Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 2, 5, 7, 9, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Amendola et al. (US 20150010833), hereinafter Amendola, in view of Goldstein et al. (US 20170069940), hereinafter Goldstein, and in further view of Cervenka et al. (EP 3896762), hereinafter Cervenka.
Regarding claim 1, Amendola teaches:
A metal-aqueous battery (Abstract, [0245-0249]), comprising:
a double cell comprising ([0008], [0246], Fig. 1, adjacent cells 100a, 100b):
a pair of single cells, each of the single cells comprising ([0244-0247], 102, 104):
an anode ([0244], 102);
a cathode ([0244], 104);
a cathode spacer interposed between the separator and the cathode and configured to form a gap between the separator and the cathode ([0245]).
Amendola fails to teach:
a separator interposed between the anode and the cathode;
a current collector interposed between the pair of single cells such that cathodes of the single cells face each other across the current collector.
Additionally, Goldstein teaches:
a double cell comprising ([0124], [0130-133]):
a pair of single cells, each of the single cells comprising ([0016]):
an anode ([0016]);
a cathode ([0016]);
a separator interposed between the anode and the cathode ([0016]);
a cathode spacer interposed between the separator and the cathode and configured to form a gap between the separator and the cathode ([0129], Fig. 3C);
a current collector interposed between the pair of single cells such that cathodes of the single cells face each other across the current collector ([0008], [0121-0124]).
Additionally, Cervenka teaches:
A metal-aqueous battery, comprising (Abstract):
an anode (Abstract);
a cathode (Abstract);
a separator interposed between the anode and the cathode (Claim 9, [0023]).
Amendola, Goldstein, and Cervenka are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to incorporate Cervenka’s separator and Goldstein’s current collector into Amendola’s stacked aqueous metal-anode cells to prevent direct electrode contact, provide controlled ion transport, reduce external wiring, and produce a compact stacked battery assembly. Selecting the relative orientation of the cell faces and providing a spacing member to maintain a desired cathode-side gap would have been a predictable design choice based on the desired electrolyte volume, fluid access, and electrode separation.
Regarding claim 2, Amendola, Goldstein, and Cervenka teach the limitations of claim 1, as stated above. Amendola fails to teach:
Each of the single cells further comprises a plate in a sheet form at a predetermined thickness comprising a first main surface and a second main surface facing the first main surface, disposed on an outer surface of the single cell, and having an inner space open toward the first main surface;
The anode is accommodated in the inner space;
The separator is stacked on the first main surface to cover an open surface of the inner space.
Goldstein teaches:
Each of the single cells further comprises a plate in a sheet form at a predetermined thickness comprising a first main surface and a second main surface facing the first main surface, disposed on an outer surface of the single cell, and having an inner space open toward the first main surface ([0013], [0016], Claim 1);
The anode is accommodated in the inner space ([0016]);
The separator is stacked on the first main surface to cover an open surface of the inner space ([0022-0023]).
Amendola and Goldstein are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to replace or supplement Amendola’s molded cell frame with Goldstein’s sheet-form tray structure to provide a thin, mechanically rigid, readily manufactured cell housing. Placing the anode in the tray recess and positioning the separator across the tray opening would have been an ordinary arrangement for retaining the electrode and separating it from the opposing cathode.
Regarding claim 5, Amendola and Goldstein teach the limitations of claim 2, as stated above. Further, as stated above, Amendola teaches stacked metal-aqueous cells held under compression and recognizes the need to maintain controlled spacing and electrical contact among the anode, electrolyte region, cathode, and current collectors.
Further, as stated above, Goldstein teaches a sheet-form or planar anode accommodated within a metallic tray or enclosure and arranged in a stacked electrode assembly with a separator and cathode. Goldstein further teaches mechanically securing and compressing cell components during assembly.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to place a resilient pressing member, compression pad, spring plate, or elastically deformable support behind Goldstein’s sheet anode to urge the sheet anode toward the separator.
A skilled artisan would have recognized that a sheet metal anode may change thickness, flatness, or surface profile during discharge because active metal is consumed, corrosion, products are generated, and uneven current distribution may produce nonuniform dissolution. Manufacturing tolerances, thermal cycling, swelling, vibration, and repeated handling can similarly create a gap between the sheet anode and adjacent separator or current-collecting structure. Such a gap increases ionic path length, raises local resistance, produces uneven current density, and may cause localized passivation or incomplete utilization of the metal.
Providing a pressing part behind the anode would predictably compensate for these dimensional changes by maintaining the anode in its intended position. The pressing part would preserve a substantially uniform contact pressure, reduce movement of the sheet, maintain a controlled electrolyte path, and help keep the active face of the anode aligned with the separator and opposing cathode.
Locating the pressing part between the rear wall of the plate and the anode would have been the natural and mechanically effective location because the rigid plate wall provides the reaction surface against which the pressing part can act. Placement elsewhere would either interfere with the separator, obstruct the active electrode surface, or fail to direct the force toward the separator.
The choice among a coil spring, leaf spring, corrugated sheet, resilient polymer pad, elastomeric element, or compressible conductive foam would have been a predictable selection among known mechanical biasing structures. The spring constant, amount of precompression, surface area, and thickness would have been routine design variables. The modification would have required no change in battery chemistry and would have performed only its known mechanical function. A person of ordinary skill in the art therefore would have reasonable expected the pressing member to maintain electrode position and contact throughout anode consumption.
Regarding claim 7, Amendola, Goldstein, and Cervenka teach the limitations of claim 1, as stated above. Amendola further teaches electrically conductive current collectors and teaches that such collectors may include sheets, screens, wires, rods, and other conductive configurations ([0148]). Amendola also teaches electrical connection between neighboring cells through centrode structures. Amendola fails to teach a wire configured to electrically connect the anode and the current collector to each other.
Goldstein teaches that monopolar battery cells conventionally employ electrical connections such as wires extending between cell terminals and further teaches anode and cathode elements electrically connected to conductive enclosure portions ([0121]).
Amendola and Goldstein are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to use a wire or equivalent conductive lead to connect the anode and current collector where direct physical contact was inconvenient or where assembly tolerances required a flexible electrical connection. Using a wire in place of another known conductor would have been a predictable design choice.
Regarding claim 9, Amendola and Goldstein teach the limitations of claim 2, as stated above. Amendola further teaches molded plastic frames surrounding individual cells defining electrolyte-containing spaces ([0245-0246]). Goldstein further teaches a separator between the anode and cathode ([0129], [0133]).
Amendola and Goldstein are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to configure Goldstein’s or Amendola’s frame as an open-center spacer of selected thickness to support the separator perimeter, preserve an active central region, and establish a desired electrolyte chamber thickness. Selecting the spacer thickness would have been a matter of routine optimization based on electrolyte volume, sealing compression, and electrode spacing.
Regarding claim 18, Amendola, Goldstein, and Cervenka teach the limitations of claim 1, as stated above. Amendola further teaches a stack configured such that a plurality of the double cells is stacked (Fig. 5, 8A). Additionally, Goldstein teaches multi-cell and bipolar battery assemblies formed by stacking individual battery cells ([0124], [0130-133]).
Amendola and Goldstein are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to repeat and stack the double-cell unit of claim 1 to increase system voltage, current capacity, and total energy storage. Repetition of a known cell module in a stack would have been a predictable scaling technique routinely used in battery construction.
Claims 3 are rejected under 35 U.S.C. 103 as being unpatentable over Amendola in view of Hinatsu et al. (US 20100012503), hereinafter Hinatsu.
Regarding claim 3, Amendola and Goldstein teach the limitations of claim 2, as stated above. Amendola further teaches an electrolyte flow-management system that distributes liquid electrolyte to individual cells, receives electrolyte in an electrolyte supply tank, allows electrolyte to flow through underlying cells, and returns or collects electrolyte for treatment and recirculation. Amendola further teaches supply and return portions communicating with the cells (Abstract, Fig, 4A, 4B, 8H, 11B). Hinatsu further teaches electrochemical structural plates having chamber openings and passages communicating with separate reaction chambers in an electrolyzer module (Abstract, Fig. 1a-1c).
Amendola and Goldstein are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide spaced inlet and outlet openings in Goldstein’s cell tray using the fluid management teachings of Amendola and Hinatsu to enable electrolyte introduction, removal, circulation, and gas management. Positioning the inlet and outlet on separated portions of the side surface would have been a routine optimization to encourage flow across the cell chamber and reduce stagnant regions.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola in view of Hinatsu, and in further view of Cooper (US 5578183).
Regarding claim 4, Amendola and Goldstein teach the limitations of claim 2, as stated above. Amendola teaches a rechargeable metal-aqueous battery, particularly a zinc-air battery, having a zinc anode, and the disposition of zinc-containing active material within the anode region and circulating electrolyte through the cell ([0149-0150], [0281]).
Cooper teaches the anode is in a form of a pellet (Abstract). Specifically, Cooper teaches zinc pellets manufactured for the use as anode material in zinc batteries. Cooper explains that particulate zinc is mechanically compressed into compact, coherent, porous pellets and used in stationary, quasi-stationary, or moving packed-bed zinc particle anodes.
As stated above, Hinatsu teaches structural plates in an electrochemical module having openings, passages, and perforated regions through which electrolyte and gasses may travel (Abstract, Fig. 1a-1c). Hinatsu further teaches arranging chamber and passage structures so that fluids can move through the electrochemical module while solid electrochemical components remain mechanically retained.
Amendola, Cooper, and Hinatsu are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to replace Amendola’s sheet or bulk zinc anode with Cooper’s known zinc pellet anode and to retain those pellets within Goldstein’s recessed plate using a perforated support of the type suggested by Hinatsu. A skilled artisan would have been motivated to use zinc pellets because Cooper identifies them as suitable fuel particles for zinc battery and because palletization provides a reproducible particle size, coherent mechanical form, substantial exposed surface area, and replaceable or replenishable metal fuel. A pellet would predictably increase electrolyte-accessible surface area while avoiding the pumping and handling difficulties associated with loose zinc powder or slurry.
Once pellets were placed in Goldstein’s plate cavity, a retaining structure would necessarily be required to prevent the pellets from moving into the separator, cathode gap, electrolyte outlet, or associated flow passages. A perforated support would have been a predictable solution because it preforms two established functions simultaneously. It physically retains the solid zinc pellets and permits aqueous electrolyte to flow through the support and contact the pellet surfaces. A person of ordinary skill would have selected through-holes smaller than the pellet diameter because holes larger than the pellets would defeat the known retaining function. The relative sizes of the pellets and openings are therefore dictated by the intended function rather than being an inventive discovery. Selecting an opening diameter below the minimum pellet diameter would have been routine dimensional optimization.
It also would have been obvious to incline or obliquely arrange the support. In a gravity-loaded particle bed, an inclined retaining surface direct pellets towards the collection region, distributes the particles across the active area, discourages isolated voids or bridging, and facilitates loading and removal. The exact angle would have been selected according to pellet size, coefficient of friction, electrolyte flow rate, desired bed depth, and cavity geometry. These are known result-effective variable that could have been optimized through routine experimentation.
The modification would not change the fundamental operating principle of Amendola’s zinc anode. Zinc would remain the oxidizable anode material, electrolyte would remain in ionic communication with the zinc and cathode, and the perforated support would perform the predictable mechanical function of retaining the pellet bed while allowing electrolyte access. A skilled artisan therefore would have had a reasonable expectation of success.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola in view of Cervenka.
Regarding claim 6, Amendola, Goldstein, and Cervenka teach the limitations of claim 1, as stated above. Amendola further teaches a metal anode selected from aluminum, zinc, magnesium, sodium, lithium, iron, and alloys containing those elements ([0250]). Specifically, Amendola teaches a zinc metal anode ([0250]).
Cervenka teaches a metal anode selected from aluminum, zinc, magnesium, sodium, lithium, iron, and alloys containing those elements ([0021], Claim 7).
Amendola and Cervenka are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to select from one or more of the recited metals based on desired cell voltage, capacity, cost, corrosion behavior, and compatibility with the selected aqueous electrolyte. Selection among a finite group of known metal-anode materials would have constituted routine material optimization.
Claims 8 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Amendola in view of Nonoyama et al. (US 9431661), hereinafter Nonoyama.
Regarding claim 8, Amendola, Goldstein, and Cervenka teach the limitations of claim 1, as stated above. Amendola further teaches an air-contacting cathode containing carbon and one or more oxygen-reduction catalysts, together with a corrosion-resistant current collector and an air-permeable hydrophobic catalytic membrane (Fig. 1, [0077], [0274]). Amendola fails to expressly teach the cathode comprises a noble metal catalyst loaded on a carrier.
Nonoyama teaches the cathode comprises a noble metal catalyst loaded on a carrier (Abstract, Fig. 1, 2, 4). Specifically, Nonoyama teaches a cathode catalyst layer containing noble-metal catalyst particles supported in a catalyst-containing layer adjacent to a polymer-electrolyte membrane and gas-diffusion layer.
Amendola and Nonoyama are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to employ Nonoyama’s supported noble-catalyst in Amendola’s air cathode to provide known oxygen-reduction activity, increase catalyst dispersion, improve catalyst utilization, and reduce the quantity of noble metal required.
Regarding claim 10, Amendola and Goldstein teach the limitations of claim 2, as stated above. As shown above, Goldstein teaches an open cell enclosure containing the electrode assembly but fails to expressly teach a porous protective layer corresponding to and covering the open surface of the plate. Amendola further teaches an air-permeable hydrophobic membrane incorporated into the air-contacting electrode and positioned over the cell’s active region ([0247], Fig. 1).
Additionally, Nonoyama teaches porous gas-diffusion layers adjacent to catalyst layers in a membrane-electrode assembly (Col. 3, ln. 52-60).
Amendola, Goldstein, and Nonoyama are considered analogous art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide a porous layer over Goldstein’s cell opening using the porous membrane or gas-diffusion structures of Amendola or Nonoyama to protect underlying cell components while permitting passage of gas, electrolyte, or reaction species. Forming the layer with a shape corresponding to the cell opening would have been a routine dimensional design choice.
Claims 11 are rejected under 35 U.S.C. 103 as being unpatentable over Amendola, in view of Cervenka, and in further view of Nonoyama.
Regarding claim 11, Amendola, Goldstein, and Cervenka teach the limitations of claim 1, as stated above. Cervenka teaches a separator positioned between the cathode and anode that electrically insulates the electrodes while permitting ion transport through the separator ([0023], Claim 9). Nonoyama further teaches a polymer-electrolyte membrane that conducts protons between electrode catalyst layers (Fig. 2).
Cervenka and Nonoyama are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to select an ion-conductive separator based on the ionic species carrying charge in the chosen battery chemistry. Such selection would have been a routine material optimization intended to permit the desired ion transport while suppressing electrode shorting and undesired species crossover.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola in view of Nonoyama, and in further view of Hinatsu.
Regarding claim 12, Amendola, Hinatsu, and Cervenka teach the limitations of claim 1, as stated above. Amendola further teaches a frame surrounding a cell and defining a space that accepts electrolyte. Amendola further teaches airflow tunnels or pathways between adjacent cells ([0245]).
Additionally, Goldstein teaches peripheral sealing and spacing structures in planar battery cells ([0129]).
Additionally, Hinatsu teaches structural electrochemical plates having separate chamber openings and passages communicating with electrochemical chambers (Abstract, Fig. 1a-1c).
Amendola, Goldstein, and Hinatsu are analogous in the art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to form Amendola’s or Goldstein’s spacing frame with an open center and to provide spaced inlet and outlet passages using Hinatsu’s chamber-flow teachings so that electrolyte could enter, traverse, and leave the cathode-side gap. Supporting the separator at its edge while leaving the active central region open would have been a predictable frame configuration, and locating the inlet and outlet apart from one another would have been routine flow-path optimization.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola, in view of Hinatsu, and in further view of Cervenka.
Regarding claim 13, Amendola and Goldstein teach the limitations of claim 2, as stated above. Amendola further teaches an electrolyte-management system configured to supply, collect, circulate, and treat electrolyte associated with the battery cells (Fig. 1-4). In Amendola’s illustrated cells, the aqueous electrolyte occupies the space between the metal anode and the air-contacting cathode.
Hinatsu teaches an electrochemical module having separate fluid chambers disposed on opposite sides of ion-conducting or electrode structures ([0015], Fig. 1). Hinatsu’s structural plates define multiple chambers and passages that permit different fluids and gaseous reaction products to be maintained and conveyed through respective portions of the electrochemical module.
Cervenka teaches that flow-type electrochemical cells conventionally employ separate anolyte and catholyte fluids ([0001-0003]). Cervenka explains that the electrolytes may be stored outside the cell and supplied to the corresponding reaction regions, where ion exchange occurs through a separating structure.
Amendola, Hinatsu, and Cervenka are considered analogous art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to modify Amendola’s metal-aqueous battery so that a first electrolyte is accommodated in the metal-anode chamber defined by the plate and a second electrolyte is accommodated in the cathode-side gap, as suggested by the separate chamber and anolyte/catholyte teachings of Hinatsu and Cervenka.
A person of ordinary skill would have been motivated to provide separate electrolytes because the reactions occurring at the anode and cathode frequently favor different chemical environments. A single common electrolyte requires a compromise among pH, ionic species, concentration, gas solubility, corrosion behavior, and electrode-reaction kinetics. Maintaining separate first and second electrolytes would predictably permit each fluid to be independently selected for compatibility with the respective electrode reaction.
In particular, separating the two electrolytes would have provided the following predictable benefits:
allowing the first electrolyte to be optimized for reaction with the metal anode;
allowing the second electrolyte to be optimized for the cathode reaction and absorption or transport of gaseous reactants;
reducing direct chemical interaction between incompatible electrolyte constituents;
limiting crossover of reaction products that could passivate or contaminate the opposite electrode;
permitting independent adjustment of pH, ionic concentration, temperature, and flow rate;
maintaining a high concentration of the desired reactant near each respective electrode; and
facilitating independent regeneration, replacement, or treatment of the two electrolytes.
The plate’s inner space is the natural location for the first electrolyte because it contains the anode, while the cathode-side gap is the natural location for the second electrolyte because it places that electrolyte directly adjacent the cathode. This arrangement would follow from the physical organization of the modified cell and would require no change to the fundamental operating principle of the prior-art devices.
The use of separate chambers and an ion-conducting separator was well established in electrochemical devices. The separator would permit ionic charge transfer while substantially preventing bulk mixing of the two liquids. A skilled artisan therefore would have had a reasonable expectation that the first and second electrolytes could be accommodated in the respective spaces and perform their known functions.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola, in view of Roy (US 4833046).
Regarding claim 14, Amendola, Hinatsu, and Cervenka teach the limitations of claim 13, as stated above. Amendola teaches a rechargeable metal-aqueous battery, having an aqueous electrolyte. Amendola fails to teach an electrolyte comprises an alkali metal hydride.
Roy teaches an electrolyte comprising an alkali metal hydride for use in an electrochemical cell ([0009]).
Amendola and Roy are considered analogous art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to substitute the aqueous electrolyte of Amendola with the alkali metal hydride electrolyte taught by Roy because such substitution merely involves replacing one known electrolyte with another known electrolyte that performs the same function of conducting ions within a rechargeable electrochemical cell. The substitution represent the predictable use of prior art elements and would have yielded no more than the expected result of providing an operative electrolyte for the rechargeable metal aqueous cell. Such substitution is considered an obvious matter of design base on the simple substitution of one known equivalent electrolyte for another to obtain predictable results.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola in view of Kaczur (US 20160017503).
Regarding claim 15, Amendola, Hinatsu, and Cervenka teach the limitations of claim 13, as stated above. Amendola teaches a rechargeable metal-aqueous battery.
Kaczur teaches an electrochemical carbon-dioxide-processing system having separate anolyte and catholyte feeds. Kaczur teaches supplying carbon dioxide to a cathode region and teaches that the catholyte may comprise an alkali-metal bicarbonate. Kaczur therefore teaches an aqueous carbon-dioxide-containing catholyte in which bicarbonate ions are present.
Amendola, Hinatsu, and Kaczur are considered analogous art to the claimed invention because they are in the same field of electrochemical systems.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to use Kaczur’s carbon-dioxide/bicarbonate-containing catholyte as the second electrolyte in the cathode-side gap of the modified Amendola cell.
A skilled artisan would have been motivated to make the substitution because the cathode-side electrolyte is positioned to contact or receive a gaseous cathode reactant. Kaczur teaches that an aqueous bicarbonate-containing catholyte is suitable for receiving and electrochemically processing carbon dioxide. Incorporating that electrolyte into the cathode-side gap would therefore have provided a known liquid medium for absorbing, transporting, and retaining carbon dioxide near the cathode.
When carbon dioxide is introduced into an aqueous electrolyte, dissolved carbon dioxide participates in an acid-base equilibrium that produces bicarbonate and protonic species. Thus, use of an aqueous carbon-dioxide/bicarbonate catholyte would predictably result in a second electrolyte containing both bicarbonate ions and protons, even though the relative concentrations would depend on pH, concentration, pressure, and temperature.
A person of ordinary skill in the art would have understood that the bicarbonate-containing second electrolyte provides several predictable benefits:
bicarbonate provides an aqueous ionic form associated with absorbed carbon dioxide;
the bicarbonate system permits carbon-containing species to remain dissolved and circulate through the cathode compartment;
the electrolyte provides ionic conductivity within the cathode-side gap;
the bicarbonate equilibrium assists in buffering changes in catholyte pH;
circulation of the catholyte permits continued introduction and removal of carbon-containing species;
separation from the metal-anode electrolyte prevents the catholyte composition from directly interfering with the metal-side reaction; and
the known ion-conductive separator permits charge-balancing ions to move between the respective electrolyte regions without requiring bulk mixing.
The modification would not require changing the mechanical structure of the modified Amendola cell. It would merely involve selecting Kaczur’s known bicarbonate-containing aqueous catholyte for use in the already-provided second-electrolyte chamber. Each component would continue to perform its previously known function. A skilled artisan would have had a reasonable expectation of success because Kaczur teaches that bicarbonate-containing aqueous catholytes are operable in electrochemical carbon-dioxide systems and Hinatsu teaches maintaining separate fluids within respective electrochemical chambers, as stated above.
Claim 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over Amendola in view of Cervenka.
Regarding claim 16, Amendola, Hinatsu, and Cervenka teach the limitations of claim 13, as stated above. Amendola teaches a rechargeable metal-aqueous battery. Further, the combination applied to claim 13 teaches separate first and second electrolytes accommodated in respective electrode-side chambers.
Cervenka teaches an aqueous secondary-battery electrolyte and recognizes that electrolyte properties and electrochemical performance vary with temperature. Cervenka describes elevated-temperature operation and includes evaluation of electrolyte conductivity as a function of temperature ([0020], [0034]). Cervenka also teaches that concentrated aqueous electrolytes can operate at elevated temperatures ([0020], [0034]).
Amendola and Cervenka are considered analogous art to the claimed invention because they are in the same field of batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to modify the temperature of the electrolytes as an obvious matter of design choice and routine optimization.
A person of ordinary skill in the art would have understood that temperature is a conventional operating parameter in an aqueous electrochemical cell and that adjusting temperature predictably affects:
electrolyte ionic conductivity;
electrolyte viscosity;
diffusion and mass-transfer rates;
electrode-reaction kinetics;
activation and concentration polarization;
gas generation and dissolution;
water evaporation;
corrosion of the metal electrode;
separator and seal durability; and
overall system efficiency.
Once Cervenka teaches that the aqueous electrolyte may be operated at elevated temperatures and that conductivity varies with temperature, selecting a useful temperature within the moderate elevated-temperature range of approximately 40°C to 80°C would have required only routine experimentation.
A skilled artisan would have balanced the predictable advantages of heating against the known disadvantages. Increasing the temperature above ambient would generally be expected to increase conductivity, reduce viscosity, and improve reaction kinetics and mass transport. However, excessively high temperatures would be expected to increase water loss, corrosion, gas evolution, seal degradation, and thermal-management requirements.
The claimed range represents a broad intermediate range between ordinary ambient operation and the boiling point of water at atmospheric pressure. It would therefore have been a predictable engineering selection for obtaining improved conductivity and reaction rate without imposing the more severe materials and water-management problems associated with operation near or above the boiling point.
Nothing in the claim requires a particular temperature-dependent mechanism, critical transition, or unexpected result at either 40°C or 80°C. The endpoints merely define the selected operating range. In the absence of evidence that the claimed range produces a result materially different from adjacent temperatures, selection of the range would have constituted no more than the optimization of a known result-effective variable.
Moreover, claim 16 is satisfied when either the first electrolyte or the second electrolyte is within the range. Thus, the skilled artisan need only select the operating temperature of one of the known aqueous electrolyte streams within the conventional moderate elevated-temperature range.
The modification would involve adjusting a heater, system set point, or operating environment and would not alter the battery’s structure or chemical operating principle. A skilled artisan would have had a reasonable expectation that the electrolyte would remain operable throughout at least a portion of the recited range.
Regarding claim 17, Amendola, Hinatsu, and Cervenka teach the limitations of claim 13, as stated above. Amendola teaches a rechargeable metal-aqueous battery. Further, the combination applied to claim 13 teaches separate first and second electrolytes accommodated in respective electrode-side chambers.
The claimed relative-temperature relationship would have been an obvious matter of design choice and routine optimization.
Once separate first and second electrolyte streams are provided, a person of ordinary skill would necessarily select an operating temperature for each stream. There are only three possible relative relationships:
the first electrolyte is warmer than the second;
the first and second electrolytes are at the same temperature; or
the first electrolyte is cooler than the second.
Claim 17 encompasses the first two of these three predictable alternatives.
Operating the two electrolytes at the same temperature would have been the simplest and most conventional design choice. A common temperature:
simplifies temperature-control hardware;
permits use of a common heater, thermal enclosure, or heat exchanger;
minimizes thermal stress across the separator;
reduces unwanted heat transfer between the electrolyte chambers;
simplifies control logic and monitoring;
decreases the number of independent set points;
reduces manufacturing and operating complexity; and
provides more uniform start-up and steady-state conditions.
Thus, if both electrolyte streams were maintained within the same heated battery housing or controlled to the same selected operating temperature, the first-electrolyte temperature would necessarily be equal to the second-electrolyte temperature and would satisfy the claim.
Alternatively, operating the first electrolyte at a temperature higher than the second would also have been a predictable design option. The first electrolyte contacts the metal anode, and a skilled artisan may desire additional heating on the metal side to improve ionic conductivity, reduce viscosity, accelerate transport of reactants and products, and increase the rate of the desired anode reaction.
The second electrolyte, by contrast, may contain dissolved carbon dioxide and bicarbonate species. A skilled artisan could select a lower second-electrolyte temperature to avoid unnecessary heating, limit water loss, or preserve gas absorption and retention. Thus, maintaining the first electrolyte at a temperature equal to or somewhat higher than the second would have been a logical optimization of the two different electrode-side environments.
The exact temperature difference would have been selected according to known engineering considerations, including:
composition and concentration of each electrolyte;
desired reaction rate at each electrode;
conductivity and viscosity;
gas solubility;
heat generated during operation;
ambient heat loss;
electrolyte flow rate;
corrosion behavior;
separator thermal tolerance; and
total energy consumed by heating.
Determining the preferred relative set points would have required only routine measurement of cell voltage, current efficiency, conductivity, gas uptake, and thermal losses. No new structure or operating principle would have been required.
The claim does not recite a minimum temperature difference when the first electrolyte is warmer, nor does it identify any critical or unexpected technical effect resulting specifically from the first electrolyte being equal to or warmer than the second. Because equality alone satisfies the claim, maintaining both electrolytes at a common operating temperature would be sufficient.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola, in view of Hinatsu, and in further view of Kaczur.
Regarding claim 19, Amendola, Goldstein, and Cervenka teach the limitations of claim 1, as stated above. As stated above, Amendola teaches a metal-aqueous battery and an electrolyte-management system having electrolyte storage, supply, circulation, return, and treatment equipment fluidly connected to a plurality of metal-aqueous cells.
As stated above, Hinatsu teaches an electrolyser module capable of electrochemically generating hydrogen and having separate electrochemical chambers, electrode assemblies, separators, and fluid passages.
Kaczur teaches an electrochemical carbon-dioxide system in which an anolyte feed is supplied to an anode region and a separate catholyte feed containing carbon dioxide and alkali-metal bicarbonate is supplied to a cathode region (Abstract, [0008], Fig. 9). Kaczur therefore teaches both distinct electrolyte supplies and electrochemical processing or storage of carbon dioxide in dissolved ionic or salt form.
Amendola, Hinatsu, and Kaczur are analogous in the art of fluid-fed electrochemical systems. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to modify Amendola’s metal-aqueous battery and electrolyte circulation system to provide first and second electrolyte supply units, as taught by Kaczur with the first electrolyte supplied to the metal-anode chamber and a carbon-dioxide/bicarbonate-containing second electrolyte supplied to the cathode-side chamber.
A skilled artisan would have been motivated to combine the references because a single common electrolyte imposes a compromise between the chemical conditions preferred at the metal anode and those preferred for carbon-dioxide uptake at the cathode. Separate supplies allow independent selection and control of:
electrolyte composition;
concentration;
pH;
temperature;
flow rate;
dissolved-gas loading;
reaction-product concentration; and
replacement or regeneration schedule.
The first electrolyte could therefore be optimized for metal oxidation and hydrogen evolution, while the second electrolyte could be optimized for carbon-dioxide absorption and bicarbonate formation.
Amendola already provides the essential fluid-management infrastructure: storage vessels, supply conduits, pumps or gravity feed, cell manifolds, returns, and treatment equipment. Duplicating or dividing that known infrastructure into separate first and second circuits would have been a predictable modification rather than a new operating principle.
Kaczur teaches precisely why a second circuit would be useful: the catholyte is intentionally supplied with carbon dioxide and bicarbonate while the anolyte is separately supplied to the anode. Separate circulation prevents uncontrolled bulk mixing, preserves the desired half-cell environments, and permits continuous treatment of each fluid.
Hinatsu provides the hydrogen-generation motivation and confirms that hydrogen-producing electrochemical reactions are conventionally carried out in separated fluid chambers. The combination would permit the oxidation energy of the metal anode to support hydrogen generation while the opposite electrolyte absorbs or processes carbon dioxide.
The expected results would have been predictable:
oxidation of the active metal at the anode;
hydrogen generation associated with the aqueous anode-side reaction;
carbon-dioxide absorption into the cathode-side aqueous electrolyte;
conversion of absorbed carbon dioxide to bicarbonate or another dissolved carbon-containing species;
ionic communication through the separator;
continuous replenishment and removal of both electrolytes.
Because each reference uses conventional tanks, pumps, conduits, separators, and aqueous electrolytes, a person of ordinary skill in the art would have had a reasonable expectation that the combined system would operate according to the known functions of its parts.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Amendola, in view of Curley et al. (US 10056636), hereinafter Curley, and in further view of Jastrzebski (WO 2022155753).
Regarding claim 20, Amendola, Hinatsu, and Kaczur teach the limitations of claim 19, as stated above. The combination of claim 19 fails to teach first and second heating apparatuses respectively disposed between the battery and the first and second electrolyte supply units.
Curley teaches a flow-battery system in which an aqueous electrolyte reservoir is fluidly connected to a plurality of electrochemical cells and an inline heater is used in the electrolyte circulation system ([0020], Fig. 5).
Jastrzebski teaches separate anolyte and catholyte chambers and reservoirs, a heater for maintaining the electrolytes at operating temperature, and maintenance of the electrolyte in external anolyte and catholyte reservoirs at or above the required operating temperature (Abstract, [0055-0056]).
Amendola, Curley, and Jastrzebski are analogous in the art of circulated-electrolyte electrochemical systems. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide an inline heating apparatus in each of the first and second electrolyte supply lines between the corresponding reservoir and the battery.
A skilled artisan would have recognized that electrolyte temperature directly affects conductivity, viscosity, diffusion, reaction rate, gas solubility, plating or dissolution behavior, and cell polarization. Supplying electrolyte below its intended operating temperature can cause unstable cell voltage, uneven current distribution, slower start-up, greater passivation, and reduced reaction efficiency.
Placing each heater in the supply path between the reservoir and battery would have been advantageous because it allows the fluid to be heated immediately before entering the cell. This location:
reduces heat loss between heating and use;
provides rapid start-up;
permits accurate control of the inlet temperature;
avoids heating the entire storage reservoir when only the circulated stream requires heating;
permits the heater to respond to current cell load and flow rate;
enables independent temperature control of the two electrolyte streams; and
simplifies replacement or servicing of the heater as an inline component.
Providing two heaters rather than one common heater would have been motivated by the different compositions and functions of the first and second electrolytes. A common heater would not permit different temperature set points and could create an unwanted fluid connection or thermal compromise between the streams. Independent heaters allow the anode electrolyte to be optimized for metal oxidation and hydrogen generation while the cathode electrolyte is optimized for carbon-dioxide absorption, bicarbonate stability, and cathode reaction kinetics.
Duplicating Curley’s known inline heater for each of two known electrolyte circuits would have been a straightforward duplication of components performing the same known function in parallel. Where a system contains two independently circulated fluids, providing one conventional conditioning component in each circuit is an ordinary engineering arrangement. The heater power, residence time, flow rate, heat-transfer area, and set point would have been routine design variables calculated from the electrolyte heat capacity, desired temperature rise, fluid flow rate, and anticipated heat loss. No inventive experimentation would have been required.
Jastrzebski further confirms a reasonable expectation of success by expressly teaching thermal control of both anolyte and catholyte and their reservoirs. Curley confirms that an inline heater is suitable in a flow-battery electrolyte path. Combining those teachings with the two electrolyte circuits of the Claim 19 combination would predictably produce the claimed first and second heating apparatuses.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Tamara Orduna whose telephone number is (571)431-1457. The examiner can normally be reached Mon-Fri 8:00-5:00 EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jennifer Dieterle can be reached at (571) 270-7872. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/TAMARA ORDUNA/Examiner, Art Unit 1776 /Jennifer Dieterle/Supervisory Patent Examiner, Art Unit 1776
Prosecution Insights