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
This is a final office action in response to Applicant’s remarks and amendments filed on 09/04/2025. Claims 1-2, 4-11, and 13 are currently amended. Claims 3 and 12 are canceled. Claim 14 is new. Claims 1-2, 4-11, and 13-14 are presented for examination.
The 35 U.S.C. 103 rejections in the previous office action are maintained. New grounds of rejection necessitated by Applicant’s amendment are presented below.
Response to Arguments
Applicant's arguments filed 09/04/2025 have been fully considered but they are not persuasive.
Applicant argues (p. 6) that one having ordinary skill in the art would not modify the method of Zhou to include method steps taught by Zhao because the Zhao reference teaches a positive electrode material for a lithium ion battery while the Zhou reference teaches a positive electrode material for a sodium ion battery. It is well known that active materials for lithium ion-based batteries and sodium ion-based batteries differ greatly in terms of their compositions and therefore the method for the former cannot be applied to the latter.
The Examiner respectfully disagrees. As discussed in the rejection of claim 1, both Zhou and Zhao teach methods for making monocrystalline layered oxide materials (the formula taught by Zhou is Na0.6-1Mn0.15-0.5Fe0.15-0.5M0-0.26N0-0.05Ni0-0.7O2 where M and N are doping and coating elements [0064]-[0068]; Wen, cited in the rejection of claim 1, evidences that materials having the formula NaxTMO2, TM = transition metals such as Mn, Fe, and Ni, are layered oxides, p. 29813 ¶1). Zhou further teaches that the working principle of sodium ion batteries is the same as that of lithium ion batteries ([0002]). A skilled artisan therefore would reasonably expect that the benefits taught by Zhao, i.e., the promotion of single-crystal growth and reduction of agglomeration during sintering (P2 L43-46), would also be desirable for a sodium active material having a similar crystal structure and find it obvious to try pre-treating the active material of Zhou in view of Wen and Gong with a source of the active ion as taught by Zhao.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 11 and 13 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 11 recites “A sodium ion battery, comprising… an electrolyte containing the sodium salt” and depends on claim 1, which requires “a sodium salt” to prepare a positive electrode material for said battery. However, the instant specification does not support using the same sodium salt for the electrolyte and as a starting material for the method for preparing the positive electrode material. The electrolyte is described as containing “sodium salt” at p. 3, l. 23-26 of the originally filed specification. Example embodiments use sodium hexafluorophosphate as the electrolyte sodium salt (p. 8, l. 23-24) but use sodium carbonate to form the positive electrode material (p. 8 – p. 13). For examination purposes, the claim will be interpreted as requiring that the electrolyte include any sodium salt rather than “the sodium salt” of claim 1. The claim should be amended to distinguish between the sodium salt used in the method of claim 1 and the sodium salt required for the electrolyte of claim 11.
Claim 13 is rejected due to its dependence on claim 11.
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.
Claims 1-2, 4-11, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Zhou (CN-115275134-A, cited in the IDS filed 08/30/2024; English-language equivalent US 2024/0021807 A1 is referenced below) in view of Wen (Copper Substitution in P2-Type Sodium Layered Oxide to Mitigate Phase Transition and Enhance Cyclability of Sodium-Ion Batteries, 2022; cited 12/31/2024), Gong (WO 2023/164986 A1), and Zhao (CN-116354416-A). The rejections below refer to the machine translations of Gong and Zhao mailed 12/31/2024.
Regarding claim 1, Zhou discloses a method for preparing a positive electrode material for sodium ion battery (mono-crystalline cathode material [0021]), comprising:
weighing (raw materials are weighed in Examples 1-9, starting on p. 6) an amount of a sodium salt ([0085]), an amount of an oxide of zinc ([0090]), an amount of an iron salt ([0088]), an amount of a manganese salt ([0086]), an amount of a nickel salt ([0087]), and an amount of a copper salt ([0090]);
S3: sintering the weighed materials (first sintering [0081]), adding an N source for coating ([0082]; N source is a coating element [0064]), and finally crushing to obtain the positive electrode material for sodium ion batteries ([0082]), wherein the N source is selected from compounds comprising Al, Ti, Co, B, P, Zr, W, Sr and Mg ([0068]).
Zhou does not disclose wherein the raw materials are weighed according to a ratio of Na:Zn:Fe:Mn:Ni:Cu=0.78:0.04:0.25-0.36:0.34:0.25:0.04. However, Zhou teaches that the molar ratio of the Na, Fe, Mn, Ni, and M elements in the finished positive electrode material of Examples 1-9 is substantially similar to the elemental molar ratio of the raw materials (see table below). Zhou further teaches that the finished positive electrode material should have the chemical formula of Na0.6-1Mn0.15-0.5Fe0.15-0.5M0-0.26N0-0.05Ni0-0.7O2 ([0064]-[0068]). A person having ordinary skill in the art before the effective filing date of the invention would therefore find it obvious to use starting materials having a stoichiometric ratio of Na:Zn:Fe:Mn:Ni:Cu corresponding to the chemical formula taught by Zhou in the method of Zhou, thereby arriving at a ratio of Na:Zn:Fe:Mn:Ni:Cu of (0.6 – 1):(0 – 0.26):(0.15 – 0.5):(0.15 – 0.5):(0 – 0.7):(0 – 0.26), overlapping the claimed ratio of 0.78:0.04:0.25-0.36:0.34:0.25:0.04 and establishing a prima facie case of obviousness [MPEP § 2144.05(I)].
Elemental molar ratio of raw materials (Na:Mn:Ni:Fe:M)
Elemental molar ratio of finished powder (Na:Mn:Ni:Fe:M)
Example 1
0.87 : 0.33 : 0.33 : 0.33 : 0.01 ([0100])
0.87 : 0.32 : 0.32 :0.33 : 0.01 ([0107])
Example 2
0.79 : 0.30 : 0.18 : 0.30 : 0.22 ([0139])
0.79 : 0.30 : 0.18 : 0.30 : 0.22 ([0140])
Example 3
0.85 : 0.30 : 0.18 : 0.30 : 0.22 ([0143])
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0143])
Example 4
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0147])
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0148])
Example 5
0.81 : 0.33 : 0.33 : 0.33 : 0.01 ([0152])
0.81 : 0.33 : 0.33 : 0.31 : 0.01 ([0153])
Example 6
0.84 : 0.34 : 0.25 : 0.30 : 0.11 ([0157])
0.84 : 0.25 : 0.34 : 0.30 : 0.11 ([0158])
Example 7
0.84 : 0.5 : 0 : 0.5 : 0 ([0162])
0.84 : 0.5 : 0 : 0.5 : 0 ([0163])
Example 8
0.91 : 0.1 : 0.42 : 0.32 : 0.16 ([0166])
0.91 : 0.1 : 0.42 : 0.31 : 0.16 ([0167])
Example 9
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0170])
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0170])
Though Zhou discloses that the doping element is preferably Zn and may comprise a combination of Zn and Cu ([0067]), Zhou does not disclose a specific embodiment wherein the method for preparing a positive electrode active material comprises weighing both an amount of a copper salt and an amount of an oxide of zinc such that the electrode active material is for a copper-zinc-based sodium ion battery.
Wen teaches the benefits of using both Cu and Zn as dopants in sodium layered transition metal oxides (NaxTMO2, TM = Mn, Ni, Fe) used as positive electrode active materials in sodium ion batteries (P29813 ¶1; Fig. 2 on P29814). NaxTMO2 comprising Zn has higher electrochemical stability, but the presence of Zn reduces the capacity of the active material and causes volume changes that introduce stacking faults in the oxide (P29814, C1 bridging C2). Adding Cu to the composition decreases the volume change and enhances the electrochemical performance of the material (P29815 C1 ¶1). Therefore, a person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have included both Zn and Cu as starting materials in the method of Zhou to prepare a positive electrode material for a copper-zinc-based sodium ion battery, with a reasonable expectation that doing so would increase the stability and electrochemical performance of the finished active material as taught by Wen (P29815 C1 ¶1).
Though Zhou teaches that the method should yield a mono-crystalline positive electrode material having a powder compacted density of 2.8-4.2 g/cm3 ([0016]), a specific surface area of 0.35-1.2 m2/g ([0019]), and a particle size D50 of 2.00-16.0 µm ([0020]), Zhou in view of Wen does not disclose S1: wet pre-sodium: the iron salt, the manganese salt, the nickel salt, the copper salt, and a the sodium salt to a measuring cup and stirring with water to dissolve to obtain a mixed salt solution; adding the oxide of zinc and the mixed salt solution to a sand grinder for sand grinding for a certain period of time to obtain a mixed solution; or S2: spray drying the mixed solution containing copper-zinc-based elements of S1 to obtain a precursor powder of positive electrode material for copper-zinc-based sodium ion battery.
Gong teaches a method of preparing a mono-crystalline positive electrode material for sodium ion batteries. The method comprises the steps of:
Mixing a sodium salt (P2 L47-49), and oxides or salts of M (M may be Fe, Ni, Cu, and Zn, P2 L22-32) in water to form a slurry (P2 L16-20);
Adding the slurry from step a) to a sand grinder for sand grinding for a certain period of time to obtain a mixed slurry (P2 L16-20);
Spray drying of the mixed slurry to obtain precursor powder (P2 L16-20); and
Sintering the mixed slurry to obtain the positive electrode material (P2 L16-20).
This process yields a positive electrode active material having a compacted density of 2.8-3.6 g/cm3, a specific surface area of 0.2-1.0 m2/g, and a particle size D50 of 1-30 µm (P3 L51-54). Gong further teaches that using a sand grinder to prepare the mixed slurry in step b) ensures uniform mixing of raw materials at the molecular level (for water-soluble compounds) and at the nano level (for water-insoluble compounds), which improves the electrochemical activity of the sintered product (P3 L32-37). The spray-drying method can maintain the uniform distribution of multiple raw materials during the drying process of the evenly mixed slurry, ensuring that component segregation of multiple raw materials does not occur during the molding process (P3 L47-49).
Therefore, a person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have modified the method of Zhou in view of Wen by:
stirring the raw materials with water to dissolve to obtain a mixed salt solution and adding the mixed salt solution to a sand grinder for sand grinding for a certain period of time to obtain a mixed solution, and
spray drying the mixed solution to obtain a precursor powder,
with a reasonable expectation that doing so would improve the electrochemical properties of the finished positive electrode material as taught by Gong (P2 L8-11).
Zhou in view of Wen and Gong does not disclose wherein the positive electrode is pre-sodium treated, i.e., that a first portion of the sodium salt is mixed with the other salts to obtain a mixed salt solution as in S1 of the claimed invention and a second portion of the sodium salt is mixed with the precursor powder of S2, wherein an amount of the first portion of the sodium salt added is 50% of the weighed amount of the sodium salt and wherein an amount of the second portion of the sodium salt added is 50% of the weighed amount of the sodium salt.
Zhao teaches a method of preparing a pre-lithium treated single-crystal positive electrode material for a lithium ion battery (P1 L16-18). The material consists of a layered oxide (P1 L35-36), like those of Zhou, Gong, and Wen. The method comprises the steps of:
Contacting an aqueous solution of salts including a first lithium source, which may be lithium carbonate (P4 L32-35), with a transition metal oxide precursor, then drying the mixed material to obtain a precursor powder (P3 L17-18); and
Mixing the precursor powder with a second lithium source, which may be the same as the first (P4 L32-35), and sintering to obtain a sintered material (P3 L20-21).
This preparation allows part of the lithium source to enter the surface and surface layer during the pretreatment process, providing a driving force for the formation of the single crystal material. It can also make the single crystal material less easy to agglomerate during the sintering process, which is beneficial to obtain a better capacity retention rate (P2 L43-46).
In seeking to promote growth and reduce agglomeration of the material of Zhou in view of Wen and Gong, a person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have modified the method of Zhou in view of Wen and Gong by adding only a portion of the weight of sodium salt to the mixed salt solution and mixed the remaining sodium salt with the precursor powder obtained by spray drying with a reasonable expectation of improving the single crystal growth and reducing agglomeration as taught by Zhao (P2 L43-46).
Zhao teaches that the amount of the first lithium source is 5-15 mole parts relative to 100 molar parts of the total lithium source, and therefore Zhou in view of Wen, Gong, and Zhao does not teach wherein only 50% of the weighed weight of sodium salt is added to the mixed salt solution. However, Zhou teaches that, though the working principle of sodium ion batteries is the same as that of lithium ion battery, the ionic radius of sodium ion is larger and the diffusion kinetics are slower ([0002]). A skilled artisan would therefore expect that the preparation of sodium-based layered oxides would may require different parameters than the preparation of lithium-based layered oxides, and would vary the proportion of sodium salt added to the mixed salt solution of Zhou in view of Wen, Gong, and Zhao in order to yield a material having the desired crystal structure and distribution, thereby arriving at a synthesis in which “only 50% of the weighed weight of sodium salt is added to the mixed salt solution” without an unreasonable amount of experimentation. Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical [MPEP § 2144.05].
Regarding claim 2, Zhou in view of Wen, Gong, and Zhao teaches the invention as discussed in claim 1. Zhou further teaches wherein the oxide of zinc is zinc oxide ([0089]); the nickel salt ([0087]) or the manganese salt ([0087]) is carbonate, sulfate, oxalate or acetate; the iron salt is selected from ferrous sulfate or ferrous oxalate ([0088]); and the copper salt is copper sulfate ([0089]).
Regarding claim 4, Zhou in view of Wen, Gong, and Zhao teaches the invention as discussed in claim 1, wherein in step S1, the sodium salt is sodium carbonate, sodium acetate, or sodium chloride (Zhou: [0085]).
Regarding claim 5, Zhou in view of Wen, Gong, and Zhao teaches the invention as discussed in claim 1, wherein S3 includes a first sintering at a temperature of 870°C – 945°C and a second sintering at a temperature of 300°C – 800°C (Zhou: overlapping ranges of 880°C – 980°C for first sintering and 350°C – 800°C for second sintering, [0083] – [0084], establish a prima facie case of obviousness [MPEP § 2144.05(I)]).
Regarding claim 6, Zhou in view of Wen, Gong, and Zhao teaches the invention as discussed in claim 1. Zhou further teaches wherein the coating is conducted in a solid-phase or liquid-phase (Examples 1-3, 5, 6, and 7 use a solid-phase coating method, e.g. ([0100]); Examples 4 ([0147]) and 8 ([0166]) use a liquid-phase coating method).
Regarding claim 7, Zhou in view of Wen, Gong, and Zhao teaches the invention as discussed in claim 1, wherein the crushing is by air flow crushing (Zhou: Table 2 on P6 teaches that a jet mill was used in example embodiments), to obtain the positive electrode material having a median particle size D50 of 5.2-14 μm (Zhou: overlapping range of 3.4-10.2 μm, Table 3 on P10 and [0174], establishes a prima facie case of obviousness [MPEP § 2144.05(I)]).
Regarding claim 8, Zhou in view of Wen, Gong, and Zhao teaches the invention as discussed in claim 1. Zhou further teaches wherein the chemical formula of the positive electrode material for copper-zinc-based sodium ion battery is Na0.6-1Mn0.15-0.5Fe0.15-0.5M0-0.26N0-0.05Ni0-0.7O2 (see rejection of claim 1), which corresponds to the claimed formula NamCuxZnyFezM1-x-y-zO2, wherein 0.75≤m≤1.08 (overlapping range of 0.6≤m≤1), wherein M is Ni, Mn, and N, 0.20≤z≤0.45 (overlapping range of 0.15≤z≤0.5), and 0≤x+y≤0.26 (M in the Zhou formula represents doping agents including Cu and Zn, see rejection of claim 1).
Zhou in view of Weng, Gong, and Zhao does not explicitly disclose wherein, in the claimed formula above, 0.005≤ x ≤0.10 and 0.005≤y≤0.09.
However, Wen, who motivates the particular choice of Zn and Cu as doping elements (M) for the method of Zhou, teaches a composition having Zn0.075 and Cu0.075 ([P29815 C1 L12]). A person having ordinary skill in the art before the effective filing date of the invention would therefore find it obvious to have include an equal amount of Cu and Zn when adding these compounds, yielding an active material having the formula Na0.6-1Cu0-0.13Zn0-0.13Mn0.15-0.5Fe0.15-0.5N0-0.05Ni0-0.7O2 corresponding to the claimed formula of NamCuxZnyFezM1-x-y-zO2, wherein 0.005 ≤ x ≤ 0.10 and 0.005≤y≤0.09 (overlapping ranges of 0<x ≤0.13 and 0< y≤0.13).
Regarding claim 9, Zhou in view of Wen, Gong, and Zhao teaches a pre-sodium treated positive electrode material for copper-zinc-based sodium ion battery, prepared by the method according to claim 1 (Zhou: ([0091]).
Regarding claim 10, Zhou in view of Wen, Gong, and Zhao teaches a positive electrode for sodium ion battery, comprising a positive electrode active substance that is the pre-sodium treated positive electrode material for copper-zinc-based sodium ion battery of claim 9 (Zhou: ([0091]).
Regarding claim 11, Zhou in view of Wen, Gong, and Zhao teaches a sodium ion battery, comprising the positive electrode for sodium ion battery of claim 10, a negative electrode, and an electrolyte containing the sodium salt (Zhou: ([0093]).
Regarding claim 13, Zhou in view of Wen, Gong, and Zhao teaches a power system, energy storage system or a mobile storage device, comprising the sodium ion battery of claim 11 (Zhou: ([0096]).
Claims 1 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Zhou (CN-115275134-A, cited in the IDS filed 08/30/2024; English-language equivalent US 2024/0021807 A1 is referenced below) in view of Wen (Copper Substitution in P2-Type Sodium Layered Oxide to Mitigate Phase Transition and Enhance Cyclability of Sodium-Ion Batteries, 2022; cited 12/31/2024), Gong (WO 2023/164986 A1), and Zhao (CN-116354416-A). The rejections below refer to the machine translations of Gong and Zhao mailed 12/31/2024.
Regarding claim 1, Zhou discloses a method for preparing a positive electrode material for sodium ion battery (mono-crystalline cathode material [0021]), comprising:
weighing (raw materials are weighed in Examples 1-9, starting on p. 6) an amount of a sodium salt ([0085]), an amount of an oxide of zinc ([0090]), an amount of an iron salt ([0088]), an amount of a manganese salt ([0086]), an amount of a nickel salt ([0087]), and an amount of a copper salt ([0090]);
S3: sintering the weighed materials (first sintering [0081]), adding an N source for coating ([0082]; N source is a coating element [0064]), and finally crushing to obtain the positive electrode material for sodium ion batteries ([0082]), wherein the N source is selected from compounds comprising Ca, Ti, Mg, Al, W, Zr, Sr, B, Ba, Ce, Mo, Co, P, or Li ([0065]).
Zhou does not disclose wherein the raw materials are weighed according to a ratio of Na:Zn:Fe:Mn:Ni:Cu=0.78:0.04:0.25-0.36:0.34:0.25:0.04. However, Zhou teaches that the molar ratio of the Na, Fe, Mn, Ni, and M elements in the finished positive electrode material of Examples 1-9 is substantially similar to the elemental molar ratio of the raw materials (see table below). Zhou further teaches that the finished positive electrode material should have the chemical formula of Na0.6-1Mn0.15-0.5Fe0.15-0.5M0-0.26N0-0.05Ni0-0.7O2 ([0064]-[0068]). A person having ordinary skill in the art before the effective filing date of the invention would therefore find it obvious to use starting materials having a stoichiometric ratio of Na:Zn:Fe:Mn:Ni:Cu corresponding to the chemical formula taught by Zhou in the method of Zhou, thereby arriving at a ratio of Na:Zn:Fe:Mn:Ni:Cu of (0.6 – 1):(0 – 0.26):(0.15 – 0.5):(0.15 – 0.5):(0 – 0.7):(0 – 0.26), overlapping the claimed ratio of 0.78:0.04:0.25-0.36:0.34:0.25:0.04 and establishing a prima facie case of obviousness [MPEP § 2144.05(I)].
Elemental molar ratio of raw materials (Na:Mn:Ni:Fe:M)
Elemental molar ratio of finished powder (Na:Mn:Ni:Fe:M)
Example 1
0.87 : 0.33 : 0.33 : 0.33 : 0.01 ([0100])
0.87 : 0.32 : 0.32 :0.33 : 0.01 ([0107])
Example 2
0.79 : 0.30 : 0.18 : 0.30 : 0.22 ([0139])
0.79 : 0.30 : 0.18 : 0.30 : 0.22 ([0140])
Example 3
0.85 : 0.30 : 0.18 : 0.30 : 0.22 ([0143])
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0143])
Example 4
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0147])
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0148])
Example 5
0.81 : 0.33 : 0.33 : 0.33 : 0.01 ([0152])
0.81 : 0.33 : 0.33 : 0.31 : 0.01 ([0153])
Example 6
0.84 : 0.34 : 0.25 : 0.30 : 0.11 ([0157])
0.84 : 0.25 : 0.34 : 0.30 : 0.11 ([0158])
Example 7
0.84 : 0.5 : 0 : 0.5 : 0 ([0162])
0.84 : 0.5 : 0 : 0.5 : 0 ([0163])
Example 8
0.91 : 0.1 : 0.42 : 0.32 : 0.16 ([0166])
0.91 : 0.1 : 0.42 : 0.31 : 0.16 ([0167])
Example 9
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0170])
0.88 : 0.30 : 0.18 : 0.30 : 0.22 ([0170])
Though Zhou discloses that the doping element is preferably Zn and may comprise a combination of Zn and Cu ([0067]), Zhou does not disclose a specific embodiment wherein the method for preparing a positive electrode active material comprises weighing both an amount of a copper salt and an amount of an oxide of zinc such that the electrode active material is for a copper-zinc-based sodium ion battery.
Wen teaches the benefits of using both Cu and Zn as dopants in sodium layered transition metal oxides (NaxTMO2, TM = Mn, Ni, Fe) used as positive electrode active materials in sodium ion batteries (P29813 ¶1; Fig. 2 on P29814). NaxTMO2 comprising Zn has higher electrochemical stability, but the presence of Zn reduces the capacity of the active material and causes volume changes that introduce stacking faults in the oxide (P29814, C1 bridging C2). Adding Cu to the composition decreases the volume change and enhances the electrochemical performance of the material (P29815 C1 ¶1). Therefore, a person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have included both Zn and Cu as starting materials in the method of Zhou to prepare a positive electrode material for a copper-zinc-based sodium ion battery, with a reasonable expectation that doing so would increase the stability and electrochemical performance of the finished active material as taught by Wen (P29815 C1 ¶1).
Though Zhou teaches that the method should yield a mono-crystalline positive electrode material having a powder compacted density of 2.8-4.2 g/cm3 ([0016]), a specific surface area of 0.35-1.2 m2/g ([0019]), and a particle size D50 of 2.00-16.0 µm ([0020]), Zhou in view of Wen does not disclose S1: wet pre-sodium: the iron salt, the manganese salt, the nickel salt, the copper salt, and a the sodium salt to a measuring cup and stirring with water to dissolve to obtain a mixed salt solution; adding the oxide of zinc and the mixed salt solution to a sand grinder for sand grinding for a certain period of time to obtain a mixed solution; or S2: spray drying the mixed solution containing copper-zinc-based elements of S1 to obtain a precursor powder of positive electrode material for copper-zinc-based sodium ion battery.
Gong teaches a method of preparing a mono-crystalline positive electrode material for sodium ion batteries. The method comprises the steps of:
Mixing a sodium salt (P2 L47-49), and oxides or salts of M (M may be Fe, Ni, Cu, and Zn, P2 L22-32) in water to form a slurry (P2 L16-20);
Adding the slurry from step a) to a sand grinder for sand grinding for a certain period of time to obtain a mixed slurry (P2 L16-20);
Spray drying of the mixed slurry to obtain precursor powder (P2 L16-20); and
Sintering the mixed slurry to obtain the positive electrode material (P2 L16-20).
This process yields a positive electrode active material having a compacted density of 2.8-3.6 g/cm3, a specific surface area of 0.2-1.0 m2/g, and a particle size D50 of 1-30 µm (P3 L51-54). Gong further teaches that using a sand grinder to prepare the mixed slurry in step b) ensures uniform mixing of raw materials at the molecular level (for water-soluble compounds) and at the nano level (for water-insoluble compounds), which improves the electrochemical activity of the sintered product (P3 L32-37). The spray-drying method can maintain the uniform distribution of multiple raw materials during the drying process of the evenly mixed slurry, ensuring that component segregation of multiple raw materials does not occur during the molding process (P3 L47-49).
Therefore, a person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have modified the method of Zhou in view of Wen by:
stirring the raw materials with water to dissolve to obtain a mixed salt solution and adding the mixed salt solution to a sand grinder for sand grinding for a certain period of time to obtain a mixed solution, and
spray drying the mixed solution to obtain a precursor powder,
with a reasonable expectation that doing so would improve the electrochemical properties of the finished positive electrode material as taught by Gong (P2 L8-11).
Zhou in view of Wen and Gong does not disclose wherein the positive electrode is pre-sodium treated, i.e., that a first portion of the sodium salt is mixed with the other salts to obtain a mixed salt solution as in S1 of the claimed invention and a second portion of the sodium salt is mixed with the precursor powder of S2, wherein an amount of the first portion of the sodium salt added is 50% of the weighed amount of the sodium salt and wherein an amount of the second portion of the sodium salt added is 50% of the weighed amount of the sodium salt.
Zhao teaches a method of preparing a pre-lithium treated single-crystal positive electrode material for a lithium ion battery (P1 L16-18). The material consists of a layered oxide (P1 L35-36), like those of Zhou, Gong, and Wen. The method comprises the steps of:
Contacting an aqueous solution of salts including a first lithium source, which may be lithium carbonate (P4 L32-35), with a transition metal oxide precursor, then drying the mixed material to obtain a precursor powder (P3 L17-18); and
Mixing the precursor powder with a second lithium source, which may be the same as the first (P4 L32-35), and sintering to obtain a sintered material (P3 L20-21).
This preparation allows part of the lithium source to enter the surface and surface layer during the pretreatment process, providing a driving force for the formation of the single crystal material. It can also make the single crystal material less easy to agglomerate during the sintering process, which is beneficial to obtain a better capacity retention rate (P2 L43-46).
In seeking to promote growth and reduce agglomeration of the material of Zhou in view of Wen and Gong, a person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have modified the method of Zhou in view of Wen and Gong by adding only a portion of the weight of sodium salt to the mixed salt solution and mixed the remaining sodium salt with the precursor powder obtained by spray drying with a reasonable expectation of improving the single crystal growth and reducing agglomeration as taught by Zhao (P2 L43-46).
Zhao teaches that the amount of the first lithium source is 5-15 mole parts relative to 100 molar parts of the total lithium source, and therefore Zhou in view of Wen, Gong, and Zhao does not teach wherein only 50% of the weighed weight of sodium salt is added to the mixed salt solution. However, Zhou teaches that, though the working principle of sodium ion batteries is the same as that of lithium ion battery, the ionic radius of sodium ion is larger and the diffusion kinetics are slower ([0002]). A skilled artisan would therefore expect that the preparation of sodium-based layered oxides would may require different parameters than the preparation of lithium-based layered oxides, and would vary the proportion of sodium salt added to the mixed salt solution of Zhou in view of Wen, Gong, and Zhao in order to yield a material having the desired crystal structure and distribution, thereby arriving at a synthesis in which “only 50% of the weighed weight of sodium salt is added to the mixed salt solution” without an unreasonable amount of experimentation. Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical [MPEP § 2144.05].
Regarding claim 14, Zhou in view of Wen, Gong, and Zhao teaches method according to claim 1, wherein, in S3, wherein the N source is selected from compounds comprising Ca, Ba, Ce, Mo, or Li (Zhou: [0065]).
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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/C.C.D./Examiner, Art Unit 1723 /TIFFANY LEGETTE/Supervisory Patent Examiner, Art Unit 1723