Lithium ion battery negative electrode material and preparing method thereof

Abstract

The invention relates to a lithium ion battery negative electrode material and a preparing method thereof. The negative electrode material comprises an organosilicone waste contact mass, a silicon-carbon composite material and a carbon material matrix. The preparing method of the lithium ion battery negative electrode material includes the steps that a carbonaceous organic material serves as a raw material and is subjected to splitting decomposition to obtain carbon particles; the silicon-carbon composite material is formed by the carbon particles and silicon through a modifying reaction; according to the modifying reaction, the carbon particles and the silicon are dissolved in solvent and subjected to electrolysis, and the silicon-carbon composite material is obtained through smashing and screening after ultrasonic treatment is carried out. The lithium ion battery negative electrode material is high in first-time discharge efficiency and good in conducting performance, IACS% reaches 60-70%, and the room-temperature diffusion rate of lithium ions in the electrode material is high; the negative electrode material is good in cycle performance, capable of preventing agglomeration of nano active bodies and beneficial for stabilization of an electrode structure and battery performance, and therefore the life of a battery is longer; the preparing method is easy to operate and low in cost and belongs to waste utilization, and mass production is easy to realize.

Description

technical field [0001] The invention relates to the field of battery materials, in particular to a negative electrode material of a lithium ion battery and a preparation method thereof. Background technique [0002] Lithium-ion batteries are batteries with lithium metal as the positive electrode material and carbon as the main negative electrode material; when the battery is charged, lithium ions are generated on the positive electrode and move to the negative electrode through the electrolyte; while the negative electrode material has a layered structure, There are many micropores, so the lithium ions moving to the negative electrode are embedded in the micropores, the more lithium ions are embedded, the higher the charging capacity; similarly, when the battery is discharged, the lithium ions embedded in the negative electrode come out and move back to the positive electrode . At present, lithium-ion batteries are widely used in various electrical appliances due to their a...

AI Technical Summary

Problems solved by technology

However, in silicon-carbon composite anode materials, although the volume expansion caused by lithium intercalation is uniform, even if the expansion and contraction are reversible, the volume change will produce a large irreversible capacity, resulting in low initial charge and discharge efficiency. Therefore, it is necessary to Buffer the volume change of silicon, try not to damage the film produced on the electrode surface, try not to cause new surface exposure during the cycle, and reduce the loss of irreversible capacity; secondly, silicon is a typical semiconductor structure material. The room temperature diffusion rate in the silicon electrode material needs to improve the conductivity of the silicon material, which is also in urgent need of improvement; again, due to the volume effect, the use of a single silicon material as an electrode will lead to poor cycle performance, so in order to improve the single silicon material Most of them use silicon-carbon composite materials, which can prevent the agglomeration of nano-active bodies and facilitate the stability of the electrode structure; it can also appropriately reduce the lithium intercalation capacity of the composite material, thereby improving the cycle performance of the material.

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