Patent ID: 12206084

DETAILED DESCRIPTION

The present Li-Oxygen reserve batteries are described using the basic Li-Oxygen reserve battery embodiment10shown in the cross-sectional schematic ofFIG.2. As discussed above, such Li-Oxygen reserve battery is presented by way of example and without any intention of limiting the disclosed embodiments to Lithium metal and in general, any other metal, including those disclosed above may be used to replace the Lithium metal as the anode.

As can be seen inFIG.3, the reserve battery embodiment10comprises a metal anode, such as a Lithium metal electrode that is separated from the battery non-aqueous electrolyte by a Solid Electrolyte Interphase (SEI) layer. A porous cathode, such as a Carbon-based O2cathode is the next component of the battery core into which a gas such as Oxygen gas or a gas comprising Oxygen can be allowed to enter to activate the reserve battery. The above components of the Li-Oxygen reserve battery are packaged inside a sealed housing11. To achieve a hermetically sealed reserve battery with a shelf life of over 20 years, the battery terminals12can be provided with glass or other similar electrical insulation as they pass through the sealed housing11.

In another sealed housing compartment18, oxygen gas is provided under pressure as shown inFIG.3. The sealed compartment18and the battery core housing11can share a common wall19. The common wall19can be provided with a relatively small opening14into the battery core, which can be sealed by a metallic diaphragm13. In general, the housings11and18can be formed from stainless steel and the diaphragm13can also be a thin stainless sheet that is welded to the wall19.

Also provided inside the oxygen gas compartment18is a movable mass member15, which can be biased firmly against surface21of the compartment18, such as, by a preloaded compressive spring16. The mass member15can be provided with a sharp cutting member17, which is positioned above the hole14.

The Li-Oxygen reserve battery embodiment10operates as follows. In normal conditions, the diaphragm13prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. If the device to which the reserve battery10is attached is accelerated in the direction of arrow22, the acceleration would act on the mass member15, generating a downward dynamic force. The compressive spring16is preloaded such that when the acceleration in the direction of the arrow22has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the mass member15would begin to move downward towards the diaphragm13. If the acceleration in the direction of the arrow22is long enough in duration, the mass member15would gain enough speed for the cutting member17to reach the diaphragm13and rupture it, thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. If the duration of the applied acceleration in the direction of the arrow22is very short, for example due to accidental drop of the object to which the reserve battery10is attached, the mass member15and spring16system is configured such that the cutting member17is not displaced down enough to rupture the diaphragm13.

In the schematic ofFIG.3only one inertia-based activation mechanism is shown to be provided. It is appreciated that when a larger amount of gas flow is desired, more than one activation mechanism of this type or another type and corresponding hole14and diaphragm13may also be provided.

It is appreciated by those skilled in the art that gases present in air, such as nitrogen, water vapor, and carbon dioxide can react with the metal anode, liquid electrolyte, and cathode electrode and negatively impact the discharge performance of currently available Lithium-Air batteries. In addition, it has been extensively reported (for example, J. Read, K. Mutolo, M. Ervin, W. Behl, J. Wolfenstine, A. Driedger and D. Foster, “Oxygen Transport Properties of Organic Electrolytes and Performance of Lithium/Oxygen Battery,”Journal of Electrochemical Society, vol. 150, no. 10, pp. A1351-A1356, 2003) that a higher oxygen partial pressure improves battery capacity, especially at high discharge rates, by increasing the oxygen saturation concentration in the liquid electrolyte and by enhancing the oxygen diffusion rates in the porous cathode active sites. Therefore, pure oxygen can be used in the compartment18to activate and discharge the battery.

The reserve battery embodiment10ofFIG.1is assembled in the inactive state with the pressurized oxygen in the adjacent compartment18. As a result, as long as oxygen gas is not allowed to enter the battery core through the provided hole14by the diaphragm13, the battery stays in its inactive state, thus serving as a reserve battery. Once the diaphragm13has been ruptured as was previously described, the presence of oxygen immediately starts the reduction/oxidation reactions inside the battery core and, as a result, a voltage differential is established across the anode and cathode sides of the cell. In the porous carbon cathode electrode, oxygen is reduced to lithium peroxide that accumulates in the pores of the electrode. At the same time, lithium metal from the anode electrode is oxidized to lithium ions, which transport to the cathode electrode through the liquid electrolyte and polymeric separator to the porous carbon cathode electrode. The battery discharge reactions will continue until all the stored oxygen or the available Li metal is consumed.

In the Lithium-Oxygen embodiment10ofFIG.3, the mass-spring based inertial activation mechanism of the battery is positioned inside the pressurized oxygen comportment of the battery. An alternative positioning of the mass-spring inertial based activation mechanism inside the porous carbon-based O2cathode side of the reserve battery assembly is shown in the cross-sectional view ofFIG.4and indicated as the reserve battery embodiment20. In the schematic ofFIG.4, all other components of the reserve battery are similar to that of the embodiment10ofFIG.3. It is appreciated that to support the preloaded compressive spring24of the mass-spring based inertial activation mechanism, a support structure23, for example a beam structure23or a base support structure25must be provided.

One advantage of locating the mass-spring based inertial activation mechanism inside the battery core may be that it makes the battery assembly easier and allows more space for the pressurized oxygen.

The Li-Oxygen reserve battery embodiment20ofFIG.4operates as follows. In normal conditions, the diaphragm13prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. If the device to which the reserve battery20is attached is accelerated in the direction of the arrow26, the acceleration would act on the mass member27, which is movable within the housing11, generating a downward dynamic force. The compressive spring24is preloaded such that when the acceleration in the direction of the arrow26has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the mass member27would begin to move upward as viewed inFIG.4and towards the diaphragm13. If the acceleration in the direction of the arrow26is long enough in duration, the mass member27would gain enough speed for the cutting member28to reach the diaphragm13and rupture it, thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. If the duration of the applied acceleration in the direction of the arrow26is very short, for example due to accidental drop of the object to which the reserve battery20is attached, the mass member27and spring24system is configured such that the cutting member28is not displaced up enough to rupture that diaphragm13.

The Lithium-Oxygen reserve battery embodiments10and20ofFIGS.3and4, respectively, are configured to be activated when the device to which they are attached is subjected to a prescribed acceleration profile, such as firing of a gun. In certain applications, however, the reserve battery is required to be activated manually or via certain actuation device that is positioned external to the reserve battery. The reserve battery embodiment30ofFIG.5is configured to allow for activation manually or using an external positioned actuation device.

In the schematic ofFIG.5, all other components of the reserve battery are similar to that of the embodiment10ofFIG.3, except that its mass-spring inertial activation mechanism is removed and is replaced by a mechanism that allows for manual activation or using an externally positioned actuation device as described below.

As can be seen inFIG.5, the Lithium-Oxygen reserve battery embodiment30is provided with an activation mechanism comprising a metallic bellow31, such as that formed with the same metal with which the container18is constructed, such as stainless steel. The bellow31is fixedly attached to the top surface of the oxygen gas container18, such as by welding or brazing, and the attachment is tested to ensure that is fully sealed. The bellow is configured to have the required flexibility so that when pressed to activate the battery as described below, it would essentially act as a spring element and return to its normal state. The bellow is provided with a sealed cap33, which may be integral to the bellow31. A pin34is fixedly attached to the cap33of the bellow31, which can be provided with a guide36inside the oxygen gas container18as can be seen inFIG.5. The pin34is provided with a sharp tip35, which is positioned over the hole14and proximate to the diaphragm13.

The Li-Oxygen reserve battery embodiment30ofFIG.5operates as follows. In normal conditions, the diaphragm13prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. The user then may manually press the cap33of the bellow31down in the direction of the arrow37. As a result, the bellow31begins to deform, allowing the pin34to slide down the guide36, causing the sharp tip35of the pin34to rupture the diaphragm13, thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. It is appreciated by those skilled in the art that the cap33of the bellow31may also be displaced down by an externally positioned linear or rotary electrical, piezoelectric-based or pneumatic or the like actuation device on command, for example provided by a system control system, as is well known in the art.

In the Lithium-Oxygen embodiment30ofFIG.5, the manual or externally actuated activation mechanism of the battery is positioned at the pressurized oxygen comportment of the battery and must therefore be capable of withstanding the oxygen gas pressure while staying fully sealed. An alternative positioning of the activation mechanism is inside the porous carbon-based O2cathode side of the reserve battery assembly as shown in the cross-sectional view ofFIG.6. The resulting Lithium-Oxygen reserve battery is indicated as the embodiment40. In the schematic ofFIG.6, all other components of the reserve battery are similar to that of the embodiment10ofFIG.3. Another advantage of locating the activation mechanism inside the battery core is that it makes the battery assembly easier and allows more space for the pressurized oxygen.

As can be seen inFIG.6, the Lithium-Oxygen reserve battery embodiment40is provided with an activation mechanism that comprises a metallic bellow41, such as being formed of the same metal with which the battery core housing11is constructed, such as stainless steel. The bellow41is fixedly attached to the side surface of the battery core housing11, such as by welding or brazing, and the attachment is tested to ensure that is fully sealed. The bellow41is provided with a sealed cap42, which may be integral to the bellow41. A pin43is fixedly attached to the cap42of the bellow41, which can be provided with a guide44inside the battery core housing11as can be seen inFIG.6. The pin43is provided with an enlarged frontal section45that is movable within the housing11and that is close or in contact with the flexible member46that bends as a bending flexure or rotates about a joint and on which is provided a sharp tip member47, which is positioned under the hole49and proximate to the diaphragm48as can be seen inFIG.6.

The Li-Oxygen reserve battery embodiment40ofFIG.6operates as follows. In normal conditions, the diaphragm48prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. The user then may manually press the cap42of the bellow41in the direction of the arrow51. As a result, the bellow41begins to deform, allowing the pin43to slide in the guide44, causing the sharp tip45of the pin43to bend/rotate the member46upward towards the diaphragm48, thereby causing the sharp tip member47to rupture the diaphragm48, thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. It is appreciated by those skilled in the art that the cap42of the bellow41may also be displaced down by an externally positioned linear or rotary electrical or piezoelectric-based or pneumatic or the like actuation device on command, for example provided by a system control system, as is well known in the art.

It is appreciated that once the novel Lithium-Oxygen reserve battery embodiments ofFIGS.3-6are activated, they would generally stay activated until it runs out of either oxygen gas or Lithium metal. In many applications in which electrical energy may only be needed for relatively short periods of times and relatively long enough times in between, then it is highly desirable for a reserve battery to be capable of being activated only when needed and then be deactivated, i.e., reverted to its reserve battery state. The reserve batteries are herein described as if it is implemented in the Lithium-oxygen reserve battery embodiment50ofFIG.7.

In the schematic ofFIG.7, all components of the Lithium-oxygen reserve battery are similar to that of the embodiment10ofFIG.3, except that its mass-spring inertial activation mechanism is removed and is replaced by the activation/deactivation mechanism shown in the blow-up view “A”, which is illustrated in detail inFIG.8.

As can be seen in the blow-up view “A” ofFIG.8, the Lithium-Oxygen reserve battery embodiment50is provided with an activation mechanism comprising two components. The first component is the actuation mechanism that comprises a metallic bellow52, that can be formed of the same metal with which the battery core housing11(FIG.7) is constructed, such as stainless steel. The bellow52is fixedly attached to the side surface of the battery core housing11, such as by welding or brazing, and the attachment is tested to ensure that is fully sealed. The bellow52is provided with a sealed cap53, which may be integral to the bellow52. A pin54is fixedly attached to the cap53of the bellow52, which can be provided with a guide55inside the battery core housing11as can be seen inFIG.8. The pin54is provided with an enlarged frontal conical section56that is close or in contact with a sloped surface57of the member58as shown inFIG.8.

The second component of the actuation mechanism is a normally closed valve59. The normally closed valve59comprises a valve cap61, which is provided with a stem member62that passes through a hole that is provided in the base64of the oxygen gas container18,FIG.7. The opposite side of the stem member62is provided with the member58, which is used to provide support for the preloaded compressive spring65and its bottom surface57is sloped as can be seen inFIG.8to engage the surface of the conical section56of the actuation mechanism. An elastomeric gasket63is also provided between the surface of the oxygen gas container surface64and a surface of the valve cap61. The compressive spring65is preloaded enough to ensure that in its normally closed state, no oxygen gas can escape into the battery core from the pressurized oxygen container18. The pressurized oxygen gas itself also assists in sealing of the valve in its normally closed state.

The Li-Oxygen reserve battery embodiment50ofFIG.7operates as follows. In normal conditions, the valve59is closed and prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. The reserve battery50is therefore in its inactive state and provides a long shelf life that can significantly exceed the military required 20 years. The user may then manually press the cap53of the bellow52in the direction of the arrow66,FIG.8. As a result, the bellow52begins to deform, allowing the pin54to slide forward in the guide55, causing the conical section56to move forward, thereby engaging the sloped surface57of the member58and forcing it to begin to move upward as seen in the view ofFIG.8. As a result, the cap61is lifted from over the elastomeric gasket63, thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. When the applied force to the cap53of the bellow52in the direction of the arrow is removed, the compressed bellow52would spring back (which might be assisted by an internal compressive spring that is provided around the pin54inside the bellow—not shown), thereby allowing the preloaded compressive spring65and the pressurized oxygen gas to close the valve59and stop transfer of pressurized gas into porous carbon-based O2cathode section of the battery core. The battery is thereby reverted to its reserve state and the battery core would stop generating electrical energy once its present oxygen gas has been consumed.

It is appreciated by those skilled in the art that the cap53of the bellow52,FIG.8, may also be displaced forward in the direction of the arrow66by an externally positioned linear or rotary electrical or piezoelectric-based or pneumatic or the like actuation device on command, for example provided by a system control system, as is well known in the art.

It is noted that in the embodiments30,40and50ofFIGS.5,6and7, respectively, the activation mechanism bellow is positioned outside of the reserve battery housing. Such positioning of the activation device bellow may then be used to provide a “safety pin” for the reserve battery to protect it against accidental activation, such as during the battery fabrication and packaging and during the process of installing in the final product. The “safety pin” may in general be positioned between the bellow cap (33,42and53inFIGS.5,6and8, respectively) and the outer surface of the reserve battery. An example of such a bellow actuation preventing “safety pin” as applied to the activation mechanism of the reserve battery embodiment30ofFIG.5is shown in the schematics ofFIG.8Aand the top view ofFIG.8B.

In the schematic ofFIG.8Athe reserve battery activation mechanism of the Lithium-Oxygen reserve battery embodiment30ofFIG.5as mounted on the top surface145(32inFIG.5) of the oxygen gas container146is shown. As was described for the embodiment ofFIG.5, the bellow140(31inFIG.5) is fixedly attached to the surface145. The bellow140is provided with a sealing cap143, which is larger than the cap33of the embodiment ofFIG.5. The sliding pin144(34inFIG.5) with the sharp tip is also shown inFIG.8A. The “safety pin” of the activation mechanism comprises a “U” shaped member147, which is positioned around the bellow140and under the edges148of the cap143as can be seen inFIG.8Aand the top view ofFIG.8B. It is noted thatFIG.8Ais the cross-sectional view C-C ofFIG.8B. The “U” shaped member147would then prevent accidental depression of the cap143and thereby accidental activation of the reserve battery. A pin149can also be provided that passes through matching holes (not seen inFIG.8A) through the ends of the “U” shaped member147as shown inFIG.8Bto prevent the “U” shaped member147from falling off as the reserve battery is handled. With the described “safety pin” assembly, the reserve battery is rendered non-operational. To make the reserve battery operational, the user would pull the pin149out to allow the “U” shaped member147to be pulled out from under the cap143, thereby freeing the bellow140to be depressed to rupture the membrane13(FIG.5), thereby activating the reserve battery as was previously described.

The valve59configuration may be readily adapted to provide an inertial activation mechanism that does not rely on rupturing a diaphragm, such as was described for the Lithium-oxygen reserve battery embodiment20ofFIG.4. Such a Lithium-oxygen reserve battery embodiment60is shown in the cross-sectional schematic ofFIG.9. Such a Lithium-oxygen reserve battery embodiment60has two basic advantages over the embodiment20ofFIG.4. The first advantage is that it does not require the support structure (23or25inFIG.4). As a result, it makes the reserve battery fabrication and assembly simpler. Secondly, since the pressurized oxygen gas assists in keeping the valve closed and sealed, the preloaded compressive spring is only required to provide a relatively small force to keep the valve components together before and after activation.

In the Lithium-Oxygen embodiment60ofFIG.9, the inertial activation mechanism comprises a mass member67, which is movable in the housing11and which is connected to the valve cap69by a connecting member68that passes through a hole provided in the base of the pressurized oxygen gas container18. An elastomeric gasket71is provided under the valve cap69and is pressed down by the preloaded compressive spring72and the pressure of the oxygen gas to ensure that there is no leakage of the oxygen gas into the battery core through the provided hole in the oxygen gas container. A support member73is fixedly attached to the bottom surface77of the pressurized oxygen gas container18. A sliding member74is then provided that is normally pressed slightly against the side of the valve cap74by the preloaded compressive spring75. All other components of the Lithium-oxygen reserve battery embodiment60are similar to that of the embodiment10ofFIG.3.

The Li-Oxygen reserve battery embodiment60ofFIG.9operates as follows. In normal conditions, the preloaded compressive spring72and the pressurized oxygen gas in the container18keep the valve closed and prevent oxygen gas from entering the porous carbon-based O2cathode of the battery core. If the device to which the reserve battery60is attached is accelerated in the direction of the arrow76, the acceleration would act on the inertia of the mass member67and the connecting member68and the cap69, generating an upward dynamic force. The compressive spring72is preloaded such that when the acceleration in the direction of the arrow76has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the assembly of the mass member67, connecting member68and the cap69would begin to move upward as viewed inFIG.9. If the acceleration in the direction of the arrow76is long enough in duration, the cap69is moved up enough to allow the pressurized oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. Once the cap69has moved up, the gap between the bottom surface of the cap69and the surface77of the container18is configured to be enough to allow the “locking” member74to be pushed under the cap69and prevent the cap to close the flow of the oxygen gas into the battery core once the acceleration in the direction of the arrow76has ceased. Thereby, the reserve battery is activated and stays activated after the acceleration event, for example due to the firing of a munition in which the reserve battery is mounted. If the applied acceleration in the direction of the arrow76is below the prescribed threshold, for example due to accidental drop of the object to which the reserve battery60is attached, the valve stays closed and the reserve battery is not activated.

It is appreciated that the Lithium-oxygen reserve battery embodiment50ofFIG.7can be activated using a linear or rotary electrical or piezoelectric-based actuation device such as a solenoid as was previously described. However, an external power source is needed at the time of initial reserve battery activation. This requirement may not be desirable in some munition applications.

The Lithium-oxygen reserve battery embodiment70ofFIG.10is configured to be activated during the munitions firing for a short period of time to activate the reserve battery long enough to generate the electrical energy needed to operate the electrically actuated activation mechanism of the reserve battery as required by the system being powered by the reserve battery.

In the Lithium-Oxygen reserve battery embodiment70ofFIG.10, the battery activation mechanism comprises the normally closed valve59,FIG.8, and the actuation mechanism84. The components of the normally closed valve59are similar to that used in the embodiment ofFIG.8. All other components of the Lithium-oxygen reserve battery embodiment70are similar to that of the embodiment10ofFIG.3.

The actuation mechanism84of the Lithium-Oxygen reserve battery embodiment70ofFIG.10is similar to the one used in the embodiment50ofFIG.7(also shown in the blow up view ofFIG.8), and similarly comprises a metallic bellow78, such as being formed of the same metal with which the battery core housing11(FIG.10) is constructed, such as stainless steel. The bellow78is fixedly attached to the side surface of the battery core housing11, such as by welding or brazing, and the attachment is tested to ensure that is fully sealed. The bellow78is provided with a sealed cap79, which may be integral to the bellow78. A connecting member82is fixedly attached to the cap79of the bellow78, which is provided with a guide83inside the battery core housing11as can be seen inFIG.10. The connecting member82is provided with an enlarged frontal conical section mass member81(56inFIG.8) that is close or in contact with the sloped surface57of the member58of the normally closed valve59as can also be seen inFIG.8. A preloaded tensile spring86may also be provided to ensure that in normal conditions, the mass member does not force the valve59to open. It is appreciated by those skilled in the art that instead of the preloaded tensile spring86, a preloaded compressive spring (not shown) may be placed inside the bellow78to serve the same function.

The Li-Oxygen reserve battery embodiment70ofFIG.10operates as follows. In normal conditions, as can be seen in the blow-up view ofFIG.8, the valve59is in its closed state and prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. In this state, the biasing forces of the compressively preloaded spring65(FIG.8) and the pressure of the oxygen gas ensures that the valve59stays closed. The reserve battery70is therefore in its inactive state and provides a long shelf life that can significantly exceed the military required 20 years. If the device to which the reserve battery70is attached is accelerated in the direction of the arrow85, the acceleration would act on the inertia of the mass member81and the connecting member82and the cap79, generating a downward dynamic force as seen in the view ofFIG.10. The tensile spring86is preloaded such that when the acceleration in the direction of the arrow85has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the assembly of the mass member81and the connecting member82and the cap79would begin to move down as viewed inFIG.10. If the acceleration in the direction of the arrow85is long enough in duration, the bellow78begins to deform, allowing the conical mass member81to move down, thereby engaging the sloped surface57of the member58(FIG.8) and forcing it to begin to move to the right as seen in the view ofFIG.10. As a result, the cap61is lifted from over the elastomeric gasket63(FIG.8), thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. Then once the acceleration in the direction of the arrow85has ceased, the mass member81is forced to return to its pre-acceleration position shown inFIG.10by the preloaded tensile spring83and the valve59is closed and the flow of oxygen gas into the battery core is stopped.

If the applied acceleration in the direction of the arrow85is below the prescribed threshold, for example due to accidental drop of the object to which the reserve battery70is attached, the preloading level of the tensile spring86is not overcome, and the mass member81does not engage the sloped surface57of the member58and the valve59stays closed.

The Lithium-Oxygen reserve battery embodiment70ofFIG.10is also provided with a linear or rotary electrical or piezoelectric-based or the like actuation device, such as a solenoid80, which can be used to similarly apply an actuating force to the cap79by its linearly displacing core89to open the valve59as was described above to let an inflow of oxygen gas into the battery core on demand. In the present embodiment70, the inertial activation in response to a prescribed acceleration profile as was previously described is configured to allow enough oxygen gas into the battery core to power the device electronics and power control system and to operate the on/off activation actuation device, in this case the solenoid80.

In the Lithium-Oxygen reserve battery embodiment70ofFIG.10, the inertial activation in response to a prescribed acceleration profile is configured to allow enough oxygen gas into the battery core to power the device electronics and power control system and to operate the on/off activation actuation device, in this case the solenoid80. Alternatively, the Lithium-Oxygen reserve battery embodiment70may be paired with a capacitor (or supercapacitor)91, which is charged by the electrical energy generated by the initial activation of the reserve battery. The electrical energy stored in the capacitor91can then be used by the object to which the reserve battery is attached (e.g., a gun fired munition), and to re-activate the reserve battery as needed by the actuator80. Such a combined Lithium-Oxygen reserve battery and capacitor (super-capacitor) reserve power sources are hereinafter referred to as the “Lithium-Oxygen hybrid reserve batteries.”

It is appreciated that the Lithium-oxygen reserve battery embodiment70ofFIG.10is configured to be activated during the munitions firing for a short period of time to activate the reserve battery long enough to generate the electrical energy needed to operate the electrically actuated activation mechanism of the reserve battery as required by the system being powered by the reserve battery. The actuation mechanism shown is the schematic ofFIG.10is a linear solenoid. However, other linear or rotary electrical or piezoelectric-based or the like actuators may also be used for this purpose. In the embodiment70ofFIG.10, the linear solenoid actuation device is shown to be positioned external to the reserve battery housing. In many munition applications, it is highly desirable that all components of the reserve battery be inside a hermetically sealed housing. To this end, the reserve battery embodiment70is modified as described below to house all externally positioned components of the reserve battery inside the hermetically sealed battery housing as shown in the embodiment90ofFIG.11.

In the Lithium-Oxygen reserve battery embodiment90ofFIG.11, the battery activation mechanism comprises the normally closed valve59,FIG.8, and the linear solenoid (or piezoelectric-based actuation) mechanism. The configuration and all the components of the normally closed valve59are similar to those used in the embodiment ofFIG.8. All other components of the Lithium-oxygen reserve battery embodiment70are similar to that of the embodiment10ofFIG.3.

The actuation mechanism of the Lithium-Oxygen reserve battery embodiment90ofFIG.11comprises a metallic bellow92, which can be formed of the same metal with which the battery core housing11is constructed, such as stainless steel. The bellow92is fixedly attached to the side surface93of the battery core housing11, such as by welding or brazing, and the attachment is tested to ensure that is fully sealed. The bellow92is provided with a sealed cap94, which may be integral to the bellow92. A linear solenoid actuator95(or a piezoelectric or the like electrically actuated device) is positioned inside the bellow and fixed to the cap94as can be seen inFIG.11. InFIG.11, the terminals101indicate the powering terminals of the solenoid95, which are passed through the electrical insulations (not shown) provided in the cap94. The actuating core96of the solenoid95is then attached to a conical section shaped mass member97. The mass member97is fixedly attached and sealed to the bellow92. The conical section mass member97(56inFIG.8) is positioned close or in contact with the sloped surface98(57inFIG.8) of the member99(58inFIG.8) of the normally closed valve59as can also be seen inFIG.11. The solenoid95is provided with a proper return spring so that while it is not energized, the mass member97is at the position shown inFIG.11and does not force the valve59to open. The cap94may be provided with a small hole to prevent the air (gas) trapped inside the below92from resisting its extension.

The Li-Oxygen reserve battery embodiment90ofFIG.11operates as follows. In normal conditions, the valve59is in its closed state and prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. In this state, the biasing forces of the compressively preloaded spring102(65inFIG.8) and the pressure of the oxygen gas ensures that the valve59stays closed. The Li-Oxygen reserve battery90is therefore in its inactive state and provides a long shelf life that can significantly exceed the military required 20 years. If the device to which the reserve battery90is attached is accelerated in the direction of the arrow104, the acceleration would act on the inertia of the mass member97and the solenoid core96, generating a downward dynamic force as seen in the view ofFIG.11. The biasing spring in the solenoid96(not shown) is preloaded such that when the acceleration in the direction of the arrow104has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the assembly of the mass member97and the solenoid core96would begin to move down as viewed inFIG.11. It is appreciated that a preloaded tensile spring (not shown) may instead be provided around the solenoid core96(similar to preloaded tensile spring86inFIG.10) to perform the same function. If the acceleration in the direction of the arrow104is long enough in duration, the bellow92begins to deform, allowing the conical mass member97to move down, thereby engaging the sloped surface98of the member99(58inFIG.8) and forcing it to begin to move to the right as seen in the view ofFIG.11. As a result, the cap106(61inFIG.8) is lifted from over the elastomeric gasket103(63inFIG.8), thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. Then once the acceleration in the direction of the arrow104has ceased, the mass member97is forced to return to its pre-acceleration position shown inFIG.11by the preloaded biasing spring of the solenoid95, the extended bellow92, preloaded compressive spring102and the oxygen gas pressure, thereby closing the valve59and stopping the flow of oxygen gas into the battery core.

If the applied acceleration in the direction of the arrow104is below the prescribed threshold, for example due to accidental drop of the object to which the reserve battery90is attached, the preloading level of the aforementioned biasing tensile springs are not overcome, and the mass member97assembly does not engage the sloped surface98of the member99and the valve59stays closed.

It is appreciated by those skilled in the art that the linear solenoid actuator95(or other similar linear or rotary actuators) may be of a latching type. In such a case, at any point in time following initial inertial activation, the battery may be activated and made to remain activated without requiring power to be continuously be applied to the actuator95. The solenoid may also be actuated less than the distance that activates the latching mechanism, thereby providing the capability to reactivate the reserve battery several times until it is desired to stay permanently activated, at which time the solenoid is actuated to the point of activating its latching mechanism.

It is also appreciated by those skilled in the art that all electronic and drive components and the capacitor107that are used to sense the reserve battery embodiment90power level and activate the battery as needed may also be integrated inside the reserve battery housing11. Such self-contained Li-Oxygen reserve batteries would greatly simplify their integration into various devices such as gun-fired munitions.

In the Li-Oxygen reserve battery embodiment90, the inertial activation in response to the prescribed acceleration profile is configured to allow enough oxygen gas into the battery core to power the device electronics and power control system and to operate the solenoid95to open and close the valve59when needed to supply the required electrical energy. The reserve battery embodiment90may also be provided with a capacitor or super-capacitor107as was shown inFIG.10to form a “Lithium-Oxygen hybrid reserve battery”.

In the Lithium-Oxygen reserve battery embodiment90ofFIG.11, similar to the embodiment70ofFIG.10, the inertial activation in response to a prescribed acceleration profile is configured to allow enough oxygen gas into the battery core to power the device electronics and power control system and to operate the on/off activation actuation device, in this case the solenoid95. Alternatively, the Lithium-Oxygen reserve battery embodiment90may be paired with a capacitor (or supercapacitor)107, which is charged by the electrical energy generated by the initial activation of the reserve battery. The electrical energy stored in the capacitor107can then be used by the object to which the reserve battery is attached (e.g., a gun fired munition), and to re-activate the reserve battery as needed by the actuator95. Such a combined Lithium-Oxygen reserve battery and capacitor (super-capacitor) reserve power source forms a previously described “Lithium-Oxygen hybrid reserve battery”.

It is appreciated by those skilled in the art that such “Lithium-Oxygen hybrid reserve batteries” are particularly advantageous for use in applications in which they are required to provide low power for long periods of times and only occasionally have to provide high power, usually for relatively short periods of time. In such applications, the reserve battery only needs to be activated for very short periods of times to charge the capacitor and have the capacitor supply the low power to usually low power electronics for hours and sometimes for days until either high power is required to be provided or when the capacitor power is low and it needs to be recharged, at which time the capacitor supplies power to the activation actuator,FIGS.10and11.

In one embodiment of the present “Lithium-Oxygen hybrid reserve batteries”, a controller/processor, such as an electronic control circuit107acan be provided to detect the voltage level of the hybrid reserve battery electrical energy storage capacitor (e.g.,91inFIG.10) and energize the battery activation actuator (80inFIG.10) for a prescribed amount of time to allow a prescribed amount of oxygen gas to flow into the battery core for its activation. In addition, the electronic control circuit may be provided with a microprocessor107band memory107cso that it could be programmed to provide a prescribed power level based on a received sensory input and/or planned profile. The control circuit electrically connecting the capacitor (energy storage device) to the terminals101of the solenoid95(actuation device).

It is also appreciated by those skilled in the art that the Lithium-Oxygen reserve battery embodiment90may also be activated directly by energizing the solenoid95in non-shock loading activation applications.

The Lithium-oxygen reserve battery embodiment90ofFIG.11is configured to be activated either during the munitions firing for a short period of time and then by the integrated actuation device or directly by the integrated actuation device, in this case the linear solenoid95. The Lithium-oxygen reserve battery embodiment90may also be constructed without the electrical actuator as shown in the schematic ofFIG.12(indicated as the embodiment100) and instead be provided with at least a pair of bosses108with (interior or exterior) threads109on the outside surface of the battery housing or those110with internal threads, for the used to attach the desired actuation device (linear or screw type rotary electrical or piezoelectric-based linear actuator or the like). In both options, the bosses are fixedly attached to the battery housing surface, such as by welding or brazing or the like and fully sealed to keep the battery core hermetically sealed for long shelf life. The Lithium-oxygen reserve battery embodiment100operates as was previously described for the reserve battery embodiment90ofFIG.11.

In the schematic ofFIG.13A, the blow-up view “B”,FIG.12, showing the valve59and the actuating conical mass section97and the bellow92is redrawn. In an alternative configuration, the valve59may be replaced with the configuration shown in the embodiment60ofFIG.9. With the replaced valve, the blow-up view “B” would then become as shown inFIG.13B.

Then in the normal conditions, as was described for the embodiment ofFIG.9, the preloaded compressive spring115and the pressurized oxygen gas in the container18keep the valve closed and prevent oxygen gas from entering the porous carbon-based O2cathode of the battery core,FIG.12. Then if the device to which the reserve battery100is attached is accelerated in the direction of the arrow112, the acceleration would act on the inertia of the mass member97, generating a downward dynamic force. The compressive spring115is preloaded such that when the acceleration in the direction of the arrow112has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the mass member97begin to move downward as viewed inFIG.12. Here, the spring rate of the metal bellow is considered to be negligible, otherwise it must also be considered. If the acceleration in the direction of the arrow112is long enough in duration, the cap116is moved to the right enough to allow the pressurized oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. Once the cap116has moved to the right, the gap between the bottom surface of the cap116and the surface119of the container18is configured to be enough to allow the “locking” member121to be pushed under the cap116and prevent the cap to close the flow of the oxygen gas into the battery core once the acceleration in the direction of the arrow112has ceased. Thereby, the reserve battery is activated and stays activated after the acceleration event, for example due to the firing of a munition in which the reserve battery is mounted. If the applied acceleration in the direction of the arrow112is below the prescribed threshold, for example due to accidental drop of the object to which the reserve battery100is attached, the valve stays closed and the reserve battery is not activated.

In an alternative configuration ofFIG.13B, once the valve (59inFIG.12) is opened due to the prescribed acceleration event, the valve stays open and the reserve battery100stays activated from then on. On the other hand, the valve configuration shown inFIG.12and its blow-up view ofFIG.13Aprovides a reserve battery that requires activation of its electrical actuation device (e.g., a linear electrical solenoid) to open the valve59to reactivate the reserve battery after its initial inertial (or direct solenoid operated electrical) activation. In this embodiment, to keep the battery permanently activated after cycles of activation/deactivation, the actuation mechanism needs to be kept energized. To avoid the waste of electrical energy to keep the actuation device energized, the modification shown in the blow-up schematic ofFIG.13Cis made to the activation mechanism of the reserve battery.

In the activation mechanism ofFIG.13C, the same valve59of the embodiment100ofFIG.12is used. The conical section mass member120(97inFIG.13B) is similarly fixedly attached to the bellow123(92inFIG.13B). The conical section mass member120is also positioned close or in contact with the sloped surface124of the member125(113inFIG.13B) of the normally closed valve59as can also be seen inFIG.13B. The actuation mechanism that is provided for the reserve battery activation (for example, the linear solenoid95ofFIG.11or other linear or rotary electrical actuator or the like) is provided with a proper return spring so that while it is not energized, the mass member120is at the position shown inFIG.13Cand does not force the valve59to open.

The mass member120is also provided with a link member127, which is attached to the mass member120by a pin joint128. The link member127is provided by a preloaded compressive spring129, which is attached to the mass member129by the pin joint131and is biased to rotate the link member127in the clockwise direction as viewed inFIG.13Cand mostly rest against the surface124of the member125.

Then in the normal conditions, as was described for the embodiment ofFIG.9, the preloaded compressive spring115(FIG.13B) and the pressurized oxygen gas in the container18keep the valve closed and prevent oxygen gas from entering the porous carbon-based O2cathode of the battery core,FIG.12. Then if the device to which the reserve battery100is attached is accelerated in the direction of the arrow112, the acceleration would act on the inertia of the mass member120,FIG.13C, generating a downward dynamic force. The compressive spring (115inFIG.13b) of the valve59is preloaded such that when the acceleration in the direction of the arrow112has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the mass member120begins to move downward as viewed inFIG.13C. Here, the spring rate of the metal bellow is considered to be negligible, otherwise it must also be considered. If the acceleration in the direction of the arrow112is long enough in duration, the cap126is moved to the right, allowing the pressurized oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. It is noted that the actuation device ofFIG.13Cis configured such that the above prescribed acceleration profiles would not move the mass member120down enough along the surface124to have the tip132of the link member127to pass the tip133of the member125as can be seen inFIG.13C.

The Lithium-oxygen reserve battery embodiment100ofFIG.12is configured to be activated either during the munitions firing for a short period of time and then by the integrated actuation device (such as the linear actuator95as shown inFIG.11) or directly by the integrated actuation device95. The Lithium-oxygen reserve battery embodiment100may then be activated and deactivated on command by the indicated integrated actuation device. However, during each activation process, the integrated actuation device ofFIG.13Cadvances the mass member120down along the surface124such that the tip132of the link member127would not pass the tip133of the member125, so that the integrated actuation device could be commanded to bring the mass member120back to its position shown inFIG.13C, thereby closing the flow of oxygen gas into the battery core and reverting the battery to its reserve state.

However, at any moment, the integrated actuation device can be used to displace the mass member down enough so that the tip132of the link member127would clear the tip133of the member125, thereby the link member127would rotate in the clockwise direction until it is stopped by the stop member135of the mass member120. As a result, once the integrated actuation device is de-energized, the link132engages the lower surface136of the member125and prevents the mass member120from returning to its position shown inFIG.13C. In the meanwhile, the opened valve59would stay open and the oxygen gas would continue flowing into the reserve battery core.

The Lithium-oxygen reserve battery embodiment10ofFIG.3was shown to be configured to activate when subjected to a prescribed acceleration profile in the direction of the arrow22. The reserve battery embodiment10may, however, be modified so that it could be activated by electrical initiation of a pyrotechnic charge, i.e., using an electrical initiator. Such a Lithium-oxygen reserve battery embodiment130is shown in the cross-sectional schematic ofFIG.14.

In the Lithium-oxygen reserve battery embodiment130ofFIG.14, the activation mechanism comprises a metallic bellow137that is fixedly attached to the surface21of the pressurized oxygen container18, such as by welding or brazing. An end member138is also attached to the other end of the bellow, such as by welding or brazing. The attachments of the bellow to the surface21and the end member138must be sealed and the bellow137and end member138can be formed from the same material as the container18, such as stainless steel. An electrically initiated gas generating pyrotechnic device141is provided inside the sealed bellow137. Initiator service wires141are indicated by the numeral142inFIG.14.

The common wall19between the container18and the battery core (inside housing11) is provided with a relatively small opening14into the battery core, which is normally sealed by a metallic diaphragm13. In general, the housings11and18are made with stainless steel and the diaphragm13is also a thin stainless sheet that is welded to the wall19. The end member138is provided with a sharp cutting member139, which is positioned above the hole14.

The Li-Oxygen reserve battery embodiment130operates as follows. In normal conditions, the diaphragm13prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. Then if the electrical gas generating pyrotechnic device141is initiated, the pressure due to the generated gas would extend the bellow137, thereby causing the end member138to move down and for the sharp cutting member139to reach and rupture the diaphragm13, thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery.

It is appreciated by those skilled in the art that the activation mechanisms such as the externally actuated manual or powered actuation activation mechanisms of the embodiments ofFIGS.5,6,7,10,11and12may be configured with other types of mechanisms and powered actuators but to perform the same intended functions. The mechanisms and their actuation devices shown and described are primarily intended to describe the basic methods of activating the present Lithium-Oxygen reserve batteries and examples of mechanisms that can be used to activate them for continuous use or for multiple activation/deactivation. For example, the activation mechanism of the embodiment50ofFIG.7may be readily modified for manual operation as shown in the embodiment150ofFIG.15or by externally powered actuation devices as described below.

In the Li-Oxygen reserve battery embodiment150ofFIG.15, the valve assembly59,FIG.7, is still used and may be positioned more centrally as shown inFIG.15. However, since its sloped section57is no longer needed, it is eliminated as can be seen in the schematic ofFIG.15. The bellow-based actuation mechanism of the embodiment50ofFIG.7is then modified and repositioned as follows. The mechanism bellow155is similarly attached to the outer surface of the oxygen container18, such as by welding or brazing. The bellow155is then provided with a cap156, which seals the bellow155and is attached to it, such as by welding or brazing. The guide153is similarly attached to the interior surface of the container18against the bellow155. A pin151is provided as shown inFIG.15, which can freely slide in the guide153and is fixedly attached to the cap156on one end and to the valve assembly59cap154on the other end. A ring or the like member152is also fixedly attached to the cap156for manual activation of the reserve battery.

The Li-Oxygen reserve battery embodiment150ofFIG.15operates as follows. In normal conditions, the valve59is closed and prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. The reserve battery150is therefore in its inactive state and provides a long shelf life that can significantly exceed the military required 20 years. The user may then manually pull the ring152, thereby pulling the pin151up and lifting the cap154from over the elastomeric sealing gasket (63inFIG.7), thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. Then when the user releases the ring152, the extended bellow155would tend to spring back and assisted with the compressed oxygen gas pressure acting on the cap154would close the valve59and stop transfer of pressurized gas into porous carbon-based O2cathode section of the battery core. The battery is thereby reverted to its reserve state and the battery core would stop generating electrical energy once its present oxygen gas has been consumed.

It is appreciated by those skilled in the art that the cap156of the bellow155,FIG.15, may also be displaced up and down, as viewed inFIG.15, by an externally positioned linear or rotary electrical or piezoelectric-based or pneumatic or the like actuation device as was described, for example, for the embodiment70ofFIG.10, on commands provided by the system controls as is well known in the art.

The Lithium-Oxygen reserve battery embodiments10and20ofFIGS.3and4, respectively, are configured to be activated when the device to which they are attached is subjected to a prescribed acceleration profile, such as firing of a gun. In many munition applications, such as in rockets, the reserve battery is required to be activated at prescribed accelerations that are low in magnitude, for example in tens of Gs rather than thousands in the case of gun-fired munitions, and lasts a few tens of milliseconds. In such applications, the activation mechanisms of the embodiments10and20ofFIGS.3and4, respectively, may not be suitable since they may require very large inertial mass (16and27inFIGS.3and4, respectively) to make them capable of rupturing the provided diaphragms to activate the reserve battery. The activation mechanism of the Lithium-Oxygen reserve battery embodiment160ofFIG.16is configured for such relatively low G prescribed firing accelerations or the like applications.

In the schematic ofFIG.16, all other components of the reserve battery are similar to that of the embodiment10ofFIG.3, except for its inertial activation mechanism. As can be seen inFIG.16, the Lithium-Oxygen reserve battery embodiment160is provided with an activation mechanism that comprises a link161, which is attached to the surface163of the pressurized oxygen container by the rotary joint162. In normal conditions the link161is in the configuration shown inFIG.16, in which the tip174of the link rests on provided “step” on the tip171of the inertial mass170. In this configuration, the inertial mass170is being pushed against the tip174of the link161by the preloaded compressive spring173. The preloaded compressive spring173is positioned between the inertial mass170and the support172, which is fixedly attached to the surface163of the pressurized oxygen container. The link161is also held in its position shown inFIG.16by the preloaded compressive spring167, which is attached to the link161by the pin joint168on one end and to the inside of the pressurized oxygen container by the pin joint169on the other end. The link161is also provided with a sharp cutting member164, which in the normal condition ofFIG.16is positioned above the hole165in the side163of the pressurized oxygen container that is covered by the diaphragm166, which can be metallic and attached to the container surface by welding or brazing.

The Li-Oxygen reserve battery embodiment160ofFIG.16operates as follows. In normal conditions, the diaphragm166prevents oxygen gas from entering the porous carbon-based O2cathode of the battery core. If the device to which the reserve battery160is attached is accelerated in the direction of the arrow175, the acceleration would act on the inertial mass170, generating a downward dynamic force. The compressive spring173is preloaded such that when the acceleration in the direction of the arrow175has reached a prescribed threshold, then the generated dynamic force would overcome the spring preload and the inertial mass170would begin to move downward as viewed inFIG.16. If the acceleration in the direction of the arrow175is long enough in duration, the inertial mass170moves down enough so that the tip171clears the tip174of the link161. The preloaded compressive spring167will then accelerate the link161in rotation in the clockwise direction until the sharp cutting member164strikes the diaphragm166and causes it to rupture, thereby allowing the oxygen gas to begin to flow into the porous carbon-based O2cathode section of the battery core and activate the reserve battery. If the duration of the applied acceleration in the direction of the arrow175is very short, for example due to accidental drop of the object to which the reserve battery160is attached, the inertial mass170and spring173system is configured such that the link161is not released and thereby the reserve battery is not activated.

In various embodiments disclosed above, for any components described as being movable within the porous carbon-based O2cathode, the porous carbon-based O2cathode is configured to permit such movement, such as having a corresponding void.

While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.