DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
2. Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application No. JP 2023-067217, filed on 04/17/2023.
Specification
3. The disclosure is objected to because of the following informalities:
Page 3, paragraph 17 of the instant specification refers to a “silicone clathrate” material. The examiner notes this is a different material than silicon clathrate, and believes this is a typo of “silicon clathrate”. This also occurs in paragraphs 49 and 52.
Page 3, paragraph 17 of the instant specification capitalizes “method” in the middle of a sentence
Page 6, paragraph 36 of the instant specification refers to “polyvinylidene fluoride (PVdF) …” while page 9 paragraph 54 abbreviates this to be “PDVF”. The examiner recommends the abbreviations are adjusted to be consistent throughout the instant specification.
4. Appropriate correction is required.
Claim Rejections - 35 USC § 103
5. 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.
6. 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.
7. 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.
8. 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.
9. Claims 1 and 3-6 are rejected under 35 U.S.C. 103 as being unpatentable over Krishna et al. (US 20150376016 A1; Henceforth, Krishna) in view of Harata et al. (US 20210066713 A1; Henceforth, Harata).
10. Regarding claim 1, the instant claim is drawn to a method for manufacturing a silicon clathrate active material, comprising the following steps: oxidizing a surface of a sodium-containing silicon clathrate at least partially, and washing the oxidized sodium-containing silicon clathrate with an acid.
11. Krishna teaches a method to produce a type II silicon clathrate (Abstract). The method include steps of heating sodium hydride with silicon powder, followed by milling and mixing steps ([0034]). The powder is then annealed ([0034]; [0036]). Type II silicon clathrate can then be isolated by the thermal decomposition of the annealed powder ([0037]), followed by the addition of sodium using a low sodium vapor pressure ([0038]). Krishna teaches a further washing/etching step can be done to remove sodium and type I silicon clathrates by first rinsing the type II silicon clathrate with an alcohol, in order to remove excess sodium ([0040], [0051]), followed by etching the type II silicon clathrate with an acid ([0040]). A combination of hydrofluoric acid (HF) and nitric acid (HNO3) can be used ([0040]). Krishna teaches the acid wash is believed to work in a commensurate way to how it interacts with diamond phase silicon, where HF is known to etch the oxide layer formed, and the nitric acid dissolved the oxidized components ([0064]), based on the interactions observed in paragraph [0063]. The examiner notes this implies there is an oxide on the surface of the silicon clathrate structure before the acid wash, meaning the surface is at least partially oxidized, but this is not explicitly taught.
12. Harata teaches a production method for producing silicon clathrate II (Abstract). Harata teaches the silicon clathrate II has a pore with a diameter of less than 100 nm and a volume greater than 0.025 cm3/g (Abstract). Harata teaches the introduction of a sodium “getter agent” to help reduce the sodium trapped within an allow of sodium and silicon clathrate II ([0027]). After this reaction, a cleaning step of adding water is performed to remove sodium, sodium hydroxide, and the like ([0048]). Harata teaches this oxidizes the surface of the sodium clathrate, introducing oxygen into the material, which Harata teaches is expected to enhance the stability and the performance of a resulting negative electrode active material ([0049]).
13. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Krishna by substituting the alcohol washing step with the water washing step of Harata in the same field of endeavor. Harata demonstrates precedent in the art to use water to wash away excess sodium from the formation of the sodium silicon clathrate II structures. A person of ordinary skill in the art would have had the reasonable expectation that the substitution of the washing step of Krishna with that of Harata, would have yielded predictable results, as Harata teaches the step has the same function as the alcohol washing step of Krishna. See MPEP 2143 (I) B.
14. Regarding claim 3, the instant claim is drawn to method according to claim 1, wherein the sodium-containing silicon clathrate has at least partially a clathrate II type structure.
15. Krishna and Harata teach the method of claim 1. Both Krishna and Harata teach the sodium-containing silicon clathrate structure is at least partially a clathrate type II structure (Krishna: [0037]-[0040] and [0044]-[0046]; Harata: Abstract).
16. Regarding claim 4, the instant claim is drawn to method according to claim 1, wherein the sodium-containing silicon clathrate has a porous structure.
17. Krishna and Harata teach the method of claim 1. Harata teaches the silicon clathrate II has a pore with a diameter of less than 100 nm and a volume greater than 0.025 cm3/g (Abstract). Harata teaches having a pore of this diameter does not deform upon pressing the electrode while also minimizing the expansive force produced by the silicon clathrate material on the negative electrode ([0023]). The latter point advantageously inhibits the negative electrode active material from being degraded during charging and discharging ([0012]).
18. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Krishna by substituting the alcohol washing step with the water washing step of Harata in the same field of endeavor, wherein the sodium-containing silicon clathrate also has a porous structure. There would have been a motivation, as taught by Harata, to utilize a sodium-containing silicon clathrate structure with pores with a diameter less than 100 nm and a volume of more than 0.025 cm3/g, since the material would not deform upon pressing the electrode, minimize the expansion of the active material in the electrode, and minimize the degradation during charging and discharging due to changes in volume ([0012] and [0023]).
19. Regarding claim 5, the instant claim is drawn to method according to claim 1, wherein the silicon clathrate active material is used as a negative electrode active material of a lithium ion battery.
20. Krishna and Harata teach the method of claim 1. Krishna teaches sodium clathrates are being actively investigated by others in the field for use as anode materials in lithium ion batteries due to their high charge storage capacity ([0004]), but does not explicitly teach their silicon clathrate material is used in the negative electrode of a lithium ion battery. Harata teaches the silicon clathrate II active material is suitable for a negative electrode for a lithium ion battery (Abstract). Harata teaches an example (Example 1, [0124]-[0135]) where the silicon clathrate II active material is incorporated into a negative electrode ([0127]-[0129]) and was made into a lithium ion battery ([0135]).
21.2. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Krishna by substituting the alcohol washing step with the water washing step of Harata in the same field of endeavor, wherein silicon clathrate active material is used as a negative electrode active material of a lithium ion battery. There would have been a motivation, as taught by Krishna, to utilize sodium clathrates in anode materials for lithium ion batteries, due to their high charge storage capacity ([0004]). A person of ordinary skill in the art would have had the reasonable expectation that utilizing the silicon clathrate material made through the modifications outlined in claim 1, above, would have predictably been usable as a negative electrode active material in a lithium ion battery, as the class of materials have a high charge storage capacity, and the modification made to the method of Krishna, as outlined above, would not alter the functionality of the material, since the acid etching step would remove the oxide formed from washing with water ([0064]).
22. Regarding claim 6, the instant claim is drawn to method for manufacturing a lithium ion battery, comprising manufacturing a silicon clathrate active material by the method according to claim 1, and forming a negative electrode active material layer using the silicon clathrate active material.
23. Krishna and Harata teach the method of claim 1. Krishna teaches sodium clathrates are being actively investigated by others in the field for use as anode materials in lithium ion batteries due to their high charge storage capacity ([0004]), but does not explicitly teach their silicon clathrate material is used in the negative electrode of a lithium ion battery. Harata teaches the silicon clathrate II active material is suitable for a negative electrode for a lithium ion battery (Abstract). Harata teaches an example (Example 1, [0124]-[0135]) where silicon clathrate II is made ([0124], in view of [0094]) incorporated into a negative electrode as an active material ([0125]-[0129]) and was made into a lithium ion battery ([0135]).
24. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Krishna by substituting the alcohol washing step with the water washing step of Harata in the same field of endeavor, wherein silicon clathrate active material is used as a negative electrode active material of a lithium ion battery. There would have been a motivation, as taught by Krishna, to utilize sodium clathrates in anode materials for lithium ion batteries, due to their high charge storage capacity ([0004]). A person of ordinary skill in the art would have had the reasonable expectation that utilizing the silicon clathrate material made through the modifications outlined in claim 1, above, would have predictably been usable as a negative electrode active material in a lithium ion battery, as the class of materials have a high charge storage capacity, and the modification made to the method of Krishna, as outlined above, would not alter the functionality of the material, since the acid etching step would remove the oxide formed from washing with water ([0064]).
25. Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Krishna and Harata in view of Asano et al. (“Surface Oxidation of Na doped Type II Si Clathrate Films”, Proceedings of the 78th Japan Society of Applied Physics Autum Meeting, Japan, The Japan Society of Applied Physics, September 5th, 2017, p. 12-378; Henceforth, Asano) as evidenced by Eguchi (JP 2005089369 A).
26. Regarding claim 2, the instant claim is drawn to the method according to claim 1, wherein the surface of the sodium-containing silicon clathrate is at least partially oxidized by exposing a sodium-containing silicon clathrate to an ambient atmosphere.
27. Krishna and Harata teach the method of claim 1. Neither teaches that the surface of the sodium-containing silicon clathrate is at least partially oxidized by exposing a sodium-containing silicon clathrate to an ambient atmosphere.
28. Asano explores the formation of an oxide layer of Na-encapsulating type II Si clathrates (paragraph 1, split translation). The clathrate material is formed by the heat treatment of sodium and a silicon substrate in argon, treated with iodine to reduce sodium content, then treated with HF to remove a surface oxide layer (paragraph 2, split translation). After 240 hours, Asano reports a change in the Si-O bond peak intensity by FT-IR, caused by the natural oxidation of the clathrate material in ambient air (paragraphs 2-3, split translation). This is further evidenced by Eguchi (JP 2005089369 A), who teaches silicon clathrates (Claim 7) can be heated in dry air or air to oxidize ([0025]) which is useful for making silicon clathrate x-ray contrast agents ([0025]-[0026], Claim 1).
29. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Krishna by adding in an air oxidation step, as taught by Asano in the same field of endeavor. Asano teaches that ambient air is known to oxidize silicon clathrate type II materials, even after HF treatment. Since Krishna teaches the heating, milling, and mixing steps are performed under an inert atmosphere to minimized the reaction of Si and NaH with air ([0035]), a person of ordinary skill in the art would have had the reasonable expectation that, during the subsequent steps, the silicon clathrate material can be exposed to air and can predictably partially oxidize, as taught by Asano and Eguchi. There would have been a motivation to perform the oxidation step second, as taught by Harata, since the incorporation of oxygen into the silicon clathrate structure is expected to enhance the stability and the performance of a resulting negative electrode active material ([0049]). Since the instant claim does not explicitly specify the exact order of the steps, a person of ordinary skill would have had the reasonable expectation that performing an air oxidation step, as taught by either Asano or Egnuchi, would have predictably resulted in a better performing anode active material, as taught by Harata.
Conclusion
30. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Harata et al. (US 20210066714 A1; Henceforth, Murase) and Otaki et al. (US 20210305556 A1; Henceforth, Otaki).
31. Murase teaches a negative electrode active material containing silicon clathrate II, which is a suitable electrode for a lithium secondary battery (Abstract). The examiner notes this application teaches an identical water cleaning step as Harata ([0046]-[0047]), and also the identical use of the getter agent ([0016]).
32. Otaki teaches an active material comprising a silicon clathrate II type crystal phase, including a void inside the primary particle (Abstract), an anode layer composed of the material, a battery, and methods for their production ([0001]). The silicon clathrate type II material has a void inside of it, with a diameter less than 100 nm and the void amount is between 0.05 cc/g and 0.15 cc/g (Abstract). Otaki teaches a method of making a battery (Claim 11), a method of making an anode layer using the silicon clathrate material (Claim 10) and the method of making the sodium clathrate active material (Claim 7), in addition to the battery (Claim 6), anode layer (Claim 5), and the silicon clathrate material itself (Claims 1-4). The battery can be a secondary battery, including a lithium ion battery, or a primary battery [0070]).
33. Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN P MURPHY whose telephone number is (571)272-9321. The examiner can normally be reached Monday - Friday 8:00 am - 5:30 pm.
34. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
35. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nicholas A Smith can be reached at (571) 272-8760. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/RPM/Examiner, Art Unit 1752
/NICHOLAS A SMITH/Supervisory Primary Examiner, Art Unit 1752
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