Preparation method of low-defect nano-Prussian blue, and application of nano-Prussian blue

Abstract

The invention relates to a preparation method of low-defect nano-Prussian blue. The method is characterized by comprising the following steps: preparing solution A by ferrous oxalate and sodium oxalate, and preparing solution B by sodium ferrocyanide; adding a surfactant into the solution B, carrying out ultrasonic agitation, and marking as solution C; carrying out ultrasonic agitation on the solution A; adding the solution C into the solution A subjected to the ultrasonic agitation, and carrying out constant-temperature stirring to obtain blue precipitates; washing the blue precipitates, and carrying out vacuum drying at the temperature of 1-130DEG C overnight after the blue precipitates are washed, thus finally obtaining the Prussian blue. The invention also discloses application of the Prussian blue as a cathode material of a sodium-ion battery. The preparation method has the beneficial effects that the defects in Prussian blue in the prior art are effectively reduced, cycling stability is good, capacities are respectively 106mAhg-1 and 98mAhg-1 after circulation is carried out for 500 times at the current density of 300mAhg-1, and a capacity retention rate is high.

Description

technical field [0001] The invention relates to the interdisciplinary field of coordination chemistry and sodium-ion battery electrode material manufacturing technology, in particular to a preparation method and application of low-defect nano Prussian blue. Background technique [0002] The 21st century is an era of new energy. Old fossil energy sources including oil, coal mines, and natural gas are increasingly depleted. Environmental pollution is becoming more and more serious. Social problems caused by energy depletion and environmental pollution are becoming more and more serious. At present, regional conflicts and wars worldwide Most of them are inextricably linked with energy. How to solve the energy crisis is an important problem facing human society. The key to solving the energy crisis is the large-scale use of clean and renewable energy (water, wind, solar and tidal energy). Wind and solar energy are cheap, widely distributed, and can be promoted globally. Howeve...

AI Technical Summary

Problems solved by technology

The coordinated water molecules caused by these Fe(CN)6 vacancy will seriously affect the electrochemical sodium storage behavior of Prussian blue, which is manifested in the following four points: 1. The Fe(CN)6 vacancy reduces the redox active center, At the same time, the Na content in the crystal lattice is reduced, resulting in a smaller theoretical sodium storage capacity; 2. The absence of Fe(CN)6 will lead to an increase in the water content in the crystal lattice, and it is difficult for the coordinated water molecules to go out. It is oxidized and decomposed, resulting in a decrease in the first cycle efficiency and cycle efficiency of the battery; 3. The lattice water molecules occupy part of the Na+ insertion sites, blocking the Na+ insertion and extraction path, thereby reducing the effective capacity; 4. Fe(CN)6 deficiency Bits destroy the integrity of the crystal lattice, and Na+ will easily cause chemical bond breakage, lattice distortion and even structure collapse when Na+ is intercalated and extracted, which will lead to serious capacity attenuation during the long cycle process, making Prussian blue materials unfavorable for large-scale applications.

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