This invention provides a process for producing a lithium secondary battery. The process comprises: (a) providing a positive electrode; (b) providing a negative electrode comprising a carbonaceous material capable of absorbing and desorbing lithium ions, wherein the carbonaceous material is obtained by chemically or electrochemically treating a laminar graphite material to form a graphite crystal structure having an interplanar spacing d002 of at least 0.400 nm as determined from a (002) reflection peak in powder X-ray diffraction; and (c) providing a non-aqueous electrolyte disposed between the negative electrode and the positive electrode to form the battery structure. This larger interplanar spacing (greater than 0.400 nm, preferably no less than 0.55 nm) implies a larger interstitial space between two graphene planes to accommodate a greater amount of lithium. The resulting battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life.