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 1-17 are currently pending.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 1-5, 9 & 11-17 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (US 2020/0388830 A1) in view of Zou (US 2021/0119258 A1).
Regarding claims 1-5, 9 & 11-15, Lee teaches a lithium secondary battery comprising a cathode comprising a cathode active material layer that includes a cathode active material and an anode facing the cathode ([0047]-[0048] & [0057]), wherein the cathode active material comprises a first lithium transition metal composite oxide particle represented by LiNi0.88-Co0.1Mn0.1O2, wherein a crystal grain size of the first lithium transition metal composite oxide particle measured by an xrd analysis using the Scherrer equation recited in claim 2 is 200 nm to 500 nm which overlaps with the presently claimed ranges of claims 1 & 3-4 ([0014], [0022], [0025] & [0074]); and a second lithium transition metal composite oxide particle represented by LiNi0.87-Co0.08Mn0.03Al0.02O2 having a secondary particle structure and particle diameter (D50) that is larger than a particle diameter of the first lithium transition metal oxide particle, wherein a crystal grain size of the second lithium transition metal composite oxide can be as small as 100 nm ([0014], [0017], [0024]), wherein a weight ratio of the first lithium transition metal composite oxide particle and the second lithium transition metal composite oxide particle is from 3:7 to 7:3 ([0037] & [0074]). Lee is silent as to (1) an xrd peak area ratio, as defined by equation 3 being 17% or less (claim 1) and ranging from 10% to 17% (claim 5). Zou teaches a cathode active material for a lithium secondary battery, wherein the cathode active material is a lithium transition metal composite oxide with the same composition as Lee and having a ratio A(003)/A(110) of 5 to 120 ([0081]-[0087], [0092] & [0096]). When Zou’s ratio is equal to 5, the resulting peak area ratio as defined by equation 3 is 16.7%. It would have been obvious to one skilled in the art, before the effective filing date of the present invention, to set an xrd peak area ratio of Lee’s first composite oxide particle to 16.7% in order to improve the wettability of the electrolytic solution in the positive electrode plate thereby increasing the diffusion rate of the electrolytic solution in the electrode body as taught by Zou ([0092]).
Regarding claims 16-17, Lee as modified by Zou teaches the lithium secondary battery of claim 15. Lee further teaches the first lithium transition metal composite oxide having an average particle diameter of preferably 2 microns to 8 microns and the second lithium transition metal composite oxide having an average particle diameter of preferably 10 microns to 22 microns ([0020]-[0021]). The cross-sectional areas of the first and second lithium transition metal composite oxide particles can be approximated by using the formula for the cross-sectional area of a sphere (i.e A=4πr2) with the corresponding average diameter of the respective first and second lithium transition metal composite oxide particles. For an average particle diameter of 10 microns of the second composite oxide, when the average particle diameter of the first composite oxide ranges from anywhere between 5.2 microns and 8 microns (i.e within the range of 2 microns to 8 microns as taught in Lee), the corresponding ratio of a cross-sectional area of the first composite oxide particles and a cross-sectional area of the second composite oxide would overlap with the claimed range of 2:3.7 to 3.7:2.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Lee (US 2020/0388830 A1) and Zou (US 2021/0119258 A1), as applied to claims 1-5, 9 & 11-17 above, and further in view of Leng (US 2021/0167366 A1).
Regarding claim 8, Lee as modified by Zou teaches the cathode active material of claim 1 but does not explicitly teach the first composite oxide particle having a single particle shape having a crystallographic single crystal or polycrystalline structure. Leng teaches a lithium secondary battery comprising a cathode comprising a cathode active material mixture including a first lithium transition metal composite oxide and a second lithium transition metal composite oxide, wherein the first lithium transition metal composite oxide has a single particle shape including a crystallographic single crystal with a crystal grain size of 1 micron to 5 microns and the second lithium transition metal composite oxide is in the form of a secondary particle formed by aggregating a plurality of primary particles and wherein a particle diameter of the second lithium transition metal composite oxide is larger than a particle diameter of the first lithium transition metal composite oxide ([0019], [0027]-[0042] & [0046]-[0047]). It would have been obvious to one skilled in the art, before the effective filing date of the present invention, to use single particles including a crystallographic single crystal for Lee’s first lithium transition metal composite because a mixed cathode active material including single particles and secondary particles improves the compressive strength of the cathode active material in the cathode sheet and effectively restrains the problem of particle cracking of the cathode active material as taught by Leng ([0019]). Furthermore, when the first lithium transition metal composite oxide is mixed with the second lithium transition metal composite oxide, the gap volume of the secondary particles can be better filled thereby “inhibiting volume expansion rate of the positive electrode sheet in a cycle process and improve cycle performance while improving compaction density of the positive electrode sheet and volume energy density of the battery” as taught by Leng ([0046]).
Allowable Subject Matter
Claims 6-7 & 10 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 a statement of reasons for the indication of allowable subject matter: The closest prior arts of record (Lee and Zou, as cited in the above rejection) does not fairly teach or suggest an xrd peak intensity ratio, as defined by equation 2 of the first composite oxide particle being 9.8% or less (claim 6) and the xrd peak area ratio of the second composite oxide particle exceeding 17% (claim 10).
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NATHANAEL T ZEMUI whose telephone number is (571)272-4894. The examiner can normally be reached M-F 8am-5pm (EST).
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/NATHANAEL T ZEMUI/
Examiner, Art Unit 1727
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