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Title: 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)2LiPF6 (Adpn = adiponitrile) is synthesized and characterized, which 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 significantly high ion conductivity (~ 10-4 S/cm) and lithium-ion transference number (0.54) are obtained due to weak interactions between “hard” (charge-dense) Li+ ions and “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 Ea and within the interstitial regions between the co-crystals with higher Ea, where the bulk conductivity comprises a smaller but extant contribution. These cocrystals establish a special concept of crystal design to increase the thermal stability of LiPF6 by separating ions in Adpn solvent matrix, and also exhibit a unique mechanism of ion-conduction via low-resistance grain-boundaries, which is contrasting to ceramics or gel-electrolytes.  more » « less
Award ID(s):
2138432
PAR ID:
10488772
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Editor(s):
Vincent Dusastre
Publisher / Repository:
Springer Nature
Date Published:
Journal Name:
Nature Materials
Volume:
22
Issue:
5
ISSN:
1476-1122
Page Range / eLocation ID:
627 to 635
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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