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 .
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 (i.e., changing from AIA to pre-AIA ) 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.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-8, in the reply filed on 21 July 2026 is acknowledged.
Claims 9 and 10 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 21 July 2026.
Information Disclosure Statements
The Information Disclosure Statements filed on 28 December 2023 and 20 October 2024 have been received and considered by the Examiner.
The information disclosure statement filed on 17 July 2026 fails to comply with 37 CFR 1.98(a)(2), which requires a legible copy of each cited foreign patent document; each non-patent literature publication or that portion which caused it to be listed; and all other information or that portion which caused it to be listed. It has been placed in the application file, but the information referred to therein has not been considered. In particular, the copy of the NPL supplied with this filing is not legible, and so that document has not been considered.
Claim Objections
Claim 1 is objected to because it should more clearly specify the units of the values for t1, t2, T1, and T2 to be used in the equation recited, as well as specifying the units on the value of C obtained therefrom. For example:
“where a fitted value of a maximum compaction density of the lithium iron phosphate positive electrode material in units of g/cm3 is denoted by C…wherein T1 and t1 represent a sintering temperature in °C and a sintering time in hours of the first lithium iron phosphate material respectively, and T2 and t2 represent a sintering temperature in °C and a sintering time in hours of the second lithium iron phosphate material respectively…”.1
Claims 1, 2, and 4-7 are objected to because spaces should be used between the number and the associated units in the quantities recited in the claims.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over Wang (CN 113086959 A).
Regarding claim 1, Wang teaches a method for preparing a lithium iron phosphate positive electrode material comprising:
sequentially grinding, spray-drying and sintering a first mixture slurry of iron phosphate, a lithium source, a carbon source, and a solvent to obtain a first lithium iron phosphate material with a spherical morphology (iron phosphate, lithium carbonate, and glucose were mixed with appropriate amount of water…the mixture was ground…the mixture was spray-dried…the dried powder was calcined at 770 °C…to obtain large-particle-size lithium iron phosphate…it consists of dense secondary spherical particles; [0041] and [0045]);
sequentially grinding, spray-drying and sintering and crushing a second mixture slurry of iron phosphate, a lithium source, a carbon source, and a solvent to obtain a second lithium iron phosphate material with an irregular morphology (Mix anhydrous iron phosphate, lithium carbonate, and glucose …with an appropriate amount of water…grind the slurry…spray dry the slurry…calcine the dried powder at 780 °C…perform jet-milling to obtain small-particle-size lithium iron phosphate…it consists of primary particles or agglomerates [of irregular shape]; [0043], [0045] and Fig. 2);
mixing the first lithium iron phosphate material and the second lithium iron phosphate material to obtain lithium iron phosphate positive electrode material (Large-particle-size lithium iron phosphate A1 and small-particle-size lithium iron phosphate B1 were mixed at a mass ratio of 2:1 to obtain material 1; [0044]).
While example 1 of Wang mixes the first and second lithium iron phosphate materials at a 2:1 mass ratio, Wang also teaches that the powders can be mixed at an equal mass ratio (the mass ratio of the large-particle-size lithium iron phosphate to the small-particle-size lithium iron phosphate is 1-3:1; [0006]).
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see 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); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore, the claimed value of an equal mass ratio (1:1) merely represent an obvious variant and/or routine optimization of the values of the cited prior art.
In Example 1 of Wang the first time t1 is 8 hours, the first temperature T1 is 770 °C, the second time t2 is 8 hours, and the second temperature T2 is 780 °C ([0041] and [0043]). However, Wang also teaches that the temperature of the second temperature T2 can be as high as 790°C ([0026]), which also falls within the instantly claimed range.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see 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); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore, using the temperature of 790°C for the second temperature represents an obvious modification and/or routine optimization of the conditions presented by Wang in Example 1.
The fitted value of a maximum compaction density arrived at using the sintering conditions of t1 = 8 h, t2 = 8 h, T1 = 770 °C and T2 = 790 °C, as taught by Wang is:
C =0.0847 (8) +0.0196 (770) - 0.0095 (8) + 0.0261 (790)- 33.6716=2.64, for a fitted value of a maximum compaction density of 2.64 g/cm3, which falls in the instantly claimed range.
Regarding claim 2, Wang teaches the method of claim 1, where the fitted value of the maximum compaction density is 2.64 g/cm3, which lies in the instantly claimed range of 2.6 g/cm3-2.85 g/cm3.
Regarding claim 3, Wang does not explicitly disclose the compaction density of the first lithium iron phosphate material or the second lithium iron phosphate material. Wang does however describe that the first material is comprised of hollow spherical particles ([0007]) while the second lithium iron phosphate material is comprised of dispersed primary particles and/or agglomerations formed by the aggregation of several primary particles ([0008]). It is therefore reasonable to conclude that the material comprised of hollow spheres will have a maximum compaction density that is lower than the material comprised of non-hollow particles and agglomerates.
Additionally, the first lithium iron phosphate material and the second lithium iron phosphate material of Wang are prepared by methods that are substantially similar to those in the instant claim. In particular, starting materials, ratios, sintering temperature, and particle sizes are all similar. Furthermore, the second iron phosphate material in both Wang and in the instant invention are subjected to a crushing step that forms particles or an irregular morphology, in comparison to the similarly prepared spherical particles that are not subjected to such crushing. These two materials are therefore expected to have the same relative densities as the similar particles of the instant invention, where the maximum compaction density of the first lithium phosphate material is lower than a maximum compaction density of the second lithium iron phosphate material.
Once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning to show inherency, the burden of proof shifts to the applicant. "[T]he PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of [their] claimed product. Whether the rejection is based on inherency’ under 35 U.S.C. 102, on prima facie obviousness’ under 35 U.S.C. 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO’s inability to manufacture products or to obtain and compare prior art products." In re Best, 562 F.2d 1252, 1255, 195 USPQ 4380, 483-34 (CCPA 1977), see MPEP 2112. Applicant has not clearly shown an unobvious difference between the instant invention and the prior art’s product.
Regarding claim 4, Wang teaches the method of claim 1, but does not explicitly disclose the compaction density of the first lithium iron phosphate material or the second lithium iron phosphate material. However, because the materials are prepared by a method substantially similar to the methods disclosed in Example 1 of the instant specification (starting materials, ratios, sintering temperature, and particle sizes are all similar; see [0029]-[0036] of the instant specification and [0041]-[0045] of Wang), it is concluded that the materials disclosed by Wang will also have compactions densities within the claimed ranges.
It is again noted that the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of their claimed product. See MPEP 2112.
Regarding claim 5, Wang teaches the method of claim 1, where the D50 particle size of the first lithium iron phosphate material is 5 μm ([0045]).
Regarding claim 6, Wang teaches the method of claim 1, where the D50 particle size of the second lithium iron phosphate material is 0.8 μm ([0045]).
Regarding claim 7, Wang teaches the method of claim 1, where the D50 particles size of the ground first mixture slurry and the ground second mixture slurry is 0.45 μm ([0041] and [0043]).
Regarding claim 8, Wang teaches the method of claim 1, where in the first mixture slurry the mass ratio of iron phosphate to lithium carbonate is 1:0.25 ([0041]), which corresponds to 6.77 moles of lithium element in the lithium source for every 6.63 moles of iron phosphate, and the mole of lithium in the lithium source being 1.02 times the mole of iron in the iron phosphate.
Pertinent Prior Art
The following prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Wen et al. (“Blending of LiFePO4/C microparticles with different sizes and its effect on the electrochemical performance of LiFePO4/C-based batteries,” Ionics 2019, 25, 5269-5276) disclose the mixing of spherical and smaller non-spherical lithium iron phosphate materials to prepare electrodes with improved properties. Wen prepares their LFP by the method of Liu et al. (J. Electrochem. Soc. 2017, 164, A3666), which is also considered relevant to the instant disclosure.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
1 It is noted that a physical temperature of 1040 K falls with the range of 760 °C to 780 °C, and a time of 600 minutes falls within the range of 7-11 hours, but neither of these quantities expressed as such could be used successfully in the equation for C recited in the claim.
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