Lithium-supplementing negative electrode plate, preparation method thereof and lithium ion battery

Abstract

The invention provides a lithium-supplementing negative electrode plate, a preparation method thereof and a lithium ion battery. The lithium-supplementing negative electrode plate comprises a lithium powder composite membrane and a negative electrode current collector; and the weight of the lithium powder in the lithium powder composite membrane of the lithium supplement negative plate per unit volume is 0.5-2% of the weight of the positive electrode main material in the positive plate per unit volume. The preparation method comprises the following steps: (1) mixing graphite and silicon powder to obtain first negative electrode powder; (2) mixing a conductive agent, lithium powder and the first negative electrode powder obtained in the step (1) to obtain second negative electrode powder; (3) mixing a binder with the second negative electrode powder obtained in the step (2) to obtain third negative electrode powder; (4) rolling the third negative electrode powder obtained in the step (3) to obtain a lithium powder composite membrane; and (5) mutually laminating the lithium powder composite diaphragm obtained in the step (4) and a negative electrode current collector, and rolling together to obtain the lithium-supplementing negative electrode plate. The lithium-supplementing negative plate makes up lithium consumed in the first lithium embedding process, and the lithium supplementing process is simplified.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and relates to a lithium-replenishing negative electrode sheet, in particular to a lithium-replenishing negative electrode sheet, a preparation method thereof, and a lithium-ion battery. Background technique [0002] The current worldwide energy crisis has led to an increasingly urgent need for and development of new energy vehicles. It is an inevitable trend for pure electric new energy vehicles to gradually replace traditional gasoline vehicles. However, new energy vehicles have higher requirements for power batteries. become more prominent. At present, in the application of lithium-ion batteries, graphite materials have 5%-10% irreversible lithium loss during the first charge and discharge process, while high-capacity silicon anode materials have 15%-35% irreversible lithium loss during the first charge and discharge process. Lithium supplementation technology is now usually use...

AI Technical Summary

Problems solved by technology

However, the invention needs to redesign the battery structure, and it is difficult to ensure the consistency of the negative electrode after lithium supplementation, the process is also very complicated, and the operation is cumbersome

Images