DCT
1:23-cv-01194
Duesenfeld GmbH v. Ascend Elements Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Duesenfeld GmbH (Germany)
- Defendant: Ascend Elements, Inc. (Delaware)
- Plaintiff’s Counsel: Shaw Keller LLP
- Case Identification: 1:23-cv-01194, D. Del., 01/09/2025
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Ascend Elements, Inc. is a Delaware corporation and therefore resides in the district.
- Core Dispute: Plaintiff alleges that Defendant’s process for recycling lithium-ion batteries, specifically at its Covington, Georgia facility, infringes two patents related to a method of safely recovering materials by grinding batteries and then drying the resulting material under vacuum conditions.
- Technical Context: The technology addresses the safe and efficient recycling of electric vehicle batteries to recover critical metals, a process of increasing importance due to environmental concerns and supply chain vulnerabilities associated with mining virgin materials.
- Key Procedural History: The complaint alleges that the parties engaged in collaboration discussions, during which a representative of Ascend Elements visited Duesenfeld’s plant in Germany and Duesenfeld presented its patented technology to Ascend. The complaint notes that Ascend ultimately declined to collaborate or take a license.
Case Timeline
| Date | Event |
|---|---|
| 2015-04-28 | Earliest Priority Date for U.S. Patent No. 11,050,097 |
| 2016-10-20 | Earliest Priority Date for U.S. Patent No. 12,119,463 |
| 2021-06-29 | U.S. Patent No. 11050097 Issued |
| 2022-08 | Ascend Elements begins partial operations at Covington, GA plant |
| 2022-11-25 | Duesenfeld presents its recycling technology to Ascend |
| 2023-03 | Ascend Elements' Covington, GA plant becomes fully operational |
| 2024-10-15 | U.S. Patent No. 12119463 Issued |
| 2025-01-09 | First Amended Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 11,050,097 - "Method for the Treatment of Used Batteries, in Particular Rechargeable Batteries, and Battery Processing Installation"
The Invention Explained
- Problem Addressed: The patent’s background section describes the dangers of recycling lithium-ion batteries, which contain a reactive liquid electrolyte (Compl. ¶¶17-18). Grinding, or "comminuting," these batteries can lead to unpredictable reactions, explosions, and the creation of toxic hydrogen fluoride gas (’097 Patent, col. 3:12-17; Compl. ¶20). Prior art methods, such as using deactivation powders after grinding, were allegedly insufficient and could contaminate the final product ('097 Patent, col. 1:36-42).
- The Patented Solution: The invention proposes a method where batteries are first comminuted, and the resulting material is then "inactivated" by drying it under a vacuum ('097 Patent, col. 1:57-62). By performing the drying at low pressure (under 300 hPa) and low temperature (less than 80°C), the volatile electrolyte can be removed safely, rendering the remaining material inert and preventing the formation of hazardous hydrogen fluoride ('097 Patent, col. 3:5-17). This process creates a stable, transportable material from which valuable metals can be recovered ('097 Patent, col. 2:5-14). Figure 1 of the patent depicts the process flow, showing comminuted material (24) entering a drying device (26) connected to a vacuum installation (29).
- Technical Importance: This method provided a pathway to recycle lithium-ion batteries at scale more safely by chemically stabilizing the hazardous ground material before transport and further processing, while also preserving the purity of the recovered materials (Compl. ¶¶3, 22).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶¶23, 98).
- Essential elements of claim 1 include:
- (a) comminuting the batteries such that comminuted material is obtained;
- (b) inactivating the comminuted material such that an inactivated comminuted material is obtained, wherein the inactivating step is performed during or after the comminuting step; and
- (c) filling a transport container with the inactivated comminuted material;
- wherein the inactivating step is performed by drying the comminuted material, and
- wherein the drying occurs at a maximum pressure of 300 hPa.
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 12,119,463 - "Recycling Method for Treating Used Batteries, in Particular Rechargeable Batteries, and Battery Processing Installation"
The Invention Explained
- Problem Addressed: Similar to the ’097 Patent, this patent addresses the safe processing of comminuted battery material. The background highlights that prior art methods could form "highly toxic fluoroorganic compounds and hydrogen fluoride" and that recovering the electrolyte for reuse was difficult (’463 Patent, col. 1:43-50).
- The Patented Solution: The ’463 Patent claims a more specific set of drying conditions designed to optimize safety and material recovery. The invention is a method of drying the comminuted material by "vaporizing the organic carbonate at a pressure-temperature above a boiling point of the organic carbonate," while simultaneously controlling the process to remain under a maximum pressure of 300 hPa and a maximum temperature of 80°C ('463 Patent, col. 17:28-36). This specific thermodynamic window is intended to efficiently remove the electrolyte solvent while preventing the decomposition of the fluorine salt, thereby avoiding the creation of toxic byproducts ('463 Patent, col. 4:19-26).
- Technical Importance: The claimed method aims to provide a precise, controllable process window that allows for the recovery of electrolyte components with high purity, making them suitable for reuse, while enhancing the safety of the overall recycling operation (Compl. ¶22).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶¶25, 102).
- Essential elements of claim 1 include:
- receiving used lithium batteries into a comminuting device;
- comminuting the batteries to obtain comminuted material; and
- inactivating the material via a drying process that comprises:
- drying the comminuted material by removal of organic carbonate from the electrolyte by vaporizing it "at a pressure-temperature above a boiling point of the organic carbonate,"
- with the pressure being "not more than 300 hPa," and
- the temperature being "not more than 80° C. and lower than a decomposition temperature of the fluorine salt."
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
Product Identification
- The accused instrumentality is the battery recycling process performed by Ascend Elements at its facility in Covington, Georgia, and allegedly at other facilities (Compl. ¶¶56, 63).
Functionality and Market Context
- The complaint alleges that Ascend's process begins by feeding used batteries into a "wet shredder," which grinds them into small particles (Compl. ¶¶44, 57). A provided screenshot shows the large-scale industrial machinery used for this shredding step (Compl. p. 14). Following shredding, the comminuted material is moved to what the complaint describes as a "big rotating kiln," where Ascend "cooks off the electrolyte" to dry the material and produce a chemically stable "black mass" (Compl. ¶¶45, 58). This kiln is alleged to be a vacuum dryer (Compl. ¶45). The complaint includes a process diagram from URT, the alleged supplier of Ascend's equipment, which depicts a "shredding" step followed by a "vacuum dryer" (Compl. p. 11, ¶34). After drying, the resulting powder is filled into large sacks for transport to customers (Compl. ¶¶46-47).
- The complaint alleges Ascend's Covington plant is a significant industrial facility, supported by importation records showing shipments of approximately 500 tons of battery recycling machinery from German company URT, which allegedly supplies equipment that practices the patented method (Compl. ¶¶49, 53-54).
IV. Analysis of Infringement Allegations
U.S. Patent No. 11,050,097 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) comminuting the batteries such that comminuted material is obtained; | Ascend uses a large "wet shredder" to grind up used batteries. | ¶57 | col. 7:1-5 |
| (b) inactivating the comminuted material such that an inactivated comminuted material is obtained... wherein the inactivating step is performed by drying the comminuted material | Ascend dries the shredded material after comminution in a "big rotating kiln" to "cook[] off the electrolyte," resulting in a chemically stable black mass. | ¶58 | col. 1:57-62 |
| wherein the drying occurs at a maximum pressure of 300 hPa. | Ascend's process, allegedly adopted from URT, employs "vacuum distillation dryers," and "vacuum" pressure is generally understood to be at or below 300 hPa. | ¶59 | col. 10:45-59 |
| (c) filling a transport container with the inactivated comminuted material; | Ascend fills the dried material, a "valuable dark powder," into one-ton sacks for transport to customers. A photograph of these sacks is included in the complaint. | ¶62; p. 16 | col. 7:55-59 |
Identified Points of Contention
- Scope Questions: A central question may be whether Ascend's "big rotating kiln" (Compl. ¶45) operates as the type of drying device contemplated by the patent.
- Technical Questions: The complaint alleges on "information and belief" that the drying occurs at a pressure of 300 hPa or less, based on the general understanding of the term "vacuum" and the use of equipment from URT (Compl. ¶59). A key point of contention will be what evidence exists to prove that Ascend's process actually operates at or below this specific claimed pressure threshold.
U.S. Patent No. 12,119,463 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| receiving, into a comminuting device, used lithium batteries that include a... electrolyte comprising a fluorine salt and a solvent, the solvent including an organic carbonate; | Ascend advertises that it recycles lithium-ion batteries, which contain the claimed components, such as lithium hexafluorophosphate (a fluorine salt) and organic carbonates. | ¶¶65-67 | col. 1:43-50 |
| comminuting the used lithium batteries, by the comminuting device, and obtaining comminuted material as a result; | Ascend uses a "wet shredder" that produces comminuted material from the batteries it processes. | ¶68 | col. 13:1-5 |
| inactivating the comminuted material and obtaining inactivated comminuted material as a result, wherein the inactivating includes a drying process, | Ascend's process includes drying in a kiln to remove organic carbonate solvents from the comminuted material. | ¶¶69-70 | col. 3:9-12 |
| comprising drying... by vaporizing the organic carbonate at a pressure-temperature above a boiling point of the organic carbonate, | On information and belief, the organic carbonate solvents evaporate because the conditions in the dryer are above the boiling point of the organic carbonate. | ¶86 | col. 17:31-33 |
| the pressure being not more than 300 hPa, | Ascend's process employs "vacuum distillation dryers," which operate at low pressure, alleged to be below 300 hPa. | ¶59 | col. 17:33-34 |
| and the temperature being not more than 80° C. and lower than a decomposition temperature of the fluorine salt. | On information and belief, Ascend's ability to recover and resell high-purity electrolyte requires drying at temperatures below approximately 60°C to suppress hydrogen fluoride generation. | ¶60 | col. 17:34-36 |
Identified Points of Contention
- Scope Questions: The term "pressure-temperature above a boiling point of the organic carbonate" is a relational limitation. The parties may dispute how this condition is defined and measured within a dynamic, industrial-scale process.
- Technical Questions: The infringement allegation for the temperature limitation ("not more than 80° C.") relies on an inference that Ascend must operate below this temperature to achieve its stated business outcome of reselling recovered electrolyte (Compl. ¶60). The case may turn on whether direct evidence supports this inferred operating parameter, as opposed to Ascend operating under different conditions with different results or mitigation techniques.
V. Key Claim Terms for Construction
The Term: "inactivating" / "inactivated" (from ’097 Patent, Claim 1; ’463 Patent, Claim 1)
- Context and Importance: This term is central to the purpose of the invention, which is to render hazardous comminuted battery material safe for transport and further processing. Practitioners may focus on this term because the required degree of "inactivation" will define the scope of infringement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states that inactivation occurs "at least also by way of drying the comminuted material," suggesting drying is a sufficient, though not necessarily exclusive, means of inactivation ('097 Patent, col. 2:57-59).
- Evidence for a Narrower Interpretation: The specification repeatedly links inactivation to a specific technical outcome: drying until the "electrolyte content... is so low that an electrochemical reaction is impossible" ('097 Patent, col. 4:6-8). A defendant could argue that its process reduces, but does not eliminate, the possibility of an electrochemical reaction to the degree required by the patent.
The Term: "at a pressure-temperature above a boiling point of the organic carbonate" (from ’463 Patent, Claim 1)
- Context and Importance: This limitation defines the specific thermodynamic condition for the claimed drying process. Its construction is critical because it is a relational, not absolute, parameter that depends on the specific organic carbonates present and the pressure inside the dryer.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The complaint suggests that if vaporization of the organic carbonate occurs, this condition is necessarily met (Compl. ¶86). A plaintiff may argue the claim simply requires conditions sufficient to cause boiling, whatever they may be.
- Evidence for a Narrower Interpretation: The patent explains the physics of the process, tying the vacuum to the ability to vaporize electrolytes at lower temperatures ('463 Patent, col. 4:10-18). A defendant might argue that this language requires a specific, engineered state where the pressure is lowered to a point that reduces the boiling point below the applied temperature, not just any condition where vaporization happens to occur.
VI. Other Allegations
Willful Infringement
- The complaint does not contain a separate count for willful infringement, but the prayer for relief requests that the case be deemed "exceptional" under 35 U.S.C. § 285 (Compl. p. 28, E). The factual basis for this appears to stem from allegations that Ascend had pre-suit knowledge of Duesenfeld’s technology and patents. The complaint alleges that Ascend engaged in collaboration talks, its representatives visited Duesenfeld's plant, and Duesenfeld explicitly "notified Ascend that Duesenfeld's vacuum drying process is patented" during a presentation on November 25, 2022 (Compl. ¶¶6, 39, 40).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of evidentiary proof: can the Plaintiff demonstrate through direct evidence, rather than technical inference, that the accused process at Ascend’s Covington facility operates within the specific temperature ("not more than 80° C.") and pressure ("a maximum pressure of 300 hPa") limitations recited in the asserted claims?
- A second key question will be one of technical operation: does Ascend’s "big rotating kiln" function as a "vacuum dryer" that performs the specific "inactivating" step as defined by the patents, or is there a fundamental operational difference that places the accused process outside the scope of the claims?
- Finally, the case may raise a question of claim construction: how should the court define the relational limit "at a pressure-temperature above a boiling point of the organic carbonate," and what type of evidence is required to prove this complex condition is met within an industrial recycling process?