DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
The Amendment filed on 1/13/2026 has been entered. Claims 12 and 15 are cancelled. Claims 21 and 22 are added. Claims 1-11, 13,14, and 16-22 remain pending in the application. Applicant’s amendments to the claims have overcome each and every objection and 112(b) rejection previously set forth in the Non-Final Office Action mailed 11/05/2025.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-5 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Huang et al. (WO 2020042571, referring to previously provided translation thereof, hereinafter "Huang") in view of Oh et al. (US 2019/0198857, hereinafter "Oh").
Regarding claim 1, Huang teaches a secondary battery comprising a negative electrode (“negative electrode plate”) [0001]. The negative electrode comprises a negative electrode current collector, a first negative electrode active material layer comprising a first negative electrode active material, and a second negative electrode active material layer comprising a second negative electrode active material, wherein the first negative electrode active material layer is disposed on the surface of the negative electrode current collector and the second negative electrode active material layer is disposed on the surface of the first negative electrode active material layer [0006]. The first negative electrode active material may be artificial graphite, preferably coated with amorphous carbon (‘first artificial graphite”) [0024, “the negative electrode active material can be one or more of graphite”, “The graphite can be selected from one or more of artificial graphite”, “more preferably, it is coated and modified with amorphous carbon”]. Huang is silent regarding the first negative electrode active material comprising secondary particles and a second artificial graphite comprising primary particles.
Oh teaches analogous art of a negative electrode for a lithium secondary battery [0002]. The negative electrode comprises a composite negative electrode active material including a first carbon-based material (“first artificial graphite”) and a second carbon-based material (“second artificial graphite”) that are different from each other [0035]. The first carbon-based material may include a first artificial graphite secondary particle [0047], and an amorphous carbon coating layer positioned only on the surface of the first carbon-based material [0069-0070]. The second carbon-based material may include artificial graphite primary particles [0052]. Oh also teaches that the first carbon-based material and second carbon-based material are mixed [0021, “sintering a mixture of the first carbon-based secondary particles and second carbon-based primary particles to form a composite negative electrode active material”].
Oh teaches that the composite negative electrode active material has suppressed volume expansion and improved output and rate characteristics [0009].
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have modified the first negative electrode active material layer taught by Huang to include the composite negative electrode active material including the first carbon-based material and the second carbon-based material taught by Oh, in order to suppress volume expansion and improve output and rate characteristics of the negative electrode.
Further regarding claims 2 and 3, Huang teaches that the specific surface are of the first negative electrode active material is preferably in the range of 1 m2/g to 3 m2/g [0019, “Preferably, the specific surface area (BET) of the first negative electrode active material of the present invention can be controlled within the range of 1m2/g to 3m2/g”], which overlaps the recited ranges of 1.0 m2/g to 1.6 m2/g in claim 2 and 1.05 m2/g to 1.3 m2/g in claim 3. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Further regarding claims 4 and 5, Huang is silent regarding a ratio of a mass of the amorphous carbon coating layer in the first artificial graphite to a mass of the first artificial graphite.
Oh teaches that the amount of carbon coating layer, which may be amorphous carbon, may be 8 weight % or less based on the total weight of the negative electrode active material [0073]. The weight ratio of the first carbon-based material to the second carbon-based material may be 90:10 to 80:20 [0064]. For a weight ratio of first carbon-based material to second carbon-based material of 90:10, a ratio of the weight of the carbon coating layer in the first carbon-based material to the total weight of the carbon coating layer is 7.2% or less, which overlaps the recited ranges of 1%-5% in claim 4 and 3%-4% in claim 5. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Oh teaches that the amount of carbon coating may be in any suitable range as long as it does not hinder or reduce battery characteristics [0073, “The amount of the carbon coating layer may be in any suitable range as long as it does not hinder (or does not unacceptably reduce) the battery characteristics “].
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have modified first artificial graphite taught by modified Huang to optimize the mass of the amorphous carbon coating layer within the range taught by Oh through routine experimentation in order to prevent hindering or reducing battery characteristics. See MPEP 2144.05 II A, "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." (In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955)).
Further regarding claim 20, Huang does not specifically teach an electric apparatus comprising the secondary battery.
Oh teaches that the battery using the composite negative electrode active material may be used in a battery pack which may be used in any suitable device (“electric apparatus”).
Both Huang and Oh teach batteries meant to provide power. Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have included the secondary battery taught by Huang and modified by Oh in a device as taught by Oh, in order to provide power to said device.
Claims 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) as applied to claim 1 above, and further in view of Kang et al. (US 2022/0302450, hereinafter "Kang").
Regarding claims 6 and 7, modified Huang teaches the secondary battery of claim 1 as described in the rejection of instant claim 1. Huang does not specifically teach the second artificial graphite satisfying the conditions recited in claims 6 and 7.
Kang teaches analogous art of a negative electrode for a rechargeable lithium battery (“secondary battery”) comprising a first negative electrode active material layer and a second negative electrode active material layer [Abstract, “A negative electrode for a rechargeable lithium battery which includes a current collector, a first negative electrode active material layer on one surface or both surfaces of the current collector; a second negative electrode active material layer on the first negative electrode active material layer”]. The first negative electrode active material layer includes a first negative electrode active material comprising graphite (“second artificial graphite”) of single particles (“primary particles”) [Abstract, 0005, “For a negative electrode active material, a crystalline carbon material such as natural graphite or artificial graphite”]. The first negative electrode active material has a pellet density (“powder compacted density”) of greater than 1.6 g/cc (g/cm3) and less than or equal to 2.0 g/cc, which overlaps the recited ranges of 1.6 g/cm3-1.85 g/cm3 in claim 6 and 1.6 g/cm3-1.8 g/cm3 in claim 7 [0039]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Kang teaches that when the first negative electrode active material pellet density is within the range disclosed, the negative electrode active material has excellent or suitable density characteristics and high capacity [0039].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the second-carbon based material taught by modified Huang to have a pellet density within the range taught by Kang, in order to provide suitable density characteristics and high capacity.
Claims 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) as applied to claim 1 above, and further in view of Ma et al. (WO 2020088231, referring to Examiner-provided translation thereof, hereinafter "Ma").
Regarding claims 8 and 9, modified Huang teaches the secondary battery of claim 1, as described in the rejection of instant claim 1. Modified Huang does not specifically teach the conditions recited in claims 8 and 9.
Ma teaches analogous art of a negative electrode sheet comprising a first active material layer comprising a first negative electrode active material and a second active material layer comprising a second negative electrode active material [0008]. The degree of graphitization in the first negative electrode active material is preferably greater than the degree of graphitization of the second negative electrode active material [0059]. The degree of graphitization may be 93% in the second negative electrode active material and 96% in the first negative electrode active material, therefore the ratio of the degree of graphitization in the second negative electrode active material to the degree of graphitization in first negative electrode active material would be 0.97, which is within the range recited in claim 7 of 0.95-0.99 [Table 1].
Ma teaches that when the degree of graphitization of the first negative electrode active material is higher, there are fewer defects, lower surface activity, and an SEI is more easily formed, which improves cycle performance [0060]. Ma teaches that when the degree of graphitization of the second negative electrode active material is lower, the inter-crystal spacing is larger, resistance is reduced, and ions are prevented from accumulating on the electrode surface, which affects the battery’s fast charging capability [0060].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the degree of graphitization of the first negative electrode active material and the second negative electrode active material taught by modified Huang to have a degree of graphitization within the range taught by Ma, in order to improve cycle performance and fast charging capability of the battery.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) as applied to claim 1 above, and further in view of Jung et al. (US 2024/0372077, hereinafter "Jung").
Regarding claim 10, modified Huang teaches the secondary battery of claim 1 as described in the rejection of instant claim 1. Huang further teaches that the second negative electrode active material may be an artificial graphite (“third artificial graphite”) coated with an amorphous carbon coating layer (“second amorphous carbon coating layer”) [0024]. Huang does not specifically teach the second negative electrode active material being secondary particles.
Jung teaches analogous art of a negative electrode comprising a negative electrode active material layer having a lower layer region comprising a first active material and an upper layer region disposed on the lower layer region comprising a second active material, the second active material including secondary particles of artificial graphite (“third artificial graphite”) with a carbon coating layer disposed on the secondary particles [Abstract]. The carbon coating layer may be amorphous carbon [0054]. The carbon coating layer may be present in an amount of 0.5-10 wt % based on the total weight of the second active material, which overlaps the recited range of 2%-8% [0023]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Jung teaches that quick charging performance may be improved by using secondary artificial graphite particles provided with a carbon coating layer in the upper layer [0038, “quick charging performance can be further improved by using secondary particles of artificial graphite provided with a carbon coating layer in the upper layer”].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the second negative electrode active material taught by modified Huang to include secondary artificial graphite particles with a carbon coating layer of amorphous carbon with the ratio of the mass of amorphous carbon based on the mass of the secondary artificial graphite particles within the range taught by Jung, in order to improve quick charging performance.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) and Jung (US 2024/0372077) as applied to claim 10 above, and further in view of Cha et al. (US 2020/0335795, hereinafter “Cha”).
Regarding claim 11, modified Huang teaches the secondary battery of claim 10 as described in the rejection of instant claim 10. Huang does not specifically teach the median particle size by volume Dv50 of the negative electrode active materials.
Cha teaches analogous art of a negative electrode for a lithium secondary battery, the negative electrode comprising a current collector, and a negative electrode active material layer including a first active material layer comprising a first negative electrode active material (“first artificial graphite”) and a second active material layer comprising a second negative electrode active material (“third artificial graphite”) [Abstract, “The negative electrode for a lithium secondary battery comprises a current collector and a negative electrode active material layer formed on the current collector, wherein the negative electrode active material layer includes a first negative electrode active material and a first binder, and a second active material layer formed on the first active material layer”]. Cha teaches that the first negative electrode active material /first active material and the second negative electrode active material/second active material may be carbonaceous negative electrode active material, such as artificial graphite [0036-0037]. Cha also teaches that the average particle diameter (D50) of the first active material is larger than the average particle diameter (D50) of the second active material [0042]. Cha discloses that the average particle diameter D50 indicates a diameter of a particle where a cumulative volume is 50 volume % in a particle distribution [0043], which is the same definition of Dv50 found in the instant specification [0075 of filed specification, “Dv50 refers to a particle size corresponding to a cumulative volume distribution percentage of a measured material reaching 50%”].
Cha teaches that when the D50 of the first active material is larger than the D50 of the second active material, adherence to the current collector may be improved and contact resistance may be decreased, thus improving battery performance [0042].
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have modified the secondary battery taught by modified Huang to make the D50 of the second negative electrode active material (“third artificial graphite”) smaller than the D50 of the first negative electrode active material (“first artificial graphite”) as taught by Cha, in order to improve the negative electrode adherence to the current collector, decrease contact resistance, and improve overall battery performance.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) as applied to claim 1 above, and further in view of Ma (WO 2020088231).
Regarding claim 13, modified Huang teaches the secondary battery of claim 6 as described in the rejection of instant claim 6. Huang further teaches that the second negative electrode active material may be an artificial graphite (“third artificial graphite”) [0024]. Huang does not specifically teach the degree of graphitization of the second negative electrode active material.
Ma teaches analogous art of a negative electrode sheet comprising a first active material layer comprising a first negative electrode active material and a second active material layer comprising a second negative electrode active material [0008]. The degree of graphitization in the first negative electrode active material is preferably greater than the degree of graphitization of the second negative electrode active material [0059]. The degree of graphitization may be 93% in the second negative electrode active material and 96% in the first negative electrode active material, therefore the ratio of the degree of graphitization in the second negative electrode active material to the degree of graphitization in first negative electrode active material would be 0.97, which is within the range recited in claim 7 of 0.95-0.99 [Table 1].
Ma teaches that when the degree of graphitization of the first negative electrode active material is higher, there are fewer defects, lower surface activity, and an SEI is more easily formed, which improves cycle performance [0060]. Ma teaches that when the degree of graphitization of the second negative electrode active material is lower, the inter-crystal spacing is larger, resistance is reduced, and ions are prevented from accumulating on the electrode surface, which affects the battery’s fast charging capability [0060].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the degree of graphitization of the first carbon-based material and the second negative electrode active material taught by modified Huang to have a degree of graphitization within the range taught by Ma, in order to improve cycle performance and fast charging capability of the battery.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) as applied to claim 1 above, and further in view of Ahn et al. (US 2014/0287316, hereinafter "Ahn").
Regarding claims 14 and 15, modified Huang teaches the secondary battery of claim 1 as described in the rejection of instant claim 1. Huang is silent regarding the compacted density of the first and second negative electrode active material layers.
Ahn teaches analogous art of an anode for a lithium secondary battery comprising a first anode active material layer including a first anode active material formed on the electrode current collector, and a second anode active material layer [Abstract]. The press density (“compacted density”) of the second anode active material layer is smaller than the press density of the first anode active material layer [0021, “a second anode active material 24 having a relatively lower press density and a relatively larger average particle diameter than the first anode active material”]. The press density of the first anode active material is in a range of 1.4 g/cc (g/cm3) to 1.85 g/cc, and the second anode active material layer is in a range of 1.4 g/cc to 1.6 g/cc, both of which overlap the recited ranges in claims 14 and 15 [0029]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Ahn teaches that when the second anode active material layer has a lower press density than the first anode active material layer on which it is disposed, the damage to the surface of the anode active material layer may be prevented [0033].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the first and second negative electrode active layers taught by modified Huang to have press densities with the ranges disclosed by Ahn, in order to prevent damage to the anode active material layer.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) as applied to claim 1 above, and further in view of Ryu et al. (US 2020/0287245, hereinafter "Ryu").
Regarding claim 16, modified Huang teaches the secondary battery of claim 1 as described in the rejection of instant claim 1. Huang is silent regarding a ratio of a mass of the first negative electrode active material layer to a mass of the second negative electrode active material layer.
Ryu teaches analogous art of a negative electrode comprising a first negative electrode active material layer formed on a negative electrode current collector and a second negative electrode active material layer formed on the first negative electrode active material layer [Abstract]. The weight ratio of the first negative electrode active material layer and the second negative electrode active material layer is preferably 30:70 to 50:50, which overlaps the recited range [0062]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Ryu teaches that the performance of the battery can be adjusted by varying the ratio of the negative electrode active material layers [0062].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the negative electrode taught by modified Huang to optimize the weight ratio of the first negative electrode active material layer and the second negative electrode active material layer within the range taught by Ryu through routine experimentation. The motivation to do so would have been to adjust the performance of the battery to a suitable degree. See MPEP 2144.05 II A, "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." (In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955)).
Claims 17-19 are rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) as applied to claim 1 above, and further in view of Kim et al. (US 2023/0038741, hereinafter "Kim").
Regarding claim 17, modified Huang teaches the secondary battery of claim 1 as described in the rejection of instant claim 1. Huang is silent regarding a mass percentage of silicon-based material in the first negative electrode active material and the second negative electrode active material.
Kim teaches analogous art of an anode (“negative electrode”) for a secondary battery comprising an anode active material comprising a silicon-based active material, a first carbon-based material, and a second carbon-based material [Abstract]. The anode may include a first anode active material layer and a second anode active material layer formed on the first anode active material layer [0020]. The content of the silicon-based active material in the first anode active material layer is 6 wt% or less based on a total weight of the first anode active material layer, and a content of the silicon-based active material included in the second anode active material layer may be equal to or greater than 8 wt % and less than 40 wt % based on a total weight of the second anode active material layer [0021]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Kim teaches that the amounts of silicon-based material may be smaller in a region closer to the current collector and increase as the distance from the current collector increases in order to prevent expansion and contraction of the anode, improve high temperature storage and lifespan properties, and maintain the power of the secondary battery [0117].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the negative electrode taught by modified Huang to include a silicon-based active material in the first and second negative electrode active material layers within the ranges taught by Kim, in order to prevent expansion and contraction of the anode, improve high temperature storage and lifespan properties, and maintain the power of the secondary battery.
Further regarding claim 18, Kim teaches that the content of the silicon-based active material in the first anode active material layer is 6 wt% or less based on a total weight of the first anode active material layer [0021]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
As described previously, Kim teaches that the amounts of silicon-based material may be smaller in a region closer to the current collector and increase as the distance from the current collector increases in order to prevent expansion and contraction of the anode, improve high temperature storage and lifespan properties, and maintain the power of the secondary battery [0117].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the negative electrode taught by modified Huang to include a silicon-based active material in the first negative electrode active material layer within the range taught by Kim, in order to prevent expansion and contraction of the anode, improve high temperature storage and lifespan properties, and maintain the power of the secondary battery.
Further regarding claim 19, Kim teaches that content of the silicon-based active material included in the second anode active material layer may be equal to or greater than 8 wt % and less than 40 wt % based on a total weight of the second anode active material layer [0021]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
As described previously, Kim teaches that the amounts of silicon-based material may be smaller in a region closer to the current collector and increase as the distance from the current collector increases in order to prevent expansion and contraction of the anode, improve high temperature storage and lifespan properties, and maintain the power of the secondary battery [0117].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the negative electrode taught by modified Huang to include a silicon-based active material in the first negative electrode active material layer within the range taught by Kim, in order to prevent expansion and contraction of the anode, improve high temperature storage and lifespan properties, and maintain the power of the secondary battery.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857) and Hwang et al. (US 2022/0344661, hereinafter "Hwang").
Regarding claim 21, Huang teaches a secondary battery comprising a negative electrode (“negative electrode plate”) [0001]. The negative electrode comprises a negative electrode current collector, a first negative electrode active material layer comprising a first negative electrode active material, and a second negative electrode active material layer comprising a second negative electrode active material, wherein the first negative electrode active material layer is disposed on the surface of the negative electrode current collector and the second negative electrode active material layer is disposed on the surface of the first negative electrode active material layer [0006]. The first negative electrode active material may be artificial graphite, preferably coated with amorphous carbon (‘first artificial graphite”) [0024, “the negative electrode active material can be one or more of graphite”, “The graphite can be selected from one or more of artificial graphite”, “more preferably, it is coated and modified with amorphous carbon”]. Huang is silent regarding the first negative electrode active material comprising secondary particles and a second artificial graphite comprising primary particles wherein based on a on a mass of the first negative electrode active material, a mass percentage of the first artificial graphite is 10%-70%.
Oh teaches analogous art of a negative electrode for a lithium secondary battery [0002]. The negative electrode comprises a composite negative electrode active material including a first carbon-based material (“first artificial graphite”) and a second carbon-based material (“second artificial graphite”) that are different from each other [0035]. The first carbon-based material may include a first artificial graphite secondary particle [0047], and an amorphous carbon coating layer positioned only on the surface of the first carbon-based material [0069-0070]. The second carbon-based material may include artificial graphite primary particles [0052]. Oh also teaches that the first carbon-based material and second carbon-based material are mixed [0021, “sintering a mixture of the first carbon-based secondary particles and second carbon-based primary particles to form a composite negative electrode active material”].
Oh teaches that the composite negative electrode active material has suppressed volume expansion and improved output and rate characteristics [0009].
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have modified the first negative electrode active material layer taught by Huang to include the composite negative electrode active material including the first carbon-based material and the second carbon-based material taught by Oh, in order to suppress volume expansion and improve output and rate characteristics of the negative electrode.
Hwang teaches analogous art of a negative electrode active material for a secondary battery comprising small particles (“second artificial graphite”) in the form of primary particles and large particles (“first artificial graphite”) in the form of secondary particles [Abstract]. Hwang also teaches that the large particles may include an amorphous carbon coating layer on a surface of the secondary particles [0009-0010], and that the small particles may not include a carbon coating layer [0012]. Hwang also teaches that the small particles and large particles may be artificial graphite [0014]. Hwang teaches that a weight ratio of the small particles and large particles may be 1:1.5 to 1:3 [0017]. The mass percentage of the large particles based on a mass of the negative electrode active material would therefore be 1.5/(1+1.5), or 60% to 3/(3+1), or 75%, which overlaps the recited ratio of 10%-70%. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I). Hwang also teaches in the specific examples (Examples 1-4), that the ratio of primary particles to secondary particles is 3:7, or a mass percentage of the secondary particles of 70% based on a mass of the negative electrode active material [0061].
Hwang teaches that when the weight ratio of the small particles and large particles is within the disclosed range, it is possible to suppress am increase in side reactions with an electrolyte due to a large specific surface area of the small particles, which ultimately suppresses a reduction in capacity.
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have modified the first negative electrode active material layer taught by Huang, modified by Oh, to include the primary particles (“second artificial graphite”) and secondary particles (“first artificial graphite”) in an amount within the weight ratio taught by Hwang, in order to suppress side reactions with an electrolyte and suppress a reduction in capacity of the battery.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Huang (WO 2020042571) in view of Oh (US 2019/0198857), Jung (US 2024/0372077), and Cha (US 2020/0335795).
Regarding claim 22, Huang teaches a secondary battery comprising a negative electrode (“negative electrode plate”) [0001]. The negative electrode comprises a negative electrode current collector, a first negative electrode active material layer comprising a first negative electrode active material, and a second negative electrode active material layer comprising a second negative electrode active material, wherein the first negative electrode active material layer is disposed on the surface of the negative electrode current collector and the second negative electrode active material layer is disposed on the surface of the first negative electrode active material layer [0006]. The first negative electrode active material may be artificial graphite, preferably coated with amorphous carbon (‘first artificial graphite”) [0024, “the negative electrode active material can be one or more of graphite”, “The graphite can be selected from one or more of artificial graphite”, “more preferably, it is coated and modified with amorphous carbon”]. Huang further teaches that the second negative electrode active material may be an artificial graphite (“third artificial graphite”) coated with an amorphous carbon coating layer (“second amorphous carbon coating layer”) [0024]. Huang is silent regarding the first negative electrode active material comprising secondary particles and a second artificial graphite comprising primary particles and the second negative electrode active material comprising secondary particles.
Oh teaches analogous art of a negative electrode for a lithium secondary battery [0002]. The negative electrode comprises a composite negative electrode active material including a first carbon-based material (“first artificial graphite”) and a second carbon-based material (“second artificial graphite”) that are different from each other [0035]. The first carbon-based material may include a first artificial graphite secondary particle [0047], and an amorphous carbon coating layer positioned only on the surface of the first carbon-based material [0069-0070]. The second carbon-based material may include artificial graphite primary particles [0052]. Oh also teaches that the first carbon-based material and second carbon-based material are mixed [0021, “sintering a mixture of the first carbon-based secondary particles and second carbon-based primary particles to form a composite negative electrode active material”].
Oh teaches that the composite negative electrode active material has suppressed volume expansion and improved output and rate characteristics [0009].
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have modified the first negative electrode active material layer taught by Huang to include the composite negative electrode active material including the first carbon-based material and the second carbon-based material taught by Oh, in order to suppress volume expansion and improve output and rate characteristics of the negative electrode.
Jung teaches analogous art of a negative electrode comprising a negative electrode active material layer having a lower layer region comprising a first active material and an upper layer region disposed on the lower layer region comprising a second active material, the second active material including secondary particles of artificial graphite (“third artificial graphite”) with a carbon coating layer disposed on the secondary particles [Abstract]. The carbon coating layer may be amorphous carbon [0054]. The carbon coating layer may be present in an amount of 0.5-10 wt % based on the total weight of the second active material, which overlaps the recited range of 2%-8% [0023]. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP 2144.05 I).
Jung teaches that quick charging performance may be improved by using secondary artificial graphite particles provided with a carbon coating layer in the upper layer [0038, “quick charging performance can be further improved by using secondary particles of artificial graphite provided with a carbon coating layer in the upper layer”].
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to have modified the second negative electrode active material taught by modified Huang to include secondary artificial graphite particles with a carbon coating layer of amorphous carbon with the ratio of the mass of amorphous carbon based on the mass of the secondary artificial graphite particles within the range taught by Jung, in order to improve quick charging performance.
Cha teaches analogous art of a negative electrode for a lithium secondary battery, the negative electrode comprising a current collector, and a negative electrode active material layer including a first active material layer comprising a first negative electrode active material (“first artificial graphite”) and a second active material layer comprising a second negative electrode active material (“third artificial graphite”) [Abstract, “The negative electrode for a lithium secondary battery comprises a current collector and a negative electrode active material layer formed on the current collector, wherein the negative electrode active material layer includes a first negative electrode active material and a first binder, and a second active material layer formed on the first active material layer”]. Cha teaches that the first negative electrode active material/first active material and the second negative electrode active material/second active material may be carbonaceous negative electrode active material, such as artificial graphite [0036-0037]. Cha also teaches that the average particle diameter (D50) of the first active material is larger than the average particle diameter (D50) of the second active material [0042]. Cha discloses that the average particle diameter D50 indicates a diameter of a particle where a cumulative volume is 50 volume % in a particle distribution [0043], which is the same definition of Dv50 found in the instant specification [0075 of filed specification, “Dv50 refers to a particle size corresponding to a cumulative volume distribution percentage of a measured material reaching 50%”].
Cha teaches that when the D50 of the first active material is larger than the D50 of the second active material, adherence to the current collector may be improved and contact resistance may be decreased, thus improving battery performance [0042].
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the claimed invention to have modified the secondary battery taught by modified Huang to make the D50 of the second negative electrode active material (“third artificial graphite”) smaller than the D50 of the first negative electrode active material (“first artificial graphite”) as taught by Cha, in order to improve the negative electrode adherence to the current collector, decrease contact resistance, and improve overall battery performance.
Response to Arguments
Applicant's arguments filed 1/13/2026 with regard to claim 1 have been fully considered but they are not persuasive.
Applicant’s alleges that Oh (US 2019/0198857) does not teach the limitation “wherein the first artificial graphite and the second artificial graphite are physically mixed with each other”, because the second carbon-based material (“second artificial graphite”) is positioned on the surface of the first carbon-based material (“first artificial graphite “) [Remarks, page 15]. However, the fact that the second carbon-based material is positioned on the surface of the first carbon-based material would still require the first and second carbon-based materials to be physically mixed with each other, as described in Oh [0021, “sintering a mixture of the first carbon-based secondary particles and second carbon-based primary particles to form a composite negative electrode active material”, 0127, “80 weight % of the artificial graphite secondary particles, 20 weight % of high-strength and high-output artificial graphite primary particles … were mixed together to form a mixture” (emphasis added)]. Applicant’s argument does not explain how the second carbon-based material being positioned on the surface of the first carbon-based material would preclude the first and second carbon-based materials to be physically mixed with each other. Therefore, this argument is considered unpersuasive and the rejection of instant claim 1 is maintained.
For compact prosecution purposes, it is noted that Hwang (US 2022/0344661), cited in the rejection of instant claim 21, also teaches a negative electrode active material comprising primary particles of artificial graphite and secondary particles of artificial graphite physically mixed with each other [0061, “The prepared primary particles and secondary particles of artificial graphite were mixed in a weight ratio of 3:7 to prepare a negative electrode active material”].
Applicant’s arguments with respect to the rejection of claim 11 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new grounds of rejection is made in view of Huang (WO 2020042571) in view of Oh (US 2019/0198857), Jung (US 2024/0372077), and Cha (US 2020/0335795).
Cha teaches a negative electrode having two negative electrode active material layers, wherein Dv50 of the negative electrode active material in the first layer is larger than the Dv50 of the negative electrode active material in the second layer [0042-0043].
Conclusion
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/M.F.O./Examiner, Art Unit 1729
/ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729
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