DCT

2:26-cv-00491

Sila NanoTech Inc v. Carbon One New Energy Group Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Name: Sila Nanotechnologies, Inc. et al. v. Carbon ONE New Energy Group Co., Ltd. et al.
  • Case Identification: 2:26-cv-00491, E.D. Tex., 06/18/2026
  • Venue Allegations: Venue is alleged as proper under 28 U.S.C. § 1391(c)(3) because all Defendants are foreign entities and may be sued in any judicial district.
  • Core Dispute: Plaintiffs allege that Defendants' silicon-carbon anode materials, used in lithium-ion batteries, infringe four U.S. patents related to composite particle structures and manufacturing methods designed to improve battery performance.
  • Technical Context: The technology concerns advanced anode materials for lithium-ion batteries, aiming to replace traditional graphite with higher-capacity silicon-based composites, a key area of development for electric vehicles and consumer electronics.
  • Key Procedural History: The complaint notes that two of the asserted patents, the '528 and '825 Patents, have survived ex parte reexamination proceedings, with reexamination certificates issuing in 2025 and 2024, respectively, confirming the patentability of the reexamined claims. The complaint also alleges pre-suit notice of infringement was provided to Defendants on April 5, 2026, during licensing discussions.

Case Timeline

Date Event
2009-09-29 Priority Date for '528 and '825 Patents
2012-08-24 Priority Date for '215 and '624 Patents
2021-01-01 Sila begins commercial shipping of its Titan Silicon® products
2022-06-28 '215 Patent Issued
2022-11-29 '528 Patent Issued
2023-08-01 '825 Patent Issued
2023-10-13 '528 Patent Ex Parte Reexamination Requested
2023-10-16 '825 Patent Ex Parte Reexamination Requested
2024-03-26 '624 Patent Issued
2024-04-01 Defendants admit exporting 'Silicon Carbon Materials' to U.S. (period beginning)
2024-09-17 '825 Patent Reexamination Certificate Issued
2025-01-07 '528 Patent Reexamination Certificate Issued
2025-02-01 Carbon One begins importation of accused products to Panasonic (period beginning)
2026-04-05 Plaintiffs allege providing pre-suit notice of infringement to Defendants
2026-06-18 Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,515,528 - "Electrodes, lithium-ion batteries, and methods of making and using same"

The Invention Explained

  • Problem Addressed: High-capacity anode materials like silicon undergo significant volume expansion and contraction during battery charging and discharging, which can cause irreversible mechanical damage, loss of electrical contact, and degradation of the battery's performance and lifespan '528 Patent, col. 2:1-10
  • The Patented Solution: The invention proposes a composite particle structure for anodes. In this design, active silicon nanoparticles are disposed within a porous, three-dimensional, electrically-conductive "dendritic particle" matrix, typically made of carbon '528 Patent, abstract This scaffold-like matrix provides structural support, maintains electrical connectivity, and contains internal pore space to accommodate the silicon's volume changes, thereby enhancing the battery's stability and cycle life '528 Patent, col. 5:41-52 '528 Patent, Fig. 1(a)
  • Technical Importance: This approach allows for the use of high-capacity silicon in anodes by mitigating its primary failure mechanism, enabling the development of batteries with higher energy density and longer life.

Key Claims at a Glance

  • The complaint asserts at least Claim 1 of the '528 Patent Compl. ¶58
  • The essential elements of independent Claim 1 are:
    • A composite particle, comprising:
    • an electrically-conductive matrix having a three-dimensional structure comprising pores; and
    • a plurality of silicon nanoparticles at least partially disposed within the electrically-conductive matrix,
    • wherein: a content of silicon in the composite particle is in a range of 15 wt. % to 90 wt. %;
    • the pores comprise pores with widths in a range of 1 nm to 100 nm; and
    • the pores define a pore volume that is different from a volume that is occupied by the plurality of silicon nanoparticles.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 11,715,825 - "Electrodes, lithium-ion batteries, and methods of making and using same"

The Invention Explained

  • Problem Addressed: The patent addresses the same fundamental problem as the '528 Patent: managing the detrimental effects of silicon's volume expansion in battery anodes to unlock its high energy capacity '825 Patent, col. 2:1-10
  • The Patented Solution: The patent claims a specific method for manufacturing the silicon-carbon composite particles. The claimed method involves producing a composite silicon-carbon (Si-C) particle by depositing one or more silicon nanoparticles from a gaseous material containing silicon and hydrogen (e.g., silane gas) onto a carbon-comprising particle '825 Patent, col. 25:10-16 This process is designed to create the scaffold structure described in the related patents.
  • Technical Importance: This patent protects a specific manufacturing process for creating the novel anode material, adding a layer of intellectual property protection beyond the product composition itself.

Key Claims at a Glance

  • The complaint asserts at least Claims 1 and 19 of the '825 Patent Compl. ¶68
  • The essential elements of independent method Claim 1 are:
    • A method of manufacture, comprising:
    • producing a composite Si-C particle comprising one or more internal Si nanoparticles,
    • wherein the one or more internal Si nanoparticles are deposited from a gaseous material comprising Si and H, and
    • wherein the one or more internal Si nanoparticles comprise 15 wt. % to 90 wt. % of the composite Si-C particle.
  • Dependent Claim 19 is a product-by-process claim for "The composite Si-C particle produced in accordance with the method of claim 1." '825 Patent, col. 27:1-2

U.S. Patent No. 11,374,215 - "Scaffolding matrix with internal nanoparticles"

  • Patent Identification: U.S. Patent No. 11,374,215, "Scaffolding matrix with internal nanoparticles", issued June 28, 2022 Compl. ¶43
  • Technology Synopsis: The patent describes a battery electrode composition comprising composite particles. The particles consist of an active material (like silicon) and a "porous scaffolding matrix comprising a monolithic particle" within which the active material is disposed '215 Patent, abstract '215 Patent, col. 26:51-58 This structure is intended to solve the problem of active material degradation from volume changes by providing structural support, electrical connection, and space for expansion '215 Patent, col. 1:59-col. 2:2
  • Asserted Claims: Claims 1 and 14 Compl. ¶76
  • Accused Features: The CI-SC(1800) and CI-SC(2000) anode materials are alleged to be compositions that infringe, as they are alleged to be composite particles containing silicon within a porous scaffolding matrix Compl. ¶¶1, 76

U.S. Patent No. 11,942,624 - "Scaffolding matrix with internal nanoparticles"

  • Patent Identification: U.S. Patent No. 11,942,624, "Scaffolding matrix with internal nanoparticles", issued March 26, 2024 Compl. ¶49
  • Technology Synopsis: As a continuation of the same family as the '215 Patent, this patent also describes a battery electrode composition with composite particles that include an active material and a porous, electrically-conductive scaffolding matrix '624 Patent, abstract The matrix is designed to structurally support the active material, maintain electrical interconnection, and accommodate volume changes during battery operation '624 Patent, col. 1:59-col. 2:2
  • Asserted Claims: Claims 1 and 25 Compl. ¶85
  • Accused Features: The CI-SC(1800) and CI-SC(2000) silicon-carbon anode products are alleged to be compositions that embody the claimed composite particle structure Compl. ¶¶1, 85

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are Defendants' Carbon One CI-SC(1800) and CI-SC(2000) silicon-carbon anode products, and all reasonably similar products Compl. ¶1

Functionality and Market Context

The complaint alleges the Accused Products are silicon-carbon anode materials used to manufacture lithium-ion batteries Compl. ¶1 It is alleged that Defendants market these products as part of a "fully vertically integrated industry chain" and have a production capacity of 1,000 tons per year for silicon-carbon anode products Compl. ¶18 Compl. ¶25 An image from Defendants' materials shows a facility labeled "Zhejiang Lichen 1,000 tons/year Silicon-carbon Anode," which the complaint identifies as the location where the Accused Products are produced Compl. p. 8 Compl. ¶25 Plaintiffs allege that Defendants export these materials to the United States for customers, including Panasonic, to use in high-capacity batteries Compl. ¶20 Compl. ¶21 The complaint includes a map from Defendant's website illustrating its "Global Production Network" Compl. p. 6

IV. Analysis of Infringement Allegations

The complaint references, but does not include, exemplary claim charts Compl. ¶¶58, 67 The following tables summarize the infringement allegations for the lead patents based on the complaint's narrative and the patent specifications.

'528 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A composite particle, comprising: The Accused Products are silicon-carbon anode materials sold as particles for use in batteries. ¶1 col. 5:1-4
an electrically-conductive matrix having a three-dimensional structure comprising pores; The Accused Products are described as "silicon-carbon" materials, implying a carbon matrix. The complaint alleges they infringe the patent's claims for a porous composite structure. ¶1; ¶55 col. 5:17-23
and a plurality of silicon nanoparticles at least partially disposed within the electrically-conductive matrix, The Accused Products are "silicon-carbon anode" materials, which allegedly contain silicon nanoparticles within a carbon matrix structure. ¶1; ¶23 col. 5:3-7
wherein: a content of silicon in the composite particle is in a range of 15 wt. % to 90 wt. %; The complaint does not specify the exact weight percentage but alleges the Accused Products meet the limitations of Claim 1. ¶58 col. 6:30-33
the pores comprise pores with widths in a range of 1 nm to 100 nm; The complaint alleges infringement of Claim 1, which contains this limitation, but provides no specific data on pore width. ¶58 col. 15:47-49
and the pores define a pore volume that is different from a volume that is occupied by the plurality of silicon nanoparticles. The complaint alleges infringement of Claim 1, which contains this functional limitation, but does not provide specific data on pore volume. ¶58 col. 7:42-49

'825 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of manufacture, comprising: producing a composite Si-C particle comprising one or more internal Si nanoparticles, The complaint alleges that Defendant Zhejiang Lichen New Material Technology Co., Ltd. manufactures the Accused Products, which are composite Si-C particles. ¶22; ¶25 col. 25:10-12
wherein the one or more internal Si nanoparticles are deposited from a gaseous material comprising Si and H, The complaint alleges that Defendants manufacture the products "according to the method recited in claim 1," but does not specify the exact manufacturing steps used. ¶68 col. 10:3-14
and wherein the one or more internal Si nanoparticles comprise 15 wt. % to 90 wt. % of the composite Si-C particle. The complaint does not specify the weight percentage but alleges the manufacturing method infringes Claim 1. ¶68 col. 6:30-33
  • Identified Points of Contention:
    • Structural Questions: A primary question will be whether the accused CI-SC(1800) and CI-SC(2000) products actually possess the specific structural and compositional limitations of the asserted claims, such as the three-dimensional porous matrix, the silicon content, the pore widths, and the overall pore volume as required by Claim 1 of the '528 Patent. Evidence from materials analysis of the accused products will be central.
    • Methodology Questions: For the '825 Patent, a key point of contention will be whether Plaintiffs can prove that Defendants' manufacturing process practices the claimed method, specifically the deposition of silicon from a gaseous material. Since this process occurs in China, obtaining direct evidence may present discovery challenges.
    • Product-by-Process Scope: For Claim 19 of the '825 Patent, a legal and factual question will be whether the Accused Products are in fact "produced in accordance with the method of claim 1." This will require not only analyzing the final product's structure but also linking it to the specific patented manufacturing process.

V. Key Claim Terms for Construction

  • The Term: "electrically-conductive matrix having a three-dimensional structure" '528 Patent, Claim 1
  • Context and Importance: This term defines the core scaffold of the invention. The scope of "matrix" and "three-dimensional structure" will be critical to determining if the defendants' carbon component infringes. Practitioners may focus on this term because its construction will determine whether a wide range of porous carbon structures are covered, or only the specific "dendritic" structures emphasized in the specification.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language itself is broad, not specifying the material (beyond "electrically-conductive") or the exact geometry of the structure. This may support an interpretation covering any porous, conductive material that forms a 3D framework.
    • Evidence for a Narrower Interpretation: The abstract repeatedly uses the term "dendritic particle" to describe the structure '528 Patent, abstract The detailed description explains that the matrix is formed from a "dendritic particle 104, which itself is a three-dimensional, randomly-ordered assembly or agglomerate of nanoparticles" '528 Patent, col. 5:61-64 A defendant may argue that the claims, when read in light of the specification, should be limited to such dendritic structures.
  • The Term: "monolithic particle" '215 Patent, Claim 1
  • Context and Importance: This term, found in the related '215 Patent, defines the nature of the scaffolding matrix. Its definition is crucial because it distinguishes the claimed invention from composites made of agglomerated, non-monolithic particles. The dispute may turn on whether the accused product's carbon component qualifies as "monolithic."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term itself could be argued to simply mean "formed of a single piece," which could cover various particle types. The patent states the matrix comprises "a monolithic particle within which the Si-comprising active material is at least partially disposed" ('215 Patent, col. 26:56-58).
    • Evidence for a Narrower Interpretation: The specification provides a specific method for creating the monolithic particle: "carbonizing a polymer monolith to form a carbon monolith; [and] forming at least one monolithic particle from the carbon monolith" '215 Patent, col. 21:35-39 This suggests that the term implies not just being a single piece, but being derived from a larger, single block ("monolith"), which could support a narrower construction.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating that Defendants "aid, instruct, support, market, and otherwise act with specific intent" to cause U.S. end users and customers like Panasonic to use the Accused Products in an infringing manner Compl. ¶57 Compl. ¶66 The allegations also cover designing and manufacturing the products with the specific intent that they be imported and used in infringing batteries in the U.S. Compl. ¶57 Compl. ¶66
  • Willful Infringement: Willfulness is alleged based on both pre-suit and post-filing knowledge. The complaint alleges Defendants had knowledge of the patents "at least since April 5, 2026," the date of alleged licensing discussions, and no later than the filing of the complaint Compl. ¶56 It further alleges that Defendants "regularly monitor patents... by their competitors" as a basis for what they "knew or should have known" Compl. ¶35

VII. Analyst's Conclusion: Key Questions for the Case

  1. A central issue will be one of claim construction and scope: can the specific structural limitations in the patents, such as "dendritic particle" ('528 Patent) and "monolithic particle" ('215 Patent), be defined broadly enough to encompass the architecture of Defendants' accused silicon-carbon anode materials, or will they be narrowed to the specific embodiments described in the patents' specifications?

  2. A key evidentiary question will be one of reverse engineering and process proof: what evidence can Plaintiffs gather to demonstrate that Defendants' accused products, manufactured in China, not only possess the claimed final compositions and structures but were also made using the specific manufacturing steps recited in method Claim 1 of the '825 Patent?

  3. A third question will concern patent validity in light of prosecution history: how will the successful ex parte reexaminations of the '528 and '825 patents influence potential invalidity challenges? While not precluding a new validity analysis, the fact that the claims were confirmed by the USPTO in a post-grant proceeding may be presented by Plaintiffs as strong evidence of their robustness.