DETAILED ACTION
Application 17/931903, “LITHIUM METAL SECONDARY BATTERY”, was filed with the USPTO on 9/14/22 and claims priority from a foreign application filed on 10/15/21.
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 11/26/25.
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, 3, 6 and 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Zhamu (US 2019/0393508), Fuller (J. Fuller et al; “Ionic Liquid‐Polymer Gel Electrolytes”; 1997 J. Electrochem. Soc. 144 L67) and Shin2 (US 2009/0286163).
Regarding claim 1, Zhamu teaches a lithium metal secondary battery (title, Fig. 2), comprising: a positive electrode (“cathode active material layer” of Fig. 2); a negative electrode current collector (“anode current collector” of Fig. 2); an electrolyte layer (“porous separator” of Fig. 2, which comprise an electrolyte to facilitate ion transfer between electrodes; see also paragraph [0064]) provided between the positive electrode and the negative electrode current collector; an intermediate layer (“sulfonated elastomer composite-based protective layer” of Fig. 2) provided between the positive electrode and the negative electrode current collector and comprising an expandable and contractible (“The sulfonated elastomer composite can expand and shrink responsive to the shrinkage and expansion of the anode active material layer”, paragraph [0134]), three-dimensional structure (“sulfonated elastomeric matrix material”, paragraph [0013]); and a liquid electrolyte held within the expandable and contractible, three-dimensional structure (paragraph [0087-0089] describe a liquid electrolyte, i.e. a salt with a solvent, present in the sulfonated elastomer in a polymerized state; see also paragraph [0133]).
Zhamu further teaches wherein the electrolyte layer is provided between the positive electrode and the intermediate layer (see arrangement of Fig. 2).
Regarding the 11/26/25 amendment to claim 1, Zhamu does not appear to teach wherein the expandable and contractible, three-dimensional structure is a polymer gel electrolyte consisting of an ionic liquid, a lithium salt, and a fluororesin, wherein the fluororesin is polyvinylidene fluoride or a vinylidene fluoride-hexafluoropropylene copolymer.
In the battery art, Fuller teaches an ionic liquid-polymer gel electrolyte (title), characterized by exhibiting desirable properties such as a rubbery/flexible structure, high ionic conductivity, thermal performance stability, inertness and low volatility, and excellent long-term storage characteristics (abstract; Introduction first paragraph; page L69 at third paragraph). Fuller further teaches the ionic liquid-polymer gel electrolyte consisting of an ionic liquid, a common nonaqueous support electrolyte salt and a fluororesin (PVDHFP, EMIPF6, TEABF4, page L69 at third paragraph).
It would have been obvious to a person having ordinary skill in the art at the time of invention to utilize a polymer gel electrolyte consisting of an ionic liquid, a salt, and a fluororesin, wherein the fluororesin is polyvinylidene fluoride or a vinylidene fluoride-hexafluoropropylene copolymer, as the expandable and contractible three-dimensional structure, for the benefit of employing a polymer electrolyte having the various desirable properties specified by Fuller.
It is noted that Fuller teaches TEABF4 as the support salt, which is not characterizes as a “lithium salt” as claimed. However, the skilled artisan at the time of invention would have understood TEABF4 (taught by Fuller) and a lithium salt, such as LiPF6 or LiBF4 (each taught by Zhamu) to be substitutable alternatives capable of providing the needed ionic conductivity for lithium battery electrolyte applications. See also Shin2 which teaches TEABF4 and LiPF6 as alternative suitable lithium salts (Table 2), and even characterizes TEABF4 as a “lithium salt”, even though it does not expressly include lithium ions (Shin2 at claim 17). Therefore, even though Shin2 does not characterize the gel electrolyte as including a lithium salt, this feature is obvious since the salt of Fuller is either broadly considerable as a lithium salt, or at least is an obvious variant thereof in view of the cited art.
Regarding claim 3, the cited art remains as applied to claim 1. Zhamu further teaches wherein the electrolyte layer is a solid electrolyte layer (paragraphs [0045, 0098]).
Regarding claim 6, the cited art remains as applied to claim 1. Claim 6 further requires wherein the expandable and contractible, three-dimensional structure comprises a composition comprising the fluororesin, having undergone compression molding, and then having undergone impregnation with a liquid comprising the ionic liquid.
However, as described in MPEP 2113, “The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process”. Here, the recitation as worded does not expressly require, nor otherwise imply, any particular structure which substantially differentiates the claimed intermediate layer from that of the cited art.
Regarding claim 7, the cited art remains as applied to claim 1. Zhamu further teaches wherein the intermediate layer further comprises lithium metal (paragraph [0076] describes lithium transferring from the cathode toward the anode current collector as an initial charging/deposition process. This results in a structure with lithium metal integrated with the three-dimensional structure, similar to the process described by applicant at applicant’s published paragraph [0026]).
Claims 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Zhamu (US 2019/0393508), Fuller (J. Fuller et al; “Ionic Liquid‐Polymer Gel Electrolytes”; 1997 J. Electrochem. Soc. 144 L67) and Shin2 (US 2009/0286163), and further in view of Singh (USP 10566659), Kuwajima (US 2020/0243911) or Takami (US 2022/0255133).
Regarding claim 8, the cited art remains as applied to claim 7. Zhamu further teaches wherein the intermediate layer has the expandable and contractible, three-dimensional structure integrated with at least some of the lithium metal (paragraph [0076] describes lithium transferring from the cathode toward the anode current collector as an initial charging/deposition process. This results in a structure with lithium metal integrated with the three-dimensional structure, similar to the process described by applicant at applicant’s published paragraph [0026]), but does not appear to teach wherein the layer has a fluorine content of 2.0 at% or more.
In the battery art, Singh teaches adding an additive to a molten-salt electrolyte [i.e. an ionic salt electrolyte], wherein the additive may include 10% of a fluorine containing additive, for example, trifluoromethylethyl methyl carbonate, for the benefit of decreasing viscosity and reducing melt temperature (c6:8-25).
In the battery art, Kuwajima teaches that a fluorine content of preferably 12% by mass or more may be added to an electrolyte composition in order to increase the viscosity thereof (paragraph [0103]), with an exemplary electrolyte composition being an ionic liquid (paragraph [0163]).
In the battery art, Takami teaches that a fluorine compound may be added to a composition in an amount of 10 to 30 wt% for the benefit of improving viscosity and low-temperature performance properties thereof (paragraph [0042]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to include 2 at% or more of fluorine in the intermediate layer for the benefit of improving the viscosity and/or low temperature properties of the ionic liquid component of the layer. The claimed range is found to be obvious because the cited art teaches fluorine content as a result-effective variable and suggests ranges which appear to overlap the claimed range.
Response to Arguments
Applicant’s arguments filed on 11/26/25 have been fully considered, but are moot in view of the new ground(s) of rejection necessitated by amendment.
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.
Kano (US 2022/0407047) teaches battery comprising an expanding layer 222 comprising lithium alloy;
Shembel (US 2003/0031933) teaches that thickness of polymer electrolyte layer and standard separators can change during charge/discharge cycle;
He (US 2020/0028178) lithium battery comprising elastomer layer than expands and shrinks in respond to anode active material layer;
Pan (US 2021/0218050) battery comprising expandable, contractable polymer gel electrolyte intermediate layer.
Conclusion
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 Mon-Fri: 9 AM-5 PM (EST).
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/JEREMIAH R SMITH/Primary Examiner, Art Unit 1723