Preparation method of polypyrrole quantum dots and sodium-sulfur battery diaphragm

Abstract

The invention relates to the technical field of sodium-sulfur batteries, and aims to provide a preparation method of polypyrrole quantum dots and a sodium-sulfur battery diaphragm. The preparation method comprises the following steps: adding a pyrrole solution and the DMSO solution of ferric nitrate into a solvent thermal reaction kettle together, and uniformly stirring; carrying out solvothermalreaction at the temperature of 180 DEG C for 0.5-5 h and cooling to the room temperature to obtain a DMSO solution containing the polypyrrole quantum dots. According to the preparation method, the high strength and high heat resistance temperature characteristics of PBO resin are utilized, so that the safety and reliability of a sodium-sulfur battery are greatly improved by taking the diaphragm asa raw material. Directional branch-shaped pore channels are obtained through flash freezing pore-forming, and sodium ion transmission is facilitated. The polypyrrole quantum dots are beneficial to long-chain polysulfide adsorption, the polysulfide adsorption capacity of the diaphragm is improved, a medium polysulfide concentration gradient is established in the diaphragm, the content of sodium ions is increased, the internal impedance of the sodium-sulfur battery is reduced, growth of sodium dendrites is passivated so as to prevent the sodium dendrites from penetrating through the diaphragm,the possibility that the sodium dendrites are in contact with the positive electrode in a charging and discharging process is eliminated, and short-circuiting of the battery is prevented.

Description

technical field [0001] The invention relates to the technical field of sodium-sulfur batteries, in particular to a preparation method of polypyrrole quantum dots and a diaphragm for sodium-sulfur batteries. Background technique [0002] Lithium-ion batteries have high energy density and basically no pollution to the environment. They are currently the most widely used secondary batteries. However, the cost of lithium-ion batteries is high and lithium resources are limited, so it is urgent to develop energy storage batteries with abundant resources and low cost. Sodium-sulfur battery is a kind of energy storage battery with high energy density, low cost and abundant resources. Traditional sodium-sulfur batteries work at high temperatures, and the composites of metallic sodium Na and elemental sulfur S and carbon C are used as active materials for the negative and positive electrodes, respectively, β-Al 2 o 3 The ceramic acts as both a separator and an electrolyte. When th...

AI Technical Summary

Problems solved by technology

However, there are problems with sodium-sulfur batteries: (1) high operating temperature; (2) not suitable for intermittent work, the continuous switching of high and low temperatures may easily cause leakage of the stack, and material fatigue damage; (3) the scale of the flow battery should not be too large, etc. question

Simply expanding the pores of the diaphragm can enhance the conduction of sodium ions, but it also intensifies the shuttling of polysulfide ions, and it is also impossible to obtain high-performance sodium-sulfur batteries.

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