DETAILED ACTION
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 and 6-12 are rejected under 35 U.S.C. 103 as being unpatentable over Park et al. (US 20170179506 A1) in view of Roumi (US 20150180000 A1), Yamamura et al. (US 20170012334 A1), and Wagner (US 3539396 A).
Regarding claim 1, Park discloses an air electrode/separator assembly (paragraphs 0009, 0068, 0091, figure 3B), comprising: a separator (film 12 includes separation film), a metal negative electrode (negative electrode metal layer 11), a pair of catalyst layers covering both surfaces of the separator and comprising a catalyst for an air electrode, and an electron conductive material (paragraph 0069, positive electrode layer 13 includes catalyst and conductive material and is covering film 12 which may include a separation film), a pair of gas diffusion electrodes provided on the pair of catalyst layers on a side opposite to the hydroxide ion conductive separator (figure 3B, GDL’s 14), wherein one of the pair of catalyst layers is a catalyst layer for discharge and the other of the pair of catalyst layers is a catalyst layer for charge (paragraphs 0069, oxidation/reduction occurs each positive electrode catalyst layer 13, satisfying the limitation as each is for charge/discharge), and wherein the separator, the catalyst layer, and the gas diffusion electrode are arranged vertically (figure 3B).
Park is silent regarding the separator comprising an inner space capable of housing a metal negative electrode.
Roumi discloses electrochemical cells which may include zinc-air batteries, including a separator enclosure which encloses at least a portion of a positive or negative electrode (Roumi paragraphs 0008, 0019). Roumi further discloses that the separator enclosure is particularly useful for zinc anodes (Roumi paragraph 0019). The reference teaches that the separator enclosure provided for the negative electrode improves cycle life and prevents material loss of the electrode (Roumi paragraph 0009). Roumi and Park are analogous because they both disclose separator/cell assemblies for zinc-air batteries.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the assembly disclosed by Park to substitute the separator films with the separator enclosure disclosed by Roumi around the negative electrodes. Doing so would improve cycle life and prevent material loss.
Park in view of Roumi is silent regarding the separator being a hydroxide ion conductive separator and the catalyst layers comprising a hydroxide ion conductive material.
Yamamura discloses an air electrode including a separator composed of a hydroxide-ion-conductive inorganic solid electrolyte being a dense ceramic material and an air electrode layer disposed on the separator and containing an air electrode catalyst, an electron-conductive material, and a hydroxide-ion-conductive material (Yamamura paragraph 0022). Yamamura further discloses that the hydroxide-ion conductive material in the catalyst layer leads to an increase in contact area between the air electrode catalyst and air at the outer surface of the air electrode layer, resulting in promotion of the catalytic reaction (Yamamura paragraph 0032). The reference teaches that the hydroxide-ion-conductive separator prevents degradation and improves battery reliability and performance (Yamamura paragraph 0023).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator enclosure assembly disclosed by Park in view of Roumi to include the separator material disclosed by Yamamura, and for the catalyst layer to include the hydroxide-ion conductive material. Doing so would promote the catalytic reaction and improve reliability.
Park in view of Roumi and Yamamura is silent regarding a water absorption/desorption layer provided so as to contact both of the pair of catalyst layers, having water absorbability and desorbability and the water absorption/desorption layer is positioned below the catalyst layer.
Wagner discloses a zinc-air cell including a pair of flat planar cathodes, a flat zinc anode positioned intermediate of and spaced from each of the cathodes, and a separation system (Wagner abstract). Wagner further discloses that the cell includes absorbent layers, wherein the first absorbent layer is in contact with the pair of cathode layers and provided under them (Wagner Col. 2 lines 26-63, figure 1, cathodes 12 and 12’, u-shaped layer 14 and base 16). The reference teaches that the absorbent layer provides the means to wet the electrodes with electrolyte and prevent zinc shorting (Wagner Col. 3, line 51 – Col. 4, line 27). Wagner and Park are analogous because they both disclose zinc-air battery assemblies.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the air electrode/separator assembly disclosed by modified Park to include the absorbent layer disclosed by Wagner. Doing so would sufficiently wet the electrodes and prevent zinc shorting.
Regarding claim 6, modified Park discloses the limitations of claim 1. Park is silent regarding wherein the hydroxide ion conductive material included in the catalyst layer is a layered double hydroxide (LDH).
Yamamura discloses an air electrode including a separator composed of a hydroxide-ion-conductive inorganic solid electrolyte being a dense ceramic material and an air electrode layer disposed on the separator and containing an air electrode catalyst, an electron-conductive material, and a hydroxide-ion-conductive material (Yamamura paragraph 0022). Yamamura further discloses that the material included in the electrode layer can be an LDH material (Yamamura paragraphs 0027-0028). The reference teaches that the materials reduce the reaction resistance of the air electrode (Yamamura paragraph 0022). Yamamura and Park are analogous because they both disclose metal-air cells.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell assembly of Park to include the LDH material in the catalyst layer as disclosed by Yamamura. Doing so would reduce reaction resistance of the electrode.
Regarding claim 7, modified Park discloses the limitations of claim 1. Park is silent regarding wherein the catalyst layer comprises 20 to 50% by volume of the hydroxide ion conductive material relative to 100% by volume of solid content of the catalyst layer.
Yamamura discloses an air electrode including a separator composed of a hydroxide-ion-conductive inorganic solid electrolyte being a dense ceramic material and an air electrode layer disposed on the separator and containing an air electrode catalyst, an electron-conductive material, and a hydroxide-ion-conductive material (Yamamura paragraph 0022). Yamamura further discloses that the amount of hydroxide ion conductive material in the electrode layer in 10 to 80 vol %, relative to the amount of electrode layer (Yamamura paragraph 0027, overlapping the claimed range). The reference teaches that a relatively small amount of the hydroxide-ion-conductive material leads to an increase in contact area between the air electrode catalyst and air at the outer surface of the air electrode layer, resulting in promotion of the catalytic reaction (Yamamura paragraph 0032). Yamamura and Park are analogous because they both disclose metal-air cells.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell assembly of Park to include the hydroxide ion conductive material in the amount disclosed by Yamamura. Doing so would promote the catalytic reaction. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See also MPEP 2144.05.
Regarding claim 8, modified Park discloses the limitations of claim 1. Park is silent regarding wherein the hydroxide ion conductive separator is a layered double hydroxide (LDH) separator.
Yamamura discloses an air electrode including a separator composed of a hydroxide-ion-conductive inorganic solid electrolyte being a dense ceramic material and an air electrode layer disposed on the separator and containing an air electrode catalyst, an electron-conductive material, and a hydroxide-ion-conductive material (Yamamura paragraph 0022). Yamamura further discloses that the separator is a LDH separator and prevents intrusion of an undesired substance contained in the air and the migration of alkali metal ions contained in the electrolytic solution to the air electrode layer (Yamamura paragraph 0035). Yamamura and Park are analogous because they both disclose metal-air cells.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell assembly of Park to include the LDH separator disclosed by Yamamura. Doing so would prevent the intrusion of undesired substances into the electrode layers.
Regarding claim 9, modified Park discloses the limitations of claim 8. Park is silent regarding wherein the LDH separator is composited with a porous substrate.
Yamamura discloses an air electrode including a separator composed of a hydroxide-ion-conductive inorganic solid electrolyte being a dense ceramic material and an air electrode layer disposed on the separator and containing an air electrode catalyst, an electron-conductive material, and a hydroxide-ion-conductive material (Yamamura paragraph 0022). Yamamura further discloses that the LDH separator composited with a porous substrate for reliable retention of hydroxide ions on the separator (Yamamura paragraphs 0038-0039). Yamamura and Park are analogous because they both disclose metal-air cells.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell assembly of Park to include the composite LDH separator disclosed by Yamamura. Doing so would provide for reliable retention of hydroxide ions on the separator.
Regarding claim 10, modified Park discloses the limitations of claim 1. Park further discloses that the separator comprising the inner space comprises a pair of separators facing each other (figure 3B, paragraph 0068, films 12 may include separation film) or a folded separator (figure 1A), Park is silent regarding the separators being hydroxide ion conductive separators.
Yamamura discloses an air electrode including a separator composed of a hydroxide-ion-conductive inorganic solid electrolyte being a dense ceramic material and an air electrode layer disposed on the separator and containing an air electrode catalyst, an electron-conductive material, and a hydroxide-ion-conductive material (Yamamura paragraph 0022). The reference teaches that the hydroxide-ion-conductive separator prevents degradation and improves battery reliability and performance (Yamamura paragraph 0023).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the assembly disclosed by Park to include the separator material disclosed by Yamamura. Doing so would improve reliability of the battery.
Regarding claim 11, modified Park discloses the limitations of claim 1. Park further discloses a metal-air secondary battery (paragraphs 0005, 0009) comprising an electrolyte (paragraphs 0067-0070). Park is silent regarding a metal negative electrode housed in the inner space, wherein the water absorption/desorption layer is positioned below the catalyst layer.
Roumi discloses electrochemical cells which may include zinc-air batteries, including a separator enclosure which encloses at least a portion of a positive or negative electrode (Roumi paragraphs 0008, 0019). Roumi further discloses that the separator enclosure is particularly useful for zinc anodes (Roumi paragraph 0019). The reference teaches that the separator enclosure provided for the negative electrode improves cycle life and prevents material loss of the electrode (Roumi paragraph 0009). Roumi and Park are analogous because they both disclose separator/cell assemblies for zinc-air batteries.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the assembly disclosed by Park to substitute the separator films disclosed by Park with the separator enclosure disclosed by Roumi around the negative electrodes. Doing so would improve cycle life and prevent material loss.
Wagner discloses a zinc-air cell including a pair of flat planar cathodes, a flat zinc anode positioned intermediate of and spaced from each of the cathodes, and a separation system (Wagner abstract). Wagner further discloses that the cell includes absorbent layers, wherein the first absorbent layer is in contact with the pair of cathode layers and provided under them (Wagner Col. 2 lines 26-63, figure 1, cathodes 12 and 12’, u-shaped layer 14 and base 16). The reference teaches that the absorbent layer provides the means to wet the electrodes with electrolyte and prevent zinc shorting (Wagner Col. 3, line 51 – Col. 4, line 27). Wagner and Park are analogous because they both disclose zinc-air battery assemblies.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell assembly disclosed by Park to include the absorbent layer disclosed by Wagner. Doing so would sufficiently wet the electrodes and prevent zinc shorting.
Regarding claim 12, modified Park discloses the limitations of claim 11. Park further discloses an electrolyte-containing nonwoven fabric in the inner space (paragraph 0068, separation layer comprises electrolyte in non-woven fabric, therefore part of the “inner space” includes the fabric).
Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Park et al. (US 20170179506 A1) in view of Roumi (US 20150180000 A1), Yamamura et al. (US 20170012334 A1), and Wagner (US 3539396 A) as applied to claim 1 above, and further in view of Sayre et al. (US 20110111287 A1).
Regarding claims 2-4, modified Park discloses the limitations of claim 1. Park is silent regarding wherein the water absorption/desorption layer comprises a water absorbent resin and silica gel, and wherein the water absorbent resin is at least one selected from the group consisting of a polyacrylamide-based resin, potassium polyacrylate, a polyvinyl alcohol-based resin, and a cellulose-based resin.
Sayre discloses a metal-air battery comprising a cathode, comprising: a catalyst; an electronic conductor; and a hydrophobic gas permeable binder; an electrolyte; and an anode (Sayre paragraphs 0025-0026). Sayre further discloses that the battery may also include hygroscopic and/or deliquescent binder materials in order to keep the cell wet and resist dry-out (Sayre paragraph 0051). The reference teaches that these materials may include polyvinyl alcohol, 2-hydroxy cellulose, and silica gel (Sayre paragraph 0051). Sayre and Park are analogous because they both disclose metal-air cell assemblies.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the layer disclosed by modified Park to include the water absorbent cellulose-based or polyvinyl alcohol resin and silica gel as disclosed by Sayre. Doing so would resist dry-out.
Claims 5 is rejected under 35 U.S.C. 103 as being unpatentable over Park et al. (US 20170179506 A1) in view of Roumi (US 20150180000 A1), Yamamura et al. (US 20170012334 A1), Wagner (US 3539396 A), and Sayre et al. (US 20110111287 A1) as applied to claim 2 above, and further in view of Hattori et al. (US 20180083290 A1).
Regarding claim 5, modified Park discloses the limitations of claim 2. Park is silent regarding wherein the catalyst layer comprises 0.01 to 10% by volume of the water absorbent resin in terms of solid content relative to 100% by volume of solid content of the catalyst layer.
Hattori discloses a zinc-air secondary battery comprising an air electrode, a hydroxide ion conductive separator, a negative electrode immersed in an electrolyte solution, a positive electrode current collecting body, and a housing (Hattori paragraphs 0015-0016). Hattori further discloses that the electrode contains a binder which may be CMC (a water absorbent cellulose-based binder) in an amount of less than or equal to 10 vol% (Hattori paragraphs 0031-0033, substantially overlapping the claimed range). The reference teaches that the electrode formulation enhances electrode characteristics (Hattori paragraph 0009). Hattori and Park are analogous because they both disclose metal-air battery assemblies.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included the absorbent binder disclosed by modified Park in the amount disclosed by Hattori. Doing so would enhance electrode characteristics.
Conclusion
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/B.T.L./Examiner, Art Unit 1727
/BARBARA L GILLIAM/Supervisory Patent Examiner, Art Unit 1727
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