▎ 摘　　要

NOVELTY - Negative electrode active material comprises carbon composite containing carbon particles as a core and a fibrous carbon having a graphene structure. The fibrous carbon is formed on surfaces and/or inside the carbon particles. The carbon composite has a volume of all mesopores of 0.005-1 cm3/g. A volume of the mesopores, each with a pore diameter of 100-400 Angstrom , is not less than 25% of the volume of all mesopores. USE - Negative electrode active material for electricity storage device, lithium-ion secondary battery, and lithium-ion capacitor (claimed). ADVANTAGE - The negative electrode active material has enhanced low-temperature characteristics, increased energy density, and increased output power. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) method for manufacturing the negative electrode active material for an electricity storage device comprising heat treating carbon particles and/or their precursors at 600-2000degrees C in the presence of a transition metal-containing compound; (2) lithium-ion secondary battery comprising a negative electrode active material, which is the negative electrode active material for an electricity storage device, and an electrolyte solution of aprotic organic solvent containing a lithium salt; and (3) lithium-ion capacitor comprising an active material, which allows lithium ions and/or anions to be reversibly doped into and de-doped from the active material, used for a positive electrode active material, negative electrode active material for an electricity storage device, an electrolyte solution of an aprotic organic solvent containing a lithium salt, and a negative electrode and/or a positive electrode pre-doped with lithium ions so that after the positive electrode and the negative electrode are short-circuited, potentials of the positive electrode and the negative electrode are each less than or equal to 2 V (relative to lithium (Li)/Li+).