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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 2/26/2026 has been entered.
Response to Amendment
The amendment filed 2/26/2026 is entered and fully considered.
Response to Arguments
Applicant points out that the claimed invention utilizes a heat treatment to thermally decompose binder/conductive material the separated positive electrode plate and separate the electrode active material from the current collector. In contrast, applicant argues that the LI reference only performs a crushing and sieving to separate the active material and current collector. However, the examiner maintains that the LI reference does both pulverizing [0013] and heat treatment to remove binder and conductive agent [0014]. The pulverizing step is not claimed by applicant. However, the specification does refer to a “breaking into pieces” before heat treatment which can be a pulverization, specification page 14 lines 12-18. Accordingly, the LI reference is particularly relevant to applicant’s disclosed process of breaking into pieces and heat treating, even though the claims do not specifically require the pulverizing step and only require the heat treatment step for separation.
Applicant further argues the prior art does not teach dipping the stack cell in acetone for the disassembly step to produce the cathode plate, anode plate and separator. Applicant argues that the acetone causes ceramic particles to detach and be left in solution during the separation of the constituent parts. However, the examiner notes that the specification does not note that acetone is required for the separation of parts. The specification states that the same solvent used for the manufacture of the separator can be used page 13 line 22 but it is preferably acetone page 14 line 1. The examiner maintains that the prior art teaches submerging the stack in a solvent for disassembly and that solvent can be acetone.
Applicant also argues that SUZUKI teaches using a PVDF current collector. The examiner notes that SUZUKI does have a separate embodiment in which a resin and conductive filler are used as a current collector which is removed as shown in fig. 3. However, the examiner relied on the embodiment where the current collector and separator are connected using a sealing material which is swelled and released by dipping Fig. 4. In this instance the current collector can be metal (aluminum) or a resin [0271]. This embodiment is also used because the LI reference pulverizes both the electrode active material and current collector together.
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.
Claim(s) 1, 5-14 and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over LI et al. (CN101383442; citations to machine translation) in view of SUZUKI et la. (US 2022/0328894), BOTTINO et al. “Solubility Parameters of Poly(vinylidene fluoride)” (1988), and CAO et al. (CN105895854l citation to machine translation).
Regarding claim 1,
LI teaches a method of recovering cathode active material waste by crushing the electrode sheets (active material and collector) and decomposing the material with thermal treatment [0010]-[0014]. The current collector material is sieved (separated) from the active material [0013]. The heat treatment removes binder and conductive material [0014]. The recovered active material still has aluminum (current collector) present after separation and requires a reaction (washing) step in which sodium hydroxide and water (aqueous) washes and dries the material [0015]. Lithiation of the recovered active material is then done by adding lithium precursor and sintering (annealing) [0016].
The reference is silent to the initial dismantling of the battery to obtain the electrode sheets of active material and current collector. However, SUZUKI teaches submerging a battery in a solvent to isolate a first active material layer [0281] and fig. 7. The reference teaches the sealing material can be PVDF and using a swelling solvent [0281]-[0282]. The reference does not described that solvent used to swell the sealing material as acetone. However, when dismantling a cell that uses a sealing material such as PVDF, such as shown in SUZUKI, one of ordinary skill would select a solvent that swells PVDF. An additional reference BOTTINO is provided to show that acetone provides good swelling (GS) for PVDF, Table 1. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to consult additional literature for determining solvents with good swelling for PVDF and use that in the separation process.
At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to use known techniques of disassembling batteries in order to recycle the cathode materials.
The reference also performs a washing step with sodium hydroxide (alkaline) instead of an aqueous lithium compound solution. However, CAO teaches a washing step for recovered cathode active material that removes carbon residue [0017] and uses lithium hydroxide or sodium hydroxide [0022]. At the time of filing the invention it would have been prima facie obvious to include a lithium hydroxide step as a simple substitution of known equivalent alkaline solutions for washing recycled cathode material previously subjected to thermal decomposition of organics.
Regarding claim 5,
LI teaches the thermal treatment is done at 600°C [0014]. The reference is silent to the atmosphere used and is therefore resumed to be atmospheric air.
Regarding claim 6,
CAO provides an example of using 2.0M LiOH [0049] which is the equivalent to 5 mass% and falls within the claimed range.
Regarding claim 7,
LI and CAO both teach the washing step as a batch process with a stirrer. The washing of the same material with the same solutions is going to result in the same impregnation.
Regarding claim 8,
LI teaches the lithiation of the recovered material with lithium carbonate [0016].
Regarding claim 9,
LI teaches detecting the lithium content before lithiation and adding an appropriate amount to result in a lithium to cobalt ratio of 1.05 to 1.1 [0016]. The amount of lithium therefore depends on the cobalt and lithium remaining after the recycle process (amount of material lost).
Regarding claims 10-11,
LI teaches detecting the lithium content before lithiation and adding an appropriate amount to result in a lithium to cobalt ratio of 1.05 to 1.1 [0016]. The target cathode active material is therefore Li1.05-1.1CoO2. When adding lithium precursor to reach that chemical formula the reference is implicitly teaching adding a ratio of 0-1.1 Li precursor to cobalt. If the recycle process produces a cathode material with the desired lithiation no additional Li precursor is added. Alternatively, if the LCO is completely delithiated, up to a ratio of 1.1 Li precursor would need to be added to hit the target. Accordingly, the teaching of adding an appropriate amount of lithium precursor to reach the desired formula implicitly teaches adding a ratio of 0-1.1 Li per amount of cobalt.
Regarding claim 12,
LI teaches the annealing is at 750°C [0016]. The reference is silent to the atmosphere used and is therefore resumed to be atmospheric air.
Regarding claim 13,
LI uses a lithium precursor of lithium carbonate which has a melting point of about 723°C. Annealing at 750°C is higher than the melting point.
Regarding claim 14,
LI teaches the same thermal decomposition of binders and conductive material at the same temperature. Therefore the recovered product is presumed to be the same (without carbon on the surface). In addition, the recovered product may be referring to product after washing. The washing step in CAO specifically removes any carbon residue remaining (on the surface or otherwise).
Regarding claim 17,
The references do not teach the amount of F remaining in the cathode active material. However, the same material is thermally decomposed at the same temperature and washed with the same solution. The resulting concentration of F is expected to be the same.
Claim(s) 3, 4, 15 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over LI et al. (CN101383442; citations to machine translation) in view of SUZUKI et la. (US 2022/0328894), BOTTINO et al. “Solubility Parameters of Poly(vinylidene fluoride)” (1988), and CAO et al. (CN105895854l;citation to machine translation) further in view of ZHOU et al. “Enhancing the performances of Li-ion batteries by carbon-coating: present and future” (2011).
Regarding claims 3, 4, 15 and 19,
The LI reference teaches recovery of cathode active material but does not teach coating the active material with a surface coating. However, protective/passivating coatings of cathode active material is well known in the art. ZHOU for example teaches protecting the electrode from electrolyte contact abstract although preventing swelling/shrinking of the cathode material is also a commonly noted benefit. The ZHOU reference specifically notes that carbon shells can be made by coating the particles with a precursor and heat treating at 700° page 5. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to deposit a protective shell over the cathode active material in LI to improve cathode and battery performance.
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over LI et al. (CN101383442; citations to machine translation) in view of SUZUKI et la. (US 2022/0328894), BOTTINO et al. “Solubility Parameters of Poly(vinylidene fluoride)” (1988), and CAO et al. (CN105895854; citation to machine translation) further in view of ZHU (US 2018/0047975).
Regarding claim 16,
CAO teaches that the recycling process can be used for lithium cobalt oxide or lithium cobalt manganese oxide (NCM) [0049] and [0053]. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to use NCM instead of LCO as a simple substitution of cathode active materials that can be recycled by crushing, separating and thermally decomposing. The reference does not expressly teach the content of Ni. However, in NCM cathodes one of ordinary skill would recognize what each component does and tailor the cell performance/cost accordingly. See ZHU (US 2018/0047975) [0003]. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to make and recycle cathode active material of various compositions to obtain desired performance profile.
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over LI et al. (CN101383442; citations to machine translation) in view of SUZUKI et la. (US 2022/0328894), BOTTINO et al. “Solubility Parameters of Poly(vinylidene fluoride)” (1988), and CAO et al. (CN105895854; citation to machine translation) further in view of LIM et al. (US 2018/0323435).
Regarding claim 18,
LI teaches adding a lithium precursor and annealing but does not teach using a spray dryer. However, LIM teaches that when lithiating a cathode active material with lithium precursor the coating and heat treatment can be done by spray dryer abstract. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to provide lithium precursor to cathode active material by spray dryer as a simple substitution of known coating techniques used to apply lithium to cathode active material powder substrates.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AUSTIN MURATA whose telephone number is (571)270-5596. The examiner can normally be reached M-F 8:30-5.
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/AUSTIN MURATA/Primary Examiner, Art Unit 1712