PTAB

IPR2017-02116

Samsung SDI Co., Ltd. v. UBE Industries, Ltd.

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1. Case Identification

2. Patent Overview

  • Title: Lithium Secondary Battery and Electrolyte Thereof
  • Brief Description: The ’001 patent is directed to a non-aqueous electrolyte solution for a lithium secondary battery and the battery itself. The invention aims to improve battery performance by using an electrolyte containing a specific combination of two organic compound additives (vinylene carbonate and a second compound like a sultone) dissolved in a solvent of cyclic and chain carbonates, where the additives have similar reduction potentials.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 and 9-10 are obvious over Simon-161 in view of Mori and Simon-93.

  • Prior Art Relied Upon: Simon-161 (FR Publication No. 2719161), Mori (Japanese Patent JP11121032A), and Simon-93 (B. Simon et al., J. Power Sources, 43-44 (1993) 65-74).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Simon-161 discloses all elements of the challenged claims except for the use of two specific organic additives within the claimed concentration range. Simon-161 teaches a lithium-ion battery with a graphite anode and an electrolyte containing cyclic and linear carbonates. It further discloses using single additives, including vinylene carbonate (VC) in one embodiment and sultones (like propane sultone) in another. Mori was cited to teach the benefits of using two additives (VC and ethylene sulfite) simultaneously to improve battery efficiency. Simon-93, which shares authors with Simon-161, was cited to provide specific data showing that propane sultone at 1.1% by weight improves self-discharge, making it a logical choice for the second additive.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would be motivated to combine these references because they all address the same problem of performance loss due to graphite anode exfoliation in lithium-ion batteries. Petitioner asserted that Mori's teaching of improved performance from using two additives would motivate a POSITA to modify the electrolyte in Simon-161. The positive results for propane sultone in Simon-93 would guide a POSITA to select it from the options in Simon-161 and combine it with VC.
    • Expectation of Success: Petitioner contended that because the references presented a finite number of predictable solutions—namely, combining known additives to solve a known problem—a POSITA would have had a reasonable expectation of success. The combination of VC and propane sultone at concentrations taught by the prior art was presented as a logical starting point for routine optimization.

Ground 2: Claims 1-3 and 9-10 are obvious over Simon-161 in view of Simon-93.

  • Prior Art Relied Upon: Simon-161 (FR Publication No. 2719161) and Simon-93 (B. Simon et al., J. Power Sources, 43-44 (1993) 65-74).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground asserted that Simon-161 alone suggests the claimed combination. Simon-161 discloses VC as an additive in a first embodiment and sultones (including propane sultone) as additives in an adjacent, second embodiment. Petitioner argued this structure makes their combination obvious. Simon-93 was then used to supply the rationale for selecting propane sultone specifically from the list of options in Simon-161's second embodiment, as Simon-93 demonstrates its effectiveness in improving self-discharge at a specific concentration (1.1% by weight). The claimed additive concentrations (0.1-4% by weight) were argued to be obvious either by falling within the broader range disclosed in Simon-161 (0.01-10% for VC) or by being close to the specific examples in the art.
    • Motivation to Combine: The primary motivation was that combining adjacent, similar embodiments from a single reference (Simon-161) is a predictable variation for a POSITA. The fact that Simon-93 was written by the same authors as Simon-161 and addressed the identical technical problem would further motivate a POSITA to look to its teachings to optimize the selection and concentration of additives for the Simon-161 system.
    • Expectation of Success: Petitioner argued that a POSITA would have a high expectation of success because the approach involves combining known elements from a single reference, guided by specific, positive performance data for one of those elements from a related publication (Simon-93). This presented a limited number of options for a skilled artisan to pursue.

4. Key Claim Construction Positions

  • "Graphite" (claim 9): Petitioner proposed this term should be construed as "natural or artificial graphite." This construction was argued to be consistent with the broadest reasonable interpretation standard and supported by the patent's specification, which explicitly lists "artificial graphite and natural graphite" as examples of carbonaceous materials for the anode. This construction is important for mapping the teachings of the prior art, such as Simon-161, which also explicitly teaches using natural or artificial graphite.

5. Key Technical Contentions (Beyond Claim Construction)

  • Priority Date Entitlement: Petitioner dedicated significant argument to contending that the ’001 patent is not entitled to its claimed priority date from Japanese application JP’222 (May 24, 1999). The argument was that the JP’222 application fails to provide adequate written description support for the "reduction potential" limitation required by all challenged claims (i.e., that the two additives have reduction potentials within 0.4V of each other). By invalidating this priority claim, Petitioner argued the effective priority date is no earlier than April 18, 2000, which renders references like Mori (published April 30, 1999) available as prior art under 35 U.S.C. §102(b).

6. Relief Requested

  • Petitioner requested the Patent Trial and Appeal Board institute an inter partes review and cancel claims 1-3 and 9-10 of the ’001 patent as unpatentable.