Stabilizing electrode-electrolyte interface for high-performance SiOx anode by dual electrolyte additive

Abstract

Macro- and micro-interface instability of SiOx anode caused by its dramatic volume variation during cycling will result in low Coulombic efficiency and rapid capacity degradation. In this work, an organic-inorganic composite interfacial layer rich in benzene ring groups, polyisocyanates, and LiF was obtained on SiOx anode by the introduction of 4-fluorophenyl isocyanate (FPI) and fluoroethylene carbonate (FEC) co-additives in electrolyte. The SiOx anode material shows a capacity retention of 69.2% after 100 cycles at a current density of 1 A g−1 and rate capacity of 523 mA h g−1 at the current density of 3 A g−1, while the SiOx anode cycling in reference electrolyte has almost no capacity.