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 .
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.
Amendments
Applicants amendments to the claims and specification filed on 28 April 2026 have been entered and considered for this action. The prior objections and rejections under 35 USC § 112 are withdrawn.
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 1-3, 6, and 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over Dougherty (US 12,412,940 B1; effective filing date of 27 January 2021) in view of Chai et al. (CN 110527836 A), Zheng et al. (RSC Adv. 2016, 6, 43613–43625), Hao et al. (Mater. Res. Bull., 2012, 47, 4048-4053; NPL document #1 on the IDS filed 30 June 2023), and Wang et al. (Microchimica Acta 2018, 185, 140). The previously provided English machine translation of Chai (CN 110527836 A) is referenced in the analysis below.
Regarding claim 1, Dougherty teaches recycling method for a mixed waste material of lithium ion batteries (recovery of lithium and various non-lithium components from lithium ion battery waste materials; abstract) including waste material from lithium nickel manganese cobalt oxide and lithium iron phosphate materials (col. 4, lines 26-30), comprising the following steps:
S1: adding the mixed waste material of lithium nickel manganese cobalt oxide and lithium iron phosphate to an acid solution for acid-leaching (the comminuted and dried material will then be transferred to a leaching tank where it is intimately mixed with a leach solution… the leach solution will be an aqueous acid; col. 4, lines 61-64), and conducting solid-liquid separation to obtain an acid-leaching liquor (the slurry from the leaching tank is filtered to remove particulates and so form a leachate; col. 5, lines 54-55) ;
S2: using a resin to adsorb nickel, cobalt, and manganese in the acid-leaching liquor (the leachate then passes to a separation system, preferably an ion-exchange system where the divalent metal ions are captured on the resin… ion exchange resins … may bind at least two or three different metal ions (e.g., two or three of cobalt, nickel, manganese; col. 5, lines 60-66), and washing a resulting saturated resin with an elution solvent (Elution of the bound ions may then be performed in a sequential manner using suitable elution solvents; col. 6, lines 5-7), and a post-adsorption solution (the pass through fraction; col. 6, line 23);
S3: heating the post-adsorption solution, and adding a lithium-precipitating reagent to obtain a lithium salt precipitate and a post-precipitation solution (lithium could be precipitated via carbonation, either by CO2 or Na2CO3, which would result in precipitation of Li2CO3….this may be performed at elevated temperatures; col. 6, lines 27-30).
Dougherty further teaches that the solvent used to elute the metal ions from the resin may be sulfuric acid (col. 6, lines 48-50) and that metals may be eluted together to obtain a mixed solution (it might also be more advantageous to strip the nickel and copper together; col. 6, lines 61-62).
Dougherty does not explicitly teach obtaining a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate. Nor does Dougherty teach concentrating the post-precipitation solution, adding a carbon source, or stirring to obtain a dispersed material, and subjecting the dispersed material to electrospinning to obtain a sheet material and drying and roasting the sheet material to obtain a ferric phosphate/carbon material.
However, Chai also teaches a method of recovering metals from waste lithium ion batteries (title) that comprises use of an ion-exchange resin to bind nickel, cobalt, and manganese while letting lithium pass through (to simultaneously adsorb valuable metals such as nickel, cobalt and manganese…so that lithium ions in the solution are not adsorbed … but remain completely in the solution after adsorption; [0025]). Chai further teaches that the cobalt, nickel, and manganese may be eluted together with sulfuric acid to form a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (washed with sulfuric acid to obtain a mixed solution of nickel-cobalt-manganese sulfate; [0010]), and that such a solution can be used as a raw material for the synthesis of ternary precursors ([0027]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the elution method of Chai in the recycling method of Dougherty. One of ordinary skill in the art would have been motivated to do so because Chai teaches that their method achieves high total recovery rates for nickel, cobalt and manganese, and is simple and easy to scale up ([0022]), and that recovered cobalt-manganese-nickel solution can be used as a raw material for ternary precursors.
Zheng also works in the field of recovery of metal materials from spent lithium ion batteries (abstract) and uses leaching with sulfuric acid and subsequent precipitation of lithium carbonate to recover lithium from the spent batteries. Zheng further teaches that FePO4 can also be recovered from the spent lithium ion batteries and subsequently mixed with a carbon source for reuse in battery materials (Fig. 22). Zheng additionally teaches that the final filtrate in the recovery scheme can be concentrated as part of the recovery process for the precipitated materials (p. 43614, col. 1, ¶ 5). In Zheng’s scheme this final solution being concentrated is a lithium-containing solution, but it would have been obvious to one of ordinary skill in the art to concentrate any post-precipitation solution in order to enhance the recovery of materials contained therein.
While Zheng teaches the recovery of the FePO4 prior to the precipitation of the lithium carbonate, it is noted that the courts have held that the selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results. In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946). MPEP 2144.04(IV)(C).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to first recover lithium carbonate by heating the post-adsorption solution and adding a lithium-precipitating regent to obtain a lithium salt and a post-precipitation solution, as taught by Zheng. Such a step would leave FePO4 as the last major component in solution, and it would have been obvious to concentrating the post-precipitation solution, as taught by Zheng. One of ordinary skill in the art would have been motivated to do so because Zheng teaches that the recovery and regeneration of the materials in spent lithium ion batteries, including iron phosphate materials, is necessary to prevent environmental pollution and resource depletion (Introduction).
Furthermore, Hao is also in the field of lithium ion battery cathode materials, and Hao teaches that ferric phosphate can be converted into an cathode material with enhanced electrochemical performance (abstract) and which avoids the sensitivity issues associated with forming LiFePO4 (LiFePO4 can also easily deteriorate by the improper use and storage, all of these bring many difficulties to the modification research and practical application; Introduction, ¶ 1). Hao further teaches that formation of the ferric phosphate/carbon composite material can be carried by a process comprising mixing ferric phosphate (FPO) and a carbon source (PAN), stirring to obtain a dispersed mixture, and then subjecting the dispersed mixture to electrospinning to obtain a sheet material (thin film product), and drying and roasting the sheet material to obtain a ferric phosphate/carbon material (annealed at 800 °C [which will also dry the material] …finally obtained P-FPO/C composite material; Section 2.1, ¶ 3).
Wang teaches an alternate method of preparing conductive electrospun FePO4/carbon nanofibers (abstract) by stirring a mixture comprising iron ions, phosphate ions, polyvinylpyrrolidone (PVP) and DMF, electrospinning this mixture, and then roasting at 300 °C in a muffle furnace (p. 2, col. 2, ¶ 2).1 This muffle furnace step is interpreted as occurring in air, or it would have been obvious to perform in air, because no alternate conditions are specified as they are for the subsequent tube furnace annealing step which specifically requires an N2 atmosphere. Wang also teaches that the concentration of iron ions in their starting aqueous solution is 319.9 mg Fe2(SO4)3 in 1 mL of water, which is equivalent to an iron concentration of 89 mg Fe/1 mL, or 89 g/L.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to concentrate the post-precipitation solution obtained by the method of modified Dougherty to an iron concentration of 89 g/L, to add a carbon source of PVP to the concentrated post-precipitation solution, and to stir to obtain a dispersed mixture and to subject this dispersed mixture to electrospinning to obtain a sheet material, as taught by Hao and Wang. It would have been further obvious to dry and roast the sheet material at 300 °C in air to obtain a ferric phosphate/carbon material, as taught by Wang.
One of ordinary skill in the art would have been motivated to do so because Hao teaches that ferric phosphate/carbon composite materials have enhanced electrochemical performance and decreased deterioration in battery applications, and because Wang teaches that their method using an aqueous iron/phosphate mixture at these concentrations can also provide conductive FePO4/C composites, a recognized goal in the art, as taught by Hao (To improve the electrochemical performance of [FePO4], the approach of mixing it with electronically conductive materials has been studied; p. 4048, col. 2, ¶ 2). By applying the method of Wang, one of ordinary skill in the art would simply be replacing Hao’s method of preparing electrospun FePO4/carbon composites with another. MPEP 2143(I)(B).
Regarding claim 2, modified Dougherty teaches the method of claim 1 where in S1 the acid solution is sulfuric acid (col. 2, line 35).
Regarding claim 3, modified Dougherty teaches the method of claim 1 where in S1 a mass ratio of the acid solution (liquid) to the mixed waste material (solid) can be 5:1 ( suitable solid-to-liquid ratios include … 1:5; col. 5, lines 47-48), which lies in the instantly claimed range.
Regarding claim 6, modified Dougherty teaches the method of claim 1, where Dougherty teaches in S3 the lithium-precipitating reagent is sodium carbonate (col. 6, line 28) and the heating is conducted at elevated temperatures of up to 90°C-95 °C (col. 6, lines 30-31), which lies in the instantly claimed range of 40 °C to 120 °C.
Regarding claim 9, modified Dougherty teaches the method according to claim 1, where Wang teaches in step (S4) dimethylformamide (DMF) is added to the aqueous iron-containing solution and then the carbon source (PVP) is added to this mixture, and the resulting mixture is stirred to obtain a dispersed mixture (First, 319.9 mg Fe2(SO4)3 was dissolved in 1 mL water, and 5mg GO was dispersed in 4 mL DMF, respectively. Subsequently, after mixing these two solutions, 0.5 g PVP… [was] added under constant stirring; p. 2, col. 2, ¶ 2).
It is noted that the courts have held that, absent unexpected results, the selection of any order of adding ingredients is considered prima facie obvious. In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930). MPEP 2144.04(IV)(C).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to first dissolve the carbon source in the dimethylformamide and to then add pour this solution into to the concentrated post-precipitation (aqueous iron-containing solution), thereby arriving at the instantly claimed invention. It would have been obvious to do so because one would merely be swapping the order of mixing with the expected result of having all components in the final mixture ready to subject to the electrospinning step.
Regarding claim 10, modified Dougherty teaches the method of claim 1, where Wang teaches in S4 the material is heated to 300 °C at a rate of 3 °C/min. Under these conditions the material will spend 17 min in the temperature range of 40 °C to 90 °C, during which time drying is expected to occur, thereby meeting the limitations of the instant claim.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Dougherty (US 12412940 B1; effective filing date of 27 January 2021) in view of Chai et al. (CN 110527836 A), Zheng et al. (RSC Adv. 2016, 6, 43613–43625), Hao et al. (Mater. Res. Bull., 2012, 47, 4048-4053; NPL document #1 on the IDS filed 30 June 2023), and Wang et al. (Microchimica Acta 2018, 185, 140), as applied to claim 1 above, and further in view of Kochhar et al. (US 2020/0078796 A1). The previously provided English machine translation of Chai (CN 110527836 A) is used in the analysis below.
Regarding claim 5, modified Dougherty teaches the method of claim 1, where Chai teaches using the obtained mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate as a ternary material precursor. Neither Chai nor Dougherty specifically teach subjecting the solution to precipitation to obtain a ternary precursor.
However, Kochhar also teaches a process for recovering materials from batteries comprising steps of acid leaching and isolating a mixed nickel, cobalt, manganese product (Fig 1A, elements f and m). Kochhar further teaches subjecting the nickel, manganese, cobalt product to precipitation to obtain a precipitated product such as Ni/Mn/Co hydroxide ([0122]), which is ternary precursor.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to subject the mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate obtained by the method of modified Dougherty to a precipitation, as taught by Kochhar. One of ordinary skill in the art would have been motivated to do so in order to isolate a solid product that can be used a ternary precursor, as taught by Chai and Kochhar.
Response to Arguments
It is noted that Applicant’s arguments, page 6 (¶ 4) of the reply filed 28 April 2026, recite claim limitations that do not match the limitations recited in the concurrently filed claims. In particular, while Applicant appears to be arguing for a claim where the carbon source is limited to only polyvinylpyrrolidone and polyvinylidene fluoride, the claims filed on 28 April 2028 include the carbon the source of polyacrylonitrile in the limitations.
Applicant's arguments, page 7, with respect to the order of steps have been fully considered but they are not persuasive.
In particular, Applicant states that “by adopting the method of precipitating lithium first and then recovering iron, this application can reduce the lithium doping during the iron-recovery process, thus obtaining the ferric phosphate/carbon material instead of the lithium iron phosphate/carbon material.” Applicant goes on to argue that “it is essential to make sure that lithium is eliminated first, followed by the recovery of iron.” These statements seem to be arguing that by changing the order of steps relative to those presented in the prior art that the inventors of the instant application achieve the unexpected result that the iron phosphate product obtained has higher purity/lower lithium content than the product that is achievable using the order of steps taught by the prior art.
However, arguments presented by the applicant cannot take the place of evidence in the record. In re Schulze, 346 F.2d 600, 602, 145 USPQ 716, 718 (CCPA 1965) and In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed. Cir. 1984). Examples of statements which are not evidence and which must be supported by an appropriate affidavit or declaration include statements regarding unexpected results, commercial success, solution of a long-felt need, inoperability of the prior art, invention before the date of the reference, and allegations that the author(s) of the prior art derived the disclosed subject matter from the inventor or at least one joint inventor.
Therefore, absent objective evidence that the order of recovering iron phosphate and lithium carbonate truly achieves something unexpected, the finding that the claimed order of steps is prima facie obvious over that in the prior art (D3/Zheng) is maintained.
Applicant also asserts, page 8, that one incorporating the teachings of Zheng into Dougherty would “merely combine lithium carbonate and ferric phosphate with the carbon source.” However, this conclusion ignores the contributions of Hao (D4), which teaches that it is advantageous to instead incorporate ferric phosphate into the carbon material.
Applicant also asserts that the method of Zheng and Hao are hard to integrate, page 8, ¶ 2, but it is difficult to see how this is the case. Zheng provides a method to isolate ferric phosphate from recycled batteries and Hao teaches that such a material can be incorporated into a composite material.
Applicant’s arguments, pages 8-10, with respect to the details of the electrospinning process have been fully considered and are persuasive. In particular, it is correct that Hao does not teach roasting in air or in the temperature range recited in the amended claim. Therefore, the prior rejection has been withdrawn.
However, upon further consideration, a new grounds of rejection is made in view of Wang. Wang teaches a process of preparing conductive ferric phosphate/carbon composite materials by a process that meets the limitations of the amended claim, and it would have been obvious to substitute this known method for preparing such a material for the similar method used by Hao.
Conclusion
Applicant's amendment necessitated the new grounds 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 Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
1 It is noted that Wang also teaches a subsequent annealing step at 700 °C in an N2 atmosphere, but a method having such a step is encompassed by the open claim language of the instant claim.
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