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 .
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-8 and 16-17 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, regards as the invention.
Claim 1 recites “lithium coating composition, comprising a lithium-containing metal and a polymer chemically connected to a lithium surface in the lithium-containing metal” implying the coating composition that includes the polymer and solid Li particles to which the polymer is bound. However, the specification does not disclose such a composition. The specification specifically discloses a polymer composition bound to a layer containing Li metal [0110-0116]. For examination purposes, the phrase “A lithium coating composition, comprising a lithium-containing metal and a polymer” will be interpreted as “A lithium coating composition comprising a polymer formed on the surface of a lithium metal containing layer”.
Claim 8 recites “a catalyst dosage”. This term is used in claim 8 to claim a relative amount of catalyst used for a polymerization reaction, however, the specification does not disclose this amount. This term is indefinite because catalyst dosages differ by reaction. There is no one specific catalyst dosage. For examination purposes, the term “catalyst” dosage will be interpreted as “any catalyst dosage for a polymerization reaction in the prior art”.
Claim 16 recites “a swelling rate of the polymer layer is selected from 5% to 50%” whereby the units for swelling rate range are incorrectly given as a percentage. Swelling rate is a dynamic property and the units for the swelling rate should be in percentage per unit time. For examination purposes, the term “swelling rate” will be interpreted as the “swelling ratio”, a closely related static property measured as a percentage.
Claims 2-7 and 17 are rejected as containing the unclear language of the parent claims.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-7 and 9-15, 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Cho et al (US2002182488A1) and further in view of Fujimoto (GB 2225577), Zhamu et al. (US 2018/0294476) and Zhaolin et al. (Energy Storage Materials,37,2021,215-223).
Claim 1: Cho et al teaches a method for suppressing dendrite growth and improving interfacial stability on the anode surface of a lithium battery comprising formation of a LiF protective layer on the lithium metal anode surface with enhanced adhesion using a fluorine-containing polymeric layer [0002, 0011]. The LiF layer is spontaneously formed as a result of the reaction between the activated lithium surface and the fluorine-containing polymer. Cho teaches it is imperative to optimize the surface contact between the polymeric layer with the lithium anode in order to improve reactivity, by etching the lithium surface and pressing to improve attachment of the polymer under pressurized conditions [0030, 0033]. Therefore, the adhesion of the polymeric layer is important for this process. Cho specifically teaches polymers such as polyvinylidene fluoride for the formation of the protective layer [0012]. Cho does not teach a polymer with the Formula I, but teaches any fluorine containing polymer may be used [0012].
Fujimoto teaches fluoroalkyl 2-cyanoacrylate polymers with good adhesive properties that can be used in a wide range of industries as adhesives and coatings (Page 1, lines 1-20). Fujimoto specifically teaches a polymer of fluoro-monomer, 3,3,4,4,5,5,6,6,6-nonafluorohexyl 2-cyanoacrylate (Page 3 lines 15-20).
Cho does not explicitly teach the number of repeat units in the polymer. However, Zhamu teaches a lithium secondary battery comprising an ultrahigh molecular weight (UHMW) polyacrylonitrile polymer having a molecular weight between 0.5 x l06 and 9 x l06 grams/mole (i.e., 9.4 x l03 to 1.6 x l05 repeat units ) and is disposed on the lithium metal anode to overcome the lithium metal dendrite [0011-0013, 0016]. Zhamu teaches such an UHMW polymer has high elasticity and is capable of expanding or shrinking congruently or conformably with the anode layer, maintaining a good contact between the lithium and the protective layer, thereby enabling the re-deposition of lithium ions. [0015].
Cho does not teach the cyano group in the polymer forms a chemical connection with lithium metal. However, Zhaolin teaches the suppression of dendrites on the Li metal anode facilitated by a double protective layer comprising an inner layer of LiF and Li3N, and a layer of solid-state copolymer electrolyte comprising 2-cyanoethyl acrylate and poly (ethylene glycol) methyl ether acrylate, attached to the surface of the lithium anode wherein the cyano group of the polymer directly connects with the Li metal thus reinforcing the binding of the polymer and improving interfacial stability (abstract, Pages 216, 219 and 221).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing the instant invention to have used Fujimoto’s naturally adhesive Formular 1 polymer in Cho’s polymer coating composition because Fujimoto, Zhamu and Zhaolin teach such a polymer would have enhanced adhesion to the surface of the lithium anode, thereby improving the reactivity with Li and the formation of the LiF protective layer without excessive reaction conditions.
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Fig. 1: 3,3,4,4,5,5,6,6,6-nonafluorohexyl 2-cyanoacrylate
Claim 2: Fujimoto teaches a polymer of the fluoro-monomer shown in fig. 1 (Page 3 lines 15-20), wherein for each occurrence of Rf, a fluorine substitution rate in Rf is 69 %.
Claim 3: Fujimoto teaches a polymer of the fluoro-monomer shown in fig. 1 (Page 3 lines 15-20), wherein for each occurrence of Rf, a number of fluorine atoms in Rf is 9.
Claim 4: Fujimoto teaches a polymer of the fluoro-monomer shown in fig. 1 (Page 3 lines 15-20), wherein for each occurrence of Rf, the mass proportion of fluorine element in the polymer is 50%.
Claim 5: Fujimoto teaches a polymer of the fluoro-monomer shown in fig. 1 (Page 3 lines 15-20), wherein for each occurrence of Rf, Rf contains 6 main chain carbon atoms.
Claim 6: Fujimoto teaches a polymer of the fluoro-monomer shown in fig. 1 (Page 3 lines 15-20), wherein each occurrence of the fluorine-substituted aliphatic group is a straight chain structure.
. Claim 7: Fujimoto teaches a polymer of the fluoro-monomer shown in fig. 1 (Page 3 lines 15-20), wherein for each occurrence of Rf, a structure of Rf is independently shown in Formula III-1.
Claim 9: As per claim 1, the combination of Cho, Zhaolin, Zhamu and Fujimoto, as shown above, teaches a coating comprising a fluoro-polymer chemically connected to lithium. Cho also teaches a lithium battery comprising a lithium metal anode (i.e., negative electrode plate), a cathode, and an electrolyte disposed between the two electrodes; and a lithium metal anode protective layer between the electrolyte and the lithium metal anode, [0009].
Claim 10-11: Cho teaches a battery assembly comprising an electrolyte solution wherein Li, polymeric layer, polyethylene (PE) separator, polymeric layer and Li are sequentially stacked and immersed in the solution to form a lithium battery [0048]. Cho does not explicitly teach the polymer layer contains the electrolyte or the concentration of the electrolyte. However, Zhamu teaches a polymer coating on the negative electrode immersed in a 1 M LiPF6 electrolyte solution dissolved in a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) (EC-DEC, 1:1 v/v) [0012, 0018-0020, 0098]. Therefore, it would have been obvious at the time the invention was made to have prepared Cho’s battery with a liquid electrolyte solution with a concentration of 1 mol/L because Zhamu teaches such an electrolyte is a functional electrolyte.
Claims 12-13: Cho teaches a battery comprising and anode, a cathode and an electrolyte LiCF3SO3 [0048] wherein the anode (i.e., negative electrode plate) is prepared by coating the anode with a polymeric mixture prepared from commercial polymers [0046-0047]. Cho does not teach the mass ratio of the polymer to the electrolyte within the range 199:1 to 1:1 or the mass proportion of the electrolyte within the range 0.5% to 50%. However, Zhaolin teaches a polymer electrolyte prepared by in-situ polymerization of a precursor polymer electrolyte composition comprising monomer 2-cyanoethyl acrylate (CA) and poly (ethylene glycol) methyl ether acrylate and 5 wt % of the electrolyte, Li6.75La3Zr1.75Ta0.25O12 (LLZTO) (i.e., the proportion of the electrolyte in the polymer layer is 5% and mass ratio of the polymer to the electrolyte is 95:5) (Page 216, paragraph 4).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing the instant invention to have modified Cho’s method of preparation of polymer coating by using 5 wt % of the LiCF3SO3 electrolyte in the composition because Zhaolin teaches such a coating composition is functional.
Claim 14: Cho does not teach elastic modulus. Zhamu does not explicitly teach the elastic modulus of the polymer, however, Zhamu discloses a graph representing the tensile stress-strain curves of the a polyacrylonitrile copolymer (Fig 4A). The elastic modulus was calculated from the graph to be 19.6 MPa as shown in Fig. 1. Therefore, it would have been obvious at the time the invention was made to have made Cho electrolyte polymer with a polymer with an elastic modulus of 19.6 MPa because Zhamu teaches such is a functional electrolyte matrix.
Fig 1. Calculated secant elastic modulus.
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Claim 15: Cho does not teach elastic deformation of the polymer electrolyte. However, Zhamu teaches the elastic deformation of the UHMW polymer is typically 5%-300% [0080]. Zhamu teaches the elastic deformation is preferably greater than 2% [0014, 0066] indicating the polymer is highly elasticity and fully recoverable, and the recovery is instantaneous [0080]. Zhamu does not identically teach the range of 20% to 500%. However, overlapping ranges have been held to support a case of obviousness. (See MPEP 2144.05.I). Therefore, it would have been obvious at the time the invention was made to have made Cho polymer coating with elastic deformation within the range 5%-300%, that has high elasticity and instantaneous recovery.
Claim 18: Cho teaches a battery assembly comprising an electrolyte solution wherein lithium anode coated with the polymeric layer, polyethylene (PE) separator, polymeric layer and lithium anode are sequentially stacked and immersed in the solution to form a lithium battery [0048].
Claim 19: Cho teaches electronic devices such as mobile phones comprising lithium batteries [0004].
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Cho et al (US2002182488A1) and further in view of Fujimoto (GB 2225577), Zhamu et al. (US 2018/0294476), Zhaolin et al. (Energy Storage Materials,37,2021,215-223) and Meng (CN 11102969659A).
Claim 8: Cho teaches a method of coating a lithium layer including the thickness of the lithium and the masses on the polymer monomer [0049, 0058]. Cho does not teach the relative proportions of a polymer and a lithium-containing metal, or reaction catalysis. However, Meng ‘659 teaches a method for protecting a negative electrode wherein the lithium metal embedded in the electrode initiates in-situ polymerization reaction of a polymer monomer, ethyl cyanoacrylate [0046, 0050]. Meng does not explicitly teach the mol ratios used in the preparation of the battery assembly. However, Meng ‘659 teaches a process of optimizing the in-situ polymerization reaction [0049] wherein the content of the lithium in each of the trial reactions [0051, 0059, 0067, 0075] relative to the polymer monomer (see the calculated mol% in Table 1) is greater than the catalyst dosage of 0.2 mol% taught by Fujimoto in the preparation of synthesis of 3,3,4,4,5,5,6,6,7,7.8,8,8-tridecafluorooctyl 2-cyanoacrylate (Page 8 lines 25-35). Fujimoto teaches a method of coating an electrode by polymerization, wherein piperidine was used as a catalyst to promote polymerization (Page 4 lines 13-15).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing the instant invention to have modified Cho’s method of preparation of a negative electrode by using a mol% of lithium greater than a catalyst loading of 0.2 mol% because in accordance with the teachings of Meng ‘659 and Fujimoto, the lithium has a dual role of catalyzing the reaction and chemically binding to the polymer. Thus, more lithium than the catalytic amount is needed to provide polymer binding sites.
Table 1:
Example
% of ethyl cyanoacrylate
in monomer solution
mass of monomer (g)
Mols of monomer
mols of Li
mol %
1
90
0.9
0.0072
0.00072
10
2
80
0.8
0.0064
0.00072
11
3
50
0.5
0.0040
0.00072
18
4
40
0.4
0.0032
0.00072
22
Claim 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over Cho et al (US2002182488A1) and further in view of Fujimoto (GB 2225577), Zhamu et al. (US 2018/0294476), Zhaolin et al. (Energy Storage Materials,37,2021,215-223)and Amin-Sanayei et al. (US12497503B2).
Claims 16: Cho teaches an electrode coated with a polymer layer and potential swelling of the coating due to the electrolyte [0065] but does not teach the swelling rate. However, Amin-Sanayei teaches a fluorine-containing polymer coating composition for an anode electrode (Col 3 lines 1-25) having a low-swelling phase for good wet adhesion and a higher swelling phase for good dry adhesion properties (Col 4 lines 58-63), wherein the measured swelling ratio (i.e., swelling rate) of the fluorine-containing polymer immersed in an electrolyte solvent (Col 17 Lines 5-35) is between 22% and 300% (Table 1) (Figs. 1, 2 and 4), and preferably less than 90% (Col 11 lines 40-43). Amin-Sanayei does not identically teach the range 5% to 50%. However, overlapping ranges have been held to support a case of obviousness. (See MPEP 2144.05.I). Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have prepared an electrode comprising a polymer with a swelling rate of 50% because Amin-Sanayei teaches such a swelling rate is favorable for an electrode polymer coating.
Claims 17: Cho teaches how to enhance ionic conductivity of the polymeric layer but does not teach the specific ionic conductivity of the polymer [0046]. However, Zhamu teaches the high-elasticity polymer used for the protective layer preferably and typically has a lithium ion conductivity of at least 10-5 S/cm [0021]. Zhamu does not identically teach the range of 5×10-3 S/cm to 1×10-6 S/cm. However, overlapping ranges have been held to support a case of obviousness. (See MPEP 2144.05.I). Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have made Cho’s negative electrode with polymer coating with an ionic conductivity of 1×10-5 S/cm because Zhamu teaches such a ionic conductivity is favorable for an electrode polymer coating.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Cho et al (US2002182488A1) and further in view of Fujimoto (GB 2225577), Zhaolin et al. (Energy Storage Materials,37,2021,215-223) and Meng et al. (CN 110518293).
Claim 20: As per claim 1, the combination of Cho, Fujimoto and Zhaolin, as shown above, teaches a coating comprising a polyacrylonitrile polymer chemically connected to lithium. Cho further teaches a preparation method of an anode (i.e., negative electrode plate), comprising: providing a lithium metal anode laminated on a copper foil, with one side of the lithium layer exposed [0045];
providing a polymeric layer to react with the lithium anode on the one side of the negative electrode plate [0050]. Cho does not teach preparation of the polymer from the corresponding monomers.
Meng ‘293 teaches a preparation method of a negative electrode plate, comprising: providing a negative electrode sheet (2) covered with a lithium foil (i.e., lithium containing layer ) [0029, 0036], which is subsequently rolled with a positive electrode sheet (1) and a separator (3) and arranged in a battery case [0012, 0036]; providing a polymer monomer solution (i.e., reaction mixture) containing a monomer, 2-cyano-ethyl acrylate, a lithium salt and an electrolyte additive [0013, 0037]; and the polymer solution is injected into the solid lithium ion battery assembly coating the exposed surface of the lithium foil (Fig. 2) [0032]; and subjected to a dry atmosphere and negative pressure, at a preset temperature to allow in-situ polymerization reaction of the pre-charged lithium and the electrolyte, and polymerizing the monomer compound in-situ to form polymerized solid electrolyte (5), wherein a reaction temperature of the in-situ polymerization is selected from 20°C to 90°C [0030, 0061] (Fig. 3). Meng ‘293 does not identically teach the temperature range of 30°C to 100°C. However, overlapping ranges have been held to support a case of obviousness. (See MPEP 2144.05.I). Meng ‘293 teaches this preparation method can improve solid-solid interface contact between the electrolyte and the electrode active material and the use of in-situ polymerization reaction can greatly reduce the preparation process of solid-state lithium-ion batteries [0031, 0032].
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified Cho’s method of preparing the negative electrode pre-treating the electrode with a polymer monomer/electrolyte mixture and subjecting it to in-situ polymerization at 30°C, in order to improve the solid-solid interface between the negative electrode and the polymer electrolyte and reduce the preparation time.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Cui et al (CN107123788A) teaches dual protection layer on the lithium negative electrode wherein an organic layer (i.e., polymer) comprising α-cyanoacrylate is formed in situ when a nitrogen-containing part (i.e., the cyano group) in the organic layer (polymer) reacts with metal lithium, resulting in formation of an organic protection layer (i.e., polymer layer) and a protective inorganic layer comprising Li3N at the interface that help prevent lithium dendrite formation [abstract, 0008, 0014].
Li et al. (CN112968178A) teaches the preparation of a lithium negative electrode wherein a polymer electrolyte is chemically bonded to lithium in the metal lithium layer through the lithium reactive group and is compounded on the surface of the metal lithium layer [0004]. Li teaches the polymerization of polymer monomers to form a coating layer on a lithium metal wherein the polymerization reaction is catalyzed by a radical initiator. Li does not explicitly teach the molar ratios of the monomer and the initiator. However, Li teaches the mass ratio of the inorganic particles to the polymerized monomer is not more than 9 [0010] the initiator is 0.1 to 1% of the mass of the polymerized monomer [0015].
Yun et al. (US 2020/0168902) teaches a negative electrode for a lithium metal battery comprising a protective layer comprising a polyacrylonitrile polymer that inhibits the growth of dendrite [0001, 0023, 0044, 0071].
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/L.N.R./Examiner, Art Unit 1712
/MICHAEL B CLEVELAND/Supervisory Patent Examiner, Art Unit 1712
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