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 .
Claims 1–6 and 8–20 are rejected under 35 U.S.C. 103 as set forth below. Claim 7 is cancelled.
Claim Rejections - 35 USC § 103
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 1-6, and 8-12 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al. (US 9362592), hereinafter Yu, in view of Lee et al. (WO 2009096671), hereinafter Lee, in further view of Ahn et al. (KR 20160099970), hereinafter Ahn, in further view of Park et al. (KR 20170101582), hereinafter Park.
Regarding claim 1, Yu teaches a method for manufacturing a gel polymer electrolyte secondary battery (Abstract). Regarding step (S1), Yu teaches manufacturing a gel polymer electrolyte secondary battery including a cathode, an anode, a separator, and a gel polymer electrolyte in a battery case (Abstract). The cathode and anode correspond to the claimed first and second electrodes. Yu does not expressly teach that the separator is the claimed ceramic-coated separator.
Lee, however, teaches a separator comprising a porous substrate having a plurality of pores and a porous coating layer formed on at least one surface thereof, wherein the coating layer comprises inorganic particles and a binder polymer (Abstract; [0029]–[0035]). The inorganic particles correspond to the claimed ceramic particles, and the binder polymer corresponds to the claimed first binder polymer. Thus, Yu in view of Lee teaches each element of step (S1).
Regarding step (S2), Lee further teaches a polymer dot-pattern layer formed on the surface of the porous coating layer and explains that the polymer dot-pattern layer enhances the bonding force between the electrode and separator so that the electrode and separator do not separate during assembly ([0013]–[0015]). Thus, Lee teaches applying a composition comprising a second binder polymer in a patterned configuration and bonding the coated separator to the electrodes. Lee does not expressly teach the claimed zigzag folding arrangement.
Ahn, however, teaches forming an electrode assembly using a repeatedly folded separator and positioning electrodes in regions defined between overlapping portions of the folded separator ([0055]). Thus, Ahn teaches the remaining zigzag-folding and electrode-insertion limitations of step (S2).
Regarding step (S3), Yu teaches introducing a gel polymer electrolyte composition comprising an electrolyte solvent, electrolyte salt, and polymer electrolyte monomer into a battery case containing the electrode assembly and thereafter polymerizing the monomer to form the gel polymer electrolyte (col. 2, lin. 59–col. 3, lin. 6). Yu therefore teaches injecting a gel polymer electrolyte composition into the electrode assembly to obtain the battery.
Regarding step (S4), Park teaches activation/formation charging of a lithium secondary battery and teaches that the charging process may be performed in two or more processes ([0043]). Park further teaches formation temperatures of 0–90°C, preferably 25–80°C, and more particularly 45–60°C ([0037]). The 45–60°C range overlaps the claimed temperature of 50°C or higher. Park further teaches formation pressures of 0–20 kgf/cm², preferably 0.5–12 kgf/cm², and particularly 1–6 kgf/cm². These ranges overlap the claimed pressure of 0.1–5 kgf/cm² ([0033]).
Yu, Lee, Ahn, and Park are considered analogous art to the claimed invention because they are in the same field of lithium secondary battery manufacture. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to modify Yu to employ Lee's inorganic-particle/binder-coated separator because Lee teaches that the structure improves separator stability and electrode-to-separator adhesion. It would further have been obvious to employ Ahn's folded separator arrangement as one of a finite number of known electrode-stack configurations to arrange alternating positive and negative electrodes while maintaining electrical separation. Finally, one of ordinary skill would have been motivated to apply Park's temperature- and pressure-controlled multistage formation procedure because Park teaches controlling such parameters during activation of lithium secondary batteries. The proposed combination does not require changes to the respective principles of operation of the references; rather, each known battery-manufacturing feature performs the same function as it does individually. One of ordinary skill therefore would have had a reasonable expectation of successfully combining the teachings.
Regarding claim 2, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 2 further requires that laminating step (S2) be carried out at a temperature of 30°C or lower. Lee teaches assembling and bonding the separator and electrodes using the patterned polymer layer but does not specify a specific lamination temperature ([0046-0047]). The specific temperature selected for bringing an adhesive-coated separator and electrode into contact would have been a design choice, depending on whether heating was required to activate, soften, or cure the binder. Lee's patterned polymer itself provides adhesion and does not require that the assembly be performed at an elevated temperature. Thus, in the absence of a need for thermal activation, a person of ordinary skill would naturally have considered room-temperature processing, i.e., approximately 20–25°C, which falls squarely within the claimed range of 30°C or lower. Such a choice would have provided the predictable advantages of eliminating an unnecessary heating step, reducing energy consumption and process complexity, and reducing thermal exposure of the electrode and separator materials. The claimed upper limit of 30°C therefore represents no more than selection of a conventional ambient processing condition from the finite and predictable alternatives available to the skilled artisan, particularly where the claim does not establish that processing at 30°C or lower produces an unexpected result relative to conventional ambient-temperature assembly.
Regarding claim 3, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 3 further requires that the laminating step (S2) be carried out at ambient pressure or at a pressure of 3 kgf/cm² or less. Lee teaches that its patterned polymer layer provides bonding between the electrode and separator but does not expressly specify the external pressure used during assembly ([0046-0047]). The amount of pressure applied when bonding two layered battery components would have been a known result-effective process variable because increasing pressure increases interfacial contact, whereas excessive pressure compresses the porous separator and may deform the electrode/separator structure. Thus, a person of ordinary skill would have recognized that pressure should be selected only to the extent necessary to establish adequate contact and adhesion. Because Lee already provides a polymer dot-pattern layer specifically for enhancing adhesion, the skilled artisan would have reason to use relatively low pressure rather than unnecessarily high pressure. Ambient pressure and pressures up to 3 kgf/cm² represent predictable low-pressure choices that maintain contact while limiting compression of the porous separator. Optimization of the applied pressure to balance adhesion against separator compression would have required no more than routine experimentation, and the claimed range does not reflect a different principle of operation or an identified unexpected result. Accordingly, use of ambient pressure or pressure of 3 kgf/cm² or less would have been an obvious design choice.
Regarding claim 4, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 4 further requires that the laminating step (S2) not be carried out under pressure. Lee teaches that the patterned polymer layer itself enhances the bonding force between the separator and electrode and does not teach that externally applied pressure is necessary to obtain such bonding. Once Lee provides the adhesive polymer at the interface, the skilled artisan would have been presented with the predictable alternatives of applying external pressure or allowing the polymeric adhesive itself to maintain the electrode/separator interface without an additional pressurizing operation. Where adequate adhesion is achieved without pressure, omitting an unnecessary pressure-applying step would predictably have simplified the manufacturing process, eliminated the need for press equipment or an additional processing operation, and avoided compression of the porous separator. Eliminating an unnecessary process step that serves no required function is a predictable engineering design choice. Accordingly, performing the assembly without externally applied pressure would have been obvious where Lee's patterned binder provides sufficient adhesion, absent evidence that the absence of pressure produces an unexpected technical effect.
Regarding claim 5, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 5 further requires that the first binder polymer be included in an amount of 0.1–10 wt% based on the total weight of the ceramic coating layer. Lee teaches an inorganic-particle-to-binder-polymer ratio of 50:50 to 99:1 and, more preferably, 70:30 to 95:5 ([0035]). Lee therefore encompasses embodiments containing approximately 5 wt% binder polymer, which falls within the claimed range.
It is well established that where the claimed ranges overlap or lie within the ranges disclosed by the prior art, a prima facie case of obviousness exists. Therefore, it would have been obvious to one of the ordinary skills in the art to select a weight percentage within the claimed ranges as a matter of routine optimization of a result-effective variable.
Regarding claim 6, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 6 further requires that the first binder polymer be an acrylate-based binder polymer. Lee expressly identifies polymethyl methacrylate as a suitable binder polymer for the inorganic-particle coating ([0009], [0029]).
Regarding claim 8, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 8 further requires a polymerization initiator having a 10-hour half-life temperature of 60°C or lower, a polymerizable compound, a lithium salt, and a nonaqueous organic solvent. Yu teaches a gel polymer electrolyte composition comprising a polymer electrolyte monomer, a polymerization initiator, an electrolyte salt, and an electrolyte solvent. Yu identifies peroxide and azo polymerization initiators, including AMVN (col. 5, lin. 47–col. 6, lin. 2), and teaches nonaqueous organic electrolyte solvents and electrolyte salts (col. 8, lin. 30–66). AMVN has a 10-hour half-life at temperatures below 60°C.
Regarding claim 9, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 9 further requires that the polymerization initiator have a 10-hour half-life temperature of 55°C or lower. Yu identifies AMVN as a suitable polymerization initiator, and it has a 10-hour half-life at approximately 51°C (col. 5, lin. 47-col. 6, lin. 2).
Regarding claim 10, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 10 further requires 0.1–10 parts by weight polymerization initiator. Yu teaches 0.01–5 parts by weight of polymerization initiator (col. 6, ll. 3–11). It is well established that where the claimed ranges overlap or lie within the ranges disclosed by the prior art, a prima facie case of obviousness exists. Therefore, it would have been obvious to one of the ordinary skills in the art to select parts by weight within the claimed ranges as a matter of routine optimization of a result-effective variable.
Regarding claim 11, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 11 further requires that pressure be applied during formation at least once using a pressurizing device. Park expressly teaches conducting battery activation using a pressurizing device while maintaining the lithium secondary battery under pressure during charging ([0090]).
Regarding claim 12, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Park reports a formation temperature of 45–60°C, which overlaps the claimed 50–60 °C range ([0037]). Park reports pressures ranging from 0.5–12 kgf/cm², which overlap with the claimed first-stage pressure of 0.1–1 kgf/cm² ([0033], [0090-0091]). Park further teaches a first pressure condition at approximately SOC 15, with pressure changing around SOC 15–16. Park thereafter teaches increasing pressure and, in Example 2, applying 5 kgf/cm² beginning around SOC 30–31 and maintaining that pressure through SOC 60 ([0033], [0090-0091]). Thus, Park teaches pressure and SOC conditions overlapping the claimed first and second formation stages. Park also explicitly teaches that pressure changes as SOC increases. The exact selection of pressure-transition SOC values within Park's disclosed operating regions would have been an obvious design choice because SOC-dependent pressure is expressly recognized by Park as a controllable formation parameter. A person of ordinary skill would have optimized the transition points according to the degree of cell expansion and desired formation characteristics, and doing so would have involved routine experimentation with a reasonable expectation of success.
Claims 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Yu in view of Lee, Ahn, and Park, and further in view of Lim et al. (US 20190074538), hereinafter Lim, and further in view of Song et al. (CN 111527642), hereinafter Song.
Regarding claim 13, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 13 further requires storing the battery after formation at 60°C or higher under a pressure of 3 kgf/cm² or more. Lim teaches elevated-temperature battery processing at approximately 60–80°C and approximately 0.5–5 kgf/cm² pressure ([0018]) and further teaches battery aging/storage ([0025]). Song teaches performing activation/formation of a secondary battery by pressurizing the secondary battery at 60° C and 0.5-5 kgf/cm² and charging the battery to a SOC of 65% while applying the pressure ([0035]).
Lim therefore expressly establishes that both elevated temperature and external pressure are known process variables in post-assembly processing of lithium secondary batteries. Lim's temperature range expressly satisfies the claimed minimum temperature, and its pressure range encompasses pressures of 3–5 kgf/cm². Song further demonstrates that pressure and elevated temperature may be applied concurrently during activation/formation of a secondary battery.
To the extent Lim does not expressly state that the precise combination of ≥60°C and ≥3 kgf/cm² is maintained during the particular storage stage recited in the claim, doing so nevertheless would have been an obvious design choice. Temperature, pressure, and storage are each known to affect stabilization and dimensional behavior of a recently formed battery. Once the skilled artisan is taught to age the battery and separately taught to apply 60–80°C temperature and pressures up to 5 kgf/cm² during battery processing, maintaining those known conditions during storage would have been one of a finite number of predictable process arrangements. The skilled artisan would have had reason to maintain pressure during elevated-temperature storage to restrain dimensional changes and maintain interfacial contact within the electrode assembly. The claimed combination merely employs Lim's known temperature and pressure conditions during a known battery-aging operation and would have been expected to perform their established functions.
Regarding claim 14, Lim and Song teach the limitations of claim 13, as stated above. Claim 14 further requires carrying out the storing step for 30 minutes to 5 hours. Lim teaches aging/storage but does not expressly disclose this numerical duration. Song teaches the pressuring and heating step lasts for 30 min ([0067]). Song further teaches that, following the pressurized charging/activation sequence, the battery is subjected to an aging period before subsequent chagrining, discharging and degassing operations. Song therefore further demonstrates that the duration of a battery aging/processing step is a selectable process parameter associated with battery formation.
The duration of an elevated-temperature aging operation, however, is inherently a result-effective process variable because the extent of thermal aging necessarily depends upon both temperature and exposure time. A person of ordinary skill seeking to implement Lim's elevated-temperature aging process would necessarily have been required to select a treatment duration. The skilled artisan would have balanced sufficient aging against manufacturing throughput, energy consumption, and the possibility of unnecessary prolonged thermal exposure. A shorter duration at an elevated temperature would have been a predictable alternative to a longer aging treatment because increasing temperature generally permits the desired thermal treatment to occur over a shorter processing interval. Selection of a duration between 30 minutes and 5 hours therefore would have amounted to routine optimization of a known aging process rather than a change in its principle of operation. The claimed duration would have been an obvious design choice available to the skilled artisan.
Regarding claim 15, Lim and Song teach the limitations of claim 13, as stated above. Claim 15 further requires that pressure be applied during storage at least once using a pressurizing device. Lim teaches applying external pressure during elevated-temperature battery processing ([0018], [0025]), while Park teaches applying controlled external pressure to a lithium secondary battery using a pressurizing device, as stated above. The selection of a pressurizing device to implement Lim's external-pressure treatment would have been a straightforward choice of a known apparatus for applying pressure. Park and Lim are concerned with the same type of lithium secondary battery and the same general battery-processing environment. A person of ordinary skill would therefore have had reason to employ Park's pressurizing device to provide and maintain Lim's prescribed external pressure because the device is specifically designed to perform that function. The combination amounts to no more than using a known device for its known purpose and would have yielded the predictable result of the controlled application of external pressure to the battery.
Claims 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over Yu in view of Lee, Ahn, and Park, and further in view of Jeong et al. (KR 20190060522), hereinafter Jeong.
Regarding claim 16, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 16 further requires vacuum sealing after electrolyte injection and before formation at a pressure of less than −95 kPa. Yu teaches electrolyte injection before formation, while Jeong teaches vacuum processing and vacuum sealing of a gel polymer electrolyte secondary battery, including vacuum conditions approaching −95 kPa ([0030-0031]).
Yu and Jeong are in the same field of gel polymer electrolyte battery manufacture. To the extent Jeong does not expressly disclose a pressure numerically below −95 kPa, the precise magnitude of vacuum would have been a result-effective process variable readily selected by the skilled artisan. The fundamental purpose of applying vacuum is to reduce internal gas pressure, remove entrapped gas, facilitate evacuation, and permit effective sealing. Increasing vacuum from approximately −95 kPa to slightly below −95 kPa does not alter the principle of operation; it merely increases the pressure differential driving evacuation. A person of ordinary skill seeking more complete gas removal would predictably increase the vacuum until adequate evacuation was obtained, subject to the structural limits of the pouch and processing equipment. The claimed threshold therefore represents optimization of the degree of vacuum within the same known vacuum-sealing process, and no unexpected effect is apparent merely from crossing the −95 kPa numerical boundary.
Regarding claim 17, Yu, Lee, Ahn, Park, and Jeong teach the limitations of claim 16, as stated above. Claim 17 further requires a vacuum-sealing pressure of −100 to −120 kPa. Jeong teaches vacuum sealing at reduced pressure and therefore establishes vacuum magnitude as an operating parameter of the same battery-sealing process. A person of ordinary skill implementing Jeong's vacuum sealing would necessarily select a vacuum level based on the amount of gas to be removed, pouch construction, equipment capabilities, and desired processing time. Increasing the magnitude of the vacuum is a predictable way to increase evacuation force and reduce residual gas. Accordingly, selection of a stronger vacuum within the claimed range would have been an optimization of a known result-effective variable rather than a new method of operation. The claimed numerical range would therefore have been an obvious design choice, absent evidence that the particular range provides an unexpected result. The pressure convention used by the claim should separately be construed in view of the specification, particularly for numerical values exceeding approximately one atmosphere of negative gauge pressure.
Claims 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yu in view of Lee, Ahn, and Park, Jeong, and further in view of Shin et al. (KR 20190112656), hereinafter Shin.
Regarding claim 18, Yu, Lee, Ahn, Park, and Jeong teach the limitations of claim 16, as stated above. Claim 18 further requires vacuum sealing for 5–30 seconds. Shin teaches short-duration vacuum processing of pouch-type secondary batteries, including approximately 10–20 ([0181]). Jeong and Shin are in the same field of vacuum processing of lithium secondary batteries. It would have been obvious to employ Shin's expressly disclosed vacuum-processing duration in Jeong's vacuum treatment, since both processes seek to evacuate a pouch-type battery. The motivation would have been to obtain sufficient evacuation while limiting process time and improving manufacturing throughput.
It is well established that where the claimed ranges overlap or lie within the ranges disclosed by the prior art, a prima facie case of obviousness exists. Therefore, it would have been obvious to one of the ordinary skills in the art to select a short duration vacuum processing within the claimed ranges as a matter of routine optimization of a result-effective variable.
Regarding claim 19, Yu, Lee, Ahn, and Park teach the limitations of claim 1, as stated above. Claim 19 further requires degassing after formation at a pressure of less than −95 kPa. Park teaches formation charging, while Shin teaches vacuum degassing of a lithium secondary battery at reduced pressures approaching −95 kPa ([0201]). A person of ordinary skill would have recognized that gases generated during initial charging should be removed during subsequent degassing and that the degree of vacuum directly affects the pressure differential available to remove such gases. Thus, vacuum magnitude is a result-effective variable. Increasing Shin's vacuum slightly beyond −95 kPa would predictably increase the driving force for removal of entrapped gas without changing the fundamental operation of the degassing process. The skilled artisan would have selected the vacuum level based on the quantity of gas generated, the desired residual-gas level, the pouch strength, and the vacuum equipment's capability. Accordingly, the use of a vacuum below −95 kPa would have been a routine optimization and a predictable design choice in carrying out Shin's known post-formation degassing process.
Regarding claim 20, Yu, Lee, Ahn, Park, and Shin teach the limitations of claim 19, as stated above. Claim 20 further requires degassing at −100 to −120 kPa. Shin teaches the same vacuum-degassing process but does not expressly disclose the entirety of the claimed numerical range. The claimed difference concerns only the magnitude of vacuum used to perform the same known function. The skilled artisan would have understood that stronger vacuum provides a greater pressure differential and therefore facilitates removal of gas from the battery. Selection of a particular vacuum level would have involved balancing gas-removal efficiency against equipment limitations, pouch integrity, and processing time. Thus, varying Shin's known vacuum level toward a stronger vacuum would have been a predictable optimization of a known result-effective variable. In the absence of evidence that −100 to −120 kPa produces an unexpected result relative to the known vacuum-degassing conditions, the claimed range would have constituted an obvious design choice.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Yu in view of Lee, Ahn, and Park, Jeong, Shin and further in view of Bhardwaj et. al. (US 20130095357), hereinafter Bhardwaj.
Regarding claim 21, Yu, Lee, Ahn, Park, and Shin teach the limitations of claim 19, as stated above. Jeong teaches a lithium secondary battery including a gel polymer electrolyte and a method of manufacturing the same, including injecting a gel polymer electrolyte composition into a battery case, performing precharging and aging, and performing vacuum processing and curing of the gel polymer electrolyte ([0018], [0025], [0030-0031]).
Bhardwaj teaches a lithium polymer battery cell in which pressure and temperature are applied during manufacture to increase the stiffness of the battery cell and improve the battery cell’s resistance to mechanical stress (Abstract, [0008-0009]). In particular, Bhardwaj teaches applying pressure and an elevated temperature to the battery cell for a predetermined period of time to increase the stiffness of the resulting battery cell.
Jeong and Bhardwaj are considered analogous art to the claimed invention because they are in the same field of secondary batteries. It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to modify the gel polymer electrolyte secondary battery of Jeong to apply pressure and temperature during manufacture as taught by Bhardwaj. One of ordinary skill in the art would have been motivated to make such a modification to increase the stiffness and mechanical stability of the resulting battery cell and thereby improve the battery’s resistance to deformation and mechanical stress.
With respect to the recited stiffness of 4.0 MPa or more, Bhardwaj teaches that the application of pressure and temperature is used to increase battery-cell stiffness. The particular stiffness value is considered a result-effective variable that would have been optimized by one of ordinary skill in the art through routine experimentation to obtain a desired level of stiffness. Such optimization would have involved selecting appropriate pressure, temperature, and treatment time based on the desired mechanical properties of the resulting battery and would have been expected to produce the claimed stiffness of 4.0 MPa or more.
Conclusion
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/TAMARA ORDUNA/Examiner, Art Unit 1776
/Jennifer Dieterle/Supervisory Patent Examiner, Art Unit 1776
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