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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 February 27th 2026 has been entered.
Response to Amendment
The Amendment filed February 27th 2026 has been entered. Claims 1-20 remain pending in the application. Applicant’s arguments to the rejections of the claims have been fully considered but are not persuasive. Thus, the rejections have been maintained. However, upon further consideration, a new grounds of rejection is made in view of Yokoyama in further view of Oshita. New rejections follow.
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.
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 1-4, 7-11, 14-18, & 20 are rejected under 35 U.S.C. 103 as being unpatentable over Ho et al. US 2019/0157681 A1 and further in view of Yokoyama US 11,114,664 B2 and Oshita et al. US 2018/0248186 A1. Further evidence provided by Sigma Aldrich “Methylphosphonic acid”.
Regarding Claim 1, Ho discloses a cathode active material [Abstract], however fails to disclose a coating layer derived from a phosphorous containing compound with the chemical formula with the limitations of Claim 1.
Yokoyama discloses a coated cathode active material comprising a positive electrode active material and a coating layer [Column 2 Lines 31-34]. Yokoyama discloses that the coating layer contains phosphorous [Column 2 Lines 32-34], and specifies that the coating layer comprises inorganic or organic phosphoric acid as the phosphorous containing compound [Column 2 Lines 18-20]. Thus Yokoyama disclose a coating layer comprising a phosphorous containing compound derived from the structure of general formula (1) in Claim 1. Further, Yokoyama discloses the phosphorous containing compound is organic phosphoric acid which Yokoyama clarifies is methylphosphonic acid [Column 3 Lines 12-13, Column 16 Lines 8-12], thus modified Ho discloses that R1 is alkyl, which is linear, and R2 is hydroxyl. Structure image of methylphosphonic acid is shown below, evidenced by Sigma Aldrich:
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Yokoyama discloses that a cathode active material comprising this coating suppresses the reaction with water during the preparation of a cathode slurry, which leads to reduce internal resistance [Column 4 Lines 52-59].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to incorporate the coating layer of Yokoyama on the cathode active material of Ho to achieve a coated cathode active material with reduced reaction with water during slurry preparation and thus reduced internal resistance.
Modified Ho discloses that the cathode active material has a small specific surface area to enable more efficient drying (a larger surface area allows for greater interaction with the solvent and slows drying) [0085, 0153], and discloses that a higher specific surface area of the cathode active material also requires more binder, which reduces the energy density of the battery [0007]. However, modified Ho is silent as to the specific value of the specific surface area of the cathode active material being within the claimed range.
Oshita discloses a positive electrode active material for a battery [Abstract] wherein the recommended specific surface area is 1.0-7.0 m2/g [0054], which overlaps with the claimed range.
Oshita discloses that a specific surface area within this range is beneficial for charge/discharge capacity as well as safety of the battery [0054].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to use the recommended specific surface area of the positive electrode active material of Oshita for the cathode active material of modified Ho to achieve a specific surface area of 1.0-7.0 m2/g to improve charge/discharge capacity and battery safety, further supported by Ho’s disclosure that a smaller specific surface area is beneficial for efficient drying of the active material.
Regarding Claim 2-4, modified Ho discloses, with the modification of Yokoyama’s coating layer, that the coating layer is derived from a phosphorous containing compound as stated in addressing Claim 1. Further, Yokoyama discloses the phosphorous containing compound is organic phosphoric acid which Yokoyama clarifies is methylphosphonic acid [Column 3 Lines 12-13], thus modified Ho discloses that R1 is alkyl and R2 hydroxyl.
Regarding Claim 7, Ho discloses that the cathode active material is selected from LiCoO2, LiNiO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4--, and LiFeO2 [0046]. More specifically, Ho discloses that the cathode active material is NMC333, NMC532, NMC622, NMC811, or NCA [0046] which the instant discloses mentions as cathode active materials [0066-0068] and uses in the examples (NMC811 used in Example 1 [0194], NMC532 used in Examples 10 & 13 [0221], NMC622 used in Example 14, NCA used in Example 15 [0226]).
Regarding Claim 8, Ho discloses that the cathode active material comprises a core-shell composite [0048]. Ho discloses that the shell comprises a lithium transition metal oxide [0049] such as LiCoO2, LiNiO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, and LiMn2O4-- [0049].
Regarding Claim 9, as mentioned in addressing Claim 8, Ho discloses that the shell comprises a transition metal oxide such as Fe2O3, MnO2, A12O3, MgO, ZnO, TiO2, La2O3, CeO2, SnO2, ZrO2, RuO2 [0048].
Regarding Claim 10, Ho discloses that the cathode active material is doped with a dopant such as Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, or Ge [0047].
Regarding Claim 11, modified Ho discloses a cathode slurry comprising the coated cathode active material, as modified by Yokoyama, as well as a binder and an aqueous solvent [0068, 0070].
Regarding Claim 14, Ho discloses that the solvent is water [0070].
Regarding Claim 15, Ho discloses that the solvent additionally comprises a miscible component added as a minor component [0070], such as alcohols, ketones, or alkyl acetates [0070]. Ho discloses that the amount of water is from 50-95 vol% compared to the total amount of water and solvent other than water, thus Ho discloses that the volume ratio of water to the miscible minor component is 50:50 to 95:5. In regards to the volume ratio of the solvent, the Examiner directs Applicant to MPEP 2144.05 I. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. Accordingly, it would have been obvious to one of ordinary skill in the art to have selected the overlapping ranged disclosed by Ho because selection of the overlapping portion or ranges has been held to be a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding Claim 16, Ho discloses that the slurry further comprises a conductive agent [0060], which is selected from the group of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanoplatelets, carbon fibers, carbon nano-fibers, graphitized carbon flake, carbon tubes, carbon nanotubes, activated carbon, mesoporous carbon [0060].
Regarding Claim 17, modified Ho discloses that the amount of coated cathode active material, as modified by Yokoyama, in the slurry is at least 60% by weight [0059] based on the total weight of the slurry. In regards to the weight of the cathode material in the slurry, the Examiner directs Applicant to MPEP 2144.05 I. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. Accordingly, it would have been obvious to one of ordinary skill in the art to have selected the overlapping ranged disclosed by Ho because selection of the overlapping portion or ranges has been held to be a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding Claim 18, Yokoyama discloses that the phosphorous coating on the cathode active material improves the internal resistance of the test samples Example 1 & 2 compared to Comparative Examples 1 & 2 in Figure 8), which improves the battery performance. In the absence of a specific definition of the degradation of the cathode active material in water, the Examiner’s position is that Yokoyama discloses a measurement of degradation (in this case, the internal resistance) that corresponds to the inclusion of the phosphorous coating on the cathode active material and discloses. As shown in Figure 8, Yokoyama discloses a difference in the internal resistance ratio of 100% to 93% when the phosphorous coating is included (Comparative Example 1 at 100% versus Example 1 at 93% that includes the phosphorous coating), representing a 7% improvement, thus Yokoyama discloses that the degradation of the cathode active material in water is inhibited by a percentage 7%, which falls within the claimed range. Thus, modified Ho, with the modification of Yokoyama’s coating, reads on the limitations set forth in Claim 18.
Regarding Claim 20, modified Ho discloses a cathode for a secondary battery [0118] comprising the cathode material.
Claims 5 & 6 are rejected under 35 U.S.C. 103 as being unpatentable over Ho, Yokoyama, and Oshita as applied to claim 1 above, and further in view of Kinoshita et al. US 9,040,199 B2. Further evidence provided by Sigma Aldrich “Methylphosphonic acid”.
Regarding Claim 5, modified Ho discloses a cathode active material particle that is coated with a phosphorus-containing compound, as modified by Yokoyama with regards to Claim 1. However, modified Ho fails to disclose that the amount of the phosphorus-containing compound coated per unit surface area of cathode active material particles is within the claimed range.
Kinoshita discloses a cathode active material for a battery comprising a cathode active material coated with a phosphorus-containing compound [Column 3 Lines 6-15], similar to that of modified Ho. Kinoshita discloses that the amount of the phosphorus containing compound in the shell layer is 0.01-0.5 mass%, and the mass of the shell layer compared to the core particle is 0.01-50 parts by mass [Column 6 Lines 63-66]. Thus Kinoshita discloses an amount of the phosphorus containing compound in the shell layer is 0.000001 to 0.25 parts by mass:
0.01mass% x 0.01 parts by mass = 0.000001 parts by mass phosphorus compound
0.5mass% x 50 parts by mass = 0.25 parts by mass phosphorus compound
Kinoshita discloses that positive active material with this content of phosphorus-containing compound in the shell layer enables suppression of deterioration of the particles and improves cycle characteristics [Column 5 Lines 25-28].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to modify the coated cathode active material of modified Ho to have the suggested content of phosphorus-containing compound in the coating layer as suggested by Kinoshita to provide a battery with suppressed deterioration of the cathode active material particles and improved cycle characteristics.
Thus, modified Ho discloses that the amount of the phosphorus-containing compound coated on the cathode active material particles is 0.000001-0.25 parts by mass, as modified by Kinoshita. As mentioned previously with regards to Claim 1, the phosphorus-containing compound is methylphosphonic acid, as modified by Yokoyama, which has a molecular weight of 96.02g/mol as evidenced by Sigma Aldrich. Thus modified Ho discloses that the amount in moles of the phosphorus-containing compound coated on the cathode active material particles is 1.04x10-8 to 0.0026 mol, or 0.0104 to 2600 µmol.
As mentioned previously with regards to claim 1, the cathode active material has a specific surface area of 1-7 m2/g as modified by Oshita above. Thus, the cathode active material has a surface area of 0.01-350 m2, using the parts by mass as suggested by Kinoshita above (0.1-50 parts by mass).
This would result in an amount of the phosphorus-containing compound coated per unit surface area of the cathode active material particles to be as follows:
0.0104 µmol / 0.01 m2 = 1.04 µmol/m2
2600 µmol / 350 m2 = 7.43 µmol/m2
Thus, modified Ho discloses an amount of the phosphorus-containing compound coated per unit surface area of the cathode active material particles that falls within the claimed range.
Regarding Claim 6, modified Ho is relied upon for the reasons given above in addressing Claim 1, however is silent as to the thickness of the coating layer.
Kinoshita discloses that the thickness of the coating layer is 1-10 nm [Column 7 Lines 12-14].
Kinoshita discloses that a coating layer with this thickness improves conductivity [Column 7 Lines 20-21].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to use the suggested thickness of the coating layer of Kinoshita in the coating layer of modified Ho to achieve cathode active material with improved conductivity.
Claims 12 & 13 are rejected under 35 U.S.C. 103 as being unpatentable over Ho, Yokoyama, and Oshita as applied to claims 1 & 11 above, and further in view of Goto et al. US 2019/0085109 A1.
Regarding Claims 12 & 13, modified Ho is relied upon for the reasons given above in addressing Claims 1 & 11, however fails to specifically disclose the claimed binder compositions of Claims 12 & 13.
Goto discloses a binder composition for an electrode for an electrochemical device [Abstract], specifically a lithium ion secondary battery [0027]. Goto discloses that the binder comprises a copolymer of a nitrile group-containing monomer unit, an acidic group-containing monomer unit, and a basic group-containing monomer unit [0029]. Goto discloses that the acidic group-containing monomer unit is carboxylic acid group-containing monomers [0041], meeting the limitation set forth in Claim 12 with regards to structural unit (a). Goto discloses that the basic group-containing monomer unit includes amide group-containing monomers [0056], meeting the limitation set forth in Claim 13 with regards to structural unit (b). Goto discloses that the nitrile group-containing monomer unit is acrylonitrile [0038], which is listed in the instant specification as being a suitable example of a structural unit (c) derived from an a nitrile group-containing monomer [0135-0136], thus meeting the limitation set forth in Claim 13. Goto further discloses using this binder composition in the preparation of a positive electrode slurry [0160-0161]. Thus, Goto discloses a slurry for a cathode comprising a binder composition meeting the limitations set forth in Claims 12 & 13.
Goto discloses that a binder with this composition forms an electrode with superior high-voltage cycle characteristics [0031].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to modify the binder of modified Ho with the binder of Goto to provide a cathode slurry comprising a binder with all three structural units as recited in Claims 12 & 13 to achieve a cathode with superior high-voltage cycle characteristics.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Ho, Yokoyama, and Oshita as applied to claims 1 & 11 above, and further in view of Park KR 100635735 B1 and Umetsu et al US 2019/0020034 A1. Citations to Park are mapped to the English machine translations provided.
Regarding Claim 19, modified Ho is relied upon for the reasons given above in addressing Claims 1 & 11. However, modified Ho fails to specifically disclose that the concentration of lithium ions in the cathode slurry is 0.05M to 1.25M.
Park discloses a positive electrode active material for a lithium secondary battery [Page 1 Lines 17-18]. Park further discloses an electrolyte for the battery, wherein the electrolyte comprises a lithium salt that is a source of lithium ions in the battery to enable operation [Page 3 Lines 12-15]. Park discloses that the concentration of the lithium in the electrolyte is preferably 0.6-2.0M [Page 3 Lines 18-19].
Park discloses that when the concentration of the lithium is less than 0.6M, the electrolyte has low conductivity and the performance deteriorates [Page 3 Lines 20-21]. Park also discloses that when the concentration of the lithium is greater than 2.0M, the viscosity of the electrolyte increases and the mobility of the lithium ions decreases [Page 3 Lines 21-22]. Park earlier discloses that the viscosity of the positive electrode is important for the stability of the slurry during processing [Page 1 Line 59 - Page 2 Line 6].
Additionally, in a similar application, Umetsu discloses a lithium ion secondary battery comprising a positive electrode, negative electrode, and an electrolyte [Abstract], wherein the electrolyte comprises a lithium salt as the source of lithium ions [0212], similar to that of Park. Umetsu discloses that the concentration of the lithium in the electrolyte is preferably 0.5 mol/L-2.0 mol/L [0214], similar to the range in Park.
Umetsu discloses that when the lithium concentration is within the above range, there is sufficient anions which allow for sufficient battery capacity, however if the lithium concentration goes above this range (above 2.0 mol/L) the viscosity of the electrolyte will be too high and decrease the conductivity [0214], similar to Park’s disclosure of the optimal range of lithium concentration. Umetsu earlier discloses that the viscosity is important for the positive electrode manufacturing as well because if the viscosity is too low, the thickness and coating width cannot be controlled, and if the viscosity is too high, the flow of the slurry during processing is negatively impacted and stable, uniform coating cannot be performed [0113].
One of ordinary skill in the art would have recognized that the concentration of lithium ions is a result effective variable, and would seek to optimize this parameter, and would therefore arrive at the claimed range to achieve provide a battery with good capacity and increased conductivity, as well benefits to the viscosity of the slurry such as better coating control and stability during processing. See MPEP 2144.05. Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to select a concentration of lithium ions within the claimed range to provide a battery with good capacity and increased conductivity as suggested by Park and Umetsu, as well as optimal viscosity of the slurry during processing to control and stabilize the coating process.
Claims 1-4, 7, 11, 16-18, & 20 are rejected under 35 U.S.C. 103 as being unpatentable over Yokoyama US 11,114,664 B2 and further in view of Oshita et al. US 2018/0248186 A1. Further evidence provided by Sigma Aldrich “Methylphosphonic acid”.
Regarding Claim 1, Yokoyama discloses a coated cathode active material comprising a positive electrode active material and a coating layer [Column 2 Lines 31-34]. Yokoyama discloses that the coating layer contains phosphorous [Column 2 Lines 32-34], and specifies that the coating layer comprises inorganic or organic phosphoric acid as the phosphorous containing compound [Column 2 Lines 18-20]. Thus Yokoyama disclose a coating layer comprising a phosphorous containing compound derived from the structure of general formula (1) in Claim 1. Further, Yokoyama discloses the phosphorous containing compound is organic phosphoric acid which Yokoyama clarifies is methylphosphonic acid [Column 3 Lines 12-13, Column 16 Lines 8-12], thus Yokoyama discloses that R1 is alkyl, which is linear, and R2 is hydroxyl. Structure image of methylphosphonic acid is shown below, evidenced by Sigma Aldrich:
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However, Yokoyama is silent as to the specific value of the specific surface area of the cathode active material being within the claimed range.
Oshita discloses a positive electrode active material for a battery [Abstract] wherein the recommended specific surface area is 1.0-7.0 m2/g [0054], which overlaps with the claimed range.
Oshita discloses that a specific surface area within this range is beneficial for charge/discharge capacity as well as safety of the battery [0054].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to use the recommended specific surface area of the positive electrode active material of Oshita for the cathode active material of Yokoyama to achieve a specific surface area of 1.0-7.0 m2/g to improve charge/discharge capacity and battery safety.
Regarding Claim 2-4, Yokoyama discloses that the coating layer is derived from a phosphorous containing compound as stated in addressing Claim 1. Further, Yokoyama discloses the phosphorous containing compound is organic phosphoric acid which Yokoyama clarifies is methylphosphonic acid [Column 3 Lines 12-13], thus Yokoyama discloses that R1 is alkyl and R2 hydroxyl.
Regarding Claim 7, Yokoyama discloses that the cathode active material is a lithium oxide, more specifically Li1.02(Ni0.82Co0.14Al0.04)O2 [Column 7 Lines 25-32], which reads on the claimed formula Li1+aNibCodAl(1-b-c-d)MncO2 wherein a = 0.2, b = 0.82, c = 0, and d = 0.14, which fall within the claimed ranges for a, b, c, and d.
Regarding Claim 11, Yokoyama discloses cathode slurry (positive electrode paste) comprising the coated cathode active material, as well as a binder and an aqueous solvent (NMP) [Column 9 Lines 13-23].
Regarding Claim 16, Yokoyama discloses the slurry further comprises a conductive agent [Column 9 Lines 13-14], which is acetylene black [Column 7 Lines 25-36; Column 9 Lines 13-14], which is a form of carbon black.
Regarding Claim 17, Yokoyama discloses that the coated cathode active material is added to the slurry in an amount of 93% based on the total amount of the cathode active material, binder, and conducting material, and further that the total amount of the cathode active material, binder, and conducting material comprise 70wt% of the slurry based on the total amount of the cathode active material, binder, conducting material, and the solvent [Column 9 Lines 15-23]. Thus, Yokoyama discloses that the coated cathode active material is included in an amount of (93% x 70%) = 65.1wt%, which falls within the range of the claim. In regards to the weight of the cathode material in the slurry, the Examiner directs Applicant to MPEP 2144.05 I. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. Accordingly, it would have been obvious to one of ordinary skill in the art to have selected the overlapping ranged disclosed by Ho because selection of the overlapping portion or ranges has been held to be a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding Claim 18, Yokoyama discloses that the phosphorous coating on the cathode active material improves the internal resistance of the test samples Example 1 & 2 compared to Comparative Examples 1 & 2 in Figure 8), which improves the battery performance. In the absence of a specific definition of the degradation of the cathode active material in water, the Examiner’s position is that Yokoyama discloses a measurement of degradation (in this case, the internal resistance) that corresponds to the inclusion of the phosphorous coating on the cathode active material and discloses. As shown in Figure 8, Yokoyama discloses a difference in the internal resistance ratio of 100% to 93% when the phosphorous coating is included (Comparative Example 1 at 100% versus Example 1 at 93% that includes the phosphorous coating), representing a 7% improvement, thus Yokoyama discloses that the degradation of the cathode active material in water is inhibited by a percentage 7%, which falls within the claimed range. Thus, Yokoyama reads on the limitations set forth in Claim 18.
Regarding Claim 20, Yokoyama discloses a cathode (positive electrode sheet) for a secondary battery comprising the cathode material [Column 7 Lines 13-25].
Claims 5 & 6 are rejected under 35 U.S.C. 103 as being unpatentable over Yokoyama and Oshita as applied to claim 1 above, and further in view of Kinoshita et al. US 9,040,199 B2. Further evidence provided by Sigma Aldrich “Methylphosphonic acid”.
Regarding Claim 5, Yokoyama discloses a cathode active material particle that is coated with a phosphorus-containing compound, as mentioned with regards to Claim 1. However, Yokoyama fails to disclose that the amount of the phosphorus-containing compound coated per unit surface area of cathode active material particles is within the claimed range.
Kinoshita discloses a cathode active material for a battery comprising a cathode active material coated with a phosphorus-containing compound [Column 3 Lines 6-15], similar to that of Yokoyama. Kinoshita discloses that the amount of the phosphorus containing compound in the shell layer is 0.01-0.5 mass%, and the mass of the shell layer compared to the core particle is 0.01-50 parts by mass [Column 6 Lines 63-66]. Thus Kinoshita discloses an amount of the phosphorus containing compound in the shell layer is 0.000001 to 0.25 parts by mass:
0.01mass% x 0.01 parts by mass = 0.000001 parts by mass phosphorus compound
0.5mass% x 50 parts by mass = 0.25 parts by mass phosphorus compound
Kinoshita discloses that positive active material with this content of phosphorus-containing compound in the shell layer enables suppression of deterioration of the particles and improves cycle characteristics [Column 5 Lines 25-28].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to modify the coated cathode active material of Yokoyama to have the suggested content of phosphorus-containing compound in the coating layer as suggested by Kinoshita to provide a battery with suppressed deterioration of the cathode active material particles and improved cycle characteristics.
Thus, modified Yokoyama discloses that the amount of the phosphorus-containing compound coated on the cathode active material particles is 0.000001-0.25 parts by mass, as modified by Kinoshita. As mentioned previously with regards to Claim 1, the phosphorus-containing compound is methylphosphonic acid which has a molecular weight of 96.02g/mol as evidenced by Sigma Aldrich. Thus Yokoyama discloses that the amount in moles of the phosphorus-containing compound coated on the cathode active material particles is 1.04x10-8 to 0.0026 mol, or 0.0104 to 2600 µmol.
As mentioned previously with regards to claim 1, the cathode active material has a specific surface area of 1-7 m2/g as modified by Oshita above. Thus, the cathode active material has a surface area of 0.01-350 m2, using the parts by mass as suggested by Kinoshita above (0.1-50 parts by mass).
This would result in an amount of the phosphorus-containing compound coated per unit surface area of the cathode active material particles to be as follows:
0.0104 µmol / 0.01 m2 = 1.04 µmol/m2
2600 µmol / 350 m2 = 7.43 µmol/m2
Thus, modified Yokoyama discloses an amount of the phosphorus-containing compound coated per unit surface area of the cathode active material particles that falls within the claimed range.
Regarding Claim 6, modified Yokoyama is relied upon for the reasons given above in addressing Claim 1, however is silent as to the thickness of the coating layer.
Kinoshita discloses that the thickness of the coating layer is 1-10 nm [Column 7 Lines 12-14].
Kinoshita discloses that a coating layer with this thickness improves conductivity [Column 7 Lines 20-21].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to use the suggested thickness of the coating layer of Kinoshita in the coating layer of modified Yokoyama to achieve cathode active material with improved conductivity.
Claims 8-10 & 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Yokoyama and Oshita as applied to claims 1 & 11 above, and further in view of Ho et al. US 2019/0157681 A1.
Regarding Claim 8, Yokoyama discloses a coated cathode active material comprising a positive electrode active material and a coating layer [Column 2 Lines 31-34]. However, Yokoyama does not disclose that the cathode active material has a core-shell composite.
Ho discloses a cathode active material, and that the cathode active material comprises a core-shell composite [0048]. Ho discloses that the shell comprises a lithium transition metal oxide [0049] such as LiCoO2, LiNiO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, and LiMn2O4-- [0049].
Ho discloses that the cathode active material can alternatively not comprise a core-shell composite [0053], and be comprised of a lithium-cobalt-nickel-aluminum oxide [0046, 0053] similar to that of Yokoyama.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to substitute one known cathode active material, i.e. core-shell composite of Ho, for another cathode active material, i.e. non-core-shell composite of Yokoyama, with reasonable expectation of success. The simple substitution of one cathode active material for another to obtain predictable results is not patentable. See KSR International Co v. Teleflex Inc., 127 S. Ct. 1727,82 USPQ2d 1385 (2007); MPEP 2143 B.
In addition, by teaching the two alternative cathode active materials, Ho demonstrates that these are known equivalents in the art, and the selection of either cathode active material would have been obvious to one having ordinary skill in the art. See MPEP 2144.06.
Regarding Claim 9, as mentioned in addressing Claim 8, Ho discloses that the shell comprises a transition metal oxide such as Fe2O3, MnO2, A12O3, MgO, ZnO, TiO2, La2O3, CeO2, SnO2, ZrO2, RuO2 [0048]. Thus, modified Yokoyama discloses that the shell comprises a material from the claimed list of materials.
Regarding Claim 10, Yokoyama is relied upon for the reasons given above in addressing claim 1, however is silent as to the cathode active material being doped with a dopant from the claimed list.
Ho discloses a cathode active material and that the cathode active material is doped with a dopant such as Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, or Ge [0047].
Ho discloses that alternatively, the cathode active material is not doped with a dopant [0047].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to substitute one known cathode active material, i.e. including the dopant of Ho, for another cathode active material, i.e. not including the dopant of Yokoyama, with reasonable expectation of success. The simple substitution of one cathode active material for another to obtain predictable results is not patentable. See KSR International Co v. Teleflex Inc., 127 S. Ct. 1727,82 USPQ2d 1385 (2007); MPEP 2143 B.
In addition, by teaching the two alternative cathode active materials, Ho demonstrates that these are known equivalents in the art, and the selection of either cathode active material would have been obvious to one having ordinary skill in the art. See MPEP 2144.06.
Regarding Claim 14, Yokoyama is relied upon for the reasons given above in addressing Claim 11, however is silent as to the aqueous solvent being water.
Ho discloses a cathode slurry comprising cathode active material, a binder, and a solvent [0068], similar to that of Yokoyama. Ho further discloses that the solvent is water [0070].
Ho discloses that a solvent such as this is desirable to reduce emissions of volatile organic compounds and increase processing efficiency [0070].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to modify the solvent of Yokoyama with the solvent of Ho such that the solvent is water, for the benefits of reducing the emissions of volatile organic compounds and increasing processing efficiency.
Regarding Claim 15, Ho discloses that the solvent additionally comprises a miscible component added as a minor component [0070], such as alcohols, ketones, or alkyl acetates [0070]. Ho discloses that the amount of water is from 50-95 vol% compared to the total amount of water and solvent other than water, thus Ho discloses that the volume ratio of water to the miscible minor component is 50:50 to 95:5. In regards to the volume ratio of the solvent, the Examiner directs Applicant to MPEP 2144.05 I. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. Accordingly, it would have been obvious to one of ordinary skill in the art to have selected the overlapping ranged disclosed by Ho because selection of the overlapping portion or ranges has been held to be a prima facie case of obviousness. See MPEP 2144.05 I. Thus, modified Yokoyama as modified by the solvent of Ho discloses that the solvent comprises a miscible minor component in addition to the water that reads on the limitations of Claim 15.
Claims 12 & 13 are rejected under 35 U.S.C. 103 as being unpatentable over Yokoyama and Oshita as applied to claims 1 & 11 above, and further in view of Goto et al. US 2019/0085109 A1.
Regarding Claims 12 & 13, modified Yokoyama is relied upon for the reasons given above in addressing Claims 1 & 11, however fails to specifically disclose the claimed binder compositions of Claims 12 & 13.
Goto discloses a binder composition for an electrode for an electrochemical device [Abstract], specifically a lithium ion secondary battery [0027]. Goto discloses that the binder comprises a copolymer of a nitrile group-containing monomer unit, an acidic group-containing monomer unit, and a basic group-containing monomer unit [0029]. Goto discloses that the acidic group-containing monomer unit is carboxylic acid group-containing monomers [0041], meeting the limitation set forth in Claim 12 with regards to structural unit (a). Goto discloses that the basic group-containing monomer unit includes amide group-containing monomers [0056], meeting the limitation set forth in Claim 13 with regards to structural unit (b). Goto discloses that the nitrile group-containing monomer unit is acrylonitrile [0038], which is listed in the instant specification as being a suitable example of a structural unit (c) derived from an a nitrile group-containing monomer [0135-0136], thus meeting the limitation set forth in Claim 13. Goto further discloses using this binder composition in the preparation of a positive electrode slurry [0160-0161]. Thus, Goto discloses a slurry for a cathode comprising a binder composition meeting the limitations set forth in Claims 12 & 13.
Goto discloses that a binder with this composition forms an electrode with superior high-voltage cycle characteristics [0031].
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to modify the binder of modified Yokoyama with the binder of Goto to provide a cathode slurry comprising a binder with all three structural units as recited in Claims 12 & 13 to achieve a cathode with superior high-voltage cycle characteristics.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Yokoyama, and Oshita as applied to claims 1 & 11 above, and further in view of Park KR 100635735 B1 and Umetsu et al US 2019/0020034 A1. Citations to Park are mapped to the English machine translations provided.
Regarding Claim 19, Yokoyama is relied upon for the reasons given above in addressing Claims 1 & 11. However, Yokoyama fails to specifically disclose that the concentration of lithium ions in the cathode slurry is 0.05M to 1.25M.
Park discloses a positive electrode active material for a lithium secondary battery [Page 1 Lines 17-18]. Park further discloses an electrolyte for the battery, wherein the electrolyte comprises a lithium salt that is a source of lithium ions in the battery to enable operation [Page 3 Lines 12-15]. Park discloses that the concentration of the lithium in the electrolyte is preferably 0.6-2.0M [Page 3 Lines 18-19].
Park discloses that when the concentration of the lithium is less than 0.6M, the electrolyte has low conductivity and the performance deteriorates [Page 3 Lines 20-21]. Park also discloses that when the concentration of the lithium is greater than 2.0M, the viscosity of the electrolyte increases and the mobility of the lithium ions decreases [Page 3 Lines 21-22]. Park earlier discloses that the viscosity of the positive electrode is important for the stability of the slurry during processing [Page 1 Line 59 - Page 2 Line 6].
Additionally, in a similar application, Umetsu discloses a lithium ion secondary battery comprising a positive electrode, negative electrode, and an electrolyte [Abstract], wherein the electrolyte comprises a lithium salt as the source of lithium ions [0212], similar to that of Park. Umetsu discloses that the concentration of the lithium in the electrolyte is preferably 0.5 mol/L-2.0 mol/L [0214], similar to the range in Park.
Umetsu discloses that when the lithium concentration is within the above range, there is sufficient anions which allow for sufficient battery capacity, however if the lithium concentration goes above this range (above 2.0 mol/L) the viscosity of the electrolyte will be too high and decrease the conductivity [0214], similar to Park’s disclosure of the optimal range of lithium concentration. Umetsu earlier discloses that the viscosity is important for the positive electrode manufacturing as well because if the viscosity is too low, the thickness and coating width cannot be controlled, and if the viscosity is too high, the flow of the slurry during processing is negatively impacted and stable, uniform coating cannot be performed [0113].
One of ordinary skill in the art would have recognized that the concentration of lithium ions is a result effective variable, and would seek to optimize this parameter, and would therefore arrive at the claimed range to achieve provide a battery with good capacity and increased conductivity, as well benefits to the viscosity of the slurry such as better coating control and stability during processing. See MPEP 2144.05. Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the present invention to select a concentration of lithium ions within the claimed range to provide a battery with good capacity and increased conductivity as suggested by Park and Umetsu, as well as optimal viscosity of the slurry during processing to control and stabilize the coating process.
Response to Arguments
Applicant argues that Yokoyama does not disclose a phosphorous-containing compound possessing specific properties such as the inventive feature of having a linear configuration that would lead to the unexpected and superior battery performance similar to that of the claimed invention. Examiner respectfully points out that while Yokoyama does disclose other phosphorous-containing compounds that are branched or cyclic, Yokoyama also discloses the use of methylphosphonic acid as stated in the rejection above, which has the structure below,
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wherein the alkyl has a linear configuration (structure image provided by Sigma Aldrich “Methylphosphonic acid”). Thus, Yokoyama discloses a phosphorous-containing compound having the inventive feature of a linear configuration, and would thus be expected to also produce the unexpected and superior results. Accordingly, for the reasons stated above, this argument is unpersuasive.
Applicant argues that the scope of the examples are sufficiently representative of the claimed invention. Examiner respectfully points out that, as stated in the previous Advisory Action, the evidence of unexpected results is not commensurate in scope with the claim. Claim 1 broadly claims a general cathode active material, however the examples (as shown in Table 1 of the instant specification) show few very specific cathode active materials (limited to NMC811, LNMO, Core-Shell, NMC532, NMC622, and NCA), thus the results from the limited list of cathode active materials do not represent the claim scope of cathode active materials as the claim scope is far broader. Claim 1 also broadly claims several options for R1 and R2, however the examples only show straight-chain single bonded alkyl groups for R1, which only represents one of the five options listed for R1 in Claim 1, and mostly hydroxyl groups for R2, which only represents one of the seven options listed for R2 in Claim 1, thus the results from the limited list of R1 and R2 do not represent the claim scope of cathode active materials as the claim scope is far broader. Additionally, the comparative examples only show phosphorous containing compound coatings on one type of cathode active material (NMC811). Thus, a difference in performance cannot be solely attributed to the claimed phosphorous-containing compound.
Applicant argues that the benefits as taught by Park and Umetsu for controlling and optimizing the lithium concentration would not apply to the cathode slurry since the cathode slurry and the electrolyte are distinct materials that are processed at separate stages of the manufacturing process for a battery and would not come into contact and thus the electrolyte would not affect the lithium concentration of the cathode slurry. Examiner respectfully points out that, as stated in the previous Advisory Action, one of ordinary skill in the art would recognize that Park and Umetsu teach a lithium ion concentration of an electrolyte that would lead to a concentration of lithium ions in the cathode slurry that would overlap with the claimed range. Examiner points out that the stages of manufacturing the battery are not relevant to the rejection, and that the electrolyte would lead to a concentration of lithium ions in the cathode slurry regardless of a specific stage of the manufacturing of the battery as the electrolyte would come into contact with the cathode slurry when the electrolyte is injected into the battery. Additionally, as pointed out in the rejection above and in the previous Advisory Action, Park and Umetsu both disclose reasons to optimize the lithium ion concentration, and those benefits apply to cathode slurries as well as electrolytes, such as the benefit of good capacity and increased conductivity. Finally, as pointed out in the rejection above, Park and Umetsu both disclose benefits to controlling and optimizing the lithium ion concentration and the resulting effects on the viscosity of the electrolyte, which would be beneficial to the viscosity of the cathode slurry during processing as disclosed by Park and Umetsu for the stability and control of the coating process. Accordingly, the argument is not persuasive.
Conclusion
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/A.E.G./Examiner, Art Unit 1726
/JEFFREY T BARTON/Supervisory Patent Examiner, Art Unit 1726 16 April 2026
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