KR20060134351A - Secondary battery and electrodes assembly using the same - Google Patents

Abstract

Provided are a secondary battery which is improved in interface uniformity by preventing the wrinkling of the front end of an electrode plate in case of winding, and an electrode assembly used in the secondary battery. The secondary battery comprises an electrode group which comprises a separator, and an electrode group comprising a positive electrode plate and a negative electrode plate which is arranged at both sides of the separator; a case where the electrode group is accommodated; a cap assembly which is combined with the case to seal it and is combined with a terminal connected with the electrode group; and a reinforcing material which surrounds the front end of at least one electrode plate between a positive electrode plate(11) and a negative electrode plate so as to be fixed to the positive electrode plate or the negative electrode plate. Preferably the reinforcing material is selected from polyester, polyamide, PPS, glass fiber, PVC and NOMAX paper.

Description

Secondary Battery and Electrode Assembly Used Thereof {SECONDARY BATTERY AND ELECTRODES ASSEMBLY USING THE SAME}

1 is a cross-sectional view of a rechargeable battery according to an exemplary embodiment of the present invention.

2 is a partially exploded perspective view of a rechargeable battery according to an exemplary embodiment of the present invention.

3A and 3B are diagrams illustrating in detail a pole plate of a rechargeable battery according to an exemplary embodiment of the present invention.

4A to 4C are cross-sectional views illustrating in detail a pole plate of a rechargeable battery according to an exemplary embodiment of the present invention.

The present invention relates to a secondary battery, and more particularly, to a secondary battery and an electrode assembly used for improving the interface characteristics of the battery.

A secondary battery is a battery that can be charged and discharged unlike a primary battery that cannot be charged. In the case of a low-capacity battery in which one battery cell is packaged in a pack form, a portable electronic device such as a phone, a notebook computer, or a camcorder In the case of a large capacity battery in a battery pack unit, which is used in equipment and connected to dozens of battery cells, it is widely used as a power source for driving a motor of a hybrid vehicle.

The secondary batteries are manufactured in various shapes, and typical shapes include cylindrical and rectangular shapes, and an electrode group having a separator formed as an insulator is installed in a case between the two bands and a negative electrode plate. The battery is configured by installing a cap assembly having external terminals formed on the case.

The positive and negative electrode plates are formed of a coating portion coated with an active material on a current collector and an uncoated non-coating portion, and the positive and negative electrode non-coating portions have a conductive tab as a current collector for the current generated from the positive and negative electrode plates, respectively. taps are attached to each other, and the conductive tabs are attached to the electrode group by welding or the like to induce currents generated in the positive and negative electrode plates to the positive and negative electrode terminals, respectively.

Here, in the current collector structure of the secondary battery, in the case of a high output secondary battery, the battery is manufactured in a jellyroll form in which the electrode group is wound in a vortex phase, wherein the electrode group is in contact with the core to which the electrode group is wound for the first time. There is a problem in that the pole plate is wrinkled.

In other words, in order to wind the electrode group on the core, the first tip of the electrode group must be entered between the core and the winding rolls in contact with the core. In this process, the first tip of the electrode group is crumpled due to the speed difference between them. As a result, the electrode group is wound around the core in a crumpled state, thereby degrading the interface uniformity of the electrode group.

This problem is particularly acute for high power high capacity secondary batteries, such as for HEVs (hybrid electric vehicles). As mentioned, very thin pole plates are used to roll the cores in the form of jelly rolls to achieve high power capacity, which makes the pole plates more wrinkled. Occurs badly.

Therefore, the present invention is to solve the above problems, an object of the present invention is to prevent the wrinkles of the tip of the electrode plate when winding the electrode group to the core to increase the interface uniformity of the battery and the electrode used therein In providing an assembly.

In order to achieve the above object, the secondary battery of the present invention is a secondary battery in which an electrode group in which a positive electrode plate and a negative electrode plate are positioned with a separator interposed therein is provided in a case, and the tip of at least one of the positive electrode plate and the negative electrode plate is provided. Rigid reinforcement is attached to the structure.

Therefore, the pole plate is secured by a reinforcing material to prevent wrinkles of the pole plate in the process of entering the first end of the pole plate of the electrode group to the core to wrap the electrode group to the core.

Here, the positive and negative electrode plates are formed of a coating portion coated with a current collector and an active material and an uncoated non-coating portion. In the case of the secondary battery, the non-coating portion is continuously formed along one end of each of the positive electrode plates, and the positive and negative electrode plates It is preferable that the current collector plates are electrically connected to the uncoated portions of the respective pole plates, respectively, disposed in directions facing each other.

More preferably, it is preferable that the plain part of the negative electrode plate is disposed toward the bottom of the case and the plain part of the positive electrode plate is disposed upward when the cap assembly is placed upward.

The active material forming the coating part may be attached to one or both surfaces of the current collector.

In addition, in the secondary battery, the electrode group may be wound in a vortex form with respect to the core to form a jelly roll, and the case may have a cylindrical shape.

Here, the rigid reinforcing material may be attached to the positive electrode plate and / and the negative electrode plate, and has a structure attached to the first end of each electrode plate in contact with the core.

Preferably, the rigid reinforcing material is a film structure coated with an adhesive on the surface of the material may be selected from polyester, polyamide, PPS, glass fiber, vinyl chloride, NOMAX paper, the adhesive component is acrylic, rubber, silicone It can be selected from thermosetting rubber and the like, and can be attached at the tip of the electrode plate with a width of 2-15 cm in the longitudinal direction.

In addition, the rigid reinforcing material is preferably not to be attached to the uncoated portion formed on the pole plate, because the non-coated portion is welded to the current collector plate because there is a fear that welding is not properly made when the rigid reinforcement is attached.

Here, the electrode plate may be coated with an active material on the entire surface except for the non-coated portion to form a coating portion, and the rigid reinforcing material may be attached onto the coating portion.

On the other hand, when the coating is formed on both sides of the current collector, the rigid reinforcing material may have a structure attached to both sides wrapped around the tip of the electrode plate.

Rigid reinforcement may be attached directly to the tip of the current collector constituting the pole plate. To this end, the active material is not coated on the area where the rigid reinforcing material is attached to the tip of the electrode plate.

In addition, the rigid reinforcing material may be directly attached to the current collector front end constituting the pole plate and the inner front end may extend to the active material coating portion of the current collector to cover the front end of the coating.

On the other hand, the electrode assembly according to the present invention includes a electrode group including a separator, a positive electrode plate and a negative electrode plate disposed on both sides of the separator, and a rigid reinforcing material attached to the tip of at least one of the positive electrode plate and the negative electrode plate.

The secondary battery may be used as an energy source for driving a motor of the device in a device operated by using a motor such as a hybrid electric vehicle (HEV), an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like. Can be.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a rechargeable battery according to an exemplary embodiment of the present invention.

According to the above drawings, the secondary battery according to the present embodiment includes the electrode group 10 in which the positive electrode plate 11 and the negative electrode plate 12 are positioned with the separator 13 interposed therebetween, and the electrode group 10 together with the electrolyte solution. A case 20 having one end opened to accommodate the cap 20, a cap assembly 30 installed at an upper end of the opening of the case 20 through a gasket 31, and sealing the case 20, and the electrode group. The positive electrode plate 11 of FIG. 10 includes a positive electrode current collector plate 40 electrically connected to a current collector, and a negative electrode current collector plate 50 electrically connected to a current collector of the negative electrode plate 12.

The case 20 is made of a conductive metal such as aluminum, an aluminum alloy or nickel plated steel, and the shape thereof may be formed in a cylindrical or hexahedron or other shape having an inner space in which the electrode group 10 is located. have.

In addition, the cap assembly 30 includes a cap plate 32 having an external terminal 32a and a gasket 31 that insulates the case 20 from the cap plate 32 and is broken under a set pressure condition. A vent plate 33 may be further included to prevent explosion of the battery by releasing gas, which is electrically connected to the positive electrode current collector plate 40 through the lead 35. The vent plate 33 may be used in various forms without being limited to the illustrated shape as long as it can block electrical connection between the electrode assembly and the external terminal 32a through the lead 35 under a set pressure condition.

In addition, the electrode group 10 has a structure in which the positive electrode plate 11 and the negative electrode plate 12 formed by coating each active material on the current collector are laminated with the separator 13 interposed therebetween, or the positive electrode plate 11 and the separator. 13 and the negative electrode plate 12 may be formed in a jelly roll type formed by winding them in a vortex in a state where they are laminated.

In the present embodiment, as shown in FIG. 1, a case in which an electrode group wound in a jelly roll type is positioned in a cylindrical case will be described as an example.

In addition, the present embodiment will be described by way of example a structure formed along one side end of each of the electrode plate forming the electrode group, the non-contact portion in electrical contact with the current collector plate. Of course, the present invention is not limited to the above structure and can be applied regardless of the shape of the battery or the structure of the plain portion.

The state in which the electrode group 10 is wound around the core 14 is well illustrated in FIG. 2. The electrode group 10 includes a positive electrode plate 11, a negative electrode plate 12, and a separator 13 between the positive and negative electrode plates. The tip is wound by a take-up roll (not shown) in the state where the tip thereof is in contact with the cylindrical core 14 in the state where?

Accordingly, the electrode assembly constituting the secondary battery according to the present exemplary embodiment includes coating portions 11b and 12b coated with an active material on a current collector and non-coated portions 11a and 12a not coated with an active material, as shown in FIGS. 3A and 3B. The positive and negative electrode plates 11 and 12 including the electrode group 10 stacked between the separators 13 and wound around the core (14 of FIG. 2), and the positive electrode plate 11 and the negative electrode plate 12 are included. It includes a rigid reinforcement (15) attached to the tip.

In addition, each of the active materials is coated on both surfaces of the positive electrode current collector and the negative electrode current collector, and the positive electrode plate 11 and the negative electrode plate 12 have a structure in which coating portions 11b and 12b are formed on both sides, respectively.

Here, each of the positive plates is a non-coated portion 11a in which the positive electrode active material is not coated on the current collector of the positive electrode plate 11 at the upper portion of the positive electrode plate 11 in a state in which the secondary battery is placed vertically with the cap assembly 30 facing upward. An uncoated portion 12a is formed along the longitudinal direction of (11), and in the lower part of the negative electrode plate 12, in which the negative electrode active material is not applied along the longitudinal direction of the negative electrode plate 12 as well.

In addition, a rigid reinforcing material 15 is attached to the first end of the positive electrode plate 11 in contact with the core 14 except for the plain portion 11a. Further, the rigid reinforcing material 15 is also attached to the region of the negative electrode plate 12 in contact with the core 14 except for the plain portion 12a.

This is because, in the case of the non-coated portion, when the rigid reinforcing material 15 is attached to the non-coated portion as a part to be welded to the current collector plate, there is a fear that welding of the non-coated portion and the current collector plate may not be performed properly.

According to this embodiment, the rigid reinforcing material 15 has a structure that is attached to both sides of the pole plate in a form surrounding the tip of the pole plate.

More specifically, the width of the rigid reinforcing material 15 is preferably 2 to 15 cm from the tip of each pole plate (11, 12), if the width of the reinforcing material (15) is 2cm or less, the area of the pole plate 11, When the pole plate is too small compared to the total area of 12), it is difficult to give rigidity to the pole plate so that it is difficult to adequately cope with the pole plate, and when the width of the reinforcing material 15 is 15 cm or more, the area of the reinforcing material 15 is increased. As a result, the amount of the active material coated on each of the electrode plates is reduced, which may cause deterioration of battery performance.

In addition, the rigid reinforcing material (15) should be made of a material that does not react with the active material or the electrolyte with securing the rigidity of the electrode plate, preferably made of a polyester material, the adhesive plate 16 is applied to the contact surface with the electrode plate (pole plate ( 11, 12). Here, the adhesive 16 is also used an adhesive having a characteristic of not reacting with the active material or the electrolyte, and preferably an adhesive of an acrylic component.

Meanwhile, another exemplary embodiment of the secondary battery is illustrated in FIGS. 4A to 4D. In the following description, for convenience of description, the description will be made based on the positive electrode plate, and the negative electrode plate may be equally applied.

According to another exemplary embodiment of the present secondary battery, as illustrated in FIG. 4A, a coating part 11b coated with an active material is formed on the current collector 11c of the positive electrode plate 11 to the front end of both sides of the electrode plate. Rigid reinforcing material 15 may be a structure attached to the front end of the current collector (11c) of the pole plate attached via the adhesive (16) on both sides of the coating (11b).

In addition, Figure 4b illustrates another embodiment of the present secondary battery, according to this embodiment, the positive electrode plate 11 is formed with a coating portion 11b coated with the active material on both sides of the current collector (11c), The rigid reinforcing material 15 is wrapped around the front end surfaces of the current collector 11c in a state in which the coating part is not formed, and the rigid reinforcing material 15 is attached to the front end part of the current collector 11c by the adhesive 16. It has a structure extended to 11b).

Accordingly, the rigid reinforcement 15 is directly attached to the current collector 11c on both ends of the positive electrode plate 11, and the coating portion 11b is formed on the current collector 11c in succession with the rigid reinforcement 15. have.

This structure does not coat the active material in the region to which the rigid reinforcing material 15 is attached, thereby providing the advantage of reducing the consumption of the active material together with the rigid reinforcement of the electrode plate.

In addition, according to another embodiment of the present secondary battery, as shown in FIG. 4C, the positive electrode plate 11 has a coating portion 11b coated with an active material on both sides of the current collector 11c, and the positive electrode plate 11 is The rigid reinforcing material 15 mediates the adhesive 16 in the area where the coating part is not formed in the state where the rigid reinforcing material 15 is wrapped around the tip of the electrode plate 11 without the coating part formed by the active material on both sides of the tip. Attached to the coating portion 11b and both ends of the inner side of the rigid reinforcing material 15 are extended to the upper portion of the coating portion 11b to cover the tip portion of the coating portion 11b. It is.

Various embodiments can be applied in addition to the above structure, and is not particularly limited to the attachment position of the rigid reinforcing material 15 except that the rigid reinforcing material 15 should be attached while wrapping the first end of the pole plate in contact with the core.

On the other hand, to describe in more detail the action of the rigid reinforcing material 15, in order to prevent the wrinkling of the tip of the pole plate (11, 12) in the process of winding the electrode group 10 in the form of jelly roll on the core 14 The rigid reinforcing material 15 is attached to the tips of the current collectors of the positive electrode plate 11 and the negative electrode plate 12.

In this state, when the separator 13 is laminated between the positive electrode plate and the negative electrode plate and proceeds to the core 14, the electrode group enters between the core 14 and the winding roll (not shown) in contact with the core to wind the electrode group. At this time, the tip of each electrode plate constituting the electrode group is collided with the core and the take-up roll.

Here, as mentioned above, the front end of the pole plate is wrinkled in the process of entering between the core and the winding roll in the state where the rigid reinforcing material 15 is attached to the front end of each pole plate and the stiffness of the pole plates 11 and 12 itself is secured to some extent. Electrode deformation is prevented so that it can be correctly wound on the core.

As described above, the secondary battery of the present invention can be effectively used as a battery for HEV requiring high output / large capacity, but its use is not necessarily limited to HEV.

In addition, in the present embodiment, the rigid reinforcing material has been described as a structure attached to both the positive electrode plate and the negative electrode plate, but the present invention is not necessarily limited to this structure, it can be applied even when formed on at least one of the positive electrode plate, the negative electrode plate. have.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to

As described above, according to the present embodiment, the front end of the electrode plate is prevented from being deformed in the process of winding the electrode group on the core, thereby increasing the interface uniformity, thereby increasing the reliability of the product.

Claims (16)

An electrode group including a separator and a positive electrode plate and a negative electrode plate disposed on both sides of the separator, A case in which the electrode group is built in, A cap assembly coupled to the case to seal the cap and coupled to a terminal connected to the electrode group; Rigid reinforcing material is wrapped around the front end of at least one of the positive electrode plate and the negative electrode plate attached Secondary battery comprising a. The secondary battery of claim 1, wherein the rigid reinforcing material is attached to a positive electrode plate. The secondary battery of claim 1, wherein the rigid reinforcing material is attached to a negative electrode plate. The secondary battery of claim 1, wherein the rigid reinforcing material is attached to an initial end of the electrode plate in contact with a core around the electrode group. The secondary plate of claim 1, wherein the electrode plate includes a current collector, a coating portion coated with an active material on the current collector, and an uncoated portion on which the active material is not coated on the current collector, and the rigid reinforcing material is attached to an area except for the non-coated portion. battery. The secondary battery of claim 5, wherein the rigid reinforcing material is attached to the coating part. The secondary battery of claim 6, wherein the rigid reinforcing material is directly attached to a current collector. The secondary battery of claim 7, wherein the rigid reinforcing material is directly attached to the current collector and extends over the active material coating of the current collector to cover the coating tip. The secondary battery of claim 1, wherein the rigid reinforcing material is attached to each of the electrode plates through an adhesive. The secondary battery of claim 9, wherein the adhesive is selected from acrylic, rubber, silicone, and thermosetting rubber. The secondary battery of claim 1, wherein the rigid reinforcing material is selected from polyester, polyamide, PPS, glass fiber, vinyl chloride, and NOMAX paper. An electrode group in which a positive electrode plate and a negative electrode plate are wound around a separator; A coating part formed by coating an active material on each of the electrode plates; An uncoated portion formed without applying an active material to one end portion in the longitudinal direction of each of the electrode plates; Rigid reinforcing material wrapped around the tip of at least one of the positive electrode plate and the negative electrode plate attached Electrode assembly of a secondary battery comprising a. The secondary plate of claim 12, wherein the electrode plate includes a current collector, a coating portion coated with an active material on the current collector, and an uncoated portion on which the active material is not coated on the current collector, wherein the rigid reinforcing material is attached to an area except for the non-coated portion. Electrode assembly of the cell. The electrode assembly of claim 13, wherein the rigid reinforcing material is attached to the coating part. The electrode assembly of claim 13, wherein the rigid reinforcing material is directly attached to a current collector. The electrode assembly of claim 13, wherein the rigid reinforcing material is directly attached to the current collector and extends over the active material coating of the current collector to cover the coating tip.

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