DCT

2:18-cv-09074

Advanced Electrolyte Tech LLC v. Coslight USA Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:18-cv-09074, C.D. Cal., 10/22/2018
  • Venue Allegations: Venue is alleged to be proper as Defendant Coslight USA, Inc. is a California corporation residing in the judicial district, and Defendant Zhuhai Coslight Battery Co., Ltd. is a foreign corporation.
  • Core Dispute: Plaintiffs allege that lithium-ion batteries manufactured and sold by Defendants infringe three U.S. patents directed to specific chemical compositions for battery electrolytes designed to improve performance and cycle life.
  • Technical Context: The technology concerns electrolyte formulations for rechargeable lithium-ion batteries, a critical component for determining the energy storage capacity, longevity, and safety of batteries used in ubiquitous consumer electronics.
  • Key Procedural History: The complaint alleges that U.S. Patent No. 6,033,809 underwent a supplemental reexamination, which confirmed the patentability of asserted claims. The complaint also alleges that Defendants were aware of the patents-in-suit prior to the lawsuit due to direct communications and a separate, well-known litigation involving the same patents against Samsung, which forms a basis for the willfulness allegations.

Case Timeline

Date Event
1997-08-22 ’809 Patent Priority Date
2000-03-07 ’809 Patent Issue Date
2002-07-15 ’033 and ’307 Patents Priority Date
2013-09-25 ’809 Patent Supplemental Reexamination Requested
2014-08-27 ’809 Patent Reexamination Certificate Issued
2017-08-22 ’033 Patent Issue Date
2018-08-14 ’307 Patent Issue Date
2018-10-22 Complaint Filing Date

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

U.S. Patent No. 6,033,809 - "Lithium Secondary Battery and Electrolyte Thereof" (Issued Mar. 7, 2000)

The Invention Explained

  • Problem Addressed: The patent describes the problem of gradual battery capacity degradation in lithium-ion batteries over repeated charge-discharge cycles. This loss is attributed to the decomposition of the non-aqueous solvent at the interface with the anode, particularly when using highly crystallized graphite anodes which are otherwise desirable for increasing battery capacity (Compl. ¶11-12; ’809 Patent, col. 2:26-44).
  • The Patented Solution: The invention proposes adding a small amount (0.1 to 4% by weight) of a specific class of compounds called "sultone derivatives" to a conventional electrolyte solvent (comprising a cyclic and a linear carbonate). The patent suggests this additive forms a "passivation film" on the surface of the anode, which suppresses the decomposition of the electrolyte and thereby improves the battery's cycle characteristics ('809 Patent, Abstract; col. 4:1-9).
  • Technical Importance: This approach provided a method to enhance the cycle life and stability of high-capacity lithium-ion batteries, a critical factor for the commercial viability of portable electronic devices in the late 1990s and early 2000s (Compl. ¶16).

Key Claims at a Glance

  • The complaint asserts at least dependent Claim 2 (Compl. ¶40). Claim 1, on which Claim 2 originally depended, was canceled during reexamination.
  • The essential elements of the battery defined by Claim 2 (incorporating the limitations of canceled Claim 1) are:
    • A cathode composed of a material containing a lithium complex oxide.
    • An anode composed of a material containing graphite.
    • A non-aqueous electrolyte comprising an electrolyte dissolved in a non-aqueous solvent.
    • The non-aqueous solvent contains, as main components, a cyclic carbonate and a linear carbonate.
    • The solvent further contains 0.1 to 4% by weight of a sultone derivative having a specific general formula.
    • The content of the cyclic carbonate is 10 to 70% by weight, the linear carbonate is 30 to 90% by weight, and the sultone derivative is 0.1 to 4% by weight.
  • The complaint does not explicitly reserve the right to assert additional claims, though this is common practice.

U.S. Patent No. 9,742,033 - "Non-Aqueous Electrolytic Solution and Lithium Battery" (Issued Aug. 22, 2017)

The Invention Explained

  • Problem Addressed: The patent addresses the general need to improve overall battery performance, including cycle performance, electrical capacity, and storage endurance, by optimizing the electrolyte solution ('033 Patent, col. 2:30-44).
  • The Patented Solution: The invention describes a non-aqueous electrolytic solution that includes a specific combination of additives: a dinitrile compound (adiponitrile) and an S=O group-containing compound (such as ethylenesulfite). This combination is purported to yield improved cycle and storage properties for lithium batteries ('033 Patent, Abstract; col. 2:45-53).
  • Technical Importance: This technology represents a continued effort to refine electrolyte formulations with synergistic additive combinations to further extend the operational life and reliability of lithium-ion batteries (Compl. ¶15-16).

Key Claims at a Glance

  • The complaint asserts at least independent Claim 1 (Compl. ¶51).
  • The essential elements of the electrolytic solution claimed are:
    • A non-aqueous solvent comprising from 30 to 50 volume percent of a cyclic carbonate.
    • From 0.5 to 1.5 M of at least one electrolyte selected from LiPF₆ and LiBF₄.
    • From 0.01 to 3% by weight of adiponitrile.
    • From 0.2 to 3% by weight of at least one S=O group-containing compound selected from a specific list including ethylenesulfite and 1,3-propanesultone.
  • The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 10,050,307 - "Non-Aqueous Electrolytic Solution and Lithium Battery" (Issued Aug. 14, 2018)

  • Technology Synopsis: Belonging to the same family as the ’033 Patent, this patent also addresses improving lithium battery performance through electrolyte additives. The invention is a non-aqueous electrolytic solution containing a specific combination of a dinitrile compound (succinonitrile) and an S=O group-containing compound (such as 1,3-propanesultone) to enhance cycle performance and storage properties ('307 Patent, Abstract).
  • Asserted Claims: The complaint asserts at least independent Claim 1 (Compl. ¶62).
  • Accused Features: The electrolyte compositions within the accused batteries, specifically the HP SB03XL and HP OD06XL Rechargeable Batteries, are alleged to infringe the ’307 Patent (Compl. ¶62 a-b).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are specific models of rechargeable lithium-ion batteries, including the "ASUS Zenfone Max Plus M1 battery," "HP SB03XL Rechargeable Battery," "HP OD06XL Rechargeable Battery," and "Microsoft Surface 3 Battery," as well as other, unspecified lithium secondary batteries made, used, sold, or imported by the Defendants (Compl. ¶40, 51, 62).

Functionality and Market Context

  • These products are secondary (rechargeable) batteries that function as the power source for various consumer electronic devices (Compl. ¶19, 27). The complaint provides a generic diagram of a lithium-ion battery, illustrating the roles of the anode, cathode, and electrolyte in facilitating the flow of lithium ions to store and discharge energy (Compl. p. 6, Fig. 1). The complaint notes that battery life is an important sales and marketing issue for the end-user devices in which the accused batteries are incorporated (Compl. ¶14).

IV. Analysis of Infringement Allegations

The complaint does not provide narrative infringement allegations or claim charts mapping specific product features to the claim elements. Instead, it asserts that the accused products meet all limitations of the asserted claims and references exhibits (D-K) that were not attached to the publicly filed complaint (Compl. ¶40, 51, 62). The analysis below is based on the infringement theories implied by the patent claims and the identification of the accused products.

'809 Patent Infringement Allegations

  • The complaint alleges that the accused batteries, including those for ASUS, HP, and Microsoft devices, directly infringe at least Claim 2 of the ’809 Patent (Compl. ¶40-41). The core of this infringement theory would be that the electrolyte within these batteries is composed of a non-aqueous solvent containing a cyclic carbonate, a linear carbonate, and between 0.1% and 4% by weight of a sultone derivative as defined in the patent.

'033 Patent Infringement Allegations

  • The complaint alleges that at least the HP SB03XL and HP OD06XL batteries directly infringe at least Claim 1 of the ’033 Patent (Compl. ¶51-52). This infringement theory would require evidence that the electrolyte in these specific batteries contains a non-aqueous solvent with 30-50% cyclic carbonate, a specified electrolyte salt, 0.01-3% adiponitrile, and 0.2-3% of a specified S=O group-containing compound.

Identified Points of Contention

  • Evidentiary Question: The central dispute will likely be factual and evidentiary: What is the precise chemical composition of the electrolytes in the accused batteries? The outcome may depend on the results of discovery and expert chemical analysis.
  • Quantitative Questions: For both the ’809 and ’033 patents, infringement hinges on specific weight or volume percentages of the claimed additives. A key question will be whether the accused electrolytes contain these additives within the claimed quantitative ranges. This may raise issues regarding measurement methodology and precision.
  • Scope Questions: A potential point of contention could be the definition of the chemical groups central to the inventions. For the ’809 Patent, this would be whether a compound found in the accused products falls within the patent's definition of a "sultone derivative." For the ’033 Patent, this could involve the scope of "S=O group-containing compound."

V. Key Claim Terms for Construction

Term from ’809 Patent: "sultone derivative"

  • Context and Importance: This term defines the key additive in the ’809 Patent. Infringement of Claim 2 requires the presence of a compound that meets this definition. Practitioners may focus on this term because its scope will determine whether a compound found in an accused product, even if not explicitly listed as an example in the patent, is covered by the claim.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent provides a general chemical structure (Formula I) to define the class of compounds, suggesting the term is not limited to the specific examples provided ('809 Patent, col. 2:15-29). The specification also lists numerous exemplary compounds, such as 1,3-propane sultone and 1,4-butane sultone, which could support a construction covering a range of related chemicals ('809 Patent, col. 3:1-19).
    • Evidence for a Narrower Interpretation: A party might argue that the term should be interpreted more narrowly in light of the specific embodiments and examples that demonstrate the invention's effectiveness ('809 Patent, Tables 1-3).

Term from ’033 Patent: "a non-aqueous solvent"

  • Context and Importance: Claim 1 of the ’033 Patent requires "a non-aqueous solvent comprising from 30 to 50 volume percent of a cyclic carbonate." The definition of what constitutes the "non-aqueous solvent" is critical for calculating this percentage. Infringement depends on whether the accused product's formulation falls within this range, so a dispute over the "denominator" in this calculation could be case-dispositive.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The plain language suggests the "solvent" includes all non-aqueous liquid components that dissolve the electrolyte salt. The patent provides examples of solvent systems, such as a mixture of ethylene carbonate (EC) and methyl ethyl carbonate (MEC), where the entire mixture appears to be treated as the "solvent" ('033 Patent, col. 5:36-39).
    • Evidence for a Narrower Interpretation: A party could argue that the "solvent" should be defined to exclude certain low-concentration liquid additives, potentially altering the volume percentage calculation. The patent distinguishes between the main solvent components and the additives (adiponitrile, S=O compounds), which are measured by weight percent, suggesting they may not be part of the "solvent" for the purpose of the volume percent calculation ('033 Patent, Claim 1).

VI. Other Allegations

Indirect Infringement

  • The complaint alleges induced infringement against both Defendants. The factual basis for inducement is that Defendants’ sales, advertising, and communications with electronic device manufacturers intentionally caused, directed, and encouraged those manufacturers to directly infringe by incorporating the accused batteries into their final products sold in the U.S. (Compl. ¶43, 47-49, 54, 58-60, 65, 69-71).

Willful Infringement

  • Willfulness is alleged based on Defendants having pre-suit knowledge of the patents. The complaint alleges this knowledge arose from direct communications with Plaintiffs regarding UBE’s patents and from Defendants' awareness of a prior "Samsung Litigation" that involved the same patents-in-suit (Compl. ¶28, 42, 53, 77). The complaint also alleges knowledge at least as of the filing of the instant lawsuit (Compl. ¶53, 64).

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

  1. A central question will be purely evidentiary: What is the precise chemical formulation, including the identity and concentration of all additives, of the electrolyte used in Defendants' accused batteries? The case will likely turn on the factual findings from discovery and competing expert testimony on this point.
  2. A key legal question will concern willfulness: Did Defendants have pre-suit knowledge of the patents-in-suit and their likely infringement, as alleged through prior communications and awareness of the "Samsung Litigation," sufficient to support a finding of willful infringement?
  3. The case may also involve a critical issue of claim construction: Can the chemical term "sultone derivative" in the ’809 patent be construed to read on the specific compounds found in the accused products, and how should the "non-aqueous solvent" be defined for calculating the volume percentages required by the ’033 patent?