The invention provides a secondary battery and a preparation method thereof, an
energy storage system and
electric equipment, and relates to the technical field of
energy storage. The method comprises the following steps: assembling a positive plate, a diaphragm and a negative plate, injecting an
electrolyte to obtain a secondary battery, and sequentially mixing,
coating and
drying a first positive active material, nano SiO2, two-dimensional
titanium carbide, a first conductive agent, a first binder and a first
solvent to form a
coating; mixing,
coating and
drying a second positive
electrode active material, a
carbon nanotube, a second conductive agent, a second binder and a second
solvent in sequence to form a coating; a third positive
electrode active material, an
azobenzene group modified fluorinated
acrylate copolymer, a third conductive agent, a third binder and a third
solvent are sequentially mixed, coated, subjected to edge
ultraviolet light curing treatment and dried, and the positive
electrode plate is obtained. The preparation method is helpful for reducing the edge bulging phenomenon of the positive plate in the coating process, and is helpful for improving the capacity and the
cycling stability of the secondary battery.