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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 05/06/2026 has been entered.
Status of Claims
Applicant’s amendment and arguments filed 05/06/2026 have been fully considered. Claim(s) 1 and 4 is/are amended; claim(s) 9-20 remain withdrawn; and claim(s) 2 has/have been canceled. Examiner affirms that the original disclosure provides adequate support for the amendment.
Upon considering said amendment and arguments, the previous rejection(s) under 35 U.S.C. 103 set forth in the Office action mailed 02/06/2026 has/have been withdrawn.
New grounds of rejection are presented hereinbelow.
Specification
The disclosure is objected to because of the following informalities:
Paragraph [0076] of the specification recites inter alia:
“[…] The second [peak] is attributed to the reduction of the PEGDA unreacted monomers. One can note that the height of the reduction peak of LiDFOB increases as the LiDFOB concentration increases. The height of the reduction peak of PEGDA decreases as the LiDFOB concentration increases. This indicates that increasing the amount of LiDFOB causes the amount of unreacted PEGDA monomers to decrease[1]. Without being bound to a theory, the Applicant suggests that the DFOB− anions reduce at the negative electrode in place of the PEGDA unreacted monomers[2]. The range of concentrations ranging from 1 to 3% appears to be most effective for preventing the reduction of the unreacted PEGDA monomers[3]” (emphasis by Examiner)
Emphasized portion [1], which notes that LiDFOB causes the amount of unreacted monomers to decrease, appears to conflict with portions [2] and [3] which suggest instead that DFOB− ions react at the negative electrode in place of the unreacted PEGDA monomers, in other words, preventing the reduction reaction of unreacted PEGDA monomers. It is unclear how the mechanism of portions [2] and [3] could reduce the amount of unreacted monomers present when LiDFOB appears to inhibit the unwanted reduction reactions which would otherwise be expected to consume unreacted PEGDA monomers.
Paragraph [0080] similarly recites “This indicates that LiDFOB causes the amount of unreacted TPPTA monomers to decrease”. As the property of LiDFOB to react in place of unreacted monomers and thus prevent their reduction is cited as an essential feature of the instant invention (inst. spec. [0041]), the emphasized portion of ¶[0080] is similarly objected to.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1 and 3-8 are rejected under 35 U.S.C. 103 as being unpatentable over Ryu et al. (US-20240047741-A; foreign priority date of 05/28/2021).
Regarding claim 1 and 3-4, Ryu discloses a lithium-ion electrochemical cell (“lithium-ion secondary battery”, [0126]).
An exemplary embodiment of Ryu’s lithium-ion electrochemical cell comprises an active material consisting of carbon powder (Ryu Example 1, [0130]). Although not graphite, Ryu recognizes both graphite and carbon powder (i.e., amorphous carbon) as being similar carbonaceous materials which are equivalent negative electrode active materials (Ryu [0050]).
Thus, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to substitute graphite for carbon powder in the cell of Ryu Example 1, reading on “a negative electrode comprising an active material consisting of graphite” as claimed in claim 1 (MPEP 2144.06 I).
Modified Ryu further discloses a positive electrode ([0129]).
Ryu’s Example 1 comprises a gel-type electrolyte (“gel polymer electrolyte”) comprising a matrix ([0006]) which is a polymer resulting only from the cross-linking of a monomer (“polymerizable compound”) consisting of trimethylolpropane triacrylate (TMPTA) ([0133]), thus rendering obvious or disclosing with sufficient specificity the selection of TMPTA recited in the group of monomers of claim 1.
Furthermore, Ryu discloses a finite set of other identified, suitable monomer species ([0095]) with the shared trait of functional groups capable of undergoing polymerization and being converted to a gel ([0094]):
“tetraethylene glycoldiacrylate, polyethylene glycol diacrylate (molecular weight 50-1,4-butanediol diacrylate, 1,6-hexandiol diacrylate, trimethylolpropane triacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxylate tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, poly(ethylene glycol) diglycidylether, 1,5-hexadiene diepoxide, glycerol propoxylate triglycidyl ether, vinylcyclohexene dioxide, 1,2,7,8-diepoxy octane, 4-vinylcyclohexene dioxide, butyl glycidyl ether, diglycidyl 1,2-cyclohexanedicarboxylate, ethylene glycol diglycidyl ether, glycerol triglycidyl ether, glycidyl methacrylate, or the like” ([0095]; emphasis by Examiner);
this list of monomers overlapping with a portion of the claimed group of monomers in claim 1, reciting:
“poly(ethylene glycol)diacrylate (PEGDA), poly(ethylene glycol) dimethacrylate (PEGDMA), poly(propylene glycol) diacrylate (PPGDA), poly(propylene glycol) dimethacrylate (PPGDMA),
trimethylolpropane propoxylate triacrylate (TPPTA), trimethylolpropane triacrylate (TMPTA) and mixtures thereof” (emphasis by Examiner);
including the monomers claimed in claim 3, reciting:
“poly(ethylene glycol)diacrylate (PEGDA), trimethylolpropane propoxylate triacrylate (TPPTA)”,
such that it would be obvious for a skilled artisan to explore the selection of the emphasized monomers recited in claim 1 and 3 to form Ryu’s gel-type electrolyte with a reasonable expectation of success, as Ryu recognizes the respective monomer species as equivalents based on their shared trait of functional groups capable of undergoing polymerization (MPEP 2144.03 I. E; MPEP 2144.06, 2144.07).
As compared to claim 1, reciting “a gel-type electrolyte comprising a matrix […] in which matrix there is embedded a liquid mixture comprising at least one solvent, lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium difluoro(oxalato)borate (LiDFOB) and a thermal initiator of radical polymerization”, Ryu Example 1 comprises a gel-type matrix embedded with a liquid mixture comprising a solvent (“non-aqueous organic solvent”), lithium hexafluorophosphate (“LiPF6”), and a thermal initiator of radical polymerization (“AIBN as a polymerization initiator”) ([0133]), which reads closely on the scope of claim 1 but fails to further include lithium bis(fluorosulfonyl)imide (LiFSI) and lithium difluoro(oxalato)borate (LiDFOB) as claimed.
However, Ryu envisions a variety of suitable lithium salts including Li+ with the (FSO2)2N- anion (i.e., lithium bis(fluorosulfonyl)imide (LiFSI)) ([0075]), which may be suitably combined with other salts (e.g., lithium hexafluorophosphate (LiPF6) present in Ryu’s Example 1) having the same use as electrolyte salts to serve as a medium for transporting ions ([0075-0076]). Thus, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to combine the use of LiFSI and LiPF6, both being known electrolyte salts, to form a mixed composition of the two for the same purpose as electrolyte salts in Ryu’s liquid mixture and thus reading on the “liquid mixture comprising […] lithium bis(fluorosulfonyl)imide (LiFSI)” as claimed in claim 1 (MPEP 2144.06 I).
Ryu further suggests supplementary additives in the gel-type electrolyte to stabilize ion-conductive coating films on the electrode surface (i.e., SEI films) and prevent electrolyte decomposition and negative electrode collapse under high outputs ([0099]), the additive comprising at least one selected from a finite group consisting of sultone, sulfite, sulfone, sulfate, halogen-substituted carbonate, nitrile, cyclic carbonate, phosphate, borate, and lithium salt-based compounds ([0100]). Ryu names lithium oxalyl difluoroborate (i.e., lithium difluoro(oxalato)borate (LiDFOB)) as the borate-based compound for use as an additive ([0109]).
Thus, as Ryu teaches a finite set of additives as identified, predictable solutions to stabilize SEI films on the electrode surface, it would be obvious for one having ordinary skill in the art to routinely explore selecting a borate-based additive (i.e., LiDFOB) for this purpose as an additive in modified Ryu’s gel-type electrolyte (MPEP 2143 I. E). Modified in this way, Ryu Example 1 reads on the scope of the “liquid mixture comprising […] difluoro(oxalato)borate (LiDFOB)” claimed in claim 1.
Claim 1 further recites “a gel-type electrolyte […] wherein the mass percentage of LiDFOB ranges from 1 to 3 % when a total mass of the at least one solvent, lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide, lithium difluoro(oxalato)borate (LiDFOB) is considered 100 wt.%”.
Ryu provides 3 wt% or less LiDFOB based on a “total weight composition for a gel polymer electrolyte” ([0109]), which Ryu measures as including the solvent, LiPF6, LiFSI, and LiDFOB, in addition to the monomer and initiator (5 wt% TMPTA and 0.02 wt% AIBN in Ryu Example 1) ([0133]). Given that the 5 wt% TMPTA and 0.02 wt% AIBN constitutes a relatively minor portion of the total weight, Ryu’s “total weight composition for a gel polymer electrolyte” is reasonably understood to approximate the
“a total mass of the at least one solvent, lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide , lithium difluoro(oxalato)borate (LiDFOB) is considered 100 wt.%” claimed in claim 1 for purposes of estimation.
As such, Ryu discloses a mass percentage of LiDFOB ranging up to about 3 wt% (i.e., about 0-3 wt%) when a total mass of the at least one solvent, LiPF6, LiFSI, and LiDFOB is considered 100 wt.%, which closely encompasses the range of 1-3 wt% claimed in claim 1 and of 2-3 wt% claimed in claim 4. Thereby, a skilled artisan aiming to stabilize SEI films on the electrode surface through using a suitable amount of LiDFOB additive according to Ryu’s disclosure would have routinely selected within the encompassed claimed range of claim 1 with a reasonable expectation of success (MPEP 2144.05 I).
Furthermore, when using two or more additives, Ryu notes that the total amount of additives should preferably range from at least 0.1 wt% of the total composition weight to provide sufficient effects from the additives, and less than 10 wt% to prevent side reactions during charge/discharge ([0111]). Such considerations are pertinent to LiDFOB because Ryu classifies LiDFOB as an additive; a skilled artisan would at least consider increasing the LiDFOB mass percentage from about 0.1 wt% to provide sufficient effect on the electrode SEI, and would reasonably avoid exceeding about 3 wt% in order to prevent unwanted effects (e.g., side reactions as a non-limiting example). Thus, a skilled artisan seeking to balance these considerations would consider further optimizing a range of LiDFOB mass percentage between about 0.1 wt% to 3 wt% based on the total mass considered 100 wt%, encompassing the range of 1-3 wt% claimed in claim 1 and 2-3 wt% claimed in claim 2 such that it would be obvious for a skilled artisan performing the above optimization to select within this range, with a reasonable expectation of success (MPEP 2144.05 II).
Regarding claim 5, modified Ryu discloses the lithium-ion electrochemical cell according to claim 1. Ryu Example 1 uses AIBN (2,2′-azobis(iso-butyronitrile)) as the thermal initiator ([0133], [0089]), this being an azo-type radical initiator, thus rendering obvious or disclosing with sufficient specificity the “one or more of an azo-type and a peroxide-type radical initiator” as claimed in claim 5.
Furthermore, Ryu ¶[0089] discloses the use of polymerization initiators (e.g., the thermal initiator of radical polymerization) being one or more of a peroxide-type (“organic peroxides or hydroperoxides”) or azo-type (“azo compound”) initiator as claimed in claim 5.
Regarding claim 6, modified Ryu discloses the lithium-ion electrochemical cell according to claim 1, wherein the at least one solvent is selected from the group consisting of cyclic carbonates, linear carbonates ([0080]), linear esters ([0084]), various ethers selected from a group respectively understood to be linear ethers (e.g., dimethyl ether, diethyl ether, etc.) ([0082]), fluoroethylene carbonate (FEC) which is a fluorinated derivative of a carbonate ([0080]), and a mixture thereof (“[solvents used] in combination”) ([0079]), thus reading on claim 6.
Regarding claims 7 and 8, modified Ryu discloses the lithium-ion electrochemical cell according to claim 1. Ryu Example 1 comprises a positive electrode comprising an active material which is LiNi1/3Co1/3Mn1/3O2 (NCM) ([0129]), which is a lithium oxide of at least one transition metal and thus renders obvious or discloses with sufficient specificity the “at least one of a lithium iron phosphate, a lithium manganese iron phosphate and a lithium oxide of at least one transition metal” of claim 7 and the “at least one lithium oxide of at least one transition metal is selected from the group consisting of a lithium cobalt oxide, a lithium manganese oxide, a lithium nickel oxide, a lithium nickel cobalt manganese oxide (NMC), a lithium nickel cobalt aluminum oxide (NCA) and a mixture thereof” of claim 8.
Ryu further names preferable lithium oxides as including LiCoO2 (i.e., lithium cobalt oxide), LiMnO2 (lithium manganese oxide), LiNiO2 (lithium nickel oxide), lithium nickel manganese cobalt oxides (i.e., NMC) or lithium nickel cobalt aluminum oxides (NCA) ([0042]) and a mixture thereof (“two or more compounds”, [0041]), these materials being equivalent positive electrode active materials selected to improve the capacity and/or stability of the battery ([0042]).
This group matches the group of lithium oxides of at least one transition metal recited in claim 8 such that it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to combine or substitute any lithium oxide species recited in claim 8 inside modified Ryu Example 1’s cell as equivalent positive electrode active materials to sufficiently provide or improve the battery capacity or stability characteristics (MPEP 2144.06 I, II).
Response to Arguments
Applicant’s arguments with respect to rejection of amended claim 1 as unpatentable under 35 U.S.C. 103 over previously cited prior art Zhang et al. (CN112635818A) and Zhang et al. (A Review on Electrolyte Additives for Lithium-ion Batteries) (Remarks filed 05/06/2026 pp. 7-11) have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument, made under Ryu et al. US20240047741A1 as applied above.
Applicant asserts unexpected effects to electrochemical cell performance with respect to the salts used. Particularly, Applicant emphasizes the inclusion of LiDFOB which is essential for the final properties, citing ¶[0041] of the instant specification in support, these effects being a reduction of the adverse effect of the presence of residual acrylate monomers (Remarks pp. 9-10, §2.4 and 2.5).
While this evidence of unexpected improvement has been considered, it has not been found persuasive to demonstrate nonobviousness of the instant invention over the closest prior art Ryu et al. US20240047741A1 as cited above.
Ryu ¶[0099], directed to effects of an additive such as lithium oxalyl difluoroborate (LiDFOB),
in the gel type electrolyte, recites the following:
“In addition, the composition for a gel polymer electrolyte according to the present disclosure may further include supplementary additives capable of forming a more stable ion conductive coating film on the surface of an electrode, if necessary, in order to prevent decomposition of the non-aqueous electrolyte and a collapse of the negative electrode under a high-output environment […]” ([0099], emphasis by Examiner).
In other words, Ryu ¶[0099] indicates that LiDFOB as an additive has a mechanism of stabilizing the SEI coating on the electrode, particularly with respect to the negative electrode which is otherwise prone to collapse.
Examiner highlights the following portion of ¶[0041] of the inst. spec., cited by Applicant to emphasize the importance of LiDFOB:
“[…] LiDFOB is used for its solid electrolyte interface (SEI) film-forming properties due to the reduction of the DFOB− anion around 1.6 V vs Li+/Li. Without LiDFOB, the electrolyte solution containing only LiPF6 and LiFSI or LiTFSI would have a poor cycle life due to the reduction of the acrylate groups at 1.6-1.3 V vs. Li+/Li causing a poor SEI formation on the first cycle. The mass percentage of LiDFOB can be controlled in the electrolyte solution to completely prevent the reduction of the acrylate monomers depending on the selected monomer […]”. ([0049]; emphasis by Examiner).
Additionally, ¶[0005] of the inst. spec. further recites the following:
“[residual acrylate monomers] react at the negative electrode during the first charge of the electrochemical cell also referred to as “electrochemical formation” and decompose to form on the surface of the negative electrode a highly resistive passivation layer also referred to as ‘solid electrolyte interface SEI’” ([0005])
The cited sections of the inst. spec. indicate that the overall role of LiDFOB in the cell is to stabilize SEI formation, particularly with respect to the negative electrode. While Applicant does identify the presence of residual acrylate monomers as being a specific cause of the SEI layer instability, which Ryu fails to teach or suggest, Ryu nonetheless discloses the use of LiDFOB as an additive for the same specific purpose of stabilizing the SEI on the negative electrode.
Consequently, a skilled artisan would expect LiDFOB added to the gel-type electrolyte to effectively stabilize the SEI layer, this effect of Applicant’s inventive solution therefore being expected in view of Ryu’s disclosure (MPEP 716.02 (a)).
Applicant further asserts criticality of the cited range of 1-3 wt% LiDFOB with respect to the total mass considered 100% in claim 1 in order to optimally reduce the adverse effect of residual acrylate monomers (Remarks p. 10 §2.6)
Examiner notes inst. spec. ¶[0077-0078] as supporting the criticality of this range in a cell using crosslinked PEGDA monomers, which recite “Increasing the percentage of LiDFOB above 3% does not provide a significant increase of the discharged capacity” ([0077]) and “the electrolyte of which is devoid of LIDFOB exhibits a poor cycling ability […] the electrolyte of which contains 1% of LiDFOB shows a slower loss of capacity […] the electrolyte of which contains 2 or 3% of LiDFOB exhibit a good cycling ability” ([0078], FIG. 2). Inst. spec. ¶[0079-0082] and FIG. 4 indicate similar effects between cells using crosslinked TPPTA monomers with 0% and 1% LiDFOB.
While this evidence of criticality has been considered, it has not been found persuasive, as it does not demonstrate criticality over Ryu’s closely matching range.
Ryu discloses an upper endpoint of about 3 wt% or less (Ryu [0110], see discussion of claim 1), which so closely matches the claimed upper endpoint of exactly 3% such that a skilled artisan would have expected cells with gel-type electrolytes having these respective amounts of LiDFOB to have the same properties (MPEP 2144.05 I).
Furthermore, while Ryu’s disclosure does not explicitly specify the lower claimed endpoints of 1 wt% in claim 1 and 2 wt% in claim 4, it would be understood by one of ordinary skill in the art according to Ryu’s disclosure and to general knowledge of the art that increasing the concentration of LiDFOB as an additive beyond at least some minimum value is necessary to provide a sufficient improvement in effect from the additive ([0111], [0099]). Thus, the claimed ratios would be reachable using routine procedures within Ryu’s disclosed range of LiDFOB concentration, with predictable results of increasing the effect of LiDFOB on stabilizing the SEI layer and thus improving the electrochemical cell characteristics (MPEP 2144.05 II). I
Examiner acknowledges that the data of Figs. 1 – 2 appears to support the advantage of using 1 – 3 wt%; however, the examiner notes that based on the data such a wt% range only appears critical when the cross-linking monomer is PEGDA. For example, FIG. 4 shows a markedly different behavior for 1 wt% LiDFOB using crosslinked TPPTA compared to 1 wt% LiDFOB in PEGDA. Therefore, as claim 1 allows for a significantly broader selection of cross-linking monomers, it is unclear that the claimed wt% range of LIDOB would be critical across such a broad selection of monomers.
Examiner further notes that the claimed wt% range of LiDFOB is inclusive of 1 wt%, but applicant’s most superior results appear to occur particularly at 2 - 3wt% (See Figs. 1 and 2).
As such, claim 1 appears to be incommensurate in scope with the invention argued to provide applicant’s unexpected/critical results and as MPEP 716.02(d) requires unexpected/critical results to be commensurate with the claimed scope, applicant’s arguments regarding the criticality of the claimed wt% range of LIDOB are further rendered unpersuasive.
Conclusion
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/E.C./Examiner, Art Unit 1751
/Haroon S. Sheikh/Primary Examiner, Art Unit 1751
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