Nitrogen-doped expanded graphite paper current collector and preparation and application thereof

A technology of expanded graphite and nitrogen doping, which is applied in the direction of electrode carrier/current collector, non-aqueous electrolyte battery electrode, electrochemical generator, etc., which can solve the problems of poor composite effect with active materials and easy falling off, so as to improve the rate performance , simple preparation process, high nitrogen doping effect

Active Publication Date: 2020-03-10
HUNAN UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In order to solve the technical deficiencies of the existing graphite paper, such as poor composite effect with active materials and easy falling off, the present invention innovatively provides a nitrogen-doped expanded graphite paper current collector, which aims to improve electrode stability and electrical performance

Method used

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  • Nitrogen-doped expanded graphite paper current collector and preparation and application thereof
  • Nitrogen-doped expanded graphite paper current collector and preparation and application thereof
  • Nitrogen-doped expanded graphite paper current collector and preparation and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0057] The nitrogen-doped expanded graphite paper current collector of this embodiment is prepared through the following steps: the ionic liquid 1-ethyl-3-methylimidazolium dicyandiamide salt ([Emim][dca]) (Money Chemical Technology ( Shanghai) Co., Ltd.) was diluted in ethanol solvent to 5% by volume, and the graphite paper with a thickness of 0.02mm was soaked in the diluted ionic liquid solution of 5% by volume for 30min, and then heated in an air atmosphere at 10°C / Raise the temperature of the muffle furnace to 500°C at a heating rate of 1 min, transfer the graphite paper soaked with the ionic liquid into the muffle furnace, and take it out after holding for 10 min to obtain a nitrogen-doped expanded graphite paper current collector with a thickness of 0.2 mm.

[0058] Raman spectroscopy is used to detect the nitrogen-doped expanded graphite paper current collector obtained in this embodiment, and the results are as follows figure 1 As can be seen from the figure, the ni...

Embodiment 2

[0063] The nitrogen-doped expanded graphite paper current collector of this embodiment is prepared through the following steps: the ionic liquid 1-ethyl-3-methylimidazolium dicyandiamide salt ([Emim][dca]) (Money Chemical Technology ( Shanghai) Co., Ltd.) was diluted to 10% by volume in ethanol solvent, soaked graphite paper with a thickness of 0.02mm in the diluted ionic liquid solution of 10% by volume for 30min, and then heated in an air atmosphere at 10°C / Raise the temperature of the muffle furnace to 500°C at a heating rate of min, transfer the graphite paper soaked in the ionic liquid into the muffle furnace, and take it out after holding for 10 minutes to obtain a nitrogen-doped expanded graphite paper current collector with a thickness of 0.5 mm. The nitrogen doping concentration was 25 at.%.

[0064] Adopt scanning electron microscope to observe the nitrogen-doped expanded graphite paper current collector that present embodiment obtains, and photo is as image 3 As ...

Embodiment 3

[0066] In this embodiment, the nitrogen-doped expanded graphite paper obtained in Example 2 is used as the current collector of elemental sulfur to prepare the lithium-sulfur battery positive electrode. Mix 70wt% elemental sulfur, 20wt% conductive agent acetylene black, and 10wt% binder polyvinylidene fluoride, and use N-methylpyrrolidone as a solvent, stir evenly to obtain positive electrode slurry, use a coating machine to coat, vacuum Dry in a drying oven at 60° C. to obtain a positive electrode sheet.

[0067] The nitrogen-doped expanded graphite paper current collector pole sheet of the negative electrode obtained by the present embodiment having a sulfur active material is observed with a scanning electron microscope, and the results are as follows Figure 4 As shown, it can be seen that after the current collector obtained in this example is loaded with active materials, the surface is flat and loose and porous, which is conducive to the infiltration of the electrolyte ...

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Abstract

The invention belongs to the field of battery materials, and particularly discloses a nitrogen-doped expanded graphite paper current collector, which comprises expanded graphite paper and a nitrogen-doped amorphous carbon material compounded on the surface of the expanded graphite paper in situ. The invention further discloses a preparation method for the current collector. The graphite paper is infiltrated with ionic liquid, the graphite paper infiltrated with the ionic liquid is subjected to heat preservation for 5 min to 8 h at the temperature of 400 DEG C to 1000 DEG C in the air atmosphere, and the current collector is obtained. The invention also discloses the application of the current collector in preparation of a positive electrode, a battery, especially a lithium-sulfur battery.According to the preparation method for the carbon-based current collector provided by the invention, one-step treatment of nitrogen doping and expansion of the graphite paper is realized, the nitrogen doping improves the conductivity of the graphite paper, the expansion realizes the infiltration of the graphite paper by the electrolyte, buffer space is provided for the volume change of the activematerial in the charging and discharging process, and meanwhile, the active material is restrained between the layers of the expanded graphite paper, so that the active material can be prevented fromfalling off from the current collector, and the stability of the electrode is improved.

Description

technical field [0001] The invention belongs to the technical field of batteries, and in particular relates to a carbon-based current collector and a preparation method thereof. Background technique [0002] The rapid development of electric tools has put forward higher and higher requirements on the energy density of batteries. The specific capacity of positive and negative active materials is a key factor determining the energy density of batteries. At present, the positive electrode materials of commercial lithium-ion batteries are mainly transition metal oxides. or phosphate, its theoretical specific capacity is about 150-200mAh / g, the negative electrode material is mainly carbon negative electrode, its theoretical specific capacity is 372mAh / g, and it is difficult to break through due to the limitation of current technology. Therefore, various positive and negative electrode active materials with high specific capacity have been developed. The positive electrode materia...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/66H01M4/13H01M10/0525
CPCH01M4/13H01M4/663H01M4/666H01M10/0525Y02E60/10
Inventor 成娟娟欧云刘骞刘龙飞陈友明王芳甘秀艳
Owner HUNAN UNIV OF SCI & TECH
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