Preparation method of superstructure tin carbon-molybdenum oxide composite material and application of superstructure tin carbon-molybdenum oxide composite material to electrode

Abstract

The invention belongs to the technical field of electrode material preparation, and relates to a preparation method of a superstructure tin carbon-molybdenum oxide composite material and application of the superstructure tin carbon-molybdenum oxide composite material to an electrode. The preparation method comprises the following steps: preparing an alkaline solution to enable the pH value to be 8.0-10.5, dissolving phosphomolybdate in the alkaline solution, dispersing tin-based nanoparticles in the alkaline solution, preparing a dopamine hydrochloride alkaline solution with the same volume astin-based nanoparticles, enabling phosphomolybdic acid and dopamine to be subjected to coordination polymerization reaction, adsorbing the tin-based nanoparticles in the solution, and forming a superstructure precursor through self-assembly; and centrifuging, washing and drying the superstructure precursor, and carrying out carbonizing in a protective atmosphere to obtain the product. The preparation process is simple, uniform dispersion of the tin-based nanoparticles in a three-dimensional carbon skeleton is realized by constructing a superstructure, the tin-based nanoparticles are reduced into nano tin in the carbonization process, meanwhile, a pore-forming effect can be achieved, and volume expansion and pulverization of the tin-based material in the charging and discharging process can be effectively inhibited; the polydopamine provides a carbon source and is doped with nitrogen atoms in situ at the same time, so that the conductivity of the material is improved.

Description

technical field [0001] The invention belongs to the technical field of electrode material preparation, and in particular relates to a preparation method of a superstructure tin-carbon-molybdenum oxide composite material and its application to electrodes. Background technique [0002] Lithium-ion batteries have been widely concerned because of their advantages such as high voltage, high energy density, good safety, light weight, small self-discharge, long cycle life, no memory effect, and no pollution. research hotspot. Graphite is the anode material of lithium-ion batteries that have been commercialized at present, and it has good cycle performance. However, the capacity of graphite is low, and the electrode potential after storing lithium is similar to that of metal lithium. When the battery is overcharged, metal lithium is easy to precipitate on the surface of the carbon electrode, forming dendrites and causing short circuits. [0003] Tin-based materials are considered ...

AI Technical Summary

Problems solved by technology

However, the reversible formation and decomposition of Li-Sn alloys is accompanied by a huge volume change, which easily causes the pulverization of tin particles, causing the active materials to fall off from the current collector, resulting in a short cycle life of tin-based materials.

At the same time, when the tin particles are exposed in the electrolyte, an unstable SEI film will be formed on the surface of the tin, which reduces the cycle performance of the electrode material.

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