A kind of lithium-ion battery negative electrode material self-coating precursor and preparation method thereof

Abstract

The invention relates to a preparation method of a self-coating precursor of a lithium ion battery negative electrode material. The preparation method comprises the following steps of performing dehydrogenation polycondensation reaction on a primary raw material to obtain a precursor intermediate product; smashing and balling the precursor intermediate product to obtain precursor micro powder; andheating the precursor micro powder to 400-500 DEG C, performing partial melting and self-coating on the precursor micro powder to obtain the self-coating precursor. By the preparation method, no additive coating agent is needed, no carbonization is needed, the process is simplified, and the cost is reduced.

Description

technical field [0001] The invention relates to a carbon material capable of preparing negative electrode materials of lithium ion batteries and a preparation method thereof, in particular to a precursor capable of preparing negative electrode materials of lithium ion batteries and a preparation method thereof. Background technique [0002] One of the key technologies of lithium-ion batteries lies in the exploration and research of negative electrode materials, so as to improve the performance of batteries. To achieve high voltage, high specific capacity and good cycle performance, materials are required to have better intercalation reversibility, more space for lithium intercalation, and fast deintercalation; higher discharge voltage, flat discharge curve; good Thermodynamic stability; good compatibility with electrolyte; stable charge and discharge process, small structural changes. [0003] Although a variety of anode materials for lithium-ion batteries have been studied...

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Problems solved by technology

Although this can improve the electrochemical performance of graphite to a certain extent, this structure has some disadvantages: because the surface of the particles is amorphous carbon, the reactivity is high, which usually has a negative impact on the storage performance; the surface of the particles is amorphous Another adverse consequence of carbon is to increase the irreversible capacity, resulting in low initial efficiency; the coating process needs to add a coating agent, and carbonization / graphitization is required after coating, resulting in an increase in cost

[0004] Patent CN1691374A discloses that artificial graphite and coating material are mixed and coated and then thermally polymerized. After carbonization and graphitization, a carbon negative electrode material with a carbon layer on the surface is obtained. The first charge and discharge efficiency and initial discharge capacity of the obtained material are low, and the coating The coating process is complex, requiring carbonization and graphitization, and high energy consumption; patent CN101916844A discloses a negative electrode material, the inner core is graphite, and the outer shell is a graphitized product of asphalt. Although the asphalt coating is relatively uniform, an external coating agent is required And ball milling and mixing, the product can be obtained through carbonization, shaping and graphitization process

[0005] Therefore, judging from the current situation, the preparation of lithium-ion battery negative electrode materials requires external coating agents, many process steps, high energy consumption, and high cost.

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