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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/05/2025 has been entered.
Response to Amendment
The amendments filed 11/05/2025 have been entered. Claims 1 and 7 are amended and Claim 4 is cancelled.
Support for the amendments can be found in original Claim 4 and Table 2 of the instant specification.
Claims 1, 3, 5-8, and 10-12 are pending.
Response to Arguments
Applicant's arguments with respect to amended Claim 1 have been fully considered but they are not persuasive.
On page 6, Applicant argues that the electrode material of modified Yan is not made with the same pressure as claimed in amended Claim 7 (3 MPa to 15 MPa) and would therefore have a different adhesive strength. Although this is true, Applicant does not provide sufficient evidence that this difference in pressure would result in the electrode material of modified Yan having an adhesive strength below 10 gf/cm. Example 1 in Table 2 of the instant specification is pressurized at a pressure of 1 MPa and has an adhesive strength of 18 gf/cm, which indicates that a pressure of 3 MPa is not required to have an adhesive strength of 10 gf/cm or more. Similarly, Comparative Examples 1-3 are not pressurized but still have an adhesive strength of 10 gf/cm or more.
On pages 6 and 7, Applicant argues that Yan and Zafiropoulos do not disclose the claimed porosity and that the prior art does not provide motivation to arrive at the claimed porosity range. However, Kang teaches an overlapping porosity range and that that range is optimal for a balanced sulfur utilization and cell-level energy density. Thus, there is motivation for one of ordinary skill in the art to modify the electrode material of modified Yan to have an overlapping porosity range. Regarding Zafiropoulos, the selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05).
Applicant’s arguments with respect to amended claim(s) 7 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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, 3, 5-6, and 10-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yan (US 20200168893 A1) in view of Kang (Cathode porosity is a missing key parameter to optimize lithium-sulfur battery energy density).
Regarding Claims 1, 5, and 6, Yan teaches a positive electrode consisting of a positive electrode material in the form of a free-standing film (0066 – S/CNT sponge, 0078 – S/CNT film). The positive electrode material consists of a carbon-containing sulfur melt which consists of a porous carbon material dispersed in the sulfur melt (0075, 0077). The porous materials are carbon nanotubes which can be single wall carbon nanotubes (SWCNT) or multiwall carbon nanotubes (MWCNT) (0056) (Claim 5).
Yan does not disclose the porosity of the positive electrode material.
Kang teaches that the porosity of a sulfur/carbon cathode (Abstract) can be modified to be between 40% and 70% through calendaring (Pg. 2 – Electrochemical performance of cells with different porosity). Kang suggests that a porosity between 50% and 60% is optimal for a balanced sulfur utilization and cell-level energy density (Pg. 7 – Critical parameters for cell-level design). This would meet the claimed ranges of above 45% (Claim 1) and below 68% (Claim 6).
Yan and Kang are considered analogous to the claimed invention as they relate to the same field of endeavor, namely lithium-sulfur cells.
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 modified the positive electrode material of Yan to have a porosity between 50% and 60% as taught by Kang in order to provide an optimal balance between sulfur utilization and cell-level energy density.
Modified Yan does not disclose the adhesive strength of the material.
However, it has been held that “Products of identical chemical composition cannot have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F .2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
In this case, modified Yan teaches a positive electrode material in the form of a free-standing film with the same composition (50 wt% sulfur, 50 wt% porous carbon material) as the claimed invention. Modified Yan also teaches that the material is made in substantially similar manner as the claimed invention: mixing sulfur with a porous carbon material (carbon nanotubes) and heat treating the mixture at a temperature of 150°C (Yan: 0066). Therefore, one of ordinary skill in the art would understand that the positive electrode material of modified Yan would have the same adhesive strength as the claimed invention (10 gf/cm or more) as the material of modified Yan has the same composition and is made in a substantially similar way.
Applicant is invited to provide evidence showing any differences between modified Yan and the present invention that would result in the positive electrode material of modified Yan having an adhesive strength below the claimed amount.
Regarding Claim 3, modified Yan teaches the electrode of Claim 1. Modified Yan teaches that the mass content (which is equivalent to wt.%) of the sulfur ranges from 40% to 60% (Yan: 0071). This would correspond to the porous carbon material having a mass content/wt.% of 60% to 40%, respectively. These ranges would overlap the claimed ranges of 50 wt.% to 80 wt.% of sulfur and 20 wt.% to 50 wt.% of the porous carbon material. Yan teaches an embodiment where the sulfur ratio is 50 wt.%. (Yan: 0085).
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 the overlapping portions of the disclosed wt.% ranges as selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05).
Regarding Claim 10, modified Yan teaches a lithium secondary battery comprising a positive electrode according to Claim 1, a negative electrode comprising lithium metal (Yan: 0092), a separator positioned between the positive and negative electrodes, and an electrolyte solution impregnating the positive electrode, negative electrode, and separator (Yan: 0073).
Regarding Claim 11, modified Yan teaches the battery of Claim 10. The battery is a lithium-sulfur battery (Yan: 0073) which is a secondary battery (Yan: 0003).
Regarding Claim 12, modified Yan teaches the battery of Claim 10. Modified Yan does not teach an embodiment where the loading amount (areal capacity) is from 3 to 5 mAh/cm2 (Fig. 15 shows an embodiment where the areal capacity is around 2.1 mAh/cm2 at an areal density of 2.5 mg/cm2). However, modified Yan does teach that the areal density can be greater than 2 mg/cm2 (0071). One of ordinary skill would understand that increasing areal density would increase areal capacity/loading amount.
Kang teaches that sulfur-carbon cathodes can have an areal capacity (loading amount) between 1 and 5 mAh/cm2 (Pg. 8, Fig. 4). This would overlap the claimed loading amount/areal capacity of 3 to 5 mAh/cm2.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the areal density of the cathode material of modified Yan to achieve the areal capacities taught by Kang as they are known areal capacities known in the art.
It would also have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have routinely selected the overlapping portions of the disclosed loading amount/areal capacity ranges as selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05).
Claim(s) 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yan and Kang as applied to claim 1 above, and further in view of Woo (US 20140186522 A1)
Regarding Claim 7, modified Yan teaches the positive electrode of Claim 1. Yan teaches a method of preparing the positive electrode comprising mixing sulfur and the porous carbon material to form a mixture (0075, 0077), and heating-treating the mixture (0075, 0077 – the S/CNT sponge and film are heated at 155°C). The S/CNT film is sealed in a steel vessel (filled in a container) (0077).
Modified Yan does not teach that the sulfur-carbon composite is filled in a container and pressurized at a pressure from 0.8 MPa to 15 MPa.
Woo teaches a method of forming sulfur-infiltrated mesoporous nanocomposites for a cathode (Abstract). The mesoporous material can be a porous carbon material (0049). The method involves pressurizing a mixture of sulfur and carbon in a container/reactor at a pressure between 1 and 100 bar (0.1 to 10 MPa) (Claim 6). This allows for the generation of a capillary force in the pores of the porous carbon material without unnecessarily high costs (0058).
Woo is considered analogous to the present invention as it relates to the same field of endeavor, namely lithium-sulfur batteries.
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 modified the method of modified Yan to include a pressurization step at a pressure between 1 and 100 bar (0.1 to 10 MPa) as taught by Woo as it is known step in forming a sulfur-carbon cathode that allows for the generation of a capillary force in the pores of the carbon material without unnecessarily high costs.
It would also have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have routinely selected the overlapping portions of the disclosed pressure ranges as selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05).
Examiner notes that the carbon-sulfur melts of Woo are ground to form nanocomposites (Title; Fig. 3) rather than a free-standing film.
Regarding Claim 8, modified Yan teaches the method of Claim 7. The heat treatment is performed at a temperature of 155°C (Yan: 0075, 0077).
Claim(s) 1, 3, 5-6, and 10-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zafiropoulos (US 20200303723 A1).
Regarding Claims 1, 5, and 6, Zafiropoulos teaches a positive electrode consisting of a porous carbon sulfur composite (Abstract, 0021). The porous carbon sulfur composite can be in the form of a free-standing film (0023) and can consists of a porous carbon material dispersed in a sulfur melt (0021, 0026 – the sulfur can be incorporated through melt infusion). The porous carbon sulfur composite can be graphitized (0025), meaning that the porous carbon material is graphite (Claims 1 and 5). Zafiropoulos teaches that the porosity of the positive electrode material can be between 10% and 90% (0021). This range overlaps the claimed porosity ranges of 45% (Claim 1) or more and 68% or less (Claim 6).
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 the overlapping portions of the disclosed porosity ranges as selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05).
Modified Zafiropoulos does not disclose the adhesive strength of the material.
However, it has been held that “Products of identical chemical composition cannot have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F .2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
In this case, modified Zafiropoulos teaches a positive electrode material in the form of a free-standing film with overlapping sulfur and porous carbon material weight ranges (0021 – see Claim 3 above; 0103 teaches an embodiment with about 70 wt% sulfur and 30 wt% carbon material) as the claimed invention. Modified Zafiropoulos also teaches that the material is made in substantially similar manner as the claimed invention: mixing sulfur with a porous carbon material (carbon nanotubes) and heat treating the mixture at a temperature of 155°C (0103 – Example 2). Examiner notes that the positive electrode active material is used in a cathode with a binder and current collector in Example 3; However, Zafiropoulos also teaches embodiments where the cathode is collector-less and binder-free (Abstract). One of ordinary skill in the art would understand that the positive electrode material of modified Zafiropoulos would have the same adhesive strength as the claimed invention (10 gf/cm or more) as the material of modified Zafiropoulos has the same composition and is made in a substantially similar way.
Applicant is invited to provide evidence showing any differences between modified Zafiropoulos and the present invention that would result in the positive electrode material of modified Zafiropoulos having an adhesive strength below the claimed amount.
Regarding Claim 3, modified Zafiropoulos teaches the positive electrode of Claim 1. Zafiropoulos teaches that the porous carbon sulfur composite comprises between 0% and 95% by weight sulfur (0021). This would correspond to the carbon being present in an amount between 100% and 5% by weight. These ranges overlap the claimed sulfur range of 50 wt.% to 80 wt.% and the claimed porous carbon material range of 20 wt.% to 50 wt.%.
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 the overlapping portions of the disclosed weight ranges as selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05).
Regarding Claim 10, modified Zafiropoulos teaches the positive electrode of Claim 1 and that it can be used in a lithium secondary battery comprising a lithium foil negative electrode, a separator between the positive and negative electrodes, and an electrolyte solution impregnating the positive electrode, negative electrode, and separator (Abstract, 0028, 0105).
Regarding Claim 11, modified Zafiropoulos teaches the battery of Claim 10. The battery can be a lithium-sulfur battery (0028).
Claim(s) 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zafiropoulos as applied to claim 1 above, and further in view of Woo (US 20140186522 A1).
Regarding Claim 7, modified Zafiropoulos teaches the positive electrode of Claim 1. Zafiropoulos teaches a method of making a positive electrode material comprising mixing sulfur and a porous carbon material and heat treating the mixture (0103 – Example 2). The mixture is placed in a container (0103 – vial). Examiner notes that the positive electrode active material made in Example 2 is used in a cathode with a binder and current collector in Example 3; However, Zafiropoulos also teaches embodiments where the cathode is collector-less and binder-free (Abstract).
Modified Zafiropoulos does not teach that the carbon-sulfur mixture is filled in a container and pressurized at a pressure from 0.8 MPa to 15 MPa.
Woo teaches a method of forming sulfur-infiltrated mesoporous nanocomposites for a cathode (Abstract). The mesoporous material can be a porous carbon material (0049). The method involves pressurizing a mixture of sulfur and carbon in a container/reactor at a pressure between 1 and 100 bar (0.1 to 10 MPa) (Claim 6). This allows for the generation of a capillary force in the pores of the porous carbon material without unnecessarily high costs (0058).
Woo is considered analogous to the present invention as it relates to the same field of endeavor, namely lithium-sulfur batteries.
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 modified the method of modified Zafiropoulos to include the pressurization step at a pressure between 1 and 100 bar (0.1 to 10 MPa) as taught by Woo as it is known step in forming a sulfur-carbon cathode that allows for the generation of a capillary force in the pores of the carbon material without unnecessarily high costs.
It would also have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have routinely selected the overlapping portions of the disclosed pressure ranges as selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (see MPEP 2144.05).
Examiner notes that the carbon-sulfur melts of Woo are ground to form nanocomposites (Title; Fig. 3) rather than a free-standing film.
Regarding Claim 8, modified Zafiropoulos teaches the method of Claim 7. The heat-treatment is performed at 155°C (Zafiropoulos: 0103).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Sun (US 20140099536 A1) teaches a method of preparing a carbon-sulfur complex where a pressure between 1 MPa and 2 Mpa is applied (Example 2).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZIHENG LU whose telephone number is (703)756-1077. The examiner can normally be reached Monday-Friday 8:30 - 5 ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nicholas Smith can be reached at (571) 272-8760. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ZIHENG LU/Examiner, Art Unit 1752
/NICHOLAS A SMITH/Supervisory Primary Examiner, Art Unit 1752