Preparation And Electrochemical Performance Of High Performance SNO2-based Lithium Ion Battery Anode Materials

In recent years,SnO₂ is one of the development potential which has been considered as a novel anode material for lithium ion batteries,but because in the first charge discharge process of the volume expansion of up to more than 50%,circulating repeatedly during embedding and deintercalate lithium ions easily pulverization and agglomeration,leading to decreased rapidly of SnO₂ electrochemical performance,thus limited lithium ion batteries widely used and become the bottleneck of application.How to effectively alleviate the volume effect and the phenomenon of powder,improve the cycle stability of the electrode has become the key to the study of SnO₂ anode materials.At present,the researchers mainly through the following methods to overcome the limitations of SnO₂ anode materials,has made great progress.One is the preparation of nano structure of SnO₂,such as SnO₂ nanowires,SnO₂ nanosheets,to increase the rate of voids in the material morphology by reducing particle size and change the material,which can relieve the volume effect of materials to a certain extent.Second is to build SnO₂ composite materials,such as SnO₂-carbon nanotubes composite,carbon coating,etc.,through the material surface coating of inorganic or organic matter to limit the volume effect on the structure and properties of the material damage.In this paper.SnO₂ was synthesized by hydrothermal method,and the electrochemical performance of SnO₂ Nanosheets was the best.On the basis of this,this paper makes a research on the modification of SnO₂ from the following three aspects.1.SnO₂/graphene oxide nanocomposites with different content of graphene oxide were prepared by the combination of SnO₂ and graphene oxide.The results show that the cyclic performance of SnO₂/graphene nanocomposites with graphene oxide content of 50%is the best.After 100 cycles,the discharge specific capacity is maintained at 636.2mAh/g,under the current density of 160mA/g.2.SnO₂ and multi walled carbon nanotubes were synthesized,and the SnO₂/MCNTs composites with different carbon nanotubes were prepared.The results show that the cyclic performance of SnO₂/MCNTs composite with 50%carbon nanotube content is the best.After 50 cycles,the discharge specific capacity is maintained at 480.6mAh/g,under the current density of 160mA/g.3.Coated PPy on the surface of MCNTs50-SnO₂,the PPy-MCNTs/Sno2 composites with different PPy content were prepared.Research results show that:When the content of was 11%,the cycle performance of PPy-MCNTs/Sno2 composite was the best,and the reversible capacity was maintained at 525.8mAh/g under the current density of 160mA/g.