Patent ID: 8114309

Claim:
A spine type lithium-manganese composite oxide for a lithium ion battery represented by a general formula Li 1+x Mn 2-y M y O 4 , wherein M is one or more elements selected from Al, Mg, Si, Ca, Ti, Cu, Ba, W and Pb, and, −0.1≦x≦0.2, and 0.06≦y≦0.3, and when d10, d50 and d90 are defined as a particle size at which point the cumulative frequency of volume reaches 10%, 50% and 90% respectively, d10 is not less than 2 μm and not more than 5 μm, d50 is not less than 6 and not more than 9 μm, and d90 is not less than 12 μm and not more than 15 μm, the BET specific surface area is greater than 1.0 m 2 /g and not more than 2.0 m 2 /g, and the tap density is not less than 0.5 g/cm 3 and less than 0.9 g/cm 3 .