The Research Of Tin Oxide-titanium Carbide-carbon Nanofiber Lithium Ion Battery Anode Composite

As fossil traditional energy sources are increasingly depleted,new energy fields such as electric vehicles are in the ascendant,which requires LIBs to possess higher energy densities in the future.A large number of researchers believe that Tin and its oxides will be the future potential LIBs anode materials blamed on its high specific capacity,which is more than two times as graphite.Nowadays,the tin-based anode research ambition is mainly to defeat the drastic change of the volume during the charge-discharge cycle,finally achieve its cyclic stability and high current rate magnification performance after solve the structure stability of tin based materials.In this paper,I adopted electrospinning to add commercialized TiC nanoparticles into SnOx@PCNFS,finally obtain SnOx@PCNFS-TiC composites.The SEM,TEM,physical adsorption,thermogravimetric analysis,X-ray diffraction,XPS,and electrochemical tests were used to characterize the composition,structure and electrochemical performance of the samples.The influence of the addition of TiC nanoparticles on SnOx@PCNFs was investigated by changing the amount of TiC nanoparticles added.When the amount of TiC added was 2.5%of PVP,SnOx@PCNFs-TiC 2.5%at 1.0A.When the amount of TiC added was 2.5%of PVP,the reversible discharge capacity of SnOx@PCNFs-TiC 2.5%could keep 457.2 mAh/g after 1000cycles at 1.0A/g,which was 152.8%of the blank control without TiC added and showed better electrochemical performance.However,the two main problems of SnOx@PCNFs-TiC 2.5%restrict further improvement of its electrochemical performance,one is the agglomeration of TiC nanoparticle agglomeration and the other is the precipitation of spherical nanoscale tin.In order to solve to solve the problem of spherical nano Sn precipitation,I adopted PDA coating method to let uniform and continuous carbon layer can be coated on the SnOx@PCNFs-TiC 2.5%when the coating concentration had been controlled into a suitable range,finally I obtained a SnOx/TiC@PCNFs@C composite material.The best performance is showed by SnOx/TiC@PCNFs@C2 which its coating concentaration is lmg/mL,provides reversible discharge specific capacity of 514.3 mAh/g,after the 1.0 A/g cycle at 1000 cycles;were it to increase the rate to 2.0 A/g,it would keep 259.5 mAh/g,it's 112.5%and 160.8%of SnOx@PCNFs-TiC 2.5%,respectively.The commercially available TiC nanoparticles were modified by surface oxidation,alkali etching and final dialysis to obtain a TiC-ethanol dispersion.Electrospinning solution configuration was performed to obtain SnOx@PCNFs-TiC T600,make the dispersibility of TiC nanoparticles was improved.The discharge specific capacity of SnOx@PCNFs-TiC-T600 composite at 1000 cycles of 1.0 A/g was 504 mAh/g,and the capacity at 2.0 A/g was 192.0 mAh/g,which was 110.2%and 119.0%of SnOx@PCNFs-TiC 2.5%,respectively.The experimental results show that adding TiC can promote SnOx transfer to Sn during the carbonization process which is a reduction by PCNFs and improve the conductivity of the composite system,so that the cycle and rate performance of SnOx@PCNFs can be improved.