Solvothermal preparation of tin phosphide as a long-life anode for advanced lithium and sodium ion batteries

Abstract Tin phosphide (Sn 4 P 3 ) nanoparticles with different sizes are synthesized via a facile solvothermal method at 180 °C for 10 h. The as-prepared Sn 4 P 3 nanoparticles have an average size of about 15 nm. Meanwhile, their size could be easily controlled by the solvent ratio. The long cycle stability and rate performance of the as-obtained Sn 4 P 3 nanoparticles have been tested as an anode material for lithium ion batteries for the first time. Electrochemical measurements show that the Sn 4 P 3 nanoparticles with a smallest size give the best cycling and rate performances. They deliver a discharge capacity of 612 mAh g −1 after 10 cycles and could still maintain 442 mAh g −1 after 320 cycles at the current density of 100 mA g −1 within voltage limit of 0.01–3.0 V. Even after 200 cycles at a current density of 200 mA g −1 , the specific capacity still could be remained at 315 mAh g −1 . The improved electrochemical performances of Sn 4 P 3 electrode might be largely attributed to their small-size. Furthermore, the as-prepared Sn 4 P 3 nanoparticles have also been tested as an anode material for Na-ion batteries, this Sn 4 P 3 anode can deliver a reversible capacity of 305 mAh g −1 after 10 cycles at the current density of 50 mA g −1 .