Patent ID: 7416814

Claim:
A process for producing a lithium secondary battery, which comprises steps of: (a) subjecting a carbonaceous material (A) and first particles including at least one of elements capable of forming a compound with lithium and having a melting point of at least 900° C. and a thermal expansion coefficient of not more than 9 ppm/K at room temperature, to mechanical pressure welding so as to embed said first particles in the carbonaceous material (A), to obtain second particles, (b) confirming that the carbonaceous material (A) is present around the first particles and that the first particles have an average particle size of 0.1 to 20 μm by observation with a scanning electron microscope (SEM) of the second particles, and that the carbonaceous material (A) has a d(002) interplanar spacing of 0.335 nm to 0.345 nm by X-ray diffraction analysis of the second particles, (c) mixing the second particles and a precursor of a carbonaceous material (B), enclosing the carbonaceous material (A) in the carbonaceous material (B), to obtain third particles, (d) carbonizing the third particles, thereby forming a negative electrode-active material, and (e) arranging a positive electrode, a negative electrode containing said negative electrode-active material and a lithium ion conductive, non-aqueous electrolytic solution or polymer electrolyte into a container.