Preparation method of lithium-copper composite negative electrode foil piece

Abstract

The invention relates to a preparation method of a lithium-copper composite negative electrode foil piece. An intermittent local pressure enhancement method is adopted for uniformly adhering lithium metal foil pieces on the surface of a copper foil, and a lithium-copper composite negative electrode foil piece is formed. The preparation method comprises the following concrete steps: clamping the copper foil between the lithium metal foil pieces to form a lithium foil / copper foil / lithium foil sandwich layer; adopting common rolling equipment, starting a traction system, and enabling the lithiumfoil / copper foil / lithium foil sandwich layer to pass through a grinding roller, so as to form intermittent local pressure on the lithium foil / copper foil / lithium foil sandwich layer, wherein the pressure range is 0.05-5MPa, and a pre-compounded lithium foil / copper foil / lithium foil sandwich slice is formed; and enabling the pre-compounded lithium foil / copper foil / lithium foil sandwich slice to pass through the grinding roller again, and applying pressure for shaping, wherein the pressure range is 0.02-5MPa, so that the lithium-copper composite negative electrode foil piece is obtained. The preparation method provided by the invention has the beneficial effects that layer-to-layer contact of the prepared lithium-copper composite negative electrode foil piece is uniform, contact of a lithiummetal negative electrode with the copper foil is further improved, and the problem that the lithium metal foil piece and the copper foil are infirmly bonded is avoided, so that outage of lithium metal in a working process of a battery is prevented.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a preparation method of a lithium-copper composite negative electrode foil. Background technique [0002] At present, the commonly used negative electrode material of lithium battery is graphite material. The theoretical specific capacity of graphite negative electrode is 372mAh / g. The energy density of traditional graphite negative electrode system has little room for improvement. The theoretical specific capacity of metal lithium is 3860mAh / g, and the redox potential is low. , lithium metal has natural advantages as the negative electrode of lithium-ion batteries, and lithium metal negative electrodes are considered by the industry to be the ultimate negative electrode solution for high-energy-density batteries. At present, the metal lithium / copper negative electrode foil using copper foil as current collector and tab is the key research of lithium-ion...

AI Technical Summary

Problems solved by technology

However, studies have shown that poor mechanical strength is the biggest defect of metal lithium / copper anode foils

The contact force between the lithium metal negative electrode and the copper foil layer is poor, which leads to the power failure of the lithium metal during the working process of the battery, making it impossible to achieve large-scale production and application

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