Abstract:
A battery cell manufacturing apparatus comprises a vacuum indexing conveyor for vertically suspending an anode material web, wherein a die punch is used to form a discrete anode from the anode material web. A pick and place mechanism is operable with the die punch for positioning the discrete anode between first and second separator webs for subsequent lamination. A laminator vertically receives the separator webs suspended for longitudinally extending them a force of gravity for smoothing out web surfaces adjacent the discrete anode carried therebetween prior to lamination of the separator webs to the discrete anode. A cathode assembly section includes a vacuum conveyor for guiding cathode material webs and vertically suspending them for die punching discrete cathodes which are then placed onto exposed outside surfaces of the vertically suspended separator webs in alignment with the anode laminated therewith. The discrete cathodes are then laminated to the vertically suspended separator webs for forming a laminated battery cell, which webs are then cut to form a discrete battery cell.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority from and is a national phase entry application for international application No. PCT/US00/14446, which has a priority date of May 25, 1999. This application additionally claims priority from co-pending U.S. provisional application Ser. No. 60/228,220 which was filed on Aug. 25, 2000. All referenced priority applications are incorporated herein by reference in their entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to fabrication of flat battery electrodes (cathodes and anodes), and, in particular, to the fabrication of the electrodes from continuous webs, applying them to a separator material, and laminating the electrodes and separators to form discrete battery cells.  
         BACKGROUND OF THE INVENTION  
         [0003]    The present invention relates to Polymer Lithium Ion (PLI) battery technology as described, by way of example, with reference to U.S. Pat. No. 5,470,357 to Schmutz et al. for a “Method Of Making A Laminated Lithium-Ion Rechargeable Battery Cell,” owned by Bell Communications Research, Inc. (Bellcore). The present invention, however, is not restricted to Bellcore-type technology, and can be applied to many other battery technologies. However, the Bellcore example is useful and is widely known in the industry.  
           [0004]    Those of skill in the art are aware of the chemistry of the anode and cathode electrodes, and the chemical composition of the separator materials, along with required process steps. Typically, a lamination process is performed by a pressing of electrode elements between flat plates at elevated temperature, or through calendering rollers at elevated temperature.  
           [0005]    Those skilled in the art have made a multitude of attempts at developing reliable manufacturing systems for the PLI battery technology, but results have had design drawbacks that have not produced the production throughput, yields, and performance reproducibility desired. Typically, electrode dimensions and separator dimensions are such to provide an edge to edge stack up capability. In practice, however, it has been demonstrated that this is not practicable.  
           [0006]    Further, electrodes are typically manufactured by coating a web with an electrochemical material. The web is generally made from an a thin expanded metal mesh, either copper or aluminum. Once the electrodes are cut from this web there remains exposed metal around the edges of the electrodes. If metallic filaments are not cleanly cut, they form burrs. Once a stack up of electrode elements is made and pressed together, these burrs can contact each other and form an electronically shorted cell. There is a need to have the separator extend beyond the dimensions of the electrodes (a nominal 1 mm, by way of example) to provide an electrically insulating protection from any burrs that might form. Poor cutting tools and techniques that form substantial burrs will not be corrected by this improvement.  
           [0007]    By way of further example, it has been reported in the art that crystalline growth (dendrites) can occur at an edge interface as the battery is charged and discharged. Since these crystals are salts of the electrolyte and electrode chemistry, they are conductive, and therefore, cell short circuits can occur. Having the separator material extend outside of the electrodes, and once laminated, sealing the anode therebetween, removes this failure mode from the battery.  
           [0008]    Consequently, assembly machine designs that produce cells with web materials being laminated in a continuous fashion and having the finished cell cut from the laminate without the extended separator, are no longer considered for this manufacturing application.  
           [0009]    Therefore, several concepts that considered the extended separator were developed. These were basically divided into two efforts. By way of example, a first effort produced discrete anodes, cathodes, and separator parts, stacking one atop the other with fixturing means (one embodiment featured a fine mist spray of adhesive material), then delivering the stack to lamination. A second effort produced discrete electrodes, applied heat to a separator web to energize the surface of the separator (make it “tacky or “sticky”), and applied the electrode to this heated web, eventually forming a stacked up cell, then delivered the stack to lamination.  
           [0010]    Both approaches exhibited problems in execution. The first effort was difficult as the separator material is extremely thin (typically 0.001″) and has no rigidity, so cutting and handling techniques are quite demanding. In addition, the necessity to spray on fixturing adhesive incurs the difficulties of maintaining repeatable dispensing, machine cleanliness, operator safety issues of fumes in the environment, and the necessity to remove evaporable materials in the adhesive from the assembled cell prior to further processing steps, as these materials can adversely effect cell performance.  
           [0011]    The second effort was a much improved process, but was typically executed with the web path in the horizontal plane. This made web tracking, web flatness, and web tensioning difficult to achieve.  
           [0012]    While the Bellcore patent teaches the use of both flat plate lamination and calender roll lamination, the preponderance of effort has been spent on roll lamination. There are several factors that adversely affect roll lamination from typically being a reliable manufacturing process. By way of example, as the web or stack up of cell materials enter the rolls, pressure is applied. The pressure is a function of the thickness of the introduced materials relative to the gap setting of the rolls. Since coating thicknesses of the electrode materials can vary, the applied lamination pressure will vary, and if the materials stack up, height becomes less than the minimum gap setting, no lamination will occur. As the web flows through the rolls, the material is squeezed together with entering material being thicker than exiting material. This extrusion effect can induce stresses in the web, mis-registration of cathode to anode to cathode, and wrinkles, by way of example, and, in the end, not produce uniform lamination of the layers. Typically, rollers are essentially in “instantaneous” contact with the web, a point contact, as the web flows through the rollers. As a result, temperatures of the rollers can be high relative to the temperature limits of the materials to attempt reliable bonding. Accurate and repeatable temperature measurement and temperature control of the contact surface of the rolls is difficult as the rolls are in continuous rotational motion.  
           [0013]    It is well known that for platen lamination with heated metal plates either in an oven or in a heated press, lamination uniformity suffers with the use of rigid press plates that cannot distribute forces evenly over single or multiple stacks of cell components of varying heights. Additionally, flat platen lamination has typically been applied to the entire stack of five layers of the cell, requiring heat to travel through the parts to reach the anode, thus inducing a temperature gradient across the stack, and requiring relatively higher temperatures than needed to attain the short lamination dwell times necessary for a manufacturing process.  
           [0014]    Further, there is a need to span the requirements for laboratory development (10 parts per minute), pilot production lines (50 ppm), and fully automated high speed manufacturing systems (150 ppm and up) in a cost effective and reliable manner. The present invention satisfies this and the aforementioned needs.  
         SUMMARY OF THE INVENTION  
         [0015]    In view of the foregoing background, it is therefore an object of this invention to provide an apparatus and method for preparing battery electrodes with minimum metallic burrs. It is further an object to mechanically fixture the electrodes to a separator without adhesives or thermal distortion for fully laminating the layers to provide highly repeatable stacking tolerances, uniform lamination temperatures and pressures using short lamination dwell times. It is yet another object to minimize waste (scrap) of the electrode and separator materials.  
           [0016]    These and other objects, advantages, and features of the present invention are provided by a manufacturing apparatus comprising a first conveyor for vertically suspending a first electrode material web, a first shaper for forming a first discrete electrode from the first electrode material web, and means operable with the first shaper for positioning the first discrete electrode proximate a separator web. A first laminator is provided for laminating the separator web to the first discrete electrode for forming a first laminated electrode carried by the separator web. The first laminator vertically receives the separator web vertically suspended for longitudinally extending the separator web by a force of gravity for smoothing out web surfaces adjacent the first discrete electrode carried thereby prior to lamination of the separator web to the first discrete electrode. A second conveyor vertically suspends a second electrode material web for a second shaper to form a second discrete electrode from the second electrode material web. Positioning means positions the second discrete electrode onto an exposed surface of the vertically suspended separator web, wherein the second discrete electrode is in alignment with the first laminated electrode carried thereby. A second laminator laminates the second discrete electrode to the vertically suspended separator web for forming a laminated battery cell carried thereby. The second laminator is operable with the positioning means for vertically receiving the separator web having the second discrete electrode carried thereon. A cutter is positioned for receiving the separator web having the second discrete electrode laminated thereto, and cuts the separator web for liberating a discrete battery cell from the separator.  
           [0017]    A method aspect of the invention includes manufacturing a battery cell by vertically suspending a first electrode material, an anode material web, by way of example, forming a discrete anode from the anode material web, juxtaposing the discrete anode with a separator, by way of the example herein describes, between first and second separator webs, vertically suspending the first and second separator webs for longitudinally extending the first and second separator webs by a force of gravity for smoothing out web surfaces adjacent the discrete anode carried therebetween, and laminating the first and second separator webs to the discrete anode for forming a laminated anode carried by the first and second separator webs. A second electrode material web, cathode webs by way of example as herein described, is vertically suspended for forming first and second discrete cathodes from the cathode material web. The first and second discrete cathodes are juxtaposed at exposed outside surfaces of the vertically suspended first and second separator webs, wherein the first and second cathodes are in alignment with the laminated anode carried therebetween. The first and second discrete cathodes are laminated to the vertically suspended first and second separator webs for forming a laminated battery cell carried by the first and second separator webs. The first and second separator webs are then cut for liberating a discrete battery cell therefrom.  
           [0018]    As herein described by way of example, a cathode comprises all electrode chemistry coated in a layer of copolymer material, laminated to an aluminum foil or mesh grid current collector. An anode comprises electrode chemistry also in a copolymer material laminated to a foil or mesh grid copper current collector. A separator comprises a thin coating of a polymer composition including vinylidene fluoride and hexafluoropropylene, and a plasticizer (dibutyl phthalate, by way of example), coated on a mylar release film.  
           [0019]    The electrode coating on the current collector does not cover the entire metallic surface, as clean, bare metal tabs are used as part of the electrode to allow electrical connection to the cells. Therefore, there is a need to maintain and support bare edges of the metallic web throughout the assembly process. The mesh materials are quite typically fragile. For one manufacturing process, as herein described by way of example, both the electrode materials and the separator materials are manufactured and wound onto a core, so that the materials can be dispensed into the assembly machine.  
           [0020]    As are herein described, features of the invention include a system and process for preparing flat battery electrodes from a continuous web, vacuum indexing of servo driven conveyors to accurately feed the web material, employing a vertical web path through all stations, and minimizing scrap on die punches. Zero clearance for a male/female die punch is achieved with zero clearance stripper plate for burr free electrode preparation. Heated vacuum chuck transfer mechanisms are used to heat electrodes, activate the separator surface, and fixture the electrode to the separator with no adhesive materials and no thermal distortion. Conformal flat platen lamination is vertically disposed and processed with controlled lamination parameters in multiple stages, separator to anode lamination with multiple hits, followed by cathode to separator lamination with multiple hits.  
           [0021]    Structure from Process  
           [0022]    Battery cell manufacturing costs are reduced by minimizing consumption of raw materials, by operating at rates in the order of 150 parts per minute, with a capability for higher rates. All cells are made within desired manufacturing tolerances with an edge guide and an inspection capability.  
           [0023]    The embodiment of the present invention herein described provides burr free die punching and separator dimensions that exceed typical electrode dimensions, both of which prevent internal cell short circuits. A lamination process provides for a uniform fusion of materials without damage or distortion, elimination of voids that can create varying electrical performance and cell failure, repeatable cell to cell electrical performance, and maximizes the materials ability to perform from an electrochemical perspective. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    One embodiment of the present invention, as well as alternate embodiments, are described by way of example with reference to the accompanying drawings in which:  
         [0025]    [0025]FIG. 1 is a schematic view of one embodiment of the present invention for producing a battery cell;  
         [0026]    [0026]FIG. 1A is a front elevation view of one embodiment of the present invention including an anode preparation phase thereof;  
         [0027]    [0027]FIG. 1B is a front elevation view of one embodiment of the present invention including a cathode preparation phase thereof;  
         [0028]    [0028]FIG. 1C is a front elevation view of one embodiment of the present invention including a battery cell discharge phase thereof;  
         [0029]    [0029]FIG. 2 is an exploded view of elements making up one battery cell;  
         [0030]    [0030]FIG. 3 is a web format for single electrode die punching;  
         [0031]    [0031]FIG. 4 is a web format for dual tabs out electrode die punching;  
         [0032]    [0032]FIG. 5 is a web format for dual tabs in electrode die punching;  
         [0033]    [0033]FIG. 6 is a top view of the electrode discharge vacuum indexing conveyor showing a dual tabs out electrode path with a six up grouping;  
         [0034]    [0034]FIG. 7 is a side view of an electrode preparation module;  
         [0035]    [0035]FIG. 8 is a side view of a reciprocating heated vacuum chuck electrode assembly station, and platen lamination station;  
         [0036]    [0036]FIG. 9 is a side view of a high speed turret indexing heated vacuum chuck electrode assembly station;  
         [0037]    [0037]FIGS. 10A, 10B, and  10 C illustrate partial top plan, right side elevation, and front elevation views of a guide controller and vacuum conveyor, respectively, employed in FIGS. 1A and 1B;  
         [0038]    [0038]FIGS. 11A, 11B, and  11 C illustrate front elevation, right side elevation, and top plan views of a die punch assembly, respectively, as employed in FIGS. 1A and 1B;  
         [0039]    [0039]FIGS. 12A, 12B, and  12 C illustrate top plan, side elevation, and front elevation views of a cathode die punch operable with the die punch assembly of FIG. 11A;  
         [0040]    [0040]FIG. 13A is an enlarged cross-section view of a web including anode and separator elements;  
         [0041]    [0041]FIG. 13B is an enlarged cross-section view of a web including anode and separator elements;  
         [0042]    [0042]FIGS. 14A, 14B, and  14 C are top plan, front elevation, and side elevation views of a laminator forming a part of the one embodiment of the present invention;  
         [0043]    [0043]FIG. 14D is a partial cross-section view taken through lines  7 D- 7 D of FIG. 7B;  
         [0044]    FIGS.  15 A,  15 B,and  15 C illustrate top plan, front elevation, and right side elevation views of one vacuum indexing conveyor embodiment, respectively, employed in FIGS. 1A, 1B, and  1 C. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0045]    The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which operating embodiments of the invention are shown by way of example. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.  
         [0046]    With reference initially to FIG. 1, one embodiment of the present invention may be described as an apparatus  10  for manufacturing a battery cell. By way of example, and with reference to FIG. 2, a graphic illustration of one assembly process includes a prepared cut to size anode electrode  12  (die cut from coated copper), placed between two continuous separator webs,  14 ,  16 . These three layers are then laminated as will be further described later in this section. Subsequently, two cathodes  18 ,  20  are prepared (die cut from coated aluminum), fixtured to the outside of the separator and anode laminate combination  22 , and then laminated in a heated press. A trim cut operation is performed, leaving a laminated cell  24  featuring a border  26  generally 1 mm of separator around the electrodes  18 ,  20 ,  22 , two aluminum bare metal tabs  28 ,  30  laid over the top of each other, and one copper bare metal tab  32  adjacent the aluminum tabs  28 ,  30 .  
         [0047]    With reference again to FIGS. 1 and 1A, the apparatus  10  may be described as including an anode preparation module  34 , having a web  36  of coated copper grid fed from a roll  38  of copper coated grid material into a loop  40 . The web  36  is fed vertically downward by a servo driven vacuum indexing conveyor  42  into a die punch assembly  44 . The die punch assembly  44  has been shown to be an effective cutter of the webs for forming the electrodes. However, it is expected that one of skill in the art will appreciate that alternate techniques such as water jets, laser beams, cutting blades, and the like may be used. The vertical configuration of the web feed system improves over previous system designs, enhancing web tracking accuracy, tracking stability, and feed (indexing) accuracy thru the apparatus  10  as there are no gravitational forces on horizontal web portions that typically create droop or index to index length variations. As will be further detailed later in this section with reference to FIGS.  12 A- 12 C for a cathode die punch, the die punch assembly  44  engages the web  36  with a stripper plate  45  to clamp it firmly and flatly in position, and a male tool die  47  punches through the web  36 , producing an electrode as earlier described with reference to FIG. 2. This electrode, the anode electrode  12  as herein described by way of example in the anode preparation module  34 , is then held by a vacuum and transferred from the die punch assembly  44  to a horizontal servo driven vacuum indexing conveyor  46 .  
         [0048]    As illustrated by way of example with reference to FIGS. 3 and 4, the electrodes, the anode  12 , or the cathodes  18 ,  20 , can be produced in a single stream  48  or optically in a double (2 up) stream  50  depending on machine speed and thus throughput requirements. FIG. 3 illustrates a typical “one up” die punch pattern  52  with no scrap between the electrodes. FIG. 4 illustrates a typical “two up” die punch pattern with tabs  32  outwardly facing, while FIG. 5 shows a “two up” pattern with tabs  32  inwardly facing. One embodiment of the present invention includes the electrode  12  being punched out on three sides only with the index distance of the web between punches being shorter then the width of the male  47 /female  49  die punch tooling. This provides for a minimized scrap discharge, reducing materials consumption and cost, while maintaining desired dimensional tolerances. Typically, a die punch may be such that metallic filaments (Cu, Al) within the coating  13 ,  19 ,  21  of the electrodes ( 12 ,  18 ,  20 ) can be stretched and bent over edge portions of the coating, thus creating burrs. These burrs can immediately short out the battery, or eventually cause the battery to fail. Burr free die punching is desired in order to have an economically and technically viable manufacturing process, one object of the present invention. The die punch utilized in the embodiment herein described for the present invention is based on “zero clearance” male and female punch die parts that have been machined, hardened, wire electro-discharge-machined (EDM&#39;d) and ground with standard industrial processes to produce the minimum clearance between the male and female parts, typically in the 0.0001 to 0.0002” range.  
         [0049]    In addition to the male  47 /female  49  die punch parts having close tolerance, a “zero clearance” stripper plate  45  is included. The function of the stripper plate  45  is to clamp the web materials tightly prior to the male tool die closing against the web and cutting it thru the female die  49 . By way of example, as the copper metal tends to be ductile, clearance between the clamping area and the female die can allow the filaments to stretch during the cut, again creating burrs. The present invention improves on known tooling efforts by using the zero clearance stripper plate  45  formed from brass. The openings in the stripper are machined (EDM&#39;d) slightly undersize of the male die punch dimensions. As will be later detailed, when assembled, the male die punch cuts thru the brass plate for forming a true zero clearance fitup. The embodiment herein described, by way of example, provides clean cutting and a long duration of burr free operation and improves on known methods employing coated expanded metal materials.  
         [0050]    The application of a vacuum conveying system to the electrode web material handling and electrodes further improves manufacturing capability. Past efforts to accurately feed web material thru a mechanical process have been hampered by the inherent mechanical and physical characteristics of the web, including, by way of example, lack of stiffness and lack of beam strength, it can be stretched and distorted when pulled under tension, and it can be compressed with clamping devices. As a cut to size electrode is extremely light and fragile, typical mechanical transport methods are difficult to apply. The vacuum conveyor  42  of the present invention accurately tracks the web  36  into and thru the die punch assembly  44 , regardless of web wrinkles, width variation and coating thickness variation, and also accurately delivers cut to size electrodes (anode or cathodes) as herein described. Fixturing is provided on tightly controlled centerlines to accomplish a desired electrode to electrode registration.  
         [0051]    By way of example, FIG. 6 illustrates one discharge pattern  56  of electrodes, anodes  12  by way of example, after placement on the servo driven vacuum indexing conveyor  46 . Depending on the desired apparatus  10  configuration, the electrodes  12  can be separated into groups as earlier described with reference to FIGS. 4 and 5. By way of example, two-up die punching at 75 cycles per minute produces 150 electrodes per minute, but placement of a group of 6 electrodes to the separator web then can occur at 25 cycles per minute allowing enough dwell time for the fixturing process.  
         [0052]    With reference again to FIGS. 1 and 1A, the separator webs  14 ,  16  of a coated mylar film are provided from rolls  58 ,  60  and indexed thru a fixturing and lamination station  62  with additional, yet optional, servo vacuum indexing conveyors  64 ,  66  or, alternatively, a servo pneumatic clamping drawoff system. The electrode  12  or pattern of electrodes are transferred from the discharge area of the electrode vacuum conveyor  46  by means of a hot vacuum chuck pick and place mechanism  68 , and pressed against the first separator web  14  at an anvil  70 . The electrode  12  is typically very thin, and materials of its construction typically highly thermally conductive and, as a result, it rapidly heats up but shows no tendency to become tacky or sticky, or deform at an elevated temperature. When pressed against the first separator web  14  (which is at ambient or slightly elevated from ambient temperature), it quickly energizes the surface of the separator coating and “tacks” to it. When the heated transfer head of the pick and place mechanism  68  returns, the electrode  12  remains fixtured to the first separator web  14 . This process improves on known processes, as no additional materials are needed, and no thermal distortion of the web  14  or electrode  12  occurs. The second separator web  16  is then introduced, now sandwiching the anode 12  between the webs  14 ,  16 . As indexed vertically downward, the webs  14 ,  16 , enter the lamination station  62 . The lamination station  62  allows the webs  14 ,  16  to be flat platen laminated a plurality of times to insure a complete and uniform lamination of the separator webs  14 ,  16  to the anode  12 , in a relatively short time (which time dictates machine throughput capability) and at a relatively low temperature.  
         [0053]    As will be described in further detail later in this section, the lamination station  62  of the embodiment herein described by way of example includes a heated transfer plate with controlled electric heating means, a chill plate to tie temperature boundary conditions to attain thermal uniformity, adjustable and programmable platen pressure provided through pneumatic cylinders, conformable platens, lamination platens with release characteristics. By laminating the webs  14 ,  16  in the vertical path, substantial improvements in release of the web from the lamination platens zero tension distortion of the heated web, and repeatable web tracking thru the lamination station is attached.  
         [0054]    At this stage of the manufacturing process, the laminated anode/separator web combination  22 , as earlier described with reference to FIG. 2, progresses into a free loop  72 , then on to a cathode assembly while cooling. There is no tension on the combination web  22  at this point, and it is supported by the mylar release films  15 ,  17  which extend to cover, confine and support the extended bare metal tab  32  earlier described with reference to FIG. 4.  
         [0055]    With reference again to FIGS. 1 and 1B, the combination web  22  then enters a cathode assembly section  74  of the apparatus  10 . The mylar release film  15 ,  17  is removed from the combination web  22  prior to cathode assembly using guide and stripping rollers  75  and mylar rewind spindles  76 . As the web  22  has been thru a thermal excursion and the free loop  72 , the anode laminate, separator anode combination  22  is precisely registered for guidance into the cathode assembly station  74 . Use of a laser photo-optical device  78  to read the position of the anode  12  and a typical feedback loop to the index mechanism accomplish registration for each group of anodes. With continued reference to FIGS. 1 and 1B, the cathode assembly section  74  includes two cathode preparation modules  80 ,  82  which present electrodes  18 ,  20  at two transfer points  84 ,  86  at the same time, having been formed from cathode webs  37 . Heated vacuum pick and place chucks  88 ,  90  then engage both sets of cathodes  18 ,  20 , heat them during the transfer as earlier described with reference to FIG. 1A for the anode preparation module  34  and press them onto the anode/separator web  22 .  
         [0056]    Adjustable differential pressure is used on the placement heads such that one head extends to a precision stop at the web surface, while the other head presses with lower (adjustable) fixturing pressure.  
         [0057]    Following the picking and placing of the cathodes  18 ,  20  onto the web  22 , mylar release films  92 ,  94  are introduced on both sides of the now assembled web identified by numeral  96 , prior to final lamination. This addition of mylar film material prevents exposed separator material from sticking to the lamination platens while covering, confining, and supporting the bare metal tabs  28 ,  30 ,  32  described earlier with reference to FIGS.  2 - 5 .  
         [0058]    The assembled and covered web identified by numeral  98  then enters a second lamination station  100  where the cathodes  18 ,  20  are fully laminated to the separators  14 ,  16 , again optionally over multiple indices using vacuum indexing conveyors  65 ,  67 . The multiple lamination steps within each of the lamination stations  62 ,  100  herein described by way of example, provide a substantial improvement over known configurations and provides for a full and uniform lamination with all desired process parameters controlled, and monitored. The lamination stations  62 ,  100  allow for desirable low temperatures at shortest dwell times when compared to those achievable in the art.  
         [0059]    After lamination at the lamination station  100 , the mylar film  94  is stripped from the assembled web  98  and rewound onto a rewind spindle  102 . The web now identified by numeral  104  enters a free loop  106  while cooling, and is engaged by a final servo driven vacuum indexing conveyor  108 , as illustrated with reference again to FIGS.  1  and  1 C. Another laser photo-optical device  79  registers the web  104  into the cutting station  110 , so that cutters can slice cell electrode groups apart along separator center lines. A slitting knife  111  disposed in the vertical axis cuts the web  108  along the direction of travel thereof, and one or multiple rotary knives crosscut the web for forming battery cells  24  once indexed into the cutting station  110 . A vacuum head pick and place mechanism  112  transfers the cut cells  24  onto a discharge vacuum conveyor  114 .  
         [0060]    With reference to FIG. 7, one embodiment of the present invention includes electrode preparation module  34  having powered spindle 116  upon which to mount the roll  38  of coated electrode material. The spindle  116  is actuated as material is drawn thru the apparatus  10  with high/low optical sensors into the loop  40  as earlier described with reference to FIG. 1. The web  36  of the anode  12  runs up over a roller  118  onto an adjustable flat guide  120 , then down over a roller  122 . The web  36  is held flat against the servo powered conveyor  42  by means of negative pressure created by a blower  124  pulling air thru the conveyor  42  for causing a vacuum which holds the web  36  flat against a belt, and secures it firmly during indexing so as to generally eliminate slippage. The web  36  then enters the die punch  44 , where a motor or cylinder powers a die punch tool. Cut to size electrodes are held by the vacuum pick and place head  68  operated by vacuum pump. As earlier described with reference to FIG. 1, the pick and place head  68  transfers the die cut electrodes  12  to the electrode vacuum discharge conveyor  46 . This conveyor  46  indexes the electrodes downstream to the transfer position for continued assembly of a battery cell.  
         [0061]    Depending on the desired system configuration reciprocating or continuous indexing transfer pick and place mechanisms  68  are employed. As illustrated, by way of example, with reference to FIG. 8, a reciprocating version of a heated vacuum transfer  128  includes a rotary drive  130  which swings the transfer mechanism back and forth thru a 90 degree arc. A pneumatic slide  132  extends and retracts the temperature controlled head  134  attached to the slide by means of a phenolic or other insulation material heat dam  136 , and chilled tool plate  138 . The transfer vacuum head  134  has a plurality of holes to engage the flat electrode  12  via a vacuum for removing it from the conveyor  46 .  
         [0062]    After moving thru 90 degree arc, the electrode  12  is hot (generally above room temperature), and the slide  132  extends to press the heated electrode  12  onto the vertically disposed separator/mylar web  36  supported by anvil  70 . The vacuum head retracts, leaving the electrode  12  stuck (but not laminated) to the separator  14 , as earlier described. The fixtured electrode and separator web  22  indexes thru the vacuum conveyor  64  or clamping drawoff as earlier described with reference to FIG. 1.  
         [0063]    As illustrated with reference to FIG. 9, one embodiment of the heated transfer pick and place mechanism  68  provides for continuous high speed operation (e.g.; 240 parts per minute and up). As time intervals between index advancing become short especially during high cyclic rates, a turret styled embodiment of mechanism  68 A permits time to heat the electrodes  12  sufficiently during intermediate cycles as it rotates clockwise, as herein described, by way of example, to get the electrodes to “tack” successfully to the separator web  14  which is supported by anvil  140 . The indexing turret mechanism  68 A is cam driven through 90 degree arcs indexing at four positions and includes four pneumatic slides  132 A-D. Each slide  132  includes similar heated vacuum heads as earlier described.  
         [0064]    With reference again to FIG. 8, one embodiment of the lamination station  62 ,  100 , earlier described with reference to FIG. 1, includes two independently temperature controlled platens  142 ,  144  mounted to ram driven presses  146 ,  148 . Depending on a desired apparatus embodiment, one or both platens will cycle for each index of the web  36 , with both platens will retract fully open during machine pauses or changeovers. Chill plates 150  on each press  146 ,  148  interface to the presses to stop thermal migration into the lamination elements and provide a boundary condition for the heat plate  142 ,  144  to assist in providing temperature uniformity. A heat dam (insulator) plate  152  isolates the heat plate  142 ,  144  from the chill plate  150  to minimize heat energy migrating into the apparatus  10  and to provide temperature uniformity. Heater plates  154  contain electrical heaters and temperature measuring (thermocouple/RTD) devices. Lamination platens  156  utilize thermally conductive metallic backing with elastomeric coating which conforms to the electrodes being laminated to generate uniform lamination pressures and temperatures over all the cells.  
         [0065]    The apparatus  10  above-described with reference to FIGS.  1 A- 1 C will herein be described in further detail. The anode preparation module  34  includes a web feed system having the web  36  of coated copper grid material fed from the roll  38  of anode web material into a loop  158 , then vertically down the servo driven vacuum indexing conveyor  42  into the die punch assembly  44 . As earlier described, the vertical configuration of the copper grid web  30  improves web tracking accuracy and stability, as well as feed advance (indexing) accuracy. There are no gravitational forces acting on horizontal web material to create droop or index to index length variations. With web material typically locking in firmness and thus susceptible to tension distortion, vertically suspending the web  36  permits gravity to hold a desirable smooth shape of the web, which is otherwise difficult when conveyed and processed in horizontal positions, as typically done in the art.  
         [0066]    As earlier described with reference to the known prior art, it is known that there is substantial difficulty with manufacturing of electrode materials to high tolerances required for the width and tracking of the chemical coating of anode metal mesh relative to the edges of the metal mesh. By way of example, mistracking or width variation will either cover the tab  32  (see FIG. 4) with opaque electrode coating or not cover enough of the mesh to provide for the desired battery cell performance. With reference again to FIG. 1A, to overcome such known alignment problems, the present invention incorporates an automated edge guide controller (EGC)  160 . The vacuum indexing conveyor  42  and its associated flat guide are mounted to a linear bearing wall  162  carried by a frame  164  of the apparatus  10 . The controller  160  is operated for advancing the web  36  downstream to the cutting area of the die punch  44  by a servo motor and ballscrew assembly  166  illustrated with reference to FIGS.  10 A- 10 C. Beam photo optical digital sensors  168  see through the open mesh  170  of the anode web  36  and are triggered by the opaque electrode coating  172 . Electronic feedback loops drive the servo motor assembly  166  to position the web  22  between the sensors, keeping the coating along a centerline  174  centered relative to the die punch assembly  44 .  
         [0067]    In an alternate embodiment, a vision system  176  is used on one side of the web or on both sides of the web. The vision system  176  views not only the expanded metal mesh, but perforated and opaque foils as well. A camera  178  within the vision system  176  tracks the width of the coating  172  as well as its position relative to the edge of the metal mesh  170  or foil, and the servo assembly  166  uses information therefrom to track the web  36 . In addition, the vision system  176  scans for other materials defects, such as bare spots (missing coating), web splices, by way of example, and allows the apparatus  10  to skip over that section of the material, and then resume normal operation. The amount of undesirable product is reduced, and apparatus downtime and operator intervention time required is also reduced.  
         [0068]    As earlier described with reference to FIGS. 1, 1A,  1 B,  11 A,  11 B, and  11 C, the die punch assembly  44  operates to form the electrodes  12 ,  18 ,  20 . By way of example, a cathode die punch  180  is illustrated with reference to FIGS. 12A, 12B, and  12 C. Except for the shape and layout, the anode and cathode punch are similar. The die punch  180  engages the web  36  (cathode web) with the stripper plate  45  to clamp the web firmly and flatly in position. The male tool die  47  punches through the web  36  producing a desired electrode shape which electrode is then held by a vacuum chuck and transferred using the pick and place mechanism  68  from the die punch assembly  44  to the horizontal servo driven vacuum indexing conveyor  46 .  
         [0069]    As earlier described, electrodes (anode and cathode) can be produced in a single stream or a double (2 up) stream depending on the desired machine speed and throughput requirements.  
         [0070]    In operation, one method of manufacturing includes the electrodes being punched out on three sides only where the index distance of the web between punches is shorter then the width of the male or female die punch tooling. This allows a minimized scrap discharge reducing materials consumption and cost, yet maintains dimensional tolerances.  
         [0071]    The die punch assembly  44  and die punch  180  operated therewith provides a “zero clearance” male and female punch and uses die parts that have been machined, hardened, wire electro discharge machined (EDM&#39;d) and ground with standard industrial processes to produce the minimum clearance between the male and female parts, typically in the 0.0001″ to 0.0002″ range. In addition to the male/female die elements having close tolerance, the present invention incorporates a “zero clearance” stripper plate  45 . The function of the stripper plate  45  is to clamp the web  36  tightly prior to the male die  47  closing against the web  36  and cutting it through the female die  49 . As the copper metal tends to be ductile, any clearance between the clamping area and the female die  49  may allow the grid metal filament to stretch during cutting and form burrs.  
         [0072]    In one embodiment of the punch assembly, the openings in the stripper plate  45  are wire EDM&#39;d slightly undersize of the male die  47  dimensions. When assembled, the male die  47  cuts through the brass, forming a true zero clearance fitup. The cleanest cutting and longest duration of burr free operation is assured and improves upon any method tested to date with the coated expanded metal materials.  
         [0073]    By way of example or operation, variations on materials characteristics extend to surface “tackiness”, and sticking of the web  36  to the die punch  180  including the stripper plate  45 . To avoid this, floatation air streams are used that are closely directed at the stripper plate  45  to web interface, as well as the web to female die interface. In addition, surface treatment techniques such as glass beading, and release coatings, such as electroless nickel may be employed.  
         [0074]    The apparatus  10  herein described with reference to FIGS.  1 A- 1 C, employs a vacuum conveying system for the electrode web material handling and electrodes which enhances the manufacturing process. Typical efforts to accurately feed the web material by means of a mechanical process have been hampered by inherent mechanical and physical characteristics of web material. Typically web material has no stiffness, no beam strength, can be stretched and distorted when pulled under tension, and can be compressed with clamping devices. As the cut to size electrode is extremely light and fragile, typical mechanical transport methods are difficult to apply. The vacuum conveying system accurately tracks the web into and through the die punch tool, regardless of web wrinkles, width variation and coating thickness variation, and also accurately delivers the cut to size parts to fixturing stations on tightly controlled centerlines to accomplish a desired electrode to electrode registration.  
         [0075]    With reference again to FIG. 6 one discharge pattern of discrete electrodes after placement on the servo driven vacuum indexing conveyor  46  is illustrated. Depending on a desired configuration, the electrodes can be separated into groups, e.g., two - up die punching at 75 cycles per minute produces 150 electrodes per minute, but placement of a group of 6 electrodes to the separator web then can occur at 25 cycles per minute allowing enough dwell time for the fixturing process, as earlier described. The scrap anode web  30  is pulled downward by gravity or optionally by a vacuum device  39 A.  
         [0076]    The separator web  14  is introduced from the roll  58  and indexed through fixturing and the lamination station  62  with the additional servo vacuum indexing conveyors  64 ,  66  as earlier described with reference to FIG. 1A. The electrode or pattern of electrodes are transferred from the discharge area of the die punch assembly  180  by the hot vacuum chuck pick and place mechanism  68 , and pressed against the separator  16  at the anvil  70  of a heated platform  184 . The electrode, as it is very thin, and the materials of its construction highly thermally conductive, rapidly heats up but shows no tendency to become tacky or sticky, or deform at elevated temperature. When the electrode is pressed against the separator web  16  (which is at ambient or slightly elevated from ambient temperature), it quickly energizes the surface of the separator web  16  and “tacks” to it. When the heated transfer head returns to a spaced position to the separated web, the electrode remains fixtured to the separator web  16 .  
         [0077]    The separator web  14  is then introduced, now sandwiching the electrode (anode) between the two separator webs  14 ,  16 . The sandwiched electrode web combination, illustrated by numeral  72  is advanced downstream through a loop  182  and to the vacuum indexing conveyor  66 , as illustrated with reference again to FIG. 1A.  
         [0078]    As illustrated with reference again to FIG. 1A, the separator web  16  is unwound from roll  60  and runs up and over the heated platform  184  underneath the electrode die punch pick and place mechanism  68 . As the separator web  16  heats, its surface becomes “tacky.” When the electrodes are removed from the die punch assembly  44  and applied to the heated separator web  16 , they remain fixtured thereto. Separator web tension is maintained in this application with an understanding that the mylar carrier shrinks under heat. This tension is maintained through the use of a dancer arm tension control  186  operable with the powered separator roll  60  in conjunction with the vacuum indexing discharge conveyor  46 . In such an embodiment, a heated pick and place station may not be employed. The other separator web  14  is introduced, again with a dancer tension control  187  system and the powered unwind roll  58 . The composite web of fixtured anodes to the first separator and the second separator flows through a drawoff system, including the loop  182 , and to the lamination station  62 .  
         [0079]    With reference again to FIG. 1A, a heated cross seal bar  168  is displaced above the first separator web  16 /anode/second separator web  14  while horizontal leading onto the electrode discharge conveyor  46 . The cross seal bar  188  seals the first separator web  16  to the second separator web  14  along locations  190  between the discrete anodes as illustrated with reference to FIG. 13A. This seal serves to secure the electrodes in place until they are fully laminated at the lamination station  62 . The electrodes maintain their centerline location and skewness with this process insuring reliable registration downstream.  
         [0080]    With reference again to FIG. 1A, the anode lamination station  62 , the first lamination process within the apparatus  10  herein described, allows the web  22  to be flat platen laminated three times over three indexes for providing a uniform lamination of the separator webs  14 ,  16  to the anode in a preferably short time, which provides for improved machine throughput capability and at desirably low temperatures. With reference to FIGS.  14 A- 14 D, each lamination station  62 ,  100  includes a heated transfer plate  192  with controlled electric heating means, a chill plate  194  operable with a heat dam  196  positioned between the chill plate  194  and transfer plate  192  to attain thermal uniformity at element boundaries. Adjustable and programmable platen pressure is provided via pneumatic cylinders  198 . Conformable platens with release characteristics are provided by the transfer plate. With lamination operable in a vertical attitude, as earlier described, a substantial improvement is realized in release of the web  22  from the lamination platens  192 , with zero tension distortion of the heated web, and repeatable web tracking through the lamination station. The lamination station  100  for the web  96  described earlier with reference to FIG. 1B is similar to that herein described for the lamination station  62 .  
         [0081]    The present invention provides a capability for properly laminating across a wide variety of materials. Lamination processing for the present invention includes multiple lamination sectors. By way of example, three separate pairs of plates  192  with three individual press ram cylinders 198  are herein described. By way of example, each plate  192 A,  192 B,  192 C is operable to laminate one array of electrodes (one index distance in the case of cellphone size batteries) or one large format (notebook/laptop) size battery. Each of the three lamination sectors  192 A,  192 B,  192 C has individual pressure control, pressure measurement and display to allow pressure monitoring in each lamination sub-station, and individual temperature control of each pair of plates. This “three hit” feature allows for a wide variety of lamination parameters, and maintains throughput at desirable manufacturing rates.  
         [0082]    It is known in the art that the formation of gas bubbles can be observed during the lamination process. Such is the case for the battery cell materials typically being laminated, and for the release of evaporables under applied heat. Elimination of the gas bubble formation is desired, as voids in the laminated web  22 ,  96  allow potential deposits of lithium metal to form, resulting in detrimental consequences to the battery performance and safety. By way of example, the embodiment of the present invention herein described includes the chill plate  194 C operable in the third lamination sector  192 C which removed any evidence of bubble formation in the lamination process described herein. In addition, the lamination process can be varied by using different styled lamination plates  192  such as conformable plates. By way of example, using one conformable plate  192  opposed by one hard flat plate has produced substantially improved results in lamination uniformity over a large area, a requirement for large area battery (notebook/laptop) styles. The present invention is not limited to three sectors as herein described by way of example, and it is expected that the number of sectors used will be expanded or reduced as necessary to address specific applications.  
         [0083]    At this stage of the manufacturing process, the now laminated anode and separator webs, the web  22  advances into the free loop  72 , then toward the cathode assembly. There is minimal tension on the web  22  at this point, and it is supported by the mylar release film which extends to cover, confine and support the extended bare metal tab  32 , as earlier described and as illustrated with reference to the partial enlarged cross-section view of FIG. 13.  
         [0084]    The web  22  then enters the cathode assembly section  74  of the apparatus, as illustrated again with reference to FIG. 1B. The mylar release film (or paper liner if employed) is removed from the web  22  prior to cathode assembly. The guide rollers  75  and rewind spindles  76  earlier described perform this function. As the web  22  has been through a thermal excursion and the free loop  72 , the anode laminate is now desirably and precisely registered into the cathode assembly section  74  using the laser photo-optical device  78  to read the position of the anode and provide a feedback loop to the index mechanism  65 ,  67  provide registration for each group of anodes.  
         [0085]    The cathode preparation modules  80 ,  82 , earlier described with reference to FIG. 1, present electrodes to two transfer points  84 ,  86  at the same time, as illustrated with reference to FIG. 1B. The heated vacuum chucks  88 ,  90 , including vacuum conveyor  65  with edge guides, then engage both sets of cathodes, heat them during the transfer as earlier described, and press them onto the anode/separator web  96 . Adjustable differential pressure is used on placement heads such that one head extends to a precision stop at the web surface, while the other head presses with lower (adjustable) fixturing pressure. Subsequent to this cathode assembly step, the mylar release films  92 ,  94  are introduced (or in the alternative, paper release liner) on both sides of the assembled web  98 , and prior to final lamination at the lamination station  100 . The mylar release film prevents the exposed separator material from sticking to the lamination platens and serves to cover, confine, and support the bare metal tabs. The assembled and covered web  98  then enters the second platen lamination station  100 . The cathodes are fully laminated to the separators over three sectors or indexes as earlier described. Again, the three lamination step (three hit) within each laminator configuration provides full and uniform lamination with process parameters controlled and monitored, with desirable temperatures at short dwell times.  
         [0086]    After lamination, the upper mylar film  94  is stripped from the assembled web  98  and rewound onto the rewind spindle  102 . The web  104  results and is illustrated in the partial enlarged cross-section view of FIG. 13A.  
         [0087]    As illustrated with reference to FIG. 1C, the web  104  advances downstream and enters the third free loop  106  and is then engaged by the final servo driven vacuum indexing conveyor  108 . A laser photo-optical device registers the web into the cutting station  110 , so that the cutters  111  can slice the cell group and separate them on the separator centerline. One embodiment of the present invention as herein described includes a slitting knife  111  carried in the vertical axis for cutting the web  104  along the direction of travel, and one or multiple rotary knives crosscut the cells once indexed into the cutting station. The vacuum head pick and place mechanism  112  transfers the discrete cells onto the discharge conveyor  114 , a vacuum conveyor as herein illustrated by way of example. Prior to cutting, the remaining mylar film  92  is removed and collected on a rewind roll  200 .  
         [0088]    In one preferred embodiment of the present invention, the “three hit” lamination module is used as above-described with reference to FIGS.  14 A- 14 D. As described, there is similar construction for each lamination substation in the module, with individual temperature control, pressure controls and monitors, and selectable lamination plates that can be 50, 60, 70 durometer coatings (by way of example) as well as Teflon Hardcoat aluminum. Substations are setup as heated modules or chilled modules, depending on the desired lamination process for the materials application.  
         [0089]    It is to be understood that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.