DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
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.
The factual inquiries 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.
Claim(s) 22-23, 25, 31-34, 36, and 42-44 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pestana et al. (US 10,673,062) in view of Yi (CN 110690421, see machine translation).
Regarding claims 22, 33, and 44, Pestana discloses a battery 100 comprising an anode 101, a cathode 105, and an electrolyte (C2/L44-66). The anode 101 comprises a copper [metal] current collector, and an active material of silicon, carbon, or a combination of these materials (C3/L1-7).
The silicon anode further includes conductive additives with different morphological properties, including carbon black, vapor grown carbon fibers, and a mixture of the two (C3/L60-67).
With regards to the limitation of the “active material layer comprises islands of material separated by cracks”, consider the following teachings of Pestana:
“The performance of electrochemical electrodes, while dependent on many factors, is largely dependent on the robustness of electrical contact between electrode particles, as well as between the current collector and the electrode particles. The electrical conductivity of silicon anode electrodes may be manipulated by incorporating conductive additives with different morphological properties…” (C3/L57-63);
“…Silicon regions may lose electrical contact from the anode as large volume changes coupled with its low electrical conductivity separate the silicon from surrounding materials in the anode” (C4/L29-32);
“In addition, the large silicon volume changes exacerbate solid electrolyte interphase (SEI) formation, which can further lead to electrical isolation and, thus, capacity loss. Expansion and shrinkage of silicon particles upon charge-discharge cycling causes pulverization of silicon particles, which increases their specific surface area. As the silicon surface area changes and increases during cycling, SEI repeatedly breaks apart and reforms. The SEI thus continually builds up around the pulverizing silicon regions during cycling into a thick electronic and ionic insulating layer. This accumulating SEI increases the impedance of the electrode and reduces the electrode electrochemical reactivity, which is detrimental to cycle life” (C4/L33-45); and,
“In an example scenario, the anode active material 205 before pyrolysis comprises silicon particles in a binder material and a solvent, where the active material is pyrolyzed to turn the binder into a carbon that provides a structural framework around the silicon particles and also provides carbon for electrical conductivity. The active material may be coupled to the current collector 201 using the adhesive 203…” (C4/L65-C5/L5).
This disclosure has been construed as rendering obvious 1) islands of material (i.e. silicon) separated by cracks due to the expansion, shrinkage and pulverization of silicon particles, which increased the surface area and 2) conductive particles extending from within the islands and bridge the cracks of the active material layer.
Therefore, Pestana either inherently meets the limitations, or it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the silicon anode of Pestana to comprise islands of material separated by cracks wherein at least a portion of the additives extend form within the islands and bridge the cracks of the active material by repeated charging and discharging of the battery because such charge-discharge cycling causes pulverization [cracking/island forming] of silicon particles (Pestana at C4/L33-45).
While Pestana discloses using conductive additives of different morphological properties (including carbon black and vapor grown carbon fibers) (C3/L60-67), Pestana does not explicitly disclose wherein the conductive additives form a structure providing electrical conductivity between a first island a second island, or between at least one island and the metal current collector.
Yi discloses a silicon-based negative electrode slurry for a lithium ion battery and a preparation method thereof (abstract). Yi discloses that by selecting conductive agents of different dimensions for the negative electrode slurry: a good conductive network is constructed, the conductivity of the electrode sheet can be improved, the contact deterioration caused by the expansion process of silicon particles can also be effectively improved, the problems of lattice volume expansion, silicon particle pulverization, poor contact between silicon particles and conductive agents and binders, repeated growth of SEI films on the surface of silicon particles, consumption of electrolyte and the like after charging and discharging of the silicon material can be solved and the first efficiency, rate discharge and cycle performance of the battery can be improved (abstract, [0007]). The conductive agents include a conductive paste including zero-dimensional conductive agents, one-dimensional conductive agents, two-dimensional conductive agents ([0017]). Zero-dimensional conductive agents includes conductive carbon black, acetylene carbon black, and superconducting carbon black; one-dimensional conductive agents includes carbon nanotubes and carbon fibers; and two-dimensional conductive agent is graphene ([0026]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the conductive agents of different dimensions (including zero-, one-, and two- dimensional conductive agents) as taught by Yi with the conductive agents of Pestana for the purpose of constructing a good conductive network in the anode electrode, improving conductivity, improving contact deterioration, reducing problems of lattice volume expansion and silicon particle pulverization.
Regarding claims 23 and 34, modified Pestana discloses all of the claim limitations as set forth above. Yi further teaches conductive agents in an amount of 3-15 parts ([0011]). In addition, as the electrical conductivity increases while the energy storage amount decreases with increasing conductive agents per volume/mass, the relative amount of conductive agents would have been considered a result effective variable. Yi further teaches that the amount of carbon black affects point contact while the amount of carbon nanotubes affect the long-range linkages ([0044]-[0045]). As such, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize, by routine experimentation, the amount of conductive additives (including in amount between 1-40% of the active material layer) in the electrode of Pestana to obtain the desired balance between conductivity and energy storage amount.
Regarding claims 25 and 36, modified Pestana discloses all of the claim limitations as set forth above. Yi further teaches conductive agents including carbon nanotubes and/or graphene ([0026]).
Regarding claims 31 and 42, modified Pestana discloses all of the claim limitations as set forth above. With regards to the limitation of “wherein the cracks form after one or more formation processes and/or one or more lithiation/delithiation cycles of a battery incorporating the electrode”, said limitation has been considered and construed as a product by process limitation wherein the product produced is an active material comprising cracks.
Regardless, given that Pestana teaches that the battery undergoes charge-discharge cycles and this cycling causes pulverization of the silicon particles in the anode and causes silicon regions to lose electrical contact from the anode (C4/L29-40), the combination renders obvious cracks forming after one or more formation processes and/or one or more lithiation/delithiation cycles of a battery incorporating the electrode.
Regarding claims 32 and 43, modified Pestana discloses all of the claim limitations as set forth above. Given that Pestana teaches that the battery undergoes charge-discharge cycles and this cycling causes pulverization of the silicon particles in the anode and causes silicon regions to lose electrical contact from the anode (C4/L29-40), wherein adjacent silicon particles/regions are separated because of the pulverization, the combination renders obvious islands adjacent to particular crack have mirror image surfaces facing the particular crack.
Claim(s) 24, 29, 35, and 40 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pestana et al. (US 10,673,062) in view of Yi (CN 110690421, see machine translation), as applied to claims 22 or 33 above, and further in view of Kim (WO 2020/050661, see English language equivalent US 2021/0328225).
Regarding claims 24 and 35, modified Pestana discloses all of the claim limitations as set forth above. While Pestana teaches that the silicon anodes may be formed from silicon composites with more than 50% silicon, modified Pestana does not explicitly disclose wherein the active material layer comprises between 20% to 95% silicon.
Kim discloses a negative electrode that includes silicon particles (abstract). The silicon particles may be pure silicon ([0027]), and the negative electrode active material may be included in an amount of 60-80 wt% ([0032]). Kim teaches that the amount leads to the energy density of the negative electrode being formed at a high level while maintaining amounts of conductive agent and binder at a desired level ([0032]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use [pure] silicon in the negative electrode in the amount of 60-80wt% as taught by Kim with the amount of silicon in modified Pestana tor the purpose of leading to the energy density of the negative electrode being formed at a high level while maintaining amounts of conductive agent and binder at a desired level.
Regarding claims 29 and 40, modified Pestana discloses all of the claim limitations as set forth above. While Yi teaches the conductive additives including carbon nanotubes ([0026]), modified Pestana does not explicitly disclose the conductive additives comprise one or more semiconductors.
Kim discloses a negative electrode that includes silicon particles (abstract). The negative electrode further includes carbon nanotubes, and the carbon nanotube unit may exhibit characteristics of a conductor or semiconductor depending on a structure and angle at which the graphite sheet is rolled ([0039]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a carbon nanotubes with a semiconductor structure as taught by Kim with the conductive additives of modified Pestana for the purpose of adjusting the electrical conductivity and properties of the anode.
Claim(s) 26-28 and 37-39 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pestana et al. (US 10,673,062) in view of Yi (CN 110690421, see machine translation), as applied to claims 22 or 33 above, and further in view of Park et al. (US 2016/0315318).
Regarding claims 26-28 and 37-39, modified Pestana discloses all of the claim limitations as set forth above. While Pestana discloses conductive additives (C34/L60-67), modified Pestana does not explicitly disclose (claims 26 & 37) wherein the conductive additives comprise metal, (claims 27 & 38) wherein the conductive additive comprises one or more of: gallium, indium, copper, aluminum, lead, tin, nickel; (claims 29 & 39) wherein the conductive additives comprises a transition metal.
Park discloses a negative electrode active material comprising silicon, and an alloy of copper and aluminum (abstract, [0012]). The alloy can additionally include iron, titanium, and/or zirconium ([0015]-[0017]). Copper, iron, titanium, and zirconium are all transition metals. Park teaches that the alloy makes it possible to implement a battery having a high capacity and excellent initial efficiency, and improve yield of a fabricating process of a negative electrode active material ([0019]-[0020]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the alloy of copper/aluminum and/or iron, titanium, zirconium as taught by Park with the conductive additives of modified Pestana for the purpose of implementing a battery having high capacity, excellent initial efficiency, and improving yield.
Claim(s) 30 and 41 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pestana et al. (US 10,673,062) in view of Yi (CN 110690421, see machine translation), as applied to claims 22 or 33 above, and Nakashima et al. (WO 2018/117087, see machine translation).
Regarding claims 30 and 41, modified Pestana discloses all of the claim limitations as set forth above. While Yi teaches carbon nanotubes ([0026]), which are long narrow filaments, modified Pestana does not explicitly disclose wherein the long narrow filament [carbon nanotube] also have an aspect ratio of 20 or greater.
Nakashima disclose a negative electrode for a lithium ion battery (abstract). The negative electrode comprises a silicon and/or silicon compound as an active material (page 3 of translation). The negative electrode further comprises conductive carbon fillers including carbon fibers, carbon nanofibers and carbon nanotubes (page 4). The aspect ratio of the conductive carbon fillers is preferably 20 to 10,000 (page 5). Nakashima teaches that the carbon fiber, carbon nanofiber, and carbon nanotubes of this aspect ratio are preferably from the viewpoint of absorbing volume expansion during charge/discharge from the viewpoint of conductivity (pages 4-5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a carbon fiber, carbon nanofiber, or carbon nanotube with an aspect ratio greater than 20 in a silicon negative electrode as taught by Nakashima with the silicon negative electrode Pestana for the purpose of absorbing volume expansion during charge/discharge from the viewpoint of conductivity.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 22-44 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-23 of U.S. Patent No. 11,688,848. Although the claims at issue are not identical, they are not patentably distinct from each other because the conflicting claims disclose a battery electrode, method of making said electrode, and battery, comprising a metal current collector, an active material layer on the current collector, wherein the active material layer comprises islands of material separated by cracks, the islands comprising silicon and conductive additives, wherein at least a portion of the additives extend from within the islands and bridge the cracks of the active material layer (claim 1). Because the conductive additives “extend from within the islands and bridge the cracks”, it is considered that the conflicting claims further meet the limitation of wherein the conductive additives form a structure providing electrical conductivity between a first island and second island [bridging the cracks], or between at least one island and the metal current collector (claims 1, 12, and 23). Dependent claims 2-11 and 13-22 further align with instant dependent claims 23-32 and 34-43.
Conclusion
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/JACOB BUCHANAN/ Examiner, Art Unit 1725
/NICOLE M. BUIE-HATCHER/ Supervisory Patent Examiner, Art Unit 1725