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 .
Election/Restrictions
Applicant’s election without traverse of Group I, Claims 1-14, in the reply filed on 12/24/2025 is acknowledged.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1, 3 is/are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Wei (US-20200373594-A1).
Regarding claim 1, Wei discloses a method of rebalancing an iron flow battery (see e.g., Wei; figs. 1, 5A-B, [0074]) comprising: operating the iron flow battery comprising a negative electrode, a positive electrode, a separator positioned between the negative electrode and the positive electrode (see e.g., Wei; figs. 1, 5A-B, [0041], [0074], wherein redox flow battery system 100 comprises of negative electrode 102, positive electrode 104, separator 110; fig. 5A regarding the rebalancing method shows a simplified version of the redox flow battery system 100, which is shown in more detail in fig. 1),
a negative electrolyte tank, a flow of a negative electrolyte between the negative electrolyte tank and the negative electrode, and a positive electrolyte tank, a flow of positive electrolyte between the positive electrolyte tank and the positive electrode (see e.g., Wei; figs. 1, 5A-B, [0041], regarding anolyte tank 112 flowing anolyte to negative electrode and catholyte tank 114 flowing catholyte to positive electrode); and
selectively introducing reductant from a reductant container into a rebalancing tank, which corresponds with the claimed one or more of a rebalancing tank, the negative electrolyte tank, or the positive electrolyte tank, to reduce Fe3+ ions to Fe2 ions (see e.g., Wei; fig. 5A-B, [0074]-[0076], regarding introducing reductant 563 from reductant tank 567 into the balance tank 566 to thereby perform a chemical reaction wherein Fe3+ ions are reduced to Fe2+ ions).
Regarding claim 3, Wei discloses the method of claim 1. Wei also discloses measuring a property of the iron flow battery (see e.g., Wei; fig. 9, [0092]); and controlling a flow of the reductant to the rebalancing tank, which corresponds with the claimed one or more of the rebalancing tank, or the negative electrolyte tank, or the positive electrolyte tank, based on the measured property of the iron flow battery (see e.g., Wei; [0097], regarding the previous information of measuring the average oxidation state may specifically be applied to the rebalancing method embodiment of figs. 5A-B which corresponds with controlling the reductant flow based on the measured property).
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wei (US-20200373594-A1).
Regarding claim 4, Wei discloses the method of claim 1. Wei discloses that in at least some embodiments, that there may be particulate filters (see e.g., Wei; [0065]-[0066], figs. 2-3). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have applied the particulate filters of Wei to the rebalancing method of Wei such that particulate filters filter the negative electrolyte, the positive electrolyte, or both in order to reduce impurities to metal form, and remove impurities (see e.g., Wei; [0065]-[0066]).
Regarding claim 5, Wei teaches the method of claim 4. Wei further discloses wherein the particulate filter may be in the half cell 106 (see e.g., Wei; fig. 1, [0066]), which is between the flow from the negative electrolyte tank 112 and the negative electrode 102.
Claim(s) 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wei (US-20200373594-A1) as applied to claim 1 above, and in further view of Sato (US-20180237312-A1).
Regarding claim 2, Wei discloses the method of claim 1. Wei does not explicitly disclose wherein the reductant is H2S. However, Sato discloses a method of producing an electrolyte for a redox flow battery wherein hydrogen sulfide may be used in the process (see e.g., Sato; [0159], [0025], [0091]). Sato is further analogous art because Sato discloses the electrolyte is for a vanadium-containing battery (see e.g., Sato; [0018]), which is the material used in Wei (see e.g., Wei; [0073]-[0075]). Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the reductant of Wei to hydrogen sulfide as disclosed by Sato in order to provide a rapid reaction and aggregate and precipitate vanadium sulfide (see e.g., Sato; [0159]).
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wei (US-20200373594-A1) as applied to claim 4 above, and in further view of Kiyabu (US-20220166045-A1)
Regarding claim 6, Wei teaches the method of claim 4. Wei does not explicitly disclose collecting precipitate from the filtration unit in a precipitate collection tank. However, Kiyabu discloses a redox flow battery comprising of a precipitate treatment unit with a precipitate collecting unit in a tank (see e.g., Kiyabu; fig. 8, [0063], regarding precipitate collecting unit 172 in tank 50). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the redox flow battery of Wei with a precipitate collecting unit disclosed by Kiyabu in order to have a place to hold the precipitate and perform treatment on the precipitate (see e.g., Kiyabu; [0063]).
Claim(s) 7-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wei (US-20200373594-A1) as applied to claim 1 above, and further in view of Pham (US-20150147609-A1).
Regarding claim 7, Wei discloses the method of claim 1.
Wei further discloses wherein the rebalancing tank in selective bi-directional communication (“selective bi-directional communication” interpreted as having a means of sending and receiving a medium in both directions) with the positive electrolyte tank (see e.g., Wei; fig. 5A-B, wherein the balance tank 562 is linked to the catholyte tank 118 via the balance electrodes and half-cells, the communication occurring as a chemical reaction as shown in [0075] and the process being bi-directional because the flow from the catholyte tank 118 and the flow from the balance tank 562 merge at the balance electrodes), and
wherein the reductant tank is in selective communication with the rebalancing tank (see e.g., Wei; figs. 5A-B, wherein reductant tank 567 flows into rebalancing tank 562; “selective” is interpreted as having a specific medium that is communicated, which in this case is the reductant).
Wei does not explicitly disclose introducing a portion of the positive electrolyte to the rebalancing tank; introducing the reductant into the rebalancing tank to reduce at least a portion of the Fe3+ ions in the positive electrolyte in the rebalancing tank to increase an amount of the Fe2+ ions in the positive electrolyte in the rebalancing tank; and introducing a portion of the positive electrolyte from the rebalancing tank having the increased amount of Fe2+ ions into the positive electrolyte tank.
However, Pham discloses a redox flow battery rebalancing method wherein electrolyte flows directly from an electrolyte tank to a rebalancing stack corresponding with a rebalancing tank and flows back to the electrolyte tank after being reduced (see e.g., Pham; fig. 1 regarding electrolyte flowing through rebalance stack 62, fig. 11, [0147] regarding an embodiment of a rebalancing stack wherein hydrogen reductant and unbalanced electrolyte flows into the stack, and rebalanced electrolyte flows back out). While Pham shows in fig. 1 the rebalancing for the negative electrolyte side, Wei discloses that the rebalancing method and structure may be applied to the positive electrolyte side as well (see e.g., Wei; fig. 5A-B). Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have applied the rebalancing stack of Pham such that positive electrolyte flows to the rebalancing stack, reductant flows to the rebalancing stack to reduce Fe3+ ions and increase Fe2+ ions in the positive electrolyte in the rebalancing stack, and rebalanced electrolyte with increased amount of Fe2+ ions flows into the positive electrolyte tank. One of ordinary skill in the art would have been motivated to make this modification in order to rebalance the electrolyte without a mediator solution (see e.g., Pham; [0147]) while minimizing the release of harmful contaminants (see e.g., Pham; [0007]).
Regarding claim 8, Wei discloses the method of claim 1.
Wei further discloses wherein the rebalancing tank is in selective unidirectional downstream connection with the positive electrolyte tank (see e.g., Wei; fig. 5A-B, [0075]-[0076], wherein the rebalancing tank 566 connects to the positive electrolyte tank 118 via the balancing electrodes, and performs a one way chemical reaction to produce Fe2+ ions, which corresponds with the claimed selective unidirectional downstream connection), and
wherein the negative electrolyte tank is in selective unidirectional downstream connection with the rebalancing tank (see e.g., Wei; fig. 5A-B, wherein the catholyte tank 118, which is in a one way downstream connection with the rebalancing tank 566 as described above, is connected to anolyte tank 116; therefore the anolyte tank 116 is also in a unidirectional connection with rebalancing tank 566), and
wherein the reductant tank is in selective communication with the rebalancing tank (see e.g., Wei; fig. 5A-B, wherein reductant tank 567 flows reductant to the balancing tank 566).
Wei does not explicitly disclose introducing a portion of the positive electrolyte to the rebalancing tank; introducing the reductant into the rebalancing tank to reduce at least a portion of the Fe3+ ions in the positive electrolyte in the rebalancing tank to increase an amount of the Fe2+ ions in the positive electrolyte in the rebalancing tank; and introducing a portion of the positive electrolyte from the rebalancing tank having the increased amount of Fe2+ ions into the negative electrolyte tank.
However, Pham discloses a redox flow battery rebalancing method wherein electrolyte flows directly from an electrolyte tank to a rebalancing stack corresponding with a rebalancing tank and flows back to the electrolyte tank after being reduced (see e.g., Pham; fig. 1 regarding electrolyte flowing through rebalance stack 62, fig. 11, [0147] regarding an embodiment of a rebalancing stack wherein hydrogen reductant and unbalanced electrolyte flows into the stack, and rebalanced electrolyte flows back out). While Pham shows in fig. 1 the rebalancing for the negative electrolyte side, Wei discloses that the rebalancing method and structure may be applied to the positive electrolyte side as well (see e.g., Wei; fig. 5A-B). Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have applied the rebalancing stack of Pham such that positive electrolyte flows to the rebalancing stack, reductant flows to the rebalancing stack to reduce Fe3+ ions and increase Fe2+ ions in the positive electrolyte in the rebalancing stack, and rebalanced electrolyte with increased amount of Fe2+ ions flows into the positive electrolyte tank. One of ordinary skill in the art would have been motivated to make this modification in order to rebalance the electrolyte without a mediator solution (see e.g., Pham; [0147]) while minimizing the release of harmful contaminants (see e.g., Pham; [0007]).
Regarding claim 9, Wei discloses the method of claim 1.
Wei further discloses wherein the rebalancing tank is in selective bi-directional connection (“selective bi-directional communication” interpreted as having a means of sending and receiving a medium in both directions) with the positive electrolyte tank (see e.g., Wei; fig. 5A-B, wherein the balance tank 562 is linked to the catholyte tank 118 via the balance electrodes and half-cells, the communication occurring as a chemical reaction as shown in [0075] and the process being bi-directional because the flow from the catholyte tank 118 and the flow from the balance tank 562 merge and return at the balance electrodes), and
wherein the reductant tank is in selective communication with the rebalancing tank (see e.g., Wei; fig. 5A-B, wherein reductant tank 567 flows reductant into balance tank 566).
Wei discloses in a similar embodiment wherein the negative electrolyte tank is in selective bi-directional connection with the rebalancing tank (see e.g., Wei; fig. 5C-D, [0079]-[0081] wherein anolyte tank 116 is connected to balance tank 566, the tanks sending electrolyte bi-directionally to the balance electrodes and the chemical reaction occurring at the balance electrodes providing products which continue flowing to the anolyte and balance tanks). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the embodiment of fig. 5A-B of Wei to also have the negative electrolyte tank in bi-directional connection with the balancing tank in embodiment fig. 5C-D of Wei in order to recover storage capacity or restore the average oxidation state (see e.g., Wei; [0078]).
Wei does not explicitly disclose introducing a portion of the positive electrolyte and a portion of the negative electrolyte to the rebalancing tank to form a mixed electrolyte; introducing the reductant into the rebalancing tank to reduce at least a portion of the Fe3+ ions in the mixed electrolyte in the rebalancing tank to increase an amount of the Fe2+ ions in the positive electrolyte in the rebalancing tank; and introducing a first portion of the mixed electrolyte from the rebalancing tank having the increased amount of Fe2+ ions into the positive electrolyte tank and a second portion of the mixed electrolyte from the rebalancing tank having the increased amount of Fe2+ ions into the negative electrolyte tank.
However, Pham discloses a redox flow battery rebalancing method wherein electrolyte flows directly from an electrolyte tank to a rebalancing stack corresponding with a rebalancing tank and flows back to the electrolyte tank after being reduced (see e.g., Pham; fig. 1 regarding electrolyte flowing through rebalance stack 62, fig. 11, [0147] regarding an embodiment of a rebalancing stack wherein hydrogen reductant and unbalanced electrolyte flows into the stack, and rebalanced electrolyte flows back out). While Pham shows in fig. 1 the rebalancing for the negative electrolyte side, Wei discloses that the rebalancing method and structure may also be applied to the positive electrolyte side as well (see e.g., Wei; fig. 5A-B). Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have applied the rebalancing stack of Pham to both the negative electrolyte and positive electrolyte such that positive and negative electrolyte flows to the rebalancing stack, reductant flows to the rebalancing stack to reduce Fe3+ ions and increase Fe2+ ions in the electrolyte in the rebalancing stack, and rebalanced electrolyte with increased amount of Fe2+ ions flows into the positive electrolyte tank and negative electrolyte tank. One of ordinary skill in the art would have been motivated to make this modification in order to rebalance the electrolyte without a mediator solution (see e.g., Pham; [0147]) while minimizing the release of harmful contaminants (see e.g., Pham; [0007]).
Claim(s) 10-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wei (US-20200373594-A1) as applied to claim 1 above, and further in view of Li (US-20180019486-A1).
Regarding claim 10, Wei discloses the method of claim 1.
Wei further discloses wherein the reductant tank is in selective communication with the positive electrolyte tank (see e.g., Wei; figs. 5A-B, [0074]-[0076], wherein reductant tank 567 sends reductant and through a chemical reaction of balancing electrodes, produces products which goes to the catholyte tank 118).
Wei does not explicitly disclose introducing the reductant into the positive electrolyte tank to reduce at least a portion of the Fe3+ ions in the positive electrolyte in the positive electrolyte tank to increase an amount of the Fe2+ ions in the positive electrolyte in the positive electrolyte tank.
However, Li discloses that a reducing agent may be introduced to the catholyte tank of a redox battery during battery maintenance (see e.g., Li; [0036]), which corresponds with the rebalancing method of Wei. Li further discloses that the reducing agent may be fructose (see e.g., Li; [0038]), which is the same reducing agent disclosed by Wei (see e.g., Wei; [0065]). Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have introduced reductant into the positive electrolyte tank as disclosed by Li, which would reduce Fe3+ ions to Fe2+ ions because of its chemical composition and property as a reductant (see e.g., Wei; [0065]), in order to also reduce head space gas flammability or to purge head space gas (see e.g., Li; [0036]).
Regarding claim 11, Wei discloses the method of claim 1.
Wei further discloses wherein the reductant tank is in selective communication with the positive electrolyte tank and the negative electrolyte tank (see e.g., Wei; figs. 5A-B, [0074]-[0076], wherein reductant tank 567 sends reductant and through a chemical reaction of balancing electrodes, produces products which goes to the catholyte tank 118; because catholyte tank 118 is connected to anolyte tank 116 in the same flow battery 100, the reductant tank is therefore communicating, by chemical reaction products, with both the negative and positive tanks).
Wei does not explicitly disclose introducing the reductant into the positive electrolyte tank to reduce at least a portion of the Fe3+ ions in the positive electrolyte in the positive electrolyte tank to increase an amount of the Fe+ ions in the positive electrolyte in the positive electrolyte tank; or introducing the reductant into the negative electrolyte tank to reduce at least a portion of the Fe3+ ions in the negative electrolyte in the negative electrolyte tank to increase an amount of the Fe2+ ions in the negative electrolyte in the negative electrolyte tank; or both.
However, Li discloses that a reducing agent may be introduced to the catholyte tank of a redox battery during battery maintenance (see e.g., Li; [0036]), which corresponds with the rebalancing method of Wei. Li further discloses that the reducing agent may be fructose (see e.g., Li; [0038]), which is the same reducing agent disclosed by Wei (see e.g., Wei; [0065]). Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have introduced reductant into the positive electrolyte tank as disclosed by Li, which would reduce Fe3+ ions to Fe2+ ions because of its chemical composition and property as a reductant (see e.g., Wei; [0065]), and in order to also reduce head space gas flammability or to purge head space gas (see e.g., Li; [0036]).
Claim(s) 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wei (US-20200373594-A1) as applied to claim 1 above, and in further view of Song (WO-2021231186-A1).
Regarding claim 12, Wei discloses the method of claim 1. Wei does not explicitly disclose wherein the rebalancing tank comprises a multiphase reactor. However, Song discloses a similar redox flow battery wherein rebalancing reactors, such as trickle bed reactors that can react materials in multiple phase (multiphase), serve to balance the electrolyte levels (see e.g., Song; [0037]). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the rebalancing tanks disclosed by Wei to be trickle bed reactors as disclosed by Song in order to contact the reductant and electrolyte for rebalancing reactions (see e.g., Song; [0037]).
Regarding claim 13, modified Wei teaches the method of claim 12, and wherein the multiphase reactor comprises a trickle bed reactor (see above regarding claim 12).
Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wei (US-20200373594-A1) as applied to claim 1 above, and further in view of McDonald (US-20200161685-A1).
Regarding claim 14, Wei discloses the method of claim 1. Wei does not explicitly disclose wherein operating conditions of the rebalancing tank include one or more of: an electrolyte temperature in a range of -10 to 100°C, or a pressure in the rebalancing tank in a range of 0 to 6.9MPa, or an inert gas purge. However, McDonald discloses a redox flow battery with a rebalancing reactor wherein a temperature of the rebalancing reactor may be set at target temperatures of 50 °C, 70° C, or 80° C, or any temperature between room temperature and 100° C (see e.g., McDonald; [0084]), which falls within the claimed range of -10 to 100°C. It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the rebalancing tank temperature of Wei to be any temperature between room temperature and 100 °C as disclosed by McDonald in order to increase reduction (see e.g., McDonald; [0084]), increase the recovered performance of a degraded catalyst bed, and increase rebalancing reaction rate (see e.g., McDonald; [0088]).
Conclusion
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/KEVIN SONG/Examiner, Art Unit 1728
/MATTHEW T MARTIN/Supervisory Patent Examiner, Art Unit 1728