Abstract:
An inert material is included in the electrode assembling of a battery having a thickness which compensates for a difference in dimension of the electrode assembly when thinner electrodes are used to construct a battery having reduced capacity, to thereby be accommodated in a battery case of uniform dimension regardless of the electrical characteristics of the battery.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to electrochemical power cells and battery assemblies incorporating such power cells. Various embodiments of the present disclosure find particular application for use in a configuration of primary batteries used to power implantable medical devices. 
       BACKGROUND 
       [0002]    Electrochemical cells in the form of batteries are conventionally used to power many types of electronic devices, and are available in several forms, including, for example, cylindrical, button, pouch and prismatic cells. 
         [0003]    Prismatic cells, introduced in the early 1990s, are advantageously utilized in applications which require optimal use of space, and find application, for example, in serving as a power source for medical devices, such as Implantable Cardioverter Defibrillators (ICDs) and Cardiac Resynchronization Therapy Devices (CRT-Ds), which are implanted into a patient. 
         [0004]    Batteries are comprised of an arrangement of alternating cell subassemblies, each subassembly including a positive electrode (cathode), a negative electrode (anode) and a separator layer interposed therebetween and also optionally between adjacent subassemblies. The electrodes may take the form of planar conductive members optionally embodied as plates, wound conductive layers, or other configurations of conductive material. In some embodiments, the anode electrode(s) of one or more subassemblies are connected in parallel to a positive current collector, and the cathode electrode(s) thereof are connected in parallel to a negative current collector. This provides combined current delivering capacity of each of the subassemblies as surface areas of interfacing surfaces (interfacial areas) of the cathode electrode(s) and anode electrode(s) are effectively summed. The output voltage is that of the individual assemblies. The current delivering capability of the cell is thus proportional to the total interfacial area between the anode and cathode subassemblies, and can be controlled by varying the footprint of the interfacial areas, for example an interfacing area of plates in a cell stack. Alternatively, subassemblies are connected in series in which case a voltage delivered is the combined voltage of each of the subassemblies with the current delivering capability being that of a given one of individual subassemblies. Thus, the voltage and current characteristics of a battery may be varied. 
         [0005]    The capacity of a cell, which is a measure (typically in Amp-hr) of EMF potential chemically stored by the battery, is determined by the mass of active material contained in the battery, i.e., the cathode and anode material. The battery capacity represents the maximum amount of energy that can be extracted from the battery under certain specified conditions. Cell capacity is proportional to the total mass of the anode and cathode (with the appropriate coulombic balance between the two), and is determined as a function of the footprint of the interfacial area, the number of anode and cathode subassemblies, the number of plates in each subassembly, and the thickness of the anode and cathode plates. 
         [0006]    Depending on a resultant volume of the subassemblies, for example and not limitation, a stack thickness in a prismatic battery, in achieving a battery having desired power delivering capability and power capacity, either due to changes in the number of anode or cathode plates, the thickness of the anode or cathode plates, or the total number of anode and cathode subassemblies, an overall dimension of a battery of conventional design will vary, thereby requiring battery encasements of differing size configurations. 
         [0007]    In the field of medical implantable devices, considerable testing is required to assure that a given device meets appropriate standards for use in human beings. This is also true of the encasements of the devices, which must be constructed to ensure that the device is sufficiently well sealed and of sufficient structural integrity to implant in a person. Thus, it would be advantageous if a given encasement could be used for a variety of medical devices. However, power requirements of medical devices vary and with this variation so do the batteries vary in size. The present disclosure describes an improvement over these prior art technologies. 
         [0008]    An implantable medical device is typically designed such that the battery powering it has an operating life, which is based on the total energy capacity, less than a design life of the other components. This is important for device reliability, as the battery longevity can be predicted rather easily, and the patient and/or physician may they be given sufficient warning before it is time to replace the device by the device sensing the remaining energy of the battery. If the device were designed such that the battery could potentially outlast any of the other components, such a warning to the patient and/or physician might be difficult. 
         [0009]    Frequently a medical device will be produced in different models, all being assembled from the same primary components, but with each having a different set of features. Sometimes the different feature sets will consume the device battery capacity at substantially different rates (power), resulting in significant differences in the longevity of the different models. In those situations, the battery energy capacity needs to be chosen to deliver the desired longevity in the highest cases of power consumption. In extreme cases, the differences in longevity may be so great that it is desired to provide different battery capacities in the different models, so that the longevity of the battery in the longest lasting model will not exceed the design life of any of the other device components. It is also possible that the varying power consumption of different models may require batteries of different power capability. Typically when either of these situations occur, the different batteries occupy different volumes, requiring changes in the overall device mechanical design. As components are no longer shared between device models, component costs and device costs rise. As such, it is desirable to develop a family of batteries, all using the same outer case, but with varying power and capacity. 
       SUMMARY 
       [0010]    Various embodiments of a battery are provided which allow cells having different power capability and/or capacity to be housed in an envelope of uniform size and methods for producing same. Embodiments of a battery according to this disclosure are directed to a cell or cells comprised of an alternating assembly of anode and cathode plates with an electrolyte-containing separator interposed between the anode and cathode plates, having a configuration which allows a family of devices, for example medical devices implantable in a patient, which are constructed around standardized battery encasement, but which can have different power capability and/or capacity. The approach according to the various embodiments of this disclosure allows multiple types of batteries having different power supply characteristics, which fit within the same encasement, to be efficiently produced. 
         [0011]    Briefly stated, the above objectives are achieved by inclusion of an inert material insert or inserts in the electrode assembly having a thickness which compensates for the difference in height of the electrode assembly when thinner electrodes (anodes and cathodes) or a fewer number of electrodes are used to construct a battery having reduced capacity, to thereby be accommodated in a battery case of uniform height regardless of the power output characteristics of the battery. Optionally, the inert material having an appropriately selected thickness can also replace one or more of the separators. 
         [0012]    In accordance with an embodiment of this disclosure, at least one spacer comprised of inert material, conveniently in a general form of a plate, is placed at the top and/or bottom of the electrode assembly, used to maintain constant assembly dimensions between designs. 
         [0013]    In accordance with another embodiment of this disclosure, a battery includes at least two cell subassemblies each comprised of at least one anode and at least one cathode, and a separator interposed therebetween, and at least one spacer comprised of inert material is placed within the assembly of electrode plates between cell subassemblies comprising the battery to allow constant assembly dimensions regardless of battery electrical characteristics. 
         [0014]    In accordance with yet another embodiment of the present disclosure there is provided a method of producing a product line including electronics modules, respectively having power requirements differing from one another. A plurality of a common encasement having a battery compartment and an electronics compartment are produced. The electronics compartment is configured to accept any of a plurality of electronics modules. Electrode assemblies are provided, each comprising at least one pair of an anode and a cathode with a separator disposed therebetween. The electrode assemblies are respectively configured to match the differing power requirements of the electronics modules such that some of the electrode assemblies have dimensions differing from other ones of the electrode assemblies. The electronics modules respectively inserted into the electronics compartment of a corresponding number of the plurality of the common encasement. For each of the corresponding number of the plurality of the common encasement, one of the electrode assemblies is selected to match a power requirement of the electronics module inserted in the common encasement, the selected one of the electrode assemblies is inserted into the battery compartment, and if the selected electrode assembly occupies less space than provided by the battery compartment so as to leave an unoccupied volume in the battery compartment, an inert insert is inserted into the unoccupied space so as to fill the unoccupied space to an extent necessary to prevent displacement of the electrode assembly. 
         [0015]    In some embodiments, the present disclosure provides a family of powered electronic components, such as medical devices implantable in patients, that are constructed around a standardized encasement and a standardized battery encasement, such that they are powered using batteries of uniform dimension and being configurable with different power capability and/or capacity. In some embodiments, the present disclosure provides a method for efficiently producing multiple types of batteries, optionally using stacked plate technology, having different power capability and/or capacity that fit within the same encasement configuration. 
         [0016]    The above, and other objects, features and advantages of the present disclosure will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. The present disclosure is considered to include all functional combinations of the above described features and corresponding descriptions contained herein, and all combinations of further features described herein, and is not limited to the particular structural embodiments shown in the figures as examples. The scope and spirit of the present disclosure is considered to include modifications as may be made by those skilled in the art having the benefit of the present disclosure which substitute, for elements presented in the claims, devices or structures upon which the claim language reads or which are equivalent thereto, and which produce substantially the same results associated with those corresponding examples identified in this disclosure for purposes of the operation of the devices and methods of this disclosure. Additionally, the scope and spirit of the present disclosure is intended to be defined by the scope of the claim language itself and equivalents thereto without incorporation of structural or functional limitations discussed in the specification which are not referred to in the claim language itself. 
         [0017]    Additional features and advantages of various embodiments will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of various embodiments. The objectives and other advantages of various embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the description and appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  perspective view of an exemplary medical device according to an embodiment of the present application; 
           [0019]      FIG. 2 a    is an exploded perspective view of a components of a battery of the exemplary medical device of  FIG. 1  including an electrode assembly composed of a plate electrode stack; 
           [0020]      FIG. 2 b    is an exploded front view of a battery cover, the plate electrode stack, and an encasement of the battery of the exemplary medical device of  FIG. 1 ; 
           [0021]      FIG. 2 c    is a front view of the battery of the exemplary medical device of  FIG. 1 ; 
           [0022]      FIG. 3 a    is a side elevation schematic cross-sectional view of a battery according to an embodiment of the present application; 
           [0023]      FIG. 3 b    is a front elevation schematic cross-sectional view of the battery of  FIG. 3   a;    
           [0024]      FIG. 4  is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein an inert insert is disposed above an electrode assembly; 
           [0025]      FIG. 5  is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein inert inserts are disposed above and below an electrode assembly; 
           [0026]      FIG. 6  is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein an inert insert is disposed between or within an electrode assembly; 
           [0027]      FIG. 7  is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein an inert insert is disposed above an electrode assembly; 
           [0028]      FIG. 8  is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein an inert insert is disposed above an electrode assembly; 
           [0029]      FIG. 9 a    is a simplified schematic diagram of a high-rate dual-cell battery embodiment in accordance with a prior art embodiment of a battery; 
           [0030]      FIG. 9 b    is a simplified schematic diagram of a high-rate dual-cell battery embodiment in accordance with another prior art embodiment of a battery; 
           [0031]      FIG. 9 c    is a simplified schematic diagram of a high-rate dual-cell battery embodiment in accordance with another prior art embodiment of a battery; 
           [0032]      FIG. 9 d    is a simplified schematic diagram of a high-rate dual-cell battery embodiment in accordance with another prior art embodiment of a battery; 
           [0033]      FIG. 10 a    is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein inert inserts are disposed above an electrode assembly; 
           [0034]      FIG. 10 b    is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein inert inserts are disposed above an electrode assembly; and 
           [0035]      FIG. 11  is a side elevation schematic cross-sectional view of another battery according to another embodiment of the present application wherein an inert inserts is disposed adjacent an electrode assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities of ingredients, percentages or proportions of materials, reaction conditions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. 
         [0037]    Notwithstanding that the numerical ranges and parameters setting forth the broad scope of this application are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a range of “1 to 10” includes any and all subranges between (and including) the minimum value of 1 and the maximum value of 10, that is, any and all subranges having a minimum value of equal to or greater than 1 and a maximum value of equal to or less than 10, e.g., 5.5 to 10. 
         [0038]    In some embodiments, the present disclosure provides an adjustable battery electrode assembly. In some embodiments, the present disclosure provides a system employed with a method to produce medical devices constructed around a standardized battery encasement. In some embodiments of the present disclosure, a method provides batteries having differing power capabilities and/or energy capacities, and a method is provided to efficiently producing multiple types of such batteries that fit within the same encasement. 
         [0039]    In some embodiments, the system comprises batteries that are optionally produced using a stacked plate configuration. In some embodiments, the batteries comprise cells having one or more anode assemblies and one or more cathode assemblies, which are alternately stacked to form a cell. In some embodiments, each of the anode assemblies and cathode assemblies comprise one or more anode or cathode plates, respectively. In some embodiments, plates of inert material are placed at either a top or a bottom of a cell and are used to maintain constant stack dimensions. 
         [0040]    In some embodiments, a power delivering capability of a cell is proportional to the total interfacial area between the anode subassemblies and cathode subassemblies. In some embodiments, the power delivering capability is controlled by varying the footprint of a cell stack and a number of anode subassemblies and cathode subassemblies. In some embodiments, the power delivering capacity of the cell is proportional to the total volume of anode and cathode with the appropriate coulombic balance between the two. In some embodiments, the power delivering capacity is controlled by varying the footprint of the cell stack, the number of anode subassemblies and cathode subassemblies, the number of plates in each subassembly, and the thickness of the anode plates and cathode plates. In some embodiments, the cell design can vary such that the stack thickness changes, either due to changes in the number of anode plates or cathode plates, the thickness of the anode plates or cathode plates, or the total number of anode subassemblies and cathode subassemblies, and the original stack thickness may be restored by adding plates of inert material to the top of the stack, bottom of the stack, or both. As such, a variety of cells, with different power capabilities and capacities may fit with the same tolerances within the same encasement. In some embodiments, single and dual chamber ICDs and triple-chamber CRT-Ds may each use the same mechanical platform, including battery encasement, and use different cell designs according to energy capacity requirements of each type of device. 
         [0041]    Referring to  FIGS. 1 through 2   c , an embodiment is shown of an exemplary stacked plate battery  106 . See, for example, stacked plate batteries as disclosed in U.S. Pat. No. 8,614,017, issued Dec. 24, 2013, to Viavatine, entitled “Electrochemical Cell With Electrode Elements That Include Alignment Apertures” which is incorporated by reference herein in its entirety.  FIG. 1  depicts an IMD  100 , which may be an implantable pulse generator (IPG), e.g., a pacemaker, or an implantable cardioverter-defibrillator (ICD), as examples. IMD  100  includes an encasement  900 , a battery  106  and an electronics module comprised of, for example and not limitation, a control module  104  and capacitor(s)  108 . Control module  104  controls one or more sensing and/or stimulation functions of IMD  100 , which functions may be performed via leads  109 . Battery  106  charges the capacitor(s)  108  and the powers control module  104 . 
         [0042]    An exploded perspective view of an exemplary assembly of a battery cover  110  and an electrode stack  120  is shown in  FIG. 2 a   . Anode plate electrodes  130  and cathode plate electrodes  140  are electrode elements of the battery  106 . In some examples, the anode plate electrodes  130  and the cathode plate electrodes  140  may be substantially planar, in other examples, the anode plate electrodes  130  and the cathode plate electrodes  140  may be curved along one or more axes such as in, for example and not limitation, a spiral wound assembly configured circularly or with the spirals arranged in an oblong configuration. Other formed shapes may also be used. 
         [0043]    The battery  106  has a battery case, forming a substantially sealed enclosure, comprised of a casement  111  and a top cover  110  as shown in  FIGS. 2 b  and 2 c    illustrating assembly of the battery  106 . As shown in  FIG. 2 a   , feedthroughs  112 A and  112 B (“feedthroughs  112 ”) extend through the top cover  110  and each include one of ferrules  113 A,  113 B (“ferrules  113 ”), one of feedthrough pins  114 A,  114 B (“feedthrough pins  114 ”) and one of insulators  115 A,  115 B (“insulators  115 ”). In some examples, feedthrough pins  114  have diameters of less than 0.050 inches, such as a diameter of no greater than about 0.030 inches, such as a diameter of about 0.021 inches or a diameter of about 0.012 inches. 
         [0044]    It will be appreciated by those skilled in the art having the benefit of the present disclosure alternative interconnection configurations may be used depending on the requirements of a given application. Other connections employ wires, spring contacts, button contacts, printed wiring flexible substrates, or threaded terminals, for example and not limitation. 
         [0045]    The battery  106  further includes an electrode stack  120 , which is housed within the enclosure formed by the battery case. In some examples, the battery  106  includes a fill port (not shown) as well as a liquid electrolyte within the enclosure. In some examples, the battery  106  may be an organic electrolyte battery  106 . In some embodiments the battery  106  may be a solid state battery having separators  121  formed of a polymer electrolyte film. 
         [0046]    The electrode stack  120  includes a first set of plate electrodes  130  and a second set of plate electrodes  140 . Positioned between each adjacent plate electrode  130  and plate electrode  140  is one of the separators  121 . The plate electrodes  130  form a cathode of the battery  106 , whereas plate electrodes  140  form an anode of the battery  106  such that the plate electrodes  130  combine with the plate electrodes  140  to form a voltaic cell. The plate electrodes  130  alternate with the plate electrodes  140  within electrode stack  120 . 
         [0047]    Each of the plate electrodes,  130  and  140 , includes a current collector  131  in the form of an electrically conductive substrate. The electrically conductive substrate may be made of a metal, such as alloys of copper, titanium, aluminum etc., or another electrically conductive material. As an example of construction of the anode and cathode electrodes,  130  and  140 , the current collector  131  of the top plate electrode  130  has an electrode material  133  that is disposed over the current collector  131 . In the battery  106 , the conductive substrates are substantially flat, and may include holes, be comprised of a mesh, screen, corrugated material, or other conductive material, or include other features to facilitate adhesion between and embedding of the conductive substrate in the electrode material  133 . 
         [0048]    Each of the anode electrodes  130  includes one of the current collectors  131 , a tab  132  extending therefrom, and the electrode material  133  disposed over the current collector  131 . The tab  132  comprises conductive material (e.g. copper, titanium, aluminum etc.). In some examples, the current collector  131  may be a unitary component with a tab  132 . The electrode material  133  optionally comprises elements from Group IA, IIA or IIIB of the periodic table of elements (e.g. lithium, sodium, potassium, etc.), alloys thereof, intermetallic compounds (e.g. Li—Si, Li—B, Li—Si—B etc.), or an alkali metal (e.g. lithium, etc.) in metallic form. In a further example, such as a rechargeable cell, the electrode material  133  of the anode plate electrode  130  may be lithium cobalt oxide or other suitable electrode material. The conductive substrate of the anode plate electrode  130  may comprise nickel, titanium, copper an alloy thereof or other suitable conductive material. In some examples, the separator  121  may be coupled to the electrode material  133  at the top and bottom of anode plate electrodes  130 , or the separator  121  may be simply interposed between the plate electrodes  130  and  140 . 
         [0049]    Each of the cathode plate electrodes  140  is constructed in a similar manner as the anode plate electrodes  130 . The cathode plate electrode  140  includes a conductive substrate serving as the current collector  131 , a tab  142  extending therefrom and an electrode material  133  disposed over the current collector  131  as disclosed above in relation to the anode plate electrode  130 . The electrode material  133  of the cathode plate electrodes  140  may comprise metal oxides (e.g. vanadium oxide, silver vanadium oxide (SVO), manganese dioxide etc.), carbon monofluoride and hybrids thereof (e.g., CFX+MnO2), combination silver vanadium oxide (CSVO), lithium ion, or other rechargeable chemistries, or other suitable compounds. In a further example, such as a rechargeable cell, the electrode material  133  of the cathode plate electrode  140  may be lithium titanate, graphite or other suitable electrode material. The conductive substrate of the current collector  131  of the cathode plate electrode  140  may be, for example, titanium, aluminum, nickel or other suitable materials. While the example chemistries provided are optionally employed, in an embodiment in present use a lithium cobalt oxide is used for the cathode plate electrodes  140 , i.e., the positive terminal and either lithium titanate or graphite for is used for the anode plate electrode  130 , i.e. the negative terminal. 
         [0050]    As previously mentioned, each anode plate electrode  130  includes a tab  132 . Spacers  122  are positioned between adjacent ones of the tabs  132 . Similarly, each of the cathode plate electrodes  140  includes a tab  142 , and a spacer  122  is positioned between adjacent ones of the tabs  142 . The spacers  122  function to mitigate bending of tabs  132  and  142  during assembly of electrode stack  120  and may be omitted if the current collectors are of sufficient structural integrity. The spacers  122  may also be formed from a conductive material such as titanium, aluminum/titanium clad metal or other suitable materials. Accordingly, the spacers  122  may also serve to electrically connect the anode plate electrodes  130  via the tabs  132  with each other as well as electrically connect the cathode plate electrodes  140  via the tabs  142  with each other within electrode stack  120 . 
         [0051]    As previously mentioned, tabs  132 ,  142  may be a unitary component with the electrically conductive substrates of the plate electrodes,  130  and  140 , respectively. In one example, the tabs  132  may be formed by masking a portion of an electrically conductive substrate when depositing an electrode material, e.g., lithium, on the electrically conductive substrate of a plate electrode. The electrically conductive substrate may be masked by placing a material, such as a polymer between the electrically conductive substrates and the electrode material  133 . In some examples, the mask material may be die cut to provide precise masking of the tabs  132  and  142 . 
         [0052]    The thickness of the spacers  122  is dependent on the thicknesses of the anode plate electrodes  130  and the cathode plate electrodes  140 . As an example, the spacers  122  may have a thickness of less than 0.060 inches, such as a thickness of about 0.020 inches. In other examples, the spacers  122  may have a thickness of between 0.10 inches to 0.060 inches. In a further example, such as in a rechargeable cell, the spacers  122  may have a thickness of between 0.005 inches to 0.020 inches. For example, the electrode material  133  of rechargeable cells may be formed using a slurry process, which can provide thinner electrode plates than in the case of a pressed powder process more commonly used for making electrode plate in non-rechargeable cells. In general, the thickness of the spacers  122  should be selected to match the spacing between adjacent ones of the tabs  132  and adjacent ones of the tabs  142  when the anode plate electrodes  130  and the cathode plate electrodes  140  are stacked, e.g., directly on each other. 
         [0053]    See, for example, details and techniques suitable for the construction of the electrode stack  120  as disclosed in United States Patent Publication Number 2009/0197180 by Viavattine et al., titled “Spacers Between Tabs of Plate Electrodes In An Electrochemical Cell For An Implantable Medical Device,” the entire contents of which is incorporated by reference herein. Furthermore, it is to be understood that the present disclosure is not limited to electrode assemblies composed of planar plates and is intended to include electrode assemblies of wound electrode layers, laminated electrode layers, or machined, molded, or deposited electrodes. 
         [0054]    Referring to  FIGS. 3 a   - 8  and  10   a - 11 , the encasement  900  and electronics modules  901 - 907 , (corresponding to the control module  104  and the capacitor(s)  108  of  FIG. 1 ) are shown in a schematic fashion, signaling that the actual physical configurations illustrated are simplified for both clarity purposes and to indicate that no specific shape or relative arrangement thereof is intended to limit the present disclosure. Similarly, details of electrical connections between the feedthrough pins,  114 A and  114 B, and power inputs of the electronics modules,  901 - 907 , are omitted as any type of interconnection as may devised by those skilled in the art are optionally employed. Likewise, the configuration shown of the electrical connection from the current collectors  131  to the electronics modules,  901 - 907 , i.e. feedthroughs,  112 A and  112 B, is not considered limiting as alternative interconnections employing, for example and not limitation, spring terminals, button contacts, wiring, flexible or rigid substrate printed conductors, foil, or other conductive interconnections are optionally used for practicing the method and devices of the present disclosure. Still further, while the  FIGS. 3 a   - 8  and  10   a - 11 , show, as an example, a stacked plate electrode arrangement, as noted above, other battery electrode structures or assemblies may be employed in the practice of the present disclosure. The casement  111  and top cover  110  are likewise represented schematically as battery case  150 . Additionally, in some embodiments of the present disclosure, either or both of the encasement  900  and the battery case  150  may function as a terminal for power interconnection purposes. Furthermore, insulation isolating the battery case  150  from the anode and cathode electrodes,  130  and  140 , and electrical interconnections as is required in a given configuration is omitted for purposes of simplicity and application thereof will be understood by those skilled in the art. It will be further understood that where the battery case  150  is to serve as a battery terminal the insulation will be appropriately configured to allow electrical connection of one the anode and cathode electrodes,  130  and  140 , to the battery case  150 . 
         [0055]    For exemplary purposes, each of the electronics modules,  901 - 907 , is considered to have different power supply requirements, whether it be one or all of a voltage requirement, a current delivery capability, or a power/energy capacity resulting in a given expected operational life under known conditions. Likewise, relative configurations of the encasement  900  and the electronics modules,  901 - 907 , is also exemplary and are presented to convey a concept that the encasement  900  is common to each of the differing electronics modules,  901 - 907 , which have different power supply requirements but may be stowed within a common volume of the encasement  900  as represented in FIGS.  3   a - 8  and  10   a - 11 , schematically as a common oblong shape of each of the electronics modules  901 - 904 . Hence,  FIGS. 3 a   - 8  and  10   a - 11 , depict various exemplary embodiments of the present disclosure which are directed to providing alternative power characteristic batteries which have the battery case  150  in common so as to be employable in the common encasement  900 . 
         [0056]    Referring to  FIGS. 3 a  and 3 b   , the battery  106  is schematically depicted as a battery optionally utilizing stacked plate technology, generally designated by the numeral  106 , wherein  FIG. 3 a    shows a side cross-sectional view while  FIG. 3 b    shows a front cross-sectional view. The battery  106  includes the battery case  150  in which is accommodated the stack of electrode plates comprised of the anode electrodes  130   s  and the cathode electrodes  140   s  stacked in alternating succession with the separators  121  interposed therebetween. 
         [0057]    When used in exemplary medical devices designed to be implanted in patients, the battery  106  is selected to have a high charge density providing extended life. Based on current technology, the most commonly used battery cell type for such applications is a lithium cell. However, this disclosure is not limited to such technology, and applies equally to other presently known electrochemical platforms, primary or rechargeable, as well as any developed in the future which operate to produce an electrical output. The battery  106  of  FIGS. 3 a  and 3 b    is of a design to maximize power capacity with a bulk of a volume of the battery case  150  being occupied by the anode electrodes  130   s  and cathode electrodes  140   s . A volume of the stack of the anode electrodes  130   s  and cathode electrodes  140   s  defines a power capacity (energy capacity) of the battery  106  and, for the purpose of simplicity in the present disclosure, will be considered proportional to an area of representation thereof in  FIGS. 3 a   - 8  and  10   a - 11 . In the event that another battery with less current capacity and/or a reduced operational life (based on energy capacity and power drain) were desired, the anode electrodes  130   s  and cathode electrodes  140   s  would be constructed of electrodes of less interfacial surface area, and/or thinner plates, and/or fewer electrodes. The electronics module  901  will be considered to have power supply requirements matching those provided by the battery  106 . 
         [0058]      FIGS. 4-8 and 10   a - 11  depict further embodiments of the present disclosure represented, for purposes of simplicity and clarity, by side cross-sectional views as in  FIG. 3 a   . The interconnection of cathode and anode electrodes, shown in these figures, to respective electronics modules is the same as the exemplary arrangement shown in  FIG. 3 b    with the exception that the anode electrodes and the cathode electrodes are shifted to compensate for differing electrode thicknesses or number. 
         [0059]      FIG. 4  depicts a first embodiment of a battery according to the present disclosure, generally designated by the numeral  206 . The battery  206  includes the battery case  150 , common to each of the embodiments of batteries presented herein. As noted above, the battery case  150  is exemplary, and may be of different configuration, but for the purpose of demonstrating the method of the present disclosure, is to be considered the same in each of the embodiments of the present disclosure, hence having a same reference numeral  150  throughout, thus being a battery case of common format employed for batteries of differing characteristics. Hence, the battery case  150  of the figures is such that it can be used interchangeably in a battery compartment of the encasement  900 , i.e., a space depicted beneath the electronics modules  901 - 907  of  FIGS. 3 a   - 8  and  10   a - 11 . The electrode stack  120  of  FIGS. 2 a  and 2 b    being comprised of anode electrodes  130   a  and cathode electrodes  140   a  stacked in alternating succession with the separators  131  interposed therebetween. 
         [0060]    The battery  206  has a reduced energy capacity as compared to battery  106  of  FIGS. 3 a  and 3 b   , implemented by use of the anode electrodes  130   a  and the cathode electrodes  140   a  having a reduced thickness as compared to the anode electrodes  130   s  and the cathode electrodes  140   s  of  FIGS. 3 a  and 3 b   . This reduction in capacity is effected to match requirements of the electronics module  902 . Consequently, a stack height of the battery  206  is made less than that of the battery  106 , leaving a top space open within the battery case  150 . An inert spacer  105 , sized to compensate for the difference in height, is placed atop the stack to maintain the anode electrodes and cathode electrodes,  130   a  and  140   a , in position. Optionally, the inert spacer could be made thicker, with a commensurate further reduction of thickness of the anode and cathode electrodes,  130   a  and  140   a.    
         [0061]    Referring to  FIG. 5 , a second embodiment of this disclosure depicts a battery  306  which includes the battery case  150 . A stack of electrode plates is comprised of the anode electrodes  130   a  and the cathode electrodes  140   a , of like configuration to those of  FIG. 4 , stacked in alternating succession with separators  121  interposed therebetween. The electronics module  902  is the same as that of  FIG. 4 , hence the anode electrodes  130   a  and the cathode electrodes  140   a  are likewise of the same dimensions and number as in  FIG. 4 , thus having the same reference designators. The battery  306  differs from the battery  206  in that the inert spacer  105  is replaced with two inert spacers  105   a  positioned above and below the stack. 
         [0062]    As in the case of the battery  206 , the battery  306  has a reduced energy capacity as compared to battery  106  of  FIG. 3 a   . This is achieved by use of the anode electrodes  130   a  and the cathode electrodes  140   a  having a reduced plate thickness as compared to anode electrodes  130   s  and cathode electrodes  140   s  of  FIG. 3 a   . Consequently, as with the embodiment of  FIG. 4 , a stack height of battery  306  is less than that of battery  106 , leaving unoccupied spaces within the battery case  150  in the height dimension. In accordance with the depicted example of  FIG. 5 , the top inert spacer  105   a  and the bottom inert spacer  105   b  are of appropriately selected aggregate thickness to compensate for the difference in stack height. 
         [0063]      FIG. 6  depicts a battery  406  according to a third embodiment of this disclosure, which includes the battery case  150  of  FIGS. 1-5 . A stack of electrode plates is comprised of the anode electrodes  130   a  and the cathode electrodes  140   a  stacked in alternating succession with the separators  121  interposed therebetween. As in the case of the batteries,  206  and  306 , of  FIGS. 4 and 5 , the battery  406  has a reduced energy capacity as compared to battery  106  of  FIG. 3 a   , achieved by a reduction in plate thickness of the anode electrodes  130   a  and the cathode electrodes  140   a  as compared to the anode electrodes  130   s  and the cathode electrodes  140   s  of  FIG. 3 a   . Consequently, as with the embodiments of  FIGS. 4 and 5 , a stack height of battery  406  is less than that of battery  106 , leaving unoccupied space within battery case  150  in the height dimension. In accordance with the depicted example of the third embodiment, the spacer  105  of appropriately selected thickness to compensate for this difference in stack height is placed within the stack. In this embodiment, one of the anode electrodes  130   a  is replaced with split anode electrodes  130   a   2 , and the inert spacer  105  is placed therebetween. The combined stack height is the same as that of  FIGS. 4 and 5 , hence the same electronics module  902  is optionally used in this embodiment. 
         [0064]      FIG. 7  depicts a battery  506  according to a fourth embodiment of this disclosure, which includes the battery case  150  of  FIGS. 1-6 . A stack of electrode plates is comprised of the anode electrode  130   a  and the cathode electrode  140   a  stacked with the separator  121  interposed therebetween. The battery  406  has a reduced energy capacity as compared to battery  106  of  FIG. 3 a   . In this example one pair of the anode electrode  130   a  and the cathode electrode  140   a  is illustrated instead of two pairs. When the anode and cathode electrodes,  130   a  and  140   a , of the prior figures are connected in parallel as illustrated, the single pair of the anode and cathode electrodes,  130   a  and  140   a , will produce half the current delivery capacity in comparison to the parallel connection of two pairs illustrated. If the pairs of the anode and cathode electrodes,  130   a  and  140   a , in the prior figures were connected serially (which is an embodiment included in the present disclosure as the parallel connection illustrated is exemplary and non-limiting, hence a serial connection is considered to be within the scope and spirit of the present disclosure), the battery  506  produces half the voltage of the above described batteries  106 ,  206 ,  306 , and  406 , when a serial connection is used with the understanding that the anode and cathode electrodes,  130   a  and  140   a , are of like electrochemical composition as those in the prior figures. In this example, a different electronics module  903  is shown which has an exemplary power supply requirement(s) matching that of the battery  506 . Consequently, as with the embodiments of  FIGS. 4-6 , a stack height of battery  406  is less than that of battery  106  due to reduced thickness and number of electrodes, leaving unoccupied space within battery case  150  in the height dimension. In accordance with the depicted example of the fourth embodiment, an inert spacer  105   c  of appropriately selected thickness to compensate for this difference in stack height is placed within the stack. 
         [0065]      FIG. 8  depicts a battery  606  according to a fifth embodiment of this disclosure, which includes the battery case  150  of  FIGS. 1-6 . A stack of electrode plates is comprised of an anode electrode  130   b  and a cathode electrode  140   b  stacked with the separator  121  interposed therebetween. The battery  606  has an increased energy capacity as compared to the battery  506  of  FIG. 7  by virtue of the anode electrode  130   b  and the cathode electrode  140   b  being thicker than the anode electrode  130   a  and the cathode electrode  140   a  of the other embodiments presented herein. As in the case of the fourth embodiment, one pair of the anode electrode  130   s  and the cathode electrode  140   b  is used instead of two pairs. In this example, a different electronics module  904  is used which has a power supply requirement of a greater energy capacity than the electronics module  903  and/or which has a greater operational life than the electronics module  903  of  FIG. 7 . The stack height of the battery  606  is greater than a height of the stack of the battery  506  and less than that of battery  106 , leaving unoccupied space within battery case  150  in the height dimension. In accordance with the depicted example of the fifth embodiment, an inert spacer  105   d , of an appropriately selected thickness is used to compensate for this difference in stack height. 
         [0066]    While for purposes of illustration, the battery  106  of  FIG. 3 a    is being used to set the size standard for the battery case  150  used for any battery designed with reduced capacity, it will be understood that an inert spacer could be used in the largest capacity battery desired in order to plan for the unexpected contingency that a battery having the same size battery case and increased capacity might be required in the future. Then the inert spacer could conceivably be eliminated to allow for an increase in stack height, without requiring a larger battery case to accommodate the higher energy capacity electrode assembly. 
         [0067]    It is to be understood that in the fourth and fifth embodiments, the inert spacers,  105   c  and  105   d , are optionally placed on top of the stack, and that this disclosure is not so limited and also includes embodiments wherein the inert spacers,  105   c  and  105   d  are placed in the bottom of the battery case  150  and the stack is placed on top. Alternatively, of the anode electrodes,  130   s ,  130   a  or  130   b  or the cathode electrodes,  140   s ,  140   a  or  140   b , could be split as in the third embodiment. Furthermore, the present disclosure includes another embodiment wherein the inert spacer is placed in the middle of a stack and neither of the cathode(s) or the anode(s) is/are split as done in the third embodiment. 
         [0068]    It is also to be understood that, in a further embodiment of this disclosure, the battery case  150  and the encasement  900  are optionally integrated together into a dual compartment case to be formed as one piece or an assemblage of pieces. The battery stack(s) and the inert insert(s) are disposed in a battery compartment corresponding to the battery case  150 , and the electronics modules are disposed in an electronics compartment above the battery compartment in one embodiment. In another embodiment, the battery compartment is above the electronic compartment. In yet another embodiment the compartments are side by side. It is to be further understood that the electronics modules are configured as assemblies of electronic components and may be embodied as exposed circuit boards, or circuit boards within a housing. 
         [0069]    Referring to  FIGS. 9 a -9 c   , there are applications wherein two or more battery cells of differing characteristics, such as voltage, current delivery, or energy capacity with related operational life, are advantageously employed. See, for example, applications as disclosed in U.S. Pat. No. 7,209,784, issued Apr. 24, 2007, to Schmidt, entitled “High Power Implantable Battery With Improved Safety And Method Of Manufacture,” which is incorporated by reference herein in its entirety. Details of specific requirements of such batteries are omitted for clarity purposes in the present disclosure but, suffice to say, that again various electronics modules dictate requirements of the battery cells. 
         [0070]    Referring to  FIG. 9 a   , simplified schematics of a high-rate dual cell battery are shown as disclosed in. In this embodiment battery  54  is shown having the battery case  150 , an anode  74 , a cathode  76 , a cathode  77 , a separator  86 , feedthrough  84 , feedthrough  82 , terminal  78 , and terminal  80 . The battery case  150  is merely shown schematically, as the battery case  150  can be variable in shape and construction. Battery case  150  can be a deep drawn case. See, for example, the cases discussed in U.S. Pat. No. 6,040,082 (Haas et. al.) which is incorporated by reference herein in its entirety. Battery case  150  can be a shallow drawn case. See, for example, the cases discussed in U.S. Patent Application Publication 2004/0064163, filed on Sep. 30, 2002, entitled “Contoured Battery for Implantable Medical Devices and Method of Manufacture” which is incorporated by reference herein in its entirety. Battery case  150  is preferably made of a medical grade titanium, however, it is contemplated that battery case  150  could be made of almost any type of material, such as aluminum and stainless steel, as long as the material is compatible with the battery&#39;s chemistry in order to prevent corrosion. Further, it is contemplated that battery case  150  could be manufactured from most any process including but not limited to machining, casting, thermoforming, or injection molding. 
         [0071]    In the embodiment of  FIG. 9 a   , one electrode  74  is continuous and is connected to case  150 . The alternate electrode is in two separate pieces  76  and  77 . Each piece  76  and  77  has a separate electrical lead  78  and  80  electrically connected respectively through feedthroughs  84  and  82  which are electrically isolated from case  150 . It is contemplated that battery  54  can be case negative (anode connected to case) or case positive (cathode connected to case). As shown, dual cell battery  54  has the one anode  74 , which is utilized by a first cell chamber  88  and a second cell chamber  90 , which are separated by a separator  86 . There is no requirement of a hermetic seal between cells  88  and  90 . They could be designed this way, but it would be an unnecessary complication and result in a decrease in volumetric efficiency. Separator  86  is used to prevent direct electrical contact between anode  74  and cathodes  76  and  77 . It is a porous material that allows transport of electrolyte ions. Li/SVO batteries typically use separators comprised of porous polypropylene or polyethylene, but there are many other materials used for other battery chemistries. Nevertheless, separator  86  is not required and the battery  54  can operate without it. Further, it is noted that the anode/cathode relationship could be reversed. For example, anode  74  could be replaced with a cathode as long as cathodes  76  and  77  were switched to anodes. It is understood that the orientation of the anodes and cathodes is not a critical aspect of the invention. Although lithium hexafluoroarsenate is preferably used in both cells  88  and  90  for the present embodiment, it is contemplated that most any chemical electrolyte could be used without departing from the spirit of the present disclosure for either cell chamber  88  or  90 . Cathodes  76  and  77  are located within cells  88  and  90  respectively and are connected to external leads  78  and  80  respectively, which traverse out of battery case  150  through feedthroughs  84  and  82 . While the battery  54  is shown with two feedthroughs, it is fully contemplated that battery case  150  could have one feedthrough to accommodate both leads  78  and  80 . With reference to  FIG. 9 b   , a simplified schematic of another high-rate dual cell battery is shown. In contrast to the dual cell embodiment of  FIG. 9 a   , continuous electrode  74  is not connected to case  150 . Instead electrical lead  79  extends through feedthrough  89  to make case  150  neutral. 
         [0072]    With reference to  FIG. 9 c   , a simplified schematic of another high rate dual battery is shown. In contrast to the dual cell embodiment of  FIG. 9 a   , the anode is not continuous and each piece  74  and  75  is connected to the case  150 . This would be equivalent to taking two completely separate cells and placing them in the same battery case. 
         [0073]    With reference to  FIG. 9 d   , a simplified schematic of another high rate dual battery is shown. This design is similar to the embodiment of  FIG. 9 c   , except electrical leads  96  and  98  traverse through feedthroughs  92  and  94  to make a case neutral design. 
         [0074]    The method and devices of the present disclosure are advantageously applicable to the battery configurations of  FIGS. 9 a -9 d    wherein dual cells are provided to address differing power source requirements of a given electronics module. Applying the inert inserts discussed above to the dual cell arrangement advantageously provides for numerous combinations of power supply characteristic to be delivered in a common enclosure, i.e., the battery case  150 . It will be appreciated that it is within the scope and spirit of the present disclosure to apply the alternative inert insert dispositions any of  FIGS. 4-8  to both or any one of a high power rate cell  60  and/or a low power rate cell  62  shown in  FIGS. 10 a  and 10 b    to arrive at the desired power characteristics of the dual cells. For exemplary purposes, the inert insert configuration of  FIG. 4  applied to the schematic representations of  FIGS. 9 a -9 d    is shown in  FIGS. 10 a    and  10   b.    
         [0075]    Referring to  FIG. 10 a   , an embodiment of a battery  706  of the present disclosure which is applicable to the battery configurations of  FIGS. 9 a  and 9 b    and which is constructed to address the power requirements of an electronics module  905  is shown. The common electrode  74  is shown embodied as a common anode electrode  130   a  for exemplary and non-limiting purposes. The other electrodes,  76  and  77 , are respectively embodied as cathode electrodes  140   c  and  140   d . Of course, the disposition of cathodes and anodes may be reversed. The separator  86  is embodied as the separators  121  which are depicted as discontinuous across cells of the battery  706 , but could also be continuous as implied in  FIGS. 9 a -9 d   . An inert insert  105   e  is provided in a stack of a high power rate cell  60  and inert insert  105   f  is used in a stack of a low power rate cell  62 . Illustration of electrical connections of the current collectors  121  to external terminals is omitted from  FIG. 10 a    for purposes of clarity and because any of various connection methods may be employed within the scope and spirit of the present disclosure which are consistent with the schematics of  FIGS. 9 a    and  9   b.    
         [0076]    Referring to  FIG. 10 b   , an embodiment of a battery  806  of the present disclosure, which is applicable to the battery configurations of  FIGS. 9 c  and 9 d   , and which is constructed to address the power requirements of an electronics module  906  is shown. The split electrodes,  74  and  75 , are shown embodied as anode electrodes,  130   c  and  130   d , for exemplary and not limiting purposes. The other electrodes,  76  and  77 , are respectively embodied as the cathode electrodes  140   c  and  140   d . Of course, the disposition of cathodes and anodes may be reversed. The separator  86  is embodied as the separators  121  which are depicted as discontinuous across cells of the battery  706 , but could also be continuous as implied in  FIGS. 9 a -9 d   . The inert insert  105   e  is provided in a stack of a high power rate cell  60  and the inert insert  105   f  is used in a stack of a low power rate cell  62 . Illustration of electrical connections of the current collectors  121  to external terminals is omitted from  FIG. 10 b    for purposes of clarity and because any of various connection methods may be employed within the scope and spirit of the present disclosure which are consistent with the schematics of  FIGS. 9 a    and  9   b.    
         [0077]    Referring to  FIG. 11 , a further embodiment of the present disclosure includes a battery  906  having a stack of anode electrodes  130   e , separator  121 , and cathode electrodes  140   e  having a width less than the interior of the battery case  150 . An inert insert  105   g  is use to fill the space and stabilize the stack. Reducing the stack width decrease the current delivery capability, which along with a reduced energy capacity may increase or decrease operational life which depends in part on the current drain of the electronics module  907 . It is further understood that the stack of anode electrodes  130   e , separator  121 , and cathode electrodes  140   e , can also be concurrently reduced in height and a further inert insert used to compensate for the height reduction. It should also be understood that the further inert insert may either be separate from the inert insert  105   g  or may be integrated with the inert insert  105   g.    
         [0078]    In the foregoing embodiment, the inert inserts are optionally formed of an electrically insulating material which is inert so that adverse reactions with the electrodes and electrolyte included as a solution with the electrodes or included as a solid state electrolyte embedded in separators. Suitable materials include, but are not limited to: polyethylenetetrafluoroethylene, ceramics, non-woven glass, glass fiber material, polypropylene, and polyethylene. Alternatively, there are situations wherein the inert inserts may be formed of conductive materials such as when inert insert is positioned either at the top or bottom of the stack and forms an electrical connection to any of the battery case, feedthroughs or other terminals such as button terminals commonly used in coin type batteries. The conductive material should not adversely react with the electrodes or electrolyte. In such situations when electrical contact is made to the anode electrodes, suitable materials of composition include, but are not limited to, stainless steel, nickel, titanium, or aluminum. 
         [0079]    Having described preferred embodiments of this disclosure with reference to the accompanying drawings, it is to be understood that this disclosure is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of this disclosure as defined in this disclosure and the appended claims. Such modifications include substitution of components for components specifically identified herein, wherein the substitute components provide functional results which permit the overall functional operation of the devices and methods of this disclosure to be maintained. Such substitutions are intended to encompass presently known components and components yet to be developed which are accepted as replacements for components identified herein and which produce results compatible with operation of the devices and methods of this disclosure. 
         [0080]    In summary, it will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.