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 Application
Claims 1-19 are pending. Claims 11-19 are withdrawn. Claim 1 is currently amended.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 7/6/2026 has been entered.
Response to Arguments
Applicant’s arguments with respect to amended claim(s) 1 have been considered but are not found persuasive.
Applicant argues that a person of ordinary skill in the art would lack a sufficient reason, motivation, or suggestion to combine Chen 491 with 718 as they differ substantially with respect to both the starting materials employed and the resulting precursors (e.g., oxalate vs phosphate). Examiner respectfully disagrees as the modification drawn from Chen 718 does not alter the chemistry of Chen 491, but rather substitutes the mechanical mixing apparatus of Chen 491. A rotating packed bed provides intense physical micro-mixing and rapid mass transfer, which a person having ordinary skill in the art would readily recognize as pure mechanical benefits that would predictably improve the kinetics of liquid-phase co-precipitation reactions in general, regardless of whether the precipitant is an oxalate or a phosphate.
Applicant further argues against the specific applicability of the rotating packed bed to the proposed combination. Examiner respectfully disagrees. Applying the rotating packed bed of Chen 718 to the method of Chen 491 is a simple substitution of one known mixing device for another to obtain predictable results (e.g., Chen 718 provides a list of possible dispersion methods which includes mechanical mixing and rotating packed bed in [0049-Chen 718]). Because the rotating packed bed is a conventional mechanical tool used to facilitate rapid dispersion in liquid-phase reactions, a skilled artisan would have readily applied it to Chen 491’s co-precipitation step to achieve the expected result of uniform mixing and nucleation.
Applicant further argues that there is no reasonable expectation of success in obtaining the claimed “nanometer level material” because Chen 718 teaches that micron-scale phosphate precursor can be prepared by mechanical stirring. Examiner respectfully disagrees. It’s unclear how the Applicant concluded that the mechanical stirring produced a micron-scale phosphate precursor without any paragraph citations. The formation of a nanometer-level precipitate is an inherent physical result of utilizing a high-gravity rotating packed bed during the co-precipitation step of modified Chen 491, as it mixes similar materials (i.e., a manganese-iron salt mixture with oxalic acid [0058- Chen 491]) in a rotating packed bed (MPEP 2112.01 (I)). An evidentiary reference Song also teaches that the intense micro-mixing and rapid mass transfer characteristics of rotating packed beds inherently restrict crystal growth, driving the predictable formation of nanoscale precipitate particles [Song 0061].
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.
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.
Claim(s) 1-3, 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen (CN103887491A, translation previously attached, hereinafter “Chen 491”), in view of Chen (CN104752718A, translation previously attached/previously cited, hereinafter “Chen 718”) and evidenced by Song (US20150210546A1).
Regarding claim 1, Chen 491 discloses a method for preparing nanometer-level lithium iron manganese phosphate precursor (title; LiMn0.5Fe0.5PO4 having an average particle size of 160nm [0060]), the method comprising:
preparing a first liquid material and a second liquid material,
wherein the first liquid material is a mixed solution of manganese salt and iron salt (a manganese-iron salt mixture [0058, 0029- Chen 491]),
the second liquid material is oxalic acid ([0058- Chen 491]; i.e., complexing precipitant [0030- Chen 491])
subjecting the first liquid material and the second liquid material to a co-precipitation reaction to obtain a first slurry (i.e., mechanically stirred [0058- Chen 491])
However, Chen 491 does not disclose wherein the co-precipitation reaction is performed in a rotating packed bed and the first slurry contains a precipitate that is a nanometer-level material.
In this regard, Chen 718 teaches a method for preparing lithium iron manganese phosphate precursor wherein a mixed solution comprising manganese salt and iron salt is prepared by mechanical stirring, shearing, ball milling, sand milling, and High-gravity dispersion ([0049-Chen 718]), wherein the High-gravity dispersion is also known as “HiGee” and is a type of rotating packed bed, wherein the rotating packed bed are known to provide intense physical micro-mixing and rapid mass transfer, which a person having ordinary skill in the art would readily recognize as pure mechanical benefits that would predictably improve the kinetics of liquid-phase co-precipitation reactions in general. Thus, it would have been obvious for a person having ordinary skill in the art to have used a rotating packed bed, such as the HiGee, as an alternative dispersing method to the mechanical stirring, with a reasonable expectation to disperse the manganese salt and iron salt in the mixture [0049-Chen 718]. A person having ordinary skill in the art would envisage the first slurry of modified Chen 491 to inherently form a nanometer-level precipitate as it mixes similar materials (i.e., a manganese-iron salt mixture with oxalic acid [0058- Chen 491]) in a rotating packed bed, as modified by Chen 718 [0049-Chen 718].
An evidentiary reference, Song, is also directed to a method for preparing nanometer-level lithium iron manganese phosphate precursor (i.e., LiMnFePO4 wherein M is selected from the group comprising Mn and n is in a range of 0 to 1; [0028]) wherein the method involves mixing a metal (e.g., Mn) salt aqueous solution, amorphous iron phosphate, and a phosphoric acid to crystalize [0055] in a reactor (e.g., “agitator in a form of packed bed 30” [0028] to actively perform mass transfer and heat transfer, causing strong micro-mixing to form a highly uniform-supersaturated solution within a very short time, wherein a nano-sized iron-phosphate precipitate may form in this process [Song 0061]. A person having ordinary skill in the art would envisage the co-precipitation reaction in the rotating packed bed of modified Chen 491 to form a precipitate in a nanoscale due to the strong micro-mixing within a very short time [Song 0061].
Chen 491 further discloses the steps of:
washing and filtering the first slurry to obtain a filter cake [0058- Chen 491];
mixing the filter cake with water [0059- Chen 491],
adding a carbon source (i.e., carbon nanotubes [0060- Chen 491]]) and stirring until uniform to obtain a second slurry (i.e., emulsified and dispersed [0060-Chen 491])
Regarding the step of “homogenizing the second slurry”, Examiner notes that the previously disclosed step of emulsifying (note: interpretated as mixing two or more liquids into a smooth, stable, unified mixture) and dispersing reads on the claimed step of “homogenizing the second slurry (note: homogenize is interpreted as to blend into a mixture that is the same throughout per Merriam-Webster definition).
Chen 491 further discloses:
drying the homogenized second slurry to obtain the lithium iron manganese phosphate precursor (i.e., spray-dried using a spray dryer [0060- Chen 491])
Regarding claim 2, modified Chen discloses the method according to claim 1, wherein the manganese salt comprises manganese sulfate [0058 Chen 491] and wherein the iron salt comprises ferrous sulfate [0058- Chen 491] (see Example 1).
Regarding claim 3, modified Chen discloses the method according to claim 1, wherein the concentration of the first liquid material is 0.1 mol/L [0058-Chen 491], which falls within the claimed range of 0.1-3mol/L, and the concentration of the second liquid material is 0.1 mol/L [0058-Chen 491], which falls within the claimed range of 0.1-3mol/L.
Regarding claim 8, modified Chen discloses the method according to claim 1, wherein the carbon source is carbon nanotubes [0058- Chen 491].
Claim(s) 4,6,9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen (CN103887491A, translation attached, hereinafter “Chen 491”), in view of Chen (CN104752718A, translation previously attached/cited, hereinafter “Chen 718”) and Gao (CN101837966A, translation previously attached/previously cited), and evidenced by Song (US20150210546A1).
Regarding claim 4, modified Chen discloses the method according to claim 1. However, Chen 718 does not disclose wherein the rotating packed bed is selected from a horizontal rotating packed bed or a vertical rotating packed bed.
In this regard, Gao teaches a method for preparing a nanometer lithium ferric phosphate by using a rotating packed bed reactor [Gao 0002], wherein a mixed solution comprising ferric nitrate is put into a rotating packed bed to crystallize [Gao 0036], wherein the rotating packed bed is a vertical rotating packed bed (see Fig 1). A person having ordinary skill in the art would have been motivated to modify the HiGee of Chen, such that it rotates vertically, as Gao teaches that such rotating packed bed reactor completes the liquid phase precipitation in a few seconds to a few minutes [Gao 0027-0028].
Regarding claim 6, modified Chen discloses the method according to claim 1, wherein a temperature of co-precipitation reaction is 40°C [0058-Chen 491], which falls within the claimed range of 20-80°C.
However, Chen 491 does not disclose a rotational speed of the rotating packed bed is 500-3000rpm.
In this regard, Gao teaches that the rotation speed of the rotating packed bed is controlled between 500-3000 rpm [0022 Gao], which is the same as the claimed range of 500-3000rpm.
A person having ordinary skill in the art would have been motivated to select the disclosed range of rotation speed, as Gao teaches that such process can reduce the time for liquid phase precipitation to a few seconds to a few minutes [0028 Gao].
Regarding claim 9, modified Chen discloses the method according to claim 1. However, Chen 491 does not explicitly disclose wherein homogenizing is performed using a rotating packed bed selected from a horizontal rotating packed bed or a vertical rotating packed bed.
In this regard, Chen 718 teaches that the dispersion methods used in each step of preparation process can be mechanical stirring, shearing, ball milling, sand milling, high gravity [0049-Chen 718], wherein the high gravity dispersion envisages a rotating packed bed.
Thus, it would have been obvious for a person having ordinary skill in the art to have used the high gravity (“Higee”) in the homogenization step with a reasonable expectation to form a uniformly mixed second slurry comprising the filter cake and the carbon source [0049-Chen 718].
However, Chen 718 does not disclose wherein the rotating packed bed selected from a horizontal rotating packed bed or a vertical rotating packed bed, as claimed.
In this regard, Gao teaches a method for preparing nanometer lithium ferric phosphate by using a rotating packed bed reactor [Gao 0002], wherein a mixed solution is put into a vertical rotating packed bed to facilitate precipitation (see Fig 1). A person having ordinary skill in the art would have been motivated to modify the high gravity method of Chen, such that it rotates vertically, as Gao teaches that such rotating packed bed reactor is simple and low energy consuming, while effectively reducing the time for liquid phase precipitation [0027-0028 Gao].
Claim(s) 5,7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen (CN103887491A, translation previously attached, hereinafter “Chen 491”), in view of Chen (CN104752718A, translation previously attached/cited, hereinafter “Chen 718”), Song (US20150210546A1, previously cited), and evidenced by Song (US20150210546A1).
Regarding claim 5, modified Chen discloses the method according to claim 1. Chen does not explicitly disclose wherein a feeding mode of the first liquid material and the second liquid material is one of co-current, counter-current or cross-current, and wherein a feeding speed of the first liquid material and the second liquid material is controlled at 10mL-5000mL/min, respectively.
In this regard, Song also teaches a method for making lithium metal phosphate using a high gravity level of the packed bed [Song 0099], wherein metal-doped iron and phosphate solutions are simultaneously pumped in the same direction to the outlet (i.e., co-current) at a flow rate of 0.4 L/min ([0099]; i.e., 400 ml/min) which falls within the claimed range of “10ml-5000ml/min”.
A person having ordinary skill in the art would modify the high gravity dispersion of Chen to include a co-current feeding mode wherein the feeding speed of the first liquid material and the second liquid material are within the claimed range (e.g., 400ml/min [Song 0099]), as Song teaches that such mixing forms a highly uniform-supersaturated solution within a very short time (less than 10 ms) and form a nano-sized precipitate [0061 Song].
Regarding claim 7, modified Chen discloses the method according to claim 1, wherein the wet cake is filtered and washed [0058 Chen 491]. However, Chen does not disclose wherein an equipment for washing and filtering is one of centrifugal filter, filter press, bag filter, membrane filter, vacuum suction filter or vacuum filter.
In this regard, Song teaches that the washing and filtering is performed using a reduced-pressure filter (i.e., vacuum suction filter) or a centrifuge [0055 Song]. A person having ordinary skill in the art would reasonably select the centrifugal filter and/or the vacuum suction filter from the finite list of filtering methods, as Song teaches that such methods may completely remove the reaction medium from the precipitate particles [0047 Song], and further reduces the drying time.
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen (CN103887491A, translation previously attached, hereinafter “Chen 491”), in view of Chen (CN104752718A, translation previously attached/cited, hereinafter “Chen 718”), Kim (KR102172027B1, translation previously attached/previously cited), and evidenced by Song (US20150210546A1).
Regarding claim 10, modified Chen discloses the method according to claim 1, wherein drying is carried out using spray drying equipment [0060- Chen 491], but does not disclose an inlet and outlet temperature of the spray drying equipment.
In this regard, Kim also teaches a method for making lithium transition metal phosphate, wherein lithium source, iron phosphate, and manganese source are mixed [0045 Kim] with a carbon source [0048 Kim], followed by spray drying [0049-0054 Kim], wherein an inlet temperature is 250 to 300°C [0054 Kim], which falls within the claimed range of “100-280°C” and an outlet temperature (“exhaust hot air temperature” [0054 Kim]) of 100 to 150°C [0054 Kim], which falls within the claimed range of “50-180°C”. A person having ordinary skill in the art would select the overlapping range of the inlet and outlet temperature, as Kim teaches that such inlet and outlet temperature increases the shape, size, and crystallinity of the precipitate particles [0054 Kim].
Conclusion
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/T.S./Examiner, Art Unit 1751
/Haroon S. Sheikh/Primary Examiner, Art Unit 1751
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