CAS-TWAS > Green Technology > Stable silicon-ionic liquid interface for next-generation lithium-ion batteries

Ionic Liquids and Green Reaction/Separation Engine

Stable silicon-ionic liquid interface for next-generation lithium-ion batteries

Abstract

 
We are currently in the midst of a race to discover and develop new battery materials capable of providing high energy-density at low cost. By combining a high-performance ​Si electrode architecture with a room temperature ionic liquid electrolyte, here we demonstrate a highly energy-dense lithium-ion cell with an impressively long cycling life, maintaining over 75% capacity after 500 cycles. Such high performance is enabled by a stable half-cell coulombic efficiency of 99.97%, averaged over the first 200 cycles. Equally as significant, our detailed characterization elucidates the previously convoluted mechanisms of the solid-electrolyte interphase on ​Si electrodes. We provide a theoretical simulation to model the interface and microstructural-compositional analyses that confirm our theoretical predictions and allow us to visualize the precise location and constitution of various interfacial components. This work provides new science related to the interfacial stability of ​Si-based materials while granting positive exposure to ionic liquid electrochemistry.
 
Microstructure of nSi-cPAN and morphological effects of PYR13FSI IL on anode.
 
Nature Communications
 
6,
 
Article number:
 
6230
 
doi:10.1038/ncomms7230
Received
 
Accepted
 
Published