DETAILED ACTION
Application 18/027297, “ELECTROLYTE SOLUTION FOR LITHIUM-SULFUR BATTERY AND LITHIUM-SULFUR BATTERY COMPRISING SAME”, is the national stage entry of a PCT application filed on 6/22/22 and claims priority from a foreign application filed on 6/3/21.
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 12/15/25.
Response to Arguments
Applicant’s arguments filed on 12/15/25 have been fully considered, but are not persuasive. Applicant presents the following arguments.
Ye fails to teach the lithium battery being a lithium sulfur battery; therefore, the anticipation rejections based on Ye must be withdrawn.
In response, this argument has been found persuasive and the anticipation rejection over Ye has been withdrawn.
Kim teaches Li-S battery, but focuses entirely on the separator rather than the electrolyte, and provides no motivation to utilize an electrolyte as described in claim 1.
In response, Kim is not required to teach the claimed electrolyte composition because the art rejections rely on Ye to teach this feature. In the grounds of rejection where Kim is relied on as the primary reference, Ye also provides the motivation to select this composition. In the grounds of rejection where Ye is relied on as the primary reference, no additional motivation is required to select an electrolyte composition disclosed by Ye. The non-final rejection presents both grounds of rejections as alternatives. In this Final Rejection, the two ground(s) of rejection have been separated for aiding clarity of record. It is noted that changing the order of references in the statement of rejection, but relying on the same teachings of those references does not constitute a new ground of rejection (MPEP 1207.03(a) II 4).
There is not motivation to combine Ye and Kim to arrive at the claimed invention.
In response, the art rejections present both a motivation to modify Ye in view of Kim, and a motivation to modify Kim in view of Ye. Therefore, a rationale for modification has been properly presented by the Office.
Ye and Kim are distinct from one another and therefore combination of the references is neither logically motivated nor technically obvious.
In response, the fact that the references are distinct from one another does not weigh against their combination. As described in MPEP 2141.01(a), references which lie within analogous art to the claimed invention may be relied on in an obviousness rejection. In this case, all references lie within the battery art and are therefore found to be analogous to the claimed invention.
Ye teaches that 1,3 dioxolane compounds deteriorate battery performance when used alone, and therefore makes their use nonobvious in the proposed combinations. Applicant cites paragraphs [0092-0096] of Ye in support of the argument.
In response, claim 1 as worded describes an electrolyte solution which “comprises” and additive, wherein the additive “comprises” a compound represented by Formula 1. Even if paragraphs [0092-0096] did suggest that that 1,3 dioxolane compounds deteriorate battery performance when used alone, claim 1 as worded does not require a 1,3 dioxolane compound used alone. Applicant’s argument is not commensurate in scope with the claimed invention, and is unpersuasive for at least this reason.
Ye discourages the use of certain compounds, such as electrolyte solutions comprising 1,3 dioxolane, in Li-S batteries. Applicant cited paragraphs [0092-0096] for support.
In response, paragraphs [0092-0096] do not appear to mention Li-S batteries; therefore, applicant’s argument is not properly supported by evidence. The cited sections of Ye do not mention Li-S batteries; therefore, they do not teach away from Li-S batteries.
The claimed invention, which uses substituted 1,3-dioxolane, goes against the teachings of the references.
In response, Ye teaches electrolytes comprising 1,3-dioxolane, for example at Ye’s claim 6. Therefore, Ye does not teach away from the inclusion of 1,3-dioxolane (or substituted variants thereof), as argued by applicant.
The invention of claim 1 leads to unexpected and superior results; thereby overcoming any prima facie case of obviousness. Specifically, comparison of applicant’s Comparative Example 1 to Examples 3, 9 and 15 demonstrate that Li-S batteries comprising a substituted 1,3-dioxolane provide significantly increased capacity retention compared to Li-S batteries without a 1,3-dioxolane as shown in the Table on page 8 of applicant’s remarks. It is noted that applicant appears to calculate values for the “Increase rate” column by dividing the number of cycles of the Examples 3, 9 and 15 by the Comparative Example 1, and subtracting 100%.
In response, applicant’s showing of unexpected results is insufficient to outweigh the prima facie case of obviousness for at least the following reasons.
i) To be of probative value, “ “objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support.” In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range” (MPEP 716.02d). Here, the evidence provided by applicant in support of the argument of unexpected results does not demonstrate that the results are achieved over the entire claimed range. For example, Example 15 shows that 2-ehtyl-2-methyl-1,3 dioxolane at 0.5 wt% provides an increase rate of 84.1 %. However, claim 1 does not require a particular wt% of the additive, and Example 20 suggests that when 2-ehtyl-2-methyl-1,3 dioxolane is included at 6.5 wt%, the capacity retention is actually reduced to 42 cycles compared to 44 cycles. Thus, even if the improvement in cycle retention is taken as evidence of unexpected results, the improvement does not appear to be achieved over the breadth of claim 1.
ii) Evidence of unexpected results must demonstrate that a noted difference in properties is really unexpected (MPEP 716.02). Here, the originally filed disclosure suggests that improvement in cycle retention is achieved to varying degrees by controlling the electrolyte solution (applicant’s Table 3), but the disclosure does not characterize this improvement as surprising or unexpected. Although applicant argues that the improvement amounts to an unexpected result, the arguments of counsel cannot take the place of evidence on the record (MPEP 716.01(c)). Moreover, applicant’s Examples 1-21 suggest that the additive provide only a modest improvement in the cycling retention for at least some of the embodiments. Because the improvement is not characterized as surprising or unexpected, and because the improvement may be modest as shown in Table 3, the evidence record does not establish that the improvement is actually an unexpected result sufficient to overcome the prima facie case of obviousness.
iii) “Where the unexpected properties of a claimed invention are not shown to have a significance equal to or greater than the expected properties, the evidence of unexpected properties may not be sufficient to rebut the evidence of obviousness” (MPEP 716.02(c)). Here, as described in the art rejections, Ye teaches that an electrolyte composition including a compound represented by applicant’s Formula 1, such as 2-methyl-1,3-dioxolane, may provide a battery with improved reliability, high temperature storage and low temperature discharge characteristics, as described in the art rejections. The evidence of record has not established that the improvement identified by applicant has a significance equal to or greater than the advantage identified by Ye, which is a desirable expected result. Thus, the evidence is found to be insufficient to overcome the prima facie case of obviousness.
Ye’s Comparative Examples 1 and 3 demonstrate that the sole addition of 1,3 dioxolane leads to significantly higher temperature thickness expansion rate with no improvements in the low temperature discharge rate, thereby teaching away from the claimed invention.
In response, claim 1 as worded does not require 1,3-dioxolane as a sole additive, thus, the argument is not commensurate in scope with the invention of claim 1.
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.
Grounds of rejection modifying Kim in view of Ye
Claims 1-4 and 6-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 2020/0136112) in view of Ye (US 2016/0036092).
Regarding claims 1-4, Kim teaches a lithium-sulfur battery (e.g. Fig. 2; paragraph [0018]) comprising: a positive electrode; a negative electrode; a separator between the positive electrode and the negative electrode; and an electrolyte (Fig. 2; paragraph [0018, 0064]).
Kim further teaches that lithium sulfur batteries are known to be the most promising form of lithium secondary battery, with advantages associated with the abundance, low toxicity and low weight of sulfur, and high theoretical energy densities (paragraph [0004]).
Kim further teaches that as the electrolyte, those known in the art may be used (paragraph [0064]), but does not teach wherein the electrolyte is an electrolyte solution comprising each of a lithium salt, and organic solvent, and an additive comprising a compound represented by Formula 1, as required by claim 1.
In the battery art, Ye teaches a lithium battery (paragraph [0028]) comprising: a positive electrode; a negative electrode; a separator between the positive electrode and the negative electrode (paragraph [0028]); and an electrolyte solution (see paragraphs [009, 0024]). Ye further teaches the electrolyte solution comprising: a lithium salt (paragraph [0009]); an organic solvent (paragraph [0009]); and an additive (paragraph [0009]), wherein the additive comprises a compound represented by applicant’s Formula 1, such as 2-methyl-1,3-dioxolane (structural formula 1 at claim 1; e.g. “2-methyl-1,3-dioxolan (compound 4)” at paragraph [0024] reads on claims 1-5 when R1 is methyl and R2-R6 are each hydrogen).
Ye further teaches wherein the electrolyte solution is capable of providing a lithium battery with improved reliability, high temperature storage and low temperature discharge characteristics (paragraphs [0007-0008]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to modify the lithium sulfur battery of Kim by employing the electrolyte of Ye [readable on the electrolyte of claim 1] for the benefit of providing the battery with improved reliability, high temperature storage and low temperature discharge characteristics due to the desirable electrolyte as taught by Ye.
Regarding claim 6-7, Kim and Ye remain as applied to claim 1. As described above, Kim does not teach the battery including the claimed electrolyte composition.
Ye further teaches wherein the compound represented by Formula 1 is 2-methyl-1,3-dioxolane (paragraph [0024]), and the electrolyte solution contains 0.1 to 5% by weight of the compound represented by Formula 1 relative to the total weight of the electrolyte solution (“0.5% ~ 2%” at paragraph [0025] lies within the claimed range).
It would have been obvious to employ this electrolyte composition for the same benefit of providing the battery with improved reliability, high temperature storage and low temperature discharge characteristics due to the desirable electrolyte as taught by Ye.
Grounds of rejection modifying Ye in view of Kim
Claims 1-4 and 6-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ye (US 2016/0036092) in view of Kim (US 2020/0136112).
Regarding claims 1-4, Ye teaches a lithium battery (paragraph [0028]) comprising: a positive electrode; a negative electrode; a separator between the positive electrode and the negative electrode (paragraph [0028]); and an electrolyte solution (see paragraphs [009, 0024]).
Ye further teaches the electrolyte solution comprising: a lithium salt (paragraph [0009]); an organic solvent (paragraph [0009]); and an additive (paragraph [0009]), wherein the additive comprises a compound represented by applicant’s Formula 1, such as 2-methyl-1,3-dioxolane (structural formula 1 at claim 1; e.g. “2-methyl-1,3-dioxolan (compound 4)” at paragraph [0024] reads on claims 1-5 when R1 is methyl and R2-R6 are each hydrogen).
Ye further teaches wherein the electrolyte solution is capable of providing a lithium battery with improved reliability, high temperature storage and low temperature discharge characteristics (paragraphs [0007-0008]).
Ye further teaches wherein the lithium battery comprises a conventional transition metal lithium oxide positive electrode (paragraph [0031]), but does not teach wherein the lithium battery is a lithium sulfur battery.
In the battery art, Kim teaches a lithium-sulfur battery (e.g. Fig. 2; paragraph [0018]) comprising: a positive electrode; a negative electrode; a separator between the positive electrode and the negative electrode; and an electrolyte (Fig. 2; paragraph [0018, 0064]). Kim further teaches that lithium sulfur batteries are known to be the most promising form of lithium secondary battery, with advantages associated with the abundance, low toxicity and low weight of sulfur, and high theoretical energy densities (paragraph [0004]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to modify the lithium battery of Ye by reconfiguring it to be a lithium sulfur battery [such as by changing materials including positive electrode active material] for the benefit of providing battery improvements associated with the abundance, low toxicity and low weight of sulfur, and high theoretical energy densities, as taught by Kim.
Regarding claim 6-7, Ye and Kim remain as applied to claim 1. Ye further teaches wherein the compound represented by Formula 1 is 2-methyl-1,3-dioxolane (paragraph [0024]), and the electrolyte solution contains 0.1 to 5% by weight of the compound represented by Formula 1 relative to the total weight of the electrolyte solution (“0.5% ~ 2%” at paragraph [0025] lies within the claimed range).
Relevant or Related Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure, though not necessarily pertinent to applicant’s invention as claimed.
Takahashi (US 2008/0081261) lithium battery comprising dioxane compound additive;
Yang (US 2020/0106132) lithium sulfur battery comprising a dioxolane of Formula 1.
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 JEREMIAH R SMITH whose telephone number is (571)270-7005. The examiner can normally be reached Mon-Fri: 9 AM-5 PM (EST).
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/JEREMIAH R SMITH/Primary Examiner, Art Unit 1723