Implementation of binder-free SnO2 NWs@C electrode and LiTFSI-based electrolyte for high-performance lithium-ion battery

This study has investigated the effect of carbon coating on the electrochemical performance of SnO2 Nanowires (NWs) as an electrode along with a bis (trifluoromethane) sulfonimide lithium (LiTFSI)-based electrolyte in a lithium-ion battery (LIB). The vapor–liquid–solid approach has been used to grow SnO2 NWs on the stainless steel mesh current collector. The obtained results have demonstrated that the utilization of the LiTFSI-based electrolyte improved the battery performance with the SnO2 NWs electrode over the LiPF6-based electrolyte. This may be due to the formation of a stable and thin solid electrolyte interphase layer. Since bare SnO2 NWs exhibit inferior cycling stability due to their high volumetric expansion and poor conductivity, incorporating carbon coating could improve performance. Although the initial discharge specific capacity obtained for the carbon-coated SnO2 NWs (SnO2 NWs@C) electrode (1328.4 mAh g−1) was in the order of the first discharge capacity for the SnO2 NWs, the SnO2 NWs@C electrode possessed capacity retention with six times improvement as compared to the pristine SnO2 NWs after 120 cycles. The Coulombic efficiency of 99% has been achieved for the SnO2 NWs@C electrode over 120 cycles. Field emission scanning electron microscopy images revealed that the carbon coating could keep the overall structure of the electrode upon cycling. It has been evidenced that the SnO2 NWs@C electrode with LiTFSI-based electrolyte has an excellent potential to implement in high-performance LIBs.