PURPOSE: To lengthen the life of a secondary lithium cell, heighten the energy efficiency thereof and reduce the weight thereof, by using carbon fibers of high degree of graphitization to constitute a positive and a negative electrodes, and using one or both of LiI and LiBr as an electrolyte.

CONSTITUTION: A negative electrode is made of carbon fibers of high degree of graphitization instead of metallic lithium. A positive electrode is also made of carbon fibers. A least one of LiI and LiBr is used as an electrolyte. An organic nonaqueous solvent is used as an electrolytic solution. A secondary lithium cell comprises the negative and the positive electrodes, the electrolyte and the electrolytic solution. Since the negative electrode is made of the carbon fibers, lithium atoms having undergone intercalation are taken into the carboni fibers so that the lithium atoms thereafter do not come into contact with the electrolytic solution and hot have the opportunity to react therewith. As a result, the life of the secondary lithium cell is made much longer than that of a secondary lithium cell with a negative electrode of metallic lithium although the energy efficiency of the former cell drops slightly.