Three-dimensional carbon material and preparation method thereof, as well as metal lithium composite electrode and preparation method thereof

Abstract

The invention discloses a method for preparing a three-dimensional carbon material. The method comprising: S1) soaking a sponge in a soluble catalyst precursor aqueous solution, after drying, obtaining a soaked sponge; the soluble catalyst being a salt compound of iron series element; S2) heating the soaked sponge in a protective atmosphere and keeping the temperature, and obtaining the three-dimensional carbon material. Compared with the prior art, according to the invention, the sponge is used as a solid carbon source, the sponge adsorbs catalyst precursor in an early stage, and then in theprotective atmosphere, the sponge is pyrolyzed and carbonized, the catalyst is generated in situ, and the carbon nanotube grows at the same time; the three-dimensional carbon material with the carbonnanotube winding a carbonized sponge framework is prepared, the method is simple without requiring post processing; moreover, the three-dimensional carbon material maintains the elasticity and the three-dimensional framework structure of the sponge, has certain conductivity, also has a larger specific surface area and rich void structures, and after depositing metal lithium, and the three-dimensional carbon material maintains the elasticity and the three-dimensional framework structure of the sponge can achieve high current density and high surface capacity without dendrite formation.

Description

Technical field [0001] The invention belongs to the technical field of nano materials, and in particular relates to a three-dimensional carbon material and a preparation method thereof, a metal lithium composite electrode and a preparation method thereof. Background technique [0002] Carbon nanotubes are one-dimensional carbon nanomaterials with a unique tubular structure. Compared with traditional carbon materials, carbon nanotubes have excellent mechanical and electrical properties, and have broad application prospects in energy storage. [0003] Many scholars have conducted research on the preparation of carbon nanotubes from solid carbon sources. For example, the Chinese Patent Publication No. CN107032326A discloses a method for preparing spiral carbon nanotubes by solid-phase catalysis, which uses urea or melamine powder as a solid state. Carbon source, carbon nanotubes are prepared under the atmosphere of protective gas, but the material obtained by this method is powder; s...

AI Technical Summary

Problems solved by technology

However, as the negative electrode material of lithium batteries, lithium metal has always had the problem of lithium dendrites: during the growth process of lithium dendrites, it is easy to pierce the separator, resulting in a short circuit of the battery and a potential safety hazard; at the same time, lithium dendrites are separating and depositing lithium. In the process of continuous generation and fragmentation, some free lithium (dead lithium) on the surface of lithium metal is produced, and the surface of lithium metal needs to continuously regenerate the solid electrolyte interface film (SEI), so that the cycle stability and coulombic efficiency of lithium metal batteries greatly affected

[0006] At present, there are many studies devoted to the application of three-dimensional carbon materials to lithium metal negative electrodes, but they all focus on circulation under low current density and small surface capacity. mA / cm 2 Kneading capacity 0.625mA·h / cm 2 Under circulation, some people also try to circulate under high current density and small surface capacity. For example, the Chinese patent with the publication number CN106784635 discloses a three-dimensional carbon material. 2 Kneading capacity 1mA·h / cm 2 Under cycle, but rarely achieve high current density and high areal capacity

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