Electrode material and method for forming electrode material

An object is to provide an electrode material with high electrical conductivity and a power storage device using the electrode material. An object is to provide an electrode material with high capacity and a power storage device using the electrode material. Provided is a particulate electrode material including a core containing a compound represented by a general formula Li2MSiO4 (in the formula, M represents at least one kind of an element selected from Fe, Co, Mn, and Ni) as a main component, and a covering layer containing a compound represented by a general formula LiMPO4 as a main component and covering the core. Further, a solid solution material is provided between the core and the covering layer. With such a structure, an electrode material with high electrical conductivity can be obtained. Further, with such an electrode material, a power storage device with high discharge capacity can be obtained.