`Petition for Inter Partes Review
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________________________________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
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`____________________________________________
`
`Eve Energy Co., Ltd.
`Petitioner
`
`v.
`
`Varta Microbattery Gmbh
`Patent Owner
`
`Case No. IPR2022-01484
`
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 9,153,835
`
`Claims 14-25
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`VARTA Ex. 2008 Page 1 of 5
`EVE Energy v. VARTA
`IPR2022-1484
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`
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`U. S. PATENT NO. 9,153,835
`Petition for Inter Partes Review
`the positive electrode case and the electrode group, between the negative electrode
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`case and the electrode group, or both.” Ex1004, [0019], FIG. 1.
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`See Ex1002, ¶¶143-145.
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`(k) Obviousness Over Kobayashi, Kaun, and Brenner
`Kobayashi, Brenner, and Kaun all relate to button cells with a spiral wound
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`electrode assembly. See Ex1004, [0008]; Ex1023, [0017], [0091].
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`Instead of beading, Kaun uses an insert molded gasket placed between
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`housing top 28p and cup 28n to provide a gas-tight seal. Ex1023, [0116]. As
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`discussed above, Kaun provides a sealing mechanism that closes the button cell
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`without being beaded over (no portion of housing cup 28n edge being deformed or
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`crimped radially inward). Supra §VI.A.1.f. Using insulator/gasket 32 allows for
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`sealing of the button cell using a housing cup whose edge remains essentially
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`perpendicular to its flat bottom area. Ex1023, FIG. 7.
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`As can be seen clearly in Figure 1 of Kobayashi (annotated below), a
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`VARTA Ex. 2008 Page 2 of 5
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`U. S. PATENT NO. 9,153,835
`Petition for Inter Partes Review
`significant portion of the available space within the cell is reduced by the process of
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`crimping the cell closed. The process of crimping the cell closed can require
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`significant extra space for the cell housing, but such space cannot be used for active
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`materials, thus reducing the overall capacity of the cell.
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`Because of the unbeading nature of Kaun’s sealing mechanism, Kaun
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`increases the effective volume and capacity within the cell housing. The increased
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`volume allows for a corresponding increase to the number of electrode layers in the
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`electrode assembly of Kobayashi and Brenner, which would improve energy density
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`of the cell. As such, a POSITA would have been further motivated to combine the
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`cell taught in Kobayashi with the unbeaded sealing mechanism of Kaun to improve
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`the energy density of the cell. A POSITA, therefore, would have been motivated to
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`use the unbeaded sealing mechanism taught in Kaun to seal the cell housing of
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`Kobayashi. See KSR, 550 U.S. at 400 (“mere application of a known technique to a
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`37
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`VARTA Ex. 2008 Page 3 of 5
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`U. S. PATENT NO. 9,153,835
`Petition for Inter Partes Review
`piece of prior art ready for the improvement” supports a conclusion of obviousness).
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`Such modifications would have been well within the skill of a POSITA.
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`Furthermore, a POSITA would have understood that the expansion of the
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`electrode mainly causes radial forces. See Ex1007 (Higuchi), p.4; Ex1023 (Kaun)
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`at [0062]. As a result, crimping would not be needed since it is not necessary to
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`crimp in the axial direction for constraint. The quality of the curled edge can then
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`be omitted so as to improve the energy density.
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`A POSITA would have known that using metal foils that are connected to the
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`positive and negative electrodes before the priority date of the ’835 patent. See
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`Ex1020 (Arai), Ex1021 (Okochi). The metal foils are configured such that they rest
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`flat between an end face of the spiral winding and the flat top or bottom of the
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`housing to which it is connected. Using metal foils to replace 4a and 4b to connect
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`the electrodes to the housing would have helped the goal of maximizing the use of
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`the interior volume of the housing, reduced the weight of the battery, and thus
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`increased the energy density of the battery, as known to a POSITA. Thus, a POSITA
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`would have found that using the metal foils is within the knowledge of a POSITA,
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`and substituting metal foils would have involved the simple substitution of one
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`known element for another to obtain predictable results. KSR at 401.
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`For the overlapping area as discussed above, there is good sealing due to the
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`force-fitting connection. For non-overlapping area near the edge of the overlapping
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`VARTA Ex. 2008 Page 4 of 5
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`U. S. PATENT NO. 9,153,835
`Petition for Inter Partes Review
`area (as seen below in red) that includes insulation (pink), there will likely be sealing
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`and leakage issues.
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`Brenner discloses
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`that
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`indentation 104 would
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`improve
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`the sealing
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`characteristics of cup 105 and top 101 in this area by allowing radial pressure to be
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`exerted, which is exactly what is needed to address the leakage and sealing issue as
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`discussed above. Ex1005, [0030]. It would be natural and obvious for a POSITA to
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`improve radial sealing in button cells closed without being beaded over by looking
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`to Brenner to improve the sealing characteristics and leakage behavior.
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`Given both Kobayashi with the modification of Kaun and Brenner are in the
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`same field using similar technology and structure, substituting the relevant structure
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`in Kobayashi with the modification of Kaun with the slightly “radially inward”
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`structure in Brenner would have involved the simple substitution of one known
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`element for another to obtain predictable results. KSR at 401.
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`See Ex1002, ¶¶146-160.
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`2.
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`Claim 15
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`39
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