ELECTROCHEMICAL ENERGY STORAGE APPARATUS AND DEVICE

An electrochemical energy storage apparatus and a device are provided. The electrochemical energy storage apparatus includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte, where the positive electrode plate includes a positive electrode current collector, a positive electrode active substance layer disposed on at least one surface of the positive electrode current collector, and a safety layer disposed between the positive electrode active substance layer and the positive electrode current collector; the positive electrode active substance layer includes a positive electrode active substance; the safety layer includes a binding substance, a conductive substance, and an overcharge sensitive substance; the overcharge sensitive substance is a polymer containing monosaccharide structural units and containing at least one of carbonate groups or phosphate groups; the electrolyte includes a solvent and an electrolytic salt; and the solvent includes a carbonate-based solvent.