CATHODE SHEET AND METHOD FOR PREPARING SAME, AND LITHIUM-ION BATTERY

The present invention relates to the technical field of lithium-ion batteries, and particularly provides a positive electrode sheet and a preparation method therefor, and a lithium-ion battery comprising the positive electrode sheet. The positive electrode sheet comprises a positive electrode active material layer, and the positive electrode active material layer comprises a positive electrode material, a negative thermal expansion material, a conductive agent, and a binder, wherein the characteristic value J of the positive electrode sheet satisfies: 0.001≤J≤0.005. wherein J=R(F)/ρ, R(F) represents the peak intensity ratio between the main peak (F) of the negative thermal expansion material and the (003) characteristic peak of the positive electrode material in the XRD pattern of the positive electrode sheet, and p represents the surface density of the positive electrode sheet, with a unit of mg/cm.