Framework material for lithium metal battery negative electrode and preparation method of framework material as well as lithium metal battery negative electrode

Abstract

The invention discloses a framework material for a lithium metal battery negative electrode and a preparation method of the framework material and the lithium metal battery negative electrode. The method comprises the following steps: mixing a soybean product with a KOH solution and carrying out ultrasonic treatment; carrying out liquid nitrogen freezing on the obtained precursor solution and thencarrying out vacuum freeze-drying to obtain a lamellar precursor; finally, carrying out activated carbonization at the temperature of 700 to 800 DEG C to obtain the framework material for the lithiummetal battery negative electrode. By adopting the method, soybean product biomass and a one-step activation carbonization mode, the method is simple and feasible, and raw materials are wide in sourceand easily obtained; in addition, the cycle stability of the battery is improved by taking the soybean product biomass as a negative electrode material of the lithium metal battery. The framework material for the lithium metal battery negative electrode has higher surface area, narrow pore size distribution and large amount. The framework material for the lithium metal battery negative electrodehas the characteristics that the specific surface area reaches as high as 3134m<2>.g<-1>; the mesoporous is 2.2 to 2.8nm and micropore are concentrated between 0.8nm and 1.4nm; after charge-dischargecycle of the lithium metal battery cycle for dozens of circles, stable charge-discharge voltage is still maintained and the polarization phenomenon is almost avoided.

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...

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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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