KR20190055994A - Secondary battery - Google Patents

Abstract

According to various embodiments of the present invention, the present invention relates to a secondary battery, which has improved stability without a voltage drop phenomenon by minimizing the flow of an electrode assembly inside a case during a drop impact/collision. To this end, the secondary battery according to various embodiments of the present invention comprises: an electrode assembly including a first electrode plate having a first active material coating part and a first active material non-coating part, a second electrode plate having a second active material coating part and a second active material non-coating part and a separator interposed between the first and second electrode plates, and formed by being wound in a jelly-roll shape having a winding front end and a winding end while the first electrode plate, the separator, and the second electrode plate are stacked; and an adhesive layer interposed between the second electrode plate and the separator as the outermost part of the electrode assembly having the winding end.

Description

Secondary battery

Various embodiments of the present invention relate to a secondary battery.

A secondary battery is a battery that can be charged and discharged unlike a non-rechargeable primary battery. The secondary battery of low capacity is used for portable electronic devices such as smart phones, feature phones, notebook computers, digital cameras and camcorders, and the secondary battery of large capacity is used for motor driving power for electric vehicles and hybrid electric vehicles, And so on.

Such a secondary battery includes an electrode assembly composed of an anode and a cathode, a case accommodating the same, and an electrode terminal connected to the electrode assembly. The case can be classified into a circle, a square, and a pouch type according to its shape. Among them, the pouch type secondary battery can be formed into a laminate outer cover material which is easily deformed into various shapes and has a small weight.

The above-described information disclosed in the background of the present invention is only for improving the understanding of the background of the present invention, and thus may include information not constituting the prior art.

The various embodiments of the present invention prevent the electrode assembly from flowing inside the case in case of a falling impact and / or a collision, thereby improving the safety of suppressing the voltage drop phenomenon and the heat generation phenomenon due to the fine short between the positive electrode plate and the negative electrode plate Thereby providing a secondary battery.

A secondary battery according to various embodiments of the present invention includes a first electrode plate having a first active material coating portion and a first active material non-coating portion, a second electrode plate having a second active material coating portion and a second active material non- And a separator interposed between the first electrode plate and the second electrode plate, wherein the first electrode plate, the separator, and the second electrode plate are laminated and wound in the form of a jelly roll having a winding end and a winding end, Assembly; And an adhesive layer interposed between the second electrode plate and the separator as an outermost portion of the electrode assembly having the winding termination.

Wherein the second electrode plate as the outermost portion of the electrode assembly having the winding termination includes the second active material uncoated portion and the adhesive layer interposed between the second active material uncoated portion and the separator, The plate may be a positive electrode substrate.

Wherein the second active material uncoated portion and the adhesive layer of the second electrode plate as the outermost portion of the electrode assembly having the winding termination are covered at least once with the electrode assembly and the adhesive layer is provided between the cathode substrate and the separator .

The second active material uncoated portion of the second electrode plate as the outermost portion of the electrode assembly having the winding termination faces the other second active material uncoated portion on the inside or the first active material non- Or a part of the adhesive layer is attached to the winding end so as to fix the shape so that the electrode assembly is not loosened.

The adhesive force between the adhesive layer and the second active material coating portion may be equal to or greater than the adhesive force between the separating film and the second active material coating portion.

The adhesive layer may include a PS (Poly Styrene) adhesive or a rubber adhesive.

The adhesive layer may be a pressure sensitive adhesive tape including a rubber adhesive layer.

The separator may comprise a binder coated on the surface.

The binder may include a silicone-based binder, an acrylate-based binder, or a PVDF (polyvinylidene fluoride) binder.

The separator may comprise an inorganic material coated on the surface.

The secondary battery according to various embodiments of the present invention prevents the electrode assembly from flowing inside the case in the event of a drop impact and / or a collision, thereby suppressing a fine short phenomenon between the positive electrode plate and the negative electrode plate, And heat generation phenomenon can be suppressed. That is, the secondary battery according to various embodiments of the present invention further includes an adhesive layer including a PS-based adhesive or a rubber-based adhesive between the anode uncoated portion at the winding end and the cathode non-coated portion at the winding end in the electrode assembly, Do not deform the igniter or the separator of the winding end in the event of an impact and / or impact, and do not break it. Therefore, a fine short phenomenon does not occur between the positive electrode plate and the negative electrode plate in the electrode assembly even when the secondary battery is dropped and / or impacted, and thus the secondary battery is improved in safety by suppressing the voltage drop phenomenon and the exothermic phenomenon.

1A through 1C are an exploded perspective view, a plan view, and a partial perspective view of a secondary battery according to various embodiments of the present invention.
2A and 2B are views showing a state before the electrode assembly is wound up in a secondary battery according to various embodiments of the present invention.
3A and 3B are views showing a state before an electrode assembly is wound up in a secondary battery according to various embodiments of the present invention.
4 is a view showing a state after the electrode assembly is wound in a secondary battery according to various embodiments of the present invention.
5 is a view showing a state after the electrode assembly is wound up in a secondary battery according to various embodiments of the present invention.
6 is a view showing a state after the electrode assembly is wound up in a secondary battery according to various embodiments of the present invention.
7A to 7E are partially enlarged sectional views showing the relationship between the positive electrode plate, the adhesive layer and the separator among the secondary batteries according to various embodiments of the present invention.

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

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more faithful and complete, and will fully convey the scope of the invention to those skilled in the art.

In the following drawings, thickness and size of each layer are exaggerated for convenience and clarity of description, and the same reference numerals denote the same elements in the drawings. As used herein, the term " and / or " includes any and all combinations of one or more of the listed items. In the present specification, the term " connected " means not only the case where the A member and the B member are directly connected but also the case where the C member is interposed between the A member and the B member and the A member and the B member are indirectly connected do.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise, " and / or " comprising, " when used in this specification, are intended to be interchangeable with the said forms, numbers, steps, operations, elements, elements and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

It is to be understood that the terms related to space such as "beneath," "below," "lower," "above, But may be utilized for an easy understanding of other elements or features. Terms related to such a space are for easy understanding of the present invention depending on various process states or use conditions of the present invention, and are not intended to limit the present invention. For example, if an element or feature of the drawing is inverted, the element or feature described as "lower" or "below" will be "upper" or "above." Thus, " lower " is a concept encompassing " upper " or " lower ".

Referring to FIGS. 1A to 1C, an exploded perspective view, a plan view, and a partial perspective view of a secondary battery according to various embodiments of the present invention are shown.

1A through 1C, a secondary battery 100 according to various embodiments of the present invention includes an electrode assembly 110 and a laminate sheath 120.

The electrode assembly 110 includes a negative electrode plate 111 (or a first electrode plate), a positive electrode plate 112 (or a second electrode plate), and a separator 113 interposed between the negative electrode plate 111 and the positive electrode plate 112 ). The electrode assembly 110 may be formed by winding a laminate of the negative electrode plate 111, the separator 113, and the positive electrode plate 112 in the form of a jelly roll.

 The negative electrode plate 111 includes, for example, but not limited to, a negative electrode active material layer coated on both surfaces of a negative electrode current collector plate made of a conductive metal thin plate, for example, copper or nickel foil or a mesh. The negative electrode active material layer may include, for example, but not limited to, a carbon-based material, Si, Sn, a tin oxide, a tin alloy composite, a transition metal oxide, a lithium metal nitride or a metal oxide. The negative electrode uncoated portion in which the negative electrode active material layer is not formed on the negative electrode collector plate can be fixed (for example, welded) to the substantially flat negative electrode tab 114, for example, but not limited thereto. That is, one end of the negative electrode tab 114 may be electrically connected to the negative electrode uncoated portion, and the other end may protrude and extend outward. An insulating member 114a is attached to the negative electrode tab 114 to prevent the negative electrode tab 114 from being short-circuited with the laminate facing member 120.

The positive electrode plate 112 includes, for example, but not limited to, a positive electrode active material layer coated on both surfaces of a metal thin plate having excellent conductivity, for example, a positive electrode current collector plate made of aluminum foil or mesh. Here, the cathode active material layer may include, for example, but not limited to, chalcogenide compounds. For example, composite metal oxides such as LiCoO2, LiMn2O4, LiNiO2, and LiNiMnO2 may be used. The positive electrode tab 115 may be fixed (for example, welded) to the positive electrode uncoated portion where the positive electrode collector plate is not provided with the positive electrode active material layer, for example, but not limited thereto. An insulating member 115a is attached to the positive electrode tab 115 to prevent the positive electrode tab 115 from being short-circuited with the laminate facing member 120.

The separator 113 is interposed between the negative electrode plate 111 and the positive electrode plate 112 to prevent electrical shorting of the negative electrode plate 111 and the positive electrode plate 112. A pair of the separators 113 is substantially provided, and the anode plate 111 is sandwiched between the pair of separators 113. The separator 113 may be made of any one selected from the group consisting of, for example, polyethylene, polypropylene, and a porous copolymer of polyethylene and polypropylene. The separator 113 may be wider than the negative electrode plate 111 and the positive electrode plate 112 to prevent electrical shorting between the negative electrode plate 111 and the positive electrode plate 112. The separator 113 will be described below again.

The laminate sheathing member 120 receives the electrode assembly 110 and is formed by sealing the outer periphery of the electrode assembly 110. The laminate sheathing 120 has a first outer sheath 121 and a second outer sheath 121 having one end connected to the first outer sheath 121 and having a recess 123 having a predetermined depth to receive the electrode assembly 110, And an enclosure 122.

In addition, the peripheries 124 of the first and second external parts 121 and 122 corresponding to the outer periphery of the electrode assembly 110 are mutually thermally fused to each other so that the electrode assembly (not shown) 110 are accommodated.

That is, the laminate facing member 120 is formed by integrally forming a rectangular plate-like laminate facing member 120 in the middle with respect to the longitudinal direction of one side so as to form the first exterior member 121 and the second exterior member 122 do. The second external portion 122 is formed with a recess 123 having a predetermined depth at which the electrode assembly 110 can be received through a press or a drawing process, And a sealing portion 124 for sealing with the first enclosure 121 is formed at the periphery. The sealing portion 124 may be formed along one side and the other side where the first exterior portion 121 and the second exterior portion 122 are in contact with each other.

The second enclosure 122 also includes four extended areas that are away from the first enclosure 121 and a flat area that is connected to these four extended areas and that is also the bottom of the recess 123. Here, a relatively long region may be defined as a long-side extension region and a relatively short region may be defined as a short-side extension region, among the four extension regions.

The negative electrode tab 114 and the positive electrode tab 115 of the electrode assembly 110 are drawn out to the outside through the region where the first enclosure 121 and the second enclosure 122 are fused. At this time, the insulating members 114a and 115b formed on the negative electrode tab 114 and the positive electrode tab 115 are sealed together with the sealing portion 124. [ That is, the insulating members 114a and 115b are formed at portions where the negative electrode tab 114 and the positive electrode tab 115 come in contact with the sealing portion 124 so that the negative electrode tab 114 and the positive electrode tab 115 are connected to the laminate outer member 120 To be electrically short-circuited.

The laminate sheathing 120 may be formed in a multilayer structure including, but not limited to, a first insulating layer 120a, a metal layer 120b, and a second insulating layer 120c. Of course, a variety of adhesive layers and functional layers may be further added, but a description thereof will be omitted so as not to obscure the gist of the present invention.

The first insulating layer 120a is formed on the inner surface of the laminate outer cover 120, and is made of a material having insulation and heat adhesiveness. The first insulating layer 120a is formed on one side of the metal layer 120b and forms the inner surface of the laminate facing member 120 facing the electrode assembly 110. [ The first insulating layer 120a may be formed of casted polypropylene (CPP) or its equivalent which does not react with an electrolyte or the like, but is not limited thereto. When the electrode assembly 110 is received in the recess 123 of the second enclosure 122 and covered with the first enclosure 121, the first insulation layer 120a of the laminate enclosure 120 is brought into contact with each other . Therefore, when the sealing part 124 is thermally fused, the first insulating layer 120a is adhered to each other, and the laminate facing member 120 is sealed.

The metal layer 120b is sandwiched between the first insulating layer 120a and the second insulating layer 120c to prevent moisture and oxygen from being introduced into the metal layer 120b and if the electrolyte is filled in the inside of the laminate 120, , And serves to prevent the outflow thereof. In addition, the metal layer 120b serves to maintain the mechanical strength of the laminate sheathing material 120. In general, the metal layer 120b may be formed of, but not limited to, aluminum, an aluminum alloy, an iron, and an iron alloy.

The second insulating layer 120c is an outer surface of the laminate 120, and serves to alleviate mechanical and chemical impacts with external electronic devices. The second insulating layer 120c is formed on the other surface of the metal layer 120b and forms the outer surface of the laminate facing member 120. [ The second insulating layer 120c may be formed of, but not limited to, nylon, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), or the like.

The second exterior portion 122 of the laminate exterior material 120 of the secondary battery 100 according to various embodiments of the present invention includes a plurality of extended regions 125, 126, and 127 extending in a direction away from the first exterior portion 121, And a flat area 128 connected to the plurality of extension areas 125, 126, 127 and approximately parallel to the first enclosure 121. [

Here, a plurality of extension regions 125, 126, and 127 and a single flat region 128 may define a recess 123 that substantially receives the electrode assembly 110. Furthermore, two of the plurality of extension regions may be defined as a relatively long extended region 125, and the remaining two extended regions may be defined as a relatively shortened short extension region 126, The corner between the extension region 125 and the short side extension region 126 may be defined as a corner extension region 127. [

2A and 2B, a state before the electrode assembly 110 is wound up in the secondary battery 100 according to various embodiments of the present invention is shown. In FIGS. 2A and 2B, a plurality of dashed lines shown in the vertical direction indicate an area where the electrode assembly 110 is folded during the winding process of the electrode assembly 110, a winding area, or a winding turn number. In practice, the width of this folded region is characterized by a gradual widening as the number of winding turns increases, but for ease of understanding of the present invention, it is indicated by the dotted line with no width in the figures, May not exactly match the electrode assembly 110 shown in Fig. 2B, the negative electrode plate 111 and the positive electrode plate 112 are shown separately from the first and second surfaces for the sake of convenience. Further, in Figs. 2A and 2B, the right end is the winding end, and the left end is the winding end. In addition, the winding direction is assumed to be clockwise. These features and assumptions may be shared in all embodiments of the present invention.

2A and 2B, a secondary battery 100 according to an embodiment of the present invention includes a negative electrode plate 111 having a negative electrode tab 114 formed at the winding end thereof, a pair of separators (not shown) covering the negative electrode plate 111, 113a and 113b and the positive electrode plate 112 between the separators 113a and 113b (or the first and second separators) and the positive electrode plate 112 having the positive electrode tab 115 formed at the winding end thereof, As shown in FIG.

The winding end refers to a region where the winding is started during the winding process of the electrode assembly 110 (i.e., a region where the winding clamp is caught), and the winding termination refers to a region where the winding is terminated during the winding process of the electrode assembly 110 it means. Thus, the negative electrode tab 114 at the winding end is positioned substantially at the inner periphery (or the inner center) in the wound electrode assembly 110, and the positive electrode tab 115 at the winding end is disposed at the outer periphery Or outer surface or inner surface). In addition, the winding termination is generally located at the outermost portion of the electrode assembly 110.

The negative electrode plate 111, the positive electrode plate 112 and the separators 113a and 113b of the electrode assembly 110 will be described in more detail. The electrode assembly 110 described below is merely an example for the understanding of the present invention, and the formation position of the tab, the active material layer (active material coating portion) and / or the non-coating portion (non-active material coating portion) It should be understood that various changes may be made.

The negative electrode plate 111 includes a negative electrode collector plate 111a, a first negative electrode active material layer (or first negative electrode active material coating portion) 111g, a second negative electrode active material layer (or second negative electrode active material coating portion) 111h, And a negative electrode tab 114. The negative electrode current collector plate 111a includes a substantially flat negative first face 111b and a substantially flat negative second face 111c opposite to the first negative electrode face 111b. The first active material layer 111g of the negative electrode is coated on the first surface 111b of the negative electrode of the negative electrode collector plate 111a and the second active material layer 111h of the negative electrode is coated on the second surface of the negative electrode collector plate 111a 111c.

Here, the negative first uncoated portion (or the first negative electrode active material uncoated portion) 111d (the first negative electrode first active material uncoated portion) 111d on which the negative first active material layer 111g is not coated on the winding front end of the negative first face 111b And a negative second uncoated portion (or a first negative electrode active material uncoated portion) 111e (the first negative electrode first active material uncoated portion) which is not coated with the negative second active material layer 111h on the winding end of the negative second face 111c (Corresponding to approximately two turns from the end), and the negative third uncoated portion 111f (or the negative third uncoated portion 111f) on which the second cathode active material layer 111h is not coated on the winding tip of the second cathode side 111c Coated portion) (corresponding to approximately one turn from one end) may be provided. In addition, the negative electrode uncoated portion may not be provided at the winding end of the negative electrode first surface 111b. Of course, the negative electrode second active material layer 111h may be extended instead of the negative second uncoated portion 111e, or the negative uncoated portion may be provided on the winding first end 111b of the negative first face 111b. Whether or not the active material is coated on the first surface 111b and the second surface 111c in the negative electrode plate 111 at the winding end can be varied depending on the characteristics of the secondary battery. It is to be understood that the invention is not limited thereto. Here, at the winding end of the negative electrode current collecting plate 111a, an extension of approximately 3 mm may be formed without coating the active material.

On the other hand, the negative electrode tab 114 is provided on the negative first uncoated portion 111d or the negative second uncoated portion 111e of the negative electrode plate 111 by, for example, ultrasonic welding, laser welding, As shown in FIG.

On the other hand, the pair of separators 113a and 113b are disposed on the negative first uncoated portion 111d of the negative electrode plate 111, the second uncoated portion 111e of the negative electrode, the third uncoated portion 111f of the negative electrode, The length and width of the pair of separators 113a and 113b may be substantially equal to or greater than the length and width of the negative electrode plate 111. The negative electrode active material layer 111h and the negative electrode active material layer 111h,

The positive electrode plate 112 includes a positive electrode collector plate 112a, a positive first active material layer (or positive first active material coating portion) 112g, a positive electrode second active material layer (or positive electrode second active material coating portion) 112h, And includes a positive electrode tab 115. The positive electrode current collector plate 112a includes a substantially flat positive first face 112b and a substantially flat positive second face 112c opposite to the positive first face 112b. The positive first active material layer 112g is coated on the positive first side 112b of the positive electrode collector plate 112a and the positive second active material layer 112h is coated on the second positive side of the positive electrode collector plate 112a 112c.

Here, the positive first uncoated portion (or the positive first active material non-coated portion) 112d (the first positive electrode first active material non-coated portion) 112d in which the positive first active material layer 112g is not coated at the winding- And a positive second uncoated portion (or a positive first active material non-coated portion) 112e (corresponding to the first side 112b) on which the positive first active material layer 112g is not coated, (Corresponding to approximately two turns from the end), and the positive third non-coated portion (or the positive second active material layer 112c), which is not coated with the positive electrode second active material layer 112h at the winding end of the positive second surface 112c Uncoated portion) 112f (corresponding to approximately two turns from one end). In addition, the anode uncoated portion (or the anode active material non-coated portion) may not be provided at the winding tip of the anode second surface 112c.

Here, the positive electrode tabs 115 are formed on the positive first uncoated portion 112d or the positive third uncoated portion 112f of the positive electrode plate 112 by, for example, ultrasonic welding, laser welding, or resistance welding As shown in FIG.

The adhesive layer 130 may be formed by spraying / coating the end of the positive electrode plate 112, that is, the entire area or a partial area of the positive first uncoated portion 112d of the positive electrode plate 112. The adhesive layer 130 may include, for example, but not limited to, a PS (Poly Styrene) adhesive or a rubber adhesive. The adhesive strength of the adhesive layer 130 such as the PS adhesive or the rubber adhesive can be adjusted by using a silicone binder, an acrylate binder or a PVDF (Polyvinylidene Fluoride) binder for bonding the separators 113a and 113b to the negative electrode plate 111 or the positive electrode plate 112, ) Binder. ≪ / RTI >

The width and length of the adhesive layer 130 may be equal to or less than the width and length of the positive first unoccupied portion 112d of the positive electrode plate 112, for example, but not limited thereto.

3A and 3B, a state before the electrode assembly 110 is wound up in a secondary battery 100 according to various embodiments of the present invention is shown.

3A and 3B, in the negative electrode plate 111, a negative first uncoated portion (or negative electrode active material layer 111b), which is not coated with the first negative electrode active material layer 111g on the winding front end of the negative first surface 111b, 1 active material non-coated portion) 111d can be formed corresponding to approximately three turns from one end and the negative first active material layer 111g is not coated at the winding end of the negative first face 111b 4 uncoated portion (or the first negative electrode active material coating portion) 111i may be formed corresponding to approximately two turns from the other end.

Next, in the positive electrode plate 112, a positive second uncoated portion (or a positive second active material non-coated portion) 112f in which the positive second active material layer 112h is not coated at the winding end of the positive second surface 112c, And the anode first and second active material layers 112g and 112h are not coated with the positive electrode first and second active material layers 112g and 112h on the winding front ends of the positive and negative first and second faces 112b and 112c, (Or the anode active material non-coated portions) 112e, 112i may be formed corresponding to one turn from one end.

It is to be understood that such an electrode assembly is also only one example for the understanding of the present invention, and the present invention is not limited in this form.

Referring to FIG. 4, the rechargeable battery 100 according to various embodiments of the present invention shows a state after the electrode assembly 110 is wound. Here, the electrode assembly 110 shown in FIGS. 2A and 2B is in a pre-wound state, and the electrode assembly 110 shown in FIG. 4 is in a post-wrapped state, and the outline of the electrode assembly 110 and the electrode assembly 110 may be slightly different. 4, the relationship between the cathode plate 111, the separators 113a and 113b, and the anode plate 112 is substantially the same as that shown in Fig. 4, The form shown is more accurate. However, the negative electrode plate 111, the separators 113a and 113b and the positive electrode plate 112 are in close contact with each other. However, for easy understanding of the present invention, these components are shown as being spaced apart from each other in FIG.

As shown in FIG. 4, the adhesive layer 130 may be formed on the inner side of the outermost periphery including the winding end of the positive electrode plate 112. Accordingly, the adhesive layer 130 substantially adheres the separator 113a or 113b to the inside of the outermost periphery including the winding termination of the anode plate 112. [ 4 shows that the adhesive layer 130 adheres the separator 113a to the positive electrode plate 112. However, if the separator 113b is wound one more turn relative to the separator 113a, the adhesive layer 130 is separated from the separator 113b ) To the positive electrode plate (112).

More specifically, the adhesive layer 130 covers the electrode assembly 110 at least once. That is, the adhesive layer 130 is formed on the positive first uncoated portion 112d (or on the positive first side end uncoated portion) so that the negative second uncoated portion 111e (or negative first side end uncoated portion) and / Or the positive third non-solid portion 112f (or the positive second side end solid portion) through the separators 113a and 113b.

When the negative first active material layer 111g is further extended instead of the negative second uninhabited portion 111e as described above, the adhesive layer 130 is formed on the negative first active material layer 111g with separators 113a and 113b ) Can be faced through. However, the positive electrode first uncoated portion 112d of the positive electrode plate 112 (that is, the uncoated first side end surface of the positive electrode) is also provided with a constant The anode active material layer 112g may be formed to extend further from the cathode active material layer 112b of the separator 113a and the anode active material layer 112b of the separator 113a, And the outermost positive first unoccupied portion 112d (first turn at the outermost periphery) face each other. That is, the adhesive layer 130 may be interposed only between the outermost positive first uncoated portion 112d and the positive third unoccupied portion 112f inside thereof.

On the other hand, the adhesive strength (or peel strength) between the adhesive layer 130 and the first positive electrode uncoated portion 112d is set to a value between the separators 113a and 113b and the first and second active material layers 111g and 111h of the negative electrode plate 111 It is preferable that the adhesive force is designed to be equal to or greater than the adhesive force between the separators 113a and 113b and the first and second active material layers 112g and 112h of the positive electrode plate 112. [

For example, although not limited thereto, the adhesive strength between the separators 113a and 113b and the anode active material layers 111g and 111h of the anode plate 111, or between the separators 113a and 113b and the cathode active material layer 112g The adhesive force between the adhesive layer 130 and the first positive electrode uncoated portion 112d and the adhesive force between the adhesive layer 130 and the separator 113a are also approximately 3 to 10 mN / To 10 mN / mm or more. After the secondary battery is disassembled, the adhesive layer 130 is stretched from the positive first uncoated portion 112d from the adhesive layer 130 or the separator 113a in the direction of approximately 180 to form the adhesive layer 130, Quot; means a value when peeled from the non-printed portion 112d or the separator 113a.

The separator may be further provided with an adhesive layer (or a binder) on its surface, such as, but not limited to, a silicone adhesive, an acrylate adhesive, or a PVDF (polyvinylidene fluoride) adhesive. This adhesive layer basically adheres well to the first and second active material layers 112g and 112h of the positive electrode plate 111 and / or the first and second active material layers 111g and 111h of the negative electrode plate 112, The positive electrode first, second and third uncoated portions 112d, 112f and 112e of the negative electrode first, second and third uncoated portions 111d, 111e and 111f of the positive electrode plate 112 of the positive electrode plate 112 Respectively. As a result, a fine short phenomenon occurs between the positive electrode plate 111 and the negative electrode plate 112 in the winding termination region of the electrode assembly 110 when the secondary battery is dropped or impacted, thereby causing a voltage drop phenomenon and a heat generation phenomenon By the present inventors.

Accordingly, the present inventors have found that an adhesive layer 130 including a PS-based adhesive or a rubber-based adhesive in addition to the adhesive layer (or binder) such as the above-described silicone adhesive, acrylic adhesive, or PVDF adhesive is applied to the cathode non- In the presence of a large amount of water.

The adhesive layer 130 strongly bonds the separator 113a to the positive first uncoated portion 112d of the positive electrode plate 112 (or the uncoated first side endless portion of the positive electrode) of the secondary battery 100, So that the electrode assembly 110 is prevented from flowing inside the case 120 during a falling impact / impact of the electrode assembly 110. That is, the separator 113a is not separated from the positive first uncoated portion 112d of the positive electrode plate 112 by the adhesive layer 130. [ Therefore, a fine short phenomenon does not occur between the positive first uncoated portion 112d of the positive electrode plate 112 and the negative second uncoated portion 111e of the negative electrode plate 111, thereby suppressing the voltage drop phenomenon and the heat generation phenomenon do.

Here, the adhesive layer 130 may be a pressure sensitive adhesive tape including a rubber adhesive layer. That is, the adhesive tape may include a base material and a rubber-based adhesive layer formed on the surface of the base material. Here, the rubber adhesive layer may be formed of, for example, natural rubber, polyisoprene rubber, styrene-butadiene rubber, styrene-isoprene rubber, styrene-isoprene-styrene block copolymer rubber, styrene- Styrene block copolymer rubber, a styrene-ethylene-butylene block copolymer rubber, a styrene block copolymer, a styrene block copolymer rubber, a styrene block copolymer rubber, a styrene block copolymer rubber, Polyisobutylene, or a modified product thereof. In addition, the substrate may be an OPS (Oriented Polystyrene) which reacts with an electrolyte to exhibit adhesiveness, or an OPS which does not react with an electrolyte such as PET (polyethylene terephthalate), PI (polyimide), PE (polyethylene) It is possible.

5 is a view showing a state after the electrode assembly 210 is wound up in a secondary battery according to various embodiments of the present invention.

5, the adhesive layer 230 is formed on the second uncoated portion 111e of the negative electrode (or on the first uncoated side of the negative first surface), so that the adhesive layer 230 separates the separator 113a from the negative electrode plate 111 And adheres strongly to the negative second uncoated portion 111e (or negative first surface end uncoiled portion). Therefore, the electrode assembly 210 is prevented from flowing in the case 120 when the secondary battery is dropped / impacted. That is, the separator 113a is not separated from the second unoccupied portion 111e of the negative electrode plate 111 by the adhesive layer 230. [ Therefore, a fine short phenomenon does not occur between the second uncoated portion 111e of the negative electrode plate 111 and the positive first uncoated portion 112d of the positive electrode plate 112, thereby suppressing the voltage drop phenomenon and the heat generation phenomenon do.

6 is a view showing a state after the electrode assembly 310 is wound up in a secondary battery according to various embodiments of the present invention.

6, the adhesive layer 130 is formed on the positive first uncoated portion 112d (or the uncoated first side end uncoated portion) so that the adhesive layer 130 separates the separator 113a from the positive electrode plate 112 And the other adhesive layer 230 is adhered to the negative second uncoated portion 111e of the negative electrode plate 111 (or the negative second uncoated portion 111e of the negative first side end uncoated portion) The adhesive layer 230 strongly adheres the separator 113a to the negative second uncoated portion 111e of the negative electrode plate 111 (or the uncoated first side end face portion of the negative electrode). Therefore, the separator 113a is formed by the adhesive layers 130 and 230 from the positive second uncoated portion 112d of the positive electrode plate 112 and the negative second uncoated portion 111e of the negative electrode plate 111 during drop impact / collision of the secondary battery Do not separate. Therefore, a fine short phenomenon does not occur between the positive first uncoated portion 112d of the positive electrode plate 112 and the negative second uncoated portion 111e of the negative electrode plate 111, thereby suppressing the voltage drop phenomenon and the heat generation phenomenon do.

In addition, although not shown, the adhesive layer is formed on the positive third uncoated portion 112f (or the second uncoated side of the positive electrode) of the positive electrode plate 112 so that the adhesive layer separates the separator 113b from the positive electrode And can be adhered to the second non-coated portion 112f. At this time, the adhesive layer is formed only in a region corresponding to the positive first unoccupied portion 112d of the positive electrode plate 112 inside the winding end portion of the electrode assembly 110 (i.e., the second turn from the outermost portion of the electrode assembly) It is preferable that the adhesive layer is not exposed to the outermost portion beyond the winding end portion of the electrode assembly. If the adhesive layer is exposed outermost through the winding end of the electrode assembly, contaminants may stick to the battery during the manufacturing process of the battery. In addition, these embodiments are applicable to all embodiments of the present invention in common.

7A to 7E are partially enlarged cross-sectional views showing the relationship between the positive first uncoated portion, the adhesive layer and the separator among the secondary batteries according to various embodiments of the present invention. Here, the positive first uncoated portion 112d (or the positive first side end innermost portion) is formed of the positive third unoccupied portion 112f (or the positive second side end unoccupied portion) and / or the negative second uncoated portion 111e (Or the first side end unoccupied portion of the negative electrode).

7A, a PE (polyethylene), a PP (polypropylene), or a separator 113 having at least one of them as a base film is adhered to the positive first uncoated portion 112d through the adhesive layer 130 . The separator 113 does not have a binder, a polymer, or an inorganic ceramic coating layer formed on its surface, and thus is used for a normal low-capacity and low-cost machine. Since the separator 113 does not have a surface coating layer, the adhesive strength to the positive first uncoated portion 112d is usually small. However, as described above, the positive electrode first uncocked portion 112d is strongly adhered / Can be bound.

7B, a heat-resistant insulating separator 313 including an inorganic ceramic layer such as alumina or boehmite may be adhered to the positive first non-coated portion 112d through the adhesive layer 130. [ The heat-resistant insulating separator 313 is formed by coating at least one ceramic layer on one surface or both surfaces of a conventional PE or PP separator. Of course, the ceramic layer can be bonded to the PE or PP separator by a binder, and such a binder can be strongly adhered to the cathode active material layer and / or the anode active material layer. Such a binder has a weak adhesive force to the positive first uncoated portion 112d but the separator 313 can be strongly adhered to the positive first uncoated portion 112d by the adhesive layer 130 as described above. This heat-resistant insulating separator 313 is excellent in heat resistance / safety and can be used for a high-capacity, high-output cell.

7C, the polymer-coated separator 413 may be adhered to the positive first unhaded portion 112d through the adhesive layer 130. As shown in FIG. The polymer-coated separator 413 is formed by coating a polymer on either or both sides of a PE or PP separator. Such a polymer can be strongly adhered to the positive electrode active material layer and / or the negative electrode active material layer. The polymer-coated separator 413 serves to improve the adhesion between the separator and the positive electrode plate and / or the negative electrode plate.

7D, a multilayer coating separator 513 having an inorganic ceramic layer and a polymer layer may be adhered to the positive first non-coated portion 112d through the adhesive layer 130. [ The multilayer coating separator 513 simultaneously realizes the adhesion of the polymer-coated separator and the safety of the heat-resistant insulating separator, and can be used for a high capacity battery.

7E, a separator 613 having a coating layer made of an inorganic ceramic layer and a binder may be adhered to the positive first non-coated portion 112d through the adhesive layer 130. [ Such a separator 613 is excellent in adhesiveness, safety, and price competitiveness, and can be used for a high capacity battery in general.

Here, the separator having the above-described heat-resistant insulating separator, the polymer coating separator, the separator having the inorganic ceramic layer and the polymer layer, and the coating layer made of the inorganic ceramic layer and the binder may include a binder (adhesive component) After the completion of the process, the separator is adhered to the positive electrode plate and / or the negative electrode plate by the binder through the thermocompression process. However, as described above, such a binder has an excellent adhesive force to the active material layer of the positive electrode plate and the negative electrode plate, but the adhesive force to the non-coated portion is relatively weak.

Accordingly, in order to compensate for this, in the present invention, by further interposing an adhesive layer containing PS-based adhesive or rubber-based adhesive between the uncoated end portions of the positive electrode plate and / or the negative electrode plate and the separator, adhesion strength between the end of the electrode assembly and the separator is improved .

Thus, the electrode assembly has one solid or bulk feature, so that each component of the electrode assembly does not move separately during dropping / impacting, thereby suppressing the voltage drop phenomenon and the heat generation phenomenon.

It is to be understood that the present invention is not limited to the above-described embodiment, but may be modified in various ways within the spirit and scope of the present invention as set forth in the following claims It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

100; The secondary battery according to the embodiment of the present invention
110; An electrode assembly 111; Cathode plate
111a; Cathode collector plate 111b; Cathode first side
111c; Cathode second surface 111d; Cathode negative first portion
111e; A negative second uncoated portion 111f; Cathode third solid portion
111g; Cathode first active material layer 111h; Cathode second active material layer
112; A positive electrode plate 112a; Anode collector plate
112b; A positive first side 112c; Anode second side
112d; A positive first uncoated portion 112e; The positive second uncoated portion
112f; A positive third unhardened portion 112g; The positive first active material layer
112h; A second positive electrode active material layer 113, 113a, 113b; Separator
114; Cathode tab 115; Bipolar tab
130; An adhesive layer 120; Laminate Outer Material

Claims (10)

A first electrode plate having a first active material coating portion and a first active material non-coating portion, a second electrode plate having a second active material coating portion and a second active material non-coating portion, and a second electrode plate having a first active material coating portion and a second active material non- An electrode assembly including a separator interposed therebetween, the electrode assembly being formed by winding the first electrode plate, the separation membrane, and the second electrode plate in a laminated state and in the form of a jelly roll having a winding end and a winding end; And
And an adhesive layer interposed between the second electrode plate and the separator as an outermost portion of the electrode assembly having the winding termination. The method according to claim 1,
Wherein the second electrode plate as the outermost portion of the electrode assembly having the winding termination includes the second active material uncoated portion and the adhesive layer interposed between the second active material uncoated portion and the separator, Wherein the plate is a positive electrode substrate. 3. The method of claim 2,
Wherein the second active material uncoated portion and the adhesive layer of the second electrode plate as the outermost portion of the electrode assembly having the winding termination at least cover the electrode assembly at least once and the adhesive layer adheres between the anode substrate and the separator Secondary battery. The method of claim 3,
The second active material uncoated portion of the second electrode plate as the outermost portion of the electrode assembly having the winding termination faces the other second active material uncoated portion on the inside or the first active material non- And a part of the adhesive layer is attached to the winding end to fix the shape so that the electrode assembly is not loosened. 3. The method of claim 2,
Wherein the adhesive force between the adhesive layer and the second active material coating portion is equal to or greater than the adhesive force between the separating film and the second active material coating portion. The method according to claim 1,
Wherein the adhesive layer comprises a PS (poly styrene) adhesive or a rubber adhesive. The method according to claim 6,
The adhesive layer may be a secondary battery made of an adhesive tape including a rubber- The method according to claim 1,
Wherein the separator comprises a binder coated on the surface. 9. The method of claim 8,
Wherein the binder comprises a silicone-based binder, an acrylate-based binder, or a PVDF (polyvinylidene fluoride) binder. The method according to claim 1,
Wherein the separator comprises an inorganic material coated on the surface.

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