Zhuhai CosMX Battery Co Ltd v. Ningde Amperex Technology Ltd

1. Case Identification

• Case #: IPR2025-00524
• Patent #: 12,015,118
• Filed: April 2, 2025
• Petitioner(s): Zhuhai CosMX Battery Co., Ltd.
• Patent Owner(s): Ningde Amperex Technology Ltd
• Challenged Claims: 1-20

2. Patent Overview

• Title: Lithium-Ion Battery Electrodes
• Brief Description: The ’118 patent discloses an electrode for a lithium-ion battery, a battery containing the electrode, and an electronic device containing the battery. The core invention is an electrode with a two-layer structure on a current collector, where the layers have specified active material particle sizes and compaction densities to improve battery performance.

3. Grounds for Unpatentability

Ground 1: Anticipation by Ishigaki - Claims 1-20 are anticipated by Ishigaki under 35 U.S.C. §102.

• Prior Art Relied Upon: Ishigaki (Japanese Publication No. 2013-211096A).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Ishigaki expressly or inherently disclosed every limitation of claims 1-20. Ishigaki teaches a positive electrode for a lithium-ion battery with two sequentially laminated active material layers on a current collector foil. Petitioner asserted that Ishigaki discloses a 90% cumulative diameter (D90) for its particles of 10 µm or less, which satisfies the claim limitation of less than 40 µm. Crucially, Petitioner argued Ishigaki teaches a compaction density range of 2.0 to 4.2 g/cm³, which overlaps the claimed range of greater than 3.2 g/cc, and expressly discloses preferred embodiments with densities of 3.4 g/cc, 3.5 g/cc, and 3.6 g/cc, thereby anticipating the limitation. The materials disclosed in Ishigaki, such as lithium nickel cobalt manganese oxide, were also argued to anticipate the Markush groups in dependent claims.

Ground 2: Obviousness over Ishigaki and Kim - Claims 1-20 are obvious over Ishigaki in view of Kim under 35 U.S.C. §103.

• Prior Art Relied Upon: Ishigaki (Japanese Publication No. 2013-211096A) and Kim (Application # 2013/0302685).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that if Ishigaki’s broad disclosure of compaction densities is not found to anticipate, the combination with Kim renders the claims obvious. Ishigaki provides the complete two-layer electrode structure, while Kim provides an explicit teaching for the claimed density range. Kim teaches a cathode layer density of 3.31 g/cc or greater, explaining that densities below this value "may be too small to obtain a high electrical capacity." This teaching provides the specific density and rationale that Petitioner argued was, at worst, only implicit in Ishigaki.
  • Motivation to Combine: A POSITA seeking to optimize the high-capacity, two-layer electrode of Ishigaki would combine its teachings with Kim. Kim’s explicit instruction on the criticality of a compaction density greater than 3.31 g/cc to achieve high capacity—a universal goal in the art and a stated objective of Ishigaki—would have motivated a POSITA to apply Kim’s specific density values to Ishigaki’s compatible electrode structure.
  • Expectation of Success: A POSITA would have a high expectation of success, as combining the teachings involved applying a specific, beneficial operating parameter (density) from Kim to the structurally complete and compatible battery electrode taught by Ishigaki to achieve a predictable improvement in performance.

Ground 3: Obviousness over Wang and Saka - Claims 1-20 are obvious over Wang in view of Saka under §103.

• Prior Art Relied Upon: Wang (Application # 2011/0168550) and Saka (Application # 2017/0256776).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Wang discloses all structural and material limitations of the claims—including a two-layer cathode with different particle sizes—but does not provide specific numeric values for compaction density. Wang teaches a process of compressing the layers to achieve a "desired net density." Saka, which discloses a similar two-layer cathode, provides the missing specific density values. Petitioner presented calculations based on Saka’s examples showing numerous embodiments with first-layer densities greater than 2.8 g/cc and second-layer densities approaching or exceeding 3.3 g/cc, thereby teaching the claimed density limitations.
  • Motivation to Combine: A POSITA implementing Wang's method would be motivated to look to analogous art like Saka for guidance on what constitutes a "desired net density." Since Saka provides extensive data on achievable densities and their performance characteristics in a similar two-layer structure, a POSITA would consult Saka to supply the specific numerical targets for Wang's compression process.
  • Expectation of Success: The combination had a high expectation of success because it involved using Saka's well-documented density data to optimize the known manufacturing process described by Wang.

• Additional Grounds: Petitioner asserted an additional obviousness challenge based on Wang in view of Li (Chinese Publication No. 202905885), where Li was used to provide specific compaction density values (e.g., 3.8 g/cm³ and 4.1 g/cm³) for the electrode structure taught by Wang.

4. Key Claim Construction Positions

• "average particle size": Petitioner argued this term, used in claims 3, 4, 12, and 13, should be construed to mean Dv50 (the median particle size by volume). This construction was based on the specification of the ’118 patent and its consistency with standard metrics in the art. This interpretation was central to Petitioner's analysis comparing the claimed particle size ratios to the "median diameter" values disclosed in prior art like Ishigaki.

5. Key Technical Contentions (Beyond Claim Construction)

• Primary vs. Secondary Particles: Petitioner argued that a POSITA would understand that active materials like those in the patent and prior art form primary (nano-scale) particles that aggregate into secondary (micro-scale) particles. Petitioner contended that laser diffraction measurement, as used in the art, primarily detects the size of these secondary particles. This technical point was used to argue that the particle sizes disclosed in the prior art correspond directly to the claimed particle sizes, even when different terminology (e.g., "median diameter" vs. "average particle size") is used.

6. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under §325(d), asserting that the prior art references presented in the petition (Ishigaki, Kim, Wang, Saka, Li) are substantially different from the art considered during prosecution and that the examiner misapprehended the teachings of the cited art.
• Petitioner also argued against discretionary denial under §314(a) and the Fintiv factors, stating that the petition was filed shortly after the one-year statutory bar, the parallel district court litigation is in a very early stage with minimal investment of resources, and the petition raises compelling challenges to patentability. Petitioner further stipulated that, if review is instituted, it would not pursue the same grounds or any grounds that could have been reasonably raised in the IPR in the co-pending litigation.

7. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-20 of Patent 12,015,118 as unpatentable.