This application provides a method for preparing a positive
electrode sheet, a positive
electrode sheet, and a
lithium-
ion battery. The method for preparing the positive
electrode sheet includes
lithium intercalation treatment of a
niobium-based material to obtain a
lithium-containing
niobium-based composite. The lithium-containing
niobium-based composite, a positive electrode active material, a conductive agent, and a binder are mixed to obtain a
slurry. The
slurry is then formed on the surface of a
current collector to prepare the positive electrode sheet. This application first performs
lithium intercalation treatment on the niobium-based material. When lithium ions are intercalated into the
crystal lattice of the niobium-based material, not only is
electron transfer involved, causing a change in the valence state of the niobium ions in the niobium-based material, but the
crystal structure of the niobium-based material is also altered, creating effective
electron transport paths between crystals and enhancing
electron migration capabilities. By mixing the lithium-containing niobium-based composite obtained after
lithium intercalation with the positive electrode active material, conductive agent, and binder, the excellent ionic and
electronic conductivity of the lithium-containing niobium-based composite can improve
fast charging efficiency.