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
Restriction to one of the following inventions is required under 35 U.S.C. 121:
I. Claims 1-19, drawn to a method for recovering lithium, classified in C25B1/14.
II. Claim 20, drawn to an electrochemical cell, classified in C25B11/04.
The inventions are independent or distinct, each from the other because:
Inventions I and II are related as process and apparatus for its practice. The inventions are distinct if it can be shown that either: (1) the process as claimed can be practiced by another and materially different apparatus or by hand, or (2) the apparatus as claimed can be used to practice another and materially different process (MPEP § 806.05(e)). In the instant case the apparatus of invention II can be used as a lithium ion battery, a process materially different than the lithium extraction and recovery method of invention I.
Restriction for examination purposes as indicated is proper because all the inventions listed in this action are independent or distinct for the reasons given above and there would be a serious search and/or examination burden if restriction were not required because one or more of the following reasons apply:
the inventions have acquired separate statuses in the art in view of their different statutory categories;
the inventions have acquired separate statuses in the art due to their recognized divergent subject matter;
the inventions require a different field of search (e.g., searching different classes/subclasses or electronic resources, or employing different search strategies or search queries);
the prior art applicable to one invention would likely not be applicable to another invention; and/or
the inventions are likely to raise different non-prior art issues (i.e., under 35 U.S.C. § 101 and/or 112).
Applicant is advised that the reply to this requirement to be complete must include (i) an election of an invention to be examined even though the requirement may be traversed (37 CFR 1.143) and (ii) identification of the claims encompassing the elected invention.
The election of an invention may be made with or without traverse. To reserve a right to petition, the election must be made with traverse. If the reply does not distinctly and specifically point out supposed errors in the restriction requirement, the election shall be treated as an election without traverse. Traversal must be presented at the time of election in order to be considered timely. Failure to timely traverse the requirement will result in the loss of right to petition under 37 CFR 1.144. If claims are added after the election, applicant must indicate which of these claims are readable upon the elected invention.
Should applicant traverse on the ground that the inventions are not patentably distinct, applicant should submit evidence or identify such evidence now of record showing the inventions to be obvious variants or clearly admit on the record that this is the case. In either instance, if the examiner finds one of the inventions unpatentable over the prior art, the evidence or admission may be used in a rejection under 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a) of the other invention.
During a telephone conversation with Atty. Michelle Manning on 01/02/2026 a provisional election was made without traverse to prosecute the invention of group I, claims 1-19. Affirmation of this election must be made by applicant in replying to this Office action. Claim 20 is withdrawn from further consideration by the examiner, 37 CFR 1.142(b), as being drawn to a non-elected invention.
Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i).
The examiner has required restriction between product or apparatus claims and process claims. Where applicant elects claims directed to the product/apparatus, and all product/apparatus claims are subsequently found allowable, withdrawn process claims that include all the limitations of the allowable product/apparatus claims should be considered for rejoinder. All claims directed to a nonelected process invention must include all the limitations of an allowable product/apparatus claim for that process invention to be rejoined.
In the event of rejoinder, the requirement for restriction between the product/apparatus claims and the rejoined process claims will be withdrawn, and the rejoined process claims will be fully examined for patentability in accordance with 37 CFR 1.104. Thus, to be allowable, the rejoined claims must meet all criteria for patentability including the requirements of 35 U.S.C. 101, 102, 103 and 112. Until all claims to the elected product/apparatus are found allowable, an otherwise proper restriction requirement between product/apparatus claims and process claims may be maintained. Withdrawn process claims that are not commensurate in scope with an allowable product/apparatus claim will not be rejoined. See MPEP § 821.04. Additionally, in order for rejoinder to occur, applicant is advised that the process claims should be amended during prosecution to require the limitations of the product/apparatus claims. Failure to do so may result in no rejoinder. Further, note that the prohibition against double patenting rejections of 35 U.S.C. 121 does not apply where the restriction requirement is withdrawn by the examiner before the patent issues. See MPEP § 804.01.
Claim Objections
Claims 1, 3, 5-8, 16, and 18-19 are objected to because of the following informalities:
Claim 1 line 8 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claim 1;
Claim 3 line 5 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 1-3;
Claim 5 line 5 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 1 and 5;
Claim 6 line 3 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 1 and 5-6;
Claim 7 line 5 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 1 and 7;
Claim 8 line 2 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 1 and 7;
Claim 8 line 3 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 1 and 7;
Claim 16 line 2 recites “the LixTi2(PO4)3”, but should recite “[[the]] LixTi2(PO4)3” to be grammatically correct;
Claim 18 line 5 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 15 and 18;
Claim 19 line 5 recites “the lithium-recovery solution”, but should recite “the aqueous lithium-recovery solution” to be consistent with the terminology used in claims 15 and 19.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claim 17 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding claim 17, claim 17 recites the limitation "the aqueous leachate solution" in lines 4-5. There is insufficient antecedent basis for this limitation in the claim. Specifically, claims 15 and 17 recite a “lithium ion-containing aqueous solution”, rather than an “aqueous leachate solution”. It is therefore unclear whether the limitation “the aqueous leachate solution” is intended to be a separate solution, whether it is intended to narrow the “lithium ion-containing aqueous solution”, or if the term was intended to read “the lithium ion-containing aqueous solution”.
Claim 17 is therefore indefinite.
Examiner recommends amending claim 17 to recite “the lithium ion-containing aqueous solution”.
Claim Rejections - 35 USC § 102
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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 15-16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Choi (US Pat. Pub. 2022/0246998 A1).
Regarding claim 15, Choi teaches a method for electrochemically extracting and recovering lithium ions (“ESS for Lithium Extraction” para. 47 et seq.) from a lithium ion-containing aqueous solution (“Aqueous solutions from which lithium can be extracted …” para. 50), the method comprising:
contacting the lithium ion-containing aqueous solution with a lithium-storage electrode comprising LixTi2(PO4)3, where x = 1, or TiP2O7, (“suitable materials for Li-storage electrode 1 include … TiP2O7 … LiTi2(PO4)3” para. 49) and a counter electrode (“the same types of chloride storage electrodes that are used in the ES Ss [sic] for desalination” Id.);
carrying out an electrochemical lithium ion extraction from the lithium ion-containing aqueous solution using the lithium-storage electrode, whereby the lithium-storage electrode becomes lithiated (“conversion of the first delithiated lithium storage material into a first lithiated lithium storage material;” para. 6, see also para. 49);
carrying out an electrochemical oxidation in the lithium ion-containing aqueous solution simultaneously with the electrochemical lithium ion extraction (i.e., oxidation of Bi to BiOCl, “the charging results in the removal of the chloride ions … the conversion of the dechlorinated chloride storage material into a chlorinated chloride storage material” para. 6, see also paras. 49 and 75); and
contacting the lithiated lithium-storage electrode with an aqueous lithium-recovery solution, wherein the aqueous lithium-recovery solution is not the same solution as the lithium ion-containing aqueous solution (“a discharging electrolyte solution;” para. 6), and carrying out an electrochemical delithiation of the lithiated lithium-storage electrode, whereby lithium ions from the lithiated lithium-storage electrode are released into the aqueous lithium-recovery solution (“discharging a discharging electrochemical cell comprising: a discharging electrolyte solution; … a lithium storage anode comprising the first lithiated lithium storage material;” para. 6 and “lithium ions and chloride ions are released into an electrolyte solution during the other of the two charging steps (lithium recovery),” para. 49).
Regarding claim 16, Choi further teaches the lithium-storage electrode comprises LixTi2(PO4)3, where x = 1, (“suitable materials for Li-storage electrode 1 include … LiTi2(PO4)3” para. 49).
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.
Claims 1 and 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over La Mantia (DE 102012212770 A1) in view of Chen et al. (“Recovery of Li2CO3 from Spent LiFePO4 by Using a Novel Impurity Elimination Process” Molecules 2023, 28, 3902).
Regarding claim 1, La Mantia teaches a method for electrochemically extracting and recovering lithium ions (“a method for the efficient extraction of lithium from salt solutions” para. 2), the method comprising:
contacting an aqueous leachate solution (para. 21) with a lithium-storage electrode (“a lithium iron phosphate electrode (LFP)” Id.) and carrying out an electrochemical lithium ion extraction from the aqueous leachate solution using the lithium-storage electrode, whereby the lithium-storage electrode becomes lithiated (“lithium ions were stored in the FePO4 cathode at a constant current density of -0.5 mA cm-2” para. 21, see also para. 22); and
contacting the lithiated lithium-storage electrode with an aqueous lithium-recovery solution, wherein the lithium-recovery solution is not the same solution as the aqueous leachate solution (“the two electrodes (LFP and Ag) were transferred to the recovery cell … The recovery solution was a 50 mM aqueous KCl solution” para. 23), and carrying out an electrochemical delithiation of the lithiated lithium- storage electrode, whereby lithium ions from the lithiated lithium-storage electrode are released into the aqueous lithium-recovery solution (“a constant current density of 0.5 mA cm-2 at the LiFePO4 cathode was set, causing the battery electrodes to release the stored Li+ and Cl- ions (reverse reaction) into the recovery solution” Id.).
La Mantia does not teach the method is a method of extracting lithium ions from lithium iron phosphate, wherein the method comprises a step of leaching lithium ions from lithium iron phosphate into the aqueous leachate solution.
However, Chen teaches a method of recovering lithium from spent lithium iron phosphate (SLFP) (see e.g., abstract), wherein the recovery method comprises leaching lithium ions from lithium iron phosphate into an aqueous leachate solution (“extraction efficiency of Li, Fe, and P when using an H2SO4 concentration ranging from 0.2 mol L-1 to 0.6 mol L-1” § 2.1.1. and “All solutions were prepared using ultrapure water” § 3.1.), which is desirable for recovering lithium from lithium iron phosphate batteries (e.g., abstract).
As La Mantia teaches a method for the electrochemical recovery of lithium from aqueous solutions, La Mantia is analogous art to the instant invention. As Chen teaches a method for the extraction and recovery of lithium ions from lithium iron phosphate, Chen is analogous art for the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia such that it is a method for extracting lithium ions from lithium iron phosphate, by adding a step of leaching lithium ions from lithium iron phosphate into the aqueous leachate solution, as taught by Chen. A person having ordinary skill in the art would have been motivated to make this modification to achieve the predictable benefit of recovering lithium from spent lithium iron phosphate batteries, as taught by Chen. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)).
Regarding claim 5, La Mantia further teaches carrying out an electrochemical hydrogen evolution reaction simultaneously with the electrochemical delithiation of the lithiated lithium-storage electrode, whereby water molecules in the aqueous lithium-recovery solution are reduced and hydroxide ions are produced, and lithium hydroxide is accumulated in the lithium-recovery solution (“an additional amount of energy is needed to transfer lithium into the recovery solution. This difference is due to energy losses in the transfer process, which is caused by … water splitting …” para. 43; as evidenced by e.g., the instant specification, water splitting during the delithiation corresponds to hydrogen evolution at the cathode, which results in the formation of hydroxide ions and the formation/accumulation of lithium hydroxide, see para. 50 and eq. 6).
Regarding claim 6, modified La Mantia does not teach a step of introducing carbon dioxide, a bicarbonate salt, or a carbonate salt into the aqueous lithium-recovery solution to recover lithium as LiHCO3 or Li2CO3 from the lithium-recovery solution.
However, Chen further teaches a step of introducing a carbonate salt (sodium carbonate, § 3.2.4. and Fig. 6) to recovered lithium hydroxide (§ 3.2.3. and Fig. 6), which provides the predictable benefit of producing lithium carbonate, a valuable starting material in battery production (see e.g., abstract).
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia by adding a step of introducing sodium carbonate, a carbonate salt, into the aqueous lithium-recovery solution to recover lithium as Li2CO3 from the lithium-recovery solution, as taught by Chen. A person having ordinary skill in the art would have been motivated to make this modification to achieve the predictable benefit of recovering lithium carbonate, a valuable starting material in battery production, as taught by Chen. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)).
Regarding claim 7, modified La Mantia teaches the limitations of claim 1, as described above.
La Mantia further teaches carrying out an electrochemical oxygen reduction reaction simultaneously with the electrochemical delithiation of the lithiated lithium-storage electrode, whereby oxygen molecules present in the aqueous lithium-recovery solution are reduced and hydroxide ions are produced, and lithium hydroxide is accumulated in the lithium-recovery solution (“an additional amount of energy is needed to transfer lithium into the recovery solution. This difference is due to energy losses in the transfer process, which is caused by … oxygen reduction” para. 43, as evidenced by e.g., the instant specification, oxygen reduction during delithiation results in the formation of hydroxide ions and the formation/accumulation of lithium hydroxide, see para. 51 and eq. 7).
Regarding claim 8, modified La Mantia does not teach a step of introducing carbon dioxide, a bicarbonate salt, or a carbonate salt into the aqueous lithium-recovery solution to recover lithium as LiHCO3 or Li2CO3 from the lithium-recovery solution.
However, Chen further teaches a step of introducing a carbonate salt (sodium carbonate, § 3.2.4. and Fig. 6) to recovered lithium hydroxide (§ 3.2.3. and Fig. 6), which provides the predictable benefit of producing lithium carbonate, a valuable starting material in battery production (see e.g., abstract).
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia by adding a step of introducing sodium carbonate, a carbonate salt, into the aqueous lithium-recovery solution to recover lithium as Li2CO3 from the lithium-recovery solution, as taught by Chen. A person having ordinary skill in the art would have been motivated to make this modification to achieve the predictable benefit of recovering lithium carbonate, a valuable starting material in battery production, as taught by Chen. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)).
Claims 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over La Mantia in view of Chen as applied to claim 1, above, and further in view of Kanoh (US Pat. No. 5198081).
Regarding claim 9, modified La Mantia teaches the limitations of claim 1, as described above.
Modified La Mantia does not teach carrying out an electrochemical oxygen evolution reaction simultaneously with the electrochemical lithium ion extraction, whereby water molecules in the aqueous leachate solution are oxidized to form protons in the aqueous leachate solution.
However, Kanoh teaches a method of electrochemically recovering lithium ions from an aqueous solution (abstract), wherein during the lithium ion extraction an electrochemical oxygen evolution reaction is simultaneously performed, whereby water molecules in the aqueous leachate solution are oxidized to form protons in the aqueous leachate solution (while Kanoh does not explicitly teach the counter reaction during intercalation, this reaction is oxidation of water to oxygen, as evidenced by La Mantia para. 9 “Kanoh et al. were the first to propose an electrochemical process for the extraction of lithium from aqueous solutions … At the counter electrode, oxidation to O2 occurs during the anodic pass” para. 9).
As Kanoh teaches a method for electrochemically recovering lithium ions from an aqueous solution, Kanoh is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia, such that during the lithium ion extraction an electrochemical oxygen evolution reaction is simultaneously performed, whereby water molecules in the aqueous leachate solution are oxidized to form protons in the aqueous leachate solution, as taught by Kanoh. A person having ordinary skill in the art would have been motivated to make this modification because Kanoh teaches electrochemical oxygen evolution is a suitable anodic counter reaction to the electrochemical intercalation of lithium ions in a lithium-storage cathode. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Regarding claim 10, modified La Mantia, via Chen, further teaches the aqueous leachate solution further comprises sulfate ions (“extraction efficiency of Li, Fe, and P when using an H2SO4 concentration ranging from 0.2 mol L-1 to 0.6 mol L-1” § 2.1.1.).
Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over La Mantia in view of Chen as applied to claim 1, above, and further in view of Choi (US Pat. Pub. 2022/0246998 A1).
Regarding claim 11, modified La Mantia teaches the limitations of claim 1, as described above.
Modified La Mantia does not teach the lithium-storage electrode comprises LixTi2(PO4)3, where 1 ≤ x ≤ 3.
However, Choi teaches that LixTi2(PO4)3, where x = 1, is a suitable lithium-storage electrode material for the recovery of lithium ions via intercalation from an aqueous solution (“suitable materials for Li-storage electrode 1 include … LiTi2(PO4)3” para. 49).
As Choi teaches a method for the electrochemical recovery of lithium ions from an aqueous solution, Choi is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia by using LixTi2(PO4)3, where x = 1, as the lithium-storage electrode material, as taught by Choi. A person having ordinary skill in the art would have been motivated to make this modification because Choi teaches LixTi2(PO4)3, where x = 1, is a suitable lithium-storage electrode material for the recovery of lithium ions via intercalation from an aqueous solution. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)). Furthermore, use of a material known in the art as suitable for a purpose (i.e., LixTi2(PO4)3, where x = 1, as a lithium-storage electrode material) establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 12, modified La Mantia teaches the limitations of claim 1, as described above.
Modified La Mantia does not teach the lithium-storage electrode comprises TiP2O7.
However, Choi teaches that TiP2O7 is a suitable lithium-storage electrode material for the recovery of lithium ions via intercalation from an aqueous solution (“suitable materials for Li-storage electrode 1 include … TiP2O7 …” para. 49).
As Choi teaches a method for the electrochemical recovery of lithium ions from an aqueous solution, Choi is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia by using TiP2O7 as the lithium-storage electrode material, as taught by Choi. A person having ordinary skill in the art would have been motivated to make this modification because Choi teaches TiP2O7 is a suitable lithium-storage electrode material for the recovery of lithium ions via intercalation from an aqueous solution. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)). Furthermore, use of a material known in the art as suitable for a purpose (i.e., TiP2O7 as a lithium-storage electrode material) establishes a prima facie case of obviousness (MPEP § 2144.07).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over La Mantia in view of Chen as applied to claim 1, above, and further in view of Yao et al. (“Crystalline polycyclic quinone derivatives as organic positive-electrode materials for use in rechargeable lithium batteries” Materials Science and Engineering B 177 (2012) 483).
Regarding claim 13, modified La Mantia teaches the limitations of claim 1, as described above.
Modified La Mantia does not teach the lithium-storage electrode comprises 5,7,12,14-pentacenetetrone.
However, Yao teaches that 5,7,12,14-pentacenetetrone is a suitable material for a lithium-storage electrode (see e.g., abstract).
As Yao teaches materials for lithium-storage electrodes, Yao is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia, such that the lithium-storage electrode comprises 5,7,12,14-pentacenetetrone, as taught by Yao. A person having ordinary skill in the art would have been motivated to make this modification because Yao teaches 5,7,12,14-pentacenetetrone is a suitable material for a lithium-storage electrode. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)). Furthermore, use of a material known in the art as suitable for a purpose establishes a prima facie case of obviousness (MPEP § 2144.07).
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over La Mantia in view of Chen as applied to claim 1, above, and further in view of Wu et al. (“An organic cathode material based on a polyimide/CNT nanocomposite for lithium ion batteries” J. Mater. Chem. A, 2013, 1, 6366).
Regarding claim 14, modified La Mantia teaches the limitations of claim 1, as described above.
Modified La Mantia does not teach the lithium-storage electrode comprises polyimide.
However, Wu teaches a polyimide material that is suitable for a lithium-storage electrode (see title and para. bridging p. 6369-6370) and shows enhanced cycling stability (para. bridging p. 6369-6370).
As Wu teaches a material for lithium-storage electrodes, Wu is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia, such that the lithium-storage electrode comprises polyimide, as taught by Wu. A person having ordinary skill in the art would have been motivated to make this modification because Wu teaches polyimide is a suitable material for a lithium-storage electrode, and polyimide composites provide enhanced cycling stability. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)). Furthermore, use of a material known in the art as suitable for a purpose establishes a prima facie case of obviousness (MPEP § 2144.07).
Claims 15-16 and 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over La Mantia (DE 102012212770 A1) in view of Choi (US Pat. Pub. 2022/0246998 A1).
Regarding claim 15, La Mantia teaches a method for electrochemically extracting and recovering lithium ions from a lithium ion-containing aqueous solution (“a method for the efficient extraction of lithium from salt solutions” para. 2), the method comprising:
contacting the lithium ion-containing aqueous solution (para. 21) with a lithium-storage electrode (“a lithium iron phosphate electrode (LFP)” Id.) and a counter electrode (“a silver/silver chloride electrode (Ag) as the anode” Id.);
carrying out an electrochemical lithium ion extraction from the lithium ion-containing aqueous solution using the lithium-storage electrode, whereby the lithium-storage electrode becomes lithiated (“lithium ions were stored in the FePO4 cathode at a constant current density of -0.5 mA cm-2” para. 21, see also para. 22);
carrying out an electrochemical oxidation in the lithium ion-containing aqueous solution simultaneously with the electrochemical lithium ion extraction (“a chloride capture electrode (Ag) as the anode” para. 12, see also paras. 21-22); and
contacting the lithiated lithium-storage electrode with an aqueous lithium-recovery solution, wherein the lithium-recovery solution is not the same solution as the lithium ion-containing aqueous solution (“the two electrodes (LFP and Ag) were transferred to the recovery cell … The recovery solution was a 50 mM aqueous KCl solution” para. 23), and carrying out an electrochemical delithiation of the lithiated lithium- storage electrode, whereby lithium ions from the lithiated lithium-storage electrode are released into the aqueous lithium-recovery solution (“a constant current density of 0.5 mA cm-2 at the LiFePO4 cathode was set, causing the battery electrodes to release the stored Li+ and Cl- ions (reverse reaction) into the recovery solution” Id.).
La Mantia does not teach the lithium-storage electrode comprises LixTi2(PO4)3, where 1 ≤ x ≤ 3, TiP2O7, 5,7,12,14-pentacenetetrone, or polyimide.
However, Choi teaches that LixTi2(PO4)3, where x = 1, and TiP2O7 are suitable lithium-storage electrode materials for the recovery of lithium ions via intercalation from an aqueous solution (“suitable materials for Li-storage electrode 1 include … TiP2O7 … LiTi2(PO4)3” para. 49).
As Choi teaches a method for the electrochemical recovery of lithium ions from an aqueous solution, Choi is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of La Mantia by using LixTi2(PO4)3, where x = 1, or TiP2O7 as the lithium-storage electrode material, as taught by Choi. A person having ordinary skill in the art would have been motivated to make this modification because Choi teaches LixTi2(PO4)3, where x = 1, and TiP2O7 are suitable lithium-storage electrode materials for the recovery of lithium ions via intercalation from an aqueous solution. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)). Furthermore, use of a material known in the art as suitable for a purpose establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 16, modified La Mantia further teaches, via Choi, the lithium-storage electrode comprises LixTi2(PO4)3, where x = 1 (“suitable materials for Li-storage electrode 1 include … LiTi2(PO4)3” para. 49).
Regarding claim 18, modified La Mantia teaches the limitations of claim 15, as described above.
La Mantia further teaches carrying out an electrochemical hydrogen evolution reaction simultaneously with the electrochemical delithiation of the lithiated lithium-storage electrode, whereby water molecules in the aqueous lithium-recovery solution are reduced and hydroxide ions are produced, and lithium hydroxide is accumulated in the lithium-recovery solution (“an additional amount of energy is needed to transfer lithium into the recovery solution. This difference is due to energy losses in the transfer process, which is caused by … water splitting …” para. 43, as evidenced by e.g., the instant specification, water splitting during the delithiation is due to hydrogen evolution, which results in the formation of hydroxide ions and the formation/accumulation of lithium hydroxide, see para. 50 and eq. 6).
Regarding claim 19, modified La Mantia teaches the limitations of claim 15, as described above.
La Mantia further teaches carrying out an electrochemical oxygen reduction reaction simultaneously with the electrochemical delithiation of the lithiated lithium-storage electrode, whereby oxygen molecules present in the aqueous lithium-recovery solution are reduced and hydroxide ions are produced, and lithium hydroxide is accumulated in the lithium-recovery solution (“an additional amount of energy is needed to transfer lithium into the recovery solution. This difference is due to energy losses in the transfer process, which is caused by … oxygen reduction” para. 43, as evidenced by e.g., the instant specification, oxygen reduction during delithiation results in the formation of hydroxide ions and the formation/accumulation of lithium hydroxide, see para. 51 and eq. 7).
Allowable Subject Matter
Claims 2-4 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 17 would be allowable if rewritten to overcome the rejection under 35 U.S.C. 112(b) set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 2, the prior art of record, alone or in combination, does not reasonably teach or render obvious the cumulative limitations of claim 2 and its base claim. In particular, the prior art of record does not teach or disclose “a method for electrochemically extracting and recovering lithium ions from lithium ion phosphate” (claim 1), wherein the method further comprises “carrying out an electrochemical phosphate ion extraction from the aqueous leachate solution” (claim 2).
The closest prior art is considered to be La Mantia (DE 102012212770 A1) and Chen et al. (“Recovery of Li2CO3 from Spent LiFePO4 by Using a Novel Impurity Elimination Process” Molecules 2023, 28, 3902).
La Mantia in combination with Chen renders obvious the limitations of claim 1, as described above. However, La Mantia does not teach the counter reaction to the lithium intercalation is phosphate intercalation, but rather chloride intercalation. Furthermore, the lithium containing aqueous solution La Mantia does not comprise phosphate, and the lithium leaching process of Chen specifically avoids introduction of phosphate into the solution (“the extraction efficiency of Fe and P is close to 0%” § 2.1.1.). It therefore cannot reasonably be considered that a person having ordinary skill in the art would have a motivation to modify the method of La Mantia, or modified La Mantia, by adding a step of carrying out an electrochemical phosphate ion extraction from the lithium ion solution, nor would a person having ordinary skill in the art have a reasonable expectation of success making this modification (i.e., it would likely not be possible to recover phosphate given the leachate solution has a minimal concentration of phosphate to start).
It is therefore considered that the prior art of record, alone or in combination, does not teach or render obvious the cumulative limitations of claim 2 and its base claim. Claim 2 would therefore be allowable over the prior art if rewritten in independent form including all limitations of the base claim.
Regarding claims 3 and 4, claims 3 and 4 depend from claim 2, and would therefore be allowable if claim 2 were rewritten in independent form for the same reasons enumerated for claim 2, above.
Regarding claim 17, the prior art of record, alone or in combination, does not reasonably teach or render obvious the cumulative limitations of claim 17 and its base claim. In particular, the prior art of record does not teach or disclose “A method for electrochemically extracting and recovering lithium ions from a lithium ion-containing aqueous solution, the method comprising: contacting the lithium ion-containing aqueous solution with a lithium-storage electrode comprising LixTi2(PO4)3, where 1 ≤ x ≤ 3, TiP2O7, 5,7,12,14-pentacenetetrone, or polyimide” (claim 15), wherein the method further comprises “carrying out an electrochemical phosphate ion extraction from the lithium ion-containing aqueous solution” (claim 17).
The closest prior art is considered to be Choi (US Pat. Pub. 2022/0246998 A1), La Mantia (DE 102012212770 A1), Chen et al. (“Recovery of Li2CO3 from Spent LiFePO4 by Using a Novel Impurity Elimination Process” Molecules 2023, 28, 3902), Geng et al. (“Synthesis of layered double hydroxide-based hybrid electrode for efficient removal of phosphate ions in capacitive deionization” Water Science & Technology (2022) Vol 86 No 11, 3014), and Nam and Choi (“Electrochemical Bi/BiPO4 Cells for a Sustainable Phosphate Cycle” ACS Energy Lett. 2023, 8, 802).
It will be noted that Nam is a disclosure by an inventor or joint inventor within the grace period under 35 U.S.C. § 102(b)(1), and therefore does not constitute prior art.
Choi anticipates the limitations of claim 15, as described above. However, Choi does not teach the counter reaction to the lithium intercalation is phosphate intercalation, but rather chloride intercalation. While Choi uses a bismuth electrode and seawater as the lithium ion solution, and is therefore capable of phosphate intercalation as evidenced by Nam, Nam further indicates this intercalation process requires high phosphate concentrations and a narrow range of solution pH values and applied potentials (see e.g., Fig. 2). It therefore cannot reasonably be considered that the method of Choi necessarily results in phosphate intercalation. Choi therefore cannot be considered to disclose carrying out an electrochemical phosphate ion extraction from the lithium ion solution on the basis of inherency (MPEP § 2112).
While methods of intercalating phosphate into electrodes are known in the prior art (see e.g., Geng), these prior art methods are directed to water purification, and there is no clear motivation in the prior art that would have led a person having ordinary skill in the art to combine electrochemical phosphate removal with the lithium recovery process of Choi.
Furthermore, modifying the method of Choi by adding a step of electrochemical phosphate ion extraction cannot reasonably be considered a simple combination of prior art elements to yield predictable results (MPEP § 2143(I)(A)) because, as evidenced by e.g., Geng, due to their different goals, the methods of phosphate intercalation reported in the prior art use substantially different conditions from those of Choi.
La Mantia in combination with Choi renders obvious the limitations of claim 15, as described above. However, La Mantia does not teach the counter reaction to the lithium intercalation is phosphate intercalation, but rather chloride intercalation. Furthermore, the lithium containing aqueous solution La Mantia does not comprise phosphate. It therefore cannot reasonably be considered that a person having ordinary skill in the art would have a motivation to modify the method of La Mantia, or modified La Mantia, by adding a step of carrying out an electrochemical phosphate ion extraction from the lithium ion solution, nor would a person having ordinary skill in the art have a reasonable expectation of success making this modification (i.e., it would likely not be possible to recover phosphate given the leachate solution has a minimal concentration of phosphate to start).
It is therefore considered that the prior art of record, alone or in combination, does not teach or render obvious the cumulative limitations of claim 17. Claim 17 would therefore be allowable over the prior art if rewritten in independent form including all limitations of the base claims and to overcome the rejection under 35 U.S.C. § 112(b).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Zhang (CN 116926572 A) teaches a method for electrochemically extracting and recovering lithium from ions from lithium ion phosphate, wherein the method comprises leaching lithium ions from lithium iron phosphate into an aqueous leachate solution and simultaneously contacting the aqueous leachate solution with a lithium-storage electrode and carrying out an electrochemical lithium ion extraction using a lithium iron phosphate cathode (see e.g., abstract).
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/ALEXANDER R. PARENT/Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795