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.