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

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. [Display omitted] • 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. [ABSTRACT FROM AUTHOR]