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 .
Specification
The disclosure is objected to because of the following informalities: paragraph [0037] is unclear, specifically regarding the interpretation of significant digits and conventional rounding, and appears to contain sentences with grammatical errors. It is not sufficiently clear how rounding and significant digits are to be applied by one of ordinary skill in the art. This is particularly pertinent because the claimed invention recites single values, not recited as ranges, that cannot be interpreted without a clear understanding of where the bounds of each value lie after rounding, significant digits, and other estimation techniques are to be applied.
Appropriate correction is required.
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, 3-8, 10, 12-13, and 15-17 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al. 2015 (US 20150030517 A1) in view of Fujii 2008 (JP 2008004317 A), and Li et al. 2012, (CN 116750738 A), referred to herein as Yu, Fujii, and Li, respectively. Yu and Li were provided on the IDS filed on 09/19/2024. A translation of Li is provided with this Office action.
Regarding claim 1, Yu teaches a preparation method of an iron phosphate precursor for batteries (abstract), comprising steps of:
providing a phosphoric acid and an iron powder (abstract),
reacting the phosphoric acid with the iron powder to generate a first product (abstract), and
heat-treating the first product to form the iron phosphate precursor (calcining, abstract).
Yu does not teach:
wherein the iron powder has an apparent density of the iron powder ranging from 2.3 g/cm3 to 2.6 g/cm3,
and a particle size composed of a first particle-size range and a second particle-size range, the first particle-size range is greater than the second particle-size range,
and a weight of the iron powder in the second particle-size range accounts between 10 % and 30 % of the total weight of the iron powder;
and (c) heat-treating the first product in an air or oxygen atmosphere.
However, regarding limitations II and III, since a powder must always have a particle size range, and any range can arbitrarily be divided into a first particle-size range and second particle-size range wherein a weight of the iron powder in the second particle-size range accounts between 10 % and 30 % of the total weight of the iron powder, these limitations are necessarily present in the invention disclosed by Yu.
Regarding limitation I, Fujii teaches that the apparent density is a parameter that is known in the art to affect the rate of the solid-phase reaction between phosphate and the interior of the iron particles (0012), and further teaches values for apparent density just outside the claimed range, of 1.91 g/cm^3 (0023) and 3.01 g/cm^3 (0025). It would be obvious to one skilled in the art to optimize the apparent density within this range of values by selecting an iron powder with an apparent density ideal for the reaction to occur, and thus one of ordinary skill in the art would arrive at the claimed ranges of values, since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.). Furthermore the courts have held that in the case where the claimed range "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. 1990).
Regarding limitation IV, while Yu does not explicitly teach an air or oxygen atmosphere, Li teaches an analogous process for forming iron phosphate (abstract) wherein an air atmosphere is used during the calcination (0033). It would be obvious to one skilled in the art to combine the teachings of Yu and Li; one would be motivated to do so because Li teaches that the calcination in air allows the dehydration of the iron phosphate to obtain a battery-grade product (0033). One skilled in the art would therefore arrive at the claimed invention prior to the effective filing date.
Regarding claim 3, Yu, Fujii, and Li teach the invention as applied to claim 1. Yu further teaches that the holding time of step (c) is at least one hour (2 + 1 hours, 0037). Yu does not teach that the step (c) is performed at a temperature ranging from 610°C to 670°C. However, Li teaches the calcination step wherein the temperature is 650 C (0041). It would be obvious to combine the teachings of Li with the teachings of the prior art by using the calcination temperature taught by Li; one would be motivated to do so because Li teaches that when the temperature is too low the particle size decreases, and when the temperature is too high, agglomerates form disadvantageously (0041).
Regarding claim 4, Yu, Fujii, and Li teach the invention as applied to claim 1. Fujii further teaches that the particle size distribution is a parameters that affects the solid-phase reaction (0013). It would therefore be obvious to one skilled in the art to optimize the size distribution as a result effective variable, in order to obtain a particle size appropriate for the reaction of iron powder, and thus arrive at the claimed ranges of values, since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
Regarding claim 5, Yu, Fujii, and Li teach the invention as applied to claim 1. Yu further teaches that the first product is amorphous phosphates ("amorphous body of ferric phosphate," 0031) and the formula of the first product is written as a-FePO4xH20, wherein x > 0 (0031).
Regarding claim 6, Yu, Fujii, and Li teach the invention as applied to claim 1. Yu further teaches allowing deionized water to dissolve a first quantity of the phosphoric acid for forming a first phosphoric acid solution at a first temperature (0029, Fig. 2 Step 201), as recited in step (b11) of the instant claim; processing a reaction of the first phosphoric acid solution and the iron powder at a second temperature, lowering the reaction temperature to a third temperature after the second temperature is reached by the reaction temperature, and maintaining the reaction temperature for a first time period (Fig. 2 Step 202), as recited in step (b12) of the instant claim; and lowering the reaction temperature to a fourth temperature and adding a second phosphoric acid solution consisting of a second quantity of the phosphoric acid, and processing a reaction of the first phosphoric acid solution, the second phosphoric acid solution and the iron powder for a second time period, so as to produce the first product (Fig. 2 Step 203), as recited in step (b13) of the instant claim.
Regarding claim 7, Yu, Fujii, and Li teach the invention as applied to claim 6. Yu further teaches that the weight ratio of the first quantity to the second quantity is 3:1 (0031), as recited.
Regarding claim 8, Yu, Fujii, and Li teach the invention as applied to claim 6. Yu further teaches that the first temperature ranges from 35 °C to 45 °C (equal to or larger than 40°C and equal to or less than 50°C, 0029), the second temperature is equal to or less than 60 °C (0029), the third temperature is equal to or less than 50 °C (0029), and the fourth temperature is equal to or less than 30 °C (0031). Regarding the overlap of the taught range with the instant range of 35-45 C, as set forth in MPEP 2144.05, in the case where the claimed range "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. 1990).
Regarding claim 10, Yu, Fujii, and Li teach the invention as applied to claim 6. Yu further teaches that the step (b) further comprises steps of: (b21) performing a first grinding action to grind the first product to have an average particle size D50 smaller than a first length (0033); and (b22) processing the reaction for a third time period (0033).
While Yu does not explicitly teach a D99 value, the D99 value being less than a first length is a condition that is always satisfied, since the D99 value can always be smaller than an arbitrary length; therefore this claim limitation is met by the prior art.
Regarding claim 12, Yu, Fujii, and Li teach the invention as applied to claim 10. Yu further teaches adding a carbon source and a metal compound to form a precursor solution with the first product (0024, wherein the metal compound is LiOH or Li2CO3), and performing a spray drying action to the precursor solution when the precursor solution is ground to have a particle size less than a length in the second grinding action (0033).
Yu teaches a continuous grinding step (0033) which is interpreted to meet the limitation of a second grinding step as instantly claimed, since these grinding steps are analogous in that they both arrive at the final particle size distribution being below a certain length in order to proceed with spray drying (0033).
Yu does not teach a D70 value, and the particle size D70 being less than a second length. However, while Yu does not explicitly teach a D70 value, the D70 value being less than a second length is a condition that is always satisfied, since the D70 value can always be smaller than an arbitrary length; therefore this claim limitation is met by the prior art.
Regarding claim 13, Yu, Fujii, and Li teach the invention as applied to claim 12. Yu further teaches that the spray drying action is implemented by a rotary spray dryer, an entrance temperature of the rotary spray dryer is 210 °C, an exit temperature of the rotary spray dryer is 95 °C, and a rotational speed of the rotary spray dryer ranges from 300 Hz to 400 Hz (350 Hz, 0034).
Regarding claim 15, Yu, Fujii, and Li teach the invention as applied to claim 12. Yu further teaches that the first grinding action is performed at a rotational speed ranging from 450 rpm to 650 rpm (0032). Yu does not teach that the second grinding action is performed at a rotational speed ranging from 450 rpm to 650 rpm. However, since Yu teaches the continuous grinding (0033), it would be obvious to one skilled in the art to implement the rotational speed of the first grinding action for the rest of the grinding actions, and thus arrive at the claimed invention.
Regarding claim 16, Yu, Fujii, and Li teach the invention as applied to claim 12. Yu further teaches that the metal compound and the iron phosphate precursor form an iron phosphate precursor composite material in the step (c) (mixing Fe7(PO4)6 and lithium reactant, 0035), and are heat-treated to form a battery composite material, wherein the chemical formula of the battery composite material is LiFePO4, and the metal compound is a lithium-containing compound (0035).
Regarding claim 17, Yu, Fujii, and Li teach the invention as applied to claim 16. Yu further teaches lithium carbonate (0035), which meets the limitation of wherein the lithium-containing compound is one selected from the group consisting of lithium hydroxide, lithium carbonate and a mixture thereof, and Yu teaches that the battery composite material is a lithium ferric phosphate nano-co-crystalline olivine (LFP-NCO) (claim 4).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Yu, Fujii, and Li, as applied to claim 6, and in further view of Huang et al. 2015, CN 104817059 A. Huang was provided on the IDS filed on 09/19/2024.
Regarding claim 9, Yu, Fujii, and Li teach the invention as applied to claim 6. Yu further teaches that the first time period is at least 3 hours (0029).
Yu, Fujii, and Li do not teach that the second time period ranges from 5 hours to 9 hours. However, Huang teaches an analogous process for the preparation of battery-grade iron phosphate (title) comprising an aging step which is conducted at room temperature for 0.5- 24 hours (0030), which includes the value of 23 hours taught by Yu (0031). It would be obvious to combine the teachings of Yu, Fujii, and Li with the teachings of Huang; one would be motivated to do so in order to age the product formed, as Huang teaches (0030), and furthermore one would be motivated to optimize the time of the second time period to a value less than the 23 hours taught by Yu, because Huang teaches that iron reacts with difficulty due to the long aging time (0006) with phosphoric acid. As set forth in MPEP 2144.05, in the case where the claimed range "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. 1990). It would have therefore been obvious to one of ordinary skill in the art before the effective filing date of the invention to perform a method for preparing iron phosphate as suggested by Yu, Fujii, Li, and Huang, where the time of the second time period is in any workable or optimum range overlapping with 0.5 to 24 hours as taught by Huang including the claimed range in order to obtain a time duration suitable to age the reaction appropriately.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Yu, Fujii, and Li, as applied to claim 10, and in further view of Tahara et al. 2012 (US 20120292560 A1), herein referred to as Tahara.
Regarding claim 11, Yu, Fujii, and Li teach the invention as applied to claim 10. Yu further teaches a third time period range of at least 5 minutes (0033), which overlaps with the claimed range of 6 hours to 12 hours. As set forth in MPEP 2144.05, in the case where the claimed range "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. 1990).
They do not teach that a D99 value (recited in claim 10) is smaller than a first length wherein the first length is less than 100 microns. However, Tahara teaches an analogous method of producing lithium iron phosphate from a precursor (abstract) wherein Tahara teaches that particle size of the precursor is preferably 100 microns or less (0056), which therefore overlaps with the claimed range of D99 being 100 microns or less, since D99 represents 99% of particles, and Tahara’s teaching refers to all particles. As set forth in MPEP 2144.05, in the case where the claimed range "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. 1990). It would be obvious to combine the teachings of Tahara and Yu, Fujii, and Li; one would be motivated to do so because Tahara teaches that when the particle size of the precursor exceeds 100 microns, when using the precursor to then form the positive active material (of a battery, 0002), the current collector of the positive active material formed from the precursor may be disadvantageously damaged (0056). One skilled in the art would therefore arrive at the claimed invention prior to the effective filing date.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Yu, Fujii, and Li, as applied to claim 12, and in further view of Lan et al. 2021, Preparation of LiFePO4 Powders by Ultrasonic Spray Drying Method and Their Memory Effect, Materials (Basel). 2021 Jun 10;14(12):3193, herein referred to as Lan.
Regarding claim 14, Yu, Fujii, and Li teach the invention as applied to claim 12. Yu teaches that the D50 after continuous grinding can be less than 1 micron (0033). They do not teach that a D70 value (recited in claim 12) is less than a second length ranging from 1 to 10 microns. However, Lan teaches the preparation of LiFePO4 powders (title) wherein the uniform distribution of particle sizes is advantageous for use in batteries, and irregular particle shape and large sizes are disadvantages (Introduction, paragraph 2). It would be obvious to one skilled in the art that the size taught by Yu would be reasonably optimized to arrive at a uniform distribution, as taught by Lan, and therefore would necessarily also possess a D70 value that is less than the range of 1 to 10 microns as claimed; absent evidence of critical results, the courts have held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Thus one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Yu, Fujii, and Li, as applied to claim 16, and in further view of Churikov et al. 2013, Thermodynamics of LiFePO4 Solid-Phase Synthesis Using Iron(II) Oxalate and Ammonium Dihydrophosphate as Precursors., J. Chem. Eng. Data 13 June 2013; 58 (6): 1747–1759, herein referred to as Churikov.
Regarding claim 18, Yu, Fujii, and Li teach the invention as applied to claim 16. They do not teach that the step (c) includes heat-treating at a temperature of 325°C for 0.5 hours, heat-treating at a temperature of 550°C for 0.5 hours, and heat-treating at a temperature of 650°C for 1 hour.
However, Churikov teaches an analysis of the synthesis of LiFePO4 (title, abstract) which is pertinent to the field of endeavor of Yu, Fujii, and Li, since Churikov teaches the thermodynamic stability of precursors to LiFePO4 (abstract). Churikov teaches heat treatment of precursor mixture at 360 C for 34 minutes, 500 C for 48 minutes, and 650 for 63 minutes (Table 2, p. 1750). These values are interpreted to substantially meet the claimed temperature values, respectively, barring evidence of criticality of the range of temperatures between the taught values and the claimed values, since the instant specification does not define a range of values regarding importing the decorating term “about” to numerical values [0037]. It would be obvious to one skilled in the art to combine the teachings of Churikov and Yu, Fujii, and Li; one would be motivated to do so in order to control the crystal phases of the product to obtain the final product of LiFePO4, as Churikov teaches (p. 1750 col. 2 pp. 2), since Churikov teaches that these temperatures each yield different crystal phases (Table 2, p. 1750-1751, “Chemical and Phase Transformations during the LiFePO4 Synthesis”). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Allowable Subject Matter
Claim 2 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.
Claim 2 recites a particle size range and a BET surface area that are not known or standard selections in the art. The closest prior art is considered to be Yu, which does not disclose the BET surface area of the iron powders. Furthermore the combination of teachings or suggestions in the art would not allow one of ordinary skill in the art to arrive at such a combination of values for these two parameters.
Conclusion
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/Eileen Moudou/ Examiner, Art Unit 1738
/MICHAEL FORREST/ Primary Examiner, Art Unit 1738
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