Abstract:
A conformable battery wherein the outer casing has an upper face plate, a lower face plate, and at least one perimetric wall, and an interior of the battery comprising a grid of walls extending from the upper face plate to the lower face plate and connecting to the at least one perimetric wall, thereby dividing the interior of the battery into at least two compartments and increasing the battery&#39;s structural stiffness and ability to sustain increased internal pressure. Each compartment contains an electrochemically active plate stack, and a network of electrical conductors provides electrical connection between the plate stacks in each of the compartment. The battery may further comprise a reservoir containing an acid additive which, when released into each of the compartments, shifts the battery from a low power mode into a high power mode.

Description:
[0001]    This application is related to U.S. patent application Ser. No. 10/456,625, filed on Jun. 9, 2003, which claims priority of U.S. Provisional Application No. 60/386,167, filed on Jun. 7, 2002. Elements of the Conformable Battery concept incorporate activation means described in the Bimodal Battery of U.S. Pat. No. 6,187,471, issued to the current inventor on Feb. 13, 2001, and are included herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to batteries. More particularly, the invention comprises a battery which can be manufactured in a variety of shapes and geometries that can better utilize available space in specific applications. 
         [0004]    2. Description of the Prior Art 
         [0005]    Most high power, high energy density batteries used in the aerospace, defense, electric vehicle and other industries today consist of cylindrical or rectilinear, prismatic-shaped cells used singly, or connected in parallel or series into battery packs, depending on the voltage and current requirements of the mission. These batteries are classified as either primary or secondary depending on the intended use and design of the battery. 
         [0006]    In a primary battery, the stored energy is released in an irreversible process, and the battery is depleted when the total energy of the cell is released. A secondary battery is one where the stored energy is released in a reversible process, and the battery is capable of being repeatedly charged and discharged. 
         [0007]    Examples of secondary batteries include lead acid, nickel cadmium, and nickel metal hydride batteries, which have found widespread use in the commercial market place as rechargeable electrical power sources for use in tools, starting motors, flash lights, electric vehicles, and a variety of other uses. Aerospace qualified nickel cadmium and nickel hydrogen batteries are used in space and satellite applications to provide renewable sources of electrical energy, recharged with solar panels extended from the satellite structure. Secondary lithium ion batteries are now being introduced as high energy density power sources for both space and electric vehicle applications. 
         [0008]    In most of the above examples, the battery consists of multiple cylindrical or prismatic cells built up by connecting these cells into cell packs, usually a rectilinear package similar in form to a standard automobile battery. In the case of the nickel hydrogen batteries, called common vessel batteries, in addition to the electrical connection between cells, there is also a network of tubing that allows pressurized hydrogen to flow from cell to cell. Primary batteries also utilize cylindrical and prismatic cells connected in series or parallel, depending on the voltage and current needs of the application. 
         [0009]    A reserve battery is a primary battery that can be stored for long periods of time prior to discharge, requiring some form of activation to bring it to a full operational state. The reserve battery is inhibited from open circuit self-discharge during the pre-activation state by having the electrolyte stored separately from the electrodes or by having the electrolyte infused into the plate stack of the battery in a non-conductive state. 
         [0010]    Aerospace and defense applications usually employ a so-called “thermal” battery as a reserve battery. For the thermal battery, the electrolyte permeates the plate stack as a solid state salt and is non-conductive for the range of storage temperatures in the pre-activation state. The thermal battery is activated by the ignition of an internal pyrotechnic that heats the electrolyte salt to a liquid state, wherein the electrolyte is capable of conducting current, thereby activating the battery. 
         [0011]    In other reserve battery designs, the plate stack is dry and the electrolyte is stored in liquid form in a separate storage reservoir. Upon activation, the electrolyte is injected into the plate stack, allowing the battery to discharge current into the load attached to the terminals of the battery. In the lithium thionyl chloride reserve battery, for example, an acidic form of the thionyl chloride electrolyte is contained in the separate reservoir and injected into the plate stack to achieve activation. 
         [0012]    The bimodal battery (U.S. Pat. No. 6,187,471) is an alternative design of the reserve lithium battery which allows it to function as a low-drain battery during periods of storage, and then, after activation, to function as a very high current battery to meet high power density missions. In the bimodal battery, the plate stack is infused with non-acidic, neutral thionyl chloride based electrolyte which allows it to function as a low-current drain power source. Activation is achieved by injecting and mixing an acid additive that creates an acidic form of the electrolyte in the plate stack. The acid electrolyte allows the battery to function as a very high current power source for a relatively short period of time. 
         [0013]    Both thermal and thionyl-chloride reserve batteries are used in aerospace and defense applications to power missile and launch vehicle electronics, ignition of pyrotechnics for staging and separation, electric actuators for moving fins and control surfaces, and passive and active on-board sensors. These applications require heavy current for a limited duration of time. 
         [0014]    Secondary batteries are used, once a satellite has been launched into space, to continuously power the electronics, the telecommunication data links and sensors. These batteries can be recycled in space for multi-year missions using large solar arrays to recharge the batteries. 
         [0015]    Many of the high energy density, high power density batteries used for aerospace and defense create high levels of thermal energy and internal pressure during their operation. These effects are taken into account when designing batteries, such as thermal management techniques to remove heat from the core of the battery, and special pressure containment vessels and relief valves to manage internal pressure buildup. As a result of these thermal and pressure requirements, system designers are often constrained by the form and fit factors of the batteries designed for aerospace applications. 
         [0016]    Thin flat-plate and conformable batteries have been developed in the commercial electronics industry to maximize packaging density, allowing system designers to efficiently add the battery to the electronics system without having to design the electronics package around the shape of the battery. Cell phones, for example, have snap-on batteries with relatively thin rectilinear shapes. Thin-line button cells are used in watches to conform to the shape of the watch. These batteries, however are not required to deliver the high currents required in the aerospace applications cited heretofore. What is needed in the aerospace and defense industry are battery concepts that give the aerospace engineer or missile designer the same design flexibility, to efficiently fit the battery into the electronics environment without having to distort that environment. 
       SUMMARY OF THE INVENTION 
       [0017]    The intent of the conformable battery concept of the present invention is to bring the design flexibility already exploited in low-drain batteries of commercial electronics to the high energy and power density batteries of missile and aerospace electronics. Electronics are usually laid out on printed wire circuit boards (PWBs) or cards, which are planar, rectangular-shaped plates, sometimes stacked in parallel into electronics boxes to conserve space. Conformable batteries built in the same shape can be slid into the electronics box enclosure along with the printed circuit cards. Missile bodies are cylindrical in shape with electronics on disks that are stacked in parallel in a cylindrical electronics box. Thin-walled conformable batteries could also be built in a curved shape that fits around the electronics and conform to the outer shape of the missile. 
         [0018]    Space satellites are sometimes built in modular fashion as rectangular or cylindrical boxes with components and subsystems stacked on shelves within the enclosure. Conformable batteries powering the satellite could be built as a flat plate that can act as one or more of the shelves. In this concept, the battery would be acting as a multi-functional element of the system. It would serve as a power source, but also as a structural member of the satellite structure. 
         [0019]    In the Conformable Battery concept of the invention, the battery casing is formed by sandwiching a grid of short vertical walls between top and bottom plates, thus forming individual compartments, mechanically and electrically isolated from each other. The walls of these compartments act as stiffeners between the two outer casing plates providing substantial mechanical strength and stiffness, similar to light-weight aluminum or composite aerospace structures made from honeycomb structures sandwiched between two face sheets. The multi-compartments can serve as enclosures for individual cell plate stacks which can then be linked together electrically with series or parallel connections. 
         [0020]    Depending on how the individual compartments are shaped, the architecture of the Conformable Battery allows for distribution of individual cell plate stacks across different geometries including: rectangular or cylindrical flat plate batteries, curved plate batteries, cylindrical batteries with an open core, or other three dimensional shapes that conform to the geometric requirements of specific applications. 
         [0021]    In addition to enabling the batteries to be used as structural elements of missiles and satellites, the thin plate geometries have the added value of increasing the surface area of the external packaging, thereby facilitating better transfer of heat from the plate stacks to the external environment. This is especially important in the case of high rate of discharge batteries, where the heat of the electrochemical reactions occurring during discharge can be trapped in the core of cylindrical or prismatic geometries, increasing internal pressures and degrading performance. 
         [0022]    The internal structure of stiffeners also contributes to the ability of the casing to contain substantial internal gas pressures that can be generated during charge/discharge cycles, especially in the case of nickel-hydrogen batteries, by distributing and channeling the mechanical load on the large area face plates through the grid of vertical compartment walls. 
         [0023]    The Conformable Battery concept and architecture is applicable to a number of secondary and primary battery chemistries. In the case of secondary batteries, this includes, but is not limited to: lead acid, nickel cadmium and nickel metal hydride batteries, which have found widespread use in the commercial market place as rechargeable electrical power sources, and aerospace qualified nickel cadmium and nickel hydrogen batteries used in space and satellite applications, and secondary lithium ion and batteries for use in space applications, as well as, terrestrial electrical vehicle applications. 
         [0024]    The Conformable Battery concept and architecture is also applicable to the field of primary batteries, including, but not limited to, common alkaline primaries, lithium ion, and low-drain lithium oxyhalide (e.g. lithium thionyl chloride). As regards the conventional primary reserve batteries, the Conformable Battery concept, although feasible, might be impractical for certain classes of the primary reserve batteries, for example, the high temperature reserve thermal batteries (too much heat radiated away from the battery during operation), or the reserve lithium thionyl chloride battery with the separate acid electrolyte reservoir (difficult to maintain a vacuum in the multi-compartment flat plate architecture, then pump large quantities of electrolyte throughout the individual compartments). In conventional lithium reserve batteries, the electrolyte must be forcibly injected in the plate stack under relatively high pressure in order to assure rapid contact of the electrolyte with the dry plate stack. 
         [0025]    Limitations associated with the Conformable Battery architecture for primary reserve batteries, however, do not extend to the Bimodal Battery concept. In fact, the Bimodal Battery is an excellent candidate for use as a Conformable Battery. In the case of the Bimodal Battery, where most of the neutral electrolyte is already stored in the multiple compartments, only the acid additive need be injected into the compartments during activation, and the activation process can be carried out under moderately low pressures. This low pressure, moderate temperature environment is why the Bimodal Battery is an excellent candidate for implementing the Conformable Battery concept, as opposed to the conventional thermal or lithium thionyl chloride reserve battery with separate reservoir. 
         [0026]    The Bimodal Battery is potentially 30-40% smaller in size than conventional primary reserve lithium batteries since the acid component held in reserve prior to activation is much smaller, volumetrically, than the total electrolyte held in reserve in the conventional lithium reserve battery. The bimodal battery is also potentially lighter in weight, since the mechanisms required to pump and mix the additive are smaller and operate at a much lower pressure. This more benign, lower pressure activation reduces the need for high pressure, heavy containment vessels, and could also provide more margin of safety since the activation is less stressful. In the Bimodal Battery, the lower pressure of activation allows some flexibility in the types of geometries that can be accommodated. 
         [0027]    In order to improve the manufacturability of the Conformable Battery, much of the wiring to connect the multiple compartments, as well as the fluidic paths required to move electrolyte additives into the multiple compartments, can be embedded in the top and bottom plates enclosing the battery casing. 
         [0028]    The present invention provides a battery architecture wherein the outer casing of the battery may be configured in a variety of shapes to fit specific applications including flat planar designs (circular, square, rectangular) and three-dimensional geometric shapes (e.g. curved plates, thin cylinders with hollow cores, other geometric shapes). 
         [0029]    Accordingly, it is a principal object of the invention to provide an internal structure to a battery, forming multiple compartments where the walls of the compartments are bonded to the outer skin, contributing to the batteries&#39; structural stiffness, integrity, and ability to sustain moderate to high internal pressure. 
         [0030]    It is another object of the invention to provide a battery that can be configured in different external shapes, by selective arrangement of individual plate stacks in separate, electrically isolated compartments, contiguous to each other, depending on the desired geometry, with each compartment containing an isolated electrochemically active plate stack. 
         [0031]    It is a further object of the invention to provide a battery that can provide higher voltages through series connection of multiple plate stacks, and/or multiple voltages through voltage taps at various locations throughout the multi-compartment plate stack compartments. 
         [0032]    Still another object of the invention is to provide a battery where plate stack cells are distributed over flat rectangular or circular shaped flat plates, curved plates, or other three dimensional shapes, depending on the requirement of the application, creating a large surface area in the external casing in order to enhance heat dissipation. 
         [0033]    It is an object of the invention to provide an architecture for the reserve lithium Bimodal Battery with the attributes of the Conformable Battery, including a relatively large external surface area to facilitate heat transfer from the core of the battery to the external environment, a multi-compartment architecture to allow for higher voltages through series connections, as well as the ability to provide for multiple voltage taps. 
         [0034]    It is an object of the invention, in the case of the Bimodal Battery, to provide a manifold system with tubing or channels to distribute the acid additive from a central dispensing reservoir to each of the plate stack compartments in a multi-compartment battery. 
         [0035]    It is an object of the invention, in the case of the Bimodal Battery, to provide a return manifold system, when needed, to move excess electrolyte into an electrolyte collection reservoir, as the acid additive is pumped into each compartment of the multi-compartment battery. 
         [0036]    It is an object of the invention in the Bimodal Battery, to provide an alternate means of handling excess electrolyte in each of the multi-compartments by creating “dimples” in the outer casing at each compartment (concave curvature) which are then popped out to a planar or convex curvature when the acid additive, under pressure, is added to each compartment, increasing the liquid volume in each compartment. This eliminates the need for a separate return manifold system for the Bimodal Battery. 
         [0037]    It is an object of the invention to provide a means of introducing acid additive into each compartment of the Bimodal Battery without recourse to a separate return manifold by partially filling each compartment with neutral electrolyte thus leaving a void within the compartment for additional electrolyte. 
         [0038]    It is an object of this invention to provide alternative means of electrically connecting the plate stacks within the multiple compartments by means of a multi-layer composite structure within the battery case consisting of electrical grids, insulating layers and interlayer connecting vias to provide series and/or parallel electrical connections between compartments. 
         [0039]    It is an object of this invention to provide alternative means of inter-compartment fluidic connection (liquid or gaseous phase) to move electrolyte and additives, or gaseous products, in and out of the compartments by means of layered structures integral to the outer casing using what is known in the aerospace industry as “platelet” technology. In platelet technology, channels and vias are cut out of thin metal plates using conventional metal stamping or laser cutting techniques, then superimposed, stacked up, and then soldered, brazed or diffusion bonded in such a manner that closed channels are formed, allowing fluids to circulate between compartments. 
         [0040]    It is the object of the invention to prevent “soft shorts” (that is, parasitic currents between compartments at different voltage levels) before and after activation of the Bimodal Battery, through a variety of means, including pressure sensitive one-way valves between the central well and the compartments, frangible membranes, or pressure sensitive plugs between the central well and compartments, and, after activation, means for retarding the flow of electrolyte between compartments by lengthening the electrolytic path between compartments or placing pin-hole orifices in the path to restrict flow. 
         [0041]    It is the object of the invention to prevent parasitic currents before and after activation by placing acid additive in frangible glass or ceramic ampoules within the volume of the plate stack itself, enclosing both within a sealed metallic foil pouch. 
         [0042]    It is an object of this invention to provide a means of fracturing the ampoules and allowing the acid to mix with the acid electrolyte by detonating a small pyrotechnic charge in the central well or elsewhere in the battery, creating a shock wave which propagates through the battery, shattering the ampoules. 
         [0043]    It is the object of this invention to provide a mechanical means of fracturing the ampoules by providing a series of mechanical “tampers”, one for each ampoule, which transfers the energy from the pyrotechnic charge in the central well directly into the ampoule, fracturing it and allowing the acid additive to mix with neutral electrolyte. 
         [0044]    It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
         [0045]    These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0046]    Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
           [0047]      FIG. 1A  is a perspective view of the outer casing of a nine compartment, rectangular-shaped conformable battery. 
           [0048]      FIG. 1B  is an exploded view of a nine compartment, rectangular-shaped battery of  FIG. 1A , showing the grid of compartment walls with top and bottom outer casing plates. 
           [0049]      FIG. 2A  is a perspective view of the outer casing of an eight compartment, circular-shaped conformable battery. 
           [0050]      FIG. 2B  is an exploded view of a circular battery of  FIG. 2A , showing the grid of pie-shaped compartment walls with top and bottom outer casing plates. 
           [0051]      FIG. 3  is a perspective view of the outer casing of an eighteen compartment conformable battery in the form of a truncated cylinder with an open core. 
           [0052]      FIG. 4  is a top view of the bimodal form of a rectangular battery with electrolyte additive injected into the compartments from a side well. 
           [0053]      FIG. 5  is a top view of the bimodal form of a circular battery with electrolyte additive injected into pie-shaped compartments from a central well. 
           [0054]      FIG. 6A  is an exploded side perspective view of a five (5) layered, composite structure serving as the outer casing as well as providing a series electrical connection grid for the bimodal battery of  FIG. 1A . 
           [0055]      FIG. 6B  is a top view of the interior layer of the five (5) layer outer casing composite structure of  FIG. 6A . 
           [0056]      FIG. 6C  is a top view of the mid layer of the five (5) layer outer casing composite structure of  FIG. 6A . 
           [0057]      FIG. 7A  is an exploded side perspective view of a three (3) layer outer casing composite structure providing fluid channels to the nine compartment bimodal battery of  FIG. 4 . 
           [0058]      FIG. 7B  is a top view of the interior layer of the three (3) layer outer casing composite structure of  FIG. 7A . 
           [0059]      FIG. 7C  is a top view of the mid layer of the three (3) layer outer casing composite structure of  FIG. 7A . 
           [0060]      FIG. 8A  is a side view of a single compartment of a bimodal battery with a “dimpled”, concave top. 
           [0061]      FIG. 8B  is a side view of a single compartment with a convex top, after introduction of acid additive under pressure. 
           [0062]      FIG. 9A  is a side view of a one-way pressure sensitive ball valve between the central well and one compartment before activation. 
           [0063]      FIG. 9B  is a side view of a one-way pressure sensitive ball valve between the central well and one compartment after activation. 
           [0064]      FIG. 10A  is a side view of a spring-loaded one-way pressure sensitive flapper valve between the central well and one compartment before activation. 
           [0065]      FIG. 10B  is a side view of a spring-loaded one-way pressure sensitive flapper valve between the central well and one compartment after activation. 
           [0066]      FIG. 11A  is a side view of a pressure sensitive frangible membrane with a pin-hole orifice between the central well and one compartment before activation. 
           [0067]      FIG. 11B  is a side view of a pressure sensitive frangible membrane with a pin-hole orifice between the central well and one compartment after activation. 
           [0068]      FIG. 12  is a top view of a means of lengthening the electrolyte flow path from central well to the individual compartments through fluid channel in the spokes and rim of the internal battery structure. 
           [0069]      FIG. 13  is a top view of an alternate means of lengthening the flow path through channels in the layered multifunctional plate structure. 
           [0070]      FIG. 14  is a top view of a compartment with a rectangular shaped frangible capsule or ampoule containing acid additive. 
           [0071]      FIG. 15  is a top view of a frangible ampoule that conforms more closely to the shape of the compartment. 
           [0072]      FIG. 16A  is the top view of an alternate central well structure containing pyrotechnic-driven tampers to mechanically shock and fracture the glass ampoules. 
           [0073]      FIG. 16B  is the top view of the alternate central well structure, after detonation of the pyrotechnic device, driving tampers into the compartments. 
           [0074]      FIG. 17A  is an enlarged view of the interface between the tamper and the glass ampoule in the wedge-shaped compartment enclosed in a metal foil envelope. 
           [0075]      FIG. 17B  is the enlarged view of the interface, after detonation, with the tamper crumpling the foil enclosure and fracturing the glass ampoule. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0076]      FIG. 1A through 3  depict the basic structure of the conformable battery architecture. 
         [0077]    A thin walled, flat-plate, substantially rectangular battery  10  is depicted at  FIGS. 1A and 1B . The battery  10  has an outer casing  11  consisting of a casing top  12 , a casing bottom  14 , and casing side walls  16 . 
         [0078]    A thin walled, flat-plate, circular battery  20  is depicted at  FIGS. 2A and 2B . The battery  20 , again, has an outer casing  21  consisting of a casing top  22 , a casing bottom  24 , and a casing circumferential wall  26 . 
         [0079]    A truncated, semi-cylindrical battery  30  is depicted at  FIG. 3 . The battery  30  has a casing  31  consisting of an inner casing wall  32 , an outer casing wall  34 , and casing side walls  36 . The semi-cylindrical battery  30  of  FIG. 3  is similar to the rectangular battery  10  of  FIGS. 1A and 1B , with the plates curved to form the semi-cylindrical shape. (Hereinafter, with the exception of shape, the descriptions of the structure of the flat-plate battery  10  will apply equally to the semi-cylindrical battery  30 .) 
         [0080]    These basic configurations illustrate the advantages of the conformable battery concept where various geometries can be produced to better meet the requirements of specific applications from a form, fit and function point of view. 
         [0081]    The flat plate or conformal configuration facilitates compartmentalization of individual plate stacks for multi-compartment architectures, allowing multiple voltage taps, or higher voltage operation with series connection of multiple compartments. The dotted lines  18 / 28 / 38  in  FIGS. 1A ,  2 A, and  3  illustrate how these flat-plate/conformal designs can be compartmentalized, with compartment walls bonded to the outer skin of the battery contributing to structural stiffness and integrity. Each compartment in subsequent Figures will be shown to contain the electrochemically active plate stacks (positive and negative electrodes, with separators, immersed in neutral electrolyte). 
         [0082]    Interior walls  18 / 28 / 38  are bonded to the interior surfaces of the outer casings  11 / 21 / 31 , forming individual compartments  18 / 28 / 38  within the batteries  10 / 20 / 30 , each compartment  15 / 25 / 35  isolated from each of the other compartments  15 / 25 / 35 . Within each compartment  15 / 25 / 35 , is an electrochemically active plate stack (not shown) (positive and negative electrodes, with separators, immersed in neutral electrolyte, as known in the art). In addition to isolating the compartments  15 / 25 / 35  from one another, the bonding of the interior walls  18 / 28 / 38  to the interior surfaces of the outer casings  11 / 21 / 31  contributes to the structural stiffness and integrity of the outer casing  11 / 21 / 31 . 
         [0083]    At  FIG. 4 , the rectilinear battery  10  of  FIGS. 1A and 1B  is shown in further detail. An acid reservoir  40  is located at one end of the battery  10  and separated from each of the compartments  15  by a perimetric wall  42 . An acid additive  44  is contained within acid reservoir  40 . Acid additive  44  is dispensed via a spring-loaded piston activation mechanism  41  from the acid reservoir  40  into each of the compartments  15  through a network of tubes  46  connecting acid reservoir  40  and the various compartments  15 . Each compartment  15  is isolated from the tubes  46  by a valve  48  (shown generically in  FIG. 4 , to be further described hereinafter) which is designed to inhibit “soft shorts”, or the ionic species from one compartment migrating from one compartment to others, which may be at a higher voltage level in a series connected battery. 
         [0084]    It would be evident to one skilled in the art that while most batteries are of a rectilinear shape, other polygonal or free form shapes are equally feasible. Herein after, the term rectangular or rectilinear may also be interpreted as applying to other polygonal or free form shapes. 
         [0085]    At  FIG. 5 , the circular battery  20  of  FIGS. 2A and 2B  is shown in further detail. A central well  23  is located at the center of circular battery  20 , enclosed by a circumferential wall  27 , separating the central well  23  from each of the compartments  25 . An acid additive  44  is contained within central well  23 . Acid additive  44  is dispensed from the central well  23  into each of the compartments  25  through a valve  48  (shown generically in  FIG. 5 , to be further described hereinafter) passing through circumferential wall  27  into each of the compartments  25 . Each valve  48  is designed to inhibit “soft shorts”, or the ionic species from one compartment migrating from one compartment to others which may be at a higher voltage level in a series connected battery. 
         [0086]    It would be evident to one skilled in the art that while a circular battery has been described, oval or free form shapes are equally feasible. Herein after, the term circular may also be interpreted as applying to other substantially rounded or free form shapes. 
         [0087]      FIGS. 6A through 6C  show an alternate means of electrically connecting plate stacks in the various compartments in series and/or parallel connections via a multi-layer composite structure in the upper (and/or lower) outer casing of the battery.  FIGS. 7A  trough  7 C show an alternative means of pumping fluids, including the acid additive, into each of the compartments, and retrieving excess electrolyte when required. As in  FIGS. 6A through 6C , the means for accomplishing this is via a multilayered composite structure in the upper (and/or lower) outer casing of the battery. 
         [0088]    The alternative electrical and fluidic multilayer composite structures are proposed to assist the manufacture and assembly of the battery, since the composite outer casing structures can be easily manufactured on a production line, and reduce the amount of touch labor required in final battery assembly. 
         [0089]      FIGS. 6A through 6C  illustrate a five (5) layer system for electrically interconnecting the compartments  65  in a series connection format, with the five (5) layer system forming one wall  60  of the outer casing of the battery. The multilayer structure is described as follows. Layers  61  and  67  constitute the outer and inner layers of the composite casing structure, with insulating layers  62  and  66  protecting the electrical grid, shown as layer  64 . Both the insulating layer  66  and bottom layer  67  have vias  63  (positive) and  69  (negative) as depicted in  FIG. 6B , allowing the plate stacks in compartment  65 , separated by interior walls  68  to be electrically connected (soldered) to the grid  64  during battery assembly. 
         [0090]    At  FIG. 6C , the mid layer  64  contains a network of ribbon conductors  60 A connecting, in series, the positive tab  63 A of one plate stack in compartment  65  with the negative tab  69 A of the same plate stack. Each of the plate stacks in the various compartments  65  are thus connected in series, such that the voltages are additive. The ribbon connectors  60 A are typically formed from conductive materials such as, but not limited to, copper, and are mounted on a non-conductive polymeric material. The ribbon connectors  60 A terminate at positive lead  63 B and negative lead  69 B for charging and discharging the battery. 
         [0091]      FIG. 7A  depicts a three (3) layer system forming one wall  70  of an outer casing for a battery stack plate (not shown), consisting of an interior layer  77  forming an interior side of outer casing  70  facing the battery (not shown), a mid layer  74  containing channels cut into the plate providing channels for the movement of the electrolytes into and out of the various compartments  75 , and an outer layer  71  comprising a solid plate forming the outer skin of the battery casing  70 . 
         [0092]    At  FIG. 7B , the interior layer  77  is shown. Apertures  72  and  73  allow passage of the acid additive  44  to the supply manifold  76  and from the return manifold  78  ( FIG. 7C ), respectively, into the plate stack (not shown) of each compartment  75  The spring-loaded piston activation mechanism  41  of  FIG. 4  would pump acid additive  44  into the channel grid in layer  74  through port  72 A and retrieve excess electrolyte through port  73 A. 
         [0093]    The mid plate  74  is depicted at  FIG. 7C . A supply manifold  76  and a return manifold  78  are formed in plate  74 , each connecting, respectively, to opposite ends of reservoir  40  ( FIG. 4 ) with the supply manifold  76  connecting to an upper end of reservoir  40  through aperture  72 A, and return manifold  78  connecting to a lower end of reservoir  40 , behind the activation piston, through aperture  73 A. Supply manifold  76  conveys an acid additive  44  from the reservoir  40  to each of the compartments  75 , while return manifold  78  conveys excess acid additive  44  and electrolyte to the reservoir  40 . 
         [0094]    In the case of the series connected battery, as illustrated in  FIGS. 6A-6C , the voltage on the tabs  63 B/ 69 B would be nine times that of the voltage differential in each of the plate stacks, since in a series connection, the voltages are additive. 
         [0095]    In the case of a series connected Bimodal Battery, cited above, where the nine compartments in  FIG. 6A-6C  were connected in series, special precautions must be undertaken to isolate the electrolyte in each compartment from that of each of the other so that there is no current flow through a common electrolyte path causing “soft shorts” and the premature internal discharge of the battery. This is especially necessary during the period of storage or low current mode of operation prior to activation to the high current mode. This could be accomplished by providing a frangible blocking material (not shown) between layers  77  and  74  to prevent intra-compartment electrolyte paths that would lead to premature compartment discharge. The material would be frangible in the sense that an elevated pressure of electrolyte delivered through manifold  76 , during activation, would be sufficient to tear or punch through the frangible material, and allow electrolyte additive to enter the compartments. 
         [0096]      FIGS. 8A and 8B  are side views of one compartment  80  containing a battery plate stack  83  which presents a means of handling excess electrolytes in each compartment  80  of a multi-compartment battery. The top surface  82  of each compartment  80  is formed with a concave shape, such that prior to activation, when the compartment  80  has only neutral electrolyte  81  or has a lower volume of electrolytes  81 , the upper surface  82  is dimpled. As acid additive  44  is introduced into the plate stack  83  of each compartment  80  via port  86 , the pressure created causes the upper surface  82  to pop outwardly to a planar (not shown) or convex shape. This capacity to expand the interior volume of the compartments  80  would eliminate the need for the return manifold  78  ( FIG. 7C ). 
         [0097]      FIG. 9A  is a side view of a one-way pressure sensitive ball valve  90  between the central well  23  and a compartment  25  before and after activation. The ball  92  is held against the valve seat  94  by means of a spring  96 . Upon activation, as shown in  FIG. 9B , pressure differential between the acid additive  44  in the central well  23  and compartment  25  exerts a positive pressure on the ball  92  via orifice  98  causing the ball to retract, allowing acid additive to flow into the compartment  25  via orifice  98  until the pressure is equilibrated. After the pressure has equilibrated post activation, the ball returns to the valve seat, blocking the flow of electrolyte from compartment to compartment via the central well. This inhibits parasitic currents from further discharging the battery. 
         [0098]      FIG. 10A  is a side view of a one-way valve  100  wherein a moveable flapper  102 , held against a valve seat  104  by means of a spring  106 , is caused to open after activation (see  FIG. 10B ), by the differential pressure between the central well  23  and the compartment  25 , rotating the flapper and allowing the acid additive to flow through orifice  108  into compartment  25  until the pressure is equilibrated. After the pressure has equilibrated post activation, the flapper  102  returns to the valve seat  104 , blocking the flow of electrolyte from compartment to compartment via the central well. This inhibits parasitic currents from further discharging the battery. 
         [0099]      FIG. 11A  is a side view of a pressure sensitive frangible membrane  112  with a pin-hole orifice  114  between the central well  23  and compartment  25  before activation. Before activation, the frangible membrane  112  blocks the acid additive from entering compartment  25  through pin-hole orifice  114 . Upon activation, as shown in  FIG. 11B , the differential pressure between the acid additive in  23  and compartment  25  causes the membrane  112  to fracture, allowing acid additive to flow into compartment  25  via the pin-hole  114  until the pressure is equilibrated. After activation, the flow of electrolyte from compartment to compartment is restricted by the size of the pin hole  114 , thereby reducing the effects of the parasitic currents, although not totally eliminating the effect as is done by the ball and flapper valves described above. 
         [0100]      FIG. 12  is a top view of an alternate means of reducing the effects of the parasitic currents after activation by lengthening the electrolyte flow path from central well to the individual compartments thus retarding the movement of electrolyte from compartment to compartment. After activation, the acid additive under pressure flows form the central well  23  through orifice  122  and along a passage in the spoke  124 , through a passage in the rim  126 , into cell stack compartment  25  through orifice  128 . 
         [0101]      FIG. 13  is a top view of a means of lengthening the flow path using the three (3) layer outer casing composite structure illustrated in  FIGS. 7A ,  7 B, and  7 C, but with a serpentine channel built into the composite structure using the “platelet” technology described previously. In  FIG. 13 , the acid additive, under pressure, enters the serpentine channel  134  in the multifunctional plate through orifice  132  in the central well  23  and exits into the compartment  25  through orifice  136 . This lengthening of the electrolyte path from the central well  23  to compartment  25  retards the parasitic currents after activation. 
         [0102]    As mentioned above, an alternate means of eliminating the parasitic currents is to hold the acid additive, not in the central well, but in frangible ampoules, contained adjacent to the plate stack in the compartments, enclosed with the plate stack in a sealed foil pouch.  FIG. 14  is a top view of a compartment with a rectangular shaped, frangible ampoule  142  containing acid additive. 
         [0103]      FIG. 15  is a top view of a frangible ampoule  152  that conforms more closely to the shape of the compartment and distributes acid additive more evenly to the plate stack. 
         [0104]      FIG. 16A  is the top view of an alternate central well structure  23 A containing pyrotechnic-driven tampers  162  surrounding a pyrotechnic charge  164 , held within a structure  166  that allows the tampers to move outward on the ignition of the pyrotechnic. Not shown are top and bottom plates that form a high pressure vessel with the side structure  166 . 
         [0105]      FIG. 16B  shows the post initiation movement of the tampers into the compartments  25 . Once the tampers are deployed, a lip and seal  168  on the tamper body  162  seals the internal pressure vessel so that high temperature gas from the detonation of the pyrotechnic  164 , does not reach the compartments  25 . 
         [0106]      FIG. 17A  is an enlarged view of the interface between the tamper  162  and the ampoule  142  contained within a foil envelope  167  that also contains the wedge-shaped plate stack  169 . 
         [0107]      FIG. 17B  is the enlarged view of the interface after detonation with the tamper  162  crumpling the foil enclosure  167  and fracturing the glass ampoule, distributing the acid additive into the plate stack  169 . 
         [0108]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.