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 .
Status of Claims
Claims 1-15 are pending.
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 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.
Claims 1-5, 7-13, 15 are rejected under 35 U.S.C. 103 as being unpatentable over Park et al (US 2023/0261336 A1; effective filing date 2/15/2022) in view of Peng et al (CN 216354302U; machine translation), and further in view of Chen et al (US 2022/0328938 A1; effective filing date 4/13/2021).
Regarding Claim 1,
Park teaches a welding method used for an electrode assembly, comprising the steps of pressing and welding a plurality of electrode tabs 11 (with separators 13 therebetween) of the electrode assembly to each other or welding the plurality of electrode tabs to an electrode (Paragraph 0085). As shown in Figure 3 below, the electrode tab unit (plurality of electrode tabs) protruding from a side are stacked and aligned on one end portion and overlap with the electrode lead 17. The laser irradiation part irradiates the plurality of electrode tabs and electrode lead with laser (Paragraph 0051).
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Park teaches the presence of plurality of electrode tabs but does not teach that the electrode tabs are ultra-thin electrode tab having a thickness of 15 um or less, and the number of electrode tabs stacked in one direction is atleast 40.
However, Peng teaches a method of welding electrode tabs by laser welding (Paragraph 0062), and Peng teaches that the electrode tab can have a thickness of 0.01 to 0.5 mm (which is 10 um to 500 um). This range shows overlap with the claimed range of 15 um or less. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use the method of Park for electrode tabs that have thickness as shown in Peng in order to produce a battery with high electrode reliability and high strength at the welding area (Paragraph 0005).
Furthermore, Chen teaches a method of joining battery cell tabs with laser welding system (Paragraph 0062) such that anywhere from one to one hundred electrode pairs are included in the flexible battery pouch (Paragraph 0047). Each electrode comprises an electrode tab, hence there are between one and one hundred electrode tabs stacked. This range overlaps with the claimed range of atleast more than 40 electrode tabs stacked in one direction. In figure 1 of Chen, it is seen that the positive foils 28 stack up to form a first stack 14 (akin to the electrode tabs and tab unit), and the element 29, battery cell tab is akin to the electrode lead. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to stack atleast 40 electrode tabs in order to form a battery pouch that is commonly used in applications such as in vehicles (Paragraph 0047).
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Regarding Claim 2,
Park teaches a laser irradiation part that emits the laser but does specifically teach that the laser is a diode pumped solid state laser. However, Chen teaches that the laser beam is a solid-state laser beam, a disk laser beam with a wavelength in the near infrared range (Paragraph 0067). The instant specification also points to a diode-pumped solid state laser being a disk laser (Paragraph 0045; instant specification). Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use a solid state laser/disk laser in order to effectively laser weld the battery cell tabs (Paragraph 0066).
Regarding Claim 3,
Park teaches that the overlapping area is irradiated with the laser to form a welding pattern with welding spots that are regularly spaced apart on an uppermost plane on which the laser is incident. In Figure 4 below, element 120 are the welding spots that are regularly spaced apart. Element 17 is the electrode lead which is the upper most plane and is the overlapping section with electrode tabs.
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Figure 1 shows the overlapping region between the electrode tabs 15 and the lead 17. Figure 1 also shows that the overlapping area is irradiated with the laser 50.
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Regarding Claim 4,
Park shows in Figure 4 below that the welding spots are regularly spaced apart. Furthermore, Park teaches that the gaps g1 and g2 in the x direction (which is analogous to the width direction in claimed invention) can be 0.5 to 2 mm. Park also teaches that the gap g3 is from 0.25 to 1.5 mm which is in the y direction (analogous to the length direction where the electrode tabs protrude). In the instant specification, it states that the reciprocal number of welding spot density may correspond to a distance between the closest welding spots spaced apart from each other in each direction (a distance between the centers of the welding spots spaced apart from each other; instant specification, Paragraph 0064). The claim limitation is that number of welding spots per unit length (i.e. welding spot density) in the length direction is greater than in the width direction. Based on this limitation, and the reciprocal of the welding spots per unit length, it can be stated that the distance between the spots is less in the length direction than in the width direction. Hence, based on the above gaps g1, g2, g3 from Park it is evident that the distance between spots in the length direction is less than the distance between spots in the width direction. Adding the measurement of r1 and r2 to the gaps g1 and g2 in order to get the distance between spot centers will also result in the claimed relationship in length and width direction.
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Regarding Claim 5,
Park teaches that the gaps g1 and g2 in the x direction (which is analogous to the width direction in claimed invention) can be 0.5 to 2 mm. In the instant specification, it states that the reciprocal number of the welding spot density may correspond to a distance between the closest welding spots spaced apart from each other in each direction (a distance between the centers of the welding spots spaced apart from each other; instant specification, Paragraph 0064). Park teaches that the radius r1 is 0.5 mm, 1 mm (Paragraph 0066). Hence, the total distance between centers of the welding spots is r1 +g1 +r1. In an instance, this distance is 3 mm (1+1+1 mm). The reciprocal of the second welding spot density as claimed results in the distance range being 2 -3.33 mm. 3 mm lies within the reciprocal range and hence meets the limitation of this claim.
Park also teaches that the gap g3 is from 0.25 to 1.5 mm which is in the y direction (analogous to the length direction where the electrode tabs protrude). Gap g3 is the distance between the centers of the weld spots. Hence, the reciprocal of g3 is the second welding spot density. The reciprocal range is 1.25 to 1.66 mm. There is overlap between the g3 range and the reciprocal range. Hence, Parks meets the limitations of this claim.
Regarding Claim 7,
Park teaches that the laser emitted from the laser irradiation part 50 passes through the hollow of the upper jig 42 and is emitted onto one object (electrode lead 17), and the plurality of objects (electrode tabs 15; Paragraph 0051) to be welded to each other (Paragraph 0055). As can be seen the laser is above the electrode tabs and electrode lead assembly.
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Regarding Claim 8,
Park teaches in Paragraph 0053 a mask jig which is also the upper jig and has a hollow defined therein (i.e. slits) through which the laser emitted from the laser irradiation part 50 passes. The hollow may be defined to pass through the upper jig 42 from a top surface to a bottom surface, and face a weld portion of one object (e.g., electrode lead 17).
Regarding Claim 9,
Park teaches that the electrode lead 17 connected to the positive electrode tabs may be made of an aluminum (Al) material, which is the same as that of the positive electrode, and the electrode lead 17 connected to the negative electrode tabs may be made of a copper (Cu) material (Paragraph 0041). Park also states that the negative electrode tab and negative electrode lead has copper material (Paragraph 0080).
Regarding Claim 10,
Park teaches a pouch type secondary battery in a battery case that comprises electrode assembly, and electrolyte (Paragraph 0032). The electrode assembly 10 includes a plurality of electrodes 11 stacked with a separator 13 therebetween, and a plurality of electrode tabs 15 connected to the plurality of electrodes 11 and welded to each other. The electrode assembly further includes an electrode lead 17 welded to the plurality of electrode tabs 15 (Paragraph 0033). In figure 1, it shows that the electrode tabs 15 protrude from a side of the electrode assembly, and are combined together to form the tab bundle. The electrode lead connected to the tabs is welded to the tabs by laser welding (Paragraph 0038).
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Park teaches the presence of plurality of electrode tabs but does not teach that the electrode tabs are ultra-thin electrode tab having a thickness of 15 um or less, and the number of electrode tabs stacked in one direction is atleast 40.
However, Peng teaches a method of welding electrode tabs by laser welding (Paragraph 0062), and Peng teaches that the electrode tab can have a thickness of 0.01 to 0.5 mm (which is 10 um to 500 um). This range shows overlap with the claimed range of 15 um or less. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use the method of Park for electrode tabs that have thickness as shown in Peng in order to produce a battery with high electrode reliability and high strength at the welding area (Paragraph 0005).
Furthermore, Chen teaches a method of joining battery cell tabs with laser welding system (Paragraph 0062) such that anywhere from one to one hundred electrode pairs are included in the flexible battery pouch (Paragraph 0047). This implies that there are between one and one hundred electrode tabs stacked. This range overlaps with the claimed range of atleast more than 40 electrode tabs stacked in one direction. In figure 1 of Chen, it is seen that the positive foils 28 stack up to form a first stack 14 (akin to the electrode tabs and tab unit), and the element 29, battery cell tab is akin to the electrode lead. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to stack atleast 40 electrode tabs in order to form a battery pouch that is commonly used in applications such as in vehicles (Paragraph 0047).
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Regarding Claim 11,
Park teaches that the overlapping area is irradiated with the laser to form a welding pattern with welding spots that are regularly spaced apart on an uppermost plane on which the laser is incident. In Figure 5 below, element 120 are the welding spots that are regularly spaced apart. Element 17 is the electrode lead which is the upper most plane and is the overlapping section with electrode tabs.
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Figure 1 shows the overlapping region between the electrode tabs 15 and the lead 17. Figure 1 also shows that the overlapping area is irradiated with the laser 50.
Regarding Claim 12,
Park shows in Figure 4 below that the welding spots are regularly spaced apart. Furthermore, Park teaches that the gaps g1 and g2 in the x direction (which is analogous to the width direction in claimed invention) can be 0.5 to 2 mm. Park also teaches that the gap g3 is from 0.25 to 1.5 mm which is in the y direction (analogous to the length direction where the electrode tabs protrude). In the instant specification, it states that the reciprocal number of the welding spot density may correspond to a distance between the closest welding spots spaced apart from each other in each direction (a distance between the centers of the welding spots spaced apart from each other; instant specification, Paragraph 0064). The claim limitation is that number of welding spots per unit length in the length direction is greater than in the width direction. Based on this limitation, and the reciprocal of the welding spots per unit length, it can stated that the distance between the spots is less in the length direction than in the width direction. Hence, based on the above gaps g1, g2, g3 from Park it is evident that the distance between spots in the length direction is less than the distance between spots in the width direction. Adding the measurement of r1 and r2 to the gaps g1 and g2 in order to get the distance between spot centers will also result in the claimed relationship in length and width direction.
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Regarding Claim 13,
Park teaches that the gaps g1 and g2 in the x direction (which is analogous to the width direction in claimed invention) can be 0.5 to 2 mm. In the instant specification, it states that the reciprocal number of the welding spot density may correspond to a distance between the closest welding spots spaced apart from each other in each direction (a distance between the centers of the welding spots spaced apart from each other; instant specification, Paragraph 0064). Park teaches that the radius r1 is 0.5 mm, 1 mm (Paragraph 0066). Hence, the total distance between centers of the welding spots is r1 +g1 +r1. In an instance, this distance is 3 mm (1+1+1 mm). The reciprocal of the second welding spot density claimed range results in the distance range being 2 -3.33 mm. 3 mm lies within the reciprocal range and hence meets the limitation of this claim.
Park also teaches that the gap g3 is from 0.25 to 1.5 mm which is in the y direction (analogous to the length direction where the electrode tabs protrude). Gap g3 is the distance between the centers of the weld spots. Hence, the reciprocal of g3 is the second welding spot density. The reciprocal range is 1.25 to 1.66 mm. There is overlap between the g3 range and the reciprocal range. Hence, Parks meets the limitations of this claim.
Regarding Claim 15,
Park does not teach that the electrode lead is positioned under the electrode tab unit in the overlapping area, so as to apply the laser from above,
However, Chen teaches in Figure 1 that the electrode tabs (stack and unit) are positioned above the electrode lead. In figure 1 of Chen, it is seen that the positive foils 28 stack up to form a first stack 14 (akin to the electrode tabs and tab unit), and the element 29, battery cell tab is akin to the electrode lead. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to stack atleast 40 electrode tabs in order to form a battery pouch that is commonly used in applications such as in vehicles (Paragraph 0047).
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Claims 6, 14 are rejected under 35 U.S.C. 103 as being unpatentable over Park et al in view of Peng et al and Chen et al, and further in view of Roh et al (US 2021/0252638 A1).
Regarding Claim 6, and Claim 14,
Park teaches that the welding spots on the upper most plane or layer are of diameter about 1 mm for aluminum material and 0.5 mm for copper material. The value for copper material lies within the claimed range of 0.2 to 0.8 mm.
Park does not teach that the welding spot has a diameter of 0.1 to 0.8 mm on a lowermost plane in the overlapping area.
However, Roh teaches in Paragraph 0054 that a laser welding method for electrode tabs such that the back bead (i.e. welding spot on the lowermost plane) formed on the rear surface of the welded portion at the electrode side has a diameter that is slightly smaller than that of the front bead (welding spot on uppermost plane). The front bead 510a of the welded portion at the positive electrode side and the negative electrode side may protrude in an embossed shape having a diameter of about 0.3 mm to about 0.4 mm, and a distance between central points of the welding spots may be about 0.6 mm. In an embodiment, the back bead 510b of the welded portion at the positive electrode side and the negative electrode side may have a diameter that is about 30% to about 70% of the diameter of the front bead 510a (Paragraph 0056). This teaches that the uppermost welding spot has a diameter within the claimed range, and the welding spot on lowermost plane will have a diameter of 0.225 to 0.3 mm (70%). This range also lies within the claimed range. Hence, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use the welding spot diameters in Roh in the method of Park in order to form a welded portion that maintains a welded state without shearing or fracturing even by performing drop test, and in turn improving the welding reliability (Paragraph 0052).
Conclusion
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/SUHANI JITENDRA PATEL/Examiner, Art Unit 1783
/MARIA V EWALD/Supervisory Patent Examiner, Art Unit 1783