PTAB

IPR2016-01528

OneD Material LLC v. Nexeon Ltd

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method of Fabricating Fibres Composed of Silicon or a Silicon-Based Material and Their Use in Lithium Rechargeable Batteries
  • Brief Description: The ’831 patent discloses an electrode for a lithium-ion battery comprising an interconnected mass of elongated silicon structures, such as fibres or hairs. The structure, which includes a binder and/or electronic additive, is designed to form a porous, felt-like composite that mitigates charge/discharge capacity loss common with silicon anodes.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-3, 7-8, and 10 by the Gao Thesis

  • Prior Art Relied Upon: Gao (a 2001 PhD Thesis titled "Synthesis and electrochemical properties of carbon nanotubes and silicon nanowires").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the Gao Thesis disclosed every limitation of the challenged claims. Gao described fabricating an electrode for an electrochemical cell using silicon nanowires (“elongated structures”). The method involved mixing the nanowires (90% by weight) with an electronic additive (5% carbon black) and a binder (5% PVDF), and dispersing this suspension onto a substrate to form a porous, interconnected mass. Petitioner asserted that this inherently created a "porous composite electrode layer" where the nanowires were arranged in a "random or disordered manner," as required by the independent and dependent claims. Gao also taught that the nanowires were polycrystalline with an amorphous oxide surface, meeting the "disrupted crystalline or amorphous structure" limitation.
    • Key Aspects: This ground asserted that the very recipe for making the electrode in Gao—mixing silicon nanowires with a standard binder and additive—necessarily resulted in the structure claimed by the ’831 patent.

Ground 2: Obviousness of Claims 1-3, 7-8, and 10-11 over Zhou Patent in view of Zhou Article

  • Prior Art Relied Upon: Zhou (Patent 6,514,395) and the Zhou Article (a 2001 journal article titled "Alloy Formation in Nanostructured Silicon").
  • Core Argument for this Ground:
    • Prior Art Mapping: The Zhou patent disclosed using silicon nanowires in an electrode for lithium-ion battery applications, showing an interconnected mass of elongated structures. However, it did not explicitly detail the use of a binder or an electronic additive. The Zhou Article, published by the same inventors based on the same research project, supplied these missing details, disclosing that the electrodes were fabricated by mixing silicon powder with conductive carbon black and a PVDF binder at a 90:5:5 weight ratio. This combination taught the complete "porous composite electrode layer" of claim 1. The Zhou patent also disclosed nanowire dimensions corresponding to an aspect ratio greater than 40:1, meeting the limitation of claim 11.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references because they originated from the same research group and described the same technology. The Zhou Article provided the specific, practical details of how to implement the electrode system generally described in the Zhou patent, making the combination logical and straightforward.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination merely involved using the explicit experimental parameters from the article with the corresponding invention described in the patent.

Ground 3: Obviousness of Claims 5, 13-14, 17, and 19 over Gao Thesis in view of Winter

  • Prior Art Relied Upon: Gao (2001 PhD Thesis) and Winter (a 2004 Chem. Rev. article titled "What Are Batteries, Fuel Cells, and Supercapacitors?").

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground built upon the teachings of Gao by adding Winter to address claims reciting porosity and electrolyte filling. While Gao disclosed a porous electrode and the use of an electrolyte, it did not specify a percentage pore volume. Winter, a general review article on battery technology, taught that a "typical" composite battery electrode has 30% porosity to enhance surface area and that "the pores of the electrode structures are filled with electrolyte." This teaching supplied the missing limitations of claim 5 (10-30% pore volume) and claim 13 (electrolyte filling the pores), rendering them and the corresponding limitations in independent claim 14 obvious.
    • Motivation to Combine: A POSITA, starting with the silicon nanowire electrode from Gao, would be motivated to optimize its performance. Winter provided well-known, conventional design parameters for porosity that were known to improve electrode function by increasing reaction surface area and lowering polarization. A POSITA would naturally apply these standard industry principles to the Gao electrode.
    • Expectation of Success: The result was predictable, as it involved applying a known, beneficial property (optimal porosity) to a known electrode structure to achieve an expected improvement in performance.

  • Additional Grounds: Petitioner asserted seven additional grounds, including obviousness challenges based on: Gao in view of the Zhou patent; Gao in view of Li (a 2000 journal article); Gao in view of Cui (a 2000 journal article); and various combinations of the Zhou patent, the Zhou Article, and Winter. These grounds relied on similar arguments, using the additional references to supply teachings on aspect ratios, nanowire welding, and resistivity.

4. Key Claim Construction Positions

  • "Elongated structures": Petitioner argued this term should be construed broadly to mean any elongate structure known in the field, including fibres, hairs, nanowires, nanoribbons, rods, or whiskers, consistent with its interchangeable use in the specification.
  • "Intersections": Proposed as any location where two elongated structures cross over and contact one another, based on the patent's description of laying down fibres in a random, felt-like manner.
  • "Disrupted crystalline": Argued to include both polycrystalline and amorphous structures, as would be understood by a POSITA in the context of silicon nanostructures.
  • "Welds": As used in claim 20, Petitioner proposed this term means the fusing, merging, or joining of intersecting nanowires that occurs during battery cycling, a known phenomenon described in the prior art.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 5-8, 10-11, 13-14, 16-17, 19-20, 22-23, and 25 of the ’831 patent as unpatentable.