The intrinsic specific surface area and the intrinsic pore size are measured after removing free substances on the surface of the tested material and even some substances inside the tested material via the extreme water washing. When in a battery, the tested material (the positive electrode material) may contact with electrolyte, which may lead to similar extraction of substances. Therefore, the extreme water washing can be regarded as a simulation of long-term operation of positive electrode materials. In this regard, the intrinsic specific surface area and the intrinsic pore size may truly reflect the properties of the tested material after long-term cycling, especially the particle strength and the binding strength of Li ions therein. The positive electrode material in accordance with the present disclosure has an intrinsic specific surface area and an intrinsic pore size within the required ranges, indicating that, even after prolonged battery cycling, the positive electrode material in accordance with the present disclosure may still have controlled pore configuration. This means that, even after prolonged operation, the positive electrode material in accordance with the present disclosure can still provide a transference path with suitable length for transferring lithium ions, avoiding loss in capacity and rate performance caused by long transference paths. At the same time, a certain ability to resist electrolyte erosion is kept, avoiding a large number of side reactions.

In a preferred embodiment, the positive electrode material has D₅₀ of 7.8-14.2 nm.

In a preferred embodiment, the positive electrode material has a compacted density of 2.0-3.8 g/cm³.