DCT
5:22-cv-04510
Zhuhai CosMX Battery Co Ltd v. Ningde Amperex Technology Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Zhuhai CosMX Battery Company, Limited (P.R. China)
- Defendant: Ningde Amperex Technology Limited (P.R. China)
- Plaintiff’s Counsel: Norton Rose Fulbright US LLP
- Case Identification: 5:22-cv-04510, N.D. Cal., 08/04/2022
- Venue Allegations: Plaintiff asserts that venue is proper because Defendant is not a U.S. resident and may be sued in any judicial district, and alternatively, because a substantial part of the events giving rise to the action occurred in the Northern District of California.
- Core Dispute: Plaintiff seeks a declaratory judgment that its lithium-ion battery products do not infringe two of the Defendant's patents related to battery electrolytes and separators.
- Technical Context: The dispute is in the field of lithium-ion battery technology, focusing on chemical compositions and structural components designed to enhance battery performance and longevity, particularly for consumer electronics like smartphones and laptops.
- Key Procedural History: The complaint notes a history of communications, alleging that Defendant (ATL) sent three separate letters to Plaintiff (CosMX) between June 2021 and August 2022 asserting infringement of various patents. The final letter, dated August 2, 2022, identified the two patents-in-suit. This action was filed two days later. The complaint also mentions that Defendant sued Plaintiff in the Eastern District of Texas on June 24, 2022, over different patents.
Case Timeline
| Date | Event |
|---|---|
| 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 |
| 2021-06-01 | ATL sends first letter to CosMX alleging infringement of '987 Patent |
| 2022-06-21 | ATL sends second letter to CosMX alleging infringement |
| 2022-06-24 | ATL sues CosMX in E.D. Tex. on different patents |
| 2022-08-02 | ATL sends third letter to CosMX alleging infringement of patents-in-suit |
| 2022-08-04 | Complaint for Declaratory Judgment Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,833,363 - "Electrolyte and Electrochemical Device"
The Invention Explained
- Problem Addressed: The patent describes that in high-voltage electrochemical devices (e.g., batteries operating above 4.4V), the positive electrode material becomes less stable, causing the electrolyte to decompose on the electrode's surface, which in turn leads to a decrease in battery capacity (Compl., Ex. 1, '363 Patent, col. 1:24-33).
- The Patented Solution: The invention proposes an improved electrolyte containing a specific mixture of a dinitrile compound, a trinitrile compound, and propyl propionate. This combination is said to form a "firm protective film" on the cathode that is resistant to decomposition at high potentials, thereby inhibiting the unwanted side reactions and preserving battery performance ('363 Patent, col. 1:47-54).
- Technical Importance: This technology aims to improve the cycle life and storage stability of high-voltage lithium-ion batteries, a critical factor in the industry's push for higher energy density in consumer electronics and electric vehicles ('363 Patent, col. 1:12-23).
Key Claims at a Glance
- The complaint challenges "all claims" of the '363 Patent and specifically references a limitation from the independent claims (Compl. ¶28). Independent claim 1 is representative.
- Independent Claim 1 requires:
- An electrolyte comprising a dinitrile compound, a trinitrile compound, and propyl propionate.
- The weight percentage of the dinitrile compound (X) and the trinitrile compound (Y) must satisfy two conditions:
- Their sum (X+Y) is between about 2 wt % and about 11 wt % of the total electrolyte weight.
- Their ratio (X/Y) is between about 0.1 and about 8.
- The complaint seeks a declaratory judgment of non-infringement for any claim of the patent (Compl. ¶31).
U.S. Patent No. 10,964,987 - "Separator and Energy Storage Device"
The Invention Explained
- Problem Addressed: During the charge-discharge cycles of a lithium-ion battery, a physical gap can form between the electrode and the separator component. This gap increases internal resistance and reduces the battery's cycle capacity and overall service life ('987 Patent, col. 1:23-30).
- The Patented Solution: The invention is a separator comprising a standard "porous substrate" but with an additional "porous layer" arranged on its surface. This layer, made of inorganic particles and a binder, is engineered with a specific ratio between the particle size (Dv90) and the layer's thickness. This design reportedly improves adhesion to the electrode, maintains the pore structure under pressure, and enhances the battery's overall performance and safety ('987 Patent, col. 1:38-55, col. 2:59-62).
- Technical Importance: This innovation addresses a mechanical failure mode in batteries, aiming to improve reliability and performance by ensuring a stable physical interface between the separator and the electrode throughout the battery's life ('987 Patent, col. 1:30-35).
Key Claims at a Glance
- The complaint challenges "every claim" of the '987 Patent by arguing a core limitation is not met (Compl. ¶36). Independent claim 1 is representative.
- Independent Claim 1 requires:
- A separator comprising a porous substrate.
- A porous layer arranged on a surface of the porous substrate.
- The porous layer comprises inorganic particles and a binder.
- A ratio of the inorganic particles' size (Dv90) to the porous layer's thickness is in a range from 0.3 to 3.0.
- The complaint seeks a declaratory judgment of non-infringement for any claim of the patent (Compl. ¶39).
III. The Accused Instrumentality
Product Identification
- The complaint identifies the accused instrumentalities as "CosMX lithium ion battery products," including but not limited to those used in laptops, smartphones, and tablets, collectively referred to as the "CosMX Products" (Compl. ¶4).
Functionality and Market Context
- The complaint, being for declaratory judgment of non-infringement, describes the absence of claimed features in its products. It alleges that for the '363 Patent, the combined weight percentage of the dinitrile and trinitrile compounds in the CosMX Products is "less than 2 wt %" (Compl. ¶28). For the '987 Patent, it alleges the CosMX Products "do not include a porous layer" on the separator's substrate (Compl. ¶36).
- Plaintiff positions itself as a "world leader in the lithium ion battery industry" and a "top supplier" to the world's leading electronics companies, suggesting the commercial significance of the accused products (Compl. ¶19).
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
’363 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality (as denied by Plaintiff) | Complaint Citation | Patent Citation |
|---|---|---|---|
| an electrolyte, comprising a dinitrile compound, a trinitrile compound, and propyl propionate | The complaint does not contest the presence of these components, focusing instead on their relative quantities. | ¶28 | col. 6:1-3 |
| where X and Y meet conditions represented by Formula (1) and Formula (2): about 2 wt %≤(X+Y)≤about 11 wt % | The combined weight percentage of the dinitrile and trinitrile compounds in the CosMX Products is alleged to be less than 2 wt %. | ¶28 | col. 6:6-8 |
’987 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality (as denied by Plaintiff) | Complaint Citation | Patent Citation |
|---|---|---|---|
| a porous substrate | The complaint does not contest the presence of a substrate. | ¶36 | col. 11:26-27 |
| a porous layer arranged on a surface of the porous substrate | The CosMX Products are alleged to not include this feature. | ¶36 | col. 11:27-29 |
| wherein the porous layer comprises inorganic particles and a binder... | The complaint's denial of a "porous layer" implies the absence of this composite structure as claimed. | ¶36 | col. 11:29-30 |
- Identified Points of Contention:
- ’363 Patent: The dispute appears to be primarily an evidentiary one. The central question is factual: what is the precise combined weight percentage of the specified nitrile compounds in the CosMX Products? The term "about 2 wt %" may also become a focus of claim construction, as its interpretation could determine whether a composition measured at slightly below 2.0 wt % infringes.
- ’987 Patent: The dispute raises a core question of claim scope and technical characterization. The case will likely turn on how the term "a porous layer arranged on a surface of the porous substrate" is construed. The key issue is whether any component or feature of the separator in the CosMX Products meets that definition, which will require both legal interpretation and factual analysis of the product's structure.
V. Key Claim Terms for Construction
’363 Patent:
- The Term: "about 2 wt %"
- Context and Importance: Plaintiff’s non-infringement argument rests on its products having a concentration of "less than 2 wt %" (Compl. ¶28). The scope of "about" is therefore dispositive. If construed broadly, it could capture products with concentrations slightly below 2.0 wt %, undermining Plaintiff's position.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification explicitly states the term "about" is used to "describe and depict minor variations" and may refer to a range of "±10% of the stated value" or less, suggesting the inventors intended some flexibility beyond the precise number ('363 Patent, col. 4:6-13).
- Evidence for a Narrower Interpretation: The patent provides numerous working examples in tables with specific, non-approximated weight percentages (e.g., '363 Patent, Table 1-1). A party could argue that the meaning of "about" should be constrained by the precision of these disclosed embodiments.
’987 Patent:
- The Term: "a porous layer arranged on a surface of the porous substrate"
- Context and Importance: This term describes the core structural element that Plaintiff alleges is absent from its products (Compl. ¶36). The entire non-infringement case for this patent depends on whether the accused separators are found to lack a feature meeting the legal construction of this phrase.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself is structurally broad, requiring only a "layer" with "inorganic particles and a binder" on the substrate's "surface" ('987 Patent, col. 11:26-30). An argument could be made that any distinct coating with these components qualifies.
- Evidence for a Narrower Interpretation: The specification describes a detailed method for creating this layer using a non-solvent induced phase separation process, involving coating solutions and coagulating solutions ('987 Patent, col. 2:18-29, col. 5:67-col. 6:60). A party could argue that a true "porous layer" as contemplated by the inventors is one formed by this specific process and having the resulting structure, rather than any generic coating.
VI. Other Allegations
- Indirect Infringement: The complaint seeks a declaratory judgment that it has not induced or contributed to infringement by its customers (Compl. ¶¶2, 32, 40). It makes the factual assertion that it "has never had any intent to cause its customers or anyone else to infringe" the asserted patents, directly addressing the knowledge and intent elements required for such claims (Compl. ¶¶29, 37).
- Willful Infringement: As this is a declaratory judgment action brought by the accused infringer, there is no allegation of willfulness against it in the complaint. However, the complaint affirmatively pleads that Plaintiff received multiple letters from Defendant identifying the patents-in-suit prior to filing, establishing pre-suit knowledge (Compl. ¶¶20, 23). This pleaded fact would likely form the basis of a willfulness counterclaim by the Defendant.
VII. Analyst’s Conclusion: Key Questions for the Case
A central issue for the '363 Patent will be one of evidentiary proof and definitional nuance: Does a quantitative analysis of the CosMX Products show a combined nitrile compound concentration falling within the claimed range, and how much deviation from "2 wt %" will the court permit under the claim term "about"?
The core dispute for the '987 Patent will be one of claim construction and technical comparison: Can the phrase "a porous layer arranged on a surface of the porous substrate," when interpreted in light of the specification's detailed manufacturing process, be construed to read on the structure of the separators used in the CosMX Products?