| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium secondary battery using a positive electrode for the lithium secondary battery, capable of exhibiting a high capacity and high discharge ratio characteristic. <P>SOLUTION: In this lithium ion secondary battery 20, an electrode group 6 wound with a positive electrode plate W1 and a negative electrode plate W3 is stored in a battery vessel 7. The positive electrode plate W1 is formed by coating aluminum foil with a positive electrode mix. A positive electrode active material, three kinds of carbon materials and a binder are blended with the positive electrode mix. Iron phosphate lithium having an olivine crystal structure expressed by chemical formula Li<SB>1+x</SB>Fe<SB>1-x</SB>PO<SB>4</SB>(0<x<1). is used in the positive electrode active material. The iron phosphate lithium is set in a range of 5-30 m<SP>2</SP>/g in the BET specific surface area. The three kinds of carbon materials are adjusted in a range of 0.1-1.2 in the total sum of the surface area expressed by the product of respective weights and its BET specific surface area, assuming the surface area of the iron phosphate lithium as 1. <P>COPYRIGHT: (C)2010,JPO&INPIT |
