| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery capable of balancing input/output performance, and of expressing high input/output performance in a wide SOC range, and having high battery energy density for expressing the high input/output performance. <P>SOLUTION: For a negative electrode active material for this lithium secondary battery, a graphitic material satisfying the following requirements (1)-(4) at the same time is used: (1) the average particle diameter thereof is 3-15 μm; (2) an R value (I<SB>D</SB>/I<SB>G</SB>) being an intensity ratio of a peak intensity I<SB>D</SB>in the range of 1,300-1.400 cm<SP>-1</SP>measured by a Raman dispersion spectrum to a peak intensity I<SB>G</SB>in the range of 1,580-1,620 cm<SP>-1</SP>is 0.2-0.4; (3) a half-value bandwidth Δ value of a peak in the range of 1,300-1.400 cm<SP>-1</SP>is 40-100 cm<SP>-1</SP>; and (4) an intensity ratio X value (I<SB>(110)</SB>/I<SB>(004)</SB>) of a peak intensity I<SB>(110)</SB>of the (110) surface in X-ray diffraction to a peak intensity I<SB>(004)</SB>of the (004) surface is 0.1-0.45. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
