Improving the cycling stability of Sn₄P₃ anode for sodium-ion battery

Experimental results from electrochemical characterizations and ex-situ X-ray diffraction (XRD) of the Sn₄P₃ anode upon cycling reveal that Sn agglomeration from the Sn₄P₃ particles plays a major role in the fast capacity fading of the Sn₄P₃ anode for sodium-ion batteries. TiC is demonstrated to be an effective additive to enhance the cycle stability of Sn₄P₃ by suppressing Sn agglomeration during cycling. Sn₄P₃/30-wt%TiC composite delivers a stable capacity of 300 mAh g^-1 or 700 Ah L^-1 over 100 cycles at current density of 100 mA g^-1. The high density TiC (4.93 g cm^-3), as compared to conventional carbon based additives, makes it attractive for achieving higher volumetric capacity of the anode.