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 .
Response to Amendment
This is a final Office Action in response to Applicant’s remarks and amendments filed 05/06/2026. Claims 1, 9, 10, 12, and 18 are amended. Claim 3 is cancelled. Claims 1-2 and 4-19 are pending in the current Office Action.
The rejections set forth in the non-final Office Action mailed 02/06/2026 are maintained, with rejection of claim 1 rewritten to address the amendments.
The 112(b) rejection of claim 9 set forth in the Office Action mailed 02/06/2026 is withdrawn.
The 112(b) rejections of claims 10, 12, and 18 set forth in the Office Action mailed 02/06/2026 are maintained.
Response to Arguments
Applicant's arguments filed 05/06/2026 have been fully considered but they are not persuasive.
Applicant argues Mason fails to disclose “wherein the anode active material has a volume-based particle size distribution as a ratio D10/D50 ranging from 0.40 to 0.75 and a ratio Dmin/D50 ranging from 0.3 to 1” and Mason’s disclosure merely provides independent numerical values but does not disclose any relationships between these values. Examiner notes that while Mason’s disclosure does not disclose any relationships between these parameters, Mason discloses an encompassing range for D10/D50 ratio through an embodiment, as addressed in the bridging paragraph of pages 4-5 of the previous Office Action mailed 02/06/2026. As discussed on pg. 4, paragraph 4 of the previous Office Action, Mason further discloses why one of ordinary skill would have reasonably arrived at Mason’s disclosed D10 and D50 ranges, and thus the claimed D10/D50 and Dmin/D50 ratios, including reducing undesired agglomeration of particles and improving dispersibility. Therefore, while the disclosure of individual particle size parameters of D10 and D50 do not suggest the effects or relationships of the specific ratios, a skilled artisan would still reasonably arrive at the claimed ranges for the D10/D50 and Dmin/D50 ratios through routinely optimizing Dmin, D10, and D50. The Examiner further notes that recognizing the effects of a ratio previously disclosed in the prior art does not overcome the prior art. Thus, Applicant’s argument regarding the D10/D50 and Dmin/D50 ranges is not found persuasive.
Applicant further argues Mason fails to disclose the claim limitation “Dmin of the anode active material is 2 µm or more” and that Mason provides not evidence that Dmin would be controlled in a manner similar to D10. As addressed in the previous Office Action in the bridging paragraph of page 5-6, while Mason does not explicitly disclose Dmin, a skilled artisan would recognize that in possessing particle size distribution values D10, D50, D90, and D98 and a desire to control such parameters for the sake of reducing undesired agglomeration and improving dispersibility of composite particles (Mason, [0070]), Mason necessarily possesses a Dmin value and envisages control in a similar manner. Furthermore, as Mason’s D10 is preferably at least 2 µm, Mason is capable of allowing a Dmin of 2 µm.
Applicant further argues Mason lacks any mechanism or process capable of achieving the claim limitation of “Dmin of the anode active material is 2 µm or more”. The Examiner notes that the instant claim 1 is a product claim and a skilled artisan could select any technique to arrive at the claimed product, and thus this argument is not persuasive.
Furthermore, Applicant argues the claimed combination of “a ratio D10/D50 ranging from 0.4 to 0.75” and “a ratio Dmin/D50 ranging from 0.3 to 1” is a significant distinction as the claimed combination of the ratios yields unexpected technical advantages over the prior art.
The examiner notes Applicant’s working embodiments appear to achieve improved life-span, high-temperature storage, and power properties when D-10/D50 is controlled to be 0.47 to 0.73 (See Examples 4 and 5) and when Dmin/D50 is 0.3 to 0.47 (See Examples 1 and 4). However, the claimed ranges for D10/D50 of 0.4 to 0.75 and Dmin/D-50 of 0.3 to 1 are significantly broader than the working embodiments that Applicant claims exhibit improved life-span, high-temperature storage, and power properties. As such, it is unclear if the combination of D10/D50 and Dmin/D-50- is critical across the claimed broader ranges as the data provided is narrower than the claimed range. Thus, the claimed invention appears incommensurate with the scope of the invention argued to provide unexpected results.
Furthermore, Mason ([0067]-[0069]) suggests that controlling D50 leads to high-capacity retention over repeated charge-discharge cycles similar to Applicant’s claimed special technical effect of improved life-span properties and thus it seems that the improvements noted by the instant specification are expected by the prior art of record.
Furthermore, even if the data presents unexpected results, it is still unclear whether the claim is commensurate in scope with Applicant’s argument due to the presence of other facts that appear to also contribute to the advantageous results argued by Applicant to be achieved by the D10/D50 and or D-min/D50 ranges. That is, based on [0071] of the instant specification, the specific surface area of the anode active material also contribute to cycle properties. Similarly, based on [0083] of the instant specification, average pore diameter also has an impact on cycle properties. Neither specific surface area not average pore diameter are included in claim 1. Thus, Applicant’s argument regarding unexpected results is not found persuasive.
As such, in light of the discussion above, Applicant’s arguments are unpersuasive and the 35 U.S.C. 103 rejection made in view of Mason is maintained.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 10, 12, and 18 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 10, 12, and 18 recite the limitation “the composite active material particle” (line 2). It is noted that claims 1 and 15 include the limitation, “a plurality of composite active material particles” (lines 2 and 5, respectively). It is unclear which of the composite active material particles is being further limited, and whether applicant desired to further limit a composite active material particle that has a carbon coating or otherwise. For the purposes of this Office Action, claims 10, 12, and 18 have been interpreted as being directed to any of the composite active material particles.
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.
Claims 1-2, 4-11, and 15-18 are rejected under 35 U.S.C. 103 as being unpatentable over
Mason et al. (US 20220336790 A1).
Regarding claims 1-2, 4-5, and 15, Mason discloses an anode active material for a secondary battery ([0001];[0149]) comprising a first active material including silicon (i.e. silicon deposited in pores of porous conductive material, [0007]) and a second active material including carbon (i.e. conductive porous carbon particle framework, [0037]), and a carbon coating covering at least a portion of a surface of at least one of the plurality of composite active material particles ([0079]). Mason further discloses a lithium secondary battery comprising of an anode comprising of the anode active material described above, a cathode, and an electrolyte between the anode and the cathode ([0001];[0149]), reading on claim 15.
Mason discloses a D10, a particle diameter corresponding to a volume fraction of 10%, of at least 2 µm reduces undesired agglomeration of particles and further improves dispersibility of particles ([0070];[0074]). Mason further discloses a D50, a particle diameter corresponding to a volume fraction of 50%, of preferably 4 to 6 µm, which overlaps the scope of claim 5 such that
it would have been obvious for one having ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the overlapping portion of the ranges with reasonable expectation that such selection would successfully result in particles with good fluidization properties, improved dispersibility, structural robustness, and high capacity retention over repeated charge-discharge cycles ([0067-0069];[0074]). This yields a D10/D50 of at least 0.33 to 1 which encompasses claim 1’s range of 0.40 to 0.75 such that one of ordinary skill in the art, before the effective filing date of the claimed invention, would have routinely selected within the encompassed portion of the D10/D50 range with a reasonable expectation of achieving an anode active material with satisfactory dispersibility, fluidization properties, structural robustness, and high capacity retention (MPEP 2144.05 I).
It would have been further obvious to one of ordinary skill in the art, before the
effective filing date of the claimed invention, to arrive at the claimed range by routinely
optimizing the D10/D50 ratio for the benefits of not only a narrow particle size distribution, but
also improved dispersibility of composite particles, good fluidization properties, as well as
structural robustness and high capacity retention over repeated charge-discharge cycles (MPEP
2144.05 II).
Mason discloses desired D10, D50, D90, D98 values ([0067-0074]). While Mason does not explicitly disclose a Dmin, a skilled artisan would recognize Mason necessarily possesses a Dmin, a minimum particle diameter. A skilled artisan would further recognize that Mason would
necessarily envisage control of Dmin in a manner similar to D10 as set forth above for the sake of reducing undesired agglomeration and improving dispersibility of composite particles ([0070]), thus rendering obvious the claimed ranges of Dmin of claims 1 and 4 for the reason of reducing agglomeration and improving composite particle dispersibility. While Mason does not explicitly disclose a Dmin/D50 ratio, Mason must necessarily possess one. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed. invention, to have arrived at the claimed ranges of Dmin/D50 of claims 1 and 2 by way of selecting the encompassed portion of the ranges in an effort to reduce agglomeration and
improve dispersibility of the composite particles. (MPEP2144.05 I-II).
Regarding claim 6, Mason discloses all limitations as set forth above.
Mason further discloses the composite particles having BET surface area (i.e. specific surface area) preferably in a range from 2 to 15 m2/g, more preferably no more than 10 m2/g ([0076]), therefore providing sufficient specificity to, while also encompassing, the claimed range of 2 to 8 m2/g. Mason further discloses a low BET surface area is preferred to minimize the formation of the solid electrolyte interphase (SEI) at the surface of the composite particles during the first charge-discharge cycle, but an excessively low BET surface area results in unacceptably low charging rate and capacity ([0076]).
Assuming, arguendo, applicant is able to convincingly prove that the disclosed range is not sufficiently specific, it would still have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected and optimized within the encompassed portion of the ranges for the specific surface area to achieve a desired balance between minimizing SEI formation and an acceptable charging rate and capacity (MPEP 2144.05 I-II).
Regarding claims 7 and 16, Mason discloses all limitations as set forth above.
Mason further discloses a conductive porous carbon particle framework in which silicon
is deposited in the pores of the porous conductive composite material ([0007];[0037];[0044]).
This reads upon the claim limitation, “wherein at least one of the plurality of composite active
material particles has a structure in which at least a portion of the first active material is
embedded in the second active material.”
Regarding claims 8 and 17, Mason discloses all limitations as set forth above.
Mason further discloses at least 85% of the electroactive material mass (i.e. silicon) in
the composite particles is located within the internal pore volume of the conductive porous
particle framework such that there is very little electroactive material located on the external
surfaces of the composite particle ([0051]). In other words, Mason discloses at most 15% of the
first active material is exposed to the surface of the at least one of the plurality of composite
active material particles which is within the scope of the claimed “at least a portion”.
Regarding claim 9, Mason discloses all claim limitations as set forth above.
Mason further discloses the composite particles preferably comprise from 0.35 wt % to 0.65 wt % of silicon ([0047]), and a conductive carbon porous particle framework, wherein the composite particles comprise at least 80 wt % in total of silicon and carbon ([0048]), which falls within the claimed range, per the calculations below.
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Regarding claims 10 and 18, Mason discloses all claim limitations as set forth above.
Mason further discloses the composite particles comprise of a porous conductive particle framework including micropores and/or mesopores (Abstract) which reads on the claim limitation, “wherein the composite active material particle includes a plurality of the pores at an inside or on the surface of the composite active material particle.”
Regarding claim 11, Mason discloses all claim limitations as set forth above.
Mason further discloses the PD50 pore diameter of the conductive porous particle
framework is preferably no more than 10 nm ([0093]) which overlaps with the claimed average diameter of the pores being 1 to 500 nm. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have routinely selected within the overlapping ranges with reasonable expectation of achieving an active material with suitable characteristics (MPEP 2144.05 I).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Mason et al. (US
20220336790 A1) as applied to claim 1 above, and in further view of Lee et al. (US
20250038181 A1), hereinafter Lee ‘181.
Regarding claim 12, Mason discloses all claim limitations as set forth above.
Mason discloses a high porosity carbon framework in which the pore volume is
predominantly micropores, pores less than 2 nm in diameter, has sufficient strength to
accommodate the volumetric expansion of silicon without fracturing or degrading the porous
carbon framework ([0016];[0019]).
Mason further discloses the conductive porous particle framework is characterized by a total volume of micropores and macropores in the range from 0.4 to 2.2 cm3/g ([0019]), but does not explicitly disclose a porosity of the composite active material particle based on a total volume of the composite active material.
Lee ‘181 teaches as similar silicon-carbon composite anode active material with a porosity of 1% to 40%, which is within with the claimed porosity range of 0.1 vol% to 40 vol% ([0146]). The 1% to 40% being vol% as Lee ‘181 defines porosity (%) = pore volume per unit mass/(specific volume + pore volume per unit mass) ([0150]). Lee ‘181 further teaches a porosity below 1 vol% results in difficulty in controlling the volume expansion of the electrode active material during charge and discharge, while a porosity exceeding 40 vol% reduces mechanical strength of the electrode active material ([0146]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected and/or optimized within the taught range for the porosity to achieve an anode active material that has satisfactory volume expansion characteristics during charge and discharge, while maintaining overall electrode mechanical strength (MPEP 2144.05 I-II).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Mason (US20220336790A1) as applied to claim 1 above, and further in view of Lee et al. (US20230049476 A1), hereinafter Lee ‘476.
Regarding claim 13, Mason discloses all claim limitations as set forth above. Mason discloses the composite particles may include a carbon coating to improve conductivity of the surface of the composite particles where the thickness of the carbon coating may suitably be in the range from 2 to 30 nm ([0078-0080]). While Mason does not explicitly disclose a content of the carbon coating in a range from 0.1 wt% to 15 wt% based on the total weight of anode active material, as Mason possesses a carbon coating, the carbon coating must necessarily be present in some wt% based on the total weight of the anode active material.
Lee ‘476 teaches a similar anode active material with a carbon coating with a carbon
content of 2% by weight to 30% by weight, based on the total weight of the silicon-silicon complex oxide-carbon composite (i.e. the anode active material, [0145]), which overlaps with the claimed 0.1 to 15 wt %.
Lee ‘476 further teaches if the carbon content of the coating is less than 2% by weight, a sufficient effect of enhancing conductivity cannot be expected and could lead to deterioration of the electrode lifespan, and if the carbon content exceeds 30% by weight, the discharge capacity and bulk density may decrease and the charge-discharge capacity per unit volume may be deteriorated ([0146]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected and optimized within the overlapping ranges for the coating carbon content to achieve a desired balance between conductivity, electrode lifespan, discharge capacity, and bulk density (MPEP 2144.05 I-II).
Claims 14 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Mason et
al. (US 20220336790 A1) as applied to claims 1 and 15 above, and in further view of Kim et al.
(US 20190355971 A1).
Regarding claims 14 and 19, Mason discloses all limitations as set forth above.
Mason discloses the carbon of the conductive porous carbon particle framework may be crystalline carbon ([0037]). Mason further discloses a carbon coating is advantageous for its reduction in BET surface area of the particulate material as well as improving the conductivity of the surface of the composite particles ([0080]).
Mason does not disclose the use of a low crystalline carbon for the coating layer, or a coating with lower crystallinity than that of the carbon in the composite particle.
Kim teaches a similar anode active material where a silicon-carbon composite consists of crystalline carbon ([0022]). Kim further teaches an amorphous carbon coating layer on the surface of a silicon-carbon composite further improves the conductivity of the composite and thus may improve performance ([0033-0034]). A skilled artisan would recognize that amorphous carbon is smaller in crystallinity than crystalline carbon.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to improve Mason by utilizing an amorphous carbon coating as taught by Kim such that the carbon coating is of smaller crystallinity than the porous carbon conductive framework of crystalline carbon for the benefit of improved conductivity and performance of the composite.
Conclusion
THIS ACTION IS MADE FINAL. 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 ESTHER J TAN whose telephone number is (571)272-3479. The examiner can normally be reached M-F 7:30 AM-4:00 PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Leong can be reached at (571)270-1292. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/E.J.T./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 7/21/2026
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