Positive electrode material, positive electrode plate and battery

A positive electrode material includes a first lithium manganese iron phosphate material in an aggregate form, a second and third lithium manganese iron phosphate materials in an aggregate and/or single-crystal-like form, and a fourth and fifth lithium manganese iron phosphate materials in a single-crystal-like form. D 50 5 D 50 4 D 50 3 D 50 2 D 50 1 , D 50 2 =aD 50 1 , D 50 3 =bD 50 1 , D 50 4 =cD 50 1 , D 50 5 =dD 50 1 , and 5 m D 50 1 15 m. 0.35 a 0.5, 0.2 b 0.27, 0.17 c 0.18, and 0.15 d 0.16. Molar ratios of manganese to iron in the first, the second, the third and the fourth lithium manganese iron phosphate materials increase sequentially, and a molar ratio of manganese to iron in the fifth lithium manganese iron phosphate material is greater than that in the third lithium manganese iron phosphate material.