KR101819693B1 - Electrode Assembly Comprising a Plurality of Electrode Units and Single Separator Sheet - Google Patents

Abstract

The present invention relates to a battery comprising a plurality of anode unit bodies on which a cathode active material is applied on a current collector; A plurality of cathode unit pieces coated with a negative electrode active material on a current collector; And one separator sheet for continuously winding the positive electrode unit bodies and the negative electrode unit bodies so as to be interposed between the positive electrode unit bodies and the negative electrode unit bodies, And a safety-reinforcement separator (SRS) coating layer is formed on at least one surface of the electrode assembly.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electrode assembly including a plurality of electrode unit bodies and a separator sheet,

The present invention relates to an electrode assembly comprising a plurality of electrode unit bodies and a separator sheet.

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.

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.

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.

FIG. 1 schematically illustrates a typical structure of a conventional stack / folding type electrode assembly.

Referring to FIG. 1, the electrode assembly 100 includes unit cells 120, 140, 160, and 180 having a structure in which a cathode is disposed between anodes and a separation membrane is disposed between anodes and a cathode, And a unit cell 110, 130, 150, 170 having a structure in which a separator is interposed between the anode and the cathode.

The separation film 190 interposed between the unit cells 110, 120, 130, 140, 150, 160, 170 and 180 of the electrode assembly 100 is formed of a unit cell 120, 130, 140, 150, 160, 170, 180. The electrode assembly 100 includes a plurality of unit cells 110, 120, 130 , 140, 150, 160, 170, 180) and winding the separation film (190).

However, in the case of such a stack / folding type electrode assembly, a process of separately fabricating each unit cell and a process of fabricating a final electrode assembly by winding the separately prepared unit cells on a separation film The overall manufacturing process is complicated, the defect rate increases, the process efficiency is lowered, and the overall manufacturing cost is increased.

In addition, the stack / folding type electrode assembly controls the capacity of the battery cells by controlling the number of unit cells included in the electrode assembly. As described above, each unit cell includes an anode, a cathode, The size of the battery cell can be controlled by controlling the quantity of the unit cells. Therefore, when the capacity of the battery cell is adjusted by controlling the quantity of the unit cells, the overall size of the electrode assembly can be finely adjusted Is not easy.

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 have succeeded in various experiments. As described later, one separator sheet is configured to wind a plurality of the anode unit bodies and the cathode unit bodies so that the anode, the cathode, It is possible to simplify the entire manufacturing process, to make it easier to manufacture, to reduce the defective rate of the product, and to save the overall cost, and the electrode assembly And the present invention has been accomplished on the basis of this finding.

According to an aspect of the present invention, there is provided an electrode assembly comprising:

A plurality of anode unit pieces on which a cathode active material is applied on a current collector;

A plurality of cathode unit pieces coated with a negative electrode active material on a current collector; And

A separator sheet continuously winding the anode unit bodies and the cathode unit bodies so as to be interposed between the anode unit bodies and the cathode unit bodies;

And,

The separator sheet may have a structure in which an SRS (Safety-Reinforcing Separators) coating layer is formed on at least one surface on which the anode unit members and the cathode unit members are positioned before winding.

Accordingly, since the one separator sheet winds up the plurality of the anode unit bodies and the cathode unit bodies, it is not necessary to separately manufacture the unit cells including the anode, the cathode, and the separator interposed between the anode and the cathode, The process can be simplified, can be manufactured more easily, the defect rate of the product can be reduced, the overall cost can be saved, and the size of the electrode assembly can be finely adjusted.

In one specific example, on the vertical section of the electrode assembly, at least one of the electrode unit pieces located at the outermost position is formed on the other surface except for one surface facing the opposite electrode unit, May be a structure including an active material uncoated portion that is not coated.

More specifically, the positive electrode unit body and the negative electrode unit body constituting the electrode assembly may each have a structure in which an active material is coated on the current collector.

In this case, among the electrode unit assemblies, the electrode assembly located at the outermost perimeter of the vertical section of the electrode assembly has no separate electrode unit on the other surface except for one surface facing the electrode unit of opposite polarity on the basis of the current collector , The size of the electrode assembly may increase, while the capacity may be lowered compared to an electrode assembly of the same size, while not participating in the reaction.

Accordingly, the electrode assembly according to the present invention is characterized in that, on a vertical section, at least one of the electrode unit bodies located at the outermost positions is formed on the other surface except for one surface facing the opposite electrode unit, By including the non-coated active material uncoated portion, the overall size of the electrode assembly can be made more compact, or a higher capacity can be exhibited as compared with an electrode assembly of the same size.

In one specific example, the anode unit bodies and the cathode unit bodies are positioned at the outermost position from the innermost electrode unit body in a state where the anode unit bodies and the cathode unit bodies are sequentially positioned at a predetermined interval on one surface of the separator sheet, May be wound in one direction toward the electrode unit body.

In other words, the anode unit bodies and the cathode unit bodies are manufactured by winding the separator sheet in one direction with the separator sheet being positioned on one side of the separator sheet before winding the separator sheet.

In another specific example, the anode unit bodies and the cathode unit bodies are stacked on the other side of the separator sheet from the electrode unit disposed at one end of the separator sheet, while being sequentially positioned at a predetermined interval on one surface of the separator sheet, The electrode unit body located at one end of the electrode unit body and the electrode unit body located at the other end of the electrode unit body.

That is, the anode unit bodies and the cathode unit bodies are manufactured by winding the separator sheet in both directions from both end portions toward the center portion, while being positioned only on one surface of the separator sheet before winding the separator sheet.

In this case, the electrode assembly includes a first winding section wound from the electrode unit disposed at one end of the separation membrane sheet, and a second winding section wound from the electrode unit located at the other end of the separation membrane sheet, The two winding portions can be made to have different sizes in plan view.

In other words, the electrode assembly can form an outer surface including a stepped step structure. In the state that the electrode unit bodies having different sizes are located on one surface of the separator sheet, both ends of the separator sheet are directed toward the center portion The first winding section and the second winding section having different sizes from each other can be constituted.

Therefore, in the case of forming the outer surface including the stepped step structure, each part having a different size can be more easily constituted than an electrode assembly in which the separator sheet is wound in one direction.

In addition, in order to improve the safety of the battery, the separator sheet may have a structure in which an SRS coating layer is formed on at least one surface of the separator sheet before the winding, in which the anode unit bodies and the cathode unit bodies are located.

The separation membrane on which the SRS coating layer is formed is produced by using inorganic particles and a binder polymer on the polyolefin-based separation membrane as the active layer component. In addition to the pore structure contained in the separation membrane substrate itself, ) Having a uniform pore structure.

When the separation membrane having such an SRS coating layer is used, it is advantageous in that an increase in thickness of the battery due to swelling at the time of chemical conversion can be suppressed as compared with the case where a conventional separation membrane is used, When a gelable polymer is used in electrolyte solution impregnation, it can also be used as an electrolyte.

In addition, the separation membrane having the SRS coating layer can exhibit excellent adhesive force characteristics by controlling the content of the inorganic particles and the binder polymer in the separation membrane, so that the battery assembly process can be easily performed.

Therefore, since the anode unit bodies and the cathode unit bodies are located only on one side of the separator sheet, the separator sheet has the SRS coating layer formed on only one side of the separator sheet on which the anode unit bodies and the cathode unit bodies are located, Excellent adhesion can be exerted to the unit bodies.

In the case of a conventional electrode assembly using a unit cell having a separator interposed between an anode and a cathode, an SRS coating layer must be formed on both sides of the separator in order to provide an adhesive force to the anode and the cathode, Since the electrode assembly according to the present invention has a relatively small area for forming the SRS coating layer, the cost for forming the SRS coating layer can be reduced.

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.

That is, the SRS coating layer is formed on one surface and / or the other surface of the separation film on which the unit cells are located, and / or on both sides of the separation membrane constituting each unit cell, The electrode assembly according to the present invention can sufficiently exhibit the above effect by forming the SRS coating layer on only one side of the separator sheet on which the positive electrode unit members and the negative electrode unit members are located before winding the separator sheet.

Therefore, unlike the conventional stack / folding type electrode assembly, the electrode assembly according to the present invention does not need to form the SRS coating layer on both sides of the separator constituting each unit cell, Only the SRS coating layer is formed, so that the process, time and cost required for forming the SRS coating layer can be saved.

In another specific example, the positive electrode unit bodies and the negative electrode unit bodies are spaced apart from each other by a predetermined interval so that the electrode unit bodies having polarities different from each other on the one surface and the other surface of the separator sheet, The electrode units may be arranged so as to be wound in one direction from the electrode unit disposed at the innermost position to the electrode unit located at the outermost position.

In other words, the electrode assembly according to the present invention may have a structure in which the anode unit bodies and the cathode unit bodies are all located on one surface and the other surface of the separator sheet before winding the separator sheet. In this case, the anode unit bodies and the cathode unit bodies The separator sheet may be positioned on both sides of the separator sheet with the separator sheet sandwiched therebetween at positions where the electrode unit bodies having mutually different polarities correspond to each other.

At this time, the anode unit bodies and the cathode unit bodies are positioned alternately from the electrode unit disposed at the innermost position to the electrode unit positioned at the outermost position, with respect to one surface or the other surface of the separator sheet, before winding the separator sheet Structure.

Therefore, the electrode assembly manufactured by winding the separator sheet may have a structure in which the electrode unit bodies having polarities different from each other on the vertical section face each other with the separator sheet facing each other.

In addition, the separator sheet may have a structure in which an SRS coating layer is formed on one surface and the other surface of the anode unit bodies and the cathode unit bodies.

Therefore, unlike the conventional stack / folding type electrode assembly, the electrode assembly according to the present invention does not need to form the SRS coating layer on both sides of the separator constituting each unit cell, Since the SRS coating layer is formed only on one side and the other side of the sheet, the process, time and cost required for forming the SRS coating layer can be saved.

Meanwhile, the gap between the anode unit bodies and the cathode unit bodies may be gradually increased toward the winding direction of the separator sheet.

As described above, the anode unit bodies and the cathode unit bodies are sequentially wound before being wound on the separator sheet, on one surface of the separator sheet, or on one surface and the other surface of the separator sheet at predetermined intervals.

Accordingly, the anode unit bodies and the cathode unit bodies are sequentially stacked as they are wound by the separator sheet, and as the lamination of the anode unit bodies and the cathode unit bodies progresses, the overall thickness of the electrode assembly increases, The spacing between the unit bodies and the cathode unit bodies gradually increases toward the winding direction of the separator sheet so that electrode assemblies having different polarity from each other can stably face each other at the correct positions.

Further, in order to exhibit the above effect, the gap between the anode unit bodies and the cathode unit bodies may be increased in proportion to the thickness of the wound electrode unit bodies.

In one specific example, the electrode assembly may be a structure including a total of 5 to 50 anode unit bodies and cathode unit bodies.

If the number of the anode unit bodies and the cathode unit bodies included in the electrode assembly is less than a total of five, the desired capacity and electrical performance can not be exhibited due to an excessively small quantity, and the anode unit bodies And the total number of the cathode unit pieces exceeds 50, there is a problem that the product defect rate due to the insufficient winding of the separator sheet may increase due to an excessive amount of water.

In addition, the number of the anode unit bodies and the cathode unit bodies is appropriately controlled in the above-described range according to the mounting space and the desired capacity in the device to which the electrode assembly is applied, and the anode assembly, the separator, The overall size of the electrode assembly can be more finely adjusted than in the conventional stack / folding type electrode assembly for controlling the number of unit cells.

Meanwhile, the present invention provides a battery cell including the electrode assembly. The battery cell is not particularly limited in its kind, but a battery cell having advantages such as high energy density, discharge voltage, and output stability A lithium ion battery, a lithium ion polymer battery, or the like.

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 &lt; 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.

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, etc. 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, in the electrode assembly according to the present invention, one separator sheet is configured to wind a plurality of positive electrode unit bodies and negative electrode unit bodies, whereby a structure including an anode, a cathode, and a separator interposed between the anode and the cathode It is possible to simplify the entire manufacturing process, to make it easier to manufacture, to reduce the defect rate of the product, to save the overall cost, and to more finely adjust the size of the electrode assembly There is an effect.

1 is a schematic diagram schematically illustrating the general structure of a typical stack / folding type electrode assembly of the prior art;
2 is a schematic view illustrating a method of manufacturing an electrode assembly according to an embodiment of the present invention;
3 is a schematic view schematically showing the structure of the electrode unit bodies located at the outermost part of FIG. 2;
4 is a schematic view schematically showing the structure of an electrode assembly manufactured according to the manufacturing method of FIG. 2;
5 is a schematic view illustrating a method of manufacturing an electrode assembly according to another embodiment of the present invention;
6 is a schematic view illustrating a method of manufacturing an electrode assembly of a battery cell according to another embodiment of the present invention;
7 is a schematic view schematically showing a structure of a battery cell manufactured according to the manufacturing method of FIG.

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 a schematic view illustrating a method of manufacturing an electrode assembly according to an embodiment of the present invention. FIG. 3 is a schematic view schematically showing the structure of electrode unit bodies positioned at the outermost portion of FIG. FIG. 4 is a schematic view schematically showing the structure of the electrode assembly manufactured according to the manufacturing method of FIG.

2 through 4, the electrode assembly 200 includes five anode unit bodies 211, 214, 215, 218, 219 and four cathode unit bodies 212, 213, 216, 220 in a state in which the separator sheet 220 is sequentially placed on one surface of the separator sheet 220 in a single direction.

At this time, the first electrode unit body 211 located at the innermost side of the electrode assembly 200 is coated with the active material 211b and 211c on both sides of the current collector 211a, The ninth electrode unit 219 positioned at the outermost portion is provided with an active material 219b only on one surface of the current collector 219a facing the seventh electrode unit 217 with the separator sheet 220 interposed therebetween, On the other side of the current collector 219a facing the separator sheet 220, an active material unformed portion having no active material is included.

Therefore, the ninth electrode unit 219 is positioned such that the other surface of the current collector 219a on which the active material is not coated is positioned at the outermost portion of the electrode assembly 200, The electrode assembly 200 can be formed in a small size and when the battery cell is damaged by the conductive material, it is possible to prevent the generation of heat and fire that may occur due to the direct contact of the active material with the conductive material, .

An SRS coating layer is formed on one surface of the separator sheet 220 on which the electrode unit bodies 211, 212, 213, 214, 215, 216, 217, 218 and 219 are located, , 215, 216, 217, 218, 219).

The electrode unit pieces 211, 212, 213, 214, 215, 216, 217, 218 and 219 are arranged at predetermined intervals 221, 222, 223, 224, 225, 226, 227 , 228).

Specifically, the first electrode unit body 211 and the second electrode unit body 212 are spaced apart from each other by an interval corresponding to the width of the first electrode unit body 211.

The spaced apart spaces 222, 223, 224, 225, 226, 227 and 228 between the electrode unit bodies 212, 213, 214, 215, 216, 217, 218, 212, 213, 214, 215, 216, 217, 218 wound around the ninth electrode unit 219 toward the ninth electrode unit 219.

The first electrode unit 211 moves to a spaced-apart position between the first electrode unit 211 and the second electrode unit 212 in an inverted state during the winding process, Is wound on one surface of the second electrode unit 212 so as to face the separator sheet 220 therebetween.

The first electrode unit body 211 and the second electrode unit body 212 facing each other with the separator sheet 220 sandwiched therebetween are simultaneously wound by the separator sheet 220 so that the second electrode unit 212, The other surface of the first electrode unit 211 facing the first electrode unit 213 faces one surface of the third electrode unit 213 with the separator sheet 220 interposed therebetween.

The winding 230 proceeds sequentially to the ninth electrode unit 219 so that the first electrode unit 211 is positioned on the innermost side and the eighth electrode unit 218 and the ninth electrode unit 219 Are located at the outermost portions of the electrode assembly 200 facing each other.

5 is a schematic view illustrating a method of manufacturing an electrode assembly according to another embodiment of the present invention.

Referring to FIG. 5, the electrode assembly 500 includes the anode unit pieces 511, 514, 515, 518, 519 and the cathode unit pieces 512, 513, 516, 517, 520 on one side of the separator sheet 530, And then winding the separator sheet 530 in one direction (540) while sequentially positioned on the other surface.

Specifically, the electrode assembly 500 includes five anode unit bodies 511, 514, 515, 518, 519 and five cathode unit bodies 512, 513, 516, 517, 513, 515, 518, and 519 and the negative electrode unit bodies 512, 513, 516, 517, and 520 have polarities different from each other with the separator sheet 530 sandwiched therebetween So that the electrode unit pieces face each other.

SRS coating layers are formed on one surface and the other surface of the separator sheet 530 on which the electrode unit bodies 511, 512, 513, 514, 515, 516, 517, 518, 519, 512, 513, 514, 515, 516, 517, 518, 519, 520).

The electrode unit bodies 511, 512, 513, 514, 515, 516, 517, 518, 519, 520 are disposed in an alternating manner on one surface and the other surface of the separator sheet 530, 513, 515, 516, 517, 518, 519, and 520 are spaced apart from each other at predetermined intervals 531, 532, 533, and 534 on one surface and the other surface of the separator sheet 530.

A gap 531 corresponding to the width of the first electrode unit 511 and the second electrode unit 512 is formed between the first electrode unit 511 and the third electrode unit 513, Respectively.

The spaced apart intervals 532, 533 and 534 between the electrode unit bodies 513, 515, 517 and 519 are the same as the distance between the electrode unit bodies 511, 512, 513, 514, 515, 516, 517, 518).

The first electrode unit 511 and the second electrode unit 512 facing each other with the separator sheet 530 sandwiched therebetween are simultaneously wound by the separator sheet 530 so that the first electrode unit 511 and the third electrode unit 511, And then one surface of the first electrode unit body 511 is wound so as to face the one surface of the third electrode unit body 513 with the separator sheet 530 therebetween.

The first electrode unit body 511 is located at the innermost position and the eighth electrode unit body 518 and the tenth electrode unit body 520 are located at the tenth And the electrode unit bodies 520 are located at the outermost positions where the electrode units 520 face each other.

6 is a schematic view illustrating a method of manufacturing an electrode assembly for a battery cell according to another embodiment of the present invention, and FIG. 7 is a schematic view schematically showing the structure of a battery cell manufactured according to the manufacturing method of FIG. Are shown.

6 and 7, the electrode assembly 600 includes the anode unit pieces 611, 614, 615, 616, and 619 and the cathode unit pieces 612, 613, 617, and 618 on one side of the separator sheet 620 And then winding the separator sheet 620 in the direction from the both side ends to the central portion in the state that the separator sheet 620 is sequentially positioned on the other side.

Specifically, the electrode assembly 600 includes five anode unit pieces 611, 614, 615, 616 and 619 and four cathode unit pieces 612, 613, 617 and 618, The anode unit pieces 611, 614, 615, 616, and 619 and the cathode unit pieces 612, 613, 617, and 618 are located on the same side of the separator sheet 620.

SRS coating layers are formed on one surface and the other surface of the separator sheet 620 on which the electrode unit pieces 611, 612, 613, 614, 615, 616, 617, 618, 613, 614, 615, 616, 617, 618, 619).

The first to fifth electrode unit bodies 615 to 617 constitute a first winding unit 541 from the first 1-1 electrode unit body 611 wound up from one end of the separator sheet 620. The separator sheet 620, The second-fourth electrode unit body 619 forms a second winding unit 642 from the second-1 electrode unit body 616 wound from the other end of the second winding unit 641. [

The electrode unit bodies 616, 617, 618, and 619 constituting the electrode unit bodies 611, 612, 613, 614, and 615 and the second winding unit 642 constituting the first winding unit 641, They are of different sizes.

The electrode unit pieces 611, 612, 613, 614, 615, 616, 617, 618 and 619 are arranged on a surface of the separator sheet 620 at predetermined intervals 621, 622, 623, 624, 628, 626, ).

Specifically, a spacing 621 corresponding to the width of the 1-1 electrode unit body 611 is formed between the 1-1 electrode unit body 611 and the 1-2 electrode unit body 612, .

Thereafter, the spaced apart intervals 622, 623, and 624 between the electrode units 612, 613, 614, and 615 are wound toward the first to fifth electrode unit bodies 615 from the first to second electrode unit bodies 612 The electrode units 611, 612, 613, 614, and 615 are gradually increased in proportion to the thickness of the electrode units 611, 612, 613, 614, and 615.

Similarly, a spacing 625 corresponding to the width of the second-1 electrode unit body 616 is formed between the second-1 electrode unit body 616 and the second -2 electrode unit body 617 The spaced apart spaces 626 and 627 between the electrode unit pieces 617 and 618 and 619 are formed in such a manner that the electrodes 621 and 622 wound around the second electrode unit unit 617 toward the second electrode unit unit 619 616, 617, 618, and 619. The thickness of the unit pieces 616, 617, 618, and 619 is gradually increased in proportion to the thickness of the unit pieces 616, 617, 618, and 619.

The 1-1 electrode unit body 611 and the 2-1 electrode unit body 616 constituting the innermost electrode unit bodies of the first winding section 641 and the second winding section 642 are each wound in the winding direction Electrode unit unit 611 and the first-second electrode unit unit 612 in a state in which the second-first electrode unit unit 616 and the second-second electrode unit unit 617 are separated from each other, &Lt; / RTI &gt;

One surface of the 1-1 electrode unit body 611 and one surface of the 2-2 electrode unit body 616 are then bonded to one surface of the 1-2 electrode unit body 612 and one surface of the 2-2 electrode unit body 617, To be opposed to each other with the separator sheet 620 sandwiched therebetween.

The winding process 631 and 632 sequentially proceed to the 1-5th electrode unit 615 and the 2-4 electrode unit 619 so that the first winding unit 641 and the second winding unit The first 1-1 electrode unit body 611 and the second -1 electrode unit body 616 are located on the innermost side of the first electrode unit 642 and the 1-5th electrode unit body 615 and the 2-4 fourth electrode unit 619 are The electrode assembly 200 having the outermost structure facing each other is completed.

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 (17)

A plurality of anode unit pieces on which a cathode active material is applied on a current collector;
A plurality of cathode unit pieces coated with a negative electrode active material on a current collector; And
A separator sheet continuously winding the anode unit bodies and the cathode unit bodies so as to be interposed between the anode unit bodies and the cathode unit bodies;
And,
The separator sheet has a safety-reinforcement separator (SRS) coating layer on only one side of the separator sheet, on which the anode unit bodies and the cathode unit bodies are located,
The positive electrode unit bodies and the negative electrode unit bodies are arranged in the order from the electrode unit body located at the innermost position toward the electrode unit body located at the outermost position Is wound on the electrode assembly. The electrode assembly according to claim 1, wherein at least one of the electrode unit members located at the outermost positions on the vertical section of the electrode assembly has electrode active materials on the other surface excluding one surface facing the opposite electrode unit, Wherein the electrode assembly includes an active material uncoated portion that is not coated. delete A plurality of anode unit pieces on which a cathode active material is applied on a current collector;
A plurality of cathode unit pieces coated with a negative electrode active material on a current collector; And
A separator sheet continuously winding the anode unit bodies and the cathode unit bodies so as to be interposed between the anode unit bodies and the cathode unit bodies;
And,
The separator sheet has a safety-reinforcement separator (SRS) coating layer on only one side of the separator sheet, on which the anode unit bodies and the cathode unit bodies are located,
The anode unit bodies and the cathode unit bodies are stacked on the separator sheet in a state in which the separator sheet is sequentially positioned at a predetermined interval on one side of the separator sheet, Wherein the electrode assembly is wound in both directions from an electrode unit disposed at one end to an electrode unit disposed at one end. The electrode assembly according to claim 4, wherein the electrode assembly includes a first winding section wound from an electrode unit disposed at one end of a separation membrane sheet and a second winding section wound from an electrode unit located at another end of the separation membrane sheet, Wherein the attachment and the second winding portion are formed to have different sizes from each other in plan view. delete delete delete delete The separator sheet according to any one of claims 1, 2, 4, and 5, wherein the distance between the anode unit bodies and the cathode unit bodies gradually increases toward the winding direction of the separator sheet . 11. The electrode assembly according to claim 10, wherein a distance between the anode unit bodies and the cathode unit bodies increases in proportion to the thickness of the wound electrode unit bodies. The electrode assembly according to claim 1 or 4, wherein the electrode assembly includes a total of 5 to 50 anode unit pieces and cathode unit pieces. delete A battery cell comprising an electrode assembly according to claim 1 or claim 4. 15. The battery cell according to claim 14, wherein the battery cell is a lithium secondary battery. A device comprising at least one battery cell according to claim 14. 17. The method of claim 16, 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- . &Lt; / RTI &gt;

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