Battery pack with waterproof and heat-dissipating case

A battery pack including a core pack having a number of battery cells; a waterproof and heat-dissipating case formed of a flexible material that surrounds the core pack; and wiring that is electrically connected to the core pack and is drawn out of the waterproof and heat-dissipating case. A waterproof structure that prevents water penetration is formed in a portion of the waterproof and heat-dissipating case from where the wiring is drawn. Accordingly, water from the outside is effectively prevented from entering the battery pack and heat of the battery cells may be effectively dissipated out of the battery pack.

RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2009-0113352, filed on Nov. 23, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

The general inventive concept of the present invention relates to a battery pack having a waterproof and heat-dissipating case.

2. Description of the Related Art

Recently, as the technology for portable appliances has progressed and demand for such products has increased, demand for secondary batteries as a power source for the portable appliances has also seen a rapid increase.

SUMMARY

An aspect of the present invention includes a waterproof battery pack.

Another aspect of the present invention includes a battery pack capable of effectively dissipating heat that is generated during an operation out of the battery pack.

According to one or more embodiments of the present invention, a battery pack includes: a core pack comprising a plurality of battery cells; a waterproof and heat-dissipating case formed of a flexible material and for surrounding the core pack; and wiring that is electrically connected to the core pack and is drawn out of the waterproof and heat-dissipating case, wherein a waterproof structure for preventing water penetration is formed in a portion of the waterproof and heat-dissipating case from which the wiring is drawn.

The core pack may include a holder case including a plurality of cell spaces in which the plurality of battery cells are accommodated.

Terminals of the plurality of battery cells may be exposed out of the cell spaces and the core pack may include a lead plate that connect the terminals of the plurality of battery cells to one another.

The waterproof and heat-dissipating case may include a fibrous material selected from the group consisting of polyamide, ceramic-based fiber, cellulose fiber, woven fabric, and non-woven fabric.

One selected from the group consisting of polyimide, polyethylene imide (PE), polyethylene terephthalate (PET), poly tetra fluoro ethylene, and expanded poly tetra fluoro ethylene may be combined to the fiber.

The waterproof and heat-dissipating case may include a material selected from the group consisting of polyimide, polyethylene imide (PE), polyethylene terephthalate (PET), poly tetra fluoro ethylene, and expanded poly tetra fluoro ethylene.

The waterproof structure may include an accommodating portion including an opening portion at one side through which the waterproof and heat-dissipating case accommodates the core pack and a cover that covers the opening portion, and the wiring may be drawn out of the battery pack via a bonding portion between the accommodating portion and the cover.

The battery pack may further include an adhesive portion that bonds the accommodating portion, the cover, and the wiring, between the accommodating portion and the cover. The adhesive portion may include at least one selected from the group consisting of a double-sided tape and a waterproof adhesive.

Silicon may be coated on an external surface of the wiring.

The battery pack may further include a sealing portion that fills outside the wiring and surrounds the wiring, wherein the sealing portion is disposed between the accommodating portion and the cover after the wiring is drawn out of the battery pack.

The accommodating portion and the cover may be bonded to each other by using a thermal fusion method that applies heat to the accommodating portion and the cover to bond the accommodating portion and the cover or an ultrasonic fusion method that applies an ultrasonic wave to bond the accommodating portion and the cover.

DETAILED DESCRIPTION

Recognizing that sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, the present invention is not limited to the illustrated sizes and thicknesses.

In order to clarify the present invention, elements extrinsic to the description are omitted from the details of this description, and like reference numerals refer to like elements throughout the specification.

In several exemplary embodiments, constituent elements having the same configuration are representatively described in a first exemplary embodiment by using the same reference numeral and only constituent elements other than the constituent elements described in the first exemplary embodiment will be described in other embodiments.

A secondary battery may be used as a single battery according to the type of external devices it is used for. Also, a battery pack, which is a unit formed by electrically connecting a number of batteries, may be used.

Small-sized devices such as a mobile phone operate for a predetermined period of time according to the capacity of a single battery. However, mobile appliances such as laptop computers, camcorders, machines that consume a large amount of power, such as electromotive bicycles, electronic scooters, electric automobiles, and hybrid electric automobiles, consume a large amount of power for periods of operation.

Electromotive bicycles, electronic scooters, and electric automobiles are usually used outdoors, and in climates where rain or snow may occur, water may penetrate through a battery pack mounted in these machines and may cause a short circuit.

Also, when a large amount of power is supplied by a battery pack, heat generated therefrom should be discharged out of the battery pack, but in conventional battery packs, heat is not easily discharged out of the battery packs, thereby degrading the efficiency of the battery packs.

FIG. 1is a perspective view illustrating an assembly structure of a battery pack according to an embodiment of the present invention, andFIG. 2is a perspective view in which the battery pack ofFIG. 1is assembled.

The battery pack illustrated inFIGS. 1 and 2includes a core pack10including a plurality of battery cells200(shown inFIG. 3), a waterproof and heat-dissipating case30surrounding the core pack10, and wiring20connected to the core pack10and extending out of the waterproof and heat-dissipating case30. A waterproof structure for preventing water penetration may be formed in a portion of the waterproof and heat-dissipating case30where the wiring20is drawn therefrom.

The core pack10may include the plurality of battery cells200, and a holder case100that accommodate the battery cells200. When the battery cells200are accommodated in the holder case100, a battery pack for charging or discharging electricity is formed.

The battery pack as described above prevents water from penetrating into the waterproof and heat-dissipating case30and dissipates heat generated in the core pack10out of the battery pack. Accordingly, the performance of the battery pack is improved and structural and electric stability thereof may be improved.

FIG. 3is a perspective view illustrating an assembly structure of the core pack10included in the battery pack ofFIG. 1.

The holder case100may have a first case100aand a second case100bthat are disposed to face each other. The holder case100includes a plurality of cell spaces150into which the battery cells200are to be inserted.

By inserting the battery cells200into the cell spaces150of the first case100aand the second case100bwhile coupling the first case100aand the second case100bto each other, the holder case100accommodating the battery cells200are assembled completely.

The battery cells200accommodated in the holder case100may be any secondary batteries that may be charged and discharged. For example, the battery cells200may be lithium ion batteries, which are effective in terms of power output and capacity. However, the battery cells200are not limited thereto, and other batteries such as nickel-cadmium batteries, nickel-hydrogen batteries, lithium batteries, etc. may also be used.

When the battery cells200are mounted in the holder case100, electrodes of the battery cells200are exposed out of the cell spaces150. A lead plate180that connects the plurality of battery cells200serially or parallel may be disposed on the holder case100.

The lead plate180includes a metal having electric conductivity, such as nickel, and has a plate shape. Alternatively, the lead plate180may be formed of any of various materials having electrical conductivity instead of nickel. The lead plate180may be connected to each of the battery cells200by welding.

The serial or parallel connection structure of the battery cells200mounted in the battery pack or number or arrangement of the battery cells200constituting the parallel blocks may be modified. Also, the arrangement of the battery cells200of the battery pack is not limited to the embodiment illustrated in the drawing.

Referring toFIG. 1, the core pack10described above is inserted into the waterproof and heat-dissipating case30. The waterproof and heat-dissipating case30is formed of a flexible material and has a structure that surrounds the core pack10. When the core pack10is inserted into the waterproof and heat-dissipating case30, water is prevented from penetrating into the core pack10, and heat generated in the core pack10may be dissipated out of the battery pack through the waterproof and heat-dissipating case30.

The waterproof and heat-dissipating case30may be formed of a fibrous material. Examples of the fiber include polyamide, ceramic fiber, cellulose fiber, woven fabric, and non-woven fabric. The waterproof and heat-dissipating case30formed of a fiber may be coated with a resin. The waterproof and heat-dissipating case30may be formed of a mixture of a fiber and a resin. Examples of the resin include polyimide, polyethylene imide (PE), polyethylene terephthalate (PET), polytetrafluoro ethylene, and expanded poly tetra fluoro ethylene.

The waterproof and heat-dissipating case30may also be formed without a fiber and formed of only a resin material. Examples of the resin include polyimide, polyethylene imide (PE), polyethylene terephthalate (PET), polytetrafluoro ethylene, and expanded poly tetra fluoro ethylene.

Expanded poly tetra fluoro ethylene is also known by a product name, GoreTex™, and is used in waterproof and heat-dissipating clothing products.

The wiring20is electrically connected to the core pack10. The wiring20includes large current terminals21and22that supply a current from the battery cells200out of the waterproof and heat-dissipating case30or allows a charging current to flow through the battery cells200, and a balancing line25for checking the state of the battery cells200. The balancing line25may include a plurality of signal lines25bconnected to the battery cells200and a connector25aconnected to an end portion of the signal lines25b. The waterproof structure may include a sealing portion41that surrounds an external surface of the wiring220. The sealing portion41is divided into three separate portions which separately surround the large current terminals21and22and the balancing line25.

When the core pack10is inserted into the waterproof and heat-dissipating case30as illustrated inFIG. 2, the wiring20is drawn out of the waterproof and heat-dissipating case30in order to supply a current from the core pack10out of the core pack10or to supply a charging current to the core pack10. The wiring20is drawn out of the battery pack after the core pack10is accommodated in the waterproof and heat-dissipating case30, and thus a region around the wiring20needs to be perfectly sealed so that water does not enter through a portion where the wiring20passes through the waterproof and heat-dissipating case30. Accordingly, a waterproof structure is formed in the portion where the wiring20is drawn from the waterproof and heat-dissipating case30.

The waterproof and heat-dissipating case30includes a pocket-shaped accommodating portion33for accommodating the core pack10, an opening portion31, and a cover32for covering the opening portion31. An end portion of the cover32is integrally connected to the accommodating portion33, and as an edge32bof the cover32is bonded to an edge33bof the accommodating portion33after the core pack10is accommodated in the waterproof and heat-dissipating case30, the waterproof and heat-dissipating case30may be sealed. The waterproof structure may be formed by coupling the accommodating portion33and the cover32.

In order to seal the portion where the wiring20is drawn from the waterproof and heat-dissipating case30, a first wing portion35is disposed at the other end portion of the cover32, and a second wing portion36is disposed on the accommodating portion33to correspond to the first wing portion35. The first wing portion35may be, but not limited thereto, formed at a 90 degree angle to the cover32. As the first wing portion35and the second wing portion36are bonded to each other, a bonding portion between the cover32and the accommodating portion33is formed, and the wiring20may be drawn out of the battery pack via the bonding portion between the first wing portion35and the second wing portion36.

The waterproof structure formed in the portion where the wiring20is drawn from the battery pack according to the current embodiment of the present invention is not limited to the coupling of the accommodating portion33and the cover32. That is, the waterproof structure may be formed by using any of various structures. For example, a hole through which the wiring20may pass is formed in a portion of the waterproof and heat-dissipating case30, and the wiring20may be drawn out of the waterproof and heat-dissipating case30through the hole, and at the same time, an edge of the hole surrounding the wiring20may be filled with a waterproof adhesive to manufacture the waterproof structure.

FIG. 4is a cross-sectional view illustrating a coupling process in which the wiring20and the waterproof and heat-dissipating case30are coupled in the battery pack ofFIG. 2.FIG. 5is a cross-sectional view illustrating the wiring20and the waterproof and heat-dissipating case30that are bonded to each other in the battery pack ofFIG. 2.

The waterproof structure of the battery pack may include adhesive tapes35aand36athat are respectively disposed on corresponding surfaces of the first wing portion35and the second wing portion36. The adhesive tapes35aand36abond the first and second wing portions35and36and the wiring20. The adhesive tapes35aand36aare examples of adhesive portions that bond the accommodating portion33and the cover32in the bonding portion from where the wiring20is drawn, but the embodiment of the present invention is not limited thereto. Alternatively, the accommodating portion33and the cover32may be bonded by using a waterproof adhesive, a thermal fusion method in which heat is applied to the first and second wing portions35and36to bond the accommodating portion33and the cover32, or an ultrasonic fusion method in which an ultrasonic wave is applied to the accommodating portion33and the cover32to bond the accommodating portion33and the cover32.

The large current terminals21and22of the wiring20include conductive lines21band22bformed of an electric conductive material such as copper and coatings21aand22athat surround the conductive lines21band22b. The waterproof structure may further include silicon coated on external surfaces of the large current terminals21and22and a balancing line25between the first wing portion35and the second wing portion36. Silicon coating is conducted to completely prevent water penetration due to the wiring20and to improve sealing properties of the adhesive tapes35aand36a.

After arranging the wiring20between the first wing portion35and the second wing portion36, pressure is applied to the first wing portion35and the second wing portion36so that the bonding portion from where the wiring20is drawn from the waterproof and heat-dissipating case30is completely sealed as illustrated inFIG. 5. Thus the waterproof structure is completed. According to the waterproof structure described above, water penetration into the waterproof and heat-dissipating case30may be effectively prevented.

FIG. 6is a cross-sectional view illustrating a coupling process in which wiring and a waterproof and heat-dissipating case are coupled in a battery pack according to another embodiment of the present invention.

The battery pack illustrated inFIG. 6has a similar configuration to the battery pack described with reference to the previous embodiment, except that a waterproof structure in a portion from where a wiring is drawn from a waterproof and heat-dissipating structure has been modified.

A first wing portion235is disposed in a cover in order to seal a portion from where a wiring220is drawn from the waterproof and heat-dissipating case, and a second wing portion236is disposed in an accommodating portion of the waterproof and heat-dissipating case corresponding to the first wing portion235. As the first wing portion235and the second wing portion236are bonded to each other, a bonding portion between the cover and the accommodating portion is formed, and the wiring220may be drawn out of the battery pack via a bonding portion between the first wing portion235and the second wing portion236.

Adhesive tapes235aand236aare disposed on corresponding surfaces of the first wing portion235and the second wing portion236, respectively. The adhesive tapes235aand236abond the first and second wing portions235and236and the wiring220. The adhesive tapes235aand236aare examples of an adhesive portion that bonds the accommodating portion and the cover in a bonding portion from where the wiring220is drawn, but the embodiment of the present invention is not limited thereto. Alternatively, a waterproof adhesive may be used, or a thermal fusion method in which heat is applied to the first wing portion235and the second wing portion236to bond the accommodating portion and the cover or an ultrasonic fusion method in which an ultrasonic wave is applied to the accommodating portion and the cover may be used to bond the accommodating portion and the cover.

Large current terminals221and222of the wiring220include a balancing line225. The waterproof structure may include a sealing portion250that surrounds an external surface of the wiring220. The sealing portion250supports the wiring220, ensures prevention of water penetration due to the wiring220, and improves adhesion properties of the adhesive tapes235aand236ato improve the sealing properties. Examples of the sealing portion250include a rubber, a resin material, and an adhesive.

After arranging the wiring line220surrounded by the sealing portion250, between the first wing portion235and the second wing portion236, pressure is respectively applied to the first wing portion235and the second wing portion236so that sealing of the bonding portion where the wiring220is drawn from the waterproof and heat-dissipating structure is ensured. According to the waterproof structure according to the embodiment of the present invention, water penetration through the waterproof and heat-dissipating case may be effectively prevented.

According to the embodiments of the present invention as described above, water may be effectively prevented from coming into a battery pack as a core pack is accommodated in a waterproof and heat-dissipating case. Also, heat generated during an operation of battery cells of the core pack may be dissipated out of the battery pack by using the waterproof and heat-dissipating case. In addition, a bonding portion of the waterproof and heat-dissipating case forms a seal around wiring electrically connected to the core pack and extending out of the battery pack, thereby forming a waterproof structure. Accordingly, water penetration due to the wiring may be effectively prevented.