| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery in which high output performance can be secured even under cryogenic temperature environment. <P>SOLUTION: A positive electrode active material is made to be a complex oxide of layered crystalline structure expressed in a composition formula LiNi<SB>X</SB>Mn<SB>Y</SB>Co<SB>Z</SB>M<SB>α</SB>O<SB>2</SB>(M:Fe, Cr, Cu, Al, Mg, Si, X+Y+Z+α=1, 0.25≤X≤0.55, 0.25≤Y≤0.55, 0.15≤Z≤0.4, and 0≤α≤0.1). The positive electrode mixture is applied to aluminum foil with the amount of 8.0-14.5 mg/cm<SP>2</SP>. A negative electrode active material is made to be an amorphous carbon of the initial charge capacity of 450 mAh/g. By adjusting the amount of application of the negative mixture to a rolled copper foil, the ratio of the negative electrode initial charge capacity to the positive electrode initial charge capacity is made to be 0.80-1.11, and the ratio of coating amount of the negative electrode mixture to coating amount of the positive electrode mixture is made to be 0.27-0.41. Even under the cryogenic temperature environment, diffusion move of the lithium ion in the positive electrode active material and the positive electrode mixture is secured. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
