DETAILED ACTION
Application 18/026107, “COMPOSITION FOR ELECTROLYTE OF LITHIUM SECONDARY BATTERY, GEL POLYMER ELECTROLYTE, AND LITHIUM SECONDARY BATTERY INCLUDING GEL POLYMER ELECTROLYTE”, is the national stage entry of a PCT application filed on 12/24/21 and claims priority from a foreign application filed on 12/24/20.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This Office Action on the merits is in response to communication filed on 7/11/25.
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 of this title, 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.
Claims 1-2 and 6-12 is/are rejected under 35 U.S.C. 103 as being obvious over Ayme-Perrot (US 2022/0263114).
Regarding claim 1, 2, 6, 7, Ayme-Perrot teaches a composition for an electrolyte (abstract, paragraph [0017, 0020]) of a lithium secondary battery (it is noted that Ayme-Perrot claim 15 and paragraph [0004] indicate that the composition is for a lithium battery, however, the intended use is found to be nonlimiting in this instance), comprising: a lithium salt (paragraph [0017, 0044]); a solvent (paragraphs [0020, 0040, 0054]); a polyalkylene carbonate-based first polymer, represented by Formula 1 as required by claim 2] and having a weight average molecular weight of 1,000 g/mol to 1,500,000 g/mol (polyalkylene carbonate having a high molar mass… example… QPac 40”, paragraph [0040]; it is noted that QPac 40 is a commercially available polypropylene carbonate having a molecular weight of in the 100,000 to 300,000 g/mol range); and a polypropylene carbonate-based second polymer including a unit represented by Formula 2 and having a weight average molecular weight of 200 g/mol to 1,000 g/mol (“polyalkylene carbonate having a low molar mass… example… Converge 212-10”, paragraph [0039-0041]; Formula 2 illustrates a polypropylene carbonate and it is noted that, Converge 212-10, as an exemplary embodiment, is a commercially available polypropylene carbonate product having a molecular weight of about 1,000 g/mol, indicating an “h” value of about 10), wherein the weight average molecular weight of the second polymer is in a range of 1/3,000 to ⅓ [or more narrowly 1/1,000 to ¼ as required by claim 6] of the weight average molecular weight of the first polymer (Converge 212-10:QPac 40 gives a molecular weight ratio of about 1:100 to 1:300).
Ayme-Perrot further teaches wherein an amount of the first polymer is in a range of 0.1 wt % to 30 wt % [or more narrowly 0.1 to 20 wt % as required by claim 7] based on a total weight of the composition (paragraph [0040] teaches that the first polymer [the low weight polyalkylene carbonate] may be included in a broad range relative to the high weight polypropylene carbonate; see also paragraph [0088] which suggests an exemplary composition including the low molecular weight polypropylene carbonate Converge 212-10 at about 18 wt%).
Ayme-Perrot teaches that the composition may include a solvent (paragraphs [0020, 0040, 0054]), but does not expressly teach the solvent being an organic solvent.
However, Ayme-Perrot does teach that the solvent should be capable of dissolving polyalkylene carbonate (e.g. claim 11 and paragraph [0020]), and in a particular embodiment suggests acetonitrile as capable of dissolving polypropylene carbonate (paragraph [0018]).
Thus, it would have been obvious to use an organic solvent, such as acetonitrile, as the solvent because the solvent must be capable of dissolving polypropylene carbonate.
It is noted that the presence of solvent could influence the weight content of the first polymer in the composition; however, the claim remains obvious because it does not set forth any particular amount of the organic solvent which must be included, and inclusion of only a small amount of solvent would not substantially affect the weight percentage of the first polymer, and very small amount of solvent would not substantially change the functionality of the composition.
Regarding claim 8 and 9, Ayme-Perrot remains as applied to claim 1. Ayme-Perrot does not expressly teach wherein an amount of the second polymer is in a range of 0.01 wt% to 50 wt%, or more narrowly 0.02 wt % to 40 wt %, based on a total weight of the first polymer.
However, Ayme-Perrot does teach that in the polyalkylene carbonate mixture, the quantity of the second polymer [low molecular weight polyalkylene carbonate] is preferably 10 to 80% by mass (paragraph [0040]), which corresponds to the second polymer being 11% to 400% the weight of the first polymer.
The claimed invention is therefore found to be prima facie obvious because the prior art range overlaps the claimed range at least at 11 to 40 wt%, and no evidence of unexpected or surprising results is associated with the claimed range so as to outweigh the prima facie case of obviousness.
Regarding claim 10, Ayme-Perrot remains as applied to claim 1. Ayme-Perrot further teaches the composition further comprising a polymerization initiator (paragraph [0076]).
Regarding claim 11, Ayme-Perrot remains as applied to claim 1. Ayme-Perrot further teaches a polymer electrolyte for a lithium secondary battery which is a polymerization product of the composition previously set forth (paragraphs [0073-0074), but does not expressly teach that the inventive produced polymer electrolyte is a gel polymer electrolyte.
However, in the battery art, a gel polymer electrolyte is understood to be a polymer electrolyte comprising a liquid phase contained in a polymer matrix.*
Ayme-Perrot clarifies that his polymer electrolyte contains a polymer matrix (abstract) and a liquid phase comprising at least alkylene carbonate contained in the matrix (paragraphs [0023, 0028]). Thus, the Ayme-Perrot inventive polymer electrolyte is understood to be a gel, or at least an obvious variant with functional equivalence thereto, because it contains a liquid phase contained within the polymer matrix.
*It is noted that applicant’s specification does not provide a definition for “gel polymer electrolyte”, but in support of the Office’s interpretation, consider Ayme-Perrot at paragraph [0009] which states, “various past and current efforts relate to the development of gel electrolytes. These are polymer systems in which a liquid electrolyte is trapped, thus favoring ion mobility”. As supporting evidence, consider also Minakata (USP 6284412) at c2:25-32 which states, “Generally, these polymeric solid electrolytes are provided in the form of solid solutions of an electrolyte and a polymer, and are known as dry type polymeric electrolytes. Further, gelled polymeric solid electrolytes are known which are obtained by incorporating an electrolyte and a solvent for the electrolyte into a polymer matrix, wherein the solvent is intended for increasing the dissociation of the electrolyte and promoting the molecular movement of the polymer”.
Thus, a gel polymer electrolyte is understood to be a polymer electrolyte formed including a polymer matrix with an ion conduction facilitating liquid phase disposed therein, and a “gelled” electrolyte may also be considered to be a type of a solid electrolyte.
Regarding claim 12, Ayme-Perrot remains as applied to claim 11. Ayme-Perrot further teaches the gel polymer electrolyte as a constituent of a lithium secondary battery comprising a positive and negative electrodes including active materials and a separator interposed therebetween (paragraphs [0050, 0080, 0105]).
Allowable Subject Matter
Claims 3-5 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is an examiner’s statement of reasons for indicating allowable subject matter:
Regarding dependent claim 3, the closest prior art includes the following references:
Ayme-Perrot (US 2022/0263114) – applied in the rejection of base claim 2, and found to be the closest prior art to the claimed invention . As described, Ayme-Perrot teaches a composition for an electrolyte comprising a lithium salt, a high molecular weight polyalkylene carbonate consistent with Formula 1, and a low molecular weight polypropylene carbonate consistent with Formula 2, However, Ayme-Perrot does not appear to teach the high molecular weight polymer having a unit represented by Formula 3, which is a unit including Formula 1 as a subunit “A”, amide groups as indicated by the “B”, and the other components as defined by the Formula;
Watson (USP 4264752) – found to be the closest closest prior art, with respect to the polymer represented by Formula 3. Teaches acrylated urethane carbonate compounds similar to claim 3 at columns 1-2. The compounds of Watson may differ from the claimed invnetion by including a “residue of organic polyisocyanate”. Moreover, Watson, drawn to coating compositions, is not clearly analogous art, and the compounds of Watson are taught as coating layers with various applications, not as a single constituent of a composition for a polymer electrolyte of a lithium secondary battery;
Coqueugniot (USP 4255243) – photocurable polycarbonate urethanes, not battery art;
Sano (US 2006/0121342) – solid electrolyte compositions which may comprising polyalkylene carbonate and a lower molecular weight compound as a plasticizer;
Hellstrom (US 2019/0051938) – teaches a gel polymer electrolyte comprising lithium salt, organic solvent, and a polymer system including a polypropylene carbonate and a low molecular weight plasticizer, but does not teach the polymer electrolyte comprising a unit represented by Formula 3;
Shin (US 2021/0202993; KR 10-2020-0020169) – a similar electrolyte composition to that claimed comprising polyalkylene carbonate, but lacking the claimed low molecular weight polypropylene carbonate [cited in ISR; by applicant, published less than one year before priority date of instant application];
Phares (US 2022/0069337) – solid electrolyte compositions including polycarbonate blend or mixture which may including polymers having similar chemistries but different molecular weights;
In the search, no reference was discovered which taught a compound representable by Formula 3, as a constituent of a composition for a polymer electrolyte which further includes lithium salt, organic solvent and the polypropylene carbonate having the claimed formula, molecular weight, and relative amount with respect to the first polymer. Therefore, dependent claim 3 is found to contain allowable subject matter. Claims 3-5 are not rejected because they each contain the allowable subject matter of claim 3, but are objected to for being dependent on the rejected base claim 2.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JEREMIAH R SMITH whose telephone number is (571)270-7005. The examiner can normally be reached Mon-Fri: 9 AM-5 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, Tiffany Legette-Thompson can be reached on (571)270-7078. 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.
/JEREMIAH R SMITH/Primary Examiner, Art Unit 1723