Ball mill-assisted synthesis of carbon-free SnSe nanoparticles for sodium-ion battery anodes

Tin selenide (SnSe) is a potential candidate for sodium-ion battery anodes owing to its high theoretical capacity, environmental benignity, and abundant resources. Herein, the resulting SnSe anodes are synthesized by mechanochemical route employing a high-energy ball mill without addition of carbon during the synthesis. This green synthesis route can be simply applied to both laboratory and industry scales since it does not require the use of any organic solvents. Exact stoichiometric ratio of Sn and Se powder is milled at 25 Hz with varying synthesis periods (2 h, 4 h, and 8 h). Among the samples, 2-h-milled sample is the choice of the anode materials in which no impurities or secondary phase formation characterized by both structural and morphological analyses as well as further electrochemical tests. The impact of binder is also investigated in which poly (acrylic acid) (PAA) performed the best, resulting a capacity retention of 350 mAh/g during 100 cycle at 27.5 mA/g current density and similar to 250 mAh/g specific capacity at 275 mA/g current density.