LG Energy Solution Ltd v. Molecular Rebar Design LLC

1. Case Identification

• Case #: IPR2024-01012
• Patent #: 10,608,282
• Filed: June 12, 2024
• Petitioner(s): LG Energy Solution, Ltd.
• Patent Owner(s): Molecular Rebar Design, LLC
• Challenged Claims: 1-16

2. Patent Overview

• Title: Binders, Electrolytes and Separator Films for Energy Storage and Collection Devices Using Discrete Carbon Nanotubes
• Brief Description: The ’282 patent discloses compositions for use in energy storage devices, such as batteries and capacitors. The core of the invention is the use of discrete carbon nanotubes (CNTs) having a specific bimodal distribution of aspect ratios to improve performance in binders, electrolytes, and separator films.

3. Grounds for Unpatentability

Ground 1: Claims 1-16 are obvious over Bosnyak-392 in view of Son

• Prior Art Relied Upon: Bosnyak-392 (WO 2010/117392) and Son (KR 10-2010-0086854).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Bosnyak-392 discloses the foundational elements of claim 1, including compositions of exfoliated, discrete, open-ended CNTs for use in energy storage device components. However, Bosnyak-392 only generally suggests that using both short and long CNTs can improve properties without providing specific distributions. Petitioner argued Son remedies this by expressly teaching a polymer composite with a bimodal distribution of CNTs (one group with a large aspect ratio, another with a small aspect ratio) to achieve improved electrical and mechanical properties. Son discloses specific aspect ratio ranges and weight ratios that Petitioner contended render the bimodal distribution of challenged claim 1 obvious.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) reviewing Bosnyak-392’s general suggestion to use short and long CNTs would combine its teachings with Son’s specific implementation of a bimodal distribution. The combination would be a straightforward application of a known technique (Son's distribution) to a similar system (Bosnyak-392's composite) to achieve the predictable result of improved material properties, an explicit goal of both references.
  • Expectation of Success: A POSITA would have a high expectation of success because both references operate in the same technical field of CNT-polymer composites and teach using varied aspect ratios to enhance performance.

Ground 2: Claims 1, 5-9, and 12-16 are obvious over Bosnyak-129 in view of Albuerne

• Prior Art Relied Upon: Bosnyak-129 (WO 2011/163129) and Albuerne (a 2010 journal article on CNT modification).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted that Bosnyak-129, from the same inventors as the ’282 patent, discloses a composition with discrete, open-ended CNT fibers having an aspect ratio of about 25 to 500 for use in energy storage devices. Petitioner argued that Albuerne, which describes methods for dispersing CNTs, provides the specific bimodal distribution limitation that was the basis for the ’282 patent's allowance. Petitioner re-plotted Albuerne’s published length-distribution data as an aspect-ratio distribution, arguing it explicitly shows that 59.7% of the CNTs have an aspect ratio of 30-70 and 1.0% have an aspect ratio of 80-140, falling squarely within the ranges of claim 1.
  • Motivation to Combine: A POSITA would combine these references as a simple substitution of one known element for another to obtain predictable results. Bosnyak-129 suggests using an acid treatment to process CNTs while also noting the goal of avoiding CNT damage. Albuerne teaches a milder nitric acid treatment specifically chosen to "preserve the carbon nanotubes" and prevent shortening. A POSITA would have been motivated to use Albuerne's superior, length-preserving acid treatment within the Bosnyak-129 framework to achieve the desired discrete CNTs with predictable characteristics.
  • Expectation of Success: A POSITA would have a high expectation of success, as the combination involves substituting a known, milder acid treatment to achieve the well-understood and predictable result of obtaining better-preserved, exfoliated CNTs.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on tertiary references. These included adding So (JP 2005-262391) to the Bosnyak-392/Son combination to teach the non-fiber carbon structures of claim 4, and adding Gu (a 2012 journal article) to teach specific charge transfer resistance values for claim 11. Gu was also combined with the Bosnyak-129/Albuerne art to address claims related to ion conductivity and impedance.

4. Key Technical Contentions (Beyond Claim Construction)

• Weight-to-Number Distribution Conversion: A central technical argument was that Son’s disclosure of a bimodal distribution by weight ratio renders the ’282 patent’s number-based distribution obvious. Petitioner provided detailed calculations, including a rigorous mathematical conversion, to demonstrate that Son’s disclosed weight ratios and example embodiments correspond to number-based percentages that fall within or overlap with the ranges claimed in the ’282 patent.
• Prior Art Data Analysis: Petitioner’s argument for the Bosnyak-129/Albuerne ground relied on its own analysis of graphical data presented in Albuerne. Petitioner converted a published length-distribution histogram from Albuerne into an aspect-ratio distribution graph, which it argued directly disclosed the specific numerical percentage ranges required by claim 1.

5. Arguments Regarding Discretionary Denial

• Fintiv Factors (§314(a)): Petitioner argued against discretionary denial under Fintiv, asserting that the parallel district court litigation was in its early stages with minimal investment. It noted the expected Final Written Decision (FWD) date would be close to the trial date, and Petitioner stipulated not to pursue the same invalidity grounds in district court if an inter partes review (IPR) is instituted.
• Advanced Bionics Test (§325(d)): Petitioner contended that denial would be improper because the petition raises new art and arguments not previously considered by the USPTO. Specifically, it argued that the primary references of Son and Albuerne were never before the examiner. Petitioner asserted the examiner materially erred by allowing the ’282 patent based on the bimodal distribution limitation, as Son and Albuerne directly teach or suggest this very feature.

6. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 1-16 of the ’282 patent as unpatentable.