Lawrence Berkeley National Laboratory
CRADA Final Report: Flexible All Solid State Lithium Batteries Made by Roll-to-Roll Freeze-Casting
- Author(s): Doeff, Marca
- et al.
This project was directed towards understanding scalability and manufacturing issues associated with a novel fabrication method for solid-state lithium batteries initially proposed by Contractor 1 (LBNL). This is based on freeze tape casting (FTC) of Al-substituted Li7La3Zr2O12 (LLZO) to form a porous ion-conducting scaffold, followed by infiltration with cathode active material and other components. The composite electrodes fabricated by this method can then be combined with thin dense layers of LLZO and a lithium foil to complete a solid-state cell. Contractor 1’s duties were to determine the best conditions for freeze tape casting of LLZO, and communicate these to Contractor 2 (ORNL) so that they could scale-up the process. Scale-up issues were identified with the first formulation provided to ORNL, but were resolved with the second formulation, and scaffolds were successfully produced at ORNL. Early in the project, hybrid cells were assembled at ORNL using components produced at Fisker (Participant) and could be cycled, although cycle lives were short, probably due to problems associated with the use of liquid electrolyte. The ultimate goal of the project was to produce a functioning completely solid-state cell, which was accomplished at the end of the project, by Contractor 1.