Preparation And Properties Of High Performance Aluminum Storage Electrode Materials

Compared with the traditional aluminum ion batteries,the research of water system aluminum ion batteries is still in the initial stage,but in various water system batteries,the power density and energy density index have great potential.At present,there are some problems in the stability of the water system aluminum ion batteries,such as the lack of suitable electrode materials and the suitable aluminum ion electrolyte to provide better work for the battery system.The electrochemical properties of K₂Ti₈O₁₇ and Cu(Fe(CN)₆)_0.667 in water system aluminum ion batteries are discussed in this paper.The specific contents are as follows:(1)Titanium dioxide was grown directly on titanium substrate by alkaline hydrothermal method.K₂Ti₈O₁₇ electrode with excellent performance was obtained after treatment in high temperature.In 1 M Al Cl₃,K₂Ti₈O₁₇ electrode exhibits 233.6 m Ah g^-1high specific mass capacity at 1 A g^-1 current density,but its cycle stability is poor.In order to improve the electrochemical stability,different concentrations of sodium acetate were added to 1 M Al Cl₃.It was found that K₂Ti₈O₁₇ electrode showed excellent specific capacity and electrochemical stability in 1 M Al Cl₃+3M CH₃COONa electrolyte.When the voltage window is-1.0?0 V and the current density is 2 A g^-1,the corresponding specific capacity is 158.6 m Ah g^-1.When the current density is 10 A g^-1,K₂Ti₈O₁₇electrode has good stability,and can be charged and discharged for 400 cycles,and the coulomb efficiency is more than 95%.(2)Three kinds of Prussian blue analogues,Cu HCF,Co HCF and Ni HCF,were synthesized by simple coprecipitation method.The electrochemical properties of different Prussian blue materials as positive materials of water system aluminum ions were studied.The results show that Cu HCF has good ratio performance in 1 M Al Cl₃.In 0.5 M Al₂(SO₄)₃,the discharge specific capacity of Cu HCF-1 reaches 61.8 m Ah g^-1 when the current density is 1 A g^-1.After 1000 cycles at the current density of 0.2 A g^-1,the capacity retention rate is 89.8%.By comparing the charge discharge behavior of Cu HCF-1 in different anions and cation electrolytes,it is found that different anions have little influence on the removal of aluminum ions in the materials,while the mechanism of the deinking of different cations in Cu HCF-1 electrode materials is different according to CV Curve.The Cu HCF-1 electrode material is also affected by the electrolyte concentration,and the charging and discharging platform increases with the increase of electrolyte concentration.