Abstract Crystalline low agglomerated tungsten diselenide (WSe2) nanoparticles were successfully produced by the aerosol synthesis method. The particle size and morphology were changed by process parameters. The products were characterized by X-ray diffraction and high-resolution transmission electron microscopy. The WSe2 nanoparticle morphology varies from a spherical shape to flake-like, layered structures. Usually, as-prepared particles consist of 5–7 single layers of WSe2. These as-synthesized WSe2 nanoparticles were used as anodes to assemble lithium-ion batteries. A high reversible capacity and very stable cycle performance can be obtained, implying that these WSe2 nanostructures could provide new types of electrode materials for rechargeable Li-ion batteries.