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 .
Response to Amendment
The amendment filed 6/22/2026 is entered and fully considered.
In view of the amendments the 112 rejections are removed. In addition, the limitations from 51 and 62 are brought into independent form and a new rejection to claim 50 is made.
Response to Arguments
Applicant argues the cited prior art does not teach the inhomogeneity of the lithium stuffed garnet thin film with respect to a normal axis while be substantially homogenous with respect to the parallel axis to the top surface. Substantially homogenous is defined in the specification as being a variation not more than 5%. The previous rejection relied on KANAMURA to teach inhomogenous solid electrolyte structure because it incorporated a dense surface portion with a porous bulk portion. Accordingly, along an axis normal to the surface the solid electrolyte is inhomogenous because it is porous and dense. Along the planar axis parallel to the surface, the solid electrolyte is either in the porous portion or in the dense portion. In either instance, the parallel axis is essentially uniform (substantially homogenous) because there is no indication there is any variation within in any layer.
Applicant notes that the KANAMURA reference does not teach the density as 94-99.9999%. The examiner agrees and relied on LI to teach the particular density of a cross section determined from SEM. Specifically, KANAMURA teaches using a dense layer of garnet solid electrolyte (with the porous layer) but does not expressly teach what density to use. However, LI teaches a dense garnet solid electrolyte layer, such as the dense layer in KANAMURA used with a porous layer can be 96% which falls within the claimed range. The dense garnet solid electrolyte layer has improved conductivity which is desirable.
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) 50, 52-57 and 64-68 is/are rejected under 35 U.S.C. 103 as being unpatentable over KANAMURA et al. (US 2009/0229700) in view of WACHSMAN et al. (US 2014/0287305) and LI et al. “Densification and ionic-conduction improvement of lithium garnet solid electrolytes by flowing oxygen sintering” (Oct. 2013).
Regarding claims 50 and 52,
KANAMURA teaches a solid electrolyte (inhomogenous) that includes a porous portion (bulk) and a dense portion (surface) abstract and [0056]. The porous portion of the solid electrolyte is loaded with active material [0058]. The porous layer is can be formed on only one surface of the dense solid electrolyte [0071] (a “top” surface and with a bulk layer) The reference does not expressly teach a current collector in contact (stacked) with the electrode layer. However, one of ordinary skill in the art would recognize that a completed cell would require a current collector in electrical connection with the electrodes. For example, WACHSMAN teaches anode and cathode in contact with current collectors in a completed cell [0016] and Fig. 3. At the time of filing the invention it would have been prima facie obvious to include current collectors in contact with the electrode materials as a known cell architecture for functioning batteries.
KANAMURA teaches a dense solid electrolyte but does not expressly teach the density as a percent. However, LI teaches that when making a garnet solid electrolyte the density can be 96% abstract. The high density is achieved by controlling atmosphere to be an oxygen atmosphere and is comparable to densities obtained by hot pressing results page 643. The oxygen sintered sample has the highest conductivity. At the time of filing the invention it would have been prima facie obvious to make a solid electrolyte according to LI to improve conductivity of the solid electrolyte.
Regarding claim 53-55,
KANAMURA teaches a dense portion of the solid electrolyte which is less porous than the specifically porous layer by definition. Insofar as the dense portion of the solid electrolyte has pores, the pores will be smaller in terms of both volume and aspect ratio (size). The reference does not expressly state there are pores present. However, LI clearly shows that a “dense” solid electrolyte will still contain some pores. At the time of filing the invention one of ordinary skill in the art could use a dense solid electrolyte layer that still contains pores according to LI as a known morphology of “dense” solid electrolytes.
Regarding claim 56 and 57,
KANAMURA teaches a dense portion of the solid electrolyte with lower porosity. The pores are “defects” as defined by applicant. Accordingly, the dense layer will have lower surface defects than the porous (bulk) layer.
Regarding claim 64,
When using the oxygen rich atmosphere to make the dense solid electrolyte, the oxygen diffuses into oxygen vacancies, LI page 645. When making the porous solid electrolyte layer, there is no need to use the oxygen atmosphere and the oxygen vacancies will remain unfilled, and therefore there will be inhomogenous oxygen vacancies between the dense and porous layers when incorporating the techniques of LI.
Regarding claim 65,
WACHSMAN teaches the current collectors can be aluminum (anode) or copper (cathode) Fig. 3.
Regarding claims 66-67,
KANAMURA teaches the solid electrolyte can be LLZ type [0104]. The WACHSMAN reference Fig. 4a teaches the same LLZ type of solid electrolyte and specifically teaches cubic and tetragonal stoichiometric structure which fall within the generic formulas (when Al2O3 is not present; q=0).
Regarding claim 68,
KANAMURA does not teach the thicknesses of the solid electrolyte and porous solid electrolyte used in the electrode layers. However, WACHSMAN teaches anodes and cathodes can have a thickness of 20-200µm [0041] when the dense region can be 1-100µm [0052]. A single electrode (porous bulk) formed on a dense (top surface) layer will have a total thickness of 21-300µm which overlaps the claimed range and is considered prima facie obvious, MPEP 2144.05.I. In addition the examiner notes that thicker electrodes hold more active material which increases capacity, but also decrease conductivity because there is more material to pass through.
Claim(s) 57-59 is/are rejected under 35 U.S.C. 103 as being unpatentable over KANAMURA et al. (US 2009/0229700) in view of WACHSMAN et al. (US 2014/0287305) and LI et al. “Densification and ionic-conduction improvement of lithium garnet solid electrolytes by flowing oxygen sintering” (Oct. 2013) further in view of ALLIE et al. (US 2017/0179472).
Regarding claims 57-59,
KANAMURA teaches making a dense portion of a solid electrolyte but does not expressly teach the number of “defects” in the layer. However, ALLIE teaches that a defect free solid electrolyte layer can be made using a hot pressing [0081]. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to have a defect density of 0 (less than 1 defect per 1 cm2 or mm2) using known techniques for making dense solid electrolyte separators because elimination of defects is desirable by definition.
Claim(s) 60, 61, and 63 is/are rejected under 35 U.S.C. 103 as being unpatentable over KANAMURA et al. (US 2009/0229700) in view of WACHSMAN et al. (US 2014/0287305) and LI et al. “Densification and ionic-conduction improvement of lithium garnet solid electrolytes by flowing oxygen sintering” (Oct. 2013) further in view of CHENG et al. “Effect of Surface Microstructure on Electrochemical Performance of Garnet Solid Electrolytes” (Jan 2015).
Regarding claims 60, 61, and 63
KANAMURA teaches a dense and porous layer of solid electrolyte but does not teach an inhomogenous grain size. However, CHENG teaches that using different microstructures (layers with smaller and larger grains) the battery cycling behavior can be improved results page 2076. At the time of filing the invention it would have been prima facie obvious to one of ordinary skill in the art to have an inhomogenous grain size in the layers of solid electrolyte to improve cycling. Larger grains will have lower density (grains per area).
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AUSTIN MURATA whose telephone number is (571)270-5596. The examiner can normally be reached M-F 8:30-5.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, MICHAEL CLEVELAND can be reached at 571272-1418. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/AUSTIN MURATA/Primary Examiner, Art Unit 1712
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