KR20150106096A - Electrode Assembly Including Thermo-Regulating Member and Lithium Secondary Battery Comprising the Same - Google Patents

Abstract

The present invention relates to an electrode assembly including a thermo-regulating member and a lithium secondary battery comprising the same and, more particularly to an electrode assembly which may include: at least one first type unit cell having an electrode unit which includes a positive electrode, a negative electrode, and a membrane; and at least one second type unit cell having an electrode unit and a heat adjusting member where a phase change material (PCM) is sealed and accommodated in a pouch made of an inert material, wherein the first and second type unit cells have an alternatively arranged structure, being wound by a separation film, and the heat adjusting member is in contact with at least a part of the electrode unit of the first type unit cell.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode assembly including a thermally regulating member and a lithium secondary battery including the electrode assembly.

The present invention relates to an electrode assembly including a thermal control member and a lithium secondary battery including the electrode assembly.

One of the biggest problems with vehicles using fossil fuels such as gasoline and diesel is that it causes air pollution. As a solution to this problem, a technique of using a power source of a vehicle as a secondary battery capable of charging and discharging has attracted attention. Accordingly, an electric vehicle (EV) that can be operated only by a battery, and a hybrid electric vehicle (HEV) that uses a battery and an existing engine have been developed, and some of them have been commercialized. BACKGROUND ART [0002] Nickel metal hydride (Ni-MH) batteries are mainly used as secondary batteries as power sources for EV, HEV and the like, but recently lithium-ion batteries have also been used.

In order to use such a secondary battery as a power source for EV, HEV, etc., a high output large capacity is required. To this end, a plurality of small secondary cells (unit cells) are connected in series and / or in parallel to form a battery module, A plurality of battery packs are connected in parallel and / or in series to form one middle- or large-sized battery pack.

However, such a high-output large-capacity secondary battery has a problem that a large amount of heat is generated during charging and discharging. If the heat of the unit cell generated during the charging and discharging process can not be effectively removed, heat accumulation occurs, resulting in deterioration of the unit cell. Furthermore, there is a possibility that when some unit cells are overheated due to various causes in this process, they may ignite or explode. Therefore, a cooling system is indispensable in a medium-to large-sized battery pack having a high output and a large capacity.

Cooling of the middle- or large-sized battery pack is generally performed by convection heat transfer by the flow of the refrigerant. For example, a refrigerant-flow cooling system has been used in which a coolant such as air flows through a cooling fan between unit cells of a battery pack or between battery modules. However, this method has a problem that the temperature deviation between the unit cells is very large.

Separately, vehicles such as EVs, HEVs, and the like are often placed in situations that operate under harsh conditions. The optimal operating conditions of the unit cells constituting the battery pack may vary depending on various factors, but are generally determined within a specific temperature range. On the other hand, since the vehicle is operated at a low temperature in winter, it is necessary to adjust the battery pack to the optimum operating temperature range as described above. In this case, the operation of the cooling system may be stopped or the temperature of the refrigerant (e.g., air) flowing into the system may be increased to perform the temperature raising operation instead of the cooling. However, if the unit cell is placed in a very low temperature state before that, damage of the battery components may be caused, and deterioration may be accelerated by a sudden temperature rise operation.

As an attempt to solve such a problem, a method has been developed in which a flame retardant is incorporated in a part of a battery element or a curing of an electrolyte is performed at a certain temperature or more in order to prevent the explosion risk of the battery due to a rapid temperature rise . However, these methods can be used as methods for preventing the explosion when the battery is in an abnormal operating state, but it is not a technique for suppressing the temperature rise inside the battery in a normal operating state, and further, And it can not be used anymore.

Therefore, there is a high need for a technique capable of further improving the safety of a battery by suppressing a temperature rise inside the battery in a normal operating state, or by at least lowering the temperature rising rate, thereby prolonging the life of the battery and suppressing a rapid increase in temperature It is true.

On the other hand, there is known a technique of using a substance having a high latent heat for a specific purpose during phase change or phase transfer. For example, it is known that a material having a high latent heat is applied to a garment, a room interior, and the like, thereby inducing a gentle temperature change despite sudden external temperature conversion, thereby providing a more comfortable environment.

Some techniques for applying such characteristics to a battery are also known. For example, WO 03/061032 discloses a method of inserting a battery into a housing containing a substance with a high latent heat in order to prevent a sudden rise in the temperature of the battery as a power source in the medical instrument for implantation to prevent adverse effects on the human body, A method of coating the battery case in the form of a heat absorbing body outside the case has been proposed. However, this method can not effectively control the temperature between the electrode assemblies of the plurality of electrode assemblies, such as the stack-folding type electrode assemblies, or between the electrode assemblies within the unit cells.

Therefore, there is a high need for a technique that can fundamentally solve various problems.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

The inventors of the present application have conducted intensive research and various experiments, and as a result, it has been found that, as will be described later, a phase change material (PCM) is inserted into a pouch made of a material inert to the electrolyte, In the case where the electrode assembly is constituted by bringing at least one unit cell having the electrode portion into surface contact with at least a part of the other unit cells having the electrode portion, the temperature change of the battery due to the driving of the device is effectively suppressed, It is possible to suppress the rapid temperature rise inside the cell at the time of use, and it is possible to improve the life and safety of the battery. Thus, the present invention has been accomplished.

Accordingly, the electrode assembly according to the present invention comprises at least one first type unit cell having an electrode section including an anode, a cathode, and a separator, a pouch made of a material in which a phase change material (PCM) And at least one second type unit cell having a heat regulating member and an electrode portion sealed together in a sealed manner; Wherein the first type unit cell and the second type unit cell are laminated by being wrapped by a separation film and arranged alternately; And the heat regulating member is in surface contact with at least a part of the electrode portion of the first type unit cell.

At this time, the phase-change material is a material that undergoes phase transformation at a predetermined temperature. Specifically, the phase-change material is a material having a high latent heat at the time of phase conversion, in which phase conversion from a liquid phase or a liquid phase to a solid phase occurs. Here, the predetermined temperature at which the phase transformation occurs may range from 25 degrees Celsius to 120 degrees Celsius to a temperature ranging from a temperature close to the upper limit of the optimum operating temperature range of the battery to a temperature at which performance or lifetime of the battery may be lowered or safety may be threatened. And more specifically, may be 25 degrees to 50 degrees. This is because the temperature of the battery can be maintained at least the phase transformation temperature when the temperature at which the phase transformation occurs is within the above range.

That is, the phase-change material is in thermal contact with the electrode portions of the unit cells to be charged or discharged, thereby cooling the battery by absorbing at least a part of the heat generated from the unit cells, , At least a portion of the heat accumulated in the phase change material may be released to the unit cells to maintain the temperature of the cell at a constant level.

Therefore, the electrode assembly according to the present invention can easily control the temperature of each of the unit cells by the phase-change material of the thermal control member existing between the unit cells, and consequently, The overall temperature control of the pack can also be facilitated.

Furthermore, when the phase-change material absorbs the heat generated from the unit cells to become a liquid state, the second type unit cell including the heat regulating member and the electrode portion is located between the first type unit cells, Can damp the expansion and contraction of the electrode during the charging or discharging of the battery while the electrode unit can ensure the shape deformation or safety of the electrode assembly which may be caused by liquefaction of the phase change material Can play a supporting role.

In one specific example, the phase change material is not limited and may be a single compound, a mixture or a complex, and the phase transformation of these materials may be achieved by a combination of two or more materials Of the mixture is phase-transformed by a reversible physical or chemical reaction at the predetermined temperature.

Specifically, the phase change material may be at least one kind selected from the group consisting of organic PCM, inorganic PCM, and paraffin PCM.

The organic PCM may include, for example, alkane, pentaerythritol, polyethylene, acetamide, propylamide, naphthalene, stearic acid, polyglycol E6000, wax, 3-heptatecanone, Cyanamide, d-lactic acid, glycerol, acetic acid, ethylenediamine, and polyglycol E400. The inorganic PCM may be at least one selected from the group consisting of MgCl ₂ .6H ₂ O, Al ₂ SO _{4) 3} and _{10H 2 O, NH 4 Al (} SO 4) 2 and _{12H 2 O, KAl (SO 4} ) 2 and _{12H 2 O, Mg (SO 3} ) 2 and 6H ₂ O, SrBr ₂ and 6H ₂ O , Sr (OH) ₂ and _{8H 2 O, Ba (OH)} 2 and _{8H 2 O, Al (NO 3} ) 2 and _{9H 2 O, Fe (NO 3} ) 2 and _{6H 2 O, NaCH 2 S 2} O 2 and _{5H 2 O, Ni (NO 3} ) 2 and _{6H 2 O, Na 2 S 2} O 2 and 5H ₂ O, ZnSO ₄ and 7H ₂ O, CaBr ₂ and _{6H 2 O, Zn (NO 3} ) 2 and 6H ₂ O , Na ₂ HPO ₄揃 12H ₂ O, Na ₂ CO ₃揃 10H ₂ O, Na ₂ SO ₄揃 10H ₂ O, LiNO ₂揃 3H ₂ O, and CaCl ₂揃 6H ₂ O. And, wherein the paraffinic PCM, for _{example, C 12 H 26, C 14} H 30, C 16 H 34, C 18 H 38, C 19 H 40, C 20 H 42, C 21 H 44, C 22 H ₄₆ , C ₂₄ H ₅₀ , C ₂₆ H ₅₄ , C ₂₇ H ₅₆ , C ₂₈ H ₅₈ and C ₃₀ H ₆₂ .

The heat regulating member may further include a material having a high thermal conductivity in addition to the phase change material in order to enhance the thermal conductivity of the phase change material. The material having a high thermal conductivity may be at least one selected from the group consisting of, for example, a metal-based material, a carbon-based material, and a ceramic-based material, but is not limited thereto. Or in the form of a porous medium or a particulate form of a foam structure with no constant shape. Here, the granular form is not limited to rod-shaped, spherical, or the like.

The material having a high thermal conductivity may be included in an amount of 5 wt% to 50 wt% based on the total weight of the pouch interior. If the amount of the material having a high thermal conductivity is larger than the above range, the desired effect can not be effectively exhibited because the phase change material is relatively small. If the material having a high thermal conductivity is too small, the heat conduction is slow, And it takes a lot of time to discharge the battery. Therefore, there is a limit to the battery temperature control at a sudden temperature change of the battery, which is not preferable.

The material inert to the electrolyte of the pouch should be a material that the phase change material therein can be maintained in a sealed state even after the phase change. Such an inert material may be, for example, a polyolefin, a polystyrene, a polyacrylate, But are not limited to, one or more materials or copolymers selected from the group consisting of polyester, polycaprolactone, polyurethane, gelatin, chitosan, cellulose, melamine resin, urea resin and derivatives thereof. At this time, the thickness of the pouch is not limited to the extent that the conduction of heat according to the present invention is not disturbed, and it is preferably 0.01 micrometer to 5 micrometers in consideration of heat conduction and safety.

The first type unit cell and the second type unit cell configured as described above may be configured differently in size and shape. However, considering the safety of the unit cells and the ease of manufacture, the overall shape of the electrode assembly may be a rectangular parallelepiped or a cuboid The planar shape and the size are preferably the same

The heat regulating member may be included in a size of 10% to 50% based on the total volume of the second type unit cell so as to be in surface contact with at least a part of the electrode portion of the first type unit cell, The overall shape of the 2-inch unit cell can be variously configured in such a range that the heat adjusting member can easily perform thermal conduction with the electrode portion of the first-type unit cell and the electrode portion of the second-type unit cell.

In one example, the heat regulating member and the electrode portion in the second type unit cell may have the same thickness and have a plane arrangement with respect to the height of the electrode assembly.

At this time, although the position of the heat regulating member is not limited, in the case where the electrode assembly according to the present invention includes two or more second type unit cells, the first type unit cell is interposed between the adjacent second type unit cells The thermal conditioning members may be arranged in a non-overlapping position in the stacking direction.

That is, the heat regulating member of the second type unit cell located on the upper side of the first type unit cell is formed on the left side or the right side when viewed from a single first type unit cell, The heat regulating member of the second type unit cell located at the lower portion may be formed on the right side or the left side, and the heat regulating member may be formed in a zigzag configuration as a whole. This is to prevent the occurrence of tilting to one side when the heat regulating members are overlapped and positioned in the stacking direction when the phase change material of the heat regulating member is liquefied, thereby securing the safety of the electrode assembly.

In the case of such a configuration, as described above, when the phase-change material absorbs heat generated from the unit cells to be in a liquid state, the heat-regulating member causes shrinkage and expansion And the electrode unit can more effectively perform the function of supporting the shape deformation or the safety of the electrode assembly which may be caused by the liquefaction of the phase change material.

The heat regulating member may be disposed at the center of the second type unit cell in a plan view, and the electrode portions may be positioned on both sides of the heat regulating member. In another example, the second type unit cell may have a structure in which one or more depressions are formed on one side facing the first type unit cell, and a thermal conditioning member is mounted on the depressed portion. At this time, the position and the number of the depressed portion to which the heat regulating member is mounted are not limited, and the thermal conductivity of the unit cells with the electrode portion within the range of 10% to 50% based on the total volume of the second- It can be appropriately selected in consideration of safety.

With such a structure, there is no risk of separating the heat regulating member and the electrode portion that may occur during operation of the battery, and there is an effect that integration is easy.

In another example, the second type unit cell may have a structure in which a strip-shaped heat adjusting member surrounds the outer surface of the electrode portion.

In such configurations, the heat regulating member and the electrode portion of the second type unit cell may be mutually bonded to each other for integration, and the bonding may be performed by adhesion or heat fusion.

On the other hand, in the electrode unit of the first type unit cell or the second type unit cell, a bi-cell having a structure in which electrodes of the same polarity are located at both ends of the unit cells, or a pool of structures in which electrodes of other polarity are located at both ends of the unit cells Cell.

The bi-cell is, for example, a cell made of a positive electrode-separator-negative electrode-separator-positive electrode or a negative electrode-separator-positive electrode-separator-negative electrode and the pull cell is a cell made of, for example, a positive electrode-separator-negative electrode.

The electrode unit may be formed only of bi-cells or may be formed of only a full cell, or a bi-cell and a pull cell may be used together. In this case, the arrangement of the unit cells must be such that the positive electrode and the negative electrode are alternately arranged in the electrode assembly after winding.

The present invention also provides a method of manufacturing the electrode assembly,

(i) preparing a first type unit cell and a second type unit cell;

(ii) arranging the first type unit cell and the second type unit cell on a sheet-like separation film for a day; And

(iii) winding a separation film on which the first type unit cells and the second type unit cells are arranged to form a laminated structure;

And a control unit.

The present invention also provides a lithium secondary battery in which the electrode assembly is embedded in a battery case together with a non-aqueous electrolyte, and the lithium secondary battery is included as a unit cell.

The battery pack can be used as a power source for a device requiring high temperature stability, long cycle characteristics and high rate characteristics. Examples of the device include Electric Vehicle (EV), Hybrid Electric Vehicle (HEV) , A plug-in hybrid electric vehicle (PHEV), or a system for power storage. However, the present invention is not limited thereto.

As described above, the electrode assembly according to the present invention is characterized in that the phase change material (PCM) is made of one or more materials having a heat regulating member sealed in a pouch made of a material inert to the electrolyte, The unit cell is configured to be in surface contact with at least a part of other unit cells having the electrode portion, thereby absorbing heat when the temperature rises during normal or abnormal operation of the battery as the device is driven, Not only the internal temperature can be properly maintained but also the phase change material of the heat adjusting member flows into the cell at the time of penetration through the needle bed to suppress the reaction inside the cell to suppress the rapid increase in temperature, Can be improved.

When the phase change material absorbs the heat generated by the unit cells and is in a liquid state, the unit cells including the heat regulating member and the electrode portion are positioned between the other unit cells having the electrode portion, The electrode part plays a role of damping the contraction and expansion of the electrode during the charging or discharging of the battery while the electrode part supports the shape deformation or safety of the electrode assembly which may be caused by liquefaction of the phase change material So that the safety of the battery can be further improved.

1 is a schematic view showing a configuration of a first type unit cell according to one embodiment of the present invention;
2 is a schematic view showing a form of a second type unit cell according to one embodiment of the present invention;
3 is a schematic view showing a method of manufacturing an electrode assembly by arranging first type unit cells and second type unit cells of FIGS. 1 and 2 on a separation film according to one embodiment of the present invention;
Fig. 4 is a schematic view of an electrode assembly after winding Fig. 3; Fig.
5 is a schematic view showing a method of manufacturing an electrode assembly by arranging first type unit cells and second type unit cells of FIGS. 1 and 2 on a separation film according to another embodiment of the present invention;
Fig. 6 is a schematic view of an electrode assembly after winding Fig. 5; Fig.
7 is a schematic view showing a form of a second type unit cell according to another embodiment of the present invention;
8 is a schematic view showing a configuration of a second type unit cell according to another embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings according to the embodiments of the present invention, but the scope of the present invention is not limited thereto.

1 and 2 show an internal view of the first type unit cells 110 and 210 and the second type unit cells 120 and 220 according to one embodiment of the electrode assembly of the present invention Side view in a cut-away form) is schematically shown

Referring to FIG. 1, a first type unit cell (a) 110 comprising a negative electrode disposed at both ends and an electrode portion 111 having a positive electrode positioned at the center and a separator between the positive electrode and the negative electrode, And a first type unit cell (b) 210 composed of an electrode part 211 located at the center of the cathode and having a separation membrane between the anode and the cathode is shown as an example.

2 shows a state in which a phase regulating member 122 in which a phase change material 123 is embedded in a pouch 124 made of a material inert to an electrolyte and a heat regulating member 122 in which a positive electrode is located at both ends and a negative electrode is located in the middle, A second type unit cell (a) 120 having an electrode part 121 in which a separator is disposed and a heat control part 223 sealed and built in a pouch 224 made of a material in which the phase change material 223 is inert to the electrolyte And a second type unit cell (b) 220 having a member 222 and an electrode part 221 having the anode at both ends and the cathode at the center and the separator 221 between the anode and the cathode, are shown as examples.

At this time, the heat adjusting members 122 and 222 have a size of 10 to 50% of the total volume in each of the second type unit cells 120 and 220, and the heat adjusting members 122 and 222 have the same thickness as the electrode parts 121 and 221 Type unit cells in a planar arrangement with the electrode portions 121 and 221. [

3, a plurality of first type unit cells (a) 110 of FIG. 1 and a plurality of second type unit cells (a) 120 of FIG. 2 are arranged on a separation film according to one embodiment of the present invention A method of manufacturing the electrode assembly 100 is schematically shown.

Referring to FIG. 3 together with FIGS. 1 and 2, the electrode assembly 100 includes three first type unit cells (a) 110 and two second type cell units (a) ), And winding the separation film 150 (152).

Specifically, the first type unit cells (a) 110 (110) are arranged on the separation film 150 so that the first type unit cells (a) 110 are positioned at the innermost side with reference to the side near the starting point of the winding 152 The second type unit cell (a) 120, the second type unit cell (a) 120, the first type unit cell (a) 110, the first type unit cell (a) , And winding 152 in a counterclockwise direction. In this case, the second type unit cell (a) 120 is formed by winding the second type unit cell (a) 120 and the third type second unit cell (a) 120 such that the heat regulating member 122 is not positioned in the same direction after being wound, (a) 120 are arranged in the same form.

Here, a plurality of first type unit cells (a) 110 and second type unit cells (a) 120 are named by attaching first, second, and so on to the nearest starting point of the winding 152.

A spacing portion 151 corresponding to the size of the unit cell is formed between the first type 1 unit cell (a) 110 and the second type 2 unit cell (a) 120, (A) 110 is wound together with the separation film 150, the cathode 112 located on the upper surface of the first type 1 unit cell (a) 110 and the cathode 112 located on the third type unit cell (a) 110 and the second type unit cell (a) 120, which are located on the lower face of the first type unit cell (a) 110 and between the anode 126 located on the upper face of the first type unit cell And a separation film 150 is interposed between the anode 125 located on the upper surface.

Specifically, the first type 1 unit cell (a) 110 is arranged between the first type 1 unit cell (a) 110 and the second type 2 unit cell (a) 120 in an inverted state in the winding process The negative electrode 111 located on the lower surface of the first type unit cell (a) 110 is moved to the separating portion 151 and the negative electrode 111 positioned on the lower surface of the first type unit cell (a) (125) and the separation film (150). The first type unit cell (a) 110 and the second type unit cell (a) 120, which face each other with the separation film 150 therebetween, are simultaneously wound by the separation film 150 The cathode 112 located on the upper surface of the first type 1 unit cell (a) 110 is electrically connected to the anode 126 located on the upper surface of the third type 2 unit cell (a) 150 facing each other.

The process progresses sequentially to the fifth type 1 unit cell (a) 110, whereby the first type unit cell (a) 110 is located at the innermost and outermost sides, and the second type unit cell Type unit cell (a) 120 are respectively positioned.

The structure of the electrode assembly 100 manufactured according to the above manufacturing method is schematically shown in Fig.

Referring to FIG. 4 together with FIGS. 1 and 2, the electrode assembly 100 manufactured by the manufacturing method of FIG. 3 includes the first type unit cell (a) 110 at the innermost and outermost sides . The thermal adjustment member 122 of the second type unit cell (a) 120 having a structure located between the first type unit cell (a) 110 and the second type unit cell (a) 120 is overlapped in the stacking direction of the electrode assembly 100 .

5 shows a first type unit cell (b) 210 of FIG. 1 and a plurality of second type unit cells (b) 220 of FIG. 2 on a separation film according to another embodiment of the present invention And a method of manufacturing the electrode assembly 200 is schematically shown.

5, the electrode assembly 200 includes four first type unit cells b 210 and three second type unit cells b 220, Are arranged on the separation film (250) in an alternating manner, and the separation film (250) is wound (252).

Specifically, the second type unit cell (b) 220 (220) is disposed on the separation film 150 so that the second type unit cell (b) 220 is positioned at the innermost side with respect to the side near the starting point of the winding 152 Type first unit cell (b) 210 → first type unit cell (b) 210 → second type unit cell (b) 220 → second type unit cell (b) 220 → The first type unit cell (b) 210, the first type unit cell (b) 210, and the first type unit cell (b) 210 are wound in a counterclockwise direction (252). At this time, the second type unit cell (b) 220 and the fourth type second unit cell (b) 220 are arranged such that the heat regulating member 222 after winding is not positioned in the same direction after the winding, The unit cells (b) 220 are arranged in the same shape, and the first type 2 unit cells (b) 220 are arranged differently from them.

The plurality of first type unit cells b 210 and the second type unit cells b 220 are named by attaching the first, second, and so on to the nearest starting point of the winding 252.

3, a spacing portion 251 corresponding to the size of the unit cell is formed between the first type II unit cell (b) 220 and the second type 1 unit cell (b) 210 The negative electrode 226 located on the upper surface of the first type II unit cell b 220 in the process of winding the first type II unit cell b 220 together with the separation film 250, A cathode 225 positioned between the anode 212 located on the upper surface of the third type 1 unit cell b 210 and the lower surface of the first type 2 unit cell b 220, (b) 210, the separation film 250 is interposed between the positive electrode 211 and the positive electrode 211.

Specifically, the first type II unit cell (b) is separated from the first type unit cell (b) by a distance 251 between the first type II unit cell (b) and the second type 1 unit cell (b) And then the cathode 225 located on the lower surface of the first type II unit cell b is separated from the anode 211 and the separation film 250 located on the upper surface of the second type 1 unit cell b, So as to face each other. The first type 2 unit cell (b) 220 and the second type 1 unit cell (b) 210 facing each other with the separation film 250 therebetween are simultaneously wound by the separation film 250 The negative electrode 226 located on the upper surface of the first type 2 unit cell b 220 is electrically connected to the positive electrode 212 located on the upper side of the third type 1 unit cell b 210, 250 facing each other.

The process progresses sequentially to the seventh first type unit cell (b) 210, so that the second type unit cell (b) 220 is located on the innermost side and the second type unit cell (b) 210 are positioned on the electrode assembly 100 is completed.

The structure of the electrode assembly 200 manufactured according to the above manufacturing method is schematically shown in Fig.

Referring to FIG. 6 together with FIGS. 1 and 2, the electrode assembly 200 manufactured by the manufacturing method of FIG. 5 is composed of the innermost and middle type unit cells (b) 220, The outermost and middle portions are composed of a first type unit cell (b) 210. The thermal regulating members 222 of the second type unit cells b and 220 having the structures located between the first type unit cells b and 210 are stacked in the stacking direction of the electrode assembly 200 .

The electrode assemblies 100 and 200 having such a structure are arranged such that the second type unit cells having the heat regulating member and the electrode portion together are located between the first type unit cells having the electrode portions, Absorbing the heat when the temperature rises during the normal or abnormal operation and releasing the heat when the temperature is lowered to maintain the internal temperature of the battery properly, thereby improving the life and safety of the battery. In addition, when the phase change material absorbs heat generated from the unit cells to become a liquid state, the heat regulating member of the second type unit cell damps the contraction and expansion of the electrode during charging or discharging of the battery The electrode unit can play a role in securing the shape deformation or safety of the electrode assembly, which may be caused by the liquefaction of the phase change material, and thus the safety of the battery can be further improved. Furthermore, as shown in FIGS. 4 and 6, when the outermost unit cells are composed of the first type unit cells constituted by the electrode portions, the safety can be further enhanced.

7 and 8 are schematic diagrams of second type unit cells according to still another embodiment.

7 shows a state in which the phase regulating member 132 in which the phase change material 133 is embedded in the pouch 134 made of a material inert to the electrolyte and the anode are positioned at both ends and the cathode is positioned at the center, (A) (a side view in a vertically cut shape of the electrode) and a plan view (b) of a second type unit cell 130 having an electrode portion 131 in which a separation membrane is located.

2, the second type unit cell 130 has a structure in which the thermal regulating member 132 is mounted on the indented portion of the electrode portion 131 facing the first type unit cell (not shown) Lt; / RTI >

8 shows a state in which the phase regulating member 142 in which the phase change material 143 is embedded in the pouch 144 made of a material inert to the electrolyte and the anode are located at both ends and the cathode is positioned at the center, (A) (a side view in the form of vertically cutting the electrode) and a plan view (b) of the second type unit cell 140 having the electrode portion 141 where the separation membrane is located.

2 and 7, the second type unit cell 140 has a structure in which the heat regulating member 142 has a strip shape and surrounds the outer surface of the electrode unit 141 .

While the present invention has been described with reference to the drawings, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (30)

A heat regulating member encapsulated in a pouch made of a material in which a phase change material (PCM) is inactive to an electrolyte, and an electrode And at least one second type unit cell having a first portion and a second portion together;
Wherein the first type unit cell and the second type unit cell are laminated by being wrapped by a separation film and arranged alternately;
Wherein the heat regulating member is in surface contact with at least a part of the electrode portion of the first type unit cell. The electrode assembly according to claim 1, wherein the phase-change material is a material having a high latent heat at the time of phase transformation at a predetermined temperature. 3. The electrode assembly of claim 2, wherein the temperature is between about 25 degrees and about 120 degrees. 4. The electrode assembly of claim 3, wherein the temperature is between about 25 degrees and about 50 degrees. The method of claim 1 wherein the phase change material is in thermal contact with the electrode portions of the unit cells being charged or discharged to absorb at least a portion of the heat generated from the unit cells or to transfer at least some of the heat accumulated in the phase- To the electrode assembly. The electrode assembly according to claim 1, wherein the phase change material is at least one selected from the group consisting of organic PCM, inorganic PCM, and paraffin PCM. The organic-based PCM of claim 6, wherein the organic PCM is selected from the group consisting of alkane having 11 to 50 carbon atoms, pentaerythritol, polyethylene, acetamide, propylamide, naphthalene, stearic acid, polyglycol E6000, wax, 3-heptatecanone, Amide, d-lactic acid, glycerol, acetic acid, ethylenediamine, and polyglycol E400. 7. The method of claim 6 wherein the inorganic material-based PCM is MgCl ₂ and _{6H 2 O, Al 2 (SO} 4) 3 and _{10H 2 O, NH 4 Al (} SO 4) 2 and _{12H 2 O, KAl (SO 4} ) 2 and _{12H 2 O, Mg (SO 3} ) 2 and 6H ₂ O, SrBr ₂ and _{6H 2 O, Sr (OH)} 2 and _{8H 2 O, Ba (OH)} 2 and _{8H 2 O, Al (NO 3} ) 2 and 9H _{2 O, Fe (NO 3)} 2 and _{6H 2 O, NaCH 2 S 2} O 2 and _{5H 2 O, Ni (NO 3} ) 2 and _{6H 2 O, Na 2 S 2} O 2 and 5H ₂ O, ZnSO ₄ and 7H ₂ O, CaBr ₂揃 6H ₂ O, Zn (NO ₃ ) ₂揃 6H ₂ O, Na ₂ HPO ₄揃 12H ₂ O, Na ₂ CO ₃揃 10H ₂ O, Na ₂ SO ₄揃 10H ₂ O, LiNO ₂ · 3H jong electrode assembly 1, characterized in that at least selected from ₂ O, and CaCl ₂ · 6H ₂ O the group consisting of. The paraffinic PCM of claim 6, wherein the paraffinic PCM is selected from the group consisting of C ₁₂ H ₂₆ , C ₁₄ H ₃₀ , C ₁₆ H ₃₄ , C ₁₈ H ₃₈ , C ₁₉ H ₄₀ , C ₂₀ H ₄₂ , C ₂₁ H ₄₄ , C ₂₂ H ₄₆ , At least one selected from the group consisting of C ₂₄ H ₅₀ , C ₂₆ H ₅₄ , C ₂₇ H ₅₆ , C ₂₈ H ₅₈ and C ₃₀ H ₆₂ . The electrode assembly according to claim 1, wherein the heat adjusting member further includes a material having a high thermal conductivity in addition to the phase change material. 11. The electrode assembly according to claim 10, wherein the material having a high thermal conductivity is at least one selected from the group consisting of a metal-based material, a carbon-based material, and a ceramic-based material. 11. The electrode assembly of claim 10, wherein the material having a high thermal conductivity is contained in the form of a porous medium or in a granular form. 13. The electrode assembly of claim 12, wherein the porous medium is a channel structure, a net structure, a honeycomb structure, or a foam structure having no uniform shape. 11. The electrode assembly of claim 10, wherein the high thermal conductivity material comprises from 5% to 50% by weight based on the total weight of the interior of the pouch. The method according to claim 1, wherein the material inert to the electrolyte is selected from the group consisting of polyolefin, polystyrene, polyacrylate, polyamide, polyester, polycaprolactone, polyurethane, gelatin, chitosan, cellulose, melamine resin, urea resin and derivatives thereof ≪ RTI ID = 0.0 > and / or < / RTI > The electrode assembly according to claim 1, wherein the first type unit cell and the second type unit cell have the same plan shape and size. 2. The electrode assembly of claim 1, wherein the thermal control member is comprised between 10% and 50% of the total volume of the second type unit cell. 2. The electrode assembly according to claim 1, wherein the heat regulating member and the electrode unit in the second type unit cell have the same thickness and are arranged in a plane with respect to the height of the electrode assembly. 19. The method according to claim 18, wherein the electrode assembly includes at least two second type unit cells, and the thermal regulating members in the second type unit cells adjacent to each other with the first type unit cell interposed therebetween overlap And wherein the electrode assembly is arranged in a non-position. 19. The electrode assembly of claim 18, wherein the heat regulating member is located at the center of the second type unit cell in a plan view, and the electrode portions are positioned on both sides of the heat regulating member. The electrode assembly according to claim 1, wherein the heat regulating member and the electrode unit are bonded to each other in the second type unit cell. 22. The electrode assembly of claim 21, wherein the bond is adhesive or heat fusion. The electrode assembly according to claim 1, wherein the second type unit cell has a structure in which at least one depressed portion is formed on one side facing the first type unit cell, and a thermal regulation member is mounted on the depressed portion. . The electrode assembly according to claim 1, wherein the second type unit cell has a structure in which a strip-shaped heat adjusting member surrounds the outer surface of the electrode part. The electrode assembly of claim 1, wherein the electrode unit is a bipolar cell having electrodes of the same polarity positioned at both ends of the unit cells, or a pull cell having a structure in which electrodes of different polarity are located at both ends of the unit cells. A method of manufacturing an electrode assembly according to claim 1,
(i) preparing a first type unit cell and a second type unit cell;
(ii) arranging the first type unit cell and the second type unit cell on a sheet-like separation film for a day; And
(iii) winding a separation film on which the first type unit cells and the second type unit cells are arranged to form a laminated structure;
Wherein the electrode assembly includes a first electrode and a second electrode. The lithium secondary battery according to any one of claims 1 to 25, wherein the electrode assembly is embedded in the battery case together with the non-aqueous electrolyte. 27. A battery pack comprising the lithium secondary battery according to claim 27 as a unit cell. 29. A device comprising a battery pack according to claim 28. 30. The system of claim 29, wherein the device is an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV) ≪ / RTI >

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