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 an active material layer, a foil and an active material layer which are arranged in sequence, and a safety coating is arranged between the foil and the active material layer; the safety coating comprises a pore-forming agent, and the pore-forming agent comprises a compound with the melting and boiling point being 50-300 DEG C. When the temperature of the safety coating rises, the porous structure of the coating is filled, the conductive network is partially blocked, and the resistance of the safety coating is gradually increased, so that the safety coating plays a role in protecting the lithium ion battery; and meanwhile, the porous structure constructed by the safe coating improves the liquid retention capacity, the rate capability and the cycle performance of the battery, and reduces the impedance of the battery. 本发明提供了一种正极极片及其制备方法与应用，所述正极极片包括顺次设置的活性物质层、箔片和活性物质层，所述箔片和活性物质层之间设置安全涂层