Alkali metal salts based on novel anions for solid polymer electrolytes

• Autores: Lixin Qiao
• Directores de la Tesis: Armand Michel (dir. tes.), María Dolores Gurruchaga Torrecilla (tut. tes.)
• Lectura: En la Universidad del País Vasco - Euskal Herriko Unibertsitatea ( España ) en 2021
• Idioma: inglés
• Tribunal Calificador de la Tesis: Maria Forsyth (presid.), David Mecerreyes Molero (secret.), Maria Martinez Ibañez (voc.), P. Tiemblo (voc.), Daniel Brandell (voc.)
• Programa de doctorado: Programa de Doctorado en Química Aplicada y Materiales Poliméricos por la Universidad del País Vasco/Euskal Herriko Unibertsitatea
• Materias:
  • Química
    • Química analítica
      • Análisis electroquímico
      • Análisis de polímeros
    • Química orgánica
      • Estructura de moléculas orgánicas
• Enlaces
  • Tesis en acceso abierto en: ADDI
• Resumen

  • The chemistry of the lithium salt employed plays a pivotal role in dictating the physico-chemical and electrochemical performance of any solid polymer electrolytes (SPEs), and thus also influences the performance of solid-state lithium metal batteries (SSLMBs). The lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, first suggested as salt for SPEs in 1986, possesses low lattice energy and the TFSI¿ anion has a large structural flexibility, both due to the anion¿s highly delocalized negative charge and flexible center [e.g., ¿SO2¿N(¿)¿SO2¿] and has therefore been commonly used for SPE-based SSLMBs. However, low lithium-ion transference number (TLi+) and poor solid electrolyte interphase (SEI) creating properties, resulting in severe cell polarization and simultaneously notorious dendritic growth on the Li° anode. Therefore, in this thesis, several novel lithium salts were designed and synthesized to suppress anionic mobility and enhance TLi+, but without sacrificing significantly the ionic conductivity, and simultaneously with the aim of forming excellent SEI layers on the Li° anode to improve interfacial compatibility and stability towards Li° anode.