DETAILED ACTION
Application 17/657333, “Lithium Ion Battery With High Purity SWCNT Additive In Cathode For Enhanced Performance”, is the continuation of a PCT application filed on 9/25/20 and claims priority from a provisional application filed on 10/4/19.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This Office Action on the merits is in response to communication filed on 9/17/25.
Response to Arguments
Applicant’s arguments filed on 9/17/25, supported by the 9/17/25 Brahim Declaration, have been fully considered, but are not persuasive and/or moot in view of the new ground(s) of rejection necessitated by amendment.
Applicant argues that the cited references, alone or considered in combination, do not teach all of the claimed features.
The argument that the references, considered in combination, fail to teach or suggest all of the claimed features is moot in view of the new ground(s) of rejection which relies on Lim (US 2016/0141618) in order to teach carbon nanotube to carbon black ratios and amounts which are similar to that claimed, so as to support a prima facie case of obviousness.
Applicant further argues that and that unexpected results and criticality are associated with the claimed invention.
The argument of unexpected results and criticality is not found persuasive because the unexpected advantage argued by applicant, improved specific energy density and specific power density of LiB power cells achieved by incorporating a desirable weight ratio of carbon nanotubes to carbon black, appears to be a known advantage at the time of invention.
More specifically, the newly cited reference Lim teaches that the output of a battery cell, measured in W/kg, peaks at a CNT:CB ratio of between 2:3 and 3:2 (see Lim Table 2, and the Examiner’s plot (see below) taken from Inventive and Comparative Examples 2-7 of Lim Table 2). Therefore, a skilled artisan at the time of invention would have found the increase in specific energy density and/or specific power density to be expected.
It is noted that the “Output” parameter of Lim may not be not be exactly the same as the “specific energy density” and “specific power density” parameters noted in applicant’s Figures A and B (also given in W/kg). Even if so, Lim establishes a different metric under which the CNT:CB ratio is a result-effective variable, with around the same relative content range (peak around a 1:1 ratio) being demonstrated as critical and providing superior results. As described in MPEP 716.02(c) “[w]here the unexpected properties of a claimed invention are not shown to have a significance equal to or greater than the expected properties, the evidence of unexpected properties may not be sufficient to rebut the evidence of obviousness”. Here, the Office accepts the Declarant’s finding that superior power and energy density results are associated with an about 1:1 CNT/CB ratio, but finds that that result i) does not appear to be actually unexpected because Lim teaches that values around 1:1 give the highest output in W/kg for both the Inventive and Comparative examples, or ii) if it is unexpected because applicant’s measured parameter is actually different from the “Output” of Lim Table 1, this finding does not shown to have significance outweighing Lim’s own finding of critical desirability around the claimed range for a possibly different output characteristic.
[Chart]
Claim Rejections - 35 USC § 103
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 of this title, 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.
Claims 1, 2, 8-10, 13, 14, 17, 21 and 24 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Iwane (US 2021/0175487), Finlayson (US 2020/0369522), Hata (US 2010/0062229) and Lim (US 2016/0141618).
Regarding claim 1, Iwane teaches a lithium ion battery cell (Figs. 1,2; paragraph [0085]) having a cathode [a positive electrode] (item 21) comprising an active material (item 21b) and 1-5 wt% of a conductive additive (paragraph [0043]; e.g. 1 wt% at paragraph [0105]), wherein the conductive additive may include single wall carbon nanotubes [SWCNT] (paragraph [0039]) and have a BET specific surface area of about 1300 m2/g (“1300 m2/g”, paragraph [0112]; paragraph [0041]), and wherein the active material is an Li metal oxide or Li iron phosphate (paragraph [0022]).
Iwane is silent regarding the carbon nanotubes having an inorganic impurity content of less than 1% by weight.
In the battery art, Finlayson teaches that high purity constituents for a battery are desired for the benefit of reducing unwanted side reactions (paragraph [0010]). Finlayson further teaches “high purity” single walled carbon nanotube having metallic impurity content including 0.6% residuals, compared to “low purity” carbon nanotube which includes 17.7% residuals (paragraph [0147]). Finlayson further teaches that such carbon nanotubes provide desirable mechanical, electrical and thermal properties to a battery (abstract, paragraph [0048]).
Furthermore, in the battery art, Hata teaches single walled carbon nanotubes intended for “energy storage devices” (paragraph [0003]), further teaches that carbon nanotubes of greater than 95% purity are desirable for the benefit of inhibiting unwanted reactions (paragraph [0113]), and gives an exemplary purity of 99.9% (paragraph [0219]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to utilize carbon nanotubes have an inorganic impurity content of less than 1% by weight, for the benefit of improving performance and/or inhibiting unwanted side reactions by use of the high purity material as taught by Finlayson and/or Hata.
Regarding the 9/17/25 amendment to claim 1, Iwane teaches that the conductive additive of the cathode may include carbon nanotubes and/or carbon black (paragraph [0039]), but does not teach wherein the cathode comprises the carbon nanotube and carbon black in a combined content of 4 to 6% by weight, and at a 1:1 weight ratio.
In the battery art, Lim teaches a cathode material comprising a mixture of carbon nanotube and carbon black provides a superior stability, output characteristic, and/or low temperature characteristic (paragraph [0017]). Lim further teaches wherein the carbon black/carbon nanotube ratio is a result-effective variable affecting the output and low temperature characteristics, and the ratio of linear [carbon nanotube] to spherical [carbon black] conductive material is preferably 1 wt% to 60 wt% for benefits such as ensuring a desirable conductive path between active material particles to achieve the desirable output and low temperature characteristics (paragraph [0022]). Lim further teaches particular examples with carbon black and carbon nanotube at weights of 4:1, 3:2, 2:3 and 1:4 wt%, with the 3:2 and 2:3 wt% embodiments providing the highest output in W/kg (see Table 2 Examples 4-7, where Examples 5 and 6 provide the highest output).
It would have been obvious to a person having ordinary skill in the art at the time of invention to a person having ordinary skill in the art at the time of invention to use as the conductive material a combination of carbon nanotube and carbon black at a total content within the range of 5 wt%, and a relative ratio of 2:3 to 3:2 for the benefit of optimizing the output characteristic, low temperature characteristic and conductive pathway in the positive electrode as taught by Lim.
The requirement that the combined content of SWCNT and carbon black is between 4% and 6% is obvious because 5 wt% lies within the 4 wt% to 6 wt% range.
The about 1:1 claimed ratio is narrower than the suggested 2:3 to 3:2 range; however, the claimed ratio is nevertheless found to be obvious because Lim suggests a trend wherein closer contents between the carbon black and the carbon nanotubes provides higher output characteristics. Specifically, the 2:3 and 3:2 values both give higher outputs than values lying outside this range (Lim Table 2), and the claimed about 1:1 value represents the midpoint of the 2:3 to 3:2 desirable output range taught by Lim. Since the Table 2 establishes that the relative amounts of carbon black and carbon nanotube affects the output, the skilled artisan would have expected that further optimization of the ratio within the 2:3 to 3:2 range could yield the highest output value and the 1:1 ratio would be obvious as routine optimization within the subrange is conducted. Moreover, it has been held that “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” (MPEP 2144.04 IIA). Here, Lim suggests a maximum output at some CNT:CB ratio between the values of 2:3 and 3:2 (see Examiner’s plot above) and it would have been obvious to use routine experimentation to determine at which ratio the maximum output lies.
Regarding claim 2, the cited art remains as applied to claim 1. Iwane further teaches wherein the active material is selected from the group consisting of: Li—NiMnCo-Oxide (NMC), Li—NiCoAl-Oxide (NCA), Li—Fe-Phosphate (LFP), Li-Cobalt-Oxide (LCO), Li-Manganese-Oxide (LMO), and any combination thereof (paragraph [0022]).
Regarding claims 8-10, 14 and 24, the cited art remains as applied to claim 1. As previously described, Lim teaches a 2:3 to 3:2 range of carbon black to carbon nanotube producing the highest output among the tested examples; therefore, the requirement that the amount of SWCNT is between 2 and 3 wt% and the amount of carbon black is between 2 and 3 wt% is obvious for reasons previously described.
As to the requirements that the amount of each conductive agent is 2 wt% of claim 8, or 3 wt% of claim 24, each embodiment is found to be obvious over the cited art because:
i) although the most desirable output Examples utilize ratios of 2:3 or 3:2, both having a total conductive material content of 5 wt%, the general teaching of the prior art is that the conductive material could be less or more than 5 wt% (Lim paragraph [0038] more broadly teaches 2 to 8% conductive material as suitable) and that the carbon black/carbon nanotube ratio does not necessarily need to be 2:3 or 3:2 (Lim paragraph [0021-0022]; Table 2). As described in MPEP 2123, the broader range disclosed by the prior art suggests obviousness, even when preferred examples outside the claimed range are disclosed;
ii) Lim Table 2 suggests desirable output associated with a 2:3 to 3:2 carbon black:carbon nanotube range and the claimed about 2 wt%:2 wt% and about 3 wt%:3 wt% embodiments overlap the suggestion in scope, or at least are close enough that similar properties would be expected, particularly considering Lim’s teaching that high output characteristics are associated with the 2:3 to 3:2 range.
As to claims 9 and 14, since the cited art teaches a range of conductive agent that may broadly be between 2 and 8 wt (Lin paragraph [0038]), the cell may be either a power cell or an energy cell, considering applicant’s teaching that power cells have 4 to 10 wt% conductive carbon content, and energy cells have 2 to 4 wt% conductive carbon content.
Regarding claim 13 and 17, the cited art remains as applied to claim 9 or 14. Iwane further teaches the cell having an anode [a negative electrode] (item 22) comprising graphite powder (paragraph [0053], carbon black as a conductive additive (paragraphs [0051,0063]), a binder (paragraphs [0051]), and having LiPF6 as an electrolyte (paragraph [0083]). A gelling agent is implied, or at least obvious, in view of Choi’s paragraph [0076] teaching that the electrolyte layer may be a gel.
Regarding claim 21, the cited art remains as applied to claim 1. Iwane further teaches wherein the cathode does not comprise multiwall carbon nanotubes (paragraph [0039] implies that the carbon nanotubes may be only single-walled carbon nanotubes; see also the teachings of the secondary references, such as Hata which are specific to single-walled carbon nanotubes).
Claims 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Iwane (US 2021/0175487), Finlayson (US 2020/0369522), Hata (US 2010/0062229), Lim (US 2016/0141618) and Hashimoto (US 2019/0172604).
Regarding claim 20, the cited art remains as applied to claim 1. Iwane does not appear to teach wherein the carbon nanotubes have a Raman G/D peak of at least 20.
In the battery art, Hashimoto teaches that carbon nanotubes for electrode applications preferably have a G/D ratio of at least 50 because carbon nanotubes having G/D over 50 effectively contribute to enhancing film strength (paragraph [0010]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to configure the carbon nanotubes to have a G/D ratio of at least 20, such as over 50, for the benefit of providing nanotubes which will enhance the strength of the electrode as taught by Hashimoto.
Claims 1, 2, 8-10, 14 18, 20, 21 and 24 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Harutyunyan (US 2020/0239317), Iwane (US 2021/0175487), Finlayson (US 2020/0369522), Hata (US 2010/0062229) and Lim (US 2016/0141618).
Regarding claim 1 and 18, Harutyunyan teaches an electrode for a lithium ion battery (paragraph [0019]), wherein the electrode comprises an active material and single wall carbon nanotubes as a conductive additive (paragraph [0019, 0071]), and wherein electrode may be a cathode wherein the active material is an Li metal oxide or Li iron phosphate (paragraph [0056-0057]).
As to claim 18, Harutyunyan further teaches that the electrode may be free from polymeric binder (paragraph [0062]).
Harutyunyan does not explicitly teach that the carbon nanotubes should be included in an amount of 1-5% by weight.
However, Harutyunyan does teach that the carbon nanotubes are desirably included in an amount of 0.1 to 4% for the benefit of providing a self-standing structure with desirable flexibility electrode (paragraph [0062]. The claimed range of 1-5% by weight of carbon nanotubes is found to be obvious over Harutyunyan because i) the claimed range overlaps the prior art disclosed range suggesting obviousness (MPEP 2144.05), and ii) Harutyunyan teaches the carbon nanotube weight % as a result-effective variable optimizable to mechanical properties of the electrode, with the routine optimization of result-effective variables being prima facie obvious.
Harutyunyan does not appear to teach wherein the BET surface area of the carbon nanotubes is about 1300 m2/g.
In the battery art, Iwane teaches a cathode comprising carbon nanotubes (paragraphs [0039]) having a BET specific surface area of 1000 to 1500 m2/g (paragraph [0041]), such as 1300 m2/g (paragraph [0112]) for the benefit of balancing desirable coverage, aggregation, heating safety and coatability properties (paragraph [0041]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to configure the single walled carbon nanotubes of Harutyunyan to have a BET specific surface area of about 1300 m2/g for the benefit of balancing desirable coverage, aggregation, heating safety and coatability properties as taught by Iwane.
Harutyunyan is silent regarding the carbon nanotubes having an inorganic impurity content of less than 1% by weight and the incorporation of the carbon nanotubes providing an increased capacity.
In the battery art, Finlayson teaches that high purity constituents for a battery are desired for the benefit of reducing unwanted side reactions (paragraph [0010]). Finlayson further teaches “high purity” single walled carbon nanotube having metallic impurity content including 0.6% residuals, compared to “low purity” carbon nanotube which includes 17.7% residuals (paragraph [0147]). Finlayson further teaches that such carbon nanotubes provide desirable mechanical, electrical and thermal properties to a battery (abstract, paragraph [0048]).
Furthermore, in the battery art, Hata teaches single walled carbon nanotubes intended for “energy storage devices” (paragraph [0003]), further teaches that carbon nanotubes of greater than 95% purity are desirable for the benefit of inhibiting unwanted reactions (paragraph [0113]), and gives an exemplary purity of 99.9% (paragraph [0219]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to utilize carbon nanotubes have an inorganic impurity content of less than 1% by weight, for the benefit of improving performance and/or inhibiting unwanted side reactions by use of the high purity material as taught by Finlayson and/or Hata.
Regarding the 9/17/25 amendment to claim 1, Harutyunyan does not teach wherein the cathode comprises the carbon nanotube and carbon black in a combined content of 4 to 6% by weight, and at a 1:1 weight ratio.
In the battery art, Lim teaches a cathode material comprising a mixture of carbon nanotube and carbon black provides a superior stability, output characteristic, and/or low temperature characteristic (paragraph [0017]). Lim further teaches wherein the carbon black/carbon nanotube ratio is a result-effective variable affecting the output and low temperature characteristics, and the ratio of linear [carbon nanotube] to spherical [carbon black] conductive material is preferably 1 wt% to 60 wt% for benefits such as ensuring a desirable conductive path between active material particles to achieve the desirable output and low temperature characteristics (paragraph [0022]). Lim further teaches particular examples with carbon black and carbon nanotube at weights of 4:1, 3:2, 2:3 and 1:4 wt%, with the 3:2 and 2:3 wt% embodiments providing the highest output in W/kg (see Table 2 Examples 4-7, where Examples 5 and 6 provide the highest output).
It would have been obvious to a person having ordinary skill in the art at the time of invention to a person having ordinary skill in the art at the time of invention to use as the conductive material a combination of carbon nanotube and carbon black at a total content within the range of 5 wt%, and a relative ratio of 2:3 to 3:2 for the benefit of optimizing the output characteristic, low temperature characteristic and conductive pathway in the positive electrode as taught by Lim.
The requirement that the combined content of SWCNT and carbon black is between 4% and 6% is obvious because 5 wt% lies within the 4 wt% to 6 wt% range.
The about 1:1 claimed ratio is narrower than the suggested 2:3 to 3:2 range; however, the claimed ratio is nevertheless found to be obvious because Lim suggests a trend wherein closer contents between the carbon black and the carbon nanotubes provides higher output characteristics. Specifically, the 2:3 and 3:2 values both give higher outputs than values lying outside this range (Lim Table 2), and the claimed about 1:1 value represents the midpoint of the 2:3 to 3:2 desirable output range taught by Lim. Since the Table 2 establishes that the relative amounts of carbon black and carbon nanotube affects the output, the skilled artisan would have expected that further optimization of the ratio within the 2:3 to 3:2 range could yield the highest output value and the 1:1 ratio would be obvious as routine optimization within the subrange is conducted.
Regarding claim 2, the cited art remains as applied to claim 1. Harutyunyan further teaches wherein the active material is selected from the group consisting of: Li—NiMnCo-Oxide (NMC), Li—NiCoAl-Oxide (NCA), Li—Fe-Phosphate (LFP), Li-Cobalt-Oxide (LCO), Li-Manganese-Oxide (LMO), and any combination thereof (paragraph [0056-0057]).
Regarding claims 8-10, 14 and 24, the cited art remains as applied to claim 1. As previously described, Lim teaches a 2:3 to 3:2 range of carbon black to carbon nanotube producing the highest output among the tested examples; therefore, the requirement that the amount of SWCNT is between 2 and 3 wt% and the amount of carbon black is between 2 and 3 wt% is obvious for reasons previously described.
As to the requirements that the amount of each conductive agent is 2 wt% of claim 8, or 3 wt% of claim 24, each embodiment is found to be obvious over the cited art because:
i) although the most desirable output Examples utilize ratios of 2:3 or 3:2, both having a total conductive material content of 5 wt%, the general teaching of the prior art is that the conductive material could be less or more than 5 wt% (Lim paragraph [0038] more broadly teaches 2 to 8% conductive material as suitable) and that the carbon black/carbon nanotube ratio does not necessarily need to be 2:3 or 3:2 (Lim paragraph [0021-0022]; Table 2). As described in MPEP 2123, the broader range disclosed by the prior art suggests obviousness, even when preferred examples outside the claimed range are disclosed;
ii) Lim Table 2 suggests desirable output associated with a 2:3 to 3:2 carbon black:carbon nanotube range and the claimed about 2 wt%:2 wt% and about 3 wt%:3 wt% embodiments overlap the suggestion in scope, or at least are close enough that similar properties would be expected, particularly considering Lim’s teaching that high output characteristics are associated with the 2:3 to 3:2 range.
As to claims 9 and 14, since the cited art teaches a range of conductive agent that may broadly be between 2 and 8 wt (Lin paragraph [0038]), the cell may be either a power cell or an energy cell, considering applicant’s teaching that power cells have 4 to 10 wt% conductive carbon content, and energy cells have 2 to 4 wt% conductive carbon content.
Regarding claim 20, the cited art remains as applied to claim 1. Harutyunyan further teaches that a Raman G/D ratio for the nanotubes is preferably in a range of 5 to 400, or greater than about 7, as an indication of purity (paragraph [0049]). Thus, it would have been obvious to a person having ordinary skill in the art at the time of invention to configure the carbon nanotubes to have a G/D ratio of at least 20 for the same benefit of ensuring that a high purity carbon nanotube is utilized.
Regarding claim 21, the cited art remains as applied to claim 1. Finlayson further teaches wherein the cathode does not comprise multiwall carbon nanotubes (paragraph [0021] implies that the carbon nanotubes may be only single-walled carbon nanotubes; see also the teachings of the secondary references, such as Hata which are specific to single-walled carbon nanotubes).
Relevant or Related Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure, though not necessarily pertinent to applicant’s invention as claimed.
Ochoa (US 2003/0099883) -electrodes with carbon nanotubes;
Harutyunyan (US 2009/0274609) -production of high purity carbon nanotubes;
Shinoda (US 2022/0376261) -electrode composition comprising carbon nanotube with high G/D ratio.
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 JEREMIAH R SMITH whose telephone number is (571)270-7005. The examiner can normally be reached on Mon-Fri: 9 AM-5 PM (EST).
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/JEREMIAH R SMITH/Primary Examiner, Art Unit 1723