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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 April 16, 2026 has been entered.
Response to Amendment
Per the Applicant’s response dated April 16, 2026, claim 1 as submitted March 19, 2026 is amended. Claims 1-2 and 4-8 remain pending.
Status of Application
The rejections as set forth within the Office Action dated December 29, 2025 are modified as necessitated by Applicant’s amendments.
Claim Rejections - 35 USC § 102
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 and 4-7 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Narayan et al. [WO2019178041A1, dated September 19, 2019, as provided on the IDS dated June 17, 2025], hereinafter Narayan.
Regarding Claim 1, Narayan discloses a redox flow battery [Narayan abstract and throughout], comprising:
a cell having a first chamber and a second chamber separated by a membrane [Narayan, 0051 Fig. 1, and throughout, first chamber with positive electrode 14, electrolyte 20, redox couple 22; second chamber with negative electrode 16, electrolyte 30, and redox couple 32; separated by membrane 18]
a first tank for storing a first electrolytic solution [Narayan, 0053 Fig. 1, and throughout, first tank 36]
a first circulation device for circulating the first electrolytic solution between the first chamber and the first tank [Narayan, 0053 Fig. 1, and throughout, first pump 40] ;
a second tank for storing a second electrolytic solution [Narayan, 0053 Fig. 1, and throughout, second tank 38]; and
a second circulation device for circulating the second electrolytic solution between the second chamber and the second tank [Narayan, 0053 Fig. 1, and throughout, second pump 42],
wherein each of the first electrolytic solution and the second electrolytic solution contains an active material, and at least one of the active material contained in the first electrolytic solution or the active material contained in the second electrolytic solution is a quinone multimer in which a plurality of quinones are connected via an alkyl chain or a hydroquinone multimer in which a plurality of hydroquinones are connected an alkyl chain [Narayan 0059, formula 8 and 9 where x is (CH2)n or other alkyls reads, reads on both quinones and hydroquinones since Narayan explicitly teaches quinones.], and wherein a diffusion coefficient of the hydroquinone multimer is 1x 10-7 cm2/sec or more [Narayan, 0062, Fig. 8].
wherein the number of quinone units of the quinone multimer or the hydroquinone multimer is 600 or less [Narayan 0059, formula 8 and 9 where x is (CH2)n anticipates the claim limitation since the number of units of quinone or hydroquinone is two in each formula].
Regarding Claim 4, Narayan discloses the redox flow battery according to claim 1 wherein each quinone constituting the quinone multimer contains a six- membered ring to which oxygen atoms are connected by double bonds, and wherein an element other than hydrogen or a functional group is connected to at least one carbon atom, other than carbon atoms to which the alkyl chain is connected and carbon atoms to which the hydroxy groups are connected, of carbon atoms constituting the six-membered ring [Narayan, 0059, Narayan discloses quinone [0059] and in formula 8 and formula 9 discloses hydroquinone, where R15, R16, R17 and R18 are each independently—NO2, —NH2, —N(R′R″)2, —N(R′R″R′″)3 +L−, —CF3, —CCl3, —CN, —SO3H, —PO3H2, —COOH, —CO2R′, —COR′, —CHO, —OH, —OR′, —O−M+, —SO3−M+, —PO3−M+, —COO−M+, —CF2H, —CF2R′, —CFH3, and —CFR′R″ where R′, R″ and R′″ are alkyl or aryl groups, which reads on the claimed element. Applying Narayan’s formula 8 and formula 9 for Narayan’s recited quinone structure [0059] inherently requires a double bond for the oxygen atom instead of the hydroxy groups as shown.]. See MPEP 2112 II. There is no requirement that a person of ordinary skill in the art would have recognized the inherent disclosure at the relevant time, but only that the subject matter is in fact inherent in the prior art reference.
Regarding Claim 5, Narayan discloses the redox flow battery according to claim 1, wherein each hydroquinone constituting the hydroquinone multimer contains a six- membered ring to which hydroxy groups are connected, and wherein an element other than hydrogen or a functional group is connected to at least one carbon atom, other than carbon atoms to which the alkyl chain is connected and carbon atoms to which the hydroxy groups are connected, of carbon atoms constituting the six-membered ring Narayan, 0059, Narayan discloses formula 8 and formula 9, where R15, R16, R17 and R18 are each independently—NO2, —NH2, —N(R′R″)2, —N(R′R″R′″)3 +L−, —CF3, —CCl3, —CN, —SO3H, —PO3H2, —COOH, —CO2R′, —COR′, —CHO, —OH, —OR′, —O−M+, —SO3−M+, —PO3−M+, —COO−M+, —CF2H, —CF2R′, —CFH3, and —CFR′R″ where R′, R″ and R′″ are alkyl or aryl groups, which reads on the claimed element].
Regarding Claim 6, Narayan discloses the redox flow battery according to claim 1, wherein the quinone multimer or the hydroquinone multimer contains at least two types of quinones or at least two types of hydroquinones [Narayan 0059, formula and formula 9 where R15, R16, R17 and R18 are each independently —H, —R′, —NO2, —NH2, —N(R′R″)2, —N(R′R″R′″)3 +L−, —CF3, —CCl3, —CN, —SO3H, —PO3H2, —COOH, —CO2R′, —COR′, —CHO, —OH, —OR′, —O−M+, —SO3−M+, —PO3−M+, —COO−M+, —CF2H, —CF2R′, —CFH3, and —CFR′R″ where R′, R″ and R′″ are alkyl or aryl groups, reads on at least two types of quinones or hydroquionones as described in Claim 1.].
Regarding Claim 7, Narayan discloses the redox flow battery according to claim 1, wherein the alkyl chain is a methylene group chain [Narayan 0059, where x is (CH2)n].
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 and 4-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yang et al. [US20190115594A1, dated April 18, 2019, as provided on the IDS dated June 17, 2025], hereinafter Yang, in further view of Yang et al. [An Inexpensive Aqueous Flow Battery for Large-Scale Electrical
Energy Storage Based on Water-Soluble Organic Redox Couples, Journal of the Electrochemical Society, as provided on the IDS dated December 21, 2022], hereinafter Yang2.
Regarding Claim 1, Yang discloses a redox flow battery [Yang 0034 and throughout], comprising:
a cell having a first chamber and a second chamber separated by a membrane [Yang 0034, Fig. 1, first chamber with positive electrode 14, electrolyte 20, redox couple 22; second chamber with negative electrode 16, electrolyte 30, and redox couple 32; separated by membrane 18];
a first tank for storing a first electrolytic solution [Yang 0036, Fig. 1, and throughout, first tank 36];
a first circulation device for circulating the first electrolytic solution between the first chamber and the first tank [Yang 0036, Fig. 1, and throughout, pump 40];
a second tank for storing a second electrolytic solution [Yang 0036, Fig. 1, and throughout, second tank 38]; and
a second circulation device for circulating the second electrolytic solution between the second chamber and the second tank [Yang 0036, Fig. 1, and throughout, pump 42];
wherein each of the first electrolytic solution and the second electrolytic solution contains an active material, and at least one of the active material contained in the first electrolytic solution or the active material contained in the second electrolytic solution is a quinone multimer in which a plurality of quinones are connected via an alkyl chain or a hydroquinone multimer in which a plurality of hydroquinones are connected an alkyl chain [Yang 0038, formulas 3 and 3’, reads on both quinones and hydroquinones],
wherein the number of quinone units of the quinone multimer or the hydroquinone multimer is 600 or less [Yang 0038, formulas 3 and 3’ anticipates the claim limitation where the number of units of quinone or hydroquinone is two, which is less than 600].
Yang is silent to wherein a diffusion coefficient of the quinone multimer or the hydroquinone multimer is 1x 10-7 cm2/sec or more. Yang2 discloses the diffusion coefficient of the redox couple must be as high as possible for reaching the performance and cost targets for large-scale energy storage applications [Yang2, A1372, column 2, mass transport processes]. Further, Yang2 teaches diffusion coefficients for various types of quinones and hydroquinones, different from the quinones and hydroquinones of claim 1, in the range of 3.4 x 10-6 to 5.0 x 10-6 [Yang2, A1376, Table 2]. Per the teachings of Yang2, the skilled artisan would understand the diffusion coefficient is a result-effective variable dependent on the application, such as the energy requirement or the type of membrane used in the flow cell. For a large-scale application where high current density is required, if the diffusion coefficient is too low, the current density of the battery will be too low and additional effort/cost is required to improve the current density through additional means, such as a different type of cell membrane or higher level of circulation of the electrolyte. For smaller applications when a lower current density is sufficient, a high diffusion coefficient may provide no additional benefit. Determining the workable range of diffusion coefficient for a given application merely requires routine experimentation, which is obvious per MPEP 2144.05II, routine optimization.] It would have been obvious to one of ordinary skill in the art before the effective filing date to use the teachings of Yang2 about diffusion coefficients for the redox flow battery of Yang with an expectation of success for a redox battery with a workable current density [Yang2 A1372, column 2, mass transport processes] for a given application.
Regarding Claim 4, Yang discloses the redox flow battery according to claim 1, wherein each quinone constituting the quinone multimer contains a six-membered ring to which oxygen atoms are connected by double bonds, and wherein an element other than hydrogen or a functional group is connected to at least one carbon atom, other than carbon atoms to which the alkyl chain is connected and carbon atoms to which the oxygen atoms are connected by the double bonds, of carbon atoms constituting the six-membered ring [Yang 0037-0038, formula 3/4 where the claimed element is sulfur, or an element from R1, or R2 where R1 and R2 are NH2, —NHR3, —N(R3)2, —O−M+, —NHCOR3, —OR3, —CH3, —C2H5, —SO3H, —PO3H2, —COOH, —OH, —N(R2)3 +X−, —CF3, CCl3, —CN, —COOR3, F, Cl, Br, —CHO, —COR2—O−M+, —SO3 −M+, —PO3 2−M+ 2, —COO−M+, pyridinyl, imidazoyl, pyrroyl, or phenyl where R3 is H or C1-10 alkyl and M+ is a positively charged counter-ion (e.g., Na+, K+, and the like)].
Regarding Claim 5, Yang discloses the redox flow battery according to claim 1, wherein each hydroquinone constituting the hydroquinone multimer contains a six- membered ring to which hydroxy groups are connected, and wherein an element other than hydrogen or a functional group is connected to at least one carbon atom, other than carbon atoms to which the alkyl chain is connected and carbon atoms to which the hydroxy groups are connected, of carbon atoms constituting the six-membered ring [Yang 0037-0038, formula 3’, 4’ where the claimed element is sulfur, or an element from R1, or R2 where R1 and R2 are NH2, —NHR3, —N(R3)2, —O−M+, —NHCOR3, —OR3, —CH3, —C2H5, —SO3H, —PO3H2, —COOH, —OH, —N(R2)3 +X−, —CF3, CCl3, —CN, —COOR3, F, Cl, Br, —CHO, —COR2—O−M+, —SO3 −M+, —PO3 2−M+ 2, —COO−M+, pyridinyl, imidazoyl, pyrroyl, or phenyl where R3 is H or C1-10 alkyl and M+ is a positively charged counter-ion (e.g., Na+, K+, and the like)].
Regarding Claim 6, Yang discloses the redox flow battery according to claim 1, wherein the quinone multimer or the hydroquinone multimer contains at least two types of quinones or at least two types of hydroquinones [Yang 0037-0038, formula 3, 3’ and formula 4, 4’, where R1 and R2 are independently selected from H, aryl, heteroaryl, C1-10 alkyl, NH2, —NHR3, —N(R3)2, —O−M+, —NHCOR3, —OR3, —CH3, —C2H5, —SO3H, —PO3H2, —COOH, —OH, —N(R2)3 +X−, —CF3, CCl3, —CN, —COOR3, F, Cl, Br, —CHO, —COR2—O−M+, —SO3 −M+, —PO3 2−M+ 2, —COO−M+, pyridinyl, imidazoyl, pyrroyl, or phenyl where R3 is H or C1-10 alkyl and M+ is a positively charged counter-ion (e.g., Na+, K+, and the like), reads on at least two types of quinone/hydroquinone as claimed].
Regarding Claim 7, Yang discloses the redox flow battery according to claim 1, wherein the alkyl chain is a methylene group [Yang 0038, formula 3, 3’ and 4, 4’, alkyl is methylene ( -CH2)n].
Claim(s) 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over Narayan or alternatively modified Yang, as applied to Claim 1, in further view Stahl et al. [US20190055193A1, dated February 21, 2019, as provided on the IDS dated June 17, 2025], hereinafter Stahl.
Regarding Claim 2, Narayan, or alternatively modified Yang, discloses the redox flow battery according to claim 1 as provided above but is silent to wherein the active material has a structure in which a plurality of quinones are connected in a ring shape via the alkyl chain or a structure in which a plurality of hydroquinones are connected in a ring shape via the alkyl chain. Stahl discloses an active material for a redox flow battery [Stahl 0078] where a plurality of hydroquinones are connected in a ring shape via the alkyl chain [Stahl 0118, Fig. 3B, structure 49], which reads on the claim limitation. It would be within the ambit of the skilled artisan to substitute Stahl’s structure 49 for the quinones/hydroquinones in the redox flow batteries of Narayan, or alternatively modified Yang, as an art recognized active material for redox flow batteries for the advantages that highly substituted hydroquinones/quinones provides: sufficient reduction potential, sufficient stability, and improved redox mediators [Stahl 0007]. It would have been obvious to one of ordinary skill in the art before the effective filing date to substitute Stahl’s structure 49 for the quinones or hydroquinones of claim 1 with an expectation of success for an environmentally benign, low-cost, sustainable, and durable redox flow battery with good performance and stability [Yang 0004-0008; Narayan 0004-0009; Stahl 0003-0007]]. See MPEP 2144.07, art recognized suitability for an intended purpose.
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Narayan or alternatively modified Yang, as applied to Claim 1, in further view of Wu et al. [CN110526826, dated December 3, 2019, relied upon US20220073448A1 for translation] as evidenced by Evans [US20180316033A1, dated November 1, 2018].
Regarding Claim 8, Yang, or alternatively Narayan, discloses redox flow battery according to claim 1 as described above but is silent to further comprising an inert gas supply part for supplying an inert gas to at least one of the first tank or the second tank. Wu discloses an inert gas, such as nitrogen or argon, supplied to both of two electrolyte solution reservoirs for purging and maintaining a pressure [Wu 0022-0023, 0076-0077, Claims 12-13]. It would have been obvious to one of ordinary skill in the art before the effective filing date to combine Wu’s teaching about purging/maintaining pressure in the electrolyte tanks with the redox flow battery of Yang or Narayan since Wu’s redox flow battery system [Wu Fig. 1] is analogous art and Wu’s teaching would be considered an improvement on Yang or Narayan’s redox flow battery since purging the electrolyte tanks would support reduction of oxidation reactions of the electrolyte with residual species or impurities as evidenced by Evans [Evans 0027].
Response to Arguments
Applicant's arguments filed March 19, 2026 have been fully considered but they are not persuasive. Applicant argues on pgs. 4-5 that the instant application is differentiated over the prior art of record with regard to new limitation “wherein a number of quinone units of the quinone multimer or the hydroquinone multimer is 600 or less”. As provided above, Narayan’s formulas 8 and 9 teach two units, which anticipates the claim. Further, Yang also teaches two units in formulas 3, 3’, 4, and 4’. Thus, the new limitation is met by the prior art of record. For purpose of compact prosecution, the Examiner performed an updated search and has provided additional prior art below relevant to the new claim limitation.
For the reasons provided above, evidence of anticipation and obviousness over the prior art as provided above outweighs evidence of novelty and nonobviousness, thus, the rejections over the prior art of record are maintained.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Stahl et al. [US20190055193A1, dated February 21, 2019, as provided on the IDS dated June 17, 2025].
Regarding the claim 1 limitations of the number of quinone or hydroquinone multimer units, the prior art of Stahl as provided above teaches 6 units.
Cheng et al. ["Cathodic voltammetric behavior of pillar [5] quinone in nonaqueous media. Symmetry effects on the electron uptake sequence." Journal of the American Chemical Society 137.31 (2015): 9788-9791].
Regarding the claim 1 limitations of diffusion coefficient and the number of quinone or hydroquinone multimer units, the prior art of Cheng et al. teaches P5Q with 5 units [Cheng abstract, Fig. 1, and throughout] and a diffusion coefficient of 4.01 X 10-5 cm2/s [Cheng p. 9789].
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/M. T. LEONARD/Examiner, Art Unit 1724
/MIRIAM STAGG/Supervisory Patent Examiner, Art Unit 1724
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