United States Patent
`Koga
`
`15)
`
`[11] Patent Number:
`
`[45] Date of Patent:
`
`4,487,819
`Dec. 11, 1984
`
`[54] FLAT BATTERY
`[75]
`Inventor:
`Ryoji Koga, Kawaguchiko, Japan
`[73] Assignee: Kawaguchiko Seimitsu Company
`Limited, Yamanashi, Japan
`[21] Appl. No.: 452,391
`
`Dec. 22, 1982
`[22] Filed:
`[30]
`Foreign Application Priority Data
`Dec. 26, 1981 [JP]
`JAPan wrceeeeserecrecsecseccseseasees 56-213908
`
`Japan .ccsscsesssssssssssessssseseeeen 57-16875
`Feb. 4, 1982 [JP]
`
`ssecssseesesssenesesenes 57-26547
`Feb. 19, 1982 [JP]
`Japan 0...
`Japan csccsssssssssssscscsscssnseverers 57-31050
`Feb. 27, 1982 [JP]
`(51)
`Int, C13 wes HO1IM 2/12; HO1IM 2/08
`[52] U.S. Ch. ooeeeeccscsecssserecessrsenseenes 429/82: 429/163;
`429/174
`[58] Field of Search............... 429/174, 162, 163, 164,
`429/166, 171, 172, 173, 185, 82, 219
`References Cited
`U.S. PATENT DOCUMENTS
`
`[56]
`
`2,307,764
`
`1/1943 Deibel et al. 0... csssesseeee 429/164
`
`2,843,650
`3,723,184
`
`7/1958 Jacquier .......ccesesesessreeeees 429/174
`3/1973 Stark et al. oe eeseeeeeeee 429/174
`
`FOREIGN PATENT DOCUMENTS
`
`111060
`13665
`95066
`
`
`8/1980 Japan .......ceccessssseeessereeses 429/174
`1/1982 Japan...
`eeeeecessseensesenescees 429/174
`6/1982 Japan... secssssscaserseseesereeeers 429/174
`
`Primary Examiner—Donald L. Walton
`Attorney, Agent, or Firm—Koda and Androlia
`
`[57]
`ABSTRACT
`A flat battery for use in a micto-size device, including a
`cathode can having a substantially U-shaped cross-sec-
`tion, an anode can having a substantially inverted U-
`shaped cross-section, an anode and cathodeactive sub-
`stances accommodatedin a battery cell constituted by
`the cathode and anode cans, a separator provided be-
`tween the anode and cathode active substances, and an
`insulative film provided at an upstanding portion of the
`cathode can to isolate the cathode can from the anode
`can and the anodeactive substance.
`
`26 Claims, 46 Drawing Figures
`
`
`
`JLab/Cambridge, Exh. 1028, p. 1
`
`JLab/Cambridge, Exh. 1028, p. 1
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 1 of 19
`
`4,487,819
`
`
` taePELaps
`
`
`
`16
`
`10
`
`FIG.2
`
`26
`
`26a
`
`34
`
`
`
`24
`
`22b
`
`26b
`
` 32 eeSKE
`
`TOSSESSSSA)
`
`22
`
`22a
`
`JLab/Cambridge, Exh. 1028, p. 2
`
`JLab/Cambridge, Exh. 1028, p. 2
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 20f 19
`
`4,487,819
`
`FIG.3
`
`26
`24
`
`Sa
`AnETES
` I
`LLLLLNS,KosSAN
`304
`
`
` 28 -\
`
`CZ
`PTSSISASNASSSS
`
`22
`
`PYRE
`
`
`XN
`
`JLab/Cambridge, Exh. 1028, p. 3
`
`JLab/Cambridge, Exh. 1028, p. 3
`
`

`

`ZLLVILIZLLLLZLLLO
`
`
`
`
`
`se
`
`
`RTE
`
`
`
`
`U.S. Patent Dec. 11, 1984
`
`Sheet 30f 19
`
`4,487,819
`
`FIG.5
`
`30
`
`26
`
`26a
`
`32
`
`28
`
`22
`
`22a
`
`
`
`JLab/Cambridge, Exh. 1028, p. 4
`
`JLab/Cambridge, Exh. 1028, p. 4
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 4 of19
`
`4,487,819
`
`FIG.7
`
`yy J
`
`“)
`
`Lab/Cambridge, Exh. 1028, p. 5
`
`
`
`
`
`30 26a=26c26 G
`
`
`
`JLab/Cambridge, Exh. 1028, p. 5
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 50f 19
`
`4,487,819
`
`FIG.9
`
`30
`
`24
`
`22d
`
`B
`
`A
`
`32.
`
`22c”
`
`22b
`
`
`
`JLab/Cambridge, Exh. 1028, p. 6
`
`JLab/Cambridge, Exh. 1028, p. 6
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 6 0f 19
`
`4,487,819
`
`FIG11
`
`
`
`4
`
`26 26a=26
`Wa
`
`
`:NNNNNNNNNNNN PADASASASANY
`
`|
`0
`3
`|
`32 VILILLLLLLLLLLLLLLLLLLLe
`
`oeSanereeerste)
`
`
`
`LVNNSSNSSSSSNSNANNNS
`
`
`22
`22a
`
`
` WN
`
`ONYIN
`
`
`JLab/Cambridge, Exh. 1028, p. 7
`
`JLab/Cambridge, Exh. 1028, p. 7
`
`

`

`U.S. Patent Dec.11,1984
`
` Sheet70f19
`
`4,487,819
`
`FIG.13
`
`26
`
`26a
`
`24
`
`
`CLLLLLLLLLLLEN\
`reereeearerereagpeeShereheeneeSpeeeres
`LLLA
`
`
`
`QQ©“_ayd
`
`
`
`42
`
`30
`
`32
`
`28
`
`peeOE
`
`22
`
`22a
`
`
`
`JLab/Cambridge, Exh. 1028, p. 8
`
`JLab/Cambridge, Exh. 1028, p. 8
`
`

`

`U.S. Patent Dec.11,1984
`
` Sheet8of19
`
`4,487,819
`
`FIG.15
`aa
`
`42
`
`30 *
`
`F1G.16
`
`42a
`
`42
`
`30
`
`30a
`
`28
`
`30
`
`32
`
`JLab/Cambridge, Exh. 1028, p. 9
`
`JLab/Cambridge, Exh. 1028, p. 9
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 9 of 19
`
`4,487,819
`
`F1G.18
`
`
`
`NONSN
`
`22
`
`22a
`
`30a AVY
`
`
`JLab/Cambridge, Exh. 1028, p. 10
`
`JLab/Cambridge, Exh. 1028, p. 10
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 10 of 19 4,487,819
`
`F1IG.20
`
`
`
`
`FIG.21
`
`JLab/Cambridge, Exh. 1028, p. 11
`
`JLab/Cambridge, Exh. 1028, p. 11
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 11 of 19
`
`4,487,819
`
`F1G.22
`
`26
`26a
`
`SSSR29
`30
`LLLLL AN
`260
`32 EES
`
`
`
`
`
`
`JLab/Cambridge, Exh. 1028, p. 12
`
`JLab/Cambridge, Exh. 1028, p. 12
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 12 of 19
`
`4,487,819
`
`F1G.27
`
`FIG.28
`
`2 a
`
`30b
`
`30b
`
`22
`
`30
`
`FIG.29
`
`FIG.30
`
`22
`
`30
`
`30¢
`
`300
`
`22
`
`30
`
`30d
`
`JLab/Cambridge, Exh. 1028, p. 13
`
`JLab/Cambridge, Exh. 1028, p. 13
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 13 of 19
`
`4,487,819
`
`FIG.31
`
`26f
`
`26
`
`24
`
`26a
`
`26c¢
`
`JLab/Cambridge, Exh. 1028, p. 14
`
`JLab/Cambridge, Exh. 1028, p. 14
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 14 of 19
`
`4,487,819
`
`26=26a
`FIG.40A ==
`x
`
`FIG.40B
`
`F1G.40C
`
`JLab/Cambridge, Exh. 1028, p. 15
`
`JLab/Cambridge, Exh. 1028, p. 15
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 15 of 19
`
`4,487,819
`
`FIG. 43
`
`_ iM
`26
`26a
`ITILLL.
`£2eee32 OPTIDITIOTITILIIAVLLe
`
`\NoNLhonknde
`
`
`
`
`
`
` NRC
`287%
`
`
`
`30°
`
`|
`
`22
`
`22a
`
`FIG.44
`
`26a
`
`26
`
`30e
`
`
`°
`LLMAN)
`
`32 S&RRKGY
`we Vy
`
`
`LLLLILLELLLLIEXLY 18
`
`
`
`
`
`22
`
`22a
`
`JLab/Cambridge, Exh. 1028, p. 16
`
`JLab/Cambridge, Exh. 1028, p. 16
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 16 of 19
`
`4,487,819
`
`FIG.33
`
`26a
`
`26
`
`30
`
`32
`
`
`LLLLLLeTSSIND
`
` c<KSS
`
`
`
`
`28
`22
`22a
`24
`
`FIG.34
`
`ZA¢EZZZLZLARR
`
`ASCsSSAN
`
`JLab/Cambridge, Exh. 1028, p. 17
`
`JLab/Cambridge, Exh. 1028, p. 17
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 17 of 19
`
`4,487,819
`
`FIG.35
`
`FIG.36
`
`
`
`
` ~\
`
`t2 ROA
`22
`22a
`
`JLab/Cambridge, Exh. 1028, p. 18
`
`JLab/Cambridge, Exh. 1028, p. 18
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 18 of 19
`
`4,487,819
`
`F1G6.38
`
`26a
`
`
`
`JLab/Cambridge, Exh. 1028, p. 19
`
`JLab/Cambridge, Exh. 1028, p. 19
`
`

`

`U.S. Patent Dec. 11, 1984
`
`Sheet 19 of 19
`
`4,487,819
`
`FIG.41
`
`wh
`LAbtttctchesJNSSNASN
`
`30
`
`26a
`
`26
`
`AeCSN
`
`PITTIIR,
`28
`32 CERRY
`Y
`SSq~qw
`
`
`
`
`
`
`22
`
`22a
`
`JLab/Cambridge, Exh. 1028, p. 20
`
`JLab/Cambridge, Exh. 1028, p. 20
`
`

`

`1
`
`FLAT BATTERY
`
`BACKGROUNDOF THE INVENTION
`1. Field of the Invention
`This invention relates to a flat battery for use in a
`micro-size device such as a wristwatch, handy measur-
`ing or caluculating instruments and so on.
`2. Prior Art
`The construction of the conventional battery cell of
`this type consist of a cup-shaped anode can, a cap-
`shaped cathode can and a gasket provided between the
`anode and cathode cans. An anode active substance, an
`electrolyte, a cathode active substance and a separator
`are contained in such cell construction.
`The sealing structure of the conventional battery
`above mentioned is performed by establishing close
`pressing contiguity among the gasket, the anode and
`cathode cans through use of the compressive counter-
`force of the gasket in whichit is deformed. Therefore,
`it is necessary to obtain a large compressive counter-
`force by increasing the thickness of the gasket. How-
`ever, by increasing the thickness of the gasket, the vol-
`ume which is occupied by the gasket is increased, for
`this reason, the size of the battery becomes enlarged, or
`the net capacity of the cell diminishes. Otherwise, it is
`necessary to reduce the thickness of the plates constitut-
`ing the anode and cathode cansfor increasing the dis-
`charge capacity in the same size cell. Furthermore,
`when the compressive force of the gasket is enlarged in
`order to ensure the leakproof property,
`the internal
`pressure of the battery cell increases, this lead to one of
`the causes of leakage.
`SUMMARYOF THE INVENTION
`
`Main object ofthe present invention intend to present
`the construction of the micro battery cell to accomplish
`the improvementof the leakage of the electrolyte and
`the increasing of the discharge capacity in the definite
`dimensionof the cell. Therefore, the contents which are
`contained in the cell construction presented hereof is
`adaptable the heretofore conventional and widly used
`membersthat are the anode active substance, the sepa-
`rator, the cathode active substance and the electrolyte.
`Andthen,it is also acceptable for this present invention
`to use the material which will be hereafter improved.
`It is another object of the present invention to pro-
`vide a flat battery which can overcome the shortcom-
`ings encountered in the prior art.
`lt is another object of the present invention to pro-
`vide a flat battery which provides an anlargementof the
`internal volume without enlarging a size of the battery
`cell, an increase of the discharge capacity and reliable
`leakproof.
`To realize the principles of the present invention, the
`above-mentioned objects are accomplished by a flat
`battery, comprising: a cathode can including a bottom
`portion and a cylindrical upstanding portion extending
`upward from the outer circumference of said bottom
`portion; an insulative film provided at said cylindrical
`upstandingportion ofsaid cathode can; a cathodeactive
`substance electrically contacted to said cathode can; an
`anode can including an upper portion and a cylindrical
`portion extending downwardfrom the outer circumfer-
`ence of said upper portion; an anode active substance
`electrically contacted to said anode can; and a separator
`isolating said cathode active substance and anodeactive
`substance to prevent an electrical short-circuit; wherein
`
`15
`
`25
`
`35
`
`40
`
`45
`
`50
`
`60
`
`65
`
`4,487,819
`
`2
`said cylindrical portion of said anodecanis fitted to said
`cylindrical upstanding portion of said cathode can
`through the intermediary of said insulative film for
`setting said anode can on said cathode can.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Other and further objects, features and advantage of
`the present invention will be more apparent by refer-
`ence to the following detailed description of the inven-
`tion taken in connection with the accompanying draw-
`ings, in which:.
`FIG.1 is a longitudinal sectional view of a conven-
`tional flat battery, showing one-half of the battery;
`FIG.2 is a longitudinal sectional view of an embodi-
`ment of a flat battery according to the present inven-
`tion, showing one-half of the battery;
`‘
`FIG. 3 is a longitudinal sectional view of another
`embodiment of a flat battery according to the present
`invention, showing one-half of the battery;
`FIG.4 is an illustrative view for describing the instal-
`lation of a separator in the flat battery in FIG.3,
`FIG. 5 is a longitudinal sectional view of another
`preferred embodimentof a flat battery according to the
`present invention, showing one-half of the battery;
`FIG.6 is a partially enlarged view showingthe fitted
`cans portion of the flat battery shown in FIG.5;
`FIG.7 is a longitudinal sectional view of a modifica-
`tion of the flat battery shown in FIG.5;
`FIG.8 is a partially enlarged view showing the dis-
`tance A less than the distance B of the flat battery
`shown in FIG.7;
`FIG.9 is a partially enlarged view showing the dis-
`tance A larger than the distance B shownin FIG.7;
`FIG.10 is an enlarged view illustrating a portion of
`the insulative film interposed between the cathode can
`and anode can of another modification of the flat bat-
`tery shown in FIG. 2 or 5;
`FIG.11 is a longitudinal sectional view of a modifica-
`tion of the flat battery shown in FIG.2 or5;
`FIG. 12 is an enlarged view showing a principal
`portion of the flat battery shown in FIG. 11,
`FIG. 13 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG. 2 or 5;
`FIG.14 is a longitudinal sectional view of one-half of
`the battery, illustrating the state of the thermal conduc-
`tive metal which is on the anodeactive substance before
`fitting the anode can onto the cathode can in theflat
`battery of FIG. 13;
`FIGS. 15 and 16 are longitudinal sectional views of
`modifications of the plate shown in FIG.13;
`FIG. 17 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG. 2 or 5;
`FIG.18is a view illustrating the state of the graphite
`layer which is on the anode active substance before
`fitting the anode can onto the cathode can in theflat
`battery of FIG. 17;
`FIG. 19 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG. 2 or 5;
`FIGS.20 and 21are partially enlarged views ofprin-
`cipal portion of the flat battery illustrated in FIG. 19;
`FIG. 22 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG.2 or 5;
`FIGS.23 to 26 are partially enlarged viewsof an air
`venting portion ofthe flat battery shown in FIG. 22;
`FIG. 27 is a top view of another modification of the
`flat battery shown in FIG. 2 or 5, with the anode can
`removed;
`
`JLab/Cambridge, Exh. 1028, p. 21
`
`JLab/Cambridge, Exh. 1028, p. 21
`
`

`

`4,487,819
`
`3
`FIG.28 is a top view ofthe flat battery as an example,
`with the anode can removed;
`FIGS. 29 and 30 are top views of another modifica-
`tion of the anode active substance shown in FIG.28;
`FIG. 31 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG.2 or 5;
`FIG.32 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG.2, 5 or 31;
`FIG. 33 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG.2 or 5;
`FIG.34 is a longitudinal sectional view of a modifica-
`tion of the flat battery shown in FIG. 33;
`FIGS. 35 and 36 are partially enlarged views of the
`principal portion of another modification of the flat
`battery shownin FIG.33;
`:
`FIG. 37 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG. 33 with
`a assembly jig and fixture;
`FIG.38 is an enlarged view of the principal portion
`of another modification of the flat battery shown in
`FIG. 33;
`FIG. 39 is a longitudinal sectional view ofthe flat
`battery shown in FIG.38for illustrating the state which
`is deformed the anode can using metal mold anddie;
`FIGS. 40 A, B and C are longitudinal sectional views
`of steps of the fitting operation of the anode can with
`prior deformation onto the cathode can;
`FIG. 41 is a longitudinal sectional view of another
`modification of the flat battery shown in FIG. 2;
`FIG.42 is a longitudinal sectional view of a modifica-
`tion of the flat battery shown in FIG.41,
`FIG. 43 is a longitudinal sectional view of the flat
`battery shown in FIG. 5, in which the circular part is
`utilized;
`FIG.44 is a longitudinal sectional view of a modifica-
`tion of the anode active substance shown in the other
`figures.
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The construction of the conventional battery of this
`type is described with reference to the longitudinal
`sectional view of FIG. 1, showing one-half of the bat-
`tery.
`In FIG.1, the battery comprises a cup-shaped anode
`can 10 made of a metallic material, and a capshaped
`cathode can 12 also made of a metallic material. A gas-
`ket 14 comprising an insulator is located between the
`anode can 10 and a curled portion 12a of the cathode
`can 12, and is held the compressed state by bending
`inwardly the rim at the upper opening 10a of the anode
`can 10. An anodeactive substance 16, an electrolyte, a
`cathode active substance 18 and a separator 20 which
`isolate said anode active substance 16 from said cathode
`active substance are contained in the battery cell.
`The anode and cathode cans 10, 12 of this conven-
`tional flat battery are insulated by the gasket 14 which
`makes the compressive counterforce between the two
`cans 10, 12, whereby the sealing structure of the con-
`ventional flat battery is performed. In addition,
`it is
`necessary to increase the thickness of the gasket 14 for
`the sake of the acquisition of a suitable compressive
`counterforce. However, the volume whichis occupied
`by the gasket 14 is in propotion to the thickness of the
`gasket 14, then it is necessary to either reduce the thick-
`ness of the plates constituting the cans or increase the
`overall volumeofthe battery for the purpose of increas-
`ing the discharge capacity at the definite dimension of
`
`4
`the cell. Furthermore, when the compressive force of
`the gasket 14 is enlarged in order to ensure the leak-
`proof property, the curled portion 12a of the cathode
`can 12 is moved inwardly by the compressive force of
`the gasket 14. Consequently the internal pressure of the
`battery cell increases. In addition, the creep deteriora-
`tion of the gasket 14 is advanced by increasing the com-
`pressive force of the gasket 14, this lead to one of the
`causes of leakage.
`FIG.2 is a longitudinal sectional view of the embodi-
`mentof the flat battery according to the present inven-
`tion, showing one-half of the battery. The arrangement
`of the cans is inverted relative to the conventional ar-
`rangement of FIG.1 in view of the assembly operation.
`In FIG.2, a cathode can 22 has a substantially U-shaped
`cross-section and is made of a metallic material consist-
`ing of brass or steel having nickel layer on a surface
`thereof, or the like. The cathode can 22 is basically
`constituted by a bottom portion 22¢ and a cylindrical
`upstanding portion 225 extending vertically upward
`from the outer circumference of the bottom flat portion
`22a. The uppersurface and the surfaces of the outer and
`inner sides of the upstanding portion 22is coated with
`a insulative film 24 composedofa fluorine-type film or
`the like to insulate from the anode can 26and anode
`active substance. Theinsulative film 24 which coats the
`cathode can may be provided to any place where is
`necessary for preventing the inner short-circuit, for
`example contact portion of the cathode can and the
`anode can or anodeactive substance. The anode can 26
`has a substantially inverted U-shaped cross-section and
`is madeof a metallic material consisting of brass or steel
`havingnickel layer on a surface thereof, or the like. The
`anode can 26 is constituted by an upperflat portion 26a
`and a cylindrical portion 26bent vertically downward
`from the outer circumference of the upper portion 26a.
`Thecylindrical portion 264 of the anode can 26is fit on
`the outer circumferential surface of the upstanding por-
`tion 226 of the cathode can 22 by the shrinkage- or
`press-fitting process, whereby a secure water-tight fit is
`achieved through the intermediary ofthe insulative film
`24. Numeral 28 represents generally a cathode active
`substance consisting of zinc as a principal ingredient and
`containing an electrolyte consisting of NaOH, KOH or
`the like. Numeral 30 denotes an anode active substance
`consisting of silver oxide, silver peroxide, manganese
`dioxide, mercury oxide, nickel hydroxide or the like as
`a principal ingredient,
`in tablet form. A separator 32
`isolates the cathode active substance 28 and anode ac-
`tive substance 30 to prevent an electrical short-circuit.
`The separator 30 consists of non-weaving cloth, viny-
`lon, cellophane or the like.
`In this embodiment, the can 22 comesin contact with
`the cathode active substance 28 and therefore serves
`also as a cathode terminal, while the can 26 comesin
`contact with the anode active substance 30 and, hence,
`serves also an anode terminal. Though notillustrated,
`the arrangement of the cathode active substance 28 and
`anode active substance 30 shown in FIG. 2 may be
`inverted according to the requirment.
`Theflat battery in this embodiment is assembled by
`containing such contents as the cathode active sub-
`stance 28, anode active substance 30 and separator 24 in
`the cathode can 22, and then,finally, pressure-fitting the
`cylindrical portion 260 of the anode can 26 on the up-
`standing portion 225 of the cathode can 22 using the
`shrinkage- or press-fitting process.
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`30
`
`55°
`
`60
`
`65
`
`
`
`JLab/Cambridge, Exh. 1028, p. 22
`
`JLab/Cambridge, Exh. 1028, p. 22
`
`

`

`4,487,819
`
`5
`Suitable materials for the insulative film 24 are ethyl-
`ene tetrafluoride and ethylene chiorotrifluoride.If there
`are other materials above mentioned and which have
`resistance against deterioration by electrolytes, an elec-
`trical insulative property, repellent property for electro-
`lyte, elasticity and heat resistance against the high tem-
`perature at the shrinkage-fitting process. Such materi-
`als, e.g. silicon-, polyamide-, polyphenylene sulfide-,
`polyimide-based material, may be adaptable to the em-
`bodiment.
`In accordance with the embodiment, since a packing
`membersimilar to the conventional gasket illustrated in
`FIG. 1 is not employed in this embodiment,it is possible
`to increase the ratio of the internal volumeto the over-
`all battery volume and improve the battery discharge
`capacity by a wide margin. Because the insulative film
`24 having the excellent elasticity is sandwiched between
`the cylindrical portion 26d of the anode can 26 and the
`outer circumferential surface of the upstanding portion
`225 of the cathode can 22, and the thickness ofthe film
`24 is very thinner than the conventional gasket, and also
`the synergy between the internal stress occured by the
`pressure fitting and the film 24 having the electrolyte-
`repellent property prevent the creep of the electrolyte
`out of the inside of the cell, whereby the leakage of the
`electrolyte of the cell is perfected.
`In FIG.2, in addition the leak-proof property can be
`ensured if a sealing material 34 such as tar orsilicon
`grease is introduced into the space portion which is
`constituted of the end face of the upstanding portion
`226 of the cathode can 22 and the bentroot of the cylin-
`drical portion 265 of the anode can 26. It should be
`noted that the portion indicated by the broken line 36in
`the figure is the core piece, which is purposing to sup-
`port the separator can be prepared when necessary.
`FIG. 3 shows a modification ofthe flat battery shown
`in FIG. 2. Like elements corresponding to those of
`FIG.2 are indicated by like numerals. An outer diame-
`ter of a separator 32 of this embodimentis made larger
`than the inner diameter of the cathode can 22. As shown
`in FIG.4, the separator 32 is placed upon the upstand-
`ing portion 226 of the cathode can 22, then the anode
`active substance 30 is located on the separator 32, both
`the separator and the anode active substance 30 are
`pressed downinto the cathode can 22 whichis placed
`the cathode active substance 28 previously. In this case,
`this method gives the effect that the circumference of
`the separator gets the radial tension forcein all direction
`and the separator adheres closely to the anode active
`substance 30 avoiding unnecessary air between the sep-
`arator and the active substance.
`the problem which is
`Beside in this embodiment,
`comprised in assembly difficulties caused whenthereis
`a variance in the diameter of the separatoror an internal
`short-circuit caused when the diameter is too small are
`eliminated. Further, the separator 32 can be smoothly
`pressed into the cathode can 22.
`FIG. 5 shows another preferred embodimentofa flat
`battery according to the present invention, with like
`parts bearing the same reference numerals as these used
`in FIG.2.
`In FIG. 5, the inner wail of the upstanding portion
`226 of the cathode can 22 is projected with a step 22c at
`the middle part thereof. As shown in the partially en-
`larged view of FIG. 6, an inner surface 225”, outer
`surface 22d’ and upper surface 226 of the upstanding
`portion 225 and the step 22c are continuously coated
`with the insulative film 24.
`
`10
`
`20
`
`25
`
`35
`
`40
`
`45
`
`50
`
`35
`
`65
`
`6
`Theouter circumferential portion of the separator 32
`set upon the step 22c of the cathode can 22 andisolates
`the cathode active substance 28 from anodeactive sub-
`stance 30 to prevent an electrical short-circuit.
`The flat battery in this embodiment is assembled as
`the following steps.
`(1) The electrolyte-containing cathode active sub-
`stance 28 is introduced into the cathode can 22.
`(2) Then, the separator 32 is inserted by placingits
`outer peripheral portion on the insulated step 22c of
`the cathode can 22.
`(3) The tablet-shaped anodeactive substance 30 is set
`on the separator 32 andin the insulated inside of the
`cathode can 22.
`(4) Finally, the cylindrical portion 266 of the anode
`can 26 is hermetically fitted on the insulated outer
`circumferential surface of the upstanding portion
`226 of the cathode can 22 in such a mannerthat the
`anode can 26 covers the battery components.
`In FIG. 5, the outer circumferential portion of the
`separator 32 is sandwiched between the step 22c of the
`cathode can 22 and the anode active substance 30,
`therefore, it is possible to certainly retain the separator
`32 in the construction of the cell.
`As shown in FIG.6, the leak-proof property can be
`further ensured if a sealing material 34 such as tar or
`silicon grease is used into the space portion which is
`comprised between the end face of the upstanding por-
`tion 22b of cathode can 22 and the bent root of the
`cylindrical portion 26) of the anode can 26. In FIG.6,
`a ring-shaped groove 27, indicated by the brokenline,
`provided near the outer circumferential portion of the
`flat upper portion 26a of the anode can 26 is proposing
`to increase the bendingelasticity of the cylindrical por-
`tion 26 whenit is fitted onto the upstanding portion 22b.
`The groove 27 is formed when so desired.
`FIG.7 showsa modification ofthe flat battery shown
`in FIG. 5. FIG.8 is a partially enlarged view oftheflat
`battery shown in FIG.7.
`As shownin FIG.8, the distance A from the step 22c
`of the cathode can 22 to the upper surface 22d of the
`upstanding portion 22d is, in this modification, so de-
`signed as to be less than the total thickness B which is
`determined by the anode active substance 30 and the
`fully compressed separator 32. Accordingly, even when
`the anode can 26 is pressure-fit on the cathode can 22
`while pressuring the anode active substance 30, a gap G
`in FIG. 7 will be maintained between the inner surface
`26c of the anode can 26 and the upper surface 22d of the
`upstanding portion 22b of cathode can 22.
`As shown in FIG.9, if the distance A from the step
`22c of the cathode can 22 to the upper surface 22d of the
`upstanding portion 225 werelarger than the total thick-
`ness B of the separator 32 and anode active substance
`30, the insulative film 24 on the upper surface 22d of the
`upstanding portion 22b would be pressed by the anode
`can 26. In this case, the film 24 may be torn bythefitting
`pressure of the anode can 26 when the anode can 26is
`fit tightly on the cathode can 22. Further, since the
`anode can 26 is brought into abutting contact with the
`upper surface 22d of the upstanding portion 225 of the
`cathode can 22 before the separator 32 is compressed
`sufficiently through the intermediary of the anode ac-
`tive substance 30,the sufficient compression ofthe sepa-
`rator 32 cannot be achieved. This causes the creation of
`a portion through which the electrolyte may flow and
`givesrise to voltage instability and self-induced deterio-
`ration owing to an internal short-circuit.
`
`JLab/Cambridge, Exh. 1028, p. 23
`
`JLab/Cambridge, Exh. 1028, p. 23
`
`

`

`7
`In accordance with this modification, the upper sur-
`face 22d of the upstanding portion 226 of the cathode
`can 22 does not contact to the inner surface 26c of the
`anode can 26, as set forth above.It is, therefore, possible
`to settle the above-mentioned problems which are
`brought by the pressure-fitting of the anode can 26 to
`the cathode can 22.
`Also, a further improvementin leak-proof property is
`madepossible by putting a water-repellent filler which
`has fluidity, such as tar or polyacetal, in the gap G in
`FIG. 7 between the inner surface 26c of the anode can
`26 and the upper surface 22d of the upstanding portion
`226 of the cathode can 22.
`FIG. 10 showsstill another modified form oftheflat
`battery shown in FIG.2 or 5 (a modification ofthe flat
`battery shown in FIG.5 is only given in the following
`as an example.), and is an enlarged view illustrating a
`portion of the insulative film 24 interposed between the
`cathode can 22 and anode can 26.
`Numeral 38 denotes glass beads blendedin the insula-
`tive film 24. The glass bead 38 has a diameter greater
`than the total roughness of the surfaces of the cathode
`can 22 and anode can 26 and therefore prevents direct
`contact between the surfaces of the cathode can 22 and
`anode can 26. When the anode can 26 and the cathode
`can 22 are assembled by shrinkagefits, therefore the
`anode can 26 and cathode can 22 will not comeinto
`direct contact with each other evenif the insulative film
`24 should tear owing to the partial formation of thinned
`sections thereof with a reduction in breakdownstrength
`and soon caused by heat. Adopting an inclusion rate of
`1 to 20% for the glass beads 38 prevents the glass beads
`from overlapping in the direction of thickness of the
`insulative film 24. The rate of inclusion of the glass
`beads is suppressed on the assumption that the overlap-
`ping thereofin the direction of film thickness will cause
`the glass beads 38 to migrate within the insulative film
`24 whenthe anode can 26is shrinkage-fit on the cath-
`ode can 22, such migration being accompanied by flaw-
`ing of the insulative film 24.
`FIG. 11 showsstill another modified form ofthe flat
`battery shownin FIG. 2 or 5 (a modification of theflat
`battery shown in FIG.5 is only given in the following
`as an example.). FIG. 12 is an enlarged view showing a
`principal portion of the flat battery illustrated in FIG.
`11.
`Asstated before, where the insulative film 24 may
`tear owing to a decline in the Young’s modulus and
`breakdownstrength thereof caused by heat, or where
`the insulative film 24 may be damaged by an externally
`applied force at such time that the anode can 26 is
`shrinkage- or press-fit onto the cathode can 22, in this
`modification, an insulative metallic oxide layer 40 is
`applied on the inner circumferential surface of the cylin-
`drical portion 26 and on a portion of the inner surface
`26c of the upper flat portion 26¢ of the anode can 26.
`Therefore, the application is such that the anode can 26
`and cathode can 22 will not be short-circuited even if
`the insulative film 24 should be damaged.
`The insulative metallic oxide layer 40 comprises an
`iron oxide (Fe304) layer provided by subjecting the part
`of the anode can 26 to an iron oxide treatment, or a
`chrome oxide (CrO) layer formed by subjecting said
`part of the anode can 26 to black chromeplating.
`FIGS. 13 through 16 show still another modified
`form ofthe flat battery shownin FIG. 2 or 5(a modifica-
`tion ofthe flat battery shown in FIG.5 is only givenin
`the following as an example.).
`
`55
`
`60
`
`65
`
`4,487,819
`
`20
`
`25
`
`30
`
`35
`
`45
`
`350
`
`8
`Reference numeral 42 denotes a metal plate of a low
`thermal conductivity, consisting of stainless
`steel,
`chromeorthe like, which is sandwiched the upperflat
`portion 26a of the anode can 26 and the anodeactive
`substance 30. When the anode can 26is shrinkage-fit on
`the cathode can 22, the low thermally conductive metal
`plate 42 prevents the heat coming off the anode can 26
`from being applied directly to the anode active sub-
`stance 30.
`In shrinkage-fitting the anode can 26 on the cathode
`can 22, it is necessary to fit the anode can 26 on the
`cathode can 22 while the tablet-formed anode active
`substance 30 is pressed by the upperflat portion 26a of
`the anode can 26, thereby pressing the outer circumfer-
`ential portion of the separator 32 into abutting contact
`with the step 22Z¢ of the cathode can 22 to prevent a
`short-circuit. If the low thermally conductive metal
`plate 42 is not provided, the anode can 26 and anode
`active substance 30 would come into direct contact.
`Since the anode can 26 is herted to a temperature of
`from 200° to 300° C. at such time, the heat would be
`directly transmitted to the anode active substance 30. In
`a case in whichsilver oxide is used for the anode active
`substance 30, when the silver oxide is heated to a tem-
`perature of above 160° C., the silver oxide gives off
`oxygen. The oxygen being given off in this manner
`elevates the internal pressure of the battery, causing the
`anode can to be raised so that a deterioration in electri-
`cal contact between the anode can 26 and anodeactive
`substance 30 is conceivable. If the anode can 26 should
`be raised,
`it is even conceivable that a short-circuit
`might occur owing to a reduction in the force restrain-
`ing the separator 32.
`In this modification, the low thermally conductive
`metal plate 42 is provided between the anode can 26 and
`anode active substance 30. The heat given off by the
`anode can 26 during shrinkage-fitting is transmitted to
`the anode active substance 30 after travelling through-
`the metal conductive plate 42. Therefore, the anode can
`26 can be fit on perfectly followed by rapid cooling of
`the anode can 26, before the heat is transmitted to the
`anode active substance 30. In consequence, the anode
`can 26 is capable of being assembled by shrinkage-fit
`without having any influence to the anode active sub-
`stance 30.
`FIG.14 is a longitudinal sectional view of one-half of
`the battery, illustrating the state of the thermal conduc-
`tive metal which is on the anode active substance before
`fitting the anode can onto the cathode can 22in theflat
`battery of FIG. 13. The low thermally conductive metal
`plate 42 projects by a height h from the upper surf