Lithium complex oxide sintered body plate
Disclosed is a lithium complex oxide sintered plate for use in a positive electrode of a lithium secondary battery. The lithium complex oxide sintered plate has a structure in which a plurality of primary grains having a layered rock-salt structure are bonded, and has a porosity of 3 to 30%, a mean pore diameter of 15 μm or less, an open pore rate of 70% or more, a thickness of 40 to 200 μm, a primary grain diameter of 20 μm or less, the primary grain diameter being a mean diameter of the primary grains, and a pore diameter distribution in which the number of peaks is one and volume-based D10, D50 and D90 pore diameters satisfy expressions: D50/D10≥2.5, D90/D50≥2.5 and D90/D10≥8.0.
1. A lithium complex oxide sintered plate for use in a positive electrode of a lithium secondary battery, wherein the lithium complex oxide sintered plate has a structure in which a plurality of primary grains having a layered rock-salt structure are bonded, and has:
a porosity of 3 to 30%,
a mean pore diameter of 15 μm or less,
an open pore rate of 70% or more, and
a thickness of 40 to 200 μm,
a primary grain diameter of 20 μm or less, the primary grain diameter being a mean diameter of the primary grains, and
a pore diameter distribution in which the number of peaks is one and volume-based D10, D50 and D90 pore diameters satisfy expressions: D50/D10≥2.5, D90/D50≥2.5, and D90/D10≥8.0,
wherein D10, D50, and D90 are determined using a cumulative pore diameter distribution.
2. The lithium complex oxide sintered plate according to claim 1 , having a ratio [003]/[104] of 5.0 or less where the ratio [003]/[104] indicates a ratio of the diffraction intensity on the (003) plane to the diffraction intensity on the (104) plane in X-ray diffractometry.
3. The lithium complex oxide sintered plate according to claim 2 , having a thickness of 80 to 200 μm.
4. The lithium complex oxide sintered plate according to claim 2 , having a thickness of 100 to 200 μm.
5. The lithium complex oxide sintered plate according to claim 1 , having a thickness of 80 to 200 μm.
6. The lithium complex oxide sintered plate according to claim 1 , having a thickness of 100 to 200 μm.