Study On The Preparation Of Vanadium Oxide Anode Material And Its Lithium Storage Performance

Intelligent textile is a high-tech product which integrates intelligent technology and clothing.It combines advanced technologies in the fields of electronic information technology,sensor technology,textile science and material science.Among them,energy storage devices occupy an important position in intelligent textiles.As an important part of secondary batteries,lithium-ion batteries are widely used in smart textiles.At present,the low theoretical capacity(only 372 mAh/g)and the poor rate performance of commercial graphite anode can not satisfy people’s demands.Vanadium oxide electrode materials have attracted widespread attention because of their high theoretical capacity(1070 mAh/g)and abundant reserves.However,the low Coulombic efficiency at the first cycle,the poor rate capacity and cycle performance still need to be addressed.These problems can be effectively solved by constructing nanoporous structure,combined with carbon coating layers and element doping.In this paper,the nanoporous V2O3/C composites and iron-doped vanadium oxide(Fe-VxOy)anode material were successfully prepared through redox and hydrothermal method,and the study on lithium storage performance.The results are as follows:The nanoporous V2O3/C composites were prepared by hydrogen reduction and hydrothermal method from commercialized V2O5 and its electrochemical properties were tested.Compared with pure V2O3,V2O3/C composites with nanosized carbon layers exhibit better electrochemical properties.The initial discharge capacity is 453 mAh/g and the reversible capacity is 371 mAh/g after 250 cycles at a current density of 50 mA/g,the capacity retention is up to 82%.At a current density of 2000 mA/g,the discharge capacity is 109.1 mAh/g.When the current is adjusted to 50 mA/g,the reversible capacity is stabilized at 250 mAh/g.The excellent stability and rate performance of the composites are attributed to the fact that the nanoporous structure and carbon-coated layers can effectively alleviate the volume change during lithiation/de-lithiation and provide good charge transfer performance.FeV alloys with different atomic ratios were prepared by melt metal spinning method,and nanoporous iron-doped vanadium oxide(Fe-VxOy)anode materials were obtained by redox process.The prepared nanoporous Fe-VxOy anode materials exhibit the best electrochemical performance with the atomic ratio of Fe to V of 30:70.The initial discharge capacity is 828.9 mAh/g and the reversible capacity is 726.4 mAh/g after 150 cycles at a current density of 100 mA/g.The capacity retention is up to 87.63%.The reversible capacity is 357.6 mAh/g at a current density of 2000 mA/g.When the current is adjusted to 50 mA/g,the reversible capacity is stabilized at 595.2 mAh/g.The excellent electrochemical performance of Fe-VxOy composites is attributed to that the nanoporous structure design combined with iron doping can effectively alleviate the volume change of vanadium oxide particles during cycles and improve the electrical conductivity and structural stability of active materials.