Prosecution Insights
Last updated: April 18, 2026
Application No. 18/324,736

DISPERSANT FOR LITHIUM ION BATTERY AND PREPARATION METHOD THEREOF, POSITIVE SLURRY, AND LITHIUM ION BATTERY

Non-Final OA §103
Filed
May 26, 2023
Examiner
WYLUDA, KIMBERLY
Art Unit
1725
Tech Center
1700 — Chemical & Materials Engineering
Assignee
BYD Company Limited
OA Round
1 (Non-Final)
70%
Grant Probability
Favorable
1-2
OA Rounds
2y 9m
To Grant
83%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
166 granted / 238 resolved
+4.7% vs TC avg
Moderate +13% lift
Without
With
+13.3%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
38 currently pending
Career history
276
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
62.8%
+22.8% vs TC avg
§102
14.6%
-25.4% vs TC avg
§112
18.9%
-21.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 238 resolved cases

Office Action

§103
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, an unsaturated phosphoric acid monomer (Species A), and bis[2-(methacryloxyethyl] phosphoric acid (Species D) in the reply filed on February 3, 2026 and the communication provided with this Office Action is acknowledged. Claims 15-17 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group II, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on February 3, 2026. In light of the search made of record with this Office Action, the following species are no longer considered to be a search burden and consequently have been rejoined: Species A, directed to the organic acid monomer: an unsaturated phosphoric acid monomer (elected) and an unsaturated carboxylic acid monomer (rejoined). Species E, directed to the unsaturated acid monomer: methacrylic acid (rejoined), crotonic acid (rejoined), maleic acid (rejoined), itaconic acid (rejoined), and fumaric acid (rejoined). Claim Objections Claims 9-14 objected to because of the following informalities: the claim should recite “5,000-100,000” in order make the range easier to read. Appropriate correction is required. 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. 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 1-14 and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida et al. (JP 2016-065142 A, see also the EPO machine generated English translation provided with this Office Action), and further in view of Gong et al. (CN 108539122 A, see also the EPO machine generated English translation provided with this Office Action). Regarding Claims 1 and 18, Yoshida discloses a dispersant, the dispersant comprising a structural unit A derived from N-vinylpyrrolidone ([0010]). Yoshida further discloses wherein the dispersant may comprise other monomer units, such as a structural unit B derived from a conjugated diene monomer (e.g. an unsaturated hydrocarbon) and a structural unit C derived from an organic acid monomer, wherein the organic acid monomer is an unsaturated carboxylic acid monomer ([0014]-[0015], [0019]). It would have been obvious to one of ordinary skill in the art to form the dispersant to comprise a structural unit B derived from a conjugated diene monomer and a structural unit C derived from an organic acid monomer, wherein the organic acid monomer is an unsaturated carboxylic acid monomer, as disclosed by Yoshida, wherein the skilled artisan would have reasonable expectation that such would successfully form the dispersant desired by Yoshida. Yoshida further discloses wherein the dispersant exhibits excellent dispersibility of carbon materials and excellent solvent resistance of a dried product obtained by drying a carbon material dispersion ([0005], [0038]) and wherein the dispersant may be used in applications such as batteries and electrodes ([0065]). However, Yoshida does not disclose wherein the dispersant is for a lithium ion battery and further does not disclose a positive slurry, comprising a positive active material, a conductive agent, a binder, a dispersant, and a solvent, wherein the dispersant is the dispersant set forth above. Gong teaches a lithium ion battery comprising a positive slurry, wherein the positive slurry comprises a positive active material, a conductive agent, a binder, an optional dispersant, and a solvent ([0028]), wherein the conductive agent may be chosen to comprise a carbon material. It would have been obvious to one of ordinary skill in the art to utilize the dispersant of modified Yoshida in a positive slurry comprising a positive active material, a conducting agent comprising a carbon material, a binder, and a solvent, as taught by Gong, wherein the skilled artisan would have reasonable expectation that such would successfully form a positive slurry that exhibits excellent dispersibility of the conductive agent and excellent solvent resistance of the dried product obtained by drying the positive slurry. Thus, modified Yoshida discloses wherein the dispersant is for a lithium ion battery ([0059] of Gong). Regarding Claim 2, modified Yoshida discloses all of the limitations as set forth above and further discloses wherein based on a total amount of the dispersant, a molar proportion of the structural unit A is in a range of 1%-30% in order to achieve excellent dispersibility of the conductive agent (comprising a carbon material) and excellent solvent resistance of the dried product obtained by drying the positive slurry (comprising the carbon material) ([0012] of Yoshida), which overlaps with the instantly claimed range of 30%-90%. It would have been obvious to one of ordinary skill in the art to form the dispersant to comprise the structural unit A in the overlapping portion of the range disclosed by modified Yoshida in order to achieve excellent dispersibility of the conductive agent and excellent solvent resistance of the dried product obtained by drying the positive slurry. Modified Yoshida further discloses wherein based on a total amount of the dispersant, a molar proportion of the structural unit B and the structural unit C combined is in a range of 0.1%-40% ([0026] of Yoshida), which overlaps the instantly claimed ranges of 5%-50% and 1%-30%, respectively. It would have been obvious to one of ordinary skill in the art to form the dispersant to comprise the structural unit B and structural unit C in the overlapping portions of the range disclosed by modified Yoshida, wherein the skilled artisan would have reasonable expectation that such would successfully form the dispersant desired by modified Yoshida. Regarding Claims 3-4, modified Yoshida discloses all of the limitations as set forth above and further discloses wherein the unsaturated carboxylic acid monomer may be chosen to comprise one or more of methacrylic acid, crotonic acid, maleic acid, itaconic acid, and fumaric acid ([0014]-[0015] of Yoshida). It would have been obvious to one of ordinary skill in the art to utilize one or more of methacrylic acid, crotonic acid, maleic acid, itaconic acid, and fumaric acid as the unsaturated carboxylic acid monomer, as disclosed by modified Yoshida, wherein the skilled artisan would have reasonable expectation that such would successfully form the dispersant desired by modified Yoshida. Regarding Claims 5-8, modified Yoshida discloses all of the limitations as set forth above and further discloses wherein the conjugated diene monomer may be chosen to comprise one or more of 1,3-butadiene, isoprene, 1,3-pentadiene, and 1,3-hexadiene ([0014], [0019] of Yoshida). It would have been obvious to one of ordinary skill in the art to utilize one or more of 1,3-butadiene, isoprene, 1,3-pentadiene, and 1,3-hexadiene as the conjugated diene monomer as disclosed by modified Yoshida, wherein the skilled artisan would have reasonable expectation that such would successfully form the dispersant desired by modified Yoshida. Regarding Claims 9-14, modified Yoshida discloses all of the limitations as set forth above and further discloses wherein a weight average molecular weight of the dispersant is most preferably in a range of 20,000-300,000 in order to achieve excellent dispersibility of the conductive agent (comprising a carbon material) and excellent solvent resistance of the dried product obtained by drying the positive slurry (comprising the carbon material) ([0027] of Yoshida), which overlaps with the instantly claimed range of 5,000-100,000. It would have been obvious to one of ordinary skill in the art to form the dispersant to have a weight average molecular weight in the overlapping portion of the range disclosed by modified Yoshida in order to achieve excellent dispersibility of the conductive agent and excellent solvent resistance of the dried product obtained by drying the positive slurry. Regarding Claim 19, modified Yoshida discloses all of the limitations as set forth above. However, modified Yoshida remains silent regarding a mass of the dispersant and consequently does not disclose wherein a mass of the dispersant does not exceed 0.4% of a mass of the positive active material. Gong further teaches an electrode slurry comprising a dispersant, wherein the dispersant may be 0.1%-2.5% of a mass of an electrode active material ([0072], [0078], [0080]), which overlaps the instantly claimed range of not exceeding 0.4%. It would have been obvious to one of ordinary skill in the art to utilize the dispersant of modified Yoshida in the overlapping portion of the range further taught by Gong, as such is a known suitable range in the art for use in an electrode slurry and the skilled artisan would have reasonable expectation that such would successfully form the positive slurry desired by Gong. Regarding Claim 20, modified Yoshida discloses a lithium ion battery ([0059] of Gong), comprising a positive plate, wherein the positive plate comprises a current collector and a positive material layer arranged on the current collector; the positive material layer comprises a positive active material, a conductive agent, a binder, and a dispersant, wherein the dispersant is the dispersant set forth above ([0024]-[0025], [0028] of Gong). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Imai et al. (US PGPub 2008/0154001 A1) teaches a copolymer comprising a structural unit A derived from N-vinylpyrrolidone ([0003]), wherein the copolymer may be utilized as a dispersant ([0051]). Any inquiry concerning this communication or earlier communications from the examiner should be directed to KIMBERLY WYLUDA whose telephone number is (571)272-4381. The examiner can normally be reached Monday-Thursday 7 AM - 3 PM EST. 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, BASIA RIDLEY can be reached at (571)272-1453. 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. /KIMBERLY WYLUDA/Examiner, Art Unit 1725
Read full office action

Prosecution Timeline

May 26, 2023
Application Filed
Mar 31, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
70%
Grant Probability
83%
With Interview (+13.3%)
2y 9m
Median Time to Grant
Low
PTA Risk
Based on 238 resolved cases by this examiner. Grant probability derived from career allow rate.

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