| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a positive electrode material for a high safety, high capacity lithium ion secondary battery in which heat is not generated suddenly. <P>SOLUTION: The lithium ion secondary battery comprises a collector, and a positive electrode material attached to the collector. The positive electrode material contains a first positive electrode material represented by a composition formula Li<SB POS="POST">x1</SB>Ni<SB POS="POST">a1</SB>Mn<SB POS="POST">b1</SB>Co<SB POS="POST">c1</SB>O<SB POS="POST">2</SB>(in the formula, 0.2≤x1≤1.2, 0.6≤a1≤0.9, 0≤b1≤0.3, 0.05≤c1≤0.3, a1+b1+c1=1.0), and a second positive electrode material represented by a composition formula Li<SB POS="POST">x2</SB>Ni<SB POS="POST">a2</SB>Mn<SB POS="POST">b2</SB>Co<SB POS="POST">c2</SB>M<SB POS="POST">d</SB>O<SB POS="POST">2</SB>(in the formula, M is Mo, W or Nb, 0.2≤x2≤1.2, 0.7≤a2≤0.9, 0≤b2≤0.3, 0.05≤c2≤0.3, 0.02≤d≤0.06, a2+b2+c2+d=1.0). A layer containing the second positive electrode material is attached to the outermost side. <P>COPYRIGHT: (C)2012,JPO&INPIT |
