Patent Application
20100251540
1. Field of the Invention
The present invention relates to a rechargeable battery, and more particularly, the present invention relates to a rechargeable battery that includes a bare cell having an electrode assembly, a can and a cap assembly, and a protective circuit board electrically connected to the bare cell, and its fabrication method.
2. Description of the Related Art
Since a rechargeable battery is capable of being recharged several times and of realizing a size-reduction and a high capacity, it recently has been actively researched and developed. Among rechargeable batteries, Nickel-Metal Hydride (Ni-MH) batteries, Lithium (Li), and Lithium-ion (Li-ion) batteries have been broadly used.
A bare cell of these rechargeable batteries is fabricated by arranging an electrode assembly including a cathode, an anode and a separator inside a can, covering a top of the can with a cap assembly in which an electrolyte solution is injected into the can before or after covering, and then sealing the can.
A core pack is formed by selectively or associatively connecting a safety device, such as a Positive Temperature Coefficient (PCT) element, a thermal fuse, a Protective Circuit Module (PCM), or other battery components to the sealed bare cell. The exterior of the rechargeable battery is completed by arranging the core pack inside an additional resin case, or filling the gap between the bare cell and the PCM with a hot-melt resin, followed by covering or labeling with a thin exterior material.
The safety device or other components are connected to cathode and anode terminals of the bare cell by a conductive structure called a lead plate. The safety device breaks an electric current, when the battery temperature reaches a high level or the battery voltage is suddenly increased by an over-charge or over-discharge, so as to prevent the battery from breakdowns or fire.
The bare cell 210 is fabricated by arranging an electrode assembly and an electrolyte inside a polygonal can, which has an approximate rectangular parallelepiped shape and an upper opening portion, and covering with a cap assembly which has a cap plate.
An electrode terminal 212 is placed on the cap assembly, which forms an upper surface of the bare cell, and is insulated from the cap plate. The cap plate is welded to the can so as to have the same electrical polarity. Accordingly, when attaching the protective circuit board portion to one side surface of the bare cell 210, the insulation plate 220 is placed for electrical insulation between the protective circuit board portion and the bare cell 210. The insulation plate 220 is made of a double-sided adhesive material so as to attach the protective circuit board portion to the bare cell 210.
The protective circuit board portion includes 3 parts. The protective circuit board portion is positioned on a side surface of the bare cell by arranging a base case 231, which is molded of a resin and is capable of receiving a protective circuit board, on the insulation plate, positioning the protective circuit board formed into a shape corresponding to that of the base case 231, and assembling a cover case 39 having a shape corresponding to the exposed exterior shape of the base case 231 and the protective circuit board positioned thereon.
The protective circuit board is formed by connecting a Protection Circuit Module (PCM) 237 and a PTC element 235 to a PCB substrate 239 and welding nickel plates acting as electrical terminals 232 and 233 to both sides thereof. The two electrical terminals 232 and 233 of the protective circuit board are respectively electrically connected to the electrode terminal 212 formed on the upper portion of the bare cell and a lower surface of the can forming the bare cell. An additional insulation material may be further attached to the electrical terminal 232 to be connected to the electrode terminal 212 for electrically insulating it from the cap plate.
Referring to
Although not shown in the drawings, the exterior of the rechargeable battery may be completed by covering the whole side surface of the core pack of the rechargeable battery with a resin thin film, or covering with a resin thin cover. Furthermore, the core pack may be packed in an additional exterior case in order for an external contact terminal to be exposed. The exterior materials including a covering material, resin cover, exterior case and the like may be applied with or without a label.
However, since every process as described above is performed manually or mechanically, time and cost for performing each process are consumed. Especially, the protective circuit board portion includes a plurality of components, so that great amounts of time and cost are required for assembling thereof.
Furthermore, generally, as the number of processes is increased, the risk of defects occurring in each process is increased.
Accordingly, an object of the present invention is to provide a rechargeable battery and its fabrication method, which has a reduced number of fabrication processes.
Another object of the present invention is to provide a rechargeable battery and a fabrication method thereof, which can realize cost saving by reducing the number of components used in the assembling process, minimize logistic costs due to a reduced number of components, and reduce processing costs and rejection rate in the assembling process.
Additional advantages, objects and features of the present invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the present invention.
According to one aspect of the present invention, a rechargeable battery is provided which includes a bare cell and a protective circuit board portion.
The protective circuit board portion may include a body portion attached to the one side surface of the bare cell and two electrical terminals respectively connected to two electrode terminals of the bare cell, and formed in one single body through resin molding that forms a coat layer of the body portion.
The protective circuit board portion may include a PCB substrate with a protection circuit and two electrical terminals extending outside the resin molding from the PCB substrate, in which external electrical terminals are formed on the surface opposed to the contact surface with the bare cell.
According to another aspect of the present invention, a method of fabrication of a rechargeable battery is provided, which includes: forming a protective circuit board portion into one single body through resin molding, attaching the protective circuit board to a bare cell, and respectively electrically connecting two electrical terminals of the protective circuit board portion to two electrodes of the bare cell.
A more complete appreciation of the present invention and many of the attendant advantages thereof, will be readily apparent as the present invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
Hereinafter, exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawing. The aspects and features of the present invention and methods for achieving the aspects and features will be apparent by referring to the embodiments to be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed hereinafter, but can be implemented in diverse forms. The matters defined in the description, such as the detailed construction and elements, are merely specific details provided to assist those of ordinary skill in the art in a comprehensive understanding of the present invention, and the present invention is only defined within the scope of the appended claims. In the entire description of the present invention, the same drawing reference numerals are used for the same elements across various figures.
The resin molded protective circuit board forms a body portion of the protective circuit board portion. The two electrical terminals 332 and 333 are led out from the body portion, bent on one narrow side surface of the bare cell 310 toward upper and lower surfaces thereof and thus respectively connected to an electrode terminal 312 through the welding between the top end of the bare cell 310 and a lower surface of a can forming the bare cell 310.
The protective circuit board portion 330 may include an external terminal 338 on the surface opposed to the contact surface with the bare cell 310, in which the external terminal 338 is formed to protrude from or be exposed on the surface so as to contact an external device.
Since a cap plate portion of the upper surface of the bare cell 310 except for the electrode terminal 312 causes an electrical short when it is contact with the electrical terminal 332 of the protective circuit board portion 330, a washer or other insulation materials may be required for the inner side surface of the extended electrical terminal 332 or the surface of a cap plate. As shown in
The elements of
The exterior of the rechargeable battery 400 may be completed by using a tape label as an exterior material rather than the additional resin case 410, in which the tape label covers the wide side surface and upper and lower surface of the rechargeable battery shown in
Referring to
According to the present invention, the body portion of the protective circuit board to which major components, such as a PCM, a PTC element, etc., are connected is formed by molding with a hot-melt resin. However, it is different from other methods of forming the protective circuit board in that a plurality of components are formed into one single body and then subjected to an assembly process.
Referring to
The electrode assembly 12, for example, is formed by laminating a cathode 13, a separator 14 and an anode 15, which are formed into a thin plate or film shape, and winding all together into a jelly-roll arrangement. Two sheets of the separator are used in order to prevent an electrical short between the two electrodes.
The cathode 13 includes a cathode collector made of a thin metal sheet, which has an excellent conductivity, such as an aluminum foil, and a cathode active material layer which is formed on both surfaces thereof and uses lithium oxides as a main ingredient. In the cathode 13, a cathode tap 16 is electrically connected to a region of the cathode collector where the cathode active material layer has not been formed.
The anode 15 includes an anode collector made of a thin metal sheet, such as a copper foil, and an anode active material layer which is formed on both surfaces thereof and uses a carbon material as a main ingredient. In the anode 15, an anode tap 17 is electrically connected to a region of the anode collector where the anode active material layer has not been formed. The cathode 13 and the anode 15 may be placed in a different position according to each other's position, and so may the cathode and anode taps 16 and 17.
The separator 14 is made of polyethylene, polypropylene, or a co-polymer thereof, and is wider than the cathode and anode taps 13 and 15 in order to prevent a short circuit between electrode plates.
The can 11 is made of an aluminum alloy, an iron, etc., and receives the electrode assembly 12 through the upper opening thereof so as to act as a container for the electrode assembly 12 and an electrolyte solution. A can 211 is capable of acting as a terminal. However, according to the embodiment, a cap plate 110 of the cap assembly acts as a cathode terminal.
The cap assembly includes the plate type cap plate 110 having a size and shape corresponding to the upper opening of the can 11. A terminal through-hole 111 is formed in a middle portion of the cap plate 110 in order for the electrode terminal to pass through. A tube shaped gasket 120 is positioned on an outer side of the electrode terminal passing through the middle portion of the cap plate 110 in order to connect the electrode terminal 130 to the cap plate 110. An insulation plate 140 is placed on a lower surface of the cap plate 110 around the terminal through-hole 111 of the middle portion of the cap plate 110. A terminal plate 150 is positioned on a lower surface of the insulation plate 140. The anode tap is welded to the terminal plate, while the cathode tap led out from the cathode is welded to the cap plate.
An insulation case 190 is positioned so as to cover the top end of the electrode assembly 12. The insulation case 190 is a polymer resin having insulation properties and has a through-hole 191 in order for the tap to pass through. The through-hole allows an electrolyte solution to pass through without an additional electrolyte solution through-hole 192.
As described above, the rechargeable battery, according to the present invention, produces the following effect.
First, the rechargeable battery can realize a cost saving by reducing the number of components used in the assembling process, and can minimize logistic costs due to a reduced number of components
Second, the rechargeable battery can reduce process costs and rejection rate in the assembling process by simplifying the assembling process due to a reduced number of components.
It should be understood by those of ordinary skill in the art that various replacements, modifications and changes in the form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. Therefore, it is to be appreciated that the above described embodiments are for purposes of illustration only and are not to be construed as limitations of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2005-0134551 | Dec 2005 | KR | national |
This application is a divisional of Applicant's Ser. No. 11/645,634 entitled RECHARGEABLE BATTERY AND ITS FABRICATION METHOD filed in the U.S. Patent & Trademark Office on 27 Dec. 2006 and assigned to the assignee of the above-captioned application. Furthermore, this application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119, §120 and §121 from the aforesaid Applicant's Ser. No. 11/272,805 and from an application for RECHARGEABLE BATTERY AND METHOD OF MAKING THE SAME earlier filed in the Korean Intellectual Property Office on 29 Dec. 2005 and there duly assigned Ser. No. 10-2005-134551.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11645634 | Dec 2006 | US |
| Child | 12818264 | US |
