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 .
DETAILED ACTION
This Office Action is in response to the communication filed on 10/9/25. Applicant’s argument have been considered but are not found persuasive. Claims 1-20 are pending. Claims 13-18 are withdrawn.
This Action is FINAL, as necessitated by amendment.
Election/Restrictions
Applicant’s election without traverse of Group I (claims 1-12 and 19-20) in the reply filed on 6/13/25 is acknowledged. Claims 13-18 are withdrawn.
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.
Claim(s) 1-12 and 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ruther et al., US 2023/0197925 A1.
Ruther teaches a system for manufacturing a prelithiated electrode using a calender press device. In one implementation, the prelithiated electrode may include an electrode composite, a metal current collector, and a lithium-containing layer. The electrode that is used in a cell will include the electrode composite prelithiated with lithium from the lithium containing layer and the current collector. The lithium-containing layer may be lithium metal or alloy deposited on a carrier material such as a copper foil or other material where the lithium does not form an alloy with the carrier material [0031-0032]. To produce the prelithiated electrode, the layers described above may be fed through a calender press device in a Lithium-Electrode-Collector layered stack (Fig. 2A). In some implementations, the prelithiated electrode may comprise an Electrode-Lithium-Collector layered stack (Fig. 2B). The calender press may comprise a first roller and a second roller between which the prelithiated electrode may be passed. The opposing cylindrical faces of the respective rollers exert a compressive pinching force on the prelithiated electrode to press the layers together. In one implementation, the pressure exerted on the stack may cause at least a portion of the lithium layer to be absorbed into the electrode layer to prelithiate the electrode layer [0033].
FIGS. 2A and 2B are simplified cross-sections of example electrode stacks 102 for an electrochemical cell prior to pressing. After pressing, at least a portion of the lithium from the lithium-containing layer may be absorbed into the electrode composite layer to prelithiate the electrode composite layer. Example electrode 200 of FIG. 2A comprises a current collector 210, an electrode composite 220, and a lithium-contain layer 230 stacked in a current collector-electrode-lithium configuration. Example electrode 250 of FIG. 2B comprises a current collector 260, an electrode composite 280, and a lithium-contain layer 270 in a current collector-lithium-electrode configuration. Electrodes 200 and 250 are similar but the arrangement of the layers and specifically the relative placement of the lithium-containing layers are different. However, in either case, the lithium-containing layer may be adjacent the electrode layer such that lithium ions from the lithium-containing layer may be absorbed into the electrode composite layer, either before, during, or after calendering of the stack. In particular, while some of the lithium ions of the lithium-containing layer may be absorbed into the electrode composite layer upon contact, calendering may aid in the further dispersion of lithium ions into the electrode composite layer [0035].
The lithium may be deposited using a technique such as evaporation (PVD, CVD, ALD) [0049]. The prelithiated electrode may comprise a passivation layer comprising one or more of Li2CO3, Li2O, Li3N, or LiOH [0062-0063]. The electrode composite layer may be formed into a slurry and cast/coated onto a film of lithium on copper. The cast layer may then be dried to remove any solvent (evaporate the solvent) that were in the slurry [0042-0043]. The laminated layer of lithium has a thickness in the range of 0.1 to 20 microns [0010; 0029; 0042].
Ruther does not explicitly teach a roll of a lithium coated current collector film was unwound from a roll wherein the lithium coated current collector film comprises the lithium coated current collector and a substrate layer on a side of the lithium coated current collector. However, one of skill in the art at the time the invention was made would have found present claims obvious in view of the teaching of Ruther. Ruther teaches a carrier material was used with the lithium-containing layer, the carrier may be subsequently removed from the surface of the electrode stack [0050]. One of skill in the art would have found it obvious to store the carrier material with the lithium-containing layer on a wound roll as storing such material on a roll is conventional in the art. Likewise, one of skill in the art would have found it obvious to store the removed carrier material on a roll by rewinding the carrier material for storage. One of skill in the art would have found it obvious to cut the prelithiated electrode produced (see at least Figure 1) into the desired size for use in an electrochemical cell, as is conventional in the art.
Ruther is silent regarding the press density of the calendered/pressed pre-lithiated electrode. However, one of skill in the are would have found the claimed press density obvious in view of the teachings of Ruther. Ruther teaches pressure laminating of a pressure in the range of 1,500 to 100,000 psi may be used to prelithiate the electrode. In another embodiment, the laminating pressure is maintained for a duration of between 0.01 and 600 minutes. In yet another embodiment, the laminating pressure is removed subsequent to the pressure laminating for a duration of between 0.01 and 600 minutes, with a duration in the range of 1 to 60 minutes [0009]. Ruther teaches the press density is variable depending to the specific pre-lithiated electrode desired. See at least [0009], [0015], [0033-0034] and [0044-0048] of Ruther. Ruther teaches monitoring the state of lithiation during pressure laminating.
Ruther further teaches the pressure applied to the stack 102 may correlate to the spacing 118 between the first roller 114 and the second roller 116, among other factors such as temperature of the stack. The spacing may be fixed or may be adjustable and may be adjustable by a controller, in some instances (this varies the press density of the pre-lithiated electrode film). For example, the controller may increase or decrease a distance between the rollers 114, 116 to ensure prelithiation of the electrode layer 106 by the lithium-containing layer 110. For example, a thicker lithium-containing layer 110 and/or electrode layer 106 may correspond to an increase in the spacing between the calender press rolls 114, 116. Thinner layers of the electrode stack 102 may correspond to a decrease in the spacing between the calender press rolls. In some instances, the spacing of the calender press 104 may be adjustable based on feedback information received from the rollers 114, 116 or other sensory components (such as force measurements, thickness of the layers measurements, temperature of the layers, etc.) associated with the manufacturing of the prelithiated electrode 102.
Ruther further teaches, in operation 304, a lithium-containing layer 230, 270 and the electrode composite layer 220, 280 may be brought into contact. Specifically, a lithium bearing surface of the lithium-containing layer 230, 270 and a silicon bearing surface of the electrode composite layer 220, 280 may be contacted to promote the lithiation process of the electrode composite layer. After contact is made, pressure may be applied to the contacted layers to facilitate the lithiation process of the electrode composite layer 220, 280. In one particular implementation, the contacted layers may be fed through a calender press device 104 to apply the pressure to the electrode stack 102. In some examples, the applied pressure from the calender 104 may establish a compressive force in the range of 1,000 psi to 150,000 psi such that the lithium of the lithium-containing layer 230, 270 is laminated to and pressed into the surface of the electrode composite layer 220, 280. In another example, the pressure may be in the range of 2,000 to 125,000 psi. In a further example, the pressure may be in the range of 3,000 psi to 100,000 psi. In yet another example, the pressure may be in the range of 4,000 psi to 75,000 psi. In yet another example, the pressure may be in the range of 4,500 psi to 50,000 psi. In a further example, the pressure may be in the range of 5,000 to 25,000 psi. The pressure may be applied to the electrode stack 102 unidirectionally to either of the contacted layers or bidirectionally to both contacted layers or intermediate surfaces. In many instances, the pressure may be applied mechanically, hydraulically, or pneumatically through any pressing device and may be either uniform or spatially varied, with the calender device 104 one example of such a pressure device. In general, pressures above 1500 psi may enhance the rate of diffusion of the lithium into the electrode composite layer 220, 280. This effect is due to an increase in ionic and electronic conductivity of the electrode composite which results from greater particle-particle contact between the silicon material, conductive additives, and the solid electrolyte within the electrode composite layer 220, 280.
Response to Arguments
Applicant's arguments filed 10/9/25 have been fully considered but they are not persuasive. All previous 35 USC 112 rejections have been withdrawn.
Applicant argues Ruther is completely silent on a method of forming a pre-lithiated electrode film having the claimed press density. Examiner disagrees. Ruther is not silent on a method of forming a pressed pre-lithiated electrode. Ruther is silent on the obtained density of the pressed pre-lithiated electrode. One of skill in the art would have found the claimed press density obvious in view of the teachings of Ruther, as explained by the Examiner above. Applicant has not addressed the motivation provided by the Examiner in rejecting the claimed invention as obvious.
Conclusion
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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
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/TRACY M DOVE/Primary Examiner, Art Unit 1725