EP-4738443-A2 - INLINE TERAHERTZ MEASUREMENT DEVICE FOR DRY ELECTRODE FILM MANUFACTURING, AND METHODS THEREOF

Abstract

A system and method for processing a dry electrode film comprising a roller system, a terahertz measurement device and a dry electrode powder mixture dispenser, are disclosed. The measurement device may comprise a terahertz source and a terahertz sensor. Such terahertz source may be emitted towards an upper and lower surface of the dry electrode film and reflected back towards the terahertz sensor to measure a physical property of the dry electrode film.

Inventors

• ZANDIATASHBAR, Ardavan
• EGGLESTON, Bonne
• WANG, Kaiping
• ERBEN, CHRISTOPH
• JIN, Shikai
• TANAKA, KENTARO
• PHAM, MINH

Assignees

• Tesla, Inc.

Dates

Publication Date

20260506

Application Date

20251017

Claims (15)

1. A system for processing a dry electrode film, comprising: a roller system comprising a calender roller; a measurement device positioned over the calender roller and comprising a terahertz source and a terahertz sensor, wherein the terahertz source is configured to emit a terahertz radiation pulse and the terahertz sensor is configured to detect a terahertz reflection of the terahertz radiation pulse; and a dry electrode powder mixture dispenser, wherein the dry electrode powder mixture dispenser is configured to dispense dry electrode material onto the calender roller, wherein the terahertz source is inline with the terahertz sensor.
2. The system of claim 1, further comprising an additional calender roller and an additional measurement device, wherein the additional measurement device is positioned over the additional calender roller.
3. The system of claim 1, wherein the terahertz radiation pulse comprises a spot size, a peak width, a frequency, or any combination thereof.
4. The system of claim 3, wherein the spot size comprises a diameter of about 0.05-0.5 mm and/or wherein the frequency is about 0.05-5.0 THz, and/or wherein the peak width is about 1-5 ps.
5. The system of any one of claims 1-4, wherein the terahertz sensor is configured to measure a physical property selected from a group consisting of a mass density, a loading, a uniformity, a thickness, a basis weight, and combinations thereof.
6. The system of any one of claims 1-5, wherein the terahertz sensor is configured to measure a time of flight of the terahertz radiation pulse, an intensity of the terahertz radiation pulse, an intensity of the terahertz reflection, or any combination thereof; preferably wherein the terahertz sensor is configured to measure an intensity of the terahertz reflection.
7. The system of any one of claims 1-6, further comprising a current collector dispenser.
8. A method of calibrating the system of any one of claims 1-7, comprising: disposing a dry electrode film over the calender roller, wherein the dry electrode film comprises a marker and a film area downstream of the marker, and wherein the film area comprises a first major surface and a second major surface opposite the first major surface; emitting a marker terahertz radiation pulse from a terahertz source to the marker to form a marker reflection; detecting the marker reflection with the terahertz sensor; emitting the terahertz radiation pulse from the terahertz source at a first time point to the film area to form a first terahertz reflection from the first major surface and a second terahertz reflection from the second major surface; detecting the first terahertz reflection at a second time point with the terahertz sensor, and detecting the second terahertz reflection at a third time point with the terahertz sensor; and sampling the film area.
9. A method of processing a dry electrode film, comprising: disposing a dry electrode film over a calender roller, wherein the dry electrode film comprises a first major surface and a second major surface opposite the first major surface; rotating the calender roller thereby forming a moving dry electrode film; emitting a terahertz radiation pulse to the moving dry electrode film at a first time point to form a first terahertz reflection from the first major surface and a second terahertz reflection from the second major surface; and detecting the first terahertz reflection at a second time point by a terahertz sensor and detecting the second terahertz reflection at a third time point by a terahertz sensor.
10. The method of claim 9, further comprising quantifying a difference between the first time point and the second time point, thereby determining a first major surface time of flight, and quantifying a difference between the first time point and the third time point, thereby determining a second major surface time of flight.
11. The method of claim 9 or 10, further comprising determining an intensity of the terahertz radiation pulse at the first time point, determining an intensity of the first terahertz reflection at the second time point, determining an intensity of the second terahertz reflection at the third time point.
12. The method of any one of claims 9-11, wherein emitting the terahertz radiation pulse comprises projecting a spot size, a peak width, a frequency, or any combination thereof, preferably wherein the spot size comprises a diameter of about 0.05-0.5 mm, and/or wherein the frequency is at least 0.05 terahertz to no greater than 5.0 terahertz, and/or wherein the peak width is at least 1.0 picoseconds to no greater than 5 picoseconds.
13. The method of any one of claims 9-12, wherein detecting comprises determining a physical property selected from a group consisting of a mass density, a loading, a uniformity, a thickness, a basis weight, and combinations thereof.
14. The method of any one of claims 9-13, further comprising disposing a current collector over the dry electrode film.
15. The method of any one of claims 9-14, further comprising dispensing a dry electrode material onto the calender roller, wherein the dry electrode material comprises a dry powder.

Description

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS This application claims the benefit of priority to U.S. Patent Application No. 18/937,956, entitled "INLINE TERAHERTZ MEASUREMENT DEVICE FOR DRY ELECTRODE FILM MANUFACTURING, AND METHODS THEREOF,". BACKGROUND Field This disclosure relates to systems for fabricating a dry electrode film and methods for processing the same. In particular, the method relates to processing and calibrating a system for processing a dry electrode film using terahertz sources and sensors. Description of the Related Art Dry electrode films for energy storage devices incorporate binder materials combined with active electrode materials. Dry electrode films are produced by calendering a powder mixture without the use of solvents, resulting in a unique manufacturing process and potential assembly challenges. For example, while properties of wet solvent produced electrode films may controlled through slurry deposition processes, dry electrode films are formed on calender rolls prior to deposition on a current collector to form an electrode. As such, other methods and systems specifically directed to controlling the properties of dry electrode films may be helpful. SUMMARY For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention are described herein. Not all such objects or advantages may be achieved in any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In some aspects, a system for processing a dry electrode film is described. The system for processing a dry electrode film comprises a roller system comprising a calender roller; a measurement device positioned over the calender roller and comprising a terahertz source and a terahertz sensor, wherein the terahertz source is configured to emit a terahertz radiation pulse and the terahertz sensor is configured to detect a terahertz reflection of the terahertz radiation pulse; and a dry electrode powder mixture dispenser, wherein the dry electrode powder mixture dispenser is configured to dispense dry electrode material onto the calender roller, wherein the terahertz source is inline with the terahertz sensor. In some embodiments, the system further comprises an additional calender roller and an additional measurement device, wherein the additional measurement device is positioned over the additional calender roller. In some embodiments, the terahertz radiation pulse comprises a spot size, a peak width, a frequency, or any combination thereof. In some embodiments, the spot size comprises a diameter of about 0.05-0.5 mm. In some embodiments, the frequency is about 0.05-5.0 THz. In some embodiments, the peak width is about 1-5 ps. In some embodiments, the terahertz sensor is configured to measure a physical property selected from the group consisting of a mass density, a loading, a uniformity, a thickness, a basis weight, and combinations thereof. In some embodiments, the terahertz sensor is configured to measure a time of flight of the terahertz radiation pulse, an intensity of the terahertz radiation pulse, an intensity of the terahertz reflection, or any combination thereof. In some embodiments, the terahertz sensor is configured to measure an intensity of the terahertz reflection. In some embodiments, the system further comprises a current collector dispenser. In some aspects, a method of calibrating the system is described. The method comprises disposing a dry electrode film over the calender roller, wherein the dry electrode film comprises a marker and a film area downstream of the marker, and wherein the film area comprises a first major surface and a second major surface opposite the first major surface; emitting a marker terahertz radiation pulse from a terahertz source to the marker to form a marker reflection; detecting the marker reflection with the terahertz sensor; emitting the terahertz radiation pulse from the terahertz source at a first time point to the film area to form a first terahertz reflection from the first major surface and a second terahertz reflection from the second major surface; detecting the first terahertz reflection at a second time point with the terahertz sensor, and detecting the second terahertz reflection at a third time point with the terahertz sensor; and sampling the film area. In some aspects, a method of processing a dry electrode film is described. The method comprises disposing a dry electrode film over a calender roller, wherein the dry electrode film comprises a first major surface and a second major surface opposite the first major surface; rotating the calender roller thereby forming a moving dry electrode film; emitting a