KR102042999B1 - Method for Preparation of Stack and Folding-typed Electrode Assembly Having Electrode Taps with Various-Sized - Google Patents

Abstract

The present invention, in a method of manufacturing a stack / folding type electrode assembly by winding in a state in which the electrode unit is placed on a separation film of a continuous length,
When the electrode units are positioned on the separation film for winding, the first electrode unit is positioned at the start of winding and the nth electrode unit is positioned at the end of the winding, and the electrode tabs are formed at one or both ends of the electrode units. It provides a manufacturing method characterized in that the protruding length of these are arranged so as to sequentially increase in the direction of the n-th electrode unit from the first electrode unit.

Description

Method for Preparation of Stack and Folding-typed Electrode Assembly Having Electrode Taps with Various-Sized}

The present invention relates to a method for manufacturing a stacked and folded electrode assembly comprising electrode tabs of various sizes.

As technology development and demand for mobile devices increase, the demand for batteries as energy sources is rapidly increasing, and accordingly, many studies on batteries that can meet various demands have been conducted.

Representatively, there is a high demand for rectangular secondary batteries and pouch secondary batteries that can be applied to products such as mobile phones with a thin thickness in terms of shape of batteries, and lithium ion batteries with high energy density, discharge voltage and output stability in terms of materials. There is a high demand for lithium secondary batteries such as lithium ion polymer batteries.

In addition, secondary batteries are classified according to the structure of the electrode assembly having a cathode / separation membrane / cathode structure, and typically, a jelly having a structure in which long sheet-shaped anodes and cathodes are wound with a separator interposed therebetween. -Roll (electrode) electrode assembly, a plurality of positive and negative electrodes cut in a unit of a predetermined size is divided into a stacked (stacked) electrode assembly sequentially stacked with a separator.

However, these conventional electrode assemblies have some problems.

First, since the jelly-roll electrode assembly is wound around a long sheet-shaped anode and cathode in a dense state to form a cylindrical or oval structure in cross section, stress caused by expansion and contraction of the electrode during charge and discharge accumulates inside the electrode assembly. If the stress accumulation exceeds a certain limit, deformation of the electrode assembly occurs. Due to the deformation of the electrode assembly, the spacing between the electrodes is non-uniform, leading to a problem that the performance of the battery is sharply lowered and the safety of the battery is threatened due to internal short circuit. In addition, since the long sheet-type positive electrode and the negative electrode must be wound, it is difficult to quickly wind the coil while keeping the distance between the positive electrode and the negative electrode, which also has a problem in that the productivity is lowered.

Second, since the stack type electrode assembly has to stack a plurality of positive and negative electrode units in sequence, the electrode plate transfer process is required separately for manufacturing the unit, and the productivity is low because a lot of time and effort are required for the sequential lamination process. Has a problem.

In order to solve this problem, the electrode assembly of the advanced structure in the mixed form of the jelly-roll type and the stack type, a bi-cell or a full cell in which a positive electrode and a negative electrode of a predetermined unit are laminated with a separator therebetween A stack / foldable electrode assembly was developed in which full cells were wound using a continuous separation film of a long length.

1 and 2 schematically show an exemplary structure and manufacturing process of a stack / foldable electrode assembly using such a full cell as a basic unit.

Referring to these drawings, as a unit cell, a plurality of full cells 10, 11, 12, 13, 14..., In which anode / separation membrane / cathode are sequentially arranged are overlapped, and a separation film 20 is disposed at each overlapping portion. Is interposed. Separation film 20 has a unit length that can wrap the full cell, bend inward for each unit length starting from the center full cell 10 to the outermost full cell 14 to wrap each successive full cell to overlap the full cell Intervened in The distal end of the separation film 20 is finished by heat fusion or by attaching an adhesive tape 25 or the like.

Such a stack / foldable electrode assembly may, for example, arrange full cells 10, 11, 12, 13, 14... On a long length of separation film 20, and one end 21 of the separation film 20. It is prepared by winding up sequentially starting at.

At this time, the arrangement combination of the full cells as the unit cell, the first full cell 10 and the second full cell 11 is located at a distance separated by a width interval corresponding to at least one full cell, so that the first full cell in the winding process After the outer surface of 10 is completely coated with the separation film 20, the lower electrode of the first full cell 10 is in contact with the upper electrode of the second full cell 11.

The full cells 11, 12, 13, 14... After the second full cell have an increased coating length of the separation film 20 in a sequential lamination process by winding, so that the interval therebetween increases sequentially in the winding direction. It is arranged to be.

In addition, when winding up the full cells, the anode and the cathode should be configured to face each other at the stacked interface. The first full cell 10 and the second full cell 11 are full cells in which the upper electrode is the anode, and the third full cell 12. The upper electrode is a full cell in which the negative electrode, the fourth full cell 13 is a full cell, the fifth full cell 14 is composed of a full cell in which the upper electrode is the negative electrode. That is, except for the first full cell 10, the full cell of which the upper electrode is the anode and the full cell of the cathode of the upper electrode are alternately arranged.

FIG. 3 is a side cross-sectional view schematically showing a general structure of a conventional representative stack / foldable electrode assembly, and FIG. 4 shows a long length of a separation film before winding and manufacturing the conventional representative stack / foldable electrode assembly. A schematic plan view showing a structure in which full cells are arranged is shown in FIG.

Referring to FIG. 3, the stack / foldable electrode assembly 30 may have a negative electrode active material on both sides of the positive electrode 40 and the negative electrode current collector 51 having the positive electrode active material 42 coated on both sides of the positive electrode current collector 41. The cathode 50, to which the 52 is applied, forms a full cell 44 sequentially stacked in a state where the separator 60 is interposed therebetween. As shown in FIG. 4, electrode tabs having the same protruding length ( After arranging 11 full cells 44 formed on the long separation film 70, the full cells 44 are wound with the long separation film 70 to manufacture the electrode assembly of FIG. 3. .

In addition, at one end of each of the positive electrode current collector 41 and the negative electrode current collector 51 of FIG. 3, the positive electrode 80 and the negative electrode lead 90 which constitute the electrode terminal of a battery (not shown) are respectively electrically connected. A plurality of positive electrode tabs 43 and negative electrode tabs 53 to which the active material is not coated are formed to protrude. At this time, the positive electrode tabs 43 and the negative electrode tabs 53 are combined in a dense form and are connected to the positive electrode lead 80 and the negative electrode lead 90, respectively. Such a structure can be more easily confirmed in FIG. 5, in which the coupling portion of the positive electrode tabs and the positive lead is schematically shown as a partial enlarged view. In FIG. 5, only the coupling structure of the positive electrode tabs and the positive lead is illustrated for convenience of description, but the structure is also applied to the coupling portion of the negative electrode tabs 53 and the negative electrode lead 90.

3 and 5 together, the positive electrode tabs 43 are closely attached in the direction of the arrow and are connected to the positive electrode lead 60. That is, the positive electrode tabs 43 are coupled to upper and lower surfaces of the positive electrode lead 80 adjacent to the full cell 45 positioned in the middle of the electrode assembly 30. Accordingly, the positive electrode tab 46 of the full cell 45 located at the middle of the electrode assembly located at a short distance from the positive electrode lead 60 and the positive electrode tab 43 of the uppermost full cell 44 located at the far end are positive. The difference in distance from the lead 60 causes a length difference in the coupling portion A of the positive electrode tabs 43. This length difference also occurs at the junction of the negative electrode tabs 53 and the negative electrode lead 90.

Due to this structure, the electrode assembly is different from each other in the area where the respective tabs in contact with the electrode lead in the electrode tab-electrode lead coupling, it is inevitable to use an electrode lead of more than necessary size. This is because the size of the electrode lead is determined based on the electrode tab having the largest contact area in order to fix the electrode tabs having a relatively thin thickness as compared to the electrode lead. In addition, for this reason, the electrode assembly of the above structure also has a problem of poor structural stability.

In order to solve the above problems, a technique of uniformly cutting by using a cutter or the like after bonding the electrode tabs to one side close to each other, but such a technique is a burr at the end of the electrode tabs during cutting May occur, and the cutting process has to be added.

Therefore, there is a high need for technology development to solve the above problems.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

The inventors of the present application, after in-depth study and various experiments, as described later, in a method of manufacturing a stack / folding electrode assembly by winding in a state in which electrode units are placed on a separation film of continuous length. The protrusion lengths of the electrode tabs formed at one or both ends of the electrode units are sequentially arranged in the direction of the n-th electrode unit from the first electrode unit, and then the lengths of the electrode tabs are uniform when wound. The process of cutting easily can be skipped, and it was confirmed that manufacturing time and manufacturing cost can be reduced, and came to complete this invention.

In order to achieve the above object, a method of manufacturing a stack / foldable electrode assembly by winding in a state in which the electrode unit is placed on a separation film of a continuous length,

When the electrode units are positioned on the separation film for winding, the first electrode unit is positioned at the start of winding and the nth electrode unit is positioned at the end of the winding, and the electrode tabs are formed at one or both ends of the electrode units. The protruding length of these is arranged so as to sequentially increase in the direction of the n-th electrode unit from the first electrode unit, and then wound.

Here, the "first electrode unit" and the "n-th electrode unit" refer to the electrode unit located closest to the site where the winding of the separation film of the continuous length is called "first electrode unit", the first electrode unit The electrode units are named by numbering the second electrode unit body, the third electrode unit body, and the fourth electrode unit body in the order of the electrode units positioned in the other direction of the separation film where the winding is finished, and the winding ends. The electrode unit of the last number closest to was named "nth electrode unit".

Therefore, a method of manufacturing a stack / foldable electrode assembly by winding the electrode units on a continuous length separation film according to the present invention may include forming electrode stacks on one or both ends of the electrode units. After arranging the protruding lengths to increase sequentially from the first electrode unit body in the direction of the n-th electrode unit body, by winding up, the electrode tabs are brought into close contact with each other to be combined, and then the length is uniformly cut using a cutter or the like. It can omit, and manufacturing time and manufacturing cost can be saved.

In one specific example, the electrode units may be at least one selected from the group consisting of a full cell, a bicell, and a single electrode, which is a positive electrode or a negative electrode.

Specifically, the full cell may have a structure in which one or more anodes and one or more cathodes are stacked with a separator interposed therebetween, and electrodes having opposite polarities on both surfaces thereof. More specifically, n is 6 to 30, the electrode units may be full cells.

In addition, the bicell may have a structure in which one or more anodes and one or more cathodes are stacked with a separator interposed therebetween, and electrodes having the same polarity are positioned on both surfaces thereof.

In one specific example, the first electrode unit and the second electrode unit on the separation film may have a structure spaced apart from each other at a width interval corresponding to at least one electrode unit.

In addition, in a state in which the separation film is wound, the first electrode unit may be positioned at the center of the electrode assembly based on the stacking direction of the electrode units.

In addition, after winding the separation film to finish winding the separation film, the process of attaching the distal end of the separation film on a portion of the separation film may be further performed.

In addition, after the winding of the separation film, the process of coupling the electrode lead to one end of the electrode tab of the electrode unit may be further performed. Specifically, after winding the separation film, in the state in which the electrode lead is positioned in the center portion of the electrode assembly based on the stacking direction of the electrode unit, it may be a structure for coupling the electrode tabs on both sides of the electrode lead.

In one specific example, the sequentially increasing protruding length of the electrode tabs in the electrode units arranged on the separation film is such that each area where the electrode tabs are coupled to the electrode lead is an electrode tab of the first electrode unit is an electrode. It can be set to be equal to the area associated with the leads.

Specifically, the protruding length of the electrode tabs may have a structure that is sequentially lengthened corresponding to the separation distance from the electrode lead based on the stacking direction of the electrode units.

Thus, the manufacturing method according to the present invention, in the electrode units arranged on the separation film, so that each area where the electrode tabs are bonded to the electrode lead is the same as the area where the electrode tab of the first electrode unit is bonded to the electrode lead. By setting the protruding length of the electrode tabs, the process of uniformly cutting the lengths of the electrode tabs can be omitted.

In one specific example, the electrode tabs of the other electrode units except for the electrode tab of the first electrode unit may have a coupling structure bent at least once so that the coupling portion faces the electrode lead. This bending structure can increase the efficiency of the bonding process between the electrode tab and the electrode lead.

In one specific example, the electrode tabs are positive electrode tabs or negative electrode tabs, and the positive electrode tab and the negative electrode tab may have a structure protruding on both sides of the electrode unit in opposite directions, or the positive electrode tab and the negative electrode tab are the same. It may be a structure protruding on one side of the electrode unit in the direction.

In one specific example, prior to the process of positioning the electrode units on the separation film for the winding,

(a) a first direction (x) in which the electrode workpiece is formed on one or more coating portions coated with the electrode mixture on one or more sheets of current collectors of continuous length; Notching to form electrode tabs protruding in a second direction (y-axis) perpendicular to the first direction during transfer to the first axis;

(b) manufacturing an electrode by cutting an electrode workpiece by the size of an electrode unit constituting one electrode;

(c) stacking the electrodes in (b) in the cut order; And

(d) supplying to the separation film in order from the electrodes positioned on the basis of the ground among the stacked electrodes;

May further include

The length of the electrode tabs formed in step (a) may be notched so as to sequentially decrease.

In addition, the step of notching the electrode tabs of a predetermined number so that the length of the electrode tabs protruding in the second direction in step (a) is sequentially reduced, and again has a cycle of restarting the notching to the length of the electrode tab of the initial notching Can be.

In addition, in the process (d), the electrode tap size may be supplied to the separation film from the smallest electrode.

Accordingly, the manufacturing method according to the present invention continuously forms the electrode tabs so that the length of the protruding electrode tabs decreases sequentially, and then resumes the notching to the length of the electrode tab at the initial stage of notching, and in the order of cutting. By supplying the stacked electrodes to the separation film in order from the electrode located on top, the electrodes can be selected and supplied to the separation film by electrode tab size in a simple manner, thereby improving the manufacturing efficiency.

In one specific example, the electrode tabs of the electrode units may be formed by press notching or laser notching using a laser scanner, and specifically, may be formed by laser notching. Such laser notching can be easily changed by simply modifying the drawing design in software using a laser scanner which is an optical scanner, thereby reducing the additional cost of the design change.

In one specific example, the electrode lead may be a metal plate, and the metal plate may be selected from, for example, an aluminum plate, a copper plate, a nickel plate, a nickel plated copper plate, and an SUS plate.

In addition, the electrode lead may be coupled with the electrode tabs by welding, and the welding may be, for example, ultrasonic welding, laser welding, or resistance welding.

The present invention also provides a stack / foldable electrode assembly prepared by the above method.

The present invention also provides a battery cell comprising the stack / foldable electrode assembly.

Specifically, the battery cell may have a planar quadrangular structure, and the first and second electrode terminals may be formed at both opposing sealing portions of the quadrangular plane.

In addition, the battery cell may be a lithium secondary battery including a positive electrode, a separator and a negative electrode.

The positive electrode may be prepared by, for example, applying a mixture of a positive electrode active material, a conductive material, and a binder onto a positive electrode current collector, followed by drying. If necessary, a filler may be further added to the mixture.

The positive electrode active material is a material capable of causing an electrochemical reaction, and as a lithium transition metal oxide, containing two or more transition metals, for example, lithium cobalt oxide (LiCoO ₂ ), lithium substituted with one or more transition metals, lithium Layered compounds such as nickel oxide (LiNiO ₂ ); Lithium manganese oxide substituted with one or more transition metals; Formula LiNi _1-y M _y O ₂ , wherein M = Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn or Ga and comprises at least one of the above elements, wherein 0.01 ≦ _y ≦ 0.7 Lithium nickel-based oxide represented by; Li _{1 + z} Ni _1/3 Co _1/3 Mn _1/3 O ₂ , Li _{1 + z} Ni _0.4 Mn _0.4 Co _0.2 O _2, etc. Li _{1 + z} Ni _b Mn _c Co _{1- (b + c + d )} M _d O _(2-e) A _e (where -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2, 0≤e≤0.2, b + c + d Lithium nickel cobalt manganese composite oxide represented by <1, M = Al, Mg, Cr, Ti, Si or Y, and A = F, P or Cl; Formula Li _{1 + x} M _{1-y M'y} PO _4-z X _z , wherein M = transition metal, preferably Fe, Mn, Co or Ni, M '= Al, Mg or Ti, X = Olivine-based lithium metal phosphate represented by F, S, or N, and represented by -0.5≤x≤ + 0.5, 0≤y≤0.5, and 0≤z≤0.1, etc., but is not limited thereto.

The conductive material is typically added in an amount of 1 to 20 wt% based on the total weight of the mixture including the positive electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery, and examples thereof include graphite such as natural graphite and artificial graphite; Carbon blacks such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride powder, aluminum powder and nickel powder; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

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

In addition, the negative electrode is prepared by, for example, applying a mixture of a negative electrode active material, a conductive material, and a binder on a negative electrode current collector, followed by drying, and optionally, a filler may be further added to the mixture. In addition, the negative electrode active material may be at least one selected from the group consisting of graphite carbon, coke carbon and hard carbon.

The present invention also provides a battery pack comprising a battery cell as a unit battery.

The battery pack is a device selected from, for example, a mobile phone, a notebook computer, a smartphone, a smart pad, a netbook, a LEV (Light Electronic Vehicle), an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device. It can be used as a power source. Since the device is known in the art, a detailed description thereof is omitted herein.

As described above, a method of manufacturing a stack / foldable electrode assembly by winding the electrode units on a separation film of a continuous length according to the present invention may be formed at one or both ends of the electrode units. By arranging the protruding lengths of the electrode tabs sequentially from the first electrode unit body in the direction of the n-th electrode unit body, and winding up, the process of uniformly cutting the length of the electrode tabs can be omitted, thereby manufacturing time and manufacturing It can reduce the cost.

1 is a schematic front view showing an exemplary structure of a stack / foldable electrode assembly using a full cell of the prior art as a basic unit;
FIG. 2 is a schematic front view showing a manufacturing process of a stack / foldable electrode assembly using a full cell of the prior art as a basic unit; FIG.
3 is a schematic side cross-sectional view showing the structure of a stack / foldable electrode assembly in which a long length of separation film is wound;
4 is a schematic plan view showing a structure in which full cells are arranged on a long length separation film before winding and manufacturing a stack / foldable electrode assembly of the prior art;
5 is an enlarged view schematically showing only a coupling structure of the positive electrode tabs and the positive electrode lead of the stack / foldable electrode assembly of the prior art;
FIG. 6 is a schematic plan view showing a structure in which full cells are arranged on a separation film of a continuous length before winding and manufacturing a stack / foldable electrode assembly according to one embodiment of the present invention; FIG.
7 is a schematic side cross-sectional view showing the structure of a stack / foldable electrode assembly wound with a separation film of continuous length according to one embodiment of the present invention;
FIG. 8 is an enlarged view schematically illustrating only a coupling structure of the positive electrode tabs and the positive electrode lead of the stack / foldable electrode assembly according to the exemplary embodiment of the present invention.

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

FIG. 6 is a plan view schematically illustrating a structure in which full cells are arranged on a separation film of a continuous length before winding and manufacturing a stack / foldable electrode assembly according to an embodiment of the present invention, and FIG. 7. Next, a side cross-sectional view schematically showing a structure of a stack / foldable electrode assembly in which a separation film of a continuous length is wound according to an embodiment of the present invention is shown.

6 and 7 together, the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 144 on the separation film 170 of the continuous length in accordance with the present invention ), A method of manufacturing a stack / foldable electrode assembly 100 by winding in a state of placing the electrode unit 130, 131, 132, 133, 134, 135, 136, on the separation film 170 for winding When the 137, 138, 139, and 144 are positioned, the first electrode unit 130 is positioned at the winding start region 171, and the eleventh electrode unit 144 is positioned at the winding end region 172.

In addition, the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, and 144 according to the present invention may protrude lengths of the electrode tabs 146 and 153 formed at both ends. The fields L ₂ and L ₃ are arranged to sequentially increase in the direction of the eleventh electrode unit 144 from the first electrode unit 130, and then wound.

In this case, the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, and 144 were set as full cells. The full cell 144 may include a cathode 140 including a cathode mixture 142 including a cathode active material on one current collector 141 and a cathode mixture 152 including an anode active material on one current collector 151. ) Is applied to the cathode 150 is laminated in a state in which the separator 160 is interposed. At this time, the positive cell 144 and the negative electrode tab 153 are formed in the full cell 144, and the positive electrode tab 143 and the negative electrode tab 153 protrude on both sides of the electrode unit 144 in opposite directions. It is formed in a structure.

In this case, the first electrode unit 130 and the second electrode unit 131 on the separation film 170 are spaced apart at a width interval L ₁ corresponding to one electrode unit 130.

Meanwhile, in the structure of the stack / foldable electrode assembly 100 in which the winding is shown in FIG. 7, the first electrode unit 130 is the electrode unit 130, 131 in the state in which the separation film 170 is wound. , 132, 133, 134, 135, 136, 137, 138, 139, and 144 based on the stacking direction of the electrode assembly 100.

In addition, after the winding of the separation film 170 is finished, at one end of the positive electrode tabs 143 of the electrode unit (130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 144) The anode lead 180 is coupled, and a cathode lead 190 is coupled to one end of the cathode tabs 153. At this time, the positive electrode lead 180 and the negative electrode at the central portion of the electrode assembly 100 based on the stacking direction of the electrode unit (130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 144) With the lead 190 positioned, the positive electrode tabs 143 and the negative electrode tabs 153 are coupled to both surfaces of the positive electrode lead 180 and the negative electrode lead 190, respectively.

In addition, the positive electrode tabs 143 and the negative electrode tabs 153 of the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, and 144 arranged on the separation film 170. The protruding lengths L ₂ and L ₃ which increase sequentially have an area where the positive electrode tabs 143 are coupled to the positive electrode lead 180, and the positive electrode tab 146 of the first electrode unit 130 includes the positive electrode lead 180. ) And the area where the negative electrode tabs 153 are coupled to the negative electrode lead 190 is the same as that of the negative electrode tab 156 of the first electrode unit 130. Is set equal to.

Due to this setting, the protruding length L ₂ of the positive electrode tabs 143 is based on the stacking direction of the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, and 144. The protruding length L ₃ of the cathode tabs 153 is formed in a structure that is sequentially lengthened corresponding to the separation distance from the anode lead 180, and the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, and 144 are formed in a structure that is sequentially lengthened corresponding to the separation distance from the cathode lead 190, based on the stacking direction.

The electrode tabs 143 and 153 of the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139 and 144 are formed by laser notching, and the electrode leads 180, 190 is a metal plate, and the electrode leads 180 and 190 are coupled to the electrode tabs 143 and 153 by laser welding.

8 is an enlarged view schematically showing only a coupling structure of the positive electrode tabs and the positive electrode lead of the stack / foldable electrode assembly according to the exemplary embodiment of the present invention.

6 to 8, the remaining electrode units 132, 133, 134, 135, and 136 except for the positive electrode tabs 146 and 165 of the first electrode unit 130 and the second electrode unit 131. The positive electrode tabs 143, 161, 162, 163, 164, 166, 167, 168, and 169 of 137, 138, 139, and 144 have a coupling structure that is bent once so that the binding site faces the positive lead 180. To have. This bending structure can increase the efficiency of the bonding process between the electrode tab and the electrode lead.

In addition, the positive electrode tabs 143, 161, 162, 163, 164, 166, 167, 168, and 169 according to the present invention each area A ₃ coupled to the anode lead 180 has a first electrode unit 130. The positive electrode tab 146 of) is the same as the area where the positive electrode lead 180 is coupled, and the coupling structure of the negative electrode tabs 153 and the negative electrode lead 190 is also the same.

9 is a schematic plan view of an electrode workpiece notched to form electrode tabs according to one embodiment of the present invention.

6 and 9 together, to position the electrode units 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 144 on the separation film 170 for the aforementioned winding. Before the process, the coating portion 182 coated with the electrode mixture 142 and the non-coating portion 183, which is not coated with the electrode mixture 143, are formed on the sheet 141 for the current collector in a continuous length. While transferring the electrode workpiece 189 in the first direction (x-axis) in the longitudinal direction of the sheet, the furnace tabs 143 protruding in the second direction (y-axis) perpendicular to the first direction are formed. A process called (a) is shown.

At this time, the lengths of the electrode tabs 143 formed are notched so as to sequentially decrease.

FIG. 10 is a schematic diagram showing a laser notching region for varying the protruding length of electrode tabs of an electrode workpiece according to one embodiment of the present invention.

9 and 10, the notching region 186 is set such that the lengths of the electrode tabs 143 formed using the laser notching method are sequentially reduced.

In addition, the notching region 186 may include a predetermined number of electrode tabs 143 such that the lengths of the electrode tabs 143 protruding in the second direction (x-axis) are sequentially reduced when the electrode tabs 143 are notched. It is set to notching and has a cycle of restarting notching again to the length of the electrode tab at the beginning of notching.

In this case, the electrode tabs of the electrode workpiece 189 are formed by laser notching using a laser scanner. Such laser notching can be easily changed by only modifying the drawing design in software using a laser scanner, which is an optical system scanner. This can reduce the additional cost of design changes.

FIG. 11 is a schematic plan view showing a process of cutting the electrode workpiece according to the size of the electrode unit constituting one electrode according to the exemplary embodiment of the present invention.

Referring to FIG. 11, a cutting region 192 is formed in the electrode assembly 189 on which the electrode tabs 143 are formed to cut the electrode assembly 189 according to the size of the electrode unit constituting one electrode. The electrode workpiece 189 is cut out along this cutout region 192 to produce an electrode (not shown).

12 is a schematic side cross-sectional view illustrating a process of sequentially stacking electrodes manufactured by cutting an electrode workpiece according to an exemplary embodiment of the present invention.

Referring to FIGS. 11 and 12, the electrodes 187 manufactured by cutting the electrode workpiece 189 are stacked in the cut order and stored in the magazine 186.

The stacked electrodes 187 are sequentially taken from the electrode 188 positioned above the ground based on the ground, and supplied to the separation film (not shown).

At this time, the electrode tab 185 is supplied to the separation film from the smallest electrode 188.

As described above, a method of manufacturing a stack / foldable electrode assembly by winding the electrode units on a separation film of a continuous length according to the present invention may be formed at one or both ends of the electrode units. A process of arranging the protruding lengths of the electrode tabs sequentially increases from the first electrode unit body in the direction of the n-th electrode unit body, and then winding the electrode tabs so that the electrode tabs are brought into close contact with each other and then uniformly cut using a cutter or the like. Since it can be omitted, the production time and cost can be reduced to achieve the effect.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

Claims (21)

In the method of manufacturing a stacking / folding type electrode assembly by winding the electrode unit on a continuous film separating the position,
When the electrode units are positioned on the separation film for winding, the first electrode unit is positioned at the start of winding and the nth electrode unit is positioned at the end of the winding, and the electrode tabs are formed at one or both ends of the electrode units. The protrusion lengths of these are arranged so as to sequentially increase in the direction of the n-th electrode unit from the first electrode unit, then wound up,
Before positioning the electrode units on the separation film for the winding,
(a) a first direction (x) in which the electrode workpiece is formed on one or more coating portions coated with the electrode mixture on one or more sheets of current collectors of continuous length; Notching to form electrode tabs protruding in a second direction (y-axis) perpendicular to the first direction during transfer to the first axis;
(b) manufacturing an electrode by cutting an electrode workpiece by the size of an electrode unit constituting one electrode;
(c) stacking the electrodes in (b) in the cut order; And
(d) supplying to the separation film in order from the electrodes positioned on the basis of the ground among the stacked electrodes;
Contains more,
Notching is performed so that the lengths of the electrode tabs formed in step (a) decrease sequentially.
In the process (a), notching the electrode tabs of a predetermined number so that the lengths of the electrode tabs protruding in the second direction are sequentially reduced, and then the notching starts again with the length of the electrode tab at the initial stage of notching. The manufacturing method to make. The method of claim 1, wherein the electrode units are at least one selected from the group consisting of a full cell, a bicell, and a single electrode, which is a positive electrode or a negative electrode. The method of claim 2, wherein the full cell has one or more positive electrodes and one or more negative electrodes stacked with a separator interposed therebetween, and electrodes having opposite polarities on both sides thereof. The method of claim 1, wherein n is 6 to 30, and the electrode units are full cells. The method of claim 2, wherein the bicell has a structure in which at least one positive electrode and at least one negative electrode are stacked with a separator interposed therebetween, and electrodes having the same polarity are positioned on both surfaces thereof. The method of claim 1, wherein the first electrode unit and the second electrode unit are spaced apart from each other at a width corresponding to at least one electrode unit on the separation film. The method of claim 1, wherein in the wound state, the first electrode unit is positioned at the center of the electrode assembly based on the stacking direction of the electrode units. The method of claim 7, wherein after the winding, the electrode lead is coupled to one end of the electrode tabs of the electrode units. The method of claim 8, wherein the electrode tabs are coupled to both surfaces of the electrode lead while the electrode leads are positioned at the center of the electrode assembly based on the stacking direction of the electrode units. The electrode tab of claim 8, wherein the protruding length of the electrode tabs of the electrode units arranged on the separation film is increased so that each of the areas where the electrode tabs are coupled to the electrode lead is formed in the electrode tab of the first electrode unit. A manufacturing method characterized in that it is set to be equal to the area combined with the lead. The method of claim 10, wherein the protruding length of the electrode tabs is sequentially lengthened corresponding to a distance from the electrode lead based on the stacking direction of the electrode units. The method of claim 9, wherein the electrode tabs of the remaining electrode units except for the electrode tab of the first electrode unit have a bonding structure that is bent at least once so that the bonding portion faces the electrode lead. The method of claim 1, wherein the electrode tabs are positive electrode tabs or negative electrode tabs, and the positive electrode tab and the negative electrode tab protrude from both sides of the electrode unit in opposite directions to each other. delete delete The method of claim 1, wherein in the process (d), the electrode having the smallest electrode tab size is supplied to the separation film.  The method of claim 1, wherein the electrode tabs of the electrode units are formed by press notching or laser notching using a laser scanner. The method of claim 8, wherein the electrode lead is coupled to the electrode tabs by welding, and the welding is ultrasonic welding, laser welding, or resistance welding. 19. Stacked / foldable electrode assembly prepared by the method according to any one of claims 1 to 13 and 16 to 18. 20. A battery cell comprising the stack / foldable electrode assembly of claim 19. A battery pack comprising the battery cell according to claim 20 as a unit battery.

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