Carbon-coated silicon negative electrode material with hollow structure and preparation method thereof

Abstract

The invention discloses a carbon-coated silicon negative electrode material with a hollow structure prepared by taking ZIF-67 as a template and a preparation method of the carbon-coated silicon negative electrode material, and the preparation method comprises the following steps: ultrasonically dispersing silicon powder into methanol, and respectively adding 2-methylimidazole and cobalt salt under a stirring condition; standing, carrying out centrifugal separation, and drying to obtain a precursor Si@ ZIF-67; ultrasonically dispersing the obtained Si @ ZIF-67 in ethanol, and adding the obtained Si @ ZIF67 into a tannic acid solution under a stirring condition; standing, centrifugally separating, washing with ethanol, drying and carbonizing to obtain a product, namely the carbon-coated silicon negative electrode material with the hollow structure. The silicon-carbon negative electrode material prepared by the method can inhibit overlarge volume expansion of silicon in the charging and discharging process to a certain extent, provides a proper space for volume expansion of silicon powder, and can solve the problem of silicon powder pulverization caused by internal stress.

Description

technical field [0001] The invention belongs to the field of electrochemical energy storage, and in particular relates to a carbon-coated silicon negative electrode material with a hollow structure and a preparation method thereof. Background technique [0002] Currently, energy crisis and environmental pollution have posed potential threats to social development and human health. Therefore, it is crucial to design and construct a green and efficient energy conversion and storage device. Lithium-ion batteries have become one of the most promising energy storage devices due to their high energy density, good rate capability, and long cycle life. Graphite is well known as an anode material for commercial lithium-ion batteries, but its low theoretical capacity (372 mAh / g) hinders its application in high-energy-density energy storage. Therefore, various electrode materials have been studied and reported to replace graphite, such as silicon, transition metal oxides, and sulfide...

AI Technical Summary

Problems solved by technology

The silicon-carbon negative electrode material prepared by this method can not only suppress the excessive volume expansion of silicon during the charging and discharging process to a certain extent, but also solve the problem of silicon powder pulverization caused by internal stress.

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