Stable lithium metal negative electrode

Abstract

The invention belongs to the technical field of a battery and particularly relates to a stable lithium metal negative electrode. The stable lithium metal negative electrode comprises a negative electrode current collector and a negative active material layer loaded on the surface of the current collector; the negative active material layer is a lithium metal layer; the negative electrode current collector comprises a current collector body and a lithium-philic nanometer array growing on the current collector body in situ; the thickness of the lithium-philic nanometer array is 0.8 <mu>m to 20 <mu>m. Compared with the prior art, the stable lithium metal negative electrode has the following advantages: the lithium-philic nanosheet array is arranged on the current collector body, so that ion transmission is facilitated, uniform distribution of lithium ions can be realized, the affinity of the stable lithium metal negative electrode and the lithium metal can be improved, a lithium-philic nucleation site is provided, and uniform nucleation and stable deposition of the lithium metal in the deposition process are realized. The array structure growing in situ can guarantee to be in tight contact with a copper current collector and reduce the effective current density of the electrode, so that uniform deposition of the lithium metal is realized; the lithium-philic current collector can inhibit the growth of lithium dendrites.

Description

technical field [0001] The invention belongs to the technical field of batteries, in particular to a stable lithium metal negative electrode. Background technique [0002] In recent years, the rapid development of electric vehicles, mobile electronic devices and rechargeable power sources makes it urgent to develop batteries with higher energy density. For this reason, people try to explore electrode materials and battery systems with high specific capacity and specific energy, and study their charging and discharging working principles. The theoretical specific capacity of metal lithium is as high as 3860mAh / g, the electrode potential is -3.045V (relative to the standard hydrogen electrode), and the reducibility is extremely strong. Therefore, metal lithium has been widely concerned by researchers as the negative electrode material of lithium batteries. But metal lithium has not been able to become the anode material of commercial secondary batteries so far. The reason is...

AI Technical Summary

Problems solved by technology

As the lithium dendrites continue to grow, not only will the solid electrolyte interface film be destroyed, but also the exposed lithium will continue to react with the electrolyte, consume the electrolyte, and will also pierce the separator to cause a short circuit inside the battery, causing a fire or even an explosion.

In addition, lithium dendrites are easy to fall off from the electrode, so they cannot be used effectively, forming "dead lithium", resulting in loss of battery capacity

[0003] At present, the three-dimensional conductive network matrix is ​​mostly used for lithium metal deposition. Although the three-dimensional conductive framework can reduce the effective current density of the electrode and make the electric field distribution on the electrode surface uniform, the existence of some large pores may increase the polarization and resistance of the electrode.

Moreover, in order to increase the content of lithium metal, these three-dimensional current collectors are generally thicker, which reduces the volumetric energy density of the electrode.

Coating lithium metal or a three-dimensional substrate with a lithium-philic layer can effectively reduce electrode polarization and impedance, but the preparation cost of such an electrode is too high

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