Uniformly dispersed teardrop-shaped tin phosphide particles for lithium-ion batteries are synthesized by the reaction of tin acetate in a mixed solution of trioctyl phosphine (TOP) and trioctylphosphine oxide (TOPO). Reversible intercalation/deintercalation of lithium ions into/from the tin phosphide is found, giving LixSnP0.94 with x up to 3.91 (740 mA h g–1), and little capacity fading between 0 and 1.2 V.