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 .
Status of Application
Claims 1-20 are pending and presented for examination. Claims 1, 15 and 20 were amended via the instant amendment dated 13 November 2025 which is acknowledged and entered.
Response to Arguments
Applicant’s remarks dated 13 November 2025 (hereinafter, “Remarks at __”) are acknowledged and entered.
The rejection of claims 1-14 and 16-20 under 35 U.S.C. 103 over Ma in view of Lu with Li as an evidentiary reference is MAINTAINED and updated below to reflect the instant amendment.
The traversal is that Ma nor Lu disclose usage of “an aqueous acidic solution to obtain an acidic leach solution” (Remarks at 6). Ma actually discloses usage of “5M sulfate acid”, while the Office previous referred to this as “sodium sulfate”, from a review of google searches,
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it appears that this actually is sulfuric acid. As such, one of ordinary skill in the art would find this to be 5M sulfuric acid not sodium sulfate.
The rejection of claims 1-14 and 16-20 under 35 U.S.C. 103 over Li in view of Turner and Lu is UPDATED below to reflect the instant amendment.
The traversal is that Li nor Turner or Lu expressly state usage of “an aqueous acidic solution to obtain an acidic leach solution” (Remarks at 7). As noted by Applicants, Li discloses that they purchase already leached graphite anode, though nothing actually occurs with the leach solution but instead the precipitated graphite. The rejection is updated to cover how leaching occurs.
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.
Claims 1-14 and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Ma in view of Turner and Lu with Li as an evidentiary reference to Ti being present in LIBs
Regarding claims 1 and 7, Ma discloses a method of producing purified graphite from a recycled battery stream (Ma at “Abstract”) comprising:
Leaching a black mass of exhausted lithium-ion batteries via leaching in 5M sulfuric acid (28% balance aqueous) with 35% w/w hydrogen peroxide to produce an acidic leach solution at room temperature and filtering to yield a precipitate comprising graphite (Ma at 19733 R col);
Sintering the precipitate with aqueous NaOH (Id.); and
Washing the precipitate with DI water (Id.).
However, Ma does not expressly state that the hydroxide roasting is performed with <40% NaOH and that a temperature of <250 C is used nor that the baking/sintering process is repeated.
Lu in a method of purifying graphite (Lu at “Abstract”) discloses alkali roasting graphite in 25% sodium hydroxide at 150 C (Lu at 756 L col).
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to perform the method of Ma in view of the aqueous alkali roasting of Lu. The teaching or suggested motivation in doing so being purification to 98.2% (Id.) and higher sulfur removal (Lu at “Fig. 3”).
Turner in a method of purifying graphite (Turner at “Abstract”) discloses that the alkali baking can be repeated (Turner at [0075]). While Ma is silent with respect to titanium being present, “Table S1” of Li discloses that TI is present in LIBs.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to perform the method of Ma in view of the multiple baking steps of Turner. The teaching or suggested motivation in doing so being removal of titanium and other heavy metal elements (Id.).
As to claim 2, precipitate to solid ratio in baking is 1:2 (Lu at 756 L col).
Turning to claim 3, given that the process step is repeated as is in Turner then the same conditions in the combination vis a vis that provided by Lu would also be the same for a second baking step.
With respect to claims 4-6, 25% NaOH is utilized and the same concept with respect to claim 3 holds true here.
Concerning claim 8, 150 C can be utilized (Lu at 756 L col). It is noted that purity and temperature bear a relationship also (Lu at “Fig. 1”) such that the temperature is an art recognized result-effective variable that one of ordinary skill in the art would control to control the purity which is also prima facie obvious (see MPEP 2144.05).
As to claims 9 and 10, baking occurs for 1 hour (Lu at 756 L col).
With respect to claims 11 and 12, alumina is present (Ma at 19735 L col).
Turning to claims 13 and 14, washing to neutral pH is performed (Lu at 756 L col).
As to claims 16 and 17, after washing an acid wash with 10% sulfuric acid is performed (Lu at 756 L col).
Regarding claim 18, Turner discloses that the feed concentration of graphite into the baking is 91.6% (Turner at “Table 1”) and Lu discloses it is 87-88% (Lu at “Abstract”).
With respect to claim 19, the final purity is 99.88% in Turner due to the dual baking (Turner at [0224]) and that of Lu is ~99.4% which abuts upon >99.5% which is prima facie obvious (Lu at “Abstract” & MPEP 2144.05).
Concerning claim 20, this is considered to be a combination of at least claims 1, 6, 7 8, 11, 18 and 19, and thusly is rejected for the same reasons as those claims laid out supra.
Claims 1-14 and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Li in view of Turner, Lu and “Graphite Recycling from the Spent Lithium-Ion Batteries by Sulfuric Acid Curing–Leaching Combined with High-Temperature Calcination” to Gao et al. (hereinafter, “Gao at __”).
Regarding claims 1, 7, 8 and 18, Li discloses a method of producing a purified graphite from a recycled battery stream (Li at “Abstract”) comprising:
Li discloses purchasing LIBs already leached (Li at “Table S1” discloses the starting purity is 94.23% and that they purchase this already precipitated from a LIB recycling center and that leaching is how this process is performed; Li at 9316 R col);
Sintering the precipitate by preparing a slurry of the precipitate with a first aqueous solution of a hydroxide base in DI water (Id.); and
Washing the precipitate with DI water (Id.).
Gao discloses in a method of recycling graphite from LIBs (the SG used contains metals from battery streams, Gao at “Table 1”) and Li explicitly recites Gao (Li at 9324 L col) that usage of sulfuric acid aqueous leach to produce an aqueous acidic leach solution can be utilized (Gao at 9448 L col).
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to perform the method of Li in view of the sulfuric acid leaching of Gao. The teaching or suggested motivation in doing so being decreased costs for processing the LIBs themselves versus buying them from someone else and that the initial purity is 95% (Li at 9324 L col).
Therefore, it would have been obvious to
However, Li does not expressly state the temperature the slurry is heated to nor doing the baking/sintering process a second time nor the hydroxide concentration.
Turner in a method of purifying graphite discloses subjecting to a second baking/sintering step (Turner at [0075]) and that the baking temperature is 150-300 C (Turner at [0107]) which overlaps that range instantly claimed which is thusly prima facie obvious (see MPEP 2144.05).
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to perform the method of Li in view of the second baking and conditions of baking of Turner. The teaching or suggested motivation in doing so being reduction in Ti and other heavy metal content (Turner at [0075]).
Lu in a method of purifying graphite discloses that at approximately the feed concentration of Li that the concentration can be between 20 and 50% and not change the final purity of the caustic baking (Lu at “Fig. 2”) and that thusly 25% is the preferred NaOH amount (Lu at discussion below the cited figure).
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to perform the method of Li in view of the NaOH concentration of Lu. The teaching or suggested motivation in doing so is optimization of purity versus cost for NaOH (Id.).
Regarding claims 2 and 3, Lu discloses the precipitate:NaOH ratio is 1:2 (Lu at 756 L col) and given the process is repeated that this would also be the ratio fo sintered precipitate to aqueous solution given the combination of references.
As to claims 4-5, given repetition of the sintering process the ratios would be the same and in this case are 25% a discussed surpa.
Turning to claims 9 and 10, caustic baking is for 14 hours (Turner at [0027]).
As to claims 11 and 12, alumina is present (Li at 9318 R col).
Concerning claims 13 and 14, washing to a pH of 7 is performed (Li at 9316 R col).
As to claims 16 and 17, Lu discloses washing with acid too (Lu at 756 R col).
With respect to claim 19, the final purity is 99.88% in Turner due to the dual baking (Turner at [0224])
Concerning claim 20, this is considered to be a combination of at least claims 1, 6, 7, 8, 11, 18 and 19, and thusly is rejected for the same reasons as those claims laid out supra.
Allowable Subject Matter
Claim 15 is allowed for reasons already of record (See Non-Final Office Action dated 14 August 2025 which is hereby incorporated by reference in its entirety).
Conclusion
Claims 1-14 and 16-20 are finally rejected. Claim 15 is allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RICHARD M RUMP whose telephone number is (571)270-5848. The examiner can normally be reached Monday-Thursday 06:45 AM to 04:45 PM.
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RICHARD M. RUMP
Primary Examiner
Art Unit 1759
/RICHARD M RUMP/Primary Examiner, Art Unit 1759