DETAILED ACTION
Application 17/421606, “Method Of Preparing Positive Electrode Active Material For Lithium Secondary Battery And Positive Electrode Active Material Prepared By The Method”, is the national stage entry of a PCT application filed on 1/7/20 and claims priority from a foreign application filed on 1/10/19.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This Office Action on the merits is in response to communication filed on 11/11/25.
Response to Arguments
Applicant’s arguments filed on 11/25/25 have been fully considered, but are not persuasive. Applicant presents the following arguments.
Paragraph [0059] of the PG-Pub of the instant application explains that a holding time of 10% to 20% of the sintering time suppresses penetration of moisture into the cathode material; therefore, the 10 to 20% ratio of claim 1 corresponds to a critical range and/or unexpected results.
In response, the relevant portion of paragraph [0059] in states, “For example, the holding time of the aging step may be performed at a ratio of 8% to 50%, for example, 10% to 20% relative to that of the sintering step. In this case, the penetration of the moisture into the positive electrode active material may be easily suppressed.” Therefore, the suppression of moisture is disclosed to be associated with an 8% to 50% low:temperature:high-temperature ratio range, and no evidence of record distinguishes the narrower 10% to 20% range from the broader desirable range of 8% to 50%.
As to a combination of Song and Roh, the two references make different materials in that Song discloses a lithium transition metal oxide including cobalt, whereas Roh teaches a lithium transition metal oxide without cobalt. Thus, the two references are not combinable.
In response, both references are within the lithium battery art, and more narrowly drawn to making lithium transition metal oxide type positive electrode active materials. Thus, the references are analogous art presumed to be combinable. It is not immediately clear why the inclusion of cobalt or lack thereof would make the references, both drawn to lithium oxide positive electrode active material manufacture, not combinable. No evidence has been provided which explains why the benefit disclosed by Roh, i.e. improvement in stabilization of a crystal compound, would not be expected were Song modified by Roh as described in the rejection. Applicant’s argument is not found persuasive at least because it is not supported by evidence or technical reasoning to demonstrate that the references are not combinable.
Roh teaches that the high temperature heat treatment may be 1 to 48 hours. This disclosure, combined with the 1 to 48 hour time range Roh teaches for the low temperature heat treatement suggests a possible ratio range of 2% to 4800%, substantially larger than the claimed range of 10% to 20%.
In response, Song is relied on for teaching a high temperature heat treatment, with the specific embodiment of 10 hours for Example 1 at paragraph [0081] cited in the body of the rejection. Song is not deficient with respect to a high temperature heat treatment; therefore, there is no need to modify the Song high temperature heat treatment time in view of Roh. Since the rejection specifically cites the Song Example 1 embodiment, it is appropriate to select a high temperature heat treatment time of 10h in view of Song, and then to find that a low temperature heat treatment in a time of 1 to 48 hours could be added to the production process in view of Roh. Therefore, an obvious ratio can be determined by considering the teaching of Soh (e.g. Example 1 as a narrower embodiment) in combination with the teaching of adding a low temperature hold in view of Roh for improving stabilization of the crystal compound.
Coupling the 10 h high temperature heat treatment time of Song with the low temperature heat treatment disclosure of Roh is improper analysis because the Board has held (see “SNF” cited by applicant at page 5 of the remarks) that when a claim recites a ratio between two elements, but the prior art is silent regarding the ratio and merely discloses ranges, it is improper to randomly pick values from the disclosed ranges in order to demonstrate the claimed ratio. Impermissible hindsight is required to randomly pick values from a disclosed range, to demonstrate that a claimed ratio is present in the prior art.
In response, this case law does not appear to correspond to the present case at least because the Office has not randomly picked values from prior art ranges in order to demonstrate the claimed ratio is suggested. More specifically, SNF criticizes a finding of obviousness because the presented finding “never explains how or why the particular combinations used to calculate the ratio were selected… it appears that Petitioner picked the specific values it used to calculate a ratio from broad, unrelated ranges…. Simply because they combine to produce a ratio that meets the ratio recited in the claims” (page 14-15 of SNF). Here however, the 10 hour time frame for the high temperature heat treatment is not randomly or arbitrarily selected. Instead, it is the time disclosed for Example 1 of the first reference Song. The Roh reference is then relied on to add a low temperature heat treatment; therefore, Roh must be relied on to determine a workable range for the second heat treatment temperature, which is included in order to stabilize crystal structure of a forming compound. It does not require impermissible hindsight to notice that the lower portion of the Roh low temperature heat treatment range, namely the 1 to 2 hour portion of the 1 to 48 hour range, provides the claimed ratio. Therefore, a prima facie case of obviousness based on this combination has been properly presented.
Additionally, it is noted that the Board in SNF also rejected an optimization rationale noting that “there is no evidence to establish that skilled artisans knew that the claimed ratio was a parameter of importance worth optimizing” (applicant’s remarks at page 5). Here however, applicant’s specification explains that the inclusion of a heat treatment step at a lower temperature provides an improved crystal structure stability, due to inhibition of unwanted moisture penetration, compared to a process without a low temperature heat treatment step (applicant’s specification at paragraphs [0007-0009]). The addition of the lower heat treatment step necessitates the presence of the ratio. The Roh reference similarly teaches that a low temperature heat treatment at 1 to 48 hours is included in order to stabilize the crystal structure (Roh T022), the same or very similar benefit. Therefore, the Board would not find that a skilled artisan would be unaware that the additional heat treatment at a properly selected time would yield an improved crystal structure stability, with proper optimization of the second heat treatment time and implicitly a ratio of high and low heat treatment times. Thus, the SNF case law is not consistent to the fact fact pattern and considerations of the current rejection.
Regarding the rejection over a combination of Song and Kajima, the rejection is based in part on a finding that the 3 to 15 hour aging treatment of Kajima is sufficient to render obvious the 1 to 2 hour aging treatment of the presently claimed invention. Applicant respectfully disagrees that 2 hours (the top of the claimed aging step time range) would be considered close to 3 hours (the bottom of the Kajima aging step time range).
In response, the finding that the times are “close” is based on the evidence of record. Specifically, applicant’s specification suggests that the aging time suitable for the invention may be 1 to 4 hours, with the 1 to 2 hour subrange characterized as “preferably” used, but without and explanation as to why this subrange is substantially different from the broader 1 to 4 hour range (applicant’s paragraph [0060]). Thus, a skilled artisan at the time of invention would have found that the 3 hour aging time of Kajima is “close” to the claimed 1 to 2 hour aging time range at least because it lies within the time range disclosed as functionally suitable for carrying out the invention. It is noted that applicant’s specification gives Examples including aging treatments of 1, 1.5 and 2 hours, and a Comparative Example which omits any aging [or 500 °C annealing] step performed during the cooling, and instead cools directly from the sintering temperature to room temperature. The inclusion if a 3 hour aging is close to the claimed invention requiring 1 to 2 hour aging, particularly considering the context that a comparative example is an embodiment without any aging step.
The 8/25/25 Non-Final rejection at page 14 states, “It follows that values within ratio range of claims 1 could be achieved by coupling a 1 to 2 hour aging [or annealing] step with the 10 hour hour heat treatment suggested by Song so as to render the claimed range obvious”. Since 1 to 2 hour aging times are not disclosed by Song or Kajiyama, it is unclear why these values are being used for sample calculations.
In response, the Office agrees that the quoted line in the 8/25/25 Non-Final rejection is unclear, since the basis of obviousness is that the prior art aging process, including 3 hour aging, does not overlap with the claimed range of 1 to 2 hours, but nevertheless provides functionally similar results thereto. Therefore, the quoted line has been removed from this Final Rejection to improve clarity.
Applicant’s arguments against the Song-Kajima rejection based on SNF and the finding observation that Kajima teaches a different high temperature heat treatment time are not found to be persuasive for the same reasons as given above with respect to the Song-Roh rejection. Namely that that Song’s Example 1 establishes the 10 hour high temperature heat treatment time, which need not be modified by a teaching of Kajima, and Kajima teaches that a low temperature aging step is obvious to include for reasons given in the body of the rejection.
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 of this title, 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, 7 and 12-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination Song (US 2011/0305955) and Roh (KR 2013-0108717).
Regarding claim 1 and 14, Song teaches a method of preparing a positive electrode active material (see title),
the method consisting essentially of: forming a mixture by mixing a lithium raw material with a high nickel-containing transition metal hydroxide containing nickel in an amount of 33-80 mol % or more based on a total number of moles of the transition metal hydroxide (paragraph [0081], the “LiNi0.6Co0.2Mn0.2O2” produced product implies 60% Ni in the transition metal hydroxide),
sintering the mixture to prepare a positive electrode active material, wherein the sintering comprises a sintering step of heat-treating at a temperature within the range of 700° C to 900° C for a time within the range of 8 to 12 hours (“860° C … about 10 hours”, paragraph [0081]), and
a cooling step of cooling to room temperature (cooling to room temperature is an inevitable or at least obvious step as the product will ultimately be used or processed at room temperature).
Song is silent regarding the atmosphere during the higher temperature heat treating step and does not appear to teach the method wherein an aging step is included within the cooling process, the aging step maintaining the temperature in the reactor at 425 to 500 °C for 1 to 2 hours in an oxygen atmosphere.
However, since Song is silent, the atmosphere can be presumed to be an air atmosphere which is an oxygen atmosphere.
In the battery art, Roh teaches a method of making a positive electrode active material (T003) comprising performing a high temperature heat treatment of the forming compound in an oxygen atmosphere such as air or oxygen (T021), and subsequently performing an annealing [readable on claimed aging] step at 400 to 600 °C for 1 to 48 hrs in an oxygen atmosphere for the benefit of stabilizing the crystal structure of the forming compound (T022).
It would have been obvious to a person having ordinary skill in the art at the time of invention to perform the higher temperature heat treatment in an oxygen atmosphere, and maintain the temperature at in the reactor at 425 to 500 °C for 1 to 2 hours in an oxygen atmosphere during the cooling, as an annealing step, for the benefit of stabilizing the crystal structure of the forming compound as taught by Roh. Although the claimed ranges are narrower than the Roh anneal ranges, claimed invention is found to be obvious because the overlap in the anneal temperature range is substantial, and the skilled artisan would have found annealing time to be an obvious to optimize result-effective variable, with shorter times desirable in terms of process efficiency balanced with longer times possibly necessary to achieve an intended effect.
It is noted that the benefit suggested by Roh, i.e. stabilizing the crystal structure (T022) appears to be the same as or similar to the problem identified by and solved by applicant in adding an aging step to the sintering process, namely production of a more stable product compared to prior art process without an aging step (applicant’s specification at paragraphs [0007-0009]).
Song teaches a sintering time of 10 hours (paragraph [0030, 0081]) while Roh teaches an annealing [aging] time of 1 to 48 hrs (T022); however, the cited art does not teach wherein the holding time of the aging step relative to the sintering step is performed at a ratio of 10% to 20%.
However, it has been held that “[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… It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions”. (MPEP 2144.05 IIA)
Here, although Song and Roh do not teach the claimed percent ratio, coupling a 1 hour aging step in view of Roh with the 10 hour range suggested by Song yields an aging time which is 10% of the sintering time, thereby overlapping the claimed range and demonstrating that that the suggested scope of the prior art overlaps the claimed range. Moreover, as described above, Roh teaches a same or similar reason for adding the aging step as does applicant, namely to improve stability of the forming positive electrode compound relative to manufacturing techniques lacking an aging step. Therefore, notwithstanding the lack of an express teaching of a preferred ratio percentage as recited in claim 1, the prior art does teach that the sintering time and aging [annealing in Roh] time are result-effective variables which could be optimized in order to influence the properties of the forming positive electrode compound such as its stability. The claimed invention remains obvious, absent an indication that the claimed time ratio range would produce a substantially different product than that suggested by the prior art.
Regarding claim 7, the cited art remains as applied to claim 1. Song further teaches a metal hydroxide (NiCoMn)OH2 configured to produce the compound LiNi0.6Co0.2Mn0.2 as an exemplary embodiment (paragraph [0083]). The claimed hydroxide, Formula 1: NixCoyMnzM1w(OH)2, wherein, 0.6≤x≤1, 0≤y≤0.4, 0≤z≤0.4, and 0≤w≤0.01, is found to be obvious over Song because the hydroxide and metal oxide of paragraph [0083] together suggest a transition metal hydroxide having transition metal contents lying within the claimed ranges.
Regarding claims 12 and 13, the cited art remains as applied to claim 1. Claims 12 and 13 further require “wherein the positive electrode active material has a moisture content of 685 ppm or less”, or more narrowly 300 ppm to 685 ppm.
Song does not explicitly teach the positive electrode active material being characterized as having a moisture content within the range of 685 ppm to less”; however, it has been held that a “whereby [or wherein] clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited” (MPEP 2111.04 I).
In this case, the limitations do not set forth any new process limitations, but instead express an intended result of the method, namely the production of a positive electrode active material having the claimed low moisture content. Since the limitations of claims 12 and 13 do not set forth any new limitations, or modify any of the previously set forth limitations, the limitations are not found to patentably distinguish the claimed method which remains obvious over the cited art.
Claims 8-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Song (US 2011/0305955), Roh (KR 2013-0108717), Mitsumoto (US 2014/0353547), Yoshida (US 2016/0315316) or Washida (US 2017/0012286).
Regarding claims 8-11, Song teaches a method of making a positive electrode active material as described in the rejection of claim 1.
Song further teaches a lithium secondary battery, comprising a positive electrode [cathode], which comprises a positive electrode active material made by the Song method (Fig. 1; paragraphs [0050-0052] describe construction of a lithium secondary battery using Song positive electrode active material).
Song is silent as to the moisture content of the produced positive electrode active material; and therefore, does not expressly teach that the positive electrode active material should have a moisture content of 685 ppm or less, or more narrowly of 300-685 ppm.
However, Song further teaches that the positive electrode active material is made utilizing steps designed to minimize moisture in the formed product (e.g. the use of the use of a drying step at paragraph [0081]), thereby implying that the finally produced positive electrode active material would possess a low moisture content.
Moreover, in the battery art:
Mitsumoto teaches that when the moisture content of a transition metal oxide positive electrode active material is controlled to 0 to 400 ppm power output retention and capacity retention can be increased (paragraph [0050]) and that prior art positive electrode active materials may have higher ppm moisture, such as 500 ppm moisture (Comparative Example 1 at Table 3).
Yoshida teaches that a lithium positive electrode active material comprising a low moisture content, such as less than 400 ppm, improves safety and performance of a battery (paragraphs [0019, 0063]).
Washida teaches that a lithium composite oxide positive electrode active material may be configured to have a moisture content of 50 to 1000 ppm for the benefit of balancing reaction with possible surface coupling agents and desirable cell characteristics (paragraph [0111]).
Thus, the requirement that that the moisture content is 685 ppm or less, or more narrowly 300 ppm to 685 ppm, is found to be obvious, as either being implicitly present based on the Song teaching of using a drying step, or otherwise is obvious over Song in view of Mitsumoto, Yoshida or Washida for the benefit of improving battery properties such as power retention, safety, performance, and other cell characteristics.
Regarding claims 12 and 13, the cited art remains as applied to claim 1. Claims 12 and 13 further require “wherein the positive electrode active material has a moisture content of 685 ppm or less”, or more narrowly 300 ppm to 685 ppm.
Song does not explicitly teach the positive electrode active material being characterized as having a moisture content within the range of 685 ppm to less”; however, it has been held that a “whereby [or wherein] clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited” (MPEP 2111.04 I).
In this case, the limitations do not set forth any new process limitations, but instead express an intended result of the method, namely the production of a positive electrode active material having the claimed low moisture content. Since the limitations of claims 12 and 13 do not set forth any new limitations, or modify any of the previously set forth limitations, the limitations are not found to patentably distinguish the claimed method which remains obvious over the cited art.
Alternatively, even if the limitations of claim 12 and 13 were found to be limiting of the claimed method, notwithstanding the lack of association with any of the claimed method steps, the claimed invention remains obvious over the cited art.
Specifically, Song further teaches that the positive electrode active material is made utilizing steps designed to minimize moisture in the formed product (e.g. the use of a drying step at paragraph [0081]), thereby implying that the finally produced positive electrode active material would possess a low moisture content.
Moreover, in the battery art:
Mitsumoto teaches that when the moisture content of a transition metal oxide positive electrode active material is controlled to 0 to 400 ppm power output retention and capacity retention can be increased (paragraph [0050]) and that prior art positive electrode active materials may have higher ppm moisture, such as 500 ppm moisture (Comparative Example 1 at Table 3).
Yoshida teaches that a lithium positive electrode active material comprising a low moisture content, such as less than 400 ppm, improves safety and performance of a battery (paragraphs [0019, 0063]).
Washida teaches that a lithium composite oxide positive electrode active material may be configured to have a moisture content of 50 to 1000 ppm for the benefit of balancing reaction with possible surface coupling agents and desirable cell characteristics (paragraph [0111]).
Thus, the requirement that that the moisture content is 685 ppm or less, or more narrowly 300 ppm to 685 ppm, is found to be obvious, as either being implicitly present based on the Song teaching of using a drying step, or otherwise is obvious over Song and Roh in view of Mitsumoto, Yoshida or Washida for the benefit of improving battery properties such as power retention, safety, performance, and other cell characteristics.
Claims 1, 7 and 12-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Song (US 2011/0305955) and Kajiyama (US 2019/0115596).
Regarding claim 1 and 14, Song teaches a method of preparing a positive electrode active material (see title),
the method consisting essentially of: forming a mixture by mixing a lithium raw material with a high nickel-containing transition metal hydroxide containing nickel in an amount of 33-80 mol % or more based on a total number of moles of the transition metal hydroxide (paragraph [0081], the “LiNi0.6Co0.2Mn0.2O2” produced product implies 60% Ni in the transition metal hydroxide),
sintering the mixture to prepare a positive electrode active material, wherein the sintering comprises a sintering step of heat-treating at a temperature within the range of 700° C to 900° C for a time within the range of 8 to 12 hours (“860° C … about 10 hours”, paragraph [0081]), and
a cooling step of cooling to room temperature (cooling to room temperature is an inevitable or at least obvious step as the product will ultimately be used or processed at room temperature).
Song is silent regarding the atmosphere during the higher temperature heat treating step and does not appear to teach the method wherein an aging step is included within the cooling process, the aging step maintaining the temperature at in the reactor at 425 to 500 °C for 1 to 2 hours in an oxygen atmosphere.
However, since Song is silent, the atmosphere can be presumed to be an air atmosphere which is an oxygen atmosphere.
In the battery art, Kajiyama teaches a method of making a positive electrode active material (paragraph [0020]) comprising performing a high temperature heat treatment of the forming compound in an oxygen atmosphere for the benefit of improving battery performance (paragraphs [0044-0045]), and subsequently performing an annealing [readable on claimed aging] step at 500 to 750 °C for preferred time of 3 to 15 hrs in an oxygen atmosphere for the benefit of inhibiting variation in the composition of the forming positive electrode active material (paragraphs [0046]). Kajiyama further explicitly teaches that the annealing step can be performed during the cooling (paragraph [0039]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to perform the higher temperature heat treatment in an oxygen atmosphere, and maintain the temperature at in the reactor at 500 to 750 °C for 3 to 15 hours in an oxygen atmosphere during the cooling, as an annealing step, for the benefit of improving performance and reducing the compositional variation of the forming compound as taught by Kajiyama.
The annealing treatment step overlaps the claimed aging temperature at least at 500 °C, rendering the claimed temperature range obvious due to overlapping ranges.
As to the time range of the annealing/aging step, the preferred range of Kajima, 3 to 15 hours, does not overlap the claimed range of 1 to 2 hours. However, as described in MPEP 2144.05, a prima facie case of obviousness may exist when the range disclosed by the prior art does not overlap the claimed range, but is merely close, particularly absent any evidence that the difference is critical. In this case, the 1 to 2 hour claimed range is close to and obvious over the 3 to 15 hour preferred range of the prior art because both times are selected in order to allow a thermal process to occur during the cooling step. It is noted that applicant’s specification gives Examples including an aging treatments of 1, 1.5 and 2 hours, and a Comparative Example which omits any aging [or 500 °C annealing] step performed during the cooling, and instead cools directly from the sintering temperature to room temperature. However, Kajiyama teaches to include a 3 hour heat treatment during the cooling so the Comparative Example is not comparable to Kajiyama’s suggestion. The claimed invention is found to be obvious because the skilled artisan would have found annealing time to be an obvious to optimize result-effective variable, with shorter times desirable in terms of process efficiency balanced with longer times possibly necessary to achieve an intended effect.
The cited art does not teach wherein the holding time of the aging step relative to the sintering step should performed at a ratio of 10% to 20%.
However, Song does teach a sintering time of 10 hours (paragraph [0030]) while Kajiyama teaches an annealing [aging] time of as low as 3 hrs (paragraph [0046]), suggesting a ratio of 30%.
Although the ratio of 30% lies outside the presently claimed range of 10 to 20%, it has been held that a prima facie case of obviousness exists when the range suggested by the prior art does not overlap the claimed range, but is merely close, absent a showing that the claimed range provides different properties than that suggested by the prior art (MPEP 2144.05 I), as discussed above.
Moreover, it has been held that “[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… It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions”. (MPEP 2144.05 IIA)
Here, although Song and Kajiyama do not teach the claimed percent ratio, the lower times of the claimed aging step, 1 to 2 hours, are found to be obvious in view of Kajiyama’s annealing step for reasons described above. In other words, since the difference in time discussed above is found to be obvious (1 to 2 hours aging in claimed invention vs 3 hour aging in view of Kajiyama), notwithstanding the acknowledged existence of the difference in time, it follow that the 10% to 20% ratio set forth in claim 1 is also obvious for similar rationale in that the sintering time and aging [annealing in Kajiyama] time are result-effective variables which could be optimized in order to influence the properties of the forming positive electrode compound such as its homogeneity. Thus, the claimed invention remains obvious, absent an indication that the claimed time ratio range would produce a substantially different product than that suggested by the prior art.
Regarding claim 7, the cited art remains as applied to claim 1. Song further teaches a metal hydroxide (NiCoMn)OH2 configured to produce the compound LiNi0.6Co0.2Mn0.2 as an exemplary embodiment (paragraph [0083]). The claimed hydroxide, Formula 1: NixCoyMnzM1w(OH)2, wherein, 0.6≤x≤1, 0≤y≤0.4, 0≤z≤0.4, and 0≤w≤0.01, is found to be obvious over Song because the hydroxide and metal oxide of paragraph [0083] together suggest a transition metal hydroxide having transition metal contents lying within the claimed ranges.
Regarding claims 12 and 13, the cited art remains as applied to claim 1. Claims 12 and 13 further require “wherein the positive electrode active material has a moisture content of 685 ppm or less”, or more narrowly 300 ppm to 685 ppm.
Song does not explicitly teach the positive electrode active material being characterized as having a moisture content within the range of 685 ppm to less”; however, it has been held that a “whereby [or wherein] clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited” (MPEP 2111.04 I).
In this case, the limitations do not set forth any new process limitations, but instead express an intended result of the method, namely the production of a positive electrode active material having the claimed low moisture content. Since the limitations of claims 12 and 13 do not set forth any new limitations, or modify any of the previously set forth limitations, the limitations are not found to patentably distinguish the claimed method which remains obvious over the cited art.
Claims 8-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Song (US 2011/0305955), Kajiyama (US 2019/0115596), Mitsumoto (US 2014/0353547), Yoshida (US 2016/0315316) or Washida (US 2017/0012286).
Regarding claims 8-11, Song teaches a method of making a positive electrode active material as described in the rejection of claim 1.
Song further teaches a lithium secondary battery, comprising a positive electrode [cathode], which comprises a positive electrode active material made by the Song method (Fig. 1; paragraphs [0050-0052] describe construction of a lithium secondary battery using Song positive electrode active material).
Song is silent as to the moisture content of the produced positive electrode active material; and therefore, does not expressly teach that the positive electrode active material should have a moisture content of 685 ppm or less, or more narrowly of 300-685 ppm.
However, Song further teaches that the positive electrode active material is made utilizing steps designed to minimize moisture in the formed product (e.g. the use of the use of a drying step at paragraph [0081]), thereby implying that the finally produced positive electrode active material would possess a low moisture content.
Moreover, in the battery art:
Mitsumoto teaches that when the moisture content of a transition metal oxide positive electrode active material is controlled to 0 to 400 ppm power output retention and capacity retention can be increased (paragraph [0050]) and that prior art positive electrode active materials may have higher ppm moisture, such as 500 ppm moisture (Comparative Example 1 at Table 3).
Yoshida teaches that a lithium positive electrode active material comprising a low moisture content, such as less than 400 ppm, improves safety and performance of a battery (paragraphs [0019, 0063]).
Washida teaches that a lithium composite oxide positive electrode active material may be configured to have a moisture content of 50 to 1000 ppm for the benefit of balancing reaction with possible surface coupling agents and desirable cell characteristics (paragraph [0111]).
Thus, the requirement that that the moisture content is 685 ppm or less, or more narrowly 300 ppm to 685 ppm, is found to be obvious, as either being implicitly present based on the Song teaching of using a drying step, or otherwise is obvious over Song in view of Mitsumoto, Yoshida or Washida for the benefit of improving battery properties such as power retention, safety, performance, and other cell characteristics.
Regarding claims 12 and 13, the cited art remains as applied to claim 1. Claims 12 and 13 further require “wherein the positive electrode active material has a moisture content of 685 ppm or less”, or more narrowly 300 ppm to 685 ppm.
Song does not explicitly teach the positive electrode active material being characterized as having a moisture content within the range of 685 ppm to less”; however, it has been held that a “whereby [or wherein] clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited” (MPEP 2111.04 I).
In this case, the limitations do not set forth any new process limitations, but instead express an intended result of the method, namely the production of a positive electrode active material having the claimed low moisture content. Since the limitations of claims 12 and 13 do not set forth any new limitations, or modify any of the previously set forth limitations, the limitations are not found to patentably distinguish the claimed method which remains obvious over the cited art.
Alternatively, even if the limitations of claim 12 and 13 were found to be limiting of the claimed method, notwithstanding the lack of association with any of the claimed method steps, the claimed invention remains obvious over the cited art.
Specifically, Song further teaches that the positive electrode active material is made utilizing steps designed to minimize moisture in the formed product (e.g. the use of a drying step at paragraph [0081]), thereby implying that the finally produced positive electrode active material would possess a low moisture content.
Moreover, in the battery art:
Mitsumoto teaches that when the moisture content of a transition metal oxide positive electrode active material is controlled to 0 to 400 ppm power output retention and capacity retention can be increased (paragraph [0050]) and that prior art positive electrode active materials may have higher ppm moisture, such as 500 ppm moisture (Comparative Example 1 at Table 3).
Yoshida teaches that a lithium positive electrode active material comprising a low moisture content, such as less than 400 ppm, improves safety and performance of a battery (paragraphs [0019, 0063]).
Washida teaches that a lithium composite oxide positive electrode active material may be configured to have a moisture content of 50 to 1000 ppm for the benefit of balancing reaction with possible surface coupling agents and desirable cell characteristics (paragraph [0111]).
Thus, the requirement that that the moisture content is 685 ppm or less, or more narrowly 300 ppm to 685 ppm, is found to be obvious, as either being implicitly present based on the Song teaching of using a drying step, or otherwise is obvious over Song and Kajiyama in view of Mitsumoto, Yoshida or Washida for the benefit of improving battery properties such as power retention, safety, performance, and other cell characteristics.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/JEREMIAH R SMITH/Primary Examiner, Art Unit 1723
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