A kind of nanocomposite material and its preparation method and lithium ion battery

Abstract

The invention discloses a nanocomposite, a method for preparing the nanocomposite, and a lithium ion battery. The nanocomposite is composed of a polyaniline nanolayer at the top, a TiO2 / oxidized graphene composite layer at the centre and a polyaniline nanolayer at the bottom, wherein the polyaniline nanolayer is a nanometer-rod-shaped polyaniline array; the TiO2 / oxidized graphene composite layer is formed in a manner that TiO2 nano-particles are distributed in the net structure of multi-layer oxidized graphene. The nanocomposite disclosed by the embodiment of he invention is good in cycling stability and high-rate discharge performance, nontoxic, environmentally friendly, and cheap in price; the preparation method of the nanocomposite is easy to operate, environmentally friendly and high-efficiency.

Description

technical field [0001] The invention relates to the field of nanometer materials, in particular to a nanocomposite material, a preparation method thereof and a lithium ion battery prepared by using the nanocomposite material. Background technique [0002] With the continuous advancement of science and technology, energy storage equipment is developing in the direction of high performance and miniaturization. Lithium-ion batteries not only have the advantages of small self-discharge rate, long cycle life, no memory effect, high working voltage, etc., but also have excellent high and low temperature discharge performance, and are environmentally friendly. Therefore, lithium-ion batteries are currently the most widely recognized energy storage devices. . [0003] In the prior art, the negative electrode materials of lithium-ion batteries mainly use materials such as carbon materials, tin-based materials, silicon-based materials, titanium-based materials, nitrides, and transiti...

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Problems solved by technology

[0003] In the prior art, the negative electrode materials of lithium-ion batteries mainly use materials such as carbon materials, tin-based materials, silicon-based materials, titanium-based materials, nitrides, and transition metal oxides, but these materials have some insurmountable shortcomings. For example: ① some materials are easy to form lithium dendrites during the formation of SEI film, which will cause a short circuit; ② some materials will cause a large volume expansion during the lithium deintercalation process, resulting in the collapse of the material structure, and then ③ There are still some Ti-based negative electrode materials that are rich in raw materials, non-toxic, harmless, cheap, stable, and safe, but the specific capacity is not high, the electronic conductivity is low, and the surface cannot form an effective electric field

In view of the above points, people began to prepare quantum dots, alloys and other materials to reduce volume expansion and improve cycle stability. However, nanomaterials with small size and high activity are easy to aggregate. After lithium is inserted into the alloy, the mechanical stability is poor, and it is easy to make the material chalking

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