DCT

2:24-cv-00728

Ningde Amperex Technology Ltd v. Zhuhai CosMX Battery Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:24-cv-00728, E.D. Tex., 01/28/2025
  • Venue Allegations: Venue is asserted based on the defendant being a foreign corporation not resident in the United States, which under 28 U.S.C. § 1391(c)(3) permits suit in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendant’s lithium-ion batteries, supplied to major consumer electronics brands, infringe six U.S. patents related to the composition and structure of battery separators, electrolytes, and electrodes.
  • Technical Context: The litigation concerns foundational components of lithium-ion batteries, a technology central to the global market for portable electronics, including smartphones, laptops, and tablets.
  • Key Procedural History: The complaint notes that Plaintiff previously sued Defendant in the same district in June 2022 for infringement of different patents. The current filing is a Second Amended Complaint and includes counts to correct the inventorship of two of the asserted patents.

Case Timeline

Date Event
2014-01-17 Earliest Priority Date (’498 Patent)
2018-02-26 Earliest Priority Date (’118 Patent)
2018-04-11 Earliest Priority Date (’148 Patent)
2018-06-20 Earliest Priority Date (’927 Patent)
2018-09-21 Earliest Priority Date (’910 and ’131 Patents)
2021-03-30 ’927 Patent Issued
2022-06-01 Prior Lawsuit ("232 Action") Filed (approx. date)
2023-02-07 ’148 Patent Issued
2023-09-26 ’910 Patent Issued
2023-10-24 ’131 Patent Issued
2024-03-05 ’498 Patent Issued
2024-06-18 ’118 Patent Issued
2025-01-28 Second Amended Complaint Filed

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

U.S. Patent No. 11,575,148 - “Porous film and lithium-ion battery”

  • Issued: February 7, 2023 (the "’148 Patent")

The Invention Explained

  • Problem Addressed: The patent addresses the formation of gaps between a battery's electrode and separator during charging and discharging cycles, which can reduce the battery's capacity and service life (’148 Patent, col. 1:29-35).
  • The Patented Solution: The invention is a porous film (separator) made from a binder and inorganic particles. The solution specifies a novel particle size distribution for the inorganic particles, defined by specific ranges for Dv10, Dv50, and Dv90 values, and a required ratio between them. This structure is designed to create pores within the binder that maintain good adhesion and high ionic conductivity, thereby improving the battery's rate performance and cycle life (’148 Patent, Abstract; col. 2:47-54; Compl. ¶22).
  • Technical Importance: This approach aimed to enhance battery longevity and performance by creating a more stable and efficient interface between the electrode and separator (Compl. ¶22).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 17, and 19 (Compl. ¶36).
  • Independent Claim 1 requires:
    • A porous film comprising a binder and inorganic particles.
    • The film containing pores formed by the binder, which at least comprise a part of the inorganic particles.
    • The inorganic particles having specific particle size distributions: Dv10 in a range of 0.015 μm to 3 μm; Dv50 in a range of 0.2 μm to 5 μm; and Dv90 in a range of 1 μm to 10 μm.
    • Dv10 being less than Dv50, and Dv50 being less than Dv90.
    • A ratio of Dv90 to Dv10 in a range of 2 to 100.

U.S. Patent No. 11,769,910 - “Electrolyte and electrochemical device”

  • Issued: September 26, 2023 (the "’910 Patent")

The Invention Explained

  • Problem Addressed: In high-voltage lithium-ion batteries, the increased oxidation activity of the positive electrode material causes it to decay, reducing battery capacity, cycle life, and efficiency. Protective films created by prior art electrolyte additives were insufficient to withstand these harsher high-voltage environments (Compl. ¶24).
  • The Patented Solution: The patent discloses a novel electrolyte formulation comprising a specific combination of four additives: a dinitrile, a trinitrile, propyl propionate, and 1,3-propane sultone. When combined in specific ratios relative to each other and to the total weight of the electrolyte, these additives form a protective film capable of withstanding the stressful conditions of high-voltage operation (Compl. ¶24).
  • Technical Importance: This formulation enables the development of more stable high-voltage batteries, which are desirable for their increased energy density compared to conventional batteries (Compl. ¶24).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and a large number of dependent claims (Compl. ¶49).
  • Independent Claim 1 requires:
    • An electrolyte comprising a dinitrile compound, a trinitrile compound, and propyl propionate.
    • Specific weight percentage ranges and ratios for the dinitrile (X), trinitrile (Y), and propyl propionate (Z) components.
    • The dinitrile compound being selected from a specific chemical group (e.g., butanedinitrile, adiponitrile).
    • The trinitrile compound being selected from a specific chemical group (e.g., 1,3,6-hexanetricarbonitrile).
    • The electrolyte further comprising a compound having a sulfur-oxygen double bond.

U.S. Patent No. 11,799,131 - “Electrolyte and electrochemical device”

  • Issued: October 24, 2023 (the "’131 Patent")

Technology Synopsis

This patent, like the ’910 Patent, addresses performance degradation in high-voltage batteries. The claimed solution involves two aspects: first, an electrolyte using specific additives (dinitriles, trinitriles, and propyl propionate) in particular ratios; and second, the use of single-sided and double-sided electrode coatings that meet a certain compaction density ratio to preserve cycle performance (Compl. ¶26).

Asserted Claims

  • At least claims 1, 2, 3, 4, 5, 6, 7, 12, 14, 15, 16, and 17 (Compl. ¶62).
  • Accused Features: The electrolyte composition and electrode structure within the Accused Products (Compl. ¶62).

U.S. Patent No. 10,964,927 - “Separator and electrochemical device”

  • Issued: March 30, 2021 (the "’927 Patent")

Technology Synopsis

This patent is directed to improving battery safety, particularly against puncture events that could cause fire or explosion. The invention is a separator whose porous substrate has an "absolute plastic deformation rate" between 40% and 1800%, a property calculated by a specific formula that measures the material's ability to stretch without fully retracting (Compl. ¶28).

Asserted Claims

  • At least claims 1, 2, 3, 4, 6, 7, 8, 9, and 10 (Compl. ¶75).
  • Accused Features: The separators within the Accused Products (Compl. ¶75).

U.S. Patent No. 11,923,498 - “Lithium-ion battery having desirable safety performance”

  • Issued: March 5, 2024 (the "’498 Patent")

Technology Synopsis

The patent addresses structural issues in prior art batteries, such as peeling of electrode material and internal short circuits. The solution is a battery design where the electrode tabs are welded into recesses formed in the active material layer, rather than on the surface, and insulating glue layers are placed on the opposing electrode to prevent contact, thereby increasing energy density and safety (Compl. ¶30).

Asserted Claims

  • At least claims 1, 2, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, and 22 (Compl. ¶88).
  • Accused Features: The physical construction of the Accused Products, including the placement of electrode tabs within recesses and the use of insulating layers (Compl. ¶88).

U.S. Patent No. 12,015,118 - “Electrode electrochemical device and electronic device”

  • Issued: June 18, 2024 (the "’118 Patent")

Technology Synopsis

This patent aims to improve battery safety against puncture by using a multi-layered electrode. The invention claims an electrode with two active material layers surrounding a current collector, where the inner layer has a particle size below a certain threshold and the total compaction density of both layers is above a specified threshold, leading to improved reliability (Compl. ¶32).

Asserted Claims

  • At least claims 1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 19, and 20 (Compl. ¶101).
  • Accused Features: The layered structure, particle size, and compaction density of the electrodes within the Accused Products (Compl. ¶101).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are lithium-ion batteries ("Accused Products") manufactured and sold by Defendant CosMX (Compl. ¶9). The complaint identifies exemplary products by cell number, including CosMX Cell No. CA386990G (found in an Acer Swift X laptop), CA496485F-Q1 (found in a Redmi Note 11), and CA476588P-Q1 (found in a Redmi Note 13) (Compl. ¶18).

Functionality and Market Context

  • The Accused Products are described as consumer-grade Li-ion batteries incorporated into devices such as PCs, notebooks, tablets, and smartphones (Compl. ¶11). The complaint alleges that CosMX is a "worldwide major supplier" and has consolidated its supply share in customers including HP, Lenovo, Dell, and Apple (Compl. ¶¶11, 13). The batteries are alleged to be designed and supplied specifically for use in consumer electronics products intended for sale in the United States (Compl. ¶15).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references but does not attach representative claim charts for the asserted patents (Compl. ¶¶41, 54, 67, 80, 93, 106). The infringement theories are therefore summarized below in prose based on the complaint's narrative allegations.

  • ’148 Patent Infringement Allegations
    The complaint alleges that the separators used in CosMX's Accused Products are porous films that infringe the ’148 Patent. The infringement theory is that these separators are made with inorganic particles and a binder, and that the particle sizes of the inorganic materials meet the specific Dv10, Dv50, and Dv90 distribution ranges and the Dv90/Dv10 ratio required by at least claim 1 of the patent (Compl. ¶¶22, 36-37). The complaint suggests that this specific separator design, allegedly copied by CosMX, is a critical component for battery safety and performance (Compl. ¶22).

  • ’910 Patent Infringement Allegations
    The complaint alleges that the Accused Products contain an electrolyte that infringes the ’910 Patent. The infringement theory is based on chemical composition, alleging that CosMX batteries use an electrolyte formulated with the combination of additives claimed in the patent: a dinitrile, a trinitrile, propyl propionate, and a compound with a sulfur-oxygen double bond. The complaint further alleges that the relative weight percentages and ratios of these components in the Accused Products fall within the specific numerical ranges required by at least claim 1 of the patent (Compl. ¶¶24, 49-50).

  • Identified Points of Contention:

    • Technical Questions: The complaint's allegations for patents like the ’148 and ’910 rest on precise, quantitative measurements of material properties and chemical composition. A primary point of contention will be factual and evidentiary: what testing and analysis does Plaintiff possess to demonstrate that the inorganic particles in CosMX's separators meet the claimed Dv size distributions, or that the electrolyte contains the claimed additives within the specified weight-percentage ratios?
    • Scope Questions: For patents concerning structural features like the ’927 Patent, a key question may be whether the test methods described in the patent for calculating properties like "absolute plastic deformation rate" are the sole basis for determining infringement. The parties may dispute the proper methodology for testing the accused separators to determine if they fall within the claimed numerical range of 40% to 1800% (Compl. ¶28; ’927 Patent, col. 4:51-52).

V. Key Claim Terms for Construction

  • The Term: "pores formed by the binder" (’148 Patent, Claim 1)

  • Context and Importance: This term is central to the claimed structure of the separator in the ’148 Patent. Its construction is critical because infringement requires not only the presence of pores, a binder, and particles, but a specific structural relationship where the binder itself forms the pores. Practitioners may focus on this term to dispute whether the accused product's structure, which may consist of simple interstitial voids between particles held together by an adhesive, meets this limitation.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: Language stating the pores "at least comprise a part of the inorganic particles" could support a reading where any pore within the binder matrix that happens to contain a particle meets the limitation, regardless of the formation mechanism (’148 Patent, Abstract).
    • Evidence for a Narrower Interpretation: The patent’s description of a phase-inversion manufacturing process, if present, could support a narrower definition requiring the binder to be the primary structural agent that creates the porous network, rather than simply acting as an adhesive filling voids between particles (’148 Patent, col. 6:10-33).

  • The Term: "absolute plastic deformation rate" (’927 Patent, Claim 1)

  • Context and Importance: Infringement of the ’927 Patent hinges entirely on whether the accused separator exhibits a physical property that falls within a specific numerical range (40% to 1800%). This term is explicitly defined by the formula (L2-L0)/L0 × 100%, where L0 is the initial length and L2 is the length after being stretched to breakage and allowed to relax (’927 Patent, col. 4:51-52; Compl. ¶28). The dispute will likely center not on the definition of the term itself, but on the precise methodology for measuring L0 and L2 on the accused products.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The parties are unlikely to argue for a broader definition than the explicit formula provided in the patent specification.
    • Evidence for a Narrower Interpretation: The patent’s specification and figures describe a specific testing protocol: a sample is stretched to break, the broken pieces are "docked along the fracture," and then "flattened to test the length L2" (’927 Patent, FIG. 1; col. 3:15-20). Disputes may arise over the exact meaning and proper execution of these procedural steps, such as the degree of force used for flattening or the precise alignment for docking, which could materially affect the measured value of L2.

VI. Other Allegations

  • Indirect Infringement: For each asserted patent, the complaint alleges induced infringement under 35 U.S.C. § 271(b). The factual basis alleged is that CosMX enters into supplier agreements with customers (e.g., Dell, HP, Apple) with the knowledge and intent that the Accused Products will be imported and sold in the U.S., creates U.S. distribution channels, and manufactures products to conform with U.S. regulations (e.g., Compl. ¶¶39, 52, 65, 78, 91, 104).
  • Willful Infringement: Willfulness is alleged for all asserted patents. The complaint bases this allegation on post-suit knowledge, stating that "CosMX has known of the [asserted patent] since the filing of the Complaint in this matter" (e.g., Compl. ¶¶38, 51, 64, 77, 90, 103). A footnote clarifies that Plaintiff is not seeking pre-suit damages at this time but reserves the right to do so, suggesting a current focus on post-filing conduct for willfulness (Compl. ¶1 n.1).

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

  • A central issue will be one of forensic materials science: What factual evidence will Plaintiff produce from sophisticated reverse engineering and testing to prove that the Accused Products meet the precise quantitative limitations of the claims, such as the particle size distributions in the ’148 Patent, the chemical composition ratios in the ’910 Patent, and the physical deformation rate in the ’927 Patent?
  • A key question of causation and claim scope will arise for the structural patents: Does the evidence show that the accused separators have "pores formed by the binder" (’148 Patent) as a result of a specific manufacturing process, or are they merely interstitial voids between particles? Similarly, does welding a tab inside a "recess" (’498 Patent) require the recess to be intentionally formed for that purpose, or can it be an incidental feature of the electrode manufacturing process?
  • The case may also turn on questions of knowledge and intent: Given the prior litigation between the parties, what evidence exists to establish when CosMX became aware of the specific technologies claimed in these newer patents? This will be critical for the willfulness allegations, particularly whether Plaintiff can establish any basis for pre-suit knowledge beyond the filing of the current complaint.