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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Status of Application
Claims 1, 4, 7-13, 15-16, 20are amended, claims 3 and 6 are cancelled, and claims 21-22 are new, submitted on 5/10/2026. Claims 1-2, 4-5, and 7-22 are presented for examination.
Claim Rejections - 35 USC § 103
1. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
2. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
3. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
4. Claims 1-2, 4-5 and 7-19 are rejected under 35 U.S.C. 103 as being unpatentable over Hasegawa (US 20180316065 A1, IDS of 4/29/2025) in view of Li (CN 110943222 A, see English equivalent US 20220037669 A1 for citation).
Regarding claim 1, Hasegawa discloses a battery cell (stacked battery 100, [0042] and FIG. 1), comprising an intermediate portion (10H, FIG. 1) and side portions (10A/10B and 10N, FIG. 1) located on two sides of the intermediate portion (center-side cell, [0070]) in a thickness direction (FIG. 1), the intermediate portion (10H, FIG. 1) comprising m battery cell sub-units and the side portions (10A+10B and 10N, FIG. 1) comprising n battery cell sub-units, m+n being an integer greater than or equal to 3 (battery cells 10A, 10B to 10H 10N, FIG. 1), wherein each of the battery cell sub-units comprises a positive electrode sheet (1 and 4, [0114] and [0117] and FIG.1), a negative electrode sheet (2 and 5, [0115] and [0118] and FIG. 1) and a separator (3 solid electrolyte layer, [0116] and FIG. 1) arranged between the positive electrode sheet and the negative electrode sheet (FIG. 1), and each of the m battery cell sub-units has a dry battery cell nail penetration short-circuit resistance greater than that of each of the n battery cell sub-units (P2> P1 and P2>P3 in FIG. 3; and 20th-50th cells vs. 10th and 60th cells in Table 2) .
Hasegawa discloses the negative electrode sheet comprises a negative electrode current collector (5 anode current collector, [0118]) and a negative electrode film layer (2 anode active material layer, [0115]) arranged on at least one surface of the negative electrode current collector, the negative electrode film layer comprises a negative electrode active material ([0115] and FIG. 1), the positive electrode sheet comprises a positive electrode current collector (4 cathode current collector, [0117]) and a positive electrode film layer (1 cathode active material layer, [0114]) arranged on at least one surface of the positive electrode current collector, the positive electrode film layer comprises a positive electrode active material ([0114] and FIG. 1).
Hasegawa discloses a concern in nail penetration test of stacked batteries that the deterioration of the battery material resulting from the temperature of the cell increases because when a cell with low short circuit resistance and a cell with high short circuit resistance are mixed, a current (“sneak current”) flows from the cell with high short circuit resistance to the cell with low short circuit resistance ([0008]).
Hasegawa does not explicitly disclose the positive electrode current collector comprising a support layer and a metal layer.
Li teaches electrode plate uses a composite current collector with a support layer made of a polymer material and a conductive layer ([0010]) made of metal conductive material ([0077]), which significantly improves mass energy density ([0010]) and provides greater short-circuit resistance than that of a conventional metal current collector thus greatly improves nail penetration safety performance of the electrochemical device ([0011]). It would have been obvious before the effective filing date of the claimed invention to modify the positive electrode current collector (metal layer) of Hasegawa with an addition layer of a support layer made of polymer in the same fashion as taught by Li in order to improve nail penetration safety performance of the electrochemical device.
Modified Hasegawa does not explicitly disclose that the support layer of the positive electrode current collector of each of the m battery cell sub-units has a thickness greater than that of the support layer of the positive electrode current collector of each of the n battery cell sub-units; nor the metal layer of the positive electrode current collector of each of the m battery cell sub-units has a thickness smaller than that of the metal layer of the positive electrode current collector of each of the n battery cell sub-units.
However, modified Hasegawa further discloses an equivalent circuit ([0036] FIG. 4) explaining a sneak current I flowing from the cell with high short circuit resistance 10H to the cell with low short circuit resistance 10A (R10H>R10A, FIG. 3). Therefore, in order to avoid temperature increasing too fast among the m battery cell sub-units of the intermediate portion which is harder for heat dissipation, a skilled artisan would reasonably envisage the need of directing some current flowing from the intermediate portion m battery cell sub-units to the side portions n battery cell sub-units, taught by Hasegawa FIG. 4, the sneak current flowing from the cell with high short circuit resistance 10H (m battery cell sub-units) to the cell with low short circuit resistance 10A (n battery cell sub-units).
It would have been obvious to a skilled artisan to prepare the thickness of the support layer of the positive electrode current collector of each of the m battery cell sub-units to be greater than that of the support layer of the positive electrode current collector of each of the n battery cell sub-units, in order to direct some current flow from the intermediate portion 10H towards the side portion 10A, as taught by Hasegawa FIG. 4, because the support layer made of polymer material dominates the overall short circuit resistance of the positive composite current collector including the support layer and a metal and the metal layer, thus arriving at the claimed “the support layer of the positive electrode current collector of each of the m battery cell sub-units has a thickness greater than that of the support layer of the positive electrode current collector of each of the n battery cell sub-units”, so as to mitigate a potential rapid temperature increase in the intermediate portion of the stacked battery of modified Hasegawa due to the difficulty to dissipate heat generated at the location in the middle of the stacked battery.
Modified Hasegawa further discloses the thickness of the cathode current collecting tabs may be different for the surface -side and the center-side cells ([0060]). Since as established above, the support layer of the positive electrode current collector of each of the m battery cell sub-units has a thickness greater than that of the support layer of the positive electrode current collector of each of the n battery cell sub-units, it would have been further obvious to a skilled artisan to prepare the metal layer (cathode current collecting tabs) of the positive electrode current collector of each of the m battery cell sub-units with a thickness smaller than that of the metal layer of the positive electrode current collector of each of the n battery cell sub-units, in order to maintain overall uniform thickness of each positive composite current collector including both the support layer and the metal layer.
Regarding claim 2, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa further discloses the center-side cell belongs to a cell region including a ((N/3)+1)th cell to a (2N/3)th cell ([0070]), which means the intermediate portion (center-side cell) has about N/3 of the cells, therefore, in light of the thickness of the cells are about the same shown in FIG. 1, a skilled artisan would reasonably envisage the thickness of the intermediate portion would be about 33% of the total thickness of the battery cell falling within the range of 20% to 40% as claimed “a thickness accounting for 20% to 40% of a total thickness of the battery cell”.
Regarding claim 4, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa does not explicitly disclose the metal layer of the positive electrode current collector of each of the m battery cell sub-units has a resistivity greater than that of the metal layer of the positive electrode current collector of each of the n battery cell sub-units.
Since as established in claim 1, in order to avoid temperature increasing too fast among the m battery cell sub-units of the intermediate portion in which it is harder for heat dissipation, modified Hasegawa has the need of directing some current flowing from the intermediate portion m battery cell sub-units to the side portions n battery cell sub-units, taught by Hasegawa FIG. 4, it would have been obvious to a skilled artisan before the effective filing date of the claimed invention to make the metal layer of the positive electrode current collector of each of the m battery cell sub-units has a resistivity greater than that of the metal layer of the positive electrode current collector of each of the n battery cell sub-units as claimed, in order to offer more help in directing some current flow from the intermediate portion 10H towards the side portion 10A, mitigating a potential rapid temperature increase in the intermediate portion of the stacked battery of modified Hasegawa due to the difficulty to dissipate first heat generated at the location in the middle of the stacked battery.
Regarding claim 5, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa does not explicitly disclose the resistivity of the metal layer of the positive electrode current collector of each of the m battery cell sub-units is 1.05 to 1.5 times the resistivity of the metal layer of the positive electrode current collector of each of the n battery cell sub-units.
However, modified Hasegawa does disclose the material of the current collecting tab differs, the specific resistance also differs ([0057]), and in Table 1 that the specific resistance data for materials used for the current collecting tab, including SUS with 72x10-6 Ω·cm and Ti with 55x10-6 Ω·cm among other choices (Table 1). It would have been obvious to a skilled artisan before the effective filing date of the claimed invention to choose SUS for the metal layer of the positive electrode current collector of each of the m battery cell sub-units and Ti for the metal layer of the positive electrode current collector of each of the n battery cell sub-units from the finite choices listed in Table 1, in order to have a higher resistance for the m battery cell sub-units in the intermediate portion. Thus, the resistivity ratio of SUS to Ti is calculated to be 1.3, falling within the range of 1.05 to 1.5 as claimed “the resistivity of the metal layer of the positive electrode current collector of each of the m battery cell sub-units is 1.05 to 1.5 times the resistivity of the metal layer of the positive electrode current collector of each of the n battery cell sub-units”.
Regarding claim 7, modified Hasegawa discloses all of the limitations as set forth above. While and the thickness difference is for example, 30 µm or more, and may be 200 µm or more ([0059]) and the resistance ratio of cathode current collecting tab for cells in the surface-side to cells in the center-side is for example 1.1 ([0055] [0071]), modified Hasegawa does not explicitly disclose the thickness of the metal layer of the positive electrode current collector of each of the m battery cell sub-units is 60% to 90% of the thickness of the metal layer of the positive electrode current collector of each of the n battery cell sub-units.
However, since resistance of a metal is inversely proportional to the cross-sectional area (A) of a conductor given by R=ρ(L/A) and the thickness (area) decreases the resistance increases proportionally, the resistance ratio of cathode current collecting tab for cells at different region being 1.1 ([0071]) translates to the thickness ratio of the positive current collecting metal layers at different region is 1.1.
Further, as established in claim 1, the metal layer of the positive electrode current collector of each of the m battery cell sub- units has a thickness smaller than that of the metal layer of the positive electrode current collector of each of the n battery cell sub-units, a skilled artisan would reasonably make the thickness ratio of the forgoing m battery cell sub-units to the n battery cell sub-units to be 1:1.1, equivalent to about 90% in the thickness ratio of the metal layers in the two regions, arriving at the higher end of the range as claimed “the thickness of the metal layer of the positive electrode current collector of each of the m battery cell sub-units is 60% to 90% of the thickness of the metal layer of the positive electrode current collector of each of the n battery cell sub-units”.
Regarding claim 8, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa discloses the deterioration of the battery material resulting from the temperature of the cell increasing ([0008]), and an equivalent circuit explaining a sneak current I flowing due to unevenness of short circuit resistance ([0036] and FIG. 4).
Modified Hasegawa does not explicitly disclose that: the positive electrode film layer of each of the m battery cell sub-units has a coating weight smaller than that of the positive electrode film layer of each of the n battery cell sub-units.
However, it is well-known that the heat generated by the m battery cell sub-units of the intermediate portion would be much harder to dissipates due to the location being in the middle portion of the battery stack; and the coating weight (or loading ) of an active material layer on an electrode is generally proportional to the heat generated during operation of a cell. A skilled artisan would reasonably envisage reducing the coating weight of an electrode active material layer for the cells located in the intermediate portion of the cell stack of Hasegawa in order to reduce the amount of heat generated in the intermediate portion, avoiding the temperature increasing too fast among the m battery cell sub-units of the intermediate portion of Hasegawa.
Therefore, it would have been obvious to a skilled artisan before the effective filing date of the claimed invention to make the positive electrode film layer of each of the m battery cell sub-units has a coating weight smaller than that of the positive electrode film layer of each of the n battery cell sub-units in order to achieve an overall balanced heat distribution among the battery cells for mitigating the deterioration of the battery material resulting from the temperature of the cell increases.
Regarding claim 9, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa does not explicitly disclose the coating weight of the positive electrode film layer of each of the m battery cell sub-units is 70% to 90% of the coating weight of the positive electrode film layer of each of the n battery cell sub-units.
Hasegawa further discloses the thickness of the cathode active material layer varies within a range of 0.1 µm to 300 µm, and may be within a range of 0.1 µm to 100 µm ([0088]); and the coverage of the coating layer on the cathode active material may be 50% or more, and may be 80% or more ([0087]). A skilled artisan would adjust the cathode active material within the taught ranges for the m battery cell sub-unit with routine experimentation in order to ensure the active material coating weight for the m battery cell sub-unit is less than that of the n battery cell sub-units for reducing heat generation in the intermediate portion of the stacked battery as well as to balance with an optimized overall capacity of the battery cell, and with a reasonable expectation in arriving at an optimized negative electrode film layer coating weight value for the m battery cell sub-units that falls within the range of 70% to 90% of the coating weight for the side battery portion as claimed “the coating weight of the negative electrode film layer of each of the m battery cell sub-units is 70% to 90% of the coating weight of the negative electrode film layer of each of the n battery cell sub-units”.
Regarding claim 10, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa does not explicitly disclose the negative electrode film layer of each of the m battery cell sub-units has a coating weight smaller than that of the negative electrode film layer of each of the n battery cell sub-units, the coating weight of the negative electrode film layer of each of the m battery cell sub-units is 70% to 90% of the coating weight of the negative electrode film layer of each of the n battery cell sub-units.
As set forth above, the heat generated by the m battery cell sub-units of the intermediate portion would be much harder to dissipates due to the location being in the middle portion of the battery stack; and the coating weight (or loading ) of an active material layer on an electrode is generally proportional to the heat generated during operation of a cell. A skilled artisan would reasonably envisage reducing the coating weight of an electrode active material layer for the cells located in the intermediate portion of the cell stack of Hasegawa in order to reduce the amount of heat generated in the intermediate portion, avoiding the temperature increasing too fast among the m battery cell sub-units of the intermediate portion of Hasegawa.
It would have been obvious to a skilled artisan before the effective filing date of the claimed invention to make the negative electrode film layer of each of the m battery cell sub-units has a coating weight smaller than that of the negative electrode film layer of each of the n battery cell sub-units, in order to achieve an overall balanced heat distribution among the battery cells for mitigating the deterioration of the battery material resulting from the temperature of the cell increases.
Hasegawa further discloses the thickness of the anode active material layer varies within a range of 0.1 µm to 300 µm, and may be within a range of 0.1 µm to 100 µm ([0084]); and the proportion of the anode active material may be within a range of 60% by weight to 99% by weight ([0078]). A skilled artisan would adjust within the taught active material range (60-99 weight% ) for the m battery cell sub-unit with routine experimentation in order to ensure the active material coating weight for the m battery cell sub-unit is less than that of the n battery cell sub-units for reducing heat generation in the intermediate portion of the stacked battery as well as to balance with an optimized overall capacity of the battery cell, with a reasonable expectation in arriving at an optimized negative electrode film layer coating weight value for the m battery cell sub-units that falls within the range of 70% to 90% of the coating weight for the side battery portion as claimed “the coating weight of the negative electrode film layer of each of the m battery cell sub-units is 70% to 90% of the coating weight of the negative electrode film layer of each of the n battery cell sub-units”.
Regarding claim 11, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa discloses the deterioration of the battery material resulting from the temperature of the cell increasing ([0008]), and an equivalent circuit explaining a sneak current I flowing due to unevenness of short circuit resistance ([0036] and FIG. 4).
Modified Hasegawa does not explicitly disclose that a binder in the positive electrode film layer of each of the m battery cell sub-units has a content greater than that of a binder in the positive electrode film layer of each of the n battery cell sub-units.
However, it is well-known that the heat generated by the m battery cell sub-units of the intermediate portion would be much harder to dissipates due to the location is in the middle portion of the battery stack, and the binder content in an electrode is generally inversely proportional to the active material loading in the active material layer, thus inversely proportional to the heat generated during operation of a cell and also increase resistance.
Therefore, a skilled artisan would have found it obvious before the effective filing date of the claimed invention, to increase the content of a binder in the positive electrode film layer for the m battery cell sub-units located in the intermediate portion of the cell stack of Hasegawa in order to reduce the first heat generated in the intermediate portion avoiding the temperature increase too fast among the m battery cell sub-units of the intermediate portion and increase the internal resistance of the m battery cell sub-units of the intermediate portion in order to have some current flowing from m battery cell sub-units of the intermediate portion to n battery cell sub-units at the side portions.
It would have been obvious before the effective filing date of the claimed invention, to arrive at the claimed “a binder in the positive electrode film layer of each of the m battery cell sub-units has a content greater than that of a binder in the positive electrode film layer of each of the n battery cell sub-units” in order to manage heat generated in the intermediate portion and maintain an overall balanced heat distribution among the battery cells for mitigating the deterioration of the battery material resulting from the temperature of the cell increases.
Regarding claim 12, modified Hasegawa discloses all of the limitations set forth above. Modified Hasegawa further discloses cathode active material: sulfide solid electrolyte material: conductive material: binder =85:13:1:1 ([0098]), which renders obvious the binder in n battery cell sub-units the positive electrode film layer is 1% by weight to the total weight of the cathode electrode.
Modified Hasegawa does not explicitly disclose the content of the binder in the positive electrode film layer of each of the m battery cell sub-units is 3% by weight to 4% by weight.
However, as established in claim 11, the binder content in the m battery cell sub-units is modified to be higher than that in the n battery cell sub-units, it would have been obvious to a skilled artisan to further adjust the binder content through routine experimentation in order to achieve an optimized balance between a reduced the temperature increase among the m battery cell sub-units of the intermediate portion and a desired overall capacity of the battery cell, and with a reasonable expectation to achieve a success binder content value for each of the m battery cell sub-units that falls within in the range of 3% by weight to 4% by weight as claimed “the content of the binder in the negative electrode sheet is of each of the m battery cell sub-units is 3% by weight to 4% by weight”.
Regarding claim 13, modified Hasegawa discloses all of the limitations set forth above. While modified Hasegawa further discloses anode active material: sulfide solid electrolyte material: conductive material: binder =55:42:2:1 ([0100]), which renders obvious the binder in n battery cell sub-units the negative electrode film layer is 1% by weight to the total weight of the negative electrode.
However, modified Hasegawa does not explicitly disclose a binder in the negative electrode film layer of each of the m battery cell sub-units has a content greater than that of a binder in the negative electrode film layer of each of the n battery cell sub-units; nor the content of the binder in the negative electrode film layer of each of the m battery cell sub-units is 3% by weight to 4% by weight.
Modified Hasegawa discloses the deterioration of the battery material resulting from the temperature of the cell increases ([0008]), and an equivalent circuit explaining a sneak current I flowing due to unevenness of short circuit resistance ([0036] and FIG. 4).
it is well-known that the heat generated by the m battery cell sub-units of the intermediate portion would be much harder to dissipates due to the location is in the middle portion of the battery stack, and the binder content in an electrode is generally inversely proportional to the active material loading in the active material layer, thus inversely proportional to the heat generated during operation of a cell and also increase resistance.
Therefore, a skilled artisan would have found it obvious before the effective filing date of the claimed invention, to increase the content of a binder in the negative electrode film layer for the m battery cell sub-units located in the intermediate portion of the cell stack of Hasegawa in order to reduce the first heat generated in the intermediate portion avoiding the temperature increase too fast among the m battery cell sub-units of the intermediate portion and increase the internal resistance of the m battery cell sub-units of the intermediate portion in order to have some current flowing from m battery cell sub-units of the intermediate portion to n battery cell sub-units at the side portions.
It would have been obvious before the effective filing date of the claimed invention, to arrive at the claimed “a binder in the negative electrode film layer of each of the m battery cell sub-units has a content greater than that of a binder in the negative electrode film layer of each of the n battery cell sub-units” in order to manage heat generated in the intermediate portion and maintain an overall balanced heat distribution among the battery cells for mitigating the deterioration of the battery material resulting from the temperature of the cell increases.
It would have been obvious to a skilled artisan to further adjust the binder content through routine experimentation in order to achieve an optimized balance between a reduced the temperature increase among the m battery cell sub-units of the intermediate portion and a desired overall capacity of the battery cell, and with a reasonable expectation to achieve a success negative electrode film layer binder content value for each of the m battery cell sub-units that falls within in the range of 3% by weight to 4% by weight as claimed “the content of the binder in the negative electrode film layer of each of the m battery cell sub-units is 3% by weight to 4% by weight”.
Regarding claim 14, modified Hasegawa discloses all of the limitations as set forth above. While modified Hasegawa discloses the deterioration of the battery material resulting from the temperature of the cell increases ([0008]), and an equivalent circuit explaining a sneak current I flowing due to unevenness of short circuit resistance ([0036] and FIG. 4), Hasegawa does not explicitly disclose that the positive electrode sheet of each of the m battery cell sub-units has a compaction density smaller than that of the positive electrode sheet of each of the n battery cell sub-units.
Since it is well-known that the heat generated by the m battery cell sub-units of the intermediate portion would be much harder to dissipates due to the location is in the middle portion of the battery stack, and the compact density of an electrode is generally proportional to energy density, thus proportional to the heat generated during operation of a cell, a skilled artisan would reasonably envisage reducing the compact density in order to reduce heat generated in the intermediate portion avoiding the temperature increase too fast among the m battery cell sub-units of the intermediate portion of Hasegawa either in the positive electrode sheet or in the negative electrode sheet for the m battery cells located in the intermediate portion of the cell stack .
Therefore, it would have been obvious to a skilled artisan before the effective filing date of the claimed invention to make the positive electrode sheet of each of the m battery cell sub-units has a compaction density smaller than that of the positive electrode sheet of each of the n battery cell sub-units, in order to achieve an overall balanced heat distribution among the battery cells for mitigating the deterioration of the battery material resulting from the temperature of the cell increases.
Regarding claim 15, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa does not explicitly disclose the compaction density of the positive electrode sheet of each of the m battery cell sub-units is 80% to 98% of the compaction density of the positive electrode sheet of each of the n battery cell sub-units.
As established above, compaction density is proportional to the heat generated during operation of a cell, rendering obvious reducing compaction density of the negative electrode sheet of the m battery cell sub-units would reasonably reduce the heat generated in the intermediate portion thus avoiding temperature increasing too fast among the m battery cell sub-units of the intermediate portion of Hasegawa’s stacked cell.
Further, Hasegawa teaches the thickness of the coating layer of the cathode active material is ranging from 0.1 nm to 100 nm, and the coverage of the coating layer on the cathode active material surface is for example, 50% or more, and may be 80% or more ([0087]). A skilled artisan would reasonably expect through routine optimizations of coating layer thickness and the coverage of the cathode active material in the cathode of the m battery cell units within taught ranges would result in a relative compact density value for m battery cell sub-units that falls within 80% to 98% of that of n battery cell sub-units, with a successful balance between reducing the amount of heat generated in the m battery cell of the intermediate portion and achieving an optimized overall capacity of the battery cell, thus arriving at the claimed “the positive electrode sheet of each of the m battery cell sub-units that has 80% to 98% of the compact density of the negative electrode sheet of each of the n battery cell sub-units”.
Regarding claim 16, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa does not explicitly disclose the negative electrode sheet of each of the m battery cell sub-units has a compaction density smaller than that of the negative electrode sheet of each of the n battery cell sub-units; nor the compaction density of the negative electrode sheet of each of the m battery cell sub-units is 80% to 98% of the compaction density of the negative electrode sheet of each of the n battery cell sub-units.
Since it is well-known that the heat generated by the m battery cell sub-units of the intermediate portion would be much harder to dissipates due to the location is in the middle portion of the battery stack, and the compact density of an electrode is generally proportional to energy density, thus proportional to the heat generated during operation of a cell, a skilled artisan would reasonably envisage reducing the compact density in order to reduce heat generated in the intermediate portion avoiding the temperature increase too fast among the m battery cell sub-units of the intermediate portion of Hasegawa either in the positive electrode sheet or in the negative electrode sheet for the m battery cells located in the intermediate portion of the cell stack .
Therefore, it would have been obvious to a skilled artisan before the effective filing date of the claimed invention to make the negative electrode sheet of each of the m battery cell sub-units has a compaction density smaller than that of the positive electrode sheet of each of the n battery cell sub-units, in order to achieve an overall balanced heat distribution among the battery cells for mitigating the deterioration of the battery material resulting from the temperature of the cell increases.
Further, as established above, compaction density is proportional to the heat generated during operation of a cell, rendering obvious reducing compaction density of the negative electrode sheet of the m battery cell sub-units would reasonably reduce the heat generated in the intermediate portion thus avoiding temperature increasing too fast among the m battery cell sub-units of the intermediate portion of Hasegawa’s stacked cell.
Further, Hasegawa teaches the average particle size (D50) of the anode active material is for example, within a range of 10 nm to 50 µm, and may be within a range of 100 nm to 20 µm; and the proportion of the anode active material in the anode active material layer is for example, 50% by weight or more, and may be within a range of 60% by weight to 99% by weight ([0078]). A skilled artisan would reasonably expect through routine optimizations of average particle sizes and the weight% of the anode active material in the anode of the m battery cell units within taught ranges would result in a relative compact density value for m battery cell sub-units that falls within 80% to 98% of that of n battery cell sub-units, with a successful balance between reducing the amount of heat generated in the m battery cell of the intermediate portion and achieving an optimized overall capacity of the battery cell, thus arriving at the claimed “the negative electrode sheet of each of the m battery cell sub-units that has 80% to 98% of the compact density of the negative electrode sheet of each of the n battery cell sub-units”.
Regarding claim 17, modified Hasegawa discloses all of the limitations as set forth above. While modified Hasegawa discloses the deterioration of the battery material resulting from the temperature of the cell increases ([0008]), and an equivalent circuit explaining a sneak current I flowing due to unevenness of short circuit resistance ([0036] and FIG. 4), modified Hasegawa does not explicitly disclose that the separator of each of the m battery cell sub-units has a thickness greater than that of the separator of each of the n battery cell sub-units.
However, it is well-known that the heat generated by the m battery cell sub-units of the intermediate portion would be much harder to dissipates due to the location being in the middle portion of the battery stack; and the thickness of a separator of a cell is generally proportional to the internal resistance of a cell. A skilled artisan would reasonably envisage before the effective filing date of the claimed invention, increasing the thickness of the separator for the cells located in the intermediate portion of the cell stack of Hasegawa to direct some current flowing from the m battery cell sub-units of the intermediate portion to the n battery cell sub-units of the side portions via making the internal resistance rH of the m battery cell sub-units of the intermediate portion relatively higher than the internal resistance rA of the n battery cell sub-units of the side portions, in order to mitigate temperature increasing too fast among the m battery cell sub-units of the intermediate portion due to the difficulty to dissipate the huge generated heat in the stacked battery of modified Hasegawa.
It would have been obvious to a skilled artisan before the effective filing date of the claimed invention to make the separator of each of the m battery cell sub-units has a thickness greater than that of the separator of each of the n battery cell sub-units as claimed, thus making the internal resistance of the m battery cell sub-units of the intermediate portion relatively higher than that of the n battery cell sub-units of the side portions, in order to mitigate the deterioration of the battery material resulting from the temperature of the cell increases.
Regarding claim 18, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa does not explicitly disclose the thickness of the separator of each of the m battery cell sub-units is 10 to 13 µm, and the thickness of the separator of each of the n battery cell sub- units is 7 to 9 µm.
However, modified Hasegawa further discloses the thickness of the separator (solid electrolyte layer 3, [0042] FIG. 1) within a range of 0.1 µm to 100 µm ([0090]), encompassing the claimed thickness ranges for both the m battery cell sub-units (10 to 13 µm) and the n battery cell sub-units (7 to 9 µm). A skilled artisan would expect to further optimize the thickness of the separator within the taught range under routine experimentation, which would reasonable result in values falling within the thickness ranges combination as claimed “the thickness of the separator of each of the m battery cell sub-units is 10 to 13 µm, and the thickness of the separator of each of the n battery cell sub- units is 7 to 9 µm”, with a success in achieving an optimized balance between battery cycling characteristics and mitigating the deterioration of the battery material resulting from the temperature of the cell increases.
Regarding claim 19, modified Hasegawa discloses all of the limitations as set forth above. Modified Hasegawa further discloses a battery pack (an exterior package, [0069]), comprising the battery cell of claim 1.
5. Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Hasegawa (US 20180316065 A1, IDS of 4/29/2025) in view of Li (CN 110943222 A, see English equivalent US 20220037669 A1 for citation), as applied to claim 19, further in view of Watanabe (US 20190245190 A1).
Regarding claim 20, Hasegawa discloses all of the limitations set forth above. Hasegawa does not explicitly disclose an electrical apparatus, comprising the battery pack, wherein the battery pack is used as a power source or an energy storage unit of the electrical apparatus.
Watanabe, in the same field of endeavor teaches a stacked battery pack (FIG. 3) used as a power source ([0095]). It would have been obvious to a skilled artisan before the effective filing date of claimed invention to use the Hasegawa’s battery pack as a power source as taught by Watanabe.
6. Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Hasegawa (US 20180316065 A1, IDS of 4/29/2025) in view of Li (CN 110943222 A, see English equivalent US 20220037669 A1 for citation), as applied to claim 1, further in view of Shayan (US20210151830 A1).
Regarding claim 21, modified Hasegawa discloses all of the limitations as set forth above. While modified Hasegawa has included a total thickness of the battery cell and a total number m+n of the battery cell sub-units as shown in FIG. 1, and the thickness of current collecting tab being 200 µm or more ([0059]), the thickness of anode, cathode active material layer, or the solid electrolyte layer being within a range of 0.1 µm to 300 µm ([0084] [0088] and [0089]), and the thickness of the current collector being 1 µm or more ([0092]), which encompasses the thickness provided in the instant disclosure, namely, a support layer of a positive electrode current collector and the thickness of the metal layer of the positive electrode current collector, the thickness of a separator (Tables 1-7). While modified Hasegawa does not explicitly disclose an average thickness of the (m+n) cell sub-units, denoted as the total thickness of the battery cell/(m+n) is > 5 mm, a skilled artisan would have found it obvious to arrive at an average thickness of the (m+n) cell sub-units of more than 5 mm, based on the forgoing encompassing thickness ranges disclosed by Hasegawa.
Assuming, arguendo, that modified Hasegawa, for some reason, is not considered to render obvious the average thickness of the (m+n) cell sub-units being more than 5 mm, as set forth above, the following obviousness rejections are also presented.
Shayan teaches batteries 100 including electrochemical cells (110, 120) stacked together (FIG. 1) and the electrochemical cell thickness measurement shows the electrochemical cell had a thickness of 8.110 mm ([0278]) with less than 2 mm of displacement followed by formation cycles (FIG. 30B), which renders obvious that an average thickness of an electrochemical cell is more than 5 mm. It would have been obvious to a skilled artisan to construct the average thickness of the (m+n) cell sub-units of modified Hasegawa to be more than 5 mm as taught by Shayan, thus arriving at the claim limitation, absent evidence to the contrary for secondary consideration.
7. Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Hasegawa (US 20180316065 A1, IDS of 4/29/2025) in view of in view of Li (CN 110943222 A, see English equivalent US 20220037669 A1 for citation), as applied to claim 1, further in view of Shi (CN 113270568 A, see machine translation for citation).
Regarding claim 22, modified Hasegawa discloses all of the limitations set forth above. While modified Hasegawa discloses using silicon as an anode active material ([0100]), modified Hasegawa does not explicitly disclose the battery cell is constituted by an alternate arrangement of A battery cell sub-units and B battery cell sub-units, the negative electrode active material of each of the A battery cell sub-units and the B battery cell sub-units comprises a silicon-based material, a content of the silicon-based material in the negative electrode active material of each of the A battery cell sub-units is 10% by weight or more based on a total weight of the negative electrode active material of the A battery cell sub-unit, a content of the silicon-based material in the negative electrode active material of each of the B battery cell sub-units is less than 10% by weight based on a total weight of said negative electrode active material of the B battery cell sub-unit.
Shi further teaches the battery cell is a stacked battery cell, which includes a plurality of negative electrode sheets 20. The plurality of negative electrode sheets 20 includes a first negative electrode sheet and a second negative electrode sheet. The first negative electrode sheet is located in the middle of the plurality of negative electrode sheets 20, and the second negative electrode sheet is located on the outside of the plurality of negative electrode sheets 20. The silicon content of the coating of the first negative electrode sheet is greater than the silicon content of the coating of the second negative electrode sheet ([n0040] and FIG. 3); and by making the silicon element mass content of the coating included in the first electrode portion 21 greater than the silicon element mass content of the coating included in the second electrode portion 22, making the negative electrode 20 more stable during charging and discharging (especially room temperature charging and discharging), reducing the occurrence of lithium plating, enhancing the kinetics of the negative electrode 20, and thus improving the cycle performance of the entire battery cell ([n0025]). Shi further teaches the silicon content of the coating of the first electrode portion 21 is 2%-20% by mass, and the silicon content of the coating of the second electrode portion 22 is 0%-10% by mass ([n0032]), which renders obvious the silicon content of A battery cell sub-units being 10% by weight or more and the silicon content of B battery cell sub-unit being less than 10% by weight based on a total weight of said negative electrode active material of the battery cell sub-unit, because the first electrode portion 21 corresponds to A battery cell sub-units and the second electrode portion 22 corresponds to B battery cell sub-units in the claim.
It would have been obvious to a skilled artisan before the effective filing date of the claimed invention to prepared the silicon negative electrode active material as taught by Shi, thus arrive at the claimed “the battery cell is constituted by an alternate arrangement of A battery cell sub-units and B battery cell sub-units, the negative electrode active material of each of the A battery cell sub-units and the B battery cell sub-units comprises a silicon-based material, a content of the silicon-based material in the negative electrode active material of each of the A battery cell sub-units is 10% by weight or more based on a total weight of the negative electrode active material of the A battery cell sub-unit, a content of the silicon-based material in the negative electrode active material of each of the B battery cell sub-units is less than 10% by weight based on a total weight of said negative electrode active material of the B battery cell sub-unit”, in order to make the negative electrode more stable during charging and discharging (especially room temperature charging and discharging), reduce the occurrence of lithium plating, enhancing the kinetics of the negative electrode, and improve the cycle performance of the entire battery cell.
Response to Arguments
8. Applicant’s arguments regarding the amended claim 1 filed on 5/10/2026 have been fully considered but are moot in view of the new ground(s) of rejection.
Conclusion
9. 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 extension fee 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 date of this final action.
Conclusion
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/K. L./Examiner, Art Unit 1751 8/25/2026
/Haroon S. Sheikh/Primary Examiner, Art Unit 1751
Prosecution Insights