Ningde Amperex Technology Ltd v. Zhuhai CosMX Battery Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Ningde Amperex Technology Limited (China)
  • Defendant: Zhuhai CosMX Battery Co., Ltd. (China)
  • Plaintiff’s Counsel: Quinn Emanuel Urquhart & Sullivan LLP; The Dacus Firm, P.C.
• Case Identification: 2:22-cv-00232, E.D. Tex., 08/04/2022
• Venue Allegations: Venue is asserted on the basis that the Defendant is not a resident of the United States and may therefore be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant’s lithium-ion batteries infringe four patents related to battery cell structure, electrolyte composition, and separator technology.
• Technical Context: The lawsuit concerns innovations in lithium-ion batteries, a technology fundamental to the global market for portable consumer electronics, electric vehicles, and energy storage systems.
• Key Procedural History: The complaint alleges Defendant had pre-suit knowledge of three of the four asserted patents via written correspondence. It also notes that Defendant was previously sued for patent infringement in August 2021 in the Western District of Texas by a different party.

Case Timeline

Date	Event
2015-08-31	'352 Patent Priority Date
2017-11-29	'706 Patent Priority Date
2018-04-11	'987 Patent Priority Date
2018-09-21	'363 Patent Priority Date
2020-11-10	'363 Patent Issue Date
2021-03-30	'987 Patent Issue Date
2021-04-06	'706 Patent Issue Date
2021-06-24	Alleged notice date for '706 and '987 Patents
2021-08-01	Prior infringement suit filed against CosMX by Maxell
2022-05-10	'352 Patent Issue Date
2022-06-21	Alleged notice date for '352 Patent
2022-08-02	Alleged notice date for '363 Patent
2022-08-04	Complaint Filing Date

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

U.S. Patent No. 10,971,706 - "Electrode assembly," Issued April 6, 2021

The Invention Explained

• Problem Addressed: The patent describes a problem in high-energy-density batteries where thinner current collectors and packaging films are used. Thinned collectors can form sharp corners, and die-cut anodes can have burrs, both of which risk piercing the aluminum plastic package film, leading to chemical reactions, corrosion, and leakage (Compl. ¶23; ’706 Patent, col. 1:27-44).
• The Patented Solution: The invention is an electrode assembly that incorporates a "protective layer." This layer is specifically arranged to cover at least one side of the cell body and extend beyond the anode electrode's edge. This design allows the protective layer to wrap around any burrs on the anode, preventing them from puncturing the battery's packaging and causing a failure (’706 Patent, Abstract; col. 2:45-64).
• Technical Importance: This approach provides a structural solution to enhance the safety and reliability of high-density lithium-ion batteries without compromising the thin form factors required for modern electronics.

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶35).
• Essential elements of Claim 1:
  • An electrode assembly, comprising a cell and a protective layer.
  • The cell comprises a cell body and an electrode tab protruding from the cell body.
  • In a height direction of the cell, at least one end of the protective layer extends beyond an anode electrode, with the extended dimension being no more than 3 mm.
  • The protective layer comprises a first binding sub-layer and an isolation sub-layer that are laminated together.
  • The protective layer is bound to the cell through the first binding sub-layer.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 11,329,352 - "Secondary battery cell and winding formation system thereof," Issued May 10, 2022

The Invention Explained

• Problem Addressed: The patent identifies a manufacturing challenge where, in an effort to increase energy density, a groove is formed on an electrode plate to weld an electrode tab. This grooving process can create metal "burrs" on the current collector. If not addressed, these burrs can pierce the battery's separator, leading to internal short circuits and safety hazards like fires. A prior art solution involved covering the groove with thick tape, but this increased the cell's overall thickness and reduced energy density (Compl. ¶25; ’352 Patent, col. 1:20-41).
• The Patented Solution: The invention is a secondary battery cell where the electrode plate is manufactured with a "die-cut notch" located on the side edge of the tab receiving groove. This notch is designed to physically remove the burrs formed on the current collector during the grooving process, thereby preventing potential short circuits without the need for density-reducing adhesive tapes (’352 Patent, Abstract; col. 2:30-40).
• Technical Importance: The invention offers a method to improve both the safety performance and energy density of a battery by eliminating a manufacturing defect at its source.

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶49).
• Essential elements of Claim 1:
  • A wound-type secondary battery comprising a first electrode tab and a first electrode plate.
  • The first electrode plate includes a first current collector, a first active substance, a first electrode tab receiving groove, and a first recess opposite the groove.
  • A "first electrode plate notch" is disposed on a side edge of the tab receiving groove and extends through both surfaces of the first current collector.
  • The tab receiving groove is formed by the current collector and at least two active substance walls.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 10,833,363 - "Electrolyte and electrochemical device," Issued November 10, 2020

• Technology Synopsis: The patent addresses the problem of electrolyte decomposition at high voltages, which degrades battery materials and reduces capacity (Compl. ¶27). The invention claims a specific electrolyte formulation containing a dinitrile compound, a trinitrile compound, and propyl propionate, with their contents and ratios controlled within specific ranges, to form a stable protective film that enhances performance and cycle life (’363 Patent, Abstract; col. 1:21-34).
• Asserted Claims: Independent claim 1 is asserted (Compl. ¶63).
• Accused Features: The specific chemical composition of the electrolyte used in the accused CosMX batteries is alleged to infringe (Compl. ¶63).

U.S. Patent No. 10,964,987 - "Separator and energy storage device," Issued March 30, 2021

• Technology Synopsis: The patent addresses the formation of a gap between the battery's electrode and separator during use, which reduces battery capacity (Compl. ¶29). The invention is a separator comprising a porous substrate and a porous layer with inorganic particles, where the ratio of the particle size (Dv90) to the thickness of the porous layer is controlled. This structure allegedly maintains excellent adhesion between the separator and the electrode, preventing gap formation and improving service life (’987 Patent, Abstract).
• Asserted Claims: Independent claim 1 is asserted (Compl. ¶77).
• Accused Features: The separator component within the accused CosMX batteries, including its material composition and structural ratios, is alleged to infringe (Compl. ¶77).

III. The Accused Instrumentality

Product Identification

The complaint identifies "lithium-ion battery products" from Defendant CosMX, with an exemplary product identified as "CosMX Cell No. CA3862E1" (Compl. ¶10, ¶19). This cell was found inside a Lenovo Battery L20D4PC1 used in a Lenovo Legion 5 laptop (Compl. ¶19).

Functionality and Market Context

The accused products are described as "consumer polymer soft pouch lithium-ion batteries" (Compl. ¶12). These are rechargeable batteries designed for use in a wide range of consumer electronics, including notebook computers, tablets, smartphones, and drones (Compl. ¶12). The complaint alleges that CosMX is a "worldwide major supplier" that provides batteries to well-known OEMs such as HP, Lenovo, Dell, and Amazon, and that the U.S. is a key export region for the company (Compl. ¶12, ¶14). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges that representative claim charts are attached as Exhibits I, J, K, and L; however, these exhibits were not included with the filed complaint document (Compl. ¶40, ¶54, ¶68, ¶82). The complaint’s body contains conclusory allegations of infringement for each patent but does not provide a narrative infringement theory or map specific features of the accused products to the limitations of the asserted claims. For example, the infringement count for the '706 patent states that CosMX infringes "at least claim 1 of the '706 patent by, without authority, making, using, selling, offering for sale, and/or importing... the Accused Products" without specifying how the accused products meet the claim elements (Compl. ¶35). A similar pleading structure is used for the '352, '363, and '987 patents.

Identified Points of Contention (’706 Patent)

• Technical Question: A central factual dispute will be whether the accused batteries contain a "protective layer" as claimed. Evidence from product teardowns will be required to determine if any such structure exists and, if so, whether it "extends beyond an anode electrode" and is composed of the claimed "first binding sub-layer and an isolation sub-layer."
• Scope Question: The analysis will question whether a standard component of a battery, if present, can be characterized as the specific "protective layer" of claim 1, or if the claim requires a distinct, additional element whose primary purpose is protection.

Identified Points of Contention (’352 Patent)

• Technical Question: The infringement analysis will turn on whether the accused batteries are manufactured with the specific "first electrode plate notch" at the edge of the electrode tab receiving groove. This is a micro-structural feature that would need to be identified through detailed inspection of the battery's internal components.
• Scope Question: The case may raise the question of whether any manufacturing imperfection or indentation near the tab groove constitutes the claimed "notch," or if the term is limited to a structure intentionally formed to remove burrs, as described in the patent's specification.

V. Key Claim Terms for Construction

’706 Patent

• The Term: "protective layer"
• Context and Importance: This term is the core of claim 1 of the '706 patent. The existence and scope of infringement will depend entirely on how this term is construed and whether a corresponding structure is found in the accused products.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent describes the layer's function in general terms, such as reducing the risk of the package bag being pierced (’706 Patent, col. 3:4-15). The claims do not limit its precise shape or material beyond requiring two sub-layers.
  • Evidence for a Narrower Interpretation: The specification repeatedly ties the layer to solving the specific problem of "burrs on the anode electrode" and sharp corners (’706 Patent, col. 2:56-64). The preferred embodiments disclose a specific laminated structure with an "isolation sub-layer" and a "binding sub-layer," suggesting a more complex and purpose-built component than a simple film or coating (’706 Patent, col. 2:18-25).

’352 Patent

• The Term: "first electrode plate notch"
• Context and Importance: This is the key inventive feature of claim 1 of the '352 patent, which distinguishes the invention from prior art methods of dealing with manufacturing burrs. Infringement will hinge on finding a structure in the accused device that meets the definition of this term.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language itself is purely structural, requiring a "notch disposed on a side edge of the first electrode tab receiving groove."
  • Evidence for a Narrower Interpretation: The background and summary of the invention frame the notch's purpose as being to "effectively remove the burrs formed on the current collector" during groove formation (’352 Patent, col. 2:35-40). A party could argue that for an indentation to be a "notch" under the patent, it must be a feature created for this specific burr-removal purpose, rather than an incidental artifact of a different manufacturing process.

VI. Other Allegations

Indirect Infringement

The complaint alleges induced infringement for all four patents. The allegations are based on Defendant CosMX supplying the accused batteries to downstream customers (e.g., Lenovo, HP, Dell) with the specific intent and knowledge that these batteries will be incorporated into products sold in the United States. This conduct allegedly includes entering into supplier agreements, creating U.S. distribution channels, and manufacturing products to comply with U.S. regulations (e.g., Compl. ¶37, ¶51, ¶65, ¶79).

Willful Infringement

Willfulness is alleged for all four patents. The complaint asserts that CosMX had knowledge of the patents prior to the lawsuit's filing, citing specific dates of written correspondence for the '706, '987, and '352 patents, and alleges that CosMX continued its infringing conduct despite this knowledge (Compl. ¶36, ¶39, ¶50, ¶53, ¶64, ¶67, ¶78, ¶81).

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

• A primary issue will be one of evidentiary proof through reverse engineering: The dispute will depend heavily on detailed technical analysis of the accused batteries. The core questions for the fact-finder will be whether the accused CosMX cells physically contain the specific structures and material compositions required by the asserted claims, such as the multi-layered "protective layer" of the '706 patent, the "electrode plate notch" of the '352 patent, the specific electrolyte formulation of the '363 patent, and the separator particle-size-to-thickness ratio of the '987 patent.
• A second critical issue will be one of claim construction: The litigation will likely feature significant disputes over the proper scope of key terms. A central question for the court will be whether terms like "protective layer" and "electrode plate notch" should be interpreted broadly based on their structural descriptions, or more narrowly in light of the specific problems they were designed to solve as detailed in the patent specifications.
• Finally, a key question for damages will be willfulness: Given the complaint’s specific allegations of pre-suit notice via written correspondence, the timing and content of that notice will be central to determining whether any infringement was willful, which could expose the defendant to the risk of enhanced damages.