Ultrathin lithium-rich alloy with embedded three-dimensional skeleton structure as well as preparation method and application of ultrathin lithium-rich alloy

Abstract

The invention discloses an ultrathin lithium-rich alloy with an embedded three-dimensional skeleton structure and a preparation method and application of the ultrathin lithium-rich alloy, and belongs to the technical field of lithium batteries. The ultrathin lithium-rich alloy with the embedded three-dimensional skeleton structure is prepared by changing the types of dissimilar substances and the proportion of the dissimilar substances to lithium element and matching with a casting substrate with a certain inclination angle, movement speed and cooling speed; and the adhesive force and wettability of the lithium-rich alloy solution on the casting substrate and the phase separation behavior in the cooling process are jointly regulated and controlled, so that the thickness and the surface state of the lithium-rich alloy layer, the bonding state of the lithium-rich alloy layer and the casting substrate and the morphology structure of a three-dimensional framework are regulated. The ultrathin lithium-rich alloy with the embedded three-dimensional skeleton structure is prepared by adopting the inclined melting tape casting method, the thickness of the film can be changed in a relatively large range, and the method has the characteristics of simplicity, high efficiency, wide application range and capability of realizing batch continuous production.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to an ultra-thin lithium-rich alloy with an embedded three-dimensional skeleton structure and a preparation method and application thereof. Background technique [0002] As an ideal anode material for next-generation high-energy-density batteries, metallic lithium anodes have gained widespread attention. Since the specific capacity of metal lithium is more than ten times that of the current commercial positive electrode active materials, and commercial positive electrode materials contain a large amount of lithium, the optimal lithium negative electrode thickness is often below 100 μm. However, due to the safety hazards caused by the growth of lithium dendrites, it is difficult to make breakthroughs in commercial applications of lithium metal anodes. Replacing lithium anodes with lithium alloy anodes is a possible solution. [0003] Due to the addition of dissimilar elem...

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Problems solved by technology

Electroless deposition is a common method for preparing alloy materials. However, due to the particularity of metal lithium, a thin layer of metal is usually deposited on the surface of metal lithium negative electrode by electroplating or electroless plating, and then alloyed with lithium. Lithium alloy thin layer is obtained by chemical reaction, and the prepared lithium alloy layer generally serves as the coating layer of metal lithium negative electrode, and it is not suitable to use the alloy layer directly as the negative electrode active material.

In addition, the chemical deposition method is difficult to prepare lithium alloy film layers on a large scale, and the prepared lithium alloy surface contains organic liquid residues or decomposition products, which limits its application.

[0004] At present, there are few reports on the preparation methods of lithium alloy thin films, and there are even fewer reports on the preparation methods for ultra-thin lithium alloys.

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