Lithium rechargeable battery
The lithium rechargeable battery of the present invention is provided with a current collector and an active material layer containing active material particles 10 supported on this current collector. The active material particles 10 are secondary particles 14 in which a plurality of primary particles 12 of a lithium transition metal oxide are aggregated, and have a hollow structure that contains a hollow section 16 formed inside the secondary particle 14 and a shell section 15 that surrounds the hollow section 16 . A through hole 18 that penetrates from the outside to the hollow section 16 is formed in the secondary particle 14 . The ratio (A/B) in a powder x-ray diffraction pattern of the active material particles 10 , where A is the full width at half maximum of the diffraction peak obtained for the (003) plane and B is the full width at half maximum of the diffraction peak obtained for the (104) plane, satisfies the equation (A/B)≦ 0.7.
1. A lithium rechargeable battery comprising:
a current collector; and
an active material layer that contains active material particles that are retained on the current collector, wherein
the active material particles are secondary particles formed by the aggregation of a plurality of primary particles of a lithium transition metal oxide and have a hollow structure having a hollow section formed within the secondary particle and a shell section that surrounds the hollow section,
a through hole that penetrates from the outside to the hollow section is formed in the secondary particle,
the lithium transition metal oxide is a compound with a layered crystal structure, and
the ratio (A/B) in the powder x-ray diffraction pattern of the active material particles, where A is the full width at half maximum of the diffraction peak obtained for the (003) plane and B is the full width at half maximum of the diffraction peak obtained for the (104) plane, satisfies the equation (A/B)≦0.65.
2. The lithium rechargeable battery according to claim 1 , wherein the ratio of the full widths at half maximum (A/B) satisfies the equation 0.45≦(A/B)≦0.65.
3. The lithium rechargeable battery according to claim 1 , wherein the average thickness, in the active material particle, of the shell section that surrounds the hollow section is 0.1 μm to 2.2 μm.
4. The lithium rechargeable battery according to claim 1 , wherein the lithium transition metal oxide contains at least nickel as a structural element.
5. The lithium rechargeable battery according to claim 1 , wherein
the lithium transition metal oxide contains tungsten, and
the content of this tungsten is 0.05 mol % to 1 mol % where the total of all the non-tungsten transition metal elements in the compound is 100 mol % as the mole percentage.
6. The lithium rechargeable battery according to claim 1 , wherein the lithium transition metal oxide is represented by the following general formula:
Li 1+x Ni y Co z Mn (1-y-z) W α M β O 2 (1)
wherein in formula (1), x, y, z, α, and β are real numbers that satisfy all of the following:
0≦x≦0.2,
0.1<y<0.9,
0.1<z<0.4,
0.0005≦α≦0.01, and
0≦β≦0.01, and
M is either not present or is one or two or more elements selected from the group consisting of Zr, Mg, Ca, Na, Fe, Cr, Zn, Si, Sn, Al, B, and F.
7. The lithium rechargeable battery according to claim 1 , wherein the active material particles are active material particles produced by a production method comprising:
a step of preparing a starting hydroxide by supplying an ammonium ion to an aqueous solution of a transition metal compound to precipitate particles of a transition metal hydroxide from the aqueous solution, with this aqueous solution containing at least one transition metal element that is a constituent of the lithium transition metal oxide;
a mixing step of preparing a prefiring mixture by mixing the transition metal hydroxide with a lithium compound; and
a firing step of firing the mixture to obtain the active material particles.
8. The lithium rechargeable battery according to claim 1 , wherein the ratio of the full widths at half maximum (A/B) satisfies the equation (A/B)≦0.48.