`
`
`
`
`
`
`
`Trials@uspto.gov
`Tel: 571-272-7822
`
`Paper 12
`Entered: July 27, 2017
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`ONED MATERIAL LLC,
`Petitioner,
`
`v.
`
`NEXEON LIMITED,
`Patent Owner.
`
`
`
`Case IPR2017-00961
`Patent 8,940,437 B2
`
`
`Before BRIAN P. MURPHY, JON B. TORNQUIST, and
`CHRISTOPHER M. KAISER, Administrative Patent Judges.
`
`TORNQUIST, Administrative Patent Judge.
`
`DECISION
`Denying Institution of Inter Partes Review
`37 C.F.R. § 42.108
`
`
`
`
`
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`I. INTRODUCTION
`OneD Material LLC (“Petitioner”) filed a Petition (Paper 4, “Pet.”)
`requesting inter partes review of claims 18–23 of U.S. Patent No. 8,940,437
`B2 (Ex. 1001, “the ’437 patent”). Nexeon Limited (“Patent Owner”) filed a
`Preliminary Response to the Petition (Paper 11, “Prelim. Resp.”).
`We have authority to determine whether to institute an inter partes
`review. 35 U.S.C. § 314; 37 C.F.R. § 42.4(a). The standard for instituting
`an inter partes review is set forth in 35 U.S.C. § 314(a), which provides that
`an inter partes review may not be instituted “unless the Director
`determines . . . there is a reasonable likelihood that the petitioner would
`prevail with respect to at least 1 of the claims challenged in the petition.”
`After considering the Petition and the Preliminary Response, we
`determine that Petitioner has not demonstrated a reasonable likelihood of
`prevailing with respect to claims 18–23 of the ’437 patent. Accordingly, we
`do not institute inter partes review.
`
`A. Related Proceedings
`The parties indicate that the ’437 patent and U.S. Patent No.
`8,597,831 (“the ’831 patent”) are at issue in Nexeon Limited v. EaglePicher
`Technologies, LLC and OneD Material LLC., Case No. 1:15-cv-00995-RGA
`(D. Del.). Pet. 2; Paper 6, 2. The parties further note that the ’831 patent is
`at issue in IPR2016–01528. Pet. 2; Paper 6, 2.
`
`B. The ’437 Patent
`The ’437 patent discloses pillared silicon particles and a method of
`fabricating the same. Ex. 1001, Abstract. The ’437 patent notes that in
`conventional lithium–ion rechargeable battery cells, graphite is used as an
`anode. Id. at 1:33–36. When the battery containing the graphite anode is
`
`2
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`charged, lithium reacts with the graphite to form LiC6, which “has a
`maximum capacity of 372 mAh/g.” Id. at 1:55–60. In contrast to
`conventional graphitic anodes, a silicon anode will react with lithium to
`form Li21Si5, which has a maximum capacity of 4,200 mAh/g. Id. at 1:63–
`2:5. Silicon anodes swell considerably during the charge/discharge cycle,
`however, causing the anodes to crack or disintegrate. Id. at 2:6–10, 2:18–26,
`2:32–41.
`The ’437 patent explains that one approach known in the art to
`overcome the problem of volumetric swelling was the use of nano-scale
`silicon powders. Id. at 2:11–52. Although these powders are not destroyed
`during the expansion process, the individual powder particles become
`isolated from one another and from the copper current collector during the
`charge/discharge cycle, again resulting in limited sustained capacity. Id.
`According to the ’437 patent, these problems have “prevented silicon
`particles from becoming a commercially viable replacement for graphite in
`lithium rechargeable batteries.” Id. at 2:48–52.
`Another approach for overcoming volumetric expansion in silicon
`anodes is the use of a silicon electrode fabricated with a regular or irregular
`array of silicon pillars. Id. at 3:21–34. These silicon pillars are able to
`absorb the volumetric expansion/contraction associated with the charge and
`discharge cycles, but the pillars are produced on a high purity, single-crystal
`silicon wafer, which is expensive. Id. at 3:24–34.
`To overcome the volumetric expansion problems of prior art silicon
`powders, and to reduce the cost of silicon anodes, the ’437 patent discloses a
`method of forming silicon pillars on the surface of silicon powders. Id. at
`3:35–56. These pillared particles may be arranged in a composite structure
`
`3
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`(particles, polymer binder, and a conductive additive) or may be directly
`bonded to the current collector. Id. at 4:35–51. According to the ’437
`patent, “[t]he structure of the particles overcomes the problems of
`charge/discharge capacity loss.” Id. at Abstract.
`
`C. Illustrative Claims
`Claims 18 and 20 are illustrative of the challenged claims and are
`reproduced below:
`18. A plurality of discrete particles wherein each particle
`comprises silicon and includes a particle core and a plurality of
`silicon-comprising pillars fabricated on the particle core and
`extending outwardly therefrom from a first end to a second end,
`wherein each pillar in the plurality of pillars is attached to the
`core at the first end of the pillar, and the second end of each
`pillar is an unattached free end, wherein in each particle, the
`fraction of the surface area of the particle core occupied by the
`pillars is in the range of 0.10 to 0.50.
`Ex. 1001, 10:20–28.
`20. A composite electrode for a lithium-ion battery
`comprising a plurality of discrete particles as claimed in
`claim 18 and further comprising at least one of a conductive
`additive and a binder.
`Id. at 10:32–35.
`
`D. The Asserted Grounds of Unpatentability
`Petitioner contends claims 18–23 of the ’437 patent are unpatentable
`based on the following grounds (Pet. 14–43):1
`
`
`1 Petitioner also relies on a declaration from Dr. Kurt W. Kolasinski (Ex.
`1051).
`
`4
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`References
`Farrell,2 Peng,3 and Green,4 in view of the
`knowledge of a person of ordinary skill in
`the art, as evidenced by Kolasinski5 and
`Kasavajjula6.
`
`Farrell, Peng, Green, and Kasavajjula, in
`view of the knowledge of a person of
`ordinary skill in the art, as evidenced by
`Kolasinski.
`
`Basis Claims Challenged
`§ 103 18–23
`
`§ 103 20 and 23
`
`Petitioner contends that Farrell and Kasavajjula are prior art to the
`
`’437 patent under 35 U.S.C. §102(a) and Green, Peng, and Kolasinski are
`prior art under § 102(b). Pet. 4–5 (asserting that Peng was published online
`on August 18, 2005). Patent Owner does not challenge the prior art status of
`any of the asserted references in the Preliminary Response.
`
`II. ANALYSIS
`
`A. Claim Construction
`In an inter partes review, “[a] claim in an unexpired patent shall be
`given its broadest reasonable construction in light of the specification of the
`
`
`2 WO 2007/037787, filed May 5, 2006 and published April 5, 2007 (Ex.
`1004).
`3 Peng, K., et al., Aligned Single–Crystalline Si Nanowire Arrays for
`Photovoltaic Applications, 1 SMALL Vol. 11, 2005, pp. 1062–1067 (Ex.
`1005).
`4 U.S. Patent Pub. No. 2006/0097691, published May 11, 2006 (Ex. 1006)
`5 Kolasinski, K., Silicon Nanostructures from Electroless Electrochemical
`Etching, 9 CURRENT OPINION IN SOLID STATE AND MATERIALS SCIENCE,
`2005, pp. 73–83 (Ex. 1007).
`6 Kasavajjula, U., et. al., Nano– and Bulk–Silicon–Based Insertion Anodes
`for Lithium–Ion Secondary Cells, 163 JOURNAL OF POWER SOURCES, 2007,
`pp. 1003–1039 (Ex. 1008).
`
`5
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`patent in which it appears.” 37 C.F.R. § 42.100(b); Cuozzo Speed Techs.,
`LLC v. Lee, 136 S. Ct. 2131, 2144–46 (2016) (upholding the use of the
`broadest reasonable interpretation standard). In determining the broadest
`reasonable construction, we presume that claim terms carry their ordinary
`and customary meaning. See In re Translogic Tech., Inc., 504 F.3d 1249,
`1257 (Fed. Cir. 2007). A patentee may define a claim term in a manner that
`differs from its ordinary meaning; however, any special definitions must be
`set forth in the specification with reasonable clarity, deliberateness, and
`precision. See In re Paulsen, 30 F.3d 1475, 1480 (Fed. Cir. 1994).
`Petitioner and Patent Owner dispute the proper construction of the
`term “first dimension.” Pet. 13–14; Prelim. Resp. 24 n.6. Because the
`current Decision does not depend on the proper construction of the term
`“first dimension,” and because the parties do not dispute the construction of
`any other claim terms, we determine that no claim terms require construction
`for purposes of this Decision. See Vivid Techs., Inc. v. Am. Sci. & Eng’g,
`Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (“only those terms need be
`construed that are in controversy, and only to the extent necessary to resolve
`the controversy”).
`
`B. Alleged Obviousness of Claims 18–23 over Farrell, Peng, and
`Green, in view of Kolasinski and Kasavajjula
`Petitioner contends the subject matter of claims 18–23 would have
`been obvious over Farrell, Peng, and Green, in view of the knowledge of one
`of ordinary skill in the art, as evidenced by Kolasinski and Kasavajjula. Pet.
`14–40.
`
`6
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`1. Farrell
`Farrell discloses “porous silicon particles prepared from a
`metallurgical grade silicon powder.” Ex. 1004, 1:10–11.7 Farrell indicates
`that these porous particles are useful “as carrier materials for a broad range
`of applications such as catalysts and drugs, adsorbents, sensors, explosives,
`photosensitizers, precursors for high surface area forms of ceramics such as
`SiC and Si3N4, and as electrodes in fuel cells.” Id. at 3:24–27.
`Farrell explains that previous methods of producing porous silicon
`particles provided low yields and were difficult to scale up for large
`diameter wafers. Id. at 1:27–32. Thus, according to Farrell, there existed in
`the art “a need for a low cost and reliable production method capable of
`producing large quantities of porous silicon.” Id. at 2:1–6.
`Farrell notes that Li et al. previously disclosed a method for stain
`etching individual silicon powder particles and subjecting the resulting
`porous particles to ultrasonic agitation to yield individual silicon
`nanoparticles. Id. at 2:7–12. According to Farrell, one advantage of this
`method is that it allows the use of powders instead of single crystalline
`silicon wafers, thereby “enabling etching of a much higher surface area per
`gram of the material.” Id. at 2:12–14. Li’s technique, however, is limited to
`silicon particles having a porosity with a “maximum thickness of only 500
`nm (0.5 microns).” Id. at 3:1–4.
`To overcome the porosity limitations of Li, Farrell discloses isolating
`silicon particles having a size greater than about 1 microns and etching these
`particles to yield porous silicon particles having a “solid core surrounded by
`
`
`7 Citations to Farrell are to the original page numbers provided in the
`document.
`
`7
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`a porous silicon layer having a thickness greater than about 0.5 microns.”
`Id. at 3:19–24. Farrell reports that “any etching method known to one of
`ordinary skill in the art may be employed” in the disclosed process, but a
`preferred method is stain etching with a solution comprising HF:HNO3:H2O
`at a ratio ranging from about 4:1:20 to about 2:1:10 by weight. Id. at 7:3–5,
`7:13–15.
`
`2. Peng
`Peng discloses the formation of one dimensional silicon nanowires
`(SiNWs) that can be “readily prepared on single–crystal Si substrates.” Ex.
`1005, 1063. Figure 1a of Peng, reproduced below, is an image of a SiNW
`array:
`
`
`Figure 1a is a scanning electron microscope
`cross-section image of a silicon nanowire array
`According to Peng, production of SiNW arrays “is quite simple” and
`involves cleaning silicon wafers and immersing the cleaned wafers “into a
`HF-based aqueous solution containing silver nitrate in sealed vessels” for a
`desired amount of time. Id. Peng reports that the length of the SiNWs can
`be effectively controlled by tuning the treatment time, and that “the
`orientations of obtained silicon nanowires are always identical with the
`orientation of initial Si substrates.” Id. at 1063–64. Peng further reports that
`
`8
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`the disclosed etching methods “can be readily extended to polycrystalline Si
`substrates.” Id. at 1064.
`
`3. Green
`Green discloses structured silicon anodes for lithium battery
`applications. Ex. 1006 ¶ 1. In particular, Green is directed to “a lithium
`battery integrated on to a silicon chip.” Id. ¶ 3, Abstract.
`Green notes that “[s]ilicon is recognized as a potentially high energy
`per unit volume host material for lithium battery applications.” Id. ¶ 2.
`Green further notes that, due to the significant volume change caused by the
`formation of Li12Si7 in lithium battery applications, conventional silicon
`wafers tend to crack and pulverize during the charge/discharge cycle. Id.
`¶¶ 2, 6. To overcome this problem, Green discloses “a method of fabricating
`sub-micron silicon electrode structures on a silicon wafer,” preferably in the
`form of “pillars.” Id. ¶ 4.
`To form the disclosed pillar structures, Green applies “Island
`Lithography.” Id. ¶ 22. In this method, cesium chloride (CsCl) is vacuum
`deposited on the surface of the Si substrate and exposed to the atmosphere at
`a controlled relative humidity. Id. As water adsorbs on the surface, the
`CsCl re-organizes into a distribution of hemispherical islands that act as “X
`masks” during ion etching, resulting in the formation of pillar structures. Id.
`Green explains that “[a]n appropriate size restriction to achieve suitable
`electrodes is that the silicon pillars should not exceed a fractional surface
`coverage (F) of ~0.5.” Id. ¶ 6.
`Green notes that “[i]n order to obtain charging rates suitable for
`various applications it is necessary to increase the surface area of the
`Si/electrolyte interface.” Id. ¶ 19. “Previous attempts using silicon particles
`
`9
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`have failed,” according to Green, “because the particle-to-particle contacts
`change and part with cycling.” Id. The disclosed pillared silicon wafers “on
`the other hand, are largely maintained” during the charge/discharge cycle,
`“as evidenced by the flatness of the pillar tops after 50 cycles.” Id. ¶¶ 6, 19.
`
`4. Kolasinski
`Kolasinski is a review article that discusses methods for producing
`silicon nanostructures using various electroless etching methods, including
`stain etching, metal-assisted etching, and chemical vapor etching. Ex. 1007,
`Abstract. Kolasinski notes that porous silicon (por-Si) is the most
`intensively studied variant of nanocrystalline silicon and can be produced
`simply via electroless etching of silicon substrates. Id. at 74. According to
`Kolasinski, this process “requires the attachment of no electrodes and can be
`performed on objects of arbitrary shape and size.” Id. at 74.
`
`5. Kasavajjula
`Kasavajjula presents a “review of methodologies adopted for reducing
`the capacity fade observed in silicon-based anodes.” Ex. 1008, Abstract.
`Kasavajjula also discusses the “challenges that remain in using silicon and
`silicon-based anodes” and proposes “possible approaches for overcoming
`them.” Id.
`Kasavajjula notes that during cycling, up to a 400% volume expansion
`of the silicon lattice occurs, resulting in “cracking and disintegration of the
`electrode.” Id. at 1005. “To overcome the large volume change and thus
`obtain better capacity retention and cycle life for Si anodes,” Kasavajjula
`notes that several approaches have been suggested in art, including the use
`of micro– and nano–scale powder anodes. Id. Kasavajjula explains,
`however, that when particle size was reduced to micrometer levels, “no
`
`10
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`particular improvement in electrochemical performance was observed.” Id.
`at 1006. According to Kasavajjula, this was due to “poor cycling
`performance” caused by the “breakdown” of the conductive network during
`volumetric expansion. Id.
`Kasavajjula identifies three known techniques for improving the
`performance of powdered silicon anodes. First, conductive additives, such
`as “graphite flakes and/or nano-scale carbon black,” can be included within
`the micro-Si anodes “to improve electronic contact between particles during
`insertion and extraction.” Id. at 1007. Second, the cycling voltage window
`may be narrowed. Id. Third, silicon particle size can be further reduced to
`nano-scale, thereby resulting in “smaller volume expansion due to reduced
`particle size.” Id.
`
`6. Analysis
`Petitioner contends independent claims 18 and 21 of the ’437 patent
`would have been obvious over the combination of Farrell, Peng, and Green,
`in view of Kolasinski and Kasavajjula. Pet. 14–39. According to Petitioner,
`Farrell discloses both etching a metallurgical grade silicon powder to form
`porous silicon particles and that “any etching method known to one of
`ordinary skill in the art may be employed” to form the porous particles; Peng
`discloses forming pillars on a silicon substrate (wafer) using metal–assisted
`etching; Kolasinski teaches performing electroless etching “on objects of
`arbitrary shape and size”; and Green discloses forming pillars on a wafer
`that do not exceed a fractional surface coverage of ~ 0.5. Id.
`Petitioner contends a person of ordinary skill in the art would use the
`etching technique described in Peng to form pillars on Farrell’s particle core
`because Farrell’s metallurgical powders are “more cost-effective than the
`
`11
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`pure silicon wafers and powders known in the art” and because Peng’s metal
`assisted etching technique is a well-known and “cost-effective fabrication
`method.” Id. at 20, 32. In support of this argument, Dr. Kolasinski testifies
`that “it would be a simple substitution to replace the polycrystalline wafer
`etched in Peng with the polycrystalline particles (or powders) etched in
`Farrell.” Ex. 1051 ¶ 168.
`We are not persuaded by Petitioner’s argument. Farrell already
`provides a metallurgical grade powder. Thus, it is not evident why the
`general cost of metallurgical grade powders would have caused the ordinary
`artisan to pillar Farrell’s porous silicon particles using the technique of Peng.
`Moreover, Petitioner does not explain persuasively why pillared particles
`would otherwise be desirable in the applications identified in Farrell, or how
`Farrell’s particles could substitute for Peng’s expensive pillared silicon
`wafers in Peng’s photovoltaic applications. See Ex. 1005, 1064 (noting that
`the disclosed “SiNW arrays give promising results for possible applications
`in high-efficiency solar-cell manufacture”), 1066 (“The most interesting
`feature of the as-synthesized SiNW arrays is the significant suppression of
`reflection over the visible-light spectral range.”); Prelim. Resp. 21 (noting
`that Farrell’s materials are not “lithium-ion battery anode materials”); see
`also In re Gordon, 733 F.2d 900, 902 (Fed. Cir. 1984) (noting that a
`proposed modification must not render a device unsuitable for its intended
`purpose). Thus, on this record, Petitioner has not explained sufficiently why
`cost concerns would have caused one of ordinary skill in the art to pillar
`Farrell’s particles using the metal–assisted etching technique of Peng.
`Petitioner also contends that a person of ordinary skill in the art would
`have sought to combine Farrell and Peng, “because they are both directed to
`
`12
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`the formation of pores and pillars (formed via etching pores further) using
`similar, known techniques for similar applications and using known
`materials.” Pet. 21, 33 (citing Ex. 1051 ¶¶ 136, 140, 153, 156–160). Farrell
`is directed to “carrier materials” for use in, among other things, “fuel cells”
`and Peng is directed to photovoltaic applications. Ex. 1004, 3:24–27; Ex.
`1005, 1062. Petitioner does not explain sufficiently why these applications
`are “similar.” Nor does Petitioner explain sufficiently why any alleged
`similarities in application between the two references would have caused
`one of ordinary skill in the art to apply Peng’s pillaring method to Farrell’s
`porous particles. Thus, on this record, we do not find Petitioner’s argument
`persuasive.
`In support of the proposed combination, Dr. Kolasinski testifies that
`one of ordinary skill in the art, “for example from reading Kolasinski (Ex.
`1007),” would readily recognize “that porous silicon is of great interest in
`energy storage application[s] such as lithium batteries,” and would have
`sought to exchange Green’s “expensive” pillared silicon wafers for the
`pillared silicon powders of Farrell and Peng, in order to reduce costs. Ex.
`1051 ¶ 168. Petitioner also contends that one of ordinary skill in the art
`would have sought to control the fraction of surface area occupied by the
`pillars of Farrell and Peng to within 0.1 to 0.5 as disclosed in Green, because
`this fraction range “would improve the ability of electrodes incorporating the
`particles to tolerate the volume changes associated with lithium alloying and
`dealloying.” Pet. 26, 38.
`As noted above, evidence that a modification would be cost-effective
`is irrelevant if the modified device cannot achieve its intended purpose.
`Here, Green’s “invention” seeks to incorporate a lithium battery “on to a
`
`13
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`silicon chip,” Ex. 1006 ¶¶ 3–4, and neither Petitioner nor Dr. Kolasinski
`present credible evidence that the pillared particles of Farrell and Peng could
`accomplish this goal. Thus, on this record, Petitioner has not explained
`sufficiently why one of ordinary skill in the art would have sought to
`combine the relevant disclosures of Farrell, Peng, and Green (as further
`evidenced by Kolasinski and Kasavajjula) to arrive at the subject matter of
`claim 18.
`To the extent Petitioner asserts that an ordinary artisan would have
`sought generally to use porous particles in lithium-ion anodes, and that such
`an ordinary artisan would have then sought to modify such porous particles
`to add pillars in order to “tolerate the volume changes associated with
`lithium alloying and dealloying” (Pet. 26), Green acknowledges that silicon
`powder anodes were known in the prior art, but notes that “[p]revious
`attempts using silicon particles have failed because the particle-to-particle
`contacts change and part with cycling.” Ex. 1006 ¶ 19. Tellingly, despite
`disclosing the use of pillars to overcome cracking of the wafer due to
`volumetric expansion, and despite disclosing the problem of failed particle-
`to-particle contacts within powdered lithium–ion anodes, we are directed to
`no persuasive disclosure in Green, or in the other references recited in
`Petitioner’s asserted Ground, that pillars formed on discrete particles could
`overcome the change in particle–to–particle contacts induced during the
`charge/discharge cycle within powdered silicon anodes.8 Id. ¶¶ 2
`
`
`8 Dr. Kolasinski identifies two references (Exs. 1009 and 1010) which he
`asserts describe Green’s publication (Ex. 1021) as disclosing pillared
`particles. Ex. 1051 ¶¶ 89–91. Although one reference does disclose that
`nanopillar surface morphology alters “particle deformation and reduces
`fracturing,” as noted by Patent Owner it is not evident that either reference
`
`14
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`(“[m]etallic and intermetallic anodic host materials . . . are reported to
`disintegrate after a few lithium insertion/extraction cycles.”), 3–4
`(explaining that the invention provides a method for producing pillars on a
`silicon wafer), 19.
`Consistent with Green’s disclosures, Kasavajjula indicates that micro–
`Si anodes have poor cycling performance “due to breakdown of the
`electronically conductive network” caused by “large Si volume expansion”
`during the alloying and de-alloying process. Ex. 1008, 1005–1006.
`Kasavajjula then goes on to identify three potential methods for improving
`the performance of powdered Si anodes. Id. at 1007. And, despite being
`aware of Green’s pillaring methods, as well as Green’s disclosure that such
`pillars allow a silicon wafer to withstand volume expansion during the
`charge/discharge cycle, Kasavajjula does not suggest using pillared particles
`to overcome capacity fade in powdered lithium–ion battery anodes. Indeed,
`in describing Green’s pillared wafers (as disclosed in Ex. 1021 and U.S.
`Patent Application 2006/0097691), Kasavajjula notes that “[i]n spite of their
`reasonable capacity retention, they showed a low faradaic efficiency through
`50 cycles, which would limit their practical use.” Id. at 1026. Thus,
`
`
`contemplates pillaring discrete particles. Prelim. Resp. 3–6, 13–14; Ex.
`1009, 367; Ex. 1010, 90. Indeed, in reviewing Green’s disclosures, Dr.
`Kolasinski testifies that Green discloses “a nanostructured silicon anode
`etched on a wafer.” Ex. 1051 ¶ 88. Likewise, Kasavajjula provides a review
`of Green’s publication and published patent application and describes his
`method as being directed to the pillaring of “Si films.” Ex. 1008, 1026.
`Thus, on this record, Petitioner has not demonstrated sufficiently that
`Exhibits 1009 and 1010 teach or suggest pillaring discrete particles, or that
`the art of record teaches or suggests the use of pillars to prevent the loss of
`particle-to-particle contacts within a powdered silicon anode. Prelim. Resp.
`13–14.
`
`15
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`Kasavajjula tends to support Patent Owner’s argument that it would not have
`been obvious, prior to the earliest filing date of the ’437 patent, to use
`discrete pillared particles in lithium–ion battery anodes.
`
`In light of the foregoing, Petitioner has not demonstrated sufficiently
`that one of ordinary skill in the art would have sought to combine Farrell and
`Peng to form a pillared particle. Nor has Petitioner demonstrated
`sufficiently that if such a particle were formed, one of ordinary skill in the
`art would have sought to use it in a silicon anode for a lithium–ion battery in
`view of the disclosures of Farrell, Peng, and Green (as well as the
`disclosures of Kolasinski and Kasavajjula).9 Thus, Petitioner has not
`demonstrated a reasonable likelihood that independent claims 18 and 21
`would have been obvious over Farrell, Peng, and Green, as evidenced by
`Kolasinski and Kasavajjula.
`As dependent claims 19, 20, 22, and 23 each depend from one of
`claims 18 or 21, Petitioner has also not demonstrated sufficiently that the
`subject matter of these claims would have been obvious over the recited
`references.
`
`C. Claims 20 and 23 over Farrell, Peng, and Green, in view of
`Kasavajjula and Kolasinski
`Claims 20 and 23 both require a composite electrode for a lithium–ion
`battery comprising a plurality of discrete particles and at least one of a
`conductive additive and a binder. Ex. 1001, 10:33–35, 10:47–50. Petitioner
`
`
`9 Independent claims 18 and 21 are directed to discrete particles, without
`reference to their intended use. Ex. 1001, 10:20–28, 10:36–44. Petitioner’s
`reasons to combine the asserted references, however, rely upon the use of
`the particles of Farrell, Peng, and Green in lithium battery applications. Pet.
`26.
`
`16
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`contends the subject matter of claims 20 and 23 would have been obvious
`over Farrell, Peng, and Green, in view of Kasavajjula and Kolasinski. Pet.
`41–43.
`Petitioner asserts that Kasavajjula discloses an electrode for a lithium–
`ion battery that utilizes both discrete particles (silicon powder) and a
`conductive additive or binder. Pet. 42–43 (citing Ex. 1008, 1007).
`Petitioner further asserts that one of ordinary skill in the art would have
`found it obvious to substitute the silicon powder particles of Kasavajjula
`with the pillared particles of Farrell, Peng, and Green, because such particles
`are “cheaper, would reduce fracturing, and [would] increase the surface area
`to improve the flow of lithium.” Id. at 43 (citing Ex. 1051 ¶¶ 36, 89–92,
`133, 168, 191–192).
`As noted above, Petitioner has not explained sufficiently why one of
`ordinary skill in the art would have combined the disclosures of Farrell,
`Peng, and Green to transform Farrell’s porous particles into pillared particles
`having a fraction of the surface area of the particle core occupied by the
`pillars in the range of 0.10 to 0.50. Accordingly, Petitioner has not
`demonstrated sufficiently that one of ordinary skill in the art would have
`sought to substitute Kasavajjula’s powders with such particles in view of the
`recited prior art references.
`And, as discussed above, despite acknowledging the problem of
`fracturing and capacity fade in silicon powder anodes due to volumetric
`expansion, and despite analyzing potential approaches for solving this
`problem, and despite being aware of Green’s pillaring methods and its
`disclosure that pillar arrays “may tolerate” volume changes in silicon wafers
`due to cycling, Kasavajjula does not disclose or suggest using pillared
`
`17
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`silicon particles. This contemporary review article therefore tends to support
`Patent Owner’s argument that one of ordinary skill in the art would not have
`found it obvious to substitute Kasavajjula’s silicon powders with pillared
`particles in view of Farrell, Peng, Green, Kolasinski, and Kasavajjula.
`In view of the foregoing, Petitioner has not demonstrated a reasonable
`likelihood that the subject matter of claims 20 and 23 would have been
`obvious over Farrell, Peng, Green, Kolasinski, and Kasavajjula.
`III. CONCLUSION
`Upon consideration of the Petition and the Preliminary Response, we
`conclude that Petitioner has not demonstrated a reasonable likelihood that
`claims 18–23 of the ’437 patent would have been obvious over the recited
`prior art. Accordingly, we do not institute inter partes review with respect
`to those claims.
`
`IV. ORDER
`
`It is hereby
`ORDERED that inter partes review is not instituted.
`
`
`
`18
`
`

`

`IPR2017-00961
`Patent 8,940,437 B2
`
`
`
`PETITIONER:
`
`Jennifer Hayes
`NIXON PEABODY LLP
`jenhayes@nixonpeabody.com
`
`PATENT OWNER:
`
`S. Richard Carden
`James Suggs
`McDONNELL BOEHNEN HULBERT & BERGHOFF LLP
`carden@mbhb.com
`suggs@mbhb.com
`
`
`
`
`
`
`
`
`
`
`
`
`19
`
`