Cross-Linked Composite Solid Polymer Electrolyte Doped with Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 for High Voltage Lithium Metal Batteries

• Published in: ACS applied materials & interfaces 2024-08, Vol.16 (34), p.44791-44801
• Main Authors: Meda, Lamartine, Masafwa, Kutemwa, Crockem, Ayssia N, Williams, Jere A, Beamon, Nila A, Adams, Jada I, Tunis, Jeremiah V, Yang, Lingyu, Schaefer, Jennifer L, Wu, James J
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.4c08181

Composite solid polymer electrolytes (CSPEs) are safer alternatives to liquid electrolytes and excellent candidates for high-voltage solid-state batteries. However, interfacial instabilities between the electrodes and CSPEs are one of the bottlenecks in pursuing these systems. In this study, a cross-linked CSPE was synthesized based on polypropylene carbonate, polyethylene glycol methyl ether acrylate, polyethylene glycol diacrylate with additives including lithium bis(trifluoromethane)sulfonimide salt, and tantalum-doped lithium lanthanum zirconium oxide (LLZTO). Mass fractions of 10, 20, and 40% LLZTO were added to the CSPE matrix. In a symmetric cell, lithium plating and stripping revealed that the interface between the lithium metal anode and CSPE with 10% of the LLZTO (CSPE-10LLZTO) shows the most stable interface. The CSPE-10LLZTO sample demonstrated high flexibility and showed no degradation over 800 h of cycling at varying current densities. The ionic conductivity for the CSPE-10LLZTO sample at 40 °C was 6.4 × 10 S/cm. An all-solid-state full cell was fabricated with LiNi Mn Co O as the cathode, CSPE-10LLZTO as the electrolyte and separator, and Li metal as the anode, delivering approximately 140 mAh/g of capacity. Differential scanning calorimetry measurements on CSPE- LLZTO showed high miscibility and the elimination of crystallinity. Raman spectroscopy revealed uniformity in the structure. These findings demonstrate the capability of the CSPEs to develop high-voltage solid-state lithium metal batteries.