Positive electrode with lithium supplementing function and preparation method and application thereof

Abstract

The invention provides a positive electrode with a lithium supplementing function and a preparation method and application thereof.The positive electrode comprises a current collector and a lithium supplementing functional layer arranged on the surface of at least one side of the current collector, and the lithium supplementing functional layer comprises a positive electrode active material layer and a first lithium supplementing layer which are arranged side by side; the first lithium supplementing layers are positioned on two sides of the positive electrode active material layer; and after the lithium supplementing material in the first lithium supplementing layer releases lithium ions, the resistivity of the pole piece is greater than or equal to 14000 omega.cm. The positive electrode active material layer and the lithium supplementing layers are arranged on the surface of the current collector, the lithium supplementing layers containing specific lithium supplementing materials are adopted to replace original ceramic layers, the lithium supplementing layers are located on the two sides of the positive electrode active material layer, the lithium supplementing effect can be achieved, the insulation effect can be achieved after lithium removal, positive and negative electrode short circuit of the battery is prevented, and the service life of the battery is prolonged. A ceramic layer without lithium storage capacity is replaced, and the overall energy density of the battery is improved.

Description

A kind of positive electrode with lithium supplement function and preparation method and application thereof technical field [0001] The invention belongs to the technical field of batteries, and relates to a positive electrode with a lithium supplement function and a preparation method and application thereof. Background technique At present, with the rapid development of electric vehicles and large-scale energy storage devices, people are increasingly interested in high-energy density lithium-ion batteries. The demand for lithium supplements is also gradually increasing, and there are more and more studies on pre-lithiation through positive lithium supplements. The common usage is to mix the positive electrode main material, conductive agent, binder, and positive electrode lithium supplementary additive according to a certain ratio during the homogenization process. For example, a positive electrode slurry is made by mixing and stirring, and then the positive electrod...

AI Technical Summary

Problems solved by technology

[0004] Most of the lithium supplementation methods in the prior art are to mix the lithium supplementary material with the positive electrode active material, or to set up a lithium supplementary layer between the current collector and the positive electrode active material layer. This lithium supplementation method will affect the electrochemical performance of the positive electrode active material Simultaneously, during industrialized production, in order to avoid battery short circuit, insulated ceramic layer is generally set at the two ends of lithium supplement layer and positive electrode active material layer, and it has reduced the energy density of battery, has limited the lithium supplement effect of lithium supplement material, further Reduced electrochemical performance of Li-ion batteries

Images