PTAB

IPR2025-00385

Zhuhai CosMX Battery Co Ltd v. Ningde Amperex Technology Ltd

Key Events

Petition

petition

Title: Electrochemical Device with Specialized Separator
Brief Description: The ’927 patent relates to an electrochemical device, such as a lithium-ion battery, featuring a separator with specific mechanical properties. The separator comprises a porous polymer substrate coated with a porous layer of inorganic particles and a binder, with the purported invention focused on defining an optimal "absolute plastic deformation rate" for the substrate to improve safety against internal short circuits caused by punctures.

Prior Art Relied Upon: Nishikawa (Application # 2015/0180002).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Nishikawa’s Example 1 discloses every element of the claimed electrochemical device, including a lithium-ion battery with a polyethylene porous substrate coated with a porous layer containing a binder and inorganic particles. Petitioner contended that the key limitation—the "absolute plastic deformation rate"—is inherently disclosed. Although Nishikawa does not use this specific terminology, it provides empirical data for elongation at break, tensile strength, and Young's modulus. Petitioner asserted that a person of ordinary skill in the art (POSA) could use these standard material properties to calculate the plastic deformation, and that the resulting values for both the machine and transverse directions fall squarely within the ranges recited in claims 1-3.

Prior Art Relied Upon: Nishikawa (Application # 2015/0180002) and Chen (RSC Advances (Mar. 2014)).
Core Argument for this Ground:
- Prior Art Mapping: As an alternative, Petitioner argued that if the Board finds Nishikawa does not inherently disclose the claimed deformation rates, the claims are obvious when combining Nishikawa with Chen. Nishikawa discloses the battery structure and materials, while Chen analyzes the mechanical properties of commercial battery separators, including a "Teijin" separator (Nishikawa's assignee). Chen provides explicit stress-strain curves for the Teijin separator, from which a POSA can directly determine the absolute and relative plastic deformation rates, finding them to be within the claimed ranges.
- Motivation to Combine: A POSA designing a battery with the Nishikawa separator would consult a reference like Chen to understand its detailed mechanical performance characteristics, including its behavior under stress up to failure. Because both references analyze separators from the same manufacturer (Teijin) for the same application, a POSA would combine their teachings to ensure the final product possessed the desired safety and performance characteristics.
- Expectation of Success: A POSA would have a high expectation of success, as the combination merely involves applying the known, tested properties of a Teijin separator (from Chen) to a battery system using a Teijin separator (from Nishikawa).

Prior Art Relied Upon: Chen (RSC Advances (Mar. 2014)) and Zhang (Patent 10,559,802).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Chen discloses uncoated "Celgard" brand porous substrates and provides stress-strain data showing they meet the claimed plastic deformation rate limitations. Chen, however, does not teach applying a porous layer to these specific separators. Zhang, which is assigned to Celgard, remedies this deficiency by teaching the application of a ceramic porous layer (containing inorganic particles and a binder) to a microporous substrate, specifically identifying Celgard brand membranes as a preferred substrate.
- Motivation to Combine: A POSA starting with the Celgard substrate from Chen would be motivated to add a porous coating to improve safety and performance, a standard practice in the art. Zhang provides an express motivation, teaching that applying its specific porous layer to a Celgard separator improves battery safety and cycle life.
- Expectation of Success: A POSA would expect success because Zhang explicitly directs applying its coating technology to the exact type of Celgard substrate analyzed in Chen. The combination represents the straightforward application of a known improvement (a coating) to a known base material to achieve a predictable result.

Petitioner argued that the terms "absolute plastic deformation rate" and "relative plastic deformation rate" should not be limited to the specific measurement protocol recited in the claims. Instead, they should be construed as denoting the underlying, well-known physical properties of a material (i.e., total plastic strain and relative plastic strain). This construction is central to the argument that prior art disclosing these properties through different but mathematically convertible metrics (e.g., elongation, tensile strength, and Young's modulus) anticipates or renders the claims obvious.

Petitioner argued that discretionary denial would be inappropriate. Under §325(d), the asserted prior art and arguments are substantially different from those considered during prosecution. Regarding Fintiv factors under §314(a), Petitioner contended that the parallel district court litigation was filed recently, minimal resources have been expended, and the trial date is uncertain. Crucially, Petitioner stipulated that if the IPR is instituted, it will not pursue the same invalidity grounds or any grounds that it reasonably could have raised in the petition in the district court action.

Petitioner requests institution of an inter partes review and cancellation of claims 1-10 of Patent 10,964,927 as unpatentable.