Apple Inc v. RJ Technology LLC

1. Case Identification

• Case #: IPR2024-00597
• Patent #: 7,749,641
• Filed: February 22, 2024
• Petitioner(s): Apple Inc.
• Patent Owner(s): RJ Technology, LLC
• Challenged Claims: 1-18

2. Patent Overview

• Title: Method for Improving a Secondary Lithium Ion Cell or Battery
• Brief Description: The ’641 patent relates to improving the capacity, average operating voltage, and specific energy of rechargeable lithium-ion batteries. The invention is premised on increasing the charge cut-off voltage to greater than the conventional 4.2V while using a specific ratio of positive to negative electrode material (1:1.0 to 1:2.5) to manage the higher voltage.

3. Grounds for Unpatentability

Ground 1: Claims 1-8 are anticipated by or obvious over Uemura

• Prior Art Relied Upon: Uemura (Application # 2002/0012830).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Uemura disclosed every limitation of independent claims 1 and 5. Uemura taught a secondary lithium-ion battery with a charge cut-off voltage of 4.3V, which is greater than the conventional 4.2V recited in the patent. Uemura also expressly taught a preferred "capacity balance ratio" of positive-to-negative electrode material from 1:1 to 1:1.5 to prevent lithium plating and dendrite formation. This disclosed range fell entirely within the claimed range of 1:1.0 to 1:2.5. Petitioner asserted that although the ’641 patent required calculating this ratio with a charge voltage limited to 4.2V, a POSITA would understand that Uemura's ratio (determined at its 4.3V operating voltage) would only shift slightly and remain well within the claimed range when recalculated at 4.2V.
  • Key Aspects: The core of this argument rested on the assertion that Uemura’s teachings directly mapped onto the two key inventive concepts of the ’641 patent: a higher-than-conventional charge voltage and a specific electrode capacity ratio to safely enable it.

Ground 2: Claims 11-18 are obvious over Uemura in view of Guyomard

• Prior Art Relied Upon: Uemura (Application # 2002/0012830) and Guyomard (PCT Publication No. 93/21665).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed dependent claims 11-18, which added limitations requiring the battery to maintain a certain percentage of capacity after 400 cycles (e.g., at least 80.72%). Petitioner contended that Uemura alone suggested these high-cyclability characteristics, as its examples showed batteries retaining 90% capacity after 300-350 cycles. Guyomard taught electrolyte compositions specifically designed to resist decomposition at high voltages (up to 5.0V), which enabled remarkable cycle stability, demonstrating a capacity loss of only about 10% after 500 cycles.
  • Motivation to Combine: A POSITA would combine these references to improve the performance of Uemura's battery. Uemura operated at a high temperature (60°C) and high voltage (4.3V), conditions that Guyomard's electrolytes were explicitly designed to address. Guyomard provided a known solution—optimizing the electrolyte composition—to a known problem (performance degradation at high voltages), motivating its application to Uemura’s similar battery system.
  • Expectation of Success: A POSITA would have had a high expectation of success because both references used similar battery materials (e.g., LiMn2O4 positive electrodes, LiPF6-based electrolytes). Applying Guyomard’s known technique of optimizing electrolyte concentrations for high-temperature, high-voltage operation to Uemura's battery was a predictable and routine modification to achieve enhanced cycle life.

Ground 3: Claims 1-8 are anticipated by or obvious over Abe

• Prior Art Relied Upon: Abe (JPH10189052).

• Core Argument for this Ground:

  • Prior Art Mapping: As an alternative to Uemura, Petitioner argued that Abe independently taught all limitations of claims 1-8. Abe taught using a charge cut-off voltage for LiMn2O4 batteries in a range of 4.2-4.3V, satisfying the "greater than 4.2V" limitation. Abe also explicitly taught adjusting the "design capacity of the negative electrode" to be greater than the positive electrode, disclosing a specific range for this ratio of 1:1 to 1:1.6. This range substantially overlapped with and rendered the claimed range of 1:1.0 to 1:2.5 obvious.
  • Key Aspects: Similar to the Uemura ground, Petitioner argued that Abe’s "design capacity ratio," determined at an operating voltage of 4.3V, would be understood by a POSITA to satisfy the claimed ratio limitation, which is calculated at a slightly lower voltage of 4.2V.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including claims 2-4, 6-8, and 11-18 over Abe in view of Guyomard, and claims 9-10 over combinations of Uemura, Abe, Guyomard, and Iwaizono (Patent 6,577,105), which taught overcharge protection circuits.

4. Key Claim Construction Positions

• "at least 7500 of capacity" (claim 11): Petitioner argued this phrase was an obvious typographical error and should be construed to mean "at least 75% of capacity," consistent with the prosecution history where the claim was renumbered.
• "ratio of...material...calculated by a...capacity" (claims 1 and 5): Petitioner adopted the Patent Owner's litigation positions for claim construction. This included construing "specific capacity" in claim 1 and "theoretic capacity" in claim 5 identically, as a ratio of capacities calculated with a charge cut-off voltage set at 4.2V.

5. Key Technical Contentions (Beyond Claim Construction)

• Electrode Capacity Ratio vs. Voltage: Petitioner's central technical argument was that the ratio of positive-to-negative electrode capacity is inherently dependent on the voltage at which it is measured. A higher charge voltage extracts more lithium from the positive electrode. Therefore, a battery designed to operate at a higher voltage (e.g., 4.3V as in Uemura/Abe) must have more negative electrode capacity to avoid dangerous lithium plating. When this same battery's ratio is recalculated at a lower voltage (4.2V, as required by the claims), less lithium is extracted, resulting in a slightly higher negative-to-positive capacity ratio. This principle was used to argue that ratios disclosed in the prior art at 4.3V would still fall within the patent's claimed range when recalculated at 4.2V.

6. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) was unwarranted because the primary prior art references (Uemura, Abe, Guyomard, Iwaizono) were never considered during the original prosecution of the ’641 patent.
• Petitioner further argued that discretionary denial under Fintiv was inappropriate because the co-pending district court litigation against Apple was stayed on October 4, 2023. Therefore, Fintiv factors 1-4 strongly favored institution, factor 5 was neutral, and factor 6 favored institution due to the petition’s compelling case of invalidity.

7. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-18 of the ’641 patent as unpatentable.