CN102208594B - Secondary battery - Google Patents

Abstract

A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate; housing the electrode assembly a housing; an electrode terminal electrically connected to the first electrode plate; a current collector coupled between the first electrode plate and the electrode terminal and electrically connecting the first electrode plate and the electrode terminal, The current collector includes a fuse part; and an insulating unit on the fuse part of the current collector.

Description

secondary battery

technical field

Aspects of embodiments of the present invention relate to a secondary battery, and more particularly, to a secondary battery protected by causing a fuse to function when an overcurrent flows due to overcharging or an abnormal phenomenon .

Background technique

Unlike primary batteries, which are not rechargeable, secondary batteries are rechargeable batteries. Secondary batteries are widely used in high-tech electronic equipment such as cellular phones, notebook computers, and camcorders, and are also used in vehicles.

A secondary battery includes an electrode assembly and an electrolyte. The electrode assembly includes positive and negative electrode plates and a separator. The electrolyte solution includes lithium (Li) ions in many cases. The positive electrode plate and the negative electrode plate of the electrode assembly may include electrode tabs protruding outward.

The electrode assembly may be accommodated in the case, and the electrode terminal may be exposed to the outside of the case. The electrode tab may protrude outside the electrode assembly to be electrically connected to the electrode terminal. The housing may have a cylindrical shape or a rectangular shape.

Contents of the invention

According to an aspect of various embodiments of the present invention, a secondary battery can prevent or substantially prevent explosion even when an overcurrent flows due to overcharging or an abnormal phenomenon.

According to an embodiment of the present invention, a secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and an electrode between the first electrode plate and the second electrode plate. a separator; a housing for accommodating the electrode assembly; an electrode terminal electrically connected to the first electrode plate; coupled between the first electrode plate and the electrode terminal and electrically connecting the first electrode plate and the electrode terminal A current collector of the electrode terminal, the current collector including a fuse portion; and an insulating unit on the fuse portion of the current collector.

In one embodiment, the insulating unit has a larger surface than the fuse part. In one embodiment, the fuse portion has a smaller cross-sectional area than other portions of the current collector. The fuse part may have a higher resistance than other parts of the current collector.

In one embodiment, the electrode terminals protrude outside the case. In one embodiment, the secondary battery further includes a cap plate sealing the opening of the case, wherein the electrode terminals protrude through terminal holes formed in the cap plate.

The insulation unit may include at least one of an insulation tape and an insulation molding. The current collector may be formed as a single integral piece.

In one embodiment, the current collector includes: a current collector plate coupled to the first electrode plate; and a lead member coupled to the electrode terminal and the current collector plate. The lead member may include: a terminal lead unit coupled to the electrode terminal; and a current collecting lead unit extending from the terminal lead unit and coupled to the current collecting plate. In one embodiment, the current collecting lead unit includes the fuse part. In one embodiment, the terminal lead unit includes the fuse part. The fuse part may be integrally formed on the lead member, and may have a smaller cross-sectional area than other parts of the lead member.

In one embodiment, the electrode terminal is a first electrode terminal, and the secondary battery further includes a second electrode terminal electrically connected to the second electrode plate and protruding to the outside of the case; and the The current collector is a first current collector, and the secondary battery further includes a battery coupled between the second electrode plate and the second electrode terminal and electrically connecting the second electrode plate and the second electrode terminal The second set of fluids. In one embodiment, the first electrode plate is a positive electrode plate, the first current collector is a positive electrode current collector, and the second electrode plate is a negative electrode plate, and the second current collector is a negative electrode current collector. In one embodiment, the first current collector includes aluminum and the second current collector includes copper.

The fuse part may be configured such that when a current having a magnitude greater than or equal to a set current flows through the current collector, the fuse part melts and separates the first electrode plate from the electrode. Terminal disconnected.

The secondary battery according to one or more embodiments of the present invention prevents or substantially prevents explosion even when an overcurrent flows due to overcharging or an abnormal phenomenon.

Description of drawings

The above and other features and advantages will become more apparent to those of ordinary skill in the art by describing in detail some exemplary embodiments of the present invention with reference to the accompanying drawings. The drawings illustrate some exemplary embodiments of the invention and, together with the description, serve to explain principles and provide a further understanding of the invention.

FIG. 1 is a perspective view of a secondary battery according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the secondary battery of FIG. 1 taken along line II-II.

3 is a partially exploded perspective view of the secondary battery of FIG. 1 , illustrating a lead member including a current collecting lead unit in which a fuse is formed and separated from an electrode assembly.

FIG. 4 is a cross-sectional view of a secondary battery according to another embodiment of the present invention.

5 is a partially exploded perspective view of the secondary battery of FIG. 4, illustrating a lead member including a terminal lead unit in which a fuse is formed and separated from an electrode assembly.

6 is a cross-sectional view of a secondary battery according to an embodiment, in which the first lead member of FIG. 2 directly contacts the cap plate.

7 is a cross-sectional view of a secondary battery according to an embodiment, in which the first lead member of FIG. 4 directly contacts the cap plate.

Detailed ways

Some exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, various embodiments of the invention may be embodied in different forms and should not be construed as limited to the exemplary embodiments illustrated and suggested herein. Rather, these exemplary embodiments are provided by way of example for understanding of the invention, and to convey the scope of the invention to those skilled in the art.

FIG. 1 is a perspective view of a secondary battery 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II of the secondary battery 100 illustrated in FIG. 1 .

1 and 2, the secondary battery 100 includes: an electrode assembly 10; a first electrode terminal 21 and a second electrode terminal 22; a cover plate 30; a case 40; a first current collector 50 and a second current collector 60; wire 70; and insulation unit 80. In one embodiment, the secondary battery 100 is a rectangular lithium (Li) ion secondary battery.

The electrode assembly 10 includes a first electrode plate 11 , a separator 13 and a second electrode plate 12 . The first current collector 50 and the second current collector 60 are electrically connected to the electrode assembly 10 . The first current collector 50 and the second current collector 60 may be electrically connected to the first electrode plate 11 and the second electrode plate 12 , respectively. The cap plate 30 may be combined with or cover the open surface of the case 40 to seal the case 40 in which the electrode assembly 10 is accommodated.

In one embodiment, when an overcurrent flows due to overcharging or an abnormal phenomenon, the fuse 70 functions to cut off the current. In one embodiment, the insulating unit 80 wraps the fuse 70 with an insulating material to electrically isolate the fuse 70 from any external contacts. In one example, the insulating unit 80 has a larger surface than the fuse 70 .

In one embodiment, the electrode assembly 10 is formed by winding the first electrode plate 11 , the separator 13 and the second electrode plate 12 in the form of a jelly roll. However, embodiments of the present invention are not limited thereto, and the electrode assembly 10 may be formed, for example, by alternately stacking first electrode plates 11 , separators 13 , and second electrode plates 12 .

In one embodiment, the first current collector 50 contacts the first electrode plate 11 exposed at one end of the electrode assembly 10 , and the second current collector 60 contacts the second electrode plate 12 exposed at the other end of the electrode assembly 10 .

The first electrode terminal 21 may be electrically connected to the first current collector 50 and may be partially exposed to the outside through the cap plate 30 . The second electrode terminal 22 may be electrically connected to the second current collector 60 and may be partially exposed to the outside through the cap plate 30 .

In the secondary battery 100, the first electrode plate 11 may be a positive electrode plate, and the second electrode plate 12 may be a negative electrode plate. Also, in one embodiment, the first current collector 50 is a positive electrode current collector, and the second current collector 60 is a negative electrode current collector. In addition, the first electrode terminal 21 may be a positive electrode terminal, and the second electrode terminal 22 may be a negative electrode terminal.

The electrode assembly 10 may be formed by winding the first electrode plate 11 and the second electrode plate 12 and interposing the separator 13 as an insulator therebetween. The case 40 accommodates the electrode assembly 10 . The first electrode terminal 21 and the second electrode terminal 22 may be a positive electrode terminal and a negative electrode terminal, respectively. In one embodiment, the first electrode terminal 21 and the second electrode terminal 22 are respectively electrically connected to the first electrode plate 11 and the second electrode plate 12 of the electrode assembly 10 so as to be exposed to the outside of the case 40 . The cover plate 30 may be combined with the opening of the case 40 .

The fuse 70 is a device for protecting a circuit, for example, by cutting off an overcurrent exceeding a preset value. In one embodiment, when an overcurrent flows, since the fuse 70 is melted and cut due to heat generated by the overcurrent, the overcurrent is blocked to prevent the overcurrent from flowing through the circuit. In this way, the stability of the circuit can be ensured.

In one embodiment, the first electrode plate 11 , the first current collector 50 , the first electrode terminal 21 , the second electrode terminal 22 , the second current collector 60 and the second electrode plate 12 are electrically connected to form a circuit. Here, if electric power is input from an external device through the first electrode terminal 21 and the second electrode terminal 22 , charging may be performed between the first electrode plate 11 and the second electrode plate 12 .

In one embodiment, an overcurrent may flow from the first electrode plate 11 to the second electrode plate 12 through the circuit due to overcharging or another abnormal phenomenon. When an overcurrent flows through the circuit, a load on the electrode assembly 10 including the first electrode plate 11 and the second electrode plate 12 may be excessive, and thus an abnormal phenomenon such as explosion may occur.

However, since the fuse 70 cuts off the overcurrent to prevent the overcurrent from flowing through the circuit, an abnormal phenomenon such as explosion of the secondary battery 100 due to the overcurrent may be prevented or substantially prevented. In this way, the stability and reliability of the secondary battery 100 against abnormal phenomena due to overcurrent can be ensured.

The electrode assembly 10 includes a first electrode plate 11 , a second electrode plate 12 and a separator 13 . In one embodiment, the first and second electrode plates 11 and 12 and the separator 13 as an insulator between the first and second electrode plates 11 and 12 are rolled to form the electrode assembly 10 .

In one embodiment, the first electrode plate 11 and the second electrode plate 12 include respective first and second uncoated portions 11 a and 12 a and first and second coated portions 11 b and 12 b . The first uncoated portion 11 a and the second uncoated portion 12 a are regions where no active material is coated on a current collector (for example, a current collector formed of a metal foil). The first coating portion 11 b and the second coating portion 12 b are regions where an active material is coated on a current collector (for example, a current collector formed of a metal foil). In one embodiment, the first uncoated portion 11a and the second uncoated portion 12a are respectively a positive electrode uncoated portion and a negative electrode uncoated portion, and the first coated portion 11b and the second coated portion 12b are a positive electrode coating part and a negative electrode coating part, respectively.

In one embodiment, the first uncoated portion 11a is formed at one side end of the first electrode plate 11 along the length direction of the first electrode plate 11, and the second uncoated portion 12a is formed at the second The other end of the electrode plate 12 along the length direction of the second electrode plate 12 .

In one embodiment, the electrode assembly 10 is formed by circularly winding and extruding the first and second electrode plates 11 and 12 and the separator 13 . In one embodiment, the electrode assembly 10 is extruded in the form of a plate to form a flat portion 18 and a curved portion 19 as illustrated in FIG. 3 .

The flat portion 18 is a portion where the outer periphery of the electrode assembly 10 is flat when the first and second electrode plates 11 and 12 and the separator 13 are rolled and extruded into a plate form. The bent portion 19 is a portion where the outer periphery of the electrode assembly 10 is bent at both ends of the flat portion 18 . That is, the flat portions 18 are connected to each other by the bent portion 19 at their ends.

The case 40 may have the shape of a rectangular can with one end open. Through the open end of the case 40 , the electrode assembly 10 may be accommodated in the case 40 together with the electrolytic solution. In one embodiment, the cover plate 30 exposes the first electrode terminal 21 and the second electrode terminal 22 and covers the casing 40 . In one embodiment, the boundary between the case 40 and the cap plate 30 is laser welded so that the case 40 in which the electrode assembly 10 is accommodated together with the electrolyte can be sealed. Alternatively, cover plate 30 may be sealed to housing 40 by any other suitable device or method.

In one embodiment, the cover plate 30 is a thin plate. In one embodiment, an electrolyte inlet 38a through which electrolyte may be injected is formed in the cover plate 30 . After the electrolytic solution is injected through the electrolytic solution inlet 38a, the sealing plug 38 may be fitted in the electrolytic solution inlet 38a. In addition, an exhaust member 39 in which a groove is formed may be formed in the cap plate 30 to be ruptured according to a set internal pressure.

In one embodiment, the first terminal hole 21 a and the second terminal hole 22 a are formed in the cap plate 30 . In one embodiment, the first terminal hole 21a and the second terminal hole 22a are respectively a positive electrode terminal hole and a negative electrode terminal hole. In one embodiment, the first electrode terminal 21 is exposed through the first terminal hole 21a, and the second electrode terminal 22 is exposed through the second terminal hole 22a.

The upper gasket 25 and the lower gasket 27 may be interposed between the cap plate 30 and the first and second electrode terminals 21 and 22 , respectively, so as to insulate the cap plate 30 from the first and second electrode terminals 21 and 22 .

The lower gasket 27 fits in the first terminal hole 21 a and the second terminal hole 22 a under the cover plate 30 , and the upper gasket 25 fits in the first terminal hole 21 a and the second terminal hole 22 a above the cover plate 30 . A washer 24 for buffering coupling force may be disposed on the upper pad 25 . Screw threads may be formed on the first electrode terminal 21 and the second electrode terminal 22 and may be engaged with nuts 29 to support the first electrode terminal 21 and the second electrode terminal 22 on the case 40 .

However, embodiments of the present invention are not limited thereto, and for example, the first electrode terminal 21 and the second electrode terminal 22 may have the form of a rivet. In one embodiment, the upper gasket 25 is fitted in the housing 40 by protruding a part of the first electrode terminal 21 and the second electrode terminal 22 through the first terminal hole 21a and the second terminal hole 22a to the outside of the case 40. Between the first terminal hole 21a and the second terminal hole 22a and the protruding parts of the first electrode terminal 21 and the second electrode terminal 22 and pressing and extending the protruding parts of the first electrode terminal 21 and the second electrode terminal 22, The first electrode terminal 21 and the second electrode terminal 22 may be fixed to the cap plate 30 .

In one embodiment, the first current collector 50 includes a first current collector plate 51 and a first lead member 52 . Similarly, in one embodiment, the second current collector 60 includes a second current collector plate 61 and a second lead member 62 . In one embodiment, the first current collecting plate 51 and the second current collecting plate 61 are respectively a positive electrode current collecting plate and a negative electrode current collecting plate, and the first lead member 52 and the second lead member 62 are respectively a positive electrode lead member and the negative electrode lead member.

In one embodiment, the first current collecting plate 51 is bonded to the first uncoated portion 11a of the electrode assembly 10, for example, by using a welding method. In one embodiment, the first current collecting plate 51 is electrically connected to the first electrode terminal 21 via the first lead member 52 . In this way, the first electrode terminal 21 is connected to the first electrode plate 11 of the electrode assembly 10 via the first lead member 52 and the first current collecting plate 51 .

Also, in one embodiment, the second current collecting plate 61 is bonded to the second uncoated portion 12a of the electrode assembly 10, for example, by using a welding method. In one embodiment, the second current collecting plate 61 is electrically connected to the second electrode terminal 22 via the second lead member 62 . In this way, the second electrode terminal 22 is connected to the second electrode plate 12 of the electrode assembly 10 via the second lead member 62 and the second current collecting plate 61 .

In one embodiment, the insulating member 26 is formed between the cover plate 30 and the first lead member 52 and the second lead member 62 . In one embodiment, the first lead member 52 and the second lead member 62 respectively include a first terminal lead unit 52 a and a second terminal lead unit 62 a and a first current collector lead unit 52 b and a second current collector lead unit 62 b. The first terminal lead unit 52a and the second terminal lead unit 62a are bonded and electrically connected to the first electrode terminal 21 and the second electrode terminal 22, respectively. In one embodiment, the first current collecting plate 51 and the first lead member 52 are formed as a single integral unit. Similarly, in one embodiment, the second current collecting plate 61 and the second lead member 62 are formed as a single integral unit, that is, the current collector 50 is formed as a single integral piece. In another embodiment, the first current collecting plate 51 and the second current collecting plate 61 are bonded and electrically connected to the first current collecting lead unit 52b and the second current collecting lead unit 62b, respectively. In one embodiment, the first current collecting lead unit 52b and the second current collecting lead unit 62b are bonded (or otherwise contacted) and electrically connected to the first uncoated portion 11a and the second uncoated portion 11a of the electrode assembly 10, respectively. Coating part 12a.

According to another embodiment of the present invention, for one of the first electrode terminal 21 and the second electrode terminal 22, no upper plate for electrically separating the first electrode plate 11 or the second electrode plate 12 from the cover plate 30' may be formed. A gasket 25 , an insulating member 26 and a lower gasket 27 . In this case, the cap plate 30' and/or the case 40 may be the first electrode terminal or the second electrode terminal.

For example, in the secondary battery 100' according to one embodiment, the upper gasket 25 and the lower gasket 27 may not be formed between the cap plate 30' and the first lead member 52, as shown in FIG. 6 . In this case, the first lead member 52 directly contacts the cap plate 30'.

In this case, the first electrode terminal 21 may directly contact the cap plate 30 through the first terminal hole 21 a without the upper pad 25 and the lower pad 27 . In addition, the first lead member 52 may directly contact the cap plate 30 . In this case, the cap plate 30 and the case 40 have the same polarity as the first electrode terminal 21 .

In one embodiment, the secondary battery 100 is a lithium ion secondary battery. However, embodiments of the present invention are not limited thereto, and the secondary battery 100 may be one of various other types of secondary batteries, such as nickel (Ni)-cadmium (Cd ) secondary battery, nickel-hydrogen (H) secondary battery or lithium (Li) secondary battery.

Further, in one embodiment, the secondary battery 100 is a rectangular battery as illustrated in FIGS. 1 and 2 . However, embodiments of the present invention are not limited thereto, and the secondary battery 100 may be one of various other types of batteries, such as a cylindrical battery or a pouch battery.

For example, in one embodiment, the first electrode plate 11 , the first current collecting plate 51 , and the first lead member 52 electrically connected to each other may be formed of the same material such as aluminum (Al). Also, for example, in one embodiment, the second electrode plate 12 , the second current collecting plate 61 , and the second lead member 62 electrically connected to each other may be formed of the same material such as copper (Cu).

In one embodiment, the fuse 70 is formed in one or both of the first current collector 50 and the second current collector 60 . In one embodiment, the fuse 70 is formed by making at least one part of the first current collector 50 and the second current collector 60 thinner than other parts, that is, the fuse 70 has a thinner thickness than the first current collector 50. Or the small cross-sectional area of other parts of the second current collector 60 . In this case, the resistance of the fuse 70 may increase compared with other parts, thereby increasing Joule heat, and therefore, if an overcurrent flows through the first current collector 50 and the second current collector 60, the fuse 70 may be caused by The heat is melted and cuts off the overcurrent.

In one embodiment, since the fuse 70 may be formed in one of the first current collector 50 and the second current collector 60 without being formed as an additional element, the secondary battery 100 including the fuse 70 may have a simple Structure. The fuse 70 may be formed in at least one of the first collector 50 and the second collector 60 .

In one embodiment, the fuse 70 may be formed in the first lead member 52 of the first current collector 50 or the second lead member 62 of the second current collector 60 . For example, the fuse 70 may be formed in the first collector 50 . In one example, the fuse 70 is integrally formed on the first lead member 52 and has a smaller cross-sectional area than other portions of the first lead member 52 . In one embodiment, the fuse 70 may be formed of Al having a melting point lower than that of Cu, and thus the performance of the fuse 70 may be improved.

In this case, the fuse 70 may be formed in the first lead member 52 to simplify the structure for forming the fuse 70 . In addition, in one embodiment, the fuse 70 is formed in one of the first current collecting lead unit 52 b and the second current collecting lead unit 62 b in order to easily secure a space for the fuse 70 and the insulating unit 80 . 3 is a partially exploded perspective view showing the first lead member 52 in the secondary battery 100 including the first current collecting lead unit 52b and separated from the electrode assembly 10, and is formed on the first lead member 52 in one embodiment. Fuses 70 in collector lead unit 52b.

In one embodiment, as shown in FIG. 3 , the fuse 70 is formed in the first current collecting lead unit 52b. In this case, the fuse 70 may be formed of Al having a melting point lower than that of Cu, and thus the performance of the fuse 70 may be improved. However, embodiments of the present invention are not limited thereto, and in another embodiment, the fuse 70 may be formed in the second current collecting lead unit 62b.

An electrolyte solution having a liquid or gel form may be filled in the case 40 accommodating the electrode assembly 10 . In one embodiment, the first collector 50 in which the fuse 70 is formed may contact the electrolyte. Also, when the fuse 70 functions due to overcurrent, sparks may be generated. As such, the spark may react with the electrolyte and thus an explosion may occur.

Therefore, in one embodiment, the secondary battery 100 includes the insulation unit 80 . In one embodiment, the insulating unit 80 is configured to prevent or substantially prevent the fuse 70 from contacting the electrolyte. In one embodiment, the insulating unit 80 wraps the fuse 70 with an insulating material to isolate the fuse 70 from the electrolyte. In one embodiment, the insulation unit 80 includes an insulation tape or an insulation molding (eg, a resin molding).

Since the insulating tape as an example of the insulating unit 80 is wound around the fuse 70 , the fuse 70 may be electrically isolated from external contact, and the structure of the secondary battery 100 may be simplified.

In addition, the fuse 70 and the insulating unit 80 may be simply formed, and the fuse 70 may protect the secondary battery 100 from abnormal phenomena such as overcharging. In addition, since the insulating unit 80 isolates the fuse 70 from the electrolytic solution and thus prevents or substantially prevents the secondary battery 100 from exploding or catching fire even when the fuse 70 functions, stability and reliability of the secondary battery 100 can be ensured. sex.

In one embodiment, the electrode assembly 10 is rolled and then flattened into a plate form, and has an inner space in the electrode assembly 10 . In one embodiment, the first current collecting plate 51 and the second current collecting plate 61 are welded to the outer end of the electrode assembly 10, and press the first uncoated part 11a and the second uncoated part 12a, respectively.

In one embodiment, the first current collecting plate 51 and the second current collecting plate 61 respectively contact the first uncoated portion 11 a and the second uncoated portion 12 a over a large area. Further, in one embodiment, the first current collecting plate 51 and the second current collecting plate 61 are respectively bonded to outer surfaces at opposite ends of the electrode assembly 10, for example, by using a laser welding method. As shown in FIG. 3 , in one embodiment, the first current collecting plate 51 includes two portions extending from the first current collecting lead unit 52 b for contacting opposite outer surfaces of the first uncoated portion 11 a. Similarly, in one embodiment, the second current collecting plate 61 includes two portions extending from the second current collecting lead unit 62b for contacting opposite outer surfaces of the second uncoated portion 12a. In one embodiment, the first current collecting plate 51 and the second current collecting plate 61 may be respectively coupled to end portions of the electrode assembly 10 at opposite ends. In one embodiment, the first current collecting plate 51 and the second current collecting plate 61 are combined by using a laser welding method, and thus the first current collecting plate 51 and the second current collecting plate 61 can be With a larger thickness, the resistance of the first current collecting plate 51 and the second current collecting plate 61 can be reduced.

As described above, even when an overcurrent flows due to overcharging or an abnormal phenomenon, the secondary battery 100 can be prevented or substantially prevented from exploding.

FIG. 4 is a cross-sectional view of a secondary battery 200 according to another embodiment of the present invention. 5 is a partially exploded perspective view showing a first lead member 252 including a first terminal lead unit 252a and separated from an electrode assembly 210 in the secondary battery 200 illustrated in FIG. A terminal lead unit 252a.

When compared with the secondary battery 100 illustrated in FIG. 2 , in the secondary battery 200 , the fuse 270 is formed in the first terminal lead unit 252 a. Descriptions of components and structures of the secondary battery 200 that are similar to those described above with respect to the secondary battery 100 will not be repeated here.

4 and 5, in one embodiment, the secondary battery 200 includes: an electrode assembly 210; a first electrode terminal 221 and a second electrode terminal 222; a cover plate 230; a case 240; Two current collectors 260; a fuse 270 and an insulating unit 280.

In one embodiment, the electrode assembly 210 is wound as a first electrode plate 211 and a second electrode plate 212 that can be used as a positive electrode plate and a negative electrode plate respectively, and as an electrode between the first electrode plate 211 and the second electrode plate 212. The spacer 213 of the insulator between them is formed. The case 240 accommodates the electrode assembly 210 . In one embodiment, the first electrode terminal 221 and the second electrode terminal 222 are positive electrode terminals and negative electrode terminals, respectively.

In one embodiment, the first electrode terminal 221 and the second electrode terminal 222 are respectively electrically connected to the first electrode plate 211 and the second electrode plate 212 of the electrode assembly 210 to be exposed to the outside of the case 240 . The cover plate 230 is combined with or covers the opening of the housing 240 . In one embodiment, the first current collector 250 and the second current collector 260 are a positive electrode current collector and a negative electrode current collector electrically connected to the first electrode plate 211 and the second electrode plate 212 , respectively.

In one embodiment, when an overcurrent flows due to overcharging or an abnormal phenomenon, the fuse 270 functions to cut off the current. In one embodiment, the insulating unit 280 wraps the fuse 270 with an insulating material to electrically isolate the fuse 270 from any external contacts.

In one embodiment, the first electrode plate 211 includes a first uncoated portion 211a and a first coated portion 211b, and the second electrode plate 212 includes a second uncoated portion 212a and a second coated portion 212b. In one embodiment, the first uncoated portion 211a and the second uncoated portion 212a are respectively a positive electrode uncoated portion and a negative electrode uncoated portion, and the first coated portion 211b and the second coated portion 212b are a positive electrode coating part and a negative electrode coating part, respectively. In one embodiment, the first electrode terminal 221 is exposed through a first terminal hole 221a that is a positive electrode terminal hole, and the second electrode terminal 222 is exposed through a second terminal hole 222a that is a negative electrode terminal hole.

In one embodiment, an electrolyte inlet 238a is formed in the cover plate 230, and a sealing plug 238 may fit in the electrolyte inlet 238a. An exhaust member 239 may also be formed in the cover plate 230 . The upper gasket 225 and the lower gasket 227 may be respectively interposed between the cap plate 230 and the first and second electrode terminals 221 and 222 to insulate the cap plate 230 from the first and second electrode terminals 221 and 222 . A washer 224 for buffering coupling force may be disposed on the upper pad 225 . The first electrode terminal 221 and the second electrode terminal 222 may be coupled with a nut 229 . Alternatively, the first electrode terminal 221 and the second electrode terminal 222 may be formed to have any other suitable structure, such as the form of a rivet.

In one embodiment, the first current collector plate 251 and the second current collector plate 261 of the corresponding first current collector 250 and the second current collector 260 are respectively bonded to the first uncoated electrode assembly 210 by using a welding method, for example. The coated portion 211a and the second uncoated portion 212a. In one embodiment, the first current collector plate 251 and the second current collector plate 261 are electrically connected to The first electrode terminal 221 and the second electrode terminal 222 .

In one embodiment, an insulating member 226 is formed between the cap plate 230 and the first lead member 252 and the second lead member 262 . In one embodiment, the first lead member 252 and the second lead member 262 respectively include a first terminal lead unit 252a and a second terminal lead unit 262a and a first current collection lead unit 252b and a second current collection lead unit 262b. In one embodiment, the first terminal lead unit 252a and the second terminal lead unit 262a are coupled and electrically connected to the first electrode terminal 221 and the second electrode terminal 222, respectively. In one embodiment, the first current collecting plate 251 and the first lead member 252 are formed as a single integral unit. Similarly, in one embodiment, the second current collecting plate 261 and the second lead member 262 are formed as a single integral unit. In another embodiment, the first current collecting plate 251 and the second current collecting plate 261 are combined and electrically connected to the first current collecting lead unit 252b and the second current collecting lead unit 262b, respectively. In one embodiment, the first current collecting lead unit 252b and the second current collecting lead unit 262b are bonded (or otherwise contacted) and electrically connected to the first uncoated portion 211a and the second uncoated portion 211a of the electrode assembly 210, respectively. The coating part 212a.

In one embodiment, the first collector 250 includes a first collector plate 251 and a first lead member 252 , and the second collector 260 includes a second collector plate 261 and a second lead member 262 . In one embodiment, the first current collecting plate 251 and the second current collecting plate 261 are respectively a positive electrode current collecting plate and a negative electrode current collecting plate, and the first lead member 252 and the second lead member 262 are respectively a positive electrode lead member and the negative electrode lead member.

In one embodiment, the first current collecting plate 251 is coupled to the first uncoated portion 211a of the electrode assembly 210, for example, by using a welding method. In one embodiment, the first current collecting plate 251 is electrically connected to the first electrode terminal 221 via the first lead member 252 . As such, in one embodiment, the first electrode terminal 221 is connected to the first electrode plate 211 of the electrode assembly 210 via the first lead member 252 and the first current collecting plate 251 .

Also, in one embodiment, the second current collecting plate 261 is coupled to the second uncoated portion 212a of the electrode assembly 210, for example, by using a welding method. In one embodiment, the second current collecting plate 261 is electrically connected to the second electrode terminal 222 via the second lead member 262 . As such, in one embodiment, the second electrode terminal 222 is connected to the second electrode plate 212 of the electrode assembly 210 via the second lead member 262 and the second current collecting plate 261 .

At the same time, according to another embodiment of the present invention, for one of the first electrode terminal 221 and the second electrode terminal 222, there may not be formed to electrically separate the first electrode plate 211 or the second electrode plate 212 from the cover plate 230'. The upper gasket 225, the insulating member 226 and the lower gasket 227. In this case, the cap plate 230' and/or the case 240 may be the first electrode terminal or the second electrode terminal.

For example, in the secondary battery 200' according to one embodiment, the upper gasket 225 and the lower gasket 227 may not be formed between the cap plate 230' and the first lead member 252, as shown in FIG. 7 . In this case, the first lead member 252 directly contacts the cap plate 230'.

In one embodiment, since the fuse 270 is formed in one of the first current collector 250 and the second current collector 260 instead of being formed as an additional element, the secondary battery 200 including the fuse 270 has a simple structure. The fuse 270 may be formed in at least one of the first collector 250 and the second collector 260 .

In one embodiment, the fuse 270 is formed in the first lead member 252 of the first current collector 250 or the second lead member 262 of the second current collector 260 . For example, in one embodiment, the fuse 270 is formed in the first current collector 250 . In this case, the fuse 270 may be formed of Al having a lower melting point than Cu, and thus the performance of the fuse 270 may be enhanced or improved.

In one embodiment, the fuse 270 may be formed in the first lead member 252 to further simplify the structure for forming the fuse 270 . Also, in one embodiment, the fuse 270 may be formed in one of the first terminal lead unit 252 a and the second terminal lead unit 262 a in order to easily secure a space for the fuse 270 and the insulation unit 280 .

In one embodiment, as shown in FIG. 5, a fuse 270 is formed in the first terminal lead unit 252a. In this case, the fuse 270 may be formed of Al having a melting point lower than that of Cu, and thus the performance of the fuse 270 may be improved.

In one embodiment, an electrolyte solution having a liquid or gel form may be filled in the case 240 accommodating the electrode assembly 210 . In one embodiment, the first collector 250 in which the fuse 270 is formed may contact the electrolyte. Also, when the fuse 270 functions due to overcurrent, sparks may be generated. As such, the spark may react with the electrolyte and thus an explosion may occur.

Therefore, in one embodiment, the secondary battery 200 includes the insulating unit 280 . The insulation unit 280 is configured to prevent or substantially prevent the fuse 270 from contacting the electrolyte. In one embodiment, the insulating unit 280 wraps the fuse 270 with an insulating material to isolate the fuse 270 from the electrolyte. In one embodiment, the insulating unit 280 includes an insulating tape or an insulating molding (eg, a resin molding).

In one embodiment, since an insulating tape as an example of the insulating unit 280 is wound around the fuse 270 , the fuse 270 may be electrically isolated from any external contact, and the structure of the secondary battery 200 may be simplified.

In addition, the fuse 270 and the insulation unit 280 may be simply formed, and the fuse 270 may protect the secondary battery 200 from abnormal phenomena such as overcharging. In addition, since the insulating unit 280 isolates the fuse 270 from the electrolytic solution and thus prevents or substantially prevents the secondary battery 200 from exploding or catching fire even when the fuse 270 functions, stability and reliability of the secondary battery 200 can be ensured. sex.

As described above, even when an overcurrent flows due to overcharging or an abnormal phenomenon, the secondary battery 200 can be prevented or substantially prevented from exploding.

Some exemplary embodiments of the present invention have been disclosed herein, and although specific terms are employed, they are used in a generic and descriptive sense only and are to be construed rather than for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. Accordingly, those of ordinary skill in the art will understand that various changes in form and details can be made without departing from the spirit and scope of the present invention as set forth in the appended claims.

Claims (16)

1. a secondary cell, comprising:

Electrode assemblie, described electrode assemblie comprises the first battery lead plate, the second battery lead plate and the dividing plate between described first battery lead plate and described second battery lead plate;

Hold the housing of described electrode assemblie;

Be electrically connected to the electrode terminal of described first battery lead plate;

Being connected between described first battery lead plate and described electrode terminal and being electrically connected the collector of described first battery lead plate and described electrode terminal, described collector comprises fuse part; And

Insulating unit in the described fuse part of described collector,

Wherein said collector is formed as single single piece.

2. secondary cell as claimed in claim 1, wherein said insulating unit has the surface larger than described fuse part.

3. secondary cell as claimed in claim 1, wherein said fuse part has the cross-sectional area less than other parts of described collector.

4. secondary cell as claimed in claim 1, wherein said fuse part has the resistance higher than other parts of described collector.

5. secondary cell as claimed in claim 1, wherein said electrode terminal reaches described outside.

6. secondary cell as claimed in claim 5, comprise the cover plate of the opening sealing described housing further, wherein said electrode terminal stretches out through the terminal hole be formed in described cover plate.

7. secondary cell as claimed in claim 1, wherein said insulating unit comprises at least one in insulating tape and insulator die goods.

8. secondary cell as claimed in claim 1, wherein said collector comprises:

Be connected to the collector plate of described first battery lead plate; With

Be connected to the lead member of described electrode terminal and described collector plate.

9. secondary cell as claimed in claim 8, wherein said lead member comprises:

Be connected to the terminal lead unit of described electrode terminal; With

Extend from described terminal lead unit and be connected to the afflux lead wire unit of described collector plate.

10. secondary cell as claimed in claim 9, wherein said afflux lead wire unit comprises described fuse part.

11. secondary cells as claimed in claim 9, wherein said terminal lead unit comprises described fuse part.

12. secondary cells as claimed in claim 8, wherein said fuse part is integrally formed in described lead member, and has the cross-sectional area less than other parts of described lead member.

13. secondary cells as claimed in claim 1,

Wherein said electrode terminal is the first electrode terminal, and described secondary cell comprises further and is electrically connected to described second battery lead plate and the second electrode terminal reaching described outside; And

Wherein said collector is the first collector, and described secondary cell comprises further and to be connected between described second battery lead plate and described second electrode terminal and to be electrically connected the second collector of described second battery lead plate and described second electrode terminal.

14. secondary cells as claimed in claim 13,

Wherein said first battery lead plate is positive electrode plate, and described first collector is positive electrode current collector, and

Wherein said second battery lead plate is negative electrode plate, and described second collector is negative current collector.

15. secondary cells as claimed in claim 14, wherein said first collector comprises aluminium, and described second collector comprises copper.

16. secondary cells as claimed in claim 1, wherein said fuse part is constructed to, when the current flowing of value that equivalent value is more than or equal to setting electric current is by described collector, described first battery lead plate and described electrode terminal also disconnect by described fuse part fractional melting.