This application provides a positive electrode plate and an electrochemical apparatus and device associated therewith. The positive electrode plate includes a positive electrode current collector, a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, and a safety layer disposed between the positive electrode active material layer and the positive electrode current collector. The safety layer includes a binding substance, a conductive substance, and a special sensitive substance, where the special sensitive substance is at least one product of esterification of polysaccharide in which a degree of esterification of monosaccharide units is 35% to 98%. The electrochemical apparatus prepared by using the positive electrode plate of this application has significantly improved safety and electrical performance (such as cycling performance).