Lysine-assisted hydrothermal synthesis of hierarchically porous Fe2O3 microspheres as anode materials for lithium-ion batteries

► Fe2O3 microspheres were prepared by a simple, template-free hydrothermal method. ► Hierarchical porous Fe2O3 microspheres are assembled by uniform nanoparticles. ► Lysine acts as a hydrolysis-controlling agent. ► The Fe2O3 microspheres have a high capacity of 705 mA h g−1 at 430th cycle.