Non-aqueous electrolyte secondary battery
View Patent ↗A non-aqueous electrolyte secondary battery has a positive electrode having a positive electrode collector, on which a positive electrode active material layer containing a positive electrode active material as a complex oxide of Li and transition metals are formed, and a negative electrode having a negative collector, on which a negative electrode active material layer is formed. The non-aqueous electrolyte secondary battery is a gel or solid non-aqueous electrolyte secondary battery having a battery device in which a positive electrode and a negative electrode are laminated with an electrolyte layer therebetween in a film-state packaging member constructed by metal foil laminated films, and containing a lithium salt, a non-aqueous solvent, and a polymer material. The concentration in mass ratio of a free acid in the electrolyte layer is 60 ppm and less. Average particle diameter of the positive electrode active material lies in a range from 10 to 22 μm, the minimum particle diameter is 5 μm or larger, the maximum particle diameter is 50 μm or smaller, and specific surface of the positive electrode active material is 0.25 m 2 /g or smaller. Lithium carbonate (Li 2 CO 3 ) contained in the positive electrode active material is 0.15 percent by weight and less. Moisture contained in the positive electrode active material is 300 ppm and less.
1. A non-aqueous electrolyte secondary battery comprising:
(a) a positive electrode comprising:
(i) a positive electrode collector; and
(ii) an electrode active material layer comprising a positive electrode material;
(b) a negative electrode;
(c) a film-state case housing the positive electrode and the negative electrode, the film-state case comprising a laminated film obtained by coating a metal foil coated with a resin, a polymer film, or a metal film, and
(d) an electrolyte, wherein the electrolyte comprises a lithium salt, a solvent and one or more polymer compounds selected from the group consisting of ether-based polymers,
wherein,
(i) said positive electrode material comprises particles,
(ii) said particles consisting essentially of a compound of formula LiMO 2 or LiMn 2 O 4 , wherein M comprises at least one material selected from the group consisting of Co, Ni, and Mn; and
(iii) the average particle diameter of said particles is at least 10 μm to at most 22 μm.
2. A non-aqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode active material has a minimum particle diameter of at least 5 μm, a maximum particle diameter of at most 50 μm, and a specific surface area of at most 0.25 m 2 /g.
3. A non-aqueous electrolyte secondary battery according to claim 1 , wherein said positive electrode material is at least one material selected from the group consisting of
(a) LiCoO 2 ;
(b) LiNiO 2 ;
(c) LiNi y Co 1-y O 2 wherein 0<y<1; and
(d) LiMn 2 O 4 .
4. A non-aqueous electrolyte secondary battery according to claim 1 , wherein said positive electrode material is at least one material selected from the group consisting of
(a) LiNi y Co 1-y O 2 wherein 0<y<1; and
(b) LiMn 2 O 4 .