| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an active material for a lithium secondary battery with a large discharge capacity and the lithium secondary battery using the same. <P>SOLUTION: The active material for the lithium secondary battery containing solid solution of lithium transition metal composite oxide having an α-NaFeO<SB>2</SB>type crystal structure is characterized in that a composition ratio of metallic elements contained in the solid solution satisfies Li<SB>1+(x/3)</SB>Co<SB>1-x-y-z</SB>Ni<SB>y/2</SB>Mg<SB>z/2</SB>Mn<SB>(2x/3)+(y/2)+(z/2)</SB>(x>0, y>0, z>0, x+y+z<1). By defining the metallic element ratio on the condition that satisfies the above formula, valences of the metallic elements at the time of synthesis can be Li<SP>1+</SP>, Co<SP>3+</SP>, Ni<SP>2+</SP>, Mn<SP>4+</SP>, and Mg<SP>2+</SP>, thereby providing a unique effect that the discharge capacity can be improved compared with a case of containing no Mg. <P>COPYRIGHT: (C)2011,JPO&INPIT |
