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 .
Election/Restrictions
Applicant’s election without traverse of Group I (Claims 1-10) in the reply filed on 4/10/26 is acknowledged.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 7/31/23, 9/5/23, 12/20/23, 5/7/24, 11/10/25, and 12/19/25 were filed. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements have been considered by the examiner.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 7-8 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over KR 20190051354 A (KR'354) in view of JPH113709 A (JP'709).
As to Claim 1:
KR'354 discloses a method for producing a secondary battery electrode, comprising dry-mixing a cathode active material, a conductive material, and a binder (e.g., polytetrafluoroethylene) in a dry state without using a solvent (KR'354, Pg. 2–4, 8–9, 11). KR'354 further discloses preparing the composition into a sheet by disposing the mixture on a current collector and rolling the current collector by a roll press method to form an active material layer (KR'354, Pg. 4–5, 8–9, 11). Since the roll press method consolidates the dry powder composition into a sheet-like layer using pressure, this corresponds to preparing the composition into a sheet by applying shear stress to the composition (KR'354, Pg. 4–5, 8–9, 11). KR'354 also discloses that this process is solvent-free (i.e., with a solvent content of 10% by mass or less relative to the composition) (KR'354, Pg. 3, 8–9, 11).
However, KR'354 does not explicitly disclose preparing an intermediate composition "substantially free of a liquid medium" by using a specific binder powder that is pre-composed essentially of a polytetrafluoroethylene resin and a conductive aid, while being free of an active material, prior to the final mixing step with the active material.
JP'709 discloses a method for preparing a polytetrafluoroethylene-containing powder as a binder component for a lithium secondary battery (JP'709, Pg. 1, 4–5, 7, 11). JP'709 teaches adding an electron conduction auxiliary agent (conductive aid) to an aqueous dispersion of polytetrafluoroethylene (PTFE resin), stirring and mixing them in advance, and then drying the mixture to prepare the polytetrafluoroethylene-containing powder (JP'709, Pg. 1, 4–5, 7, 11). JP'709 explicitly states that this binder powder is prepared "excluding the positive electrode material," thereby ensuring it is free of an active material (JP'709, Pg. 1, 4, 7, 11).
Both JP'709 and KR'354 are analogous art as they both relate to the technical field of manufacturing electrodes for non-aqueous secondary batteries, specifically focusing on the composition of binders, conductive aids, and active materials (KR'354, Pg. 1–4, 6–8; JP'709, Pg. 1–7, 11).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to incorporate the pre-prepared PTFE and conductive aid binder powder taught by JP'709 into the dry electrode manufacturing process taught by KR'354. A person of ordinary skill in the art would have been motivated to use the pre-prepared high-dispersibility binder powder of JP'709 to ensure uniform binder distribution and improved mechanical strength in the resulting electrode film, while continuing to utilize the dry-processing advantages (e.g., eliminating slurry convection and drying time) of the KR'354 method (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 10–11).
As to Claim 2:
See the rejection of Claim 1, which this claim depends on. KR'354 discloses that the dry electrode manufacturing process eliminates the use of solvents, thereby providing a dry powder mixture (KR'354, Pg. 2–3, 8–9, 11). JP'709 discloses preparing a PTFE-containing binder powder by mixing a conductive aid with an aqueous PTFE dispersion and drying the mixture at 80 °C for 24 hours to remove the water medium and prepare the powder (JP'709, Pg. 4–5, 7, 11). However, KR'354 and JP'709 do not explicitly recite the specific numerical moisture limit of “1,000 ppm or less.”
JP'709 discloses that positive electrode active materials are sensitive to moisture and that the presence of water causes deterioration, such as lithium elution, which significantly reduces battery capacity (JP'709, Pg. 3, 5, 10–11). JP'709 therefore teaches that drying the binder powder is a necessary step to prevent the elution of lithium and subsequent reactions that degrade battery performance (JP'709, Pg. 3–5, 7, 10–11). A person skilled in the art would understand that in the context of preparing binder powders for high-capacity battery electrodes, achieving a low moisture content is critical for performance. It would have been obvious to a person skilled in the art that optimizing the drying process taught in JP'709—specifically by drying the binder powder to a moisture content of 1,000 ppm or less—is a routine optimization required to ensure electrode stability and prevent the moisture-induced performance degradation explicitly identified in JP'709 (JP'709, Pg. 3–5, 7, 10–11).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to optimize the drying conditions taught in JP'709 to achieve a moisture content of 1,000 ppm or less in the binder powder, thereby ensuring that the binder remains sufficiently dry to prevent the deterioration identified in JP'709 when incorporated into the dry manufacturing process of KR'354, resulting in a secondary battery electrode with improved cycle stability (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 7, 10–11).
As to Claim 3:
KR'354 discloses the limitations of Claim 1, as set forth in the rejection of Claim 1 above. KR'354 further discloses the method for producing a secondary battery electrode, wherein the composition is prepared into a sheet via roll-pressing without the use of a solvent (KR'354, Pg. 2–5, 8–9, 11). JP'709 discloses the limitation of Claim 3, wherein the binder is produced by a production method comprising (A) mixing a polytetrafluoroethylene resin and a conductive aid in the presence of a liquid medium (JP'709, Pg. 1, 4–5, 7, 11). Specifically, JP'709 teaches the preparation of a polytetrafluoroethylene-containing powder by adding an electron conduction auxiliary agent (conductive aid) to an aqueous dispersion of polytetrafluoroethylene, stirring and mixing them, and subsequently drying the mixture (JP'709, Pg. 1, 4–5, 7, 11).
However, KR'354 does not explicitly disclose that the binder is produced by a production method comprising mixing a polytetrafluoroethylene resin and a conductive aid in the presence of a liquid medium, as KR'354 focuses on a dry-mixing and solvent-free processing route to form the electrode layer (KR'354, Pg. 2–5, 8–9, 11).
JP'709 discloses that the binder is produced by a production method comprising mixing a polytetrafluoroethylene resin and a conductive aid in the presence of a liquid medium (JP'709, Pg. 1, 4–5, 7, 11). JP'709 teaches that adding an electron conduction auxiliary to an aqueous dispersion of polytetrafluoroethylene—which is a liquid medium—allows for uniform mixing and dispersion of the components prior to drying, which prevents the undesirable fibrillation issues associated with mixing these components in a dry or improper state (JP'709, Pg. 3–5, 7, 10–11).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to produce the binder for the dry electrode process of KR'354 by mixing the polytetrafluoroethylene resin and the conductive aid in a liquid medium, as taught by JP'709, in order to improve the uniformity and dispersibility of the binder powder, thereby achieving a more homogeneous distribution of the binder in the resulting electrode and improving the mechanical strength and electrochemical performance of the secondary battery electrode (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 7, 10–11).
As to Claim 4:
See the rejection of Claim 1 and Claim 3. KR'354 discloses a method for producing a secondary battery electrode comprising preparing a composition substantially free of a liquid medium by applying shear stress to the composition, as set forth in the rejection of Claim 1 (KR'354, Pg. 2–5, 8–9, 11). JP'709 discloses the binder produced by mixing a polytetrafluoroethylene resin and a conductive aid in the presence of a liquid medium, as set forth in the rejection of Claim 3 (JP'709, Pg. 1, 4–5, 7, 11). JP'709 further discloses that the binder is produced by using an aqueous dispersion of polytetrafluoroethylene as the medium in which the conductive aid is mixed (JP'709, Pg. 1–2, 4–5, 7, 11).
However, KR'354 does not explicitly disclose the preparation of the binder using water as the specific liquid medium for the mixing of the polytetrafluoroethylene resin and the conductive aid, as KR'354 focuses primarily on the dry-mixing and solvent-free processing steps for the final electrode (KR'354, Pg. 2–5, 8–9, 11).
JP'709 discloses that the liquid medium utilized to disperse the polytetrafluoroethylene resin and conductive aid is an "aqueous dispersion" (JP'709, Pg. 1–2, 4–5, 7, 11). In the field of battery electrode chemistry, an aqueous dispersion is a system in which the dispersion medium is water (JP'709, Pg. 2, 5, 7).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to use an aqueous dispersion (water) as the liquid medium to mix the polytetrafluoroethylene resin and conductive aid as taught by JP'709 to prepare the binder component for the dry electrode manufacturing process taught by KR'354, because water is a known, cost-effective, and environmentally friendly liquid medium for handling such dispersions, facilitating the formation of a homogeneous binder powder that improves the uniformity and mechanical strength of the resulting battery electrode (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 7, 10–11).
As to Claim 7:
See the rejection of Claim 1, which this claim depends on (KR'354, Pg. 2–5, 8–9, 11; JP'709, Pg. 1, 4–5, 7, 11). KR'354 discloses the method for producing a secondary battery electrode, wherein the composition includes a positive electrode active material (KR'354, Pg. 2–4, 8–9, 10–11). Specifically, KR'354 is titled "Method for Manufacturing Positive Electrode" and teaches a process involving the dry-mixing of "cathode active material," a conductive material, and a binder (e.g., PTFE) (KR'354, Pg. 1–4, 8–9, 10–11). KR'354 further discloses that the mixture is placed on a current collector and processed via a roll press method to form an active material layer (KR'354, Pg. 4–5, 8–9, 10–11).
As to Claim 8:
See the rejection of Claim 1, which this claim depends on (KR'354, Pg. 2–5, 8–9, 11; JP'709, Pg. 1, 4–5, 7, 11). KR'354 discloses that the secondary battery is a lithium ion secondary battery, as the reference explicitly describes the "Method for Manufacturing Positive Electrode for Lithium Secondary Battery" and details the process for manufacturing electrodes for such batteries (KR'354, Pg. 1–3, 6–8).
As to Claim 10:
See the rejection of Claim 1, which this claim depends on. KR'354 discloses a method for producing a secondary battery electrode utilizing polytetrafluoroethylene (PTFE) as a binder (KR'354, Pg. 3–4, 8–9, 11). JP'709 discloses the binder powder composition limitation of Claim 1, identifying the binder resin as polytetrafluoroethylene (JP'709, Pg. 1, 4–5, 7, 11). Both references identify the binder material as polytetrafluoroethylene (PTFE), which constitutes the chemical composition of the binder used in the claimed method (KR'354, Pg. 3–4, 8–9; JP'709, Pg. 1, 4–5, 7, 11).
However, KR'354 and JP'709 do not explicitly recite the F/C ratio range of 0.4 or more and 3.0 or less in the text of references.
JP'709 discloses that the binder is composed of polytetrafluoroethylene (PTFE) resin, a material known to be defined by its specific chemical structure (JP'709, Pg. 1, 4–5, 7, 11). KR'354 similarly identifies the binder material as PTFE (KR'354, Pg. 3–4, 8–9, 11). Since the binder is identified as polytetrafluoroethylene in the references, the F/C ratio—which is a property determined by the chemical composition of PTFE—is a characteristic inherent to the material identified in the prior art. The claimed F/C ratio of 0.4 or more and 3.0 or less is a property defined by the material identity (PTFE) provided in the references (KR'354, Pg. 3–4, 8–9; JP'709, Pg. 1, 4–5, 7, 11).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to utilize the polytetrafluoroethylene binder as taught by JP'709 and KR'354, which inherently possesses the F/C ratio identified in the claim due to the chemical nature of the material itself, for use in a secondary battery electrode to achieve the desired electrochemical performance and mechanical properties required for the dry manufacturing process (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 7, 10–11).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over KR 20190051354 A (KR'354) in view of JPH113709 A (JP'709), as applied to Claim 3, and further in view of JP 2008140809 A (JP'809).
As to Claim 5:
See the rejection of Claim 1 and Claim 3. KR'354 discloses the method for producing a secondary battery electrode comprising preparing a composition substantially free of a liquid medium by applying shear stress to the composition, as set forth in the rejection of Claim 1 (KR'354, Pg. 2–5, 8–9, 11). JP'709 discloses the binder produced by mixing a polytetrafluoroethylene resin and a conductive aid in the presence of a liquid medium, as set forth in the rejection of Claim 3 (JP'709, Pg. 1, 4–5, 7, 11). JP'809 discloses that a slurry containing electrode materials can be processed using “spray-drying” to obtain granulated particles (JP'809, Pg. 1–3, 7–8, 13–16).
However, KR'354 and JP'709 do not explicitly recite the specific drying technique of “spray drying” for the binder composition, as JP'709 describes the binder powder being prepared by drying the mixture to remove the water medium, without naming a specific spray-drying apparatus (KR'354, Pg. 2–5, 8–9, 11; JP'709, Pg. 4–5, 7, 11).
JP'809 discloses that the composition containing binder and conductive materials can be produced by a method comprising spray drying the composition to obtain granulated particles (JP'809, Pg. 1–3, 6–8, 13–16). JP'809 teaches that spray drying is an effective method for forming uniform, spherical particles in the field of electrochemical electrode manufacturing (JP'809, Pg. 1–4, 7–9, 13–16).
JP'709, JP'809, and KR'354 are analogous art because all references are directed to the field of manufacturing electrodes for secondary batteries, specifically addressing the composition, preparation, and optimization of binder systems and conductive additives used in high-performance electrode films (KR'354, Pg. 1–4, 6–8; JP'709, Pg. 1–7, 10–11; JP'809, Pg. 1–4, 10–12, 15–16).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to utilize the spray-drying technique taught by JP'809 to dry the binder composition taught by JP'709, as spray drying is a well-known method for converting slurries or dispersions into uniform, granulated powder particles suitable for the dry-processing method of KR'354, ensuring the binder powder has the consistent morphology and flowability required for dry-forming a uniform electrode sheet (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 7, 10–11; JP'809, Pg. 1–4, 7–9, 13–16).
Claims 6 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over KR 20190051354 A (KR'354) in view of JPH113709 A (JP'709), as applied to Claim 1, and further in view of EP 0735093 (EP'093).
As to Claim 6:See the rejection of Claim 1, which this claim depends on. KR'354 discloses a method for producing a secondary battery electrode utilizing polytetrafluoroethylene (PTFE) as a binder in a positive electrode (KR'354, Pg. 2–4, 8–9, 11). JP'709 discloses a binder powder composition comprising PTFE and a conductive aid (JP'709, Pg. 1, 4–5, 7, 11). EP'093 discloses that the polytetrafluoroethylene resin utilized as a binder in battery electrodes has a standard specific gravity (SSG) within the range of 2.130 to 2.200 (EP'093, Pg. 3, 8).
However, KR'354 and JP'709 do not explicitly recite the specific numerical range of 2.11 to 2.20 for the standard specific gravity of the polytetrafluoroethylene resin used as the binder (KR'354, Pg. 2–4, 8–9, 11; JP'709, Pg. 1, 4–5, 7, 11).
EP'093 discloses that the polytetrafluoroethylene resin utilized as a binder in the electrode manufacturing process is selected to have a standard specific gravity (SSG) in the range of 2.130 to 2.200 (EP'093, Pg. 3). This specific range is directly within the claimed range of 2.11 to 2.20, and EP'093 teaches that this physical property is indicative of the molecular weight and fibrillation characteristics necessary for effective electrode binding (EP'093, Pg. 2–3, 8–9).
KR'354, JP'709, and EP'093 are analogous art because they all pertain to the technical field of manufacturing electrodes for non-aqueous secondary batteries, and they all specifically address the selection, characterization, and implementation of PTFE binders in electrode fabrication (KR'354, Pg. 1–4, 6–8; JP'709, Pg. 1–7, 10–11; EP'093, Pg. 1–6, 10–11).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to select a polytetrafluoroethylene resin having a standard specific gravity of 2.11 to 2.20, as taught by EP'093, when implementing the binder powder composition of JP'709 within the dry electrode manufacturing process of KR'354, because EP'093 explicitly teaches that this SSG range optimizes the fibrillation and binding performance required to produce a stable and high-performance battery electrode (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 7, 10–11; EP'093, Pg. 2–6, 8–11).
As to Claim 9:
See the rejection of Claim 1, which this claim depends on. KR'354 discloses a method for producing a secondary battery electrode utilizing a roll press method to form an active material layer (KR'354, Pg. 2–5, 8–9, 11). JP'709 discloses a binder powder composition comprising PTFE and a conductive aid produced by mixing in a liquid medium (JP'709, Pg. 1, 4–5, 7, 11). EP'093 discloses that the polytetrafluoroethylene (PTFE) resin used as a binder forms a fibrous structure through fibrillation when subjected to a compressive shearing force (EP'093, Pg. 2–3, 6, 9).
However, KR'354 and JP'709 do not explicitly recite that the PTFE resin used in the electrode has a fibrous structure with a fibril diameter (median value) of 20 nm or more (KR'354, Pg. 2–5, 8–9, 11; JP'709, Pg. 1, 3–5, 7, 11).
EP'093 discloses that the polytetrafluoroethylene resin utilized as a binder in electrode manufacturing is designed to be fibrillated under a compressive shearing force to form a fibrous structure (EP'093, Pg. 2–3, 6, 9). EP'093 teaches that this fibrous structure is the mechanism by which the PTFE resin maintains the mechanical integrity of the electrode (EP'093, Pg. 2, 6, 9–10). By selecting the PTFE binder for the dry electrode process of KR'354 and applying the shear stress required for roll-pressing, the fibrillation of the PTFE into a fibrous structure is an inherent technical result of the processing method (KR'354, Pg. 4–5, 8–9; EP'093, Pg. 2–3, 6, 9).
It would have been obvious to a person skilled in the art before the effective filing date of the instant application to utilize the PTFE binder as taught by JP'709 within the dry electrode manufacturing process of KR'354, and recognize—based on the teachings of EP'093—that subjecting this PTFE to the compressive shearing force of the roll-pressing process would necessarily result in the fibrillation of the PTFE into the fibrous structure described in the claim, thereby ensuring the mechanical integrity of the secondary battery electrode (KR'354, Pg. 2–5, 8–10; JP'709, Pg. 3–5, 7, 10–11; EP'093, Pg. 2–3, 6, 9–11).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JIMMY K VO whose telephone number is (571)272-3242. The examiner can normally be reached Monday - Friday, 8 am to 6 pm EST.
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/JIMMY VO/
Primary Examiner
Art Unit 1723
/JIMMY VO/Primary Examiner, Art Unit 1723
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