Stabilization of lithium anode with ceramic-rich interlayer for all solid-state batteries

• Published in: RSC advances 2022-05, Vol.12 (24), p.15493-1557
• Main Authors: Delaporte, Nicolas, Lajoie, Gilles, Darwiche, Ali, Vigeant, Marie-Josée, Collin-Martin, Steve, Clément, Daniel
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Anodes; Buffer layers; Ceramic coatings; Ceramics; Charge transfer; Chemistry; Cycles; Deformation; Deposition; Electrochemical analysis; Electrolytic cells; Foils; Interlayers; Lithium; Micrometers; Polymers; Solid state; Thin films
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d2ra01856j

The deposition of thin layers of polymer/ceramic on a lithium surface to produce a strong barrier against dendrites was demonstrated. Different forms (needle, sphere, rod) and types of ceramic (Al 2 O 3 , Mg 2 B 2 O 5 ) were tested and polymer/ceramic interlayers of a few micrometers (4 μm minimum) between the lithium and the PEO-based solid polymer electrolyte (SPE) were deposited. Interlayers with high amounts of ceramic up to 85 wt% were successfully coated on the surface of lithium foil. Compact "polymer in ceramic" layers were observed when Al 2 O 3 spheres were used for instance, providing a strong barrier against the progression of dendrites as well as a buffer layer to alleviate the lithium deformation during stripping/plating cycles. The electrochemical performance of the lithium anodes was assessed in symmetrical Li/SPE/Li cells and in full all-solid-state LiFePO 4 (LFP)/SPE/Li batteries. It was observed for all the cells that the charge transfer resistance was significantly reduced after the deposition of the polymer/ceramic layers on the lithium surface. In addition, the symmetrical cells were able to cycle at higher C-rates and the durability at C/4 was even improved by a factor of 8. Microscopic observations of Li/SPE/Li stacks after cycling revealed that the polymer/ceramic interlayer reduces the deformation of lithium upon cycling and avoids the formation of dendrites. Finally, LFP/SPE/Li batteries were cycled and better coulombic efficiencies as well as capacity retentions were obtained with the modified lithium electrodes. This work is patent-pending (WO2021/159209A1). Significant electrochemical performance improvement of symmetric Li/Li polymer cells at C/4 by using ceramic-rich coated lithium anodes.