Preparation method of esterified modified starch derived hard carbon negative electrode material and application of esterified modified starch derived hard carbon negative electrode material in sodium-ion battery

Abstract

The invention discloses a preparation method of an esterified modified starch derived hard carbon negative electrode material and application of the esterified modified starch derived hard carbon negative electrode material in a sodium-ion battery, and belongs to the technical field of sodium-ion battery negative electrodes. The preparation method comprises the following steps: firstly, carrying out one-step hydrothermal pretreatment on cheap cross-linked-esterified composite modified starch, and then carrying out one-step high-temperature carbonization to obtain the spherical hard carbon negative electrode material. And the compact stacking density formed by the spherical morphology is beneficial to shortening the diffusion path of ions and electrons. The acetyl group replaces part of hydroxyl groups in starch molecules, so that the content of amylose is reduced, the structural stability of the starch is enhanced, and the sodium storage performance is improved. In addition, the hard carbon negative pole piece is subjected to sodium pre-treatment through a liquid-phase sodium pre-treatment technology, so that the first efficiency of the battery is improved, and the long-cycle stability is promoted. The preparation process has the advantages of simple steps, simple equipment, good repeatability, no need of large-scale subsequent treatment, and suitableness for large-scale production.

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