Lithium battery negative electrode sheet and preparation method thereof as well as lithium battery preparation method

Abstract

The invention discloses a lithium battery negative electrode sheet and a preparation method thereof as well as a lithium battery preparation method. The lithium battery negative electrode sheet comprises a negative electrode current collector manufactured by adopting a metal foil or a metal net, a lithium layer arranged on the surface of the negative electrode current collector and a negative electrode tab connected with the negative electrode current collector; a metal lithium layer is plated on the surface of the negative electrode current collector in an electroplating manner, and compared with the conventional lithium battery, the lithium battery disclosed the invention can greatly save the battery space and improve the energy density; the metal lithium layer is plated on the metal foil or the metal net in an electroplating manner, so that the negative electrode lithium layer is thinned and the tensile strength of the lithium layer is improved; compared with the primary lithium battery, the lithium battery achieves heavy current discharge and improves the power density; the difficulty that the primary lithium battery is required to be manufactured in a drying or inert atmosphere is avoided and the manufacture cost of the battery is reduced.

Description

technical field [0001] The invention relates to the technical field of lithium battery processing, in particular to a lithium battery negative electrode sheet, a preparation method thereof, and a corresponding lithium battery preparation method. Background technique [0002] Lithium batteries have the advantages of wide operating temperature range, stable discharge voltage, low self-discharge rate, and long service life. They have been widely used in various fields, especially aerospace, military, long-life instrumentation, logistics tracking, automotive electronics, Mobile digital products and other fields. [0003] In recent years, with the continuous development of science and technology, the functions of electronic equipment have been continuously upgraded, and the application range of lithium-ion batteries has become wider and wider. Therefore, higher requirements have been put forward for the energy density and rate performance of lithium batteries. High-energy and hig...

AI Technical Summary

Problems solved by technology

Commonly used primary lithium batteries, the production of negative metal lithium sheets is usually to make metal lithium blocks or lithium ingots into metal lithium strips of a certain size by extrusion or molding; and lithium sheets produced by extrusion or molding exist Two disadvantages: one is that the thickness of the extrusion (molding) is not uniform, and the consistency of the lithium sheet is difficult to guarantee; the other is that due to the low metal strength of lithium, it is easy to break during the process of extrusion and stretching of the thin metal lithium strip. The utilization rate of lithium is low and it is difficult to make thin metal lithium strips. Currently, the thinnest lithium strips that can be achieved by extrusion or molding are about 0.06mm (ie 60μm)

Although compared with metal lithium, carbon materials have greatly improved in terms of safety performance and cycle performance, but there are still many disadvantages: the theoretical gram capacity of carbon material negative electrodes is 372mAh / g, when charging and discharging for the first time, A passivation film will be formed on the carbon surface, resulting in capacity loss and low initial charge and discharge efficiency; and because the electrode potentials of the carbon electrode and lithium metal are similar, lithium metal may still be precipitated on the surface of the carbon electrode when the battery is overcharged, forming Dendrites cause short circuits; interaction with electrolyte and possible thermal runaway at high temperatures, etc.

High-power primary lithium batteries are usually deposited or sprayed onto thin conductive supports such as metal mesh or metal strips (copper foil, nickel mesh, etc.) to increase their mechanical tensile strength and achieve thinning. The purpose of lithium metal negative electrode, but the method of deposition or spraying makes the manufacturing process obviously complicated, it is difficult to achieve continuous production, and the utilization rate of metal lithium is low

The research on high-energy lithium-ion batteries mainly lies in positive and negative electrode materials. Compared with carbon negative electrodes, alloy-based negative electrode materials generally have higher specific capacity, but poor cycle performance and volume expansion.

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