Guangdong MIC Power New Energy Co Ltd v. VARTA Microbattery GmbH

1. Case Identification

• Case #: IPR2021-01206
• Patent #: 10,971,776
• Filed: June 30, 2021
• Petitioner(s): Guangdong Mic-Power New Energy Co. Ltd., PEAG LLC d/b/a JLab Audio, Audio Partnership LLC, Audio Partnership PLC d/b/a Cambridge Audio, GN Audio A/S and GN Audio USA Inc. d/b/a Jabra
• Patent Owner(s): VARTA Microbattery GmbH
• Challenged Claims: 1-30

2. Patent Overview

• Title: Method for Producing a Button Cell
• Brief Description: The ’776 patent discloses a method for manufacturing a button cell battery that contains a cylindrical, spiral-wound electrode assembly within a two-part metal housing (cup and top). The claimed method centers on the placement and connection of a conductor tab, which is laid flat between an end of the electrode winding and an interior plane of the housing, and then welded to that interior surface after the housing is assembled.

3. Grounds for Unpatentability

Ground 1: Claims 1-30 are obvious over Kannou in view of Martin

• Prior Art Relied Upon: Kannou (Japanese Patent Publication No. 2003-31266) and Martin (Patent 8,632,907).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kannou taught all basic elements of the claimed method, including a button cell with a spiral-wound electrode assembly, a two-part housing, and conductor tabs welded to the electrodes. However, Kannou described the tabs as being "in contact" with the housing. Martin was asserted to supply the missing limitation of welding the conductor tabs to the interior housing surface after assembling the cell top and cup, a key feature relied upon for patentability during prosecution. Martin explicitly discloses this assembly and welding sequence.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the teachings to improve the electrical connectivity and stability of Kannou’s button cell. Martin's welding method provides a more robust and reliable connection than the simple "contact" disclosed in Kannou, which was a well-understood goal in battery manufacturing.
  • Expectation of Success: A POSITA would have a high expectation of success, as the combination involved applying a known technique (welding for improved electrical connection) from Martin to a known device (Kannou’s button cell) to achieve the predictable result of a more reliable battery.

Ground 2: Claims 1-30 are obvious over Kannou in view of Martin and Myerberg

• Prior Art Relied Upon: Kannou, Martin, and Myerberg (Application # 2007/0117011).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground augmented the Kannou and Martin combination with teachings from Myerberg. Petitioner asserted Myerberg explicitly taught bending conductor tabs to lie flat between the electrode assembly and the housing to create a "very volumetrically efficient cell design." This directly addressed the claim 1 limitation that "a strip-shaped first portion of the first conductor lies flat between" the electrode winding and the housing. Additionally, Myerberg disclosed using insulation discs with slots for the tabs, which Petitioner argued rendered obvious the dependent claims requiring insulators (e.g., claims 11 and 24).
  • Motivation to Combine: A POSITA would be motivated to incorporate Myerberg’s teachings into the Kannou/Martin cell for two primary reasons. First, bending the tabs flat as taught by Myerberg would increase the cell's energy capacity by minimizing wasted internal volume, a constant objective in battery design. Second, adding Myerberg's insulators would predictably reduce the risk of internal short circuits between the tabs and the electrode assembly, a known failure mode.
  • Expectation of Success: Success would be highly expected, as implementing flat-lying tabs and adding insulators were common, routine optimizations in battery design used to enhance performance and safety.

• Additional Grounds: Petitioner asserted that claims 15-16 are obvious over Kannou, Martin, and Kubota (Patent 5,654,114), which taught using adhesive tapes to fix conductors and provide insulation. Petitioner also asserted claim 25 is obvious over Kannou, Martin, and Lampe-Onnerud (Patent 7,811,708), which disclosed specific conductor foil thicknesses within the claimed range.

4. Key Claim Construction Positions

• Petitioner argued that the method steps of claim 1[a]-[g] should not be construed to require a specific order of performance. Although step 1[h] (welding) must occur "after inserting the cell top into the cell cup," the preceding steps are not explicitly ordered. Petitioner contended that even if an order were required, the prior art combinations would still render the claims obvious.

5. Arguments Regarding Discretionary Denial

• §314(a) (Fintiv Factors): Petitioner argued that discretionary denial under Fintiv was unwarranted. It was noted that a parallel district court case in Delaware had already been stayed, and motions to stay were pending in the other parallel Texas cases. Petitioner contended that the Texas cases were in their infancy, with minimal investment from the parties or the court, and that claim construction had not yet occurred.
• §325(d) (Same or Substantially Same Art): Petitioner argued that denial under §325(d) would be improper. Although the primary references, Kannou and Martin, were cited in Information Disclosure Statements (IDSs) during prosecution, they were part of large IDSs (199 and 82 references, respectively) and were not substantively examined or used in any rejection. Crucially, the specific combinations of Kannou and Martin with the secondary references (Myerberg, Kubota, Lampe-Onnerud) were never presented to or considered by the USPTO. Petitioner asserted this constituted a material error by the examiner, justifying institution.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-30 of the ’776 patent as unpatentable.