3 are only schematic views of the cells 126, 154, 226, 254, the “positive electrode” of each cell may actually include more space within the primary first battery housing 155 than shown schematically. For example, all spaces containing the primary first cathodic solution 148 and any porous surfaces in the primary first separator 142 filled with the primary first electrolyte salt 152. The “positive electrode” is not just the primary first carbon electrode 136.

FIGS. 1-3 also shows a secondary battery pack 220 being comprised of a secondary negative terminal 222 and a secondary positive terminal 224. The secondary battery pack 220 includes a secondary first battery cell 226 being comprised of a secondary first negative terminal 228 connected to the secondary negative terminal and a secondary first positive terminal 230 connected to the secondary positive terminal. The secondary battery pack 220 includes a secondary first negative electrode 232 being comprised of a secondary first electrode metal 234 and being connected to the secondary first negative terminal, and a secondary first carbon electrode 236. FIG. 2 also shows the secondary first carbon electrode 236 being comprised of secondary first carbon materials 238 and having porous structures 240. The secondary first carbon electrode 236 is connected to the secondary first positive terminal. FIGS. 1 and 3 show a secondary first separator 242 between the secondary first negative electrode and the secondary first carbon electrode. There is a secondary first cathodic solution 248 within the battery cell and in contact with the secondary first negative electrode, the secondary first separator, and the secondary first carbon electrode. In FIGS. 1 and 3, the secondary first cathodic solution comprises a secondary first solvent system 250 and a secondary first electrolyte salt 252.

The hybrid battery system 10 of the present invention includes the primary battery pack 120 with particular relatedness to the secondary battery pack 220 in order to operate safely. In embodiment of the present invention, the primary first electrode metal has a primary first melting point, and the primary first battery cell has a primary first rated temperature range. Correspondingly, the secondary first electrode metal has a secondary first melting point, and the secondary first battery cell has a secondary first rated temperature range. In the present invention, the rated temperature range (primary first rated temperature range, secondary first rated temperature range) is the temperature range corresponding to the cell discharging useful power to an external device, typically cell voltage above 2.0V. The rated temperature range is generally below the corresponding melting point, such as the primary first rated temperature range being below the primary first melting point. The secondary first rated temperature range is higher than the primary first rated range. Furthermore, the primary first negative electrode metal has a primary first electrode metal charge capacity, and the primary first cathodic solution has a primary first positive charge capacity. In the present invention, the primary first electrode metal charge capacity is lower than the primary first positive charge capacity. Additionally, the primary first battery cell 126 is comprised of a primary first battery housing 127 with a primary first battery headspace 129, and the secondary first battery cell 226 is comprised of a secondary first battery housing 227 with a secondary first battery headspace 229. In the present invention, a primary first battery headspace percentage of the primary first battery housing is greater than a secondary first battery headspace percentage of the secondary first battery housing. The proportion or ratio of the primary first battery headspace to the primary first battery housing is greater than the proportion or ratio of the secondary first battery headspace to the secondary first battery housing. FIGS. 1-3 show the primary first battery headspace 129 being greater than the secondary first battery headspace 229 schematically.

The safety and efficacy of the hybrid battery system 10 is assured by the relationships between the primary battery pack 120 relative to the secondary battery pack 220. The primary battery pack 120 has the lower primary first rated temperature range, which can correspond to an alkaline metal or an alkaline earth metal as the primary first negative electrode 132. The secondary battery pack 220 has the higher secondary first rated temperature range, which can correspond to an alkaline metal alloy or an alkaline earth metal alloy or alkaline metal—alkaline earth metal alloy as the secondary first negative electrode 232.

Embodiments of the present invention include the primary first carbon electrode 136 and the secondary first carbon electrode 236 being further comprised of inert polymer binders, and the primary first separator 142 and the secondary first separator 242 being comprised of one of a group consisting of: glass fiber and a polymer, such as polypropylene or polyethylene. Embodiments of the present invention also include the primary first solvent system 150 and the secondary first solvent system 250, each being comprised of at least one of a group consisting of thionyl chloride and sulfuryl chloride. The primary first electrolyte salt 152 and the secondary first electrolyte salt 252 can also be comprised of at least one of a group consisting of metal tetrachloroaluminate, metal tetrachlorogallate, Metal tetrachloro borate, metal bis(oxalato)borate, metal bis(trifluoromethanesulfonyl)imide, and metal trifluoromethanesulfonate, metal tetrafluoroborate, and metal hexafluoroarsenate.

There are also embodiments with the primary first cathodic solution 148 being further comprised of a co-solvent with a boiling point higher than a boiling point of the primary first solvent system 150. For example, the co-solvent can have a boiling point higher than 150 deg C. when a primary first solvent system 150 is thionyl chloride (boiling point 75 deg C.) or sulfuryl chloride (boiling point 69 deg C.). The co-solvent can raise the boiling point of the primary first cathodic solution 148 so that internal pressure in the primary first battery cell 12 is reduced even when primary first electrode metal 134 remains as residual primary first electrode metal at temperatures above the primary first rated temperature range. The primary first battery cell 126 is more stable at temperatures above the primary first rated temperature range and at temperatures above the primary first melting point of the primary first electrode metal 134. The co-solvent is preferred to have an inert reactivity or low reactivity with the primary first electrode metal 134. The co-solvent dilutes reactive components of primary first cathodic solution 148, such as thionyl chloride or sulfuryl chloride of the primary first solvent system 150. The reactivity between primary first cathodic solution 148 and any molten residual primary first electrode metal 134 is now reduced at temperatures above the primary first rated temperature range and at temperatures above the primary first melting point. The co-solvent can be comprised of at least one of a group consisting of nitrobenzene, 2-nitro-m-xylene, 4-nitro-m-xylene, benzoyl chloride, 2-methylbenzoyl chloride, ethylene (glycol) sulfite, dimethyl sulfoxide, trimethyl phosphate, benzonitrile, methyl benzoate, gamma-butyrolactone, propylene carbonate, 3-methoxy propionitrile, and N, N-dimethylformamide for embodiments of the co-solvent having a boiling point over 150 deg C. Alternate embodiments include the co-solvent as 1-nitropropane, thiophosphoryl chloride, 3-methyl-2-oxazolidinone, acetonitrile, carbon tetrachloride, trichloromethane, and dimethoxyethane, wherein the co-solvent has a boiling point at least higher than the boiling point of the primary first solvent system 150. For a primary first solvent system 150 with a boiling point lower than 150 deg C., these other embodiments of the co-solvent are available.

FIGS. 1-3 also show the primary first negative electrode being further comprised of a primary first porous transition metal layer 144 pressed on the primary first electrode metal 134. For example, Ni foam can be the primary first porous transition metal layer 144, and Li metal foil can be the primary electrode metal 134. FIGS. 1-3 show embodiments with the primary first porous transition metal layer 144 on both sides of the primary electrode metal 134, although the invention only requires one primary first porous transition metal layer 144. Both Ni foam and Li metal foil are soft, and Ni foam is porous. The Li metal can be pressed into pores of Ni foam layers. The total thickness of the primary first negative electrode 132 can be substantially lower than total thickness of three layers, due to high porosity of Nickel foam (can be >90%). This embodiment of the primary first negative electrode 132 has a better anode metal connection with primary first negative terminal 128 to minimize any anode metal portions losing electric connection. The pressed connection of the primary first electrode metal 134 into pores exposes more residual anode metal to be stripped. This construction increases safety of the primary battery pack 120 at temperatures above the primary first rated temperature range with the primary first electrode metal 134 more easily stripped. The primary first porous transition metal layer 144 can be a porous layer or multiple layers of a transition metal, like nickel, formed as a cloth, mesh, foam, or other form with pores.

FIG. 1 shows the primary battery pack 120 with one primary first battery cell 126 and additional primary cells. FIG. 3 shows a fully recited version of the hybrid battery system 10 with more than one cell in each battery pack 120, 220. The cells are modular. The primary cells are interchangeable with each other. The secondary cells are interchangeable with each other. The primary cells are not interchangeable and modular with the secondary cells. The cells are modular and interchangeable within each battery pack, not across battery packs. Each type of cell can be connected in series or in parallel. FIG. 3 shows the primary battery pack 120 further comprising a primary second battery cell 154, a primary second negative electrode 160, a primary second carbon electrode 164, a primary second separator 170, and a primary second cathodic solution 176. The primary second battery cell 154 is connected to the primary first battery cell 120 and can be connected in series or in parallel to the primary first battery cell 126. Both types of connections are indicated schematically by dashed lines in FIG. 3.

The primary first battery cell 120 and the primary second battery cell 154 are modular and have similar relationships to the secondary first battery cell 220. The primary second battery cell 154 must also be compatible with lower temperatures, like the primary first battery cell 126, corresponding to the primary first rated temperature range and below the secondary first rated temperature range. The primary second electrode metal 162 has a primary second melting point. The primary second battery cell 154 has a primary second rated temperature range, and the secondary first rated temperature range is higher than the primary second rated range. The primary second electrode metal 162 has a primary second electrode metal charge capacity, and the primary second cathodic solution 176 has a primary second positive charge capacity. The primary second electrode metal charge capacity is lower than the primary second positive charge capacity. The primary second battery cell 154 is comprised of a primary second battery housing 155 with a primary second battery headspace 157. The primary second battery headspace percentage of the primary second battery housing 155 is greater than a secondary first battery headspace percentage of the secondary first battery housing 227. The proportion or ratio of the primary second battery headspace 157 to the primary second battery housing 155 is greater than the proportion or ratio of the secondary first battery headspace 229 to the secondary first battery housing 227.

The components of the primary second battery cell 154 are directly analogous to the primary first battery cell 12. The primary second battery cell 154 is comprised of a primary second negative terminal 156 connected to the primary negative terminal 122 and a primary second positive terminal 158 connected to the primary positive terminal 124. The connections can be in series or parallel with the primary first battery cell 126. FIG. 3 shows the connections in parallel in broken lines and indicate a connection in series in other broken lines. The primary second negative electrode is comprised of a primary second electrode metal 162 and being connected to the primary second negative terminal. The primary second carbon electrode 164 is comprised of primary second carbon materials 166 and connected to the primary second positive terminal. The primary second carbon electrode has porous structures 168. The primary second separator 170 is also between the primary second negative electrode and the primary second carbon electrode. The primary second cathodic solution 176 is within the primary second battery cell and in contact with the primary second negative electrode, the primary second separator, and the primary second carbon electrode. The primary second cathodic solution comprises a primary second solvent system 178 and a primary second electrolyte salt 180.

FIG. 1 shows the secondary battery pack 220 with one secondary first battery cell 226 and additional secondary cells. FIG. 3 shows a fully recited version of the hybrid battery system 10 with more than one cell in each battery pack 120, 220. The cells are modular and interchanges within battery packs 120, 220. FIG. 3 shows the secondary battery pack 220 further comprising a secondary second battery cell 254, a secondary second negative electrode 260, a secondary second carbon electrode 264, a secondary second separator 270, and a secondary second cathodic solution 276. The secondary second battery cell 254 is connected to the secondary first battery cell 220 in series or in parallel. Both types of connections are in FIG. 3, a parallel connection is shown in broken lines and a series connection is indicated by other broken lines.

The secondary first battery cell 220 and the secondary second battery cell 254 are modular and have similar relationships to the primary first battery cell 120 (and primary second battery cell 154). The secondary second battery cell 254 must also be compatible with higher temperatures, like the secondary first battery cell 226, corresponding to temperatures above the primary first rated temperature range and the primary second rated temperature range. The secondary second electrode metal 262 has a secondary second melting point. The secondary second battery cell 254 has a secondary second rated temperature range, and the secondary second rated temperature range is higher than the primary first rated range (and the primary second rated range). The secondary second electrode metal 262 has a secondary second electrode metal charge capacity, and the secondary second cathodic solution 276 has a secondary second positive charge capacity. The secondary second battery cell 254 is comprised of a secondary second battery housing 255 with a secondary second battery headspace 257. The proportion or ratio of the primary first battery headspace 127 to the primary first battery housing 129 is greater than the proportion or ratio of the secondary second battery headspace 257 to the secondary second battery housing 255.

The components of the secondary second battery cell 254 are directly analogous to the secondary first battery cell 220. The secondary second battery cell 254 is comprised of a secondary second negative terminal 256 connected to the secondary negative terminal 222 and a secondary second positive terminal 258 connected to the secondary positive terminal 224. The connections can be in series or parallel with the secondary first battery cell 226. FIG. 3 shows the connections in parallel in broken lines and indicates a connection in series in other broken lines. The secondary second negative electrode is comprised of a secondary second electrode metal 262 and being connected to the secondary second negative terminal. The secondary second carbon electrode 264 is comprised of secondary second carbon materials 266 and connected to the secondary second positive terminal. The secondary second carbon electrode has porous structures 268. The secondary second separator 270 is also between the secondary second negative electrode and the secondary second carbon electrode. The secondary second cathodic solution 276 is within the secondary second battery cell and in contact with the secondary second negative electrode, the secondary second separator, and the secondary second carbon electrode. The secondary second cathodic solution comprises a secondary second solvent system 278 and a secondary second electrolyte salt 280.

Embodiments of the present invention include the method for powering, according to FIGS. 1, 3 and 4. The method includes connecting an external electric application device 22 of a downhole tool to the hybrid battery system 10 at the battery pack positive terminal 18 and at the battery pack negative terminal 20 and measuring a monitored temperature of the hybrid battery system 10. The method includes generating a primary first voltage discharge level by reactions with the primary first electrode metal 134 and the primary first cathodic solution 148, when the monitored temperature is within the primary first rated temperature range; and generating a secondary first voltage discharge level by reactions with the secondary first electrode metal 234 and the secondary first cathodic solution 248, when the monitored temperature is within the secondary first rated temperature range.

The downhole tool is deployed into a borehole, and the monitored temperature will change. Specifically, the monitored temperature will increase. Near the surface, generating the primary first discharge level is the main power supply due to the monitored temperature being relatively low. Deploying deeper in the borehole, the primary first discharge level and the secondary first discharge level may supply power due to the monitored temperature being in both the primary first rated temperature range and the secondary first rated temperature range. Even further into the borehole, the monitored temperature will be high. Instead of switching off or releasing the primary battery pack 120 to return to the surface, the method of the present invention increases resistance of the variable resistor 16 with the management module before the monitored temperature is greater than the primary first rated temperature range.

The method of the present invention includes stripping the primary first electrode metal 134 from the primary first battery cell 126 before the monitored temperature exceeds the primary first rated temperature range, as shown in FIG. 4. The primary battery pack 120 is stripped for safety, instead of simply being switched off. Embodiments of the method include the steps of: disconnecting the external device from the primary battery pack 120 before connecting the variable resistor 16 to the primary battery pack 120 and the step of increasing resistance. The resistance of the variable resistor 16 can be increased as the monitored temperature approaches the higher end of the primary first rated temperature range. The amount of increase can depend on how quickly the monitored temperature is reaching the end of the primary first rated temperature range. The downhole tool may also be slowed from lowering further into the borehole (and higher temperatures downhole) so that the step of stripping can be completed before the downhole tool can continue lowering into the borehole.

There are different embodiments of the method, after step of stripping the primary first electrode metal 134. In one embodiment, the next step is disconnecting the primary battery pack 120. The step of stripping has fully discharged the primary first battery cell 126, and there is no longer any primary first electrode metal 134 remaining. Thus, the primary first battery cell 126 is safe to proceed with the downhole tool, even if the temperatures are higher than the primary first rated temperature range and higher than the primary first melting point. As a practical matter, it is unlikely to remove all primary first electrode metal 134. Thus, in another embodiment, the primary first cathodic solution 148 is further comprised of: a co-solvent with a boiling point higher than a boiling point of the primary first solvent system 150. The method further includes dissolving the primary first electrolyte salt 152 in the primary first solvent system 150 with higher boiling point co-solvent so at to minimize internal vapor pressure of the primary first battery cell 126. The method further includes reducing any residual primary first electrode metal 134 with the primary first cathodic solution 148 to release heat and accumulate internal electrolyte vapor in the primary first battery headspace 129. These steps avoid an internal temperature spike in the primary battery cell 126, even when the temperatures are above the primary first rated temperature range and above the primary first melting point. The larger primary first battery headspace 129 further reduces cell internal pressure. These additional measures allow the safe continuation of the primary battery pack 120 in the hybrid battery system 10, even when the monitored temperature is above the primary first rated temperature range and above the primary first melting point.

Embodiments of the method of the present invention include the primary first voltage discharge level being greater than 2.0V in the step of generating the primary first voltage discharge level. FIG. 4 remains consistent with this embodiment. The monitored temperature remains within the primary first rated temperature range, but the power level still must be sufficient to power the external electric application device 22. A sufficient power level to power the external application device 22 is typically when average cell voltage in the primary battery pack 120 is greater than 2.0V. In a related embodiment, the method includes decreasing the primary first voltage discharge level from greater than 2.0V. This step occurs if the primary battery pack 120 simply runs out of power, even though the monitored temperature remains within the primary first rated temperature range. In this related embodiment, there is still primary first electrode metal 134 remaining, even though useful power is no longer being generated. For safety, this primary first electrode metal 134 still needs to be addressed. Thus, the related method includes increasing resistance of the variable resistor connected to the primary battery pack with the management module when the primary first voltage discharge level is less than 2.0V, and stripping the primary first electrode metal 134 from the primary first battery cell when the primary first voltage discharge level is less than 2.0V. In this related embodiment, the management module 14 spikes the variable resistor 16 on the basis of discharge level, not just monitored temperature. A primary battery pack 120 that has been drained of effective voltage discharge must be further processed to a safe and stable state.

The method for powering also includes the steps for more than one cell in a battery pack. In FIG. 3, there is the primary second battery cell 154 and the secondary second battery cell 254. In this embodiment with multiple cells, the method further includes generating a primary second voltage discharge level by reactions with the primary second electrode metal 162 and the primary second cathodic solution 176, when the monitored temperature is within the primary second rated temperature range. The primary first battery cell 126 and primary second battery cell 154 of the primary battery pack 120 are modular and interchangeable within the primary battery pack 120, and the secondary first battery cell 226 and the secondary second battery cell 254 of the secondary battery pack 220 are modular and interchangeable within the secondary battery pack 220. The step of increasing resistance of the variable resistor 16 to the primary battery pack 120 with said management module 14 is now before the monitored temperature is greater than the primary first rated temperature range and before the monitored temperature is greater than the primary second rated temperature range. Some embodiments can still include the steps of disconnecting the primary battery pack 120 from the external device 22 and connecting the variable resistor 16 to the primary battery pack 120 before the step of increasing resistance. The primary first battery cell 126 and primary second battery cell 154 are both disconnected from the external device 22, connected to the variable resistor 16, and stripped together as the primary battery pack 120. Thus, an additional step of stripping the primary second electrode metal 162 from the primary second battery cell 154 is also before the monitored temperature exceeds the primary second rated temperature range. Adding the secondary second battery cell 254 is cumulative with the secondary first battery cell 220. All of the primary cells of the primary battery pack 120 must be stripped. None of the secondary cells of the secondary battery pack 220 require the analogous step of stripping.

Now that there is the step of stripping the primary first electrode metal 134 and the step of stripping the primary second electrode metal 162, the next steps are analogous for each cell of the first battery pack 120. The next step can be disconnecting the primary battery pack 120. The steps of stripping have fully discharged the primary first battery cell 126 and the primary second battery cell 154. There is no longer any primary first electrode metal 134 or primary second electrode metal 162 remaining. Thus, the primary first battery cell 126 and the primary second battery cell 154 are safe to proceed with the downhole tool, even if the temperatures are higher than the primary first melting point and the primary second melting point. Again, as a practical matter, it is unlikely to remove all primary first electrode metal 134 and all primary second electrode metal 162. The steps of stripping stop, and the primary first battery cell 126 and the primary second battery cell 154 are made safe and stable.

In addition to the monitored temperature, the management module 14 can also set the resistance of the variable resistor 16 according to voltage discharge. However, there are now multiple cells, and individual monitoring of cell voltage is not efficient enough for present invention. When the primary second voltage discharge level is greater than 2.0V in the step of generating the primary second voltage, the method further includes decreasing the primary second voltage discharge level from greater than 2.0V. In the embodiment with multiple cells, the step of increasing resistance of the variable resistor 16 with the management module 14 is now when the average primary discharge level is less than 2.0V. Then, the primary second electrode metal 162 is stripped from the primary second battery cell 154, along with the primary first electrode metal 134 being stripped from the primary first battery cell 126. Again, the resistance of the variable resistor 16 can be spiked for the primary battery pack 120 and all primary cells 126, 154 in the primary battery pack 120 based on either voltage discharge or monitored temperature.

Embodiments of the present invention include Examples 1a-6 of components of the present invention as shown in FIGS. 1-4.

Example 1a: A Primary First Battery Cell 126

A DD-size Li—SOCl2 battery cell is fabricated with 19.5 Ah (theoretical capacity or primary first electrode metal charge capacity) lithium metal as the primary first electrode metal 134. The primary first cathodic solution 148 contains 1.0 M LiAlCl4 salt as the primary first electrolyte salt 152 in a mixed SOCl2 (primary first solvent system 150) and nitrobenzene (2:1 ratio by volume) (co-solvent). Thionyl chloride SOCl2 has a theoretical capacity or primary first positive charge capacity of 21 Ah. The Example 1a primary first battery cell 126 has a rated capacity 17.6 Ah at 165 deg C.

Example 1 b: A Primary First Battery Cell 126

A DD-size Li—SOCl2 battery cell is fabricated with 15.6 Ah (theoretical capacity or primary first electrode metal charge capacity) lithium metal as the primary first electrode metal 134. The primary first cathodic solution 148 contains 1.0 M LiAlCl4 salt the primary first electrolyte salt 152 in mixed SOCl2 (primary first solvent system 150) and benzoyl chloride (3:2 ratio by volume) (co-solvent). Thionyl chloride SOCl2 has a theoretical capacity or primary first positive charge capacity of 17 Ah. The Example 1b primary first battery cell 126 has a rated capacity 14.43 Ah at 165 deg C.

Example 1a and Example 1b are primary first battery cells 126 that can provide full power from −40 deg C. to 165 deg C. (primary first rated temperature range), or until a discharge cutoff voltage of 2.0V as in