des brevets
`
`Eurapaisches
`Patentarat
`Europeats
`Patent Office
`Office européen §
`
`(19)
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`(12)
`
`“aT
`EP 3 584 853 At
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`(11)
`
`EUROPEAN PATENT APPLICATION
`published in accordance with Art. 153(4) EPC
`
`(43) Date of publication:
`25.12.2019 Bulletin 2019/52
`
`(21) Application number: 18857031.1
`
`(22) Date offiling: 13.09.2018
`
`(84) Designated Contracting States:
`AL AT BE BG CH CY CZ DE DK EE ES FIFR GB
`GR HR HUIEIS IT LILT LU LV MC MK MT NL NO
`PL PT RO RS SE SISK SM TR
`
`Designated Extension States:
`BA ME
`
`Designated Validation States:
`KH MA MD TN
`
`(30) Priority: 13.09.2017 KR 20170117208
`
`(71) Applicant: LG Chem, Ltd.
`Seoul 07336 (KR)
`
`(72) inventors:
`¢ SHIN, Hang Soo
`Daejeon 34122 (KR)
`
`
`
`(54) int CL:
`HOTM 2/04 (2008.01)
`HO1M 2/06 2906.01)
`HO1M 2/12 (2006.01)
`HO1TM 2/10 2906.01)
`
`HOTM 2/08 (2008.01)
`HO1M 2/34 (2006.01)
`HO1M 2/02 (2006.01)
`
`(86) International application number:
`PCT/KR2018/010740
`
`(87) international publication number:
`WO 2019/054765 (21.03.2019 Gazette 2019/12}
`
`* KIM, Do Gyun
`Daejeon 34122 (KR)
`« JUNG, Sang Sok
`Daejeon 34122 (KR)
`» LEE, Byoung Kook
`Daejeon 34122 (KR)
`« LEE, Byoung Gu
`Daejeon 34122 (KR)
`« MIN, Geon Woo
`Daejeon 34122 (KR)
`« KIM, Chan Bae
`Daejeon 34122 {KR)
`
`(74) Representative: Plasseraud IP
`66, rue de la Chaussée d’Antin
`75440 Paris Cedex 09 (FR)
`
`(54)
`
`CYLINDRICAL BATTERY CELL HAVING NO BEADING PART
`
`Disclosed herein is a cylindrical battery cell in-
`(57)
`cluding a jelly-roll type electrode assembly, configured
`to have a structure in which a positive electrode and a
`negative electrode are woundin the state in which a sep-
`arator is disposed between the positive electrode and
`the negative electrode, a cylindrical battery case having
`no beading part, a cap assembly located at the open
`upper end of the cylindrical battery case, and a gasket
`mounted so as to surround the outer circumference of a
`
`safety vent and a portion of the lower surface ofthe safety
`vent in order to maintain insulation between the cap as-
`sembly and the cylindrical battery case, wherein the cap
`assembly includes the safety vent, which is configured
`
`to rupture in order to exhaust gas when the pressure in
`the battery case increases, a cap plate mounted on the
`safety vent, the cap plate having formed therein through
`holes for discharging gas, and acurrentinterrupt member
`attached to the lower end of the safety ventforinterrupt
`ing current when the pressurein the battery case increas-
`es, and wherein the gasketis located on an outer circum-
`ferential portion of the open upper surface of the battery
`case and is coupled to a washer for fixing the cap as-
`sembly.
`
`Printed by Jouve, 75007 PARIS (FR)
`
`{Cont. next page)
`
`EP3584853A1
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`EP 3 584 853 At
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`Description
`
`[Technical Field]
`
`[0001] This application claims the benefit of Korean
`Patent Application No. 2017-0117208 filed on Septem-
`ber 13, 2017 with the Korean Intellectual Property Office,
`the disclosure of which is herein incorporated by refer-
`ence in its entirety.
`[0002] The present invention relates to a cylindrical
`battery cell having no beading part, and more particularly
`to a cylindrical battery cell configured to have a structure
`in which a jelly-roll type electrode assembly is received
`in a cylindrical battery case having no beading part and
`in which a gasket, which surrounds the outer circumfer-
`ence of a safety vent and a portion of the lower surface
`of the safety vent, is coupled to a washer, whichfixes a
`cap assembly, in order to maintain insulation between
`the cylindrical battery case and the cap assembly, where-
`by the capacity of the battery cell is increased in propor-
`tion to the size of the beading pari, which is omitted.
`
`[Background Art]
`
`[0003] Secondary batteries, which can be charged and
`discharged, have been widely used as energy sources
`for wireless mobile devices. fn addition, secondary bat-
`teries have attracted considerable attention as energy
`sourcesfor electric vehicles and hybrid electric vehicles,
`which have been developed to solve problems, such as
`air pollution, caused by existing gasoline and diesel ve-
`hicles using fossil fuels. Therefore, secondary batteries
`are being applied in an increasing number of applications
`owing to the advantages thereof, and, in the future, sec-
`ondary baiteries are expected to be applied to even more
`applications and products.
`[0004]
`in general, based on the shape of a battery
`case, secondarybaiteries are classified into a cylindrical
`battery having an electrode assembly mounted in a cy-
`lindrical metal can, a prismatic battery having an elec-
`trode assembly mounted in a prismatic metal can, anda
`pouch-shaped battery having an electrode assembly
`mounted in a pouch-shaped case made of an aluminum
`laminate sheet. The electrode assembly, which is mount-
`ed in the battery case, is a power generating element
`that includes a positive electrode, a negative electrode,
`and a separator that is interposed between the positive
`electrode and the negative electrode and that can be
`charged and discharged. The electrode assembly is clas-
`sified as a jelly-roll type electrode assembly, which is
`configured to have a structure in which a tong sheet type
`pasitive electrode and a long sheet type negative elec-
`trode, to which active materials are applied, are wound
`in the state in which a separatoris disposed betweenthe
`positive electrode and the negative electrode, or a
`stacked type electrode assembly, which is configured to
`have a structure in which a plurality of positive electrodes
`having a predetermined size and a plurality of negative
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`electrodes having a predeterminedsize are sequentially
`stacked in the state in which separators are disposed
`respectively between the positive electrodes and the
`negative electrodes. Thejelly-rall type electrode assem-
`bly has advantagesin that it is easy to manufacture the
`jelly-roll type electrode assembly and thejelly-roll type
`electrode assembly has high energy density per unit
`weight.
`FIG. 1 is a vertical sectional view schematically
`{G005}]
`showing the upper part of a general cylindrical battery
`cell having a beading part.
`[0006] Referringio FIG. 1, acylindrical battery cell 100
`is manufactured by placing a jelly-roll type electrode as-
`sembly 130 in a reception unit defined in a cylindrical can
`101, injecting an electrolytic solution into the reception
`unit such that the electrode assembly 130is fully impreg-
`nated with the electrolytic solution, and coupling a cap
`assembly 110 to the upper end, which is open, of the
`cylindrical can.
`[0007] The cap assembly 110 is connected to a post-
`tive electrode tab 131, and is configured to have a struc-
`ture in which a top cap 102 and a safety vent 103 for
`lowering internal pressure are disposed in a gasket 105
`for maintaining airtightness, the gasket being mounted
`to the upperinner surfacesof a crimping part and a bead-
`ing part 120 of the cylindrical can, in the state in which
`the top cap 102 and the safety vent 103 are in tight contact
`with each other. The middie portion of the top cap 102
`protrudes upwards such that the top cap 102 functions
`as a positive electrode terminal when the top cap 102 is
`connected to an external circuit, and a plurality of through
`holes, through which gas in the cylindrical can is dis-
`charged out of the cylindrical can, is formed along the
`circumference of the protruding portion of the top cap
`102.
`
`In the case in which the beading partis formed
`{G008]
`at the cylindrical can, however, the height of the cylindri-
`cal can is reduced, whereby the capacity of the battery
`cell is reduced. Furthermore,
`in the case in which the
`height or diameter of the cylindrical can is changed at
`the time of performing a beading process, itis necessary
`to change beading conditions. As a result, productivity is
`reduced, and costis increased.
`{0009]
`In order to solve these problems, Patent Docu-
`ment 1 discloses a cylindrical battery cell having no bead-
`ing part. However, the disclosed cylindrical battery cel!
`is configured to have a structure in which a cap assembly
`is inserted into a cylindrical can by interferencefitting and
`the outer circumference of the cap assembly is welded
`to the cylindrical can. During assemblyof the cap assem-
`bly, therefore, the cap assembly or the cylindrical can
`may be easily damaged.
`{0010] Patent Document 2 discloses a cylindrical bat-
`tery cell having no beading part configured such that a
`protrusion or a support structure is formed on the inner
`surface of a cylindrical can in order to fix a cap assembly.
`However, this patent document does not disclose tech-
`nology that is capable of increasing the capacity of the
`
`

`

`3
`
`EP 3 584 853 At
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`4
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`battery cell by changing the structure of a gasket for main-
`taining insulation between the cylindrical can and the cap
`assembly.
`[0011] Therefore, there is an urgent necessityfor tech-
`nology that is capable of coupling a cap assembly to a
`cylindrical case without damage to the cap assembly
`while minimizing the size of a dead space defined in the
`cylindrical can, in whicha jelly-roll type electrode assem-
`bly is received, in order to increase the capacity of the
`cylindrical battery cell.
`
`- Related Art Documents
`
`[0012]
`
`(Patent Document 0001) Korean Patent Application
`Publication No. 2016-00885858
`
`{Patent Document 0002) Korean Patent Application
`Publication No, 2007-0080866
`
`[Disclosure]
`
`[Technical Problem]
`
`[0013] The present invention has been made in view
`of the above problems and other technical problems that
`have yet to be resolved, and itis an object of the present
`invention to provide a cylindrical battery cell configured
`to have a structure in which a jelly-roll type electrode
`assemblyis received in a cylindrical battery case having
`no beading part and in which a gasket for maintaining
`insulation between a cap assembly and the cylindrical
`battery case surrounds the outer circumference ofa safe-
`ty vent and a portion of the lower surface of the safety
`vent, and the gasket is coupled to a washer, whichfixes
`the cap assembly, whereby the size ofthe cylindrical bat-
`tery case, in whichthejelly-roll type electrode assembly
`is received, is increased in proportion to the size of the
`beading part, which is omitted.
`[0014] Consequenily, it is possible to provide a cylin-
`drical battery cell having a capacity increased in propor-
`tion to an increase in the size of an electrode assembly
`reception unit.
`
`{Technical Solution}
`
`in accordance with an aspectof the presentin-
`[0015]
`vention, the above and other objects can be accom-
`plished by the provision of a cylindrical battery cell in-
`cluding a jelly-roll type electrode assembly, configured
`to have a structure in which a positive electrode and a
`negative electrode are woundin the state in which a sep-
`arator is disposed between the positive electrode and
`the negative electrode, a cylindrical battery case having
`no beading part, a cap assembly located at the open
`upper end of the cylindrical battery case, and a gasket
`mounted so as to surround the outer circumference of a
`
`safety vent and a portion of the lowersurface of the safety
`
`vent in order to maintain insulation between the cap as-
`sembly and the cylindrical battery case, wherein the cap
`assembly includes the safety vent, which is configured
`to rupture in order to exhaust gas when the pressure in
`the battery case increases, a cap plate mounted on the
`safety vent, the cap plate having formed therein through
`holes for discharging gas, and a current interrupt member
`attached to the lower end of the safety vent for interrupt-
`ing current when the pressurein the battery case increas-
`es, and wherein the gasketis located on an outer circum-
`ferential portion of the open upper surface of the battery
`case and is coupled to a washer for fixing the cap as-
`sembly.
`in general, acylindrical battery cellis configured
`{0016}
`such that a top cap, including a current interrupt device
`(CID), for interrupting current and reducing the magni-
`tude of the pressure in the battery cell when the battery
`cell operates abnormally, and a positive temperature co-
`efficient (PTC) element, for interrupting current by in-
`creasing battery cell resistance when the temperaturein
`the battery cell increases, is coupled to the open upper
`end of a cylindrical can in order to guarantee the safety
`of the cylindrical battery cell.
`{0017}
`{n order to couple the top cap to the cylindrical
`can, the upper end portion of the cylindrical can is re-
`cessed inwards by a predetermined width, the top cap is
`loaded on the upper end of the cylindrical can, and the
`upper end portion of the cylindrical can is bent to form a
`beading part suchthat the outer circumference of the top
`cap is surrounded by the beading part. The coupling of
`the top cap using the beading part is achieved based on
`the plastic deformation and high mechanical strength of
`metal, from which the cylindrical can is made, whereby
`the coupling of the top cap is stably maintained.
`{0018] However, the space in the battery case is re-
`duced due to the formation of the beading part, whereby
`the capacity of the battery cell is reduced.
`{0019}
`inthecase in which the washer, whichislocated
`on the open upper surface of the cylindrical battery case,
`is coupled to the cap assembly, as in the present inven-
`tion, the cap assemblyis fixed in the state in which the
`washeris attached, whereby the beading part forfixing
`the cap assembly may be omitted from the battery case.
`[0020]
`Since a battery case having no beading part is
`used, as described above, it is possible to omit the proc-
`ess of forming the beading part, wherebyitis possible to
`omit the process of adjusting the size of the battery cel!
`in order to form the beading part and thus to reduce cost.
`[0021]
`In addition, since the process of forming the
`beading partis omitted, itis notnecessary touse a gasket
`configured to have a structure that surrounds a portion
`of the upper surface of the cap plate. The gasket used
`in the present invention may be configured to have a
`structure that surrounds the outer circumference of the
`
`cap plate or the outer circumference of the safety vent
`and a portion of the lower surface of the safety vent.
`[0022]
`In addition, it is possible to increase the height
`of the jelly-roll type electrode assembly in proportion to
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`EP 3 584 853 At
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`6
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`the height of the beading part, which is omitted, and there-
`fore it is possible to provide a cylindrical battery cell hav-
`ing a capacity increased in proportion to the increased
`volume of the electrode assembly.
`[0023]
`in aconcrete example, the gasket may be cou-
`pled to the washer via a thermoplastic adhesive layer.
`The thermoplastic adhesive layer is attached to the lower
`surface of the washer, the gasket is located on the ther-
`moplastic adhesive layer, and the thermoplastic adhe-
`sive layer is heated so as to melt, whereby the gasket
`and the washer may be coupled to each other.
`[0024] The thermoplastic adhesive layer is not partic-
`ularly restricted, as long as the thermoplastic adhesive
`layer provides high adhesive force without melting attem-
`peratures at which the batiery cell is normally used. For
`example, the thermoplastic adhesive layer may be at
`least one selected from a group consisting of poly-
`urethane (PU), polyethylene (PE), polypropylene (PP),
`polyvinyl aicohol
`(PVA), silicon-based resin, epoxy-
`based resin, polyester, isocyanate-based resin, and en-
`gineering plastic, andthe engineering plastic may be pol-
`yether ether ketone (PEEK), polyketone (PK), flueropol-
`ymer (FP), liquid crystal polymer (LCP), polyvinylidene
`fluoride (PVDF), polyphenylene sulfide (PPS), polyph-
`thalamide (PPA), palyamide (PA), palycyclohexylene
`dimethylene terephthalate (PCT), polybutylene tereph-
`thalate (PBT), polyethylene terephthalate (PET), poly-
`oxymethylene (POM), modified polypropylene (PP-mod-
`ified), ultra high molecular weight polyethylene (PE-UH-
`MW), high-density polyethylene (PE-HD), or tow-density
`polyethylene (PE-LD).
`[0025] The cylindrical battery cell according to the
`present invention does not include a structure for fixing
`the cap assemblyin the cylindrical battery case. The cap
`assembly may be received in the battery casein the state
`of being coupled to the washer together with the gasket.
`[0026]
`Since the washeris located on the outer circum-
`ferential portion of the open upper surface of the cylin-
`drical battery case in the state of being coupled to the
`cap assembly, the size of the washer must be set such
`that the washer cannot move toward the inside of the
`
`battery case in the state in which the washer is fixed in
`pasition. In the case in which the outer diameter of the
`washer is larger than the outer diameter of the battery
`case, however, the size of the upper end of the battery
`case js unnecessarily increased. Preferably, therefore,
`the outer diameter of the washer is equal to the outer
`diameter of the battery case.
`[0027]
`For example, the outer diameter of the cap as-
`sembly may be smatler than the outer diameter of the
`washer, and the cap assembly and the washer may be
`coupled to each other such that the center of the cap
`assembly is aligned with the center of the washer. The
`outer circumference of the washer may extend further
`outwards than the outer circumference of the cap assem-
`bly.
`[0028] Consequently, the outer circumference of the
`lower surface of the washer, which extends further out-
`
`wards than the outer circumference of the cap assembly,
`maybe coupled to the upper surface of the outer circum-
`ferential portion of the battery case by weldingin the state
`of being located so as to be placed on the upper surface
`of the outer circumferential portion of the battery case.
`[0029]
`in order to increase the force of welding be-
`tween the battery case and the washer, as described
`above, the washer may be made of the same material
`as the battery case.
`{0030} The gasket may be configured to have a struc-
`ture including a first coupling part, coupled to an outer
`circumferential portion of the lower surface of the current
`interrupt member, a step part, bent upwards perpendic-
`ularly from the outer circumference of the first coupling
`part, a second coupling part, bent outwards from the up-
`per part of the step part so as to be parallel to the first
`coupling part and coupled to the lower surface of the
`safety vent, a third coupling part, bent upwards perpen-
`dicularly from the outer circumference of the second cou-
`pling part and coupled to an outer circumference of the
`safety vent and to an outer circumferenceof the cap plate,
`and a fourth coupling part, coupled to the washer so as
`to serve as the upper outer circumference of the third
`coupling part.
`[0031] Consequently, the gasket may be configured to
`have a structure that surrounds the outer circumference
`
`of the safety vent and the outer circumference of the cap
`plate while supporting a portion of the lower surface of
`the current interrupt member,
`located under the cap
`plate. Alternatively, in the case in which the safety vent
`is configured to have a structure that surrounds the outer
`circumference of the cap plate, the gasket may be con-
`figured to have a structure that surrounds the outer cir-
`cumference of the safety vent while supporting a portion
`of the fower surface of the current interrupt member.
`{G032] The washeris coupled to the gasket and to the
`cap assembly. In order to achieve coupling between the
`washer and the cap assembly, the washer may have an
`inner diameter sufficient to cover a portion of the outer
`circumference of the cap plate.
`{0033]
`Specifically, the gasket and the cap plate may
`be fixed io the washerin the state in which the washer
`
`is coupled to the fourth coupling part of the gasket and
`to a portion of the cap plate.
`{G034]
`in a concrete example, the distance between
`the electrode assembly and the lower end of the cap as-
`sembly may be smaller than the height of the step part.
`[0035] The cylindrical battery cell according to the
`present invention uses a cylindrical battery case having
`no beading part. Comparedto the case in whichthe bead-
`ing partis provided, therefore, the length of the electrode
`tab coupled to the current interrupt memberis reduced,
`and the height of the electrode assembly is increased in
`proportion to the height of the beading part, which is omit-
`ted. Consequently, the distance between the electrode
`assembly and the lower end of the cap assembly be-
`comesrelatively short.
`[0036]
`in accordance with another aspect of
`
`the
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`7
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`EP 3 584 853 At
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`present invention, there is provided a battery pack includ-
`ing the cylindrical battery cell.
`[0037]
`Specifically, the battery pack may be used as a
`power source for a device requiring the ability to with-
`stand high temperatures, along lifespan, high rate char-
`acteristics, etc. Specific examples of the device mayin-
`clude a mobile electronic device, a wearable electronic
`device, a powertool driven by a baitery-powered motor,
`an electric automobile, such as an electric vehicle (EV),
`a hybrid electric vehicle (HEV), or a plug-in hybrid electric
`vehicle (PHEV), an electric two-wheeled vehicle, such
`as an electric bicycle (E-bike} or an electric scooter (E-
`scooter), an electric galf cart, and an energy storage sys-
`tem. However, the present invention is notlimited thereto.
`[0038] The structure and manufacturing method of the
`device are well known in the art to which the present
`invention pertains, and thus a detailed description thereof
`will be omitted.
`
`{Brief Description of Drawings}
`
`[0039]
`
`FIG. 4 is a vertical sectional view showing the upper
`part of a conventional cylindrical battery cell having
`a beading part.
`FIG. 2 is a vertical sectional view showing a cap as-
`sembly according to an embodiment of the present
`invention.
`
`FIG. 3is a vertical sectional view showing the upper
`part of a cylindrical battery cell, in which the cap as-
`sembly of FIG. 2 is received.
`FIG. 4 is an enlarged view showing part A of FIG. 3.
`
`[Best Mode}
`
`[0040] Now, preferred embodiments of the presentin-
`vention will be described in detail with reference to the
`
`accompanying drawings such that the preferred embod-
`iments of the present invention can be easily implement-
`ed by a person having ordinary skill in the art to which
`the present invention pertains. In describing the principle
`of operation of the preferred embodiments of the present
`invention in detail, however, a detailed description of
`knownfunctions and configurations incorporated herein
`will be omitted when the same may obscure the subject
`matter of the present invention.
`[0041] Wherever possible, the same reference num-
`bers will be used throughout the drawingsto refer to parts
`that performsimilar functions or operations. Meanwhile,
`in the case in which one part is ‘connected’ to another
`part in the following description of the present invention,
`not only may the one part be directly connected to the
`anotherpart, but also, the one part may be indirectly con-
`nected to the another part via a further part. In addition,
`that a certain elementis ‘included’ means that other el-
`
`ements are not excluded, but may be further included
`unless mentioned otherwise.
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`{0042} Reference will now be made in detail to the pre-
`ferred embodiments of the present invention, examples
`of which are illustrated in the accompanying drawings.
`{0043}
`FIG. 2is avertical sectional view showing a cap
`assembly according to an embodiment of the present
`invention.
`
`[0044] Referring to FIG. 2, the cap assembly, denoted
`by reference numeral 210, includes a safety vent 203
`configured to rupture in order to exhaust gas when the
`pressure in a battery case increases, a cap plate 202
`mounted on the safety vent 203, and a current interrupt
`member 204 attached to the lower end of the safety vent
`203 for interrupting current when the pressure in the bat-
`tery case increases.
`{0045} A gasket 205, which is configured to have a
`structure that surrounds the outer circumference of the
`
`cap assembly 210 and a portion of the lower surface of
`the cap assembly 210, is coupled to a washer 211 via a
`thermoplastic adhesive layer 221. The thermoplastic ad-
`hesive layer 221 is attached so as to extend from the
`portion of the washer 211 that is spaced apart inwards
`from the outer circumference of the washer 211 by a pre-
`determined distance D. The outer diameter of the washer
`
`211 is larger than the outer diameter of the gasket 205,
`and the washer 211 is coupled to the gasket 205 such
`thatthe center of the washer 211 is aligned with the center
`of the gasket 205.
`[0046] The gasket 205 is configured to have a structure
`including a first coupling part 205a, coupled to an outer
`circumferential portion of the lower surface of the current
`interrupt member 204, a step part 205b, bent upwards
`perpendicularly from the outer circumference ofthefirst
`coupling part 205a, a second coupling part 205c, bent
`outwards from the upper part of the step part 205b so as
`to be paraltelto the first coupling part and coupled to the
`lower surface of the safety vent 203, a third coupling part
`205d, bent upwards perpendicularly from the outer cir-
`cumference of the second coupling part 205c and cou-
`pled to the outer circumference of the cap plate 202,
`which surrounds the outer circumference of the safety
`vent 203, and a fourth coupling part 205e, coupled to the
`washer 211 so as to serve as the upperouter circumfer-
`ence of the third coupling part 205d.
`[0047] Alternatively, in the case in which the safety vent
`is not configured to have a structure that surrounds the
`outer circumference of the cap plate, the third coupling
`part 205d may be located so as fo be coupled to the outer
`circumference of the safety vent and to the outer circum-
`ference of the cap plate.
`{0048}
`FIG. 3 is a partial vertical sectional view sche-
`matically showing the state in which the cap assembly
`of FIG. 2 is received in a cylindrical battery case, and
`FIG. 4 is an enlarged view showing part A of FIG. 3.
`{0049} Referring to FIGS. 3 and 4, the washer 217 is
`located on an outer circumferential portion of the open
`upper surface of the cylindrical battery case 201 in the
`state of being coupled to the fourth coupling part of the
`gasket 205 and to a portion of the safety vent 203, which
`
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`EP 3 584 853 At
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`is configured to have a structure that surrounds the cap
`plate 202, via the thermoplastic adhesive layer 221.
`[0050] Alternatively, inthe case in whichthe safety vent
`203 is not configured to have a structure that surrounds
`the cap plate 202, unlike FIG. 3, the washer 211 is located
`on the outer circumferential portion of the open upper
`surface of the cylindrical battery case 201 in the state of
`being coupled to the fourth coupling part of the gasket
`205 and to a portion of the cap plate 202, via the ther-
`moplastic adhesive layer 221.
`[0051] The outer diameter of the washer 211 is equal
`to the outer diameter of the battery case 201, and the
`outer circumference 211a of the lower surface of the
`
`washer 211, to which the thermoplastic adhesive layer
`221 is not attached, is coupled to the upper surface 201a
`of the outer circumferential portion of the battery case
`201 by welding.
`[0052] The battery case 201 has no beading part 120,
`unlike the battery case 101. Consequently, it is possible
`to increase the size of the electrade assembly 230 com-
`pared to the case in which the beading part is provided.
`As a result, the distance between the electrode assembly
`and the current interrupt member, whichis located at the
`lower end of the cap assembly, is reduced so as to be
`smaller than the height of the step part of the gasket 205.
`[0053] Asis apparent from the above description, the
`cylindrical battery cell according to the present invention
`uses a battery case having no beading part and is con-
`figured to have a structure in which the cap assembly
`and the gasket are coupled to the washer via the ther-
`moplastic adhesivelayerin order to fix the cap assembly
`to the battery case. Consequenitly,
`it is possible to in-
`crease the size of the electrode assembly in proportion
`to the height of the beading part, which is omitted, where-
`by itis possible to provide a high-capacity cylindrical bat-
`tery cell.
`[0054] Those skilled in the art to which the presentin-
`vention pertains will appreciate that various applications
`and modifications are possible based on the above de-
`scription without departing from the scope of the present
`invention.
`
`<Description of Reference Numerals>
`
`[0055]
`
`400, 200: Cylindrical battery cells
`101, 201: Cylindrical battery cases
`102, 202: Top plates
`4103, 203: Safety vents
`404, 204: Current interrupt member
`105, 205: Gaskets
`205a: First coupling part of gasket
`205b: Step part of gasket
`205c: Second coupling part of gasket
`205d: Third coupling part of gasket
`205e: Fourth coupling part of gasket
`410, 210: Cap assemblies
`
`430, 230: Electrode assemblies
`131: Positive electrode tab
`
`201a: Upper surface of outer circumferential portion
`of battery case
`211: Washer
`211a: Outer circumference of jawersurface of wash-
`er
`
`221: Thermoplastic adhesive layer
`D: Distance between outer circumference of washer
`
`and outer circumference of thermoplastic adhesive
`layer
`
`{industrial Applicability}
`
`{0056} As is apparent from the above description, the
`cylindrical battery cell according to the present invention
`uses a cylindrical battery case having no beading part
`and a gasket configured to have a structure that does
`not surround the upper surface of a cap plate. Conse-
`quently, itis possible to increase the size of the cylindrical
`battery case, in which an electrode assembly is mounted,
`wherebyitis possible to provide a high-capacity cylindri-
`cal battery cell.
`{0057}
`in addition, no process of forming the beading
`part is required, wherebyit is possible to prevent a de-
`crease in productivity and an increase in cost due to the
`production of the beading part.
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`Claims
`
`1. Acylindrical battery cell comprising:
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`a jelly-roll type electrode assembly, configured
`to have a structure in which a positive electrode
`and a negative electrode are wound in a state
`in which a separator is disposed between the
`positive electrode and the negative electrode;
`a cylindrical battery case having no beading
`part;
`a cap assembly located at an open upper end
`of the cylindrical battery case; and
`a gasket mounted so as to surround an outer
`circumference of a safety vent and a portion of
`a lower surface of the safety vent in order to
`maintain insulation between the cap assembly
`and the cylindrical battery case, wherein
`the cap assembly comprises the safety vent,
`whichis configured to rupture in order to exhaust
`gas when a pressure in the cylindrical battery
`case increases, a cap plate mounted on the
`safety vent, the cap plate having formed therein
`through holesfor discharging gas, and a current
`interrupt member attached to a lower end of the
`safety vent for interrupting current when the
`pressure in the cylindrical battery case increas-
`es, and wherein
`the gasket is located on an outer circumferential
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`EP 3 584 853 At
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`upper part of the step part so as to be parallel
`to the first coupling part and coupled to a lower
`surface of the safety vent;
`a third coupling part, bent upwards perpendicu-
`larly from an outer circumference of the second
`coupling part and coupled to an outer circumfer-
`ence of the safety vent and to an outer circum-
`ference of the cap plate: and
`a fourth coupling part, coupled to the washer so
`as to serve as an upper outer circumference of
`the third coupling part.
`
`The cylindrical battery cell according to claim 1,
`wherein the washerhas an inner diameter sufficient
`
`to cover a portion of an outer circumference of the
`cap plate.
`
`The cylindrical battery cell according to claim 1,
`wherein the washeris coupled to the fourth coupling
`part of the gasket and to a portion of the cap plate.
`
`The cylindrical battery cell according to claim 1,
`wherein a distance between thejelly-roll type elec-
`trode assembly and a lower end of the cap assembly
`is smaller than a height of the step part.
`
`A battery pack comprising the cylindrical battery cell
`according to any one of claims 1 fo 11.
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`10.
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`11.
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`12.
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`portion of an open upper surface of the cylindri-
`cal battery case and is coupled to a washer for
`fixing the cap assembly.
`
`The cylindrical battery cell according to claim 1,
`wherein the gasket is coupled to the washer via a
`thermoplastic adhesive layer.
`
`The cylindrical battery cell according to claim 2,
`wherein
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`the thermoplastic adhesive lay