Patent ID: 8310811

Claim:
A positive electrode active material for a lithium ion electric storage device, the active material having a BET specific surface area of 1500 m 2 /g or more and 3000 m 2 /g or less, wherein a ratio A of the pore volume within the range of the pore diameter of 0.6 nm or more and less than 1 nm to the pore volume within the range of the pore diameter of 0.6 nm or more and 200 nm or less in the active material satisfies 0.49≦A≦0.70, and a ratio B of the pore volume within the range of the pore diameter of 1 nm or more and 6 nm or less to the pore volume within the range of the pore diameter of 0.6 nm or more and 200 nm or less in the active material satisfies 0.20≦B≦0.38.