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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 05/27/2026 has been entered.
Response to Amendment
Examiner notes the following amendments made to the claims:
Claims 1, 14, 16 amended
Claims 2 and 9 cancelled
Response to Arguments
Applicant’s arguments, filed 04/27/2026, with respect to the rejection(s) of claim(s) 1, 3-8, and 10-16 under 35 USC 103 have been fully considered and are persuasive. Specifically, by amending claim 1 to incorporate the subject matter of previously presented claim 9, and further amending the limitation to require the presence of an M3, the previously applied prior art is overcome. Therefore, the rejection has been withdrawn. Examiner does not find the argument regarding the amount limitation to be persuasive, as examiner still holds that there are ranged within the teachings of Tsai that would overlap/fall within the claimed range, even if not explicitly states the same way. However, upon further consideration, a new ground(s) of rejection is made in view of Murikawa (US 20200243827 A1), which teaches a positive electrode active material that meets the claimed formula and would be obvious to substitute. Claims 14 and 16 are now allowed as they contain allowable subject matter and have been amended to now be independent claims. Since no further arguments are provided for the dependent claims other than their dependency on claim 1, claims 3-8, 10-13, and 15 remain rejected and the rejections remain unchanged other than now relying further on Murikawa.
Claim Rejections - 35 USC § 103
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(s) 1, 3-4, 10-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tsai (US 20140178747 A1) in view of Park et Al (J. Mater. Chem., 2012,22, 12574-12581.), further in view of Lee ("Preparation of Polyimide Copolymer and Its Application as Lithium Ion Secondary Battery Binder", MASTER THESIS, 1 June 2020 (2020-06-01), Korea, pages 1- 35), and further in view of Murikawa (US 20200243827 A1).
Regarding claim 1, Tsai teaches the following elements:
A positive electrode for a rechargeable lithium battery, comprising a positive electrode active material, (“Referring to FIG. 1, the composite electrode material of the lithium secondary battery 10 includes an electrode active powder 100 and a nanoscale coating layer 102 coated on a surface 100a of the electrode active powder 100.” Tsai [0034] and “ If the electrode active powder 100 is used as the cathode material, the electrode active powder 100 may be selected from the group consisting of lithiated oxide, lithiated sulfide, lithiated selenide, lithiated telluride of vanadium, titanium, chromium, copper, molybdenum, niobium, iron, nickel, cobalt, and manganese, and a combination thereof.” Tsai [0034])
a conductive material, (“The result is a composite cathode active material. The composite cathode active material, a conductive additive, and a binder are dissolved in NMP in the proportions of 80% to 95%, 3% to 15%, and 3% to 10% respectively and evenly mixed and stirred. “ Tsai [0059])
and a binder, (“The result is a composite cathode active material. The composite cathode active material, a conductive additive, and a binder are dissolved in NMP in the proportions of 80% to 95%, 3% to 15%, and 3% to 10% respectively and evenly mixed and stirred. “ Tsai [0059])
and wherein the polyimide-based polymer having the carboxyl group is included in 0.1 to 0.8 parts by weight based on 100 parts by weight of the total amount of the mixture of the positive electrode active material, the conductive material, and the binder. (“The cathode active material containing 0.005% to 10% (concentration ratio with respect to the cathode) of metastable state polymer is stirred in a planetary-type mixing machine or a regular machine for 3 to 10 minutes. Then, a nanoscale layer about 1 nm to 30 nm thick is coated. The result is a composite cathode active material. The composite cathode active material, a conductive additive, and a binder are dissolved in NMP in the proportions of 80% to 95%, 3% to 15%, and 3% to 10% respectively and evenly mixed and stirred.” Tsai [0059]. In this case, if the composite cathode material contained, for example, 1% by weight of polymer, and was included in 80% by weight compared to the conductive additive and binder, then there would be 0.8 parts by weight polymer out of 100 parts of active material, conductive material, and binder, which would be within the claimed range.)
Tsai teaches the use of a metastable polymer in its positive electrode material, specifically, which forms a coating:
(“The cathode active material containing 0.005% to 10% (concentration ratio with respect to the cathode) of metastable state polymer is stirred in a planetary-type mixing machine or a regular machine for 3 to 10 minutes.” Tsai [0059])
Tsai is silent on the following elements of claim 1. Specifically, Tsai doesn’t teach the polymer explicitly being a polyimide based polymer:
wherein the positive electrode includes a polyimide-based polymer having a carboxyl group.
However, Tsai cites the article “A novel ion-conductive protection skin based on polyimide gel polymer electrolyte: application to nanoscale coating layer of high voltage LiNi1/3Co1/3Mn1/3O2 cathode materials for lithium-ion batteries” published by Park et al in 2012, which teaches the use of a polyimide based polymer for a positive electrode material coating:
wherein the positive electrode includes a polyimide-based polymer having a carboxyl group. (“In this study, the PI is introduced onto the LiNi1/3Co1/3Mn1/3O2 surface via thermal imidization of a polyamic acid copolymer comprised of pyromellitic dianhydride (PMDA)/oxydianiline (ODA).” Park page 2 column 1 line 11.)
By citing this article, it is clear that the authors find a polyimide coating to be known to one of ordinary skill in the art, and therefore it would have been obvious to one of ordinary skill in the art to modify the metastable state polymer of Tsai to be a polyimide based polymer.
Both Tsai and Park are silent on the polyimide based polymer containing a carboxyl group.
However, Lee teaches the use of a polyimide polymer containing carboxyl groups and shows how it can form an effective coating on a positive electrode active material (“PI-FTD containing fluorine and carboxyl groups showed the best performance. In the case of PI-FTD, it was confirmed through TEM, FT-IR, and XPS analysis that the carboxyl group forms a bond with the metal of the positive electrode active material and protects the positive electrode active material by coating the surface.” Lee page 2 line 5)
Lee, Park, and Tsai are all considered to be analogous because they are within the same field of positive electrodes containing polymer coatings. Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the polymeric coating of the positive electrode of Tsai to include a polyimide based polymer, as taught by Park, in order to improve cycling performance (“The anomalous PI wrapping layer substantially improves the high-voltage cycling performance and alleviates the interfacial exothermic reaction between delithiated LiNi1/3Co1/3Mn1/3O2 and liquid electrolyte.” Park abstract). It would additionally have been obvious to use a polyimide based polymer containing a carboxyl group in order to form additional bonds with the positive electrode active material and thus form a stronger protective coating, as taught by Lee. (“PI-FTD containing fluorine and carboxyl groups showed the best performance. In the case of PI-FTD, it was confirmed through TEM, FT-IR, and XPS analysis that the carboxyl group forms a bond with the metal of the positive electrode active material and protects the positive electrode active material by coating the surface.” Lee page 2 line 5).
Tsai, Lee, and Park are all silent on the following elements of claim 1:
and wherein the positive electrode active material is at least one of a lithium composite oxide represented by Chemical Formula 1, or a combination of the lithium composite oxide represented by Chemical Formula 1 and LiaFePO4 (0.90<a<1.8), [Chemical Formula 11 LiaM11-v1-z1M2y M3z102 wherein, in Chemical Formula 1, 0.9<a<1.8, 0<y1 1, 0<z1 1, 0<y1 +z1 <1, and M1, M2, and M3 are each independently selected from a metal of Ni, Co, Mn, Al, Sr, Mg, or La, and a combination thereof.
However, Murikawa teaches all of the elements of claim 1 that are not found in the aforementioned references:
and wherein the positive electrode active material is at least one of a lithium composite oxide represented by Chemical Formula 1, or a combination of the lithium composite oxide represented by Chemical Formula 1 and LiaFePO4 (0.90<a<1.8), [Chemical Formula 11 LiaM11-v1-z1M2y M3z102 wherein, in Chemical Formula 1, 0.9<a<1.8, 0<y1 1, 0<z1 1, 0<y1 +z1 <1, and M1, M2, and M3 are each independently selected from a metal of Ni, Co, Mn, Al, Sr, Mg, or La, and a combination thereof. (“Particles of lithium nickel cobalt aluminum composite oxide represented by Li.sub.1.05Ni.sub.0.82Co.sub.0.15Al.sub.0.03O.sub.2 were used as positive electrode active material particles.” Murikawa [0061] This material would meet all of the limitations of amended claim 1 as well as claim 10.)
Murikawa is considered to be analogous to Tsai because they are both within the same field of secondary batteries containing positive electrode active materials. it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify Tsai to substitute one positive active material with another, as this would only require a simple substitution, and the simple substitution of one known element for another is likely to be obvious when predictable results are achieved. (see MPEP § 2143, B.).
By using the polyimide based polymer of Lee in the positive electrode of Tsai, and substituting the positive electrode active material with that of Murikawa, the limitations for claims 3-4, and 10-12 would all be met without requiring any further modification or motivation.
Regarding claim 3, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai teaches all of the additional elements of claim 3:
The positive electrode for the rechargeable lithium battery of claim 1, wherein the positive electrode active material further includes a coating layer on the surface, and the coating layer includes the polyimide-based polymer. (“The cathode active material containing 0.005% to 10% (concentration ratio with respect to the cathode) of metastable state polymer is stirred in a planetary-type mixing machine or a regular machine for 3 to 10 minutes. Then, a nanoscale layer about 1 nm to 30 nm thick is coated. The result is a composite cathode active material.” Tsai [0059])
Regarding claim 4, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai teaches all of the additional elements of claim 4:
The positive electrode for the rechargeable lithium battery of claim 3, wherein a thickness of the coating layer is 1 nm to 50 nm. (“The cathode active material containing 0.005% to 10% (concentration ratio with respect to the cathode) of metastable state polymer is stirred in a planetary-type mixing machine or a regular machine for 3 to 10 minutes. Then, a nanoscale layer about 1 nm to 30 nm thick is coated. The result is a composite cathode active material.” Tsai [0059]. The thickness of the coating layer of Tsai anticipates that of the instant invention.)
Regarding claim 10, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai is silent on the following elements of claim 10:
The positive electrode for the rechargeable lithium battery of claim 1, wherein the positive electrode active material is a lithium composite oxide represented by Chemical Formula 1-1: [Chemical Formula 1-1] Lix2N iy2Coz2Al1-y2-z202 wherein, in Chemical Formula 1-1, 0.9<x2<1.2, 0.5<y2<1, and 0<z2<0.5.
However, by substituting the positive active material of Tsai with that of Murikawa, as described in claim 1, all of the limitations of claim 10 would be met without requiring further modification or motivation:
The positive electrode for the rechargeable lithium battery of claim 1, wherein the positive electrode active material is a lithium composite oxide represented by Chemical Formula 1-1: [Chemical Formula 1-1] Lix2N iy2Coz2Al1-y2-z202 wherein, in Chemical Formula 1-1, 0.9<x2<1.2, 0.5<y2<1, and 0<z2<0.5. (“Particles of lithium nickel cobalt aluminum composite oxide represented by Li.sub.1.05Ni.sub.0.82Co.sub.0.15Al.sub.0.03O.sub.2 were used as positive electrode active material particles.” Murikawa [0061] This material would meet all of the limitations of claim 10.)
Regarding claim 11, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai teaches all of the additional elements of claim 11:
A rechargeable lithium battery, comprising the positive electrode of claim 1; a negative electrode; and an electrolyte. (“Referring to FIG. 4, the lithium secondary battery 400 at least includes at least an electrode material, a non-aqueous electrolyte solution 402, and a separator 404 located in the non-aqueous electrolyte solution 402, wherein the non-aqueous electrolyte solution 402 includes a non-aqueous solvent and lithium salt. The electrode material of the fourth exemplary embodiment includes a cathode material 406 and an anode material 408, wherein the composite electrode material of the lithium secondary battery mentioned in the first to third exemplary embodiments may be used in at least one of the cathode material 406 and the anode material 408. Of course, the composite electrode material of the lithium secondary battery mentioned in the first to third exemplary embodiments may also be used in both the cathode material 406 and the anode material 408.” Tsai [0056])
Regarding claim 12, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai teaches all of the additional elements of claim 12:
The rechargeable lithium battery of claim 11, wherein the negative electrode includes a negative electrode active material, and the negative electrode active material includes a Si-based active material, a carbon-based active material, a lithium metal, or a combination thereof. (“Referring to FIG. 4, the lithium secondary battery 400 at least includes at least an electrode material, a non-aqueous electrolyte solution 402, and a separator 404 located in the non-aqueous electrolyte solution 402, wherein the non-aqueous electrolyte solution 402 includes a non-aqueous solvent and lithium salt. The electrode material of the fourth exemplary embodiment includes a cathode material 406 and an anode material 408, wherein the composite electrode material of the lithium secondary battery mentioned in the first to third exemplary embodiments may be used in at least one of the cathode material 406 and the anode material 408. Of course, the composite electrode material of the lithium secondary battery mentioned in the first to third exemplary embodiments may also be used in both the cathode material 406 and the anode material 408.” Tsai [0056] and “If the electrode active powder 100 is used as the anode material, then the electrode active powder 100 may be selected from the group consisting of mesocarbon microbeads (MCMB), mesophase graphite powder (MGP), vapor-grown carbon fiber (VGCF), carbon nanotube (CNT), coke, carbon black, natural graphite, artificial graphite, acetylene black, carbon fiber, glassy carbon, a lithium alloy, and a combination thereof.” Tsai [0034]. If the electrode powder of Tsai were used as both the cathode and anode materials, as cited in paragraph [0056], this limitation would be met, as the anode material taught by Tsai can be a carbon-based material or a lithium metal.)
Regarding claim 13, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai teaches all of the additional elements of claim 13:
The positive electrode of claim 1, wherein the positive electrode active material further includes a coating layer on the surface, wherein the coating layer includes the polyimide-based polymer, and wherein the coating layer including the polyimide-based polymer having the carboxyl group has a thickness of 3 nm to 10 nm. (“The thickness of the nanoscale coating layer 204 is, for instance, between 1 nm and 30 nm.” Tsai [0036] and “wherein the nanoscale coating layer 204 is formed from a metastable state polymer,” Tsai [0036]. If the metastable state polymer were modified by Park and Lee to meet the limitations of claim 1, as shown above, then all of the limitations of claim 13 would be met.)
The examiner takes note of the fact that the prior art range of 1 to 30nm as the thickness of the polymer-based coating layer encompasses the claimed range of 3-10nm for the same parameter. Absent any additional and more specific information in the prior art, a prima facie case of obviousness exists. In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379 (Fed. Cir. 2003). MPEP 2144.05.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tsai (US 20140178747 A1) in view of Park et Al (J. Mater. Chem., 2012,22, 12574-12581.), further in view of Lee ("Preparation of Polyimide Copolymer and Its Application as Lithium Ion Secondary Battery Binder", MASTER THESIS, 1 June 2020 (2020-06-01), Korea, pages 1- 35), further in view of Murikawa (US 20200243827 A1)
and further in view of Soo (KR20170014388A)
Regarding claim 5, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai is silent on the following elements of claim 5:
The positive electrode for the rechargeable lithium battery of claim 1, wherein the polyimide-based polymer having the carboxyl group further includes a lithium ion.
Specifically, Tsai teaches the inclusion of a lithium salt mixed with a metastable polymer in its non-aqueous electrolyte, but not explicitly in the coating of its positive electrode. (“The non-aqueous electrolyte solution 402 of the fourth exemplary embodiment includes lithium salt, an organic solvent, and the metastable state polymer additive above, wherein the metastable state polymer additive accounts for 0.01 wt % to 5 wt % of the total content of the non-aqueous electrolyte solution.” Tsai [0066])
However, Soo teaches the inclusion of a lithium salt in its coating layer formed of a polyimide based polymer, which would increase lithium ion conductivity by providing lithium ions in the coating layer.
The positive electrode for the rechargeable lithium battery of claim 1, wherein the polyimide-based polymer having the carboxyl group further includes a lithium ion. (“According to the present invention, there is formed a coating layer comprising a polyimide on the surface of the oxide-based positive electrode active material that forms the positive electrode,” Soo [0025] and “ At this time, the coating layer, may further comprise a lithium salt, thereby making it possible to further improve the lithium ion conductivity of the positive electrode.” Soo [0027])
Soo is considered to be analogous to Tsai because it is within the same field of using a polyimide based polymer as part of a positive electrode. Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the polyimide based polymer of Tsai to include a lithium salt, as taught by Soo, in order to improve the lithium ion conductivity of the positive electrode (“At this time, the coating layer, may further comprise a lithium salt, thereby making it possible to further improve the lithium ion conductivity of the positive electrode.” Soo [0027])
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tsai (US 20140178747 A1) in view of Park et Al (J. Mater. Chem., 2012,22, 12574-12581.), further in view of Lee ("Preparation of Polyimide Copolymer and Its Application as Lithium Ion Secondary Battery Binder", MASTER THESIS, 1 June 2020 (2020-06-01), Korea, pages 1- 35), further in view of Murikawa (US 20200243827 A1), further in view of Soo (KR20170014388A) and Benson (US 20210020946 A1)
Regarding claim 6, modified Tsai teaches all of the elements of claim 5, as shown above. Tsai and Soo are silent on the following elements of claim 6:
The positive electrode for the rechargeable lithium battery of claim 5, wherein the lithium ion is included in an amount of 0.1 wt% to 1 wt% based on the total weight of the polyimide-based polymer having the carboxyl group.
However, Benson teaches the elements of claim 6 that are not found in Tsai or Soo. Specifically, Benson teaches a range of lithium salt used in a lithiated polyimide polymer, the range of which includes the claimed range for the amount of lithium ions present:
The positive electrode for the rechargeable lithium battery of claim 5, wherein the lithium ion is included in an amount of 0.1 wt% to 1 wt% based on the total weight of the polyimide-based polymer having the carboxyl group. (“The lithium salt can be any salt of lithium capable of neutralizing amic acid groups. In some embodiments, the lithium salt is selected from the group consisting of lithium carbonate, lithium hydroxide, lithium bicarbonate,” Benson [0061] and “Preferably the concentration of the lithium salt in the solvent ranges from 3 to 30 wt. %,” Benson [0063]. In order to have 1% by weight of lithium ion, there would need to be 3.45% of lithium hydroxide by weight, as lithium accounts for 29% of LiOH by weight. Therefore, a solution having a 3% weight content of lithium salt in a polyimide binder/polymer solution would be within the claimed range of lithium ion present.)
The examiner takes note of the fact that the prior art range of 3-30% weight % of lithium salt in the solution, which would correlate to 0.87-8.7% Li+ content in the polyimide based polymer overlaps the claimed range of between 0.1 and 1% for the same parameter. Absent any additional and more specific information in the prior art, a prima facie case of obviousness exists. In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379 (Fed. Cir. 2003). MPEP 2144.05.
Benson is considered to be analogous to Soo and Tsai because it is within the same field of using polyimide based polymers in secondary batteries. Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the lithiated polyimide polymer of Soo to have the specific lithium salt—in this case, lithium hydroxide—content of Benson in order to improve the capacity retention of the lithium ion battery (“the capacity retention of lithium-ion batteries can be significantly improved by the use of lithiated polyamide-imide (LiPAI) polymers as electrode binders.“ Benson [0015]).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tsai (US 20140178747 A1) in view of Park et Al (J. Mater. Chem., 2012,22, 12574-12581.), further in view of Lee ("Preparation of Polyimide Copolymer and Its Application as Lithium Ion Secondary Battery Binder", MASTER THESIS, 1 June 2020 (2020-06-01), Korea, pages 1- 35), further in view of Murikawa (US 20200243827 A1), and further in view of Yoshimura (US 20200266409 A1)
Regarding claim 7, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai is silent on the following elements of claim 7:
The positive electrode for the rechargeable lithium battery of claim 1, wherein an acid value of the polyimide-based polymer having the carboxyl group is 10 to 100 KOH mg/g.
However, Yoshimura teaches all of the elements of claim 7 not found in Tsai:
The positive electrode for the rechargeable lithium battery of claim 1, wherein an acid value of the polyimide-based polymer having the carboxyl group is 10 to 100 KOH mg/g. (“According to an aspect of the present disclosure, there is provided a porous polyimide having an acid value of 7 mgKOH/g or more and 20 mgKOH/g or less determined by acid-base titration,” Yoshimura [0010])
The examiner takes note of the fact that the prior art range of 7-20mgKOH/g for the acid value of the polyimide based polymer overlaps the claimed range of 10-100 mgKOH/g for the same parameter. Absent any additional and more specific information in the prior art, a prima facie case of obviousness exists. In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379 (Fed. Cir. 2003). MPEP 2144.05.
Tsai and Yoshimura are considered to be analogous because they are both within the same field of using polyimide polymers in battery applications. In addition to the possibility that the polyimide polymer of Tsai inherently being within the claimed range for its acid value, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the polyimide polymer of Tsai to have the specific acid value range of Yoshimura in order to have improved wettability and high strength compared to when the acid value is above or below the taught range (“Aspects of non-limiting embodiments of the present disclosure relate to a porous polyimide film having good wettability and high strength as compared with when the acid value of a porous polyimide film determined by acid-base titration is less than 7 mgKOH/g or exceeds 20 mgKOH/g,” Yoshimura [0008]).
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tsai (US 20140178747 A1) in view of Park et Al (J. Mater. Chem., 2012,22, 12574-12581.), further in view of Lee ("Preparation of Polyimide Copolymer and Its Application as Lithium Ion Secondary Battery Binder", MASTER THESIS, 1 June 2020 (2020-06-01), Korea, pages 1- 35), further in view of Murikawa (US 20200243827 A1), and further in view of Jung (US 8440351 B2)
Regarding claim 8, modified Tsai meets all of the limitations of claim 1, as shown above. Tsai, Park, and Soo are silent on the following elements of claim 8:
The positive electrode for the rechargeable lithium battery of claim 1, wherein a glass transition temperature (Tg) of the polyimide-based polymer is 160 0C to 280 °C.
However, Jung teaches all of the elements of claim 8 not found in the aforementioned references. Specifically, Jung teaches the use of a polyimide coating for a positive electrode having the desired glass transition temperature.
The positive electrode for the rechargeable lithium battery of claim 1, wherein a glass transition temperature (Tg) of the polyimide-based polymer is 160 0C to 280 °C. (“The positive electrode includes a lithium-manganese-based compound core and a heat-resistant polymer disposed on the lithium-manganese-based compound core, and the heat resistant polymer has a glass transition temperature (Tg) ranging from about 80 to about 400.degree. C.” Jung page 2 column 2 line 6 and “The heat resistant polymer may be selected from the group consisting of a polyamide (PA) resin, a polyimide (PI) resin,” Jung page 2 column2 line 8. This teaches that a polyimide based resin would have a glass transition temperature that encompasses the desired range.)
The examiner takes note of the fact that the prior art range of 80 to 400 degrees C as the glass transition temperature of the polyimide based polymer encompasses the claimed range of 160 to 280 C for the same parameter. Absent any additional and more specific information in the prior art, a prima facie case of obviousness exists. In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379 (Fed. Cir. 2003). MPEP 2144.05.
Jung is considered to be analogous to Tsai as they are both related to the use of polymer coatings for positive electrodes. Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the polyimide based polymer used to meet the limitations of claim 1 to make sure that the glass transition temperature is within the range taught by Jung in order to provide a heat resistant coating on the positive electrode and suppress degradation of the positive electrode (“Accordingly, this disclosure can provide a positive electrode for a rechargeable lithium ion battery that suppresses degradation of the positive electrode, and therefore can stably maintain a lithium-manganese-based compound despite charge and discharge at a high voltage and a high temperature and can realize excellent cycle characteristics.” Jung page 2 column 2 line 64).
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tsai (US 20140178747 A1) in view of Park et Al (J. Mater. Chem., 2012,22, 12574-12581.), further in view of Lee ("Preparation of Polyimide Copolymer and Its Application as Lithium Ion Secondary Battery Binder", MASTER THESIS, 1 June 2020 (2020-06-01), Korea, pages 1- 35), further in view of Murikawa (US 20200243827 A1), further in view of Jung (US 8440351 B2) and further in view of Cristadoro (US 20150214526 A1)
Regarding claim 15, modified Tsai teaches all of the elements of claim 1, as shown above. Tsai, Park, and Lee are silent on the following elements of claim 15:
The positive electrode of claim 1, wherein the polyimide-based polymer having the carboxyl group has an acid value of 30 to 50 KOH mg/g and a glass transition temperature (Tg) of 170 0C to 250 0C.
However, Jung and Cristadoro teach all of the elements of claim 15 not found in Tsai:
Jung teaches the following elements of claim 15:
The positive electrode of claim 1, wherein the polyimide-based polymer having a glass transition temperature (Tg) of 170 0C to 250 0C. (“The positive electrode includes a lithium-manganese-based compound core and a heat-resistant polymer disposed on the lithium-manganese-based compound core, and the heat resistant polymer has a glass transition temperature (Tg) ranging from about 80 to about 400.degree. C.” Jung page 2 column 2 line 6 and “The heat resistant polymer may be selected from the group consisting of a polyamide (PA) resin, a polyimide (PI) resin,” Jung page 2 column2 line 8. This teaches that a polyimide based resin would have a glass transition temperature that encompasses the desired range.)
The examiner takes note of the fact that the prior art range of 80 to 400 degrees C as the glass transition temperature of the polyimide based polymer encompasses the claimed range of 160 to 280 C for the same parameter. Absent any additional and more specific information in the prior art, a prima facie case of obviousness exists. In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379 (Fed. Cir. 2003). MPEP 2144.05.
Jung is considered to be analogous to Tsai as they are both related to the use of polymer coatings for positive electrodes. Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the polyimide based polymer used to meet the limitations of claim 1 to make sure that the glass transition temperature is within the range taught by Jung in order to provide a heat resistant coating on the positive electrode and suppress degradation of the positive electrode (“Accordingly, this disclosure can provide a positive electrode for a rechargeable lithium ion battery that suppresses degradation of the positive electrode, and therefore can stably maintain a lithium-manganese-based compound despite charge and discharge at a high voltage and a high temperature and can realize excellent cycle characteristics.” Jung page 2 column 2 line 64).
Cristadoro teaches the following elements of claim 15:
The positive electrode of claim 1, wherein the polyimide-based polymer having the carboxyl group has an acid value of 30 to 50 KOH mg/g (“In one embodiment of the present invention, reaction product from polyimide (a) and diol (b) or triol (b) has an acid value in the range from zero to 300 mg of KOH/g,” Cristadoro [0058]. Additionally, Cristadoro [0209-0210] teaches an example product with an acid value of 40mg KOH/g. This anticipates the claimed range.)
Cristadoro is considered to be analogous to Tsai because it is within the same field of polymers being used in electrochemical cells. Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to modify the poly-imide based polymer used in modified Tsai to have the acid value taught by Cristadoro; in order to produce an electrochemical cell with improved properties (“A further aspect of the present invention refers to batteries containing at least one inventive electrochemical cell, for example two or more. Inventive batteries have advantageous properties. They have a long duration with very low loss of capacity, good cycling stability, and high temperature stability.” Cristadoro [0159])
Allowable Subject Matter
Claims 14 and 16 allowed.
The following is a statement of reasons for the indication of allowable subject matter: The subject matter of claims 14 and 16 was deemed allowable in a previous office action. Since the claims have been amended to be independent claims, they are now considered to be allowable, and, if the remaining claims were amended to incorporate allowable subject matter, then the application would be in condition for allowance.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BENJAMIN ELI KASS-MULLET whose telephone number is (571)272-0156. The examiner can normally be reached Monday-Friday 8:30am-6pm except for the first Friday of bi-week.
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, NICHOLAS SMITH can be reached at (571) 272-8760. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BENJAMIN ELI KASS-MULLET/Examiner, Art Unit 1752
/NICHOLAS A SMITH/Supervisory Primary Examiner, Art Unit 1752
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