Synthesis Of Metal Oxides As Prospective Anodes For Lithium Ion Batteries

Lithium-ion batteries(LIBs)feature a very high operating voltage,high power density,long cycle life among the all recently available rechargeable batteries.Since the 1990s,due to the development of Li-ion battery technology,it has an ever-growing demand in electric vehicles(EV),portable electronics,storage devices and hybrid electric vehicles(HEV).While,the improvements in LIBs mostly depends on achievements in working electrode materials,electrolytes,separator and external management systems.The working electrode materials plays a vital role to improve the battery life because they control the electrochemical reactions and ease the diffusion of lithium ions.Based on comprehensive literature reviews,the electrochemical performances of electrode(anode and cathode)materials are size and morphology dependent.The research work is mainly comprised of three major projects that include several nanostructured materials with specifically designed morphologies were synthesized,characterized,and used as anode materials for Li-ion battery applications.(1)The first project of current study was the preparation of small size of various copper oxide nanostructures using Tween-80.Tween-80 serves as an effective template in both low and high temeprature synthesis procedures for directing the growth of CuO nanostructures.When tested as anode material for LIBs,CuO nanowires exhibited better capacity retention with a record high reversible capacity of over 506.6 mAh/g for up to 50 cycles while thorn-like CuO delivers a capacity retention of only 430.4 mAh/g at a very high current density of 0.2 C(1C = 670 mAh/g).Owing to the porous nature of the samples they shows better electrochemical performance as compared to the previous reported literatures.However,a simple approach makes CuO nanowires a potential future electrode material for LIBs.(2)The second project was aimed to control the size and morphology of SnO2 nanostructures with their formation mechanism and investigation of their electrochemical performance as anode material for lithium-ion batteries.Through a facile and modified hydrothermal approach,this material showed relatively low irreversible capacity loss,high reversible capacity,better rate capability and long cycle life.This study opens up new horizon for scientist to look the fact that how can improve the electrochemical properties by modifying the morphological features.(3)The third part of present research work was the preparation of ternary copper,copper oxide/reduced graphene oxide(Cu-Cu2O-RGO)hybrid composite by a facile method with their formation mechanism and evaluated as anode material for LIBs.The enhanced electrochemical performance of the composites is closely correlated to its sandwich structure,with multicomponent Cu-Cu2O nanoparticles adhering firmly to both sides of RGO nanosheets.This structure might shorten the transport pathways for both electrons and lithium-ions,prevent the RGO nanosheets from stacking,as a result ternary composite enhance the electrical conductivity and accommodate the volume expansion that occurs during prolonged cycling.