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.
Claim Amendments
Applicant’s amendments to claim 1 in the reply filed 31 March 2026 are acknowledged.
Response to Arguments
Applicant is kindly thanked for noticing the typographical error and correctly identifying the PG Pub number for the Nho reference (US 2018/0261832 A1) that was applied in the prior Office Action.
Applicant’s arguments, pages 5-7 of the reply filed 31 March 2026, with respect to the rejection of claim 1 under 35 USC § 103 have been fully considered and are persuasive in that none of Li, Cao, Nho, or Lee teach the use of pin mill. Therefore, the prior rejections of all claims have been withdrawn.
However, upon further consideration, a new ground(s) of rejection is made over Li in view of Nho, Cao, Yamaguchi et al. (JP 2014199776A) and Premium Pulverizes (“Pin Mill”, retrieved from the Internet: < URL: https://www.premiumpulverisers.com/pin_mill.html>, archived 7 August 2020).
It is again noted that the broadest reasonable interpretation of "and separate the current collector" in claim 1, step (a-1) does not require that the current collector be completely removed or remain completely within the ring shaped screen, only that the dry-milling separate some of the current collector. Li does teach separating a large majority of the aluminum current collector (crushed material was then sieved through an 80-mesh standard sieve....the aluminum removal rate was calculated to be 93.0%; [0028]). This is a separation of the current collector that accompanies the dry-milling (claim 1, step 2 and [0013]) and is prior to both the heat-treatment step (step 3 and [0030]) and the washing step (step 4 and [0030]). The fact that Li performs a subsequent step to remove residual small amounts of aluminum current collector that have escaped separation by sieving does not mean they have not separated current collector using the dry-milling process.
Applicant’s arguments with respect to the dependent claims 4-14 and 16, pages 7-8, have been considered but are moot because they depend upon the allowability of claim 1 over Li, Cao, Nho and Lee.
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, 5-11, 13-14 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 101383442 A) in view of Cao et al. (CN 105895854 A), Nho et al. (US 2018/0261832 A1), Yamaguchi et al. (JP 2014199776A) and Premium Pulverizes (“Pin Mill”, retrieved from the Internet: < URL: https://www.premiumpulverisers.com/pin_mill.html>, archived 7 August 2020). The English machine translations of Li (CN101383442) and Cao (CN105895854) provided by Applicant and the English machine translation of Yamaguchi (JP 2014199776A) provided with this Action are referenced below.
Regarding claim 1, Li teaches a method of recycling a positive electrode active material (reclaiming and preparing lithium cobalt oxide waste, abstract) comprising (a-1) dry-milling (crushed using a high speed rotary crusher/pulverizer, paragraphs 11 and 28) a positive electrode scrap comprising an active material layer on a current collector (positive electrode sheet, paragraphs 28 and 11) to form the active material layer into a powdered state (material below the sieve, paragraph 28) and separate the current collector (aluminum in the material above the sieves, paragraph 28); (a-2) thermally treating the active material layer in powder form in air (put into a high-temperature electric furnace, maintain air circulation, raise temperature to 600 °C, paragraph 30) for thermal decomposition (burning) of a binder and a conductive material in the active material layer (binder and acetylene were basically completely removed, paragraph 28), to collect an active material (the residue, paragraph 30); (b) washing the active material collected from the step (a-2) with a basic aqueous solution (put into a 500 mL beaker, add 100 mL of 0.2 mol/L sodium hydroxide…keep stirring with a magnetic stirrer, react for 40 minutes, filter; paragraph 30) and drying (put it into an oven and dry it at 150°C for 12 hours; paragraph 30); and (c) annealing the active material washed from the step (b) with an addition of a lithium precursor (add 0.7 g of battery grade lithium carbonate; paragraph 32) to obtain a recycled active material (to prepare lithium cobalt oxide, paragraph 32; used to prepare a positive electrode, paragraph 34; claim 1).
Li does not teach washing the active material with a LiOH aqueous solution, as required by claim 1, instead using sodium hydroxide to remove residual aluminum (paragraph 15). Li also does not teach surface-coating the active material annealed from the step (c) with a metal component including B and/or W, or the dry-milling being performed using a pin mill having a ring-shaped screen wherein the current collector is separated during step (a-1) by being rolled into a round shape and remaining within the ring-shaped screen.
However, Cao teaches the use of lithium hydroxide as an alternative to sodium hydroxide to remove aluminum effectively from a positive electrode material (commonly used alkaline substances that are soluble in water can be used, such as sodium hydroxide [or] lithium hydroxide; alkali solution achieves the purpose of simultaneously removing carbon and aluminum from the cathode material; paragraph 42).
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 LiOH solution taught by Cao in place of NaOH the method of Li. One of ordinary skill in the art would have been motivated to do so because Cao teaches lithium hydroxide as an explicit alternative to the sodium hydroxide taught by Li for performing the same function.
Furthermore, Nho also teaches the preparation of positive electrode active materials (abstract) and further teaches that surface coating of positive electrode active material with a layer comprising a metal and boron will increase capacity and lifetime of the materials (a positive electrode active material having an increased capacity of the positive electrode material and improved long-term lifetime characteristic and cycle characteristic may be manufactured by forming a coating … comprising an oxalate compound including metal and boron on the surface of the first coating layer; [0130]).
Therefore, it would have also been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to surface coat the active material obtained by the method of modified Li with a metal component including boron (B), as taught by Nho. One of ordinary skill in the art would have been motivated to do so because such coating lead to increased battery lifetime, capacity, and cycle characteristic, as taught by Nho.
Regarding the dry-milling being performed by using a pin-mill, Yamaguchi teaches a similar method to Li for separating current collector and positive electrode active material wherein the material is dry-milled and then passed through a sieve ([0012]). Yamaguchi further teaches that the dry-milling can be performed with a pin mill and that the crusher (pin mill) can be equipped with a screen for ensuring that only particles of a certain size are discharged from the mill ([0032]-[0033]). Yamaguchi also teaches that there is an optimal size range for the screen ([0034]). Yamaguchi does not explicitly teach that the screen on the pin mill is ring shaped or that the current collector is rolled into a round shape and remains within the ring shaped screen.
However, Premium Pulverizers teaches that the screen on a pin mill that is used to select for a given size of particles (mesh size) can be a ring shaped screen (“Screen Drum”, p. 2 and 10). Premium Pulverizers further teaches that the number and type of pins (L-shape vs. round, pitch, etc.) can also be varied to suit the fineness of the product required (“Rotor”, p. 2 and “Pin Mill with Round Pins”, p. 5)
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to dry-mill the electrodes in the method of modified Li by using a pin mill with a ring shaped screen, as taught by Yamaguchi and Premium Pulverizers. One of ordinary skill in the art would have been motivated to do so because Yamaguchi teaches that pin mills with screens can be used to accomplish the same task of separating positive electrode material from an aluminum collector while crushing to a desired size, and because Premium Pulverizers teaches that the screens on a pin mill can be ring shaped.
Regarding rolling the current collector into a round shape that remains within the ring shaped screen, it is noted that both Li ([0011]) and Yamaguchi ([0002]) teach applying their methods to lithium ion battery positive electrode materials with aluminum current collectors, just like those of the instant invention. Yamaguchi further teaches using a pin mill with a ring screen where the size of the screen is optimized to achieve sufficient peeling of the current collector from the active material while also allowing for high separation efficiency of the active material ([0034]). It is therefore reasonable to conclude that when treating the electrodes of modified Li with a pin mill and optimizing screen size, as taught by Yamaguchi, that the aluminum of the current collector would behave substantially similar to the aluminum produced by the instant method, i.e. that the aluminum current collector will end up rolled into a round shape and remaining within the ring shaped screen of the pin mill.
It is additionally noted that the instant specification provides no specific milling parameters that are required or which could be used to produce the current collector rolled into a round shape that remains within the ring shaped screen. Instead it is suggested that this result is obtained by varying screen size, number of pins, and pin type (p. 13-14), which one of ordinary skill in the art would have been motivated to optimize by routine experimentation based upon the teachings of Yamaguchi and Premium Pulverizers. One of ordinary skill in the art would have been motivated to do so in order to achieve the desired level of separation of the current collector from the active material while achieving good separation efficiency, as taught by Yamaguchi.
Therefore, the limitation requiring that the current collector be separated during step (a-1) by being rolled into a round shape and remaining within in the ring shaped screen is considered an obvious variation and/or routine optimization of modified Li in view of the teachings of Yamaguchi and Premium Pulverizers.
Regarding claim 5, modified Li teaches the invention of claim 1, where Li also teaches the thermal treatment in the step (a-2) being performed at 600 °C (paragraph 30), which falls in the claimed range of 300 °C to 1000 °C.
Regarding claim 6, modified Li teaches the invention of claim 1, where Cao provided the teaching to use 2.0 M lithium hydroxide in the washing step; Cao also teaches performing this washing step after the step (a-2) and before step (c) and for 30 min (take 500 mL of 2.0 mol/L LiOH solution, wash the screened cathode material with this solution for 30 minutes; paragraph 49), which meets the limitation of up to 1 hour. A solution of LiOH that is 2.0 M LiOH will contain lithium LiOH at 5wt%, which falls in the claimed range of more than 0wt% and 15wt% or less based on 100% of the lithium compound solution, and therefore Cao teaches all the further limitations of claim 6.
Regarding claim 7, modified Li teaches the washing step (b) being performed by stirring the active material collected from the step (a-2) at the same time with immersing in the LiOH aqueous solution (put into a 500 mL beaker, add [2.0 mol/L LiOH, as taught by Cao]…keep stirring with a magnetic stirrer; paragraph 30).
Regarding claim 8, modified Li teaches the method of claim 1, where Li teaches the lithium precursor being Li2CO3 (lithium carbonate, paragraph 32).
Regarding claim 9, modified Li teaches the method of claim 1, where Li teaches the lithium precursor (lithium carbonate) is added in an amount that corresponds to an amount of lost lithium while maintaining a ratio between lithium and other metal (cobalt) in a raw active material used in the active material layer (by detecting the lithium and cobalt content in the waste lithium cobalt oxide after impurity removal, add an appropriate amount of lithium carbonate to make the Li:Co ratio 1.05 to 1.1 times the theoretical value; paragraph 16).
Regarding claims 10 and 11, modified Li teaches the method of claim 1, as analyzed above. Li further discloses performing the process described on 100 g of a positive electrode sheet (paragraph 28), 78-80% of which is the active material of lithium cobalt oxide (paragraph 11 of English translation, and page 3 table of original patent, English machine translation of table attached with the Office action mailed 19 May 2025). This 80 g of LiCoO2 contains 0.82 mol of lithium. The amount of lithium precursor added is 0.7 g of lithium carbonate (paragraph 32), which contains 0.0095 mol of lithium. The ratio of lithium added relative the amount of lithium in the active material before dry-milling step (a-1) is therefore 0.0095/0.82, or 0.011, and meets the limitations of claims 10 and 11 (see Claim Interpretation).
Regarding claim 13, modified Li teaches the method of claim 1, where Li teaches performing the annealing at a temperature (750 °C, paragraph 32) that exceeds the melting point of the lithium precursor (lithium carbonate, m.p. 723 °C, instant specification p. 20, line 21).
Regarding claim 14, modified Li teaches the method of claim 1, where Nho teaches the surface coating step includes coating the metal component including B on the surface of the active material annealed from step (c) by a liquid phase process and then thermally treating at 150 °C-300 °C (comprise a second heat treatment after removing the solvent…the second heat treatment may be performed in a temperature range of 150 °C to 300 °C; [0133]-[0134]), which lines in the instantly claimed range of 100 °C to 1200 °C.
Regarding claim 16, modified Li teaches the invention of claim 1 wherein the lithium precursor is added in amount corresponding to an amount of lithium depleted during the steps (a-1) to (b) (by detecting the lithium and cobalt content in the waste lithium cobalt oxide after impurity removal, add an appropriate amount of lithium carbonate to make the Li:Co ratio 1.05 to 1.1 times the theoretical value; paragraph 16).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 101383442 A) in view of Cao et al. (CN 105895854 A), Nho et al. (US 2018/0261832 A1), Yamaguchi et al. (JP 2014199776A) and Premium Pulverizes (“Pin Mill”, retrieved from the Internet: < URL: https://www.premiumpulverisers.com/pin_mill.html>, archived 7 August 2020), as applied to claim 1 above, and further in view of Ellis and Montenegro (US PG Pub 2013/0256198 A1, hereinafter “Ellis”). The English machine translations of Li (CN101383442) and Cao (CN105895854) provided by Applicant are used for the analysis below.
Regarding claim 4, modified Li teaches the method of claim 1, including the milling of positive electrode scrap, but do not specifically teach the shredding or cutting of the positive electrode scrap before the dry-milling step.
However, Ellis teaches that electrode scrap can be treated using shredding and milling (comminution or scrap electrochemical cells…using a crushing, milling and/or shredding operation, paragraph 72), and that scrap treated in this way can then be separated effectively based on particle size (size classification and separation of comminuted electrochemical cell materials, paragraph 72), as was done by Li (after crushing, it was screened using an 80-mesh quasi-sieve, paragraph 28). Furthermore, Ellis also teaches positive electrodes being shredded before milling (each electrode sheet was shredded …the shredded electrodes were ground, paragraph 116; claim 4).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to combine the milling of Li with the additional shredding step taught be Ellis in order to prepare material that could be effectively separated. One of ordinary skill in the art would have been motivated to do so because they would be combining prior art elements according to known methods to achieve predictable results.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 101383442 A) in view of Cao et al. (CN 105895854 A), Nho et al. (US 2018/0261832 A1), Yamaguchi et al. (JP 2014199776A) and Premium Pulverizes (“Pin Mill”, retrieved from the Internet: < URL: https://www.premiumpulverisers.com/pin_mill.html>, archived 7 August 2020), as applied to claim 1 above, and further in view of Smith and Swoffer (US Pat. No. 8,882,007 B1; hereinafter “Smith”). The English machine translations of Li (CN101383442) and Cao (CN105895854) provided by Applicant are used for the analysis below.
Regarding claim 12, modified Li teaches the method of claim 1, including performing an annealing step at 750 °C on a mixture of a lithium precursor and recovered active material, but neither Li nor Cao explicitly teach the annealing step (c) being performed in air at a temperature in with a range of 400 °C to 1000°C, as required by claim 12.
However, Smith teaches regenerating cathode materials by adding a lithium precursor (lithium hydroxide) to correct a stoichiometric lithium deficiency and heating to 700-815°C in air to obtain the desired material (column 2, lines 39-45). The temperatures used by Smith fall within the instantly claimed range of 400 °C to 1000 °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 perform the annealing step in air at 700 to 815 °C, which falls within the range of 400 °C to 1000°C, as required by claim 12. One of ordinary skill in the art would have been motivated to do so because air is the most convenient atmosphere to use, requiring no special gas introduction, and because the oxygen in air is required (atmospheric air can also be used to supply the oxygen to the furnace; Smith, column 5, lines 5-8).
Conclusion
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 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
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