KR101686600B1 - Battery Cell Having Hole for Electrolyte Wetting - Google Patents

Abstract

The present invention relates to a laminated structure comprising unit cells each having a laminated structure composed of at least one positive electrode coated with an electrode active material on one side or both sides of a current collector and one or more negative electrodes and a separator interposed between the positive and negative electrodes, An electrode assembly including a separating film winding up is mounted on a receiving portion of a battery case; Wherein the positive electrode, the negative electrode, the separation membrane, and the separation film in the electrode assembly each include at least one through hole communicating with a corresponding portion.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery cell Having Hole for Electrolyte Wetting,

The present invention relates to a battery cell including an electrolyte-impregnated hole.

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 are increasing, the demand for batteries as energy sources is rapidly increasing, and accordingly, a lot of researches on batteries 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.

Also, the secondary battery is classified according to the structure of the electrode assembly having the positive electrode, the negative electrode, and the separator interposed between the positive electrode and the negative electrode. Typically, the long battery- A stacked (stacked) electrode assembly in which a plurality of positive electrodes and negative electrodes cut in a predetermined size unit are sequentially stacked with a separator interposed therebetween, the jelly-roll type (wound type) electrode assembly having a structure in which a separator is interposed; In recent years, in order to solve the problems of the jelly-roll type electrode assembly and the stack type electrode assembly, an electrode assembly having an advanced structure, which is a combination of the jelly-roll type and the stack type, A stack / folding type electrode having a structure in which unit cells stacked with a separator interposed between an anode and a cathode are sequentially wound while being placed on a separation film Developed body lip.

The secondary battery includes a cylindrical battery and a prismatic battery in which the electrode assembly is housed in a cylindrical or rectangular metal can according to the shape of the battery case, and a pouch type battery in which the electrode assembly is housed in a pouch-shaped case of an aluminum laminate sheet .

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.

However, in the case of such a secondary battery, since the electrode assembly is embedded in the battery case together with the electrolyte solution, the electrolyte solution is sufficiently impregnated and wetted to exhibit an electrical performance. In impregnating the electrolyte solution, The uniformity of wetting uniformly over the entire surface including the central portion of the electrode assembly becomes difficult due to the influence of the lamination structure or the like and accordingly uniform electrode reaction over the entire area of the electrode is difficult when the charging and discharging cycles proceed.

This problem becomes more serious as the size of the electrode assembly and the number of stacked electrodes increase. In recent years, as the capacity of the battery increases and the area of the electrode plate of the battery increases, the wetting of the electrolyte becomes more important.

If the wetting of the electrolyte solution on the electrode assembly is incomplete, not only the capacity of the battery decreases, but also the non-uniformity of the electrode state is intensified and the electrode reaction locally concentrates and lithium metal locally precipitates there, And the time required for the wetting of the electrolyte is relatively increased, thereby deteriorating the productivity of the battery.

Furthermore, the wetting failure of the electrolyte has a problem in that the life of the battery can be shortened by accelerating degradation of the electrode even though other electrode states are good.

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 conducted intensive research and various experiments and, as will be described later, have been made so as to include at least one through hole communicating with a region where the anode, the cathode, the separation membrane and the separation film of the electrode assembly correspond to each other The wettability of the electrolytic solution to the central portion of the electrode assembly is improved through the through holes and uniform wetting is possible to all portions of the electrode assembly thereby improving the electrical performance of the battery, The productivity of the battery can be improved. In the process of manufacturing the unit cell and the electrode assembly, the separation membrane is formed on the portion corresponding to the through hole of the anode and the cathode by the needle member of the base plate, The through hole of the separation film is perforated, so that it is easy to manufacture, and the unit cell and the electrode assembly are separated from the base It is confirmed that the unit cell and the electrode assembly are easily stored and moved without being misaligned according to the flow of the unit cell and the electrode assembly because the unit cell stack and the electrode assembly stack are kept in a state of being fixed by the needle member on the rate. I have come to completion.

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

Layered structure composed of at least one positive electrode coated with an electrode active material on one side or both sides of the current collector, at least one negative electrode, and a separator interposed between the positive electrode and the negative electrode, An electrode assembly including a separation film is mounted on a receiving portion of the battery case;

In the electrode assembly, the positive electrode, the negative electrode, the separation membrane, and the separation film each include at least one or more through holes communicating with each other.

Therefore, the battery cell according to the present invention can improve the wettability of the electrolyte solution to the central portion of the electrode assembly through the through-holes, and uniformly wet all parts of the electrode assembly, And the productivity of the battery can be improved by shortening the time required for wetting of the electrolyte solution.

In one specific example, the through holes of the anode, the cathode, the separator, and the separation film communicating with each other may have the same shape.

More specifically, the through holes of the anode, the cathode, the separator, and the separator film are communicated with each other at corresponding portions. Therefore, if the through holes of the anode, the cathode, the separator and the separator film have different shapes, The positive electrode and the negative electrode are brought into direct contact with each other at the formation sites of the through holes without interposing a separation membrane or a separation film.

Therefore, the through holes of the anode, the cathode, the separator, and the separation film, which communicate with each other, may have the same shape.

At this time, the shape of the through-holes is not particularly limited as long as it does not affect the electrical performance of the electrode assembly and can improve the wettability of the electrode assembly with respect to the electrolyte. It may be a circular or elliptical structure.

At least one through hole is formed in the center of the battery cell in a plan view so as to improve the wettability of the electrolyte solution to the central portion of the electrode assembly. have.

At this time, the through hole located at the center of the battery cell among the through holes may be the largest.

Also, the through holes may be arranged in a straight line with respect to the through hole located at the center of the battery cell.

Specifically, at least one through-hole of the through-holes may be located at the center of the battery cell, and the through-holes may be arranged in a straight line passing through the through-hole located at the center of the battery cell in a plan view In this case, the straight line may be a structure that is parallel to both sides of the battery cell, or both sides of the battery cell vertically, at a center between opposite sides of the battery cell when the battery cell is a square in plan view.

Therefore, the wettability of the electrolytic solution to the central region where penetration of the electrolytic solution is difficult compared to other portions of the electrode assembly can be improved, and uniform wetting of the electrolytic solution can be performed on all portions of the electrode assembly, The performance can be improved, and the productivity of the battery can be improved by shortening the time required for wetting of the electrolyte solution.

In one specific example, the area of the through-holes formed in the separator and the separation film may be smaller than the area of the through-holes of the anode and the cathode communicating with the through-holes.

Therefore, it is possible to prevent direct contact between the positive electrode and the negative electrode by a separation membrane or a separation film between the positive electrode and the negative electrode at the through-hole portions of the positive electrode and the negative electrode, thereby preventing occurrence of internal short- have.

In this case, the area of the through-holes formed in the separation membrane and the separation film may be about 30% to 95% of the area of the through-holes of the anode and the cathode communicating with the through-holes.

If the area of the through-holes formed in the separating film and the separating film is less than 30% of the area of the through-holes of the anode and the cathode communicating with the through-holes, due to an excessively small through-hole, The penetration of the electrolytic solution into the positive electrode or the negative electrode stacked in the center becomes difficult, and the wettability and uniform wetting effect of the desired electrolytic solution can not be exhibited.

On the contrary, when the area of the through-holes formed in the separating film and the separating film is larger than 95% of the area of the through-holes of the anode and the cathode communicating with the through-holes, The direct contact between the positive electrode and the negative electrode can not be stably prevented by the film, which may cause an internal short circuit of the battery cell and a resulting fire.

On the other hand, the area of the through hole may be in a range of 1% to 30% of the total area of one surface of the battery cell in plan view.

If the area of the through hole is less than 1% of the total area of one surface of the battery cell in plan view, penetration of the electrolyte through the through hole becomes difficult, thereby improving wettability and uniform wetting of the desired electrolyte If the size of the electrode assembly exceeds 30%, the insoluble area of the electrode assembly increases, and the capacity of the electrode assembly may be reduced compared to the size of the electrode assembly.

Therefore, the area of the through hole may be in a range of 1% to 30% of the entire area of one surface of the battery cell in plan view.

In one specific example, the battery case may be a structure including a cylindrical or rectangular can, and a cap mounted on an open upper end of the can, but the present invention is not limited thereto, and the battery case may include a resin layer, Like case of a laminated sheet including a laminated sheet.

The type of the battery cell according to the present invention is not particularly limited, but specific examples thereof include a lithium ion battery having a high energy density, a discharge voltage, an output stability, etc., a lithium secondary battery such as a lithium ion polymer battery, have.

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 300 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 at least one battery cell, 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- An automobile, and a power storage device.

According to another aspect of the present invention, there is provided a unit cell stack and an electrode assembly stack for easy manufacture and storage of unit cells and electrode assemblies including through holes communicating with each other at corresponding portions.

In one specific example, a unit cell stack according to the present invention comprises:

1. A unit cell stack in which unit cells for manufacturing a battery cell are stacked,

And a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode and the negative electrode each have a structure in which the positive electrode and the negative electrode are connected to each other at a portion corresponding to the positive electrode and the negative electrode, Unit cells having a structure in which at least one or more through holes are communicated with each other;

A base plate mounted on the upper surface of the unit cells in a stacked state; And

At least one needle member protruding upward from the base plate and inserted into the through-holes of the unit cells;

As shown in FIG.

In this case, the separation membrane of the unit cell may have a structure in which the through hole is perforated by the needle member in the process of mounting the unit cell on the base plate.

Specifically, the unit cell stack has a through hole (not shown) communicating with a portion corresponding to only the positive electrode and the negative electrode except for the separator of the unit cell, before the unit cell having the laminated structure of the positive electrode, the separator and the negative electrode is mounted on the upper surface of the base plate. The through holes of the separator corresponding to the through holes of the positive electrode and the negative electrode may be perforated in the process of mounting the unit cells on the upper surface of the base plate.

More specifically, a needle member protruding upward from the base plate is formed on the upper surface of the base plate on which the unit cell is mounted, and the needle member is formed in a portion corresponding to the through hole of the anode and the cathode of the unit cell In the process of mounting the unit cells on the upper surface of the base plate, the needle members of the base plate are inserted into the through holes of the positive electrode and the negative electrode of the unit cell, The through holes of the corresponding separation membranes may be perforated.

According to the above structure, the unit cell for fabricating the battery cell according to the present invention can be easily manufactured in the form of a unit cell stack, and by being stored and moved in the form of a unit cell stack having the above structure, And the needle member of the base plate inserted into the through hole communicating with the mutual corresponding portions of the separation membrane, the unit cell can be prevented from flowing and thus the unit cell stack can be stored and moved without deviation of the unit cell arrangement .

In yet another specific example, an electrode assembly stack according to the present invention comprises:

An electrode assembly stack in which an electrode assembly for manufacturing a battery cell is laminated,

Layered structure composed of at least one positive electrode coated with an electrode active material on one side or both sides of the current collector, at least one negative electrode, and a separator interposed between the positive electrode and the negative electrode, At least one electrode assembly having a structure in which at least one through hole communicating with a corresponding portion of the anode and the cathode is perforated;

A base plate mounted on the upper surface of the electrode assembly in a stacked state; And

At least one needle member protruding upward from the base plate and inserted into the through-hole of the electrode assembly;

. ≪ / RTI >

In this case, the separation membrane and the separation film of the unit cell may have a structure in which the through hole is perforated by the needle member in the process of mounting the electrode assembly on the base plate.

The method of manufacturing the electrode assembly stack having the above structure and the effect according to the above structure are the same as those of the above-described unit cell stack.

Specifically, the positive electrode and the negative electrode, which include through holes communicating with each other, are stacked with a separator interposed therebetween to form a unit cell, and the unit cells are continuously wound by a separation film to be an electrode assembly.

At this time, in the process of mounting the electrode assembly on the base plate in a state where the through holes are formed only in the positive electrode and the negative electrode of each unit cell except for the separation membrane and the separation film, The penetrating holes of the separating film and the separating film communicating with the through holes of the positive electrode and the negative electrode can be perforated by being inserted along the through holes of the positive electrode and the negative electrode communicating with the protruded needle members at the portions corresponding to each other.

Accordingly, like the unit cell stack, the electrode assembly for fabricating the battery cell according to the present invention can be easily manufactured in the form of an electrode assembly stack, and can be stored and moved in the form of the electrode assembly stack. The flow of the electrode assembly is prevented by the needle member of the base plate inserted into the through hole communicating with the corresponding portions of the anode, cathode, separator and separator film of the electrode assembly, The electrode assembly stack can be more stably stored and moved without dislocation.

In addition, in the unit cell stack and the electrode assembly stack, the base plate in which the needle members protrude upwardly may be used for storing only the positive electrode and the negative electrode in which the through holes are formed, respectively.

In the unit cell stack and the electrode assembly stack, the needle-like members of the base plate are smaller in diameter than the diameter of the through holes of the positive electrode and the negative electrode on the horizontal cross section, and the area of the through- Hole is smaller than the area of the through hole of the anode and the cathode communicating with the hole.

Of course, when there is no need to store the unit cell or the electrode assembly for manufacturing the battery cell according to the present invention, only the needle-shaped member is used for the separation membrane and the separation film of the unit cell or the electrode assembly, Holes that communicate with each other at the portions corresponding to the through holes.

Meanwhile, in manufacturing the unit cell and the electrode assembly, the through holes of the positive electrode and the negative electrode constituting the unit cell and the electrode assembly before the through hole is formed in the separating film and / or the separating film are visually observed Since the identification can not be performed, alignment of the through holes can be performed by using a fluoroscopic apparatus using X-ray or the like, whereby the through holes of the positive electrode and the negative electrode can be properly aligned.

Likewise, in the process of winding the unit cells into the separation film in the manufacture of the electrode assembly, the alignment of the unit cells can be prevented and the alignment can be performed by utilizing the X-ray or the like. Of course.

As described above, the battery cell according to the present invention is configured to include at least one through hole communicating with a region where the anode, the cathode, the separation membrane, and the separation film of the electrode assembly correspond to each other, The wettability of the electrolytic solution to the central portion of the assembly is improved and uniform wetting is possible to all portions of the electrode assembly thereby improving the electrical performance of the battery and shortening the time taken to wet the electrolyte The through holes of the separator and the separator film are perforated at the portions corresponding to the through holes of the anode and the cathode by the needle members of the base plate in the process of manufacturing the unit cell and the electrode assembly And the unit cell and the electrode assembly are fixed on the base plate by the needle member The unit cells and the electrode assembly are stored in the form of a unit cell stack and an electrode assembly stack in the state where the unit cells and the electrode assembly are stacked.

1 is a plan view schematically showing the structure of an electrode assembly constituting a battery cell according to an embodiment of the present invention;
FIG. 2 is a vertical cross-sectional view schematically showing a laminated structure of an electrode assembly cut along the line A-A 'in FIG. 1; FIG.
3 is a vertical cross-sectional view schematically showing a stacked structure of unit cells constituting the electrode assembly of FIG. 2;
FIGS. 4 to 6 are schematic views schematically showing a method of constructing an electrode assembly according to an embodiment of the present invention; FIG.
7 is a schematic view schematically showing the structure of an electrode assembly stack according to another embodiment of the present invention;
8 is a schematic view schematically showing a structure of a unit cell stack according to another embodiment of the present invention.

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

FIG. 1 schematically shows a plan view schematically showing the structure of an electrode assembly constituting a battery cell according to an embodiment of the present invention.

Referring to FIG. 1, the electrode assembly 100 is perforated with three through-holes 101, 102, and 103 in a plan view.

The through holes 102 of one of the through holes 101, 102 and 103 are located at the center of the electrode assembly 100 and the remaining through holes 101 and 103 are located at the opposite sides of the electrode assembly 100, Are arranged on a straight line (B-B ') passing through the through holes (102) located at the center, parallel to the both sides (104, 105).

The through holes 102 located at the center of the electrode assembly 100 are formed in the same shape as the circular through holes 101 and 103 in a planar wide area Respectively.

Therefore, the electrolytic solution easily permeates into the central portion of the electrode assembly 100, so that the wettability to the electrolytic solution can be further improved.

2 is a schematic vertical cross-sectional view schematically showing a laminated structure of an electrode assembly cut along a line A-A 'in FIG.

Referring to FIG. 2, the electrode assembly 100 includes a cathode 113 interposed between two anodes 111 and 115, and between the anodes 111 and 115 and the cathode 113, One anode 123 is sandwiched between four unit cells 110 having a stacked structure in which the first and second electrodes 112 and 114 are interposed and two cathodes 121 and 125. The cathodes 121 and 125, And the anode 123 includes three unit cells 120 having a stacked structure in which separation membranes 122 and 124 are interposed.

The unit cells 110 and 120 are continuously wound by the separation film 106 and the through holes 102 communicating with the unit cells 110 and 120 and the separation film 106 are formed in the unit cells 110 and 120, It is perforated.

The through hole 102 is located at the center between the both sides 104 and 105 of the electrode assembly 100.

3 is a vertical cross-sectional view schematically showing a stacked structure of unit cells constituting the electrode assembly of FIG.

3, a unit cell 110 has a cathode 113 interposed between two anodes 111 and 115, and an anode 113 is interposed between the anodes 111 and 115 and the cathode 113, And the upper and lower surfaces of the unit cell 110 face the separation films 106, respectively.

The positive electrodes 111 and 115 of the unit cell 110, the negative electrode 113, the separators 112 and 114 and the separation film 106 are provided with through holes 111a, 112a, 113a and 106a, Respectively.

The through holes 111a and 113a of the positive electrodes 111 and 115 of the unit cell 110 and the negative electrode 113 and the through holes 112a and 106a of the separation films 112 and 114 and the separation film 106 are The through holes 111a and 113a of the anodes 111 and 115 and the cathode 113 are formed in the same shape and size as the through holes 112a and 112a of the separation films 112 and 114 and the separation film 106, 106a.

Therefore, it is possible to stably prevent direct contact between the positive electrodes 111 and 115 and the negative electrode 113 at the formation site of the through hole 102, thereby preventing an internal short circuit of the battery cell 110 and a resulting fire.

FIGS. 4 to 6 are schematic views schematically showing a method of forming an electrode assembly for a battery cell according to an embodiment of the present invention.

4 to 6, one unit cell 410 includes a cathode 413 between two anodes 411 and 415, and the anode 411 and the anode 415, And separators 412 and 414 are interposed between the first and second electrodes 413 and 413, respectively.

Another unit cell 420 includes an anode 423 between two cathodes 421 and 425 and a separator 422 and a cathode 423 between the cathodes 421 and 425 and the anode 423. [ 424 are interposed therebetween.

The unit cells 410 and 420 have the same shape and the same shape at the portions corresponding to the anodes 411, 415 and 423 and the cathodes 413, 421 and 425 except for the separators 412, 414, 422 and 424, Holes 411a, 413a, 415a, 421a, 423a, and 425a, respectively, which are formed to have a predetermined size.

The unit cells 410 and 420 have different stacked structures of the anodes 411, 415 and 423 and the cathodes 413 and 421 and 425. The unit cells 410 and 420 having different stacked structures The electrode assembly 600 is manufactured by sequentially winding the separator 501 in an alternating manner on the separator film 501.

At this time, each of the unit cells 410 and 420 is formed at a position corresponding to each other in the anodes 411, 415, and 423 and the cathodes 413, 421, and 425 using a fluoroscopic apparatus using X- The unit cells 410 and 420 constituting the electrode assembly 600 can be properly stacked and arranged as a whole by arranging the through holes 410a and 420a.

The electrode assembly 600 includes an anode 411, 415, 423 and cathodes 413, 421, 422 except for the separation film 501 and separation membranes 412, 414, 422, 424 of the unit cells 410, And 425, respectively, through holes 410a and 420a that communicate with each other at portions corresponding to each other.

The electrode assembly 600 penetrates from one surface to the other surface along the through holes 410a and 420a of the anodes 411, 415 and 423 and the cathodes 413 and 421 and 425 by the needle member 610, The through holes communicating with the through holes 410a and 420a formed in the anodes 411, 415 and 423 of the unit cells 410 and 420 and the cathodes 413 and 421 and 425 are formed in the separators 412, 414, 422, and 424 and the separation film 501.

The needle member 610 is smaller in diameter than the diameter 601a of the through holes 410a and 420a of the positive electrodes 411, 415 and 423 and the cathodes 413 and 421 and 425 on the horizontal section Holes penetrating through the separating films 412, 414, 422 and 424 and the separating film 501 at the portions corresponding to each other are electrically connected to the anodes 411, 415 and 423 and the cathodes 413, 421 and 425 The through holes 410a and 420a are formed in the same plane.

7 is a schematic view schematically showing the structure of an electrode assembly stack according to another embodiment of the present invention.

7, the electrode assembly stack 700 includes stacks 712, 714, 722, and 724 interposed between the anodes 711, 715, and 723 and the cathodes 713, 721, The electrode assembly 730 having the structure in which the unit cells 710 and 720 are continuously wound by the separation film 701 is mounted on the upper surface of the base plate 740.

A needle member 741 protrudes upward from the upper surface of the base plate 740 and the needle member 741 is inserted into a through hole communicating with a corresponding portion of the electrode assembly 730.

715 and 723 of each of the unit cells 710 and 720 except for the separation films 712 and 714 and 722 and 724 and the separation films 701, In the process of mounting the electrode assembly 730 on the base plate 740 in the state where the through holes 713, 721 and 725 are formed in the through holes, The members 741 are inserted along the through holes of the anodes 711, 715 and 723 and the cathodes 713, 721 and 725 communicating with each other at the mutually corresponding portions, thereby forming the anodes 711, 715 and 723, The through holes of the separation films 701, 702, and 724 and the separation films 712, 714, 722, and 724 communicating with the through holes of the cathodes 713, 721, and 725 may be perforated.

Thus, the electrode assembly 730 can be easily fabricated in the form of an electrode assembly stack 700 and can be stored and moved in the form of the electrode assembly stack 700, Which are inserted into the through holes communicating with the cathode electrodes 711, 715 and 723, the cathodes 713, 721 and 725, the separating films 712, 714, 722 and 724 and the separating film 701, The electrode assembly 730 is prevented from flowing by the needle member 741 of the electrode assembly 740 so that the electrode assembly stack 700 can be more stably Can be stored and moved.

8 is a schematic view schematically showing a structure of a unit cell stack according to another embodiment of the present invention.

8, the unit cell stacks 801 and 802 each have a structure in which one anode 813 is interposed between two anodes 811 and 815, Five unit cells 810 having a stacked structure in which separation membranes 812 and 814 are interposed between the two cathodes 821 and 825 are mounted on the upper surface of the base plate 830, Five unit cells 820 having a stacked structure in which separation membranes 822 and 824 are interposed between the cathodes 821 and 825 and the anodes 823 in a state in which one anode 823 is interposed between the cathodes 821 and 825 and the anode 823, And is mounted on the upper surface of the plate 840.

The structure, the manufacturing method and the effect of the unit cell stacks 801 and 802 are the same as those of the electrode assembly stack 700 except for the separation film 701 in the structure, same.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (19)

Layered structure composed of at least one positive electrode coated with an electrode active material on one side or both sides of the current collector, at least one negative electrode, and a separator interposed between the positive electrode and the negative electrode, An electrode assembly including a separation film is mounted on a receiving portion of the battery case;
In the electrode assembly, the positive electrode, the negative electrode, the separation membrane, and the separation film each include at least two through-holes communicating with each other at a portion corresponding to the at least one through-hole,
Wherein a through hole located at a center of the battery cell is the largest among the through holes. The battery cell according to claim 1, wherein the through holes of the anode, the cathode, the separator, and the separator film, which communicate with each other at the portions corresponding to each other, have the same shape. [3] The battery cell of claim 2, wherein the through holes are rectangular, circular or elliptical in plan view. delete delete The battery cell according to claim 1, wherein the through holes are arranged in a straight line with respect to a through hole located at a center of the battery cell. The battery cell according to claim 1, wherein an area of the through hole formed in the separating film and the separating film is smaller than an area of the through hole of the positive electrode and the negative electrode communicating with the through hole. The battery cell according to claim 7, wherein an area of the through hole formed in the separating film and the separating film is about 30% to 95% of the area of the through hole of the positive electrode and the negative electrode communicating with the through hole. The battery cell according to claim 1, wherein an area of the through hole is in a range of 1% to 30% with respect to a total area of one surface of the battery cell in plan view. The battery cell according to claim 1, wherein the battery case comprises a cylindrical or rectangular can, and a cap mounted on an open upper end of the can. The battery cell according to claim 1, wherein the battery case is a pouch-shaped case of a laminate sheet including a resin layer and a metal layer. The battery cell according to claim 1, wherein the battery cell is a lithium secondary battery. [3] The battery cell of claim 1, wherein the separator and / or the separator film is an oil / inorganic composite porous SRS (Safety-Reinforcing Separators) separator. A device comprising at least one battery cell according to claim 1. 15. The device of claim 14, 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 > 1. A unit cell stack in which unit cells for manufacturing a battery cell are stacked,
And a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode and the negative electrode each have a structure in which the positive electrode and the negative electrode are connected to each other at a portion corresponding to the positive electrode and the negative electrode, Unit cells having a structure in which two or more communicating through holes are perforated and at least one through hole is located in the center of the battery cell in plan view;
A base plate mounted on the upper surface of the unit cells in a stacked state; And
At least one needle member protruding upward from the base plate and inserted into the through-holes of the unit cells;
And,
Wherein a through hole located at a center of the battery cell is the largest among the through holes. 17. The unit cell stack of claim 16, wherein the separator of the unit cell is formed with a through hole by the needle member in the process of mounting the unit cell on the base plate. An electrode assembly stack in which an electrode assembly for manufacturing a battery cell is laminated,
Layered structure composed of at least one positive electrode coated with an electrode active material on one side or both sides of the current collector, at least one negative electrode, and a separator interposed between the positive electrode and the negative electrode, Wherein at least one through hole is formed in the center of the battery cell in a plan view, and at least one through hole is formed in the center of the battery cell, The electrode assembly;
A base plate mounted on the upper surface of the electrode assembly in a stacked state; And
At least one needle member protruding upward from the base plate and inserted into the through-hole of the electrode assembly;
And,
Wherein a through hole located at a center of the battery cell is the largest among the through holes. 19. The electrode assembly of claim 18, wherein the separation membrane and the separation film of the unit cell are formed by perforating the through hole with the needle member in the process of mounting the electrode assembly on the base plate.

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