Positive pole piece as well as preparation method and application thereof

The invention provides a positive pole piece and a preparation method and application thereof, the positive pole piece comprises a positive current collector, a safety coating, a pre-lithiation coating and a positive active substance layer which are sequentially stacked, the safety coating comprises a phosphate material, the pre-lithiation coating comprises a lithium-rich compound and/or a sacrificial salt pre-lithiation material, and the positive active substance layer comprises a lithium-rich compound and/or a sacrificial salt pre-lithiation material. According to the invention, the pre-lithiation coating is arranged between the safety coating and the positive active material layer of the positive pole piece, and the pre-lithiation coating can increase the energy density of the battery and improve the wettability of electrolyte under the condition that the effect of the safety coating is not influenced, so that the capacity of active materials in the safety coating and the electrode active material layer ca