is in electrical communication with the battery compartment.

49. The battery of claim 48, wherein the current interrupt device is in electrical communication with the cover of the battery compartment, and the cover includes a recess facing the pressure plate.

50. The battery of claim 49, wherein the notch is co-bounded with the perimeter of the first end of the deformed frustum.

51. A method of manufacturing a current interrupt device, comprising the steps of:

a) forming a pressure disk comprising:

i) a deformable frustum having a first end and a second end, the second end having a smaller diameter than the first end, at least one of the first end and the second end having a non-circular cross-section;

ii) a base extending radially from a periphery of the first end of the frustum; and

iii) a substantially planar housing enclosing the second end of the deformed frustum;

b) forming a rupture disc; and

c) welding the rupture disc to the substantially planar housing of the pressure disc while a temperature of the pressure disc is controlled so as not to melt through the pressure disc to the other side of the weld.

52. The method of claim 51, wherein the cross-section is elliptical.

53. The method of claim 51, wherein the cross-section of both the first and second ends is non-circular.

54. The method of claim 51, wherein the cross-section of both the first and second ends is elliptical.

55. The method of claim 51, wherein the welding is performed using a laser.

56. The method of claim 55 wherein the welding is performed at least at one point.

57. The method of claim 56, wherein the welding is performed at least at two points.

58. A method of manufacturing a battery, comprising the steps of:

a) forming a current interrupt device, comprising the steps of:

i) forming a pressure disc comprising a deformed frustum having a first end and a second end having a smaller diameter than the first end, wherein at least one of the first and second ends has a non-circular cross-section, a base extending radially from around the first end of the deformed frustum, and a substantially planar housing enclosing the second end of the deformed frustum;

ii) forming a rupture disc; and

iii) welding the rupture disc to the substantially planar housing of the pressure disc while a temperature of the pressure disc is controlled so as not to melt through the pressure disc to the other side of the weld, thereby forming the current interrupt device;

b) attaching a first electrode or a second electrode of the battery to the current interrupt device;

c) attaching the current interrupt device to a cell compartment of the battery, the cell compartment comprising a battery cartridge and a cover in electrical communication with each other; and

d) a first terminal is formed in electrical communication with the first electrode and a second terminal is formed in electrical communication with the second electrode.

59. The method of claim 58, wherein the cross-section is elliptical.

60. The method of claim 58, wherein the cross-section of both the first and second ends is non-circular.

61. The method of claim 58, wherein the cross-section of both the first and second ends is elliptical.

62. The method of claim 58, wherein the current interrupt device is welded to the outer cover of the battery compartment.

63. The method of claim 62, wherein welding the current interrupt device to the cell compartment cover is performed by seam welding a peripheral interface between the cover and the pressure disk of the current interrupt device.

64. The method of claim 63, wherein the welding of the current interrupt device to the battery compartment cover is performed by through welding at the base of the pressure disk.

65. The method of claim 62, further comprising the step of welding the cover of the cell compartment to the cell cartridge of the cell compartment.

66. The method of claim 65, wherein a gage pressure between the outer cover and the battery cell cartridge is greater than or equal to about 20kg/cm²At this time, the welding connecting the outer cap and the battery cell cartridge is broken.

67. A method as in claim 58 wherein a gage pressure range between said rupture disc and said substantially planar housing is between about 4kg/cm²And about 9kg/cm²The weld connecting the rupture disc and the substantially planar housing of the pressure disc will rupture.

68. The method of claim 58, further comprising the step of forming at least one vent on the battery cartridge when an internal gauge pressure range is between about 10kg/cm²And about 20kg/cm²In between, the gas in the battery will be discharged through the exhaust device.