KR20140006722A - Method for preparing secondary battery, secondary battery prepared by the method and electrochemical cell containing the same - Google Patents

Abstract

The present invention relates to a secondary battery manufacturing method for improving wetting properties and, more specifically, to a method for manufacturing a secondary battery comprising: an electrode assembly including an electrode plate having a current collector, active materials and a tab; a lead electrically connected to the tab; and a case for receiving the electrode assembly and the method comprising the steps of: receiving the electrode assembly in the case; injecting an electrolyte into the case in which the electrode assembly is received; and applying high frequency to one or more selected from the case and the lead. [Reference numerals] (AA) Prepare a pouch type or can type case; (BB) Accommodate an electrode assembly; (CC) Inject an electrolyte; (DD) Apply high frequency/maintain reference temperature

Description

Manufacturing method of secondary battery and secondary battery and electrochemical device according to it {METHOD FOR PREPARING SECONDARY BATTERY, SECONDARY BATTERY PREPARED BY THE METHOD AND ELECTROCHEMICAL CELL CONTAINING THE SAME}

The present invention relates to a method for manufacturing a secondary battery that can improve the wetting properties of the electrolyte.

The rapid proliferation and demand of portable electronic devices such as mobile phones, notebook computers, and portable game consoles are increasing the demand for lithium ion secondary batteries used as their supply devices, and the need for high performance and high capacity lithium secondary batteries is also emerging. have. In response to this demand, researches on lithium secondary batteries having high discharge voltage and high energy density have been actively conducted.

A battery can be broadly divided into a positive electrode, a negative electrode, and an electrolyte, and also includes components such as a separator and a packaging material. A typical lithium ion battery is assembled by alternately overlapping a positive electrode, a negative electrode, and a separator, inserting a can or pouch of a predetermined size and shape, and finally injecting an electrolyte solution. At this time, the electrolyte injected later is impregnated between the anode, the cathode and the separator by a capillary force.

The electrolyte used in the lithium secondary battery should be impregnated into the active material of the electrode at the end of the lithium secondary battery manufacturing process, and due to the nonuniformity of the active material, the wettability by the electrolyte is uneven and the impedance of the battery increases, so that the active material is immersed. There is a problem that the battery performance is difficult to fall.

A metal oxide such as lithium cobalt oxide (LiCoO ₂ ) is used as a cathode active material of a battery, and a carbon material such as graphite is used as a negative electrode active material, and the electrolyte is a cyclic form such as ethylene carbonate (EC) and propylene carbonate (PC). Multicomponent organic solvents such as carbonate, dimethyl carbonate (DMC) and diethyl carbonate (DEC) are used.

However, although the positive electrode, the negative electrode, and the separator are all hydrophobic materials due to the properties of the material, since the electrolyte is a hydrophilicity material, the impregnation characteristics of the electrolyte to the electrode and the separator require considerable time and demanding process conditions.

In addition, the capacity of the lithium ion battery using the solvents is quite small and has many problems to be solved in low temperature characteristics, overcharge stability and cycle life characteristics. In addition, the high capacity of the battery is a continuous requirement, one way to implement this is to pack a more compact, such as the positive electrode, the negative electrode and the separator, in this case is accompanied by the problem of electrolyte injection.

In other words, in addition to the fundamental hydrophilic difference, as the volume of the electrolyte penetrates decreases, there is a high possibility that the electrolyte does not enter the inside of the battery and only exists locally outside. The battery manufactured as described above partially reduces the amount of electrolyte partially inside the battery, thereby greatly reducing battery capacity and performance. Many high functional materials applied to batteries have high viscosity and low cell wettability, which is often difficult to inject in the form of electrolytes. In addition, there have been several publications related to the improvement of the electrolyte injection process, but none of them provide a fundamental solution. In addition, a technique for improving the wettability of the electrode other than the separator is not yet disclosed.

Published patent application No. 10-2011-0051354

The present invention has been made to solve the above-described problems, an object of the present invention is to inject an electrolyte into the interior of the secondary battery packaging material, and then apply a high frequency to one or more of the exterior material and the electrode lead of the secondary battery electrode collector And it is to provide a technique for increasing the temperature of the electrolyte solution to improve the impregnation characteristics of the electrolyte solution.

As a means for solving the above problems, the present invention provides an electrode assembly comprising an electrode plate provided with a current collector, an active material and a tab; A lead electrically connected to the tab; And a packaging material for accommodating the electrode assembly.

Receiving the electrode assembly inside the exterior material;

Injecting an electrolyte into the exterior material containing the electrode assembly; And

It provides a secondary battery manufacturing method comprising the step of applying heat to at least one selected from the exterior material and the lead.

The step of applying the heat may be a step of applying a high frequency, thereby raising the temperature of the electrolyte solution in the range of 30 ℃ ~ 100 ℃, preferably in the range of 35 ℃ ~ 70 ℃, the temperature of the electrolyte solution thus raised It can be kept constant for 30 minutes or more and 3 hours or less.

In addition, the applying of the high frequency may be performed by bringing the coil applying the high frequency into close proximity or contact with at least one selected from the exterior member and the lead.

Meanwhile, the packaging material may be a pouch type or a can type, and the electrode assembly may be selected from the group consisting of a winding type, a stack type, and a stack / fold type structure.

In addition, the present invention provides a secondary battery manufactured by the secondary battery manufacturing method.

In addition, the present invention provides an electrochemical device selected from the group consisting of a battery module including the secondary battery and a battery pack including one or more battery modules.

According to the present invention, an electrolyte solution is impregnated by injecting an electrolyte into the inside of the secondary battery packaging material, and then applying heat to one or more selected from the packaging material and the electrode lead, and in particular, by applying a high frequency to increase the temperature of the electrode current collector and the electrolyte. There is an effect to improve.

1 and 2 are exploded perspective views showing the structure of a typical typical pouch type secondary battery.
3 is a flowchart illustrating a manufacturing process according to the present invention.
4 and 5 are graphs showing the change of the impregnation characteristics of the electrolyte when the manufacturing process according to the present invention is applied.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description with reference to the accompanying drawings, the same reference numerals denote the same elements regardless of the reference numerals, and redundant description thereof will be omitted. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

1 is a schematic exploded perspective view of a general structure of a typical pouch type secondary battery to which the present invention may be applied.

Referring to FIG. 1, a pouch type secondary battery includes an electrode assembly 30, electrode tabs 40 and 50 extending from the electrode assembly 30, and electrodes welded to the electrode tabs 40 and 50. And a pouch type exterior material 20 for accommodating the leads 60 and 70, the insulating film 80, and the electrode assembly 30.

Although not shown, the electrode assembly 30 is a power generator in which a positive electrode and a negative electrode are sequentially stacked in a state where a separator is interposed therebetween, and an electrode tab connected to a current collector is coated with a positive electrode or a negative electrode active material. The structure having a plurality may be formed to be stacked. Therefore, in the general electrode assembly, the positive electrode, the negative electrode, and the separator may be formed as a unit. For example, the electrode assembly to be applied to the secondary battery of the present invention, (a) bi-cell ('A-type bi-cell') of the anode / separator / cathode / separator / anode structure wrapped in a separator sheet in the center portion of the winding start point or (b) a plurality of electrochemical cells in which a bicell ('C-type bicell') structure having a cathode / separator / anode / separator / cathode structure is applied, or a full cell of a cathode / separator / cathode structure is a basic unit; You can apply a structure in which they overlap.

The electrode assembly may be classified according to the structure of the electrode assembly of the anode / separation membrane / cathode structure. Typically, a long sheet-shaped anode and cathode are wound with a separator interposed therein. Rolled electrode assemblies, and a plurality of positive electrode and negative electrode cut in a unit of a predetermined size are stacked (stacked) electrode assembly sequentially stacked with a separator. The stacked structure and the stacked / folded structure are preferable. Since the stacked structure is well known in the art, a description thereof will be omitted herein. Details of the electrode assembly of the stack / foldable structure are disclosed in Korean Patent Application Publication Nos. 2001-0082058, 2001-0082059, and 2001-0082060 of the present applicant. Are incorporated by reference.

The electrode tabs 40, 50 extend from each electrode plate of the electrode assembly 30, and the electrode leads 60, 70 may include a plurality of electrode tabs 40, 50 extending from each electrode plate, for example. , Respectively, are electrically connected by welding, and part of the exterior member 20 is exposed to the outside. In addition, an insulating film 80 is attached to a portion of the upper and lower surfaces of the electrode leads 60 and 70 in order to increase the sealing degree with the exterior material 20 and to secure an electrical insulation state.

The pouch type exterior material 20 mainly consists of an aluminum laminate sheet, provides a space for accommodating the electrode assembly 30, and has a pouch shape as a whole. In the case of the stacked electrode assembly 30 as shown in FIG. 1, a plurality of positive electrode tabs 40 and a plurality of negative electrode tabs 50 may be coupled together to the electrode leads 60 and 70 so as to be coupled to the inner top of the exterior material 20. Is spaced apart from the electrode assembly 30 by a predetermined distance.

2 is an exploded perspective view of a pouch type secondary battery in which an electrode terminal protrudes on both sides of an exterior member, as another example of a pouch type secondary battery to which the present invention can be applied.

In the pouch type secondary battery of FIG. 2, the electrode leads 61 and 71 are positioned at both sides of the exterior members 21 and 22, respectively, and the battery case includes the upper exterior material 21 and the lower exterior material 22 separated from each other. There is a difference from the pouch type secondary battery of FIG. The remaining components, the electrode tabs 41 and 51, the electrode terminals 61 and 71, the insulating film 81, and the like are the same as those of the pouch type battery of FIG. 1, and the pouch type battery of FIG. 2 is an electrode assembly 31. ) Is put into the case and the lower case 22 and the upper case 21 are sealed by thermocompression bonding or the like.

The manufacturing method of the present invention is not limited to being applied to the secondary battery of the type described in FIG. 1 and FIG. 2, and may be applied to a can type secondary battery in addition to the pouch type secondary battery.

A secondary battery manufacturing process applied to the present invention as described above with reference to Figure 3, the step of receiving the electrode assembly inside the packaging material; Injecting an electrolyte into the exterior material containing the electrode assembly; And applying heat to at least one selected from an exterior member and a lead, preferably applying a high frequency wave.

At this time, the step of applying the heat is not necessarily a step of applying a high frequency, other means for increasing the temperature of the electrolyte may be used to increase the impregnation of the electrolyte.

In the present invention, after preparing a pouch type or can type exterior material that accommodates the structure of the electrode assembly described above to accommodate the electrode assembly therein, and injecting the electrolyte solution, the secondary battery is completed through a sealing process. . Then, in the present invention, for example, by applying a high frequency to the inside of the secondary battery through the exterior material or lead as described above in Figures 1 and 2 to increase the temperature of the electrode assembly and the temperature of the electrolyte solution to improve the impregnation characteristics Characterized in that.

In this case, the above-described application of the high frequency can be performed to any one or more selected from the exterior member and the lead, but it is more efficient to apply the high frequency side to the exterior member. The temperature of the current collector and the electrolyte is increased by the application of high frequency, and the temperature of the electrolyte is maintained at a specific temperature (hereinafter, referred to as a 'reference temperature') at a predetermined time, for example, 30 minutes to 3 hours. By doing so, the impregnation characteristics of the electrolyte solution can be improved.

In particular, the reference temperature indicates the temperature of the electrolyte that is maintained constant, it may be selected in the range of 30 ℃ ~ 100 ℃. If the reference temperature is less than 30 ℃ it is difficult to achieve the effect of the enhancement of the impregnation characteristics, the electrolyte may evaporate if it exceeds 100 ℃. The reference temperature is more preferably about 35 ° C to 70 ° C.

Hereinafter, the present invention will be described in more detail with reference to Examples. The following examples are only for the detailed description of the invention, which is not intended to limit the scope thereby.

[Example]

A secondary battery was manufactured by embedding an electrode assembly having a bi-cell structure in an accommodating portion of a pouch case including an upper laminate sheet and a lower laminate sheet, injecting an electrolyte solution, and then sealing the pouch. At this time, the size of the entire cell of the bi-cell was made of 57.5mm horizontal, 39mm vertical.

4 and 5 show the impregnation rate of the cell with time while keeping the temperature of the electrolyte at 40 ° C. by applying a coil applied with high frequency to the pouch.

[Comparative Example]

Except that the high frequency is not applied to the secondary battery manufactured in the above embodiment is shown in Figure 4 by comparing the impregnation characteristics in the same state, that is, at room temperature.

Impregnation characteristics in the Examples and Comparative Examples were implemented by comparing the impregnation rate, the impregnation rate was calculated by the following formula.

[Equation 1]

4 is a graph showing the impregnation rate of the cell and the impregnation rate in the comparative example when the reference temperature is 40 ℃ in the above-described embodiment.

As shown, it can be seen that the impregnation rate is significantly increased from 70.9% in the comparative example to 90.5% after 40 minutes in the heating conditions according to the present embodiment.

5 is a graph showing the results of experiments with the impregnation rate for each type of Bi-Cell.

The test subjects were subjected to the impregnation rate at the cathode in the structure (a) cathode / separator / anode / separator / cathode in the structure prepared in the above-described embodiment, (b) anode / In a bicell ('type A bicell') of a separator / cathode / separator / anode structure, the impregnation rate at the positive electrode was measured. As a result of the experiment, both of them were able to confirm the rapid increase in impregnation rate after 30 minutes, and the impregnation was completed within about 2.5 hours.

This significantly shortens the process time of waiting for a pre-aging period of about two days for impregnation before charging the secondary battery at room temperature, and also prevents an uncharged region from occurring due to the acceleration of the impregnation. It will also be reaped.

Meanwhile, hereinafter, specific materials and structural features of the components constituting the secondary battery according to the present invention will be described. These are all components of a general secondary battery, and are not limited to the following.

[Type of electrolyte]

As the electrolyte that can be applied to the embodiment according to the present invention described above, a lithium-containing non-aqueous electrolyte may be applied. The lithium-containing non-aqueous electrolyte solution consists of a non-aqueous electrolyte solution and a lithium salt.

As said non-aqueous electrolyte, N-methyl- 2-pyrrolidinone, a propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyrolactone, 1, 2- dimethoxy ethane, for example , Tetrahydroxy franc, 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethyl formamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate , Phosphoric acid triester, trimethoxy methane, dioxolon derivative, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, ether, methyl pyroionate Aprotic organic solvents, such as ethyl propionate, can be used.

The lithium salt is a material that is easy to dissolve in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide .

In some cases, an organic solid electrolyte, an inorganic solid electrolyte, or the like may be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, Polymers containing ionic dissociation groups, and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

In addition, for the purpose of improving charge / discharge characteristics, flame retardancy, etc., the non-aqueous electrolyte solution includes, for example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, and hexaphosphate triamide. Nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrroles, 2-methoxy ethanol, aluminum trichloride, etc. It may be. In some cases, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further added to impart nonflammability, or a carbon dioxide gas may be further added to improve high-temperature storage characteristics.

Anode structure

In the present invention, the electrode formed on the base unit is divided into a positive electrode or a negative electrode, and the positive electrode and the negative electrode are prepared by mutually bonding with a separator therebetween. The positive electrode is prepared by, for example, applying a mixture of a positive electrode active material, a conductive material, and a binder onto a positive electrode current collector, followed by drying and pressing. If necessary, a filler may be further added to the mixture. This structure is implemented in a sheet form can be applied to the process in the form of mounting on the loading roll.

[Positive collector]

The cathode current collector generally has a thickness of 3 to 500 mu m. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel Surface-treated with carbon, nickel, titanium, silver or the like on the surface of may be used. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the cathode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

[Positive electrode active material]

The cathode active material may be a lithium secondary battery, for example, a layered compound such as lithium cobalt oxide (LiCoO ₂ ) or lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Formula _{Li 1 + x Mn 2 - x} O 4 ( where, x is from 0 to 0.33), LiMnO _3, the lithium manganese oxide such as _{LiMn 2 O 3, LiMnO 2,} Li 2 MnO 3; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , Cu ₂ V ₂ O ₇ and the like; Ni-site type lithium nickel oxide represented by the formula LiNi _{1 - x} M _x O ₂ , wherein M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3; Formula _{LiMn 2 - x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; and the like, but Fe ₂ (MoO _{4) 3,} but is not limited to these.

The conductive material is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon blacks such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black and thermal black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component that assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 50 wt% based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butyrene rubber, fluorine rubber, various copolymers, and the like.

The filler is optionally used as a component for inhibiting expansion of the positive electrode, and is not particularly limited as long as it is a fibrous material without causing chemical change in the battery. Examples of the filler include olefinic polymers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

Cathode structure

The negative electrode is manufactured by coating, drying, and pressing a negative electrode active material on a negative electrode current collector, and optionally, the conductive material, binder, filler, and the like as described above may be further included. This structure is implemented in a sheet form can be applied to the process in the form of mounting on the loading roll.

[Cathode collector]

The negative electrode current collector is generally made to have a thickness of 3 to 500 mu m. Such a negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery. For example, the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel Surface treated with carbon, nickel, titanium, silver, or the like, aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.

[Cathode active material]

The negative electrode active material may include, for example, carbon such as non-graphitized carbon or graphite carbon; Li _x Fe ₂ O ₃ (0 ≦ _x ≦ 1), Li _x WO ₂ (0 ≦ _x ≦ 1), Sn _x Me _{1 - x} Me ' _y O _z (Me: Mn, Fe, Pb, Ge; Me' Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0 <x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8); Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; _{SnO, SnO 2, PbO, PbO} 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4, and Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

[Separation membrane]

The separator according to the present invention implements simple lamination by forming a basic unit by a simple lamination process regardless of a folding process or a roll process. In particular, the adhesion of the separator, the positive electrode, and the negative electrode in the laminator is such that the separator sheet itself is melted by heat and adhered to the inside of the laminator. This allows the pressure to be maintained continuously, thereby enabling stable interfacial contact between the electrode and the separator sheet.

As long as the separator interposed between the anode and the cathode of the separator sheet or cell has an insulating property and a porous structure capable of moving ions, the material thereof is not particularly limited, and the separator and the separator sheet may or may not be the same material. It may be.

The separator or separator sheet may be a thin insulating film having high ion permeability and mechanical strength. The separator or separator sheet generally has a pore diameter of 0.01 to 10 mu m, 300 mu m. Examples of the separator or separator sheet include olefin polymers such as polypropylene, which is resistant to chemicals and hydrophobic; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane. Preferably, a multilayer film or polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, or poly film produced by polyethylene film, polypropylene film, or a combination of these films It may be a polymer film for a polymer electrolyte or a gel polymer electrolyte, such as a vinylidene fluoride-hexafluoropropylene (polyvinylidene fluoride-hexafluoropropylene) copolymer.

It is preferable that the separator has an adhesive function by heat fusion in order to form a basic unit cell, and the separator sheet does not necessarily have such a function, but it is preferable to use an adhesive function.

The electrode assembly according to the present invention can be applied to an electrochemical cell that produces electricity by an electrochemical reaction between a positive electrode and a negative electrode. Representative examples of the electrochemical cell include a super capacitor and an ultra capacitor. ), Secondary batteries, fuel cells, various sensors, electrolysis devices, electrochemical reactors, and the like, and secondary batteries are particularly preferred.

The secondary battery has a structure in which the electrode assembly capable of charging and discharging is embedded in a battery case in a state impregnated with an ion-containing electrolyte solution. In one preferred embodiment, the secondary battery may be a lithium secondary battery.

Recently, a lithium secondary battery has attracted much attention as a power source for large devices as well as small mobile devices, and it is desirable to have a small weight when applied to such a field. As one way to reduce the weight of the secondary battery, a structure in which the electrode assembly is incorporated in a pouch type case of an aluminum laminate sheet may be preferable. Since such a lithium secondary battery is known in the art, the description thereof will be omitted.

In addition, as described above, when used as a power source for a medium-to-large device, a secondary battery having a structure capable of minimizing the deterioration of operation performance even during long-term use, having excellent life characteristics, and capable of mass production at low cost is preferable. In this regard, the secondary battery including the electrode assembly of the present invention may be preferably used in a medium-large battery module having the unit cell.

In the case of a battery pack including a battery module including a plurality of secondary batteries, a power tool (power tool); Electric vehicles selected from the group consisting of electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs); E-bikes; E-scooters; Electric golf cart; Electric truck; And it can be used as one or more power source selected from the medium-large device group consisting of electric commercial vehicles.

The medium-large battery module is configured to provide a high output capacity by connecting a plurality of unit cells in series or in series / parallel manner, which is well known in the art, and thus, description thereof is omitted herein.

In the foregoing detailed description of the present invention, specific examples have been described. However, various modifications are possible within the scope of the present invention. The technical idea of the present invention should not be limited to the embodiments of the present invention but should be determined by the equivalents of the claims and the claims.

20: exterior material, 21: upper exterior material, 22: lower exterior material
30, 31: electrode assembly
40, 41: positive electrode tab, 50, 51: negative electrode tab
60, 61: positive lead, 70, 71: negative lead
80, 81: insulation film

Claims (11)

An electrode assembly including a current collector, an active material, and an electrode plate provided with a tab; A lead electrically connected to the tab; And a packaging material for accommodating the electrode assembly.
Receiving the electrode assembly inside the exterior material;
Injecting an electrolyte into the exterior material containing the electrode assembly; And
Method of manufacturing a secondary battery comprising the step of applying heat to at least one selected from the exterior material and the lead. The method according to claim 1,
The applying the heat is a method of manufacturing a secondary battery is a step of applying a high frequency. The method according to claim 1,
The step of applying the heat or the step of applying a high frequency of the secondary battery manufacturing method characterized in that to raise the temperature of the electrolyte in the range of 30 ℃ ~ 100 ℃. The method according to claim 1,
The step of applying the heat or the step of applying a high frequency of the secondary battery manufacturing method characterized in that to raise the temperature of the electrolyte in the range of 35 ℃ ~ 70 ℃. The method according to claim 3 or 4,
The applying of the heat or the applying of high frequency is a step of maintaining a constant temperature of the elevated electrolyte solution for more than 30 minutes. The method according to claim 5,
The applying of the heat or the applying of high frequency is a step of maintaining a constant temperature of the elevated electrolyte solution for more than 30 minutes 3 hours or less. The method according to claim 2,
The step of applying the high frequency, the method of manufacturing a secondary battery is to close or contact the coil to which the high frequency is applied to at least one selected from the packaging material and the lead. The method according to claim 1,
The packaging material is a pouch type or can type secondary battery manufacturing method. The method according to claim 1,
The electrode assembly is a method of manufacturing a secondary battery, characterized in that made of any one selected from the group consisting of winding type, stack type and stack / folding type structure. Secondary battery manufactured by the secondary battery manufacturing method of claim 1. An electrochemical device comprising any one selected from the group consisting of a battery module including the secondary battery of claim 10 and a battery pack including one or more battery modules.

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