PTAB

IPR2018-00611

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

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1. Case Identification

2. Patent Overview

  • Title: Non-Aqueous Electrolytic Solution and Lithium Battery
  • Brief Description: The ’033 Patent relates to non-aqueous electrolytic solutions for use in lithium batteries to improve battery properties. The invention is directed to an electrolyte comprising a specific combination of a cyclic carbonate, the dinitrile compound adiponitrile, and an S=O group-containing compound, each within specific concentration ranges.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 and 5-16 are obvious over Akeishi in view of Kubota.

  • Prior Art Relied Upon: Akeishi (Japanese Patent Application No. JP2002-270230A), Kubota (Japanese Patent Application No. JP1995-176322).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Akeishi disclosed a lithium battery electrolyte that met most limitations of independent claim 1. Specifically, Akeishi’s examples taught an electrolyte with 34.7 vol.% cyclic carbonates, 1.47M LiPF6, and 0.8 wt.% ethylene sulfite (an S=O group-containing compound), all falling within or rendering obvious the claimed concentration ranges. Petitioner asserted that Akeishi lacked a specific teaching for the claimed concentration of adiponitrile. Kubota was argued to supply this missing element by teaching the addition of dinitriles, including adiponitrile, in a range of 0.001M to 0.1M, which converts to a weight percentage (e.g., 0.09%) that overlaps the claimed range of 0.01% to 3%.
    • Motivation to Combine: A POSITA would combine Akeishi and Kubota because both references addressed the same problem of electrolyte instability in lithium-ion batteries and disclosed electrolytes with similar base components. The combination was motivated by a desire to incorporate the known benefits of Kubota's dinitrile (improving oxidation resistance) into Akeishi's sulfite-containing electrolyte (improving SEI film formation) to achieve a more stable overall system.
    • Expectation of Success: The fundamental similarity of the base electrolytes, solvents, and salts in both references would have provided a POSITA with a reasonable expectation of success in combining the additives.

Ground 2: Claim 4 is obvious over Akeishi in view of Kubota and further in view of Hamamoto.

  • Prior Art Relied Upon: Akeishi (Japanese Patent Application No. JP2002-270230A), Kubota (Japanese Patent Application No. JP1995-176322), and Hamamoto (Patent 6,033,809).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination of Akeishi and Kubota to argue that claim 1 was obvious. Hamamoto was then added to teach the specific S=O compound recited in dependent claim 4: 1,3-propanesultone. Hamamoto was asserted to explicitly teach using 1,3-propanesultone as a preferred additive in a range of 0.1-4.0 wt.%, which overlaps the claimed range of 0.2% to 3%.
    • Motivation to Combine: A POSITA would be motivated to incorporate Hamamoto's teachings into the Akeishi/Kubota formulation to gain additional, complementary stability benefits. Hamamoto taught that sultones suppress the exfoliation of carbonaceous material at the anode, addressing another known degradation pathway and providing a further reason to include it in a comprehensive electrolyte formulation.
    • Expectation of Success: A POSITA would have reasonably expected that adding a known stabilizing agent like 1,3-propanesultone to another stabilized electrolyte would predictably enhance overall battery performance without undue experimentation.

Ground 3: Claims 1-16 are obvious over Hamamoto in view of Kubota.

  • Prior Art Relied Upon: Hamamoto (Patent 6,033,809), Kubota (Japanese Patent Application No. JP1995-176322).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner presented an alternative obviousness combination where Hamamoto provided the base electrolyte and Kubota again supplied the missing adiponitrile limitation. Hamamoto was argued to teach an electrolyte with a cyclic carbonate (e.g., ~29-47 vol.%), a LiPF6 salt (1M), and an S=O compound (1,3-propanesultone at 1-3 wt.%), all of which met or rendered obvious the limitations of claim 1. Hamamoto, however, was silent regarding adiponitrile. Kubota was relied upon to teach the addition of adiponitrile at a concentration falling within the claimed range.
    • Motivation to Combine: Both Hamamoto and Kubota were directed to improving electrolyte stability in similar battery systems. A POSITA would combine Hamamoto’s sultone-based electrolyte with Kubota’s dinitrile additive to achieve complementary protective effects—suppressing both anode degradation (from Hamamoto’s sultone) and oxidative degradation (from Kubota's dinitrile)—thereby improving overall battery cycle life.
    • Expectation of Success: Given that both references operated in the same technical field and aimed to solve the same problem with known types of additives, a POSITA would have had a reasonable expectation of success when combining them.

4. Key Claim Construction Positions

  • "solvent" (claim 1): Petitioner proposed this term be construed as "the portion of the solution in which solute is dissolved." This construction was argued to be consistent with the specification's description of a non-aqueous electrolyte solution as a "solution of electrolyte in a carbonate solvent."
  • "graphite" (claims 5, 8, 11, and 14): Petitioner proposed this term be construed as "natural or artificial graphite." This was based on explicit language in the ’033 patent specification that provides examples of carbonaceous materials, including "graphites (e.g., artificial graphite and natural graphite)."

5. Key Technical Contentions (Beyond Claim Construction)

  • A central contention was that the ’033 patent was not entitled to its earliest claimed priority date from Japanese application JP-560. Petitioner argued that the JP-560 application failed to provide adequate written description support for the key limitation of an S=O group-containing compound. This argument, if successful, would establish a later effective priority date for the ’033 patent, thereby allowing Akeishi (published September 20, 2002) to qualify as prior art under pre-AIA §102.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-16 of Patent 9,742,033 as unpatentable under 35 U.S.C. §103.