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 .
Response to Amendment
Applicant’s amendments filed on 4/10/2026 have been entered.
No amendments were made to the specification.
102 rejections from previous office action have been withdrawn in view of the amendments.
Specification
The specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. See 37 CFR 1.75(d)(1) and MPEP § 608.01(o). Correction of the following is required:
Claim 13 states “the lithium metal of the cathode electrode is one of pure lithium, and a lithium alloy.” The instant specification does not include sufficient support for this limitation. The instant specification states that “[0012] In further features, the cathode electrode includes lithium iron phosphate (LFP). [0013] In further features, (a) Rock salt layered oxides, LiNixMnyCol-x-y02,LiNixMn1-x02, Lil+xMO2 e.g. LiCoO2, LiNiO2, Li MnO2, LiNi0.5Mn0.502, NMC111, NMC523, NMC622, NMC721, NMC811, NCA etc. (b) Spinel cathode, e.g. LiMn2O4,LiNi0.5Mn1.504 (c) Olivine compounds, e.g. LiV2(PO4)3 LiFePO4, LiCoPO4,LiMnPO4 etc (d) Tavorite compounds, e.g. LiVPO4F, (e) Borate compounds, e.g. LiFeBO3, LiCoBO3, LiMnBO3 (f) Silicate compounds, e.g. Li2FeSiO4, Li2MnSiO4,LiMnSiO4F (g) Organic compounds, e.g. Dilithium (2,5-dilithiooxy)terephthalate, polyimide (h) Other types, e.g. 5,02 (i) Coated and/or doped cathode materials mentioned in (a), (b) and (j) Combination components selected from a to d type” Similarly, Paragraphs 0061 and 0066 in instant specification do not provide proper antecedent basis for the claimed subject matter.
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 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, 5-14, 21, 22 are rejected under 35 U.S.C. 103 as being unpatentable over Xiao et al (US 2019/0067675 A1) in view of Matsumara et al (US 2017/0092921 A1), in view of Roumi et al (US 9379368 B2), and further in view of Paez Duenas et al (US 2017/0162865 A1).
Regarding Claim 1,
Xiao teaches an electrochemical cell (i.e. battery) that has an anode/negative electrode with a lithium metal (Paragraph 0063), a cathode/positive electrode (Paragraph 0061). Xiao also teaches a fluoropolymer layer deposited on electroactive material of electrode to form a composite surface layer (Paragraph 0072). The fluoropolymer layer is polytetrafluoroethylene (PTFE), and reacts with lithium (electroactive material) to form LiF (lithium fluoride) as a protective coating (Paragraph 0073). This is akin to the claimed LiF layer on an electrode. Xiao also teaches that the LiF layer is formed in a method of making a negative electrode (Paragraph 0072).
Xiao teaches a current collector which is formed from aluminum or any other appropriately electrically conductive material known to those of skill in the art (Paragraph 0062). Xiao does not specifically teach the use of a three dimensional metal foam material.
However, Matsumara teaches a rechargeable battery that suppresses the formation of lithium dendrites by providing an electrically insulative layer covering the surface of an electrode (Paragraph 0019), and the current collector is of metal foam type (Paragraph 0019). The metal foam layer is 3 dimensional as shown in Fig.3. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use the metal foam current collector as shown in Matsumara in the assembly of Xiao in order to prevent of substantially reduce the likelihood of the lithium plating growing toward the cathode to cause a short circuit (Paragraph 0012).
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Xiao does not specifically teach that the wherein the PTFE layer is applied to the at least one of the anode electrode and the cathode electrode by one of pressing and rolling, wherein a temperature during the application of the PTFE layer is greater than 50 degrees Celsius. This is a product-by-process type of limitation. Per MPEP 2113, “[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. 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." Xiao does teach the product as claimed, however the prior art reference of Roumi is further used to support the use of a rolling or pressing process step for applying the PTFE layer.
Roumi teaches a method of dendrite prevention (Column 2, Lines 65-67) that utilizes a coating on the Li anode made of PTFE material (Column 19, Lines 45- 60). Roumi teaches that the PTFE layer (mechanical strength layer) is pressed at a temperature of 400 C or more (Column 29, Lines 36-50). This temperature overlaps with the claimed range of 50C or more. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to utilize the method of pressing at a given temperature as specified in Roumi for making the layers in Xiao in order to form a high mechanical strength layer in order to prevent direct electrical contact between positive and negative electrodes (Column 15, Lines 4-6).
In relation to loading of the cathode electrode being 0.5 milliamp hour (mAh) per centimeter squared (cm2) to approximately 20 mAh/cm2, Xiao teaches in an example that the electrochemical cell has a capacity of 4 mAh/cm2. Xiao also teaches the use of lithium iron phosphate LFP, carbon and binder (Paragraph 0061) which is the same as the instant specification. Xiao does not specifically teach that the loading of the cathode electrode is as claimed, but based on the similarities of Xiao and the instant invention, the cathode loading should also be in the same range. This is further corroborated by Paez Duenas et al, wherein the cathode loading (areal capacity) of LFP electrodes is between 0.5 to 6 mAh/cm2 (Paragraph 0039). Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to improve the electrochemical properties of the electrode composite, specially the areal capacity (mAh/cm2) and areal energy (mWh/cm2), and consequently the battery performances (Paragraph 0013).
Regarding Claim 2,
Xiao teaches that a fluropolymer layer of PTFE is deposited on the negative electrode, and that in case when the electroactive materials do not contain sufficient levels of lithium then defluorination occurs in the first few cycles in the battery cell where the lithium ions migrate from positive electrode to the fluoropolymer coating on silicon (Paragraph 0081). This shows that the fluropolymer layer remains after initial reaction with lithium in the forming process, and then is able to react in situ in the electrochemical cell. Hence, Xiao teaches that a portion of the PTFE layer remains after the reaction in the formation process.
Regarding Claim 3,
Xiao teaches that there is a reaction between the fluoropolymer layer and the negative electrode (active material lithium) to form a LiF protective coating. Since the fluoropolymer layer is deposited on an electroactive material film (Paragraph 0083), the LiF layer is formed between the PTFE layer and the anode.
Regarding Claim 5,
Xiao teaches the composite layer which contains the LiF particles is formed on atleast one surface of the electrode layer (Paragraph), and the electrode being formed in a negative electrode or anode (Paragraph 0070).
Regarding Claim 6,
Xiao teaches that the negative electrode is made of material such as lithium metal (Paragraph 0072).
Regarding Claim 7 and Claim 8,
Xiao teaches that the positive electrode or cathode includes materials such as Lithium iron phosphate, and lithium nickel manganese cobalt oxide (Paragraph 0061).
Regarding Claims 9, 10, 11,
Xiao teaches the presence of an electrolyte system comprising a non-aqueous liquid electrolyte solution including a lithium salt and an organic solvent mixture (Paragraph 0068). Xiao also provides an exemplary electrolyte comprising 1M LiPF6 in EC:DEC organic solvents (Paragraph 0089). It is well known in the art that EC, DEC are carbonate type solvents commonly used in electrolytes for secondary batteries.
Regarding Claim 12,
Xiao teaches the presence of a separator between the anode and cathode layers in the battery.
Regarding Claim 13,
Xiao teaches that the negative electrode comprises lithium metal and lithium-silicon alloy (Paragraph 0063).
Xiao does state that the positive electrode is made of lithium-based active material that can sufficiently undergo lithium intercalation and deintercalation, and further provides non-limiting examples of positive electrode material. Xiao does not specifically teach that the lithium material in cathode electrode is one of pure lithium or a lithium alloy.
However, Roumi teaches an electrochemical cell with a positive electrode comprising an alkali metal, an alkali metal alloy which includes Li (Column 27, Lines 25-35). Roumi teaches a method of dendrite prevention (Column 2, Lines 65-67) that utilizes a coating on the Li anode made of PTFE material (Column 19, Lines 45- 60). Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use lithium metal or lithium alloy in the cathode for Xiao as a suitable positive electrode material.
Regarding Claim 14,
Xiao teaches that the composite surface layer has a thickness of greater than or equal to about 5 nm to less than or equal to about 50 µm. Xiao also states in Example 1, that the coating thickness of the PTFE material on a Li disk is around 1 micron. This value is within the claimed range.
Regarding Claim 21,
Xiao teaches that the positive electrode is made of lithium based active material such as lithium iron phosphate LFP (Paragraph 0061), and includes polymeric binder and conductive particle such as carbon based materials (Paragraph 0062).
Regarding Claim 22,
Xiao does not specifically teach the mass percentages of 80-99 % of the LFP, 0.5-20% of the carbon, and 0.5-10 % of the binder. However, Paez Duenas teaches a positive electrode composite consisting of 0.1 wt % to 20 wt % graphene; 0.1 wt % to 20 wt % carbon black and 2 wt % to 20 wt % binder, the rest being an active material of lithium transition metal compound having an olivine structure, such as LiFePO4 (LFP). The material composition of Paez Duenas overlaps with the claimed range. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use the mass % as specified in Paez Duenas in the cathode of Xiao in order to form an electrode composite with increased thickness allows a greater load of active material, preferably a spinel or an olivine based compounds, for the same amount of other components, and thus results in improved overall performance, i.e. improved capacity and energy per area or kilogram of battery (Paragraph 0013).
Claim(s) 4 is rejected under 35 U.S.C. 103 as being unpatentable over Xiao et al, Matsumara et al, Roumi et al, Paez Duenas, further in view of Kobayashi et al (US 20160204476 A1).
Xiao does not teach that the PTFE layer has a porosity between approximately 30 percent and approximately 90 percent.
However, Kobayashi teaches a protective film for an anode that has a polymeric porous film. The polymeric film is made of a tetrafluoroethylene polymer (Paragraph 0021), and has a porosity of 35% to 98%. This range overlaps the claimed range. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use a PTFE layer with the claimed porosity in order to inhibit the growth of dendrites on the anode (Paragraph 0020).
Claim(s) 15 is rejected under 35 U.S.C. 103 as being unpatentable over Xiao et al, Matsumara et al, Roumi et al, Paez Duenas, further in view of Schmidt et al (US 20220344669 A1).
Xiao does not teach that the thickness of one side of atleast one of the anode or cathode is between approximately 1 micrometer to 50 micrometers.
However, Schmidt teaches an electrochemical cell with an electroactive material layer (as found in electrodes) adjacent to a precursor layer (made of PTFE material; paragraph 0013-0014). Schmidt also teaches that the precursor materials are able to produce LiF upon reaction with lithium metal found in negative electrode material (Paragraph 0091-0092). Furthermore, Schmidt teaches that the positive electroactive material layer has a thickness greater than 1 and less than 1000 µm (paragraph 0079). This is akin to the claimed electrode thickness. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use the thickness as provided in Schmidt in order to form chemical attachments that control the growth and microstructure of the solid-electrolyte interface layer and help to reduce or prevent premature cracking or degradation of the solid-electrolyte interface layer (Paragraph 0093).
Response to Arguments
Objection to specification is maintained by Examiner because the claim recites “the lithium metal of the cathode electrode is one of pure lithium, and a lithium alloy.” Applicant has also provided support for anode material, and does not show relevant specification citation for cathode electrode material.
Applicant’s arguments with respect to claim(s) 1 have been considered but are moot because the new ground of rejection does not rely on combination of references applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. The amendments to claim 1 overcome the 102 rejection in previous office action based on Xiao, but considering the prior art used in 103 rejection section in this office action, the limitations are rejected based on Xiao in view of Matsumara, Roumi, and Paez Duenas.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 SUHANI JITENDRA PATEL whose telephone number is (571)272-6278. The examiner can normally be reached Monday-Friday 8:00 AM - 5:00 PM.
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/SUHANI JITENDRA PATEL/Examiner, Art Unit 1783
/MARIA V EWALD/Supervisory Patent Examiner, Art Unit 1783
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