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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 14 July 2025 has been entered.
Response to Amendment
Applicant amended claims 1, 9, 14, 17, and 19-21 and cancelled claims 6, 8, 16, 18, and 23-24. Thus, claims 1-5, 7, 9-15, 17, and 19-22 are pending and considered in the present Office action.
The rejections of claims 6, 8, 16, 18, and 23-24 are withdrawn because they have been cancelled.
The rejections of claims 1-5, 7, 10-15, 17, 19 and 21-22 remain unchanged and the rejection of claim 20 over Kazacos and Rahman is maintained (see Response to Arguments section for more details).
The rejection of claim 20 over Nguyen is withdrawn in view of the amendment. The rejection of claim 9 is withdrawn in view of the amendment; however, upon further consideration a new ground of rejection is necessitated by amendment.
Response to Arguments
Applicant argues Kazacos teaches away from the claimed inorganic additive(s) based on the prior art’s suggestion of “tri-n-butyl phosphate” in Table 1. The instant claims (e.g., claims 1, 4, and 5) limit the inorganic additive to, e.g., phosphoric acid and polyphosphoric acid (claim 4), and sodium hexametaphosphate (claim 5); as detailed in the rejection, Kazacos explicitly lists phosphoric acid, polyphsophoric acid, and sodium hexametaphosphate as inorganic additives in the disclosure, thereby suggesting the claimed inorganic additives. Considering “tri-n-butyl phosphate” was not used to reject the claims, applicant’s argument based on the tri-n-butyl phosphate compound are irrelevant to the rejection of record, hence unpersuasive.
Applicant has narrowed the amount of inorganic additive (A), i.e., from less than or equal to 5% to between 0.5% and 2 %, and argued unexpected results. Applicant’s amendment and remarks appear to try to establish the newly cited claimed range (e.g., amount of inorganic additive (A) between 0.5 % and 2 %) as providing unexpected results. A successful showing of unexpected results regarding a narrower range than was originally claimed/taught would bring forth a new matter issue, as it would show that the newly claimed range is a different invention than the originally disclosed range. See MPEP 2163(I)(B). No new matter issue has been made at this time, as arguments of unexpected results are not persuasive, detailed next.
Applicant has narrowed the amount of inorganic additive (A) between 0.5 % to 2 % by weight and argued unexpected results. Specifically, applicant stated there are three examples that describe the claimed range (i.e., 0.5 wt%, 1.3 wt%, and 2wt%). Applicant’s unexpected results arguments are not persuasive for the following reasons.
The evidence relied upon should establish "that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance." Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992). "[A]ppellants have the burden of explaining the data in any declaration they proffer as evidence of non-obviousness." Ex parte Ishizaka, 24 USPQ2d 1621, 1624 (Bd. Pat. App. & Inter. 1992). Any differences between the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected. In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986), MPEP 716.02.
"A greater than expected result is an evidentiary factor pertinent to the legal conclusion of obviousness ... of the claims at issue." In re Corkill, 771 F.2d 1496, 226 USPQ 1005 (Fed. Cir. 1985). Applicants must further show that the results were greater than those which would have been expected from the prior art to an unobvious extent, and that the results are of a significant, practical advantage. Ex parte The NutraSweet Co., 19 USPQ2d 1586 (Bd. Pat. App. & Inter. 1991). MPEP 716.02(a).
To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). MPEP 716.02(d).
Applicant’s arguments of unexpected results in the Remarks dated 14 July 2025 are deficient for several reasons. First, applicant has not detailed any samples outside the claimed range, which are necessary to show criticality of the claimed range, see MPEP 716.02(d). In the absence of any discussion and comparison of the claimed range versus values outside the claimed range, there is nothing to support the alleged criticality of the claimed range. Finally, it is unclear from applicant’s argument what property is even being compared and/or evaluated for unexpectedness, let alone any showing that the samples inside the claimed range are unexpected to an unobvious extent, or that the results are of a significant, practical advantage.
Contrary to applicant argument, claim 9 is not in condition for allowance provided Kazacos’s disclosure of ammonium nitrate and potassium nitrate, see e.g., claim 13, thereby reading on the amended claim.
Applicant’s arguments with respect to Rahman are not persuasive. Specifically, applicant argues Rahman teaches away from the combination of K3PO4, SHMP, and sulfonic acid; the conclusion is based on the “SP-L” sample which shows inferior properties after the addition of PSA (the sulfonic acid in the sample). Applicant’s argument is not persuasive because the SP-L sample does not even include K3PO4 (see Table 4), thus applicant’s conclusion on the combination of K3PO4, SHMP, and sulfonic acid is unsupported by the SP-L sample.
Further, applicant argues the KSP and KSPE formulations (which do combine K3PO4, SHMP, and a sulfonic acid) teach away from the claimed combination because the addition of PSA (a sulfonic acid) revealed a deterioration in performance. This argument is not persuasive because disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994). A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. Merck & Co. v. Biocraft Labs., Inc. 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir. 1989), MPEP 2123. Further, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). In this case, while the KSP and KSPE samples may be inferior to other examples, they were still better than the blank at 10 °C, 40 °C, and 50 °C (see e.g., Table 5-6 and Fig. 2b). For example, the combination of K3PO4, SHMP, and a sulfonic acid (i.e., PSA in example KSP-S) did not see precipitation until 16 and 29 days at 50 °C and 20 °C, respectively, compared to the blank which observed precipitation much sooner, i.e., on days 0 and 1 at 50 °C and 20 °C, respectively. In other words, the combination of K3PO4, SHMP, and a sulfonic acid (i.e., PSA) would be seen as an improvement over no additives (blank) at both 50 °C and 20 °C, thus still motivating to Kazacos to combine K3PO4, and SHMP in the presence of a sulfonic acid. Further, at 20 °C, Rahman shows the combination of K3PO4, SHMP, and a sulfonic acid (PSA) delayed the appearance of precipitation to 29 days (see e.g., sample KSP-S in Table 6) compared to a formula including only SHMP and PSA (i.e., excluding K3PO4, see e.g., sample SP-S in Table 6), which observed precipitation at 21 days; in other words, Rahman suggests the combination of K3PO4, SHMP, and a sulfonic acid is seen as advantageous in view of its ability to delaying the appearance of precipitation by 8 days at 20 °C. In view of the foregoing, one of ordinary skill in the art would appreciate the combination of K3PO4, and SHMP in the presence of a sulfonic acid with the expectation of delaying precipitation at various temperatures, as suggested by Rahman.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1-5, 7, 9-13, 17, and 21-22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kazacos et al. (US 6,143,443, of record).
Regarding Claims 1-5, 7, 10-11, 17 and 21-22, Kazacos suggests an electrochemical cell (i.e., a vanadium redox flow battery, e.g., col. 12 lines 40-44) including a negative electrode, a positive electrode, and an electrolyte composition (see e.g., title, cols. 6-7, col. 11) comprising: a sulfonic acid of formula R-SO3H, in which R represents a (C1-C4) alkyl or a (C6-C14) aryl optionally substituted with a (C1-C4) alkyl (e.g., alkyl sulfonic acid, methyl sulfonic acid, ethyl sulfonic acid, aryl sulfonic acid, benzene sulfonic acid, naphthalene sulfonic acid, toluene sulfonic acid), optionally sulfuric acid (i.e., H2SO4, see e.g., col. 12 lines 45-62, col. 103 lines 21-35, where sulfonic acid and sulfuric acid are considered as a mixture), redox metal ions (i.e., various species of vanadium, e.g., V(II), V(III), etc., col. 12 line 63 to col. 13 line 55, col. 104 lines 57-58), at least one inorganic additive (A) comprising at least one phosphorus atom whose oxidation state is less than or equal to +5 (i.e., stabilizing agent, e.g., orthophosphoric acid, sodium hexametaphosphate, phosphoric acid, pyrophosphate, polyphosphoric acid, ammonium phosphate, etc., see e.g., col. 13 lines 41-42, 57-60, claims 1, 6, 11, 12-18) in an amount of 0.5% to 2 % by weight relative to the total weight of the electrolyte composition (e.g., 0.5-3 % by weight overlaps with that claimed, col. 97 line 37 to col. 98 line 14, col. 110 line19, claims 17-18), and water (i.e., “aqueous solution”), see col. 12-14, 102-104, Tables, and claims.
Regarding Claim 9, Kazacos suggests a corrosion inhibitor having a general formula (1) or (2): NO2X (1) or NO3X (2) in which X is chosen from: K or NH4 (see e.g., claim 13 where NH4NO3 (ammonium nitrate) and KNO3 (potassium nitrate) are explicitly disclosed).
Regarding Claims 12-13, Kazacos has recognized the use of an inorganic additive comprising at least one phosphorus atom whose oxidation state is less than or equal to +5 (i.e., stabilizing agent, e.g., orthophosphoric acid, sodium hexametaphosphate, phosphoric acid, pyrophosphate, etc., see rejections of claims 1, 4, 5) for increasing the concentration of the redox metal ions and/or avoiding or reducing and/or slowing down or delaying the precipitation of the redox metal ions in the electrolyte composition, or stabilizing an electrolyte composition at a temperature between 0 °C and 60 °C, see tables (and discussions thereof), claim 1, col. 105 lines 1-15, col. 118 lines 53-67. Further, the features recited in claims 12-13 appear to be inherent properties or functions of the stabilizing agent. MPEP 2112.01, I., PRODUCT AND APPARATUS CLAIMS — WHEN THE STRUCTURE RECITED IN THE REFERENCE IS SUBSTANTIALLY IDENTICAL TO THAT OF THE CLAIMS, CLAIMED PROPERTIES OR FUNCTIONS ARE PRESUMED TO BE INHERENT. "Products of identical chemical composition can not have mutually exclusive properties." In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. See MPEP 2112.01. In this case, Kazacos suggests the claimed inorganic additive (e.g., phosphoric acid) in the same electrolyte composition recited in instant claim 1 (see rejection of claim 1); thus, the properties/functions thereof (to slow or delay the precipitation of the redox metal ion) are expected. Finally, the recitations of the claim(s) are intended use; a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. In this case, Kazacos suggestion of claimed electrolyte composition including the same inorganic additives (e.g., phosphoric acid), which is capable of performing the intended use. "[A]pparatus claims cover what a device is, not what a device does." Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987). See MPEP 2114.
Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kazacos (cited earlier) in view of Peng et al. (Int. J. Electrochem. Sci., 7 (2012) 643 – 649, of record), hereinafter Peng.
Regarding Claim 14, Kazacos suggests the amount of the inorganic additive (A) is between 0.5-2 % by weight (i.e., 0.5%-3% overlaps with that claimed, see rejection of claim 1, and col. 97 line 37 to col. 98 line 14, col. 110 line19, claims 17-18). While Kazacos suggests the combination of sulfonic acid and sulfuric acid in the electrolyte (see rejection of claim 1), a specific mole ratio of the sulfonic acid to sulfuric acid is not suggested. However, Peng uses a sulfonic acid/sulfuric acid mixed acid solution in the electrolyte of a vanadium redox flow battery; a molar ratio of sulfonic acid to sulfuric acid at 1.5M/1.5M (see experimental page 644) improved electrochemical activity of the electrolyte by increasing the kinetics of the redox reaction and reducing mass transport resistance, and improved the energy density of the cell, see conclusions on page 648, and page 647. It would be obvious to one having ordinary skill in the art the molar ratio of sulfonic acid to sulfuric acid in Kazacos is 1/1, with the expectation of improving the electrochemical activity of the electrolyte, as suggested by Peng.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kazacos and Peng in view of He et al. (Electrochimica Acta 106 (2013) 556– 562, of record), hereinafter He.
Regarding Claim 15, as set forth under the rejection of claim 14 Kazacos as modified by Peng suggests the molar ratio of sulfonic acid to sulfuric acid (i.e., 1.5M/1.5M (which is equivalent to the claimed 50/50, which simplifies to 1/1 or 1)); the modification does not suggest the molar ratio of sulfonic acid to sulfuric acid is between 5/95 to 15/85 (i.e., ~0.05 to ~0.18). However, Peng has recognized larger molar ratios of sulfonic acid to sulfuric acid (e.g., 1.5M/1.5M (i.e., 50/50)) results in improved electrochemical activity, see e.g., conclusions. He discloses the combination of sulfonic acid and sulfuric acid in the electrolyte of vanadium redox flow batteries; the amount of sulfonic acid to sulfuric acid, even at a very small molar ratio (i.e., 0.0004 M/3M (0.0001)), results in improved thermal stability and electrochemical performance, see e.g., page 557. It would be obvious to one having ordinary skill in the art to utilize a small molar amount of sulfonic acid with respect to sulfuric acid with the expectation of improving electrochemical performance, as suggested by Peng and He. Further, the prior art (Peng and He) has recognized that molar ratio of sulfonic acid and sulfuric acid (between 0.0004M/3 M to 1.5M/1.5M, i.e., 0.0001 to 1) is a result effective variable for electrochemical performance. The presence of a known result-effective variable would be motivation for a person of ordinary skill in the art to experiment to reach another workable product or process (i.e., thereby reaching the claimed molar ratio between 0.05 to 0.17). Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05, II.
Claim(s) 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kazacos in view of Clark et al. (US 2006/0063065, of record), hereinafter Clark.
Regarding Claims 19, Kazacos suggests the sulfonic acid molar concentration is between 0.1 M and 4 M, and the sulfuric acid molar concentration is between 0.1 M and 4 M, see e.g., col. 12. Clark contemplates sulfuric and sulfonic acids for the vanadium redox couples; methane sulfonic acid (MSA) is suitable at a molar concentration range of 0.1 M to 4M, see e.g., [00120021, 0031-0031], thereby allowing the metal ions to dissolve, [0024]. It would be obvious to one having ordinary skill in the art to utilize a molar concentration of 0.1M to 4M for each of the sulfuric acid and the sulfonic acid with the expectation of dissolving the vanadium ions into the electrolyte, as suggested by Kazacos and Clark.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kazacos (cited earlier) in view of Rahman et al. (Journal of Power Sources 340 (2017) 139–149, of record), hereinafter Rahman.
Regarding Claim 20, Kazacos suggests the additive is sodium hexametaphosptae (SHMP), but does not suggest the additive is a mixture of potassium phosphate and sodium hexametaphosphate; however, Rahman suggests an additive in the vanadium flow battery electrolyte comprising a mixture of potassium phosphate and sodium hexametaphosphate, e.g., KS11 showed the best performance with only a 2% decrease in the concentration of vanadium after 40 days, see e.g., page 146 and conclusions on page 148. Kazacos suggests the combination of potassium phosphate and sodium hexametaphosphate delays precipitation at various temperatures, see e.g., various samples and data in Tables. It would be obvious to one having ordinary skill in the art the additive is a mixture of potassium phosphate and sodium hexametaphosphate because there is an expectation of minimizing precipitation of highly saturated vanadium solution in vanadium flow battery applications, as suggested by Rahman.
Conclusion
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/ANNA KOROVINA/Examiner, Art Unit 1729
/ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729