A kind of preparation method of nacl modified graphene network coating β-feooh lithium ion battery negative electrode material

Abstract

A preparation method of a NaCl-modified graphene net-coated Beta-FeOOH lithium ion battery negative electrode material comprises the steps of dispersing graphene oxide in deionized water to obtain a suspension liquid A; adding analytically-pure FeCl<3>.6H<2>O and NaCl into the deionized water, adding the mixture to the suspension liquid A to obtain a suspension liquid B; pouring the suspension liquid B into a homogeneous-phase hydrothermal reaction kettle for hydrothermal reaction to obtain a product C; respectively washing the product C with water and alcohol, and dispersing the washed product in the water to obtain a product D; and freezing and drying the product D to obtain the NaCl-modified graphene net-coated Beta-FeOOH lithium ion battery negative electrode material. The performanceof Beta-FeOOH is improved by employing a composite graphene method, and the reason is that the graphene is good in conductivity and has relatively large specific area; by graphene wrapping, the problem of poor conductivity of Beta-FeOOH can be effectively solved, volume expansion also can be prevented, so that the battery structure is more stable; and by adding the NaCl, the grain size of the product can be controlled, the active sites of oxidization-reduction reaction during lithium intercalation and de-intercalation of the FeOOH are increased, so that the capacity and the cycle stability ofthe battery are improved.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a preparation method of a NaCl-modified graphene network-coated β-FeOOH lithium-ion battery negative electrode material. Background technique [0002] Transition metal oxides / hydroxides have become a research hotspot in recent years because of their high specific capacity (>1000mAh / g). The hydroxide FeOOH in the transition metal is a very potential lithium ion negative electrode material, and there are many crystal forms: α, β, γ, etc. Among them, the β-FeOOH anions are arranged in a body-centered cubic (bcc) array, and the structure is not as dense as that of α, γ-FeOOH, which is more conducive to the diffusion of Li+. In addition, the capacity of β-FeOOH is higher or even exceeds that of other iron oxides. However, like most oxide electrodes, β-FeOOH has the disadvantages of poor conductivity and obvious volume expansion during charge and discharge, wh...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to propose a preparation method of NaCl modified graphene net-coated β-FeOOH lithium-ion battery negative electrode material, which can effectively solve the problem of poor conductivity of β-FeOOH by wrapping it with graphene, and can also inhibit volume expansion. Make the battery structure more stable, NaCl can adjust the particle size of the product, increase the active site of redox reaction when FeOOH intercalates and removes lithium, thereby improving the specific capacity and cycle stability of the battery

Images