Synergistic effect of vinylene carbonate (VC) and LiNO3 as functional additives on interphase modulation for high performance SiO anodes

Abstract

Recently, silicon suboxide (SiO) attracts much attention as a promising anode material for high energy density lithium-ion batteries due to its high specific capacity. However, the active particle pulverization together with repeated rupture/reconstruction of the solid electrolyte interphase (SEI) film upon lithiation/delithiation process has been a critical issue that deteriorates the electrode cycling stability and therefore impedes its deployment in commercial batteries. To address this challenge, herein, vinylene carbonate (VC) and lithium nitrate (LiNO 3 ) are employed as synergistic additives to improve the electrode-electrolyte interface property. To circumvent the low solubility in carbonate solvent, LiNO 3 is incorporated directly into the electrode while VC still into the electrolyte solution. The synergistic addition of LiNO 3 and VC enhances the electrode reaction kinetics and improves significantly the cycling stability of the SiO anode. The SiO electrode with simultaneous addition of LiNO 3 and VC delivers a high reversible capacity of 1062.3 mA h g −1 and an excellent cycling performance with 94.5% capacity retention and 99.80% Coulombic efficiency for 160 cycles, demonstrating the superior effectiveness of VC and LiNO 3 in modulating the interface chemistry and structure of SiO anode. • VC and LiNO 3 as electrolyte and electrode additives construct durable SEI film. • High capacity and excellent cycling stability are achieved for submicro-SiO. • The synergistic mechanism of VC and LiNO 3 additives is elucidated.