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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 3 September 2026 has been entered.
Status of Claims
Claims 1, 2, 4 and 12 are amended. Claims 8-11 are cancelled. Claims 1-2, 4 and 12, as filed 3 September 2026, are examined herein. No new matter is included.
Response to Arguments
The affidavit submitted on 3 September 2026 has been fully considered.
Regarding the rejection under 35 USC 103, Applicant argues that Sugiura’s heat treatment at 900-1100 ˚C followed by cooling at 200 ˚C/hour is not compatible with Tsukasaki’s Li2S-P2S5 solid electrolyte, which crystallizes above 180-200 ˚C, causing a catastrophic loss of ionic conductivity. Therefore, a PHOSITA would not modify Tsukasaki with Sugiura. Applicant further argues that Sugiura’s porosity range of 3-15% is designed for a liquid electrolyte battery, therefore the range should not be applied to solid electrolytes. This is persuasive. Applicant further argues that the instant invention achieves a unique 3D solid-solid contact network maximizing solid-to-solid conduction paths. Applicant further argues unexpected results and critical threshold effects. Applicant’s arguments are moot in light of a newly cited reference, Bielefeld.
Claim Interpretation
Claim 1 includes the limitation “a porosity … is between 8.1% and 10.1%.” The broadest reasonable interpretation of the instant claim limitation is determined to include that the porosity is measured in volume %.
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.
Claim(s) 1-2, 4 and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Iwane (WO 2021131467 A1, with paragraph numbering from US 20220320590 A1) in view of Nagakane (JP 2013097892 A), using the English translation provided by Applicant, in view of Bielefeld (Bielefeld, Anja, Dominik A. Weber, and Jürgen Janek. "Microstructural modeling of composite cathodes for all-solid-state batteries." The journal of physical chemistry C 123.3 (2019): 1626-1634)
Regarding claim 1, Iwane teaches all-solid lithium-ion secondary battery (abstract) comprising a positive electrode active material layer (abstract) which contains a positive electrode active material (abstract) and a solid electrolyte ([0077] “crystalline solid electrolyte – Li2S-P2S5), wherein an D50 of the positive electrode active material A is ([0024]) “more preferably 1.0 µm to 4.5 µm”) and teaches [0122] that the particles are made from LiCoO2 and cobalt oxide by sintering. However, Iwane does not clarify if the particles are secondary (composite) particles. Iwane’s taught diameter overlaps the claimed range of secondary particles, (3.6 µm to 4.9 µm). Iwane further teaches that the positive electrode active material consists of ([0039]) a layered rock salt-type structure, which is within the scope of the claimed list of alternatives.
Iwane does not explicitly teach the positive electrode active material consisting of secondary particles and does not explicitly teach an average particle diameter of the primary particles is 1.2 µm to 2.3 µm. Iwane does not disclose an average particle diameter of the primary particles of the solid electrolyte.
Nagakane discloses (abstract) discloses a positive electrode material for lithium-ion secondary batteries. Nagakane at [0015] discloses the use of secondary particles of the positive active material, which allows for uniform dispersion of the solid electrolyte and increased specific surface area, “thus the number of sites for releasing and occluding lithium ions can be increased.” The person of ordinary skill would be motivated to replace the particle of Iwane with the secondary particle of Nagakane, with a reasonable expectation of successfully improving dispersing of the solid electrolyte and increasing the number of sites to release and occlude lithium ions.
At [0029] Nagakane discloses the primary particle diameter of the positive active material may be 1.8 µm or less. (overlaps the claimed range of 1.3 – 2.3 µm) Nagakane discloses that if the primary particle is too large, the specific surface area will be too low, causing less ion diffusion, and that if the primary particle is too small, the aggregation force between the particles becomes too strong.
A person of ordinary skill in the art would have been motivated, as of before the effective filing date of the instant invention, to optimize the primary particle size of modified Iwane’s active particle, based on the teachings of Nagakane, with a reasonable expectation of balancing ion diffusion and aggregation forces, and achieving a successful secondary particle, thus meeting the instant claim limitation.
Nagakane further discloses [0063-0064] a glass-like solid electrolyte, which may have a particle size between 0.1 and 10 µm. (Overlaps the claimed range of < 0.8 µm.) Nagakane discloses that if the particle is too small, secondary aggregation may cause the ion conductivity to be lowered. If the particle is too large, ion conductivity may be lowered.
A person of ordinary skill in the art would have been motivated, as of before the effective filing date of the instant invention, to optimize the primary particle size of Iwane’s solid electrolyte, based on the teachings of Nagakane, with a reasonable expectation of achieving good ion conductivity, thus meeting the instant claim limitation.
Iwane and Nagakane are both silent on the porosity of the positive active material layer and are therefore silent on wherein a porosity of the positive electrode active material layer is between 8.1% and 10.1%.
Bielefeld, in the field of (abstract) solid state battery composite cathodes, discloses (page 1627 col. 2) the modeling of composite cathodes for ASSB having active material, solid electrolyte, a conductive agent, a binder, and a pore volume. This modeling includes active materials having a 4 µm particle size, which falls within the claimed range of 3.6-4.9 µm. (see FIG. 5). At page 1631, it is desirable to have a high utilization level of active material and also a high specific active interface area between ionic and electronic conduction clusters. At FIG. 8, which is modeled using a 5 µm active material particle, the volume percent composition of active material versus solid electrolyte is plotted versus specific active interface area, where 5% and 10% porosity shows a much better result than 20% porosity.
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Bielefeld FIG. 8
At FIG. 9, a high utilization level for both active material and solid electrolyte is achieved for any porosity level less than about 22%. At page 1633, col. 1, “porosity has shown to be an important property for ASSB composite electrodes that can crucially influence conduction clusters and therefore cell performance”
Bielefeld’s modeling used (page 1628) lithium thiophosphate (LPS) solid electrolyte, with (Table 1) a particle size of 3 µm, which is slightly larger than the claimed range of 1.2-2.3 µm. While this is not exactly the electrolyte chemistry of the instant invention, and the particle size of the solid electrolyte is larger (3 µm for Bielefeld versus 1.2-2.3 µm for the instant invention), a person of ordinary skill would understand from Bielefeld that a) porosity in the range of 5-10% provides the highest possible specific active interface area, which is desirable, and b) that optimizing of porosity is expected to improve battery performance, and therefore the person of ordinary skill in the art would have been motivated to optimize the porosity of the active material layer of modified Iwane, to obtain improved performance properties, with a reasonable expectation of success, thus rendering obvious the selection of a porosity value in the claimed range.
Regarding claim 2, Iwane in view of Nagakane and Bielefeld teaches all of the limitations as set forth above, however Iwane does not explicitly teach wherein a ratio of a content of the positive electrode active material to a total content of the positive electrode active material and the solid electrolyte in the positive electrode active material layer is 70 vol% or more.
Iwane discloses ([0043] positive electrode layer is preferably 60% to 90% by mass) and further discloses higher levels of active material will prevent peeling.
A person of ordinary skill in the art would have been motivated, as of before the effective filing date of the instant invention, to optimize the amount of positive active material in modified Iwane’s positive electrode layer, in order to prevent peeling, with a reasonable expectation of achieving an electrolyte layer meeting the instant claimed volume percent.
Regarding claim 4, Iwane in view of Nagakane and Bielefeld teaches all of the limitations as set forth above, and Iwane further teaches wherein the positive electrode active material includes ([0041]) LiNMC. This candidate is within the scope of the claimed list of alternatives.
Regarding claim 12, Iwane in view of Nagakane and Bielefeld teaches all of the limitations as set forth above, and Iwane teaches wherein the positive electrode active material layer consists of the positive electrode active material and the sulfide solid electrolyte. ([0019]) However Iwane does not explicitly teach wherein the positive electrode active material layer further includes a conductive aid.
Nagakane discloses [0053-0054] that the positive electrode active material may be coated with graphite, acetylene black, or amorphous carbon, acting as a conductive additive for imparting conductivity.
A person of ordinary skill in the art would have been motivated, as of before the effective filing date of the instant invention, to modify the positive electrode active material layer of modified Iwane by adding the graphite of Nagakane, with a reasonable expectation of successfully achieving a desired level of electrical conduction.
Conclusion
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CLAIRE A. RUTISER
Examiner
Art Unit 1751
/C.A.R./Examiner, Art Unit 1751
/Haroon S. Sheikh/Primary Examiner, Art Unit 1751
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