LG Energy Solution Ltd v. Molecular Rebar Design LLC

1. Case Identification

• Case #: IPR2024-01006
• Patent #: 8,808,909
• Filed: June 7, 2024
• Petitioner(s): LG Energy Solution, Ltd.
• Patent Owner(s): Molecular Rebar Design, LLC; Black Diamond Structures, LLC
• Challenged Claims: 1-8

2. Patent Overview

• Title: Lithium Ion Batteries Using Discrete Carbon Nanotubes, Methods for Production Thereof and Products Obtained Therefrom
• Brief Description: The ’909 patent discloses compositions for lithium-ion batteries that comprise discrete, oxidized carbon nanotubes (CNTs) with lithium-ion active materials attached to their surface. The claims specify ranges for CNT aspect ratio, oxidation level, and weight percentage.

3. Grounds for Unpatentability

Ground 1: Claims 1-2 and 5-8 are obvious over Ohata in view of Kavan.

• Prior Art Relied Upon: Ohata (Application # 2004/0160156) and Kavan (a 2010 Journal of Power Sources article).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Ohata taught a composition for lithium-ion batteries comprising a masterbatch of discrete carbon nanotubes in a resin, mixed with a lithium-ion active material. Ohata disclosed specific examples of CNT aspect ratios (50, 100, 200) and weight percentages (0.2% to 3.0%) that fall within the ranges of claims 1c and 5, respectively. Kavan taught the benefits of using oxidized CNTs in battery electrodes to improve performance. Kavan explicitly disclosed functionalizing multi-walled CNTs (MWNTs) by oxidation, resulting in a 7% atomic oxygen presence, which Petitioner calculated to correspond to a 9.1% oxidation level by weight—a value squarely within the 1% to 15% range of claim 1d. Kavan also taught using these oxidized CNTs with active materials like titanium dioxide (TiO₂), which satisfies the "titanium" limitation of claim 2. Petitioner asserted the attachment of the active material to the CNTs (claim 1b) was taught by Kavan, which described the oxidative functionalization as "crucial for proper anchoring" of the active material.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Kavan’s teaching of oxidized CNTs with Ohata’s battery paste composition. The motivations included improving the dispersion of nanotubes (a stated goal of Ohata), enhancing electrochemical charge transfer, and increasing the affinity and interaction between the nanotubes and the active material, all of which were known benefits of oxidation taught by Kavan.
  • Expectation of Success: A POSITA would have expected success because both references addressed CNTs in lithium-ion battery electrodes, the use of oxidized CNTs was conventional, and the material compositions described were similar and compatible.

Ground 2: Claims 1-2 and 5-8 are obvious over Lee in view of Wepasnick.

• Prior Art Relied Upon: Lee (Application # 2010/0136431) and Wepasnick (a 2011 Carbon journal article).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Lee disclosed an anode active material for lithium-ion batteries comprising carbon nanotubes bound to a non-carbonaceous, lithium-ion active material (e.g., silicon, Si), satisfying limitations for a composition with discrete CNTs and attached active material (claims 1a, 1b). Lee disclosed a CNT aspect ratio range (10 to 10,000) that overlapped with the claimed range (10 to 500) and provided examples of CNT weight percentages (9.1% and 10%) that fell within the claimed range (0.1% to 10%). Wepasnick provided a detailed academic study on oxidizing CNTs using various wet chemical oxidants, demonstrating how to precisely control and achieve specific oxidation levels. Wepasnick’s data showed that oxidation levels between 5.7% and 14.6% by weight were achievable, which fully encompassed and rendered obvious the claimed 1% to 15% range. Lee’s disclosure of silicon, copper, antimony, and aluminum as active materials met the limitations of claim 2.
  • Motivation to Combine: A POSITA would have been motivated to apply the conventional oxidation techniques detailed in Wepasnick to the CNTs in Lee’s anode material. Lee’s primary goal was to improve structural integrity and cycle lifetime by enhancing the bonding between components. Wepasnick taught that oxidation creates functional groups on CNTs that serve as "foothold" attachment points, which would directly enhance the bonding described in Lee.
  • Expectation of Success: Success was predictable as Wepasnick detailed established, commonly used oxidation procedures. Further, oxidized nanotubes were known to be compatible with and beneficial for polymer-based composites like those described by Lee.

Ground 3: Claims 3 and 4 are obvious over Lee, Wepasnick, and Zhamu.

• Prior Art Relied Upon: Lee (Application # 2010/0136431), Wepasnick (a 2011 Carbon journal article), and Zhamu (Application # 2012/0064409).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the Lee-Wepasnick combination to address claims 3 and 4, which require the addition of graphene. Lee’s composition explicitly included a generic "conducting agent." Petitioner argued it would have been obvious to use graphene, as taught by Zhamu, for this purpose. Zhamu described anode active materials containing "nano graphene sheets" for use in lithium-ion batteries. For claim 4, which recited a weight ratio of graphene to CNTs, Petitioner pointed to an example in Lee where the conducting agent-to-CNT ratio was 30:5 (or 6:1). Substituting graphene as the conducting agent would result in a 6:1 ratio, which fell within the broadly claimed range of 0.1:99.9 to 99.9:0.1.
  • Motivation to Combine: A POSITA would have been motivated to use Zhamu’s graphene as the conducting agent in Lee’s composition because graphene was a well-known conductive additive with known benefits for thermal management, structural integrity, and electrical conductivity—all desirable properties for the anode composition described by Lee.
  • Expectation of Success: Lee taught that any commonly used conducting agent could be used, and graphene was such an agent. The compositions in Lee and Zhamu were similar, making the substitution straightforward and predictable.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that the PTAB should not exercise discretionary denial under 35 U.S.C. §314(a) based on the Fintiv factors. It contended that the petition was filed diligently, months before the statutory deadline, and that the co-pending district court litigation was in its early stages. Petitioner also stipulated that it would not pursue the same grounds in the district court if an inter partes review (IPR) is instituted.
• Petitioner further argued that denial under §325(d) would be inappropriate because the petition presented new prior art and arguments. None of the primary references (Ohata, Kavan, Lee, Wepasnick, or Zhamu) were cited or considered during the original prosecution of the ’909 patent.

5. Relief Requested

• Petitioner requested the institution of an IPR and the cancellation of claims 1-8 of Patent 8,808,909 as unpatentable.