CN117374417A - Electrode assembly, battery cell, and method for manufacturing battery cell - Google Patents

Electrode assembly, battery cell, and method for manufacturing battery cell Download PDF

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Publication number
CN117374417A
CN117374417A CN202310799927.5A CN202310799927A CN117374417A CN 117374417 A CN117374417 A CN 117374417A CN 202310799927 A CN202310799927 A CN 202310799927A CN 117374417 A CN117374417 A CN 117374417A
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CN
China
Prior art keywords
unit cell
current collector
electrode
collector
electrode assembly
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Pending
Application number
CN202310799927.5A
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Chinese (zh)
Inventor
金圭范
柳彩璘
裵贤洙
尹礼进
尹晶炫
尹蕙婉
李知炫
任钟钻
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SK On Co Ltd
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SK On Co Ltd
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Publication date
Priority claimed from KR1020230066205A external-priority patent/KR20240006430A/en
Application filed by SK On Co Ltd filed Critical SK On Co Ltd
Publication of CN117374417A publication Critical patent/CN117374417A/en
Pending legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)

Abstract

The present disclosure relates to an electrode assembly, a battery cell, and a method of manufacturing the battery cell, the electrode assembly including: a unit cell stack including a first unit cell and a second unit cell, each of the first unit cell and the second unit cell including a first electrode including a first current collector and a first active material layer, a second electrode being an opposite electrode of the first electrode, and including a second current collector and a second active material layer, and a separator interposed between the first electrode and the second electrode; and a first electrode tab first side portion including a first collector first side deformation portion formed by folding or winding one side end portion in the width direction of the first collector of each of the first unit cell and the second unit cell, a shortest distance from an upper surface of the first collector of the second unit cell to an upper surface of the first collector of the first unit cell being the same as a height of the first collector first side deformation portion of the second unit cell.

Description

Electrode assembly, battery cell, and method for manufacturing battery cell
Technical Field
The present disclosure relates to an electrode assembly.
Further, the present disclosure relates to a battery cell including the electrode assembly.
Furthermore, the present disclosure relates to a method of manufacturing the battery cell.
Background
The demand for secondary batteries (Secondary Battery) as energy sources has increased dramatically with the development of the electronics, communications and aerospace industries. In particular, as the importance of environmental policies expands worldwide, the electric automobile market is growing rapidly. Therefore, research and development of secondary batteries are actively being conducted at home and abroad.
Among various secondary batteries, research and development of lithium secondary batteries are most active. This is because the lithium secondary battery has a high discharge voltage and a high energy density. A plurality of unit cells (unit cells) having a separator interposed between a positive electrode and a negative electrode are stacked in an electrode assembly constituting a lithium secondary battery. Here, the plurality of positive electrodes and the plurality of negative electrodes of each unit cell may be combined into one body by welding. Fig. 1 is a schematic view of a conventional electrode assembly manufacturing method. A plurality of unit cells including a first electrode including a first current collector 2 and a first active material layer formed on at least one side of the first current collector, a second electrode including a second current collector 3 and a second active material layer formed on at least one side of the second current collector, and a separator interposed between the first electrode and the second electrode are stacked in the electrode assembly 1. The electrode assembly may be manufactured by combining the first current collector 2 and the second current collector 3 of each unit cell extending to the outside of the stack, respectively, as one body and pressing P, and then welding the electrode leads 4 thereto. As a result, current can be supplied to each electrode.
However, in combining the plurality of first current collectors 2 and the second current collector 3, the current collectors located at the periphery may be applied with a relatively strong tensile force T. As a result, the first current collector 2 and the second current collector 3 may sometimes break during welding of the electrode leads 4 or during operation of the secondary battery. Breakage of the first and second current collectors 2, 3 may cause short-circuiting (short) of the electrodes and overcurrent to occur, causing ignition and explosion of the secondary battery. Therefore, it is necessary to develop a technique capable of preventing the current collector from breaking.
Disclosure of Invention
First, the technical problem to be solved
An object of the present disclosure is to provide an electrode assembly capable of preventing breakage of a current collector.
It is another object of the present disclosure to provide a battery cell including the electrode assembly that can improve stability.
It is a further object of the present disclosure to provide a method capable of conveniently manufacturing the battery cell.
(II) technical scheme
An electrode assembly of one embodiment of the present disclosure includes: a unit cell stack including a first unit cell and a second unit cell that is the nearest neighboring unit cell on the first unit cell, each of the first unit cell and the second unit cell including a first electrode including a first current collector and a first active material layer on at least one side of the first current collector, a second electrode that is an opposite electrode of the first electrode, and a second active material layer on at least one side of the second current collector, and a separator interposed between the first electrode and the second electrode; and a first electrode tab first side portion including a first collector first side deformation portion in which one side end portion in the width direction of the first collector of each of the first unit cell and the second unit cell is folded or wound, a shortest distance from an upper surface of the first collector of the second unit cell to an upper surface of the first collector of the first unit cell being the same as a height of the first collector first side deformation portion of the second unit cell.
The battery cell of one embodiment of the present disclosure includes: the electrode assembly; and an electrode lead connected to the first electrode tab first side of the electrode assembly.
The manufacturing method of the battery cell according to one embodiment of the present disclosure includes the steps of: preparing the electrode assembly; and connecting an electrode lead to a first electrode tab first side of the electrode assembly.
(III) beneficial effects
The electrode assembly of one embodiment of the present disclosure may prevent the current collector from being broken.
The battery cell of one embodiment of the present disclosure may improve stability.
The manufacturing method of the battery cell according to one embodiment of the present disclosure can conveniently manufacture the battery cell.
Drawings
Fig. 1 is a schematic view of a conventional electrode assembly manufacturing method.
Fig. 2 to 13 are schematic views of an electrode assembly according to an embodiment of the present disclosure.
Fig. 14 is a schematic diagram of a battery cell of one embodiment of the present disclosure.
Fig. 15 to 18 are schematic views of a manufacturing process of a unit cell stack according to an embodiment of the present disclosure.
Description of the reference numerals
1: electrode assembly 2: first current collector
3: second current collector 4: electrode lead
10: unit cell stack
11: first unit cell
11a: first current collector 11b: second current collector
11c: the first active material layer 11d: second active material layer
11e: diaphragm
12: second unit cell
12a: first current collector 12b: second current collector
12c: first active material layer 12d: second active material layer
12e: diaphragm
13: third unit cell
13a: the first current collector 13b: second current collector
13c: the first active material layer 13d: second active material layer
13e: diaphragm
14: fourth unit cell
14a: first current collector 14b: second current collector
14c: first active material layer 14d: second active material layer
14e: diaphragm
20: electrode joint
21a: first side of the first electrode joint
21aa: first side deformation portion of first current collector
21ab: first side undeformed portion of first current collector
22a: first side of second electrode joint
22aa: first side deformation portion of second current collector
22ab: first side undeformed portion of second current collector
22b: second electrode joint second side part
22ba: second side deformation portion of second current collector
22bb: second side undeformed portion of second current collector
100: electrode assembly
200: electrode lead
1000: battery cell
Detailed Description
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
One embodiment of the present disclosure relates to an electrode assembly.
In the present specification, the term "battery cell" refers to a lithium secondary battery capable of charging and discharging electric energy, and specifically refers to a basic unit of a lithium ion battery. The main components of the battery cell are a positive electrode (Cathode), a negative electrode (Anode), a separator, and an electrolyte. The battery cell includes the main constituent and a case accommodating the main constituent. The battery cells are generally used in different meanings from the battery modules and the battery packs.
In the present specification, the term "electrode assembly" refers to an element that performs an electrochemical reaction of converting chemical energy into electrical energy in a battery cell. That is, the battery cell includes the electrode assembly and a case accommodating the electrode assembly. Specifically, the battery cell includes the electrode assembly, electrode leads connected to the electrode assembly to supply current to the respective electrodes, and a case accommodating the electrode assembly.
The electrode assembly includes at least a unit cell (unit cell) stack and an electrode tab. The unit cell refers to the minimum unit of a battery including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The positive electrode includes a positive electrode collector and a positive electrode active material layer on at least one side of the positive electrode collector. The negative electrode includes a negative electrode collector and a negative electrode active material layer on at least one side of the negative electrode collector. The electrode tab refers to a portion where a collector constituting the unit cell stack is connected to an electrode lead.
In the present specification, the case where two values are identical to each other may include a case where the two values are identical to each other and a case where a difference between the two values is within an error range (for example, within ±5%, ±3%, ±1%).
In this specification, two elements are perpendicular or parallel to each other and may include cases where the angle formed by the two elements is within an error range of right angles or 180 degrees (for example, within ±5%, within ±3%, within ±1%) in addition to the angle formed by the two elements being completely right angles or the two elements being completely parallel.
The electrode assembly of one embodiment of the present disclosure includes at least a unit cell stack 10 and an electrode tab 20.
The unit cell stack includes at least two unit cells. The unit cell stack includes a first unit cell 11 and a second unit cell 12. The second unit cell 12 is the nearest neighboring unit cell on the first unit cell 11.
Each of the first unit cell 11 and the second unit cell 12 has the construction of the electrode assembly described above. Specifically, each of the first unit cell 11 and the second unit cell 12 includes a first electrode, a second electrode that is an opposite electrode to the first electrode, and a separator 11e, 12e interposed between the first electrode and the second electrode. The first electrode includes a first current collector 11a, 12a and a first active material layer 11c, 12c on at least one surface of the first current collector 11a, 12 a. The second electrode includes a second current collector 11b, 12b and a second active material layer 11d, 12d on at least one surface of the second current collector 11b, 12 b.
Here, when the first electrode is a positive electrode, the first current collectors 11a, 12a are positive electrode current collectors, the first active material layers 11c, 12c are positive electrode active material layers, the second electrode is a negative electrode, the second current collectors 11b, 12b are negative electrode current collectors, and the second active material layers 11d, 12d are negative electrode active material layers. In contrast, when the first electrode is a negative electrode, the first current collectors 11a, 12a are negative electrode current collectors, the first active material 11c, 12c layers are negative electrode active material layers, the second electrode is a positive electrode, the second current collectors 11b, 12b are positive electrode current collectors, and the second active material layers 11d, 12d are positive electrode active material layers.
The current collector functions to supply electrons to the active material from the outside or to receive electrons from the active material and transport the electrons to the outside. Lithium secondary batteries generally use an aluminum current collector as a positive electrode current collector. Lithium secondary batteries generally use a copper current collector as a negative electrode current collector.
The positive electrode active material is a material for supplying lithium ions to the negative electrode when the battery is charged. The positive electrode active material of the lithium secondary battery includes LCO, LMO, NCM, NCA, LFP and the like. The negative electrode active material is a material for storing lithium ions when the battery is charged. A representative negative electrode active material of a lithium secondary battery is graphite.
The electrode assembly 100 of the present disclosure includes at least a first electrode tab first side portion 21a constituted by a first current collector 11a extending from one widthwise side end of the unit cell stack 10.
In the present specification, the height direction may refer to a direction parallel to a direction opposite to a direction of gravity. The width direction may refer to a direction perpendicular to the height direction and longer in two directions perpendicular to each other. The length direction may refer to a shorter direction that is perpendicular to the height direction and that is other than the width direction, which is a longer direction, among the two directions perpendicular to each other.
In the electrode assembly 100 of the present disclosure, when the first electrode tab first side 21a is deformed into a specific shape and the first unit cell 11 and the second unit cell 12 satisfy a specific relationship, each electrode tab may be formed side by side with each unit cell. At this time, tension is not applied to the electrode tabs during the process of bonding (or welding) the electrode leads to the electrode assembly 100. Accordingly, the electrode assembly 100 of the present disclosure may prevent the current collector from being broken during use of the electrode assembly 100.
The first electrode tab first side portion 21a includes a first current collector first side deformed portion 21aa. This is formed by folding (folded) or winding (rolled) one side end portion of the first current collector 11a, 12a of each of the first unit cell 11 and the second unit cell 12. That is, each of the first unit cell 11 and the second unit cell 12 includes a first current collector first side deformation portion 21aa whose end is folded or wound. Here, the direction in which the current collector is deformed may be downward as in the direction of gravity.
In the electrode assembly 100 of the present disclosure, when the height H1 of the first current collector first side deformation portion 21aa of the unit cell located at the upper portion is equal to the shortest distance H1 from the first current collector of the unit cell located at the upper portion to the first current collector of the unit cell located at the lower portion, the first electrode tab first side portion 21a is not applied with unnecessary tension.
Here, the thickness of the unit cells located at the upper part may be the same as or different from the thickness of the unit cells located at the lower part.
The height of the deformation may refer to the shortest distance from the uppermost surface to the lowermost surface of the deformation.
That is, in the electrode assembly 100 of the present disclosure, the shortest distance H1 from the topmost end of the first current collector of the second unit cell 12 to the topmost end of the first current collector of the first unit cell 11 is the same as the shortest distance H1 from the topmost end to the bottommost end of the first current collector first side deformation portion 21aa of the second unit cell 12.
Fig. 2 and 3 are schematic views of the electrode assembly 100 in this case. Referring to fig. 2 and 3, the electrode assembly 100 includes a unit cell stack 10 and a first electrode tab first side 21a, and the unit cell stack 10 includes a first unit cell 11 and a second unit cell 12. The first electrode tab first side portion 21a includes a first current collector first side deformed portion 21aa. The shortest distance H1 from the topmost end of the first current collector 12a of the second unit cell 12 to the topmost end of the first current collector 11a of the first unit cell 11 is the same as the height H1 of the first current collector first side deformation portion 21aa. Fig. 2 shows the case where the thickness of each unit cell is the same. Fig. 3 shows a case where the thickness of each unit cell is different.
In one embodiment, the electrode assembly 100 of the present disclosure may include a second electrode tab second side portion 22b, the second electrode tab second side portion 22b being constituted by the second current collectors 11b, 12b, 13b, 14b extending from the other side end portion in the width direction of the unit cell stack 10.
The electrode assembly 100 may further include a second electrode tab second side portion 22b, the second electrode tab second side portion 22b including a second collector second side deformation portion 22ba in which the other side end portion of the second collector 11b, 12b of each of the first unit cell 11 and the second unit cell 12 in the width direction is folded or wound. In addition, in one embodiment, the shortest distance H2 from the topmost end of the second collector 12b of the second unit cell 12 to the topmost end of the second collector 11b of the first unit cell 11 may be the same as the height H2 of the second collector second side deformation portion 22ba of the second unit cell 12.
That is, the electrode tab of the second electrode may be formed at the opposite side of the electrode tab of the first electrode. The electrode tab of the second electrode may be a second electrode tab second side 22b located on an opposite side of the first electrode. The second electrode tab second side portion 22b may include the second current collectors 11b, 12b deformed into a specific shape like the first electrode tab first side portion 21 a. The relationship satisfied by the first current collectors 11a, 12a may be the same as the relationship satisfied by the second current collectors 11b, 12b.
Fig. 4 and 5 are schematic views of the electrode assembly 100 in this case. Referring to fig. 4 and 5, the electrode assembly 100 may further include a second electrode tab second side 22b. The second electrode tab second side portion 22b may include a second current collector second side deformation portion 22ba. The shortest distance H2 from the topmost end of the second current collector 12b of the second unit cell 12 to the topmost end of the second current collector 11b of the first unit cell 11 may be the same as the height H2 of the second current collector second side deformation portion 22ba. Fig. 4 shows the case where the thickness of each unit cell is the same. Fig. 5 shows a case where the thickness of each unit cell is different.
In one embodiment, the electrode assembly 100 of the present disclosure may include a second electrode tab first side 22a, which is composed of the second current collectors 11b, 12b, 13b, 14b extending from one lateral end of the unit cell stack 10 in the width direction.
The electrode assembly 100 may further include a second electrode tab first side 22a, the second electrode tab first side 22a including a second current collector first side deformation 22aa in which one side end of the second current collector 11b, 12b of each of the first unit cell 11 and the second unit cell 12 in the width direction is folded or wound. In addition, in one embodiment, the shortest distance H2 from the upper surface of the second collector 12b of the second unit cell 12 to the upper surface of the second collector 11b of the first unit cell 11 may be the same as the height H2 of the second collector first side deformation portion 22aa of the second unit cell 12.
That is, the electrode tab of the second electrode may be formed on the same side as the electrode tab of the first electrode. The electrode tab of the second electrode may be a second electrode tab first side portion located on the same side as the electrode tab of the first electrode. The second electrode tab first side portion 22a may include second current collectors 11b, 12b deformed into a specific shape like the first electrode tab first side portion 21 a. The relationship satisfied by the first current collectors 11a, 12a may be the same as the relationship satisfied by the second current collectors 11b, 12b.
Fig. 6 and 7 are schematic views of the electrode assembly 100 in this case. Referring to fig. 6 and 7, the electrode assembly 100 may further include a second electrode tab first side 22a. The second electrode tab first side portion 22a may include a second current collector first side deformed portion 22aa. The shortest distance H2 from the topmost end of the second current collector 12b of the second unit cell 12 to the topmost end of the second current collector 11b of the first unit cell 11 may be the same as the height H2 of the second current collector first side deformation portion 22aa. Fig. 6 shows the case where the thickness of each unit cell is the same. Fig. 7 shows a case where the thickness of each unit cell is different.
In one embodiment, the electrode assembly 100 may also include a first electrode tab second side portion (not shown) composed of the first current collectors 11a, 12a, 13a, 14a extending from the other side end portion in the width direction of the unit cell stack 10. In this case, the positive electrode and the negative electrode may be formed on both sides of the battery cell.
In the unit cell stack 10, the order in which the first unit cells 11 and the second unit cells 12 are stacked is not limited.
In one embodiment, the first unit cell 11 and the second unit cell 12 may be sequentially stacked. The sequential stacking of the first unit cell 11 and the second unit cell 12 may mean that the first unit cell 11 and the second unit cell 12 are stacked in the order of negative electrode/separator/positive electrode/separator/negative electrode/separator/positive electrode or positive electrode/separator/negative electrode/separator/positive electrode/separator/negative electrode.
In addition, in another embodiment, the first unit cells 11 and the second unit cells 12 may be alternately stacked. The alternating stacking of the first unit cells 11 and the second unit cells 12 may mean that the first unit cells 11 and the second unit cells 12 are stacked in the order of negative electrode/separator/positive electrode/separator (selectivity)/positive electrode/separator/negative electrode or positive electrode/separator/negative electrode/separator (selectivity)/negative electrode/separator/positive electrode.
Fig. 8 and 9 are schematic views of the electrode assembly 100 in this case. Referring to fig. 8 and 9, in the unit cell stack 10, the first unit cells 11 and the second unit cells 12 are alternately stacked. At this time, the shortest distance H1 from the upper surface of the first collector 12a of the second unit cell 12 to the upper surface of the first collector 11a of the first unit cell 11 may be the same as the height H1 of the first collector first side deformation portion 21 aa. Fig. 8 shows the case where the thickness of each unit cell is the same. Fig. 9 shows a case where the thickness of each unit cell is different.
In one embodiment, the undeformed portion may be located at the electrode joint. That is, the electrode tab may include an undeformed portion between the deformed portion and the unit cell stack 10. The electrode collector in this case is shown in fig. 2 to 9.
In one embodiment, the electrode tab of the first electrode may include an undeformed portion directly extending from the unit cell stack 10, in addition to the first current collector first side deformed portion 21aa and the first current collector second side deformed portion. When the undeformed portions of one side or the other side of the electrode tab of the first electrode, which each of the first unit cell 11 and the second unit cell 12 has, are parallel to each other and their respective lengths L1 are the same, the first electrode tab first side portion 21a and/or the first electrode tab second side portion of each unit cell may be formed side by side with the first current collector of each unit cell.
In one embodiment, the first electrode tab first side portion 21a may further include a first current collector first side undeformed portion 21ab located between the unit cell stack 10 and the first current collector first side deformed portion 21aa, and formed by the first current collectors 11a, 12a of each of the first and second unit cells 11, 12 extending in the width direction. The first collector first side undeformed portion 21ab of the first unit cell 11 may be parallel to the first collector first side undeformed portion 21ab of the second unit cell 12. The length L1 of the first-collector first-side undeformed portion 21ab of the first unit cell 11 may be the same as the length L1 of the first-collector first-side undeformed portion 21ab of the second unit cell 12. The electrode collector in this case is shown in fig. 2 and 3.
In one embodiment, the first electrode tab second side portion may further include a first current collector second side undeformed portion located between the unit cell stack 10 and the first current collector second side deformed portion 21ba, and formed by the first current collectors 11a, 12a of each of the first and second unit cells 11, 12 extending in the width direction. The first current collector second side undeformed portion of the first unit cell 11 may be parallel to the first current collector second side undeformed portion of the second unit cell 12. The length L1 of the first-collector second-side undeformed portion of the first unit cell 11 may be the same as the length L1 of the first-collector second-side undeformed portion of the second unit cell 12.
In one embodiment, the electrode tab of the second electrode may include an undeformed portion directly extending from the unit cell stack 10, in addition to the second current collector first side deformed portion 22aa and the second current collector second side deformed portion 22 ba. When the undeformed portions of one side or the other side of the electrode tab of the second electrode of each of the first unit cell 11 and the second unit cell 12 are parallel to each other and their respective lengths L2 are the same, the second electrode tab first side 22a and/or the second electrode tab second side 22b of each unit cell may be formed side by side with the second current collector of each unit cell.
In one embodiment, the second electrode tab second side 22b may further include a second current collector second side undeformed portion 22bb located between the unit cell stack 10 and the second current collector second side deformed portion 22ba, and formed by the second current collectors 11b, 12b of each of the first and second unit cells 11, 12 extending in the width direction. The second-side undeformed portion 22bb of the second current collector of the first unit cell 11 may be parallel to the second-side undeformed portion 22bb of the second current collector of the second unit cell 12. The length L2 of the second-collector second-side undeformed portion 22bb of the first unit cell 11 may be the same as the length L2 of the second-collector second-side undeformed portion 22bb of the second unit cell 12. The electrode collector in this case is shown in fig. 4 and 5. Specifically, fig. 4 and 5 show the case where the first electrode tab is located on a different side from the second electrode tab. Fig. 4 shows the case where the thickness of each unit cell is the same. Fig. 5 shows a case where the thickness of each unit cell is different.
In one embodiment, the second electrode tab first side portion 22a may further include a second current collector first side undeformed portion 22ab located between the unit cell stack 10 and the second current collector first side deformed portion 22aa, and formed by the second current collectors 11b, 12b of each of the first and second unit cells 11, 12 extending in the width direction. The second current collector first side undeformed portion 22ab of the first unit cell 11 may be parallel to the second current collector first side undeformed portion 22ab of the second unit cell 12. The length L2 of the second-collector first-side undeformed portion 22ab of the first unit cell 11 may be the same as the length L2 of the second-collector first-side undeformed portion 22ab of the second unit cell 12. The electrode collector in this case is shown in fig. 6 and 7. Specifically, fig. 6 and 7 show the case where the first electrode tab is located on the same side as the second electrode tab. Fig. 6 shows the case where the thickness of each unit cell is the same. Fig. 7 shows a case where the thickness of each unit cell is different.
Even when the electrode tab has an undeformed portion, the order in which the first unit cell 11 and the second unit cell 12 are stacked in the unit cell stack 10 is not limited. In one embodiment, the first unit cell 11 and the second unit cell 12 may be sequentially stacked. In addition, in another embodiment, the first unit cells 11 and the second unit cells 12 may be alternately stacked. The electrode collector in this case is shown in fig. 8 and 9. Fig. 8 shows the case where the thickness of each unit cell is the same. Fig. 9 shows a case where the thickness of each unit cell is different.
The above-described case may be directly applied to the case where the unit cell stack of the electrode assembly of the present disclosure includes a plurality of unit cells.
In an embodiment of the present disclosure, the unit cell stack 10 may further include a third unit cell 13 and a fourth unit cell 14 that is the nearest neighboring unit cell on the third unit cell 13. In addition, each of the third unit cell 13 and the fourth unit cell 14 may include a first electrode including a first current collector 13a, 14a and a first active material layer 13c, 14c on at least one side of the first current collector 13a, 14a, a second electrode which is an opposite electrode to the first electrode, and a second active material layer 13d, 14d on at least one side of the second current collector 13b, 14b, and a separator 13e, 14e interposed between the first electrode and the second electrode. In addition, the first electrode tab first side portion 21a may further include a first current collector first side deformed portion 21aa in which one side end portion in the width direction of the first current collector 13a, 14a of each of the third unit cell 13 and the fourth unit cell 14 is folded or wound.
At this time, the shortest distance H1 'from the upper surface of the first collector 14a of the fourth unit cell 14 to the upper surface of the first collector 13a of the third unit cell 13 may be the same as the height H1' of the first collector first side deformation 21aa of the fourth unit cell 14. The electrode assembly in this case is shown in fig. 10 and 13.
In one embodiment, the shortest distance H1' from the upper surface of the first collector 14a of the fourth unit cell 14 to the upper surface of the first collector 13a of the third unit cell 13 may be the same as the shortest distance H1 from the upper surface of the first collector 12a of the second unit cell 12 to the upper surface of the first collector 11a of the first unit cell 11. Fig. 10 shows a case in which the thickness of the fourth unit cell is the same as the thickness of the third unit cell and the thickness of the second unit cell is the same as the thickness of the first unit cell. Fig. 11 shows a case in which the thickness of the fourth unit cell is different from the thickness of the third unit cell and the thickness of the second unit cell is different from the thickness of the first unit cell.
In one embodiment, the shortest distance H1' from the upper surface of the first collector 14a of the fourth unit cell 14 to the upper surface of the first collector 13a of the third unit cell 13 may be different from the shortest distance H1 from the upper surface of the first collector 12a of the second unit cell 12 to the upper surface of the first collector 11a of the first unit cell 11. The electrode collector in this case is shown in fig. 12 and 13. Fig. 12 shows a case where the thickness of the fourth unit cell is the same as the thickness of the third unit cell and the thickness of the second unit cell is the same as the thickness of the first unit cell. Fig. 13 shows a case in which the thickness of the fourth unit cell is different from the thickness of the third unit cell and the thickness of the second unit cell is different from the thickness of the first unit cell.
That is, when the thickness of each of the unit cells in the electrode assembly 100 is the same as the height of the current collector deformation of each unit cell, the thickness of each of the unit cells may be the same or different. In addition, the first electrode tab and/or the second electrode tab may further include an undeformed portion. The above can be directly applied to the explanation of the undeformed portion.
In one embodiment, the heights H1, H2 of each of the first current collector first side deformed portion 21aa, the first current collector second side deformed portion, the second current collector first side deformed portion 22aa, and the second current collector second side deformed portion 22ba may also be the same.
As described above, when the shape of the electrode tab is changed such that the electrode tab and the electrode collector in the electrode assembly 100 are on the same line, unnecessary tension is not applied during the manufacturing of the battery cell using the electrode assembly 100. As a result, even though the electrode leads are connected to the electrode current collectors without a separate pressurizing process, the battery cell can be manufactured.
Another embodiment of the present disclosure relates to a battery cell (battery cell) including the electrode assembly 100. The battery cell may include an electrode assembly 100 and an electrode lead connected to a first electrode tab first side 21a of the electrode assembly 100. The electrode lead may be a lead of the first electrode. In addition, the connection method is not particularly limited. Typically, the electrode leads are connected to the electrode tabs by welding.
Fig. 14 is a schematic diagram of a battery cell of one embodiment of the present disclosure. The battery cell includes the electrode assembly 100 and an electrode lead 200, and the electrode lead 200 is connected to an electrode tab (first electrode tab first side) of the electrode assembly 100.
In one embodiment, the battery cell may further include an electrode lead connected to the second electrode tab second side 22b of the electrode assembly 100. The electrode lead may be a lead of the second electrode. That is, in the battery cell, the electrode tab of the first electrode and the electrode tab of the second electrode may be located at different sides.
In one embodiment, the battery cell may further include an electrode lead connected to the second electrode tab first side 22a of the electrode assembly 100. The electrode lead may be a lead of the second electrode. That is, in the battery cell, the electrode tab of the first electrode and the electrode tab of the second electrode may be located at the same side.
In one embodiment, the battery cell may further include an electrode lead connected to the first electrode tab second side portion of the electrode assembly 100, an electrode lead connected to the second electrode tab first side portion 22a, and an electrode lead connected to the second electrode tab second side portion 22 b. The electrode lead connected to the second side of the first electrode tab may be a lead of the first electrode. The electrode leads connected to the second electrode tab first side portion 22a and the second electrode tab second side portion 22b may be leads of a second electrode. That is, in the battery cell, the electrode tabs of the first electrode and the electrode tabs of the second electrode may be located at both sides of the battery cell.
Yet another embodiment of the present disclosure relates to a method of manufacturing a battery cell using the electrode assembly 100. The manufacturing method of the battery unit comprises the following steps: preparing the electrode assembly 100; and connecting (connecting) an electrode lead to the first electrode tab first side 21a of the electrode assembly 100.
In one embodiment, the electrode lead may be connected by welding (welding) the electrode lead to the electrode tab, and a specific method of the welding is not particularly limited.
In one embodiment, preparing the electrode assembly 100 includes the steps of: preparing a unit cell stack 10, the unit cell stack 10 including a first unit cell 11 and a second unit cell 12 that is the nearest neighboring unit cell on the first unit cell 11, each of the first unit cell 11 and the second unit cell 12 including a first electrode including a first current collector 11a, 12a and a first active material layer 11c, 12c on at least one side of the first current collector 11a, 12a, a second electrode that is an opposite electrode to the first electrode, and including a second current collector 11b, 12b and a second active material layer 11d, 12d on at least one side of the second current collector 11b, 12b, and a separator 11e, 12e interposed between the first electrode and the second electrode; and forming (forming) a first electrode tab first side portion 21a, the first electrode tab first side portion 21a including a first current collector first side deformed portion 21aa formed by folding or winding one side end portion in the width direction of the first current collectors 11a, 12a of each of the first unit cell 11 and the second unit cell 12, a shortest distance from the first current collector 12a of the second unit cell 12 to the first current collector 11a of the first unit cell 11 being the same as a height of the first current collector first side deformed portion 21aa of the second unit cell 12.
That is, in one embodiment, the electrode assembly 100 may be prepared by processing (processing) the unit cell stack after stacking the unit cells to satisfy the conditions specified in the present disclosure.
In one embodiment, preparing the electrode assembly 100 may include the steps of: preparing the first unit cell 11, wherein the first unit cell 11 is formed with a first current collector first side deformation portion 21aa, and the first current collector first side deformation portion 21aa is formed by folding or winding one side end portion in the width direction of the first current collector 11 a; and disposing (positioning) the second unit cell 12 on the upper portion of the first unit cell 11, the second unit cell 12 being formed with a first current collector first side deformation portion 21aa formed by folding or winding one side end portion in the width direction of the first current collector 12 a. Preparation of the first unit cell 11 and arrangement of the second unit cell 12 may be performed to form a first electrode tab first side part 21a including a first current collector first side deformation part 21aa, wherein a shortest distance from an upper surface of the first current collector 12a of the second unit cell 12 to an upper surface of the first current collector 11a of the first unit cell 11 is the same as a height of the first current collector first side deformation part 21aa of the second unit cell 12.
In the battery cell and the method of manufacturing the battery cell of the present disclosure, the content thereof is described centering on the first electrode tab first side portion. However, in the present disclosure, all the descriptions concerning the first electrode tab second side portion, the second electrode tab first side portion, and the second electrode tab second side portion described above may also be applied.
That is, in one embodiment, the preparation of the electrode assembly 100 may be performed by stacking (stacking) unit cells satisfying the conditions specified in the present disclosure.
In one embodiment, the winding may be performed in a clockwise or counterclockwise direction. Fig. 15 shows the case where the winding is performed in the clockwise direction.
In one embodiment, the folding may be performed in a clockwise or counter-clockwise direction. In addition, the folding may fold the current collector in an angular form. In addition, the folding may fold the current collector in a gentle (round) form. Fig. 16 shows a case where the folding is performed in a clockwise direction and the folding folds the current collector in an angular form. Fig. 17 shows a case where the folding is performed in a clockwise direction and the folding folds the current collector in a gentle form.
In one embodiment, the folding may be performed in a zig-zag direction. Fig. 18 shows the case where the folding is performed in a zigzag direction.

Claims (17)

1. An electrode assembly, comprising:
a unit cell stack including a first unit cell and a second unit cell that is the nearest neighboring unit cell on the first unit cell, each of the first unit cell and the second unit cell including a first electrode including a first current collector and a first active material layer on at least one side of the first current collector, a second electrode that is an opposite electrode of the first electrode, and a second active material layer on at least one side of the second current collector, and a separator interposed between the first electrode and the second electrode; and
a first electrode tab first side portion including a first current collector first side deformation portion formed by folding or winding one side end portion in the width direction of the first current collector of each of the first unit cell and the second unit cell,
the shortest distance from the upper surface of the first current collector of the second unit cell to the upper surface of the first current collector of the first unit cell is the same as the height of the first current collector first side deformation portion of the second unit cell.
2. The electrode assembly of claim 1, wherein,
the electrode assembly further includes:
a second electrode tab second side portion including a second current collector second side deformation portion formed by folding or winding an end portion of the second current collector on the other side in the width direction of each of the first unit cell and the second unit cell,
the shortest distance from the upper surface of the second current collector of the second unit cell to the upper surface of the second current collector of the first unit cell is the same as the height of the second current collector second side deformation portion of the second unit cell.
3. The electrode assembly of claim 1, wherein,
the electrode assembly further includes:
a second electrode tab first side portion including a second current collector first side deformed portion formed by folding or winding one side end portion in the width direction of the second current collector of each of the first unit cell and the second unit cell,
the shortest distance from the upper surface of the second current collector of the second unit cell to the upper surface of the second current collector of the first unit cell is the same as the height of the second current collector first side deformation portion of the second unit cell.
4. The electrode assembly of claim 1, wherein,
the first unit cells and the second unit cells are alternately stacked.
5. The electrode assembly of claim 1, wherein,
the first electrode tab first side further includes:
a first current collector first side undeformed portion located between the unit cell stack and the first current collector first side deformed portion and formed by the first current collector of each of the first unit cell and the second unit cell extending in a width direction,
the first-side undeformed portion of the first collector of the first unit cell is parallel to the first-side undeformed portion of the first collector of the second unit cell,
the length of the first-side undeformed portion of the first collector of the first unit cell is the same as the length of the first-side undeformed portion of the first collector of the second unit cell.
6. The electrode assembly of claim 2, wherein,
the first electrode tab first side further includes:
a first current collector first side undeformed portion located between the unit cell stack and the first current collector first side deformed portion and formed by the first current collector of each of the first unit cell and the second unit cell extending in a width direction,
The second electrode tab second side portion further includes:
a second current collector second side non-deformed portion that is located between the unit cell stack and the second current collector second side deformed portion and is formed by the second current collector of each of the first unit cell and the second unit cell extending in the width direction,
the first-side undeformed portion of the first collector of the first unit cell is parallel to the first-side undeformed portion of the first collector of the second unit cell,
the second side undeformed portion of the second current collector of the first unit cell is parallel to the second side undeformed portion of the second current collector of the second unit cell,
the length of the first side undeformed portion of the first collector of the first unit cell is the same as the length of the first side undeformed portion of the first collector of the second unit cell,
the length of the second side undeformed portion of the second current collector of the first unit cell is the same as the length of the second side undeformed portion of the second current collector of the second unit cell.
7. The electrode assembly of claim 3, wherein,
the first electrode tab first side further includes:
a first current collector first side undeformed portion located between the unit cell stack and the first current collector first side deformed portion and formed by the first current collector of each of the first unit cell and the second unit cell extending in a width direction,
The second electrode tab first side further includes:
a second current collector first side undeformed portion located between the unit cell stack and the second current collector first side deformed portion and formed by the second current collector of each of the first unit cell and the second unit cell extending in a width direction,
the first-side undeformed portion of the first collector of the first unit cell is parallel to the first-side undeformed portion of the first collector of the second unit cell,
the first side undeformed portion of the second current collector of the first unit cell is parallel to the first side undeformed portion of the second current collector of the second unit cell,
the length of the first side undeformed portion of the first collector of the first unit cell is the same as the length of the first side undeformed portion of the first collector of the second unit cell,
the length of the first side undeformed portion of the second current collector of the first unit cell is the same as the length of the first side undeformed portion of the second current collector of the second unit cell.
8. The electrode assembly of claim 5, wherein,
the first unit cells and the second unit cells are alternately stacked.
9. The electrode assembly of claim 1, wherein,
the unit cell stack further includes a third unit cell and a fourth unit cell that is the nearest neighboring unit cell on the third unit cell,
each of the third unit cell and the fourth unit cell includes a first electrode including a first current collector and a first active material layer on at least one side of the first current collector, a second electrode that is an opposite electrode of the first electrode, and a second active material layer on at least one side of the second current collector, and a separator interposed between the first electrode and the second electrode,
the first electrode tab first side further includes:
a first current collector first side deformation portion formed by folding or winding one side end portion in the width direction of the first current collector of each of the third unit cell and the fourth unit cell,
the shortest distance from the upper surface of the first current collector of the fourth unit cell to the upper surface of the first current collector of the third unit cell is the same as the height of the first current collector first side deformation portion of the fourth unit cell,
The shortest distance from the upper surface of the first collector of the fourth unit cell to the upper surface of the first collector of the third unit cell is the same as the shortest distance from the upper surface of the first collector of the second unit cell to the upper surface of the first collector of the first unit cell.
10. The electrode assembly of claim 1, wherein,
the unit cell stack further includes a third unit cell and a fourth unit cell that is the nearest neighboring unit cell on the third unit cell,
each of the third unit cell and the fourth unit cell includes a first electrode including a first current collector and a first active material layer on at least one side of the first current collector, a second electrode that is an opposite electrode of the first electrode, and a second active material layer on at least one side of the second current collector, and a separator interposed between the first electrode and the second electrode,
the first electrode tab first side further includes:
a first current collector first side deformation portion formed by folding or winding one side end portion in the width direction of the first current collector of each of the third unit cell and the fourth unit cell,
The shortest distance from the upper surface of the first current collector of the fourth unit cell to the upper surface of the first current collector of the third unit cell is the same as the height of the first current collector first side deformation portion of the fourth unit cell,
the shortest distance from the upper surface of the first collector of the fourth unit cell to the upper surface of the first collector of the third unit cell is different from the shortest distance from the upper surface of the first collector of the second unit cell to the upper surface of the first collector of the first unit cell.
11. A battery cell, comprising:
the electrode assembly of claim 1; and
an electrode lead connected to the first electrode tab first side of the electrode assembly.
12. A method of manufacturing a battery cell, comprising the steps of:
preparing the electrode assembly of claim 1; and
an electrode lead is connected to a first electrode tab first side of the electrode assembly.
13. The method for manufacturing a battery cell according to claim 12, wherein,
preparing the electrode assembly includes the steps of:
preparing a unit cell stack including a first unit cell and a second unit cell that is the nearest neighboring unit cell on the first unit cell, each of the first and second unit cells including a first electrode including a first current collector and a first active material layer on at least one side of the first current collector, a second electrode that is an opposite electrode of the first electrode, and a second active material layer on at least one side of the second current collector, and a separator interposed between the first and second electrodes; and
And forming a first electrode tab first side portion including a first current collector first side deformation portion formed by folding or winding one side end portion of the first current collector of each of the first unit cell and the second unit cell in a width direction, a shortest distance from the first current collector of the second unit cell to the first current collector of the first unit cell being the same as a height of the first current collector first side deformation portion of the second unit cell.
14. The method for manufacturing a battery cell according to claim 12, wherein,
the electrode assembly includes the steps of:
preparing the first unit cell, the first unit cell being formed with a first current collector first side deformation portion formed by folding or winding one side end portion of the first current collector in the width direction; and
the second unit cell is disposed at an upper portion of the first unit cell, the second unit cell is formed with a first current collector first side deformation portion formed by folding or winding one side end portion of the first current collector in a width direction,
Preparing the first unit cell and disposing the second unit cell to form a first electrode tab first side portion including a first current collector first side deformation portion, the shortest distance from the upper surface of the first current collector of the second unit cell to the upper surface of the first current collector of the first unit cell being the same as the height of the first current collector first side deformation portion of the second unit cell.
15. The method for manufacturing a battery cell according to claim 13 or 14, wherein,
the winding is performed in a clockwise or counter-clockwise direction.
16. The method for manufacturing a battery cell according to claim 13 or 14, wherein,
the folding is performed in a clockwise or counter-clockwise direction.
17. The method for manufacturing a battery cell according to claim 13 or 14, wherein,
the folding is performed in a zig-zag direction.
CN202310799927.5A 2022-07-06 2023-07-03 Electrode assembly, battery cell, and method for manufacturing battery cell Pending CN117374417A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
KR10-2022-0082829 2022-07-06
KR10-2023-0066205 2023-05-23
KR1020230066205A KR20240006430A (en) 2022-07-06 2023-05-23 Electrode assembly, battery cell comprising the same and method for manufacturing said battery cell

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Publication Number Publication Date
CN117374417A true CN117374417A (en) 2024-01-09

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