The present invention provides a lithium secondary battery for an ISS which can be discharged at not less than 20 ItA when temperature is -30 degrees centigrade and can be charged at not less than 50 ItA. The positive electrode material consists of a mixture of lithium-containing metal phosphate compound particles whose surfaces are coated with an amorphous carbon material and a conductive carbon material, in which atoms of the surface carbon materials are chemically bonded to one another. The negative electrode material contains at least one kind of particles selected from among graphite particles whose surfaces are coated with an amorphous carbon material, having a specific surface area of not less than 6m 2 /g and soft carbon particles. A mixed electrolyte contains lithium hexafluorophosphate and lithium bis fluorosulfonyl imide.