Zhuhai CosMX Battery Co Ltd v. Ningde Amperex Technology Ltd

1. Case Identification

• Case #: IPR2025-00431
• Patent #: 11,799,131
• Filed: January 28, 2025
• Petitioner(s): Zhuhai CosMX Battery Co., Ltd.
• Patent Owner(s): Ningde Amperex Technology Limited
• Challenged Claims: 1-7, 12, and 14-17

2. Patent Overview

• Title: Electrochemical Device with Specific Electrolyte and Electrode Structure
• Brief Description: The ’131 patent discloses electrochemical devices, such as lithium-ion batteries, having an electrolyte containing a specific combination of a dinitrile compound, a trinitrile compound, and propyl propionate within defined weight percentage ratios. The patent also claims an electrode structure comprising a current collector with both single-sided and double-sided coating portions having a specific ratio of compaction densities to improve battery performance and stability.

3. Grounds for Unpatentability

Ground 1: Claims 1, 2, 4-7, 12, and 14-17 are obvious over Zeng in view of Sunose.

• Prior Art Relied Upon: Zeng (China Application # CN 106099187A) and Sunose (Japan Application # 2009-252349).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Zeng’s Embodiments 4 and 6 disclose a high-voltage lithium-ion battery electrolyte containing all the required chemical components of independent claim 1: a dinitrile (adiponitrile and 1,2-bis(2-cyanoethoxy)ethane), a trinitrile (1,3,6-hexanetricarbonitrile), and propyl propionate. Petitioner’s calculations showed that Zeng teaches weight percentage ratios for these components (X+Y, X/Y, and Y/Z) that fall within or render obvious the claimed ranges. Sunose, which addresses electrode manufacturing, was alleged to disclose the claimed electrode structure: a cathode with both single-sided and double-sided coating portions on a current collector, with compaction density ratios (D1/D2) that fall within the claimed range of about 0.8 to 1.2. Dependent claims were allegedly met by specific compounds and densities disclosed in the references.
  • Motivation to Combine: A POSITA reading Zeng, which focuses on electrolyte chemistry but not electrode structure, would combine its teachings with Sunose. Sunose was presented as teaching a solution to improve adhesion and reduce breakage in rolled electrodes by using its specific single- and double-sided coating structure, which a POSITA would integrate with Zeng's high-performance electrolyte to build a more robust and reliable battery.
  • Expectation of Success: Petitioner contended a POSITA would have a reasonable expectation of success because both references relate to improving lithium-ion batteries, operate in the same field of endeavor, and their respective components are compatible.

Ground 2: Claims 1, 2, 4-7, 12, and 14-17 are obvious over Zhou in view of Sunose.

• Prior Art Relied Upon: Zhou (China Application # CN 105552439 A) and Sunose (Japan Application # 2009-252349).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Zhou’s Example 8 discloses an electrolyte with the claimed dinitrile (adiponitrile) and trinitrile (1,3,6-hexanetricarbonitrile) in weight percentages satisfying the claimed X+Y and X/Y ratios. While Example 8 used ethyl acetate (EA) instead of propyl propionate (PP), Zhou was alleged to expressly identify PP as one of a few predictable and suitable substitutes for EA. Petitioner argued that substituting PP for EA would result in an electrolyte that meets all composition limitations, including the Y/Z ratio. As in Ground 1, Sunose was asserted to supply the missing electrode structure limitations.
  • Motivation to Combine: The motivation was twofold. First, a POSITA would substitute one known ester (EA) for another known, performance-enhancing ester (PP) from a finite list of predictable solutions in Zhou to improve kinetic performance. Second, for the same reasons as Ground 1, a POSITA would combine Zhou's improved electrolyte with Sunose's advantageous electrode structure.
  • Expectation of Success: Success was expected due to the predictable nature of substituting one similar ester for another from a short, disclosed list and the general compatibility of the components from analogous arts.

Ground 3: Claims 3 and 16 are obvious over Zeng and Sunose, further in view of Su.

• Prior Art Relied Upon: Zeng (China Application # CN 106099187A), Sunose (Japan Application # 2009-252349), and Su (China Patent # 108023117).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination of Zeng and Sunose from Ground 1, which provides the electrolyte and cathode structure. Claims 3 and 16 require the electrode to be an anode with a specific compaction density range. Petitioner argued that while Zeng and Sunose focus on the electrolyte and cathode, a POSITA would know a complete battery requires an anode. Su was alleged to disclose an anode with the same single- and double-sided coating configuration as Sunose's cathode and a compaction density for the double-sided portion (D2) that falls within the range recited in claims 3 and 16 (1.2 g/cm³ to 1.8 g/cm³).
  • Motivation to Combine: A POSITA building the battery taught by Zeng and Sunose would need an anode configuration. Su was presented as providing an anode structure specifically designed to increase energy density, a recognized industry need also addressed by Zeng and Sunose. The structural similarity between Su's anode and Sunose's cathode would make it a logical and compatible choice for integration.
  • Expectation of Success: Petitioner argued success would be expected as all references address improving performance in wound/rolled lithium-ion batteries and the proposed combination integrates compatible components (electrolyte, cathode, anode) to create a complete, high-performance cell.
• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations including Matsuoka (to explicitly disclose a weight percentage for PP) and Kim (to provide motivation to consider and adjust the trinitrile-to-PP ratio).

4. Arguments Regarding Discretionary Denial

• Petitioner argued that institution is appropriate and discretionary denial under Fintiv is unwarranted. The petition asserted that the primary prior art references, including Zeng, Zhou, and Su, were not substantively evaluated during prosecution, as only English-language abstracts were submitted in an Information Disclosure Statement (IDS). It further argued that other key references like Sunose and Matsuoka were not cited at all, meaning the Examiner did not consider the core combinations presented in the petition and that this new art undercuts the Examiner’s stated reasons for allowance.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-7, 12, and 14-17 of the ’131 patent as unpatentable.