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 .
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, 4-7, 10-13 and 15-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhou et al. (WO-2021088166-A1; see English equivalent US-20220223859-A1 for citations) as evidenced by Cen et al. (J. Phys. Energy 5; see attached NPL for citations).
Regarding Claims 1 and 10-11, Zhou discloses a positive electrode sheet (positive electrode; [0020, 0033, 0048-0049, 0051]) comprising:
a positive electrode current collector [0020, 0048, 0073],
at least a side of the positive electrode current collector being provided with a positive electrode active material layer [0020, 0040, 0048-0050, 0073],
at least a side of the positive electrode active material layer being provided with a lithium compensation layer (lithium supplementing material layer; [0040, 0048-0050, 0073]).
Zhou discloses that the positive electrode active material layer can be selected from a list of materials which include lithium iron phosphate [0041]. Therefore, although Zhou does not disclose a specific embodiment wherein the positive electrode active material layer comprises lithium iron phosphate, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the positive electrode active material layer to comprise lithium iron phosphate with a reasonable expectation that such a selection would result in a successful positive electrode active material layer.
Zhou discloses that the lithium supplementing material can be selected from a group of materials which include materials such as Li2NiO2 and Li2NiO3 [0008, 0011, 0088]. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the lithium supplementing material to be Li2NiO2 or Li2NiO3 with a reasonable expectation that such a material would result in a successful lithium compensation layer. These materials are understood to be ternary materials, absent a special definition provided in the instant specification, as evidenced by Cen (see Cen: Introduction; Fig. 1). Therefore, the lithium compensation layer rendered obvious by Zhou comprises a ternary material.
Zhou discloses that lithium compensation layer can comprise a binder and a conductive agent [0014-0015, 0036-0039, 0072, 0088]. In a specific example, the lithium compensation layer comprises 90% lithium supplementing material, 5% binder, and 5% conductive agent [0072, 0088]. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have provided the lithium compensation layer such that it comprises 90% lithium supplementing material (i.e. ternary material), 5% binder, and 5% conductive agent with a reasonable expectation that such a conjugation would result in a successful lithium compensation layer. The addition of a conductive agent and a binder corresponds to the recited limitation of Claim 11. Providing the lithium compensation layer such that it comprises 90% lithium supplementing material (i.e. ternary material) based on the weight of the lithium compensation layer is within the claimed range of 80%-92% as recited in Claim 1, and within the claimed range of 90%-92% as recited in Claim 10.
Regarding Claim 2, Zhou renders obvious all of the limitations as set forth above. Zhou further discloses that the lithium compensation layer is provided between the positive electrode current collector and the positive electrode active material layer [0020, 0048-0050, 0073].
Regarding Claims 4-5, Zhou renders obvious all of the limitations as set forth above. Zhou further discloses that the positive electrode lithium supplementing material (i.e. ternary material) can account for 1% to 10% of the positive electrode active material (i.e. lithium iron phosphate) in the positive electrode active material layer [0047]. In a specific embodiment (Example 2), the ratio of lithium supplementing material to positive electrode active material is 5:100 (see Table 1; [0078, 0119]). Therefore, although Zhou does not explicitly disclose that “a percentage ratio of a mass of the ternary material to a mass of the lithium iron phosphate is 1%-10%” as required by Claim 4, or that “the percentage ratio of the mass of the ternary material to the mass of the lithium iron phosphate is 3%-5%” as required by Claim 5, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have provided the ratio of ternary material to lithium iron phosphate to be 5:100, which corresponds to a percentage ratio of a mass of the ternary material to a mass of the lithium iron phosphate of 4.76%. This percentage ratio is within the claimed ranges of Claims 4 and 5.
Additionally, Zhou discloses that when the ternary material (positive electrode supplementing material) is added at the optimal ranges, a best lithium supplementing effect is achieved, and the reversible capacity of the energy density of a lithium-ion battery is increased the most [0129]. When the content of ternary material is too low, there is not enough lithium to supplement the lithium consumed by the SEI layer [0004, 0049, 0129]. When the content of ternary material is too high, some lithium is intercalated into the negative electrode active material during charging, but cannot be used during discharging, thereby hindering the improvement of the energy density [0129]. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have optimized the content of ternary material in the positive electrode sheet (thereby inherently optimizing the ratio of ternary material to lithium iron phosphate), including selecting the percentage ratio of the mass of ternary material to the mass of lithium iron phosphate to be 3%-5%, which is within the range recited in Claim 4, and corresponds to the range recited in Claim 5, with a reasonable expectation that such a content of ternary material would result in a successful balance between ensuring the supplementation of lithium consumed during initial charging and ensuring an improvement in energy density (MPEP 2144.05, II).
Regarding Claims 6-7, Zhou renders obvious all of the limitations as set forth above. Zhou discloses that the thickness of the lithium compensation layer (lithium supplementing material layer) is strictly controlled to reduce polarization of lithium compensation layer [0049, 0124]. A lithium compensation layer which is too thick does not facilitate transport of electrons [0124]. However, the lithium compensation layer generates an in situ delithiated product on the current collector during a first cycle of charging which greatly reduces the risk of a micro short circuit and improves safety of a corresponding electrochemical apparatus [0049-0050, 0123-0124]. Accordingly, the lithium compensation layer is understood to have a required minimum thickness to achieve the beneficial isolation layer.
Therefore, although Zhou does not specifically disclose that a single-side thickness (H2) of the lithium compensation layer and a single-side thickness (H1) of the positive electrode active material layer satisfy the condition “5H2≤H1≤30H2” as required by Claim 6, or “10H2≤H1≤15H2” as required by Claim 7, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have found it obvious to have optimized the thickness of the lithium compensation layer within the positive electrode, thereby inherently optimizing the thickness of the lithium compensation layer in relation to the positive electrode active material layer, including a thickness which satisfies the relationship “10H2≤H1≤15H2”. One of ordinary skill in the art would have had a reasonable expectation that such a thickness would result in a successful balance between ensuring the formation of delithiated product on the current collector while still facilitating the transport of electrons (MPEP 2144.05, II). The relationship rendered obvious by Zhou falls within the range recited in Claim 6 and corresponds to the range recited in Claim 7.
Regarding Claim 12, Zhou renders obvious all of the limitations as set forth above. Zhou discloses a method for preparing the positive electrode sheet according to Claim 1, comprising: forming the positive electrode active material layer and forming the lithium compensation layer [0020, 0048-0049, 0073].
Regarding Claim 13, Zhou renders obvious all of the limitations as set forth above. Zhou further discloses a secondary battery (electrochemical apparatus), comprising the positive electrode sheet according to claim 1 [0051, 0076].
Regarding Claim 15, Zhou renders obvious all of the limitations as set forth above. Zhou further discloses an electric device (electronic apparatus), comprising the secondary battery according to Claim 13 [0068-0069].
Regarding Claim 16, Zhou renders obvious all of the limitations as set forth above, including that the lithium compensation layer comprises 90% ternary material, 5% conductive agent and 5% binder (see rejection of Claim 1, above). Zhou discloses, more broadly, that the lithium compensation layer can comprise 80%-90% lithium supplementing material (i.e. ternary material), 5%-10% conductive agent and 5%-10% binder [0034, 0036-00339]. This corresponds to a mass ratio of ternary material, conductive agent, and binder of (80-90) : (5-10) : (5-10). This range overlaps the claimed range. Therefore, although Zhou does not disclose a specific embodiment wherein “a mass ratio of the ternary material, the conductive agent, and the binder in the lithium compensation layer being (80-90): (4-8): (6-12)”, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the range recited in the prior art, including the overlapping portion of the range, with a reasonable expectation that such a selection would result in a successful content of ternary material, conductive agent, and binder for a successful lithium compensation layer (MPEP 2144.05, I).
Regarding Claim 17, Zhou discloses a positive electrode sheet (positive electrode; [0020, 0033, 0048-0049, 0051]) comprising:
a positive electrode current collector [0020, 0048, 0073],
at least a side of the positive electrode current collector being provided with a positive electrode active material layer [0020, 0040, 0048-0050, 0073],
at least a side of the positive electrode active material layer being provided with a lithium compensation layer (lithium supplementing material layer; [0040, 0048-0050, 0073]).
Zhou discloses that the positive electrode active material layer can be selected from a list of materials which include lithium iron phosphate [0041]. Therefore, although Zhou does not disclose a specific embodiment wherein the positive electrode active material layer comprises lithium iron phosphate, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the positive electrode active material layer to comprise lithium iron phosphate with a reasonable expectation that such a selection would result in a successful positive electrode active material layer.
Zhou discloses that the lithium supplementing material can be selected from a group of materials which include materials such as Li2NiO2 and Li2NiO3 [0008, 0011, 0088]. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the lithium supplementing material to be Li2NiO2 or Li2NiO3 with a reasonable expectation that such a material would result in a successful lithium compensation layer. These materials are understood to be ternary materials, absent a special definition provided in the instant specification, as evidenced by Cen (see Cen: Introduction; Fig. 1). Therefore, the lithium compensation layer rendered obvious by Zhou comprises a ternary material.
Zhou discloses that lithium compensation layer can comprise a binder and a conductive agent [0014-0015, 0036-0039, 0072, 0088], and in each example the lithium compensation layer comprises both a binder and a conductive agent, thereby rendering obvious the use of a binder and conductive agent in the lithium compensation layer.
Zhou discloses that the lithium compensation layer can comprise 80%-90% lithium supplementing material (i.e. ternary material), 5%-10% conductive agent and 5%-10% binder [0034, 0036-00339]. This corresponds to a mass ratio of ternary material, conductive agent, and binder of (80-90) : (5-10) : (5-10), which overlaps the claimed range. Therefore, although Zhou does not disclose a specific embodiment wherein “a mass ratio of the ternary material, the conductive agent, and the binder in the lithium compensation layer being (80-90): (4-8): (6-12)”, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the range recited in the prior art, including the overlapping portion of the range, with a reasonable expectation that such a selection would result in a successful content of ternary material, conductive agent, and binder for a successful lithium compensation layer (MPEP 2144.05, I).
Claim(s) 3 and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhou et al. (WO-2021088166-A1; see English equivalent US-20220223859-A1 for citations) as evidenced by Cen et al. (J. Phys. Energy 5; see attached NPL for citations) as applied to Claims 1 and 13, above, and in further view of Huang et al. (CN-115692635-A; cited in IDS filed 09/12/2025; see English equivalent US-20240170644-A1 for citations).
Regarding Claim 3, Zhou renders obvious all of the limitations as set forth above, including that the positive electrode sheet comprises a positive electrode active material comprises lithium iron phosphate and a lithium compensation layer comprising a ternary material (see rejection of Claim 1, above). Zhou discloses that the role of the lithium supplementing material (corresponds to ternary material) in the lithium compensation layer is to supplement lithium consumed by the negative electrode SEI film [0004, 0049, 0126, 0129]. Zhou further discloses that various changes can be made to the illustrative embodiments [0132]. Zhou does not teach that “the ternary material comprises one or more of a ternary material containing a nickel element, a cobalt element and a manganese element, and a ternary material containing a nickel element, a cobalt element and an aluminum element”.
Huang teaches a similar secondary battery including lithium iron phosphate and a ternary material [Abstract, 0007-0009]. Huang teaches that lithium iron phosphate batteries suffer an active lithium loss during the initial formation and subsequent use process, and that the batteries need to be replenished with lithium in order to increase the battery capacity [0027]. Huang teaches that a ternary material can be successfully used to replenish a lithium iron phosphate battery with lithium, thereby improving battery capacity [0008]. The ternary material comprises lithium nickel manganese cobalt oxide or lithium nickel cobalt aluminum oxide [0009].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have added the ternary material taught by Huang to the lithium compensation layer instead of or in addition to the lithium supplementing material disclosed by Zhou, with a reasonable expectation that the addition of a lithium nickel manganese cobalt oxide or lithium nickel cobalt aluminum oxide would result in a successful lithium compensation layer capable of supplementing lithium consumed by an SEI layer (MPEP 2144.06; MPEP 2144.07).
Regarding Claim 14, Zhou renders obvious all of the limitations as set forth above, including that the positive electrode sheet comprises a positive electrode active material comprises lithium iron phosphate and a lithium compensation layer comprising a ternary material (see rejection of Claim 1, above). Zhou does not specify the operating voltage of the secondary battery, and therefore does not teach that the operating voltage is 2 V-3.8 V.
Huang teaches that lithium iron phosphate batteries suffer an active lithium loss during the initial formation and subsequent use process, and that the batteries need to be replenished with lithium in order to increase the battery capacity [0027]. Huang teaches that a ternary material can be successfully used to replenish a lithium iron phosphate battery with lithium, thereby improving battery capacity [0008]. The ternary material comprises lithium nickel manganese cobalt oxide or lithium nickel cobalt aluminum oxide [0009].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have added the ternary material taught by Huang to the lithium compensation layer of Zhou, with a reasonable expectation that the addition of a ternary material as taught by Huang would result in a successful positive electrode sheet capable of use in a secondary battery (MPEP 2144.06; MPEP 2144.07).
Huang further teaches that the lithium-ion battery can be operated with an upper limit of 3.8 V to 4.0 V and a lower limit of 2 V to 2.8 V [0017-0018, 0036]. Advantageously, such an operating voltage can take into account the operating voltage ranges of both the lithium iron phosphate material and the ternary material, thus simultaneously taking advantage of the high safety and long service life of the lithium iron phosphate material and the high energy density of the ternary material [0036].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the operating range of the secondary battery of modified Zhou to have a lower limit within a range of 2 V to 2.8 V and an upper limit within a range of 3.8 V to 4.0 V, including selecting the lower limit to be 2 V and the upper limit to be 3.8 V, with a reasonable expectation that such a voltage range would result in a successful secondary battery capable of providing high safety / long service life and high energy density (MPEP 2144.05, I).
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhou et al. (WO-2021088166-A1; see English equivalent US-20220223859-A1 for citations) as evidenced by Cen et al. (J. Phys. Energy 5; see attached NPL for citations) as applied to Claim 1, above, and in further view of Bie et al. (WO-2022067812-A1; see English equivalent US-20220359874-A1 for citations).
Regarding Claim 8, Zhou renders obvious all of the limitations as set forth above, including that the positive electrode active material layer comprises lithium iron phosphate, and that the lithium compensation layer comprises a ternary material (see rejection of Claim 1, above). Although Zhou discloses that the positive electrode sheet is designed to improve energy density [0049-0050, 0126, 0129], Zhou does not specify the compacted density of the lithium compensation layer, and therefore does not teach that the compacted density is 3 g/cm3-3.8 g/cm3.
Bie teaches a positive electrode comprising lithium iron phosphate and a ternary material [Abstract, 0011, 0024]. Bie teaches that the compaction density of the positive electrode active material can be within 2.6-3.5 g/cm3 [0026]. The positive electrode active material of Bie comprises both the lithium iron phosphate material and the ternary material [0024], and corresponds to the combination of the positive electrode active material layer and the lithium compensation layer of Zhou. Advantageously, by adjusting the mass per unit area and the compacted density, resistivity and extractable capacity per unit area of the positive electrode plate can be regulated, thereby ensuring that the prepared battery has high kinetic performance and energy density [0027].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the compacted density of both the positive electrode active material layer and the lithium compensation layer of Zhou to be within the range of 2.6-3.5 g/cm3 rendered obvious by Bie with a reasonable expectation that selecting any portion of this range, including 3 g/cm3-3.5 g/cm3, would result in a successful positive electrode active material layer and a successful lithium compensation layer (MPEP 2144.05, I). Modified Zhou thereby renders obvious that a compacted density of the lithium compensation layer is including 3 g/cm3-3.5 g/cm3, which is within the claimed range of including 3 g/cm3-3.8 g/cm3.
Claim(s) 1-8 and 10-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ma et al. (CN-114583098-A; cited in IDS filed 09/12/2025; see also attached English translation for citations) in view of Huang et al. (CN-115692635-A; cited in IDS filed 09/12/2025; see English equivalent US-20240170644-A1 for citations).
Regarding Claims 1 and 10-11, Ma discloses a positive electrode sheet (positive electrode; [0025]), comprising:
a positive electrode current collector (1, Fig. 1; [0003, 0025]),
at least a side of the positive electrode current collector being provided with a positive electrode active material layer (second layer 22, Fig. 1; [0003, 0025]),
at least a side of the positive electrode active material layer (second layer) being provided with a lithium compensation layer (first layer 21, Fig. 1; [0003, 0025]),
the positive electrode active material layer comprising lithium iron phosphate [0028, 0057].
Ma discloses that the lithium compensation layer (first layer) comprises a lithium supplement which replenishes lithium in the positive electrode active material layer (second layer) [0025, 0027-0029]. Ma does not teach that the lithium compensation layer comprises a ternary material.
Huang teaches a similar secondary battery including lithium iron phosphate and a ternary material [Abstract, 0007-0009]. Huang teaches that lithium iron phosphate batteries suffer an active lithium loss during the initial formation and subsequent use process, and that the batteries need to be replenished with lithium in order to increase the battery capacity [0027]. Huang teaches that a ternary material can be successfully used to replenish a lithium iron phosphate battery with lithium, thereby improving battery capacity [0008].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have used a ternary material as taught by Huang instead of or in addition to the lithium supplement material taught by Ma with a reasonable expectation that the use of a ternary material in the lithium compensation layer (first layer) would result in a successful secondary battery capable of replenishing lithium in the positive electrode active material layer (second layer) (MPEP 2144.06, MPEP 2144.07).
Ma discloses that, in some embodiments, the mass percentage of ternary material (i.e. lithium supplement) in the lithium compensation layer (first layer) is 95% to 97% [0009, 0029]. The lithium compensation layer can further comprise 2-3% of a conductive agent and 1-2% of a binder [0009, 0032]. Ma also discloses that the lithium supplement can further include at least one of lithium carbonate, lithium bicarbonate, lithium hydroxide or free lithium [0035]. These substances have a high lithium replenishment efficiency, but may produce gas and release heat [0035]. Accordingly, their content must be controlled to ensure safety, and the total mass percentage of these substances is less than 10% [0035].
Therefore, although not disclosed in a specific embodiment, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have included less than 10 mass% of a substance with high lithium replenishment efficiency in addition to the ternary material, conductive agent and binder rendered obvious by modified Ma. Accordingly, the lithium compensation layer rendered obvious by modified Ma comprises about 85-97% ternary material, 2-3% conductive agent, 1-2% binder, and less than 10% high efficiency lithium supplement.
The content of ternary material rendered obvious by the prior art (i.e. 85-97%) overlaps the range of 80%-92% recited in Claim 1 and the range of 90-92% recited in Claim 10. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the range recited in the prior art, including the overlapping portion of the range (i.e. 90-92%), with a reasonable expectation that such a selection would result in a successful lithium compensation layer (MPEP 2144.05, I).
The addition of a conductive agent and a binder to the lithium compensation layer corresponds to the recited limitation of Claim 11.
Regarding Claim 2, modified Ma renders obvious all of the limitations as set forth above. Ma further discloses that the lithium compensation layer (first layer 21, Fig. 1) is provided between the positive electrode current collector (1, Fig. 1) and the positive electrode active material layer (second layer 22, Fig. 1) (see Fig. 1; [0003, 0012-0013, 0025]).
Regarding Claim 3, modified Ma renders obvious all of the limitations as set forth above, including that the lithium compensation layer (first layer) comprises a ternary material. Although Ma does not explicitly teach that “the ternary material comprises one or more of a ternary material containing a nickel element, a cobalt element and a manganese element, and a ternary material containing a nickel element, a cobalt element and an aluminum element”, Huang teaches that the ternary material comprises lithium nickel manganese cobalt oxide or lithium nickel cobalt aluminum oxide [0009].
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the ternary material to be lithium nickel manganese cobalt oxide (i.e. “a ternary material containing a nickel element, a cobalt element and a manganese element”) or lithium nickel cobalt aluminum oxide (i.e. “a ternary material containing a nickel element, a cobalt element and an aluminum element”) with a reasonable expectation that such a selection would result in a successful ternary material.
Regarding Claims 4-5, modified Ma renders obvious all of the limitations as set forth above. Although Ma does not explicitly teach a percentage ratio of a mass of the ternary material to a mass of the lithium iron phosphate, Ma does disclose the following:
The mass percentage of the lithium supplement in the first layer (reads on ternary material in the lithium compensation layer) is within the range of 95% to 97%, and the mass percentage of positive electrode material in the second layer (reads on lithium iron phosphate in the positive electrode active material layer) is within the range of 95% to 97% [0029].
The thickness of the lithium compensation layer (first layer) can be within a range of 1-25 µm, and the thickness of the positive electrode active material layer (second layer) can be within a range of 80-200 µm [0008, 0031].
The thickness of the lithium compensation layer (first layer) is selected in view of maintaining the structural stability of the active material layer [0029]. However, if the thickness of the lithium compensation layer (first layer) is too large, the path that the released lithium ions need to travel will be too long, which is detrimental to the transmission of lithium ions [0031]. Ma also discloses that the cyclic capacity decay of a battery is tied to the consumption of lithium from the positive electrode active material [0022-0024]. However, if the thickness of the positive electrode active material layer (second layer) is too large, overall conductivity of the positive electrode will be affected, and the requirements of the binder will be increased [0031].
Therefore, although Ma does not explicitly teach that a percentage ratio of a mass of the ternary material to a mass of the lithium iron phosphate is “1%-10%” as required by Claim 4, or “3%-5%” as required by Claim 5, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention to have optimized the thickness of the lithium compensation layer and the thickness of the positive electrode active material layer, thereby optimizing the mass ratio of the ternary material to the lithium iron phosphate material, in order to achieve a balance between capacity / conductivity and structural stability / lithium ion transmission (MPEP 2144.05, II). One of ordinary skill in the art would have had a reasonable expectation that optimizing the thickness of each layer such that a percentage ratio of a mass of the ternary material to a mass of the lithium iron phosphate is 3%-5% would result in a successful positive electrode sheet. The range rendered obvious by the prior art is within the range recited in Claim 4, and corresponds to the range recited in Claim 5.
Regarding Claim 6, modified Ma renders obvious all of the limitations as set forth above. Ma discloses a specific embodiment (Example 2; [0064]) wherein the thickness of the first layer (lithium compensation layer) is 5.4 µm, and the thickness of the second layer (positive electrode active material layer) is 94.5 µm [0058]. As such, the single-side thickness H2 of the lithium compensation layer (i.e. 5.4 µm) and the single-side thickness H1 of the positive electrode active material layer (i.e. 94.5 µm), which satisfy the condition 5H2≤H1≤30H2 (i.e. 27 µm ≤ 94.5 ≤ 162 µm).
Regarding Claim 7, modified Ma renders obvious all of the limitations as set forth above. Although Ma does not disclose that the single-side thickness H1 of the positive electrode active material layer and the single-side thickness H2 of the lithium compensation layer satisfy the condition 10H2≤H1≤15H2 in a single embodiment, Ma broadly discloses that the thickness (i.e. H1) of the positive electrode active material layer (second layer) can be within a range of 80-200 µm, and the thickness (i.e. H2) of the lithium compensation layer (first layer) can be within a range of 1-25 µm [0008, 0031].
The ranges rendered obvious by the prior art result encompass a thickness of the positive electrode active material layer and a thickness of the lithium compensation layer which satisfy the condition 10H2≤H1≤15H2 (e.g. if H1 = 100 µm and H2 = 7 µm). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the ranges disclosed in the prior art, including selecting the portions which satisfy the condition 10H2≤H1≤15H2, with a reasonable expectation that such thicknesses would result in a successful positive electrode sheet (MPEP 2144.05, I).
Additionally, Ma also discloses that the thickness of the lithium compensation layer (first layer) is selected in view of maintaining the structural stability of the active material layer [0029]. However, if the thickness of the lithium compensation layer (first layer) is too large, the path that the released lithium ions need to travel will be too long, which is detrimental to the transmission of lithium ions [0031]. Ma also discloses that the cyclic capacity decay of a battery is tied to the consumption of lithium from the positive electrode active material [0022-0024]. However, if the thickness of the positive electrode active material layer (second layer) is too large, overall conductivity of the positive electrode will be affected, and the requirements of the binder will be increased [0031].
Therefore, it would further have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have optimized the thicknesses of the positive electrode active material layer and the lithium compensation layer, including selected the single-side thickness H1 of the positive electrode active material layer and the single-side thickness H2 of the lithium compensation layer satisfy the condition 10H2≤H1≤15H2, with a reasonable expectation that such thicknesses would result in a successful positive electrode sheet capable of balancing between capacity / conductivity and structural stability / lithium ion transmission (MPEP 2144.05, II).
Regarding Claim 8, modified Ma renders obvious all of the limitations as set forth above. Although Ma does not specifically teach the compacted density of the lithium compensation layer, Ma does disclose that the lithium supplement agent releases gas after lithium supplementation, and that the thickness (T1) of the lithium compensation layer (first layer) and the weight (G) per area of the active material layer 2 (i.e. the combination of the first layer 21 and the second layer 22; see Fig. 1) must be selected in order to prevent damage to the structure of the active material layer [0026]. The ratio of G/T cannot be too large, so as to ensure that there is sufficient lithium supplement agent in the active material layer for lithium supplementation [0026]. On the other hand, the ratio cannot be too small in order to prevent excessive lithium supplement agent from releasing gas and damaging the structure of the active material layer during supplementation [0026].
Therefore, although modified Ma does not explicitly teach that a compacted density of the lithium compensation layer is 3 g/cm3-3.8 g/cm3, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have optimized the thickness of the lithium compensation layer and the weight per unit area of the active material layer 2 (i.e. the combination of the lithium compensation layer and the positive electrode active material layer), including selecting a thickness and a weight per unit area that result in a lithium compensation layer with a density of 3 g/cm3-3.8 g/cm3 (MPEP 2144.05, II). One of ordinary skill in the art would have had a reasonable expectation that such a density would result in lithium compensation layer capable of supplying sufficient lithium without damaging the structure of the positive electrode sheet.
Regarding Claim 12, modified Ma renders obvious all of the limitations as set forth above. Ma further discloses a method for preparing the positive electrode sheet according to claim 1, comprising: forming the positive electrode active material layer and forming the lithium compensation layer [0012-0013, 0026, 0049-0050, 0056-0058].
Regarding Claim 13, modified Ma renders obvious all of the limitations as set forth above. Ma further discloses a secondary battery, comprising the positive electrode sheet according to claim 1 [0017, 0040, 0047, 0053, 0062].
Regarding Claim 14, modified Ma renders obvious all of the limitations as set forth above, including that the positive electrode sheet of the secondary battery comprises lithium iron phosphate and a ternary material (see rejection of Claim 1, above). Although Ma discloses charge conditions for cycle performance testing [0090], Ma does not teach the operating voltage of the secondary battery.
Huang teaches a similar secondary battery including a positive electrode comprising lithium iron phosphate and a ternary material [Abstract, 0007-0009]. Huang teaches that the lithium-ion battery can be operated with an upper limit of 3.8 V to 4.0 V and a lower limit of 2 V to 2.8 V [0017-0018, 0036]. Advantageously, such an operating voltage can take into account the operating voltage ranges of both the lithium iron phosphate material and the ternary material, thus simultaneously taking advantage of the high safety and long service life of the lithium iron phosphate material and the high energy density of the ternary material [0036].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the operating range of the secondary battery of modified Ma to have a lower limit within a range of 2 V to 2.8 V and an upper limit within a range of 3.8 V to 4.0 V, including selecting the lower limit to be 2 V and the upper limit to be 3.8 V, with a reasonable expectation that such a voltage range would result in a successful secondary battery capable of providing high safety / long service life and high energy density (MPEP 2144.05, I).
Regarding Claim 15, modified Ma renders obvious all of the limitations as set forth above. Ma further discloses an electric device (electronic device), comprising the secondary battery according to claim 13 [0017, 0053].
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ma et al. (CN-114583098-A; cited in IDS filed 09/12/2025; see also attached English translation for citations) in view of Huang et al. (CN-115692635-A; cited in IDS filed 09/12/2025; see English equivalent US-20240170644-A1 for citations) as applied to Claim 1, above, and in view of Zhou et al. (WO-2021088166-A1; see English equivalent US-20220223859-A1 for citations).
Regarding Claim 16, modified Ma renders obvious all of the limitations as set forth above, including that the lithium compensation layer comprises a conductive agent and a binder, and that the mass ratio of the ternary material, the conductive agent, and the binder is (85-97) : (2-3) : (1-2) (see rejection of Claim 1, above). Ma discloses these contents as “some embodiments” of the application [0032], and further notes that the above description is merely a preferred embodiment, and can be modified within the scope of the invention [0095]. Ma does not teach contents of conductive agent or binder which result in the claimed range of “a mass ratio of the ternary material, the conductive agent, and the binder in the lithium compensation layer being (80-90): (4-8): (6-12)”.
Zhou teaches a positive electrode comprising a double layer structure [0008, 0017, 0049, 0040, 0130] containing a similar lithium compensation layer (lithium supplementing material layer) [0008, 0014-0015, 0034, 0036-0039]. Zhou teaches that the lithium compensation layer can comprise a conductive additive and a binder, and that the conductive additive and binder can each be added to the lithium compensation layer at higher contents (i.e. 5-10 wt%) [0015, 0036-0039]. Such a lithium compensation layer is able to successfully supplement lithium consumed during charging [0004, 0049-0050, 0126, 0129].
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have substituted the content of conductive additive and binder in the lithium compensation layer of modified Ma as taught by Zhou with a reasonable expectation that providing a higher content of conductive additive (i.e. 5-10 wt%) and a higher content of binder (i.e. 5-10 wt%) would result in a successful lithium compensation layer (MPEP 2143, B).
The contents of ternary material, conductive agent, and binder as rendered obvious by modified Ma overlap the claimed ranges. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the ranges rendered obvious by the prior art, including the overlapping portion of the ranges, with a reasonable expectation that such ranges of ternary material, conductive agent, and binder would result in a successful lithium compensation layer (MPEP 2144.05, I).
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ma et al. (CN-114583098-A; cited in IDS filed 09/12/2025; see also attached English translation for citations) in view of Huang et al. (CN-115692635-A; cited in IDS filed 09/12/2025; see English equivalent US-20240170644-A1 for citations) and in view of Zhou et al. (WO-2021088166-A1; see English equivalent US-20220223859-A1 for citations).
Regarding Claim 17, Ma discloses a positive electrode sheet (positive electrode; [0025]), comprising:
a positive electrode current collector (1, Fig. 1; [0003, 0025]),
at least a side of the positive electrode current collector being provided with a positive electrode active material layer (second layer 22, Fig. 1; [0003, 0025]),
at least a side of the positive electrode active material layer (second layer) being provided with a lithium compensation layer (first layer 21, Fig. 1; [0003, 0025]),
the positive electrode active material layer comprising lithium iron phosphate [0028, 0057].
Ma discloses that the lithium compensation layer (first layer) comprises a lithium supplement which replenishes lithium in the positive electrode active material layer (second layer) [0025, 0027-0029]. Ma does not teach that the lithium compensation layer comprises a ternary material.
Huang teaches a similar secondary battery including lithium iron phosphate and a ternary material [Abstract, 0007-0009]. Huang teaches that lithium iron phosphate batteries suffer an active lithium loss during the initial formation and subsequent use process, and that the batteries need to be replenished with lithium in order to increase the battery capacity [0027]. Huang teaches that a ternary material can be successfully used to replenish a lithium iron phosphate battery with lithium, thereby improving battery capacity [0008].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have used a ternary material as taught by Huang instead of or in addition to the lithium supplement material taught by Ma with a reasonable expectation that the use of a ternary material in the lithium compensation layer (first layer) would result in a successful secondary battery capable of replenishing lithium in the positive electrode active material layer (second layer) (MPEP 2144.06, MPEP 2144.07).
Ma discloses that, in some embodiments, the mass percentage of ternary material (i.e. lithium supplement) in the lithium compensation layer (first layer) is 95% to 97% [0009, 0029], and the lithium compensation layer can further comprise 2-3% of a conductive agent and 1-2% of a binder [0009, 0032]. Therefore, modified Ma renders obvious that the lithium compensation layer further includes a conductive agent and a binder.
Ma discloses these contents as “some embodiments” of the application [0032], and further notes that the above description is merely a preferred embodiment, and can be modified within the scope of the invention [0095]. Ma does not teach contents of conductive agent or binder which result “a mass ratio of the ternary material, the conductive agent, and the binder in the lithium compensation layer being (80-90): (4-8): (6-12)”.
Zhou teaches a positive electrode comprising a double layer structure [0008, 0017, 0049, 0040, 0130] containing a similar lithium compensation layer (lithium supplementing material layer) [0008, 0014-0015, 0034, 0036-0039]. Zhou teaches that the lithium compensation layer can comprise 80-90 wt% of lithium supplementing material, 5-10 wt% of conductive agent, and 50-10 wt% of binder [0015, 0036-0039]. Such a lithium compensation layer is able to successfully supplement lithium consumed during charging [0004, 0049-0050, 0126, 0129].
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have substituted the content of lithium supplementing material (i.e. ternary material), conductive agent and binder in the lithium compensation layer of modified Ma as taught by Zhou with a reasonable expectation that providing a mass ratio of the ternary material, the conductive agent, and the binder to be (80-90) : (5-10) : (5-10) would result in a successful lithium compensation layer (MPEP 2143, B).
The contents of ternary material, conductive agent, and binder as rendered obvious by modified Ma overlap the claimed ranges. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the ranges rendered obvious by the prior art, including the overlapping portion of the ranges (i.e. (80-90): (5-8): (6-10)), with a reasonable expectation that such ranges of ternary material, conductive agent, and binder would result in a successful lithium compensation layer (MPEP 2144.05, I).
Response to Arguments
Applicant’s arguments filed 01/21/2026 have been considered but were not found persuasive. Specifically, Applicant argued that the prior arts Gong and Ma do not disclose the newly cited weight fraction of ternary material (Remarks, Pgs. 6-8). The Examiner notes that Ma allows for a weight fraction which overlaps the range claimed in Claim 1, as noted in the rejections of record, above. Newly presented claims 16 and 17 are rejected over Ma in view of newly cited Zhou. Additionally, to expedite compact prosecution, the claims are further rejected over newly cited Zhou.
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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/D.C.N./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 3/3/2026