Positive electrode, electrode group and nonaqueous electrolyte battery

An electrode group comprising:

• a positive electrode comprising a positive electrode active material-containing layer which contains a positive electrode active material comprising a first positive electrode active material having a spinel type crystal structure;
• and
• a negative electrode comprising a negative electrode active material-containing layer which contains a negative electrode active material comprising a first negative electrode active material having a spinel type crystal structure,
• the electrode group satisfying the following formulas (1) to (3):
• 0.5≤a1/b1≤1.5 (1);
• 0.4≤a2/b2≤1.4 (2);
• and
• 0.5≤a3/b3≤2.3 (3).
• provided that, in the above formulas (1) to (3),
• a1 is a pore volume [mL/g] per 1 g weight of the positive electrode active material-containing layer by mercury intrusion porosimetry;
• a2 is a pore specific surface area [m2/g] of the positive electrode active material-containing layer by the mercury intrusion porosimetry;
• and a3 is a median diameter [μm] in a pore distribution of the positive electrode active material-containing layer by the mercury intrusion porosimetry;
• and
• b1 is a pore volume [mL/g] per 1 g weight of the negative electrode active material-containing layer by mercury intrusion porosimetry;
• b2 is a pore specific surface area [m2/g] of the negative electrode active material-containing layer by the mercury intrusion porosimetry;
• and b3 is a median diameter [μm] in a pore distribution of the negative electrode active material-containing layer by the mercury intrusion porosimetry.