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
Claims 1-8, 10, and 11 are still pending. Claims 6-8 continue to be withdrawn from consideration as being drawn to a non-elected invention. Claims 1-5, 10, and 11 are being examined in this office action.
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, 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.
Claim(s) 1-4, 10, and 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yun et al (Nanoletters, 2018, 18, pp. 475-481).in view of Chung et al (Advanced Materials, 2018, 1805571) and with or without Moganty et al (WO 2014/078846).
With respect to claim 1, Yun discloses a composite energy-storage cathode comprising a conductive porous substrate (electrospun carbon nanofibers) with a specific surface area of 22.88 m2/g overlapping the claimed 1 to 100 range. See abstract and p. 477, first column, first full paragraph. Yun further discloses that a sulfur layer is formed on the substrate with a sulfur loading of at least 3 mg/cm2 (examples with 5.1 and 10.2 mg/cm2) and a total sulfur content of at least 70-80 wt% (e.g. 78.99 wt%). See p. 477, paragraph bridging col. 1 and 2 and p. 479, first column, first full paragraph.
Yun did not explicitly recite the electrolyte with an electrolyte-to-sulfur ratio of 7 to 4 μL/mg. Chung discloses an analogous carbon/sulfur cathode cell and disclosed the use of 6 μL/mg electrolyte to sulfur ratio (paragraph bridging pp. 1 and 2) which overlaps the claimed range. It would have been obvious to one of ordinary skill in the art at the time of the filing to utilize the low electrolyte to sulfur ratio of Chung for the battery of Yun in order to achieve the highest potential energy density.
With respect to this cathode being a “hot-pressed” carbon/sulfur cathode, the method of which the present invention uses to obtain the levels of sulfur loading and content constitutes the process of making the invention and the process steps taking to arrive at the claimed structure. Structure claims are limited only to the structure implied by the process steps. See MPEP 2113(I).
However, it is noted in the alternative that both Chung and Moganty teach that loading the sulfur into the cathode can be further improved by applying the sulfur under elevated temperatures and pressures (i.e. hot-pressing). See Chung, abstract, paragraph bridging pp. 1 and 2, and fig. 1. See Moganty abstract. It would have been obvious to one of ordinary skill in the art at the time of the filing to utilize the hot-pressing of Chung or Moganty for the cathode of Yun in order to increase the potential sulfur loading of the cathode.
With respect to claim 2, Yun uses electrospun carbon nanofibers that are made into a “flat microstructure” (paragraph bridging pp. 479 and 480). This constitutes a carbon paper giving the claim language its broadest reasonable interpretation.
With respect to the claims 3 and 4, Yun teaches a porous substrate constructed in an analogous manner to the present invention (e.g. electrospun PAN that is carbonized), but did not specify its weight per unit area. However, because Yun was constructed in entirely the same manner, it would arguably inherently already possess overlapping weight per unit area.
With respect to claim 10, Yun set forth 7 mAh/cm2 (abstract) which overlaps the claimed range.
With respect to claim 11, Yun disclosed overlapping areal specific capacity (see claim 10 above) and disclosed the battery energy density in terms of Wh/kg or Wh/L (first paragraph p. 475). However, the claim is defining the energy density in terms of mWh/cm2 which is essentially a battery thickness dependent measure of the same energy density. Because Yun (or Yun in view of either Chung or Moganty) set forth a specific capacity overlapping the claimed specific capacity expressed per cm2 of the cathode size, one of ordinary skill in the art would recognize that the battery either inherently possesses similarly overlapping energy density expressed per cm2 or it would have been obvious to one of ordinary skill in the art at the time of the filing to construct the battery of Yun in dimensions such that it provides the claimed energy density. Adjusting the size (i.e. thickness, length, and width) such that the battery fits in the desired application requires only routine skill in the art.
Claim(s) 3 and 4 in the alternative are rejected under 35 U.S.C. 103 as obvious over Yun in view of Chung with or without Moganty in further view of Zhamu et al (US 2011/0165462).
With respect to these claims in the alternative, even if this density was not merely a factor of the electrospinning process but also a function what the final density of fiber mat is compressed down to (see earlier rejection of these claims), then Zhamu teaches an alternative electrospinning process where the end result of the electrospun fibers is compressed down into a mat for eventual battery use (fig. 5 and par. 0135). Because the ultimate density of porous substrate per unit area will balance substrate integrity and electroconductivity against sulfur loading capacity, it would have been obvious to one of ordinary skill in the art at the time of the filing to modify the cathode substrate of Yun with the roller process of Zhami to control the ultimate weight per unit area of the substrate. Finding the desired level of weight per unit area requires only routine skill in the art.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yun in view of Chung with or without Moganty as applied to claim Dillard et al (US 10,971,733).
Yun set forth all the limitations of the claim but the average pore diameter of Yun (5.51 and 3.94 nm, p. 477, first column) does not read on the pore diameter of claim 5. Dillard however teaches an alternative carbon nanofiber electrode (including electrospun carbon nanofibers) and suggested that the average pore diameter is a result effective variable that was known to vary to arrive at the preferred sulfur loading properties (col.8, l. 65- col. 9, l. 30). It would have been obvious to one of ordinary skill in the art at the time of the filing for Yun to vary its average pore diameter as suggested by Dillard in order to arrive at the desired electroconductivity and sulfur loading balance.
Response to Arguments
Applicant's arguments filed 1/8/2026 have been fully considered but they are not persuasive. Applicant further urges that Yun and Chung differ from amended claim 1. In particular Yun does not disclose a hot-pressing process and does not teach the technical feature of a sulfur content of 70-80% in combination with an electrolyte of 7 to 4 μL/mg sulfur content. By contrast Chung teaches sulfur loadings of 10 mg/cm2 with a sulfur content of 65%. Chung also relies on carbon paper and not a porous substrate prepared by electrospinning.
Addressing the Yun arguments first, as discussed previously and reiterated in the modified rejections above, this hot-pressing does not further define the actual structure of the claim. If Yun otherwise recited the claimed sulfur content and substrate properties, it is unclear how hot pressing further defines the actual composition as this is just the method of achieving the levels of sulfur content. Moreover, even if this limitation were interpreted as being a positive recitation of structure, the examiner already established with Moganty and Chung that hot-pressing was well known in this art. As to the suggestion of 70-80% sulfur, this argument appears to be contradicted by Yun’s explicit teaching of 78.99% sulfur content (p. 479, first full paragraph).
Addressing the Chung arguments, it is unclear the relevance of Chung teaching 10 mg/cm2 as this reads on the claimed “at least 3 mg/cm2” and closely aligns with amounts suggested by Yun. As to Chung’s sulfur content of 65%, it is noted Chung earlier stated the desired sulfur loadings were “over 65%” (p. 1, second column, first full paragraph) and was clearly not limited to sulfur contents outside of the amended claim range. As to the difference between carbon paper and electrospun fibers, it is noted that the high surface area conductive substrate limitations were already met by Yun, which did teach electrospun fibers.
Applicant further urges that this combination of claimed sulfur content with the electrolyte to sulfur ratio is critical and exhibited a number of unexpected outstanding performance characteristics. First, it is noted that a number of these characteristics were already known in the art (see Chung, p. 6 last paragraph) and are clearly not unexpected. Second, although applicant urges these critical features of amended claim 1, the specification does not seem to support any criticality. In particular, table 2 only looked at examples with 70 or 73 % sulfur (both values read on the claims) and electrolyte-to-sulfur ratios of 7-4 (also all reading on the claims). The comparative example had sulfur content and an electrolyte to sulfur ratio reading on the claims and saw worse performance. How can either of these variables be deemed critical when we don’t any examples of these not being met and also see some examples being met where the performance was clearly worse with the claimed variables?
To further reinforce the unexpected advantages of the present invention, applicant urges that par. 0066 of the application PGPUB (par. 0065 in the actual specification) establishes that active material was hosted in the empty space of the carbon fibers rather than in the loose skeleton of a conductive substrate. The relevance of this point is not understood. There is nothing in the claims about any of this nor is it clear how this rebuts the present rejection where all the limitations of the claims are clearly suggested in the art.
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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/KAJ K OLSEN/Supervisory Patent Examiner, Art Unit 1714
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