Electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery provided with same
An electrode for nonaqueous electrolyte secondary batteries, which is provided with a collector and a positive electrode active material layer that is arranged on the collector and contains a positive electrode active material. The positive electrode active material is configured to contain compound particles which have a layered structure composed of two or more transition metals, and which have an average particle diameter DSEM of from 1 μm to 7 μm (inclusive), a ratio of the 50% particle diameter D 50 in a volume-based cumulative particle size distribution to the average particle diameter DSEM, namely D 50 /DSEM of from 1 to 4 (inclusive), and a ratio of the 90% particle diameter D 90 in the volume-based cumulative particle size distribution to the 10% particle diameter D 10 in the volume-based cumulative particle size distribution, namely D 90 /D 10 of 4 or less. The positive electrode active material layer has a void fraction of 10-45%.
1. An electrode for nonaqueous electrolyte secondary batteries comprising:
a collector; and
a positive electrode active material layer that is arranged on the collector and contains a positive electrode active material,
wherein the positive electrode active material is configured
to contain compound particles which are single particles which have a layered structure composed of two or more transition metals, and which have an average particle diameter DSEM of 1 to 7 μm based on the observation with an electron microscope,
a ratio of the 50% particle diameter D 50 in a volume-based cumulative particle size distribution to the average particle diameter DSEM (D 50 /DSEM) of 1 to 4, and
a ratio of the 90% particle diameter D 90 in the volume-based cumulative particle size distribution to the 10% particle diameter D 10 in the volume-based cumulative particle size distribution (D 90 /D 10 ) of 4 or less, and
the positive electrode active material layer has a void fraction of 10 to 45% and a density of 2.7 to 3.9 g/cm 3 .
2. The electrode for nonaqueous electrolyte secondary batteries according to claim 1 , wherein, in the positive electrode active material layer, a peak diameter of a void in a void distribution curve is 0.06 to 0.3 μm.
3. The electrode for nonaqueous electrolyte secondary batteries according to claim 1 , wherein, in the positive electrode active material layer, an average diameter of the void is 0.03 to 0.2 μm.
4. The electrode for nonaqueous electrolyte secondary batteries according to claim 3 , wherein, in the positive electrode active material layer, a ratio of the peak diameter of the void to the average diameter of the void (peak diameter/average diameter) is 1.1 to 2.4.
5. The electrode for nonaqueous electrolyte secondary batteries according to claim 1 , wherein the positive electrode active material contains Ni, Mn, or Al as a main component.
6. A nonaqueous electrolyte secondary battery comprising the electrode for nonaqueous electrolyte secondary batteries described in claim 1 .