A kind of preparation method of nitrogen and phosphorus co-doped flexible carbon fiber membrane negative electrode material

Abstract

The invention discloses a preparation method for an ultra-thin nitrogen-phosphorus co-doped flexible carbon fiber membrane used as a negative electrode material of a lithium / sodium ion battery, and belongs to the fields of electrochemistry and new energy materials. Filter paper and hydrazine hydrate are subjected to a hydrothermal reaction directly to obtain nitrogen-doped filter paper; the nitrogen-doped filter paper is mixed with urea, dried and put into an atmosphere tubular furnace to be calcined; the filter paper is carbonized into carbon fiber paper at a high temperature; the urea is decomposed at the high temperature to generate gas to enable the carbon fiber paper to be stripped into an ultra-thin carbon fiber membrane to obtain the nitrogen-phosphorus co-doped carbon fiber membrane. According to the nitrogen-phosphorus co-doped carbon fiber membrane, the shortcoming of the carbon fiber is overcome and the energy band structure is improved; the specific capacity of the material and the lithium ion diffusion rate are improved; a three-dimensional conductive network is formed in the carbon fiber material, so that the conductivity of the material is improved; the electrode material has good mechanical flexibility property, so that the electrode material is applicable to manufacturing of a flexible electrode; the electrode material has no additive; and when the electrode material is used as the negative electrode material of the lithium / sodium ion battery, ultrahigh specific capacity and excellent cycling stability are represented.

Description

technical field [0001] The invention discloses a nitrogen-phosphorus co-doped carbon fiber membrane flexible negative electrode material and a preparation method thereof, belonging to the fields of electrochemistry and new energy materials. Background technique [0002] Bending and folding flexible electronic devices have been widely loved by people in recent years, and flexible lithium-ion batteries are the core components of flexible electronic devices. Traditional lithium-ion batteries are mainly made by mixing and coating active materials, conductive agents, and binders on metal current collectors, and drying and rolling. The addition of binders reduces the electronic conductivity of electrode materials and hinders Lithium ions diffuse in the electrode material, increasing the polarization of the electrode material. The conductive agent hardly contributes to the capacity, so the presence of the conductive agent and the binder will reduce the energy density of the batter...

AI Technical Summary

Problems solved by technology

Traditional lithium-ion batteries are mainly made by mixing and coating active materials, conductive agents, and binders on metal current collectors, and drying and rolling. The addition of binders reduces the electronic conductivity of electrode materials and hinders Lithium ions diffuse in the electrode material, increasing the polarization of the electrode material

The conductive agent hardly contributes to capacity, so the presence of conductive agent and binder will reduce the energy density of the battery

In addition, traditional lithium-ion battery anode materials use copper foil as a current collector, which reduces the energy density of the battery

In the case of large bending deformation, the active material and the current collector are prone to detachment, which further affects the electrochemical performance of the material.

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