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 .
Summary
The Applicant’s arguments and claim amendments received June 4, 2026 have been entered into the file. Currently, claim 1 is amended; and claims 2 and 12-16 are cancelled; resulting in claims 1 and 3-11 pending for examination.
Claim Rejections - 35 USC § 103
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.
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, 3-7, and 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Minami, et al. (US 2017/0309950 A1) in view of Hirose, et al. (US 11,005,095 B2).
Regarding claim 1, Minami teaches a negative electrode for a secondary battery including negative electrode active material particles (lithium silicate composite oxide particles) including a lithium silicate, silicon particles, and a metallic compound (¶ [0008], Ln. 1-7). Minami teaches that the lithium silicate phase is preferably composed mainly of Li2SiO3 or Li2Si2O5 in terms of stability, manufacturability, and lithium ion conductivity (¶ [0031], Ln. 6-9), specifically teaching negative electrode active material particles including Li2SiO3, Si, and ZrO2 in Example 1 (¶ [0056], Ln. 1-6).
Minami further teaches that the negative electrode active material particles of Example 1 are passed through a 4.0 µm mesh sieve prior to coating with carbon, and the average particle size is adjusted to 5 µm with a sieve after coating with carbon (¶ [0056], Ln. 11-18). Thus, the negative electrode active material particles of Example 1 do not include particles having a diameter of less than 3 µm, meeting the limitation of having a content of particles having a diameter of less than 3 µm of 5 vol% or less. Minami does not expressly teach an embodiment in which both Li2SiO3 and Li2Si2O5 are included in the negative electrode active material particles, such that the phase fraction ratio I(225)/I(213) is 0.05-0.8.
Hirose teaches a negative electrode active material including a negative electrode active material particle including a silicon compound particle (Col. 7, Ln. 29-31). The silicon compound particle includes crystalline Li2Si2O5 as the main Li silicate, and Li2SiO3 and Li4SiO4 are also present in the bulk of the silicon compound particle (Col. 10, Ln. 19-24). Hirose teaches that Li2Si2O5 has a higher water resistance than both Li2SiO3 and Li4SiO4, and the presence of Li2Si2O5 improves the water resistance and thus increases the slurry stability (Col. 7, Ln. 53-62).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the lithium silicate phase of Minami to include both Li2SiO3 and Li2Si2O5-, based on the teachings of Hirose. One of ordinary skill in the art would be motivated to include Li2Si2O5- in addition to Li2SiO3 in the negative electrode active material particles of Example 1 in order to improve the water resistance and therefore increase the stability of the slurry. It would be obvious to one of ordinary skill in the art to include Li2Si2O5- with reasonable expectation of success, as Li2Si2O5- is already taught as a by Minami to include in the lithium silicate phase. One of ordinary skill in the art would find it obvious to include small amounts of Li2Si2O5 in the negative electrode active material particle of Minami-, such that the lithium silicate phase is still composed mainly of Li2SiO3. In including Li2Si2O5 in an amount such that the lithium silicate phase is still composed mainly of Li2SiO3, it would be obvious to one of ordinary skill in the art to include an amount such that the resulting phase fraction ratio I(225)/I(213) is within the claimed range of 0.05-0.8.
Regarding claims 3-4, Minami in view of Hirose teaches all of the limitations of claim 1 above and Minami further teaches that Si is included in the base particles in an amount ranging from 35-75% by mass, teaching that this range results in higher capacity and improved cycle characteristics (¶ [0034], Ln. 9-13). Minami teaches that a metallic compound is included in the particles in an amount ranging from 0.01-10% by mass, teaching that this range results in improved cycle life without affecting the specific capacity (¶ [0038], Ln. 8-15). In Examples 1-5, the negative electrode active material includes Si, Li2SiO3, and ZrO2 mixed at varying mass ratios, resulting in a content of a lithium element contained in the negative electrode active material particles of approximately 8-9% by weight, within the claimed range of 2-10 wt% and 4-9 wt% (¶ [0056], [0063]-[0066]). As Minami teaches examples including approximately 8-9% lithium element by weight, one would find it obvious that the modified negative electrode active material particles of Minami in view of Hirose would include approximately 8-9% lithium metal by weight. One of ordinary skill in the art would be motivated to include the combined lithium silicates at a content resulting in this lithium range, such that the Si and metallic compound contents provide higher capacity, improved cycle characteristics, and improved cycle life without affecting the specific capacity.
Regarding claim 5, Minami in view of Hirose teaches all of the limitations of claim 1 above and Minami further teaches that the negative electrode active material particles preferably have an average particle size of 4-10 µm (¶ [0040], Ln. 1-4), teaching that the average particle size of the negative electrode active material particles is adjusted to be 5 µm using a sieve in Example 1 (¶ [0056], Ln. 18-19). Minami teaches that the average particle size is the particle size at which the integrated volume is 50% in the particle size distribution (D50) (¶ [0040], Ln. 1-10).
Regarding claims 6-7, Minami in view of Hirose teaches all of the limitations of claim 1 above and Minami further teaches that the negative electrode active material particle includes an electrically conductive layer on its surface (¶ [0045], Ln. 1-3). Minami teaches that the electrically conductive agent of the electrically conductive layer is preferably carbon, specifically carbon black, acetylene black, ketjen black, or graphite (¶ [0045], Ln. 10-20). In Example 1, the negative electrode active material particles are mixed with coal pitch and heated to form a carbon covering (amorphous carbon including soft carbon) (¶ [0056], Ln. 11-17).
Regarding claim 9, Minami in view of Hirose teaches all of the limitations of claim 1 above and Minami further teaches that the negative electrode may include another active material in addition to the negative electrode active material particles, teaching that the other active material is preferably a carbonaceous negative electrode active material such as graphite (¶ [0029], Ln. 9-16). Bulk graphite is included in the negative electrode of Example 1 (graphite-based particles including at least one of natural and artificial graphite) (¶ [0059], Ln. 1-4).
Regarding claim 10, Minami in view of Hirose teaches all of the limitations of claim 9 above and Minami further teaches that the carbonaceous negative electrode active material content ranges from 70-95% by mass (¶ [0030], Ln. 6-9), indicating 5-30% by mass negative electrode active material including a lithium silicate phase. Minami teaches negative electrode active material particles (lithium silicate composite oxide particles), bulk graphite powder, CMC, and SBR, are included in the negative electrode in a mass ratio of 30:70:1:1 in the negative electrode of Example 1, resulting in a content of negative electrode active material particles of 30 wt% based on the total weight of the negative electrode active material particles and bulk graphite powder, within the claimed range of 5-40 wt% (¶ [0059], Ln. 1-4).
Regarding claim 11, Minami in view of Hirose teaches a negative electrode meeting the limitations of claim 1 above, and Minami further teaches a non-aqueous electrolyte secondary battery including the negative electrode, a positive electrode, and a separator disposed between the positive electrode and negative electrode (anode facing the cathode) (¶ [0018], Ln. 1-6). Minami further teaches that the positive electrode is a layered lithium composite oxide (lithium secondary battery) (¶ [0020], Ln. 1-2).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Minami, et al. (US 2017/0309950 A1) in view of Hirose, et al. (US 11,005,095 B2) as applied to claim 6 above, and further in view of Tsukigata, et al. (US 2024/0274803 A1).
Regarding claim 8, Minami in view of Hirose teaches all of the limitations of claim 6 above and Minami further teaches that the electrically conductive layer preferably has a thickness in the range of 1-200 nm, forming a layer thick enough to impart electrical conductivity and cover the base particle, and thin enough to allow diffusion of lithium ions into the base particle (¶ [0047], Ln. 1-11). Minami does not expressly teach that the content of the amorphous carbon is in a range of 1-25 wt% based on a total weight of the negative electrode active material particle.
Tsukigata teaches a negative electrode active material including silicon monoxide particles covered with carbon coating and doped with lithium (¶ [0064], Ln. 1-4), further teaching that the lithium doping is performed such that the lithium is present as Li2SiO3 (¶ [0082], Ln. 12-13). Tsukigata teaches that the carbon coating is preferably 1.0-5.0 mass% relative to an entirety of the coated particle (¶ [0081], Ln. 1-3). Tsukigata teaches that this range ensures sufficient conductivity without being excessive, such that charge and discharge capacities are achieved (¶ [0081], Ln. 6-12).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the electrically conductive layer of Minami in view of Hirose to be included in a content within 1.0-5.0 mass% based on the teachings of Tsukigata. One of ordinary skill in the art would be motivated to include the carbon coating within this range in order to ensure sufficient conductivity without compromising charge and discharge capacities.
Response to Arguments
Response-Claim Rejections – 35 U.S.C. 102 and 103
In light of the Applicant’s amendment to claim 1 to incorporate limitations of dependent claim 2, the previous rejections of claims 1, 3-7, and 9-11 under 35 U.S.C. 102(a)(1) and 102(a)(2) over Minami, et al. (US 2017/0309950 A1) have been overcome. However, upon further consideration, the reference is applicable under 35 U.S.C. 103 and used in combination with Hirose, et al. (US 11,005,095 B2) in the rejections above. Any arguments with respect to the reference that are still deemed valid will be addressed herein.
Applicant's arguments filed June 4, 2026 have been fully considered but they are not persuasive. The Applicant argues that Minami does not teach the limitation that a content of particles having a diameter of less than 3 µm is 5 vol% or less, that one would not be motivated to include Li2Si2O5 in the negative electrode active material of Minami in a small amount based on the teachings of Hirose, and that the claimed phase fraction ratio results in better results.
With respect to the argument, see pages 1-2 of the remarks, that Minami does not teach the limitation that a content of particles having a diameter of less than 3 µm is 5 vol% or less, this argument is not persuasive. The Applicant argues that the disclosure in Minami that the active material base particles are passed through a 4.0 µm sieve prior to carbon coating and then adjusting the particle size to be 5 µm using a sieve includes a typographical error, and that the initial sieving should include a "40 µm" sieve. This argument is not persuasive. The U.S. Patent Application Publication published October 26, 2017 as well as the corresponding US Patent (US 10,177,403 B2) published January 8, 2019 disclose that a 4.0 µm sieve was used. Additionally, the reference teaches that the negative electrode active material particles preferably have an average particle size of 4-10 µm (¶ [0040], Ln. 1-4). The raw materials used in the example have a particle size of 10 µm, which are then ground prior to sieving (¶ [0056], Ln. 1-13). Thus, passing the ground particles through a 40 µm sieve would seemingly not have a separation effect on the material, and it would not be intuitive to one skilled in the art that the disclosure of 4.0 µm should clearly be 40 µm. The Applicant has not provided an argument or scientific reasoning as to why the ground particles would be passed through a 40 µm, rather than a 4.0 µm as disclosed.
The Applicant further argues that the sieving process is ambiguous, noting that Minami does not specify whether the powder passing through sieve or the powder remaining on the sieve is used in subsequent processing. This argument is not persuasive. As indicated above, Minami teaches that the negative electrode active material particles preferably have an average particle size of 4-10 µm (¶ [0040], Ln. 1-4). Additionally, the raw materials used have a particle size of 10 µm before being ground, heat-treated, and ground again (¶ [0056], Ln. 1-12). Thus, in passing the material through a 4.0 µm sieve, the material remaining on the sieve would be used in subsequent processing as the material passing through would be smaller than the preferred particle size.
With respect to the argument, see pages 2-3 of the remarks, that one would not be motivated to include Li2Si2O5 in the negative electrode active material of Minami in a small amount based on the teachings of Hirose, this argument is not persuasive. Minami teaches that the lithium silicate phase is preferably composed mainly of Li2SiO3 or Li2Si2O5 in terms of stability, manufacturability, and lithium ion conductivity (¶ [0031], Ln. 6-9), further teaching that the lithium silicate included as the main component is preferably included at a content of 80% or more by mass of the total lithium silicate phase (¶ [0031], Ln. 9-13). Additionally, Minami teaches several examples, with each example including Li2SiO3 as the main lithium silicate. Thus, given the teachings of the primary reference, one of ordinary skill in the art would be motivated to include a lithium silicate phase in the negative electrode active material that is primarily Li2SiO3-. The teachings of the secondary reference, Hirose, are used to teach the inclusion of Li2Si2O5 in the negative electrode active material. Hirose teaches that Li2Si2O5 has a higher water resistance than both Li2SiO3 and Li4SiO4, and the presence of Li2Si2O5 improves the water resistance and thus increases the slurry stability (Col. 7, Ln. 53-62). Therefore, one of ordinary skill in the art would find it obvious to include Li2Si2O5 in the negative electrode active material of Minami while maintaining Li2SiO3 as the main component, and would include Li2Si2O5 in a small amount. It would be obvious to one of ordinary skill in the art to include Li2Si2O5- with reasonable expectation of success, as Li2Si2O5- is already taught as a by Minami to include in the lithium silicate phase. One of ordinary skill in the art would be motivated to include Li2Si2O5- in addition to Li2SiO3 in the negative electrode active material particles of Minami in order to improve the water resistance and therefore increase the stability of the slurry.
With respect to the argument, see pages 3-4 of the remarks, that the claimed phase fraction ratio achieves better results, this argument is not persuasive. The Applicant argues that Examples 2-4 achieve a capacity retention of 90% or more, and initial discharge capacity of 1300 mAh/g or more, and an initial capacity efficiency of 86% or more. Firstly, it is noted that Example 4 includes a phase fraction ratio of 0.88, seemingly outside the claimed range of 0.05-0.8 provided traditional rounding is applied. However, in including 0.88, Examples 2-5 and 11 all include phase fraction ratios within the claimed range of 0.05-0.8, while Examples 1 and 9-10 include phase fraction ratios outside the claimed range. Examples 1 and 9 both achieve a capacity retention of 90% or more, and initial discharge capacity of 1300 mAh/g or more, and an initial capacity efficiency of 86% or more, thus it is not clear how the better results are attributed to the claimed phase fraction ratio. The evidence relied upon should establish "that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance" (MPEP 716.02(b)). Further, the data reflects testing completed on a lithium half-cell, including an anode which is prepared using the lithium-silicon oxide particles, binder, conductive material, and thickener coated on a copper current collector; a lithium metal counter electrode; a polyethylene separator; and an electrolyte prepared using LiPF6, EC/EMC solvent, and FEC additive. Claim 1 is drawn to an anode active material. Thus, the results are not commensurate in scope with the claims (MPEP 716.02(d)).
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 SARAH J JACOBSON whose telephone number is (703)756-1647. The examiner can normally be reached Monday - Friday 8:00am - 5:00pm.
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/SARAH J JACOBSON/Examiner, Art Unit 1785
/Rebecca L Grusby/Primary Examiner, Art Unit 1785
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