A lithium metal battery negative electrode framework material and its preparation method and lithium metal battery negative electrode

Abstract

The invention provides a lithium metal battery negative electrode framework material and a preparation method thereof and a lithium metal battery negative electrode. The method includes: mixing soybean products and KOH solution, ultrasonication; freezing the obtained precursor solution with liquid nitrogen and then vacuum freeze-drying to obtain Layered precursor; finally activated and carbonized at 700-800°C to obtain the negative electrode framework material for lithium metal batteries. The method adopts soybean product biomass, and through one-step activation and carbonization, the method is simple and easy, and the raw materials are widely available; and as the negative electrode material of the lithium metal battery, the cycle stability of the battery can be improved. It has a high surface area, a narrow pore size distribution, and a large number. The specific surface area of ​​the lithium metal battery anode skeleton material is as high as 3134m 2 g ‑1 The mesopores are 2.2-2.8nm, and the micropores are concentrated at 0.8nm and 1.4nm; after dozens of cycles of charging and discharging, the lithium metal battery still maintains a stable charging and discharging voltage, and there is almost no polarization.

Description

technical field [0001] The invention relates to the technical field of lithium metal batteries, in particular to a lithium metal battery negative electrode framework material, a preparation method thereof, and a lithium metal battery negative electrode. Background technique [0002] In order to better meet the development of human society, new energy storage devices have become a research hotspot. Lithium metal has up to 3860mAh·g -1 The specific capacity is much higher than that of traditional lithium-ion batteries, and it has the advantages of lower electrode potential (-3.04V vs standard hydrogen electrode), which is an ideal next-generation battery; but lithium metal is directly used as the negative electrode, in practical applications There are still urgent problems to be solved: (1) Li dendrites will form due to the uneven deposition / dissolution of Li during the charge-discharge cycle; Li dendrites will pierce the separator during the growth process, resulting in shor...

AI Technical Summary

Problems solved by technology

Lithium metal has up to 3860mAh·g -1 The specific capacity is much higher than that of traditional lithium-ion batteries, and it has the advantages of lower electrode potential (-3.04V vs standard hydrogen electrode), which is an ideal next-generation battery; but lithium metal is directly used as the negative electrode, in practical applications There are still urgent problems to be solved: (1) Li dendrites will form due to the uneven deposition / dissolution of Li during the charge-discharge cycle; Li dendrites will pierce the separator during the growth process, resulting in short circuits inside the battery, Thus causing safety problems; (2) The formation of lithium dendrites will cause the metal lithium negative electrode to expand infinitely, and the broken lithium dendrites will form "dead lithium" at the same time; and the active lithium metal will also react with most of the organic electrolyte The formation of SEI leads to the consumption of lithium metal and electrolyte, resulting in the decrease of Coulombic efficiency of the battery, poor cycle and other adverse effects

However, the preparation methods of the existing framework materials are complicated and the raw materials are expensive, which is not conducive to large-scale production.

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