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. and its various subsidiaries (collectively "CosMX") (China)
  • Plaintiff’s Counsel: Maier & Maier PLLC
• Case Identification: 2:26-cv-00139, E.D. Tex., 02/18/2026
• Venue Allegations: Venue is alleged to be proper because the Defendant entities are not residents of the United States and therefore may be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant’s lithium-ion battery products, which are supplied to major consumer electronics brands, infringe six U.S. patents related to various aspects of battery safety, structure, and performance.
• Technical Context: The lawsuit concerns foundational technologies in lithium-ion batteries, a critical component market for a vast range of consumer electronics, from smartphones to laptops.
• Key Procedural History: The complaint notes that the parties have been involved in two prior patent infringement lawsuits in the same district (No. 2:22-cv-00232 and No. 2:24-cv-00728). Plaintiff highlights that in the earlier action, the Court denied Defendant's motion to transfer and that Defendant filed counterclaims, which Plaintiff argues establishes the Court's jurisdiction over the Defendant.

Case Timeline

Date	Event
2014-01-17	U.S. Patent 12,278,330 Priority Date
2017-11-17	U.S. Patent 11,699,808 Priority Date
2018-11-05	U.S. Patent 10,916,769 Priority Date
2019-12-11	U.S. Patent 12,294,082 Priority Date
2020-03-03	U.S. Patent 12,334,494 Priority Date
2020-04-28	U.S. Patent 12,374,686 Priority Date
2021-02-09	U.S. Patent 10,916,769 Issue Date
2022-06-01	Plaintiff files "232 Action" against Defendant
2023-07-11	U.S. Patent 11,699,808 Issue Date
2024-05-06	U.S. Patent 12,294,082 Issue Date
2024-09-01	Plaintiff files "728 Action" against Defendant
2025-04-15	U.S. Patent 12,278,330 Issue Date
2025-06-17	U.S. Patent 12,334,494 Issue Date
2025-07-29	U.S. Patent 12,374,686 Issue Date
2026-02-18	Complaint Filing Date

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

U.S. Patent No. 10,916,769 - "Cathode, electrochemical device and electronic device comprising same,"

The Invention Explained

• Problem Addressed: The patent background describes the safety problems associated with lithium-ion batteries, particularly the risk of fire or explosion when a battery is punctured by an external force (Compl. ¶33; ’769 Patent, col. 1:26-34). It notes that conventional methods for improving safety often compromise the battery's energy density ’769 Patent, col. 1:35-41
• The Patented Solution: The invention is a cathode with a specific layered structure designed to prevent internal short circuits during a puncture event Compl. ¶33 It comprises a current collector, a first (inner) active material layer, a second (outer) active material layer, and an insulating layer. The key innovation is a deliberate "gap" between the first active material layer and the insulating layer on the collector surface, which alleviates manufacturing overlap problems that can lead to safety failures ’769 Patent, abstract ’769 Patent, col. 5:12-24 This structure is intended to improve mechanical safety without reducing energy density Compl. ¶33
• Technical Importance: The technology purports to solve the critical trade-off between safety and energy density, a central challenge in the design of batteries for portable electronics Compl. ¶33

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶47
• The essential elements of Claim 1 include:
  • A cathode comprising a current collector, a first cathode active material layer, a second cathode active material layer, and an insulating layer.
  • The first active material layer is disposed between the current collector and the second active material layer.
  • The first active material layer covers a "first portion" of the collector surface, while the insulating layer covers a "second portion" that is different from the first.
  • A structural requirement that "a thickness of the insulating layer is greater than a thickness of the first cathode active material layer."
• The complaint does not explicitly reserve the right to assert dependent claims, though this is common practice.

U.S. Patent No. 11,699,808 - "Battery,"

The Invention Explained

• Problem Addressed: The patent addresses poor sealing reliability and inefficient space usage in soft-pack batteries, where the side seal (flange) structure can be prone to opening during transportation, use, or storage (Compl. ¶35; ’808 Patent, col. 1:19-24).
• The Patented Solution: The invention is a battery with a specific physical geometry for its body and flange portion. The side face of the battery body and a segment of the flange are both designed as "protrusion structures" that protrude away from the battery body ’808 Patent, col. 2:20-23 This design maintains a sufficient gap for adhesive application, thereby enhancing the adhesive force and ensuring a tight seal Compl. ¶35 ’808 Patent, col. 2:25-36
• Technical Importance: This structural design aims to improve the mechanical robustness and sealing integrity of soft-pack batteries, which is important for the safety and longevity of the consumer electronics in which they are used Compl. ¶35

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶60
• The essential elements of Claim 1 include:
  • A battery comprising an electrode body and a package.
  • The package comprises a first part covering a plane of the electrode body and a second part protruding from the first part.
  • The second part comprises a "curved structure" that "curves around a curved side face of the electrode body."
  • The second part is adhered to the curved side face via an adhesive layer.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 12,278,330 - "Lithium-ion battery having desirable safety performance,"

• Technology Synopsis: The patent describes a battery structure intended to solve problems of high internal resistance and peeling of active material caused by placing electrode tabs (leads) at the end of an electrode plate Compl. ¶37 The patented solution involves placing the tabs in recesses formed near the middle of the electrodes and adding insulating glue layers on the opposing electrode to reduce overall thickness, increase safety, and improve energy density (Compl. ¶37; '330 Patent, col. 2:54-64).
• Asserted Claims: At least claim 11 Compl. ¶73
• Accused Features: The complaint accuses the fundamental structure and manufacturing of CosMX's batteries, specifically the placement of electrode tabs and use of insulating layers Compl. ¶73

U.S. Patent No. 12,294,082 - "Negative electrode and electrochemical apparatus containing same, and electronic apparatus,"

• Technology Synopsis: The patent addresses poor cycle performance in lithium-ion batteries resulting from polarization and lithium plating Compl. ¶39 The invention is a negative electrode with an optimized structure, where active material layers are arranged differently on separate portions of the current collector to achieve a more uniform current density distribution, thereby improving safety and cycle performance (Compl. ¶39; '082 Patent, abstract).
• Asserted Claims: At least claim 10 Compl. ¶86
• Accused Features: The infringement allegations target the specific structure of the negative electrode within CosMX's battery products Compl. ¶86

U.S. Patent No. 12,334,494 - "Electrolyte and electrochemical device,"

• Technology Synopsis: The technology aims to improve battery stability under high-voltage conditions while mitigating self-discharging issues Compl. ¶41 The solution combines a specific electrolyte containing a nitrile compound with a negative electrode designed with two distinct regions: one with an active substance layer and one without. This configuration is intended to balance the performance benefits of the nitrile compound against potential safety issues like copper dissolution from the current collector (Compl. ¶41; '494 Patent, abstract).
• Asserted Claims: At least claim 14 Compl. ¶99
• Accused Features: The complaint accuses the composition of the electrolyte and the design of the negative electrode in CosMX's batteries Compl. ¶99

U.S. Patent No. 12,374,686 - "Electrochemical apparatus and electronic apparatus containing the electrochemical apparatus,"

• Technology Synopsis: This patent addresses technical challenges such as high impedance, temperature rise, and cycling expansion, particularly in batteries using silicon-based materials in the negative electrode Compl. ¶43 The invention is a negative electrode where the tab is specifically positioned on a side edge of the long axis of the current collector. This placement is claimed to reduce impedance, control temperature rise, and improve overall cycle performance and safety (Compl. ¶43; '686 Patent, col. 13:5-10).
• Asserted Claims: At least claim 1 Compl. ¶112
• Accused Features: The allegations target the design of the negative electrode in CosMX's batteries, focusing on the placement of the negative tab Compl. ¶112

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are lithium-ion battery products manufactured and sold by CosMX Compl. ¶18 The complaint identifies exemplary products by cell number, including CA476588P-Q1, CA-3072C5P-Q2, and CA285388L-Q3-X2 Compl. ¶¶29-30

Functionality and Market Context

The accused products are rechargeable lithium-ion batteries incorporated into a wide range of consumer electronics, such as the Redmi Note 13 smartphone and the Gigabyte AERO X16 laptop Compl. ¶29 The complaint alleges that CosMX is a "world leader in the lithium ion battery industry" and a major supplier to leading global electronics brands, including Dell, HP, Apple, Lenovo, and Microsoft, indicating the products' significant market presence Compl. ¶¶20, 23 Exhibit 6 provides an example of a consumer electronic device, purchasable in the United States, that allegedly contains an accused CosMX battery Compl. ¶29 Compl. Ex. 6

IV. Analysis of Infringement Allegations

The complaint states that representative claim charts for each asserted patent are attached as Exhibits 13 through 18 Compl. ¶52 Compl. ¶65 Compl. ¶78 Compl. ¶91 Compl. ¶104 Compl. ¶117 However, these exhibits were not provided for this analysis. In their absence, the infringement theory is summarized below based on the narrative allegations in the complaint.

• '769 Patent Infringement Allegations: The complaint alleges that CosMX’s batteries directly infringe at least claim 1 of the ’769 Patent Compl. ¶47 The core of this allegation is that the accused batteries incorporate a cathode with the specific multi-layer structure recited in the claims, including the claimed relationship between the active material layers and the insulating layer, which is designed to enhance safety Compl. ¶33 The factual basis for this allegation would depend on technical analysis of the internal construction of the accused batteries.
• '808 Patent Infringement Allegations: The complaint alleges infringement of at least claim 1 of the ’808 Patent Compl. ¶60 This allegation centers on the physical construction of the accused batteries. It asserts that the shape of the battery package, specifically the side face and flange portion, embodies the "protrusion structures" and "curved structure" claimed in the patent to improve sealing and mechanical integrity Compl. ¶35
• Identified Points of Contention:
  • Technical Questions: A central technical question for all asserted patents will be one of structural and compositional identity. For the patents directed to internal components (e.g., ’769, ’330, ’082, ’494, and ’686 Patents), the dispute will likely depend on evidence from reverse engineering. Key questions will be whether the accused batteries' cathodes, negative electrodes, and electrolytes physically and chemically match the specific structures and compositions required by the claims.
  • Scope Questions: For the ’808 Patent, which claims a specific external shape, a primary point of contention may be one of definitional scope. The case may turn on how the court construes terms like "protrusion structure" and "curved structure". The question will be whether the physical form of the accused batteries' sealing flanges falls within the meaning of these terms as understood in the context of the patent.

V. Key Claim Terms for Construction

• The Term: "a thickness of the insulating layer is greater than a thickness of the first cathode active material layer" ’769 Patent, Claim 1
• Context and Importance: This limitation defines a specific, measurable geometric relationship between two key layers of the claimed cathode. Infringement of claim 1 requires this condition to be met. Practitioners may focus on this term because the dispute could turn on whether the accused products are manufactured with this precise dimensional relationship, or if any observed difference is incidental and falls within manufacturing tolerances rather than being a designed feature.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party advocating for a broader interpretation may argue that the term "greater than" should be given its plain and ordinary mathematical meaning, such that any measurable difference where the insulating layer is thicker than the first active material layer satisfies the limitation.
  • Evidence for a Narrower Interpretation: A party advocating for a narrower interpretation may point to the patent’s specification, which describes an exemplary embodiment with an insulating layer of 15 µm and a first active material layer of 8 µm—a substantial difference ’769 Patent, col. 13:45-48 This could support an argument that the term requires a functionally or structurally significant difference in thickness, not a de minimis one.
• The Term: "curved structure" ’808 Patent, Claim 1
• Context and Importance: The infringement theory for the ’808 Patent relies on the physical shape of the accused battery's external package. The definition of "curved structure" is therefore critical to determining whether the accused products, which have a specific flange design, fall within the scope of the claim.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party may argue that "curved structure" should be interpreted broadly to encompass any shape that is not flat or strictly angular, consistent with its plain meaning. The specification mentions that the structure may comprise an "elliptical arc structure or a circular arc structure," which could be argued as exemplary rather than limiting ’808 Patent, col. 3:15-17
  • Evidence for a Narrower Interpretation: A party may argue that the patent's consistent reference to an "arc-shaped structure" and the depiction in Figure 1, which shows a smooth, continuous curve, limits the term to a specific geometric arc rather than any non-linear shape. This interpretation might exclude, for example, a simple bend or a shape formed by multiple straight-line segments.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that CosMX induces infringement by its customers and distributors Compl. ¶50 Compl. ¶63 The alleged inducing acts include entering into supplier agreements to include the accused batteries in products sold in the U.S., creating distribution channels, manufacturing products to conform with U.S. regulations, and establishing offices in the U.S. to provide technical support Compl. ¶50
• Willful Infringement: The complaint alleges that CosMX’s infringement is willful and deliberate Compl. ¶51 Compl. ¶64 The basis for knowledge is alleged to be "at least since the filing of the Complaint in this matter," which may primarily support a claim for post-suit willfulness Compl. ¶49 Compl. ¶62

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

This case appears to present several complex technical and legal questions for the court. The outcome may depend on the answers to two central inquiries:

• A core issue will be one of structural and compositional evidence: Will detailed physical and chemical analysis of the accused CosMX batteries reveal the specific internal architectures—including the cathode safety gap of the ’769 Patent, the recessed electrode tabs of the ’330 Patent, and the unique electrode and electrolyte configurations of the other patents—as required by the asserted claims?
• A key question of definitional scope will be whether the term "curved structure" in the ’808 Patent, which pertains to the battery’s external package, can be construed to read on the physical form of the accused products' sealing flanges, or if the designs are sufficiently different to be non-infringing.