LAUSR

Si-based anode materials have attracted considerable attention because of their ultra high reversible capacity. However, the poor cycling stability caused by the large volume change during the cycling prevented the commercial application of Si anode for lithium-ion batteries (LIBs). To overcome these challenges, in the present study, we designed a nitrogen plasma treated core-bishell nanostructure where the Si nanoparticle was encapsulated into SiOx shell and N-doped TiO2-δ shell. Here, the SiOx inside shell and TiO2 outside shell act as binary buffer matrices to accommodate the large volume change and also help to stabilize the SEI films on the shell surface. More importantly, plasma-induced N-doped TiO2-δ shell with many Ti3+ species and oxygen vacancies, plays a key role in improving the electrical conductivity of Si anode. Owing to the synergistic effects of SiOx and N-doped TiO2-δ bishells, the cycling stability and rate performance of Si anode are significantly enhanced. The as-obtained sample exhibits superior cycling stability with a capacity retention of 650 mAh g-1 at 200 mA g-1 after 300 cycles. This strategy is favorable for improving electrochemical performances of Si-based anodes to employ in practical LIBs.