Facilely Fabricating V₂O₃@C Nanosheets Grown on rGO as High-Performance Negative Materials for Lithium-Ion Batteries by Adjusting Surface Tension

Abstract

The flourish of insertion reaction-type V 2 O 3 negative materials with large reversible capacity and outstanding rate performance is facing a huge trouble. In this study, we have successfully prepared a V 2 O 3 @C/rGO composite by adjusting surface tension. The small V 2 O 3 @C nanosheets are fastened to reduced graphene oxide, which remarkably elevates the electron and lithium ion transfer rate. More importantly, the obvious interaction between V 2 O 3 and reduced graphene oxide is beneficial for faster charge transfer. The above features of the V 2 O 3 @C/rGO composite are responsible for obtaining larger reversible capacity and superior rate capability. When applied to lithium-ion batteries as a negative material, it delivers a large reversible discharge capacity of 754 mA h g −1 at the 100th cycle under 100 mA g −1 , although under 2000 mA g −1 , V 2 O 3 @C/rGO still can give a large capacity of 409 mA h g −1 . This study would shed novel light on the preparation of 2D materials and the efficient application of insertion reaction-type materials.

Facile Synthesis of Ultrasmall SnO2/Sn Nanoparticles Grown on the N-Doped Carbon Framework as a Long-Life Anode Material

“…Reducing the particle size is an effectual strategy. Smaller particle size can help diminish the volume variation in the Li + insertion and release process and shorten the lithium ion diffusion distance. − Integrating SnO 2 with N-doped carbon is another effectual strategy, which can further dramatically mute the volume variation in the Li + insertion and release process and quicken the lithium ion and electron transfer speed. − Introducing an appropriate amount of Sn is also an effectual strategy to suppress the volume change in the lithium insertion and release process and improve cyclic stability, − which could be interpreted by the two-stage electrochemical reaction process of SnO 2 : a conversion process (converting SnO 2 into Sn) and an alloying process of Sn. During the conversion reaction stage, the introduced Sn can be a buffer for volume change; in the alloying reaction stage, the formed Li 2 O in the first stage can also relieve the volume change and protects active materials from aggregating.…”