KR20150047874A - Electrochemical device including a porous protective material formed junction part between a electrode tap and a electrode lead - Google Patents

Abstract

The present invention relates to an electrochemical device including a porous protective material formed in a junction part between an electrode tab and an electrode lead, the device comprising: an electrode assembly which includes a positive electrode including a protruding positive electrode tab, a negative electrode including a protruding negative electrode tab, and a separator interposed between the positive and negative electrodes; a positive electrode lead which has one end bonded to the positive electrode tab; a negative electrode lead which has one end bonded to the negative electrode tab; a battery case which accommodates the electrode assembly inside so that the other end of the positive electrode lead and the other end of the negative electrode lead are exposed to the outside; a non-aqueous electrolyte which impregnates the electrode assembly, and is injected to the battery case; and a porous protective material which is attached to at least one from a first bonding part in which the positive electrode tab and the positive lead are bonded, and a second bonding part in which the negative electrode tab and the negative lead are bonded, wherein the first bonding part and the second bonding part are accommodated inside the battery case. According to the present invention, the porous protective material is attached to the bonding part between the electrode tab and the electrode lead, and thus the battery case is protected by a concave-convex structure formed in the bonding part. The porous protective material absorbs the electrolyte, and an injection amount of the electrolyte to the inside of the cell is increased, thereby enhancing lifespan of the electrochemical device.

Description

[0001] The present invention relates to an electrochemical device including a porous protective material formed at a junction of an electrode tab and an electrode lead,

The present invention relates to an electrochemical device including a porous protective material formed on a joint portion between an electrode tab and an electrode lead, and more particularly, to an electrochemical device including a porous protective material formed on a surface of the electrode tab, To an electrochemical device having an improved lifetime by increasing the amount of electrolyte injected.

Recently, interest in energy storage technology is increasing. As the application fields of cell phones, camcorders, notebook PCs and even electric vehicles are expanding, efforts for research and development of electrochemical devices are becoming more and more specified. The electrochemical device has received the most attention in this respect. Of these, the development of a rechargeable secondary battery has become a focus of attention. Recently, in developing such a battery, Research and development on the design of electrodes and batteries are underway.

Among the currently applied secondary batteries, the lithium secondary battery developed in the early 1990s has advantages such as higher operating voltage and higher energy density than conventional batteries such as Ni-MH, Ni-Cd and sulfuric acid-lead batteries using an aqueous electrolyte solution .

Typically, in terms of the shape of an electrochemical device, there is a high demand for a prismatic secondary battery and a pouch-type secondary battery that can be applied to products such as mobile phones with a thin thickness, and a lithium ion battery having high energy density, discharge voltage, There is a high demand for lithium secondary batteries such as batteries, lithium ion polymer batteries and the like.

1 is a cross-sectional view showing an electrochemical device in which a conventional electrode tab and an electrode lead are connected to each other.

Referring to FIG. 1, the coupling structure between the electrode tabs and the electrode leads of the electrochemical device 10 can be confirmed. For example, the positive electrode tabs protruded from the anode 121 are in close contact with one another and are connected to the positive electrode lead 131. The positive electrode lead 131 is generally joined to the positive electrode tab by welding, and may be positioned on the upper side of the uppermost positive electrode tab or on the lower side of the lowermost positive electrode tab.

On the other hand, since the concavo-convex structure of the joint portion formed by welding the electrode lead and the electrode tab can come into contact with and damage the pouch-shaped battery case, it is possible to protect the pouch- have.

However, when the pressure is externally applied, there is still a problem that the concavoconvex structure may damage the pouch-shaped battery case by penetrating the protective tape.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an electrochemical device capable of protecting a battery case from a concavo-convex structure formed at a junction portion of an electrode tab and an electrode lead.

It is another object of the present invention to provide an electrochemical device having an improved lifetime by increasing the amount of electrolyte injected into a cell.

According to an aspect of the present invention, there is provided an electrode assembly including an anode including a protruded anode tab, a cathode including a protruded anode tab, and a separator interposed between the anode and the cathode; A positive electrode lead having one end bonded to the positive electrode tab; A negative electrode lead having one end joined to the negative electrode tab; A battery case accommodating the electrode assembly inside the other end of the positive electrode lead and the other end of the negative electrode lead exposed to the outside; A nonaqueous electrolyte solution impregnated with the electrode assembly and injected into the battery case; And a porous protective member attached to at least one of a bonding portion of the positive electrode tab and the positive electrode lead and a bonding portion of the negative electrode tab and the second electrode bonding portion, And the second junction is received inside the battery case.

Here, the thickness of the porous protective material may be 100 占 퐉 or more.

The porous protective material may be a polymer, or a mixture of an inorganic material and a polymeric binder.

The polymer may be at least one selected from the group consisting of polyethylene, polypropylene, polyethyleneterephthalate, polyvinylalcohol, polystyrene, polyimide, and polyvinylidene fluoride fluoride), or a mixture of two or more thereof.

The inorganic material may be any one selected from the group consisting of titanium dioxide, silicon dioxide, aluminum oxide and barium titanate, or a mixture of two or more thereof.

The polymer binder may be at least one selected from the group consisting of polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-co- hexafluoro propylene, polyvinylidene fluoride-co-trichlorethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, But are not limited to, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, , Cellulose acetate butyrate (cellulose acetate butyrate), cellulose acetate phthalate But are not limited to, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, One selected from the group consisting of carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer, and polyimide. Or a mixture of two or more of them.

The porous protective member may have a membrane structure, a fibrous structure, or a foam structure.

The first joint portion and the second joint portion may be formed by welding, and the welding may be any one selected from the group consisting of ultrasonic welding, resistance welding, and laser welding, or two or more thereof .

At least one of the positive electrode tab, the negative electrode tab, the positive electrode lead, and the negative electrode lead may be formed of any one selected from the group consisting of aluminum, copper, nickel, and silver, or a mixture of two or more thereof.

The positive electrode may include a positive electrode active material containing a lithium-containing oxide, and the lithium-containing oxide may be a lithium-containing transition metal oxide.

At this time, the lithium-containing transition metal _{oxides, Li x CoO 2 (0.5 <} x <1.3), Li x NiO 2 (0.5 <x <1.3), Li x MnO 2 (0.5 <x <1.3), Li x Mn 2 _{O 4 (0.5 <x <1.3} ), Li x (Ni a Co b Mn c) O 2 (0.5 <x <1.3, 0 <a <1, 0 <b <1, 0 <c <1, a + b + c = 1), Li _x Ni _{1 -y} Co _y O ₂ (0.5 <x <1.3, 0 <y <1), Li _x Co _{1 -y} Mn _y O _{2 <1), Li x Ni 1} -y Mn y O 2 (0.5 <x <1.3, O≤y <1), Li x (Ni a Co b Mn c) O 4 (0.5 <x <1.3, 0 <a <2, 0 <b <2 , 0 <c <2, a + b + c = 2), Li x Mn 2 -z Ni z O 4 (0.5 <x <1.3, 0 <z <2), Li x Selected from the group consisting of Mn _{2 -z} Co _z O ₄ (0.5 <x <1.3, 0 <z <2), Li _x CoPO ₄ (0.5 <x <1.3) and Li _x FePO ₄ Or a mixture of two or more thereof.

The negative electrode may include a negative electrode active material containing lithium metal, a carbon material, a metal compound, or a mixture thereof.

The metal compound may be at least one selected from the group consisting of Si, Ge, Sn, Pb, P, Sb, Bi, Al, Ga, In, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ag, Or a mixture of two or more thereof.

Meanwhile, the battery case may be a pouch type.

The electrochemical device may be a lithium secondary battery.

According to the present invention, by attaching the porous protective material to the joint portion of the electrode tab and the electrode lead, it is possible to protect the battery case from being damaged by the concavo-convex structure formed in the joint portion.

Furthermore, the life of the electrochemical device can be improved by increasing the amount of the electrolyte injected into the cell by absorbing the electrolyte solution.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given above, serve to further the understanding of the technical idea of the invention, It should not be construed as limited.
1 is a cross-sectional view schematically showing an electrochemical device to which a conventional electrode tab and an electrode lead are connected.
FIG. 2 is a cross-sectional view schematically showing an electrochemical device including a porous protection material formed at a junction between an electrode tab and an electrode lead according to an embodiment of the present invention.
3 is a schematic view illustrating an electrode assembly including a porous protection member formed at a junction between an electrode tab and an electrode lead according to an embodiment of the present invention.
4 is a graph showing that the capacity degradation rate is decreased when the amount of electrolyte injected into the cell of the electrochemical device is increased.

Hereinafter, the present invention will be described in detail with reference to the drawings. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

In addition, since the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention, It is to be understood that equivalents and modifications are possible.

FIG. 2 is a cross-sectional view schematically showing an electrochemical device including a porous protection member formed by attaching to an electrode tab and an electrode tab according to an embodiment of the present invention. FIG. 3 is a cross- And a porous protection member formed by adhering to a bonding portion between the electrode lead and the electrode lead.

2 and 3, an electrochemical device 100 according to the present invention includes a positive electrode 121 including a protruded positive electrode tab, a negative electrode 122 including a protruded negative electrode tab, And a separator (123) interposed between the cathode (122) and the electrode assembly (120); A positive electrode lead (131) having one end joined to the positive electrode tab; A negative electrode lead (132) having one end joined to the negative electrode tab; A battery case 110 accommodating the electrode assembly 120 inside the other end of the positive electrode lead 131 and the other end of the negative electrode lead 132 exposed to the outside; A nonaqueous electrolyte solution impregnated with the electrode assembly 120 and injected into the battery case 110; And a second joint portion (142) to which the negative electrode tab and the negative electrode lead (132) are joined, the first joint portion (141) to which the positive electrode tab and the positive electrode lead (131) The first joint 141 and the second joint 142 are accommodated in the battery case 110. The first joint 141 and the second joint 142,

As described above, since the concavo-convex structure of the joint portion formed by welding the electrode lead and the electrode tab can damage the pouch-shaped battery case, it is possible to protect the pouch-shaped battery case by attaching a protective tape having a thickness of several tens of 탆 However, when pressure is externally applied, the protruding and contracting structure may break the protective tape and damage the pouch-shaped battery case.

Accordingly, the present invention includes a porous protective member attached to the joint portion to protect the battery case from damage from the concavo-convex structure of the joint portion. At this time, the porous protective member may be attached only to a portion corresponding to the concavo-convex structure formed on the joining portion, but may be attached to surround all portions of the joining portion.

Meanwhile, the connection portion may not be sufficiently supplied with the nonaqueous electrolyte due to various factors such as the position of the inside of the battery case. However, as in the present invention, the porous protective member attached to the connection portion may be a non- Thereby increasing the amount of electrolyte injected into the cell, thereby improving the lifetime of the electrochemical device.

4 is a graph showing that the capacity degradation rate of the electrochemical device is lowered when the amount of electrolyte injected into the cell of the electrochemical device is increased. Referring to this, when the amount of the electrolyte injected is increased by about 6% by weight, the lifetime improvement effect is about 10%.

The thickness of the porous protective material 150 may be 100 μm or more. If the thickness of the porous protective material 150 is equal to or greater than the thickness of the porous protective material 150, the concavo-convex structure formed on the bonded portion may be difficult to penetrate through the porous protective material, It is possible to further prevent the case from being damaged.

At this time, the porous protective material 150 may be composed of a polymer, or a mixture of an inorganic material and a polymeric binder.

The polymer may be at least one selected from the group consisting of polyethylene, polypropylene, polyethyleneterephthalate, polyvinylalcohol, polystyrene, polyimide, and polyvinylidene fluoride fluoride), or a mixture of two or more thereof.

The inorganic material may be any one selected from the group consisting of titanium dioxide, silicon dioxide, aluminum oxide, and barium titanate, or a mixture of two or more thereof. The polymeric binder may include polyvinylidene fluoride, (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride -co-trichlorethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, ethylene Polyethylene-co-vinyl acetate, polyethylene oxide, ene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanohexanoate, But are not limited to, ethyl polyvinyl alcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, styrene-butadiene rubber, Acrylonitrile-styrene-butadiene copolymer, and polyimide, or a mixture of two or more thereof.

The porous protective material 150 may be formed of a membrane structure, a fibrous structure such as a woven structure or a nonwoven structure, a foam structure or a tape coated with an inorganic material, or the like, if it has a structure including a plurality of pores, .

The first joint portion 141 and the second joint portion 142 may be formed by welding, and the welding may be performed by any one selected from the group consisting of ultrasonic welding, resistance welding, and laser welding Or two or more of them.

At least one of the positive electrode tab, the negative electrode tab, the positive electrode lead 131 and the negative electrode lead 132 may be any one selected from the group consisting of aluminum, copper, nickel, and silver, or a mixture of two or more thereof &Lt; / RTI &gt;

On the other hand, the anode 121 may be composed of a cathode current collector and a cathode active material layer coated on one side or both sides thereof. Here, as a non-limiting example of the positive electrode current collector, there is a foil manufactured by aluminum, nickel, or a combination thereof, and the positive electrode active material layer may include a positive electrode active material, a conductive material, and a binder.

The cathode active material may include a lithium-containing oxide, and a lithium-containing transition metal oxide may be preferably used. For _{example, Li x CoO 2 (0.5 <} x <1.3), Li x NiO 2 (0.5 <x <1.3), Li x MnO 2 (0.5 <x <1.3), Li x Mn 2 O 4 (0.5 <x 1, 0 <c <1, a + b + c = 1), Li _x (Ni _a Co _b Mn _c ) O _{2 Li x Ni 1 -y Co y O} 2 (0.5 <x <1.3, 0 <y <1), Li x Co 1 -y Mn y O 2 (0.5 <x <1.3, 0≤y <1), Li x Ni _{1 -y} Mn _y O ₂ (0.5 <x <1.3, 0≤y <1), Li _x (Ni _a Co _b Mn _c ) O ₄ (0.5 <x <1.3, 0 <a <2, 0 <b <2, 0 <c <2 , a + b + c = 2), Li x Mn 2 -z Ni z O 4 (0.5 <x <1.3, 0 <z <2), Li x Mn 2 -z Co z _{O 4 (0.5 <x <1.3} , 0 <z <2), Li x CoPO 4 (0.5 <x <1.3) , and any one thereof is selected from the group consisting of _{Li x FePO 4 (0.5 <x} <1.3) of The lithium-containing transition metal oxide may be coated with a metal such as aluminum (Al) or a metal oxide. In addition to the lithium-containing transition metal oxide, sulfide, selenide and halide may also be used.

The conductive material is not particularly limited as long as it is an electron conductive material that does not cause a chemical change in an electrochemical device. In general, carbon black, graphite, carbon fiber, carbon nanotube, metal powder, conductive metal oxide, organic conductive material and the like can be used. Commercially available products as the conductive material include acetylene black series (manufactured by Chevron Chemical Co., (Chevron Chemical Company or Gulf Oil Company products), Ketjen Black EC series (Armak Company), Vulcan XC-72 (Cabot Company) and Super P (MM (MMM)). For example, acetylene black, carbon black and graphite.

Meanwhile, the cathode 122 may be composed of a negative electrode collector and a negative electrode active material layer coated on one side or both sides thereof. Examples of the negative electrode current collector include a foil made of copper, gold, nickel, or a copper alloy or a combination thereof, and the negative electrode active material layer may include a negative electrode active material, a conductive material, and a binder.

As the negative electrode active material, a lithium metal, a carbon material, a metal compound, or a mixture thereof may be used.

Concretely, as the carbon material, both low-crystalline carbon and highly-crystalline carbon may be used. Examples of the low crystalline carbon include soft carbon and hard carbon. Examples of highly crystalline carbon include natural graphite, Kish graphite, pyrolytic carbon, liquid crystal pitch carbon fiber high temperature sintered carbon such as mesophase pitch based carbon fiber, meso-carbon microbeads, mesophase pitches and petroleum or coal tar pitch derived cokes.

Examples of the metal compound include metal elements such as Si, Ge, Sn, Pb, P, Sb, Bi, Al, Ga, In, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ag, Mg, , And the like. These metal compounds may be a single substance, an alloy, an oxide (TiO ₂ , SnO ₂ Or the like), a nitride, a sulfide, a boride, an alloy with lithium, or the like, but an alloy with a single substance, an alloy, an oxide, and lithium can be increased in capacity. Among them, it may contain at least one element selected from Si, Ge and Sn, and it may further increase the capacity of the battery including at least one element selected from Si and Sn.

The binder used for the positive electrode and the negative electrode has a function of holding the positive electrode active material and the negative electrode active material on the current collector and connecting the active materials, and a commonly used binder may be used without limitation.

For example, polyvinylidene fluoride-hexafluoropropylene (PVDF-co-HFP), polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate various kinds of binders such as polymethyl methacrylate, styrene butadiene rubber (SBR), and carboxyl methyl cellulose (CMC) can be used.

Meanwhile, the separator 123 may be formed of a porous substrate. The porous substrate may be any porous substrate used in an electrochemical device. For example, the porous substrate may be a polyolefin porous membrane or a nonwoven fabric. But it is not particularly limited thereto.

Examples of the polyolefin-based porous film include polyolefin-based polymers such as polyethylene, polypropylene, polybutylene, and polypentene, such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene and ultra-high molecular weight polyethylene, One membrane can be mentioned.

The nonwoven fabric may include, in addition to the polyolefin nonwoven fabric, for example, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate ), Polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, and polyethylenenaphthalene, which may be used alone or in combination, And nonwoven fabrics formed by mixing these polymers. The structure of the nonwoven fabric may be a spun bond nonwoven fabric or a meltblown nonwoven fabric composed of long fibers.

The thickness of the porous substrate is not particularly limited, but it is 1 탆 to 100 탆, or 5 탆 to 50 탆.

The size and porosity of the pores existing in the porous substrate are also not particularly limited, but may be 0.001 탆 to 50 탆 and 10% to 95%, respectively.

The electrolyte salt included in the nonaqueous electrolyte solution which can be used in the present invention is a lithium salt. The lithium salt can be used without limitation as those conventionally used in an electrolyte for a lithium secondary battery. For example is the above lithium salt anion ^{F -, Cl -, Br -} , I -, NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, PF 6 -, (CF 3) 2 PF _{^{4 -, (CF 3) 3}} PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, CF 3 CF 2 SO 3 - _{, (CF 3 SO 2) 2} N -, (FSO 2) 2 N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, ( CF ₃ SO ₂ ) ₃ C ^- , CF ₃ (CF ₂ ) ₇ SO ₃ ^- , CF ₃ CO ₂ ^- , CH ₃ CO ₂ ^- SCN ^- and (CF ₃ CF ₂ SO ₂ ) ₂ N ^- .

Examples of the organic solvent included in the above-mentioned non-aqueous electrolyte include those commonly used in electrolytic solutions for lithium secondary batteries, such as ether, ester, amide, linear carbonate, cyclic carbonate, etc., Can be mixed and used.

Among them, a carbonate compound which is typically a cyclic carbonate, a linear carbonate, or a mixture thereof may be included.

Specific examples of the cyclic carbonate compound include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, Propylene carbonate, 2,3-pentylene carbonate, vinylene carbonate, vinylethylene carbonate, and halides thereof, or a mixture of two or more thereof. Examples of such halides include, but are not limited to, fluoroethylene carbonate (FEC) and the like.

Specific examples of the linear carbonate compound include any one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate (EMC), methyl propyl carbonate and ethyl propyl carbonate And mixtures of two or more of them may be used as typical examples, but the present invention is not limited thereto.

In particular, ethylene carbonate and propylene carbonate, which are cyclic carbonates in the carbonate-based organic solvent, are high-viscosity organic solvents having a high dielectric constant and can dissociate the lithium salt in the electrolyte more easily. In addition, such cyclic carbonates can be used as dimethyl carbonate and diethyl carbonate When a low viscosity, low dielectric constant linear carbonate is mixed in an appropriate ratio, an electrolyte having a higher electric conductivity can be produced.

As the ether in the organic solvent, any one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether and ethyl propyl ether or a mixture of two or more thereof may be used , But is not limited thereto.

Examples of the ester in the organic solvent include methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate,? -Butyrolactone,? -Valerolactone,? -Caprolactone,? -Valerolactone and? -Caprolactone, or a mixture of two or more thereof, but the present invention is not limited thereto.

The injection of the nonaqueous electrolyte solution can be performed at an appropriate stage of the manufacturing process of the electrochemical device according to the manufacturing process and required properties of the final product. That is, it can be applied before assembling the electrochemical device or in the final stage of assembling the electrochemical device.

The electrochemical device includes all devices that perform an electrochemical reaction. Examples of the electrochemical device include capacitors such as all types of secondary cells, fuel cells, solar cells, and super-capacitor devices. Particularly, a lithium secondary battery including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery among the above secondary batteries is preferable.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

10, 100: electrochemical device 110: battery case
120: electrode assembly 121: anode
122: cathode 123: separator
131: positive electrode lead 132: negative electrode lead
141: first connection part 142: second connection part
150: Porous protection material

Claims (17)

An electrode assembly including a positive electrode including a protruded positive electrode tab, a negative electrode including a projected negative electrode tab, and a separator interposed between the positive electrode and the negative electrode;
A positive electrode lead having one end bonded to the positive electrode tab;
A negative electrode lead having one end joined to the negative electrode tab;
A battery case accommodating the electrode assembly inside the other end of the positive electrode lead and the other end of the negative electrode lead exposed to the outside;
A nonaqueous electrolyte solution impregnated with the electrode assembly and injected into the battery case; And
And a porous protective material adhered to at least one of a bonding portion between the positive electrode tab and the positive electrode lead and a second bonding portion between the negative electrode tab and the negative electrode lead,
Wherein the first junction and the second junction are housed inside the battery case. The method according to claim 1,
Wherein the thickness of the porous protective material is 100 占 퐉 or more. The method according to claim 1,
Wherein the porous protective member comprises a polymer, or a mixture of an inorganic substance and a polymeric binder. The method of claim 3,
The polymer may be at least one selected from the group consisting of polyethylene, polypropylene, polyethyleneterephthalate, polyvinylalcohol, polystyrene, polyimide, and polyvinylidene fluoride. , Or a mixture of two or more thereof. The method of claim 3,
Wherein the inorganic material is any one selected from the group consisting of titanium dioxide, silicon dioxide, aluminum oxide, and barium titanate, or a mixture of two or more thereof. The method of claim 3,
The polymer binder may be selected from the group consisting of polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-co-hexafluoro propylene ), Polyvinylidene fluoride-co-trichlorethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, polyvinylidene fluoride-co-trichlorethylene, But are not limited to, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, Cellulose acetate butyrate, cellulose acetate propionate But are not limited to, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, But is not limited to any one selected from the group consisting of carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer and polyimide. Wherein the electrochemical device is a mixture of two or more. The method according to claim 1,
Wherein the porous protective member comprises a membrane structure, a fiber structure, or a foam structure. The method according to claim 1,
Wherein the first joint and the second joint are formed by welding, respectively. 9. The method of claim 8,
Wherein the welding is selected from the group consisting of ultrasonic welding, resistance welding and laser welding, or two or more of them. The method according to claim 1,
Wherein at least one of the positive electrode tab, the negative electrode tab, the positive electrode lead and the negative electrode lead is made of any one selected from the group consisting of aluminum, copper, nickel, and silver, or a mixture of two or more thereof. device. The method according to claim 1,
Wherein the positive electrode comprises a positive electrode active material containing a lithium-containing oxide. 12. The method of claim 11,
Wherein the lithium-containing oxide is a lithium-containing transition metal oxide. 13. The method of claim 12,
The lithium-containing transition metal _{oxides, Li x CoO 2 (0.5 <} x <1.3), Li x NiO 2 (0.5 <x <1.3), Li x MnO 2 (0.5 <x <1.3), Li x Mn 2 O 4 (0.5 <x <1.3), Li x (Ni a Co b Mn c) O 2 (0.5 <x <1.3, 0 <a <1, 0 <b <1, 0 <c <1, a + b + c 1), Li _x Ni _{1- y} Co _y O ₂ (0.5 <x <1.3, 0 <y <1), Li _x Co _{1 -y} Mn _y O _{2 ), Li x Ni 1 -y Mn} y O 2 (0.5 <x <1.3, O≤y <1), Li x (Ni a Co b Mn c) O 4 (0.5 <x <1.3, 0 <a <2 , 0 <b <2, 0 <c <2, a + b + c = 2), Li x Mn 2 -z Ni z O 4 (0.5 <x <1.3, 0 <z <2), Li x Mn 2 in _{-z Co z O 4 (0.5 <} x <1.3, 0 <z <2), Li x CoPO 4 (0.5 <x <1.3) and _{Li x FePO 4 (0.5 <x} <1.3) which is selected from the group consisting of Or a mixture of two or more thereof. The method according to claim 1,
Wherein the negative electrode comprises a negative electrode active material comprising lithium metal, a carbon material, a metal compound, or a mixture thereof. 15. The method of claim 14,
The metal compound may be at least one selected from the group consisting of Si, Ge, Sn, Pb, P, Sb, Bi, Al, Ga, In, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ag, Or a mixture of two or more thereof. The method according to claim 1,
Wherein the battery case is of a pouch type. The method according to claim 1,
Wherein the electrochemical device is a lithium secondary battery.

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