WO2018225994A1 - Electrode, and secondary battery comprising same - Google Patents

Electrode, and secondary battery comprising same Download PDF

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Publication number
WO2018225994A1
WO2018225994A1 PCT/KR2018/006325 KR2018006325W WO2018225994A1 WO 2018225994 A1 WO2018225994 A1 WO 2018225994A1 KR 2018006325 W KR2018006325 W KR 2018006325W WO 2018225994 A1 WO2018225994 A1 WO 2018225994A1
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WO
WIPO (PCT)
Prior art keywords
coating layer
electrode
coating
active material
length
Prior art date
Application number
PCT/KR2018/006325
Other languages
French (fr)
Korean (ko)
Inventor
김남원
박필규
송한갑
정안수
Original Assignee
주식회사 엘지화학
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020180062420A external-priority patent/KR102473689B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to CN201880004667.5A priority Critical patent/CN110024196B/en
Priority to US16/344,659 priority patent/US11043669B2/en
Priority to PL18813454T priority patent/PL3522282T3/en
Priority to JP2019530150A priority patent/JP7088600B2/en
Priority to EP18813454.8A priority patent/EP3522282B1/en
Publication of WO2018225994A1 publication Critical patent/WO2018225994A1/en

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    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • 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
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/24—Electrodes for alkaline accumulators
    • 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

Definitions

  • the present invention relates to an electrode and a secondary battery including the same, and more particularly to an electrode which prevents the occurrence of cracking of the electrode wound in the core portion and a secondary battery comprising the same.
  • the secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged, and is widely used in small advanced electronic devices such as mobile phones, PDAs, and notebook computers.
  • the secondary battery includes an electrode assembly, a core portion inserted into the core of the electrode assembly, a can containing the electrode assembly into which the core portion is inserted, and a cap assembly mounted in an opening of the can, wherein the electrode assembly includes: It has a structure in which a plurality of electrodes and a plurality of separators are alternately stacked.
  • the plurality of electrodes forms an electrode active material layer coated with an electrode active material on a surface of a current collector, and an uncoated portion provided at an end of the electrode active material layer and free of the electrode active material.
  • a stack of a plurality of electrodes and a plurality of separators is wound around the core to form an electrode assembly, the electrode assembly is inserted into a can, and the cap assembly is coupled to an opening of the can.
  • the plurality of electrodes have a problem in that cracks are generated when the stepped portion between the electrode active material layer and the uncoated portion is folded when the core is wound.
  • the present invention has been invented to solve the above problems, the problem to be solved of the present invention implements an electrode that gradually increases the step height between the electrode active material layer and the uncoated portion, thereby In the winding, the stepped portion between the electrode active material layer and the uncoated portion can be stably wound without folding, and as a result, to provide an electrode and a secondary battery including the same, which can prevent cracking.
  • a secondary battery according to the first aspect of the present invention for achieving the above object includes an electrode assembly in which electrodes and separators are alternately stacked and wound, and the electrode includes a current collector and an electrode active material on a surface of the current collector.
  • One end may be formed shorter than the length, and a step may be formed between one end of the first coating layer and one end of the second coating layer as it moves outward from the winding center.
  • the electrode may include a first uncoated portion having no electrode active material at the start of the winding, and the first uncoated portion, one end of the first coating layer, and one end of the second coating layer may form a stepped step.
  • one end of the second coating layer may be formed as small as the circumferential length of the core portion at one end of the first coating layer.
  • the electrode may form a step between the end of the second coating layer and the end of the first coating layer by forming a length of the end of the second coating layer coated on the winding end shorter than the end length of the first coating layer.
  • the electrode may include a second uncoated portion having no electrode active material at an end of the winding, and the second uncoated portion, the end of the first coating layer, and the end of the second coating layer may form a stepped step.
  • the first coating layer and the second coating layer may have the same coating thickness.
  • the first coating layer and the second coating layer may have a different coating thickness.
  • the electrode may further include a third coating layer for tertiary coating of the electrode active material on the outside of the second coating layer, and a fourth coating layer for quaternarily coating the electrode active material on the outside of the third coating layer.
  • the electrode may be formed such that one end length of the third coating layer coated at the beginning of the winding is smaller than one end length of the second coating layer, and one end length of the fourth coating layer is smaller than one end length of the third coating layer.
  • One end of the first, second, third and fourth coating layers may form a stepped step.
  • An electrode tab may be provided on the first uncoated portion.
  • the electrode tab may be provided on the first non-coated portion in contact with one end of the first coating layer to remove a step between the electrode tab and the first coating layer.
  • the electrode according to the second invention the current collector; A first coating layer in which an electrode active material is first coated on a surface of the current collector; And a second coating layer having a second coating of an electrode active material on the outer side of the first coating layer, wherein the length of one end of the corresponding second coating layer is formed to be shorter than the length of one end of the first coating layer so as to form the first coating layer.
  • a step may be formed between one end of the coating layer and one end of the second coating layer.
  • One end of the current collector may include a first uncoated portion having no electrode active material, and the first uncoated portion, one end of the first coating layer, and one end of the second coating layer may form a step connected in a step shape.
  • An electrode tab may be provided at the first non-coating portion, and the electrode tab may be provided at the first non-coating portion in contact with one end of the first coating layer to remove a step between the electrode tab and one end of the first coating layer.
  • the present invention has the following effects.
  • the secondary battery of the present invention is characterized by forming a step between the first coating layer and one end of the second coating layer to form an electrode by forming the first and second coating layer on the surface of the current collector Due to such a feature, a gentle inclination angle can be realized between one end of the first coating layer and one end of the second coating layer, thereby stably winding the electrode to the core without folding the electrode. It can increase.
  • the electrode is characterized by including a first uncoated portion at the start of the winding, and because of this feature to form a step connected to the first uncoated portion, the first coating layer and the second coating layer A gentle inclination angle can be realized, and as a result, the electrode can be more stably wound around the core portion.
  • the electrode of the present invention is characterized in that between the end of the first coating layer and the end of the second coating layer is formed as small as the circumferential length of the core portion, due to this feature, while the electrode is stably wound around the core portion and Performance can be secured stably.
  • the electrode of the present invention is characterized by the step of forming the end of the first coating layer and the second coating layer located at the winding end stepped to implement a gentle inclination angle, such that the end of the electrode more closely It can wind up and can raise an electrode winding force and a bonding force as a result.
  • the electrode of the present invention is characterized in that it comprises a second uncoated portion at the end of the winding, and because of this feature to form a step connected to the end of the second coating layer, the end of the first coating layer and the second uncoated portion A gentle inclination angle can be realized, and as a result, the end portion of the electrode can be more stably wound around the core portion.
  • the electrode of the present invention is characterized by forming the same thickness of the first coating layer and the second coating layer, it is possible to form a step that gradually increases due to this feature, as a result the first coating layer and the second coating layer It can wind up stably without folding in between.
  • the secondary battery of the present invention is characterized in that the electrode tab is coupled to the first uncoated portion, the electrode tab is coupled to the surface of the first uncoated portion connected to one end of the first coating layer, due to this feature It is possible to remove the step between the tab and the first coating layer, and as a result, it can be stably wound without folding between the electrode tab and the first coating layer when the electrode is wound.
  • FIG. 1 is a perspective view illustrating a rechargeable battery according to a first exemplary embodiment of the first invention.
  • FIG. 2 is a cross-sectional view showing an electrode assembly before winding according to a first embodiment of the first invention
  • FIG. 3 is a sectional view showing an electrode according to a first embodiment of the first invention.
  • FIG. 4 is a sectional view showing an electrode according to a second embodiment of the first invention.
  • FIG. 5 is a sectional view showing an electrode according to a third embodiment of the first invention.
  • FIG. 6 is a sectional view showing an electrode according to a fourth embodiment of the first invention.
  • FIG. 7 is a perspective view of an electrode according to a second invention.
  • the secondary battery 100 includes a core part 110 and an electrode assembly 120 wound around the core part 110.
  • the core part 110 may be removed from the electrode assembly 120 when the winding of the electrode assembly 120 is completed.
  • the electrode assembly 120 having a long sheet shape is wound on the core part 110 to roll the electrode.
  • the assembly 120 is formed, and the electrode assembly 120 has a structure in which the electrode 121 and the separator 122 are alternately stacked.
  • the electrode 121 includes a current collector 121z, a first coating layer 121a coated with an electrode active material on a surface of the current collector 121z, and the first coating layer ( The second coating layer 121b coated with an electrode active material on the outer side of 121a) is included.
  • the length of one end B of the second coating layer 121b based on the winding direction of the electrode 121 is one end A of the first coating layer 121a. Formed shorter than the length, the step between the end (A) of the first coating layer 121a and the end (B) of the second coating layer 121b as it moves outward from the winding center (see dotted line shown in FIG. 3). ) Is formed.
  • the electrode 121 is gently inclined by forming a step (see dotted line shown in FIG. 3) between one end A of the first coating layer 121a and one end B of the second coating layer 121b. It is possible to implement, and one end (A) of the first coating layer (121a) having the gentle inclination and one end (B) of the second coating layer (121b) is wound without being folded in the core portion 110 in a stable manner It can be wound up, and as a result, the quality of a secondary battery can be improved.
  • the winding start of the electrode 121 in close contact with the core portion 110 may include a first uncoated portion 121c without an electrode active material.
  • the electrode 121 forms the first uncoated portion 121c while the left end of the current collector 121z extends, thereby forming the first uncoated portion 121c and the first coating layer (
  • One end A of 121a and one end B of the second coating layer 121b may form a stepped step (see dotted line shown in FIG. 3) having a gradual height.
  • the electrode 121 has the first uncoated portion 121c, one end A of the first coating layer 121a, and one end B of the second coating layer 121b sequentially on the core part 110. As a result, it is possible to prevent a stable winding force and the occurrence of cracks as a result.
  • one end (B) of the second coating layer 121b in the electrode 121 is as small as the circumferential length of the core portion 110 at one end (A) of the first coating layer (121a), preferably It may be formed to be equal to the circumferential length of the core portion 110. That is, even if the length between one end B of the second coating layer 121b and one end A of the first coating layer 121a is shorter than the circumferential length of the core part 110, the second coating layer 121b is used. Due to the step-shaped step between the one end (B) and one end (A) of the first coating layer (121a) can be wound around the core portion 110 without cracking. However, between one end B of the second coating layer 121b and one end A of the first coating layer 121a may not be stably in close contact with the core part 110.
  • the electrode 121 is coated.
  • the electrode active material may be greatly reduced, and as a result, battery performance may be greatly reduced.
  • the length between one end B of the second coating layer 121b and one end A of the first coating layer 121a in the electrode 121 is provided as the circumferential length of the core part 110. As a result, the winding power and battery performance can be improved.
  • first coating layer (121a) and the second coating layer (121b) may have the same coating thickness, thereby forming a step height uniformly, as a result it can induce a more stable winding.
  • first coating layer 121a and the second coating layer 121b may have different coating thicknesses. This may control the coating thickness of the first coating layer 121a and the second coating layer 121b according to the shape and size of the secondary battery, and as a result, a stable winding force may be obtained.
  • the electrode assembly 120 having the long sheet shape including the electrode 121 when the electrode assembly 120 having the long sheet shape including the electrode 121 is wound around the core unit 110, the electrode ( Due to the step formed in the step shape in step 121 can be stably wound on the core portion 110, as a result of which the electrode 121 can be folded or prevent the occurrence of cracks.
  • the secondary battery 100 includes an electrode 121, wherein the electrode 121 is a current collector 121z and the current collector 121z.
  • the electrode 121 has a length of the end D of the second coating layer 121b coated on the winding end shorter than the length of the end C of the first coating layer 121a.
  • a step (see dotted line shown in FIG. 4) is formed between the end D of the second coating layer 121b and the end C of the first coating layer 121a.
  • the electrode 121 is gently inclined by forming a step (see dotted line shown in FIG. 4) between the end C of the first coating layer 121a and the end D of the second coating layer 121b.
  • the end D of the second coating layer 121b has a shorter length and a higher height than the end C of the first coating layer 121a to form a step, thereby implementing a gentle inclination.
  • the end C of the first coating layer 121a and the end D of the second coating layer 121b may be stably wound while being sequentially wound on the outermost side of the electrode assembly 110 wound on the core part 110. As a result, the electrode 121 may be prevented from being folded or cracked to increase the quality of the secondary battery.
  • the electrode 121 includes a second uncoated portion 121d having no electrode active material at the winding end (the right end of the current collector when viewed in FIG. 4), and the second uncoated portion 121d and the first uncoated portion.
  • An end C of the coating layer 121a and an end D of the second coating layer 121b may form a stepped step.
  • the second uncoated portion 121d, the end C of the first coating layer 121a, and the end D of the second coating layer 121b may form a stepped step having a gradual height.
  • the electrode 121 has the second uncoated portion 121d, the end C of the first coating layer 121a, and the end D of the second coating layer 121b sequentially on the core part 110. As a result, it is possible to prevent a stable winding force and the occurrence of cracks as a result.
  • the secondary battery 100 may include an electrode tab 123 in the first uncoated portion 121c of the electrode 121.
  • the electrode tab 123 may be provided in the first uncoated portion 121c in contact with one end A of the first coating layer 121a. Accordingly, the electrode tab 123 and the first coating layer may be provided. The gap 121 and the step between the 121a may be removed to stably wind the electrode 121.
  • the electrode tab 123 and the first coating layer 121a may have the same thickness, thereby completely removing the step between the electrode tab 123 and the first coating layer 121a. As a result, the electrode 121 can be wound more stably.
  • the secondary battery 100 includes an electrode 121, wherein the electrode 121 is a current collector 121z and the current collector 121z.
  • the electrode 121 is formed to have a length of one end B of the second coating layer 121b smaller than the length of one end A of the first coating layer 121a based on the winding direction of the electrode 121.
  • the length of one end E of the third coating layer 121e is smaller than the length of one end B of the second coating layer 121b
  • the length of one end F of the fourth coating layer 121f is the third coating layer. It can be formed smaller than the length of one end E of 121e. Accordingly, one end of the first, second, third and fourth coating layers may form a stepped step (see dotted line shown in FIG. 6).
  • the electrode 121 may realize a step having a gentle slope of one end of the first, second, third and fourth coating layers, and may be stably wound on the core part 110 to obtain stable winding force. .
  • the electrode 121 of the second invention includes a current collector 121z, a first coating layer 121a obtained by first coating an electrode active material on the surface of the current collector 121z, and the first agent.
  • the first coating layer includes a second coating layer 121b coated with an electrode active material on the outside of the first coating layer, and the length of one end B of the second coating layer 121b is based on the winding direction of the electrode 121. It is formed shorter than the length of one end (A) of the coating layer 121a, and as it moves outward from the winding center, between one end (A) of the first coating layer (121a) and one end (B) of the second coating layer (121b). Steps are formed in the.
  • the electrode 121 of the second invention may form a step at one end to obtain a stable winding force at the time of winding the core part later.
  • the first embodiment of the first invention is a secondary battery, but the second invention has a difference in that the electrode that goes into the secondary battery.

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

The present invention relates to a secondary battery comprising an electrode assembly in which electrodes and separators are alternately stacked and wound, wherein the electrode comprises: a current collector; a first coating layer formed by firstly coating an electrode active material on a surface of the current collector; and a second coating layer formed by secondly coating an electrode active material on the outside of the first coating layer, and wherein the length of one end of the second coating layer is formed to be shorter than the length of one end of the first coating layer on the basis of the winding direction of the electrode, such that a step is formed between the one end of the first coating layer and the one end of the second coating layer as the electrodes are wound from the center of the winding toward the outside.

Description

전극 및 그를 포함하는 이차전지Electrode and secondary battery comprising same
관련출원과의 상호인용Citation with Related Applications
본 출원은 2017년 06월 09일자 한국특허출원 제10-2017-0072588호 및 2018년 05월 31일자 한국특허출원 제10-2018-0062420호에 기초한 우선권의 이익을 주장하며, 해당 한국특허출원의 문헌에 개시된 모든 내용은 본 명세서의 일부로서 포함된다.This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0072588 dated June 09, 2017 and Korean Patent Application No. 10-2018-0062420 dated May 31, 2018. All content disclosed in the literature is included as part of this specification.
기술분야Field of technology
본 발명은 전극 및 그를 포함하는 이차전지에 관한 것으로서, 특히 코어부에 권취되는 전극의 크랙 발생을 방지한 전극 및 그를 포함하는 이차전지에 관한 것이다.The present invention relates to an electrode and a secondary battery including the same, and more particularly to an electrode which prevents the occurrence of cracking of the electrode wound in the core portion and a secondary battery comprising the same.
일반적으로, 이차전지는 충전이 불가능한 일차 전지와는 달리, 충전 및 방전이 가능한 전지를 말하는 것으로서, 휴대폰, PDA, 노트북 컴퓨터 등의 소형 첨단 전자기기 분야에서 널리 사용되고 있다.In general, the secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged, and is widely used in small advanced electronic devices such as mobile phones, PDAs, and notebook computers.
이러한 이차전지는 전극조립체와, 상기 전극조립체의 권심에 삽입하는 코어부와, 상기 코어부가 삽입된 전극조립체를 수용하는 캔, 및 상기 캔의 개구부에 실장하는 캡 조립체를 포함하며, 상기 전극조립체는 복수의 전극과 복수의 분리막이 교대로 적층되는 구조를 가진다. 그리고 상기 복수의 전극은 집전체의 표면에 전극활물질이 코팅된 전극활물질층과, 상기 전극활물질층의 단부에 구비되고 전극활물질이 없는 무지부를 형성한다.The secondary battery includes an electrode assembly, a core portion inserted into the core of the electrode assembly, a can containing the electrode assembly into which the core portion is inserted, and a cap assembly mounted in an opening of the can, wherein the electrode assembly includes: It has a structure in which a plurality of electrodes and a plurality of separators are alternately stacked. The plurality of electrodes forms an electrode active material layer coated with an electrode active material on a surface of a current collector, and an uncoated portion provided at an end of the electrode active material layer and free of the electrode active material.
상기와 같은 이차전지는 복수의 전극과 복수의 분리막이 적층된 적층체를 상기 코어부를 통해 권취하여 전극조립체를 형성하고, 상기 전극조립체를 캔에 삽입하며, 상기 캔의 개구부에 캡 조립체를 결합시켜서 제조한다.In the secondary battery as described above, a stack of a plurality of electrodes and a plurality of separators is wound around the core to form an electrode assembly, the electrode assembly is inserted into a can, and the cap assembly is coupled to an opening of the can. Manufacture.
그러나 상기한 복수의 전극은 상기 코어부에 권취시 상기 전극활물질층과 상기 무지부 사이의 단차 부분이 접히면서 크랙이 발생하는 문제점이 있었다.However, the plurality of electrodes have a problem in that cracks are generated when the stepped portion between the electrode active material layer and the uncoated portion is folded when the core is wound.
본 발명은 상기와 같은 문제점을 해결하기 위해 발명된 것으로, 본 발명의 해결 하고자 하는 과제는 전극활물질층과 무지부 사이의 단차 높이가 점진적으로 증대되는 전극을 구현하며, 이에 따라 코어부에 전극의 권취시 전극활물질층과 무지부 사이의 단차 부분이 접히지 않고 안정적으로 권취할 수 있고, 그 결과 크랙 발생을 방지할 수 있는 전극 및 그를 포함하는 이차전지를 제공하는데 있다.The present invention has been invented to solve the above problems, the problem to be solved of the present invention implements an electrode that gradually increases the step height between the electrode active material layer and the uncoated portion, thereby In the winding, the stepped portion between the electrode active material layer and the uncoated portion can be stably wound without folding, and as a result, to provide an electrode and a secondary battery including the same, which can prevent cracking.
상기와 같은 목적을 달성하기 위한 제1 발명에 따른 이차전지는, 전극과 분리막이 교대로 적층되고 권취되는 전극조립체를 포함하며, 상기 전극은, 집전체, 상기 집전체의 표면에 전극활물질을 1차 코팅한 제1 코팅층, 및 상기 제1 코팅층의 외측에 전극활물질을 2차 코팅한 제2 코팅층을 포함하고, 상기 전극의 권취 방향을 기준으로 상기 제2 코팅층의 일단 길이를 상기 제1 코팅층의 일단 길이 보다 짧게 형성하여, 권취 중심에서 바깥방향으로 나아감에 따라 상기 제1 코팅층의 일단과 상기 제2 코팅층의 일단 사이에 단차가 형성될 수 있다.A secondary battery according to the first aspect of the present invention for achieving the above object includes an electrode assembly in which electrodes and separators are alternately stacked and wound, and the electrode includes a current collector and an electrode active material on a surface of the current collector. A first coating layer coated with a second coating, and a second coating layer having a second coating of an electrode active material on the outside of the first coating layer, the length of one end of the second coating layer being based on a winding direction of the electrode. One end may be formed shorter than the length, and a step may be formed between one end of the first coating layer and one end of the second coating layer as it moves outward from the winding center.
상기 전극은 권취 시작부에 전극활물질이 없는 제1 무지부를 포함하며, 상기 제1 무지부, 상기 제1 코팅층의 일단 및 상기 제2 코팅층의 일단은 계단형태의 단차를 형성할 수 있다.The electrode may include a first uncoated portion having no electrode active material at the start of the winding, and the first uncoated portion, one end of the first coating layer, and one end of the second coating layer may form a stepped step.
상기 전극조립체를 권취하기 위한 코어부를 포함하며, 상기 제2 코팅층의 일단은 상기 제1 코팅층의 일단에서 상기 코어부의 둘레 길이만큼 작게 형성할 수 있다.Comprising a core for winding the electrode assembly, one end of the second coating layer may be formed as small as the circumferential length of the core portion at one end of the first coating layer.
상기 전극은 권취 끝부에 코팅된 상기 제2 코팅층의 끝단의 길이를 상기 제1 코팅층의 끝단 길이 보다 짧게 형성하여 상기 제2 코팅층의 끝단과 상기 제1 코팅층의 끝단 사이에 단차를 형성할 수 있다.The electrode may form a step between the end of the second coating layer and the end of the first coating layer by forming a length of the end of the second coating layer coated on the winding end shorter than the end length of the first coating layer.
상기 전극은 권취 끝부에 전극활물질이 없는 제2 무지부를 포함하며, 상기 제2 무지부, 상기 제1 코팅층의 끝단 및 상기 제2 코팅층의 끝단은 계단형태의 단차를 형성할 수 있다.The electrode may include a second uncoated portion having no electrode active material at an end of the winding, and the second uncoated portion, the end of the first coating layer, and the end of the second coating layer may form a stepped step.
상기 제1 코팅층과 상기 제2 코팅층은 동일한 코팅두께를 가질 수 있다.The first coating layer and the second coating layer may have the same coating thickness.
상기 제1 코팅층과 상기 제2 코팅층은 서로 다른 코팅두께를 가질 수 있다.The first coating layer and the second coating layer may have a different coating thickness.
상기 전극은, 상기 제2 코팅층의 외측에 전극활물질을 3차 코팅하는 제3 코팅층과, 상기 제3 코팅층의 외측에 전극활물질을 4차 코팅하는 제4 코팅층을 더 포함할 수 있다.The electrode may further include a third coating layer for tertiary coating of the electrode active material on the outside of the second coating layer, and a fourth coating layer for quaternarily coating the electrode active material on the outside of the third coating layer.
상기 전극은 권취 시작부에 코팅된 상기 제3 코팅층의 일단 길이를 상기 제2 코팅층의 일단 길이보다 작게 형성하고, 상기 제4 코팅층의 일단 길이를 상기 제3 코팅층의 일단 길이보다 작게 형성하며, 상기 제1, 제2, 제3 및 제4 코팅층의 일단은 계단형태의 단차를 형성할 수 있다.The electrode may be formed such that one end length of the third coating layer coated at the beginning of the winding is smaller than one end length of the second coating layer, and one end length of the fourth coating layer is smaller than one end length of the third coating layer. One end of the first, second, third and fourth coating layers may form a stepped step.
상기 제1 무지부에는 전극탭을 구비할 수 있다.An electrode tab may be provided on the first uncoated portion.
상기 전극탭은 상기 제1 코팅층의 일단과 접하는 상기 제1 무지부에 구비되면서 상기 전극탭과 상기 제1 코팅층 사이에 단차를 제거할 수 있다.The electrode tab may be provided on the first non-coated portion in contact with one end of the first coating layer to remove a step between the electrode tab and the first coating layer.
한편, 제2 발명에 따른 전극은, 집전체; 상기 집전체의 표면에 전극활물질을 1차 코팅한 제1 코팅층; 및 상기 제1 코팅층의 외측에 전극활물질을 2차 코팅한 제2 코팅층을 포함하고, 상호 대응하는 상기 제2 코팅층의 일단의 길이는 상기 제1 코팅층의 일단 길이 보다 소정 길이 짧게 형성하여 상기 제1 코팅층의 일단과 상기 제2 코팅층의 일단 사이에 단차를 형성할 수 있다.On the other hand, the electrode according to the second invention, the current collector; A first coating layer in which an electrode active material is first coated on a surface of the current collector; And a second coating layer having a second coating of an electrode active material on the outer side of the first coating layer, wherein the length of one end of the corresponding second coating layer is formed to be shorter than the length of one end of the first coating layer so as to form the first coating layer. A step may be formed between one end of the coating layer and one end of the second coating layer.
상기 집전체의 일단에는 전극활물질이 없는 제1 무지부를 포함하며, 상기 제1 무지부, 상기 제1 코팅층의 일단 및 상기 제2 코팅층의 일단은 계단형태로 연결되는 단차를 형성할 수 있다.One end of the current collector may include a first uncoated portion having no electrode active material, and the first uncoated portion, one end of the first coating layer, and one end of the second coating layer may form a step connected in a step shape.
상기 제1 무지부에는 전극탭을 구비하며, 상기 전극탭은 상기 제1 코팅층의 일단에 접하는 상기 제1 무지부에 구비되면서 상기 전극탭과 상기 제1 코팅층의 일단 사이에 단차를 제거할 수 있다.An electrode tab may be provided at the first non-coating portion, and the electrode tab may be provided at the first non-coating portion in contact with one end of the first coating layer to remove a step between the electrode tab and one end of the first coating layer. .
상기와 같은 실시예를 통해 본 발명은 하기와 같은 효과를 가진다.Through the above embodiments, the present invention has the following effects.
첫째: 본 발명의 이차전지는 집전체의 표면에 제1 및 제2 코팅층을 형성하여 전극을 형성하되, 상기 제1 코팅층의 일단과 상기 제2 코팅층의 일단 사이에 단차를 형성하는 것에 특징을 가지며, 이와 같은 특징으로 인해 상기 제1 코팅층의 일단과 상기 제2 코팅층의 일단 사이에 완만한 경사각을 구현할 수 있고, 이에 따라 코어부에 전극을 접히지 않고 안정적으로 권취할 수 있으며, 그 결과 제품성을 높일 수 있다.Firstly, the secondary battery of the present invention is characterized by forming a step between the first coating layer and one end of the second coating layer to form an electrode by forming the first and second coating layer on the surface of the current collector Due to such a feature, a gentle inclination angle can be realized between one end of the first coating layer and one end of the second coating layer, thereby stably winding the electrode to the core without folding the electrode. It can increase.
둘째: 본 발명의 이차전지에서 전극은 권취 시작부에 제1 무지부를 포함하는 것에 특징을 가지며, 이와 같은 특징으로 인해 제1 무지부, 제1 코팅층 및 제2 코팅층으로 연결되는 단차를 형성하여 보다 완만한 경사각을 구현할 수 있으며, 그 결과 코어부에 전극을 보다 안정적으로 권취할 수 있다.Secondly, in the secondary battery of the present invention, the electrode is characterized by including a first uncoated portion at the start of the winding, and because of this feature to form a step connected to the first uncoated portion, the first coating layer and the second coating layer A gentle inclination angle can be realized, and as a result, the electrode can be more stably wound around the core portion.
셋째: 본 발명의 전극에서 제1 코팅층의 단부와 제2 코팅층의 단부 사이는 코어부의 둘레 길이만큼 작게 형성하는 것에 특징을 가지며, 이와 같은 특징으로 인해 코어부에 전극을 안정적으로 권취함과 동시에 전지 성능을 안정적으로 확보할 수 있다.Third: In the electrode of the present invention is characterized in that between the end of the first coating layer and the end of the second coating layer is formed as small as the circumferential length of the core portion, due to this feature, while the electrode is stably wound around the core portion and Performance can be secured stably.
넷째: 본 발명의 전극은 권취 끝단부에 위치한 제1 코팅층과 제2 코팅층의 단부를 단차지게 형성하여 완만한 경사각을 구현하는 것에 특징을 가지며, 이와 같은 특징으로 인해 전극의 끝단부를 보다 면밀착되게 권취할 수 있고, 그 결과 전극 권취력과 결합력을 높일 수 있다.Fourth: The electrode of the present invention is characterized by the step of forming the end of the first coating layer and the second coating layer located at the winding end stepped to implement a gentle inclination angle, such that the end of the electrode more closely It can wind up and can raise an electrode winding force and a bonding force as a result.
다섯째: 본 발명의 전극은 권취 끝단부에 제2 무지부를 포함하는 것에 특징을 가지며, 이와 같은 특징으로 인해 제2 코팅층의 끝단, 제1 코팅층의 끝단 및 제2 무지부로 연결되는 단차를 형성하여 보다 완만한 경사각을 구현할 수 있고, 그 결과 코어부에 전극의 끝단부를 보다 안정적으로 권취할 수 있다.Fifth: The electrode of the present invention is characterized in that it comprises a second uncoated portion at the end of the winding, and because of this feature to form a step connected to the end of the second coating layer, the end of the first coating layer and the second uncoated portion A gentle inclination angle can be realized, and as a result, the end portion of the electrode can be more stably wound around the core portion.
여섯째: 본 발명의 전극은 제1 코팅층과 제2 코팅층의 두께를 동일하게 형성하는 것에 특징을 가지며, 이와 같은 특징으로 인해 점진적으로 높아지는 단차를 형성할 수 있고, 그 결과 제1 코팅층과 제2 코팅층 사이를 접히지 않고 안정적으로 권취할 수 있다.Sixth: The electrode of the present invention is characterized by forming the same thickness of the first coating layer and the second coating layer, it is possible to form a step that gradually increases due to this feature, as a result the first coating layer and the second coating layer It can wind up stably without folding in between.
일곱째: 본 발명의 이차전지는 제1 무지부에 전극탭을 결합하되, 상기 전극탭은 상기 제1 코팅층의 일단부가 연결된 제1 무지부의 표면에 결합하는 것에 특징을 가지며, 이와 같은 특징으로 인해 전극탭과 제1 코팅층 사이에 단차를 제거할 수 있고, 그 결과 코어부에 전극 권취시 전극탭과 제1 코팅층 사이가 접히지 않고 안정적으로 권취시킬 수 있다.Seventh: The secondary battery of the present invention is characterized in that the electrode tab is coupled to the first uncoated portion, the electrode tab is coupled to the surface of the first uncoated portion connected to one end of the first coating layer, due to this feature It is possible to remove the step between the tab and the first coating layer, and as a result, it can be stably wound without folding between the electrode tab and the first coating layer when the electrode is wound.
도 1은 제1 발명의 제1 실시예에 따른 이차전지를 도시한 사시도.1 is a perspective view illustrating a rechargeable battery according to a first exemplary embodiment of the first invention.
도 2는 제1 발명의 제1 실시예에 따른 권취 전 전극조립체를 도시한 단면도.2 is a cross-sectional view showing an electrode assembly before winding according to a first embodiment of the first invention;
도 3은 제1 발명의 제1 실시예에 따른 전극을 도시한 단면도.3 is a sectional view showing an electrode according to a first embodiment of the first invention;
도 4는 제1 발명의 제2 실시예에 따른 전극을 도시한 단면도.4 is a sectional view showing an electrode according to a second embodiment of the first invention;
도 5는 제1 발명의 제3 실시예에 따른 전극을 도시한 단면도.5 is a sectional view showing an electrode according to a third embodiment of the first invention;
도 6은 제1 발명의 제4 실시예에 따른 전극을 도시한 단면도.6 is a sectional view showing an electrode according to a fourth embodiment of the first invention;
도 7은 제2 발명에 따른 전극을 도시한 사시도.7 is a perspective view of an electrode according to a second invention;
이하, 첨부한 도면을 참조하여 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자가 용이하게 실시할 수 있도록 본 발명의 실시예를 상세히 설명한다. 그러나 본 발명은 여러 가지 상이한 형태로 구현될 수 있으며 여기에서 설명하는 실시예에 한정되지 않는다. 그리고 도면에서 본 발명을 명확하게 설명하기 위해서 설명과 관계없는 부분은 생략하였으며, 명세서 전체를 통하여 유사한 부분에 대해서는 유사한 도면 부호를 붙였다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.
[제1 발명의 이차전지][Secondary Battery of First Invention]
제1 발명의 제1 실시예First embodiment of the first invention
제1 발명의 제1 실시예에 따른 이차전지(100)는 도 1에 도시되어 있는 것과 같이, 코어부(110), 상기 코어부(110)의 둘레에 권취되는 전극조립체(120)를 포함한다. 여기서 상기 코어부(110)는 상기 전극조립체(120)의 권취가 완료되면 상기 전극조립체(120)로부터 제거될 수 있다.As shown in FIG. 1, the secondary battery 100 according to the first embodiment of the first invention includes a core part 110 and an electrode assembly 120 wound around the core part 110. . The core part 110 may be removed from the electrode assembly 120 when the winding of the electrode assembly 120 is completed.
즉, 제1 발명의 제1 실시예에 따른 이차전지(100)는 도 2에 도시되어 있는 것과 같이, 긴 시트 형태의 전극조립체(120)를 상기 코어부(110)에 권취하여 롤 형태의 전극조립체(120)를 형성하며, 상기 전극조립체(120)는 전극(121)과 분리막(122)이 교대로 적층되는 구조를 가진다.That is, in the secondary battery 100 according to the first embodiment of the first invention, as shown in FIG. 2, the electrode assembly 120 having a long sheet shape is wound on the core part 110 to roll the electrode. The assembly 120 is formed, and the electrode assembly 120 has a structure in which the electrode 121 and the separator 122 are alternately stacked.
상기 전극(121)은 도 3에 도시되어 있는 것과 같이, 집전체(121z), 상기 집전체(121z)의 표면에 전극활물질을 1차 코팅한 제1 코팅층(121a), 및 상기 제1 코팅층(121a)의 외측에 전극활물질을 2차 코팅한 제2 코팅층(121b)을 포함한다.As shown in FIG. 3, the electrode 121 includes a current collector 121z, a first coating layer 121a coated with an electrode active material on a surface of the current collector 121z, and the first coating layer ( The second coating layer 121b coated with an electrode active material on the outer side of 121a) is included.
여기서 상기 전극(121)은 도 3을 참조하면, 상기 전극(121)의 권취 방향을 기준으로 상기 제2 코팅층(121b)의 일단(B) 길이를 상기 제1 코팅층(121a)의 일단(A) 길이 보다 짧게 형성하여, 권취 중심에서 바깥방향으로 나아감에 따라 상기 제1 코팅층(121a)의 일단(A)과 상기 제2 코팅층(121b)의 일단(B) 사이에 단차(도 3에 표시된 점선 참조)가 형성된다.Here, referring to FIG. 3, the length of one end B of the second coating layer 121b based on the winding direction of the electrode 121 is one end A of the first coating layer 121a. Formed shorter than the length, the step between the end (A) of the first coating layer 121a and the end (B) of the second coating layer 121b as it moves outward from the winding center (see dotted line shown in FIG. 3). ) Is formed.
즉, 상기 전극(121)은 상기 제1 코팅층(121a)의 일단(A)과 상기 제2 코팅층(121b)의 일단(B) 사이에 단차(도 3에 표시된 점선 참조)를 형성하여 완만한 경사를 구현할 수 있으며, 상기 완만한 경사를 가진 상기 제1 코팅층(121a)의 일단(A)과 상기 제2 코팅층(121b)의 일단(B)이 순차적으로 코어부(110)에 권취되면서 접히지 않고 안정적으로 권취할 수 있고, 그 결과 이차전지의 품질성을 높일 수 있다.That is, the electrode 121 is gently inclined by forming a step (see dotted line shown in FIG. 3) between one end A of the first coating layer 121a and one end B of the second coating layer 121b. It is possible to implement, and one end (A) of the first coating layer (121a) having the gentle inclination and one end (B) of the second coating layer (121b) is wound without being folded in the core portion 110 in a stable manner It can be wound up, and as a result, the quality of a secondary battery can be improved.
한편, 상기 코어부(110)에 밀착되는 상기 전극(121)의 권취 시작부에는 전극활물질이 없는 제1 무지부(121c)를 포함할 수 있다.On the other hand, the winding start of the electrode 121 in close contact with the core portion 110 may include a first uncoated portion 121c without an electrode active material.
즉, 전극(121)은 도 3에서 보았을 때 집전체(121z)의 왼쪽 단부가 연장되면서 제1 무지부(121c)를 형성하며, 이에 따라 상기 제1 무지부(121c), 상기 제1 코팅층(121a)의 일단(A) 및 상기 제2 코팅층(121b)의 일단(B)은 점진적인 높이를 가진 계단형태의 단차(도 3에 표시된 점선 참조)를 형성할 수 있다. That is, as shown in FIG. 3, the electrode 121 forms the first uncoated portion 121c while the left end of the current collector 121z extends, thereby forming the first uncoated portion 121c and the first coating layer ( One end A of 121a and one end B of the second coating layer 121b may form a stepped step (see dotted line shown in FIG. 3) having a gradual height.
이에 따라 전극(121)은 상기 제1 무지부(121c), 상기 제1 코팅층(121a)의 일단(A) 및 상기 제2 코팅층(121b)의 일단(B)이 상기 코어부(110)에 순차적으로 권취되며, 그 결과 안정된 권취력과 크랙 발생을 방지할 수 있다.Accordingly, the electrode 121 has the first uncoated portion 121c, one end A of the first coating layer 121a, and one end B of the second coating layer 121b sequentially on the core part 110. As a result, it is possible to prevent a stable winding force and the occurrence of cracks as a result.
한편, 상기 전극(121)에서 상기 제2 코팅층(121b)의 일단(B)은 상기 제1 코팅층(121a)의 일단(A)에서 상기 코어부(110)의 둘레 길이만큼 작게, 바람직하게는 상기 코어부(110)의 둘레 길이와 동일하게 형성할 수 있다. 즉, 상기 제2 코팅층(121b)의 일단(B)과 상기 제1 코팅층(121a)의 일단(A) 사이의 길이가 상기 코어부(110)의 둘레 길이 보다 짧더라도 상기 제2 코팅층(121b)의 일단(B)과 상기 제1 코팅층(121a)의 일단(A) 사이의 계단형태의 단차로 인하여 상기 코어부(110)에 크랙 발생 없이 권취할 수 있다. 다만, 상기 제2 코팅층(121b)의 일단(B)과 상기 제1 코팅층(121a)의 일단(A) 사이가 상기 코어부(110)에 안정적으로 밀착되지 못할 수 있다.On the other hand, one end (B) of the second coating layer 121b in the electrode 121 is as small as the circumferential length of the core portion 110 at one end (A) of the first coating layer (121a), preferably It may be formed to be equal to the circumferential length of the core portion 110. That is, even if the length between one end B of the second coating layer 121b and one end A of the first coating layer 121a is shorter than the circumferential length of the core part 110, the second coating layer 121b is used. Due to the step-shaped step between the one end (B) and one end (A) of the first coating layer (121a) can be wound around the core portion 110 without cracking. However, between one end B of the second coating layer 121b and one end A of the first coating layer 121a may not be stably in close contact with the core part 110.
또한, 상기 제2 코팅층(121b)의 일단(B)과 상기 제1 코팅층(121a)의 일단(A) 사이의 길이가 상기 코어부(110)의 둘레 길이 보다 클 경우 상기 전극(121)에 코팅되는 전극활물질이 크게 감소할 수 있으며, 그 결과 전지 성능이 크게 떨어질 수 있다.In addition, when the length between one end B of the second coating layer 121b and one end A of the first coating layer 121a is larger than the circumferential length of the core part 110, the electrode 121 is coated. The electrode active material may be greatly reduced, and as a result, battery performance may be greatly reduced.
따라서 상기 전극(121)에서 상기 제2 코팅층(121b)의 일단(B)과 상기 제1 코팅층(121a)의 일단(A) 사이의 길이는 상기 코어부(110)의 둘레 길이만큼으로 구비하며, 그 결과 권취력과 전지성능을 높일 수 있다.Therefore, the length between one end B of the second coating layer 121b and one end A of the first coating layer 121a in the electrode 121 is provided as the circumferential length of the core part 110. As a result, the winding power and battery performance can be improved.
한편, 상기 제1 코팅층(121a)과 상기 제2 코팅층(121b)은 동일한 코팅두께를 가질 수 있으며, 이에 따라 단차 높이를 균일하게 형성할 수 있고, 그 결과 보다 안정된 권취를 유도할 수 있다.On the other hand, the first coating layer (121a) and the second coating layer (121b) may have the same coating thickness, thereby forming a step height uniformly, as a result it can induce a more stable winding.
물론, 상기 제1 코팅층(121a)과 상기 제2 코팅층(121b)은 서로 다른 코팅두께를 가질 수 있다. 이는 이차전지의 형태 및 크기에 따라 상기 제1 코팅층(121a)과 상기 제2 코팅층(121b)의 코팅두께를 조절할 수 있고, 그 결과 안정된 권취력을 얻을 수 있다.Of course, the first coating layer 121a and the second coating layer 121b may have different coating thicknesses. This may control the coating thickness of the first coating layer 121a and the second coating layer 121b according to the shape and size of the secondary battery, and as a result, a stable winding force may be obtained.
이와 같은 구성을 가진 제1 발명의 제1 실시예에 따른 이차전지(100)는 상기 전극(121)을 포함한 긴 시트 형태의 전극조립체(120)를 코어부(110)에 권취하면, 상기 전극(121)의 일단에 계단 형태로 형성된 단차로 인해 코어부(110)에 안정적으로 권취할 수 있으며, 그 결과 전극(121)이 접히거나 또는 크랙발생을 방지할 수 있다.In the secondary battery 100 according to the first embodiment of the present invention having the above configuration, when the electrode assembly 120 having the long sheet shape including the electrode 121 is wound around the core unit 110, the electrode ( Due to the step formed in the step shape in step 121 can be stably wound on the core portion 110, as a result of which the electrode 121 can be folded or prevent the occurrence of cracks.
이하, 본 발명의 다른 실시예를 설명함에 있어 전술한 실시예와 동일한 구성과 기능을 가지는 구성에 대해서는 동일한 구성부호를 사용하며, 중복되는 설명은 생략한다.Hereinafter, in describing other embodiments of the present invention, the same reference numerals are used for components having the same configuration and function as the above-described embodiment, and overlapping descriptions are omitted.
제1 발명의 제2 실시예Second embodiment of the first invention
제1 발명의 제2 실시예에 따른 이차전지(100)는 도 4에 도시되어 있는 것과 같이, 전극(121)을 포함하되, 상기 전극(121)은 집전체(121z), 상기 집전체(121z)의 표면에 전극활물질을 1차 코팅한 제1 코팅층(121a), 및 상기 제1 코팅층(121a)의 외측에 전극활물질을 2차 코팅한 제2 코팅층(121b)을 포함한다.As shown in FIG. 4, the secondary battery 100 according to the second embodiment of the first invention includes an electrode 121, wherein the electrode 121 is a current collector 121z and the current collector 121z. The first coating layer 121a coated with an electrode active material on the surface of the substrate), and the second coating layer 121b coated with an electrode active material on the outside of the first coating layer 121a.
여기서 상기 전극(121)은 도 4를 참조하면, 권취 끝부에 코팅된 상기 제2 코팅층(121b)의 끝단(D)의 길이를 상기 제1 코팅층(121a)의 끝단(C) 길이 보다 짧게 형성하여 상기 제2 코팅층(121b)의 끝단(D)과 상기 제1 코팅층(121a)의 끝단(C) 사이에 단차(도 4에 표시된 점선 참조)를 형성한다.Here, referring to FIG. 4, the electrode 121 has a length of the end D of the second coating layer 121b coated on the winding end shorter than the length of the end C of the first coating layer 121a. A step (see dotted line shown in FIG. 4) is formed between the end D of the second coating layer 121b and the end C of the first coating layer 121a.
즉, 상기 전극(121)은 상기 제1 코팅층(121a)의 끝단(C)과 상기 제2 코팅층(121b)의 끝단(D) 사이에 단차(도 4에 표시된 점선 참조)를 형성하여 완만한 경사를 구현할 수 있다. 다시 말해, 상기 제2 코팅층(121b)의 끝단(D)은 상기 제1 코팅층(121a)의 끝단(C) 보다 길이는 짧고, 높이는 높게 단차를 형성하여 완만한 경사를 구현하며, 이에 따라 상기 제1 코팅층(121a)의 끝단(C)과 상기 제2 코팅층(121b)의 끝단(D)는 코어부(110)에 권취된 전극조립체(110)의 최외측에 순차적으로 권취되면서 안정적으로 권취할 수 있으며, 그 결과 전극(121)이 접히거나 크랙 발생을 방지하여 이차전지의 품질성을 높일 수 있다.That is, the electrode 121 is gently inclined by forming a step (see dotted line shown in FIG. 4) between the end C of the first coating layer 121a and the end D of the second coating layer 121b. Can be implemented. In other words, the end D of the second coating layer 121b has a shorter length and a higher height than the end C of the first coating layer 121a to form a step, thereby implementing a gentle inclination. The end C of the first coating layer 121a and the end D of the second coating layer 121b may be stably wound while being sequentially wound on the outermost side of the electrode assembly 110 wound on the core part 110. As a result, the electrode 121 may be prevented from being folded or cracked to increase the quality of the secondary battery.
한편, 상기 전극(121)은 권취 끝부(도 4에서 보았을 때 집전체의 오른쪽 단부)에 전극활물질이 없는 제2 무지부(121d)를 포함하며, 상기 제2 무지부(121d), 상기 제1 코팅층(121a)의 끝단(C) 및 상기 제2 코팅층(121b)의 끝단(D)은 계단형태의 단차를 형성할 수 있다.Meanwhile, the electrode 121 includes a second uncoated portion 121d having no electrode active material at the winding end (the right end of the current collector when viewed in FIG. 4), and the second uncoated portion 121d and the first uncoated portion. An end C of the coating layer 121a and an end D of the second coating layer 121b may form a stepped step.
즉, 제2 무지부(121d), 상기 제1 코팅층(121a)의 끝단(C) 및 상기 제2 코팅층(121b)의 끝단(D)은 점진적인 높이를 가진 계단형태의 단차를 형성할 수 있다. That is, the second uncoated portion 121d, the end C of the first coating layer 121a, and the end D of the second coating layer 121b may form a stepped step having a gradual height.
이에 따라 전극(121)은 상기 제2 무지부(121d), 상기 제1 코팅층(121a)의 끝단(C) 및 상기 제2 코팅층(121b)의 끝단(D)이 상기 코어부(110)에 순차적으로 권취되며, 그 결과 안정된 권취력과 크랙 발생을 방지할 수 있다.Accordingly, the electrode 121 has the second uncoated portion 121d, the end C of the first coating layer 121a, and the end D of the second coating layer 121b sequentially on the core part 110. As a result, it is possible to prevent a stable winding force and the occurrence of cracks as a result.
제1 발명의 제3 실시예Third Embodiment of the First Invention
제1 발명의 제3 실시예에 따른 이차전지(100)는 도 5에 도시되어 있는 것과 같이, 전극(121)에 구비된 제1 무지부(121c)에 전극탭(123)을 구비할 수 있다. 특히, 상기 전극탭(123)은 상기 제1 코팅층(121a)의 일단(A)과 접하는 상기 제1 무지부(121c)에 구비될 수 있으며, 이에 따라 상기 전극탭(123)과 상기 제1 코팅층(121a) 사이에 틈새 및 단차를 제거하여 안정적으로 전극(121)을 권취할 수 있다.As illustrated in FIG. 5, the secondary battery 100 according to the third embodiment of the first invention may include an electrode tab 123 in the first uncoated portion 121c of the electrode 121. . In particular, the electrode tab 123 may be provided in the first uncoated portion 121c in contact with one end A of the first coating layer 121a. Accordingly, the electrode tab 123 and the first coating layer may be provided. The gap 121 and the step between the 121a may be removed to stably wind the electrode 121.
여기서 상기 전극탭(123)과 상기 제1 코팅층(121a)은 동일한 두께를 가질 수 있으며, 이에 따라 상기 전극탭(123)과 상기 제1 코팅층(121a) 사이에 단차를 완벽하게 제거할 수 있고, 그 결과 보다 보다 안정적으로 전극(121)을 권취할 수 있다.Here, the electrode tab 123 and the first coating layer 121a may have the same thickness, thereby completely removing the step between the electrode tab 123 and the first coating layer 121a. As a result, the electrode 121 can be wound more stably.
제1 발명의 제4 실시예Fourth Embodiment of the First Invention
제1 발명의 제4 실시예에 따른 이차전지(100)는 도 6에 도시되어 있는 것과 같이, 전극(121)을 포함하되, 상기 전극(121)은 집전체(121z), 상기 집전체(121z)의 표면에 전극활물질을 1차 코팅한 제1 코팅층(121a), 상기 제1 코팅층(121a)의 외측에 전극활물질을 2차 코팅한 제2 코팅층(121b), 상기 제2 코팅층(121b)의 외측에 전극활물질을 3차 코팅하는 제3 코팅층(121e) 및 상기 제3 코팅층(121e)의 외측에 전극활물질을 4차 코팅하는 제4 코팅층(121f)을 포함할 수 있다.As illustrated in FIG. 6, the secondary battery 100 according to the fourth embodiment of the first invention includes an electrode 121, wherein the electrode 121 is a current collector 121z and the current collector 121z. The first coating layer (121a) of the first coating the electrode active material on the surface of the), the second coating layer (121b), the second coating layer 121b of the second coating the electrode active material on the outside of the first coating layer (121a), It may include a third coating layer 121e for tertiary coating of the electrode active material on the outside and a fourth coating layer 121f for fourth coating of the electrode active material on the outside of the third coating layer 121e.
여기서 상기 전극(121)은 상기 전극(121)의 권취 방향을 기준으로 상기 제2 코팅층(121b)의 일단(B) 길이를 상기 제1 코팅층(121a)의 일단(A) 길이 보다 작게 형성하고, 상기 제3 코팅층(121e)의 일단(E) 길이를 상기 제2 코팅층(121b)의 일단(B) 길이보다 작게 형성하며, 상기 제4 코팅층(121f)의 일단(F) 길이를 상기 제3 코팅층(121e)의 일단(E) 길이보다 작게 형성할 수 있다. 이에 따라 상기 제1, 제2, 제3 및 제4 코팅층의 일단은 계단형태의 단차(도 6에 표시된 점선 참조)를 형성할 수 있다.In this case, the electrode 121 is formed to have a length of one end B of the second coating layer 121b smaller than the length of one end A of the first coating layer 121a based on the winding direction of the electrode 121. The length of one end E of the third coating layer 121e is smaller than the length of one end B of the second coating layer 121b, and the length of one end F of the fourth coating layer 121f is the third coating layer. It can be formed smaller than the length of one end E of 121e. Accordingly, one end of the first, second, third and fourth coating layers may form a stepped step (see dotted line shown in FIG. 6).
따라서 상기 전극(121)은 상기 제1, 제2, 제3 및 제4 코팅층의 일단이 완만한 경사를 가진 단차를 구현하고, 코어부(110)에 순차적으로 권취되면서 안정된 권취력을 얻을 수 있다.Therefore, the electrode 121 may realize a step having a gentle slope of one end of the first, second, third and fourth coating layers, and may be stably wound on the core part 110 to obtain stable winding force. .
[제2 발명의 전극][Electrode of Second Invention]
제2 발명의 전극(121)은 도 7에 도시되어 있는 것과 같이, 집전체(121z), 상기 집전체(121z)의 표면에 전극활물질을 1차 코팅한 제1 코팅층(121a), 및 상기 제1 코팅층의 외측에 전극활물질을 2차 코팅한 제2 코팅층(121b)을 포함하고, 상기 전극(121)의 권취 방향을 기준으로 상기 제2 코팅층(121b)의 일단(B) 길이를 상기 제1 코팅층(121a)의 일단(A) 길이 보다 짧게 형성하여, 권취 중심에서 바깥방향으로 나아감에 따라 상기 제1 코팅층(121a)의 일단(A)과 상기 제2 코팅층(121b)의 일단(B) 사이에 단차가 형성된다.As shown in FIG. 7, the electrode 121 of the second invention includes a current collector 121z, a first coating layer 121a obtained by first coating an electrode active material on the surface of the current collector 121z, and the first agent. The first coating layer includes a second coating layer 121b coated with an electrode active material on the outside of the first coating layer, and the length of one end B of the second coating layer 121b is based on the winding direction of the electrode 121. It is formed shorter than the length of one end (A) of the coating layer 121a, and as it moves outward from the winding center, between one end (A) of the first coating layer (121a) and one end (B) of the second coating layer (121b). Steps are formed in the.
이와 같이 제2 발명의 전극(121)은 일단에 단차를 형성하여 차후 코어부 권취시 안정된 권취력을 얻을 수 있다.As described above, the electrode 121 of the second invention may form a step at one end to obtain a stable winding force at the time of winding the core part later.
참고로, 제1 발명의 제1 실시예는 이차 전지를 그 대상으로 하나, 제2 발명은 그 이차 전지 내부에 들어가는 전극을 그 대상으로 함에 차이가 있다.For reference, the first embodiment of the first invention is a secondary battery, but the second invention has a difference in that the electrode that goes into the secondary battery.
본 발명의 범위는 상기 상세한 설명보다는 후술하는 특허청구범위에 의하여 나타내어지며, 특허청구범위의 의미 및 범위 그리고 그 균등 개념으로부터 도출되는 다양한 실시 형태가 가능하다.The scope of the present invention is shown by the following claims rather than the detailed description, and various embodiments derived from the meaning and scope of the claims and their equivalents are possible.

Claims (14)

  1. 전극과 분리막이 교대로 적층되고 권취되는 전극조립체를 포함하며,An electrode assembly in which electrodes and separators are alternately stacked and wound;
    상기 전극은,The electrode,
    집전체, 상기 집전체의 표면에 전극활물질을 1차 코팅한 제1 코팅층, 및 상기 제1 코팅층의 외측에 전극활물질을 2차 코팅한 제2 코팅층을 포함하고,A current collector, a first coating layer primarily coated with an electrode active material on a surface of the current collector, and a second coating layer secondary coated with an electrode active material on an outer side of the first coating layer,
    상기 전극의 권취 방향을 기준으로 상기 제2 코팅층의 일단 길이를 상기 제1 코팅층의 일단 길이 보다 짧게 형성하여, 권취 중심에서 바깥방향으로 나아감에 따라 상기 제1 코팅층의 일단과 상기 제2 코팅층의 일단 사이에 단차가 형성되는 이차전지.One end length of the second coating layer is formed to be shorter than one end length of the first coating layer based on the winding direction of the electrode, and thus, one end of the first coating layer and one end of the second coating layer are moved outward from the winding center. Secondary battery is formed between the steps.
  2. 청구항 1에 있어서,The method according to claim 1,
    상기 전극은 권취 시작부에 전극활물질이 없는 제1 무지부를 포함하며, The electrode includes a first non-coating portion having no electrode active material at the start of the winding,
    상기 제1 무지부, 상기 제1 코팅층의 일단 및 상기 제2 코팅층의 일단은 계단형태의 단차를 형성하는 이차전지.The first battery, one end of the first coating layer and one end of the second coating layer is a secondary battery to form a step-shaped step.
  3. 청구항 1에 있어서,The method according to claim 1,
    상기 전극조립체를 권취하기 위한 코어부를 포함하며, Comprising a core for winding the electrode assembly,
    상기 제2 코팅층의 일단은 상기 제1 코팅층의 일단에서 상기 코어부의 둘레 길이만큼 작게 형성하는 이차전지.One end of the second coating layer is formed to be as small as the circumferential length of the core portion at one end of the first coating layer.
  4. 청구항 1에 있어서,The method according to claim 1,
    상기 전극은 권취 끝부에 코팅된 상기 제2 코팅층의 끝단의 길이를 상기 제1 코팅층의 끝단 길이 보다 짧게 형성하여 상기 제2 코팅층의 끝단과 상기 제1 코팅층의 끝단 사이에 단차를 형성하는 이차전지.The electrode forms a step between the end of the second coating layer and the end of the first coating layer by forming a length of the end of the second coating layer coated on the winding end shorter than the end of the first coating layer.
  5. 청구항 4에 있어서,The method according to claim 4,
    상기 전극은 권취 끝부에 전극활물질이 없는 제2 무지부를 포함하며, The electrode includes a second non-coating portion having no electrode active material at the winding end,
    상기 제2 무지부, 상기 제1 코팅층의 끝단 및 상기 제2 코팅층의 끝단은 계단형태의 단차를 형성하는 이차전지.The second uncoated portion, the end of the first coating layer and the end of the second coating layer is a secondary battery to form a step-shaped step.
  6. 청구항 1에 있어서,The method according to claim 1,
    상기 제1 코팅층과 상기 제2 코팅층은 동일한 코팅두께를 가지는 이차전지.The first coating layer and the second coating layer is a secondary battery having the same coating thickness.
  7. 청구항 1에 있어서,The method according to claim 1,
    상기 제1 코팅층과 상기 제2 코팅층은 서로 다른 코팅두께를 가지는 이차전지.The first coating layer and the second coating layer is a secondary battery having a different coating thickness.
  8. 청구항 1에 있어서,The method according to claim 1,
    상기 전극은,The electrode,
    상기 제2 코팅층의 외측에 전극활물질을 3차 코팅하는 제3 코팅층과, 상기 제3 코팅층의 외측에 전극활물질을 4차 코팅하는 제4 코팅층을 더 포함하는 이차전지.The secondary battery further comprises a third coating layer for tertiary coating of the electrode active material on the outside of the second coating layer, and a fourth coating layer for the fourth coating of the electrode active material on the outside of the third coating layer.
  9. 청구항 8에 있어서,The method according to claim 8,
    상기 전극은 권취 시작부에 코팅된 상기 제3 코팅층의 일단 길이를 상기 제2 코팅층의 일단 길이보다 작게 형성하고, 상기 제4 코팅층의 일단 길이를 상기 제3 코팅층의 일단 길이보다 작게 형성하며,The electrode forms one end length of the third coating layer coated at the beginning of the winding less than the one end length of the second coating layer, one end length of the fourth coating layer is formed smaller than the one end length of the third coating layer,
    상기 제1, 제2, 제3 및 제4 코팅층의 일단은 계단형태의 단차를 형성하는 이차전지.One end of the first, second, third and fourth coating layer to form a stepped stepped step.
  10. 청구항 2에 있어서,The method according to claim 2,
    상기 제1 무지부에는 전극탭을 구비하는 이차전지.A secondary battery having an electrode tab on the first uncoated portion.
  11. 청구항 10에 있어서,The method according to claim 10,
    상기 전극탭은 상기 제1 코팅층의 일단과 접하는 상기 제1 무지부에 구비되면서 상기 전극탭과 상기 제1 코팅층 사이에 단차를 제거하는 이차전지.The electrode tab is provided in the first uncoated portion in contact with one end of the first coating layer while removing the step between the electrode tab and the first coating layer.
  12. 집전체;Current collector;
    상기 집전체의 표면에 전극활물질을 1차 코팅한 제1 코팅층; 및A first coating layer in which an electrode active material is first coated on a surface of the current collector; And
    상기 제1 코팅층의 외측에 전극활물질을 2차 코팅한 제2 코팅층을 포함하고,It includes a second coating layer of the second coating the electrode active material on the outside of the first coating layer,
    상호 대응하는 상기 제2 코팅층의 일단의 길이는 상기 제1 코팅층의 일단 길이 보다 짧게 형성하여 상기 제1 코팅층의 일단과 상기 제2 코팅층의 일단 사이에 단차를 형성하는 전극.The length of one end of the second coating layer corresponding to each other is formed shorter than the length of one end of the first coating layer to form a step between one end of the first coating layer and one end of the second coating layer.
  13. 청구항 12에 있어서,The method according to claim 12,
    상기 집전체의 일단에는 전극활물질이 없는 제1 무지부를 포함하며,One end of the current collector includes a first non-coating portion having no electrode active material,
    상기 제1 무지부, 상기 제1 코팅층의 일단 및 상기 제2 코팅층의 일단은 계단형태로 연결되는 단차를 형성하는 전극.The first uncoated portion, one end of the first coating layer and one end of the second coating layer to form a step that is connected in a step shape.
  14. 청구항 13에 있어서,The method according to claim 13,
    상기 제1 무지부에는 전극탭을 구비하며,The first plain portion is provided with an electrode tab,
    상기 전극탭은 상기 제1 코팅층의 일단에 접하는 상기 제1 무지부에 구비되면서 상기 전극탭과 상기 제1 코팅층의 일단 사이에 단차를 제거하는 전극.The electrode tab is provided on the first uncoated portion in contact with one end of the first coating layer and the step of removing the step between the electrode tab and one end of the first coating layer.
PCT/KR2018/006325 2017-06-09 2018-06-01 Electrode, and secondary battery comprising same WO2018225994A1 (en)

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PL18813454T PL3522282T3 (en) 2017-06-09 2018-06-01 Electrode and secondary battery comprising the same
JP2019530150A JP7088600B2 (en) 2017-06-09 2018-06-01 Electrodes and secondary batteries containing them
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KR20130020550A (en) * 2011-08-18 2013-02-27 삼성에스디아이 주식회사 Secondary battery
JP2015125832A (en) * 2013-12-25 2015-07-06 トヨタ自動車株式会社 Manufacturing method for electrode for secondary battery
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JPH11214035A (en) * 1998-01-20 1999-08-06 Toshiba Battery Co Ltd Battery
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KR20130020550A (en) * 2011-08-18 2013-02-27 삼성에스디아이 주식회사 Secondary battery
JP2015125832A (en) * 2013-12-25 2015-07-06 トヨタ自動車株式会社 Manufacturing method for electrode for secondary battery
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