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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 08/19/2025 has been entered.
Information Disclosure Statement
The information disclosure statement filed 08/26/2025 fails to comply with 37 CFR 1.98(a)(2), which requires a legible copy of each cited foreign patent document; each non-patent literature publication or that portion which caused it to be listed; and all other information or that portion which caused it to be listed. It has been placed in the application file, but the information referred to therein has not been considered.
Response to Amendment
This is a non-final Office action in response to Applicant’s remarks and amendments filed on 08/19/2025. Claims 7 and 16 are amended. Claim 1 – 6 remain withdrawn. Claims 7 – 22 are pending review in the current Office action.
Response to Arguments
Applicant’s arguments with respect to claim(s) 7 and 16 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Specifically, the examiner utilizes a prior art combination and teachings which was not previously relied upon to reject claims 7 and 16 {i.e. Yubuchi in view of Zhou}.
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) 7, 9 – 15, and 16 – 22 are rejected under 35 U.S.C. 103 as being unpatentable over Yubuchi (An argyrodite sulfide-based superionic conductor synthesized by a liquid-phase technique with tetrahydrofuran and ethanol. Journal of Materials Chemistry A, 7(2), pp.558-566, First published Nov. 19th, 2018) in view of Zhou (Solvent-engineered design of argyrodite Li6PS5X (X= Cl, Br, I) solid electrolytes with high ionic conductivity. ACS Energy Letters, 4(1), pp.265-270 with Supporting Information, pp. S1 – S12). {Examiner Note: All prior art was cited in the previous Office action mailed 05/23/2025}
Regarding Claim 7, Yubuchi discloses a method for synthesizing lithium argyrodites (Fig. 1; Last paragraph of Introduction section, pg. 559), comprising dissolving a mixture of precursors in a solvent or a solvent mixture (Fig. 1 and First paragraph of Material synthesis section, pg. 559), wherein one of the precursors is a solid Li3PS4-containing precursor, that is a THF-based, solid Li3PS4 containing suspension (First paragraph of Material synthesis section, pg. 559).
Yubuchi further discloses wherein a precursor other than the Li3PS4-containing precursor is added to the solvent or solvent mixture before the Li3PS4-containing precursor is added to the same solvent or solvent mixture, that is Yubuchi teaches adding the precursors Li2S and LiBr to an ethanol solvent prior to adding the THF-based, solid Li3PS4 containing suspension to the same ethanol solvent (Fig. 1 and first paragraph of Material synthesis section, pg. 559).
However, since Yubuchi teaches adding the Li3PS4-containing precursor in the form of suspension, Yubuchi does not explicitly disclose adding the Li3PS4-containing precursor without additional liquid to the same solvent or solvent mixture.
Zhou teaches solvent-engineered lithium argyrodites represented by Li6PS5X where X is Cl, Br, I (Second paragraph in left column on pg. 266). In the method of preparation, Zhou teaches using Li2S, Li3PS4·3THF, and LiX (X = Cl, Br, I) as the precursors and THF and ethanol as the solvents (Second paragraph in left column on pg. 266). Furthermore, Zhou’s taught method of preparation includes a drying step and an annealing step (Second paragraph in left column on pg. 266 and first paragraph of Experimental section in Supporting Information pg. S2). In Zhou the Li3PS4·3THF precursor is also taught to be in the form of a suspension; however Zhou also teaches, as an alternative to the suspension form of the precursor, that powder Li3PS4∙3THF can be used (First paragraph and second paragraph of Experimental section in Supporting Information pg. S2).
Since Zhou’s method steps for the powder Li3PS4·3THF precursor are similar to the steps taught by Yubuchi, and since Zhou teaches that powder Li3PS4·3THF is a viable, more direct alternative to the suspension form of the precursor (Second paragraph of Experimental section in Supporting Information pg. S2), it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to directly use Li3PS4·THF powder as the Li3PS4-containing precursor of Yubuchi, and thus obtain the claimed method step, because such a modification would be, as shown by Zhou, a selection of a functionally equivalent precursor recognized in the art and one with ordinary skill in the art would have a reasonable expectation of success in doing so [See MPEP2144.06(II)].
Yubuchi further discloses drying the mixture at 150°C, which is within the claimed range of above about 22°C in a chamber under vacuum to yield a precipitate (First paragraph of Material synthesis section, pg. 559) and annealing the precipitate at a temperature of 550°C, which is within the claimed range of higher than 150°C, under dry Ar, which is an inert gas atmosphere, to yield a lithium compound having an argyrodite crystal structure (First paragraph of Material synthesis section, pg. 559 and Right column paragraph of Electrolyte characterization section, pg. 561).
Regarding Claim 9, modified Yubuchi discloses all limitations as set forth above. Yubuchi teaches measuring the ion conductivity of the Li6PS5Br solid electrolyte using lithium ion blocking Au/SE/Au cells by applying impedance spectroscopic analysis (First paragraph in right column of Electrolyte characterization section, pg. 562). The measured ion conductivities of the electrolyte samples varied based on factors such as heat treatment temperature, molding pressure, pellet form {i.e. sintered/green compact} (Refer to Table 2 and first paragraph in right column of Electrolyte characterization section, pg. 562). At a heat treatment temperature of 150°C, the sample provided a room temperature ion conductivity as low as 0.13 mS cm-1 and at a heat temperature of 550°, the sample provided a room temperature ion conductivity as high as 1.9 mS cm-1 (Table 2).
In the instant specification, ion conductivity is taught to be measured through an electrochemical impedance spectroscopy method in the frequency range from 1 MHz to 100 mHz with an amplitude of 100 mV using Bio-Logic VSP300 and further, for the measurements, dense pellets prepared by cold pressing with C/Al as blocking electrodes were used ([0077]).
Yubuchi does not explicitly disclose wherein the lithium compound having an argyrodite crystal structure exhibits an ionic conductivity in the range of 0.1 mS cm-1 to 0.6 mS cm-1 at about 22°C; however, since the testing conditions and preparation method appear to affection the measured ion conductivity (First paragraph in right column of Electrolyte characterization section, pg. 562), one with ordinary skill in the art would reasonably expect the solid electrolyte of modified Yubuchi (given the same test/operation condition), at about 22°C, to exhibit an ion conductivity within the claimed range, because modified Yubuchi discloses a preparation method and solid electrolyte with the scope of the preparation method and solid electrolyte composition disclosed/claimed by the applicant (Instant specification: [0077];[0089];[0093];[0101]) to provide such a conductivity.
Regarding Claim 10, modified Yubuchi discloses all limitations as set forth above. Yubuchi teaches an example of the prepared solid electrolyte material, Li6PS5Br, having a conductivity of 3.1 mS cm-1 at 25°C (Table 2; First paragraph in right column of Electrolyte characterization section, pg. 562).
Yubuchi does not particularly teach the lithium compound having an argyrodite crystal structure exhibiting an ionic conductivity of at least 1.5 mS cm-1 at 90°C; however, since the conductivity of the material is shown to increase with temperature (Refer to Fig. 3), and Yubuchi already teaches measuring, at 25°C, an ionic conductivity as high as 1.9 mS cm-1, one with ordinary skill in the art would reasonably expect Yubuchi’ s lithium argyrodite material to have, at 90°C, an ionic conductivity within the claimed range of at least 1.5 mS cm-1.
Regarding Claim 11, modified Yubuchi discloses all limitations as set forth above. The Li3PS4-THF precursor of modified Yubuchi is a powder Li3PS4-THF precursor; therefore, in modified Yubuchi the precursors comprise Li2S combined with Li3PS4-THF (Yubuchi: First paragraph of Material synthesis section, pg. 559 and Zhou: Second paragraph of Experimental section in Supporting Information pg. S2), which is within the claimed selection of Li3PS4, Li3PS4-ACN, or Li3PS4-THF.
Regarding Claim 12, modified Yubuchi discloses all limitations as set forth above. The Li3PS4-THF precursor of modified Yubuchi is a powder Li3PS4-THF precursor; thus, in modified Yubuchi the precursors comprise Li3PS4, Li2S, and LiBr (Fig. 1; First paragraph of Material synthesis section, pg. 559 and Zhou: Second paragraph of Experimental section in Supporting Information pg. S2), which is within the claimed scope of LiX, where X represents at least one halide or a combination of halides
Regarding Claim 13, modified Yubuchi discloses all limitations as set forth above. Figure 2(c) in Yubuchi shows the crystal structure of the prepared lithium argyrodite, Li6PS5Br (Refer to LP-550 pattern). Within the figure, a peak is shown at about 2θ = 25°, 2θ = 30°, and 2θ = 31°;therefore, Yubuchi’ s lithium compound having an argyrodite crystal structure has the claimed XRD pattern of a peak at 26 +/- 1 degree, a second peak at about 30 degrees, and a third peak at about 31 degrees.
Regarding Claim 14, modified Yubuchi discloses all limitations as set forth above. Yubuchi further discloses wherein the lithium compound having an argyrodite crystal structure is represented by Li6PS5Br (Last paragraph of Introduction section, pg. 559), which is within the claimed scope of LimPSnXo, because m = 6 which is within the range of 4-8, n = 5 which is within the range of 3-6, X is Br which a halide, and o = 1 which is in the range of 0-3.
Regarding Claim 15, modified Yubuchi teaches a lithium argyrodite crystal structure represented by Li6PS5Br (Last paragraph of Introduction section, pg. 559).
Yubuchi does not disclose the lithium compound having an argyrodite crystal structure having a chloride content expressed by Li6PS5Cl·xLiCl wherein x is between 0 – 2.
Zhou teaches solvent-engineered lithium argyrodites represented by Li6PS5X where X is Cl, Br, I (Second paragraph in left column on pg. 266). In the method of preparation, Zhou teaches using Li2S, Li3PS4·3THF, and LiX (X = Cl, Br, I) as the precursors and THF and ethanol as the solvents (Second paragraph in left column on pg. 266). Furthermore, Zhou’s taught method of preparation includes a drying step and an annealing step (Second paragraph in left column on pg. 266 and first paragraph of Experimental section in Supporting Information pg. S2). In Table 3, Zhou shows the conductivities of Li6PS5Br and Li6PS5Cl, and the Li6PS5Cl example is shown to have a relatively higher conductivity. The Li6PS5Cl is further taught by Zhu to be applied as a solid electrolyte material in a TiS2/Li11Sn6 all-solid state battery (Second paragraph in right column on pg. 268).
Since Yubuchi and Zhou teach similar methods of making, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to modify the halide material of Yubuchi, by using Cl in place of Br, and thus obtain Li6PS5Cl , with a reasonable expectation of success in obtaining a halide-containing lithium argyrodite suitable for solid electrolyte applications with a conductivity higher/comparable to the conductivity of Li6PS5Br.
The lithium argyrodite, Li6PS5Cl, has a chloride content expressed as Li6PS5Cl·xLiCl wherein x = 0; therefore, the lithium argyrodite of modified Yubuchi has a chloride content that is within the claimed range of between 0 – 2 {I.e. The broadest reasonable interpretation of “between” is inclusive of endpoints.}.
Regarding Claim 16, modified Yubuchi discloses a method for synthesizing lithium argyrodites (Fig. 1; Last paragraph of Introduction section, pg. 559).
Yubuchi teaches using the lithium argyrodite as a solid electrolyte material coating for LiNi1/3Mn1/3Co1/3O2 (NMC) electrode powder and implementing the coated NMC powder in an all-solid state cell as an electrode with a Li-In foil serving as a counter electrode (Second paragraph of Material synthesis section, pg. 559 – 560 and Electrochemical characterization section, pg. 560). Furthermore, Yubuchi teaches an example of the prepared solid electrolyte material, Li6PS5Br, having a conductivity as high as 3.1 mS cm-1 at 25°C (Table 2; First paragraph in right column of Electrolyte characterization section, pg. 562). Since Yubuchi teaches the lithium argyrodite exhibiting an ionic conductivity as high as 3.1 mS cm-1 at 25°C, one with ordinary skill in the art would expect, at about 22°C, Yubuchi’s taught lithium argyrodite to have an ionic conductivity within the claimed range of at least 0.1 mS cm-1.
As such, Yubuchi further discloses a method for synthesizing lithium argyrodites, comprising: supplying a solid electrolyte composition comprising a solid, halide-containing crystalline lithium argyrodite characterized by an ionic conductivity of at least 0.1 mS cm-1 at about 22°C; and arranging the solid electrolyte composition to form an electrochemical cell for storing energy, the cell further having an anode and a cathode (Material synthesis section, pg. 559 – 560 and Electrochemical characterization section, pg. 560).
Furthermore, Yubuchi discloses wherein supplying the electrolyte composition comprises the steps of dissolving a mixture of precursors in a solvent or a solvent mixture (Fig. 1 and First paragraph of Material synthesis section, pg. 559), wherein one of the precursors is a solid Li3PS4-containing precursor, that is a THF-based, solid Li3PS4 containing suspension (First paragraph of Material synthesis section, pg. 559), and wherein a precursor other than the Li3PS4-containing precursor is added to the solvent or solvent mixture before the Li3PS4-containing precursor is added to the same solvent or solvent mixture, that is Yubuchi teaches adding the precursors Li2S and LiBr to an ethanol solvent prior to adding the THF-based, solid Li3PS4 containing suspension to the same ethanol solvent (Fig. 1 and first paragraph of Material synthesis section, pg. 559)
However, since Yubuchi teaches adding the Li3PS4-containing precursor in the form of suspension, Yubuchi does not explicitly disclose adding the Li3PS4-containing precursor without additional liquid to the same solvent or solvent mixture.
Zhou teaches solvent-engineered lithium argyrodites represented by Li6PS5X where X is Cl, Br, I (Second paragraph in left column on pg. 266). In the method of preparation, Zhou teaches using Li2S, Li3PS4·3THF, and LiX (X = Cl, Br, I) as the precursors and THF and ethanol as the solvents (Second paragraph in left column on pg. 266). Furthermore, Zhou’s taught method of preparation includes a drying step and an annealing step (Second paragraph in left column on pg. 266 and first paragraph of Experimental section in Supporting Information pg. S2). In Zhou the Li3PS4·3THF precursor is also taught to be in the form of a suspension; however Zhou also teaches, as an alternative to the suspension form of the precursor, that powder Li3PS4∙3THF can be used (First paragraph and second paragraph of Experimental section in Supporting Information pg. S2).
Since Zhou’s method steps for the powder Li3PS4·3THF precursor are similar to the steps taught by Yubuchi, and since Zhou teaches that powder Li3PS4·3THF is a viable, more direct alternative to the suspension form of the precursor (Second paragraph of Experimental section in Supporting Information pg. S2), it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to directly use Li3PS4·THF powder as the Li3PS4-containing precursor of Yubuchi, and thus obtain the claimed method step, because such a modification would be, as shown by Zhou, a selection of a functionally equivalent precursor recognized in the art and one with ordinary skill in the art would have a reasonable expectation of success in doing so [See MPEP2144.06(II)].
Yubuchi further discloses drying the mixture at 150°C, which is within the claimed range of above about 22°C in a chamber under vacuum to yield a precipitate (First paragraph of Material synthesis section, pg. 559); and annealing the precipitate at a temperature of 550°C, which is within the claimed range of higher than 150°C, under dry Ar, which is an inert gas atmosphere, to yield a lithium compound having an argyrodite crystal structure (First paragraph of Material synthesis section, pg. 559 and Right column paragraph of Electrolyte characterization section, pg. 561).
Regarding Claims 17 – 18, modified Yubuchi discloses all limitations as set forth above. Yubuchi further discloses where a molar ratio of sulfur to halide is 5:1 {i.e. molar ratio of sulfur to halide in Li6PS5Br} which is within the claimed ranges of 1.5:1 – 5:1 (Claim 17) and further is within the claimed range of at least 2.5:1 (Claim 18).
Regarding Claim 19, modified Yubuchi discloses all limitations as set forth above. The Li3PS4-THF precursor of modified Yubuchi is a powder Li3PS4-THF precursor; therefore, in modified Yubuchi the precursors comprise Li2S combined with Li3PS4-THF (Yubuchi: First paragraph of Material synthesis section, pg. 559 and Zhou: Second paragraph of Experimental section in Supporting Information pg. S2), which is within the claimed selection of Li3PS4, Li3PS4-ACN, or Li3PS4-THF.
Regarding Claim 20, modified Yubuchi discloses all limitations as set forth above. The Li3PS4-THF precursor of modified Yubuchi is a powder Li3PS4-THF precursor; thus, in modified Yubuchi the precursors comprise Li3PS4, Li2S, and LiBr (Fig. 1; First paragraph of Material synthesis section, pg. 559 and Zhou: Second paragraph of Experimental section in Supporting Information pg. S2), which is within the claimed scope of LiX, where X represents at least one halide or a combination of halides
Regarding Claim 21, modified Yubuchi discloses all limitations as set forth above. Yubuchi further discloses wherein the lithium compound having an argyrodite crystal structure is represented by Li6PS5Br (Last paragraph of Introduction section, pg. 559), which is within the claimed scope of LimPSnXo, because m = 6 which is within the range of 4-8, n = 5 which is within the range of 3-6, X is Br which a halide, and o = 1 which is in the range of 0-3.
Regarding Claim 22, modified Yubuchi discloses all limitations as set forth above. Yubuchi further teaches a lithium argyrodite crystal structure represented by Li6PS5Br (Last paragraph of Introduction section, pg. 559).
Modified Yubuchi does not disclose the lithium compound having an argyrodite crystal structure having a chloride content expressed by Li6PS5Cl·xLiCl wherein x is between 0 – 2.
Zhou teaches solvent-engineered lithium argyrodites represented by Li6PS5X where X is Cl, Br, I (Second paragraph in left column on pg. 266). In the method of preparation, Zhou teaches using Li2S, Li3PS4·3THF, and LiX (X = Cl, Br, I) as the precursors and THF and ethanol as the solvents (Second paragraph in left column on pg. 266). Furthermore, Zhou’s taught method of preparation includes a drying step and an annealing step (Second paragraph in left column on pg. 266 and first paragraph of Experimental section in Supporting Information pg. S2). In Table 3, Zhou shows the conductivities of Li6PS5Br and Li6PS5Cl, and the Li6PS5Cl example is shown to have a relatively higher conductivity. The Li6PS5Cl is further taught by Zhu to be applied as a solid electrolyte material in a TiS2/Li11Sn6 all-solid state battery (Second paragraph in right column on pg. 268).
Since Yubuchi and Zhou teach similar methods of making, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to modify the halide material of Yubuchi, by using Cl in place of Br, and thus obtain Li6PS5Cl , with a reasonable expectation of success in obtaining a halide-containing lithium argyrodite suitable for solid electrolyte applications with a conductivity higher/comparable to the conductivity of Li6PS5Br.
The lithium argyrodite, Li6PS5Cl, has a chloride content expressed as Li6PS5Cl·xLiCl wherein x = 0; therefore, the lithium argyrodite of modified Yubuchi has a chloride content that is within the claimed range of between 0 – 2 {I.e. The broadest reasonable interpretation of “between” is inclusive of endpoints.}.
Claim(s) 7 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Yubuchi (An argyrodite sulfide-based superionic conductor synthesized by a liquid-phase technique with tetrahydrofuran and ethanol. Journal of Materials Chemistry A, 7(2), pp.558-566), Zhou (Solvent-engineered design of argyrodite Li6PS5X (X= Cl, Br, I) solid electrolytes with high ionic conductivity. ACS Energy Letters, 4(1), pp.265-270 with Supporting Information, pp. S1 – S12) and Rao (Formation and conductivity studies of lithium argyrodite solid electrolytes using in-situ neutron diffraction. Solid State Ionics, 230, pp.72 – 76). {Examiner Note: All prior art was cited in the previous Office action mailed 05/23/2025}
Regarding Claims 7 and 9, Yubuchi discloses a method for synthesizing lithium argyrodites (Fig. 1; Last paragraph of Introduction section, pg. 559), comprising dissolving a mixture of precursors in a solvent or a solvent mixture (Fig. 1 and First paragraph of Material synthesis section, pg. 559), wherein one of the precursors is a solid Li3PS4-containing precursor, that is a THF-based, solid Li3PS4 containing suspension (First paragraph of Material synthesis section, pg. 559).
Yubuchi further discloses wherein a precursor other than the Li3PS4-containing precursor is added to the solvent or solvent mixture before the Li3PS4-containing precursor is added to the same solvent or solvent mixture, that is Yubuchi teaches adding the precursors Li2S and LiBr to an ethanol solvent prior to adding the THF-based, solid Li3PS4 containing suspension to the same ethanol solvent (Fig. 1 and first paragraph of Material synthesis section, pg. 559).
However, since Yubuchi teaches adding the Li3PS4-containing precursor in the form of suspension, Yubuchi does not explicitly disclose adding the Li3PS4-containing precursor without additional liquid to the same solvent or solvent mixture.
Zhou teaches solvent-engineered lithium argyrodites represented by Li6PS5X where X is Cl, Br, I (Second paragraph in left column on pg. 266). In the method of preparation, Zhou teaches using Li2S, Li3PS4·3THF, and LiX (X = Cl, Br, I) as the precursors and THF and ethanol as the solvents (Second paragraph in left column on pg. 266). Furthermore, Zhou’s taught method of preparation includes a drying step and an annealing step (Second paragraph in left column on pg. 266 and first paragraph of Experimental section in Supporting Information pg. S2). In Zhou the Li3PS4·3THF precursor is also taught to be in the form of a suspension; however Zhou also teaches, as an alternative to the suspension form of the precursor, that powder Li3PS4∙3THF can be used (First paragraph and second paragraph of Experimental section in Supporting Information pg. S2).
Since Zhou’s method steps for the powder Li3PS4·3THF precursor are similar to the steps taught by Yubuchi, and since Zhou teaches that powder Li3PS4·3THF is a viable, more direct alternative to the suspension form of the precursor (Second paragraph of Experimental section in Supporting Information pg. S2), it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to directly use Li3PS4·THF powder as the Li3PS4-containing precursor of Yubuchi, and thus obtain the claimed method step, because such a modification would be, as shown by Zhou, a selection of a functionally equivalent precursor recognized in the art and one with ordinary skill in the art would have a reasonable expectation of success in doing so [See MPEP2144.06(II)].
Yubuchi further discloses drying the mixture at 150°C, which is within the claimed range of above about 22°C in a chamber under vacuum to yield a precipitate (First paragraph of Material synthesis section, pg. 559).
In one example, Yubuchi teaches annealing, that is performing a heat treatment to enhance crystallinity, at a temperature of 150 °C under dry Ar, which is an inert atmosphere, to yield a lithium compound having an argyrodite crystal structure (Table 2; First paragraph of Material synthesis section, pg. 559 and Right column paragraph of Electrolyte characterization section, pg. 561). The heat treatment temperature of 150 °C is significantly close to the claimed annealing temperature range of “higher than 150°C”; therefore Yubuchi renders obvious the claimed range, because one with ordinary skill in the art would expect substantially the same properties [MPEP 2144.05(II)].
In table, 2, Yubuchi also teaches examples of the solid electrolyte prepared from a heat treatment temperature of 550 °C, and the example prepared from the higher temperature was shown to provide a higher ion conductivity (Table 2; First paragraph in right column of Electrolyte characterization section, pg. 562). One with ordinary skill in the art would further appreciate/recognize that higher heat treatment temperatures would require more energy to be consumed during manufacturing of the solid electrolyte, as minimizing cost by using lower annealing temperatures is a known industrial requirement for lithium argyrodite solid electrolyte manufacturing (Rao: Abstract).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to select heat treatment temperatures within the claimed range of above 150 °C, but also closer to a temperature of 150 °C, to optimize the conductivity and manufacturability of the solid electrolyte material, with a reasonable expectation of success and without undue experimentation [MPEP 2144.05(II)].
Furthermore, one with ordinary skill in the art would recognize that such a selection of heat treatment temperatures, based on the ion conductivity obtained from the sample heat treated at 150 °C, would be capable of providing an ion conductivity significantly close to 0.13 mS cm-1, and thus within the claimed range of 0.1 mS cm-1 to 0.6 mS cm-1 at about 22°C (Claim 9).
Claim(s) 8 is rejected under 35 U.S.C. 103 as being unpatentable over Yubuchi (An argyrodite sulfide-based superionic conductor synthesized by a liquid-phase technique with tetrahydrofuran and ethanol. Journal of Materials Chemistry A, 7(2), pp.558-566) and Zhou (Solvent-engineered design of argyrodite Li6PS5X (X= Cl, Br, I) solid electrolytes with high ionic conductivity. ACS Energy Letters, 4(1), pp.265-270 with Supporting Information, pp. S1 – S12) as applied to claim 7 above, and further in view of Yubuchi (Lithium-ion-conducting argyrodite-type Li6PS5X (X= Cl, Br, I) solid electrolytes prepared by a liquid-phase technique using ethanol as a solvent. ACS Applied Energy Materials, 1(8), pp.3622-3629, cited in previous Office action mailed 05/23/2025, hereinafter Yubuchi II.
Regarding Claim 8, Yubuchi discloses all limitations as set forth above. Yubuchi teaches performing the drying step for three hours at a temperature of 150°C (First paragraph of Material synthesis section, pg. 559). Yubuchi further teaches performing the heat-treating step, which corresponds to the claimed annealing step, at a temperature of 550°C, but does not explicitly disclose the duration of the heat treatment (First paragraph of Material synthesis section, pg. 559).
Therefore, modified Yubuchi does not specifically disclose wherein the drying and annealing steps are performed in about 2 hours or less.
Kambara teaches sulfide-solid electrolytes having an argyrodite crystal structure, and further teaches such electrolytes including halides such as Br and/or Cl ([0021];[0038]). The preparation method taught by Kambara teaches an annealing step, that is Kambara teaches a step of heat treating, under atmospheric pressure and an inert gas atmosphere such as nitrogen and argon, and cooling to obtain the argyrodite-solid electrolyte ([0061];[0107]). Kambara generally teaches heat treatment durations ranging from 0.5 hours to as long as 12 hours ([0062]).
Yubuchi II teaches a wet chemical synthesis method for the lithium argyrodite, Li6PS5Br (Abstract). Yubuchi II teaches different drying temperatures, such as 80°C, 150°C, and 200°C for the same duration of 3 hours (Refer to 2.1 Preparation of Materials section, pg. 3623). Since Yubuchi II teaches being able to dry the material at 80°C in 3 hours, one with ordinary skill in the art would reasonably expect, despite Yubuchi II teaching a duration of 3 hours for all three drying temperatures, that higher temperatures such as 150°C and 200°C, would not necessarily require as long as a drying time, and therefore, for higher temperatures, drying times shorter than 2 hours would be viable for sufficiently removing the ethanol solvent.
Since Yubuchi teaches drying for 3 hours at a temperature of 150°C and teaches using an ethanol solvent like Yubuchi II, and Kambara teaches that annealing times as short as 30 minutes are sufficient for forming sulfide-solid electrolytes having an argyrodite crystal structure, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to control the durations of Yubuchi’s drying and annealing step to be within the claimed range of about 2 hours or less, to optimize the synthesis time of the electrolyte material {i.e. Short synthesis time is indicated to be desired by Yubuchi in the right column paragraph of Introduction section, pg. 558} with a reasonable expectation of success in sufficiently removing the solvent from the precursor solution and forming the lithium argyrodite with a crystallinity suitable for electrolyte material applications.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Rangasamy et al. ("An iodide-based Li7P2S8I superionic conductor." Journal of the American Chemical Society 137, no. 4: pp.1384-1387 and Supporting Information pp. S1 – S6).
Rangasamy teaches an iodide based Li7P2S8I solid electrolyte with an argyrodite structure and further teaches forming the solid electrolyte material by mixing Li3PS4-ACN and LiI as precursors in acetonitrile, but does not teach/appear to suggest an annealing step (Refer to Abstract, first paragraph in right column on pg. 1384, and first paragraph of Experimental Section in Supporting Information pg. S1).
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/A.Y.O./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 2/13/2026