▎ 摘　　要

NOVELTY - Preparing a graphene-elemental silicon composite aerogel involves mixing the silicon source, deionized water and absolute ethanol to obtain a first mixed solution, adding a graphene oxide aqueous solution to the first mixed solution, and uniformly dispersing by ultrasound to obtain a second mixed solution, adding the hydrochloric acid ethanol solution to second mixed solution, stirring uniformly and adjusting the pH of the mixed solution to 2-3, adding ammonia water ethanol solution to the mixed solution, stirring uniformly and adjusting the pH of the mixed solution to 6.5-7.8, and then waiting for the gel at 20-70 degrees C, adding obtained gel to anhydrous ethanol for solvent replacement to obtain a composite wet gel, subjecting obtained the composite wet gel to a carbon di-oxide supercritical drying treatment to obtain a composite aerogel. USE - Method for preparing graphene-elemental silicon composite aerogel. ADVANTAGE - The method enables to prepare a graphene-elemental silicon composite aerogel having greater than 90% active material content, which significantly improves cycle performance. DETAILED DESCRIPTION - Preparing a graphene-elemental silicon composite aerogel involves mixing the silicon source, deionized water and absolute ethanol to obtain a first mixed solution, adding a graphene oxide aqueous solution to the first mixed solution, and uniformly dispersing by ultrasound to obtain a second mixed solution, adding the hydrochloric acid ethanol solution to second mixed solution, stirring uniformly and adjusting the pH of the mixed solution to 2-3, adding ammonia water ethanol solution to the mixed solution, stirring uniformly and adjusting the pH of the mixed solution to 6.5-7.8, and then waiting for the gel at 20-70 degrees C, adding obtained gel to anhydrous ethanol for solvent replacement to obtain a composite wet gel, subjecting obtained the composite wet gel to a carbon di-oxide supercritical drying treatment to obtain a composite aerogel. The composite aerogel obtained in step (6) is subjected to high temperature reduction and naturally cooled to room temperature to obtain a graphene-silica composite aerogel. The obtained graphene-silica composite aerogel is mixed with magnesium powder under the protection of an inert gas. The heat treatment is performed, and after treatment is completed, it is naturally cooled to room temperature. The product is immersed in an excessive amount of hydrochloric acid ethanol solution, and then repeatedly washed with ethanol and deionized water, and dried in a vacuum drying box to obtain it.