electrochemical performance

sodium-ion batteries

sodium ion

hard carbon

electrolyte additive

specific capacity

capacity retention

batteries sibs

cycling stability

Journal of alloys and compounds

Application of film-forming electrolyte additive has been demonstrated to be an effective and economical approach to improve the performances of lithium ion batteries. However, investigations on the influence of electrolyte additives on the performances of sodium ion batteries is very limited. In this work, with vinylene carbonate (VC) as electrolyte additive, the cyclic stability of MoO 2 anode for sodium ion batteries is greatly improved. After 1000 cycles at 300 mAg −1 , the capacity retention of MoO 2 electrode achieves 96.5% in comparison with that of 20.1% without additive. The poor long-term cyclic performance of MoO 2 is mainly ascribed to the sever electrolyte reduction reaction during cycling, which results in significantly increase of electrode polarization. The VC-induced solid electrolyte interphase film effectively suppresses the decomposition of baseline electrolyte, and therefore, hinders the increase of interfacial reaction resistance and improves the interfacial stability of MoO 2 electrode. • Sever capacity fading mechanism of MoO 2 anode for sodium ion batteries is understood. • Vinylene carbonate as electrolyte film-forming additive is proposed to greatly improve the capacity stability of MoO 2 anode. • Capacity retention of MoO 2 electrode achieves 96.5% in comparison with that of 20.1% without additive.

Improving the cyclic stability of MoO2 anode for sodium ion batteries via film-forming electrolyte additive