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 .
DETAILED ACTION
This Office Action is in response to the communication filed on 3/25/26. Applicant’s arguments have been considered but are not entirely persuasive. Claims 1, 2, 5, 6, 9, 10 and 11-14 are pending. Claims 9, 10 and 12-14 are allowable.
This Action is FINAL, as necessitated by amendment.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 5/22/26 has been considered by the examiner.
Claims Analysis
Claim 2 recites “particles are obtained by grinding the active layer for 30 seconds at 10,000 rpm using a blender including four blades have an average diameter (D50) of 200 mm to 500 mm”, which is an intended use limitation that has not been given patentable weight. The electrode of claim 1 requires “a sheet-shaped active layer”.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1, 2, 5 and 6 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites the limitation "the active layer" in line 3. There is insufficient antecedent basis for this limitation in the claim. Examiner suggests “the sheet-shaped active layer”. See also lines 9, 12 and 14-15 that recite “the active layer”.
Claim 1 recites the limitation "the total weight" in line 10. There is insufficient antecedent basis for this limitation in the claim. Examiner suggests “a total weight”.
Claim 2 recites the limitation "the active layer" in lines 3-4. There is insufficient antecedent basis for this limitation in the claim.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
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.
Claim(s) 1, 2 and 6 is/are rejected under 35 U.S.C. 102(a)(1)/103 as being anticipated by, and alternatively unpatentable over, Li et al., WO 2021/178284 A1.
Li teaches an electrode film (sheet-shaped active layer) produced by combining 95% graphite (electrode active material), 2.5% activated carbon (electrically conductive material) and 2.5% PTFE (binder) composition by weight. The combination was mixed at low shear using a Resodyn Acoustic mixer LabRAM II to prevent pre-mature fibrillization until a substantially homogenous mix was obtained. The resulting mixture was then added to main port of a TSE (for example as available from THERMOFISHER SCIENTIFIC) at a rate of 1.6 kg/hr. The TSE had a 20 mm barrel diameter and a die plate with 15 mm nozzle attached at the end. Screw speed was 300 revolutions per minute (RPM), 8% torque and an outlet pressure of 4.9 bar. The extruder was comprised of varying screw designs capable of kneading, fibrillating and pushing the mixture through the chamber as illustrated in FIG. 3 [0082]. The TSE chamber was kept at 40 °C. The material was extruded through a die plate with a 15 millimeter (mm) nozzle at a pressure of 9.6 bar and produced a continuous rod shape. The rod of test electrode material was chopped into a fine powder and passed through a 355 micron mesh. A comparator electrode film was made using the identical composition, but the material formed using a jet mill at ~90 psi pressure, 41 standard cubic feet per minute (SCFM) of house compressed air. The resulting electrode material was then passed through 355 micron sieve. [0085] The test and comparator materials were analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) with results illustrated in FIG. 4. Cross-section SEM images (a and b) and EDS mapping of fluorine (c and d) of the dry processed graphite anode films indicated a higher degree of PTFE binder fibrillization in the screw fibrillator dry process anode (b, d) than jet mill baseline dry process anode (a, c). Both films contain 95% graphite, 2.5% active carbon, 2.5% PTFE by weight. The comparator material is illustrated in FIG. 4a demonstrates binder fibril formation and functional binding of the electrochemically active graphite. FIG. 4b illustrates the test material produced by processing in a TSE. The fibril formation of the test sample shows a significant increase in the presence of fibrils and a much more uniform binder distribution. The area in jet mill sample (FIG. 4a) that has high PTFE fiber density was <40%, while that in TSE sample (FIG. 4b) estimated to >80%, indicating about 2 times increase of binder fibrillization and/or distribution uniformity. In addition, there is large amount of non-fibrillized PTFE left in the jet mill film, indicated by the spherical spots in the fluorine-map of the cross-section of jet mill film (FIG. 4c), while the major morphology in the fluorine-map of the cross session of TSE film is linear shape (FIG. 4d), indicating most of PTFE has been effectively fibrillized. Sieved powder of the test and comparator materials were passed through a vertical roll mill to obtain an initial free-standing film. This was then passed through a horizontal roll mill until a thickness of 65 pm and/or electrochemical loading of 3.5 mAh/cm2 were obtained. The resulting films were subjected to physical testing for robustness by placing a 60 mm long sample with a width of 20 mm between two clamps. Using a 25 KgF load cell, the sample was stretched by moving the top clamp at a rate of 2.00 mm/min until the sample broke. The bottom clamp was held stationary. The results are illustrated in Table 1 [0083-0087].
Li teaches combining one or more electrode additives that alter one or more physical or electrochemical characteristics of the resulting electrode. An electrode additive may be a conductive carbon. It is appreciated that activated carbon and conductive carbon are each conductive to relative degrees. Conductive carbons are small (< 1 mm) materials that disperse readily and/or may dry coat the electrode materials to provide electronic linkages through the electrode. The dispersed conductive carbon network may be described in some cases as “chain of pearls.” In other cases, conductive carbons may be high aspect ratio fibers or platelets that can wrap powders and/or form a web type network. In some aspects, electrodes may use combinations of conductive carbons. On the other hand, activated carbon generally refers to very high surface area microporous materials. Conductive carbons may or may not be porous but in many cases are also high surface area but with more of the surface area due to exterior of small particles rather than internal pore volume as is the case for activated carbons. Commercial activated carbons are generally much larger particles than conductive carbons [0060].
The electrode film has a tensile strength at or in excess of greater than 0.6 N/mm2, optionally 0.9 N/mm2 [0049; claim 23]. Thus, the claims are anticipated.
The claims are alternatively unpatentable. Tensile strength is defined as the maximum load that a material can support without fracture when being stretched, divided by the original cross-sectional area of the material. One of skill would have found that the electrode film having the tensile strength disclosed by Li at least suggests a tensile strength ratio between a machine direction and a traverse direction of 1. The MD and TD strengths are balanced due to molecular orientation in both directions.
*
Claim(s) 1, 2, 5 and 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ozaki et al., US 2007/0020514 A1.
Ozaki teaches an electrode for a secondary battery wherein a sheet material for electrode is laminated on the surface of a current collector. The sheet material is prepared by mixing and kneading a powdered positive electrode active material or negative electrode active material and a finely powdered conductive material as main components to which a fluorine-containing polymer resin is added. The sheet is stretched in mono-axial or multi-axial directions (abstract). The powdered active material and the conductive material are three-dimensionally bound to each other with a fiberized fluorine-containing polymer resin. The sheet material has a peel strength in the thickness direction of 0.01-0.07 N/mm2 and a tensile strength in the stretching direction of 0.02-0.05 N/mm2 which are measured by a mono-axial tensile strength tester. The fluorine-containing polymer resin is a polytetrafluoroethylene resin [0005-0008]. The mixing proportion by mass of the materials is such that when the proportion of LiCoO2 is assumed to be 100, CB (carbon black conductive material) and PTFE (fiberized binder) are 4, respectively [0018].
The sheet material is produced in a plurality of steps. In the first step, the respective materials (LiCoO2, CB and PTFE) are weighed. Then, at the second step, the materials are introduced into a mixer to mix them by a rotating agitation blade, and, furthermore, at the third step, the mixture is transferred into a vessel of a kneader kept at a given temperature (e.g., 90°C) and kneaded by a rotating blade under application of pressure. PTFE is fiberized by the mixing at the second step and the kneading at the third step to entangle LiCoO2 and CB, resulting in a mixture in which they are three-dimensionally bound to each other. Then, at the fourth step, the mixture kneaded by the kneader is chopped fine by a chopper to obtain fine particles, which are then screened by a sieve. In this example, the particles are screened so that particles of 20 mesh or less (0.8 mm or less) can be used. Thereafter, at the fifth step, the particles to which a given amount of isopropyl alcohol (IPA) is added as a liquid lubricant are subjected to a pretreatment of mixing by a mixer to obtain a mixture. Then, at the sixth step, the resulting mixture is introduced in a hopper of a calendering machine and passed between two rollers to preform the mixture into a sheet-like material. Furthermore, at the seventh step, the sheet-like material is stretched by passing between two rollers so as to give the thickness of the final product. By carrying out this stretching process a plurality of times (e.g., 2-3 times), a void content of 15-30% can be attained, and besides a sheet-like electrode having a given thickness, for example, 70-350 mm is formed. By the stretching at the sixth step and the seventh step, the fiberization of PTFE is also accelerated (secondary fiberizing) and adjustment of the void content is carried out in addition to the adjustment of the thickness. The stretching process by rollers is basically a stretching in mono-axial direction, but a single sheet-like electrode may be stretched in multi-axial direction [0019-0020]. Ozaki teaches the carbon material may be carbon fibers or the like [0014].
Ozaki does not explicitly teach the claimed tensile strength of the active layer. However, Ozaki teaches the mixture is preformed and further subjected to stretching process in mono-axial or multi-axial direction to form a sheet material for electrode, and hence the sheet material can be adjusted to a desired thickness to increase the volumetric proportion of the active material in the electrode layer and simultaneously the void content can be adjusted, and, as a result, the electrode density can be increased. For these reasons, the void content is preferably 15-30% and the thickness is preferably 70-350 mm. The adjustment of void content and thickness which relate to mechanical strength of the sheet material for electrode is preferably carried out in such a manner that the sheet material has mechanical strengths of a peel strength in thickness direction of 0.01-0.07 N/mm2 and a tensile strength in stretching direction of 0.02-0.05 N/mm2. Ozaki teaches the mechanical strength of the sheet material is dependent on void content and thickness of the sheet material which may be adjusted.
Allowable Subject Matter
Claims 9, 10 and 12-14 are allowed. The claims are directed toward the method of claim 9 for preparing the electrode of claim 1 wherein the method comprises the steps of:
(1) preparing a mixed material by mixing the electrode active material, the electrically conductive material and the binder that are stored at -20 °C to -1 °C;
(2) preparing a primarily fiberized material by fiberizing the mixed material at 50 °C to 70 °C;
(3) preparing a ground material by grinding the primarily fiberized material at room temperature; and
(4) secondarily fiberizing particles selected from the ground material,
wherein in step (2), imparting a shear force of 20 N-m to 200 N-m to the mixed material with a kneader; the particles are selected from the ground material in step (3), wherein the particles have a particle size of 1 mm or less, and wherein the particles are selected before secondarily fiberizing the particles in step (4), and
wherein the particles are selected from the ground material in step (3) before secondarily fiberizing the particles in step (4), and wherein the particles have a Hausner ratio of 1.6 or less.
The prior art does not teach or suggest the method recited by claim 9 wherein the stored temperature is -20°C to -1°C, the fiberizing occurs at 50 °C to 70 °C while imparting a shear force, and the selected particles of step (3) have the recited properties. Furthermore, the prior art does not teach or suggest the method recited by claim 14 wherein the ground material is secondarily fiberized at 40-60°C with a 3 roll mill rotating at 5-20 RPM.
Response to Arguments
Applicant's arguments filed 3/25/26 have been fully considered but they are not entirely persuasive. Claims 9, 10 and 12-14 have been amended and are now in condition for allowance. The prior art rejections in view of Bruckner, Zhong and Kim are withdrawn.
Regarding Ozaki and Li, Applicant argues the references do not teach or suggest the tensile strength limitations of claim 1. Examiner disagrees. Examiner notes arguments regarding methods of forming the electrode of claim 1 found in the present specification are not persuasive. Claims 1, 2 , 5 and 6 are not directed toward a method of forming an electrode.
Li teaches the electrode film has a tensile strength at or in excess of greater than 0.6 N/mm2, optionally 0.9 N/mm2 [0049; claim 23]. Tensile strength is defined as the maximum load that a material can support without fracture when being stretched, divided by the original cross-sectional area of the material. One of skill would have found that the electrode film having the tensile strength disclosed by Li at least suggests a tensile strength ratio between a machine direction and a traverse direction of 1. The MD and TD strengths are balanced due to molecular orientation in both directions. Applicant has not provided any persuasive arguments and/or persuasive evidence that the claimed electrode is structurally distinct and/or nonobvious from the electrode of Li. Examiner notes the claim limitation “linear particles” is given the broadest reasonable interpretation. The conductive material of claim 1 is not limited to “vapor-grown carbon fiber”, as asserted by Applicant. Li teaches the conductive material may be activated carbon. See also [0060] of Li.
Applicant does not provide any specific arguments regarding the teachings of Ozaki. Ozaki does not explicitly teach the claimed tensile strength of the active layer. However, Ozaki teaches the mixture is preformed and further subjected to stretching process in mono-axial or multi-axial direction to form a sheet material for electrode, and hence the sheet material can be adjusted to a desired thickness to increase the volumetric proportion of the active material in the electrode layer and simultaneously the void content can be adjusted, and, as a result, the electrode density can be increased. For these reasons, the void content is preferably 15-30% and the thickness is preferably 70-350 m. The adjustment of void content and thickness which relate to mechanical strength of the sheet material for electrode is preferably carried out in such a manner that the sheet material has mechanical strengths of a peel strength in thickness direction of 0.01-0.07 N/mm2 and a tensile strength in stretching direction of 0.02-0.05 N/mm2. Ozaki teaches the mechanical strength of the sheet material is dependent on void content and thickness of the sheet material which may be adjusted. Examiner notes the claim limitation “linear particles” is given the broadest reasonable interpretation. The conductive material of claim 1 is not limited to “vapor-grown carbon fiber”, as asserted by Applicant. Ozaki teaches the carbon material may be carbon fibers or the like [0014].
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TRACY DOVE whose telephone number is (571)272-1285. The examiner can normally be reached M-F 9:00-3:00.
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, Nicole Buie-Hatcher can be reached at 571-270-3879. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/TRACY M DOVE/Primary Examiner, Art Unit 1725
Prosecution Insights