KR20160133135A - Battery Cell Comprising Electrolyte-Containing Member for Supplying Electrolyte - Google Patents

Abstract

The present invention provides a battery cell which includes: an electrode assembly formed in a structure including a positive electrode, a negative electrode, and a separation film interposed between the positive electrode and the negative electrode and in a structure including a positive terminal and a negative terminal protruding to at least one outer circumferential side; a battery case sealing the electrode assembly along with an electrolyte when accommodating the electrode assembly; and a member embedded with an electrolyte located in the battery case with an electrolyte embedded therein, and providing the electrolyte during a manufacturing process of a battery cell.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery cell including an electrolyte built-

The present invention relates to a battery cell including an electrolyte-containing member.

In recent years, the demand for environmentally friendly alternative energy sources has become an indispensable factor for the future, as the increase in the price of energy sources due to depletion of fossil fuels and the interest in environmental pollution are amplified. Various researches on power generation technologies such as nuclear power, solar power, wind power, and tidal power have been continuing, and electric power storage devices for more efficient use of such generated energy have also been attracting much attention.

Particularly, as technology development and demand for mobile devices increase, the demand for batteries as energy sources is rapidly increasing. Recently, the use of secondary batteries as a power source for electric vehicles (EV) and hybrid electric vehicles (HEV) In addition, the use area has been expanded for use as a power auxiliary power source through a grid, and accordingly, a lot of researches on a battery that can meet various demands have been conducted.

Typically, in terms of the shape of a battery, there is a high demand for a prismatic secondary battery and a pouch-type secondary battery which can be applied to products such as mobile phones with a small thickness, and has advantages such as high energy density, discharge voltage, There is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries.

In particular, in recent years, a pouch-shaped battery having a structure in which a stacked or stacked / folded electrode assembly is embedded in a pouch-shaped battery case of an aluminum laminate sheet has attracted much attention due to low manufacturing cost, small weight, And its usage is gradually increasing.

Generally, most of the secondary batteries including the pouch-type battery are activated during the manufacturing process of the battery cell by charging and discharging. In order to manufacture the final battery cell, the gas generated during the activation process is removed This is called a degassing process.

1 is a schematic view schematically showing a degassing process of a conventional pouch-shaped battery cell.

1, the battery cell 100 is formed by impregnating an electrolyte solution in a state where the electrode assembly 110 is housed in the housing part 121 of the battery case 120, and sealing the outer periphery 122 by heat fusion. .

The electrode assembly 110 is kept in close contact with the battery case 120 in one direction, and undergoes an activation process through charging and discharging.

The battery cell 100 having undergone the activation process is formed with three through holes 130 in a portion of the battery case 120 opposed to a portion where the electrode assembly 110 is in close contact with the battery cell 100. Through the through hole 130, , The gas generated in the activation process of the battery cell 100 is discharged to the outside of the battery case 120 and is removed.

In the battery cell 100 where the gas is removed, the portion of the battery case 120 in which the through hole 130 is drilled is removed, and the remaining portion 123 is sealed by heat fusion.

Thereafter, the battery cell 100 is completed by pressing with a high-temperature press so as to form a uniform outer shape.

However, since the degassing process of the pouch-shaped battery cell is performed by applying a predetermined vacuum and pressure, the electrolyte inside the battery cell is inevitably discharged together with the gas, so that the amount of the electrolyte in the battery cell is reduced This causes a deterioration in performance of the battery cell.

Accordingly, by changing the predetermined process conditions such as lowering of the degree of vacuum and pressure applied in the degassing process of the battery cell, the amount of the electrolyte discharged together with the gas is reduced to solve the above problems.

However, the change of the process conditions may increase the time required for the degassing process of the battery cell, or fail to satisfy the degree of vacuum and pressure required for the degassing process, so that the gas inside the battery cell is not completely removed, Lt; / RTI >

Therefore, there is a high need for a technique capable of fundamentally solving such 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 carried out intensive research and various experiments and, as will be described later, by including the electrolyte built-in member for providing the electrolytic solution built in the inside of the shell during the manufacturing process of the battery cell, The performance of the battery cell can be prevented from deteriorating and the deaeration process can be performed under desired conditions to reduce the time required for the process, It is possible to reduce the defective rate, and the present invention has been accomplished.

According to an aspect of the present invention, there is provided a battery cell comprising:

An electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, the positive electrode terminal and the negative electrode terminal protruding from at least one side of the separator;

A battery case for sealing the electrode assembly together with the electrolytic solution in a state of housing the electrode assembly; And

An electrolyte built-in member which is disposed in the battery case with an electrolyte built therein and provides an electrolyte solution in a process of manufacturing the battery cell;

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Therefore, by providing the electrolytic solution in which the electrolyte built-in member is built in the process of manufacturing the battery cell, it is possible to prevent the performance of the battery cell from deteriorating by replenishing the electrolyte discharged from the degassing process of the battery cell, The time required for the process can be reduced, and the gas inside can be completely removed to reduce the defect rate of the product.

In one specific example, the battery case may be a pouch-shaped case made of a laminate sheet including a resin layer and a metal layer, and the outer periphery of the electrode assembly receiving part may be sealed by heat fusion.

However, the type of the battery case is not limited thereto. Specifically, the battery case may be perforated and sealed to perform the degassing process of the battery cell, and the electrolyte built-in member may be disposed therein together with the electrode assembly and the electrolyte. If there is sufficient space available, the type is not very limited.

The amount of the electrolytic solution contained in the electrolyte-containing member may be 1 to 20 wt% based on the total amount of electrolyte present in the battery case.

If the amount of the electrolytic solution contained in the electrolytic solution-containing member is less than 1% by weight based on the total amount of the electrolytic solution existing in the battery case, the amount of the electrolytic solution provided by the electrolytic solution-containing member is excessively small, I can not.

On the other hand, when the amount of the electrolytic solution contained in the electrolyte built-in member is more than 20% by weight based on the total amount of electrolytic solution existing in the battery case, the amount of electrolytic solution provided by the electrolytic solution containing member is excessively large, There is a problem that the overall volume of the battery cell may increase to accommodate the electrolyte-containing member.

Meanwhile, the electrolyte built-in member may have a structure in which an electrolytic solution is embedded in a shell, and the shell may be ruptured to discharge electrolyte therein, and in particular, it may have a capsule structure .

That is, the electrolyte built-in member is a capsule structure, which may be a structure that replenishes the electrolyte by rupturing the shell in the process of manufacturing the battery cell, thereby discharging the electrolyte contained in the shell.

In this case, the shell of the electrolyte-containing member may be ruptured by pressure or impact to discharge the electrolyte solution therein, or may be melted by the temperature rise of the battery cell to flow out the electrolytic solution therein.

That is, the cause of rupture of the shell of the electrolyte built-up member may vary, and more specifically, it may be ruptured by pressure or impact, or melted by the temperature rise of the battery cell, Electrolyte solution can be replenished.

At this time, when the shell is melted by the temperature rise of the battery cell, the shell of the electrolyte internal component may be melted at a temperature of 80 to 200 degrees Celsius.

If the shell of the electrolyte-containing member is melted at a temperature of less than 80 degrees Celsius, the temperature of the battery cell is increased due to the increase in the temperature of the battery cell before the degassing process of the battery cell, , The shell of the battery cell built-in member is melted to allow the electrolyte inside to flow out, thereby deforming the outer shape of the battery cell or causing damage. When the electrolyte is leaked in the subsequent degassing process, The desired effect can not be obtained.

On the other hand, when the shell of the electrolyte built-up member is melted at a temperature exceeding 200 degrees Celsius, excessively high heat is externally applied to the battery cell for melting the shell, Or deterioration of the battery cell, thereby deteriorating safety.

In one specific example, the shell of the electrolyte containing member may be made of at least one member selected from the group consisting of polyolefin, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and combinations thereof, And the type of the electrolyte-containing member is not limited to a material that does not deteriorate the performance of the battery cell even if the shell of the electrolyte-containing member is ruptured or melted and remains in the battery cell.

Meanwhile, the electrolyte built-in member may be located at a portion where the positive electrode terminal and / or the negative electrode terminal of the electrode assembly protrude from the inside of the battery case.

As described above, the electrolyte built-in member may be formed of a capsule structure having an electrolyte inside the shell. The electrolyte built-in member may include a predetermined volume. In order to place the electrolyte built-in member in the battery case, Space is needed.

Generally, in the pouch-shaped battery cell, the inner surface of the battery case is spaced apart from the electrode assembly by a predetermined distance in a region where the positive electrode terminal and / or the negative electrode terminal of the electrode assembly protrude, and the positive electrode terminal and / V-forming portion bent in a shape of a V-shape is formed, thereby providing a relatively large space inside the battery case.

Therefore, the electrolyte-containing member may be located in a region where the positive electrode terminal and / or the negative electrode terminal of the electrode assembly protrude, that is, the portion where the V-forming portion is formed, inside the battery case.

In addition, the electrolyte built-in member is easily ruptured in a desired condition in a state where it is located in a region where the positive electrode terminal and / or the negative electrode terminal of the electrode assembly protrude in the battery case, The shape thereof is not limited to a specific shape. Specifically, the shape may be a sphere or a column shape.

In this case, when the electrolyte built-in member has a spherical shape, the shell of the electrolyte built-up member easily ruptures at a certain pressure or impact even if pressure or impact is applied at any position, .

In one specific example, the shell of the electrolyte containing member may be a structure including a notch formed along the central portion so that it can be easily ruptured.

More specifically, the notch is thinner than other portions of the shell, so that when a pressure or an impact is applied to the electrolyte containing member, the notch formed along the center portion is ruptured, It can be easily discharged.

In addition, the electrolyte containing member may be a structure for providing an electrolyte after the degassing process in the process of manufacturing the battery cell.

That is, in the battery cell, the electrolyte is discharged to the outside of the battery cell together with the gas in the degassing process during the manufacturing process, so that the battery cell is replenished with the electrolytic solution in the battery cell, And then ruptured to provide an electrolytic solution.

Meanwhile, the present invention provides a method of manufacturing the battery cell,

a) placing an electrolyte built-in member in an empty space of the electrode assembly receiving portion in a state in which the electrode assembly is housed in the receiving portion of the battery case;

b) sealing the battery case with the electrode assembly impregnated with the electrolytic solution to manufacture a primary battery cell;

c) charging and discharging the primary battery cell to activate the primary battery cell;

d) applying vacuum and pressure to the primary battery cell to discharge the gas therein;

e) final sealing of the primary battery cell;

f) pressing the primary battery cell with a high-temperature press to produce a final battery cell;

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That is, the battery cell has a primary cell which is sealed together with the electrolyte solution in a state where the electrode assembly and the electrolyte-containing member are positioned inside the battery case to charge and discharge the secondary battery cell, and a degassing And then pressing the finally sealed battery cell with a high-temperature press.

As described above, the electrolyte built-in member may have a structure in which an electrolytic solution is embedded inside the shell.

Therefore, the shell is ruptured after the degassing process, and the electrolytic solution in the electrolytic solution-containing member flows out, thereby replenishing the electrolytic solution in the battery cell.

In this case, the shell of the electrolyte-containing member may be ruptured by the pressure applied during the process f) or may be melted by the temperature rise in the process f).

In other words, the shell of the electrolytic solution-containing member is subjected to pressure or temperature applied by the press in the process of pressurizing with a hot press so that the finally sealed primary cell forms a uniform outer shape after the degassing process Ruptured or melted, whereby the electrolyte inside can be discharged.

Therefore, since a separate process for rupturing the shell of the electrolyte built-up member is unnecessary, it can be easily applied without changing the conventional battery cell manufacturing process.

In one specific example, the type of the battery cell is not particularly limited, but specific examples thereof include a lithium ion battery having advantages such as a high energy density, a discharge voltage, and an output stability, a lithium secondary battery such as a lithium ion polymer battery, Battery.

Generally, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt.

The positive electrode is prepared, for example, by coating a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector, and then drying the mixture. Optionally, a filler may be further added to the mixture.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where 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; Fe ₂ (MoO ₄ ) ₃ , and the like. However, the present invention is not limited to these.

The conductive material is usually added in an amount of 1 to 30% 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 black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey 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 which 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 30% by weight based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

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

The negative electrode is manufactured by applying and drying a negative electrode active material on a negative electrode collector, and if necessary, the above-described components may be selectively included.

Examples of the negative electrode active material include carbon such as non-graphitized carbon and 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 < 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.

The separation membrane and the separation film are interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 mu m, and the thickness is generally 5 to 130 mu m. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant 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.

Further, in one specific example, in order to improve the safety of the battery, the separation membrane and / or the separation film may be an organic / inorganic composite porous SRS (Safety-Reinforcing Separators) separation membrane.

The SRS separator is manufactured by using inorganic particles and a binder polymer on the polyolefin-based separator substrate as an active layer component. In addition to the pore structure contained in the separator substrate itself, the SRS separator is formed by interstitial volume between inorganic particles And has a uniform pore structure.

The use of such an organic / inorganic composite porous separator has the advantage of suppressing an increase in thickness of the cell due to swelling at the time of chemical conversion compared with the case of using a conventional separator, When a gelable polymer is used when liquid electrolyte is impregnated, it can also be used as an electrolyte.

In addition, the organic / inorganic composite porous separator can exhibit excellent adhesion characteristics by controlling the contents of the inorganic particles and the binder polymer in the separator, so that the cell assembly process can be easily performed.

The inorganic particles are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles usable in the present invention are not particularly limited as long as the oxidation and / or reduction reaction does not occur in the operating voltage range of the applied battery (for example, 0 to 5 V based on Li / Li +). Particularly, when inorganic particles having an ion-transporting ability are used, the ion conductivity in the electrochemical device can be increased and the performance can be improved. Therefore, it is preferable that the ionic conductivity is as high as possible. In addition, when the inorganic particles have a high density, it is difficult to disperse the particles at the time of coating, and there is a problem of an increase in weight during the production of the battery. In the case of an inorganic substance having a high dielectric constant, dissociation of an electrolyte salt, for example, a lithium salt, in the liquid electrolyte also contributes to increase ionic conductivity of the electrolyte.

The nonaqueous electrolyte solution containing a lithium salt is composed of a polar organic electrolyte and a lithium salt. As the electrolytic solution, a non-aqueous liquid electrolytic solution, an organic solid electrolyte, an inorganic solid electrolyte and the like are used.

Examples of the nonaqueous liquid electrolytic solution include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyrolactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane , Acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate Nonionic organic solvents such as tetrahydrofuran derivatives, ethers, methyl pyrophosphate, ethyl propionate and the like can 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.

The lithium salt is a material that is readily soluble 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 have.

For the purpose of improving the charge-discharge characteristics and the flame retardancy, the non-aqueous liquid electrolyte may contain, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like are added It is possible. 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.

The present invention also provides a device comprising one or more of the battery cells, wherein the device is a mobile phone, a tablet computer, a notebook computer, a power tool, a wearable electronic device, an electric vehicle, a hybrid electric vehicle, a plug- , And a power storage device.

Since the devices are well known in the art, a detailed description thereof will be omitted herein.

As described above, the battery cell according to the present invention includes the electrolyte built-in member that provides the electrolyte solution built in the inside of the shell, thereby replenishing the electrolyte discharged in the degassing process of the battery cell, By performing the degassing process under the desired conditions, the time required for the process can be reduced, and the gas inside can be completely removed and the defective rate of the product can be reduced.

1 is a schematic view schematically showing a degassing process of a conventional pouch-shaped battery cell;
2 is an exploded perspective view schematically illustrating the structure of a battery cell according to one embodiment of the present invention;
3 is a vertical cross-sectional view schematically showing the structure of the V-forming portion of the battery cell of FIG. 2;
FIG. 4 is a schematic view schematically showing various structures of the electrolyte built-in member included in the battery cell of FIG. 2;

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.

FIG. 2 is an exploded perspective view schematically showing a structure of a battery cell according to an embodiment of the present invention.

2, the battery cell 200 includes an electrode assembly 220, electrode tabs 231 and 232 extending from the electrode assembly 220, electrode leads 231 and 232 welded to the electrode tabs 231 and 232, (241, 242), and a battery case (210) for accommodating the electrode assembly (220).

The electrode assembly 220 is a power generation element in which an anode and a cathode are sequentially stacked with a separation membrane interposed therebetween, and has a laminated structure. The electrode tabs 231 and 232 extend from the respective electrode plates of the electrode assembly 220 and the electrode leads 241 and 242 are formed by a plurality of electrode tabs 231 and 232 extending from each electrode plate, And they are partially exposed to the outside of the battery case 210. [0050] An insulating film 250 is attached to the upper and lower surfaces of the electrode leads 241 and 242 in order to increase the degree of sealing with the battery case 210 and at the same time to ensure an electrically insulated state.

The battery case 210 is made of an aluminum laminate sheet, provides a space for accommodating the electrode assembly 220, and has a pouch shape as a whole.

The upper end of the battery case 210 is spaced apart from the electrode assembly 220 such that the plurality of positive electrode tabs 231 and the plurality of negative electrode tabs 232 can be coupled to the electrode leads 241 and 242 together.

An electrolyte built-in member 260 for providing an electrolyte in the manufacturing process of the battery cell 200 is disposed in the upper end space of the battery case 210 separated from the electrode assembly 220.

3 is a vertical cross-sectional view schematically showing the structure of the V-forming portion of the battery cell of FIG.

3, a plurality of positive electrode tabs 231 protruding from the positive electrode 221 of the electrode assembly 220 are connected to the positive electrode lead 241 in the form of a welded portion integrally joined by, for example, welding . The positive electrode lead 241 is sealed by the battery case 210 in a state in which the opposite end 241a to which the positive electrode tab weld portion is connected is exposed. The upper ends of the battery case 210 are spaced apart from the upper end surface of the electrode assembly 220 by a certain distance L and the positive electrode tabs 241 of the welded portion are integrally joined to each other, Shaped portion 231 is bent in a substantially V shape to form a V-forming portion.

The battery case 210 is sealed with the outer periphery by thermal fusion in a state where the electrode assembly 220 and the electrolyte built-in member 260 are accommodated. After the activation process by charging and discharging, one side of the battery case 210 By the perforation, a degassing process for discharging the gas inside is performed.

At this time, a predetermined vacuum and pressure are applied between the degassing steps to discharge the gas inside the battery case 210. The inner upper end of the battery case 210 is spaced apart from the upper surface of the electrode assembly 220 The shape of the battery case 210 is indented 270 due to the vacuum and pressure applied during the degassing process.

However, in the battery cell 200 according to the present invention, the electrolyte built-in member 260 is disposed at the upper end of the inside of the battery case 210. Therefore, compared with the conventional battery cell, the shape of the battery case 210 There is no or relatively little deformation of the substrate, and thus a more uniform outer surface can be formed.

FIG. 4 is a schematic view schematically showing various structures of the electrolyte built-in member included in the battery cell of FIG.

Referring to FIG. 4, the electrolyte-containing members 410 and 420 have a capsule structure in which an electrolytic solution is embedded in the shells 411 and 421, respectively.

The electrolyte-containing members 410 and 420 are respectively in the form of a sphere and a column.

The spherical and columnar electrolyte containing members 410 and 420 are formed with notches 412 and 422 along the central portion so that the shells 411 and 421 can be easily ruptured.

The notches 412 and 422 have a relatively thin thickness compared to other portions of the shells 411 and 421 so that when pressure or impact is applied to the electrolyte built-in members 410 and 420, And 421 are more easily ruptured, so that the built-in electrolyte can flow out.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (20)

An electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, the positive electrode terminal and the negative electrode terminal protruding from at least one side of the separator;
A battery case for sealing the electrode assembly together with the electrolytic solution in a state of housing the electrode assembly; And
An electrolyte built-in member which is disposed in the battery case with an electrolyte built therein and provides an electrolyte solution in a process of manufacturing the battery cell;
The battery cell comprising: The battery cell according to claim 1, wherein the battery case is a pouch-shaped case made of a laminate sheet including a resin layer and a metal layer, and the outer periphery of the electrode assembly receiving part is sealed by heat fusion. The battery cell according to claim 1, wherein the amount of the electrolyte contained in the electrolyte-containing member is 1 to 20% by weight based on the total amount of electrolyte present in the battery case. The battery cell according to claim 1, wherein the electrolyte-containing member has a structure in which an electrolytic solution is embedded in a shell, and the shell is ruptured to discharge electrolyte therein. The battery cell according to claim 4, wherein the electrolyte-containing member is formed in a capsule structure. The battery cell according to claim 4, wherein the shell of the electrolyte-containing member is ruptured by pressure or impact to discharge electrolyte therein. The battery cell according to claim 4, wherein the shell of the electrolyte-containing member is melted due to the temperature rise of the battery cell to discharge the electrolyte inside. The battery cell according to claim 7, wherein the shell of the electrolyte containing member is melted at a temperature of 80 to 200 degrees Celsius. The battery cell according to claim 4, wherein the shell of the electrolyte-containing member is made of at least one selected from the group consisting of polyolefin, polyvinyl alcohol (PVA), polyvinyl chloride (PVC) . The battery cell according to claim 1, wherein the electrolyte-containing member is located at a position where the positive electrode terminal and / or the negative electrode terminal of the electrode assembly protrude from the inside of the battery case. The battery cell according to claim 1, wherein the electrolyte-containing member is in the shape of a sphere or a column. The battery cell according to claim 4, wherein the shell of the electrolyte-containing member includes a notch formed along the center portion so that the shell can easily be ruptured. The battery cell according to claim 1, wherein the electrolyte-containing member provides an electrolyte solution after a degassing process in a process of manufacturing the battery cell. 14. A method of manufacturing a battery cell according to any one of claims 1 to 13,
a) placing an electrolyte built-in member in an empty space of the electrode assembly receiving portion in a state in which the electrode assembly is housed in the receiving portion of the battery case;
b) sealing the battery case with the electrode assembly impregnated with the electrolytic solution to manufacture a primary battery cell;
c) charging and discharging the primary battery cell to activate the primary battery cell;
d) applying vacuum and pressure to the primary battery cell to discharge the gas therein;
e) final sealing of the primary battery cell;
f) pressing the primary battery cell with a high-temperature press to produce a final battery cell;
And forming a battery cell. 15. The method according to claim 14, wherein the electrolyte-containing member has a structure in which an electrolytic solution is embedded inside the shell. 16. The method according to claim 15, wherein the shell of the electrolyte-containing member is ruptured by a pressure applied in step f). 16. The method according to claim 15, wherein the shell of the electrolyte-containing member is melted by a temperature rise in process f). The battery cell according to claim 1, wherein the battery cell is a lithium secondary battery. A device comprising a battery cell according to claim 1. 20. The device of claim 19, wherein the device is selected from the group consisting of a cell phone, a tablet computer, a notebook computer, a power tool, a wearable electronic device, an electric vehicle, a hybrid electric vehicle, a plug- . ≪ / RTI >

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