The present invention relates to a Reserve Battery activated by an Electric Igniter which can find use in many devices including Electronic Fuzes, used by the Military for their ordnance where captive power is required. In general all the Reserve Batteries are designed on the same principle except that one or more of the active components are separately stored so that the Battery is totally inert while in storage. In practice, the liquid electrolyte is stored away separately in a reservoir, from the rest of the active components like anode, cathode and separator. When it is required to be activated, an external source has to cause to activate the Battery by making the electrolyte to come in contact with the electrodes. Electrolyte flows from the reservoir and wets the cell electrodes, which activates the Reserve Battery for powering a circuit in the device where it is employed such as electronic fuze or electronics of safety and arming device or a self-destruction mechanism.

Often Reserve Batteries have been large, bulky, heavy and expensive to make, and contain large areas of wasted space due to mechanical separators. For these reasons, the production and use of Reserve Batteries has generally been less than optimal and costly. Hence one of the objectives of the invention is to improve the design so as to reduce the size and increase the efficiency in performance of the Battery.

Another objective of this invention is to provide a Reserve Battery which can give sustained power output for a tonger period than conventional Reserve Batteries used in the Fuze of Artillery shells and also capable of functioning at any orientation in all the three axis. The Battery under our invention will also meet the requirements of MIL-STD 331C and MIL-STD 810G.

Further it has to be a reliable source of portable electrical power, meant for long periods of storage and is designed to be activated very quickly with little degradation in performance over time. In some applications, the Reserve Battery must have a prolonged shelf life even at extreme temperatures. Once activated, the Reserve Battery electrically powers a circuit from a few seconds to a few hours as per the customer demand. No maintenance is required for the Reserve Battery during storage prior to use, permitting it to be permanently installed in the equipment.

Accordingly as per our invention, a Reserve Battery activated by electric igniter comprising an electrode stack arrangement; an ampoule containing electrolyte; an activating system; a housing in which the said electrode stack arrangement, ampoule and activating system can be placed, characterized wherein the
electrode stack arrangement wound around a former comprising single or plurality of lithium electrode and carbon electrode separated by a separator wherein the fragile glass ampoule containing Thionyl Chloride electrolyte is
positioned at the hollow portion inside the former whereas the said activating system comprising of an electric igniter system positioned inside the former just above the base of the ampoule and capable of breaking the ampoule on firing the electric igniter, wherein the former is having electrolyte outlet holes at its periphery on the top and bottom sides to act as channels to facilitate the flow of electrolyte into the voids between the electrodes wound around the former, to
cause to activate the electrode stack arrangement to generate electrical power
and finally a metallic Battery case housing the said electrode stack arrangement, ampoule and activating system capable of closing by a Battery top lid.

According to this invention an ignition means such as electric igniter is used and on activation it causes ampoule to get crushed and the electrolyte comes out of the ampoule, where it is stored and comes in contact with the electrodes and the generation of electrical power commences. Based on the current requirement, voltage, duration, activation time and the storage life required, one has to select the active components, surface area of the electrode, volume of the electrolyte, cell geometry and number of the cells during the design of the Battery.

The state of art manufacturing method followed in the configuration of the former with electrodes is unique in its design combined with fast activation to have the desired out put voltage. The method of preventing the current leakage is another unique feature of our invention.

In one of the embodiments under our invention, we have gone for a single cell design to meet a specification formulated based on the market demand. Now the invention will be described in more detail with reference to the accompanying drawings bringing out an embodiment of the arrangement according to the invention in which figures and descriptions are given as under.

Fig 1 - Exploded view of igniter activated Reserve Battery

Fig 2 - Sectional view of Former assembly

Fig 3 - Isometric view of Battery Top lid

Fig 4 - Isometric view of the electrode stack arrangement.

Fig 5 - isometric view of the detailed electrode stack arrangement.

Fig 6 - Shows an example of typical activation graph of the Electrical igniter
activated Reserve Battery

Fig 7- Typical operational graph of the Electrical igniter activated Reserve Battery.
Wherein

(1)Battery top Lid, (2) Former, ( 2a ) Flow regulator ring, (2b) End seal ring, ( 3) Hollow metal sleeve, (4) O- ring, (5) Electrical Igniter system, (6) Glass Ampoule, (7) Electrode stack arrangement, (8) Flexible rubber sleeve, (9) End cap, (10) Teflon sleeve, (11) Battery case, (12) Metal disc, (13)1st Terminal of the Igniter, (14) Positive terminal, (15) 2nd terminal of the Igniter, (16) Grub Screw,(17) Lithium electrode,(18) Carbon electrode, (19) Separator, (20) Electrolyte (21) Metal housing, (22) Electrical igniter, (23) Electrolyte outlet holes, (24) Slot for locating electrical igniter system, (H.T) High Temperature, (R.T) Room Temperature, (L.T) Low Temperature

The major parts of the Reserve Battery under our invention are, an Electrode stack arrangement (7); a glass ampoule (6) containing an electrolyte (20); an electric igniter system (5) as an activating means; a specially designed former (2) to hold on electrode stack arrangement (7); and finally a Battery case (11) with Battery top lid (1) in which the said electrode stack arrangement, glass ampoule (6) and igniter (22) are placed. The Battery case (11) is made of metal, preferably Nickel or SS 304 or plated MS, to withstand the corrosive action of electrolyte. The shape is selected from any suitable profiles like cylindrical, square, conical, or based on the customer's requirement. The battery case can hold one or more cells, as defined by the voltage requirements. In the preferred embodiment under this invention, the battery case is in cylindrical shape made of SS 304 and houses one cell system.

The bottom of the Battery case is closed with a metal disc (12), by welding and is .made leak proof. The Battery case can hold the former (2) wound with the electrode stack arrangement (7) as well as the glass ampoule (6) placed in the designated cavity of the former.

The former (2) houses the glass ampoule (6) and the electrical igniter system (5). The former can be of cylindrical shape for housing the glass ampoule (6). In the preferred embodiment under this invention, the former is made in the shape of a "Rook" as seen in the game of Chess with special base rings. The shape and
contours of the former is specially chosen, so as to prevent shorting as well as crushing the electrode stack arrangement during the activation of the battery. The former is provided with a flow regulator ring (2a) to supply the electrolyte in a controlled manner once the battery is activated. It also safeguards the electrode stack from getting crushed due to- the high pressure created during the firing of the igniter. The End seal ring (2b) is provided at the bottom of the former to
ensure proper sealing with the battery case, thereby ensuring uniform space for the electrolyte to flow smoothly without imparting high pressure on the electrode.

The former is fortified by a hollow metal sleeve (3) along its inner circumference, to give added strength. The former with metal sleeve arrangement is provided with electrolyte outlet holes (23) on top and bottom sides, which act as outlets for the electrolyte to flow out and enter the stack arrangement (7), when the Battery
is activated. The size of the holes are small enough to prevent the glass splinters of the crushed ampoule from entering into the stack arrangement, while sufficient number of holes are provided to ensure the flow of the electrolyte quickly to activate the battery. The former is also provided with a slot (24) on the top side for housing the electric igniter system (5). The electrical igniter system comprises
of an electrical igniter (22) assembled in a metal housing (21) which can be held inside the designated slot (24) of the former. The leads of the electric igniter system are soldered to appropriate terminals of the top lid (1). One O-ring (4) isplaced at the neck of the former (2) which helps in snuggly fitting it inside the
battery case and make it air tight when the former is assembled with electrode stack assembly and placed inside the Battery case (11). The bottom of the former is closed with one end cap (9) after assembling the glass ampoule inside the former.

The glass ampoule (6) is made from glass tube, preferably of boro silicate chemistry, and will hold the electrolyte in it, as boro silicate glasses are known for having very low coefficients of thermal expansion (~3x10-061°C at 22°C), making them resistant to thermal shock, more so than any other common glass. Such glass is less effected by thermal stress and is commonly used for the construction of reagent bottles also. The electrolyte is filled in the ampoule, in a dry inert atmosphere with a very low relative humidity, less than 2.0% and low temperature, less than 20°C and then the neck is closed suitably by tig welding or flame welding or laser welding to prevent the electrolyte from coming out of the ampoule before the Battery is activated. The neck of the ampoule (6) is protected by putting a flexible rubber sleeve (8), preferably made of viton rubber. The electrolyte (20) used in this Battery is Thionyl Chloride with additives selected from Bromine, Chlorides of Potassium, Aluminum, Lithium.

The Electrode stack arrangement (7) in the said invention is comprising of lithium electrode (17) pressed on a wire mesh selected from nickel, stainless steel, silver or any suitable metal which functions as cathode, and carbon powder pasted on a wire mesh selected from nickel, stainless steel, silver or any suitable metal forms the carbon electrode (18) and functions as anode. The lithium electrode is made by pressing a lithium sheet of predefined thickness on the selected wire mesh, to which a Nickel strip which functions as the lead for drawing electric power is attached, preferably by resistance welding, before pressing the Lithium sheet. Later on, this nickel strip is soldered to the body of the Battery case (11), once the former with electrode stack assembly is inserted into the Battery case. The process is done in a dry inert atmosphere with very low relative humidity content less than 2.0% and low temperature, less than 20°C, as lithium is highly reactive and hydrolyzes even if it is exposed to atmospheric moisture, and can form nitrate compounds in presence of moisture. The carbon electrode (18) is made by pasting a mixture of carbon powder having a large surface area per weight and a binder, preferably polytetrafluoroethylene suspension on wire mesh selected from nickel, stainless steel, silver or any suitable metal, to which a nickel strip is attached preferably by resistance welding. This nickel strip which functions as the positive lead is welded to the positive terminal (14) of the top lid, once the former with electrode assembly is inserted in the Battery case. The electrodes are separated by an insulating material, selected form woven or non woven cellulosic paper, polythene film, nylon film, and glass mat, preferably a non woven glass mat insulating medium called herein after as separator (19) in the present invention.

The electrode stack arrangement (7) can have one or more number of cells based on voltage requirements. But in the present case the electrode stack arrangement comprises of an alternate Lithium electrode and Carbon electrode separated by a non conductive separator in the form of a strip. Said electrode stack arrangement is wound around the former (2). The former wound with the electrode stack assembly is further wound with a Teflon sheet (10) without leaving any open surface of the electrode or former to prevent shorting of the cell by way of coming into contact with the battery case (11).

The Battery top lid (1) is made from the same material used for the battery case and is having 4 holes drilled and threaded suitably. Out of these, three holes are fitted with glass to metal pins, which act as lead terminals of the Battery. Two of' the terminals (13 and 15) are connected to the electrical igniter system for providing power input for activation of the Battery, and one terminal (14) is connected to the positive lead of the stack assembly which acts as one of the output terminals. One hole is essentially left idle for filling the void space between the former (2) and the battery top lid (1) with the sealant, once the Battery assembly is completed, and the Battery case is closed with the Battery top lid and welded suitably by TIG welding or Laser welding. Subsequently the sealant is filled as mentioned above and the hole is closed with a grub screw (16).

When the Battery is required to be activated, the requisite electrical charge is supplied to the appropriate terminals of the Battery, for firing the electric igniter (22). The pressure developed due to the explosion caused by the electric igniter will crush the glass ampoule held inside the former and makes the electrolyte (20) to come out of the electrolyte outlet holes (23) of the former with sufficient force and come in contact with the electrode stack arrangement (7) made available on the outer surface of the former, thereby activating the Battery.

Special features of the Battery under our invention are as under.

• This Battery is designed in such a way, that it can be activated and is operable in any orientation in all the three axis.

• The former is protected with a metal sleeve from inside, preventing collapse of the stack due to the shock of ignition, hence is highly reliable and fail safe.

• Flow regulator ring provided on the former ensures controlled supply of the electrolyte and also prevent the electrode stack from crushing.

• Long duration Battery with sustained power out put.

• Flexibility in increasing the voltage by introducing plurality of electrode stacks.

The prototype under our invention using a single cell was made and evaluated and the performance was found satisfactory. Multi cell stack also can be made as per voltage requirement. The performance characteristics of the prototype are given in Fig.6 and Fig.7 by way of example. The general characteristics of the prototype mono cell Battery made under our invention are as under.

Open circuit voltage : 3.00 to 3.65 based on temperature
Voltage on load : 2.5 to 3.60 V
Current : 5 mA to 100mA
Capacity : 250 mAh (minimum)
Activation Time : <2.5 sec
Run Time : > 10 min to 150 hours ( based on load)
Dimensions of the mono cell Battery
Diameter (nominal) : 17.8 mm max.
Length (nominal) : 43 millimeters (w/o terminals)
Weight (nominal) : 30 grams max.
Operating Temperature Range : -40°C to +70°C Storage Temperature : -54°C to +70°C
Connector : 3 Pins: Two for Electric Initiation, One for drawing electrical power.

(The Battery body functions as the second terminal for drawing electric power) Activation Mechanism : Electric Ignition;

All fire: 0.25A, 10ms Pulse No fire: 0.15A for 5 minutes Battery Case & Mounting Flange : Stainless Steel

Battery under our invention has got wide usage in different type of Fuzes used in Ammunition as well as in other devices and equipments used by the Military. Further these batteries can be used as emergency back up for communication equipment where the normal source of power is either not available or is interrupted during combat operations in remote as well as forward areas.

We have brought out the novel features of the invention by explaining one of the preferred embodiments under the invention enabling the man in the art to understand and visualize our invention. It is also to be understood that the invention is not limited in its application to the details of construction or to the arrangements of the components set forth in the above description or illustrated in the drawings. It is be to noted that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described herein above and as defined in the appended claims.

We Claim

1. A Reserve Battery activated by electric igniter comprising an electrode stack arrangement; an ampoule containing electrolyte; an activating system; a housing in which the said electrode stack arrangement, ampoule and activating system can be placed, characterized wherein the electrode stack arrangement (7) wound around a Former (2) comprising single or plurality of lithium electrode (17) and carbon electrode (18) separated by a separator (19) wherein the fragile glass ampoule (6) containing Thionyl Chloride electrolyte (20) is positioned at the hollow portion inside the former (2) whereas the said activating system comprising of an electric igniter system (5) positioned inside the former just above the ampoule and capable of breaking the ampoule on firing the electric igniter (22) wherein, the former is having electrolyte outlet holes (23), at its periphery on the top and bottom sides to act as channels to facilitate the flow of electrolyte (20) into the voids between the electrodes wound around the former (2), to cause to activate the electrode stack arrangement to generate electrical power; and finally a metallic Battery case (11) housing the said electrode stack arrangement, ampoule and activating system capable of closing by a Battery top lid (1).

2. A Reserve Battery activated by electric igniter as claimed in claim 1, wherein the activating means is an electrical igniter system (5) positioned in the designated slot (24) of the former and comprises of an electric igniter (22) assembled in a metal housing (21) capable of focusing the explosive power of the igniter on the weakest area of the ampoule and forcing the electrolyte into the electrode stack without destroying the electrode stack due to the shock generated during the igniter firing and wherein the leads of the igniter are soldered to the appropriate terminals of the top lid (1).

3. A Reserve Battery activated by electric igniter ais claimed in claim 1, wherein the former (2) is made in the shape of a "Rook" and fortified by a hollow metal sleeve (3) along its inner surface and capable of housing the glass ampoule (6) and the electrical ignition system (5), wherein on the outer surface of the former is provided with an electrolyte flow regulator (2a) at the upper side and an end seal ring (2b) at the bottom to seal with the case capable of facilitating the smooth flow of electrolyte thereby avoiding the shorting of the electrode arrangement and preventing crushing of the electrode stack and further provided with a slot (24) on the top side for housing the ignition system (5), and assembled in the Battery case (11) tightly by means of one O-ring (4) provided at the neck of the former (2).

4. A Reserve Battery activated by electric igniter as claimed in claim 3 wherein the former (2) is provided with electrolyte outlet holes (23) on top and bottom sides, to act as channels for electrolyte to flow out and enter the electrode stack arrangement (7), where in the size and number of the holes are so selected to prevent the glass splinters of the crushed ampoule from entering into the electrode stack area, when the Battery is activated.

5. A Reserve Battery activated by electric igniter as claimed in claim 1 wherein the electrode stack assembly (7) is having one or more of cells based on the voltage requirements, comprises of an alternate rectangular Lithium electrode and Carbon electrode separated by a non conductive separator in the form of a strip and the said stack assembly is wound around the former (2) and further wound with a Teflon sleeve (10) without leaving any open surface of the electrode or former to prevent shorting of the cell, wherein

a) the lithium electrode (17) made by pressing the lithium sheet of predefined thickness on a metal mesh selected from nickel, stain less steel, silver, or any other suitable metal and connected to a Nickel strip, that functions as the negative lead for drawing electric power, which in turn is connected to the Battery case (11), and

b) the carbon electrode (18) made from a mixture of carbon powder having large surface area per weight ratio and a binder preferably Polytetrafluroethylene suspension on a metal mesh selected from nickel, stain less steel, silver, or any other suitable metal, and welded to a nickel strip which acts as the positive lead and is connected to the positive terminal (14) of Battery top lid (1), orice the-former (2) with electrode assembly is inserted in the Battery case (11).

6. A Reserve Battery activated by electric igniter as claimed in claim 1, wherein the electrolyte (20) is thionyl chloride liquid with additives selected from Bromine, chlorides of Potassium, Aluminum, and Lithium and stored in an ampoule made from glass tube preferably made with borosilicate glass and provided with a flexible rubber sleeve (8) preferably made with viton rubber to protect the neck end of the ampoule from breakage due to mishandling or mechanical shocks during transportation.

7. A Reserve Battery activated by electric igniter as claimed in claim 1 having a Battery top lid (1) with 4 holes drilled and threaded suitably, wherein three holes are fitted with one glass to metal pin (terminal) each, which act as lead terminals of the Battery and of which, two of the terminals (13 and 15) are capable of connecting to the electrical igniter system for providing power input for activation of the Battery and the third terminal i.e. positive . terminal (14) is capable of connecting to the positive lead of the stack assembly which acts as one of the output terminals whereas the fourth hole for enabling to fill the void space between the former and the battery top lid with the sealant prior to closing the hole with a grub screw (16).

8. A Reserve Battery activated by electric igniter as claimed in claim 1, wherein the electrodes are Separated by a separator (19), selected form cellulosic paper, polythene film, nylon film, and glass mat, preferably a non woven glass mat insulating medium.

9. A Reserve Battery activated by electric igniter as claimed in claim 1, wherein it is capable of operating at a temperature ranging from - 40°C to +70°C and with a storage temperature ranging from -54°C to +70°C and meeting the requirements of MIL-STD 331C and MIL-STD 81OG.

10. A Reserve Battery activated by electric igniter as claimed in claim 1 to 9 substantially herein described with reference to and illustrated in figure 1 to 7 of the accompanying drawings.