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`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 1 of 12 PageID #: 15
`
`EXHIBIT A
`
`EXHIBIT A
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 2 of 12 PageID #: 16
`I lllll llllllll Ill lllll lllll lllll lllll lllll 111111111111111111111111111111111
`US009153835B2
`
`c12) United States Patent
`Pytlik et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 9,153,835 B2
`Oct. 6, 2015
`
`(54) BUTTON CELLS AND METHOD FOR
`PRODUCING SAME
`
`(75)
`
`Inventors: Eduard Pytlik, Ellwangen (DE); Jiirgen
`Lindner, Ellwangen (DE); Ulrich
`Barenthin, Ellwangen (DE); Winfried
`Gaugler, Ellwangen (DE)
`
`(73) Assignee: Varta Microbattery GmbH (DE)
`
`( *) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 624 days.
`
`(21) Appl. No.:
`
`13/146,669
`
`(22) PCT Filed:
`
`Feb.9,2010
`
`(86) PCT No.:
`
`PCT /EP2010/000787
`
`§ 371 (c)(l),
`(2), ( 4) Date:
`
`Sep.7,2011
`
`(87) PCT Pub. No.: W02010/089152
`PCT Pub. Date: Aug. 12, 2010
`
`(65)
`
`Prior Publication Data
`
`US 2012/0015224 Al
`
`Jan. 19, 2012
`
`(30)
`
`Foreign Application Priority Data
`
`Feb.9,2009
`Jun. 18, 2009
`Dec.22,2009
`
`(DE)
`(DE)
`(DE)
`
`10 2009 008 859
`10 2009 030 359
`10 2009 060 788
`
`(51)
`
`Int. Cl.
`H01M4/00
`H01M6/10
`
`(2006.01)
`(2006.01)
`(Continued)
`
`(52) U.S. Cl.
`CPC ........ HOlM 1010427 (2013.01); HOlM 210222
`(2013.01); HOlM 6110 (2013.01); HOlM
`1010431 (2013.01); HOlM 10105 (2013.01);
`
`(58) Field of Classification Search
`USPC ................... 429/162, 174, 94, 164, 171, 172;
`29/623.1, 623.5
`IPC .......................... H01M 2/0222,2/08, 6/08, 6/10
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`6/1976 Reynier et al.
`3,960,599 A
`4,224,387 A * 9/1980 Nakayama .................... 429/133
`(Continued)
`
`FOREIGN PATENT DOCUMENTS
`
`DE
`DE
`
`10/1982
`31 13 309 Al
`5/1988
`36 38 793 Al
`(Continued)
`
`OTHER PUBLICATIONS
`
`US Official Action dated Aug. 29, 2014 from related U.S. Appl. No.
`13/378,117.
`
`Primary Examiner - Patrick Ryan
`Assistant Examiner -
`Julian Anthony
`(74) Attorney, Agent, or Firm - DLA Piper LLP (US)
`
`(57)
`
`ABSTRACT
`
`A button cell includes a housing cup and a housing top sepa(cid:173)
`rated from one another by an electrically insulating seal and
`which form a housing with a flat bottom area and a flat top
`area parallel to it and an electrode-separator assembly within
`the housing including at least one positive and at least one
`negative electrode in the form of flat layers and connected to
`one another by at least one flat separator, wherein the elec(cid:173)
`trode layers are aligned essentially at right angles to the flat
`bottom and top areas and the button cell is closed without
`being beaded over.
`
`(Continued)
`
`13 Claims, 3 Drawing Sheets
`
`400
`
`1402
`
`401
`
`407
`
`408
`
`4()6
`
`405
`
`411
`
`410
`
`403
`404,_
`
`409
`
`412
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 3 of 12 PageID #: 17
`
`US 9,153,835 B2
`Page 2
`
`(51)
`
`Int. Cl.
`H01M6/12
`H01M6/46
`H01M2/02
`H01M6/08
`H01M2/08
`HOlM 10104
`HOlM 10105
`HOlM 10124
`HOlM 10134
`(52) U.S. Cl.
`CPC .............. HOlM 10124 (2013.01); HOlM 10134
`(2013.01); Y02E 601124 (2013.01); YlOT
`29149108 (2015.01)
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2010.01)
`(2006.01)
`(2006.01)
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,487,819 A
`6,265,100 Bl
`6,443,999 Bl *
`7,488,553 B2
`7,566,515 B2 *
`200110009737 Al
`2002/0034680 Al
`2005/0271938 Al
`
`12/1984 Koga
`7/2001 Saaski et al.
`912002 Cantave et al ............... 29/623.l
`212009 Tsukamoto et al.
`712009 Suzuki et al. ................. 429/162
`7/2001 Lane
`3/2002 Inoue et al.
`12/2005 Suzuki et al.
`
`2007/0200101 Al*
`2008/0003500 Al
`2012/0015224 Al
`
`8/2007 Asao et al. .................... 2521500
`112008 Issav et al.
`112012 Pytlik et al.
`
`FOREIGN PATENT DOCUMENTS
`
`DE
`196 47 593 Al
`DE
`697 00 312 T2
`DE
`198 57 638 Al
`DE
`10 2009 008 859
`DE
`10 2009 017 514 Al
`EP
`0 202 857 Bl
`EP
`1372209
`EP
`1 808 916
`EP
`1 968 134 Al
`GB
`1088271 A
`JP
`1-307176
`JP
`7-153488
`JP
`8-293299
`JP
`2000-77040
`JP
`2002-352789
`JP
`2003-31266
`JP
`2004-158318
`JP
`3902330
`JP
`2007-294111
`JP
`2008-251192
`JP
`2008-262825
`JP
`2008-262826
`WO
`2010/089152
`* cited by examiner
`
`5/1998
`212000
`612000
`8/2010
`10/2010
`7 /1991
`12/2003
`7/2007
`9/2008
`10/1967
`12/1989
`6/1995
`1111996
`3/2000
`12/2002
`112003
`6/2004
`4/2007
`1112007
`10/2008
`10/2008
`10/2008
`8/2010
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 4 of 12 PageID #: 18
`
`U.S. Patent
`
`Oct. 6, 2015
`
`Sheet 1of3
`
`US 9,153,835 B2
`
`101
`
`109
`
`103
`
`200
`
`~ 204
`
`203
`
`20i
`
`T
`
`115'
`
`205
`
`.....
`rig.
`
`2
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 5 of 12 PageID #: 19
`
`U.S. Patent
`
`Oct. 6, 2015
`
`Sheet 2 of 3
`
`US 9,153,835 B2
`
`301
`
`300
`
`/
`
`303
`
`F~g. 3a
`
`301
`
`304
`305
`
`Fig. 3b
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 6 of 12 PageID #: 20
`
`U.S. Patent
`
`Oct. 6, 2015
`
`Sheet 3 of 3
`
`US 9,153,835 B2
`
`411
`
`410
`
`400
`
`I 402
`
`403
`404~-
`
`408
`
`~--+-'"'""· 406
`m~mt..--L-4os
`
`409
`
`412
`
`Fig. 4
`
`Fig~ 5
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 7 of 12 PageID #: 21
`
`US 9,153,835 B2
`
`1
`BUTTON CELLS AND METHOD FOR
`PRODUCING SAME
`
`RELATED APPLICATIONS
`
`This is a §371 of International Application No. PCT/
`EP2010/000787, with an inter-national filing date of Feb. 9,
`2010 (WO 2010/089152Al, publishedAug. 12, 2010), which
`is based on German Patent Application Nos. 10 2009 008
`859.8, filed Feb. 9, 2009, 10 2009 030 359.6, filed Jun. 18,
`2009, and 10 2009 060 788.9, filed Dec. 22, 2009, the subject
`matter of which is incorporated by reference.
`
`TECHNICAL FIELD
`
`This disclosure relates to button cells comprising two
`metallic housing half-parts separated from one another by an
`electrically insulating seal and which form a housing with a
`flat bottom area and a flat top area parallel to it, as well as
`within the housing, an electrode-separator assembly compris(cid:173)
`ing at least one positive and at least one negative electrode,
`which are in the form of flat layers and are connected to one
`another by at least one flat separator, and to a method for
`producing such button cells.
`
`BACKGROUND
`
`2
`tact with one another, increasing the scrap rate. On the other
`hand, it has been found that button cells having a stack of
`electrodes and separators very quickly start to leak.
`Traditionally, button cells have been closed in a liquid-tight
`manner by beading the edge of the cell cup over the edge of
`the cell top in conjunction with a plastic ring, which is
`arranged between the cell cup and the cell top and at the same
`time acts as a sealing element and for electrical insulation of
`the cell cup and of the cell top. Button cells such as these are
`10 described, for example, in DE 31 13 309.
`However, alternatively, it is also possible to manufacture
`button cells in which the cell cup and the cell top are held
`together in the axial direction exclusively by a force-fitting
`15 connection, and which do not have a beaded-over cup edge.
`Button cells such as these and methods for their production
`are described in German Patent Application 10 2009 017 514.
`Irrespective of the various advantages which button cells such
`as these without beading may have, they can, however, not be
`20 loaded as heavily in the axial direction as comparable button
`cells with a beaded-over cup edge, in particular with respect
`to axial mechanical loads which are caused in the interior of
`the button cell. For example, the electrodes of rechargeable
`lithium-ion systems are continually subject to volume
`25 changes during charging and discharging processes. The
`axial forces which occur in this case can, of course, lead to
`leaks more readily in the case of button cells without beading
`than in the case of button cells with beading.
`It could therefore be helpful to provide a button cell in
`30 which the problems mentioned above do not occur, or occur
`only to a greatly reduced extent. In particular, it could be
`helpful to provide a button cell that is resistant to mechanical
`loads which occur in the axial direction than conventional
`35 button cells, in particular even when they are manufactured as
`button cells without a beaded-over cup edge.
`
`Button cells normally have a housing consisting of two
`housing half-parts, a cell cup and a cell top. By way of
`example, these may be produced from nickel-plated deep(cid:173)
`drawn metal sheet as stamped and drawn parts. The cell cup
`normally has positive polarity, and the housing top negative
`polarity. The housing may contain widely differing electro(cid:173)
`chemical systems, for example, zinc/Mn02 , primary and sec(cid:173)
`ondary lithium systems, or secondary systems such as nickel/
`cadmium or nickel/metal hydride.
`By way of example, rechargeable button cells based on
`nickel/metal hydride or lithium-ion systems are in wide(cid:173)
`spread use. In the case of lithium-ion button cells, the elec(cid:173)
`trochemically active materials are normally not arranged 40
`within the button cell housing in the form of individual elec(cid:173)
`trodes, in the form of tablets, separated from one another by a
`separator. Instead, prefabricated electrode-separator assem(cid:173)
`blies are preferably inserted flat into the housing. In that case,
`a porous plastic film is preferably used as a separator, onto 45
`which the electrodes are laminated or adhesively bonded flat.
`The entire assembly comprising the separator and the elec(cid:173)
`trodes generally have a maximum thickness of a few hundred
`µm. To allow button cell housings of normal dimensions to be
`filled, a plurality of such assemblies are therefore frequently 50
`placed flat one on top of the other. This allows stacks of any
`desired height, in principle, to be produced, in each case
`matched to the available dimensions of the button cell hous(cid:173)
`ing into which the stack is intended to be installed. This
`ensures optimum utilization of the available area within the 55
`housing.
`By virtue of the design, however, various problems also
`occur in the case of button cells which contain such stacks of
`electrode-separator assemblies. On the one hand, it is neces(cid:173)
`sary, of course, for the electrodes of the same polarity each to
`be connected to one another within the stack, and then each to
`make contact with the corresponding pole of the button cell
`housing. The required electrical contacts result in material
`costs, and the space occupied by them is, furthermore, no
`longer available for active material. In addition, the produc(cid:173)
`tion of the electrode stacks is complicated and expensive
`since faults can easily occur when the assemblies make con-
`
`SUMMARY
`
`We provide a button cell including a housing cup and a
`housing top separated from one another by an electrically
`insulating seal and which form a housing with a flat bottom
`area and a flat top area parallel to it, and an electrode-separa(cid:173)
`tor assembly within the housing including at least one posi(cid:173)
`tive and at least one negative electrode in the form of flat
`layers and connected to one another by at least one flat sepa(cid:173)
`rator, wherein the electrode layers are aligned essentially at
`right angles to the flat bottom and top areas and the button cell
`is closed without being beaded over.
`We also provide a method for producing the button cell
`including inserting an electrode-separator assembly with
`electrodes in the form of a flat layer into the housing such that
`the electrode layers are aligned essentially at right angles to
`the flat bottom and top areas, wherein the housing includes a
`metallic cup part and a metallic top part.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 schematically illustrates the cross section through
`60 one preferred example of a button cell.
`FIG. 2 illustrates the effect of heat treatment of a wound-up
`electrode-separator assembly, which is used in preferred
`examples of our method.
`FIG. 3 shows an electrode-separator assembly in the form
`65 of a winding, as can be installed in a button cell.
`FIG. 4 shows a section illustration of a further preferred
`example of a button cell.
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 8 of 12 PageID #: 22
`
`US 9,153,835 B2
`
`3
`FIG. 5 schematically illustrates the cross section through
`one preferred example of a button cell in which the edge of the
`cell cup is not beaded over the edge of the cell cop.
`
`DETAILED DESCRIPTION
`
`Our button cell comprises two metallic housing half-parts
`separated from one another by an electrically insulating seal
`and form a housing with a flat bottom area and a flat top area
`parallel to it. As already mentioned initially, the two housing
`half-parts are generally a so-called "housing cup" and a
`"housing top." In particular, parts composed of nickel-plated
`steel or metal sheet are preferred as housing half-parts. Fur(cid:173)
`thermore, trimetals, for example, with the sequence of nickel,
`steel (or stainless steel) and copper (with the nickel layer
`preferably forming the outer layer and the copper layer pref(cid:173)
`erably forming the inside of the button cell housing) are
`particularly suitable for use as the metallic material.
`By way of example, an injection-molded or film seal can be
`used as a seal. The latter are described, for example, in DE
`196 47 593.
`Within the housing, a button cell comprises an electric(cid:173)
`separator assembly with at least one positive and at least one
`negative electrode. These are each in the form of flat electrode
`layers. The electrodes are connected to one another via a flat
`separator. The electrodes are preferably laminated or adhe(cid:173)
`sively bonded onto this separator. The electrodes and the
`separator generally each have thicknesses only in the µm
`range. In general, a porous plastic film is used as the separator.
`In contrast to the button cells mentioned initially, our but- 30
`ton cell is distinguished in particular by the electrode layers
`having a very particular orientation, specifically being
`aligned essentially at right angles to the flat bottom and top
`areas. While button cells known from the prior art with
`stacked electrode-separator assemblies always contain these 35
`assemblies inserted flat such that the electrode layers are
`aligned essentially parallel to the flat bottom and top areas,
`the situation in our button cell is the opposite of this.
`The right-angled alignment of the electrode layers has an
`unexpectedly considerable advantage, specifically because it
`has been found that this alignment results in a considerable
`improvement in the sealing characteristics of our button cell,
`particularly for button cells based on lithium-ion systems.
`The electrodes ofrechargeable lithium-ion systems are con(cid:173)
`tinually subject to volume changes during charging and dis(cid:173)
`charging processes. Volume changes such as these also occur,
`of course, in the electrodes of our button cell. However, the
`mechanical forces which are created during this process no
`longer act primarily axially, as in the case of a stack of
`electrode-separator assemblies which are inserted flat.
`Because of the right-angled alignment of the electrodes, they
`in fact act radially. Radial forces can be absorbed very much
`better than axial forces by the housing of a button cell. The
`improved sealing characteristics are presumably a result of
`this.
`Particularly preferably, the electrodes and the flat separator
`of our button cell are each in the form of strips or ribbons. By
`way of example, the production of our button cell can be
`based on a separator material in the form ofan endless ribbon,
`onto which the electrodes are applied, in particular laminated, 60
`once again in particular in the form of strips or at least rect(cid:173)
`angles.
`In the housing of our button cell, this assembly is particu(cid:173)
`larly preferably in the form of a winding, in particular in the
`form of a spiral winding. Windings such as these can be 65
`produced very easily using known methods (see, for example,
`DE 36 38 793), by applying the electrodes flat, in particular in
`
`4
`the form of strips, to a separator which is in the form of an
`endless ribbon, in particular by laminating them on. In this
`case, the assembly comprising electrodes and separators is
`generally wound onto a so-called "winding mandrel." Once
`the winding has been removed from the winding mandrel an
`axial cavity remains in the center of the winding. This allows
`the winding to expand into this cavity, if necessary. However,
`in some circumstances, this can lead to problems in making
`electrical contact between the electrodes and the metallic
`10 housing half-parts, and this will be described in more detail in
`the following text.
`The electrode winding is preferably arranged within a but(cid:173)
`ton cell (so that the electrode layers of the winding are aligned
`at right angles to the flat bottom area and top area of the
`15 housing) such that the end faces of the winding face in the
`direction of the flat bottom area and of the flat top area.
`Preferably, our button cells have a fixed winding core in the
`center of the winding, which at least partially fills the axial
`cavity in the center of the winding. A winding core such as
`20 this fixes the electrode winding in the radial direction and
`prevents possible implosion of the winding into the axial
`cavity. When the winding expands in this way, this also results
`in the reduction in the pressure which the end faces of the
`winding exert in the axial direction, and therefore in the
`25 direction of output conductors which may be arranged there
`(this is described in more detail further below). If this is
`prevented, then there are generally also no problems with
`making electrical contact between the electrodes and the
`metallic housing half-parts.
`In addition, a winding core such as this also makes the
`button cell more robust against external mechanical influ(cid:173)
`ences. In general, it is no longer possible for the electrode
`winding in the button cell to be damaged by external
`mechanical pressure in the axial direction.
`Preferably, the electrode winding is a spiral electrode
`winding, the axial cavity which has been mentioned in the
`center of the winding is preferably essentially cylindrical (in
`particular circular-cylindrical). On the casing side, it is
`bounded by the winding, and at the end it is bounded by
`40 corresponding surfaces of the bottom area and of the top area
`of the button cell housing.
`Correspondingly, the winding core which is contained in
`our button cell is preferably also in the form of a cylinder, in
`particular a hollow cylinder. The height of a cylinder such as
`45 this preferably corresponds to
`the respective distance
`between the flat bottom area and the flat top area, which is
`parallel to it.
`Particularly preferably, the winding core may have radially
`self-expanding characteristics. For example, it is possible for
`50 the winding core to be inserted in a radially compressed
`configuration into the axial cavity in the winding of a button
`cell. When the radially compressed winding core expands, it
`exerts a radial pressure on the electrode winding surrounding
`it, thus ensuring a contact pressure in the axial direction as
`55 well.
`By way of example, an axially slotted hollow cylinder may
`be used as a radially self-expanding winding core. However,
`alternatively, it is also conceivable to use other radially self(cid:173)
`expanding materials, for example, based on plastic.
`Particularly preferably, the winding core is composed of a
`metal such as stainless steel or plastic.
`Particularly preferably, the assembly comprising elec(cid:173)
`trodes and a separator in our button cell has one of the fol(cid:173)
`lowing layer sequences:
`negative electrode/separator/positive electrode/separator
`or
`positive electrode/separator/negative electrode/separator.
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 9 of 12 PageID #: 23
`
`US 9,153,835 B2
`
`5
`Assemblies such as these can be produced and wound very
`easily without short circuits occurring between electrodes of
`opposite polarity.
`The separators which can be used in our button cell are
`preferably films composed of at least one plastic, in particular
`of at least one polyolefin. By way of example, the at least one
`polyolefin may be polyethylene. However, it is also possible
`to use multilayer separators, for example, separators com(cid:173)
`posed of a sequence of different polyolefin layers, for
`example, with the sequence polyethylene/polypropylene/ 10
`polyethylene.
`It is not essential to use a plurality of separate separators to
`produce assemblies with the abovementioned sequence. In
`fact, a separator can also be looped around the end of one of 15
`the electrodes, thus resulting in both sides of this electrode
`being covered by the separator.
`The separators which can preferably be used in our button
`cell preferably have a thickness of between 3 µm and 100 µm,
`in particular of between 10 µm and 50 µm.
`The electrodes preferably have a thickness of between 10
`µm and 1000 µm, in particular of between 30 µm and 500 µm.
`Preferably, the negative electrode and the positive elec(cid:173)
`trode in the electrode-separator assembly are arranged offset
`with respect to one another within the assembly. In this case, 25
`an offset arrangement is intended to mean that the electrodes
`are arranged such that this results in a respectively different
`separation between the electrodes and the flat bottom and top
`areas in the button cell. In the simplest case, for example, a
`positive and a negative electrode can be slightly offset as 30
`strips of the same width applied to the opposite sides of a
`separator ribbon, as a result of which the distance between the
`positive electrode and the upper separator edge is greater than
`the comparable distance measured from the negative elec(cid:173)
`trode. This then applies in the opposite sense, of course, to the 35
`distance from the lower separator edge.
`Particularly preferably, preferably as a result of this offset
`arrangement, the positive electrode, in particular an edge of
`the positive electrode, rests directly on the cup part, in par(cid:173)
`ticular in the flat bottom area of the cup part, while the 40
`negative electrode, in particular an edge of the negative elec(cid:173)
`trode, rests directly on the top part, in particular in the flat top
`area of the top part. In this example, a direct electrical and
`mechanical contact is made between the electrodes and the
`cup and top parts. The offset arrangement of the electrodes 45
`with respect to one another therefore makes it possible for the
`electrodes to make contact with the respective housing parts,
`without any need to use additional electrical contacts and
`connecting means.
`However, alternatively, it is also preferable for at least one
`of the electrodes, preferably both the at least one negative
`electrode and the at least one positive electrode in our button
`cell, to be connected to the flat bottom and top areas via one
`or more output conductors. By way of example, the output
`conductors may be output-conductor lugs composed of cop- 55
`per or some other suitable metal. On the electrode side, the
`output conductors may, for example, be connected to a cur(cid:173)
`rent collector. The output conductors can be connected to the
`housing and/or to the current collectors by, for example,
`welding or via an clamped joint.
`In the simplest case, the current collectors of the positive
`and negative electrodes can also themselves act as output
`conductors. Collectors such as these are generally metallic
`films or meshes which are embedded in the respective elec(cid:173)
`trode material. Uncovered subareas, in particular end pieces, 65
`of collectors such as these can be bent around and can be
`brought into contact with the button cell housing.
`
`6
`The use of output conductors may be particularly advanta(cid:173)
`geous if the negative electrode and the positive electrode
`within the assembly are arranged with respect to one another
`such that this results in the electrodes each being at the same
`distance from the flat bottom and top areas. Or, in other
`words, if the electrodes are not arranged offset with respect to
`one another within the electrode-separator assembly, as has
`been described above.
`However, if the distance between electrodes of opposite
`polarity and the flat bottom and top areas is the same, this
`results in the risk of a positive and a negative electrode touch(cid:173)
`ing the metallic cup or top part at the same time, thus resulting
`in a short circuit. Preferably, the button cell may therefore
`comprise at least one insulating means, which prevents a
`direct mechanical and electrical contact between the end
`faces of the winding and the flat bottom and top areas.
`In one development, it is preferable forthe electrodes in our
`button cell such as this to be connected via the already men(cid:173)
`tioned separate output conductors to the flat bottom and top
`20 areas. These ensure the electrical contact between the elec(cid:173)
`trodes and the housing.
`In this case, it is preferable for at least a subsection of the
`output conductor or conductors in the bottom area and in the
`top area of the housing to rest flat on the inside of the housing
`half-parts. Ideally, the output conductors naturally make elec(cid:173)
`trical contact with the insides of the housing when they are at
`least slightly pressed against the housing (if they are not
`welded to it in any case). This can be achieved surprisingly
`efficiently by a suitable arrangement of the winding core that
`has been mentioned, in our button cell.
`By way of example, the insulating means may be a flat
`layer composed of plastic, for example, a plastic film, which
`is arranged between the end faces of the winding and the flat
`bottom and top areas of the housing of our button cell.
`Corresponding to the above statements, the button cell is,
`in particular, a rechargeable button cell. Our button cell par(cid:173)
`ticularly preferably has at least one lithium-intercalating elec(cid:173)
`trode.
`The ratio of the height to the diameter of button cells is, by
`definition, less than 1. For our button cell, this ratio is par(cid:173)
`ticularly preferably between 0.1 and 0.9, in particular
`between 0.15 and 0.7. In this case, the height means the
`distance between the flat bottom area and the flat top area
`parallel to it. The diameter means the maximum distance
`between two points on the casing area of the button cell.
`The button cell is particularly preferably a button cell
`which is not beaded over, as is described in DE Patent Appli(cid:173)
`cation 10 2009 017 514.8, mentioned above. Correspond(cid:173)
`ingly, there is preferably an exclusively force-fitting connec-
`50 tion between the housing half-parts. Therefore, our button
`cell does not have a beaded-over cup edge, as is always the
`case with known button cells. The button cell is closed with(cid:173)
`out being beaded over.
`Button cells such as these which are not beaded over gen(cid:173)
`erally make use of conventional cell cups and cell tops, which
`each have a bottom area and a top area, a casing area, an edge
`area which is arranged between the bottom and top areas and
`the casing area, and a cut edge. Together, the cell cup and cell
`top form a housing, which forms a receptacle for the conven-
`60 tional internal components of a button cell, such as electrodes,
`separator and the like. As in the normal way, the bottom area
`of the cell cup and the top area of the cell top are aligned
`essentially parallel to one another in this housing. The casing
`areas of the cell cup and cell top in the finished button cell are
`aligned essentially at right angles to the bottom and top areas,
`and preferably have an essentially cylindrical geometry. The
`internal and external radii of the cell cup and cell top are
`
`

`

`Case 2:20-cv-00052-JRG Document 1-1 Filed 02/24/20 Page 10 of 12 PageID #: 24
`
`US 9,153,835 B2
`
`7
`preferably essentially constant in the casing areas. The edge
`areas, which have been mentioned, of the cell cup and cell top
`form the transition between the casing areas and the top and
`bottom areas. They are preferably therefore bounded on the
`one hand by essentially flat bottom and top areas, and on the
`other hand by the essentially cylindrical casing areas, which
`are arranged at right angles to them. By way of example, the
`edge areas may be in the form of a sharp edge, or else may be
`rounded.
`The procedure for producing a button cell which is not
`beaded over is generally to first of all apply a seal to the casing
`area of a cell top. In a further step, the cell top is then inserted,
`with the seal fitted, into a cell cup thus resulting in an area in
`which the casing areas of the cell cup and cell top overlap. The
`size of the overlap area and the ratio of the overlapping area to
`the non-overlapping areas are in this case governed by the
`respective height of the casing areas of the cell cup and cell
`top, and by the depth of the insertion. With regard to the
`casing area of the cell top, it is preferable for between 20%
`and 99%, in particular between 30% and 99%, particularly
`preferably between 50% and 99%, to overlap the casing area
`of the cell cup (the percentages each relate to the height of the
`casing or of the casing area). Before being inserted into the
`housing cup and/or the housing top, the other conventional
`components of a button cell (electrodes, separator, electrolyte
`and the like) are inserted. After the cell top has been inserted
`completely into the cell cup a pressure is exerted on the casing
`area of the cell cup, in particular in the area of the cut edge, to
`seal the housing. In this case, a joined-together housing part
`should as far as possible not be subjected to any loads, or only
`to very small loads, in the axial direction. Therefore, the
`pressure is applied in particular radially. Apart from the seal(cid:173)
`ing of the housing which has already been mentioned the
`external diameter of the cell housing can therefore also be
`calibrated.
`It is particularly important for the heights of the casing
`areas of the cell cup and cell top to be matched to one another
`such that the cut edge of the cell cup is pressed against the
`casing area of the cell top by the pressure on the casing area of
`the cell cup. The heights of the casing areas are therefore 40
`preferably chosen such that it is impossible to bend the cut
`edge of the cell cup around inward over the edge area of the
`cell top which has been completely inserted into the cell cup.
`Correspondingly, the edge of the cell cup is not beaded over
`the edge area of the cell top. In consequence, the cell cup of a
`button cell manufactured using our method has a casing area
`with an essentially constant radius in the direction of the cut
`edge.
`In the case of button cells produced using a method such as
`this, there is preferably an exclusively force-fitting connec- 50
`tion between the housing components comprising the cell
`cup, the cell top and the seal. This ensures that the compo(cid:173)
`nents are therefore held together in a preferred manner, essen(cid:173)
`tially only by static-friction force.
`Button cells without any beading over are particularly pref- 55
`erably produced using a cell cup which is conical at least in
`one subarea of its casing, such that at least its internal diam(cid:173)
`eter increases in the direction of the cut edge. This makes it
`considerably easier to insert the cell top into the cell cup. The
`dimensions of the cell cup and cell top are preferably matched 60
`to one another such that relatively large opposing forces pref(cid:173)
`erably do not occur until the top has been inserted virtually
`completely into the cup. The cone angle in this case is pref(cid:173)
`erably between 10 minutes and 3°, in particular between 30
`minutes and 1 ° 30 minutes.
`The cell top, which is inserted into the cell cup with the
`applied seal, is preferably cylindrical, at least in a part of the
`
`8
`casing area. This may relate in particular to that part of the
`casing area which overlaps the conical subarea of the cell cup
`casing that has been mentioned, after the cell top has been
`inserted into the cel