| abstract |
(57) [Summary] [Structure] In a non-aqueous secondary battery in which a material capable of inserting and extracting lithium ions or metallic lithium is used for the negative electrode, the composition formula Li x Ni 1-y Co y O w F a (however, 0 <x ≦ 1.3,0 ≦ y ≦ 1,1.8 ≦ w + 0.5a ≦ 2.2 and 0.25 ≦ a ≦ 2. ) A fluorine-containing composite oxide represented by [Effect] The cycle characteristics are excellent because the crystal structure of the positive electrode active material is less likely to collapse during charge and discharge. |