A nitrogen-doped carbon sphere using lignin as raw material and its preparation method and application

Abstract

The invention belongs to the field of nanometer material preparation, and particularly discloses N-doped carbon spheres with lignin as the raw material and a preparing method and application thereof. The preparing method comprises the steps of dissolving alkali lignin in water, and then adding hydrogen peroxide for reaction to obtain demethoxy lignin reaction liquid; making aniline or aniline derivatives react with sodium nitrite to obtain diazonium salt reaction liquid; mixing the reaction liquid for reaction; adding dilute sulphuric acid for sedimentation, and conducting washing and drying to obtain a lignin-based azo polymer, dissolving the polymer in an organic solvent, and adding water to change the microfacies environment to obtain lignin azo polymer colloidal spheres; calcining the lignin azo polymer colloidal spheres under inert gas shielding, and conducting cooling to obtain the N-doped carbon spheres. The porous N-doped carbon spheres with uniform structure can be obtained through carbonization of the lignin azo polymer colloidal spheres, and the N-doped carbon spheres show excellent initial coulomb efficiency and long-term circulation stability when applied to a lithium ion battery negative electrode active material and are an environment-friendly reproducible nano electrode material.

Description

technical field [0001] The invention belongs to the field of nanomaterial preparation, and in particular relates to a nitrogen-doped carbon sphere using lignin as a raw material and a preparation method and application thereof. Background technique [0002] Today's society is suffering from more and more serious environmental problems and energy crises, and seeking a green and sustainable development path has increasingly become an urgent problem for manufacturers, especially the energy industry that is highly dependent on fossil resources. Rechargeable batteries play an important role in energy storage devices. Carbon materials occupy the dominant position in battery anode active materials due to their large quantity and ease of operation, but commercialized graphite has disadvantages such as low rate, poor stability, and easy reaction with electrolyte. Although new carbon materials such as carbon nanotubes, graphene, mesoporous carbon, and carbon nanofibers have good elec...

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Problems solved by technology

But only less than 10% of the lignin has been effectively used, and more than 90% of the lignin will be burned directly, which not only pollutes the environment, but also wastes resources

When lignin is directly prepared as a carbon material for battery active materials, the capacity is low and the stability is poor; when it is used as an additive, it cannot be used efficiently (the amount added is less than 50%), and the lignin used is also limited to a certain type

[0005] At present, there are new ideas and ideas for the preparation of carbon materials from lignin, such as the melt blending method (ACS Sustain.Chem.Eng., 2014, 2:2002-2010) and the electrospinning method (ACS Appl .Mater.Inter., 2013,5:12275-12282) obtained carbon fiber has good electrochemical properties, but there are shortcomings of low output, high energy consumption, and poor economic benefit, so it is difficult to apply on a large scale

Comparing the literature, it can be found that in the process of preparing carbon materials based on lignin as raw material, everyone pays more attention to the improvement of the preparation method itself, rather than modifying lignin itself to prepare carbon materials, so that Due to the structural defects of lignin, the prepared materials cannot always show excellent performance, which also greatly hinders the process of high-value utilization of lignin.

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