A soft co-crystalline solid electrolyte for lithium-ion batteries

Alternative solid electrolytes are the next key step in advancing lithium batteries with better thermal and chemical stability. A soft solid electrolyte, (Adpn) 2 LiPF 6 (Adpn, adiponitrile), is synthesized and characterized that exhibits high thermal and electrochemical stability and good ionic con...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Nature materials 2023-05, Vol.22 (5), p.627-635
Hauptverfasser: Prakash, Prabhat, Fall, Birane, Aguirre, Jordan, Sonnenberg, Laura A., Chinnam, Parameswara Rao, Chereddy, Sumanth, Dikin, Dmitriy A., Venkatnathan, Arun, Wunder, Stephanie L., Zdilla, Michael J.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Alternative solid electrolytes are the next key step in advancing lithium batteries with better thermal and chemical stability. A soft solid electrolyte, (Adpn) 2 LiPF 6 (Adpn, adiponitrile), is synthesized and characterized that exhibits high thermal and electrochemical stability and good ionic conductivity, overcoming several limitations of conventional organic and ceramic materials. The surface of the electrolyte possesses a liquid nano-layer of Adpn that links grains for a facile ionic conduction without high pressure/temperature treatments. Further, the material can quickly self-heal if fractured and provides liquid-like conduction paths via the grain boundaries. A substantially high ion conductivity (~10 −4  S cm –1 ) and lithium-ion transference number (0.54) are obtained due to weak interactions between ‘hard’ (charge dense) Li + ions and the ‘soft’ (electronically polarizable) –C≡N group of Adpn. Molecular simulations predict that Li + ions migrate at the co-crystal grain boundaries with a (preferentially) lower activation energy E a and within the interstitial regions between the co-crystals with higher E a values, where the bulk conductivity is a smaller but extant contribution. These co-crystals establish a special concept of crystal design to increase the thermal stability of LiPF 6 by separating ions in the Adpn solvent matrix, and also exhibit a unique mechanism of ion conduction via low-resistance grain boundaries, which contrasts with ceramics or gel electrolytes. Alternative solid electrolytes with enhanced thermal and chemical stability are key for advancing lithium batteries. A soft solid electrolyte with improved stability and ionic conductivity, overcoming several limitations of conventional materials, is now reported.
ISSN:1476-1122
1476-4660
DOI:10.1038/s41563-023-01508-1