NZ323614A - Electrochemical cell label with integrated tester - Google Patents

Abstract

A label for an electrochemical cell with a condition tester for the cell integrated with the label to form a label/tester composite (8) is disclosed. The label/tester composite has a thermochromic material (12) in thermal contact with an electrochemically conductive material (40). A substructure containing a cured conductive material and preferably also a thermochromic material is formed on a releasable web and transferred from the web to the inside surface of the heat shrinkable base film (10). A partition coating (60) may be applied over the transferred conductive material. Preferably, a sheet of paper or plastic film having a large window opening therein for entrapping air is applied over the partition coating and aligned over the heat generating portion of the conductive material. The label/tester composite is applied to the cell housing with the insulating paper or plastic film with the window opening against the cell housing. The tester may be activated by depressing one or two regions on its surface thereby connecting the conductive material to the terminals of the cell, thereupon the conductive material becomes heated, causing a change in the appearance of the thermochromic material to indicate the condition of the cell.

Description

*7"^ ^ f% ^ ^ , / ELECTROCHEMICAL CELL LABEL WITH INTEGRATED TESTER This invention relates to a label containing an electrochemical cell condition tester thereon and cells containing the label Commercially avadable testers to determine the condition of an electrochemical cell are typically of the thin film heat responsive type This type of tester typically contains an electncally conductive coating on one side of a heat resistant film and a thermochronuc coating on the other side Such testers are commercially available in the form of strips which are not integrated into the cell or cell label To use the tester one must apply it to the terminal ends of the cell being tested. This completes an electrical circuit in the conductive coating and causes heating in that coating The width of the conductive coating can be varied along its length, resulting in the narrower portion being heated to a highei temperature than the wider portion As a threshold temperature is reached along different portions of the conductive coating, a portion of the thermochromic coating m proximity thereto may change it clarity to reveal an underlying color coating A graphic scale alongside the various portions of the thermochronuc coating indicates the condition of the cell Examples of such testers and their application are disclosed in U S patents 4,723,656 and 5,188,231 The use of testers on electrochemical cells nas lon^ been known (See, eg US patent 1,497 388) However, incorporation onto a label of a heat responsive tester of the type disclosed, eg lnUS patent 4,702,564, using modern technology and high speed equipment poses significant problems One or more of the tester components, for example the conductive coating, normally requires heat treatment oi curing Modern battery labels are made of heat shrinkable plastic One significant manufacturing problem has been how to cure the conductive coating without causing deformation or shrinking of the underlying heat sensitive label Stand alone heat responsive testers have heretofore applied the conductive coating onto a polyester film Since such film is capable of withstanding the curing temperatu/es, the conductive coating can be cured while on the film However, such film is not useful for modern battery labels The object of the present invention is to overcome this problem or to at least provide the public with a useful choice The invention will be better understood with reference to the drawings in which 1 WO 97/29523 PCT/US96/18854 Fig. 1 is an enlarged partial isometric view, shown partially m cross-section, of the composite cell tester integrated with the label and forming the label/tester composite of the invention Figs 2A and 2B are enlarged end views of intermediate products used m the manufacture of the label/testei composite shown m Fig. 1 Fig 2C is au end view of a portion of the completed label/tester composite of Fig. 1 Fig 3 is plan view of a portion of the tester composite of Fig 1 illustrating preferred partition pattern and underlying conductive coating Fig 4 is an enlarged cross sectional representation of a contact area shown with the conductive layer depressed mto contact with an illustrative conductive material Fig 5 is a perspective view showing the label/tester being appbed to the cell Fig 6 is a perspective view showing the label/tester secured to the cell with the negative end of the cell visible at the top of the illustration Fig 7 is an isometnc view of another embodiment of the cell tester integrated with the label forming the label/tester composite of the invention Fig 8A is a schematic representation showing manufacture of a portion of the label/testei composite by transfer of the thermochronuc coating and conductive coatmg from a release web to the partial composite of Fig 8B Fig. 8B is an end view of a portion of the label/tester composite shown in Fig 7 Fig 8C is an end view of the completed label/tester embodiment of Fig 7 Fig 9 are plan views of the partition coatmg, conductive coating and dielectric coating therebetween for the embodiment represented in Fig 7 Fig. 10 is an assembled plan view of the coatings depicted in Fig 9 Fig 11 is an isometnc view of another embodiment of the cell tester integrated with the label forming the label/tester composite of the invention Fig 12 are plan views of the msulating substrate, partition coating, conductive coating and dielectric coating therebetween for the embodiment represented m Fig 11 Fig 13 is an assembled plan view of the elements depicted in Fig 12 Fig 14 is an isometnc view of another embodiment of the cell tester integrated with the label forming the label/tester composite of the invention 2 Printed from Mimosa WO 97/29523 PCT/CS96/18854 Fjg 15 are plan views of the insulating substrate, partition coating, conductive coatmg and dielectric coating therebetween for the embodiment represented m Fig 14 Fig. 16 is an assembled plan view of the elements depicted in Fig 15 Fig. 17 is is a perspective view showing the label/tester embodiment illustrated in Figs 14-16 being applied to the cell The present invention overcomes the above mentioned impediments to feasible manufacture of reliable on-cel] thermochromic testers The present invention avoids the need to cure the conductive coating on the label thereby eliminating deformation or shnnkmg of the label and making it possible to integrate a heat responsive tester with the cell label In the present invention the conductive coating is cured on a releasable heat resistant web and then transferred from the web to the cell label The invention in one embodiment is directed to an electrochemical cell and a label/tester composite thereon The composite includes a film having a thermochromic material disposed thereon, an electncally conductive matenal in thermal contact with the thermochromic matenal and means for thermally insulating the conductive matenal from the cell housing, said means compnsing a first opening in a substantially electncally nonconductrve matenal wherein said opening is of sufficient size to cover a substantial portion of the conductive matenal The opening preferably covers at least 40% of the heat generating portion of the conductive matenal The electncally nonconductrve matenal may be provided with a smaller second opening spaced apart from the first opening A portion of the overlying conductive matenal may be manually pushed through the second opening so that it makes electrical contact with a cell terminal A portion of the conductive matenal at an end of the label/tester composite may form a plurahty of conductive fingers which may be manually depressed so that it contacts the opposite cell terminal The conductive fingers also assures that the end of the label/tester composite containing said fingers can be heat shrunk evenly over one of the cell shoulders m proximity to a cell terminal In a preferred embodiment the tester may be activated by depressing both a first region of the label/tester composite over said conductive fingers and a second region over said second opening A desirable structure of the composite tester integrated with the cell label (label/tester composite 5) is shown in Fig 1 The label/tester composite 5 has a thickness under 100 mil (2 5 mm), desirably between about 4 mil and 20 mil (0 1 mm and 0 5 mm) Label/tester composite 5 3 Printed from Mimosa WO 97/29523 PCT/IJS96/18854 comprises a label backing 10 (base film), preferably having a print layer 6 on its inside surface Label backing 10 serves as a substrate for the tester components integrated therewith Print layer 6 may be fonned of conventional non-conductive ink and may contain text, logo, or other printed design giving the cell label an identifiable appearance Print layer 6 may have void regions, for example, over a portion of the tester creating a window for viewing a color change in the tester when the tester is activated A heat sensitive coating, preferably a thermochromic coating 12, is fonned over a portion oi print layer 6 Preferably a color coating 15 is formed over thermochromic coating 12 Label backmg 10 is a heat shnnkable film, preferably unplasticized polyvmylchlonde or polypropylene Thermochromic coating 12 may be composed of conventional reversible thermochromic inks This class of ink is known m the art and, for example, alluded to mUS Patent 4,717,710 When the thermochromic coating 12 becomes heated to a response activation temperature, preferably between about 35°C to 50° C, it turns from opaque to clear thereby exposing the underlying color coating 15 A preferred thermochromic ink for use in the composite tester of the invention is available as Type 37 or Type 45 thermochroaiic ink from Matsui International Co , lnc Color coating 15 may be any conventional printing ink with colorant chosen to give the coating a sharp, distinct color Although it is preferable to include color coating 15, this coating could be eliminated by incorporating additional coloring agents within coating 12 An adhesive coating 20 is applied over color coating J 5 and also directly over the inside surface of the remaining portion of label 10 over print layer 6 Thus thermochromic coating 12 and color coating 15 preferably he between label backing 10 and adhesive coating 20, e g, as shown in Fig 2C Suitable adhesive 20 may be advantageously selected from the well known acrylic or rubber based class of high performance pressure sensitive adhesives The adhesive is desirably transparent, particularly if a portion of the adhesive is interposed between the label and the thermochromic layer A suitable adhesive 20 may be fonned from a solvent based adhesive polymer solution sold under the trade designation AROSET 1860-2-45 by Ashland Chemical Co , Dublin Ohio This adhesive and its use is referenced in U S patent 5,190,609 For use in the context of the present invention adhesive 20 may be prepared by first coatmg a release coated web (not shown) e g sdicone coated paper, with th^ AROSET adhesive polymer solution and drying (or curing) the adhesive while still on the web The dned adhesive 20 may then be transferred from the web to the msit'i surfacc of label 10, i e over the label's exposed print coating 6 and tester color coating 15 (Fig 2D) 4 Printed from Mimosa Alternatively, adhesive 20 may be formed of a high performance curable (crosslinkablc) acrylic adhesive as disclosed in U S patent 4,812,541, herem incorporated by reference, e g examples 1 and 2 therein Conductive coating 40 may be selected from known thin film highly electncally conductive coatings Advantageously, coating 40 has a thickness of between about 0 25 mil and 1 0 mil (0 006 mm and 0 025 mm), preferably about 0 5 mil (0 012 mm) It may have a sheet resistivity of between about 10 and 100 miUiohms/sq A preferred conductive coating 40 for the composite label/tester of the invention is formed of a polymer based silver ink This ink is composed of silver flakes dispersed m a polymer solution A suitable silver mk is available from Olin Hunt Conductive Materials (now sold by Acheson Dispersions) under the trade designation 725A(6S-54) polymer thick high conductive film The resistivity of the ink and consequently that of conducive coating 40 may be adjusted for better cabbration of the tester This can be done by mixing into the silver ink a polymer based conductive graphite ink having a higher resistivity than the silver mk. A preferred polymer based conductive graphite ink is available under the trade designation 36D071 graphite ink from 01m Hunt Conductive Materials Suitable conductive coating 40 compositions may contain between 75 and 100 wt% silver ink and between 0 and 25 wt% polymer based conductive graphite ink The sheet resistivity of conductive coating 40 can also be controlled by adjusting its thickness The electncally conductive coating 40 is formed by applying the silver ink in varying geometrical patterns, for example, in a pattern which gradually narrows with length Such patterns for the conductive coating are disclosed, for example, in U S patent 5,188,231, herein incorporated by reference The silver mk may be applied by conventional printing methods after which it is dried and heat cured The total resistance of conductive coating 40 may be between about 1 and 2 ohms Preferably, as shown m Fig I, there 13 a dielectric mk coating 30 between adhesive 20 and conductive coating 40 Dielectric coating 30 also provides structural support to conductive coating 40 and protects conductive coating 40 from attack by adhesive 20 Dielectric coating 30 desirably has the additional requirement that it does not interfere with the proper shrinkage of the label's major edges 120 and 125 over cell shoulders 130 and 135, respectively, when heat is Printed from Mjmosa WO 97/29523 PCTrtJS96/18854 appbed to these edges Diclectnc coatmg 30 preferably has a thickness between about 0 2 and 0 5 mil (0 005 and 0 012 mm) A preferred dielectric coating 30 is a U V (ultra violet hght) curable polymer coating containing acrylate functional obgomers such as that available under the trade designation 47MSB132 U V Dielectric Blue from Olin Hunt Conductive Materials Adhesive coating 20 and dielectric coating 30 together have a combined thickness of less than about 1 6 mil (0 04 mm) and together they function as substitute for heat resistant film, e g polyester Dielectric coating 30 can be of a suitable color to eliminate, the need for color coating 15 Preferably, as shown in Fig 1, another dielectric coating 50 is located over conductive coating 40 Dielectric coating 50 is advantageously included to isolate and insulate conductive coating 40 from the cell housing (casing 80) In a preferred embodiment (Fig 1) the ends of conductive coating 40 are not coated with dielectric 50, so that they may be pressed into contact with the positive and negative terminals of a cell A preferred dielectric coating 50 is a U V curable polymer coating containing acrylate functional oligomer such as that available under the trade designation 47MSB132 U V Dielectric Blue coating from Olin Hunt Conductive Materials Dielectnc coating 50 has a thickness preferably between about 0 2 and 0 5 mils (0 005 and 0 012 mm) Both dielectric coatings 30 and 50 may be conveniently applied by conventional screen printing (Oat or rotary screen), gravure or flexographic printing.

A insulating partition coating 60 (Fig 1) is located over dielectric coating 50 Partition coatmg 60 electncally insulates conductive coating 40 from cell casing 80 (Fig 5) Partition coatmg 60 is multifunctional in that in addition to it being electncally insulating, a portion of it forms a region whereby the tester can be pressed into electncal contact with the terminals Also, another portion of partition coating 60 provides thermal insulation for the conductive coatmg 40 When the label/tester composite is apphed to the cell partition 60 contacts the cell casing 80 (Fig 5) Partition coatmg 6 is apphed in a pattern creating cavities that extend clear through the coatmg thickness At least a majonty of the cavities create air pockets for thermal insulation between conductive coatmg 40 and cell casing 80 and thus allow the surface of conductive coating 40 to reach higher equibbnum temperature As illustrated best in Fig 3 partition coating 60 is formed of a body portion 62 and end portions 64a and 64b (Fig 3) Body portion 62 desirably has a thickness between about 1 5 mil (0 038 mm) and 3 0 mil (0 075 mm) End portions 64(a) and 64(b) are each located preferably at extremities of partition coating 60 and 6 Printed from Mimosa WO 97/29523 PCT/US96/18854 comprise respective partition extremity portions 65a and 65b, and respective radiating nbs 66a and 66b As illustrated in Fig 3, dielectric coaung 50 (located between conductive coating 40 and partition coating 60) covers body portion 62 but not extremity portions 65 a and 65b Partition portions 65a and 65b containing one or more cavities, e g , 67a and 67b, respectively withm their boundary These cavities form a part of extremities 75a and 75b respectively Extremities 75a and 75b allow the ends of conductive coating 40 to make electrical contact with the cell's negative and positive terminals, respectively, when finger pressure is apphed to the region of the label directly over both extremities The body 62 of the partition pattern will be of relatively greater thickness than the other of the tester coatings in order to create proper partition of the conductive coating 40 from the cell and also to create insulating air pockets under the tester Various curable materials, for example, acrylate functional epoxies, acrylate functional urethanes, and acrylate functional polyesters having suitable printing and durability characteristics may be employed for partition 60 Such materials are preferably U V curable and capable of being printed by screen process (flat or rotary) so that the required degree of thickness between about 1 5 and 7 0 mils (0 038 and 0 175 mm) for the body of the partition can be attained This degree of thickness would be difficult to attain using solvent based inks or other solvent coating which must be pattern printed The partition matenal, as all other tester components, should withstand exposure to elevated temperatures up to about 170" F, commonly employed during cell performance testing A preferred matenal for partition pattern 60 is formed of compounded polymers containing U V curable polymer such as acrylate functional epoxy or acrylate functional urethane polymer The compounded matenal contains reactive oligomer, reactive monomer and thickening fillei The thickenmg filler may be silica filler such as AEROSIL 200 from Degussa Inc Chemicals Division It gives ".he matenal a rhcology which makes it easier to pnnt and keeps the matenal cohesive before curing A preferred compounded blend for partition coating 60 is Prepolymer blend product designation EBECRYL 4833 (Radcure Specialties Co , Norfolk Virginia) containing urethane acrylate oligomer and N-vinyl-2-pyrrohdone (50 to 80 Wt%), reactive monomer hexane diol diacrylate (20-40 wt%), and AEROSIL 200 (0 1 to 5 wt%) The compounded blend is apphed in the desired pattern using conventional screen printing process The printed matenal is then cured by U V light to produce a hard, manually incompressible and thermally stable pamtion coatmg 60 of desired pattern Pamtion coating 60 has a thickness 7 Printed from Mimosa WO 97/29523 PCT/US96/18854 between about 0 1 mil (0 0025 mm) and 7 mil (0 175 mm) The partition body portion 62 has a thickness preferably between about 1 5 mil (0 038 mru) and 7 mil (0 175 mm) A preferred partition 60 with conductive coatmg 40 showing therethrough is illustrated m Fig 3 Extremities 75a and 75b (Fig. 3) are comprised of partition end portion 65a and 65b, respectively and a portion of the conductive coating, namely 42a and 42b, respectively The partition portion 65a and 65b each has a thickness desirably between 0 1 mil (0 0025 mm) and 2 0 mil (0 05 mm) Portion 65a and 42a have a combined thickness between about 0 35 mil (0 009 mm) and 3 0 mil (0 075 mm) Similarly, portion 65b and 42b have a combined thickness between about 0 35 mil (0 009 mm) and 3 0 mil (0 075 mm) The partition portions 65a and 65b form cavities (67a and 67b, respectively) which are advantageously of a polygonal, rectangular, oval, elliptical or circular shaped cavities extending through the thickness of partition coating 60 Smce dielectric coatmg 50 covers only the body portion 62 of partition 60, end portions of conductive coating 40, i.e , portions 42a and 42b, preferably rest directly on partition portion 65 a and 65b, respectively, with no coatings intervening therebetween When the region of the label over conductive portion 42a is pressed, conductive portion 42a pushes down through the cavity 67a in the underlying partition coating and passed partition portion 65a until it makes electrical contact with a cell terminal or conductive surface in electncal contact with a cell terminal Similarly when the region of the label over conductive portion 42b is pressed, conductive portion 42b pushes down through the cavity 67b m the partition surface and passed partition portion 65b until it makes electncal contact with a cell terminal or conductive surface in electncal contact with a cell terminal When pressure is removed the conductive portions 42a and 42b will return substantially to its ongmal position above the partition surface This may be accomplished many, many times There may be a senes of ribs 66a and 66b (Fig 3) radiating away from end portions 65a and 65b, respectively These ribs tend to converge when the tester/label composite 5 is heat shrunk over the cell shoulders and thus permit extremities 75a and 75b to be heat shrunk neatly over the cell shoulders without bulging or distorting 8 Printed from Mimosa WO 97/29523 PCTAJS96/18854 The conductive coating 40 normally comprises a low resistance portion 40a and a high resistance portion 40b as shown m Fig 3 The high resistance portion 40b may have a gradually narrowing width from one end to the other as shown in Fig 3 The narrower end 40b, will reach higher surface equilibrium temperatures than the wider end 40b2 because of higher watt density (power consumed per unit surface area) at the narrower end The partition pattern which covers the low resistance portion 40a is in the form of a plurality of parallel ribs 60a, preferably formed of the above disclosed partition matenal Ribs 60a preferably extend along the length of the low resistance portion 40a The partition pattern 60b which covers the high resistance portion 40b may desirably be formed of a plurality of small islands, e g dabs, of the pamtion matenal, thus creating thermally insulating air spaces or cavities heTebetween A composite tester/label 5 can be manufactured m the following preferred manner A heat shnnkable label backing 10 may be a base film preferably of unplastictred polyvinylchlonde, or polypropylene film preferably of about 6 mils (0 15 mm) thickness is first heat-stretched m the machine direction (the direction in which the label is wrapped around the cell) resulting in a film thickness between about 1 5 and 4 mil (0 0375 and 0 1 mm) A partial layered substructure 7 (Fig 2B) is first produced by coating label 10 with print layer 6 using conventional non-conductive mks The non-conductive ink preferably has a total metal content of less than about 1000 ppm (dned weight basis) The ink should not degrade when exposed to alkaline environment such as may be present durmg manufacture of the cells The thermochromic coating 12 may then be applied over a small section of the pnnted label along the label's width using conventional flat or rotary screen printing method Thermochromic coatmg 12 may be U V cured whereupon its thickness is between about 1 0 and 3 0 mils (0 025 and 0 075 mm) Thermochromic coating 12 may then be overcoated with color coating 15 by conventional gravure, flexographic, or screen printing process (Color coating 15 can be eliminated by relying on dielectnc 30 to provide the indicator color, which would become visible when thermochromic coating 12 reached its response temperature ) Label 10 may be covered with a coating of adhesive 20 on the prmied undersurface of the label Adhesive 20 may be prepared and apphed to the undersurface of the printed label forming substructure 7 in the manner above descnbed Next, a transferable layered substructure 35 may be made by coating a heat stable release coated web 18 with a desired pattern of conductive coating 40 Substructure 35 or portion thereof may be referred to herein as a preform (If the conductive coating is readdy curable at a 9 Printed from Mimosa WO 97/29523 PCT/US96/I8854 temperature below the temperature at which label 10 begins to shrink or otkenvise distort, the conductive coating may alternatively be applied directly onto label 10 and cuied thereon, without the need for web 18 ) Web 18 may be any heat resistant film, for example a polyester, paper oi polycarbonate film precoated with a conventional rcfease coating, typically silicone Conductive coating 40 desirably contains a mixture of conductive silver itskes dispersed in a polymer solution as above described Web 18 with the silver flake dispwsion coated thereon is then passed through a heated oven untd the coating is sufficiently cured In addition to heat the conductive coatmg 40 may also be exposed to ultraviolet (U V ) radiation to cnhance its curing Thereupon conductive coating 40 is coated with the above refireciced dielcctnc mk 30 by conventional screen process, gravure or flexographic printing (Optic !ly, thermochromic coating 12 could be applied directly over dielectric ink 30 wh.de ink ^ is Still on web 18 instead of applymg coating 12 over print layer 6 ) Web 18 containing dielectnc mk 30 is passed through a conventional U V curing unit to polymerize and cure the coating The layered substructure 35 (Fig 2A) composed of conductive coating 40 coated with dielectnc ink 30 may then be transferred from web 18 to layered substructure 7 (Fig 2B) by pressing the exposed dielectnc coating 30 to the bottom of adhesive portion 20 Thereupon, web 18 can be easdy removed from substructure 35 by peeling, thereby leaving substructure 35 adhered to substructure 7 A second dielectnc ink coa! " 50 which may be of same composition , but preferably of different color shade, as dielectric ink 30 may be coated in any desired pattern directly onto the exposed conductive coatmg 40 Dielectnc coatmg 50 may be printed onto conductive coatmg 40 by employing conventional screen process, gravure or flexographic printing technique The coating 50 is then cured in conventional manner by subjecting it to madiation from mercury vapor lamps, whereupon it has a thickness of about O 2 mil After dielectnc coatmg 50 has been apphed and cured a partition pattern 60 is then apphed over coating 50 Partition pattern 60 is preferably composed of a prepolymer blend of acrylated urethane oligomer (or acrylated epoxy oligomer), reactive monomer and thickening filler such as AEROSIL 200, as above referenced The blend is advantageously apphed by conventional flat oi rotary screen process printing methods In tins process a screen fabnc is coated to a stencil thickness of 18 to 80 microns The screen mesh is desirably between about 100 and 200 threads per inch The printed blend is then U V cured The cured partition pattern 60 has a thickness of between about 1 5 and 7 mils (0 038 and Printed from Mimosa WO 97/29523 PCT/US96/18854 0 175mm) Tlie layered construction of composite label/tester 5, shown best in Figs 1 and 2C, is now complete It may be protected with a release liner and stored until it is desired to apply it to the cell The label/tester composite 5 of the invention is apphed to a cell by first removing the release liner from the label and wrapping the label around the cell casing 80 as illustrated in Fig 5 Exposed portions of adhesive coating 20 adheres to the cell casing As aforementioned, the label edges 120 and 125 are preferably devoid of exposed adhesive After the label is wrapped around the casing, beat may be apphed to label edges 120 and 125 to heat shrink these edges around the cell shoulders 130 and 135, resulting in the configuration shown in Fig 6 Since extremities 75a and 75b are preferably adjacent respective label edges 120 and 125, these extremities will also become heat shrunk over the cell shoulders 130 and 135, respectively They will thereby come to rest in close proximity to cell surfaces 11 Oi and 115i, respectively, as shown in Fig 6 Cell portions 1 lOi and 115i are electncally conductive and form part of the cell's terminal ends 110 and 115, respectively After the label/tester 5 is secured to the cell, the portions of conductive coating 40 which form extremities 75a and 75b will remain insulated from electrical contact with the cell's terminals by partition portions 65a and 65b, respectively, until the tester is activated The tester may be activated by manually pressing the surface of label 10 simultaneously over regions 42a and 42b As may be seen best from Fig 4, when a human finger 92 depresses conductive region 42a, this portion of the conductive coating penetrates through a cavity in partition portion 65a until it contacts conductive surface 1 lOi Similarly, when the conductive region 42b is depressed that portion of the conductive coatmg penetrates through the cavity in partition portion 65b until it comes into contact with conductive surface 115i which is in contact with positive terminal 115 When cell portions 1 lOi and 115i are simultaneously contacted by the respective conductive portions 42a and 42b, heating in conductive coating 40 occurs which in turn activates thermochronuc coatmg 12 Although a dual activation design described herein is preferred, alternatively one end of the conductive coatmg may be permanently secured to the cell so that it is in permanent electncal contact with one of the cell's terminals This can be accomplished by using conductive adhesive between a portion of conductive coating 40 and a cell terminal or portion of the cell m electncal contact with the terminal The other end of the conductive coatmg or portiou thereof could employ an activating mechanism, e g. 75(a) or 75b, described 11 Printed from Mimosa WO 97/29523 PCT/US96/18854 hereinabove In such embodiment, m order to activate the tester, the user would need only to depress one end of the label/tester composite 5 Another embodiment of the label/tester composite of the invention is composite 8 illustrated schematically in Fig 7 which can be described with reference to Figs 8A-8C as follows (The coatmgs shown in Figs 7 and 8A-8C having the same reference numbers as above discussed with reference to Figs 1 and 2A-2C can be of the same composition and apphed by the same methods of printing as described in the foregoing) The label/tester composite 8 (Fig 8C) is constructed bv first forming a first layered substructure 9 shown in Fig. 8B Substructure 9 (Fig 8B) is fonned by applying a graphics print layer 6 to the inside surface of label 10 and then adhesive coating 20 onto pnnt layer 6 (Preferred adhesive for coating 20 and preferred methods of application have been described in the foregoing) A transferable layered substructure 36 on releasable web 18 may then be prepared by first applying a conductive coating (silver mk above desenbed) onto a releasable (eg. silicone coated) web 18 and then heat curing the coatmg to form cured conductive coating 40 (Substructure 36 or portion thereof may be referred to herein as a preform ) Then color coatmg 15 may be appbed over conductive coatmg 40 and m turn thermochromic coating 12 applied over color coating 15 Substructure 36 (Fig 8A) compnsing coatings 12, 15, and 40 may then be transferred from release coated web 18 to layered substructure 9 by pressing thermochromic coating 12 of substructure 36 onto adhesive coating 20 of substructure 9 and then peeling away web 18 Thereupon dielectnc coating 50 may be applied over the exposed conductive coatmg 40 and partition coating 60 may be apphed over dielectnc coating 50, thus forming the final label/tester composite illustrated in Figs 8 and 9C A preferred configuration for the conductive coating 40, dielectnc coating 50 and partition coatmg 60 referenced in Figs 7 and 8C is illustrated in Fig 9 Partition coating 60, illustrated in Fig 9, is formed of a body portion 162 and end portions 164a and 164b Body portion 162 desirably has a thickness between about 1 5 mil (0 038 mm) and 7 0 mil (0 18 mm) Body portion 162 is preferably fonned in a pattern of cnss-crossed horizontal and vertical nbs which form a plurality of air pockets 163 which provide thermal insulation between the label/testei composite 8 and cell casing 80 End portions 164a and 164b are each located respectively at opposing extremities of coating 60 as illustrated in Fig 9 End portions 164a and 164b each comprise respective partition end portions 165a and 165b and respective partition tip portions 166a and 166b Partition end portions 165a and 165b form cavities 167a and 167b, 12 Printed from Mimosa WO 97/29523 PCT/US96/18854 respectively which are preferably of polygonal, rectangular, oval, elliptical, or circular shape The partition end portions 165a and 165b form boundaries around one or more such cavities, l e spaces, in the partition coating 60 at opposing ends thereof The area of these cavities (facing conductive coating 40) may be between about 1 5 mm2 and 20 0 mm2, preferably between about 8 and 20 mm2, and form a part of extremities 175a and 175b, respectively Partition tip portion 166a preferably comprises a pair of slanted ribs 166a, and 166a, which jut out from one end of the partition coatmg Partition tip portion 166b preferably comprises a pair of slanted nbs 166b, and 166bj which jut out from the opposite end of the partition coating Electncally conductive coating 40 (Fig 9) compnses low resistance portions 140a and 140b at respective ends of the conductive coating and a high resistance portion 140c therebetween In practice the high resistance portion 140c forms the heat generating portion of the conductive coatmg 40, te it is designed to be capable of generating sufficient heat so that the thermochromic coatmg 15 in thermal contact therewith will change in appearance when the ends of conductive coating 40 are pressed mto electncal contact with the termmals of a fresh cell The heat generatmg portion 140c may have a gradually narrowing width along a major portion of the length of the conductive coatmg so that the narrower end 140c, will reach a higher surface equilibnum temperature than the wider end I40c2 when the tester is activated This allows determination of the strength of the cell For example, if the cell is weak only the portion of theimochromic coatmg 40 over the nanowest portion (140c,) will change in appearance When the cell is fresh the thermochromic coatmg over the entire beat generatmg portion (140c, and 140c2) of the conductive coatmg 40 will change m appearance In the embodiment shown in Fig 9, preferably two or more conductive fingers 143a jut out from the end of conductive portion 142a and similarly two or more fingers 143b jut out from opposing low resistance end 140b The individual fingers 143a are separated from each other by small spaces (m) therebetween Similarly individual fingers 143b are separated from each other by small spaces (n) therebetween When the ends of the label/tester composite are heat shrunk over the cell shoulders 130 and 135, the spaces between each set of fingers become smaller, thus tending to merge the individual fingers in each set The small spaces between the fingers prevent bulging or warping of the ends of the label/tester composite when heat is apphed thereto to heat shrink those ends over the cell shoulders 13 Printed from Mimosa WO 97/29523 PCT/US96/18854 Coatings 40, 50 and 60 of Fig 9 are shown assembled in Fig 10 In this embodiment dielectnc coatmg 50 is sandwiched between conductive coating 40 and partition 60 Dielectnc coatmg 50 is shorter than both conductive coatings 40 and partition coating 60 and covers only the body portion 162 of partition coatmg 60 Thus, end portions of conductive coating 40, l e portions 142a and 142b as well as conductive fingers 143a and 143b can rest directly on the partition coatmg, preferably with no intervening coatings therebetween In this assembly, partition ribs 166a, and 166^ provide support and electncal insulation for the overlying conductive coatmg 143a at one end of the tester Partition nbs 166b, and 166b} provide support and electrical insulation for the overlying conductive coating 143b at the opposite end of the tester Extremities 175a and 175b at opposing ends of the label/tester composite 8 are each compnsed of partition end portion 165a and 165b, respectively, and a portion of the conductive coating, namely 142a and 142b, respectively The partition end portions 165a and 165b have a thickness desirably between 0 1 mil (0 0025 mm) and 2 0 md (0 05 mm) Portions 165a and 142a have a combined thickness between about 0 35 mil (0 009 mm) and 3 0 mil (0 075 mm) Similarly, portions i 65b and 142b have a combined thickness between about 0 35 mil (0 009 mm) and 3 0 mil (0 075 mm) When the region of the label over conductive portion 142a is pressed, the conductive portion 142a pushes down through the underlying gap fonned in partition portion 165a and passes therethrough until it makes electncal contact with a cell terminal or conductive surface in electncal contact with a cell tenmnal When pressure is removed, the conductive pomon returns to its ongmal position above the partition surface Conductive fingers 143a which rests on partition nbs 166a, and 166^ respectively, can also be to come mto electncal contact with a cell terminal by pressing down on the portion of the label directly over said fingers Thereupon, conductive portions 143a passes through the cavity in the partition coatmg between ribs 166a, and 166aj until it makes electncal contact with a cell terminal or conductive surface m electncal contact with a cell terminal When pressure is removed conductive portion 143a returns to its ongmal position above partition nbs 166a, and 166a, Conductive fingers 143b on the opposite end of the tester can be made to come mto electncal contact with a cell terminal in the same manner by pressing down on the portion of the label directly over end portion 143b, whereupon 14 Printed from Mimosa WO 97/29523 PCTAJS96/18854 said conductive fingers pass through the cavity in the partition coatmg between nbs 166b, and 166h2 to make electncal contact with a cell terminal The label/tester composite 8 shown in the alternate embodiment of Fig 7 may be applied to the cell in the same manner as described with reference to the embodiment of Fig 1, namely, by wrapping the label around the cell casing 80 with the adhesive side of the label in contact with the cell casing and then heat shrinking the ends of the label over the cell shoulders 130 and 135 A preferred embodiment of the label/tester composite of the invention is composite 11 illustrated schematically in Fig 11 The details of the topmost layers of composite 11, namely layers 40, 50, 60 and 210 are illustrated best in Figs 12 and 13 ( The coatings shown in Figs 11-13 having the same reference numbers as above discussed with respcct to any of the preceding embodiments may be of the same composition and apphed by the same methods of printing as desenbed m the foregoing ) The tester/label composite 11 shown m Fig 11 may be the same as composite 8 shown m Fig 7 and is prepared by the same method above described with reference to Figs 8A-8C except that an additional layer, namely, insulating substrate 210, is added over the partition coatmg 60 so that when the tester/label composite is applied to the cell, the insulatmg substrate 210 contacts the cell casing 80 Insulating substrate 210 provides electncal and thermal insulation, and is compnsed of matenal which has one or more holes or openings 220 therethrough which form one or more thermally insulatmg air pockets when the composite 11 is applied to the cell casmg Most of the thermal insulation is provided by air trapped in the hole or opening 220 and therefore the substrate 210 matenal does not itself have to have an extremely high thermal insulatmg property Substrate 210 is desirably of a matenal having a thermal conductivity of less than about 10 watt m1K"' The matenal is also preferably substantially electncally nonconductive (i e , essentially electncally nonconductive when compared to metals) Desirably, the wbstrate 210 matenal has a volume resistivity of greater than about 2 7 x 106 ohm-cm (sheet resistivity greater than about 550 megohms per sq @ 2 mil) Substrate 210 should also be sufficiently heat resistant that it does not shrink or distort when exposed to emperatures up to about 140°F Accordingly, substrate 210 may be selected from a wide range of matenals such as plastic film, polymenc foam, paper and combinations thereof Substrate 210 desirably has a thickness between 2 and 12 mil (0 05 and 0 3 mm), preferably between 4 and 7 mil (0 1 and 0 18 mm), and is most preferably Printed from Mimosa WO 97/29523 PCT/US96/1S854 of paper The paper may be uncoated or coated paper The density of the paper is not critical, although porous paper may be preferable because it provides somewhat better thermal insulation Instead of paper, substrate 210 may be a plastic film having the above described properties For example, if a plastic film is chosen, it may desirably be selected from among high density polyethylene, high density polypropylene, polyester, polystyrene, and nylon Alternatively, substrate 210 may a polymeric foam such as polyurethane foam Substrate 210 may be formed of composite matenal comprising laminates of two or more plastic films, or plastic film extruded onto paper orpolymenc foam Such composite material for substrate 210, for example, may be polyester lammated to polyethylene, e g by coextrusion, or spun bound polyester extruded onto paper In the latter case the polyester side of the composite would face and contact cell casmg 80 While composite materials are not regarded as necessary, they do offer an added degree of protection against seepage into the tester interior of residual trace amounts of KOH or other contaminates, which can be present on the cell casmg The openmg(s) in substrate 210 is preferably in the form of a single window 220 which is large enough to cover a substantial portion of the heat generatmg portion (140c, and 140c2) of conductive coatmg 40 (Fig 12) (The term "heat generating portion of conductive coatmg 40" as used herem shall refer to the portion of the conductive coatmg 40 which overlies the thermochromic coating 12 (Fig 11) and generates sufficient heat when the conductive coatmg is electncally connected to the terminals of a fresh, undischarged cell to cause a responsive change m appearance of the thennochronuc coatmg in thermal contact therewith ) Window 220 desirably covers a gi eater surface area than the largest of any cavities 167a and 167b through which a portion of conductive coatmg 40 may be manually pushed to activate the tester Cavities 167a and 167b cover an area desirably between about 1 5 and 20 mm2 on the side facing conductive coatmg 40 and said cavities have a depth between about 0 1 mil (0 0025 mm) and 2 0 mfl (0 05 mm) The wmdow 220 should be large enough to provide the desired thermal insulation between the heat generatmg portion of conductive coatmg 40 and cell casmg 80 Wmdow 220 should also be large enough that it does not interfere with attainment of a visually acute thermochromic display when the cell is activated The width of window 220, i e its dimension along the cell's circumferential direction should not he so great in relation to the window's depth that the pressure of label 10 when it is wrapped 16 Printed from Mimosa WO 97/29523 PCT/US96/18854 around cell casing 80 causes any portion of the tester (exclusive of substrate 210) to sink mto the window area and contact the usually cylindrical cell housing A preferred window 220, therefore, is oiie of an elongated or oblong slot confi,iuration, e g rectangular or elliptical or other such configurations having a smaller width than length The window 220 is aligned in relation to the cell so that its width is substantially in the circumferential direction of the ccll For example, a rectangular window 220 is illustrated in Fig 12 The rectangular window 220 in this embodiment may typically have a width of about 1 5mm, length of about 20mm and thickness of about 0 15mm Such dimensions reflect a width sufficiently small and thickness sufficiently great to prevent any portion of the label/tester composite (exclusive of substrate 210) from contacting the cell housing through said window when the label 10 is wrapped around the cell In the embodiment shown in Fig 12 window 220 desirably has an area which is at least 40% and preferably at least 60% of the surface area of one side of the heat generatmg portion of conductive coating 40 In the embodiment shown m Fig 12 window 220 may have an area which is as high as at least 80% of the surface area of one side of the heat generating portion of conductive coating 40 In connection with such embodiment the body portion 162 of partition coatmg 60 may contain a pattern of gaps or openings m its surface such as openings 163 shown in Fig. 9 However, the body portion 162 is preferably a continuous coatmg with no openings or gaps in its surface Such embodiment utilizing a continuous body portion 162 m combination with an insulating substrate 210 having a large window opening 220 therethrough is illustrated m Fig 12 Body portion 162 has a thickness between 0 1 mil (0 0025 mm) and 7 mil (0 18 mm), preferably between about 0 1 mil (0 0025 mm) and 2 mil (0 05 mm) When a continuous body 162 is employed for partition coating 60 (Fig 12) it may be possible to eliminate dielectnc coating 50 But the inclusion of dielectnc coatmg 50 is nevertheless very desirable because it provides additional electncal insulation between conductive coating 40 and cell casing 80 and also helps to prevent any residual KOH on the cell casing or caustic vapors generated by the cell from penetrating into conductive coating 40 and thermochromic coatmg 12 As illustrated in Fig 12 end portions 164a and 164b may of the same design and structure as previously desenbed with respect to the embodiment illustrated in Fig. 9 When the label/tester composite 11 is assembled and apphed to the cell casmg. air trapped within window 220 serves to thermally insulate the side of conductive coating 40 closest to the insulating substrate 210 The entrapped air causes the opposite side of conductive coating 17 Printed from Mimosa WO 97/29523 PCT/US96/18854 40 and thermochromic coating 12 in heat communication therewith to reach a higher temperature when the tester is activated than if no window or other openings were employed in substrate 210 A pattern of small openings in insulating substrate 210 could be used to provide air insulation instead of or all or part of window 220 For example, window 220 could be made smaller and additional openings made m substrate 210 around or in the vicinity of the window However, the substrate material formmg the pattern of small openings in msulatmg substrate 210 tends to transfer some heat or reflect light and thereby interferes with the appearance of the thermochromic display when the tester is activated That is, a pattern of small openings m substrate 210 tends to show through the display area when the tester is activated Thus, the best effect is achieved when a single large wmdow 220 is employed in insulating substrate 210 over the heat active portion of conductive coating 40 Also, it has been determined that a single large window 220 can provide the required degree of thermal insulation from air trapped therem making it unnecessary to have additional openings in substrate 210 A depth of between about 2 and 12 mil (0 05 and 0 3 mm), preferably between 4 and 7 mil (0 1 and 0 18 mm) foT window 220 has been determined to satisfactorily provide the required thermal insulation Such range is sufficiently low that it does not require any adjustment m the cell casing diameter for commercial alkaline cells In the embodiment shown in Fig 12 window 220 may have a typical dimension 20mm x 1 5mm x 0 15mm There is a thin adhesive coating 215, for example, of thickness between about 0 1 and 0 3 mil (0 0025 and 0 075 mm) between insulating substrate 210 and partition coating 60 bonding substrate 210 to partition coating 60 During assembly the adhesive coating 215 (Fig 12) may conveniently be apphed directly onto body pomon 162 of pamtion coating 60 after coatmg 60 is apphed over dielectnc coatmg 50 The adhesive may be appbed to body portion 162 in a continuous or discontinuous coatmg, for example in the form of dots or lines which may be regularly or irregularly spaced Adhesive 215, for example, may be apphed over portion 162 of coatmg 60 as a senes of closely spaced horizontal or vertical parallel lines In this manner somewhat less adhesive can be employed than if a continuous coatmg were used Substrate 210 is apphed to adhere to the adhesive coated pomon 162 of partition coating 60 and with wmdow 220 aligned over the heat generatmg portion (140c, and 140c2) of conductive coating 60 A portion of the adhesive coatmg 215 on body 162 may underlie the wmdow 220 but it does not enter the window volume Alternatively, adhesive 215 may be apphed directly to a surface of insulatmg substrate 210 which in turn may be apphed to adhere to body portion 162 of partition coatmg 60 18 Printed from Mimosa PCTYUS96/18854 Adhesive 215 does not require high bondmg strength and can be selected from wide range of heat resistant adhesives Preferably adhesive 215 is a U V (ultraviolet light) curable pressure sensitive adhesive A suitable adhesive of this type is available in a prepolymer liquid mixture under the trade designation Deco-Rad 7024 U V curable adhesive from Deco-Chem Co , Mishawaka, Indiana This prepolymer liquid may be apphed to partition body 162 by conventional printing methods, for example, by flexographic printing and then subjected to ultraviolet light to cure the coating After substrate 210 is bonded to partition body 162, tester/label composite 11 may then be apphed to cell casing 80 with ends 164a and 164b heat shrunk over cell shoulders 130 and 135, respectively, in the manner described with reference to the previous embodiments In another preferred embodiment shown in Figs 14-17 an aperture 310 (Figs 14 and 15) may be made m the insulatmg substrate 210 Aperture 310 extends through partition coating 60 and dielectnc coating 50 as shown in Fig. 15 Aperture 310 may be of circular, oblong, or polygonal shape, preferably of circular shape having a diameter between about 0 065 and 0 094 niches (1 65 and 2 39 mm) In such embodiment the conductive finders 143a shown in the previous embodiment (Fig 12) have been eliminated at the positive end of conductive coating 40 Instead the positive end 343 of conductive coating 40 as well as end 365 of underlying partition coatmg 60 may be straight edges as illustrated in Fig 15 Insulating substrate 210, partition coatmg 60 and dielectnc coating 50 all with aperture 310 therethrough are shown in assembled tonn in Fig 16 These lavers form a portion of the assembled label/tester composite 13 illustrated schematically in Fig 14 The remaining coatings and substrates shown m Fig 14 may be of same composition and structure as desenbed m the previous embodiments (In general the coatings and substrates shown m Figs 14-17 having the same reference numbers as above discussed with respect to any of the preceding embodiments may be of the same composition and apphed by the same methods of printing as described m the foregoing.) Optionally, if desired, composite 13 (Fig 14) may include a protective coating between thermochromic coating 12 and adhesive 20 Such coating, for example, may be of the same composition as partition coatmg 60, and can provide thermochromic coatmg 12 with additional protection against chemical attack by trace chemicals such as potassium hydroxide which can appear on the surface of casing 80 19 Printed from Mimosa End 360 of partition coating 60 may extend sufficiently to cover a portion of spaces "n" between conductive fingers 142b and 143b when the coatings are overlayed as shown in Fig 16 Additionally, the portion of partition coating 60 which underlies conductive fingers 142b and 143b can advantageously be of the configurations previously described (Figs 3, 9 or 12) or preferably may be m the form of a plurality of ribs or fingers 366b (366b, - 366b,) which jut out from edge 360 of partition coating 60 as illustrated in Figs 15 and 16 One or more nbs, e g 366b„ may jut out at nght angles to end 360 and several, e g , 366b, and 366b3 may form other angles with end 360 Such plurality of nbs, typically 5 to 10 ribs, each preferably having a thickness between about 0 1 mil (0 0025 mm) and 2 0 mils (0 05 mm) keep conductive fingers 143b sufficiently spaced from cell terminal 115i (Fig 17) to prevent inadvertent contact therewith when composite 13 is applied to the cell Yet the spaces between nbs 366b are sufficiently large to allow conductive fingers 142b and 143b to be pushed theretrough when manual pressure is apphed Advantageously, the spaces between ribs 366b are between about 0 5 and 2 5 mm wide, and each of the conductive fingers 142b and 143b are between about 1 0 and 2 0 mm wide, with spaces "n" therebetween between about 0 5 and 2 0 ram Tester/label composite 13 is apphed to cell 70 as illustrated m Fig 17 by wrapping it around the cell casmg 80 After composite 13 is wrapped around the cell heal is apphed to the label to shrink edges 120 and 125 over cell shoulders 130 and 135, respectively In so doing fingers 142b and 143b of conductive coatmg 40 and fingers 366b of partition coating 60 shrink evenly over cell shoulder 130 However, as shown in Fig 17 conductive coatmg end 343 or pamtion coatmg end 365 does not extend up to and over cell shoulder 135 Instead conductive coating end 343 and pamtion coating end 365 may be positioned over the cell casing body 80 and will remain in such position even after heat is apphed to shrink the label edges 120 and 125 over shoulders 130 and 135, respectively Thus, the only portion of composite 13 which becomes heat shrunk over cell shoulder 135 is label edge 125 which does not contam any portion of the testei After the tester/label composite 13 is applied to the cell the tester may be activated at any time by simultaneously depressing both the region of composite 13 over aperture 310 and the region of composite 13 over conductive fingers 142b and 143b As manual pressure is applied to composite 13 in the region of the composite immediately over aperture 310, a portion of Printed from Mimosa WO 97/29523 PCT/US96/18854 conductive coating 40 is pushed through aperture 310 and contacts cell casing 80 which in turn may be m electncal contact with the positive terminal 115 of a conventional alkaline cell As manual pressure is apphed over conductive fingers 142b and 143b at the opposite end of the tester, a portion of these conductive fingers is pushed through the spaces between underlying nbs 366b (366b, - 366b4) of partition coating 60 until it contacts cell surface llOi m electncal contact with negative terminal 110 Once the ends of conductive coating 40 become manually connected to the cell terminals current flows through conductive coating 40 thus causing heating which in turn causes a change in clanty or color in thermochromic layer 12 The strength of the cell (e g, good or weak) may be determined as previously desenbed depending on the region along the length of thermochromic layer 12 which has changed in clanty or color While the above desenbed embodiment is preferred, it will be appreciated that it is possible to permanently connect conductive fingers 142b and 143b to cell terminal 115 This may be achieved, for example, using conductive adhesive to bond the conductive fingers directly to conduaive surface 11 Oi or other surface in electncal contact with terminal 110 In such embodiment the underlying nbs 366 (e g nbs 366b, - 366b4) protruding from pamtion coating 60 (Fig 15) may be eliminated In order to activate the tester, the user then need only apply manual pressure to composite 13 in the region of the composite immediately over aperture 310 to cause a portion of conductive coating 40 to be pushed therethrough until it contacts casing 80 or other surface in electncal contact with the cell's opposite terminal 115 Although the present invention has been desenbed with reference to specific embodiments and matenal« it should be understood that modification to these embodiments as well as substitiits materials are possible For example, having desenbed the desired performance uiiaractenstics of the adhesive coating 20, it may become apparent to those skilled in the art that alternatives to the preferred pressure sensitive adhesives desenbed herein are possible Also, although preferred specific matenalshave been desenbed for the electncally and thermally insulating layers, it should be recognized that substitute matenals within the concept of the invention are possible Accordingly, the present invention is not intended to be limited to the specific embodiments and matenals desenbed herein, but is defined by the claims and equivalent thereof 21 Printed from Mimosa

Claims (23)

1. WO 97/29523 PCT/US96/18854 WHAT IS CLAIMED IS 1 In combination, an electrochemical cell and a label/tester composite, said cell comprising positive and negative terminals and a metal housing, a portion of said metal housing forming one of said terminals, said metal housing having a cylindrical wall with first and second shoulders at respective ends thereof, said label/tester composite being attached to the cell housing, said composite including a film around said housing, said film having a thcrmochromic matenal disposed on the side of the film facing said housing, an electncally conductive matenal in thermal contact with the thcrmochromic matenal, said conductive matenal being between said thermochromic matenal and said housing, and means for thermally insulating said conductive matenal from the cell housing, wherein said insulating means compnses a substantially electncally nonconductive matenal, and wherein said label/tester composite comprises means for enabling at least one end of the composite to be heat shrunk evenly over one of said cell shoulders, said means for at least one end of the composite to be heat shrunk evenly over one of said shoulders compnses at least two conductive fingers protruding from said conductive matenal, said composite further compnsmg a partition coating between said conductive matenal and said electncally nonconductive matenal, wherein a portion of said partition coating forms a plurality of protruding nbs, wherein said conductive fingers rest on said nbs, wherein said nbs define therebetween a plurality of cavities through which said conductive fingers may be manually pushed in order to electncally contact said conductive fingers with one of said terminals

2. 2 The combination of clatm 1 wherein said electncally nonconductive matenal has an opening therethrough throagh which a pomon of the conductive matenal may be manually pushed to electncally contact said pomon of the conductive matenal with the cell housing

3. 3 The combination of claim 2 wherein the tester is activatable by exemng manual pressure over both said conductive fingers resting on said nbs and said portion of the conductive material over said opening and wherein said tester is deactivated when said manual pressure is removed

4. 4 In combination, an electrochemical cell and a label/tester composite, said cell compnsmg positive and negative terminals and a metal housing, said label/tester composite bemg 22 Printed from Mimosa WO 97/29523 PCT/US96/18854 attached to the cell housing, a portion of said housing forming one of said terminals, said composite including a film around said housing, said film having a thermochromic material disposed thereon, an electncally conductive matenal in thermal contact with the thermochromic matenal, said conductive matenal being between said thermochromic matenal and said housing, wherein a pomon of said conductive matenal is capable of generatmg sufficient heat when electncally connected to the terminals of said cell when undischarged to cause a change in appearance in said thermochromic matenal, said composite further compnsmg means for thermally insulating said conductive matenal from the cell housing, said means compnsmg a first opening m a substantially electncally nonconductive matenal, and said first opening being of sufficient size to equal at least 40% of the surface area of one side of said heat generating pomon of said conductive matenal, said electncaUy nonconductive matenal having a second opening therethrough wherein said second opening is spaced apart from said first opening whereby the tester may be activated by pushing a pomon of the conductive matenal through said second opening to electncally contact said pomon of the conductive matenal with a pomon of the cell housing.

5. 5 The combination of claim 4 wherein said first opening in said electncally nonconductive matenal is an elongated slot having a smaller width than length and aligned in relation to the cell so that its width is substantially ui the circumferential direction of the cell housing

6. 6 The combination of claim 4 wherein said electncaUy nonconductive matenal is of sufficient thickness to provide thermal insulation from air trapped m said first opening

7. 7 The combination of claim 4 wherein the cell is cylmdncal and the thickness of said electncally nonconductive matenal and the width of said first opening are predetermined so that no portion of the label/tester composite excluswe of said electncaUy nonconductive matenal contacts the ceU housing through said first opening when the composite is attached to the cell

8. 8 The combination of claim 4 wherein said electncally nonconductive matenal has a volume resistivity greater than about 2 7x10° ohm-cm and a thermal conductivity less than about 10 watt m1 K"1 23 Printed from Mimosa

9. 9 The combination of claim 8 wherein the thickness of said electncally nonconductrve material is between about 2 mils and 12 mils (0 05 mm and 0 3 mm)

10. 10 The combination of claim 8 wherein said first opening in the electncally nonconductive matenal covers an area of at least 60% of the surface area of one side of said heat generating portion of said conductive matenal

11. 11 The combination of claim 8 wherein saVd electncally nonconductive matenal is t selected from the group consisting of paper, plastic film, polymenc foam and any combination 1 i thereof

12. 12 The combination of claim 8 wherein said electncally nonconductive matenal comprises papei

13. 13 The combination of claim 4 wherein the metal housing of said cell has a cylindrical wall with first and second shoulders at respective ends thereof^ and wherein said label/tester composite comprises means for enabling at least one end of the composite to be"

14. 14 The combination of claim 1 3 "wherein said means for said at least one end of the composite to be heat shrunk evenly compnses at least two conductive fingers protruding from said conductive matenal

15. 15 The combination of claim 14 farther compnsmg a partition coating between said conductive matenal and said electncally nonconductrve matenal

16. 16 The combination of claim 15 wherein a portion of said partition coating covers said first opening in said electncally nonconductive matenal and wherein said portion of the partition coating covering said first opening is a continuous coating having no gaps in its surface

17. 17 The combination of claim 15 wherein a portion of said partition coating forms a plurality of protruding ribs, wherein said conductive fingers rest on said nbs, wherein said ribs define therebetween a plurality of cavities through which said conductive fingers may be pushed 24 /? " - •- U i' @

18. 18 The combination of claim 4 wherein said film having the thermochromic matenal disposed thereon is a heat shnnkable film selected from the group consisting of unplasticized polvvmylchlonde and polypropylene

19. 19 The combination of claim 4 wherein said film is a heat shnnlable film printed with graphics on one side thereof and wheiein said film has pressure sensitive adhesive on the same side thereof as the graphics and said composite is attached to the cell bv wrapping it around the cell housing so that the adhesive contacts the housing

20. 20 The combination of claim 4 wherein the label/tester composite has a thickness of less than 100 mils (2 5 mm)

21. 21 The combination of claim 4 wherein s?id second opening in the electncal!}' nonconductive matenal has a diameter between about 1 6 and 2 4 mm

22. 22 The combination of claim 17 wherein at least one of said cavities defined by said nbs has a depth of between about 0 1 mil (0 0025 mm) and 2 0 mil (0 05 mm)

23. 23 In combination, an electrochemical cell and a label/tester composite substantially as herein described with reference to figures 1 to 6 or figures 7 to 10 or figures 11 to 1 3 or figures 14 to 1 "7 of the accompanying drawings 25