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 .
Status of Claims
Claims 1-19 were rejected in the Office Action from 10/20/2025.
Applicant filed a response, amended claim 1 and 5, and added claim 20.
Claims 1-20 are currently pending in the application and are being examined on the merits in this Office Action.
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.
Claim(s) 1-10, 16-17 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hao et al. (CN111653829) and further, in view of Zhou et al. (CN114361591A).
The Examiner has provided a machine translation of CN111653829 and CN114361591A. The citation of the prior art in this rejection refer to the machine translation.
Regarding claims 1-3 and 5, Hao teaches an electrolyte for a lithium secondary battery (page 1, lines 10), wherein the electrolyte for a lithium secondary battery comprises a sulfate ester (i.e., vinyl sulfate also known as ethylene sulfate) and difluorophosphate ions (i.e., lithium difluorophosphate) (page 1, lines 35-40).
With regards to the limitation “a molar ratio of the sulfate ester to the difluorophosphate ions is (0.2 to 30):1, and a molar concentration of the sulfate ester is 0.04 mol/L to 0.16 mol/L.”, Hao teaches 0.5% to 5% of the sulfate ester (i.e., vinyl sulfate) and 0.2% to 2% of the difluorophosphate ions (i.e., lithium difluorophosphate) (page 1, lines 35-40) of a total mass of the electrolyte and further, teaches ethylene carbonate as a solvent (page 2, lines 40-47). As such, the limitations are met as follow:
Vinyl sulfate has a formula of C2H3O4S.
Lithium difluorophosphate is the source of difluorophosphate ions.
Solvent is ethylene carbonate with known density of 1320g/L.
Vinyl sulfate mass percentage is 0.5%-5% with known molecular weight of 123.102g/mol and Lithium difluorophosphate mass percentage is 0.2%-2% with known molecular weight of 107.908g/mol.
For Sulfate Ester (i.e., Vinyl Sulfate):
0.5% → 1320g/L x 0.005 = 6.6g/L
5% → 1320g/L x 0.05 = 66.0g/L
6.6g/L / 123.102g/mol = 0.053614 mol/L
66g/L / 123.102g/mol = 0.536142 mol/L
Range: 0.0536mol/L – 0.5361mol/L (for claim 3)
For difluorophosphate ions (i.e., Lithium difluorophosphate):
0.2% → 1320g/L x 0.002 = 2.64g/L
2% → 1320g/L x 0.02 = 26.4g/L
2.64g/L / 107.908g/mol = 0.024465 mol/L
26.4 g/L / 107.908g/mmol = 0.244653 mol/L
Range: 0.02447mol/L - 0.24465mol/L
Molar ratio of sulfate ester to difluorophosphate ions:
Minimum ratio: 0.053614 mol/L / 0.244653 mol/L = 0.21:1
Maximum ratio: 0.536140 mol/L / 0.024465 mol/L = 21.9:1
Range: (0.21 to 21.9):1 (for claim 2)
It is noted that Hao differ in the exact same molar ratio range as recited in the instant claim however, one of ordinary skill in the art before the effective filing date of the claimed invention would have considered the invention to have been obvious because the molar ratio range of Hao overlap the instant claimed molar ratio and therefore is considered to establish a prima facie case of obviousness. It has been held in the courts that in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Hao does not teach the specifics of the sulfate ester comprising at least one of 4-methyl-ethylene sulfate, 4-fluoro-ethylene sulfate, 4- n-propyl-ethylene sulfate, and 4,4'-biethylene sulfate.
Zhou, directed to an electrolyte and battery (page 1, line 14), teaches an electrolyte where 4-methyl-ethylene sulfate is added (page 2, line 28). Further, Zhou teaches 4-methyl-ethylene sulfate form SEI films that can effectively stabilize system and improve performance and thermal shock resistance after cycling.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Hao to include an ethylene sulfate such as 4-methyl-ethylene sulfate, as taught by Zhou, in order form SEI films that can effectively stabilize system and improve performance and thermal shock resistance after cycling.
Regarding claim 4, Hao teaches a molar concentration of the difluorophosphate ions in the electrolyte for a lithium secondary battery is 0.01 mol/L to 0.04 mol/L (see calculations above).
Regarding claim 5, Hao teaches the sulfate ester comprises ethylene sulfate (i.e., vinyl sulfate also known as ethylene sulfate) (page 1, lines 35-40).
Regarding claim 6, Hao teaches the difluorophosphate ions are provided by the following substance: APO2F2, wherein A comprises at least one of Li (i.e., lithium difluorophosphate) (page 1, lines 35-40).
Regarding claims 7-8, Hao teaches the electrolyte comprises a positive electrode film-forming additive such as 1,3-propane sultone (page 1, lines 35-40).
Regarding claims 9-10, regarding the limitation “wherein a ratio of a molar amount of the positive electrode film-forming additive to a sum of molar amounts of the sulfate ester and the difluorophosphate ions in the electrolyte for a lithium secondary battery is (0.05 to 0.6):1.” and “wherein a molar concentration of the positive electrode film-forming additive in the electrolyte for a lithium secondary battery is 0.01 mol/L to 0.03 mol/L.”, Hao teaches the positive electrode film-forming additive (i.e., 1,3-propane sultone) accounts for 0.2% to 3% of the total mass of the electrolyte (page 1, lines 35-40). As such, the limitations are met as follow:
Solvent is ethylene carbonate with known density of 1320g/L.
1,3-propane sultane has a formula of C3H6O3S with known molecular weight of 122.14g/mol
For 1,3-propane sultone
0.2% → 1320g/L x 0.002 = 2.64g/L
3.0% → 1320g/L x 0.03 = 39.6g/L
2.64g/L / 122.14g/mol = 0.0216M
39.6g/L / 122.14g/mol = 0.324M
Molar concentration range of 1,3-propane sultane in the electrolyte: 0.0216mol/L to 0.324mol/L (for claim 10)
Using the data above, the molar ratio is calculated as follows:
1,3-propane sultone
0.2% → 2.64g/L → 0.0216 mol/l
3.0% → 39.6MOL/l → 0.3242 mol/L
Range: 0.0216-0.342 mol/L
Sulfate ester
0.5% → 6.6g/L → 0.0536 mol/L
5.0% → 0.5361 mol/L → 0.5361 mol/L
Range: 0.0536-0.5361 mol/L
Lithium difluorosulfate
0.2% → 2.64g/L → 0.02447 mol/L
2.0% → 26.4g/L → 0.24465 mol/L
Range: 0.02447-0.24465 mol/L
Sum of the sulfate ester and lithium difluorophosphate:
Minimum: 0.0536+0.02447 = 0.07808 mol/L
Maximum: 0.5361+0.24465 = 0.78079 mol/L
Sum range: 0.07808-0.78079 mol/L
Minimum ratio: 0.0216 mol/L / 0.78079 = 0.0277:1
Maximum ratio: 0.32422mol/L / 0.07808 mol/L = 4.15:1
Molar ratio range of 1,3-propane sultone to a sum of a molar amount of the sulfate ester and the difluorophosphate ions in the electrolyte: (0.0277-4.15):1 (for claim 9).
It is noted that Hao differ in the exact same molar ratio and molar concentration range as recited in the instant claim however, one of ordinary skill in the art before the effective filing date of the claimed invention would have considered the invention to have been obvious because the molar ratio and molar concentration range of Hao overlap the instant claimed molar ratio and therefore is considered to establish a prima facie case of obviousness. It has been held in the courts that in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding claim 16, Hao teaches a secondary battery with the electrolyte according to claim 1 (page 1, lines 40-42).
Regarding claim 17, Hao teaches the secondary battery comprises a positive electrode active material comprising LiNi0.5Co0.2Mn0.3O2 which encompasses the claimed formula.
Regarding claim 19, Hao teaches an electric device (i.e., smart phones, computers, electric vehicles) comprising the battery of claim 16 (page 1, lines 19-25).
Claim(s) 11-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hao et al. (CN111653829) in view of Zhou et al. (CN114361591A), as applied to claim 1 above, and further in view of Liang et al. (U.S. Patent Application Publication 2022/0123368).
Regarding claim 11 and 14, Hao teaches the electrolyte as described above in claim 1 but does not teach the electrolyte further comprises tetrafluoroborate ions provided by at least one of the following substances: tetrafluoroboric acid, sodium tetrafluoroborate, potassium tetrafluoroborate, and lithium tetrafluoroborate.
Liang, also directed to a secondary battery, teaches a battery with an electrolyte comprising lithium tetrafluoroborate (paragraph [0010]). Further, Liang teaches the lithium tetrafluoroborate is used to reduce cost of the electrolyte solution or inhibit negative effects caused by other salts in the electrolyte (paragraph [0029]).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Hao an include a lithium tetrafluoroborate in the electrolyte in order to reduce cost of the electrolyte solution or inhibit negative effects caused by other salts in the electrolyte as taught by Liang.
Regarding claim 12-13, with regards to the limitations “a ratio of a molar amount of the tetrafluoroborate ions to the sum of molar amounts of the sulfate ester and the difluorophosphate ions in the electrolyte for a lithium secondary battery is (0.0025 to 0.02):1.” and “a molar concentration of the tetrafluoroborate ions in the electrolyte for a lithium secondary battery is 0.0005 mol/L to 0.001 mol/L.”, Liang teaches a content of the tetrafluoroborate ions is 3 mass% or less. As such, the limitations are met as follow using the above data:
Ethylene carbonate with known density of 1320g/L.
Lithium tetrafluoroborate has a known molecular weight of 93.742g/mol
Molarity ranges of sulfate ester and lithium difluorophosphate: 0.053614-0.536141 mol/L and 0.024465-0.244653 mol/L respectively
Sum of sulfate ester + lithium difluorophosphate = 0.078079 to 0.780794 mol/L
Molarity of Lithium tetrafluoroborate:
0.0wt% → 0.000g/L → 0.000mol/L
3.0wt% → 1320g/L x 0.03 = 39.60g/L / 93.742g/mol = 0.4224 mol/L
Range: 0.0000-0.4224 mol/L (for claim 13)
Molar ratio of Lithium tetrafluoroborate:
Minimum ratio: 0mol/L/0.780794mol/L = 0:1
Maximum ratio: 0.422436mol/L / 0.078079 mol/L = 5.41:1
Range: (0-5.41):1 (for claim 12)
It is noted that Hao differ in the exact same molar ratio and molar concentration range as recited in the instant claim however, one of ordinary skill in the art before the effective filing date of the claimed invention would have considered the invention to have been obvious because the molar ratio and molar concentration range of Liang overlap the instant claimed molar ratio and therefore is considered to establish a prima facie case of obviousness. It has been held in the courts that in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hao et al. (CN111653829) in view of Zhou et al. (CN114361591A), as applied to claim 1 above, and further in view of Kim (U.S. Patent Application Publication 2023/0024358) and in the alternative, in view of Kuwajima et al. (U.S. Patent Application Publication 2021/0399340)
Regarding claim 15, Hao teaches the electrolyte for a lithium secondary battery as described above in claim 1.
Hao does not teach the electrolyte for a lithium secondary battery satisfies at least one of the following conditions: a water content in the electrolyte for a lithium secondary battery is less than or equal to 20 ppm; and a content of HF in the electrolyte for a lithium secondary battery is less than or equal to 150 ppm.
Kim, also directed to battery (i.e., electrochemical cell) (abstract), teaches that for conventional lithium-ion batteries, it is recommended that the water content in the electrolyte is kept below 10ppm and such to be directly related to higher specific capacity (paragraph [0136]-[0137]).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Hao to include in the electrolyte a water content below 10ppm in order to optimize the specific capacity of the battery as suggested by Kim.
In the alternative, Kuwajima, directed to an electrolyte, teaches an electrolyte with an HF content of 5 to 200ppm (paragraph [0605]). Further, Kuwajima teaches too small of an amount of HF impair characteristics of the battery and too large impar oxidation resistance (paragraph [0605]).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Hao to include in the electrolyte an amount of HF of 5 to 200ppm in order to optimize characteristics of the battery and oxidation resistance as suggested by Kuwajima.
It is noted that Hao differ in the exact same ppm ranges as recited in the instant claim however, one of ordinary skill in the art before the effective filing date of the claimed invention would have considered the invention to have been obvious because the ppm ranges Kuwajima overlap the instant claimed molar ratio and therefore is considered to establish a prima facie case of obviousness. It has been held in the courts that in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hao et al. (CN111653829) in view of Zhou et al. (CN114361591A), as applied to claim 1 and 16-17 above, and further in view Harayama et al. (U.S. Patent Application Publication 2018/0269533).
Regarding claim 18, Hao teaches the electrolyte for a secondary battery as described above in claims 1 and 16 including the positive electrode active material as recited in claim 17.
However, Hao is silent with regards to a BET specific surface area of the positive electrode active material is less than or equal to 3 m2/g.
Harayama, also directed to a battery (abstract), teaches the battery having a positive electrode active material comprising NMC (same as Hao) having a BET specific area of 0.7m2/g (paragraph [0075]). Harayama teaches the positive electrode active material allows impregnation of the electrolyte and is capable of intercalating and deintercalating lithium ions (paragraph [0030]-[0031], [0062]-[0064]).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Hao to include in the positive electrode active material a BET specific area of 0.7m2/g in order to allow impregnation of the electrolyte as taught by Harayama.
Allowable Subject Matter
Claim 20 is 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 prior art fails to teach or fairly suggest the sulfate ester comprises 4,4'-biethylene sulfate.
Response to Arguments
Applicant’s argument filed on 01/15/2026 are deemed moot in view of the new grounds of rejection presented in this Office Action, necessitated by Applicant’s amendment to the claims which significantly affected the scope thereof (i.e., by incorporating new limitations into the independent claims, which require further search and consideration). The new limitations have been fully addressed above in view of Zhou.
Pertinent Prior Art
The following prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Chen et al. (CN-109585924-A). The Examiner has provided a machine translation of CN-109585924-A. The citation of the prior art in this rejection refer to the machine translation. Chen, directed to electrolyte additives for batteries (title), teaches 4-fluoro-ethylene sulfate as an additive for electrolytes improve cycle performance (page 2).
Correspondence
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.
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/CHRISTIAN ROLDAN/Primary Examiner, Art Unit 1723