DCT
1:19-cv-01419
CF Traverse LLC v. Amprius Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: CF Traverse LLC (Delaware)
- Defendant: Amprius, Inc. (Delaware)
- Plaintiff’s Counsel: Robins Kaplan LLP
- Case Identification: 1:19-cv-01419, D. Del., 07/30/2019
- Venue Allegations: Venue is asserted on the basis that Defendant is a Delaware corporation and is therefore deemed to reside in the District of Delaware.
- Core Dispute: Plaintiff alleges that Defendant’s lithium-ion batteries and related components infringe six patents concerning high-capacity electrodes that utilize silicon-based anode structures.
- Technical Context: The technology addresses the challenge of increasing the energy density of lithium-ion batteries by using silicon, which has a much higher storage capacity than traditional graphite but is prone to mechanical failure from expansion and contraction during battery cycling.
- Key Procedural History: The complaint alleges that Defendant has had actual knowledge of the asserted patents since at least July 20, 2018, as a result of a notice letter sent by Plaintiff, forming the basis for the willfulness allegations.
Case Timeline
| Date | Event |
|---|---|
| During 2007 | Inventor reportedly began developing the asserted silicon anode technology. |
| 2008-02-25 | Earliest Patent Priority Date ('258, '683, '310, '181, '998, '017 Patents). |
| 2013-04-16 | U.S. Patent No. 8,420,258 Issues. |
| 2014-02-18 | U.S. Patent No. 8,652,683 Issues. |
| 2014-02-25 | U.S. Patent No. 8,658,310 Issues. |
| 2016-08-09 | U.S. Patent No. 9,412,998 Issues. |
| 2016-08-30 | U.S. Patent No. 9,431,181 Issues. |
| 2018-05-22 | U.S. Patent No. 9,979,017 Issues. |
| 2018-07-20 | Defendant allegedly receives notice letter from Plaintiff. |
| 2019-07-30 | Complaint Filed. |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,420,258 - "High Capacity Electrodes", issued April 16, 2013
The Invention Explained
- Problem Addressed: Traditional graphite anodes in lithium-ion batteries have limited energy density (Compl. ¶13). While silicon can store roughly ten times more lithium ions, it expands dramatically (e.g., 400%) during charging, causing the material to fracture and detach from the electrode substrate, which severely limits battery lifespan (’258 Patent, col. 1:40-47).
- The Patented Solution: The invention proposes an electrode structure comprising a plurality of conductive "support filaments" (e.g., carbon nano-tubes or nano-wires) grown on a substrate (’258 Patent, col. 2:9-13). These filaments are then coated with a high-capacity "ion absorbing material," such as silicon (’258 Patent, col. 3:41-43). A key aspect of the solution is an uncoated "trunk" region of the filament near the substrate, which acts as a flexible joint, allowing the silicon-coated portion to expand and contract without detaching from the electrode base (’258 Patent, col. 6:1-10; Fig. 2A).
- Technical Importance: This filament-and-trunk architecture is designed to harness the high energy capacity of silicon while managing the destructive mechanical stresses caused by its volumetric changes, a central challenge in developing next-generation batteries (Compl. ¶¶15-16).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (Compl. ¶22).
- Claim 1 of the ’258 Patent recites a system with the following essential elements:
- A first electrode including a substrate and a plurality of electron conductive support filaments attached to it.
- An ion absorbing material attached to the support filaments, configured to expand in volume at least 5 percent up to 400 percent when absorbing ions.
- A separator to separate the first and second regions of electrolyte.
- A second electrode, with the full assembly configured to operate as a rechargeable battery.
U.S. Patent No. 8,652,683 - "High Capacity Electrodes", issued February 18, 2014
The Invention Explained
- Problem Addressed: As with its parent, the ’258 Patent, this patent addresses the mechanical degradation and reduced longevity of silicon anodes caused by the material's significant volume expansion during ion intercalation (’683 Patent, col. 1:40-47).
- The Patented Solution: The invention is structurally similar to that of the ’258 Patent, describing an electrode built from support filaments on a substrate that are coated with an ion-absorbing material like silicon (’683 Patent, Abstract). The solution again relies on the filamentary structure, optionally with an uncoated trunk region, to provide mechanical flexibility during volume changes (’683 Patent, col. 6:1-10; Fig. 2A). The independent claim asserted from this patent requires the ion absorbing material to be "conformal."
- Technical Importance: The invention provides another potential solution to manage the mechanical stress inherent in using high-capacity silicon anodes, aiming to improve the cycle life and commercial viability of such batteries (Compl. ¶¶15-16).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (Compl. ¶30).
- Claim 1 of the ’683 Patent recites a system with the following essential elements:
- A first electrode including a substrate and a plurality of support filaments attached to it.
- A conformal ion absorbing material attached to the support filaments, configured to expand in volume at least 5 percent when absorbing ions.
- A separator to separate the first and second regions of electrolyte.
- A second electrode, with the full assembly configured to operate as a rechargeable battery.
U.S. Patent No. 8,658,310 - "High Capacity Electrodes", issued February 25, 2014
- Technology Synopsis: This patent, part of the same family, also addresses the problem of silicon anode degradation from volume expansion by using a structure of support filaments on a substrate (Compl. ¶¶15-16). The asserted claim distinguishes this invention by requiring a "non-particulate" ion absorbing material attached to the support filaments, suggesting a focus on the physical form of the deposited silicon layer ('310 Patent, Claim 1).
- Asserted Claims: At least independent claim 1 (Compl. ¶38).
- Accused Features: The complaint alleges that Amprius' lithium-ion batteries, including the SiNW-1400 model, infringe by incorporating an electrode system with a substrate, support filaments, and a non-particulate ion absorbing material configured for volumetric expansion (Compl. ¶¶37-38).
U.S. Patent No. 9,431,181 - "Energy Storage Devices Including Silicon and Graphite", issued August 30, 2016
- Technology Synopsis: This patent also relates to managing silicon expansion in battery anodes. The asserted claim describes an electrode with an ion absorbing material (silicon) attached to a substrate, an "over-layer including graphite" that covers the silicon, and "support filaments in contact with the ion absorbing material," where the ion absorbing material covers less than 25% of the support filaments ('181 Patent, Claim 1). This configuration suggests a specific structural approach using a protective graphite layer and a defined ratio of coated-to-uncoated filament area to maintain structural integrity and conductivity.
- Asserted Claims: At least independent claim 1 (Compl. ¶46).
- Accused Features: The complaint accuses batteries used in "Thl 5000 mobile phones" of infringing by allegedly incorporating this structure, including a silicon ion absorbing material, a graphite over-layer, and support filaments where less than 25% of the filament is covered (Compl. ¶¶45-46).
U.S. Patent No. 9,979,017 - "Energy Storage Devices", issued May 22, 2018
- Technology Synopsis: This patent addresses silicon anode degradation by focusing on a protective coating. The asserted claim recites an electrode with an ion absorbing material attached to a substrate and an "over-layer including carbon" that coats the material ('017 Patent, Claim 17). The invention appears centered on the use of a carbon over-layer to enhance the performance or stability of the underlying active material.
- Asserted Claims: At least independent claim 17 (Compl. ¶54).
- Accused Features: The "Thl 5000 batteries" are accused of infringing by including an ion absorbing material attached to a substrate and a carbon over-layer that coats the material (Compl. ¶¶53-54).
U.S. Patent No. 9,412,998 - "Energy Storage Devices", issued August 9, 2016
- Technology Synopsis: This patent also addresses silicon anode degradation through specific structural limitations. Asserted claim 36 describes an electrode with a substrate, a plurality of support filaments, and an ion absorbing material including silicon, where the material covers "less than 25% of the supporting filaments" ('998 Patent, Claim 36). Similar to the '181 patent, this invention focuses on maintaining a significant uncoated portion of the filaments to accommodate expansion.
- Asserted Claims: At least independent claim 36 (Compl. ¶62).
- Accused Features: The complaint accuses the "Thl 5000 batteries" of infringing by incorporating an electrode with support filaments and a silicon-based ion absorbing material that covers less than 25% of those filaments (Compl. ¶¶61-62).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are Amprius’ lithium-ion batteries and anodes, including specific product lines such as SiNW-1400, SiNW-1600, SiNW-1800, SiNW-2000, various ANW models, the "Amprius Very Long Endurance Battery," "Amprius CWB and SiNW/NCM622," and batteries used in "Thl 5000 mobile phones" (Compl. ¶¶21, 29, 37, 45, 53, 61).
Functionality and Market Context
- The complaint alleges these products are rechargeable lithium-ion batteries that incorporate silicon in their anodes to achieve high energy density (Compl. ¶¶2-3, 16). The infringement allegations describe the functionality of the accused products in terms of their core battery components: a first electrode (anode) with a substrate, conductive filaments, and an expanding ion-absorbing material; a second electrode (cathode); and a separator (Compl. ¶¶22, 30, 38). The complaint positions this technology as a "significant advancement" necessary for "smaller electronic devices [that] require more energy in less space" (Compl. ¶¶14, 17).
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
'258 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a first electrode disposed in a first region of electrolyte and including a substrate, a plurality of electron conductive support filaments attached to the substrate, | The SiNW-1400 battery includes a first electrode with a substrate and a plurality of electron conductive support filaments attached to the substrate. | ¶22 | col. 2:8-11 |
| and an ion absorbing material attached to the support filaments and configured to expand in volume at least 5 percent up to 400 percent when absorbing ions; | The SiNW-1400 has an ion absorbing material attached to the support filaments that is configured to expand in volume at least 5 percent up to 400 percent when absorbing ions. | ¶22 | col. 2:11-13 |
| a separator configured to separate the first region and a second region of electrolyte; and a second electrode disposed in the second region of electrolyte, the first and second electrodes and separator configured to operate as a rechargeable battery. | The SiNW-1400 battery includes a separator, a second electrode, and is configured to operate as a rechargeable battery. | ¶22 | col. 2:13-17 |
'683 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a first electrode disposed in a first region of electrolyte and including a substrate, a plurality of support filaments attached to the substrate, | The SiNW-1400 battery includes a first electrode with a substrate and a plurality of support filaments attached to the substrate. | ¶30 | col. 12:5-8 |
| and a conformal ion absorbing material attached to the support filaments and configured to expand in volume at least 5 percent when absorbing ions; | The SiNW-1400 battery has a conformal ion absorbing material attached to the support filaments that is configured to expand in volume at least 5 percent when absorbing ions. | ¶30 | col. 12:8-11 |
| a separator configured to separate the first region and a second region of electrolyte, and a second electrode disposed in the second region of the electrolyte, with the first and second electrodes and separator configured to operate as a rechargeable battery. | The SiNW-1400 battery includes a separator and a second electrode, with the components configured to operate as a rechargeable battery. | ¶30 | col. 12:12-17 |
- Identified Points of Contention: The complaint's infringement allegations are conclusory, tracking the claim language nearly verbatim for each element without providing specific technical facts about the accused products' structure or operation.
- Technical Questions: The primary question will be evidentiary. What technical proof does the complaint provide that the accused "SiNW" (presumably Silicon NanoWire) products are constructed as claimed? For instance, what evidence demonstrates they are comprised of distinct "support filaments" with a separate "ion absorbing material attached," rather than being monolithic silicon structures? The complaint does not present any reverse engineering, microscopy, or compositional data.
- Scope Questions: For the ’683 Patent, the analysis will question whether the accused product's ion absorbing material is "conformal." As the patent does not explicitly define this term, its construction will be critical. The complaint does not allege any facts that would support a finding that the material is conformal beyond simply stating that it is.
V. Key Claim Terms for Construction
The Term: "support filaments" (’258 Patent, Claim 1; ’683 Patent, Claim 1)
- Context and Importance: This term is foundational to the claimed structure. The dispute may turn on whether Defendant's silicon nanowire anodes constitute "support filaments" with an ion absorbing material "attached to" them, or if they are unitary structures that fall outside this definition. Practitioners may focus on this term because it distinguishes the invention from a simple silicon layer or a monolithic silicon nanostructure.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification discloses that the support filament material may include "a carbon nano-tube (CNT), a carbon nano-fiber (CNF), a nano-wire NW... metal, semiconductor, insulator, silicon, and/or the like" (’258 Patent, col. 3:24-28). This broad list, which includes silicon itself, may support an argument that the term is not limited to a multi-component, coated structure.
- Evidence for a Narrower Interpretation: The figures and detailed description consistently depict a distinct core filament (230) with a separate "intercalation layer" (240) coated on its surface (’258 Patent, Fig. 2A; col. 4:9-11). This may support an argument that the claim requires a two-component structure (a core support and a separate coating), not a single, monolithic element.
The Term: "conformal" (’683 Patent, Claim 1)
- Context and Importance: This term is a key limitation in the asserted claim of the ’683 Patent and is absent from the corresponding claim of the ’258 Patent. Its definition will be critical for determining infringement of the ’683 Patent and differentiating its scope. Practitioners may focus on this term because it is a potential point of non-infringement if the accused products lack this specific property.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent specification does not provide an explicit definition for "conformal." A party may argue for its plain and ordinary meaning, suggesting the ion absorbing material generally follows or conforms to the shape of the underlying support filaments.
- Evidence for a Narrower Interpretation: In the context of materials deposition, "conformal" can imply a high degree of uniformity in thickness and continuous coverage over a surface. A party could argue that without an express definition to the contrary, this more stringent technical meaning should apply, raising the evidentiary bar for proving infringement.
VI. Other Allegations
- Willful Infringement: The complaint alleges willful infringement for all six asserted patents. The basis for this allegation is Defendant's purported actual knowledge of the patents since at least July 20, 2018, when Plaintiff allegedly sent Defendant a letter identifying the patents and Defendant's related product development. The complaint alleges that infringement continued despite an "objectively high likelihood" that Defendant's activities constituted infringement (Compl. ¶¶23, 31, 39, 47, 55, 63).
VII. Analyst’s Conclusion: Key Questions for the Case
The dispute as framed by the complaint raises two central questions for the court:
- A primary issue will be one of structural equivalence: Can Plaintiff produce technical evidence to demonstrate that the nanostructures within Amprius's commercial battery anodes are, in fact, constructed as "support filaments" with a distinct "ion absorbing material attached," as claimed, rather than being a different, un-claimed structure such as monolithic silicon nanowires?
- A key question of claim construction will be the definitional scope of terms that differentiate the various patents. For example, what technical standard must be met for an ion-absorbing layer to be considered "conformal" under the ’683 patent or "non-particulate" under the ’310 patent, and what evidence shows the accused products meet these specific limitations?