Patent Publication Number: US-2022216575-A1

Title: Method for producing a battery and battery

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of application Ser. No. 14/896,293 entitled “A METHOD FOR PRODUCING A BATTERY AND BATTERY”, filed Jun. 13. 2014 which is a national phase application of PCT/EP2014/062429, entitled “BATTERY AND METHOD FOR PRODUCTING A BATTERY”, filed Jun. 13, 2014. 
    
    
     BACKGROUND 
     The invention relates to an accumulator having a plurality of electrode plates. The invention further relates to a method for manufacturing an accumulator. 
     The invention in particular relates to the field of lead-acid batteries as for example used for motor vehicle starter batteries. Such accumulators consist of a plurality of series-connected galvanic cells separated from one another by an electrically insulating partition. Each of the galvanic cells thereby comprises an electrode plate stack in the form of a block, in which negative and positive electrode plates are alternatingly arranged side by side. The individual electrode plates are connected together in parallel. To this end, the connecting lugs of electrode plates having the same polarity are connected together for example by a so-called battery cell connector (also referred to as a terminal connector) being molded thereon in a lug casting process. This process is described in e.g. DE 10 2009 014 116 B3 and DE 10 2007 022 246 A1. The battery cell connector is thereby placed from above onto the connecting lugs arranged at specific distances from one another and connected to same. 
     Because of the high currents of such accumulators and the potentially resultant high temperatures, the battery cell connector needs to be of relatively substantial design. The battery cell connector is usually made from lead such that its considerable structure is relatively heavy. In addition, the raw materials, particularly lead, are comparatively expensive. 
     The invention is thus based on the task of specifying a generic accumulator which is able to be more cost-effectively manufactured as well as being lighter. To be further specified is a corresponding method for manufacturing an accumulator by means of which lighter and more cost-effective accumulators can be produced. 
     This task is solved in accordance with claim  1  by an accumulator having a plurality of adjacently arranged electrode plates which form at least one electrode plate stack in the form of a block, whereby each electrode plate comprises a frame having a grid arranged therein and whereby at least the grid is filled with an active mass, and whereby each electrode plate comprises at least one connecting lug protruding beyond the frame, wherein the connecting lugs of same-polarity electrode plates are arranged adjacent to one another in a row, whereby the connecting lugs arranged adjacent each another in a row are materially bonded together electrically and mechanically into a connecting lug block by at least one weld or solder point arranged between the connecting lugs. The connecting lugs thereby fuse into the connecting lug block, whereby weld or solder points are formed between the connecting lugs. This fusing can be realized for example by electrode welding. 
     The invention thus surprisingly makes it possible to entirely eliminate the battery cell connector previously set onto the connecting lugs and instead electrically and mechanically connect the connecting lugs arranged adjacent each another in a row into a connecting lug block, and do so by means of at least one weld or solder point arranged between the connecting lugs. Forming the connecting lug block can furthermore ensure the accumulator has a high current-carrying capacity. Yet significantly less lead is required thereto than in the past since the material of the connecting lugs themselves is used to form the connecting lug block. Any gaps there might be between the connecting lugs can be filled by spacer shims inserted into same to join the connecting lugs into the connecting lug block during the course of welding or soldering. In so doing, the spacer shims do not necessarily have to fill the full width of the gap between the connecting lugs but can instead also be somewhat narrower. In the latter case, the connecting lugs can for example first be somewhat mechanically compressed by welding tongs pressed against the respective outer connecting lugs as part of a welding process and thereby deformed toward one another. The deformability of the connecting lugs allows compensating for certain intervening gaps. Depending on the thickness of the electrode plates, the connecting lug block can also potentially be produced entirely without the cited spacer shims by the connecting lugs being pressed together in line with the above-described principle and then directly welded or soldered to one another. 
     One advantageous feature of the connecting lug block can therefore encompass the absence of gaps between the connecting lugs in the connecting lug block. 
     The block-form electrode plate stack can in principle have any given block form, e.g. a prismatic form or a rectangular form. Frame refers to any type of frame used with electrode plates, both a circumferential frame consisting of an upper and a lower frame section as well as a left and a right frame section, as well as also a non-circumferential frame, e.g. a frame only having an upper and a lower frame section. 
     The invention enables not only optimizing the manufacturing process and thus the costs of an accumulator by the described economizing with respect to the lead which is not used due to omitting the battery cell connector, but it also streamlines the manufacturing process. Joining connecting lugs adjacently arranged in a row into a connecting lug block as described can in fact be realized in substantially easier and more reliable manner than molding a battery cell connector onto the upper edges of the connecting lugs. Moreover, forming the connecting lug block as described results in a sturdier accumulator and one which is immune to vibration. 
     In many cases, a connecting lug has the same thickness as an electrode plate frame. In addition, the grid arranged within the frame can in many cases also have the same thickness as the frame, although can also be of lesser thickness. However, other thickness ratios are also possible with electrode plates. One advantageous embodiment of the invention provides for the connecting lugs to have a greater thickness in at least one area provided for the forming of the connecting lug block than the frame of the electrode plate. This has the advantage of the greater thickness of the connecting lug completely or at least partially compensating for the above-cited gaps between the connecting lugs so that it is entirely possible in many cases for the connecting lugs to be directly connected into the connecting lug block without the previously cited “gap fillers” in the form of spacer shims. In its area of greater thickness, the connecting lug can be symmetrically or asymmetrically thickened relative to the grid or to the frame respectively. 
     According to one advantageous further development of the invention, the thickness of the connecting lug is on average twice as great at least in the area of the connecting lug block as the thickness of the electrode plate in the area of the frame after its completion with active mass and necessary coatings, e.g. papier mâché and/or a separator material. The thickened connecting lug enables being able to largely prevent gaps between the connecting lugs in alternating positive and negative electrode plates of substantially identical thickness. The connecting lug block can thus be produced easily and quickly by directly welding or soldering the connecting lugs together. 
     According to one advantageous further development of the invention, the connecting lugs are materially bonded to one another directly or by way of intermediary material layers arranged between two neighboring connecting lugs. This allows the connecting lug block to be easily and quickly produced by directly welding or soldering the connecting lugs together, hereby further reducing the accumulator&#39;s manufacturing costs. The above-cited spacer shims can for example be used as the intermediary material layers. 
     According to one advantageous further development of the invention, no terminal connector is attached to the end of a connecting lug opposite from the frame; i.e. no battery cell connector serving to connect the electrode plate stack to an adjacent electrode plate stack of another cell of the accumulator, nor a pole body of an external terminal of the accumulator. This can thereby maximize the reduction in lead and thus further optimize the accumulator&#39;s costs and weight. 
     According to one advantageous further development of the invention, a terminal connector serving to connect the electrode plate stack to an adjacent electrode plate stack of another cell of the accumulator or a pole body of an external terminal of the accumulator is materially bonded to the connecting lug block. Thus, as opposed to the prior art, it is advantageous for a terminal connector or a pole body to be connected to the connecting lug block and not to the external ends of the connecting lugs. Doing so thereby allows smaller and lighter terminal connectors/pole bodies to be used than is needed in the case of prior art accumulators. Hence, a terminal connector can for example simply be materially fixed laterally as an extension as it were of the connecting lug block. A pole body can be similarly connected to the connecting lug block, as will be described below referencing example embodiments. 
     The task initially cited above is further solved according to claim  7  by a method for manufacturing an accumulator in accordance with any one of the preceding claims which comprises the following features: 
     a) producing at least one electrode plate stack from a plurality of electrode plates by arranging same adjacent one another and forming a block, wherein connecting lugs of same-polarity electrode plates are arranged adjacent to one another in a row, 
     b) mechanically bonding the connecting lugs arranged adjacent each another in a row into a connecting lug block by producing at least one weld or solder point arranged between said connecting lugs. 
     This thus produces an accumulator having the advantages as described above, in particular low weight and more economical manufacturing costs. 
     According to one advantageous further development of the invention, the method comprises a material bonding of the connecting lug block to at least one terminal connector which serves to connect the electrode plate stack to an adjacent electrode plate stack of another cell of the accumulator, or at least one pole body of an external terminal of the accumulator. 
     According to one advantageous further development of the invention, the electrode plates are in each case produced with the frame, the area provided within the frame for the grid and the connecting lug in a casting process. Producing the electrode plates in a casting process allows a streamlined economical manufacture of large quantities of the electrode plates. A continuous casting process, which produces a continuous linear blank, is particularly advantageous. 
     As part of the casting process, the grid to be created in the frame can either be produced directly; i.e. by means of the mold employed, or a closed material area can first be produced which is then transformed into the desired grid shape in an expanded metal process as will be described below. The grid can then be subsequently filled with the active mass. 
     According to one advantageous further development of the invention, the casting process comprises the following: Producing a profiled linear blank in a casting process, whereby only by means of the process of casting the linear blank is a greater thickness formed on one or both sides in at least one of the areas which will ultimately form the frame and/or connecting lug than in areas which will ultimately form the grid. This has the advantage of the connecting lugs being able to be produced at the same time as the advantageous increased thickness at least in the area where same will be connected into the connecting lug block in a simple process and one that entails no additional costs. A specific synergy thereby arises between the inventive aspect to the joining of the connecting lugs into the connecting lug block and the described casting process since the casting process itself already allows a particularly economical manufacture of the electrode plates and also equally comprises the basis for particularly effective joining of the connecting lugs into the connecting lug block with no extra costs. 
     According to one advantageous further development of the invention, the grid is produced in an expanded metal process following the above-cited casting process, thereby further economizing the manufacture of the electrode plates. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following will reference drawings in describing the invention in greater detail based on example embodiments. 
       Shown are: 
         FIG. 1  the manufacturing of a linear blank; 
         FIG. 2  an electrode plate; 
         FIG. 3  a lead-acid battery; 
         FIG. 4  an isometric view of a block-shaped electrode plate stack; 
         FIG. 5  a side view of the upper region of an electrode plate; 
         FIG. 6  adjacently arranged electrode plates prior to the connecting lug block being formed; 
         FIG. 7  the electrode plates according to  FIG. 6  after the connecting lug block being formed: 
         FIGS. 8-11  connecting a terminal connector to the connecting lug block; 
         FIGS. 12-15  connecting a pole body to the connecting lug block; 
         FIG. 16  adjacently arranged electrode plates prior to the connecting lug block being formed; and 
         FIG. 17  the electrode plates according to  FIG. 16  after the connecting lug block being formed. 
     
    
    
     DETAILED DESCRIPTION 
     The figures use the same reference numerals for comparable elements. 
       FIG. 1  shows a casting machine  1  which produces a linear blank  2  for electrode plates of lead-acid batteries in a continuous casting process. Lead is fed into the casting machine  1  on the input side (not shown). The casting machine  1  melts the lead and dispenses it on the output side over a profiled continuous mold as a linear blank  2  in the extruded form depicted in  FIG. 1 . The linear blank  2  can then be further processed as will be described below. 
     The distinctiveness to the casting machine  1  according to  FIG. 1  lies in the linear blank  2  being produced with a one-sided profile such that the blank  2  has different thicknesses D when viewed across width B. The linear blank  2  can also be produced with a profile on both sides such that the blank  2  has different thicknesses D on the two sides when viewed across width B. It can be recognizable in  FIG. 1  that the blank  2  emerging from the casting machine  1  has a substantially flat, smooth upper surface  8  and a profiled lower surface. The blank  2  exhibits regions  3 ,  5 ,  7  of greater thickness D than the regions  4 ,  6  in between. The regions  3 ,  5 ,  7  of greater thickness D protrude from the lower surface in relation to the regions  4 ,  6 . On the right,  FIG. 1  shows a detail of the linear blank  2  which has been turned 180° about its longitudinal axis so as to show the profiled lower surface, illustrating the one- sided profile structure of the linear blank  2  extending in the longitudinal direction L. 
     Depending on embodiment, the greater thickness D can also be limited to just the middle region  5 . 
     The casting machine  1  is thereby designed entirely without an extruding unit; i.e. it realizes solely a casting process without any extrusion step. 
     As will be described below, the regions  4 ,  6  of lesser thickness are transformed into the grid-like regions in an expanded metal process; the upper and lower frame elements as well as part of the contact lugs of the electrode plates being produced from the regions  3 ,  5 ,  7  of greater thickness. 
       FIG. 2  shows (in  FIG. 2 a   ) a plan view of an electrode plate  14  subsequent the expanded metal process. The electrode plate  14  is depicted to illustrate the relationship of the linear blank  2  to further electrode plates which are only partially reproduced at lower contrast or by means of broken lines. 
     As can be seen, the electrode plate  14  comprises an upper frame element  10  with a contact lug  11  molded thereon, a lower frame element  9 , and a grid-like region  12  extending between the upper and the lower frame element  9 ,  10 . To illustrate the relationship to the linear blank  2  according to  FIG. 1 , the corresponding  Fig. 1  reference numerals for the regions of the blank  2  are additionally included. 
     The respective arrows shown in  FIG. 2 a    pointing away from the upper frame element  10  and the lower frame element  9  indicate in which direction stretching force is applied to the electrode plates  14  in the expanded metal process. 
     Individual electrode plates  14  are separated from the electrode strip which emerges subsequent the expanded metal process by the individual electrode plates being cut off, as represented by the triangles  13  in  FIG. 2 a   . The contact lugs  11  are also correspondingly cut from the upper frame element  10  of the respective opposite electrode plate. The interstices  15  between the contact lugs  11  are produced by being punched out. 
       FIG. 2  shows (in  FIG. 2 b    on the right) a side view of the manufactured electrode plate  14 . from which the profile structure can be recognized. 
       FIG. 3  shows a lead-acid battery  30  having a plurality of electrode plates  14  of the above-described type. The lead-acid battery  30  comprises a cover part  33  having external terminals  31 ,  32 . The external terminals  31 ,  32  are connected to respective positive/negative electrode plates via the respective pole bodies. The connecting lugs  11  of the negative electrode plates  14  are connected together by a negative electrode connector  35 , the connecting lugs  11  of the positive electrode plates  14  are connected together by a positive electrode connector  36 . The electrode connectors  35 ,  36  are formed in prior art accumulators by battery cell connectors described at the outset. In the case of the inventive accumulator, connecting lug blocks are respectively formed at this point instead. 
     The lead-acid battery  30  comprises a lower housing part  34  in which the electrode plates  14  are disposed. The electrode plates  14  are provided with a pasty active masse  37 . Each electrode plate  14  including pasty active mass  37  is additionally encased in a separator material  38 . 
       FIG. 4  shows a plurality of electrode plates  14  adjacently arranged at alternating polarity and forming an electrode plate stack in the form of a block. It can be recognized that the connecting lugs  11  of electrodes having the same polarity are adjacently arranged in a row such that two rows  40 ,  41  of connecting lugs are formed. 
       FIG. 5  is a side view example of the upper region of an electrode plate  14  showing the upper frame section  10  with the grid  12  beginning beneath it. The connecting lug  11  is disposed above the frame section  10  and is formed with a greater thickness in the example according to  FIG. 5  than the frame or frame section  10  respectively.  FIG. 5  shows an example of a thickening of the connecting lug  11  at the upper region of said connecting lug which is formed symmetrically to frame  10 . The thickening can also be asymmetrical, in particular provided on one side, this being advantageous when the electrode plates are produced in a casting process. In this case, the upper thickened region of the connecting lug  11  is to be imagined as being shifted laterally to the left or right so as to result in a unilateral flush arrangement to the frames  9 ,  10 . Doing so has no effect on the principle of joining the connecting lugs as described below. 
     The thickening of the connecting lug  11  is so strongly pronounced in this case that this area bridges the distance to an adjacent connecting lug of like polarity. 
     Separators  38  can be seen to the left and right of the upper frame section  10  and the grid  12 . 
       FIG. 6  shows a side view of an electrode plate stack as follows from  FIG. 4 , wherein the respective electrode plates as formed as per  FIG. 5 . It can be seen that the thickened areas of the connecting lugs  11  of same-polarity electrode plates have virtually no interstices between them and thus directly join one another. Accordingly, the thickened areas of the connecting lugs of the electrode plates of opposite polarities which are further to the rear are not fully discernible per se, such that they are rendered in  FIG. 6  by dotted lines. 
     The adjacently arranged connecting lugs  11  are now materially bonded together by welding or soldering. This can for example be realized by means of the respective outer connecting lugs being pressed together in response to forces acting thereon as per the arrows depicted in  FIG. 6 , e.g. by means of welding tongs. This directly presses all the connecting lugs  11  against each other so as to also render electrically conductive connections. The welding current now only needs to be switched on in the welding tongs and the connecting lug block  70  as seen in  FIG. 7 , into which the individual connecting lugs  11  are now joined, forms shortly thereafter. 
     The following will describe exemplary possibilities for connecting terminal connectors (battery cell connectors) and pole bodies for external terminals, based on the arrangement with the connecting lug block  70  depicted in  FIG. 7 , whereby it is pointed out that  FIGS. 5 to 7  depict the electrode plates  14  and particularly the thickened areas of the connecting lugs  11  with exaggerated thicknesses for illustrative purposes.  FIGS. 8 to 15  depict the same arrangement as in  FIG. 7  although with more realistic proportions. 
     According to  FIG. 8 , as a result of the connecting lug block  70  now provided, a terminal connector  80  to now be newly designed is connected to the connecting lug block  70  by the terminal connector  80  being advanced to the connecting lug block  70  in the direction of the arrow depicted in  FIG. 8  and subsequently soldered or welded to the connecting lug block  70  in for example the same way as described with respect to  FIG. 6 . The extended connecting lug block  70  as depicted in  FIG. 9 , to which the terminal connector  80  is materially fixed, then results. 
     As can be seen, the terminal connector  80  according to  FIG. 8  exhibits an angled region of lesser material thickness. The terminal connector  80  is joined to the connecting lug block  70  in this angled region. As per  FIGS. 10 and 11 , a simple block-shaped terminal connector  100  can also be connected to the connecting lug block  70  in the same way. The connecting lug block  70  lengthened by the terminal connector  100  as depicted in  FIG. 11  then results. 
       FIGS. 12 to 15  show possibilities for connecting a pole body to the connecting lug block  70 . Such a pole body serves to establish the electrical contact to an external terminal  31 ,  32  of the accumulator  30 . The terminal  31 ,  32  is then positioned on the pole body and connected thereto by welding or soldering. 
     In one embodiment according to  FIG. 12 , a solder preform  120  is placed on the connecting lug block  70 . The solder preform  120  is for example of conical shape so as to produce a conical pole body. Liquefied lead  121  is now introduced into the solder preform  120 . The pole body being created is then “high-soldered” so to speak; i.e. filled with liquefied lead  121  until the solder preform  120  reaches the desired height for the pole body.  FIG. 13  shows the resulting high-soldered pole body, namely a pole body  130  built atop the connecting lug block  70 . Such a method has the advantage of the pole body  130  having a very secure hold on the connecting lug block and particularly offering greater stability and better current derivative values than the prior art solutions. 
       FIG. 14  shows a possibility for soldering or welding a prefabricated pole body  140  onto the side of the connecting lug block  70 , as depicted by the arrow in  FIG. 14 . The structure as depicted in  FIG. 15  with a pole body  140  materially coupled to the connecting lug block  70  then results. 
       FIGS. 16 and 17  depict an alternative formation of the connecting lug block  70 .  FIG. 16  starts again proceeds from an arrangement as per  FIG. 6 , although with the difference that electrode plates are provided in which the connecting lugs  11  are not thickened but have for example the same thickness as the frame  9 ,  10 . Interstices thereby result between adjacent connecting lugs. These interstices are bridged by intermediary material layers  160  inserted in between them, e.g. in the form of spacer shims which can be made of lead. The intermediary material layers  160  can initially be clamped between the connecting lugs  11 , for example. The procedure of welding or soldering the connecting lugs  11  into the connecting lug block  70  described above with reference to  FIG. 6  follows thereafter, whereby the intermediary material layers  160  can also be soldered or welded at the same time and thereby also become a component of the connecting lug block  70 , as can be seen in  FIG. 17 .