CATHODE ACTIVE MATERIAL AND PREPARATION METHOD THEREFOR, CATHODE PLATE, BATTERY, AND ELECTRICAL DEVICE

Provided is a cathode active material including lithium iron phosphate. A number-based particle size distribution curve of the primary particles has the first to third characteristic peaks. A peak position Dof the first characteristic peak is from 100 nm to 300 nm, and a number percentage Ncorresponding to the peak position Dof the first characteristic peak ranges from 25% to 35%. A peak position Dof the second characteristic peak of the primary particles is from 320 nm to 400 nm, and a number percentage Ncorresponding to the peak position Dof the second characteristic peak ranges from 4% to 9%. A peak position Dof the third characteristic peak of the primary particles is from 450 nm to 620 nm, and a number percentage Ncorresponding to the peak position Dof the third characteristic peak ranges from 0.5% to 2%.