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 .
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, 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.
Claims 1-6 and 8-15 are rejected under 35 U.S.C. 103 as being unpatentable over Kwon et al. (WO 2023121397 A1). It is noted that the disclosures of Kwon et al. are based on a machine translation of the reference included with this action.
Regarding claims 1 and 3:
Kwon et al. teaches a positive electrode that includes a positive electrode active material layer, wherein the positive electrode active material layer includes a first lithium iron phosphate, i.e. large-particle lithium iron phosphate particle, and a second lithium iron phosphate, i.e. small-particle lithium iron phosphate particle, as positive electrode active materials, wherein the first lithium iron phosphate has an average particle size D50 larger than that of the second lithium iron phosphate (0012).
Kwon et al. also teaches a polytetrafluoroethylene cathode binder (0140) and a lithium secondary battery manufactured using the positive electrode (0002).
Given that there is no disclosure in Kwon et al. that the positive electrode active material includes water or organic solvent, it is clear that the positive electrode active material would necessarily be dry.
In light of the overlap between the claimed positive electrode and that disclosed by Kwon et al., it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a positive electrode that is both disclosed by Kwon et al. and encompassed within the scope of the present claims and thereby arrive at the claimed invention.
Regarding claim 2:
Kwon et al. teaches within the positive electrode active material layer, the first lithium iron phosphate and the second lithium iron phosphate may be included in a volume ratio of 10:90 to 40:60 (0019).
Although there is no explicit disclosure of a weight ratio in Kwon et al., given the broad range of the volume ratio disclosed by Kwon et al. and the broad range of the weight ratio claimed, the values would necessarily inherently overlap with the weight ratio presently claimed.
Regarding claim 4-6:
Kwon et al. teaches the average particle size D50 of the first lithium iron phosphate may be 2 μm to 8 μm (0017).
Kwon et al. teaches the average particle size D50 of the second lithium iron phosphate may be 1 μm or less (0020).
Using the average particle sizes of the first lithium iron phosphate and the second lithium iron phosphate, it is therefore calculated that the ratio of the size of the first lithium iron phosphate to the size of the second lithium iron phosphate is greater than 2:1, meeting the claimed range.
Regarding claim 8:
Kwon et al. teaches the first lithium iron phosphate and the second lithium iron phosphate are represented by Li1+aFe1-xMx(PO4-b)Xb, where M comprises one or more elements selected from the group consisting of Mg, Ni, Co, Mn, and a, b, and x are each -0.5 ≤a≤0.5, 0≤b≤0.1, and 0≤x≤0.5 (0071-0074) which would be identical to the lithium iron phosphate particle presently claimed when b=0.
Regarding claim 9:
Kwon et al. teaches the cathode binder may be included in an amount of 1 to 30 weight%, based on the total weight of the cathode active material layer (0140).
Regarding claim 10:
Kwon et al. teaches the positive active material layer may further include a conductive material, a binder, and a dispersant (0023).
Regarding claim 11:
Given that Kwon et al. teaches a positive electrode as presently claimed, the positive electrode would necessarily inherently have an energy density of about 400 watt hour per liter (Wh/L) to about 490 Wh/L.
Regarding claim 12:
Given that Kwon et al. teaches a positive electrode as presently claimed, the positive electrode active material layer would necessarily have a loading level of about 40 milligram per square centimeter (mg/cm2) to about 90 mg/cm2.
Regarding claim 13:
Given that Kwon et al. teaches a positive electrode as presently claimed, the positive electrode would necessarily inherently have a current density of about at least 5 milliampere hour per square centimeter (mAh/cm2).
Regarding claim 14:
Given that Kwon et al. teaches a positive electrode as presently claimed, the positive electrode would necessarily inherently have a current density of about 5 mAh/cm2 to about 8 mAh/cm2.
Regarding claim 15:
Kwon et al. teaches a lithium secondary battery includes a positive electrode, a negative electrode, and an electrolyte (0132). The electrolyte may include an organic solvent (0146), i.e. a non-aqueous electrolyte.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Kwon et al. (WO 2023121397 A1) in view of Gao et al. (CN 116259706 A). It is noted that the disclosures of Gao et al. are based on a machine translation of the reference included with this action.
Regarding claim 7:
Kwon et al. teaches a positive electrode as set forth above.
However, Kwon et al. does not teach the polytetrafluoroethylene binder comprises fibrillated polytetrafluoroethylene.
Gao et al. teaches a lithium battery (n0001) comprising a dry positive electrode and a dry positive electrode material (n0015), and after polytetrafluoroethylene fibers are meltrecrystallized and fiberized, they can achieve or approach the fiber network structure of polytetrafluoroethylene after dry fibrillation and achieve good mechanical properties and tensile strength (n0113).
In light of the motivation for using fibrillated polytetrafluoroethylene disclosed by Gao et al. as set forth above, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use fibrillated polytetrafluoroethylene in the positive electrode of Kwon et al. in order to achieve good mechanical properties and tensile strength.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MADISON E. BROWN whose telephone number is (571)775-5984. The examiner can normally be reached M-Th 8am-6pm.
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/MADISON ELIZABETH BROWN/Examiner, Art Unit 1787
/CALLIE E SHOSHO/Supervisory Patent Examiner, Art Unit 1787
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