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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 6/4/2026 has been entered.
Response to Amendment
The Amendment filed on 5/6/2026 has been entered. Claims 1-9 remain pending in the application. Claims 7-9 are withdrawn.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-4 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Xu et al. (Artificial Soft–Rigid Protective Layer for Dendrite-Free Lithium Metal Anode, hereinafter "Xu").
Regarding claim 1, Xu teaches an anode (“negative electrode”) for a lithium metal battery, or LMB (“secondary battery”) [pg. 6, col. 1, “The design of an organic–inorganic hybrid artificial protective layer not only provides a practically feasible approach to enable and improve Li metal anodes but also sheds new light on the understanding of interfacial stabilization, Li protection, materials synergy, and eventual practical applications of high-energy-density LMBs”]. Xu teaches that an artificial protective layer, or APL (“coating layer”), consisting of PVDF-HFP (“polyvinylidene fluoride-based polymer) and LiF, is coated on a Cu electrode (“current collector”) [pg. 3., col. 1, “In contrast, after the Cu electrode being coated with an APL”, pg. 4, Figure 3 caption, “APL-modified Cu foils”]. Xu does not teach any other components in the APL. When the APL is applied directly to the Cu electrode, the anode does not include any negative active material. Xu teaches that is not until the Cu electrode is cycled, that Li metal is deposited between the APL and the Cu electrode [pg. 4, col. 1, “morphologies of Li deposits without or underneath various protective layers were investigated”, “Notably, the APL, endowed with excellent shape conformability and high modulus by soft PVDF-HFP and rigid LiF, respectively, guided dense and uniform Li deposition”, Xu Fig. 3e]. This mechanism is substantially the same as that taught in [0025] of the published application of the present invention for an “anodeless” battery [0025, “In addition, during charging and discharging of the lithium secondary battery, lithium ions released from a positive active material are deposited on a negative current collector and lithium deposited on the negative current collector acts and is used as a negative active material”]. While Xu does not explicitly call the Cu electrode a current collector, the Cu electrode/foil is performing the function of a current collector, as seen in Fig. 3e. Therefore, prior to the Li deposition, the anode taught by Xu comprising bare Cu electrode coated with the APL has the same structure as claimed.
Further regarding claim 2, Xu teaches that the APL contains PVDF-HFP in a larger amount that LiF [pg. 2, col. 2, “As-obtained APL, with a PVDF-HFP/LiF mass ratio of 2:1”].
Further regarding claim 3, Xu teaches that the APL contains PVDF-HFP and LiF in a mass ratio of 2:1, which is within the recited range of 9:1 to 5:5 [pg. 2, col. 2, “As-obtained APL, with a PVDF-HFP/LiF mass ratio of 2:1”].
Further regarding claim 4, as described in the rejection of claim 1 above, Xu teaches that the APL contains PVDF-HFP [pg. 2, col. 1, “In this contribution, poly(vinylidene-co-hexafluoropropylene) (PVDF-HFP) and LiF are rationally hybridized”].
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 5 is rejected under 35 U.S.C. 103 as being unpatentable over Xu (Artificial Soft–Rigid Protective Layer for Dendrite-Free Lithium Metal Anode) as applied to claim 1 above, and further in view of Xiao et al. (US 2019/0312254, hereinafter "Xiao").
Regarding claim 5, Xu teaches the negative electrode of claim 1, as described in the rejection of instant claim 1. Xu does not specifically teach the LiF having a particle diameter of 5 nm to 1000 nm.
Xiao teaches analogous art of a protective coating for a lithium-containing electrode, the protective coating (“coating layer”) including a fluoropolymeric matrix and LiF compounds [Abstract, “The protective coating has a first layer including a first fluoropolymeric matrix and Li—F compounds”]. Xiao teaches that the protective coating includes a layer of a PTFE-derived coating comprising crystalline LiF, identified as nano-sized LiF particles [0099, “FIGS. 6 and 7A-7C provide structural characterization of the PTFE-derived coatings”, “the nano-sized particles in the fluoropolymeric matrix shown in FIGS. 5A-5C were identified as LiF”]. Xiao also teaches a PVDF-derived coating in the protective coating which comprises the crystalline LiF [0100, “FIGS. 8 and 9A-9C provide the structural characterization of the PVDF-derived coatings”, “the asterisks identify peaks associated with crystalline LiF”]. Xiao teaches that the nano-sized particles in the coatings (found to be crystalline LiF) have a characteristic length of 100 nm, which is within the recited range of 5 nm to 1000 nm [0098, “some nano-sized (˜100 nm characteristic length) particles were embedded in the matrix”].
Both Xiao and Xu teach a protective coating layer that reduces lithium dendrite growth in an electrode. Xiao teaches a protective coating layer including a fluoropolymeric matrix and LiF compounds that can advantageously prevent or reduce lithium dendrite growth in an electrode [0056, “It has been discovered that a multi-layer, for example, a two layer, protective coating including a fluoropolymeric matrix and lithium-fluoride (Li—F) bonds or Li—F compounds on a Li-containing electrode can advantageously prevent and/or reduce lithium dendrite growth and mossy lithium formation on the Li-containing electrode”]. The APL of Xu also suppresses lithium dendrite growth [pg. 6, col. 1, “In summary, an artificial protective layer with favorable synergy of softness and rigidity was demonstrated to achieve high-efficiency, long-life, and dendrite-free Li metal anodes”].
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute the known particle size of the LiF taught by Xiao in the APL of Xu, and the result, the formation of a protective coating layer, would have been predictable (see MPEP 2143 I B, “The rationale to support a conclusion that the claim would have been obvious is that the substitution of one known element for another yields predictable results to one of ordinary skill in the art”).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Xu (Artificial Soft–Rigid Protective Layer for Dendrite-Free Lithium Metal Anode) as applied to claim 1 above, and further in view of Jung et al. (KR 20190024761, cited in Applicant IDS, referring to US 2021/0336274 as English translation thereof, hereinafter "Jung").
Regarding claim 6, Xu teaches the negative electrode of claim 1, as described in the rejection for instant claim 1. Xu does not specifically teach the thickness of the coating layer being within the recited range of 1 µm to 10 µm.
Jung teaches analogous art of a lithium secondary battery comprising a negative electrode, wherein a negative electrode current collector may comprise a protective film (“coating layer”) [0092, “the lithium secondary battery according to a second embodiment of the present invention may form a protective film (55) on the negative electrode current collector”]. Jung teaches that the protective film may comprise a lithium ion conducting polymer, such as PVDF-HFP, and a lithium salt [0094, “materials used in lithium ion conducting polymers and/or inorganic solid electrolytes may be used, and as necessary, a lithium salt may be further included”, 0095, “Examples of the lithium ion conducting polymer may include any one selected from the group consisting of … polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP)”]. Jung teaches a specific example of the protective film coated on the current collector being 10 µm, which is within the recited range of 1 µm to 10 µm [0146, “the result was dried for 3 hours at 50° C. to form a protective film (thickness: 10 μm) on the Cu current collector”].
Jung teaches that a protective film having a smaller thickness is advantageous for the output of a battery but also needs to be thick enough to suppress side reactions between with an electrolyte [0106, “The protective film (55) having a smaller thickness is advantageous for output properties of a battery … needs to be formed to a certain thickness or higher in order to suppress side reactions between an electrolyte and lithium formed on the negative electrode current collector”]. Jung teaches that the thickness of the protective film is preferably 10 nm to 50 µm in order to enhance safety and prevent performance decline [0106].
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to modify the coating layer taught by Xu to have the thickness taught by Jung, in order to prevent side reactions of the negative electrode with an electrolyte, enhance safety, and prevent performance decline of the battery.
Response to Arguments
Applicant's arguments filed 5/6/2026 have been fully considered but they are not persuasive.
Applicant alleges that Xu does not disclose, teach, or suggest a negative electrode that “does not include a negative active material” as claimed [Remarks, pg. 6-8].
In response to this argument it is noted that, as described in the rejection of instant claim 1 above, Xu teaches that an artificial protective layer, or APL (“coating layer”), consisting of PVDF-HFP and LiF, is coated on a Cu electrode (“current collector”) [pg. 3., col. 1, “In contrast, after the Cu electrode being coated with an APL”, pg. 4, Figure 3 caption, “APL-modified Cu foils”]. The structure of Xu’s bare Cu electrode coated with the APL does meet the claimed structure of a negative electrode not including a negative active material, because no Li metal has been deposited yet. Xu teaches that the Li metal is deposited afterwards between the APL and the Cu electrode. [pg. 4, col. 1, “morphologies of Li deposits without or underneath various protective layers were investigated”, “Notably, the APL, endowed with excellent shape conformability and high modulus by soft PVDF-HFP and rigid LiF, respectively, guided dense and uniform Li deposition”]. The instant specification discloses a similar mechanism wherein a negative electrode initially does not comprise lithium metal as a negative active material but lithium metal is then deposited between the current collector and the coating layer:
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The applicant further alleges that Xu teaches away from the presently claimed anode-free configuration because it would undermine the express purpose of Xu’s coating layer [Remarks, pg. 7].
In response to this argument it is noted that Xu teaches that the APL guides dense and uniform Li deposition [pg. 4, col. 1]. Therefore, a person having ordinary skill in the art would find it obvious to apply the coating layer to a bare Cu foil containing no negative active material in order to then allow for future uniform deposition of Li metal under the coating layer. Furthermore, "[t]he prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of these alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed…." In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d 1141, 1146 (Fed. Cir. 2004) [see MPEP 2123(II)].
Thus these arguments are not considered persuasive and the rejection of claims 1-6 is maintained.
Conclusion
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/M.F.O./Examiner, Art Unit 1729
/ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729
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