The Influence Of Different Metal Ions On The Structure And Electrochemical Properties Of Silicate/carbon Nanotube Film Materials

Chemical energy storage is in the stage of rapid development.And as the main energy storage devices,the energy density and power density of batteries play a decisive role on energy storage efficiency.These two factors are mainly affected by the specific capacity of the electrode material in the battery.Therefore,develooping electrode materials with high specific capacity,excellent cycle performance and rate performance is a crucial step in the development of energy storage batteries.In this paper,SiO₂ was uniformly loaded on the surface of carbon nanotube(CNT)film by sol-gel method.The composite films with excellent electrochemical properties,such as CNT@cobalt silicate and CNT@nickel silicate,were prepared by a SiO₂ conversion hydrothermal method.By adjusting the preparation conditions,the morphology was controlled,and the electrochemical properties as LIBs and SIBs anode materials were studied systematically.Firstly,CNT@SiO₂ films were obtained by adjusting the TEOS conditions.Subsequently,CNT@cobalt silicate film was prepared by hydrothermal method with SiO₂ as the medium.As LIBs or SIBs anode material,the sample shows high specific capacity.Through the synergistic effect of bimetallic ions,the addition of appropriate amount of iron ions and nickel ions significantly improved the rate performance of cobalt silicate.Secondly,CNT@nickel silicate composite film with higher specific capacity,better cycling stability and rate performance was prepared by hydrothermal method.When the original sol concentration was 0.3 mol L^-1,the CNT@nickel silicate film with the most excellent electrochemical performance could be obtained could be obtained.As anode material of LIB,the specific discharge capacity of this material can reach 570 m A h g^-1 at 50 m A g^-1.As anode material of SIB,at 50 m A g^-1,the specific discharge capacity of the material can reach 390 m Ah g^-1,and when the current density increasing to 500 m A g^-1,a high specific capacity of 205 m Ah g^-1 can still be maintained.With excellent electrochemical properties,CNT@nickel silicate prepared by SiO₂mediated hydrothermal method in this study is of promising application value for the development of LIBs or SIBs.