CATHODE ACTIVE MATERIAL AND PREPARATION METHOD THEREOF, POSITIVE ELECTRODE PLATE, BATTERY, AND ELECTRICAL DEVICE

Provided are a cathode active material and a preparation method thereof, a positive electrode plate, a battery, and an electrical device. The cathode active material includes secondary particles. The secondary particles are formed with aggregated primary particles. The secondary particles include open pores and closed pores. An open pore porosity Pof the cathode active material accounts for 25% to 85% of a total porosity Pof the cathode active material.