Zhuhai CosMX Battery Co Ltd v. Ningde Amperex Technology Ltd

1. Case Identification

• Case #: IPR2025-00389
• Patent #: 11,923,498
• Filed: January 15, 2025
• Petitioner(s): Zhuhai CosMX Battery Co., Ltd.
• Patent Owner(s): Ningde Amperex Technology Ltd
• Challenged Claims: 1-22

2. Patent Overview

• Title: Lithium-Ion Battery with Insulating Layers for Safety
• Brief Description: The ’498 patent discloses a lithium-ion battery designed to improve safety and energy density. The invention focuses on a specific arrangement of insulating layers to reduce the occurrence of internal short circuits and lithium precipitation, which are common failure modes in such batteries. Key features include recesses in the electrode active material layers for attaching leads and the precise placement of first and second insulating glue layers to protect these connection points.

3. Grounds for Unpatentability

Ground 1: Obviousness over Sato and Takemura - Claims 1-3, 6, 8, 17, and 19 are obvious over Sato in view of Takemura.

• Prior Art Relied Upon: Sato (Application # 2011/0111276) and Takemura (Japanese Patent Pub. No. 2000-67907).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Sato disclosed all fundamental elements of the challenged claims, including a lithium-ion battery with positive and negative electrodes, each having an active material layer, a current collector, and a recess where a lead is attached. Sato also taught applying a first insulating tape over the positive lead and a second insulating tape on the positive active material surface to prevent lithium deposition. However, Sato did not explicitly disclose placing this second tape on the positive active material directly "opposite to the second recess" of the negative electrode. Takemura remedied this by teaching the precise placement of an insulating tape on the positive active material directly across from the negative lead connection and its exposed current collector to prevent short-circuiting caused by lithium plating.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine these references to solve the well-known and critical problem of lithium plating on the exposed negative current collector. A POSITA would have recognized that Takemura's specific placement of the insulating tape was a known and effective solution that could be readily applied to Sato’s similar battery configuration to improve its safety and reliability, especially during rapid charging.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success because the combination involved applying a known technique (Takemura's insulation placement) to a known device (Sato's battery) to achieve the predictable result of inhibiting lithium plating without obstructing the battery's normal function.

Ground 2: Obviousness over Sato, Takemura, and Kobayashi - Claims 9-11, 14, and 16 are obvious over the combination of Sato and Takemura, further in view of Kobayashi.

• Prior Art Relied Upon: Sato (Application # 2011/0111276), Takemura (Japanese Patent Pub. No. 2000-67907), and Kobayashi (Japanese Patent Pub. No. 2010-55906).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground builds on the Sato-Takemura combination from Ground 1 to address the limitations of claim 9, which additionally requires insulating a "third location" on the positive current collector opposite the surface where the positive lead is attached (i.e., insulating both top and bottom surfaces within the recess). While Sato taught insulating the top surface of the positive lead connection, Kobayashi explicitly disclosed applying insulating tapes to both the top and bottom surfaces of the exposed positive current collector and lead tab to prevent short-circuiting caused by manufacturing burrs or localized pressure.
  • Motivation to Combine: A POSITA building the battery taught by the Sato-Takemura combination would be motivated to incorporate Kobayashi's teaching of dual-sided insulation. Protecting exposed conductive surfaces from inadvertent contact and short-circuiting is a fundamental design goal in battery manufacturing. Kobayashi directly addressed this problem at the exact location recited in the claims—the exposed current collector in the recess.
  • Expectation of Success: Applying an additional piece of insulating tape to the bottom surface of an exposed conductor is a simple mechanical step with a predictable outcome of enhanced short-circuit protection.

Ground 3: Obviousness over Takemura, Oh-539, and Kobayashi - Claims 1-3, 9-11, and 17 are obvious over Takemura in view of Oh-539 and Kobayashi.

• Prior Art Relied Upon: Takemura (Japanese Patent Pub. No. 2000-67907), Oh-539 (Application # 2011/0104539), and Kobayashi (Japanese Patent Pub. No. 2010-55906).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented an alternative combination where Takemura served as the base reference for a conventional wound battery. Takemura showed leads attached at the ends of the electrodes. Oh-539 taught an improved design with centrally-located recesses for lead attachment, which reduces internal resistance and improves high-rate discharge capability. Kobayashi provided the teaching for insulating both the top and bottom of the lead connection within the recess.
  • Motivation to Combine: A POSITA would be motivated to modify Takemura's end-lead design with Oh-539's centrally-located recesses to gain well-known performance advantages. After making this modification, the POSITA would then incorporate Kobayashi's dual-sided insulation for the same reasons as in Ground 2: to prevent short-circuiting in the newly created central recess, a known area of risk. This combination represented the optimization of a conventional design using known, advantageous techniques.
  • Expectation of Success: The combination involved repositioning leads and applying insulation, both of which were common practices in battery design using known techniques. A POSITA would fully expect the combined design to function as intended with improved discharge rates and safety.
• Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds adding Nakamura for specific recess dimensions (Grounds 2 and 5), and grounds adding Oh-144 for insulating the winding ends of the electrode coil (Grounds 3, 6, and 8).

4. Arguments Regarding Discretionary Denial

• §325(d) Factors: Petitioner argued that denial under §325(d) would be improper because the primary prior art references, Sato and Takemura, were never presented to or considered by the USPTO during prosecution. The new art and arguments were argued to be substantially different from what the Examiner previously reviewed, addressing perceived deficiencies in the prior art of record.
• Fintiv Factors: Petitioner contended that the Fintiv factors strongly favor institution. The petition was filed before the deadline to answer the complaint in the parallel district court litigation, meaning party and judicial resources have been minimally invested. Furthermore, Petitioner stipulated that if the IPR is instituted, it will not pursue the same grounds or any grounds that could have been reasonably raised in the IPR in the district court action, mitigating concerns of duplicative efforts.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-22 of the ’498 patent as unpatentable under 35 U.S.C. §103.