Prosecution Insights
Last updated: April 19, 2026
Application No. 16/641,168

ELECTROLYTE COMPLEX FOR LITHIUM-SULFUR BATTERY, ELECTROCHEMICAL DEVICE INCLUDING THE SAME AND METHOD FOR PREPARING THE ELECTROCHEMICAL DEVICE

Final Rejection §102
Filed
Feb 21, 2020
Examiner
BERMUDEZ, CHARLENE
Art Unit
1721
Tech Center
1700 — Chemical & Materials Engineering
Assignee
ULSAN NATIONAL INSTITUTE OF SCIENCE AND TECHNOLOGY
OA Round
6 (Final)
35%
Grant Probability
At Risk
7-8
OA Rounds
4y 3m
To Grant
54%
With Interview

Examiner Intelligence

Grants only 35% of cases
35%
Career Allow Rate
26 granted / 74 resolved
-29.9% vs TC avg
Strong +19% interview lift
Without
With
+18.6%
Interview Lift
resolved cases with interview
Typical timeline
4y 3m
Avg Prosecution
24 currently pending
Career history
98
Total Applications
across all art units

Statute-Specific Performance

§103
55.7%
+15.7% vs TC avg
§102
23.4%
-16.6% vs TC avg
§112
18.8%
-21.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 74 resolved cases

Office Action

§102
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 . Summary Since the Office Action mailed on 14 July 2025, no amendments to the claims were made and claims 1, 4-7, and 9-13 remain in the application, which is being further examined in this Office Action, as well as applicant remarks being fully considered and responded to. The 102 rejection is maintained in this Office Action. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim Rejections - 35 USC § 102 Claims 1, 4-7, 9-13 and 15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Mikhaylik et al (US 2014/0062411 A1). This reference cited as Mikhaylik in this Office Action hereinafter. Regarding claim 1, Mikhaylik discloses an electrochemical device for a lithium-sulfur battery (“The lithium batteries described herein may include an anode having lithium ( e.g., lithium metal, a lithium intercalation compound, or a lithium alloy) as the active anode species and a cathode having sulfur as the active cathode species.” [0026]) comprising: a positive electrode (“Cathode 30 may include an active cathode material 32” [0030]), a negative electrode (“anode 10 comprising an active anode material layer 18” [0030]), and an electrolyte complex (“battery 6 includes a first polymer layer 24 residing at the anode and a second polymer layer 40 residing at the cathode” [0039]); wherein the positive electrode comprises sulfur (“an active cathode material 32 (e.g., sulfur)” [0030]), wherein the negative electrode comprises lithium (“an active anode material layer 18 ( e.g., lithium metal)” [0030]), wherein the electrolyte complex comprises a first solid phase electrolyte (“a second polymer layer 40 residing at the cathode” [0039]) and a second solid phase electrolyte (“a first polymer layer 24 residing at the anode” [0039]), wherein the first solid phase electrolyte and the second solid phase electrolyte are different from each other (“a "heterogeneous electrolyte" is an electrolyte including at least two different liquid solvents ( oftentimes referred to herein as first and second electrolyte solvents, or anode-side and cathode-side electrolyte solvents)” [0028]) and form a layered structure (“The two different liquid solvents may be miscible or immiscible with one another, although in many aspects of the invention, electrolyte systems include one or more solvents that are immiscible ( or can be made immiscible within the cell) to the extent that they will largely separate and at least one can be isolated from at least one component of the cell. A heterogeneous electrolyte may be in the form of a liquid, a gel, or a combination thereof.” [0028], and furthermore “The first and second electrolyte solvents were chosen for this particular electrochemical cell because dibutyl Ether does not dissolve polysulfide and is immiscible with polysulfides Solutions in 1,2-dimethoxyethane. Accordingly, the first and second electrolytes were expected to partition in this electrochemical cell.” [0120]), wherein the first solid phase electrolyte faces the positive electrode (“a second polymer layer 40 residing at the cathode” [0039]) and the second solid phase electrolyte faces the negative electrode (“a first polymer layer 24 residing at the anode” [0039]), wherein the first solid phase electrolyte comprises a first organic solvent having dielectric constant of 30 or more (“The cathode-side electrolyte solvent may have a relatively higher solubility towards polysulfides, but may be more reactive towards lithium metal. By separating the electrolyte solvents during operation of the battery such that the anode-side electrolyte solvent is present disproportionately at the anode and the cathode-side electrolyte solvent is present disproportionately at the cathode, the battery can benefit from desirable characteristics of both electrolyte solvents (e.g., relatively low lithium reactivity of the anode-side electrolyte solvent and relatively high polysulfide solubility of the cathode-side electrolyte solvent).” [0026], “electrolyte Solvents such as 1,2-dimethoxyethane have relatively high polysulfide solubility but are more reactive towards lithium metal, and, therefore, can cause corrosion of the anode and/or poor lithium morphology. Accordingly, in Some embodiments, batteries described herein include a heterogeneous electrolyte comprising at least a first electrolyte solvent and a second electrolyte solvent, wherein the first electrolyte solvent, which has characteristics that are more favorable towards the anode, is present disproportionately at the anode during operation of the battery, and the second electrolyte solvent, which has characteristics that are more favorable towards the cathode, is present disproportionately at the cathode.” [0031], and “Specific liquid electrolyte solvents that may be favorable towards the cathode ( e.g., have relatively high polysulfide solubility, and/or can enable high rate capability and/or high sulfur utilization) include, but are not limited to dimethoxyethane (DME, 1,2-dimethoxyethane) or glyme, diglyme, triglyme, tetraglyme, polyglymes, sulfolane” [0062] with italics added for emphasis on the common rationale behind selecting compounds for the corresponding first organic solvent and on dimethoxyethane and sulfolane being an alternative compounds to each other where sulfolane is a sulfone-based component that has a dielectric constant of 43.4), a first lithium salt (“a polymer layer is formed by depositing a mixture of a monomer and a solvent (e.g., an electrolyte solvent), optionally including other components such as crosslinking agents, lithium salts, etc., onto an electrode surface.” [0057] with italics added for emphasis, where “ionic electrolyte salts for use in the electrolytes of the present invention include, but are not limited to, LiSCN, LiBr, LiI, LiClO4, LiAsF6, LiSO3CF3, LiSO3CH3, LiBF4, LiB(Ph)4, LiPF6, LiC(SO2CF3)3, and LiN(SO2CF3)2.” [0070] and a “The cathode and porous separator were filled with 84 wt % of 1,2-dimethoxyethane and 16 wt % of salt-lithium bis(trifluoromethanesulfoneimide) ( e.g., a second electrolyte solvent).” [0116] was used in Example 6), a first polymer formed by polymerization of a first crosslinkable monomer (“a polymer layer is formed by depositing a mixture of a monomer and a solvent (e.g., an electrolyte solvent), optionally including other components such as crosslinking agents, lithium salts, etc., onto an electrode surface. The mixture may then be polymerized and/or crosslinked to form a polymer gel.” [0057]) and a first inorganic particle (“polymer layer(s) in contact with the anode or cathode, the polymer layer(s) may optionally comprise a filler. The filler may be dispersed within the polymer, may be added as a layer on the polymer, and/or may fill any pores in the polymer. The filler may comprise, for example, a metal, a polymer, or a ceramic. In one embodiment, the filler is a heterogeneous insoluble material. The filler may comprise, in some embodiments, a metal oxide, an oxy-hydroxide, a sulfide, a nitride, or a combination thereof. For example, the filler may include one or more of Al2O3, AlOOH, SiO2 , AlN, BN, and Li3N” [0054]), wherein the second solid phase electrolyte comprises a second organic solvent having dielectric constant of 20 or less (“By separating the electrolyte solvents during operation of the battery such that the anode-side electrolyte solvent is present disproportionately at the anode and the cathode-side electrolyte solvent is present disproportionately at the cathode, the battery can benefit from desirable characteristics of both electrolyte solvents (e.g., relatively low lithium reactivity of the anode-side electrolyte solvent” [0026], “For instance, an electrolyte including the solvent dioxolane generally has relatively low reactivity towards lithium and has good lithium ion conductivity, but has relatively low polysulfide solubility” [0031], further supported in “partitioning of a heterogeneous electrolyte such that a first electrolyte solvent that has characteristics favorable towards the anode (e.g., low reactivity towards lithium, good lithium ion conductivity, and relatively low polysulfide solubility) is present disproportionately at the anode” [0043] with italics collectively added to link the common rationale behind selecting dioxolane as the corresponding second organic solvent, which is known in the art to have a dielectric constant of about 7.13), a second polymer formed by polymerization of a second crosslinkable monomer (“a polymer layer is formed by depositing a mixture of a monomer and a solvent (e.g., an electrolyte solvent), optionally including other components such as crosslinking agents, lithium salts, etc., onto an electrode surface. The mixture may then be polymerized and/or crosslinked to form a polymer gel.” [0057]) and a second inorganic particle (“polymer layer(s) in contact with the anode or cathode, the polymer layer(s) may optionally comprise a filler. The filler may be dispersed within the polymer, may be added as a layer on the polymer, and/or may fill any pores in the polymer. The filler may comprise, for example, a metal, a polymer, or a ceramic. In one embodiment, the filler is a heterogeneous insoluble material. The filler may comprise, in some embodiments, a metal oxide, an oxy-hydroxide, a sulfide, a nitride, or a combination thereof. For example, the filler may include one or more of Al2O3, AlOOH, SiO2 , AlN, BN, and Li3N” [0054]), wherein the second lithium salt and the second polymer are dispersed in the second solid phase electrolyte (“a polymer layer is formed by depositing a mixture of a monomer and a solvent (e.g., an electrolyte solvent), optionally including other components such as crosslinking agents, lithium salts, etc., onto an electrode surface. The mixture may then be polymerized and/or crosslinked to form a polymer gel.” [0057] and “The filler may be dispersed within the polymer” [0054]), wherein the first organic solvent is selected from the group consisting of sulfone-based organic solvent (sulfolane” [0062] with italics added for emphasis on sulfolane, which is sulfone based and has a dielectric constant of 43.4), carbonate-based organic solvent and gamma-butyrolactone, and wherein the second organic solvent is selected from the group consisting of tetrahydrofuran and dioxolane (“relatively low lithium reactivity of the anode-side electrolyte solvent” [0026], “For instance, an electrolyte including the solvent dioxolane generally has relatively low reactivity towards lithium” [0031]). Regarding claim 4¸ Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein the first lithium salt is at least one selected from the group consisting of lithium bis(trifluoromethane sulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium hexafluoroantimonate, lithium difluoromethane sulfonate, lithium aluminate, lithium tetrachloroaluminate, lithium chloride, lithium iodide, lithium bis(oxalate)borate, and lithium trifluoromethane sulfonyl imide (“ionic electrolyte salts for use in the electrolytes of the present invention include, but are not limited to, LiSCN, LiBr, LiI, LiClO4, LiAsF6, LiSO3CF3, LiSO3CH3, LiBF4, LiB(Ph)4, LiPF6, LiC(SO2CF3)3, and LiN(SO2CF3)2.” [0070] and a “The cathode and porous separator were filled with 84 wt % of 1,2-dimethoxyethane and 16 wt % of salt-lithium bis(trifluoromethanesulfoneimide) ( e.g., a second electrolyte solvent).” [0116] was used in Example 6). Regarding claim 5, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein the first crosslinkable monomer is at least one selected from the group consisting of polyethylene glycol diacrylate (“Monomers can also be crosslinked, if desired, with any suitable crosslinker, such as aziridines, divinyibenzene, diacrylates,” [0053]), triethylene glycol diacrylate (“Monomers can also be crosslinked, if desired, with any suitable crosslinker, such as aziridines, divinyibenzene, diacrylates,” [0053]), trimethylolpropane ethoxylate triacrylate, and bisphenol A ethoxylate dimethacrylate (“Monomers can also be crosslinked, if desired, with any suitable crosslinker, such as aziridines, divinyibenzene, diacrylates, dimethacrylates,” [0053]). Regarding claim 6, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein the first inorganic particle is at least one selected from the group consisting of alumina (Al2O3), silicon dioxide (SiO2), titanium dioxide (TiO2), barium titanate (BaTiO3), lithium oxide (Li2O), lithium fluoride (LiF), lithium hydroxide (LiOH), lithium nitride (Li3N), barium oxide (BaO), sodium oxide (Na2O), lithium carbonate (Li2CO3), calcium carbonate (CaCO3), lithium aluminate (LiAlO2), strontium titanate (SrTiO3), tin oxide (SnO2), cerium oxide (CeO2), magnesium oxide (MgO), nickel oxide (NiO) calcium oxide (CaO), zinc oxide (ZnO), zirconium dioxide (ZrO2), and silicon carbide (SiC) (“the filler may include one or more of Al2O3, AlOOH, SiO2, AlN, BN, and Li3N” [0054] with italics added for emphasis on the disclosed compounds that correspond to the claimed first inorganic particle). Regarding claim 7, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein a thickness of the first solid phase electrolyte is 100 µm or less (“The thickness of a polymer layer may vary, e.g., over a range from about 0.1 microns to about 100 microns” [0056]). Regarding claim 9, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein the second organic solvent is dioxolane (“A gel polymer electrolyte was formed by mixing 8.9 g of electrolyte ( dimethoxyethane ( 40% ), dioxolane ( 40% )” [0100] with italics added for emphasis in Example 1). Regarding claim 10, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein the second lithium salt is at least one selected from the group consisting of lithium bis(trifluoromethane sulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium hexafluoroantimonate, lithium difluoromethane sulfonate, lithium aluminate, lithium tetrachloroaluminate, lithium chloride, lithium iodide, lithium bis(oxalate)borate, and lithium trifluoromethane sulfonyl imide (“ionic electrolyte salts for use in the electrolytes of the present invention include, but are not limited to, LiSCN, LiBr, LiI, LiClO4, LiAsF6, LiSO3CF3, LiSO3CH3, LiBF4, LiB(Ph)4, LiPF6, LiC(SO2CF3)3, and LiN(SO2CF3)2.” [0070] and a “The cathode and porous separator were filled with 84 wt % of 1,2-dimethoxyethane and 16 wt % of salt-lithium bis(trifluoromethanesulfoneimide) ( e.g., a second electrolyte solvent).” [0116] was used in Example 6). Regarding claim 11, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein the second crosslinkable monomer is at least one selected from the group consisting of polyethylene glycol diacrylate (“Monomers can also be crosslinked, if desired, with any suitable crosslinker, such as aziridines, divinyibenzene, diacrylates,” [0053]), triethylene glycol diacrylate (“Monomers can also be crosslinked, if desired, with any suitable crosslinker, such as aziridines, divinyibenzene, diacrylates,” [0053]), trimethylolpropane ethoxylate triacrylate, and bisphenol A ethoxylate dimethacrylate (“Monomers can also be crosslinked, if desired, with any suitable crosslinker, such as aziridines, divinyibenzene, diacrylates, dimethacrylates,” [0053]). Regarding claim 12, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein the second inorganic particle is at least one selected from the group consisting of alumina (Al2O3), silicon dioxide (SiO2), titanium dioxide (TiO2), barium titanate (BaTiO3), lithium oxide (Li2O), lithium fluoride (LiF), lithium hydroxide (LiOH), lithium nitride (Li3N), barium oxide (BaO), sodium oxide (Na2O), lithium carbonate (Li2CO3), calcium carbonate (CaCO3), lithium aluminate (LiAlO2), strontium titanate (SrTiO3), tin oxide (SnO2), cerium oxide (CeO2), magnesium oxide (MgO), nickel oxide (NiO) calcium oxide (CaO), zinc oxide (ZnO), zirconium dioxide (ZrO2), and silicon carbide (SiC) (“the filler may include one or more of Al2O3, AlOOH, SiO2, AlN, BN, and Li3N” [0054] with italics added for emphasis on the disclosed compounds that correspond to the claimed first inorganic particle). Regarding claim 13, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein a thickness of the second solid phase electrolyte is 100 µm or less (“The thickness of a polymer layer may vary, e.g., over a range from about 0.1 microns to about 100 microns” [0056]). Regarding claim 15, Mikhaylik discloses the electrochemical device for a lithium-sulfur battery with all the features set forth in claim 1 above, and wherein an interfacial resistance between the electrolyte complex and the positive or negative electrode is reduced by integration of the electrolyte complex and the positive or negative electrode (“in one set of embodiments a heterogeneous electrolyte is used. Any liquid or gel material capable of storing and transporting ions ( e.g., lithium ions for a lithium battery) may be used, including a combination of liquids, a combination of liquid(s) and a polymer, etc., so long as the material(s) facilitates the transport of lithium ions between the anode and the cathode. The electrolyte may be electronically non-conductive to prevent short circuiting between the anode and the cathode.” [0060]). Response to Arguments Applicant's arguments filed 14 October 2025 have been fully considered but they are not persuasive. Applicant appears to remark that prior art reference does not disclose the claim limitations in claim 1 of “the second solid phase electrolyte faces the negative electrode, … wherein the second solid phase electrolyte comprises a second organic solvent …, and wherein the second organic solvent is selected from the group consisting of tetrahydrofuran and dioxolane.”, but instead discloses that tetrahydrofuran and dioxolane are taught to face the positive electrode. In response to applicant remark described above, this Office Action reflects a clearer perspective of what Mikhaylik teaches. To reiterate the citations in this Office Action, the organic solvent selected toward the positive electrode, or the corresponding first organic solvent, has a relatively higher solubility towards polysulfides such as 1,2-dimethoxyethane ([0026] and [0031]) in which sulfolane is disclosed to be an alternative to ([0062]), and the organic solvent selected toward the negative electrode, or the corresponding second organic solvent, has a relatively low lithium reactivity in which dioxolane functions as in Mikhaylik. Applicant appears to remark that Mikhaylik does not discuss the importance of controlling the solvents with regard to dielectric constant. In response to applicant remark described above, claim 1 requires first and second organic solvents to have the recited dielectric constants, which all organic solvents have inherent dielectric constants known in the art, and does not require prior art reference to disclose or teach the significance behind the controlled dielectric constant. 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 CHARLENE BERMUDEZ whose telephone number is (571)272-0610. The examiner can normally be reached Tuesdays and Thursdays generally from 10 AM to 7 PM EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Allison Bourke can be reached at (303) 297-4684. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /CHARLENE BERMUDEZ/Examiner, Art Unit 1721 /SADIE WHITE/Primary Examiner, Art Unit 1721
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Prosecution Timeline

Feb 21, 2020
Application Filed
May 19, 2022
Non-Final Rejection — §102
Jun 02, 2022
Applicant Interview (Telephonic)
Jun 02, 2022
Examiner Interview Summary
Aug 24, 2022
Response Filed
Nov 11, 2022
Final Rejection — §102
Feb 09, 2023
Examiner Interview Summary
Feb 09, 2023
Applicant Interview (Telephonic)
Feb 21, 2023
Response after Non-Final Action
Mar 16, 2023
Response after Non-Final Action
Apr 14, 2023
Request for Continued Examination
Apr 17, 2023
Response after Non-Final Action
Oct 23, 2023
Non-Final Rejection — §102
Feb 07, 2024
Response Filed
Apr 11, 2024
Final Rejection — §102
Jun 11, 2024
Interview Requested
Jun 24, 2024
Applicant Interview (Telephonic)
Jun 24, 2024
Examiner Interview Summary
Jul 17, 2024
Response after Non-Final Action
Aug 09, 2024
Response after Non-Final Action
Sep 13, 2024
Request for Continued Examination
Sep 19, 2024
Response after Non-Final Action
Jul 11, 2025
Non-Final Rejection — §102
Aug 21, 2025
Applicant Interview (Telephonic)
Aug 21, 2025
Examiner Interview Summary
Oct 14, 2025
Response Filed
Dec 30, 2025
Final Rejection — §102
Apr 02, 2026
Request for Continued Examination
Apr 05, 2026
Response after Non-Final Action

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Prosecution Projections

7-8
Expected OA Rounds
35%
Grant Probability
54%
With Interview (+18.6%)
4y 3m
Median Time to Grant
High
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