NEGATIVE-ELECTRODE ACTIVE MATERIAL, NEGATIVE ELECTRODE USING SAME, AND LITHIUM-ION SECONDARY BATTERY

摘要

[Problem] To provide: a negative-electrode active material that results in a sufficiently high discharge capacity, even at high discharge rates; a negative electrode using said negative-electrode active material; and a lithium-ion secondary battery. [Solution] This negative-electrode active material, particles of which contain silicon and a silicon oxide, is characterized in that surface layers of said particles are less dense than core sections thereof. This negative-electrode-active-material structure results in a sufficiently high discharge capacity at high discharge rates.