Core-shell NiO/C porous composite lithium ion battery negative electrode material

Abstract

The invention discloses a core-shell NiO / C porous composite lithium ion battery negative electrode material. The preparation method comprises the following steps: preparing nano NiO particles; carrying out surface modification on nano NiO by using a surface modifier so that the nano NiO particles are uniformly dispersed and beneficial to Mg(OH)2 coating; carrying out gradient temperature treatment by a hydrothermal process to sequentially coat Mg(OH)2 and an amorphous carbon layer on the prepared nano NiO particle surface; and removing the Mg(OH)2 by using hydrochloric acid to form ducts between the NiO particles and carbon layer. The preparation method enhances the electric conductivity of the composite material and ensures the structure stability of the material. In the recycling process, lithium ions are disembedded to prevent NiO from generating powdering aggregation; and elastic expansion space is reserved in the material, thereby avoiding breaking the base material during NiO expansion and enhancing the cycle life. The prepared material provides effective channels for embedding / disembedding of lithium ions, so that the lithium storage characteristic of the NiO material is fully displayed.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, in particular to a core-shell NiO / C porous composite (HKNC) lithium ion battery negative electrode material. Background technique [0002] Nano-nickel oxide (NiO) can undergo reversible oxidation-reduction reactions with lithium metal, and maintain a high specific capacity and excellent cycle performance after multiple charge-discharge cycles, making it a new type of lithium ion with good development prospects. battery anode material. In this field, domestic and foreign research on NiO anode materials has only been involved in recent years and has achieved certain results, but the progress is relatively slow. The preparation methods of nano-NiO powder mainly include chemical precipitation method, sol-gel method and hydrothermal synthesis method, etc. The structure, grain size and electrochemical performance of nano-NiO powder prepared by different methods have certain differences. ...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a core-shell NiO / C porous composite lithium-ion battery negative electrode material, aiming to solve the main factors affecting the performance of NiO negative electrode material: NiO is a semiconductor with low electrical conductivity; Ions enter the lattice of NiO, resulting in large lattice distortion, and the volume expansion caused by lattice distortion is intensified; NiO particles will agglomerate, resulting in the loss of activity of the material

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