DCT

1:19-cv-01637

SK Innovation Co Ltd v. LG Chem Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-01637, D. Del., 09/03/2019
  • Venue Allegations: Venue is alleged as proper because Defendants LG Chem, Ltd. and LG Electronics, Inc. are foreign entities, and all Defendants have allegedly committed acts of infringement and purposefully transacted business in the United States and the judicial district.
  • Core Dispute: Plaintiff alleges that Defendants’ secondary battery modules, used in electric vehicles, infringe a patent related to the structural assembly of battery cells designed to improve safety and reliability.
  • Technical Context: The technology concerns the mechanical construction of multi-cell lithium-ion battery packs, a foundational component for the rapidly growing electric vehicle (EV) market.
  • Key Procedural History: The complaint alleges that during the prosecution of a Korean patent application owned by Defendant LG Chem, the Korean Intellectual Property Office cited the Korean counterpart to the patent-in-suit, potentially creating a basis for pre-suit knowledge. The complaint also references separate, ongoing litigation between the parties in the same district.

Case Timeline

Date Event
2012-11-20 '398 Patent Priority Date
2017-04-20 Korean IPO cites '398 Patent counterpart in LG Chem patent prosecution
2017-07-04 '398 Patent Issue Date
2019-09-03 Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,698,398 - "Secondary Battery Module"

The Invention Explained

  • Problem Addressed: In battery modules where multiple cells are stacked together, gaps can form between the cells due to vibration, swelling, or deterioration of adhesion over time. These gaps can lead to electrical arcing ("sparks") between cells, creating a risk of fire or explosion and degrading the module's performance and reliability (’398 Patent, col. 2:16-29).
  • The Patented Solution: The invention introduces a specific structural arrangement to ensure robust and lasting adhesion between stacked battery cells. It uses an adhesive pad placed between the cells, but critically, this pad is disposed within a "partition member" that acts as a frame. This structure is intended to precisely align the cells, contain the adhesive, and prevent the formation of voids or gaps, thereby enhancing the module's stability and safety (’398 Patent, col. 5:58 - col. 6:16; FIG. 5).
  • Technical Importance: As battery packs for applications like EVs became larger and more powerful, ensuring their mechanical and electrical stability became a critical engineering challenge for safety and longevity (’398 Patent, col. 1:59-64).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶26).
  • The essential elements of Claim 1 are:
    • A first unit cell and a second unit cell, each having a contact surface.
    • A partition member with a frame, disposed between the two unit cells.
    • An adhesive pad that is disposed only within the frame, such that the frame completely surrounds the pad.
    • The adhesive pad is "coextensive and in contact with the contact surface" of the cells.
  • The complaint reserves the right to assert additional claims (Compl. ¶24).

III. The Accused Instrumentality

Product Identification

  • The accused products are secondary battery cells, modules, and packs made by Defendants (Compl. ¶18). The complaint specifically identifies the "VISTA 2.0 Cell Module Assembly" as an exemplary infringing product (Compl. ¶27).

Functionality and Market Context

  • The accused VISTA 2.0 Cell Module Assembly is a key component of the battery system for General Motors' Chevrolet Bolt electric vehicle (Compl. ¶27, ¶37). The complaint alleges these assemblies are assembled by LGE in Michigan using cells made by LG Chem and are supplied to GM for use in EVs sold in the United States, positioning the products as commercially significant components in the U.S. automotive supply chain (Compl. ¶27-¶29, ¶37). The complaint includes a photograph of the accused VISTA 2.0 Cell Module Assembly as a whole to provide context. The image shows an assembled battery module in a long, rectangular housing (Compl. ¶39).

IV. Analysis of Infringement Allegations

'398 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a first unit cell and a second unit cell, each unit cell having a contact surface; The accused VISTA 2.0 Cell Module Assembly is alleged to be constructed from stacked unit cells, each with a contact surface. A photograph of a representative cell is provided. ¶40 col. 4:20-23
a partition member disposed between the first and second unit cells, the partition member having a frame; The assembly allegedly includes a partition member, depicted in a photograph as a black, rectangular frame, that is placed between the unit cells. ¶41 col. 5:58-62
an adhesive pad disposed only within the frame of the partition member so that the frame completely surrounds the adhesive pad; An adhesive pad is allegedly placed entirely inside the boundaries of the partition member's frame. The complaint provides a photograph showing the pad situated within the frame. ¶42 col. 6:5-11
wherein the adhesive pad is coextensive and in contact with the contact surface of the first and second unit cells. The adhesive pad is alleged to be coextensive with and in contact with the cell surfaces. A photograph shows the pad being applied to a cell surface. ¶43 col. 6:54-57
  • Identified Points of Contention:
    • Scope Questions: The infringement analysis may turn on the definition of "coextensive." A central question for the court will be whether this term requires the adhesive pad's dimensions to be identical to the cell's contact surface, or if it allows for minor differences in size and shape so long as the pad substantially covers the surface within the frame. The visual evidence in the complaint shows an adhesive pad that appears slightly smaller than the overall unit cell. An image shows the accused adhesive pad with the partition member removed, illustrating its shape and size relative to the cell (Compl. ¶42).
    • Technical Questions: What evidence demonstrates that the accused "partition member" (Compl. ¶41) performs the alignment and positioning function described in the patent (col. 5:58-65), as opposed to another primary function such as spacing or thermal management? The complaint alleges the structure exists but does not detail its specific function in the accused product.

V. Key Claim Terms for Construction

  • The Term: "coextensive"
  • Context and Importance: This term is central to the final limitation of claim 1. Its construction will likely determine whether the physical arrangement of the accused product, where the adhesive pad may not cover 100% of the cell's contact surface, meets the claim. Practitioners may focus on this term because the visual evidence in both the patent's figures and the complaint's photographs suggests a potential mismatch between the area of the adhesive pad and the full area of the cell's contact surface.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent specification describes the purpose of the adhesive pad as enhancing adhesion to prevent gaps and improve reliability (’398 Patent, col. 5:14-26). An argument could be made that as long as the pad is functionally sufficient to achieve this purpose, it is "coextensive" in the context of the invention, even if not dimensionally identical.
    • Evidence for a Narrower Interpretation: The plain and ordinary meaning of "coextensive" implies being of equal extent or scope. A defendant may argue this requires the adhesive pad to have the same area and boundaries as the contact surface it is applied to. The language "coextensive and in contact" could be argued to impose two distinct requirements: one of contact, and one of identical scope.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement by LGE based on its encouraging automobile manufacturers like GM to use the accused assemblies in EVs sold in the U.S. (Compl. ¶28). It alleges contributory infringement by LGE for selling the VISTA 2.0 assembly, which is asserted to be an especially-made component with no substantial non-infringing use (Compl. ¶29). It further alleges LG Chem induces LGE to infringe by supplying the battery cells for these specific assemblies (Compl. ¶31).
  • Willful Infringement: The willfulness claim is based on alleged pre-suit and post-suit knowledge. Pre-suit knowledge is alleged to stem from an April 20, 2017 office action from the Korean Intellectual Property Office, which cited a Korean counterpart of the '398 Patent during the prosecution of one of LG Chem's own patent applications (Compl. ¶33). Post-suit willfulness is alleged from the date of service of the complaint (Compl. ¶33).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of claim construction: How will the court construe the term "coextensive"? The case may pivot on whether this term imposes a strict, dimensional requirement for the adhesive pad to be identical in area to the cell's contact surface, or whether it permits a more functional interpretation where substantial coverage is sufficient.
  • A second central question will be evidentiary: While the complaint's photographic evidence shows a physical structure that appears to map to the claim elements, SK Innovation will need to prove not only the structure but also that the accused components function as claimed. The dispute may focus on whether the accused "partition member" and "adhesive pad" achieve the specific functional results described in the patent specification, particularly regarding precise alignment and the prevention of gaps.