Lithium secondary battery, and process for producing the same

Abstract

A lithium secondary battery, which comprises a positive electrode, a negative electrode containing a lithium ion-storable/dischargeable negative electrode-active material and a lithium ion conductive, non-aqueous electrolytic solution or polymer electrolyte can have distinguished charging/discharging characteristics and a higher safety, when the negative electrode material contains particles comprising carbonaceous materials and at least one of elements capable of forming a compound with Li; the elements have a melting point of at least 900° C. and a thermal expansion coefficient of not more than 9 ppm/K at room temperature; the particles are embedded in a plurality of layers of the carbonaceous materials; the particles being subjected to a mechanical treatment to make particle sizes of the particles smaller than the initial particle size in advance.