PLATE-SHAPED PARTICLES FOR POSITIVE ELECTRODE ACTIVE MATERIAL OF LITHIUM SECONDARY BATTERIES, FILMS OF SAID MATERIAL, AS WELL AS LITHIUM SECONDARY BATTERIES

An object of the present invention is to provide a lithium secondary battery which has improved capacity, durability, and rate characteristic as compared with conventional lithium secondary batteries. A plate-like particle or a film for a lithium secondary battery cathode active material is represented by the following general formula: General formula:Li p (Ni x ,Co y ,Al z )O 2 (wherein 0.9 ¤ p ¤ 1.3,0.6 < x ¤ 0.9,0.1 < y ¤ 0.3, 0 ¤ z ¤ 0.2, x + y + z = 1) The particle or the film contains cobalt and lithium and has a layered rock salt structure. The (003) plane is oriented so as to intersect the plate surface of the particle or film.