KR20230050929A - Electrode assembly for secondary battery and secondary battery comprising the same - Google Patents

Abstract

According to an embodiment of the present invention, an electrode assembly for a secondary battery comprises: a plurality of cathodes arranged in a stacked structure and a plurality of anodes arranged between the cathodes, respectively. At this time, the cathodes may be provided as a first cathode whose shape does not change with changes in ambient temperature and a second cathode whose shape changes with changes in ambient temperature.

Description

Electrode assembly for secondary battery and secondary battery including the same

The present invention relates to an electrode assembly for a secondary battery and a secondary battery including the same, and more particularly, an electrode for a secondary battery capable of stably protecting the electrode assembly by effectively preventing a thermal runaway phenomenon caused by an abnormally high temperature when an abnormally high temperature occurs in the electrode assembly. It relates to an assembly and a secondary battery including the same.

In general, as the development of the high-tech electronics industry makes it possible to reduce the size and weight of electronic equipment, the use of various types of mobile devices including portable electronic devices is increasing, and the use of electric vehicles or hybrid vehicles is also expanding. .

Recently, the need for batteries having high energy density as a power source for mobile devices, electric vehicles, or hybrid vehicles is increasing day by day. Accordingly, the demand for high-performance secondary batteries is increasing, and research for improving the performance of secondary batteries is being conducted more actively. In particular, secondary batteries are being designed to have a compact internal structure according to trends such as high performance, thinning, and miniaturization.

However, when abnormally high temperature occurs inside the secondary battery for various reasons, a thermal runaway phenomenon occurs due to the abnormal high temperature, and there is a problem in that the secondary battery explodes due to the thermal runaway. As described above, in order to solve the problem of secondary batteries exploding due to thermal runaway due to abnormally high temperatures, various technologies are being continuously researched and developed.

For example, after detecting the abnormal high temperature of the secondary battery in real time with a sensor, if the abnormal high temperature is detected in the secondary battery, the electric circuit of the secondary battery is adjusted to cut off the current supplied to the secondary battery or to discharge the secondary battery. A technology for discharging the electrolyte inside the secondary battery to the outside is also being developed in order to eliminate the risk of explosion due to the abnormal high temperature of the secondary battery.

Related prior art documents include Korean Patent Registration No. 10-0989969 (title of invention: device for preventing high-temperature explosion of battery pack, registration date: 2010.10.19), Korean Patent Registration No. 10-1093928 (name of invention: battery cell Battery pack and method capable of preventing high-temperature swelling, registration date: 2011.12.07), and Korean Patent Registration No. 10-2144922 (name of invention: battery explosion prevention device, battery pack and operation method, registration date: 2020.08. 10) is.

Korean Registered Patent No. 10-0989969 (registered on October 19, 2010) Korean Registered Patent No. 10-1093928 (registered on December 7, 2011) Korean Registered Patent No. 10-2144922 (registered on 2020.08.10)

An embodiment of the present invention provides an electrode assembly for a secondary battery capable of stably protecting the electrode assembly from abnormally high temperature by effectively preventing thermal runaway caused by abnormally high temperature when an abnormally high temperature occurs in the electrode assembly, and a secondary battery including the same .

In addition, an embodiment of the present invention is an electrode assembly for a secondary battery capable of effectively blocking the thermal runaway phenomenon due to the occurrence of an abnormally high temperature of the electrode assembly with a simple structural change in which at least one of the negative electrodes of the electrode assembly is formed in a bimetal structure, and including the same A secondary battery is provided.

In addition, in the embodiment of the present invention, since the negative electrode deforms according to the bimetallic characteristics and creates a resistance space between the negative electrode and the positive electrode when an abnormal high temperature of the electrode assembly occurs, the electrode assembly Provided is an electrode assembly for a secondary battery capable of increasing the stability of and a secondary battery including the same.

According to one embodiment of the present invention, there is provided an electrode assembly for a secondary battery including a plurality of negative electrodes disposed in a stacked structure, and positive electrodes respectively disposed between the negative electrodes. In this case, the negative electrodes may be provided as a first negative electrode whose shape does not change according to a change in ambient temperature, and a second negative electrode whose shape changes according to a change in ambient temperature.

Preferably, the second negative electrode is deformed in a direction away from the positive electrode stacked on either side of either side of the second negative electrode when the ambient temperature rises above a preset temperature when an abnormally high temperature of the secondary battery electrode assembly occurs. Thus, a resistance space may be generated between the anode and the corresponding anode.

When the temperature of the electrode assembly for a secondary battery is restored to a normal temperature, the deformation of the second negative electrode is restored to an initial shape, and the resistance space generated between the second negative electrode and the corresponding positive electrode can be removed.

At least one of the negative electrodes may serve as the second negative electrode, and the rest of the negative electrodes may serve as the first negative electrode. In this case, at least one second negative electrode may be disposed in an intermediate layer of the positive electrodes along the stacking direction of the positive electrodes.

A pair of the second cathodes may be disposed symmetrically with a single number or a plurality of the anodes in the middle.

Preferably, the positive electrode may be provided with a structure in which a positive electrode active material is coated on the surface of a positive electrode current collector formed of one type of metal plate. The first negative electrode may be provided with a structure in which a negative electrode active material is coated on a surface of a first negative electrode current collector formed of one type of metal plate. The second anode may have a structure in which an anode active material is coated on a surface of a second anode current collector formed of a bimetal in which two types of metal plates having different thermal expansion coefficients are overlapped and attached.

The cathode current collector may be formed of a metal plate made of aluminum (Al). The first negative current collector may be formed of a metal plate made of copper (Cu). The second anode current collector includes a non-expandable metal plate made of nickel (Ni) or iron (Fe) having a small coefficient of thermal expansion, and an expandable metal plate made of a copper (Cu) alloy material that is face-joined with the non-expandable metal plate and has a large coefficient of thermal expansion. can be formed

The second cathode may be stacked in a direction in which the non-expandable metal plate faces the anode so as to generate a resistance space between the cathode and the anode.

Preferably, the set temperature may be set to 40 ~ 60 ℃.

Meanwhile, according to another aspect of the present invention, a secondary battery including the electrode assembly according to the above is provided.

An electrode assembly for a secondary battery according to an embodiment of the present invention and a secondary battery including the same have a structure in which the negative electrodes of the electrode assembly are provided as a first negative electrode and a second negative electrode, but the shape of the second negative electrode changes according to a change in ambient temperature. Therefore, as the shape of the second negative electrode is deformed when an abnormally high temperature occurs in the electrode assembly, a resistance space may be generated between the second negative electrode and the positive electrode, and the internal resistance of the electrode assembly may be increased due to the generation of the resistance space. In addition, as the current amount of the electrode assembly decreases due to the increase in the internal resistance of the corresponding electrode assembly, the thermal runaway phenomenon can be effectively prevented.

In addition, the electrode assembly for a secondary battery according to an embodiment of the present invention and the secondary battery including the same have a thermal runaway phenomenon due to the occurrence of an abnormally high temperature of the electrode assembly by simply changing the structure of forming the second negative electrode of the negative electrode of the electrode assembly in a bimetal structure. can be effectively blocked, and thus the electrode assembly can be stably protected against abnormally high temperatures.

In addition, the electrode assembly for a secondary battery according to an embodiment of the present invention and the secondary battery including the same have a structure in which a resistance space is created between the second negative electrode and the positive electrode while the second negative electrode is deformed according to the bimetallic characteristics when an abnormally high temperature occurs in the electrode assembly. , The amount of current of the electrode assembly may be reduced by increasing the internal resistance of the electrode assembly, thereby effectively preventing the thermal runaway phenomenon of the electrode assembly, thereby preventing the risk of explosion of the electrode assembly.

In addition, the electrode assembly for a secondary battery according to an embodiment of the present invention and the secondary battery including the same can conveniently manufacture the second negative electrode of the electrode assembly by a simple manufacturing method of forming the second negative electrode current collector with a bimetal material, and the electrode assembly When the ambient temperature rises above the set temperature when an abnormally high temperature occurs, the second cathode is deformed according to the bimetallic characteristics and a resistance space is formed between the second cathode and the anode, so that the thermal runaway phenomenon of the electrode assembly can be structurally and simply prevented. . Therefore, in this embodiment, since there is no need to separately add an overheating prevention circuit or overheating prevention structure used in conventional secondary batteries, the thermal runaway phenomenon of the electrode assembly can be prevented with a simple structure, a simple manufacturing method, and low production cost. there is.

1 is a schematic view of an electrode assembly for a secondary battery according to an embodiment of the present invention.
FIG. 2 is a view showing an operating state of the electrode assembly for a secondary battery shown in FIG. 1 when an abnormally high temperature occurs.
FIG. 3 is a view schematically showing a main part of the electrode assembly for a secondary battery shown in FIG. 1 .
FIG. 4 is a view showing an operating state when an abnormally high temperature occurs with respect to the main part of the electrode assembly for a secondary battery shown in FIG. 3 .
FIG. 5 is a diagram showing an operating state of the second negative electrode current collector of the second negative electrode shown in FIGS. 3 and 4 .
6 to 10 are views showing modified examples of the electrode assembly for a secondary battery shown in FIG. 1 .

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the examples. Like reference numerals in each figure indicate like elements.

FIG. 1 is a schematic view of an electrode assembly 100 for a secondary battery according to an embodiment of the present invention, and FIG. 2 shows an operating state of the electrode assembly 100 for a secondary battery shown in FIG. 1 when an abnormally high temperature occurs. it is a drawing FIG. 3 is a view schematically showing the main part of the electrode assembly 100 for a secondary battery shown in FIG. 1, and FIG. 4 shows an operating state when an abnormally high temperature occurs with respect to the main part of the electrode assembly 100 for a secondary battery shown in FIG. FIG. 5 is a view showing an operating state of the second anode current collector 142 of the second anode 140 shown in FIGS. 3 and 4 . 6 to 10 are views showing modifications of the electrode assembly 100 for a secondary battery shown in FIG. 1 .

A secondary battery (not shown) according to an embodiment of the present invention has an electrode assembly 100 having a structure in which a plurality of negative electrodes 120 and positive electrodes 110 are alternately stacked, and to accommodate the electrode assembly 100. It may include a battery case (not shown) for.

Here, the electrode assembly 100 is a configuration in which electricity is charged or discharged, and may be formed in a structure in which a cathode and an anode are stacked to cross each other in the vertical direction. The planar shape of the electrode assembly 100 is generally formed in a rectangular planar structure, but is not limited thereto and may be formed in a planar structure of various shapes such as a circle, an ellipse, or a pentagon.

The electrode assembly 100 may further include a separator (not shown) disposed between the positive electrode 110 and the negative electrode 120 . However, recently, an electrode assembly 100 in which a separator is omitted, such as an all-solid-state secondary battery, has been researched and developed.

And, the battery case may be provided in a shape surrounding the outside of the electrode assembly 100 . An electrolyte solution together with the electrode assembly 100 may be sealed and accommodated inside the battery case as described above.

Meanwhile, in this embodiment, the secondary battery is described as a lithium ion secondary battery for convenience of explanation, but since the separator, battery case, and electrolyte constituting the secondary battery are not closely related to the technical idea of the present invention, the separator and the battery A detailed description of the case and the electrolyte will be omitted.

Hereinafter, the electrode assembly 100 having a close relationship with the technical spirit of the present invention will be described in detail.

1 to 5, the electrode assembly 100 for a secondary battery according to an embodiment of the present invention includes a plurality of negative electrodes 120 disposed in a stacked structure and positive electrodes disposed between the negative electrodes 120, respectively. (110).

Here, the positive electrode 110 and the negative electrode 120 are formed in a thin sheet shape and may be alternately stacked in plurality from the bottom to the top of the electrode assembly 100 . The number of stacked layers of the positive electrode 110 and the negative electrode 120 may be appropriately determined according to design conditions and performance requirements of the secondary battery.

Hereinafter, in this embodiment, for convenience of description of the electrode assembly 100, the electrode assembly 100 is described as having a structure in which 20 positive electrodes 110 and 21 negative electrodes 120 are stacked, but limited thereto However, the number of stacked layers of the positive electrode 110 and the negative electrode 120 may be variously changed.

Referring to FIGS. 1 to 4 , the positive electrode 110 of this embodiment may have a structure in which a positive electrode active material 114 is coated on the surface of a positive electrode current collector 112 formed of one type of metal plate. The cathode current collector 112 may be formed of a metal plate made of aluminum (Al), and the cathode active material 114 may be applied to the upper and lower surfaces of the cathode current collector 112 in a slurry form.

The anode 110 may be provided in a structure in which 20 are stacked in a vertical direction. That is, a single-layer anode 110a may be disposed on the lowest layer of the electrode assembly 100, and a 20-layer anode 110t may be disposed on the uppermost layer of the electrode assembly 100. In addition, between the first-layer anode 110a and the 20-layer anode 110t, the second-layer anode 110b, the third-layer anode 110c, ..., the eight-layer anode ( 110h), a 9-layer anode 110i, a 10-layer anode 110j, an 11-layer anode 110k, ..., an 18-layer anode 110r, and a 19-layer anode 110s may be sequentially disposed. Here, all of the first-layer anodes 110a to the 20-layer anodes may have the same structure.

1 to 5 , the cathode 120 of this embodiment includes a first cathode 130 whose shape does not change according to a change in ambient temperature, and a second cathode whose shape changes according to a change in ambient temperature. (140).

At least one of the negative electrodes 120 constituting the electrode assembly 100 may serve as the second negative electrode 140, and the rest of the negative electrodes 120 constituting the electrode assembly 100 may serve as the first negative electrode 130. ) can be provided. At this time, at least one second negative electrode 140 may be disposed in an intermediate layer of the positive electrodes 110 along the thickness direction (eg, vertical direction) of the electrode assembly 100 in which the positive electrodes 110 are stacked. Hereinafter, in this embodiment, it will be described that the pair of second cathodes 140 are disposed in the middle layer of the electrode assembly 100. The pair of second cathodes 140 as described above may be disposed symmetrically with one or more anodes 110 in the middle.

The cathodes 120 are provided in a structure in which 21 cathodes 120 are stacked vertically, and a single anode 110 may be disposed between the cathodes 120, respectively. That is, the first-layer negative electrode 120a may be disposed on the lowermost layer of the electrode assembly 100, and the twenty-first-layer negative electrode 120u may be disposed on the uppermost layer of the electrode assembly 100. In addition, between the first-layer cathode 120a and the 21-layer cathode 120u, from the bottom to the top of the electrode assembly 100, the second-layer cathode 120b, the third-layer cathode 120c, ..., the eight-layer cathode ( 120h), 9-layer cathode 120i, 10-layer cathode 120j, 11-layer cathode 120k, ..., 18-layer cathode 120r, 19-layer cathode 120s, and 20-layer cathode 120t in turn. can be placed. Here, the first layer anode 110a to the eighth layer cathode 120h, the tenth layer cathode 120j, and the twelfth layer cathode 120b to the twenty-first layer cathode 120u may correspond to the first cathode 130, and 9 The layer cathode 120i and the 11-layer cathode 120k may correspond to the second cathode 140 .

As shown in FIGS. 1 to 4 , the first negative electrode 130 may have a structure in which a negative electrode active material 134 is coated on the surface of a first negative electrode current collector 132 formed of one type of metal plate. The shape of the first cathode 130 as described above is not deformed even when the ambient temperature rises above a preset temperature when an abnormally high temperature occurs in the electrode assembly 100 .

Here, the first negative current collector 132 may be formed of a metal plate made of copper (Cu).

In addition, the negative electrode active material 134 may be applied in a slurry form on at least one of the upper and lower surfaces of the first negative electrode current collector 132 . Specifically, the first-layer negative electrode 120a of the first negative electrodes 130 has a structure in which the negative electrode active material 134 is applied only to the top surface of the first negative electrode current collector 132, and the first negative electrode 130 has a structure of 21 layers. The negative electrode 120u has a structure in which the negative electrode active material 134 is applied only to the lower surface of the first negative electrode current collector 132 . In addition, among the first negative electrodes 130, the other first negative electrodes 120b to 120h, 120j, and 120k to 120t, except for the first layer negative electrode 120a and the twenty-first layer negative electrode 120u, are of the first negative electrode current collector 132. It is a structure in which the negative electrode active material 134 is applied to the upper and lower surfaces, respectively.

As shown in FIGS. 1 to 5 , the second anode 140 is coated with an anode active material 144 on the surface of a second anode current collector 142 formed of a bimetal in which two types of metal plates having different coefficients of thermal expansion are stacked and attached. It can be provided in one structure. The shape of the second cathode 140 may be deformed according to the bimetallic characteristics when the ambient temperature rises above a preset temperature when an abnormally high temperature of the electrode assembly 100 is generated. The set temperature as described above may be set to 40 to 60° C., but is not limited thereto and may be set in various ways according to design conditions and use environments of the electrode assembly 100 for a secondary battery.

Here, the second anode current collector 142 may be formed of a non-expandable metal plate 144 made of a material having a small thermal expansion coefficient and an expandable metal plate 146 made of a material having a large thermal expansion coefficient. The non-expandable metal plate 144 and the expandable metal plate 146 are manufactured in the form of surface bonding with each other, but when the ambient temperature rises above a preset set temperature, they are convexly bent in the direction of the expandable metal plate 146 according to the bimetallic characteristics. It can be.

The non-expandable metal plate 144 may be formed of nickel (Ni) or iron (Fe) material having a small thermal expansion coefficient, and the expansion metal plate 146 may be formed of a copper (Cu) alloy material having a large thermal expansion coefficient. As described above, since the expanded metal plate 146 is made of a copper alloy having a material similar to that of the first negative electrode current collector 132, the second negative electrode current collector 142 is a negative electrode current collector similar to the first negative electrode current collector 132. performance is possible.

In addition, the negative electrode active material 144 may be applied in a slurry form to the upper and lower surfaces of the second negative electrode current collector 142 . Specifically, the 9-layer negative electrode 120i and the 11-layer negative electrode 120k corresponding to the second negative electrode 140 have a structure in which the negative electrode active material 144 is applied to the upper and lower surfaces of the second negative electrode current collector 142, respectively. . In this case, the negative active material 144 of the second negative electrode 140 may be formed identically to the negative active material 134 of the first negative electrode 130 .

On the other hand, in this embodiment, the non-expandable metal plate 144 faces the corresponding anode 110 in order to generate a resistance space S between the second cathode 140 and the anodes 110 stacked adjacent thereto. It can be placed in a viewing direction. That is, the second negative electrode 140 of the present embodiment is disposed on the upper and lower sides of the positive electrode 110 centered on the positive electrode 110 disposed in the middle layer of the electrode assembly 100, respectively, and when an abnormally high temperature occurs, the corresponding positive electrode ( 110) may be symmetrically disposed in opposite directions with respect to the corresponding anode 110 so as to be bent and deformed in opposite directions.

Specifically, the 9-layer anode 110i and the 10-layer anode 110j are disposed in the middle layer of the electrode assembly 100, and the 9-layer cathode 110i and the 10-layer cathode 110j have the 10-layer cathode 120j in the middle. , and are in close contact with the lower and upper surfaces of the 10-layer cathode 120j, respectively. The 9-layer cathode 120i of the second cathode 140 is in close contact with the lower surface of the 9-layer anode 110i, and the non-expandable metal plate 144 may be disposed in a direction facing the lower surface of the 9-layer anode 110i. . The 11-layer cathode 120k of the second cathode 140 is in close contact with the upper surface of the 10-layer anode 110j, and the non-expandable metal plate 144 may be disposed in a direction facing the upper surface of the 10-layer anode 110j. . Therefore, in this embodiment, the 9-layer cathode 120i and the 11-layer cathode 120k of the second cathode 140 may be provided symmetrically with respect to the 9-layer anode 110i and the 10-layer cathode 110j. .

Looking at the operation and effect of the electrode assembly 100 for a secondary battery according to an embodiment of the present invention configured as above is as follows.

1 to 5, the electrode assembly 100 for a secondary battery according to an embodiment of the present invention is manufactured by alternately stacking a plurality of positive electrodes 110 and negative electrodes 120 one by one, but the electrode assembly 100 ) In the middle layer of the at least one positive electrode 110, the second negative electrode 140 having a bimetallic characteristic is disposed on the upper and lower sides of the positive electrode 110, and the first negative electrode 140 is disposed in another part of the electrode assembly 100. 130 and the anode 110 are alternately arranged one by one.

At this time, the positive electrodes 110 to be stacked as the electrode assembly 100 are stored in a stacked form in the positive electrode magazine, and the positive electrodes 110 stored in the positive electrode magazine are pulled out one by one to form the negative electrode 120 of the electrode assembly 100. are sequentially stacked on

In addition, the negative electrodes 120 to be stacked as the electrode assembly 100 are stored in a stacked form in the negative electrode magazine, and the first negative electrodes 130 and the second negative electrodes 140 are stacked in the electrode assembly 100. According to the method, the negative electrode magazine is sequentially stored in advance, and the first negative electrodes 130 and the second negative electrodes 140 stored in the negative electrode magazine are taken out one by one and sequentially stacked on the lowermost layer of the electrode assembly 100 or the positive electrode 110 do.

On the other hand, when the temperature of the electrode assembly 100 rises above a predetermined set temperature when the abnormal high temperature occurs, the second cathode 140 is a positive electrode laminated on any one of the upper and lower surfaces of the second cathode 140 ( 110) to generate a resistance space S between the anode 110.

As described above, when a resistance space (S) is generated between the second cathode 140 and the anode 110 stacked adjacent to each other, the internal resistance of the electrode assembly 100 increases to reduce the amount of current, and the amount of current Due to the reduction, the thermal runaway phenomenon of the electrode assembly 100 can be prevented in advance. Therefore, the risk of explosion of the secondary battery can be prevented, and the safety of the secondary battery or electrode assembly can be increased.

Then, when the temperature of the electrode assembly 100 is restored to the normal temperature, the second negative electrode 140 is restored to its initial shape from the deformed state, and the resistance space (S) generated between the corresponding positive electrode 110 can be removed as in the initial state.

As described above, when the resistance space (S) generated between the second cathode 140 and the anode 110 is removed as the normal state is restored from the abnormally high temperature state, the electrode assembly 100 by the corresponding resistance space (S) A decrease in the amount of current is prevented to prevent a problem that unnecessarily restricts the operating performance of the electrode assembly 100 in a normal state.

In conclusion, the electrode assembly 100 of the present embodiment can protect the electrode assembly 100 from overheating when an abnormally high temperature occurs by a method of manufacturing a design structural electrode assembly in which bimetal characteristics are applied to the second cathode 140. That is, at least one resistance space (S) is formed between the second cathodes 140 and the anodes 110 by applying the bimetal technology, which has a property of bending in one direction according to temperature characteristics, to the second cathodes 140. When an abnormally high temperature occurs, the resistance space S generated between the second cathode 140 and the anode 110 acts as internal resistance to realize a decrease in the amount of current according to the increase in resistance, and the electrode assembly 100 It increases the safety of secondary batteries by preventing thermal runaway in advance.

In the case of the electrode assembly 100, the temperature rises due to the current, and due to the temperature rise, a thermal runaway phenomenon occurs, resulting in a risk of explosion. However, in the present invention, when the temperature of the electrode assembly 100 is higher than the set temperature (eg, 50° C.), the internal resistance of the electrode assembly 100 is increased according to the bimetallic characteristics of the second cathode 140 so that current flows. has the effect of forcibly disconnecting the

6 to 10 show modified examples of the electrode assembly 100 according to an embodiment of the present invention.

6 and 7, in the electrode assembly 100 of FIGS. 6 and 7, a single or three or more positive electrodes 110 disposed in the middle layer of the electrode assembly 100 are a pair of second negative electrodes ( 140) may be provided in a structure disposed between. That is, the electrode assembly 100 of FIG. 6 has a structure in which a single positive electrode 110 is disposed between a pair of second negative electrodes 140, and the electrode assembly 100 of FIG. 7 has a pair of second negative electrodes ( 140) has a structure in which three anodes 110 are disposed between them. Therefore, it is possible to properly determine the arrangement structure of the pair of second cathodes 140 disposed in the middle layer of the electrode assembly 100 according to design conditions and situations of the electrode assembly 100 .

Referring to FIG. 8 , in the electrode assembly 100 of FIG. 8 , a structure in which a pair of second cathodes 140 (A) are disposed on an upper layer, a middle layer, and a lower layer of the electrode assembly 100 may be provided. That is, when the number of stacked cathodes 110 and anodes 120 is greatly increased, as shown in FIGS. It is determined that it is difficult to effectively prevent the abnormal high temperature phenomenon of the electrode assembly 100 . Therefore, in the present embodiment, the pair of second negative electrodes 140 (A) are disposed not only in the middle layer of the electrode assembly 100 but also in the upper and lower layers of the electrode assembly 100, thereby preventing the abnormal high temperature phenomenon of the electrode assembly more effectively. it is possible to prevent

Referring to FIG. 9 , in the electrode assembly 100 of FIG. 9 , a structure in which second cathodes 140 among the cathodes 120 of the electrode assembly 100 are arranged one by one in a predetermined stacking pattern may be provided. That is, in FIG. 9 , the second cathode 140 is disposed at three-fold stacked positions according to the stacking order of the cathodes 120 . For example, the negative electrodes 120 of the electrode assembly 100 may be stacked in a manner in which two first negative electrodes 130 are first stacked and then one second negative electrode 140 is stacked. In particular, considering the design conditions and circumstances of the electrode assembly 100, the stacking pattern of the first negative electrode 130 and the second negative electrode 140 (eg, the first negative electrode 130 and the second negative electrode 140) is 3: 1 or 4:1 stacking pattern) can be appropriately determined.

Referring to FIG. 10, in the electrode assembly 100 of FIG. 10, the first negative electrode 130 is disposed on the lowermost and uppermost layers of the negative electrodes 120 of the electrode assembly 100, and the second negative electrode 140 is the electrode It may be provided with a structure in which all of the negative electrodes 120 of the assembly 100 are disposed on all other layers except for the lowermost and uppermost layers. That is, the first negative electrode 130 may be disposed on the lower layer and the upper layer of the electrode assembly 100, respectively, and the second negative electrode 140 may be continuously disposed between the lower layer and the upper layer of the electrode assembly 100. Therefore, in the electrode assembly 100 of FIG. 10 , a thermal runaway phenomenon can be more effectively prevented by forming a plurality of resistance spaces S inside the electrode assembly 100 when an abnormally high temperature occurs.

As described above, the embodiments of the present invention have been described with specific details such as specific components and limited embodiments and drawings, but these are provided only to help a more general understanding of the present invention, and the present invention is limited to the above embodiments. It is not, and those skilled in the art can make various modifications and variations from these descriptions. Therefore, the spirit of the present invention should not be limited to the described embodiments and should not be determined, and all things equivalent or equivalent to the claims as well as the following claims belong to the scope of the present invention.

100: electrode assembly for secondary battery
110: anode
112: positive current collector
114: cathode active material
120: cathode
130: first cathode
132: first negative current collector
134 negative electrode active material
140: second cathode
142: second negative electrode current collector
144: negative electrode active material
S: resistance space

Claims (10)

a plurality of cathodes disposed in a laminated structure; And an anode disposed between the cathodes, respectively,
The cathodes may include a first cathode whose shape does not change with a change in ambient temperature; and a second negative electrode whose shape changes according to a change in ambient temperature.
According to claim 1,
The second cathode,
When an abnormally high temperature of the secondary battery electrode assembly occurs, when the ambient temperature rises above a preset temperature, the second negative electrode is deformed in a direction away from the positive electrode stacked on either side of both sides of the second negative electrode, forming a resistance space between the positive electrode and the corresponding positive electrode. Electrode assembly for a secondary battery, characterized in that for generating.
According to claim 2,
The second cathode,
When the temperature of the secondary battery electrode assembly is restored to a normal temperature, the deformation of the second negative electrode is restored to an initial shape to remove the resistance space generated between the corresponding positive electrode and the secondary battery electrode assembly.
According to claim 3,
At least one of the negative electrodes serves as the second negative electrode, and the other of the negative electrodes serves as the first negative electrode,
At least one second negative electrode assembly for a secondary battery, characterized in that disposed in the middle layer of the positive electrodes along the stacking direction of the positive electrodes.
According to claim 4,
The second cathode is a secondary battery electrode assembly, characterized in that a pair is disposed symmetrically with each other with a single or a plurality of the cathode in the middle.
According to claim 2,
The positive electrode is provided with a structure in which a positive electrode active material is coated on the surface of a positive electrode current collector formed of one type of metal plate,
The first negative electrode has a structure in which a negative electrode active material is coated on the surface of a first negative electrode current collector formed of one type of metal plate,
The second negative electrode assembly for a secondary battery, characterized in that provided with a structure in which a negative electrode active material is coated on the surface of a second negative electrode current collector formed of a bimetal formed by overlapping two types of metal plates having different thermal expansion coefficients.
According to claim 6,
The positive electrode current collector is formed of a metal plate made of aluminum (Al), and the first negative electrode current collector is formed of a metal plate made of copper (Cu).
The second negative electrode current collector may include a non-expandable metal plate made of nickel (Ni) or iron (Fe) having a small coefficient of thermal expansion; and an expanded metal plate made of a copper (Cu) alloy material that is face-joined with the non-expandable metal plate and has a large coefficient of thermal expansion.
According to claim 7,
The second cathode,
An electrode assembly for a secondary battery, characterized in that the non-expandable metal plate is stacked in a direction facing the corresponding anode so as to generate a resistance space between the anode and the anode.
According to claim 2,
The set temperature is a secondary battery electrode assembly, characterized in that set to 40 ~ 60 ℃.
A secondary battery comprising an electrode assembly according to any one of claims 1 to 9.

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