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 .
Response to Amendment/Request for Reconsideration and Claim Status
The request for reconsideration filed 9 June 2026 has been entered. Claims 3, 5, 11, 13, and 19 are canceled. Claims 1, 2, 4, 6–10, 12, 14–18, and 20 are pending in the application.
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, 6–10, 12, 14–18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Hotta et al. (US 2017/0271673 A1) in view of Wang et al. (Wang, D.; Gao, M.; Pan, H.; Wang, J.; Liu, Y. High performance amorphous-Si@SiOx/C composite anode materials for Li-ion batteries derived from ball-milling and in situ carbonization, Journal of Power Sources 256, p. 190–199, published 20 January 2014), further in view of Ha et al. (US 2017/0062810 A1), further in view of Kim et al. (US 2021/0143439 A1), and further in view of Wu et al. (Wu, S.; Yu, B.; Wu, Z.; Fang, S.; Shi, B.; Yang, J. Effect of particle size distribution on the electrochemical performance of micro-sized silicon-based negative materials, RSC Advances 8, p. 8544–8551, published 23 February 2018).
Regarding Claims 1, 2, 9, 10, 17, and 18, Hotta discloses a negative electrode material (see electrode material, [0024]; [0088]–[0090] disclose that the electrode material is for use in a negative electrode), comprising silicon composite particles (see composite particle, [0021]; [0022]–[0024] disclose the composite particle can comprise silicon), wherein the silicon composite particles comprise silicon particles (see metal, [0022], specifically silicon (Si), [0024], [0027]) and a buffer phase (see combination of carbonaceous material and metal oxide, [0022], specifically silicon oxide (SiOx (0 ≤ x ≤ 2)), [0024], [0030]; [0030] discloses that the expansion and contraction of the silicon phase is relieved by dispersing it in the silicon oxide phase and carbonaceous material, and therefore one of ordinary skill in the art will understand that the carbonaceous material and silicon oxide phase can be considered a buffer phase), and the silicon particles are dispersed in the buffer phase ([0030]).
Hotta does not explicitly disclose wherein the silicon particles are amorphous, though one of ordinary skill in the art will understand that the silicon particles can be either amorphous or crystalline.
Wang teaches a negative electrode material (see anode material, p. 191 ¶ “In this study…”), comprising silicon composite particles (see a-Si@SiOx/C composites, p. 191 ¶ “In this study…”), wherein the silicon composite particles comprise amorphous silicon particles (see a-Si as core, p. 191 ¶ “In this study…”) and a buffer phase (see double layer of SiOx and carbon, p. 191 ¶ “In this study…”), the amorphous silicon dispersed in the buffer phase (p. 191 ¶ “In this study…”). Wang teaches (p. 191 ¶ “In terms of…”) that amorphous silicon provides more paths for the insertion/extraction of lithium in comparison to crystalline silicon, and further that the volume expansion of amorphous silicon upon lithium insertion is isotropic, which causes less pulverization compared with the highly anisotropic expansion of crystalline silicon.
Hotta and Wang are analogous to the claimed invention as they are in the same field of silicon-based negative electrode materials. It would therefore have been obvious to a person of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the negative electrode material of Hotta such that the silicon particles are amorphous, as Wang teaches that amorphous silicon provides the advantages of more paths for the insertion/extraction of lithium and lessened pulverization as compared to crystalline silicon.
Hotta does not explicitly disclose wherein a non-uniformity of the amorphous silicon particles dispersed in the buffer phase is less than or equal to 30% (Claims 1, 9, and 17) or more narrowly less than or equal to 15% (Claims 2, 10, and 18) but does disclose ([0031]) that it is preferable that the silicon particles be microparticulated as finely as possible and be dispersed in the composite particle in order to relieve stress caused by large expansion and contraction of the silicon phase during lithium insertion and extraction.
Ha teaches a negative electrode material (see anode active material, [0035]), comprising silicon composite particles (see carbon-silicon composite, [0033]), wherein the silicon composite particles comprise silicon particles (see nano silicon (Si) fine particles, [0033]) and a buffer phase (see carbonaceous substance, [0033]), and the silicon particles are dispersed in the buffer phase ([0034]). Ha teaches ([0011]–[0013]) that uniform dispersion of silicon particles in the negative electrode material is most important ([0014]), and specifically that increasing the dispersion of silicon particles included in a negative electrode material reduces the deterioration in secondary battery lifespan caused by the volume change of silicon during charge/discharge ([0011]–[0013]). Note that Ha is analogous to the claimed invention as it is in the same field of silicon-based negative electrode materials.
A result-effective variable is a variable which achieves a recognized result. The determination of the optimum or workable ranges of a result-effective variable is routine experimentation and therefore obvious (MPEP § 2144.05.II). In the instant case, the dispersion uniformity of silicon particles is a variable that achieves the recognized result of affecting secondary battery lifespan, as taught by Ha, thus making the dispersion uniformity of silicon particles a result-effective variable. Therefore, it would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the negative electrode material of modified Hotta such that the non-uniformity of the amorphous silicon particles dispersed in the buffer phase is less than or equal to 30%, or more narrowly less than or equal to 15%, via routine experimentation, for the purpose of achieving a suitable secondary battery lifespan.
Hotta does not explicitly disclose wherein a sphericity of the silicon composite particles is greater than or equal to 0.88.
Kim teaches a negative electrode material (see negative active material, [0035]), comprising silicon composite particles (see Si-carbon composite, [0035]), wherein the silicon composite particles comprise silicon particles (see Si nanoparticles, [0035]) and a buffer phase (see amorphous carbon, [0035]), the silicon particles are dispersed in the buffer phase ([0043]–[0044]), and a sphericity of the silicon composite particles is greater than or equal to 0.70 ([0036]). Note that when the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists (MPEP § 2144.05.I). Also note that Kim is analogous to the claimed invention as it is in the same field of silicon-based negative electrode materials.
Kim teaches ([0037]) that when the sphericity is 0.7 or more, the surface area and therefore side reactions with electrolyte and lithium can be reduced, and uniform volume expansion can be facilitated. Thus in addition to the prima facie case of obviousness set forth above, it would further have been obvious to a person of ordinary skill in the art prior to the effective filing date of the claimed invention to select the overlapping portions of the ranges for the sphericity of the silicon composite particles with a reasonable expectation that such selection would successfully result in silicon composite particles with reduced surface area and therefore reduced side reactions with electrolyte and lithium, and facilitated uniform volume expansion.
Hotta does not explicitly disclose wherein a particle size of the negative electrode material satisfies D90 – D10 ≤ 8.5 µm. However, one of ordinary skill in the art will understand that the expression D90 – D10 is a measure of particle size distribution.
Wu teaches a negative electrode material (see micro-sized silicon-based material, p. 8545 ¶ “Herein, we used…”), comprising silicon composite particles (see SiOx/C, p. 8545 ¶ “Herein, we used…”). Wu teaches that increasing the particle size distribution increases energy density and volumetric capacity, but also increases the degree of electrode polarization and limits buffer space. Note that Wu is analogous to the claimed invention as it is in the same field of silicon-based negative electrode materials.
A result-effective variable is a variable which achieves a recognized result. The determination of the optimum or workable ranges of a result-effective variable is routine experimentation and therefore obvious (MPEP § 2144.05.II). In the instant case, the particle size distribution is a variable that achieves the recognized result of affecting the energy density, volumetric capacity, degree of electrode polarization, and buffer space of the negative electrode material, as taught by Wu, thus making the particle size distribution a result-effective variable. Therefore, it would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the negative electrode material of modified Hotta such that a particle size satisfies D90 – D10 ≤ 8.5 µm via routine experimentation, for the purpose of achieving suitable levels of energy density, volumetric capacity, degree of electrode polarization, and buffer space.
Further regarding Claims 9 and 17, Hotta further discloses an electrochemical device (see nonaqueous electrolyte battery 20, [0110], [0152], FIG. 2 and 3), comprising a negative electrode plate (see negative electrode 10, [0090], [0110]; see also negative electrode 23, [0153], FIG. 2 and 3), the negative electrode plate comprises a negative active material layer (see electrode mixture layer 12, [0090], FIG. 1; see also negative electrode layer 23b, [0153], FIG. 3), and the negative active material layer comprises the negative electrode material of Claim 1 as set forth above ([0088], [0113]).
Further regarding Claim 17, Hotta further discloses an electronic device (see electronic device, [0174]) comprising the electrochemical device of Claim 9 as set forth above ([0173]–[0174]).
Regarding Claims 4, 12, and 20, modified Hotta discloses the negative electrode material, electrochemical device, and electronic device of Claims 1, 9, and 17, respectively. Hotta further discloses ([0049]) wherein a specific surface area of the negative electrode material is 0.5 m2/g or more and 10 m2/g or less, which overlaps with the claimed range of less than or equal to 5 m2/g. Note that when the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists (MPEP § 2144.05.I).
Hotta teaches ([0049]–[0050]) that a negative electrode material having a specific surface area of 0.5 m2/g or more and 10 m2/g or less, the electrode can exert stable electrode characteristics. Thus in addition to the prima facie case of obviousness set forth above, it would further have been obvious to a person of ordinary skill in the art prior to the effective filing date of the claimed invention to select the overlapping portions of the ranges for the specific surface area of the negative electrode material with a reasonable expectation that such selection would successfully result in a negative electrode material which can exert stable electrode characteristics.
Regarding Claims 6 and 14, modified Hotta discloses the negative electrode material and electrochemical device of Claims 1 and 9, respectively. As set forth in the rejection of Claims 1 and 9 above, Hotta discloses wherein the buffer phase comprises carbon (see carbonaceous material, [0022], [0030]), oxygen, and silicon (see metal oxide, [0022]; see specifically silicon oxide (SiOx (0 ≤ x ≤ 2)), [0024], [0030]).
Regarding Claims 7 and 15, modified Hotta discloses the negative electrode material and electrochemical device of Claims 6 and 14, respectively. Modified Hotta further discloses wherein the buffer phase comprises silicon monoxide (see silicon oxide (SiOx (0 ≤ x ≤ 2)), [0024], [0030]; one of ordinary skill in the art will understand that SiOx (0 ≤ x ≤ 2) includes silicon monoxide where x = 1) and silicon dioxide (see silicon oxide (SiOx (0 ≤ x ≤ 2)), [0024], [0030]; one of ordinary skill in the art will understand that SiOx (0 ≤ x ≤ 2) includes silicon dioxide where x = 2; see specifically silicon dioxide (SiO2), [0029]).
Regarding Claims 8 and 16, modified Hotta discloses the negative electrode material and electrochemical device of Claims 1 and 9, respectively. Hotta further discloses wherein the silicon composite particles further comprise a conductive agent (see electroconductive auxiliary agent, [0071]), and the conductive agent is dispersed in the buffer phase ([0071] discloses that the electroconductive auxiliary agent is mixed in with silicon particles and the carbon precursor during the synthesis of the silicon composite particles, thus one of ordinary skill in the art will understand that the conductive agent will necessarily be dispersed in the buffer phase in the final silicon composite particles).
Response to Arguments
Applicant’s arguments in the Remarks filed 9 June 2026 have been fully considered but are not persuasive for the following reasons:
Applicant argues on p. 3–4 of Remarks that the proposed combination of Hotta and Wang is an attempt to bring in the isolated teaching of Wang into Hotta and amounts to improperly picking and choosing features from different references without regard to the teachings of the references as a whole, specifically arguing:
Hotta is not silent on the phase of the silicon, and that Hotta articulates that the silicon phase is crystalline in [0052].
It would not be evident to a person of ordinary skill in the art looking at Hotta to make the changes proposed by the office action, since such changes would increase the paths for the insertion/extraction of lithium into silicon; Hotta notes that its structure is based on the proposition that it can mitigate the swelling associated with its existing interactions between lithium and silicon, and that a problem to be overcome by Hotta is that the large swell in volume that occurs upon lithium insertion. Thus, if Hotta’s silicon is caused to provide more paths for the insertion/extraction of lithium, this further insertion of lithium would result in further swelling, which heightens the problems faced by Hotta, and requires additional mitigation. It is noted that Hotta discloses reducing the size of the particles would help to mitigate this effect, but this reduction in size would cause greater undesirable aggregation.
[0030] of Hotta notes that the inclusion of silicon dioxide prevents pulverization of the composite particles, and thus that there is no particular reason to redesign Hotta to further mitigate a problem it appears to have already completely addressed.
This argument is not persuasive. Firstly, the rejection of record does not contend that the silicon of Hotta is in the amorphous phase rather than the crystalline phase, but rather that regardless the phase of the silicon in Hotta, a person of ordinary skill in the art would have found it obvious to modify the silicon of Hotta to be amorphous in light of the teachings of Wang, namely because amorphous silicon provides more paths for the insertion/extraction of lithium in comparison to crystalline silicon, and further that the volume expansion of amorphous silicon upon lithium insertion is isotropic, which causes less pulverization compared with the highly anisotropic expansion of crystalline silicon. Secondly, it is respectfully submitted that Hotta does not discourage or teach away from increasing the number of paths for the insertion/extraction of lithium into silicon; while it is the case that Hotta describes the volume expansion of silicon upon lithium insertion as a problem that needs to be addressed, it is evident from at least [0005] and [0030] that the large amount of lithium that can be inserted and extracted into silicon is indeed an advantage of silicon that greatly enhances capacity of the active material. Hotta merely teaches that the problem of volume expansion, not amount of lithium inserted/extracted, must be addressed. As such, it can be understood that Wang’s teachings, i.e. that amorphous silicon allows for greater insertion/extraction of lithium with more isotropic volume expansion of the silicon, are indeed compatible with the goals of Hotta and that the modification of Hotta with Wang is appropriate. Thirdly, the assertion that because Hotta discloses in [0030] that the inclusion of silicon dioxide prevents pulverization of the composite particles, the problem described by Hotta has been completely addressed and no modifications would be obvious, appears to be an oversimplification of the entire disclosure of Hotta. A person of ordinary skill in the art would reasonably expect that such a problem is never completely addressed, that further optimization and modification of the composite particles of Hotta would always be possible, and that some pulverization of the composite particles of Hotta will inevitably still occur as the battery cycles. Such an expectation is further supported by the results of Hotta, wherein e.g. Hotta’s exemplary Examples 1–6 (Tables 1 and 2) indicate that the cycle characteristics, while improved compared to the comparative examples, remained less than ideal (see e.g. the capacity holding ratios after 50th cycle shown in Table 2 for Examples 1–6, which are all less than 100%).
Applicant argues on p. 5 of Remarks that the combination of Kim with the other cited references is based on impermissible hindsight, as it directly contradicts the office action’s articulated motivation for combining Wang. Specifically, Applicant argues that because Kim teaches high sphericity in order to reduce the surface area between the Si-carbon composite and its surroundings, application of the sphericity taught by Kim to modified Hotta would be contrary to the office action’s articulated motivation for combining Wang. This is because Wang teaches that amorphous silicon would allow for more paths per particle between silicon and lithium, i.e. more exposure of silicon to lithium.
This argument is not persuasive. As set forth in the rejection of record, Kim teaches ([0037]) that when the sphericity is 0.7 or more, the surface area and therefore side reactions with electrolyte and lithium can be reduced, and uniform volume expansion can be facilitated. It is respectfully submitted that lithium insertion/extraction discussed by Wang, which describes at the atomic level the intercalation/deintercalation of lithium ions into and out of a silicon structure and would be affected by whether the silicon was amorphous or crystalline, is different from side reactions with electrolyte and lithium occurring at the surface of the composite particle as a whole, as discussed by Kim. Thus, the teachings of Wang and Kim are, rather than being contradictory, directed to two different concepts and can both be applied to Hotta without impermissible hindsight.
Applicant argues on p. 5–6 of Remarks that the combined teachings of Hotta and Ha are not sufficient to establish non-uniformity as a result-effective variable which would be obvious to optimize as set forth in the office action. Applicant specifically argues:
The “result-effective variable” reasoning is improper to apply in any case where the process is not known or where the prior art does not articulate how the variable may be found in order to have a person of ordinary skill in the art arrive at an optimum value.
Hotta teaches away from the proposed optimization because Hotta teaches that particles get more difficult to uniformly disperse as they get smaller ([0045]), but teaches making the particles smaller anyway because “it is preferable that the silicon phase be microparticulated as finely as possible” ([0031]). Hotta also teaches a variety of techniques by which the detrimental effects on dispersion may be mitigated such as using a dispersion medium in a liquid phase. Thus Hotta makes it evident that, even though there are acknowledged benefits to having the silicon phase be more dispersed, Hotta’s redesign directly makes the silicon phase less dispersed while contemplating that a further redesign could be made in order to lessen the effect of this if desired, and can be summarized as “Dispersion should be sacrificed, but may not need to be sacrificed that much” which is the opposite of a call for optimization.
Ha provides ([0014]) that “it is difficult to confirm a degree of dispersion” but contemplates its own strategy for characterizing a degree of dispersion of silicon in carbon-silicon composite, as shown in e.g. FIG. 2 and [0049]; FIG. 2 shows that the particles may be – and are – significantly clustered within the zones, having areas that are mostly silicon when a straight line is drawn across them and other areas where a line can readily be drawn without passing through any clusters of silicon at al.
Thus, Ha is therefore in the same position as the Antoine Federal Circuit case, because Ha doesn’t teach non-uniformity of the particles in the claimed ranges, doesn’t teach line scanning as a measure of such non-uniformity, and makes it evident that if line scanning were applied to Ha’s subgroups, the non-uniformity would not be close to these values.
These arguments are not persuasive. It is first respectfully submitted that the teachings of Hotta do not teach away from the proposed optimization. While Hotta does disclose in e.g. [0045] the advantages of decreasing particle size, namely that this decreases the deleterious effects of volume expansion, Hotta also discloses that decreasing the particle size too significantly, i.e. to less than 20 nm, leads to issues of aggregation/non-dispersity and safety. It is additionally noted that Hotta follows its own teachings in experimental Examples 3, 4, and 5, which all recite silicon particle sizes of 20 nm or greater. Thus, it can be understood that Hotta discloses a balance of particle size considering various factors, and Applicant’s assertion that Hotta teaches “making the particles smaller anyway” and that the teachings of Hotta can be summarized as “Dispersion should be sacrificed, but may not need to be sacrificed that much” is not accurate. In fact, in light of the above, it can be understood that Hotta not only does not teach away from the proposed optimization but rather teaches the means by which the optimization can be achieved, i.e. by avoiding aggregation by utilizing silicon nanoparticles which are 20 nm or greater in size, and by emphasizing the importance of uniform dispersion of the silicon particles in at least [0030]–[0031] and [0045]. It is further noted that [0073], which Applicant asserts represents Hotta teaching a technique “by which the detrimental effects on dispersion may be mitigated”, references dispersion of the silicon dioxide particles, the silicon particles, and the carbon precursor utilized to form the composite particles in a dispersion medium in a liquid phase in order to disperse them more uniformly. Thus, [0073] is rather a further teaching which the optimization of the result-effective variable of non-uniformity can be achieved (through dispersion in a liquid phase), not an attempt to mitigate the effect of any teachings away. Secondly, regarding the reference Ha, it is noted that the reference Ha is not relied upon to teach a specific level or range of non-uniformity, but rather to teach the recognition by the prior art of non-uniformity as a result-effective variable. While Ha does provide teachings on how such a variable may be found in order to have a person of ordinary skill in the art arrive at an optimum value, any specific ranges taught by Ha, the level of non-uniformity exhibited by the example(s) of Ha, as well as whether Ha utilizes line scanning in order to measure said non-uniformity, are not relevant to the appropriateness of the rejection. Rather Ha, as already stated, teaches that the non-uniformity is a variable recognized in the art as being result-effective, and specifically as a variable that secondary battery lifespan deterioration due to volume change of silicon during charge/discharge ([0011]–[0013]). In light of the above, it can be understood that the combination of Hotta and Ha does indeed establish that the non-uniformity of the silicon particles dispersed in the buffer phase is a result-effective variable recognized in the prior art, and further as detailed above, provide a known process by which the variable can be optimized, e.g. the silicon particle size and dispersion methods of Hotta, and articulation of how the variable may be found, e.g. the method of Ha, such that the instant case is not the same as the position of the Antoine Federal Circuit case, and the rejection on the basis of non-uniformity being a result-effective variable which would be obvious to optimize in the rejection of record is appropriate.
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.
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/J.M.F./Examiner, Art Unit 1725
/BASIA A RIDLEY/Supervisory Patent Examiner, Art Unit 1725
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