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 Claims
Applicant’s amendment and arguments, filed 08/13/2025, have been fully considered. Claim(s) 1, 5, and 6 is/are amended; claim(s) 4 and 8 stand(s) as originally or previously presented; and claim(s) 2, 3, and 7 is/are canceled; no new matter has been added. Examiner affirms that the original disclosure provides adequate support for the amendment.
Upon considering said amendment and arguments, the previous claim objections and 35 U.S.C. 103 rejection set forth in the Office Action mailed 05/14/2025 has/have been withdrawn. Applicant’s amendment necessitated the new grounds of rejection below.
Claim Rejections - 35 USC § 103
3. The text forming the basis for the rejection under 35 U.S.C. 103 may be found in a prior Office Action.
Claim(s) 1, 4–6, and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zheng et al. (US 20230369671 A1) (Zheng) in view of Yu et al. (CN 113540603 A; citations to English equivalent US 20240030509 A1) (Yu), Wang et al. (WO 2018192122 A1) (Wang), Myung et al. (KR 20200032663 A) (Myung), Xiao et al. (CN 117089706 A) (Xiao), Wang et al. (CN 110028088 A) (Wang II), and Kang et al. (CN 110078099 A) (Kang).
Regarding claim 1, Zheng discloses a method of using a wet method to recycle metal elements in lithium batteries (e.g., Abstract), including the following steps:
Step 1, pretreating lithium batteries and removing organic components and fluorine so as to obtain a mixture of powders containing positive-electrode materials (note, in ¶ 0132, step 911’s heating and at least partially removing waste components such as binder—which is, e.g., polyvinylidene difluoride (PVDF; e.g., ¶ 0048) and, thus, contains fluorine—and electrolytes (which one skilled in the art would understand would include organic solvents such as ethylene carbonate or propylene carbonate, as in ¶ 0048), followed by step 912’s separating to obtain positive electrode/active material powders in ¶ 0135; see also annotated FIG. 10 below).
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Zheng further discloses that step 912, as part of Step 1, includes separating the electrode material by, e.g., physical sorting (rotary sieving, shaking, or sonication sieving, ¶ 0135), by which metal sheets of current collectors are sorted out, and a remaining sorted portion is the mixture of powders which contains the positive-electrode materials (separating collectors from electrode material/powder, Zheng, ¶ 0135; per Zheng, e.g., ¶ 0029, the collector is a metal sheet).
However, in being unconcerned with the manner in which the electrode material is sorted, Zheng fails to explicitly disclose that in the physical sorting, at least two stages of vibrating screenings are used, in a first screening of the at least two stages of vibrating screenings, large metal sheets of the metal sheets of the current collectors are screened out, in a second screening of the at least two stages of vibrating screenings, medium metal sheets of the metal sheets of the current collectors are screened out, a screen having a mesh size of 10–40 mesh is used for the first screening, and a screen having a mesh size of 100–200 mesh is used for the second screening.
Yu, in teaching impurity removal from waste lithium batteries (Title), teaches layered screening to separate the current-collector fragment and electrode material (¶ 0010). Yu teaches tri-layered, ultrasonic vibrating screening using a parent net with 16 or 20 meshes, a transition net of 100, 140, or 200 meshes, and a sub-net of 500, 540, or 600 meshes (¶ 0019). Yu teaches that such ultrasonic vibrating screening with three nets allows targeted recycling of different materials because the parent net mainly intercepts current-collector fragments, the transition net intercepts electrode material fragments containing more impurities, the sub-net captures coarse electrode-material particles containing more impurities, and fine electrode-material particles pass through the sub-net (¶ 0021). Yu teaches that such targeted screening achieves a narrow particle-size range, improving screening accuracy and improving discharge efficiency 20–50% (¶ 0020).
Yu and Zheng are analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely battery recycling or waste treatment.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adopt Yu’s trilayered, ultrasonic vibratory screening as Zheng’s physical sorting with the reasonable expectation of improving screening accuracy and improving discharge efficiency 20–50%, as taught by Yu.
Thus, modified Zheng would disclose, in the physical sorting, at least two stages of vibrating screenings are used (Yu’s three stages), in a first screening of the at least two stages of vibrating screenings, large metal sheets of the metal sheets of the current collectors are screened out (via Yu’s parent net’s mainly capturing current-collector fragments with smaller mesh and, thus, larger particle size), in a second screening of the at least two stages of vibrating screenings, medium metal sheets of the metal sheets of the current collectors are screened out (as Yu’s transition net further captures electrode materials with impurities and the parent and transition nets use mesh sizes falling within the respectively recited ranges, any smaller or “medium” metal sheets of the current collectors that were not separated by the parent net would reasonably be caught by the transition net, as in the larger and smaller particle sizes in the instant specification, p. 11, lines 11–17 and as seen in Yu’s FIG. 1’s transition net’s containing coarse current-collector particles), a screen having a mesh size of 16 or 20 meshes is used for the first screening (Yu’s parent net), which falls within 10–40 mesh, and a screen having a mesh size of 100, 140, or 200 meshes is used for the second screening (Yu’s transition net), which falls within 100–200 mesh.
Zheng further discloses, in a separate embodiment (step 12, FIG. 1 and ¶ 0038), a purification operation that may employ strong acids such as sulfuric or nitric acid–-i.e., leaching, as seen in the instant specification’s using substantially similar acids (p. 12, l. 2–4)–-to remove impurities without affecting the electrode material’s integrity (¶ 0038).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to routinely incorporate Zheng’s impurity removal/leaching via, e.g., sulfuric acid from the embodiment of FIG. 1 while separating the electrode materials in the embodiment of FIG. 10 with the reasonable expectation of obtaining a leachate with removed impurities without affecting the electrode material’s integrity, as suggested by Zheng (see also, e.g., MPEP 2143 (A.)).
Though Zheng, as noted above, discloses or renders obvious leaching, in being unconcerned with the specifics of such, fails to explicitly disclose the recited conditions concerning the mixed aqueous solution.
Wang, in teaching acid leaching of positive electrode materials from Li-battery waste (Title), teaches leaching with a mixture of an acid and a reducing agent (e.g., ¶ 0028), where the acid is, e.g., sulfuric (¶ 0030), and the reducing agent is, e.g., hydrogen peroxide (¶ 0032). Wang further teaches that the acid’s concentration is preferably 2–4 mol/L (¶ 0029), and the reducing agent is preferably 2–8 wt% (¶ 0031), which, if assuming a solution density ~ 1.0 g/mL, converts to 0.59~2.35 mol/L based on H2O2’s MW of 34.01 g/mol. Wang further teaches that the stirring speed is preferably 100–500 rpm (¶ 0035); the temperature is preferably 30–80°C (¶ 0034); the time is 5–480 min (¶ 0028); and the solid/liquid ratio is preferably 80–150 g/L (¶ 0033), i.e., 1:6.67–12.5 (based on conversion to g/mL).
Wang is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely positive electrode material leaching.
It would have been obvious to one of ordinary skill in the art, before the claimed invention's effective filing date, that Zheng's leaching must necessarily be performed under certain conditions, and, as demonstrated by Wang, the skilled artisan would find it obvious to use a mixed solution of 2–4 mol/L sulfuric acid and 0.59~2.35 mol/L hydrogen peroxide at a stirring speed of 100–500 rpm, temperature of 30–80°C, time of 5–480 min, and S/L ratio of 1:6.67–12.5 as appropriate conditions, absent demonstrated criticality.
In employing a sulfuric acid concentration of 2–4 mol/L and a solid/liquid ratio of 1:6.67–12.5, such falls within the recited 0.5–5 mol/L and 1:2–20, respectively. Moreover, in incorporating the hydrogen peroxide at 0.59~2.35 mol/L, the temperature at 30–80°C, the stirring speed at 100–500 rpm, and time at 5–480 min, these ranges overlap and render obvious the recited 0.5–5 mol/L, 50–100°C, 50–250 r/min, and ≥ 30 min such that one skilled in the art could routinely select within each overlap with a reasonable expectation of successfully leaching the electrode powder mixture (MPEP 2144.05 (I)).
Modified Zheng further discloses that the mixture of acid and reducing agent is a solution (Wang, e.g., ¶ 0012) but is silent to the solution’s solvent and, thus, fails to explicitly disclose a mixed aqueous solution.
Myung, in teaching recovering metal from a secondary battery (Title), teaches that leaching occurs through an aqueous solution of sulfuric acid, which may further include hydrogen peroxide (¶ 0007, 0008).
Myung is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely metal recovery from batteries.
It would have been obvious to one of ordinary skill in the art, before the claimed invention's effective filing date, that modified Zheng's sulfuric acid/peroxide solution must necessarily be incorporated with some solvent, and, as demonstrated by Myung, the skilled artisan would find it obvious to use water as the solvent to form an aqueous solution and reasonably expect to form a successful leaching solution.
Modified Zheng further discloses Step 3, heating solid products, obtained after the acid leaching and solid-liquid filtration (obtained from separation of step 912 in Zheng, ¶ 0135), in an oxygen-containing atmosphere (second heat treatment, which can be performed in air or O2-enriched atmosphere in Zheng, ¶ 0136 and step 913 of FIG. 10), so as to burn up carbon (removing additives such as conductive carbon, Zheng, ¶ 0137), then a remaining portion of the solid products is ferric phosphate (note FePO4 as oxidized product from heating, Zheng, ¶ 0137).
Modified Zheng further discloses that this Step-3 heating may occur at 300–1150°C for 1~16 h (Zheng, ¶ 0138 and 0139), which overlaps and renders obvious the recited 600–700°C and 2–4 h, respectively, such that the skilled artisan could routinely select within each overlap with the reasonable expectation of performing successful heating to remove the carbonaceous additives (MPEP 2144.05 (I)).
Modified Zheng further discloses that the electrode material can include both lithium iron phosphate (LFP) and ternary material (NCM) (Zheng,e.g., ¶ 0030 and 0113; note also NCM recovery from another embodiment, FIG. 12) but fails to explicitly disclose Step 4, sending the leachate, obtained after acid leaching and solid-liquid filtration, to an extraction step, wherein diisooctyl phosphate is used as an extraction agent, so as to obtain a raffinate containing Li element and an organic phase containing Ni/Co/Mn elements.
Xiao, in teaching NCM recovery for batteries (¶ 0002, 0010), teaches, after acid leaching, performing solid-liquid filtration (during S200 after impurity removal step, e.g., ¶ 0023, 0075, 0077) followed by extraction with diisooctyl phosphate and a pyridine (S300, FIGS. 1 and 3 and ¶ 0059 and 0078; per ¶ 0072 and 0138, the extractant includes diisooctyl phosphate) to obtain a raffinate containing Li (raffinate containing second valuable metal element, ¶ 0059, which, per ¶ 0058, includes Li) and an organic phase containing Ni/Co/Mn (extract of ¶ 0059 containing first valuable metal element, which would constitute an organic phase due to the organic diisooctyl phosphate extractant; per ¶ 0058 and, e.g., ¶ 0140 and 0141 (Table 10), the extract contains Ni, Co, and Mn). Xiao teaches that this combined phosphate-pyridine extractant improves the recovery rate of both Li (second metal element) and Ni/Co/Mn (first metal element) while allowing simultaneous recovery, yielding a simpler and more cost-effective process (¶ 0009, 0010).
Xiao is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely metal recovery for batteries.
It would have been obvious to one of ordinary skill in the art, before the claimed invention's effective filing date, that Zheng's electrode material, when containing NCM, should necessarily be filtered after leaching to remove the precipitated impurities (as with Zheng’s other electrode material, ¶ 0135), and, as demonstrated by Xiao, the skilled artisan would find it obvious to perform solid-liquid separation to do so. It would have been further obvious to the skilled artisan to send the portion of Zheng’s electrode material containing NCM to an extraction step including Xiao’s pyridine and diisooctyl phosphate with the reasonable expectation of creating a raffinate including Li and an organic phase including Ni/Co/Mn, improving the recovery rate of all four metals while yielding a simpler and more cost-effective process, as taught by Xiao.
However, modified Zheng fails to explicitly disclose the recited back-extraction on the organic phase.
Xiao further teaches that, after extracting the NCM, the extract must be further processed to obtain a stripped, battery-grade salt solution of the metals (¶ 0086), wherein dilute sulfuric acid (which the skilled artisan would reasonably recognize or find obvious implies water as the solvent or diluent because such is the most common solvent/diluent for strong acids such as sulfuric, as demonstrated at least by Myung above) may be used as the back-extraction agent (¶ 0087, 0096). Xiao teaches that the dilute sulfuric acid’s concentration is 1.5–3 M (¶ 0096), which, based on solution densities of 1.09 g/mL and 1.18 g/mL for commercial 1.5 M and 3 M solutions, respectively, yields a weight-percentage range of 13.5~24.9% sulfuric acid based on the following calculations:
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It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to back-extract modified Zheng’s NCM extract into a stripped solution via aqueous sulfuric acid, as taught by Xiao, with the reasonable expectation of yielding a battery-grade salt solution, as taught by Xiao. Moreover, in employing 13.5~24.9% sulfuric acid, such overlaps and renders obvious the recited 18% such that the skilled artisan could routinely select within the overlap with the reasonable expectation of selecting a suitable sulfuric acid concentration for stripping (MPEP 2144.05 (I)).
However, modified Zheng fails to explicitly disclose precipitating lithium carbonate out of the raffinate containing Li element.
Xiao further teaches precipitating lithium carbonate out of the Li raffinate, followed by carbonizing and further processing, to obtain battery-grade lithium carbonate (¶ 0090).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to precipitate Li out of the raffinate as lithium carbonate as well as perform further processing such as carbonizing, as taught by Xiao, with the reasonable expectation of yielding a battery-grade lithium material for further use, as taught by Xiao.
However, modified Zheng is silent to the precipitating agent’s identity and the precipitating conditions and, thus, fails to explicitly disclose using sodium carbonate under the recited conditions.
Wang II, in teaching preparation of battery-grade lithium carbonate by precipitating lithium carbonate out of a lithium-rich solution (e.g., Title, ¶ 0017), teaches precipitating with a 10–30 mass% sodium carbonate solution—which, assuming a solution density ~ 1.0 g/mL, converts to 100~300 g/L— with 10–30% excess sodium carbonate because the excess sodium carbonate generates as much lithium carbonate as possible (¶ 0051). Wang II teaches that the precipitation occurs at 80–110°C (¶ 0050), and the time is over 30 min (see all examples, e.g., 90 min (Ex. 1, ¶ 0066), 40 min (Ex. 2, ¶ 0078)).
Wang II is analogous prior art to the claimed invention because they are reasonably pertinent to a problem the inventors would have faced, namely choosing the proper conditions and precipitant when recovering battery-grade lithium carbonate.
It would have been obvious to one of ordinary skill in the art, before the claimed invention's effective filing date, that modified Zheng's lithium-carbonate precipitation must necessarily be performed under certain conditions and employ a certain precipitant, and, as demonstrated by Wang II, the skilled artisan would find it obvious to precipitate with 100~300 g/mL sodium carbonate solution at 80–100°C and a time over 30 min as appropriate conditions, absent demonstrated criticality.
In incorporating the sodium carbonate solution at 100~300 g/mL, an excess of 10–30% sodium carbonate, and a temperature of 80–110°C, such overlap and render obvious the recited 300 g/L, 10%, and 95°C, respectively, such that the skilled artisan could routinely select within each overlap with the reasonable expectation of selecting appropriate conditions for the sodium carbonate solution and precipitation (MPEP 2144.05 (I)). Moreover, to recover as much lithium carbonate as possible without wasting sodium carbonate, it would have been obvious to routinely optimize the excess content of sodium carbonate, including within the overlap (MPEP 2144.05 (II)).
Though modified Zheng discloses the sodium carbonate solution, modified Zheng is silent to the solution’s solvent and, thus, fails to explicitly disclose an aqueous solution.
Myung further teaches an aqueous sodium carbonate solution for precipitating lithium carbonate (¶ 0038, 0040).
It would have been obvious to one of ordinary skill in the art, before the claimed invention's effective filing date, that modified Zheng's sodium carbonate solution must necessarily be incorporated with some solvent, and, as demonstrated by Myung, the skilled artisan would find it obvious to use water as the solvent to form an aqueous solution and reasonably expect to produce a successful precipitant solution.
Though modified Zheng, as established above, discloses or renders obvious the recited sodium-carbonate precipitation conditions, modified Zheng fails to explicitly disclose adding a distinct lithium solution when doing so.
Kang, in teaching preparing lithium carbonate from a leaching purification liquid for use in Li batteries (Title, ¶ 0004), teaches, when precipitating with sodium carbonate, adding the lithium solution and removing the lithium carbonate product in stages (¶ 0023). Kang teaches that, compared to when sodium carbonate is directly added to precipitate lithium carbonate, such reduces the entrainment and wrapping of sulfate—which would seemingly exist in modified Zheng’s lithium mother solution as a counter-ion, as seen in Xiao, e.g., ¶ 0117 and 0119—by eutectics and polycrystals, reducing impurities in the obtained lithium carbonate (¶ 0023).
Kang is analogous prior art to the claimed invention because they are reasonably pertinent to a problem the inventors would have faced, namely optimizing the recovery and purity of battery-grade lithium carbonate.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to add the lithium solution and remove the lithium carbonate product in stages when precipitating with sodium carbonate, as taught by Kang, with the reasonable expectation of reducing impurities in the obtained lithium carbonate, as taught by Kang.
Regarding claim 4, modified Zheng discloses the method of claim 1, wherein the ferric phosphate obtained by Step 3 is to be used as a raw material for preparing positive-electrode active material for lithium phosphate batteries (as used as LFP battery electrode, Zheng, e.g., FIGS. 13 and 15 and ¶ 0161), and the first stripping solution containing Ni/Co/Mn elements, which is obtained by Step 4, is to be used as a raw material for preparing ternary positive-electrode active materials (by stripping the NCM extract into a battery-grade salt solution, Xiao, ¶ 0086; see also Xiao, e.g., ¶ 0190 and Zheng, e.g., FIG. 12)
Regarding claim 5, modified Zheng discloses the method of claim 1, wherein the Step 1 includes removing a binder, so as to separate positive-electrode active materials from the current collectors (note at least partially removing binder by first heat treatment (step 911), Zheng, ¶ 0132, which the skilled artisan would appreciate would separate the active material from the collector because a binder adheres these two components together, as seen in separating the collectors in Zheng, ¶ 0135).
Regarding claim 6, modified Zheng discloses the method of claim 5.
Zheng further discloses that Step 1 may include heating to remove the binder so as to separate positive-electrode active materials from current collectors (vaporizing waste such as binder during first heat treatment, ¶ 0132; as noted above, the skilled artisan would appreciate that removing the binder would separate the active materials from the collectors) and that such may occur in many types of environments, including inert atmospheres such as Ar or N2 (¶ 0132), but fails to explicitly embody such an atmosphere and, thus, oxygen-free pyrolysis.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to routinely perform Zheng’s Step 1’s heat treatment in an inert atmosphere to remove binder—and, thus, perform oxygen-free pyrolysis—with the reasonable expectation of successfully removing the binder and separating the electrode materials from the current collectors, as suggested by Zheng.
Regarding claim 8, modified Zheng discloses the method of claim 1, wherein the Step 1 does not include a step of separating positive electrode active material from negative electrode material, so the mixture of powders obtained in Step 1 contains both the positive electrode materials and carbon (by being able to burn up the graphite-based anode in second heating, Zheng, ¶ 0136 and 0137; note also concurrent cathode and anode processing, Zheng, ¶ 0032).
Response to Arguments
Applicant’s arguments with respect to claim(s) 1 have been considered. Applicant’s amendment overcame the previous 35 U.S.C. 103 rejection–-which, as noted above, has been withdrawn–-and necessitated the new grounds of rejection citing the new reference Yu, as established above.
Conclusion
The prior art made of record but not relied upon is considered pertinent to Applicant’s disclosure:
US 20220200075 A1: also disclose multi-stage screening of battery waste to capture progressively smaller particles.
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.
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/J.S.M./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 10/2/2025