DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim(s) 8 is/are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 8 recites “the lithium hydroxide aqueous solution does not contain a salt of an alkali metal other than lithium or an alkaline earth metal” in lines 1 and 2. It is unclear if the solution is required to not comprise an alkaline earth metal at all or only to not comprise an alkaline earth metal salt.
The specification’s ¶ 0067 describes that, in some embodiments, the aqueous solution may not include a salt of an alkali metal or alkaline earth metal other than lithium, which appears to indicate that the salt of the alkaline earth metal is excluded. Therefore, under the claim’s broadest reasonable interpretation, in light of the specification, for this Office Action claim 8 will be interpreted to require that “the lithium hydroxide aqueous solution does not contain a salt of an alkali metal other than lithium or a salt of an alkaline earth metal”, as appears intended by ¶ 0067.
Appropriate correction is required.
Claim Interpretation
Claim 1 recites “recovering a lithium precursor from the third active metal solution” (line 11). For this Office Action such will be interpreted as a compound including a specific metal (here, lithium) to provide the specific metal included in an electrode active material, as specially defined in ¶ 0025.
Claim Rejections - 35 USC § 103
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 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) 1 and 4–13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Johnston et al. (WO 2021174348 A1, from 08/28/24 IDS) (Johnston) in view of Yang et al. (WO 2022127316 A1; citation to English equivalent US 20230330622 A1) (Yang) and Luc et al. (WO 2024064916 A1 (Luc).
Regarding claim 1, Johnston discloses a method of recovering an active metal of a lithium secondary battery (e.g., Abstract, fig. 1, exs. (e.g., ¶ 0174)), comprising: adding an acidic leaching liquid to a material to be recovered which contains a lithium metal oxide (adding sulfuric acid to black mass including lithium metal oxide of LiFePO4 (LFP), ¶ 0175 and step 122, fig. 2) to form a mixture including a first active metal solution and a leached residue (pregnant leach solution (PLS) (containing active metals Li and Fe) plus residue, respectively, ¶ 0175 and 0176); subjecting the formed mixture to solid-liquid separation for separating the first active metal solution from the leached residue to form a second active metal solution (via Buchner filtration to form filtered PLS (containing still Li and Fe), ¶ 0176).
Johnston further discloses adjusting the Fe:P mole ratio in the PLS by adding an iron-containing reagent of ferrous sulfate (¶ 0177), followed by raising pH by adding calcium hydroxide to the second active metal solution to form a third active metal solution from which impurities are removed or reduced (see precipitation of PLS (containing Li-rich solution, i.e., active metal), ¶ 0177).
However, Johnston fails to disclose adding a lithium hydroxide aqueous solution containing an iron salt to form the third active metal solution.
Yang teaches an analogous method of Li recovery for LIBs (e.g., ¶ 0003, ¶ 0008–0012), where pH is raised to precipitate a metal hydroxide (e.g., ¶ 0009). Yang teaches that the pH may be adjusted by adding many types of solutions, including caustics like sodium hydroxide or lithium hydroxide, and/or iron-salt-containing solutions such as ferrous sulfate (¶ 0026).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to combine Johnston’s Fe:P adjustment and pH adjustment into one step by incorporating a combined solution of a caustic like LiOH and an iron salt like ferrous sulfate with the reasonable expectation of achieving Johnston’s molar and pH adjustments with predictably greater production efficiency via the joint solution. One skilled in the art would have reasonably expected success from such because Yang recognizes that LiOH and ferrous sulfate solutions are usable together for pH adjustment.
Further, regarding the requirement of an aqueous LiOH solution, the skilled artisan would recognize that water is a ubiquitous solvent for caustic solutions like alkali hydroxides (see Johnston’s ¶ 0098).
Although modified Johnston may not explicitly disclose an aqueous LiOH solution, it would have been obvious to employ such and reasonably expect to achieve a successful hydroxide solution.
Johnston further discloses step 110 of post-processing the output solution (i.e., third active metal solution) rich in lithium sulfate to extract lithium (fig. 1, ¶ 0111 and 0177), though Johnston fails to explicitly disclose removing a lithium precursor—i.e., a compound (see claim interpretation section)—from the third active metal solution.
Luc teaches an analogous method of recovering lithium from battery manufacturing and recycling outlet streams (Title, Abstract). Luc teaches generating Li2SO4 solution from a battery recycling process and converting such into LiOH via electrodialysis (¶ 0007, 0016, 0049). Luc teaches that this process enables sulfuric acid and LiOH recovery with fewer purification techniques required by conventional industrial processes (¶ 0007).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to recover LiOH as a lithium precursor compound from Johnston’s Li2SO4-rich third active metal solution via Luc’s electrodialysis with the reasonable expectation of successfully recovering LiOH alongside sulfuric acid with fewer purification techniques than conventionally required, as taught by Luc.
Regarding claim 4, modified Johnston discloses the method of claim 1, wherein the lithium metal oxide includes a lithium iron phosphate-based active material (LFP, ¶ 0175), and the first active metal solution includes lithium sulfate (via leaching with sulfuric acid to obtain PLS with lithium sulfate, as seen in, e.g., ¶ 0107 and 0108, as well as ¶ 0132).
Johnston further discloses that, in some embodiments, the process may produce ferrous phosphate, i.e., an iron-phosphate based material, which may be separated after leaching to produce a first intermediary solution (PLS/first active metal solution) (¶ 0012) and, thus, would be part of the leached residue because such forms post-leaching (¶ 0024).
Although Johnston fails to embody that the leached residue includes an iron phosphate-based material, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have separated such from the first active metal solution via leaching as part of the leached residue with the reasonable expectation of successfully removing the impurity and preparing the first active metal solution for further processing.
Regarding claim 5, modified Johnston discloses the method of claim 1, wherein the material to be recovered is obtained by pulverizing a waste lithium secondary battery (see processing black mass from (waste) LFP batteries, i.e., lithium secondary batteries, in Johnston’s ¶ 0022, which may occur via grinding/pulverizing in Johnston’s ¶ 0088).
Regarding claim 6, modified Johnston discloses the method of claim 1, wherein the impurities contain Fe, P, and Al (see black mass—i.e., material to be recovered and containing impurities—in Johnston, e.g., ¶ 0012; see also Johnston’s ¶ 0177).
Regarding claim 7, modified Johnston discloses the method of claim 1, wherein the iron salt includes iron sulfate (ferrous sulfate, Johnston’s ¶ 0177).
Johnston further discloses that both residual iron and phosphate are precipitated from the second active metal solution (through hydroxide precipitation, e.g., ¶ 0177) and that such may form ferrous/iron phosphate upon filtering the output material (¶ 0010), though Johnston appears to fail to embody such in the above example.
It would have been obvious to precipitate and filter out Johnston’s P and Fe as iron phosphate with the reasonable expectation of successfully removing the impurity and concentrating the Li solution.
Regarding claim 8, modified Johnston discloses the method of claim 1, wherein the lithium hydroxide aqueous solution does not contain a salt of an alkali metal other than lithium or an alkaline earth metal (by adopting Yang’s mixed solution of LiOH plus ferrous sulfate).
Regarding claim 9, modified Johnston discloses the method of claim 1, wherein recovering the lithium precursor comprises converting lithium sulfate into lithium hydroxide by an electrodialysis (Luc, e.g., ¶ 0016).
Regarding claim 10, modified Johnston discloses the method of claim 1.
Luc further teaches that the method can recirculate the generated LiOH as an LiOH solution back into the battery recycling process for generating Li2SO4 by forming a closed recycling loop (¶ 0073).
Although modified Johnston may fail to explicitly disclose further comprising recycling a portion of lithium hydroxide generated by the electrodialysis to the formation of the third active metal solution, it would have been obvious to perform such based on Luc’s teaching with the reasonable expectation of predictably improving processing efficiency by forming a closed LiOH recycling loop. It would have been specifically obvious to recirculate a portion of LiOH to the formation of the third active metal solution because, as explained above, this solution forms by adding LiOH to the second metal solution.
Regarding claim 11, modified Johnston discloses the method of claim 1, wherein the acidic leaching liquid includes sulfuric acid (Johnston, e.g., ¶ 0175).
Luc further teaches that the method can recirculate the sulfuric acid generated from the electrodialysis back into the battery recycling process for leaching the processed battery materials (¶ 0073).
Although modified Johnston may fail to explicitly disclose that the method further comprises recycling sulfuric acid produced by the electrodialysis to the formation of the mixture, it would have been obvious to perform such based on Luc’s teaching with the reasonable expectation of predictably improving processing efficiency by forming a closed H2SO4 recycling loop. It would have been specifically obvious to recirculate the sulfuric acid to the formation of the mixture because Luc recognizes regenerating the acid for leaching, and the mixture forms from adding the acidic leaching liquid.
Regarding claim 12, modified Johnston discloses the method of claim 1.
Johnston further discloses that the acidic leaching liquid may include other reagents like hydrogen peroxide (¶ 0115) but fails to embody such in the above example.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ hydrogen peroxide in Johnston’s leaching liquid with the reasonable expectation of achieving successful leaching.
Regarding claim 13, modified Johnston discloses the method of claim 1 but appears to fail to disclose the concentration of the LiOH aqueous solution and, thus, that such is added in an amount from 0.1–0.5 wt% based on a total weight of the second active metal solution.
The skilled artisan, however, would reasonably recognize that LiOH solution—containing the metal salt—must be added in an amount sufficient to perform its functions—i.e., enough LiOH to raise pH (along with enough dissolved iron salt to perform Johnston’s Fe:P adjustment). On the other hand, the artisan would reasonably recognize that the vast majority of the second active metal solution should be constituted by the active metal because Johnston desires removing almost all Fe and P to leave a Li-rich solution for post-recovery processing (¶ 0177). To ensure enough LiOH solution is present for suitable pH and Fe:P adjustment while conforming to Johnston’s desire for a Li-rich solution, it would have been obvious to arrive at the recited range by routinely optimizing the LiOH’s wt% relative to the second active metal solution’s (MPEP 2144.05 (II)).
Claim(s) 2 and 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Johnston et al. (WO 2021174348 A1) (Johnston) in view of Yang et al. (WO 2022127316 A1; citation to English equivalent US 20230330622 A1) (Yang) and Luc et al. (WO 2024064916 A1 (Luc), as applied to claim 1, further in view of Park et al. (US 20230160036 A1) (Park).
Regarding claim 2, modified Johnston discloses the method of claim 1.
Johnston further discloses, after hydroxide precipitation, the ability to wash filtered solids in warm water (¶ 0177), i.e., a washing liquid, though Johnston fails to explicitly disclose washing the leached residue to generate a washing liquid; and supplying the washing liquid to the mixture or the second active metal solution. Park teaches an analogous method of recovering valuable metal from waste LIBs (Title), teaching, alongside solid-liquid separation of a leached metal mixture, washing with water (first washing 500) to further recover valuable metal ions in the unreacted residue wet with water (¶ 0046, 0047, 0049). Park teaches further washing (second washing 800) the precipitate obtained after solid-liquid separation 700 following metal precipitation step 600 to further recover lithium by capturing lithium sulfate ions (¶ 0059, 0060). Park further appears to teach that the washing solution is reusable for multiple washings (e.g., ¶ 0071, 0073, 0076).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to wash Johnston’s leached residue to generate a washing liquid with the reasonable expectation of further recovering valuable metal ions from the residue, as taught by Park. Further, given that Johnston recognizes substantially similar solid-liquid filtration after each of the leaching and metal-precipitation steps, it would have been further obvious to reuse and supply the washing liquid to Johnston’s mixture and second active metal solution and reasonably expect to further recover valuable metal/lithium ions from any unreacted residue from each filtrate/precipitate, as suggested by Park.
Regarding claim 3, modified Johnston discloses the method of claim 2.
As noted above, Park appears to teach that the washing solution is reusable for multiple washings (¶ 0071, 0073, 0076), where the skilled artisan would seemingly understand that repeated washing would reasonably further recover any leftover, water-soluble metal ions from the residue.
Although modified Johnston may fail to explicitly disclose that the washing is repeatedly performed in a plurality of cycles, it would have been obvious to perform such with the reasonable expectation of successfully recovering the desired level of metal ions left in the residue.
Regarding the requirement that the washing liquid generated from earlier cycles of the plurality of cycles is supplied to the second active metal solution, and the washing liquid generated from later cycles of the plurality of cycles is supplied to the mixture, Examiner notes that “the washing liquid generated” allows any quantity of the liquid, and the claim does not appear to exclude sending washing liquid generated from earlier cycles to the mixture and sending washing liquid generated from later cycles to the second active material solution (note that the method overall employs “comprising” language in claim 1’s preamble and, thus, is open to unrecited steps).
Although modified Johnston may fail to explicitly disclose that the washing liquid generated from earlier cycles of the plurality of cycles is supplied to the second active metal solution, and the washing liquid generated from later cycles of the plurality of cycles is supplied to the mixture, in light of the above observations and Park’s apparent suggestion for reusing the washing solution, it would have been obvious to supply the washing liquid generated by the plurality of cycles to both the second active metal solution (as part of solid-liquid filtration after metal precipitation, as in Johnston’s ¶ 0177 and Park’s second washing 800) as well as to the mixture (as part of washing leached residue, as in Park’s first washing 500 and corresponding to Johnston’s solid-liquid filtration after leaching in ¶ 0176) with the reasonable expectation of successfully recovering any metal ions entrained in the leached residue or filtrate, as suggested by Park.
Such would reasonably render obvious that the washing liquid generated from earlier cycles of the plurality of cycles is supplied to the second active metal solution, and the washing liquid generated from later cycles of the plurality of cycles is supplied to the mixture because portions of the generated washing liquid (i.e., both from earlier cycles and later cycles) would be supplied to both the second active metal solution and the mixture.
Conclusion
The cited art made of record and not relied upon is considered pertinent to applicant's disclosure:
CN 114132911 A (mach. translation attached): method of regenerating LFP, including adding supplementing mixture of, e.g., a lithium salt such as LiOH alongside an iron salt.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN S MEDLEY whose telephone number is (703)756-4600. The examiner can normally be reached 8:00–5:00 EST M–Th and 8:00–12:00 EST F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Leong, can be reached on 571-270-192. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/J.S.M./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 7/15/2026
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