In-situ synthesis of microspherical Sb@C composite anode with high tap density for lithium/sodium-ion batteries

The search for anode materials that suitable for both lithium-ion and sodium-ion batteries is one of the most top challenges in the field of rechargeable batteries. In this work, Sb@C composites are synthesized via in-situ calcination of as-prepared micro-spherical Sb2O3 in the presence of polyethylene glycol (PEG), which acts as a reductive agent and carbon source. The Sb@C composites with a structure of microspheres are composed of crystalline Sb nanoparticles coated by interconnected porous carbon. Such an unique structure not only provides a stable conductive matrix, but also leads to a high tap density of 1.35 g cm(-3). A specific capacity of 280 mAh g(-1) can be retained at 100 mA g(-1) after 500 cycles for lithium-ion batteries and 130 mA g(-1) at 100 mA g(-1) after 100 cycles for sodium-ion batteries.